Patent - Festo -
Doctrine of Equivalents & Prosecution History Estoppel
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©A. Hawkins 2002
Part 2
Festo v. Shoketsu (SMC)[1] 234 F.3d 558 (Fed. Cir. 2000) (en banc)
(November 29, 2000)[2] Reversed
Judges and Opinions
Before Mayer, Chief Judge, Newman, Michel,
Plager, Lourie, Clevenger, Rader, Schall, Bryson, Gajarsa, Linn, and Dyk,
Circuit Judges.
Opinion for the court filed by Circuit Judge
Schall, in which Chief Judge Mayer and Judges Plager, Lourie, Clevenger,
Bryson, Gajarsa, and Dyk join; in which
Judges Michel, Rader, and Linn join with respect to PARTS III-A, III-B, and
III-D; and in which Circuit Judge Michel
joins with respect to PART III-E.
Concurring opinion by Circuit Judge Plager
Concurring opinion by Circuit Judge Lourie
Opinion concurring-in-part and
dissenting-in-part with respect to PART III-C filed by Circuit Judge Michel, in
which Circuit Judge Rader joins.
Opinion
concurring-in-part and dissenting-in-part with respect to PART III-C filed by
Judge Rader, in which Judges Michel and Linn join.
Opinion
concurring-in-part and dissenting-in-part with respect to PART III-C filed by
Judge Linn, in which Judge Rader joins.
Opinion
concurring-in-part and dissenting-in-part with respect to PARTS III-A, III-B,
III-C, and IV filed by Judge Newman .
Opinion by Judge Schall
This is an appeal from the judgment of the
United States District Court for the District of Massachusetts that Shoketsu
Kinzoku Kogyo Kabushiki Co., Ltd. (also known as SMC Corporation) and SMC
Pneumatics, Inc. (collectively, "SMC") infringed U.S. Patent No.
4,354,125 (the "Stoll patent") and U.S. Patent No. B1 3,779,401 (the
"Carroll patent"), both owned by Festo Corporation
("Festo"), under the doctrine of equivalents. We took the case en
banc to resolve certain issues relating to the doctrine of equivalents that
remained in the wake of the Supreme Court's decision in Warner-Jenkinson Co. v.
Hilton Davis Chemical Co.[3] Specifically, we asked the parties to brief
the following five questions for rehearing en banc:
1. For the purposes of determining whether an
amendment to a claim creates prosecution history estoppel, is "a
substantial reason related to patentability,"[4] limited to those amendments made to overcome
prior art under § 102 and § 103, or does "patentability" mean any
reason affecting the issuance of a patent?
2. Under Warner-Jenkinson, should a
"voluntary" claim amendment--one not required by the examiner or made
in response to a rejection by an examiner for a stated reason--create
prosecution history estoppel?
3. If a claim amendment creates prosecution
history estoppel, under Warner-Jenkinson what range of equivalents, if any, is
available under the doctrine of equivalents for the claim element so amended?
4. When "no explanation [for a claim
amendment] is established," Warner-Jenkinson,[5] thus invoking the presumption of prosecution
history estoppel under Warner-Jenkinson, what range of equivalents, if any, is
available under the doctrine of equivalents for the claim element so amended?
5. Would a judgment of infringement in this case
violate Warner-Jenkinson's requirement that the application of the doctrine of
equivalents "is not allowed such broad play as to eliminate [an] element
in its entirety,"[6] In other words, would such a judgment of
infringement, post Warner-Jenkinson, violate the "all elements" rule?
We begin with a brief synopsis of our answers to
the en banc questions and a summary of how those answers affect the disposition
of this appeal. In response to En Banc Question 1, we hold that "a substantial reason related to
patentability" is not limited to overcoming prior art, but includes other
reasons related to the statutory requirements for a patent. Therefore, an
amendment that narrows the scope of a claim for any reason related to the statutory
requirements for a patent will give rise to prosecution history estoppel with
respect to the amended claim element.1[7] In response to En Banc Question 2, we hold that "voluntary" claim
amendments are treated the same as other claim amendments; therefore, any
voluntary amendment that narrows the scope of a claim for a reason related to
the statutory requirements for a patent will give rise to prosecution history
estoppel with respect to the amended claim element. In response to En Banc
Question 3, we hold that when a claim
amendment creates prosecution history estoppel, no range of equivalents is
available for the amended claim element. In response to En Banc Question 4, we hold that "unexplained"
amendments are not entitled to any range of equivalents. We do not reach En
Banc Question 5, for reasons which will become clear in our discussion of the
specific case before us.
In view of
our answers to the en banc questions, we reverse the judgment that claim 1 of
the Stoll patent and claims 5, 6, and 9 of the Carroll patent were infringed
under the doctrine of equivalents. The claim elements that were found to be
infringed by equivalents were added during prosecution of the Stoll patent and
during reexamination of the Carroll patent. The amendments that added those
elements narrowed the scope of the claims. Festo has not established
explanations unrelated to patentability for these amendments; accordingly, no
range of equivalents is available for the amended claim elements. Because the
parties agree that SMC does not produce a device that literally satisfies those
claim elements, the judgment of infringement must be reversed.
Section I of this opinion provides a brief
overview of the doctrine of equivalents and prosecution history estoppel.
Section II discusses the Supreme Court's decision in Warner-Jenkinson. Section
III sets forth our answers to the en banc questions. In Section IV, we decide
the appeal before us by applying our answers to the en banc questions to the
facts of the case.
DISCUSSION
I. The Doctrine of Equivalents and Prosecution
History Estoppel
The doctrine of equivalents prevents an accused
infringer from avoiding liability for infringement by changing only minor or
insubstantial details of a claimed invention while retaining the invention's
essential identity.[8] The doctrine of equivalents is utilized
"'[t]o temper unsparing logic and prevent an infringer from stealing the
benefit of the invention.'"[9] In pursuing these goals, the doctrine
attempts to strike a balance between ensuring that the patentee enjoys the full
benefit of his patent and ensuring that the claims give "fair notice"
of the patent's scope.[10] This balance can be easily upset, however,
because "the doctrine of equivalents, when applied broadly, conflicts with
the definitional and public-notice functions of the statutory claiming
requirement."[11]
Prosecution history estoppel is one tool that
prevents the doctrine of equivalents from vitiating the notice function of
claims.[12] Actions by the patentee, including claim
amendments and arguments made before the Patent Office, may give rise to
prosecution history estoppel.[13] "Prosecution history estoppel precludes
a patentee from obtaining under the doctrine of equivalents coverage of subject
matter that has been relinquished during the prosecution of its patent
application."[14] Therefore, "[t]he doctrine of
equivalents is subservient to . . . [prosecution history] estoppel."[15] The logic of prosecution history estoppel is
that the patentee, during prosecution, has created a record that fairly
notifies the public that the patentee has surrendered the right to claim
particular matter as within the reach of the patent.
II. Warner-Jenkinson
In this en banc rehearing, we focus our
attention on the effect of Warner-Jenkinson on our case law relating to the
doctrine of equivalents and prosecution history estoppel.[16]
The patent before the Court in Warner-Jenkinson
disclosed an improved process for purifying dyes which used a method called
"ultrafiltration."[17] During prosecution, the patentee amended the
claims to recite that the process is carried out "at a pH from
approximately 6.0 to 9.0."[18] The accused process was carried out at a pH
of 5.0.[19] In light of these facts, the Supreme Court
embarked on an "endeavor to clarify the proper scope of the doctrine"
of equivalents.[20]
The Court dismissed the arguments of
Warner-Jenkinson (the alleged infringer) that the doctrine of equivalents, as
established in Graver Tank, did not survive the 1952 revision of the Patent
Act.[21] The Court nevertheless noted its concern
that "the doctrine of equivalents, as it has come to be applied since
Graver Tank, has taken on a life of its own."[22] The Court agreed with Warner-Jenkinson
"that Graver Tank did not dispose of prosecution history estoppel as a
legal limitation on the doctrine of equivalents."[23] However, the Court rejected
Warner-Jenkinson's argument "that the reason for an amendment during
patent prosecution is irrelevant to any subsequent estoppel."[24] The Court noted that "[i]n each of our
cases cited by petitioner and by the dissent below, prosecution history
estoppel was tied to amendments made to avoid the prior art, or otherwise to
address a specific concern--such as obviousness--that arguably would have
rendered the claimed subject matter unpatentable."[25] The Court therefore saw "no substantial
cause for requiring a more rigid rule invoking an estoppel regardless of the
reasons for a change."[26]
Turning to the facts at hand, the Court noted
that, although the parties did not dispute that the upper pH limit of 9.0 was
added to avoid the prior art, "the reason for adding the lower limit of
6.0 is unclear."[27] Presented "with the problem . . . where
the record seems not to reveal the reason for including the lower pH limit of
6.0," the Court "place[d] the burden on the patent holder to
establish the reason for an amendment required during patent prosecution."[28] The Court stated that courts will have to
"decide whether the [proffered] reason is sufficient to overcome
prosecution history estoppel as a bar to application of the doctrine of
equivalents to the element added by that amendment."[29] The Court also stated that "[w]here no
explanation is established, . . . the court should presume that the patent
applicant had a substantial reason related to patentability for including the
limiting element added by the amendment."[30] Therefore, "prosecution history
estoppel would bar the application of the doctrine of equivalents as to that
element."[31] Because Hilton Davis had "not proffered
in . . . [the Supreme] Court a reason for the addition of the lower pH
limit," the Court remanded the case for this court to consider whether
Hilton Davis had offered reasons for the amendment that added the lower pH
limit and to determine whether Hilton Davis should be given the opportunity to
establish such reasons.[32]
The Court rejected the other restrictions on the
doctrine of equivalents proposed by Warner-Jenkinson.[33] Specifically, the Court refused to
"require judicial exploration of the equities of a case before allowing
application of the doctrine of equivalents,"[34] , refused to require
"proof of intent" on the part of the alleged infringer before the
doctrine of equivalents could be applied,[35] and refused to adopt "independent
experimentation" as "an equitable defense to the doctrine of
equivalents,"[36] The Court also refused to limit the doctrine
of equivalents "to equivalents that are disclosed within the patent
itself," reasoning that the "proper time for evaluating equivalency .
. . is at the time of infringement, not at the time the patent was
issued."[37]
In closing, the Court stated that it chose to
"adhere to the doctrine of equivalents," which "should be
applied as an objective inquiry on an element-by-element basis."[38] The Court noted that "[p]rosecution
history estoppel continues to be available as a defense to infringement."[39] However, "if the patent holder
demonstrates that an amendment required during prosecution had a purpose
unrelated to patentability, a court must consider that purpose in order to
decide whether an estoppel is precluded."[40] If "the patent holder is unable to
establish such a purpose, a court should presume that the purpose behind the
required amendment is such that prosecution history estoppel would apply."[41]
III.Answers
to the En Banc Questions
A.
Question 1
For the purposes of determining whether an
amendment to a claim creates prosecution history estoppel, is "a
substantial reason related to patentability,"[42] limited to those amendments made to overcome
prior art under § 102 and § 103, or does "patentability" mean any
reason affecting the issuance of a patent?
We answer Question 1 as follows: For the purposes of determining whether an
amendment gives rise to prosecution history estoppel, a "substantial
reason related to patentability" is not limited to overcoming or avoiding
prior art, but instead includes any reason which relates to the statutory
requirements for a patent. Therefore, a narrowing amendment made for any reason
related to the statutory requirements for a patent will give rise to prosecution
history estoppel with respect to the amended claim element.
It is true that in Warner-Jenkinson the Supreme
Court focused on claim amendments made to overcome or avoid prior art. [43] However, there are a number of statutory
requirements that must be satisfied before a valid patent can issue and that
thus relate to patentability. In addition to satisfying the novelty and
non-obviousness requirements of 35 U.S.C. §§ 102 and 103, 35 U.S.C.A. §§ 102,
103, the claims must be directed to patentable subject matter and the claimed
invention must be useful, as set forth in 35 U.S.C. § 101. Additionally, the
first paragraph of 35 U.S.C. § 112 requires that the patent specification
describe, enable, and set forth the best mode of carrying out the invention, 35
U.S.C. § 112, ¶ 1, while the second paragraph of section 112 requires that the
claims set forth the subject matter that the applicant regards as his invention
and that the claims particularly point out and distinctly define the invention,
35 U.S.C. § 112, ¶ 2. The Patent Office will reject a patent application that
fails to satisfy any one of these statutory requirements.[44] And any one of these requirements may be a
ground for invalidating an issued patent.[45] An amendment related to any of these
statutory requirements is an amendment made for "a substantial reason
related to patentability."
The law has been clear that amendments made to
avoid prior art give rise to prosecution history estoppel.[46] In view of the functions of prosecution
history estoppel--preserving the notice function of the claims and preventing
patent holders from recapturing under the doctrine of equivalents subject
matter that was surrendered before the Patent Office--we see no reason why
prosecution history estoppel should not also arise from amendments made for
other reasons related to patentability, as described above. Indeed, the
functions of prosecution history estoppel cannot be fully satisfied if
substantial reasons related to patentability are limited to a narrow subset of
patentability issues. Rather, substantial reasons related to patentability
include 35 U.S.C. §§ 101 and 112 issues, as well as 35 U.S.C. §§ 102 and 103
issues.
While we do not believe that the Supreme Court
itself answered this question in Warner-Jenkinson, we do believe that our
answer is not inconsistent with Warner-Jenkinson. Warner-Jenkinson describes
prior cases as applying prosecution history estoppel "typically because
what [was previously claimed] . . . was encompassed within the prior art,"[47] but no language in Warner-Jenkinson limits
prosecution history estoppel to amendments made to avoid prior art.[48] Moreover, our approach is consistent with
Warner-Jenkinson's requirement that an amendment "does not necessarily
preclude infringement by equivalents of that element."[49] Thus, if a patent holder can show from the
prosecution history that a claim amendment was not motivated by patentability
concerns, the amendment will not give rise to prosecution history estoppel.
B.
Question 2
Under Warner-Jenkinson, should a
"voluntary" claim amendment--one not required by the examiner or made
in response to a rejection by an examiner for a stated reason--create
prosecution history estoppel?
We answer Question 2 as follows: Voluntary claim
amendments are treated the same as other amendments. Therefore, a voluntary
amendment that narrows the scope of a claim for a reason related to the
statutory requirements for a patent will give rise to prosecution history
estoppel as to the amended claim element.
Both voluntary amendments and amendments
required by the Patent Office signal to the public that subject matter has been
surrendered. There is no reason why prosecution history estoppel should arise
if the Patent Office rejects a claim because it believes the claim to be unpatentable,
but not arise if the applicant amends a claim because he believes the claim to
be unpatentable.
Our answer to this question is consistent with
the doctrine of argument-based estoppel. Arguments made voluntarily during
prosecution may give rise to prosecution history estoppel if they evidence a
surrender of subject matter.[50] There is no reason why an amendment-based
surrender of subject matter should be given less force than an argument-based
surrender of subject matter.
We also believe that our answer to this question
is consistent with Warner-Jenkinson. Although the Supreme Court spoke of
"required" amendments, the claim amendment at issue in
Warner-Jenkinson, the addition of the lower pH limit of 6, was not
"required" by the prior art rejection. The original claim recited an
ultrafiltration process.[51] The asserted prior art reference taught an
ultrafiltration process conducted at a pH of above 9.[52] The amended claim recited an ultrafiltration
process conducted "at a pH from approximately 6.0 to 9.0."[53] The parties did not dispute that the upper
pH limit of 9.0 was added to distinguish the prior art.[54] The Court, however, was unable to discern
the reason for the addition of the lower pH limit of 6.[55] Accordingly, the amendment at issue in
Warner-Jenkinson appears to have been voluntary with respect to the lower pH
limit. Nevertheless, the Court held that the amendment adding the lower pH
limit could give rise to prosecution history estoppel.[56]
C.
Question 3
If a claim amendment creates prosecution history
estoppel, under Warner-Jenkinson what range of equivalents, if any, is
available under the doctrine of equivalents for the claim element so amended?
We answer Question 3 as follows: When a claim
amendment creates prosecution history estoppel with regard to a claim element,
there is no range of equivalents available for the amended claim element.
Application of the doctrine of equivalents to the claim element is completely
barred (a "complete bar").
We think it is fair to say that the question of
the scope of equivalents available when prosecution history estoppel applies to
a claim element has not been directly addressed or answered by the Supreme
Court, at least in circumstances where the claim was amended for a known
patentability reason. In Warner-Jenkinson, the Court focused its attention more
on the circumstances under which prosecution history estoppel arises than on
the range of equivalents that might generally be available despite the
existence of prosecution history estoppel.[57] The Court did not discuss the upper pH limit
of 9.0, other than to note that the upper limit, which narrowed the claim, was
selected to overcome prior art.[58] The range of equivalents, if any, that could
be asserted for the upper pH limit was not discussed by the Court. The only
statements in Warner Jenkinson as to the range of equivalents that is available
when prosecution history estoppel applies are found in the Court's discussion
of unexplained amendments.[59] For those amendments, the Court held that
"prosecution history estoppel would bar the application of the doctrine
[of] equivalents as to that element."[60]
1. In cases before Warner-Jenkinson, the Supreme
Court applied prosecution history estoppel to preclude a finding of
infringement under the doctrine of equivalents, but the Court did not analyze
the actual scope of equivalents that might be available when prosecution
history estoppel applied, i.e., the extent of the subject matter surrendered by
amendment. In Weber Electric Co. v. E.H. Freeman Electric Co.,[61] the patentee had amended his claim to an
electric lamp socket to overcome prior art that taught a socket and electric
bulb that were unlocked and locked together simply by rotation. The amended
claim recited, instead, a bulb and socket combination that unlocked and locked
by manual compression.[62] In light of this amendment, the Court did
not allow the patentee, who had "narrowed his claim . . . to obtain a
patent," to "resort to the doctrine of equivalents [and] give to the
claim the larger scope which it might have had without the amendment." Id.
Under the facts of the case, the alleged infringer practiced the exact subject
matter described in the prior art, a combination that locked the bulb by
rotational movement.[63] Thus, the Court did not need to discuss the
precise contours of the subject matter surrendered by the claim amendment. A
similar situation was presented in Smith v. Magic City Kennel Club.[64] The invention at issue in that case involved
an artificial dog race track lure.[65] The patentee overcame prior art that
disclosed a straight arm for holding the lure by amending his claims to recite
a hinged arm.[66] The accused infringer's device used a rigid
arm.[67] The Court did not allow the patentee to
resort to the doctrine of equivalents to regain the specific subject matter the
patentee had surrendered "in order to escape rejection."[68]
In Magic City Kennel Club, as in Weber, the
accused device read on the prior art, which in and of itself mandates a finding
of noninfringement,[69] In Exhibit Supply Co. v. Ace Patents Corp.,[70] the patentee amended the claim at issue to
overcome general prior art cited by the examiner. He did so by changing the
claim to recite a conductor device that was "embedded in" a game
table (pinball machine) instead of one that was "carried by" the
table.[71] The Court held that the patentee could not
thereafter, through the doctrine of equivalents, obtain coverage of accused
devices in which the "conductor means" was carried by the game table
instead of imbedded in it.[72] It is unclear from the Court's opinion
whether the accused device was in the prior art cited by the examiner in his
rejection.[73] The Court stated,
however:
Had Claim 7 been allowed in its original form,
it would have read upon all the accused devices, since in all the conductor means
complementary to the coil spring are "carried by the table." By
striking that phrase from the claim and substituting for it "embedded in
the table," the applicant restricted his claim to those combinations in
which the conductor means, though carried on the table, is also embedded in it.
By the amendment, he recognized and emphasized the difference between the two
phrases and proclaimed his abandonment of all that is embraced in that
difference.[74]
The Court never addressed the exact range of
equivalents that might still be available under the amended claim, and the
"difference between" the original claim and the amended claim, the
difference said by the Court to have been abandoned by the patentee, was never
explicitly defined.
In his dissenting opinion, Judge Michel relies
upon Goodyear Dental Vulcanite Co. v. Davis,[75] and Hurlbut v. Schillinger,[76] for the proposition that a patentee is
entitled to a range of equivalents despite the fact that the scope of a claim
has been limited by amendment. We do not believe, however, that either of these
cases addresses the issue presented in En Banc Question 3: the range of
equivalents, if any, that is available under the doctrine of equivalents for a
claim element that has been amended by an amendment that creates prosecution
history estoppel.
As issued, the claim in Goodyear described
"rubber or some other elastic material" for a dental plate.[77] During reissue the claim was amended to
describe a dental plate of hard or "vulcanized" rubber.[78] Looking to the reissue amendment, the Court
concluded that the patentee "regarded the patent to be for a manufacture
made exclusively of vulcanites by the detailed process[79] The Court determined that there could be no
infringement where the defendant's product used celluloid.[80] The Court did not discuss prosecution
history estoppel, but simply decided that under the language of the reissued
patent celluloid was not equivalent to "hard rubber or vulcanite or its
equivalent."
Hurlbut involved a patent which had been
reissued and in which a disclaimer had been filed.[81] The reissue added a second claim, but did
not amend any claim language.[82] Claim 1 recited "[a] concrete pavement
laid in detached blocks or sections, substantially in the manner shown and
described."[83] Claim 2 recited an "arrangement of tar
paper, or its equivalent, between adjoining blocks of concrete, substantially
as and for the purpose set forth."[84] The patentee disclaimed "the forming of
blocks from plastic material without interposing anything between their joints
while in the process of formation."[85] In the face of this disclaimer, the Court
construed the claims to require that the division of the concrete paving blocks
be "effected by either a permanent or temporary imposition of something
between the blocks."[86] The Court held that both claims were
infringed by a process in which a trowel was used to cut a concrete layer into
blocks.[87] In referring to equivalents the Court was
referring to the language of the claims ("substantially" in claim 1
and "or its equivalents" in claim 2). Thus, the Court did not discuss
the issue of the scope of equivalents that remained under the doctrine of
equivalents after the disclaimer.
Neither do we believe that in any of the other
cases noted by Judge Michel did the Court determine that a claim element that
was amended by an amendment that gave rise to prosecution history estoppel was
entitled to a range of equivalents.[88]
In short, the range of equivalents available to
an amended claim element simply was not before the Supreme Court in the cases
Judge Michel cites, and the Supreme Court did not discuss the issue presented
in En Banc Question 3. Although a court must follow "explicit and
carefully considered" language of the Supreme Court, [89] none of the language
cited by Judge Michel constitutes explicit and carefully considered language
regarding the range of equivalents available when a claim amendment gives rise
to prosecution history estoppel.
2. Because the Supreme Court has not fully
addressed the range of equivalents that is available once prosecution history
estoppel applies, we must independently decide the issue. Congress specifically
created the Federal Circuit to resolve issues unique to patent law,[90] such as those regarding prosecution history
estoppel, which is a judicially created doctrine.[91] Congress contemplated that the Federal
Circuit would "strengthen the United States patent system in such a way as
to foster technological growth and industrial innovation." [92] Issues such as the one before us in this
case are properly reserved for this court to answer with "its special
expertise."[93]
The Federal Circuit first addressed the range of
equivalents that is available when prosecution history applies in Hughes
Aircraft Co. v. United States[94] ("Hughes I"). In that case, we recognized
that, prior to creation of the Federal Circuit, some regional circuits had
followed a flexible bar approach to prosecution history estoppel, whereas
others had applied a strict rule of complete surrender when prosecution history
estoppel applied.[95] We decided to apply prosecution history
estoppel as a flexible bar, stating that prosecution history estoppel "may
have a limiting effect" on the doctrine of equivalents "within a
spectrum ranging from great to small to zero."[96]
LaBounty Manufacturing, Inc. v. United States
International Trade Commission,[97] is an example of the flexible bar approach.
In LaBounty, we vacated the noninfringement determination of the International
Trade Commission ("ITC") and remanded the case to the ITC for further
proceedings because the administrative law judge ("ALJ") had failed
to determine the scope of prosecution history estoppel and had held, instead,
that once an element of a claim is amended, no equivalent of that element can
be asserted.[98] In Black & Decker, Inc. v. Hoover
Service Center,[99] we held that an amendment made during
prosecution did not prevent a finding of infringement under the doctrine of
equivalents. We reasoned that although the amendment would bar infringement
under the doctrine of equivalents with respect to a device similar to the prior
art that had provoked the amendment, prosecution history estoppel did not
prevent all applications of the doctrine of equivalents.[100] [101] Similarly, in Modine Manufacturing Co. v.
United States International Trade Commission,[102] we vacated the ALJ's holding of lack of
infringement under the doctrine of equivalents due to prosecution history
estoppel because, although "the available range of equivalency is limited,
by estoppel, . . . the prosecution history and the prior art do not eliminate
equivalents."
Less than a year after Hughes I, however, a
five-judge panel of this court decided.[103] The claimed invention in Kinzenbaw was
"[a]n apparatus for forming seed planting furrows."[104] The claim element at issue related to "a
pair of depth gauge compacting wheels" that controlled the depth of the
furrow created by the planter.[105] During prosecution, in order to overcome an
examiner's rejection and to obtain his patent, the inventor narrowed his claims
by specifying, among other things, that the gauge wheels had to have a radius
less than that of the radius of the blades of the planter (called
"discs").[106] On the accused device, the gauge wheels had
a radius greater than that of the discs.[107] Consequently, the accused device could not
literally infringe. As a result, the patentee (Deere) sought to prove
infringement under the doctrine of equivalents.[108] The district court concluded that
prosecution history estoppel precluded Deere from relying upon the doctrine of
equivalents.[109] The court determined that, as far as the
gauge wheels were concerned, the inventor had intentionally narrowed his
claims, and it refused to permit Deere to avoid, through the doctrine of
equivalents, the limitation that the inventor had placed on his claims.[110]
On appeal, Deere urged that prosecution history
estoppel did not apply because the inventor's limitation of his claims to
devices in which the gauge wheels had a smaller radius than that of the discs
was unnecessary to distinguish the prior art.[111] Specifically, Deere contended that only that
portion of the claim that provided that the radius of the gauge wheels had to
exceed the distance from the axes of the wheels to the rear edges of the discs
was necessary in order to render the claims patentable over the prior art.[112] The five-judge panel rejected Deere's
argument. It stated: "We decline to undertake the speculative inquiry
whether, if . . . [the inventor] had made only that narrowing limitation in his
claim, the examiner nevertheless would have allowed it."[113] The court therefore affirmed the district
court's judgment of noninfringement.[114]
The approach to prosecution history estoppel
that was followed in Kinzenbaw prompted the following observation by Professor
Chisum: "Beginning shortly after its creation in 1982, the Federal Circuit
developed two lines of authority on the scope of an estoppel based on an
amendment or argument that distinguished the prior art. One line followed a
strict approach, according to which a court refused to speculate whether a
narrower amendment would have been allowed. The other line followed a flexible
or spectrum approach, which recognized that amendments did not invariably
preclude all equivalence . . . ."[115] Soon after Hughes I and Kinzenbaw were
decided they were the subject of comment in the American University Law Review,
which annually reviews the work of the Federal Circuit. The commentators stated
that the Federal Circuit's "two divergent lines of authority dealing with
prosecution history estoppel," the Hughes I line and the Kinzenbaw line,
had given rise to ever-increasing "uncertainty and confusion" in
patent litigation.[116] The commentary that began after Hughes I and
Kinzenbaw were decided has continued.[117]
Since Warner-Jenkinson, panels of this court
have continued to visit the question of the range of equivalents that is
available after prosecution history estoppel has been determined to exist. Two
cases in particular were remanded by the Supreme Court for further
consideration in light of Warner-Jenkinson. Honeywell, Inc. v. Litton Sys.,
Inc.;[118] United States v. Hughes
Aircraft Co.[119] In Litton Systems, Inc. v. Honeywell, Inc.,[120] this court determined that Warner-Jenkinson
had not changed the "longstanding doctrine that an estoppel only bars
recapture of that subject matter actually surrendered during prosecution."
The court noted that "the Supreme Court did not reach the question of the
proper scope of estoppel for an amended limitation," and thus concluded
that Warner-Jenkinson did not affect our already established jurisprudence on
the issue.[121] A similar analysis and conclusion were set
forth in Hughes Aircraft Co. v. United States[122] ("Hughes II"). The alleged
infringer in that case argued that Warner-Jenkinson mandated that prosecution
history estoppel act as a complete bar and preclude any finding of infringement
under the doctrine of equivalents.[123] In rejecting this argument, this court
stated that there must be a determination as to the exact "subject matter
the patentee actually surrendered."[124] Because the accused device did not
"fall within the range of subject matter surrendered," infringement
under the doctrine of equivalents was not barred.[125] The court denied rehearing en banc in both
Litton and Hughes II, over dissents from the denials.[126]
Both Litton and Hughes II follow the Hughes I
flexible bar approach to prosecution history estoppel. In that regard, they are
consistent with Professor Chisum's observation that "[m]ost Federal
Circuit panel decisions from 1984 to 1997 followed the flexible approach, which
had been initiated in 1983 by the Hughes Aircraft[Hughes I] decision . . .
."[127] Nevertheless, this court has neither
repudiated Kinzenbaw nor reconciled the inconsistency between the Hughes I and
Kinzenbaw lines of authority. Under these circumstances, it is unclear whether
in any given case the court will apply the Kinzenbaw approach as opposed to the
more generally accepted Hughes I approach. Just as importantly, even if the
Hughes I approach is applied, there is uncertainty as to the extent of the
surrender that will be held to exist. Thus, Professor Chisum has discussed two
Federal Circuit cases, Sun Studs, Inc. v. ATA Equip. Leasing, Inc.[128] and Environmental Instruments, Inc. v.
Sutron Corp.,[129] as illustrating the "predictive
difficulties of the flexible approach."[130] In a like vein, it has been stated that
"the criteria used by the court to determine the effect of an estopping
amendment have not been set forth in any clear or systematic way" and that
"[t]he Federal Circuit's well-known observation that '[d]epending on the
nature and purpose of an amendment, it may have a limiting effect from great to
small to zero,' for example, tells little about what the relationship is
between the 'nature and purpose' of an amendment and its limiting effect."[131]
3. Today, we revisit the question we first
addressed in Hughes I and come to a different conclusion as to the proper scope
of equivalents that is available when prosecution history estoppel applies than
we did in that case. We hold that prosecution history estoppel acts as a
complete bar to the application of the doctrine of equivalents when an
amendment has narrowed the scope of a claim for a reason related to
patentability. Our decision to reject the flexible bar approach adopted in
Hughes I comes after nearly twenty years of experience in performing our role
as the sole court of appeals for patent matters. In those years, the notice
function of patent claims has become paramount, and the need for certainty as
to the scope of patent protection has been emphasized. A problem with the
flexible bar approach is that it is virtually impossible to predict before the
decision on appeal where the line of surrender is drawn. The patentee would
draw the line just at or slightly short of the prior art, leaving a wide range of
equivalents untouched by prosecution history estoppel. The accused infringer,
however, would draw the line close to the literal terms of the claims, leaving
little or no range of equivalents. These considerations, we think, contribute
to the difficulty under the flexible bar approach in predicting with any degree
of certainty the scope of surrender that will be found when prosecution history
estoppel applies.
In reaching our holding, we are mindful of the
Supreme Court's teaching that binding precedent is not to be lightly discarded.
The Court has stated that stare decisis "promotes the evenhanded,
predictable, and consistent development of legal principles, fosters reliance
on judicial decisions and contributes to the actual and perceived integrity of
the judicial process."[132] The Court also has stated that while from
time to time it has overruled governing decisions that are "unworkable or
are badly reasoned," it has rarely done so "on grounds not advanced
by the parties."[133]
We believe that the current state of the law
regarding the scope of equivalents that is available when prosecution history
estoppel applies is "unworkable." In patent law, we think that rules
qualify as "workable" when they can be relied upon to produce
consistent results and give rise to a body of law that provides guidance to the
marketplace on how to conduct its affairs. After our long experience with the
flexible bar approach, we conclude that its "workability" is flawed.
Moreover, in overruling Hughes I, we are not acting "on grounds not
advanced by the parties." SMC and amici curiae have urged us to follow the
strict approach to prosecution history estoppel that we adopt today.[134]
We also believe that the flexible bar approach
"poses a direct obstacle to the realization of important objectives."[135] These objectives include giving effect, when
prosecution history estoppel arises, to a narrowing amendment's operation as a
disclaimer of subject matter,[136] preserving the notice function of patent
claims,[137] and promoting certainty in patent law.[138] The realization of these objectives cannot
help but be frustrated by the uncertainty inherent in the flexible bar
approach.
By making prosecution history estoppel act as a
complete bar, we enforce the disclaimer effect of a narrowing claim amendment.
By narrowing his claims, a patentee disclaims subject matter encompassed by the
original claims.[139] As the Supreme Court has stated, "By
amendment [the patentee] recognize[s] and emphasize[s] the difference between
the" original claim and amended claim "and proclaim[s] . . .
abandonment of all that is embraced in that difference."[140] Amendments "must be strictly construed
against the inventor and in favor of the public, and looked upon as in the
nature of disclaimers."[141] In order to construe such amendments
strictly against the patentee, no scope of equivalents can be afforded to a
claim element that was narrowed because of patentability concerns. Although we
do not understand older Supreme Court cases to have spoken directly to the
question before us, we think the language used in those cases suggesting a
strict measurement of the scope of equivalents is consistent with our answer to
this question.
Allowing some range of equivalents gives the
patentee some benefit of the doubt as to what was disclaimed, a benefit that
comes at the public's expense. A complete bar therefore best serves the notice
and definitional function of patent claims. "The object of the patent law
in requiring the patentee [to specifically define his invention] is not only to
secure to him all to which he is entitled, but to apprise the public of what is
still open to them."[142] But "the doctrine of equivalents, when
applied broadly, conflicts with the definitional and public-notice functions of
the statutory claiming requirement."[143] If prosecution history estoppel acts as a
complete bar to application of the doctrine of equivalents, both the patentee
and the public are on notice as to the scope of protection provided by a claim
element narrowed for a reason related to patentability. The patentee and the
public can look to the prosecution history, a public record, to determine if
any prosecution history estoppel arises as to any claim element. If so, that
element's scope of protection is clearly defined by its literal terms.
The Supreme Court recognized the value of a
complete bar in Warner-Jenkinson when it discussed the presumption that
prosecution history estoppel applies when an amendment is unexplained. The
Court, keeping in mind "that claims do indeed serve both a definitional and
a notice function," held that if the presumption was not rebutted,
"prosecution history estoppel would bar the application of the doctrine
[of] equivalents as to that element."[144] [145] A complete bar to the doctrine of
equivalents for unexplained amendments would give, as the Court stated,
"proper deference to the role of claims in defining an invention and
providing public notice,"[146] A complete bar similarly serves the
definitional and notice functions when explained amendments give rise to
prosecution history estoppel. Regardless of whether the amendment is explained
or unexplained, if the amendment narrows the scope of the claim for a reason
related to patentability, a complete bar to the doctrine of equivalents
provides the public and the patentee with definite notice as to the scope of
the claimed invention.
A complete bar also eliminates the public's need
to speculate as to the subject matter surrendered by an amendment that narrows
a claim for a reason related to patentability. There are several aspects of the
prosecution history estoppel inquiry where speculation is not allowed. The
Supreme Court has noted that we need not inquire into the correctness of the
examiner's rejection that led to a claim amendment.[147] Even if the rejection is improper, the
amendment may still give rise to prosecution history estoppel. Id. In addition,
we do not speculate as to whether any given amendment was material to the
prosecution of the patent because "[t]he patentee makes them all material
by the restricted form of his claim."[148] In view of the reluctance to entertain
speculative inquiries in other aspects of prosecution history estoppel, a
speculative inquiry should not be required to determine the scope of
equivalents still available for a claim element narrowed for a reason related
to patentability. A complete bar avoids such an inquiry.
Under the flexible bar approach, however, the
exact range of equivalents when prosecution history estoppel applies is
virtually unascertainable, with only the prior art marking the outer limits of
the claim's scope. There is no precise metric to determine what subject matter
was given up between the original claim and the amended claim. Consider, for
example, a claim that originally recited a value "less than twenty"
that was amended to recite a value "less than five" in light of a
rejection over prior art disclosing a value of fifteen.2[149] What subject matter was abandoned under the
flexible approach? Is the patentee limited to values that are closer to five
than fifteen, or can he reach any value less than fifteen? Can the patentee
encompass by equivalents a value of ten, or would that recapture part of the
surrendered subject matter? Put simply, it is impossible, even under this basic
example, for the public or the patentee to determine the precise range of
equivalents available under the flexible bar approach. This creates a
"zone of uncertainty which enterprise and experimentation may enter only
at the risk of infringement claims . . . [and which] discourage[s] invention
only a little less than unequivocal foreclosure of the field."[150] "The public [would] be deprived of
rights supposed to belong to it, without being clearly told what it is that
limits these rights."[151]
A complete bar, unlike a flexible bar, thus
lends certainty to the process of determining the scope of protection afforded
by a patent. With a complete bar, both the public and the patentee know that
once an element of a claim is narrowed by amendment for a reason related to
patentability, that element's scope of coverage will not extend beyond its
literal terms. There is no speculation or uncertainty as to the exact range of
equivalents that might be available. This certainty aids both the public and
the patentee in ascertaining the true scope and value of the patent without
having to resort to litigation to obtain a case by case analysis of what
subject matter the claims can cover. With a complete bar, neither the public
nor the patentee is required to pay the transaction costs of litigation in
order to determine the exact scope of subject matter the patentee abandoned
when the patentee amended the claim.
Thus, under the complete bar approach,
technological advances that would have lain in the unknown, undefined zone
around the literal terms of a narrowed claim under the flexible bar approach
will not go wasted and undeveloped due to fear of litigation. The public will
be free to improve on the patented technology and design around it without
being inhibited by the threat of a lawsuit because the changes could possibly
fall within the scope of equivalents left after a claim element has been
narrowed by amendment for a reason related to patentability. This certainty
will stimulate investment in improvements and design-arounds because the risk
of infringement will be easier to determine. In general, the difficulty in
counseling the public and the patentee on the scope of protection provided by
an amended element is greatly reduced under the complete bar approach due to
the certainty and predictability such a bar produces.
Finally, we see no overriding benefit to the
flexible bar approach. Although a flexible bar affords the patentee more
protection under the doctrine of equivalents, we do not believe that the
benefit outweighs the costs of uncertainty. The Supreme Court noted in Warner-Jenkinson
that the doctrine of equivalents has "taken on a life of its own,
unbounded by the patent claims."[152] A complete bar reins in the doctrine of
equivalents, making claim scope more discernible and preserving the notice
function of claims. The Court indicated that the application of a complete bar
allowed prosecution history estoppel to place "reasonable limits on the
doctrine of equivalents, and further insulate[] the doctrine from any feared
conflict with the Patent Act."[153] The application of a complete bar to the
doctrine of equivalents whenever a claim amendment gives rise to prosecution
history estoppel similarly reduces the conflict and tension between the patent
protection afforded by the doctrine of equivalents and the public's ability to
ascertain the scope of a patent.
D.
Question 4
When "no explanation [for a claim
amendment] is established,"[154] thus invoking the presumption of prosecution
history estoppel under Warner-Jenkinson, what range of equivalents, if any, is
available under the doctrine of equivalents for the claim element so amended?
We answer Question 4 as follows: When no explanation for a claim amendment
is established, no range of equivalents is available for the claim element so
amended.
This question is answered by Warner-Jenkinson:
Where no explanation is established, . . . .
prosecution history estoppel would bar the application of the doctrine [of]
equivalents as to that element.[155]
. In answering this question, we affirm what we
stated in Sextant:[156] when "the Warner-Jenkinson presumption
is applicable, . . . the prosecution history estoppel arising therefrom is
total and completely 'bars' the application of the doctrine of equivalents as
to the amended limitation."
E.
Question 5
Would a judgment of infringement in this case violate
Warner-Jenkinson's requirement that the application of the doctrine of
equivalents "is not allowed such broad play as to eliminate [an] element
in its entirety,"[157] In other words, would such a judgment of
infringement, post Warner-Jenkinson, violate the "all elements" rule?
We do not need to reach this question for
reasons which will become clear in our discussion of the specific case before
us. Accordingly, we leave for another
day any discussion of the "all elements" rule.
IV.Infringement
of Festo's Patents
Festo is the owner by assignment of the Stoll
patent and the Carroll patent, both of which are directed to magnetically
coupled rodless cylinders. Festo sued SMC in the United States District Court
for the District of Massachusetts, alleging infringement of the patents. The
jury found that SMC infringed the Stoll patent under the doctrine of
equivalents and assessed damages accordingly.[158] The district court previously had granted
Festo's motion for summary judgment that certain models of SMC's rodless
cylinders infringed the Carroll patent, also under the doctrine of equivalents.[159] 3[160]
A. The
Patents and Technology at Issue
Both the Stoll patent and the Carroll patent
disclose magnetic rodless cylinders. The claimed devices are composed of three
basic parts: a piston, a cylinder, and a sleeve. In basic terms, the piston is
on the inside of the cylinder, and is moved by fluid under pressure. The sleeve
is on the outside of the cylinder, and is magnetically coupled to the piston.
The magnetic attraction between the sleeve and the piston causes the sleeve to
follow the piston when it moves along the inside of the cylinder. The sleeve is
used to move objects on a conveying system.
1. The application for the Stoll patent was
filed on May 28, 1980; the patent issued on October 12, 1982.
[Drawing,
and references to drawing Omitted]
Inside the cylinder, the piston is driven by a
pressurized fluid. Stoll patent. As the piston travels through the cylinder,
the magnetically coupled sleeve follows the piston along the outside of the
cylinder.
The piston includes magnets and two
"elastomeric sealing rings.” The
sealing rings prevent any impurities from getting on the piston. There also are a pair of "guide
rings" on the piston. As the
patent explains, the guide rings, which project beyond the piston's surface,
"pass along the internal [cylinder] surface in a sliding fit," and
help prevent impurities from dirtying the piston.
The sleeve of the Stoll patent device is made of
multiple parts that include magnets and an outer body made of a magnetizable
material. According to the patent, the magnetizable material on the sleeve that
encircles the sleeve's magnets allows "magnetic leakage fields in the
vicinity of the driven assembly to be kept to a minimum," preventing any
unwanted braking forces.
Claim 1 of
the Stoll patent is representative of the claims asserted by Festo, and is the
only claim of the Stoll patent at issue on appeal:
1. In an arrangement having a hollow cylindrical
tube and driving and driven members movable thereon for conveying articles, the
improvement comprising wherein said tube is made of a nonmagnetic material,
wherein said driving member is a piston movably mounted on the inside of said
tube, said piston having a piston body and plural axially spaced, first
permanent annular magnets encircling said piston body, said piston further
including first means spacing said first permanent magnets in said axial spaced
relation, the radially peripheral surface of said magnets being oriented close
to the internal wall surface of said tube, said piston further including plural
guide ring means encircling said piston body and slidingly engaging said
internal wall and first sealing rings located axially outside said guide rings
for wiping said internal wall as said piston moves along said tube to thereby
cause any impurities that may be present in said tube to be pushed along said
tube so that said first annular magnets will be free of interference from said
impurities, wherein said driven member includes a cylindrical sleeve made of a
magnetizable material and encircles said tube, said sleeve having plural
axially spaced second permanent annular magnets affixed thereto and in
magnetically attracting relation to said first permanent annular magnets, and
second means spacing said second permanent annular magnets in said axially
spaced relation, the radially inner surface of said magnets being oriented
close to the external surface of said tube, said sleeve having end face means
with second sealing rings located axially outside said second permanent annular
magnets for wiping the external wall surface of said tube as said driven member
is moved along said tube in response to a driving movement of said piston to
thereby cause any impurities that may be present on said tube to be pushed
along said tube so that said second permanent annular magnets will be free of
interference from said impurities.
2. The application for the Carroll patent was
filed on February 17, 1972; the patent issued on December 18, 1973. A
reexamination certificate was issued on October 25, 1988, with amended claims.
The Carroll patent is directed to the same technology as the Stoll patent.
[Drawing,
and references to drawing Omitted]
In the disclosed embodiment, the sleeve is
described as a permanent magnet that is attached to a gripping device and that
surrounds part of the exterior of the cylinder. As in the device of the Stoll patent, the sleeve of the Carroll
patent moves along the cylinder in response to a magnetic piston which moves
inside the cylinder. Each end of the piston has a sealing ring set in an
annular groove. According to the
patent, the sealing rings "engage the inner wall of the cylinder and form
a fluid tight seal" that allows compressed air, or any other pressurized
fluid, injected into port or on the outside of the cylinder to move the piston
in either direction. The polarization of the magnets on the piston and the
sleeve causes the sleeve, which is located on the outside of the cylinder, to
follow the movement of the piston, which is located on the inside of the
cylinder.
Claim 9 of
the reexamined Carroll patent is representative of the claims asserted by
Festo:
9. A device for moving articles, which
comprises: a hollow cylinder formed of non-ferrous material and having opposite
axial ends; a piston mounted in the interior of the hollow cylinder and
reciprocatingly slidable therein, the piston including a central mounting
member disposed axially in the cylinder, a plurality of cylindrically-shaped
permanent magnets mounted on the central mounting member and spaced apart
axially from each other, each magnet having a bore formed axially there-through
for receiving the central mounting member, at least one pair of end members
mounted on the central mounting member and disposed on opposite axial sides of
the plurality of magnets,a pair of cushion members formed of resilient
material, the cushion members being situated near opposite axial ends of the
central mounting member to help prevent damage to the piston when the piston
contacts an axial end of the cylinder, and a pair of resilient sealing rings
situated near opposite axial ends of the
central mounting member and engaging the cylinder to effect a
fluid-tight seal therewith; a body mounted on the exterior of the hollow
cylinder and reciprocatingly slidable thereon, the body including a plurality
of annularly shaped permanent magnets surrounding the cylinder and spaced apart
from each other, the permanent magnets of the piston and body being polarized
so as to magnetically couple the body to the piston whereby movement of the
piston inside the cylinder causes a corresponding movement of the body outside
the cylinder the body further including means provided thereon for holding on
the body an article to be moved; and means for controlling the admission of
pressure fluid into the cylinder and exhaust fluid from the cylinder for moving
the piston in the cylinder, the attractive forces between the permanent magnets
of the piston and the body being such that movement of the piston causes
corresponding movement of the body below a predetermined load on the body and
such that above said predetermined load movement of the piston does not cause
corresponding movement of the body.
3. The
SMC devices that were found to infringe the Stoll and Carroll patents under the
doctrine of equivalents have two notable differences from the structures
claimed in the patents. First, the SMC devices, although having
pistons with two hard plastic guide rings, have
only a single resilient two-way sealing ring, located on one end of the
pistons. Thus, while the patents disclose and claim devices with a pair of
sealing rings, the SMC devices have only single two-way sealing rings.4[161] Second,
the outer portion of the sleeves of SMC's devices is made of an aluminum alloy,
a material that the parties agree is not a magnetizable material. Thus, while the Stoll patent discloses and claims
a sleeve made of a magnetizable material, the SMC devices have sleeves that are
not made of a magnetizable material.
B.
Prosecution History of the Patents at Issue
1. The Stoll
patent application was filed in the United States as the U.S. counterpart of a
German patent application. As filed, claim 1 of the Stoll patent initially
read:
1. A linear motor for use in a conveying system,
said motor being operable by a pressure medium
and comprising a tubular part connectible to a source of the pressure medium,
a piston which is slidable in said tubular part
and which has sealing means at each end for [w]iping engagement with an
internal surface of the tubular part and so as to form a seal for the pressure
medium,
and surfaces of the magnet arrangements which
face the tubular part being closely adjacent to the respective surfaces of the
tubular part.
and a driven assembly which is slidable on the
tubular part and which has means at each end for [w]iping engagement with an
external surface of the tubular part,
the piston and the driven assembly each carrying
a drive magnet arrangement in the form of a hollow cylindrical assembly,
each magnet arrangement having radial play
relative to the adjacent surface of the tubular part,
The original application also included two
dependent claims of relevance, claims 4 and 8:
4. A linear motor according to any of claims 1
to 3, wherein the sealing means of the piston comprise sealing rings and the
piston is provided with sliding guide rings near the sealing rings.
8. A linear motor according to any of the
preceding claims wherein the driven assembly is provided with a sleeve made of
a magentisable material, which encircles the hollow cylindrical assembly of the
magnet arrangement.
In the first
Office Action, the patent examiner rejected
all twelve original claims, and cited three patents as references
"believed pertinent." Claims 1-12 were rejected under 35 U.S.C. §
112, ¶ 1, because the "exact method of operation is unclear. Is [the]
device a true motor or magnetic clutch?" In addition, claims 4-12 were
rejected under 35 U.S.C. § 112, ¶ 2, because they were "improperly
multiply dependent."
In response, Stoll amended some claims,
including claim 1, and canceled others, including claims 4 and 8. Claim 1 was
amended to recite "plural guide ring means . . . and first sealing rings
located axially outside said guide rings" on the piston and to recite
"a cylindrical sleeve made of a magnetizable material." In the
remarks accompanying the amendments, Stoll stated that "[e]ach of the
claims now present in this application has been reviewed for compliance with
the provisions of Title 35 USC 112. Accordingly, further consideration of these
claims, particularly with respect to the provisions of Title 35 USC 112, is
respectfully solicited."
When Stoll submitted this amendment, he also
made two German patents of record in the application, No. 27,37,924 and No.
19,82,379. Stoll had received these patents in the first office action in the
corresponding German application. Stoll argued in the remarks accompanying the
amendment that the "claims now present in th[e] application" are
distinguishable over these references. Stoll stated that "i[t] is clear
that neither of these two references discloses the use of structure preventing
the interference by impurities located inside the tube and on the outside of
the tube while the arrangement is moved along the tube."
After considering this response, the examiner allowed the amended claims,
requesting that all references to "linear motors" be deleted from the
specification, because this phrase "connotes a different device having
different operational characteristics."
2. The relevant portion of the Carroll patent's prosecution history is
its reexamination. Before reexamination, claim 1 of the Carroll patent read as
follows:
1. A device for moving articles comprising
a cylinder of non-ferrous material,
a piston including a permanent magnet having a
pole-piece on each axial side thereof,
a body disposed outside and adjacent to said
cylinder, said body including a permanent magnet which substantially surrounds
the cylinder, there being a pole piece on each axial side of the permanent
magnet included in said body, and
means for controlling the admission of pressure
fluid into the cylinder and exhaust of fluid from the cylinder for moving the
piston in the cylinder,
the attractive forces between the permanent magnets
being such that movement of the piston causes corresponding movement of the
body below a predetermined load on the body and such that above said
predetermined load movement of the piston does not cause corresponding movement
of the body.
This claim did not recite the sealing rings
disclosed in the specification. Carroll
requested reexamination on March 18,
1988, citing German Patent No. 1,982,379, which was not of record in the
Carroll patent's prosecution history. In his request for reexamination, Carroll
asserted that the German patent presented a substantial new question of
patentability because the Patent Office "may find the German patent, in
combination with the other references which were cited during prosecution of
the Carroll patent[,] . . . to disclose several of the primary structural
features of the device defined by Claim 1."
The German patent described rodless cylinders
having several of the features of the device described in the Carroll patent,
including a pair of sealing rings. The Patent Office granted Carroll's request
for reexamination, finding that the German patent "discloses an article
transport device which is movable in response to a hydraulically operated
magnetic piston, which is a feature that was not found by the Examiner during
the prosecution" of the Carroll patent.
During reexamination, Carroll canceled claim 1 and added claim 9, which explicitly
recites "a pair of resilient sealing rings situated near opposite axial
ends of the central mounting member and engaging the cylinder to effect a
fluid-tight seal therewith." In the remarks accompanying the amendment,
Carroll argued that the now-amended claims5[162] "more clearly and more
specifically" define the "features of the patentee's invention that
distinguish over the art of record, including" the German patent cited in
the request for reexamination. Carroll also noted that the structure now
described in claim 9 was not disclosed in the art of record. Carroll further
stated that "the particular structure of the inner piston and outer body
now specifically set forth in new claim 9 is not taught or suggested by the
German patent," particularly noting the recitation of the placement and
plurality of magnets for both the piston and outer body and the recitation of
resilient materials and cushion materials on the ends of the piston.
The examiner allowed the amended claims, stating
that "the prior art does not teach or render obvious the claimed
combination which includes the plurality of magnets, end members, and cushion
members in the claimed relationship."
C. The
District Court Proceedings
Festo sued SMC in the district court for
infringement of both the Stoll and Carroll patents. Festo's claims of
infringement and damages and SMC's counterclaims of invalidity were referred to
a special master for consideration. The
special master determined that both the Stoll and Carroll patents were not
invalid.[163] The special master also determined that the
SMC devices at issue in this appeal did not infringe the Stoll patent,[164] but did infringe claims 5, 6, and 9 of the
Carroll patent under the doctrine of equivalents.[165]
In due course, the district court entertained
summary judgment motions from both parties on the issues of infringement and
validity. The district court denied all
summary judgment motions except Festo's motion for summary judgment of
infringement of the Carroll patent. In ruling on the motions, the district court determined that SMC
could not literally infringe the Stoll patent because SMC's devices did not
have magnetizable sleeves. The court
also determined that there was a genuine issue of material fact regarding
infringement under the doctrine of equivalents. The court addressed SMC's assertion that prosecution history
estoppel barred the application of the doctrine of equivalents to the Stoll
patent because the magnetizable sleeve element was not initially recited in
claim 1, but was added to the claim after the first Office Action. The court concluded that the reason for the magnetizable
sleeve amendment was "a mystery," because it did not appear to be
related to any of the examiner's 35 U.S.C. § 112 rejections, and it did not
appear to distinguish the invention over the prior art. The district court therefore
declined to hold that prosecution history estoppel barred a finding that the
Stoll patent was infringed under the doctrine of equivalents.
Turning to the Carroll patent, the court noted that the only argument of
noninfringement that SMC made was that the single sealing ring in its piston
was not equivalent to the pair of sealing rings recited in claim 9 of the
Carroll patent. However, Festo had
presented expert testimony that SMC's single seal was equivalent to the two
seals recited in the claims. To rebut
this testimony, SMC cited a statement Stoll had made during prosecution of the
Stoll patent to the effect that two sealing rings are necessary to prevent dirt
on the piston's magnet. The district
court found that the statement made during prosecution of the Stoll patent did
not bear on the "meaning and function of the sealing rings as
described" in the Carroll patent. The
court therefore granted Festo's motion for summary judgment of infringement of
claims 5, 6, and 9 of the Carroll patent under the doctrine of equivalents.
The
remaining issues, infringement under the doctrine of equivalents of the Stoll
patent, and validity of the Carroll and Stoll patents, were tried to a jury.
The jury rendered a verdict on July 14, 1994, concluding that both patents were
not invalid and finding that claim 1 of the Stoll patent was infringed under
the doctrine of equivalents. The
special verdict form indicates that the jury found that Festo had proven by a
preponderance of the evidence that SMC's non-magnetizable sleeve and single
sealing ring performed substantially the same function in substantially the
same way to obtain substantially the same result as the claimed magnetizable
sleeve and pair of sealing rings.
D. SMC's
Appeal
SMC appeals the judgment of infringement of the
Stoll patent, which was entered pursuant to the jury's verdict that the patent
was infringed under the doctrine of equivalents. Infringement under the doctrine of equivalents is a question of fact.[166] We must overturn the
jury's finding on a factual issue if it is not supported by substantial
evidence or if it is based on an erroneous legal determination.[167] Prosecution history estoppel is a legal
question that is subject to de novo review by this court.[168] Thus, when reviewing the jury verdict, we
will independently decide the legal question of the application of prosecution
history estoppel to the Stoll patent.
SMC also appeals the district court's judgment
of infringement of the Carroll patent, which was entered in accordance with the
court's grant of Festo's motion for summary judgment that claims 5, 6 and 9
were infringed under the doctrine of equivalents. Summary judgment "shall
be rendered forthwith if the pleadings, depositions, answers to
interrogatories, and admissions on file, together with the affidavits, if any,
show that there is no genuine issue as to any material fact and that the moving
party is entitled to a judgment as a matter of law."[169] We review the grant of a motion for summary
judgment without deference,[170] drawing all reasonable factual inferences in
favor of the non-moving party.[171]
1. When infringement is alleged to occur under
the doctrine of equivalents, two primary legal limitations on the doctrine
"are to be determined by the court, either on a dispositive pretrial
motion or on a motion for judgment as a matter of law at the close of evidence
and after the jury verdict."[172] Those legal limitations are prosecution
history estoppel and the "all elements" rule.[173]
The first legal limitation a court should
consider is prosecution history estoppel, because prosecution history estoppel
may completely bar the application of the doctrine of equivalents to a given
claim element. The first step in a prosecution history estoppel analysis is to
determine which claim elements are alleged to be met by equivalents. Then, the
court must determine whether the elements at issue were amended during
prosecution of the patent. If they were not, amendment-based estoppel will not
bar the application of the doctrine of equivalents. However, the court still
may need to consider whether statements made during prosecution give rise to
argument-based estoppel.[174]
If the claim elements at issue were amended, the
court first must determine whether the amendment narrowed the literal scope of
the claim. If so, prosecution history estoppel will apply unless the patent holder
establishes that the amendment was made for a purpose unrelated to
patentability.[175] If the patent holder fails to do so,
prosecution history estoppel will bar the application of the doctrine of
equivalents to that claim element.
In Warner-Jenkinson, the Supreme Court explained
the purpose of placing on the patent holder the burden of establishing the
reason for an amendment: allocating the burden in this manner "gives
proper deference to the role of claims in defining an invention and providing
public notice."[176] Public notice considerations also have been
fundamental to our decisions regarding the scope of prosecution history
estoppel.[177] In order to give due deference to public
notice considerations under the Warner-Jenkinson framework, a patent holder
seeking to establish the reason for an amendment must base his arguments solely
upon the public record of the patent's prosecution, i.e., the patent's
prosecution history. To hold otherwise--that is, to allow a patent holder to
rely on evidence not in the public record to establish a reason for an
amendment--would undermine the public notice function of the patent record. If
the reasons for the amendment do not appear in the public record of the
patent's prosecution, the reasons in most cases will be known only to the
patent holder. We therefore hold that a narrowing amendment will give rise to
prosecution history estoppel unless the prosecution history of the patent
reveals that the amendment was made for a purpose unrelated to patentability
concerns.6[178] If prosecution history estoppel does not bar
the application of the doctrine of equivalents, the court should consider the
second legal limitation on the doctrine, the "all elements" rule.[179] If the court determines that a finding of
infringement under the doctrine of equivalents "would entirely vitiate a
particular claim element," then the court should rule that there is no
infringement under the doctrine of equivalents.[180]
2. The
jury found that claim 1 of the Stoll patent was infringed under the doctrine of
equivalents. The two elements found
to be infringed by equivalents were the "cylindrical sleeve made of a
magnetizable material," and the "first sealing rings located axially
outside . . . [the] guide rings."[181] Both of these elements were added during prosecution
of the patent. Following the methodology outlined above, we conclude that
prosecution history estoppel bars the application of the doctrine of
equivalents to these claim elements. In view of this determination, we do not
reach the "all elements" rule.
We begin our analysis with the magnetizable
sleeve element. SMC argues that this claim element is not entitled to any range
of equivalents. SMC contends that Festo has not demonstrated that the amendment
was made for a reason unrelated to patentability and that, therefore, the
presumption of Warner-Jenkinson applies and the doctrine of equivalents is
barred. SMC asserts that the voluntary nature of the amendment is irrelevant to
the prosecution history estoppel inquiry because Warner-Jenkinson places the
burden on a patent holder to establish the reason for an amendment, regardless
of whether the amendment was required or voluntary. SMC argues that Festo
disclaimed non-magnetizable sleeves when it amended the claim to recite a
magnetizable sleeve. SMC also argues that the public, including competitors
like itself, would reasonably understand from the prosecution history of the
patent that Festo had surrendered any device with a non-magnetizable sleeve.
Festo responds that the Warner-Jenkinson presumption
does not apply to voluntary amendments. Festo emphasizes that the magnetizable
sleeve amendment was not made in response to any prior art rejection and was
not needed to overcome the 35 U.S.C. § 112 rejections of the original claims.
Accordingly, Festo argues, prosecution history does not bar the application of
the doctrine of equivalents to this claim element.
To determine whether a claim amendment gives
rise to prosecution history estoppel, we first must determine whether the
amendment narrowed the literal scope of the claim. Here we are presented with
the situation where the added claim element was introduced through a new claim,
instead of through an amendment to an original claim. Nevertheless, the
addition of the magnetizable sleeve claim element can be said to have narrowed
the scope of the original claim because the new claim replaced the original
claim. Specifically, the only original independent claim, which did not recite
a magnetizable sleeve, was replaced with an independent claim which does recite
a magnetizable sleeve. Because the amendment narrowed the literal scope of the
claim, we must determine whether Festo has established that it was made for a
reason unrelated to patentability.
We agree with SMC that the reason for the
amendment adding the magnetizable sleeve element is not evident from the
prosecution history. Original claim 1 did not recite a magnetizable sleeve,
although this feature of the invention was recited in original dependent claim
8. In response to the first Office Action, Festo replaced original claim 1 with
a claim reciting a magnetizable sleeve and canceled claim 8. Although the
amendment was submitted in the response to the first Office Action, the
amendment itself was not responsive to any of the rejections set forth in the
Office Action. As discussed above, the Office Action rejected all of the claims
under 35 U.S.C. § 112, ¶ 1 because it was not clear to the examiner whether the
claimed device was a true motor or a magnetic clutch; in addition, the Office
Action rejected claims 4-12 under 35 U.S.C. § 112, ¶ 2 for being improperly
multiply dependent. The amendment adding the magnetizable sleeve element did
not address either of these rejections. Moreover, there is no statement in the
prosecution history that explains why this element was included in the
independent claim.
In its Supplemental Brief On Remand from the
Supreme Court, Festo argued that the
amendment was made to clarify the claim. Specifically, Festo asserted that
the "'hollow cylindrical assembly'" recited in original claim 1 was
"rewritten more clearly as 'a cylindrical sleeve made of a magnetizable
material.'" This assertion is
inadequate to escape the Warner-Jenkinson presumption, however, because
nothing in the prosecution history of the Stoll patent indicates that the
magnetizable sleeve element was merely added for purposes of clarification
unrelated to patentability concerns.
On remand,
Festo also argued that the voluntary nature of the amendment that added the
magnetizable sleeve claim element prevents the amendment from giving rise to
prosecution history estoppel. Our answer to En Banc Question 2, which holds
that voluntary amendments are treated the same as other amendments, compels us
to reject this argument.
Festo has thus failed to meet its burden under
Warner-Jenkinson of establishing a reason unrelated to patentability for the
amendment that added the magnetizable sleeve element. The amendment therefore
gave rise to prosecution history estoppel.[182] Because prosecution history estoppel acts as
a complete bar to the doctrine of equivalents, application of the doctrine of
equivalents is barred as to this claim element.
We turn now to the sealing ring element. SMC
argues that the sealing ring claim element was added to distinguish the prior
art and, therefore, is not entitled to any range of equivalents. SMC asserts
that arguments accompanying the amendment make clear that the amendment was
made to distinguish the prior art. SMC contends that a competitor such as
itself reasonably would conclude from the prosecution history that Festo
surrendered the difference between the originally claimed sealing means and the
sealing rings recited in the amended claims. By the same token, SMC argues,
Festo disclaimed the difference between the original and amended claims.
Festo's principal argument is that there is no
substantial difference between original claim 1 and the amended claim with
respect to the sealing ring element. Specifically, Festo argues that the
original claim recited the sealing ring element in means-plus-function
language, whereas the amended claim recites the structure described in the
specification as performing the recited function ("the corresponding
structure"). Festo also argues that the claim amendment did not give rise
to prosecution history estoppel because it was made to respond to the 35 U.S.C.
§ 112 rejection, not to avoid the prior art. Festo contends that the statements
accompanying the amendment do not evidence a clear and unmistakable surrender
of subject matter and, therefore, did not give rise to prosecution history
estoppel.
The sealing ring element was added to claim 1
when the original independent claim 1 was replaced with the independent claim
that issued as claim 1. This amendment narrowed the literal scope of the claim
because it substituted an independent claim that recited a sealing ring element
for an independent claim that did not recite such an element. Even if the
amendment that added the sealing ring element merely replaced the
means-plus-function language with a recitation of the corresponding structure,
the amendment had the effect of narrowing the scope of the claim. A claim
element recited in means-plus-function language literally encompasses the
corresponding structure and its equivalents.[183] In contrast, a claim element that recites
the corresponding structure does not literally encompass equivalents of that
structure.[184] Thus, a claim amendment that replaces
means-plus-function language with language reciting the corresponding structure
narrows the literal scope of the claim.
We conclude that Festo has not established that
the amendment that added the sealing ring element was made for a reason
unrelated to patentability. Festo argues that the amendment was made to respond
to the 35 U.S.C. § 112 rejection. Because a claim will not issue unless it
satisfies the requirements of section 112, an amendment made to satisfy the
statute is an amendment made for a reason related to patentability.[185] The amendment also appears to have been made
to distinguish the prior art. Submitted with the amendment was a statement to
the effect that German Patent No. 27,37,924 and German Patent No. 19,82,379
"are obviously clearly distinguishable over the subject matter of the
claims now present in th[e] application," i.e., the amended claims. Also
submitted with the amendment was an assertion that "[i]t is clear that
neither of these two references discloses the use of structure preventing the
interference by impurities located inside the tube and on the outside of the
tube while the arrangement is moved along the tube." In view of these
statements, we conclude that the amendment adding the sealing ring element was
made to distinguish the German patents and, therefore, was made for a reason
related to patentability.[186] Thus, Festo cannot establish that the
amendment was made for a reason unrelated to patentability. The amendment
therefore gave rise to prosecution history estoppel and, in accordance with our
Answer to En Banc Question 3, no range of equivalents is available for the
sealing ring element.
The jury's finding of infringement was based on
an application of the doctrine of equivalents to the magnetizable sleeve and
sealing ring claim elements; accordingly, we must reverse the judgment that
claim 1 of the Stoll patent was infringed under the doctrine of equivalents.
3. The district court granted Festo's motion for
summary judgment of infringement under the doctrine of equivalents with respect
to independent claim 9 and dependent claims 5 and 6 of the Carroll patent.
Festo I (Order), slip op. at 15. The element in all three claims found to be
infringed by equivalents is "a pair of resilient sealing rings situated
near opposite axial ends of the central mounting member" (a "pair of
sealing rings").7[187][188] This element was added to claim 9 during
reexamination of the Carroll patent. Following the methodology outlined above,
we conclude that prosecution history estoppel bars the application of the
doctrine of equivalents to this element of the claims of the Carroll patent. In
view of this determination, we do not reach the "all elements" rule.
SMC argues that Festo's purpose for this
amendment is not clear.8[189]
[190] SMC states that because Festo specifically
canceled original claim 1, which did not recite a sealing ring at each end of
the piston, and added claim 9, which does recite a sealing ring at each end of
the piston, the only reasonable conclusion is that the amendment was made for a
purpose related to patentability. SMC further asserts that because claim 9 is a
combination claim, its patentability hinges on the novelty of the recited
combination, including the recited pair of sealing rings. SMC also argues that
if the purpose for the amendment is unclear, the Warner-Jenkinson presumption
applies, and application of the doctrine of equivalents is barred.
Festo responds by arguing that the amendment
adding the pair of sealing rings element was not required, and thus was
voluntary. Festo states that because the amendment was voluntary, it cannot
give rise to prosecution history estoppel under Warner-Jenkinson. Festo also
states that the amendment could not have been required to distinguish the
German patent that prompted the reexamination, because the German patent
discloses a piston with sealing rings. Festo argues that because the amendment
was not made for a purpose related to patentability, the amendment did not
create prosecution history estoppel.
To determine whether this claim amendment gave
rise to prosecution history estoppel, we first must determine whether the
amendment narrowed the literal scope of the claim. As with the elements of the
Stoll patent discussed above, the claim element at issue in the Carroll patent
was introduced through a new claim, instead of through the amendment of a
pending claim. Specifically, during reexamination, independent claim 1, which
did not recite a pair of sealing rings, was replaced by independent claim 9,
which does recite a pair of sealing rings. This amendment narrowed the literal
scope of the claims of the Carroll patent.9[191] Accordingly, we must consider the reasons
for the amendment.
As
discussed above, under Warner-Jenkinson, Festo bears the burden of establishing
that the amendment was made for a reason unrelated to patentability.[192] It has failed to do
so. Festo admits that there is "[n]o specific mention of the sealing
rings" in the prosecution history record.
Moreover, in view of our answer to En Banc Question 2, the voluntary
nature of the amendment is irrelevant to the inquiry.
The prosecution history of the Carroll patent
reveals that the amendment that added the pair of sealing rings claim element
was motivated by at least one reason related to patentability: a desire to
avoid the prior art. In the remarks accompanying the amendment that introduced
claim 9, which recites the pair of sealing rings, Carroll stated that the
amendment defined the "features of the patentee's invention that
distinguish over the art of record, including" the German patent cited in
the request for reexamination. Thus, although the German patent disclosed a
piston with sealing rings, Carroll did argue that the combination of features
recited in the claims, which includes the pair of sealing rings, distinguished
the claims over the German patent. Moreover, when the examiner allowed the
reexamined claims, he stated that "the prior art does not teach or render
obvious the claimed combination which includes the plurality of magnets, end
members, and cushion members in the claimed relationship." Although the
examiner did not specifically reference the pair of sealing rings in his
statement of reasons for allowance, his statement emphasizes that it is the
claimed combination of elements that was found to be patentable. In view of
this prosecution history, Festo cannot establish that the amendment that added
the pair of sealing rings element was made for a reason unrelated to
patentability. Indeed, the prosecution history indicates that the amendment was
made for a reason related to patentability. In accordance with our answer to En
Banc Question 3, prosecution history estoppel bars application of the doctrine
of equivalents to the pair of sealing rings element. Accordingly, we must
reverse the judgment that claims 5, 6, and 9 of the Carroll patent were
infringed under the doctrine of equivalents.
CONCLUSION
The claim elements of the Stoll and Carroll
patents that were found to be infringed by equivalents were added to the
pertinent claims during prosecution of the Stoll patent and during
reexamination of the Carroll patent through amendments that narrowed the scope
of the claims. As explained above, Festo has not established explanations for
these amendments unrelated to patentability. The amendments therefore gave rise
to prosecution history estoppel. Under these circumstances, the amended claim
elements are entitled to no range of equivalents. Thus, they cannot be
infringed by equivalents. The court's
judgment of infringement under the doctrine of equivalents of both the Stoll
and Carroll patent is therefore
REVERSED.
COSTS
Each party shall bear its own costs.
Judge Plager, concurring.
I concur in and join the opinion and judgment of
the court. It is a second-best solution to an unsatisfactory situation. Under
our preexisting law, a count for infringement under the doctrine of equivalents
became a routine part of a patent infringement suit. The game was to convince
the trier of fact, typically a jury, that even if an accused product1[193] does not infringe the claims as written, the
claimed invention and the accused product have only "insubstantial
differences," a wonderfully indeterminate phrase, lending itself to making
every decision under the doctrine an individualistic choice, if not simply a
flip of the coin.[194]
In an attempt to make the phrase
"insubstantial differences" less indeterminate, we have continued to
resort to the old "function-way-result" formulation, indicating that
in appropriate cases--whatever that might mean--the answer could be found
through those lenses.[195] Though "function" and
"result" are in many cases reasonably straightforward, the
"way" of an accused product compared to that of the claimed invention
has proved to be no more precise a criterion in its application than
"insubstantial differences," for which it was supposed to be a useful
surrogate.[196]
Worse yet, whether the trier of fact was judge
or jury, the decision about infringement under the doctrine of equivalents does
not end with the trial. Given the indeterminate nature of the test, it is not
difficult for the losing party to make a plausible argument on appeal that
there was "clear error" or that "no reasonable jury could have
thought such a thing," as the case may be. Given the indeterminate nature
of the test, this court has shown little reluctance to review these decisions.[197] The net effect has been that all too often
there is no way to know whether a particular product infringes under the
doctrine until a panel of this court says so; the rule of analysis gives little
real guidance, and equally little predictability.
In today's rulings the court attempts to limit
some of the indeterminacy of the doctrine with a set of bright-line rules,
trading off areas of uncertainty for a degree of rigidity. Unfortunately, this
attempt at injecting certainty into the doctrine contains the potential for
unintended consequences, consequences that may do nothing but exacerbate the
problem.
What will be the response of the patent bar to
the new rules? Past practice has been to claim broadly in the initial
application for a patent, and then negotiate with the United States Patent and
Trademark Office through one or more rejections until arriving at a mutually
acceptable set of claims. Under the new rules of engagement, that process will
create full prosecution history estoppel regarding every limitation that is
amended for patentability purposes, a term now broadly defined.
Patent counsels may decide that past practice
gives up too much under the new rules, and instead may start claiming narrowly
with the hope of avoiding rejections and consequent amendments. Literal
infringement will become harder to prove because claims will be drafted more
narrowly and with greater specificity. That itself may be to the good, since
much of current patent litigation involves claim construction issues resulting
from the vague, sometimes almost incomprehensible, manner in which claims have
been drafted.
An unintended consequence, however, may be that
patent litigation will lean ever more heavily on the doctrine of equivalents,
especially in those cases in which the patent application, containing narrowly
drawn claims, was approved without any amendment in the area that affects the
accused product. The patentee may have little choice but to insist on
enforcement under the doctrine of equivalents, if the patent is to be enforced
at all. Since today's decision does not change the basic rule of analysis for
infringement claims under the doctrine of equivalents, the outcome in those
cases will continue to be tested under the pre-existing "insubstantial
differences" and its surrogate "function-way-result," with all
the game-playing those indeterminate phrases provide.
In time then, the supposed benefits of the
doctrinal improvements contained in today's decision may prove illusory.
That is why I consider it a second-best
solution. A better solution would be to declare the doctrine of equivalents--a
judge-made rule in the first place--to have its roots firmly in equity, and to
acknowledge that when and in what circumstances it applies is a question of
equitable law, a question for which judges bear responsibility. We have
admitted to these roots in a number of cases.[198]
Were this court to openly acknowledge that the
doctrine of equivalents can only be legitimated by its equitable roots and
should be treated as an equitable doctrine, important consequences would flow.
Trial courts, sitting as courts of equity, would be responsible for deciding
whether the doctrine of equivalents should be applied, not unlike the practice
regarding the doctrine of inequitable conduct. On appeal to this court, we
would review a trial court's determination under the deferential standard of
abuse of discretion.
The test the trial courts would apply would be
crafted to blend both objective and subjective factors. The differences between
the claimed invention and the accused product would necessarily remain of
relevance; and in addition, traditional equitable considerations would focus on
matters such as the conduct of the accused product's sponsors, specifically,
the considerations pronounced in the Supreme Court's seminal opinion in Graver
Tank & Manufacturing Co. v. Linde Air Products Co.:[199]
[C]ourts have also recognized that to permit
imitation of a patented invention which does not copy every literal detail
would be to convert the protection of the patent grant into a hollow and
useless thing. Such a limitation would leave room for--indeed encourage--the
unscrupulous copyist to make unimportant and insubstantial changes and
substitutions in the patent which, though adding nothing, would be enough to
take the copied matter outside the claim, and hence outside the reach of law. .
. .
. . . The essence of the doctrine [of
equivalents] is that one may not practice a fraud on a patent. Originating
almost a century ago in the case of Winans v. Denmead[200] , it has been
consistently applied by this Court and the lower federal courts, and continues
today ready and available for utilization when the proper circumstances for its
application arise.
It is true that "fraud" and
"unscrupulous" conduct are not terms of precision, yet they are terms
with which judges are familiar. More importantly, they point to the underlying
reason for the doctrine; as the Court said, the essence of the doctrine is
fraud. Notions of fairness and equity are concerns which over the centuries
have permitted courts to reach beyond the fixed scope of legal rights in
"proper circumstances," to use the Court's phrase. What those
circumstances are in regard to patent rights this court over time could
determine, and in time develop a refined body of law that emphasizes the
exceptional nature of relief under the doctrine. In time, there would be a set
of known factors that could be applied predictably, thus giving a degree of
decisional certainty to the doctrine, all the while retaining flexibility in
the process to deal with new situations--the hallmark of equitable adjudication.
By contrast, the notion of "insubstantial
differences" between a particular claim and a particular product, viewed
as the governing principle, can never be anything other than an ad hoc
judgment, dependent on the eye of the beholder in the individual case. Though
we talk about considering factors such as the role of copying,
interchangeability of elements, and so on, the reality is that, as our cases
since Hilton Davis demonstrate, the decision on equivalents remains essentially
a subjective call, with repetition of verbal formulae but without
transferability from case to case of practical guidance. This to me is the
antithesis of the rule of law.
I have previously written at length on this
problem and on my suggested approach to its management,[201] and will not repeat all that was said there.
In this court's earlier attempt to address the difficulties in our equivalents
doctrine,[202] passim, the court majority elevated the
notion of insubstantial differences to the controlling criterion, on the expressed
belief that it had some abstract objectivity. Experience has now shown that
belief to have been more hope than reality. In focusing on the mechanistic idea
of insubstantial differences, the court failed to grapple with the basic
problem of uncertainty in the law. Thus, five short years later, we are again
grappling with the problem. This is a self-inflicted wound.
It would be easy now to blame the Supreme Court
for the mess we are in, since the Court, in response to our Hilton Davis
decision, has opined on the matter.[203] However, I do not believe that the Supreme
Court wishes to stand in the way of a sensible solution. For one, the Court
expressly declined to consider whether the application of the doctrine of
equivalents is a task for the judge or jury.[204] That infringement under the doctrine is a
fact issue is of no moment; equity courts deal with facts all the time. In
addition, a Supreme Court that did not balk at making the most critical aspect
of infringement law--claim construction--a matter for judges alone,[205] may, when pressed, find it appropriate to
acknowledge the equitable nature of the doctrine of equivalents and the reasons
why judges have a comparative advantage in equitable adjudication.
The Supreme Court in its Warner-Jenkinson
opinion did opine that "intent plays no role in the application of the
doctrine of equivalents."[206] That suggests that at least some of the
considerations involved in traditional equitable analysis would not be
appropriate. However, the Court's statement in that regard was preceded by a
reference to Graver Tank and the fact that, while Graver Tank leaves room for
the inclusion of intent-based elements in the doctrine, it did not require
them. From this, the Court opined that the "better view" was to exclude
intent-based considerations. Today, the Court might well conclude that, since
the so-called "objective" approach has proven unworkable, a return to
the equitable analysis approach would be the "better view."
Particularly would this be so if this court led the way, since in its
Warner-Jenkinson decision the Supreme Court was doing little more than echoing
what we had said on the subject of intent in our Hilton Davis opinion.
We are the court primarily responsible for the
state of patent law, and the Supreme Court has pronounced it our duty to
"best implement procedural improvements to promote certainty, consistency,
and reviewability to this area of the law."[207] It is time for us to 'think outside the
box,' and restore the doctrine of equivalents to its original equitable
function and purpose, thus providing a judicial process that lends itself to
making the doctrine both determinate and predictable.
Those who are wedded to the existing regimen can
no doubt find all sorts of objections to this proposed approach. I cannot say
that the approach I advocate is a panacea for all that ails the equivalents
practice. I can say that what we have does not work very well, and, as we did
in Markman, it is time to try something else, something that has substantial
jurisprudential legitimacy and holds out some promise for improvement. Until
such time as this court is of a mind to seek and design a long-term solution to
the equivalents problem, however, I have little choice but to join in even this
limited effort to cabin what is otherwise, and I fear remains, a doctrine short
on predictable results, and short on the achievement of equity to which it owes
its existence.
Judge Lourie, concurring.
I fully join the majority opinion. However, I
write separately to respond to comments and concerns of supporters of the
flexible bar rule.
It has been stated by a dissenter that most of
the members of the majority have authored opinions supporting a flexible bar. I
am one of them. My obligation is to follow precedent, and it is correct that
our court has had precedent for a flexible bar, albeit not necessarily
consistent precedent. I therefore followed what seemed to be the strongest line
of precedent at that time.[208] However, in light of experience, and
recognizing the Congressional requirement for precision in claims, 35 U.S.C. §
112, ¶2, I am persuaded that when we have the opportunity en banc to depart
from an unworkable rule by holding patent applicants to their actions in the
PTO, we should do so. Adoption of a firmer rule today is in the best interest
of the patent system.
Our holding does not violate the Supreme Court's
guidance in Warner-Jenkinson Co. v. Hilton Davis Chem. Co. The key issue decided by the Court in
Warner-Jenkinson relating to prosecution history estoppel was whether the reasons
for a claim amendment are relevant in determining whether prosecution history
estoppel should be applied.[209] The Court held that the reason for an
amendment is relevant, as amendments made for substantial reasons relating to
patentability lead to an estoppel. While the Court referred to the avoidance of
prior art as a principal reason for an amendment relating to patentability, it
did not limit the application of prosecution history estoppel to claims that
were amended for prior art reasons.[210] Hence, this court, in its present decision,
has refined the scope of "a substantial reason related to
patentability" to include any reason relating to a statutory requirement
for patentability. In other words, if a claim was not allowable for statutory
reasons without an amendment, then the amendment was presumptively made for a
reason relating to patentability. Such an amendment may relate either to prior
art or to various requirements under 35 U.S.C. §§ 101 and 112.
The Supreme Court has not addressed what scope of
equivalents remains when a claim has been clearly amended for patentability
reasons. The closest the Court came to doing so was in Warner-Jenkinson, where
it created the presumption that an amendment was made for a reason relating to
patentability when it is unclear why that amendment was made. The Court then
stated: "In those circumstances, prosecution history estoppel would bar
the application of the doctrine of equivalents as to that element."[211] It did not otherwise render any holding
concerning the scope of equivalents that remains when a claim has clearly been
amended for patentability reasons. Thus, this en banc court is free to do so
today. In fact, today we merely extend the Supreme Court's complete bar against
the application of the doctrine of equivalents, which applies when it is
unclear why an amendment was made and the patentee fails to rebut the
presumption that an amendment was made for reasons relating to patentability,
to cases in which the patentee clearly amended a claim for patentability
reasons.
It has been said that there is no hard evidence
showing that the so-called "flexible" bar impairs predictability.
While it is true that empirical data may not be available, powerful evidence
may be garnered from the experience of this court, which monthly reviews
appeals in which infringement is asserted under the doctrine of equivalents
even though the accused product is clearly not within the literal scope of the
asserted claims. Many of these appeals involve prosecution histories in which
amendments for patentability reasons have been made. Yet, equivalence is argued
in the hope that one panel might find equivalence where another would not. That
surely is persuasive evidence that the current flexible bar is not working. Our
court was created with the opportunity and mandate to observe such problems in
the law and to act upon a possible solution.[212] That is why we have been given exclusive
jurisdiction over patent appeals. 28 U.S.C. § 1295(a).
It has been suggested that there are settled
expectations in the bar and innovation community regarding the present rule.
The only settled expectation currently existing is the expectation that clever
attorneys can argue infringement outside the scope of the claims all the way
through this court of appeals. Such a settled expectation should become
unsettled. Surely, when prosecuting a patent, patent practitioners have no
settled expectations of being able to assert the doctrine of equivalents. Any
patent attorney who fails to claim all that his inventor has invented, and that
is patentable, is ill-advised to settle for a narrower claim than he considers
justified on the assumption that he can rely on the doctrine of equivalents for
broader coverage. Such reliance is a highly risky prospect given that the patent
statute requires precise claims. 35 U.S.C. § 112, ¶2. When a patent applicant
is faced with a rejection, or expects a rejection, he (or she) is master of his
claims. He can stand his ground and appeal, or amend the claims. If the latter
course of action is chosen, such conduct, which is known to the world, should
bind the applicant. The fact that the applicant may have to appeal an
unjustified rejection, incurring loss of time and expense, does not mean that
we should refrain from adding clarity to the meaning of claims by holding
patent applicants to their actions in the Patent and Trademark Office
("PTO").
Additionally, the PTO does not make "basic
assumptions" relating to a range of equivalents to be allowed.[213]
The PTO examines claims in light of the disclosure
of the patent application and against the prior art.[214] It does not issue patents with any
expectations regarding equivalents.
It is said that stare decisis compels us to stay
the course with the old rule. I thought the same regarding Zurko.[215] However, the Supreme Court, in its wisdom,
believed that decades of practice should be overturned in order to bring our
standard of judicial review of findings of fact made by the PTO into line with
the standard of review applied to other agency decisions.[216] Similarly, a majority of this court believes
that important policy considerations relating to achieving the certainty
contemplated by Congress justifies departing from an older unworkable rule.
Finally, one of the dissenters fears that
today's ruling provides would-be copiers with a free pass to appropriate the
essence of an invention and yet escape infringement. That is theoretically
true. In the future, a competitor may more closely approach the limits of the
claims in a patent in which a narrowing amendment has been made without fear of
liability. Occasional injustices may occur. However, I believe that such
occasional injustices will be greatly outnumbered by competitors who will be
able to introduce innovative products outside the scope of claims without fear
of unjustified, protracted, and expensive litigation. In today's world, the
specter of unpredictable equivalence claims haunts too many business decisions,
while the overwhelming majority of equivalence claims ultimately fail. It is
more than justified to lessen this fear and hold patent applicants to the
consequences of their public prosecution decisions. The rule we announce today
should encourage innovation, lessen uncertainty, and diminish the volume of
unnecessary litigation, while providing patentees with protection commensurate
with the disclosed and allowed scope of their inventions.
As for the biotechnology example hypothesized by
one of the dissenters, I believe the concern is largely theoretical. The first
inventors in a field are only entitled to claim what they can describe and
enable, and I am confident that competent patent attorneys can readily craft
their claims to cover that subject matter so that estoppel can be avoided.
Moreover, subsequent inventors will be better able to find and develop improved
products without fear of lawsuits. Predictability will be enhanced.
The fact is that, even under our past rule of
flexible bar, no court has rendered a decision holding infringement only under
the doctrine of equivalents by an accused gene or protein. To the extent that a
competitor has been deterred from developing a new compound for fear that it
will be held to be an infringer under an equivalence theory, I believe that our
new rule will provide a clear net gain for innovation and the public. They will
benefit from the greater certainty that new compounds not within the scope of
granted claims can be developed without fear of protracted litigation.
For these reasons, and for others aptly
expressed by the majority opinion, I join the majority opinion.
Judge Michel, concurring-in-part,
dissenting-in-part, with whom Judge Rader joins.
I join the majority opinion with respect to the
disposition of Questions 1, 2, 4, and 5. However, I must dissent from the
majority's response to Question 3 because I believe it contradicts Supreme
Court precedent and policy.
In Warner-Jenkinson Co., Inc. v. Hilton Davis
Chemical Co.,[217] the Supreme Court
encouraged our court to "refine the formulation of the test for
equivalence." I am convinced, however, that the majority's new
"complete bar rule," far from being merely such a refinement,
contravenes consistent Supreme Court authority. Not only does the majority's
new rule directly contradict one Supreme Court holding, but it undermines the
legal standard that the Supreme Court has consistently articulated in seven
other cases for determining the scope of such estoppel. Moreover, because most
patents contain claims that were amended during prosecution, the majority's
holding effectively strips most patentees of their rights to assert
infringement under the doctrine of equivalents, despite the Supreme Court's
unanimous adherence to the doctrine in Warner-Jenkinson. The majority's new
rule constitutes a rejection of the policy advanced by the Supreme Court in
Warner-Jenkinson that the all-elements rule and prosecution history estoppel
are sufficient to balance the competing needs of granting meaningful protection
to patentees and of notifying the public of the effective scope of a patentee's
claims.
I. The Majority's Rule Upsets the Balance Struck
by the Supreme Court Through Warner-Jenkinson Between the Competing Needs for
Meaningful Patent Protection and Adequate Public Notice.
Before discussing particular Supreme Court
cases, I believe it is important to summarize the doctrinal framework that the
Supreme Court has consistently employed for over a century to balance a
patentee's need for meaningful protection against copying and the public's need
for notice as to the effective scope of a patentee's claims. The Supreme Court
has consistently stated, and has done so as recently as Warner-Jenkinson, that
application of the all-elements rule, as supplemented by prosecution history
estoppel, sufficiently balances the competing needs of meaningful patent
protection and adequate public notice. Today's majority upsets this balance,
holding that the public notice function of patents can only be fulfilled by
limiting the effective scope of patents with amended limitations to the literal
wording of such limitations.
The limitations of a patent's claims provide an
initial measure of the effective scope of the patent, both literally and under
the doctrine of equivalents. The all-elements rule provides that every
limitation of a claim is material, and that an accused device lacking a
corresponding element, or an equivalent thereof, for every limitation cannot
infringe the claim, even under the doctrine of equivalents.[218] The Supreme Court has recognized for more
than a century that the public is entitled to make, use, or sell devices that
lack one or more elements corresponding to the limitations of a patent's
claims, or their equivalents.[219]
In Warner-Jenkinson, the Supreme Court
reiterated that under the all-elements rule and prosecution history estoppel,
the public receives adequate notice as to the enforceable scope of patent
claims.[220] Moreover, the Warner-Jenkinson Court
reaffirmed that, although limiting its application, the all-elements rule still
accommodates the right of patentees to assert infringement of some equivalents.[221] Under the all-elements rule, the claims
themselves provide considerable notice to the public as to the effective scope
of the patent (i.e., a patentee cannot assert infringement by a device that
lacks an equivalent of one or more limitations of the claim, as issued), while
preserving for the patentee a scope of protection under the doctrine of
equivalents to prevent copying.
When a patent applicant narrows his claims
during prosecution by adding a limitation to traverse a prior art rejection,
the substance of the communications between the applicant and the examiner may
further notify the public as to additional limits on the enforceable scope of
the patent claims. Depending on factors such as the breadth of the examiner's
rejection, the manner in which the patent applicant amends his claims to
overcome the objection, and the nature of the technology at issue, a reasonable
competitor might construe the applicant's remarks and amendments to evince a
surrender of claim scope greater than the all-elements rule would require.[222] We describe this doctrine as
"prosecution history estoppel," precisely because a hypothetical
reasonable competitor should be able to rely on the applicant's representations
and amendments as a surrender of subject matter.1[223] The doctrine of prosecution history estoppel
supplements the all-elements rule by providing a set of rules for notifying the
public whether, and to what extent, the scope of protection is even narrower
than what the all-elements rule would allow.[224]
In contrast to the doctrine of prosecution
history estoppel we have applied until today, the majority's new complete bar
rule does not supplement the all-elements rule as a way to further clarify the
scope of equivalents available to the patentee. Rather than attempt to "refine"
our case law as to how the added claim limitations should be enforced in light
of the substance of the communications between examiner and applicant, the
majority's new rule simply forecloses all application of the doctrine of
equivalents for any amended claim limitation. This approach by-passes the
all-elements rule altogether.[225]
The majority's concept of prosecution history
estoppel is hardly an "estoppel" at all. The majority's approach
gives no consideration to whether a reasonable competitor would rely on the
nature of the rejections and of the amendments and statements between the
applicant and the examiner as evidence of a surrender of subject matter.
According to the majority, once there has been a limiting amendment, no
consideration may be given to the breadth of the rejection, the closeness of
the prior art, the manner of the applicant's remarks and amendments, or the
nature of the technology. All equivalents of that limitation are foreclosed by
the mere fact of amendment. The majority's rule might more aptly be called
"bar by amendment" rather than "estoppel," which has always
been measured by what a reasonable competitor would understand the applicant to
have surrendered in order to procure his patent. I believe that looking solely
to the fact of amendment, rather than the substance of communications between
the applicant and the examiner, is contrary to the principles that the Supreme
Court (and our court) has always applied in determining the scope of estoppel.
Under the majority's rule, in contrast to the
Supreme Court's application of the all-elements rule and prosecution history
estoppel, a patentee retains no range of equivalents for a claim limitation
that has been amended for patentability reasons. This approach upsets the
Supreme Court's balance between the competing needs of sufficient public notice
and meaningful patent protection. At the very minimum, I believe the majority's
rule is unfairly harmful, because it deprives patentees of any recourse to the
doctrine of equivalents for any added or narrowed limitation, no matter how
minor the amendment. More importantly, however, I believe that precluding a
patentee's right to seek protection under the doctrine of equivalents for
amended limitations will, in many cases, "convert the protection of the
patent grant into a hollow and useless thing."[226]
Would-be copyists, of course, will exploit the
majority's bar. Unwittingly, the majority has severely limited the protection
previously available to patentees. Indeed, it may nullify the doctrine of
equivalents. Under the majority's approach, anyone who wants to steal a
patentee's technology need only review the prosecution history to identify
patentability-related amendments, and then make a trivial modification to that
part of its product corresponding to an amended claim limitation. All the other
limitations may be copied precisely. The competitor will then be free to make,
use, or sell an insubstantial variant of the patentee's invention. It appears
to me that this complete bar approach upsets the balance that the Supreme Court
has struck. Under this approach, most patentees will lose the protection
against copying that the Supreme Court unanimously reaffirmed in
Warner-Jenkinson.
II.
Supreme Court Precedent
The majority asserts that the Supreme Court has
never "addressed or answered" the question as to whether a scope of
equivalents remains after a claim limitation has been added or amended for a
reason relating to patentability. The majority quotes language from six Supreme
Court cases dealing with prosecution history estoppel,2[227] and asserts that in these six cases,
"the Court did not analyze the actual scope of equivalents that might be
available when prosecution history estoppel applied." The Court thereby
posits that "[w]e think it is fair to say" that this question remains
open. I agree with the majority that, in four of these six cases, the Supreme
Court did not address the question presently at bar. As to the other two cases,
Hubbell v. United States,[228] and Shepard v. Carrigan,[229] the majority and I draw different
conclusions. Most importantly, however, I can hardly agree with my colleagues
that, upon a review of only these six Supreme Court cases, they can rightfully
draw the conclusion that never has the Court "answered or addressed"
today's question.
The Supreme Court has decided many more than
these six cases relevant to prosecution history estoppel. Hurlbut v.
Schillinger,[230] is one particularly noteworthy case, wherein
the Supreme Court ruled that a patentee, who had disclaimed a portion of his
invention, and who had been found in prior litigation to be precluded from
asserting his claims against one accused device in light of that disclaimer,
nonetheless remained entitled to a judgment of infringement by a different
device that was more closely equivalent to his claimed invention. The majority
also disregards the legal standard repeatedly articulated by the Supreme Court
that is consistent only with a flexible approach to prosecution history
estoppel, i.e., that an amended claim may be infringed if "an omitted part
is supplied by an equivalent device or instrumentality."[231] Furthermore, the majority nowhere recognizes
that the Supreme Court has articulated a consistent, uniform doctrine for
applying the doctrine of prosecution history estoppel since the 1880s, with no
suggestion in Warner-Jenkinson or other recent cases that it sought to depart
from its earlier holdings.
Many of the cases I cite were decided in the
1800s. Before discussing them, I would like to make three general points about
this older precedent. First, the Supreme Court was very active in the patent
field in the late 1800s. From 1880 to 1900, the Court decided no fewer than
ninety patent infringement cases, with many of these cases being highly
relevant to the present appeal. From my review of these cases, and the far
fewer number of cases the Court decided in the 1900s, it appears that the Court
established the basic contours of patent law in the late 1800s, including on
equivalency and estoppel, and has reaffirmed these same principles ever since.
Indeed, more recent Supreme Court cases,[232] are remarkable in the degree to which they
cite nineteenth century cases, and in their express insistence on adhering to
older precedent.
Second, in addition to being old, many of the
cases I cite involve reissue patents.3[233] But the law of prosecution history estoppel
has developed with equal applicability to reissue patents and original patents
whose claims were amended during prosecution. By at least 1879, the Supreme
Court recognized that the process of obtaining a reissue patent precluded the
patentee from recapturing that which he had disclaimed (i.e., surrendered)
through the reissuance process.[234] Considering that Leggett, which concerns a
reissue patent, is the foundation for much of the Court's subsequent treatment
of what we now call "prosecution history estoppel,"[235] I find nothing to suggest that the presence
of a reissue patent, in several cases cited below, alters the legal standards
articulated by the Court for resolving disputes involving prosecution history
estoppel on claims issued in the original prosecution. Rather, the Supreme
Court compared the original and reissue claims to measure the scope of
estoppel, treating the reissue claims like amended claims.
Finally, although these older cases do not
specifically recite either of the synonymous phrases "prosecution history
estoppel" or "file wrapper estoppel," the principles articulated
in these cases form the core of the doctrine of prosecution history estoppel
that we have applied until today. The phrase "file wrapper estoppel"
was not employed by the Supreme Court until its decision in Exhibit Supply Co.
v. Ace Patents Corp.,[236] and the
Supreme Court did not use the phrase "prosecution history estoppel"
until Warner-Jenkinson.[237] Nonetheless, the Court recognized in
Warner-Jenkinson that many of the cases I cite below, such as Sutter and
Hubbell, indeed set forth the principles of our present doctrine of
"prosecution history estoppel."[238] I believe that the absence of the phrase
"prosecution history estoppel" in the cases I cite is hardly a
convincing basis for distinguishing them.
A.
Goodyear Dental Vulcanite Co. v. Davis
One of the first cases in which the Supreme
Court discussed the principles underlying our present doctrine of prosecution
history estoppel is also one of the most instructive.[239] concerns a reissue patent for a rubberized
dental plate, claiming "[t]he plate of hard rubber or vulcanite, or its
equivalent, for holding artificial teeth, or teeth and gums, substantially as
described." The Supreme Court recognized that the patentee, Cummings, had
restricted his claims during the reissuance process to a dental plate made of
hard "vulcanized" rubber, and thus that Cummings was precluded from
asserting that a dental plate made of celluloid (a softer, chemically distinct,
unvulcanized material) was an equivalent of the claimed invention.
Notwithstanding this restriction on the available scope of equivalents, the
Court nonetheless stated that Cummings could assert infringement by other
products that were equivalent to those recited in the patent:
If, when the patent was granted, there were
known substances, other than rubber or caoutchouc, gutta-percha, or gums, that
could be vulcanized by the Goodyear process, and converted from a soft into a
hard, elastic material, any use of that material for a dental plate might have
been an equivalent for the Cummings material, and an infringement of his
patent.[240]
The Court continued, stating that although
Cummings had limited his claims to a vulcanized product, and was thus precluded
from asserting the equivalence of a softer, celluloid, unvulcanized product,
Cummings nonetheless retained protection against equivalents. The Court stated:
"It may be conceded the patentee is protected against equivalents for any
part of his invention."[241] . Thus, the Court
recognized that although a patentee, by amending his claims, may be precluded
from asserting a large range of equivalents, he may still be able to assert his
patent against devices that fall within a narrower range of equivalents. This
statement is only consistent with a flexible approach to prosecution history
estoppel, and would be meaningless if the Court had intended a complete bar to
apply.
Moreover, the Court stated that Cummings was
protected against equivalents "whether he had claimed them or not."[242] By this statement, the Court clarified that
it was not necessary for patent applicants like Cummings to recite the words
"or its equivalent" or "substantially as described" in the
patent claims, but rather that patentees' protection against equivalents arises
independently of the particular wording of the claims.
The majority argues that the Goodyear Court
"did not discuss prosecution history estoppel." I agree that the
particular phrase "prosecution history estoppel" nowhere appears in
Goodyear. However, the principles articulated in Goodyear are the foundation of
the modern doctrine of prosecution history estoppel. Indeed, the Supreme
Court's first opinion to discuss the doctrine of "file wrapper
estoppel," Exhibit Supply Co. v. Ace Patents Corp.,[243] specifically mentions Goodyear as a basis of
that doctrine. It is also true, as the majority points out, that the Goodyear
Court did not rule in favor of the patentee, and thus that the language I cite
does not constitute a holding. I cannot agree with the majority, however, that
the Court's statements fail to constitute "explicit and carefully
considered language," and that the rule of Goodyear may be disregarded.
Rather, as I will describe in the next case I cite, the Court soon thereafter
applied these principles to hold that a patentee retains a range of enforceable
equivalents, despite having made a disclaimer that restricted his available
range of equivalents.
B. Hurlbut
v. Schillinger
Hurlbut v. Schillinger,[244] and an earlier related case, California
Artificial Stone-Paving Co. v. Schalicke,[245] concern a patent for an improvement in
concrete pavements, claiming an "arrangement of tar-paper or its
equivalent between adjoining blocks of concrete," such that the imposition
of tar-paper between the paving blocks would facilitate the removal of a block
that subsequently becomes damaged, without disrupting adjacent blocks.
Schillinger obtained a reissue patent, amending the original specification to
state, among other things, that "where cheapness is an object, the
tar-paper may be omitted and the blocks formed without interposing anything
between their joints."[246] In his reissue patent, Schillinger also
obtained a claim that omitted any reference to tar-paper or its equivalent.
After obtaining his reissue patent, Schillinger
filed a disclaimer with the Patent Office, stating that his reissue claim was
too broad, and covered kinds of pavement "of which your petitioner was not
the first inventor."[247] Schillinger disclaimed any coverage to an
arrangement of pavement wherein the tar-paper is omitted and no material is
used to separate the concrete blocks.[248]
Schillinger brought suit against several
competitors, and two of the disputes reached the Supreme Court. In the first,
California Paving,[249] the Court remarked that the accused paving
was neither separated into individual blocks, and nor had any material been
interposed between the blocks while they were still plastic. The Court noted
that Schillinger had disclaimed "the forming of blocks from plastic
material without interposing anything between their joints while in the process
of formation."[250] The Court found no infringement, concluding
that "what the defendant did was just what the patentee disclaimed."[251] Thus, it is clear from California Paving
that Schillinger's disclaimer was sufficient to preclude him from asserting
infringement by the defendant's arrangement of pavement. Although the Court did
not employ the phrase "prosecution history estoppel" to describe this
limitation on the effective scope of his patent, I think it is apparent that
Schillinger's disclaimer had invoked such an estoppel.
In Schillinger's second suit to reach the
Supreme Court, the accused product was an arrangement of pavement whose
individual blocks, while still plastic, were separated from one another by
means of a trowel.[252] The Court recognized that the stroke of a
trowel to separate the blocks was different than inserting tar-paper between
the blocks. See id. The Court also recognized that Schillinger had limited the
protective scope of his reissue patent through his disclaimer, and was thus
precluded from asserting his claims against pavement arrangements wherein the
blocks were not separated.[253] The Court nonetheless held that Schillinger
was still entitled to a range of equivalents after having made his disclaimer,
and that using a trowel to separate the blocks was equivalent to using
tar-paper. The Court stated:
The effect of the disclaimer was to leave the
patent to be one for a pavement wherein the blocks are formed by interposing
some separating material between them. To limit the patent to the permanent
interposition of a material equivalent to tar-paper, would limit the actual
invention. The use of a bottom layer of coarse cement, and placing it on a
course of fine cement, and dividing the upper course into blocks by a trowel
run partially or wholly through the upper course while it is plastic, in a line
coincident with the joints between the sections in the lower layer,
accomplishes the substantial results of Schillinger's invention, in
substantially the way devised by him, and is within the patent as it stands
after the disclaimer.[254] The Court continued, emphasizing that the
effect of the disclaimer was not to completely preclude Schillinger from
asserting equivalence, but rather that the scope of the preclusion was
determined by reference to the actual embodiments that Schillinger had
surrendered. The Court stated:
The disclaimer took out of the first claim of the
reissue only so much thereof as claimed a concrete pavement made of the plastic
material laid in detached blocks, without interposing anything in the joints in
the process of formation, leaving that claim to be one for such a pavement laid
in detached blocks, when free joints are made between the blocks, by
interposing permanently or temporarily between them, in the process of their
formation, tar-paper or its equivalent.[255] The Court concluded
that the accused pavement constituted an equivalent of the claimed invention
"as it stands after the disclaimer," and thus that Schillinger was
entitled to a judgment of infringement. The Court stated:
We are, therefore, of opinion that the first
claim of the reissue, as it stands after the disclaimer, is infringed, because
the defendant's pavement is a concrete pavement, laid in detached blocks or
sections, substantially in the manner shown and described in the specification
of the reissue, the detached blocks in the upper course being the equivalent of
the detached blocks or sections of the Schillinger pavement; and that the
second claim of the reissue is infringed, because the temporary use of the
trowel or cutting instrument, to divide the upper course into blocks, is the
equivalent of the tar-paper of the Schillinger patent . . . .[256]
Today's majority, noting that Schillinger
recited the phrases "substantially" and "or its
equivalents" in the patent claims, appears to argue that the defendant in
Hurlbut had literally infringed the claims, and that the Court "did not
discuss the issue of the scope of equivalents that remained under the doctrine
of equivalents after the disclaimer." I do not agree, however, that the
mere presence of the words "equivalent" or "substantially"
in Schillinger's claim language somehow reduces the infringement analysis to
one of literal infringement. As noted above, the Goodyear Court made clear that
a patentee is protected against equivalents, "whether he had claimed them
or not."[257] The tension at the heart of these
disputes--between meaningful patent protection and adequate public
notice--persists regardless of whether "equivalents" are recited in
the claims or are claimed implicitly through the doctrine of equivalents. I
believe that the legal framework employed by the Hurlbut Court to limit the
range of equivalents available to Schillinger applies whether or not the words
"substantially" or "or its equivalents" appear in the
claims.
The Court's holding in Hurlbut is simply an
application of the principles it established in Goodyear. In both cases, the
Court recognized that the patent applicants' disclaimers and amendments had
precluded the patentees from asserting the equivalence of certain accused
devices. In both cases, however, the Court stated that, despite the disclaimer
or amendment, the patentee retained a limited scope of equivalents. Although
the Court articulated its reasoning in Goodyear without holding in favor of the
patentee, these same principles are the foundation of the Court's clear holding
for the patentee in Hurlbut. As I read these cases, Goodyear and Hurlbut
entitle a patentee to a range of equivalents despite the fact of a limiting
amendment.
C. The Majority's
Holding Contradicts Six Other Supreme Court Cases That Declare a Flexible
Approach to Prosecution History Estoppel.
Goodyear and Hurlbut are the two cases I have
identified where the Court has most fully described its flexible approach to
prosecution history estoppel. These cases, however, are far from the only
instances where the Court has set forth legal principles that are consistent
only with a flexible approach. Following are six more cases where the Court set
forth a legal standard that provides that patentees who have amended their
original claims, and who are thus precluded from asserting a certain range of
equivalents, nonetheless retain the right to assert a more limited range of
equivalents. In three of these cases, the Supreme Court declared that a
patentee who had introduced a new claim limitation during prosecution or during
reissuance would be entitled to enforce his amended claims by showing that in
the accused device, "an omitted part is supplied by an equivalent device
or instrumentality."[258] Moreover, the Supreme Court restated this
legal standard verbatim in Warner-Jenkinson.[259] Although the Supreme Court recited this same
legal standard in the very same words on four separate occasions over the span
of 113 years, today's majority regards these cases as lacking "explicit
and carefully considered language." I cannot agree.
1. Fay v.
Cordesman
Fay v. Cordesman,[260] concerned three patents, including a reissue
patent, for a mechanical saw whose blade is alternately pushed and pulled. The
reissue patent contained five claims, all of which were substantially amended
from the single claim of the original patent.[261] Noting that the accused device, a
continuously rotating band saw, did not embody an adjustable saw guard, as
recited in an asserted claim of the reissue patent, the Court ruled that there
could be no infringement because: "If it be a claim to a combination, and
be restricted to specified elements, all must be regarded as material, leaving
open only the question whether an omitted part is supplied by an equivalent
device or instrumentality."[262] Although Fay does not recite the words
"prosecution history estoppel," its legal standard has been
repeatedly reaffirmed by the Supreme Court, through Warner-Jenkinson, as
governing the application of prosecution history estoppel.[263] Fay, as subsequently recognized by
Warner-Jenkinson, clearly indicates that, despite having amended his claims
through the reissuance process, the inventor would still be able to assert his
claims against other devices that were more closely equivalent to his
invention. Fay's legal standard would be meaningless if the Court had intended
to disallow equivalents for amended claims.
2. Shepard
v. Carrigan
In Shepard v. Carrigan,[264] the Court considered whether a skirt
protector lacking a "fluted or plaited band or border" infringed a
claim that had been amended to include such a limitation. The Court stated that
its previous holding in Fay,[265] was "decisive of the present
case,"[266] and thus that the proper inquiry was
"'whether an omitted part is supplied by an equivalent device or
instrumentality.'"[267] Despite ruling that the patentee had "explicitly
abandoned" claims to an unplaited skirt protector, the Court's legal
standard clearly contemplates that other skirt protectors could be found to
constitute "an equivalent device or instrumentality" of the invention
claimed in the reissue patent.[268] Again, the legal standard governing Shepard
is repeated, verbatim, in Warner-Jenkinson.[269] Although the Shepard Court did not use the
phrase "prosecution history estoppel" to describe the limit on
equivalents it applied, the Supreme Court subsequently interpreted Shepard as
invoking such an estoppel.[270]
3. Sutter
v. Robinson
In Sutter v. Robinson,[271] the patentee claimed an apparatus for
"resweating" tobacco. During prosecution, the applicant amended his
claims to avoid the prior art, stating that the inventive aspect was the use of
a wooden, rather than metal, vessel for the tobacco. The Court stated that
"the ultimate question" in the case was "whether, in such an
apparatus, the use of the cases, or boxes, or packages, in which the tobacco
leaves are originally packed by the producer is equivalent to the wooden
tobacco-holder mentioned in the complainants' specification."[272] Although the Court found that the accused
device could not infringe the patent in light of the applicant's amendment, the
Court's "ultimate question" clearly contemplates that other devices,
although not exact copies of the patented invention, might have infringed the
amended aspect of the claim under the doctrine of equivalents. This
"ultimate question," of course, would be irrelevant if the Court
intended a complete bar to govern equivalency disputes involving amended
claims. The Warner-Jenkinson Court cites Sutter as a proper application of the
doctrine of prosecution history estoppel.[273]
4. Phoenix
Caster Co. v. Spiegel
Phoenix Caster Co. v. Spiegel,[274] concerns claims to a furniture caster. The
claims had been repeatedly narrowed during prosecution to a caster containing
an elliptical housing opening, a collar, and a rocker-formed collar bearing.
The Court ruled that the accused device "is not of a construction similar
to" the patented invention, and that the accused device did not contain
"any equivalent for such 'rocker-formed collar bearing,'" and thus
that there was no infringement.[275] The Court did not foreclose application of
the doctrine of equivalents in light of the patentee's multiple narrowing
amendments, but still inquired whether the accused device was "similar
to" or an "equivalent for" the claimed invention.[276] Although the majority suggests that Phoenix
does not involve prosecution history estoppel, the Supreme Court subsequently
cited Phoenix as supporting the proposition at the heart of prosecution history
estoppel that "[i]t is a rule of patent construction consistently observed
that a claim in a patent as allowed must be read and interpreted with reference
to claims that have been cancelled or rejected and the claims allowed cannot by
construction be read to cover what was thus eliminated from the patent."[277]
5. Royer
v. Coure
In Royer v. Coure,[278] the circuit court held that in light of the
patentee's multiple limiting amendments, his claims were restricted to the
eight-step process described in the specification, and that to find an
infringement of the process, "'a person must be shown to have followed
substantially the same process, the same mode of reaching the result as is
described in the specifications.'"[279] The Supreme Court fully endorsed this
approach to limiting the application of the doctrine of equivalents, holding
that "[w]e are of opinion that the views set forth by the circuit court
are sound, and that the decree must be affirmed."[280] Royer thus confirms
that a patentee with an amended claim may still assert his rights against those
utilizing "substantially the same process" as the claimed invention.[281] Although the phrase "prosecution
history estoppel" is nowhere found in Royer, the Supreme Court
subsequently interpreted Royer as invoking such an estoppel.[282]
6. Hubbell
v. United States
In Hubbell v. United States[283] the patentee had repeatedly amended his
claims to a bullet cartridge. As the majority notes, the Court recognized that
these amendments "must be strictly construed against the inventor and in
favor of the public, and looked upon in the nature of disclaimers."[284] The Court, however, nowhere suggested that
these amendments foreclosed the patentee from all protection against
equivalents. To the contrary, the Court asked whether the accused device
contained the limitation at issue, or, if it did not, "'whether [the]
omitted part is supplied by an equivalent device or instrumentality.'"[285] The Court recognized that, although the
claims had been amended, the patentee was still "entitled to a fair
construction of the terms of his claim as actually granted." [286] To me, this reference to "fair
construction" can only be a reference to the doctrine of equivalents, as
the Court recognized that the patentee retained the right to prohibit
infringement by "an equivalent device or instrumentality." As noted
above, Hubbell's legal standard is quoted verbatim in Warner-Jenkinson.[287]
Although the majority suggests that the Hubbell
Court did not "discuss[] prosecution history estoppel," the Supreme
Court has indeed interpreted Hubbell as an application of prosecution history
estoppel.[288] I do not agree with the majority that the absence
of the words "prosecution history estoppel" in Hubbell and in the
other cases discussed above somehow means that the Supreme Court "did not
discuss the issue presented in En Banc Question 3." Rather, I believe that
the Supreme Court has repeatedly set forth a legal standard that preserves the
right of patentees to assert equivalents for amended claim limitations.
D. Warner-Jenkinson Reaffirms Earlier Supreme
Court Precedent.
The Supreme Court's most recent decision
regarding prosecution history estoppel is remarkable for the extent to which it
reaffirms earlier precedent and affirmatively supports the application of
flexible estoppel.[289] In analyzing whether prosecution history
estoppel precludes a finding that an accused product infringes an amended
patent claim under the doctrine of equivalents, the Court said that courts may
determine "the reason for" and the "manner" of the
amendment.[290] Such an analysis would be unnecessary, of
course, if the Court intended a complete bar.[291] The Court assumes that the
PTO may have relied "upon a flexible rule of estoppel" when
evaluating patent applications, and that if so it would be improper "to
upset the basic assumptions of the PTO."[292] As Professor Chisum has stated, to read
Warner-Jenkinson "as precluding all equivalency for a claim element added
by an amendment driven by the prior art [would be] contrary to the Supreme
Court's rejection of a 'rigid' estoppel approach."[293]
Warner-Jenkinson, however, did establish a
special presumption for cases where the prosecution history reveals no reason
for a narrowing amendment. In these limited circumstances, the Court held that
a presumption applies that the amendment was made for a reason related to
patentability, and that if the patentee is later unable to rebut that presumption,
a bar to equivalents applies to the claim limitation added by the amendment.[294] Although the Court's holding does not
explicitly resolve whether a bar would apply outside of the factual
circumstances of that case, nothing in the opinion suggests that the Court
intended to so limit the doctrine of equivalents.
That the Court's holding in Warner-Jenkinson is
indeed narrow, and not intended to upset the established law of estoppel, is
underscored by its extensive reliance on precedent dating back to 1886. In
declining the invitation to alter existing rules, the Warner-Jenkinson Court
relied on older Supreme Court decisions such as Exhibit Supply Co. v. Ace
Patents Corp., 315 U.S. 126, 62 S.Ct. 513 (1942), Keystone Driller Co. v.
Northwest Engineering Corp., 294 U.S. 42, 55 S.Ct. 262 (1935), Smith v. Magic
City Kennel Club, Inc., 282 U.S. 784, 788, 51 S.Ct. 291, 293 (1931), Computing
Scale Co. of America v. Automatic Scale Co., 204 U.S. 609, 618-20 (1907),
Hubbell v. United States, 179 U.S. 77, 83, 21 S.Ct. 24, 26-27 (1900), and
Sutter v. Robinson, 119 U.S. 530, 541, 7 S.Ct. 376, 381-82 (1886). The Court's
reliance on its earlier cases and its description of the methodology adopted in
each of those cases indicate that the Warner-Jenkinson Court did not intend to
overrule or change this well-established precedent; indeed, by citing to these
cases, the Warner-Jenkinson Court endorsed their approach. Further, many of the
cases cited in Warner-Jenkinson themselves rely on the cases I discuss above
which, I believe, declare a flexible bar.[295] The Warner-Jenkinson Court clearly endorsed
the methodology applied in this pedigree of earlier Supreme Court cases
spanning back to the nineteenth century. I believe that Warner-Jenkinson
reaffirms the principles the Court set forth in Goodyear and Hurlbut, and
underscores that these nine cases remain binding on this court today.
III.
Federal Circuit Authority
As noted above, I recognize that today's en banc
court has the authority to overrule prior decisions of this court, and thus
that our prior decisions applying flexible or measured estoppel are not binding
on the en banc court. I present the following review of our case law, however,
to highlight the magnitude of today's sudden shift, and to suggest that the
approach of today's majority is contrary to any notion that judge-made law
should evolve in a consistent, gradual, and predictable fashion.
A. Our Adoption of Flexible Estoppel in 1983
Established the Only True "Line of Authority" in This Circuit.
Consistent with Goodyear, Hurlbut, and the other
Supreme Court cases reviewed above, this court has held in over fifty decisions
that the scope of estoppel is measured by the scope of surrender. In Hughes
Aircraft Co. v. United States[296] 4[297] ("Hughes I"), this court rejected
a "wooden application of estoppel," and held that the application of
prosecution history estoppel does not strip a patentee of all resort to the
doctrine of equivalents.[298] The court stated:
Depending on the nature and purpose of an
amendment, it may have a limiting effect within a spectrum ranging from great
to small to zero. The effect may or may not be fatal to application of a range
of equivalents broad enough to encompass a particular accused product. It is
not fatal to application of the doctrine itself.[299]
Today's majority, however, suggests that since
Hughes I, this court has established two "lines of authority"
adopting "inconsistent" views on the scope of prosecution history
estoppel: one school originating with Hughes I favoring flexible estoppel; and
a second school originating with Kinzenbaw v. Deere & Co.,[300] favoring a complete bar. I disagree with
that assessment. In my opinion, there is only one "line of
authority." While the majority correctly notes that Professor Chisum
opines that there are "two lines of authority," it neglects to
mention that the second "line" consists of only two cases.[301] Kinzenbaw and Prodyne Enterprises, Inc. v.
Julie Pomerantz,[302] however, do not hold that the mere fact of
amendment triggers a complete estoppel; they simply stand for the rule that
courts will not undertake a "speculative inquiry" into whether a
claim amendment was necessary.[303]
It is true that Kinzenbaw and Prodyne contain
language which, taken alone, is arguably consistent with the complete bar
imposed by the court today. On its face, however, neither opinion departs from
our seminal ruling only the year before in Hughes I. In fact, each opinion
purports to follow and quotes Hughes I.[304]
Further, a close reading of the opinion in each
case shows that rather than substituting a complete bar for flexible estoppel
based on actual surrender, the panels did indeed look to the exact scope of
surrender. They simply found that the surrender covered the accused subject
matter.[305] In light of the holdings of these two cases,
apart from the language the majority relies on, I cannot agree with my
colleagues that we have established two conflicting lines of authority
regarding prosecution history estoppel.
B. This
Court's Original Interpretation of Warner-Jenkinson Was Sound, and the Majority
Has Not Explained Why We Should Overrule Our Earlier Cases.
This court has issued a series of decisions
since Warner-Jenkinson in which we have consistently interpreted Supreme Court
law to require flexible estoppel. Today's majority, however, fails to provide a
satisfactory explanation as to why we should overrule our earlier cases,[306] one of the three cases remanded to us in
light of the Supreme Court's ruling in Warner-Jenkinson, this court, in 1998,
most emphatically adhered to the "longstanding doctrine that an estoppel
only bars recapture of that subject matter actually surrendered during
prosecution."[307] Our court clearly stated that "the
application of prosecution history estoppel does not necessarily limit a
patentee to the literal language of the amended element -- even when an
amendment has been made to overcome the prior art." Id. We reasoned that
the Warner-Jenkinson Court did not intend to "change so substantially the
rules of the game" concerning the scope of estoppel.[308] We further noted that "the entire
context of the Warner-Jenkinson opinion shows that the Supreme Court approved
the PTO's practice of requesting amendments with the understanding that the
doctrine of equivalents would still apply to the amended language."[309]
Similarly, in Hughes Aircraft Co. v. United
States,[310] ("Hughes II"), issued the same day
as Litton, a different panel of this court indicated that "the key to
prosecution history estoppel is the surrender or disclaimer of the subject
matter by the patentee, which the patentee is then unable to reclaim through
the doctrine of equivalents."[311] While amendments "serve to narrow the
range of equivalents," not all equivalents are precluded. Id. We
interpreted Warner-Jenkinson as supporting the proposition that courts may
inquire into the reason for an amendment in order to "determine what
subject matter the patentee actually surrendered."[312]
Indeed, the very same year, in Cybor Corp. v.
FAS Tech., Inc.,[313] our court, sitting en banc, stated that
"[t]he relevant inquiry is whether a competitor would reasonably believe
that the applicant had surrendered the relevant subject matter."[314] I fail to see how the majority will
stabilize application of the doctrine of equivalents by overruling an en banc
decision that is only two years old.
Only last year, in Sextant Avionique, S.A. v.
Analog Devices,[315] this court followed Supreme Court guidance
in determining the novel question whether the Warner-Jenkinson presumption of a
complete bar applies to both explained and unexplained amendments.[316] The Sextant court looked to the policies
"foster[ed]" in Warner-Jenkinson to guide its reasoning.[317] The court noted that the Warner-Jenkinson
Court created the presumption of a bar because "claims . . . serve both a
definitional and public notice function."[318] The court noted:
This policy of "public notice" is
heavily implicated in the circumstance in which the presumption is operative
because, by definition, it is unclear to one reading the prosecution history
why a particular amendment was made. Accordingly, the Court, through the
operation of the presumption, placed the burden on the patentee to clarify his
reasons. The patentee's failure to so clarify and thereby rebut the presumption
should not work to the detriment of the public by allowing an uncertain range
of equivalency to remain as to the limitation at issue.[319]
The panel concluded that a complete bar applies
when the Warner-Jenkinson presumption arises and remains unrebutted.[320] The court stated that
under Warner-Jenkinson, courts must apply "a different rule of scope"
when an amendment is unexplained.[321] In the circumstance of an explained
amendment, however, the Sextant court explicitly followed Supreme Court and
Federal Circuit precedent in allowing the patentee a scope of protection from
infringement by equivalents.[322] The Sextant court noted that "Supreme
Court case law predating Warner-Jenkinson embraced the concept of scope in the
context of amendments made to avoid prior art."[323]
In my opinion, today's majority has not set forth
a credible explanation as to why it is overruling our prior case law
interpreting Warner-Jenkinson. The majority merely asserts, citing only
"our long experience with the flexible bar approach," that the
standard we have applied until now is "unworkable." I feel that we
owe greater deference to our past interpretations of Supreme Court law, or a
better explanation of why our case law is suddenly seen as
"unworkable."
C. From 1983 to 2000, This Court Has
Consistently Applied Flexible, or Measured, Estoppel.
Panels of this court have consistently followed
Hughes I and flexible estoppel. Indeed, in a parade of cases, from each year of
this court's eighteen-year history, successive and randomly-selected panels of
this court have unanimously applied the flexible bar rule, and done so without
mention of its newly-discovered "unworkability." As the list below
indicates, our court has embraced flexible estoppel in more than fifty cases.
Ironically, these cases were decided by panels including nearly every member of
today's majority. In fact, most of the members of today's majority have written
an opinion, and indeed have done so since Warner-Jenkinson, supporting flexible
preclusion.
To highlight the degree by which today's
majority departs from our settled law, I have provided the following list of
cases that today's ruling overturns.
Federal
Circuit Cases Applying Flexible Estoppel: 1983-2000
1983: Hughes Aircraft Co. v. United States, 717
F.2d 1351, 1362, 219 USPQ 473, 481 (Fed. Cir. 1983) (Markey, Davis, Baldwin):
("We, as has the Supreme Court, reject the view [that amendment bars all
resort to the doctrine of equivalence] as a wooden application of estoppel,
negating entirely the doctrine of equivalents and limiting determination of the
infringement issue to consideration of literal infringement alone.").
1984: Bayer Aktiengesellschaft v. Duphar Int'l
Research B.V., 738 F.2d 1237, 1243, 222 USPQ 649, 653 (Fed. Cir. 1984)
(Kashiwa, Cowen, Bennett) ("[W]henever the doctrine of file history
estoppel is invoked, a close examination must be made as to, not only what was
surrendered, but also the reason for such a surrender. The fact that claims
were narrowed does not always mean that the doctrine of file history estoppel
completely prohibits a patentee from recapturing some of what was originally
claimed.").
1985: Loctite Corp. v. Ultraseal Ltd., 781 F.2d
861, 871, 228 USPQ 90, 96 (Fed. Cir. 1985) (Baldwin, Davis, Kashiwa).
1986: Mannesmann Demag Corp. v. Engineered Metal
Prod. Co., Inc., 793 F.2d 1279, 1284, 230 USPQ 45, 48 (Fed. Cir. 1986) (Newman,
Baldwin, Cowen) ("Amendment of claims during patent prosecution does not
necessarily bar all benefit of the doctrine of equivalents."); Great
Northern Corp. v. Davis Core & Pad Co., Inc., 782 F.2d 159, 166, 228 USPQ 356,
359-60 (Fed. Cir. 1986) (Rich, Markey, Kashiwa); Moeller v. Ionetics, Inc., 794
F.2d 653, 659, 229 USPQ 992, 996 (Fed. Cir. 1986) (Nichols, Friedman, Smith);
Chemical Eng'g Corp. v. Essef Indus., Inc., 795 F.2d 1565, 1573 n.8, 230 USPQ
385, 391 n.8 (Fed. Cir. 1986) (Markey, Rich, Baldwin).
1987: Townsend Eng'g Co. v. Hitec Co., Ltd., 829
F.2d 1086, 1090, 4 USPQ 2d 1136, 1139 (Fed. Cir. 1987) (Friedman, Baldwin,
Newman); Tandon Corp. v. United States Int'l Trade Comm'n, 831 F.2d 1017, 1026,
4 USPQ 2d 1283, 1290 (Fed. Cir. 1987) (Newman, Friedman, Archer); Pennwalt
Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 939 n.2, 4 USPQ 2d 1737, 1743 n.2
(Fed. Cir. 1987) (en banc).
1988: Hi-Life Prod., Inc. v. American Nat'l
Water-Mattress Corp., 842 F.2d 323, 325, 6 USPQ 2d 1132, 1134 (Fed. Cir. 1988)
(Bissell, Markey, Davis); Water Techs. Corp. v. Calco, Ltd., 850 F.2d 660, 667,
7 USPQ 2d 1097, 1102 (Fed. Cir. 1988) (Nies, Archer, Skelton); Diversitech
Corp. v. Century Steps, Inc., 850 F.2d 675, 681, 7 USPQ 2d 1315, 1320 (Fed.
Cir. 1988) (Newman, Davis, Archer).
1989: LaBounty Mfg., Inc. v. United States Int'l
Trade Comm'n, 867 F.2d 1572, 1576, 9 USPQ 2d 1995, 1999 (Fed. Cir. 1989) (per
curiam) (Nies, Bissell, Archer) ("[T]he breadth of the amendment does not
necessarily equate with the breadth of the resulting estoppel."); Sun
Studs, Inc. v. ATA Equip. Leasing, Inc., 872 F.2d 978, 987, 10 USPQ 2d 1338,
1345 (Fed. Cir. 1989) (Newman, Friedman, Bennett) ("The scope of estoppel
must be determined in light of the prior art that occasioned the change, as
well as representations made to the patent examiner as to the reason for the
change.");Environmental Instruments, Inc. v. Sutron Corp., 877 F.2d 1561,
1566, 11 USPQ 2d 1132, 1136 (Fed. Cir. 1989) (Rich, Nies, Michel); Black &
Decker, Inc. v. Hoover Serv. Ctr., 886 F.2d 1285, 1295, 12 USPQ 2d 1250, 1258
(Fed. Cir. 1989) (Markey, Newman, Archer).
1990: Jonsson v. Stanley Works, 903 F.2d 812,
817, 14 USPQ 2d 1863, 1868 (Fed. Cir. 1990) (Re, Markey, Newman); Hormone
Research Found., Inc. v. Genentech, Inc., 904 F.2d 1558, 1564, 15 USPQ 2d 1039,
1044 (Fed. Cir. 1990) (Archer, Cowen, Michel;
Insta-Foam Prods., Inc. v. Universal Foam Sys., Inc., 906 F.2d 698, 703, 15
USPQ 2d 1295, 1298 (Fed. Cir. 1990) (Archer, Mayer, Skelton).
1991: Dixie USA, Inc. v. Infab Corp., 927 F.2d
584, 588, 17 USPQ 2d 1968, 1970-71 (Fed. Cir. 1991) (Lourie, Mayer, Friedman)
("Appellants argue that they should be able to obtain some degree of
equivalence even in the face of prosecution history estoppel, and that a total
preclusion of equivalence should not apply. As a general proposition, that
principle is correct . . ."); Vaupel Textilmaschinen KG v. Meccanica Euro
Italia S.P.A., 944 F.2d 870, 882, 20 USPQ 2d 1045, 1054 (Fed. Cir. 1991)
(Lourie, Newman, Rader); Laitram Corp. v. NEC Corp., 952 F.2d 1357, 1361, 21
USPQ 2d 1276, 1279-80 (Fed. Cir. 1991) (Newman, Archer, Rader).
1992: Charles Greiner & Co., Inc. v.
Mari-Med Mfg., Inc., 962 F.2d 1031, 1036, 22 USPQ 2d 1526, 1530 (Fed. Cir.
1992) (Rader, Plager, Smith).
1993: Texas Instruments, Inc. v. United States
Int'l Trade Comm'n, 988 F.2d 1165, 1174, 26 USPQ 2d 1018, 1025 (Fed. Cir. 1993)
(Clevenger, Nies, Kaufman) ("Application of this test [to determine
whether the patentee may assert the doctrine of equivalents,] requires, in each
case, examination of the prosecution history taken as a whole."); Wang
Labs., Inc. v. Toshiba Corp., 993 F.2d 858, 26 USPQ 2d 1767 (Fed. Cir. 1993)
(Lourie, Archer, Clevenger); Hoganas AB v. Dresser Indus., Inc., 9 F.3d 948,
951, 28 USPQ 2d 1936, 1939 (Fed. Cir. 1993) (Plager, Smith, Clevenger).
1994: Genentech, Inc. v. Wellcome Found. Ltd.,
29 F.3d 1555, 1567, 31 USPQ 2d 1161, 1170 (Fed. Cir. 1994) (Plager, Cowen,
Lourie).
1995: Southwall Techs., Inc. v. Cardinal IG Co.,
54 F.3d 1570, 1579, 34 USPQ 2d 1673, 1676 (Fed. Cir. 1995) (Michel, Lourie,
Bryson); Pall Corp. v. Micron Separations, Inc., 66 F.3d 1211, 1219, 36 USPQ 2d
1225, 1230 (Fed. Cir. 1995) (Newman, Rich, Mayer).
1996: Modine Mfg., Co. v. United States Int'l
Trade Comm'n, 75 F.3d 1545, 1556, 37 USPQ 2d 1609, 1616 (Fed. Cir. 1996)
(Newman, Mayer, Clevenger); Athletic Alternatives, Inc. v. Prince Mfg., Inc.,
73 F.3d 1573, 1582, 37 USPQ 2d 1365, 1373 (Fed. Cir. 1996) (Michel, Nies,
Clevenger); Insituform Tech., Inc. v. CAT Contracting, Inc., 99 F.3d 1098,
1101, 40 USPQ 2d 1602, 1609 (Fed. Cir. 1996) (Michel, Archer, Schall).
1997: Hilton Davis Chem. Co. v. Warner-Jenkinson
Co., Inc., 62 F.3d 1512, 1525, 35 USPQ 2d 1641, 1651 (Fed. Cir. 1997) (per
curiam); Wang Labs., Inc. v. Mitsubishi Elecs. Amer., Inc., 103 F.3d 1571,
1578, 41 USPQ 2d 1263, 1269 (Fed. Cir. 1997) (Rich, Mayer, Schall); Lockwood v.
American Airlines, Inc., 107 F.3d 1565, 1574-75, 41 USPQ 2d 1961, 1968 (Fed.
Cir. 1997) (Lourie, Mayer, Rader).
1998: Cybor Corp. v. FAS Tech., Inc., 138 F.3d
1448, 1460, 46 USPQ 2d 1169, 1178 (Fed. Cir. 1998) (en banc) (Archer); Litton
Sys., Inc. v. Honeywell, Inc., 140 F.3d 1449, 1455, 46 USPQ 2d 1321, 1326 (Fed.
Cir. 1998) (Rader, Newman, Bryson) ("In accord with the Supreme Court's
understanding, this court has repeatedly stated that application of prosecution
history estoppel does not necessarily limit a patentee to the literal language
of the amended element -- even when an amendment has been made to overcome the
prior art."); Hughes Aircraft Co. v. United States, 140 F.3d 1470, 1476,
46 USPQ 2d 1285, 1290 (Fed. Cir. 1998) (Archer, Rader, Bryson) ("[T]he key
to prosecution history estoppel is the surrender or disclaimer of subject
matter by the patentee, which the patentee is then unable to reclaim through
the doctrine of equivalents. . . . In evaluating the reason behind an
amendment, a court must 'determine what subject matter the patentee actually
surrendered.'"); Laitram Corp. v. Morehouse Indus., Inc., 143 F.3d 1456,
1464, 46 USPQ 2d 1609, 1615-16 (Fed. Cir. 1998) (Lourie, Michel, Skelton); EMI
Group North Amer. Inc. v. Intel Corp., 157 F.3d 887, 897, 48 USPQ 2d 1181, 1189
(Fed. Cir. 1998) (Newman, Plager, Bryson) ("Cancellation of a claim that
is written broadly does not always generate an estoppel to narrower subject
matter. The particular facts must be considered."); Desper Prod., Inc. v.
Qsound Labs, Inc., 157 F.3d 1325, 1338, 48 USPQ 2d 1088, 1098 (Fed. Cir. 1998)
(Plager, Clevenger, Gajarsa); Bai v. L&L Wings, Inc., 160 F.3d 1350, 1356,
48 USPQ 2d 1674, 1679 (Fed. Cir. 1998) (Lourie, Rich, Rader); Insituform Tech.,
Inc. v. Cat Contracting, Inc., 161 F.3d 688, 692, 48 USPQ 2d 1610, 1614 (Fed.
Cir. 1998) (Michel, Archer, Schall).
1999: Pharmacia & UpJohn Co. v. Mylan Pharms.,
Inc., 170 F.3d 1373, 1377, 50 USPQ 2d 1033, 1037 (Fed. Cir. 1999) (Lourie,
Newman, Schall); Sextant Avionique, S.A. v. Analog Devices, Inc., 172 F.3d 817,
830-32, 49 USPQ 2d 1865, 1870-72 (Fed. Cir. 1999) (Lourie, Smith, Gajarsa);
Augustine Med. Inc. v. Gaymar Indus., Inc., 181 F.3d 1291, 1298, 50 USPQ 2d
1900, 1905 (Fed. Cir. 1999) (Mayer, Rader, Gajarsa);Loral Fairchild Corp. v.
Sony Corp., 181 F.3d 1313, 1323, 50 USPQ 2d 1865, 1871 (Fed. Cir. 1999)
(Archer, Michel, Plager); Merck & Co. v. Mylan Pharms. Inc., 190 F.3d 1335,
1341, 51 USPQ 2d 1954, 1958 (Fed. Cir. 1999) (Newman, Lourie, Clevenger); K-2
Corp. v. Salomon S.A., 191 F.3d 1356,1368, 52 USPQ 2d 1001, 1008 (Fed. Cir.
1999) (Clevenger, Rader, Gajarsa) (In order to prevent infringers from "stealing
the benefits of an invention, . . . the doctrine of equivalents must . . .
remain within the boundaries established by the prior art, the scope of the
patent claims themselves, and any surrendered subject matter.").
2000: Bayer AG v. Elan Pharm. Research Corp.,
212 F.3d 1241, 1251, 54 USPQ 2d 1711, 1717 (Fed. Cir. 2000) (Schall, Clevenger,
Bryson); KCJ Corp. v. Kinetic Concepts, Inc., 223 F.3d 1351, 1358, 55 USPQ 2d
1835, 1842 (Fed. Cir. 2000) (Rader, Plager, Clevenger).
IV.The Majority's Rule Likely Will Have
Unintended and Adverse Consequences that Undermine the Policies Advanced by the
Supreme Court's Interpretation of the Doctrine of Equivalents.
The doctrine of equivalents was created to
prevent "fraud on a patent," such as near-literal copying of the
claimed invention with the addition of merely insubstantial changes in order to
avoid liability for literal infringement.[324] Winans v. Denmead,[325] was the first Supreme Court case to address
the doctrine of equivalents. In Winans, the Court adopted the doctrine in order
to prevent precisely the abuse that today's ruling will allow, namely, the
appropriation of patented inventions by making trivial modifications to a
claimed device. The Court recognized that "the exclusive right to the
thing patented is not secured, if the public are at liberty to make substantial
copies of it, varying its form or proportions."[326] In Graver Tank, the Court reiterated the
necessity of the doctrine of equivalents, stating:
[C]ourts have also recognized that to permit
imitation of a patented invention which does not copy every literal detail
would be to convert the protection of the patent grant into a hollow and
useless thing. Such a limitation would leave room for--indeed encourage--the
unscrupulous copyist to make unimportant and insubstantial changes and
substitutions in the patent which, though adding nothing, would be enough to
take the copied matter outside the claim, and hence outside the reach of law.[327]
Despite repeated petitions seeking to abolish
the doctrine of equivalents, the Supreme Court has steadfastly ruled that
patentees are entitled to its protection.[328] As a lower court, we must respect the
Supreme Court's decision to accord patentees the benefits of the doctrine of
equivalents. I believe that the majority's new rule, far from providing
patentees the protections the Supreme Court has guaranteed, unfairly strips
most patentees of the right to assert infringement under the doctrine of
equivalents.
A. Today's Ruling Provides Copyists with a
Fail-Safe Method to Avoid Liability for Infringement.
The majority discusses the unpredictability of
prosecution history estoppel under a flexible approach, and how its complete
bar "eliminates the public's need to speculate as to the subject matter
surrendered by a narrowing claim amendment." As a solution to this problem
of the doctrine of equivalents, today's ruling simply denies any resort to the
doctrine, for amended claim limitations.
Today's ruling will allow copyists to readily
avoid liability despite practicing the substantial equivalent of the claimed
invention. Anyone seeking to lawfully copy a patented technology will only have
to adopt the following method: (1) read the prosecution history to identify
amendments made for patentability reasons; (2) copy every other limitation
exactly, but substitute any known interchangeable structure, matter, or step
for any limitation that has been amended. Any change, no matter how
"unimportant and insubstantial," to even one amended limitation will
be sufficient to avoid liability under the majority's rule.
The ease and certainty with which this method
can be applied may be readily appreciated with reference to cases such as
Insituform Technologies, Inc. v. CAT Contracting, Inc..[329] The asserted patent in Insituform claimed a
process for impregnating the interior felt repair lining of an underground pipe
with resin by using a cup attached over a hole on the outside of the pipe to
apply a vacuum downstream of the resin. The resin is thereby made to flow along
the interior of the pipe towards the vacuum, permeating the felt and curing it.[330] The patentee had amended the asserted patent
claim in response to an examiner's patentability rejection to include the
limitation that the vacuum be applied sequentially in a stepwise fashion using
a cup that was repeatedly removed from one location along the pipe and moved
further downstream once the resin had profused near the original location of
the cup.[331]
A copyist's first step in exploiting today's
ruling to avoid liability, then, would be to identify a claim limitation that
was amended for patentability reasons. Here, that is the limitation requiring
the successive application of a cup to different locations along the outside of
the pipe. The second step, then, would be to determine the most convenient
substitute for this limitation. In this case, the copyist could simply apply
the vacuum simultaneously using two cups. As we held in Insituform, this would
be sufficient to avoid literal infringement.[332] And under today's ruling the amended
limitation is not entitled to any protection under the doctrine of equivalents,
so the copyist will have succeeded in avoiding all liability by simply
practicing the claimed invention, but using two cups.
Because today's ruling completely eliminates
protection against known substitutes for the amended limitation, any competitor
adopting this method would be free from liability, as the amended limitation is
not met literally but rather is supplied by an obvious equivalent. To me,
protection against such "close copying" is the central office of the
doctrine of equivalents. The Supreme Court clearly warned of this danger in
Graver Tank.[333]
Prosecution history estoppel, moreover, is an
equitable doctrine. By its very purpose, equity jurisprudence provides a remedy
individually tailored to the circumstances of the dispute at hand. As stated by
the Supreme Court:
The essence of equity jurisdiction has been the
power of the Chancellor to do equity and to mold each decree to the necessities
of the particular case. Flexibility rather than rigidity has distinguished it.
The qualities of mercy and practicality have made equity the instrument for
nice adjustment and reconciliation between the public interest and private
needs as well as between competing private claims.[334]
Today's ruling, however, imposes a rigid legal
rule upon the application of the equitable doctrine of prosecution history
estoppel. The complete bar eliminates the flexibility that equity demands.
Without this flexibility, courts are precluded from protecting patentees from
copyists.
B. The Ability of Copyists to Avoid Liability
Under the Complete Bar Will Be Particularly Severe in Certain Types of
Technology.
Copyists will be able to apply today's ruling,
using the fail-safe method noted above, to avoid liability in many, if not all,
areas of technology. Biotechnology is one critical field of technology that may
be particularly harmed by today's ruling. Completely barring resort to the
doctrine of equivalents for amended claim limitations may drastically limit the
scope of protection for biotechnology patents, such as those claiming a protein
molecule.[335]
A protein molecule can only be claimed as the
complete and specific sequence of amino acids comprising the protein.[336] The particular amino acids that comprise a protein
chain are frequently interchangeable with other amino acids without changing
the protein or its functions. As our court noted with respect to a patent
claiming the protein erythropoietin, "over 3,600 different [protein]
analogs can be made by substituting [interchangeable acids] at only a single
amino acid position, and over a million different analogs can be made by
substituting three amino acids."[337] Many such analogs are functionally identical
to the claimed protein. Thus, a competitor seeking to make, use, or sell a
protein that is protected by a patent containing an amended claim limitation
will only have to substitute at a particular location in the chain an
interchangeable amino acid for the particular amino acid recited in the patent
claim as occupying that location. It appears that, in order to thwart such
copying, a patent applicant would have to disclose and claim every single
analog that is functionally equivalent to the claimed protein. Considering the
vast number of specific amino acid sequences that an applicant would be forced
to disclose and claim in order to secure meaningful protection for his
invention, I feel the majority's rule puts an impossible burden on both the
applicant and the PTO.
C.Amending Claims for Patentability Reasons Is a
Common Practice That Should Not Trigger a Complete Bar.
The majority gives no hint of the magnitude of
the effects that will ensue from its new rule. The vast majority of patent
applications contain claims that are initially rejected in view of the prior
art, and are only allowed after being amended. Patent prosecution is an
iterative process in which the applicant typically submits claims that are
thought to be allowable, the examiner rejects the claims in view of the prior
art, and the applicant then amends the claims to traverse the examiner's
patentability rejections.[338]
Today's ruling may prove impractical because it
provides that the mere act of amendment to traverse a patentability rejection
eliminates all protection under the doctrine of equivalents, even for
equivalents that were not the subject of the amendment. This is ill-suited to
the iterative process by which patent applications are prosecuted. In
Warner-Jenkinson, the Supreme Court refused to apply prosecution history
estoppel regardless of the reason for amendment expressly because to do so
would "subvert the various balances" inherent in the process of
rejection followed by amendment.[339] In holding that any amendment made for
patentability reasons triggers a complete bar to protection under the doctrine
of equivalents, today's ruling will "subvert the various balances"
inherent in the process of patent prosecution.[340]
Rather than acquiesce to patentability
rejections and thereby surrender all recourse to the doctrine of equivalents,
applicants will be increasingly likely to file administrative and judicial
appeals. The PTO Board of Patent Appeals and Interferences is already
backlogged and often takes years to decide an appeal. Neither the PTO, nor our
court, is prepared to handle any significant increase in such appeals. Such an
increase could result in a significant lengthening in the average time and cost
required to prosecute an application to issuance.
Furthermore, this court's imposition of a
complete bar creates a perverse incentive for patent applicants, particularly
those who are financially unable to invoke the appeals process, to simply
abandon their applications. In many cases, it may be more effective to protect
an invention by maintaining it as a trade secret than by accepting a patent
that will publicize the invention, but provide protection only from literal
infringement.[341] As a result, the public may be deprived of
useful teachings contained in patent applications that are simply abandoned
after a rejection is made regarding a critical claim limitation.
D. Today's Ruling Will Significantly, and
Unfairly, Reduce the Value of All Unexpired Patents That Were Amended for
Patentability Reasons.
The effect
of today's ruling upon previously-issued but unexpired patents may be dramatic. While I cannot predict
all the consequences that may flow from today's decision, I think it is safe to say that the majority's rule will reduce the
effective scope, and thus, the value, of most of the 1,200,000 patents that are
unexpired and enforceable. Wholly apart from other long-term effects of the
majority's rule, I feel that today's ruling will be unfairly disruptive of
existing commercial relations. Today's ruling offers no
"grandfathering" provision for the vast numbers of unexpired patents
that contain amended claim limitations, and thus that will become increasingly
susceptible to copying under today's new rule. Patent applicants who prosecuted
their claims under the rule of a flexible bar will have protection limited now
by our new rule of complete estoppel. As today's adoption of the complete bar
was utterly unpredictable, these applicants had no way to avoid the harm that
now befalls them.
I think that today's ruling might most directly
impact untold numbers of licensing agreements that are predicated on the
assumption that patent claims with an amended limitation are still entitled to
a range of equivalents. Licensees will be tempted to exploit today's ruling
using the method for liability-free copying discussed above. A licensee could
make a minor substitution of a known interchangeable element for an amended
claim limitation, and then correctly claim that it is no longer practicing the
patented -- and licensed -- invention. The licensor would then be powerless to
enforce the license because the amended claim or claims simply would not cover
the licensee's newly-modified product or process.
As discussed above, the Supreme Court
specifically refused in Warner-Jenkinson to "upset the basic
assumptions" regarding prosecution history estoppel.[342] I feel that today's ruling will upset basic
assumptions regarding the effective scope of patents, and will unfairly disrupt
commercial relations based on these assumptions.
V.
Conclusion
In the face of over one hundred years of Supreme
Court case law, today's en banc majority lacks authority to establish a
complete bar rule. The majority also abruptly abandons eighteen years of
unvarying Federal Circuit precedent as articulated in over fifty decisions, and
does so without showing their error. Moreover, I believe that imposing a
complete and automatic bar to the doctrine of equivalents for claim limitations
amended for patentability reasons will have adverse, unfair, and unintended
consequences. I accordingly must dissent from the majority's answer to Question
3.
Judge Rader, concurring-in-part,
dissenting-in-part
A primary justification for the doctrine of
equivalents is to accommodate after-arising technology. Without a doctrine of
equivalents, any claim drafted in current technological terms could be easily
circumvented after the advent of an advance in technology. A claim using the
terms "anode" and "cathode" from tube technology would lack
the "collectors" and "emitters" of transistor technology
that emerged in 1948. Thus, without a doctrine of equivalents, infringers in
1949 would have unfettered license to appropriate all patented technology using
the out-dated terms "cathode" and "anode". Fortunately, the
doctrine of equivalents accommodates that unforeseeable dilemma for claim
drafters. Indeed, in Warner-Jenkinson Co., Inc. v. Hilton Davis Chemical Co.,[343] the Supreme Court acknowledged the
doctrine's role in accommodating after-arising technology.
Unfortunately, by barring all application of the
doctrine of equivalents for amended claims, this court does not account at all
for the primary role of the doctrine. All patent protection for amended claims
is lost when it comes to after-arising technology, while the doctrine of
equivalents will continue to accommodate after-arising technology in unamended
claims. For a reason far more important than disparate treatment of claims,
however, this result defies logic.
Prosecution history estoppel is an estoppel
doctrine. Estoppel prevents a litigant from denying an earlier admission upon
which another has already relied.*[344] [345] In the case of patent law, the admission is
the applicant's surrender of claim scope to acquire the patent. Today's rule
forfeits all protection of the doctrine of equivalents whenever applicants
amend their claims, regardless of whether they in fact surrendered coverage. By
definition, applicants could not have surrendered something that did not even
exist at the time of the claim amendment, namely after-arising technology.
The court reasons today that it will not inquire
about the scope of an estoppel because it cannot with certainty ascertain the
scope of the applicant's surrender. Although that premise is questionable for
the reasons enunciated by Judges Michel and Linn, one thing is beyond question:
That premise does not apply to after-arising technology. Because after-arising
technology was not in existence during the patent application process, the
applicant could not have known of it, let alone surrendered it. Nonetheless,
the court would apply an estoppel where none exists and defeat the doctrine of
equivalents.
Judge Linn, concurring-in-part,
dissenting-in-part, in which Judge Rader joins.
I join the majority's articulate and
well-reasoned answers to Questions 1, 2 and 4; however, I must, respectfully,
dissent from the answer of the majority to Question 3 and from Part III,
Section C of the opinion of the court. In my opinion, the majority's new rigid
bright line rule, eliminating all flexibility in the scope afforded certain
claim limitations amended for a statutory purpose just because they were
amended for a statutory purpose, goes too far. The reasons expressed by the
majority do not justify this dramatic policy shift.
With all due respect to my colleagues in the
majority, the new bright line rule, as simple as it is hoped to be in
application, wrongfully sets in place a regime that increases the cost and
complexity of patent prosecution to the detriment of individual inventors,
start-up companies, and others unable to bear these increased costs. The new
regime also places greater emphasis on literary skill than on an inventor's
ingenuity; gives unscrupulous copyists a free ride on the coattails of
legitimate inventors; and changes the rules under which prosecution strategies
were formulated for thousands of extant patents no longer subject to
correction. I find particularly apt here the concerns expressed by the Supreme
Court in Warner-Jenkinson when it considered the petitioner's request for a
bright line rule precluding "recapture" of any part of surrendered
subject matter under the doctrine of equivalents: "[t]o change so
substantially the rules of the game now could very well subvert the various
balances the PTO sought to strike when issuing the numerous patents which have
not yet expired and which would be affected by our decision."[346]
In my opinion, the approach to prosecution
history estoppel as articulated by the Supreme Court and long followed by this
court should remain the rule. As long as the reason for an amendment is
explained, an estoppel by amendment should only bar recapture of the subject
matter actually surrendered, as discerned from the amended claim language and
the reasons articulated by the applicant for the change. The mere fact that an
amendment to a claim is made pursuant to a statutory requirement is insufficient
in and of itself to conclude that all subject matter beyond the literal scope
of the amended claim language has been surrendered, even where the amendment is
made to overcome prior art.
Both by taking an expansive view of what
constitutes a "substantial reason relating to patentability" and by
applying prosecution history estoppel as a complete bar to any reliance on the
doctrine of equivalents for claim limitations narrowed by amendment, the
majority unfairly tips the balance away from patentees and toward competitors
by constraining the legitimate rights of patentees to their inventions, even
where competitors can reasonably determine the reasons for any amendments and
the scope of any subject matter surrendered. In my view, this is an ill-advised
major policy shift that is neither compelled nor justified at this time.
DISCUSSION
Purpose of the Patent
System
The Constitution authorizes Congress "[t]o
promote the Progress of . . . useful Arts, by securing for limited Times to . .
. Inventors the exclusive Right to their . . . Discoveries."[347] The foregoing evinces the founding fathers'
intent that the federal patent laws of the United States be directed to the
public purpose of fostering technological progress.[348]
An exclusive right granted by the government for
one's invention has value to an inventor as a guarantee of protection, and,
thus, stimulates inventors to add to the sum of human knowledge.[349] To obtain this exclusive right, the inventor
must disclose his invention to the public. Thus, the patent also is of value to
the public because such disclosures will stimulate others to add to the sum of
human knowledge through the creation of other inventions utilizing the lessons
learned by the patentee.[350]
Strong patent protection is key to encouraging
innovation, economic growth, and American competitiveness.[351] "From their inception, the federal
patent laws have embodied a careful balance between the need to promote
innovation and the recognition that imitation and refinement through imitation
are both necessary to invention itself and the very life blood of a competitive
economy." [352] Thus, the patent laws attempt to provide
each inventor with reasonable assurances that the reward to which he or she is
entitled will, in fact, be given. And, these same laws also attempt to provide
competitors with notice of the patent owner's rights. Strong patent protection
must both accommodate and balance justice to the patentee and notice to the
public of the patentee's rights.
Claims Use
Ordinary Language to Capture Concepts
To protect an invention through the United
States patent laws, an inventor must use patent "claims."[353] The purpose of this requirement is to give
notice of the technology that the patent controls.[354]