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United States Supreme Court
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No. 00-1543
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122 S.Ct. 1831, 152 L.Ed.2d 944, 2002.SCT.0000095
<http://www.versuslaw.com>, 70 USLW 4458, 62 U.S.P.Q.2d
1705
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May 28, 2002
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FESTO CORPORATION, PETITIONER
v.
SHOKETSU KINZOKU KOGYO
KABUSHIKI CO., LTD., ET AL.
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SYLLABUS BY THE COURT
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Argued January 8, 2002
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Decided May 28, 2002
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Petitioner Festo Corporation owns two patents for an industrial
device. When the patent examiner rejected the initial application for the
first patent because of defects in description,
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35 U. S. C. §112, the application was amended to
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add the new limitations that the device would contain a pair of
one-way sealing rings and that its outer sleeve would be made of a
magnetizable material. The second patent was also amended during a
reexamination proceeding to add the sealing rings limitation
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. After Festo began selling its device, respondents (hereinafter SMC)
entered the market with a similar device that
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uses one two-way sealing ring and a
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nonmagnetizable sleeve
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. Festo filed suit, claiming that SMC's device is so similar that it
infringes Festo's patents under the doctrine of equivalents. The District
Court ruled for Festo,
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rejecting SMC's argument that the prosecution history estopped
Festo
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from saying that SMC's device is
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equivalent
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. A Federal Circuit panel initially affirmed, but this Court granted
certiorari, vacated, and remanded in light of Warner-Jenkinson Co. v.
Hilton Davis Chemical Co., 520 U. S. 17, 29,
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which
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had acknowledged that
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competitors may rely on
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the prosecution history to estop the patentee from recapturing subject
matter surrendered by amendment as a condition of obtaining the
patent.
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On remand, the en banc Federal Circuit reversed, holding that
prosecution history estoppel applied.
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The court ruled that estoppel arises from any amendment that narrows a
claim to comply with the Patent Act, not only from amendments made to
avoid
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the prior art, as the District Court had held. The Federal Circuit
also held that, when estoppel applies, it bars
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any claim of equivalence for the element that was amended. The court
acknowledged that, under its
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prior cases, prosecution history estoppel constituted a flexible bar,
foreclosing some, but not all, claims of equivalence, depending on the
purpose of the amendment and the alterations in the text. However, the
court overruled its precedents on the ground that their case-by-case
approach had proved unworkable.
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Held: Prosecution history estoppel may apply to any claim amendment
made to satisfy the Patent Act's requirements, not just to amendments made
to avoid
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the prior art, but
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estoppel
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need not bar suit against every equivalent to the amended claim
element. Pp. 5-17.
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(a) To enable a patent holder to know what he owns, and the public to
know what he does not, the inventor must describe his work in "full,
clear, concise, and exact terms." §112. However, patent claim language may
not
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describe with complete precision the range of
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an invention's novelty. If patents were always interpreted by their
literal terms, their value would be greatly diminished.
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Insubstantial substitutes for certain elements could defeat the
patent, and its value to inventors could be destroyed by simple acts of
copying. Thus, a patent's scope is not limited to its literal terms, but
embraces all equivalents to the claims described. See Winans v. Denmead,
15 How. 330, 347. Nevertheless, because it may be difficult to determine
what is, or is not, an equivalent, competitors may be deterred from
engaging in legitimate manufactures outside the patent's limits, or lulled
into developing
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competing products that the patent secures, thereby prompting wasteful
litigation. Each time the Court has considered the doctrine of
equivalents, it has acknowledged this uncertainty as the price of ensuring
the appropriate incentives for innovation, and it has affirmed the
doctrine over dissents that urged a more certain rule. See, e.g., id., at
343, 347. Most recently, Warner-Jenkinson, supra, at 28, reaffirmed the
doctrine. Pp. 5-8.
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(b) Prosecution history estoppel requires that patent claims be
interpreted in light of the
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proceedings before the Patent and Trademark Office
(PTO).
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When the patentee originally claimed the subject matter alleged to
infringe but then narrowed the claim in response to a rejection, he may
not argue that the surrendered territory comprised an unforeseen
equivalent. See Exhibit Supply Co. v. Ace Patents Corp., 315 U. S. 126,
136-137.
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The rejection indicates that the patent examiner does not believe the
original claim could be patented. While the patentee has the right to
appeal, his decision to forgo an appeal and submit an amended claim is
taken as a concession that the invention as patented does not reach as far
as the original claim. See, e.g., Goodyear Dental Vulcanite Co. v. Davis,
102 U. S. 222, 228.
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Were it otherwise, the inventor might avoid the PTO's gatekeeping role
and seek to recapture in an infringement action the very subject matter
surrendered as a condition of receiving the patent. Pp. 8-9.
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(c) Prosecution history estoppel is not limited to amendments intended
to narrow the patented invention's subject matter, e.g., to avoid prior
art, but may apply to a narrowing amendment made to satisfy any Patent Act
requirement, including §112's requirements concerning the patent
application's form. In Warner-Jenkinson, the Court made clear that
estoppel applies to amendments made for a "substantial reason related to
patentability," 520 U. S., at 33, but did not purport to
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catalog every reason that might raise an estoppel. Indeed, it stated
that even if the amendment's purpose were unrelated to patentability, the
court might consider whether it was the kind of reason that nonetheless
might require estoppel. Id., at 40-41. Simply because estoppel has been
discussed most often in the context of amendments made to avoid the prior
art, see, e.g., id., at 30, it does not follow that amendments made for
other purposes will not give rise to estoppel. Section 112 requires that
the application describe, enable, and set forth the best mode of carrying
out the invention.
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The patent
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should not issue if these
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requirements are not satisfied, and an applicant's failure to meet
them
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could lead to the issued patent being held invalid in later
litigation. Festo's argument that amendments made to comply with §112
concern the application's form and not the invention's subject matter
conflates the patentee's reason for making the amendment with the impact
the amendment has on the subject matter. Estoppel arises when an amendment
is made to secure the patent and the amendment narrows the patent's scope.
If a §112 amendment is truly cosmetic, it would not narrow the patent's
scope or raise an estoppel. But if a §112 amendment is necessary and
narrows the patent's scope -- even if only for better description --
estoppel may apply. Pp. 10-12.
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(d) Prosecution history estoppel does not bar the inventor from
asserting infringement against every equivalent to the narrowed element.
Though
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estoppel can bar challenges to a wide range of equivalents, its reach
requires an examination of the subject matter surrendered by the narrowing
amendment. The Federal Circuit's complete bar rule is inconsistent with
the purpose of applying the estoppel in the first place -- to hold the
inventor to the representations made during the application process and
the inferences that may be reasonably drawn from the amendment. By
amending the application, the inventor is deemed to concede that the
patent does not extend as far as the original claim, not that the amended
claim is so perfect in its description that no one could devise an
equivalent. The Court's view is consistent with
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precedent
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and
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PTO practice
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. The Court has consistently applied the doctrine in a flexible way,
considering what equivalents were surrendered during a patent's
prosecution, rather than imposing a complete bar that resorts to the very
literalism the equivalents rule is designed to overcome. E.g., Goodyear
Dental Vulcanite Co. v. Davis, 102 U. S. 222, 230. The Federal Circuit
ignored Warner-Jenkinson 's instruction that courts must be cautious
before adopting changes that disrupt the settled expectations of the
inventing community. See 520 U. S., at 28. Inventors who amended their
claims under the previous case law had no reason to believe they were
conceding all equivalents. Had they known, they might have appealed the
rejection instead. Warner-Jenkinson struck the appropriate balance by
placing the burden on the patentee to prove that an amendment was not made
for a reason that would give rise to estoppel. Id., at 33. Similarly, the
patentee should bear the burden of showing that the amendment does not
surrender the particular equivalent in question. As the author of the
claim language, his decision to narrow his claims through amendment may be
presumed to be a general disclaimer of the territory between the original
claim and the amended claim. Exhibit Supply, supra, at 136-137. However,
in cases in which the amendment cannot reasonably be viewed as
surrendering a particular equivalent -- e.g., where the equivalent was
unforeseeable at the time of the application or the rationale underlying
the amendment bears but a tangential relation to the equivalent -- the
patentee can rebut the presumption that prosecution history estoppel bars
a finding of equivalence by showing that at the time of the amendment one
skilled in the art could not reasonably be expected to have drafted a
claim that would have literally encompassed the alleged equivalent. Pp.
12-16.
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(e) Whether Festo has rebutted the presumptions that estoppel applies
and that the equivalents at issue have been surrendered should be
determined in the first instance by further proceedings below. Pp.
16-17.
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234 F. 3d 558, vacated and remanded.
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Kennedy, J., delivered the opinion for a unanimous
Court.
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On Writ Of Certiorari To The United States Court Of Appeals For The
Federal Circuit Court Below: 234 F. 3d 558
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The opinion of the court was delivered by: Justice
Kennedy
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535 U. S. ____ (2002)
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This case requires us to address once again the relation between two
patent law concepts, the doctrine of equivalents and the rule of
prosecution history estoppel. The Court considered the same concepts in
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U. S. 17 (1997),
and reaffirmed that a patent protects its holder against efforts of
copyists to evade liability for infringement by making only insubstantial
changes to a patented invention. At the same time, we appreciated that by
extending protection beyond the literal terms in a patent the doctrine of
equivalents can create substantial uncertainty about where the patent
monopoly ends. Id., at 29. If the range of equivalents is unclear,
competitors may be unable to determine what is a permitted alternative to
a patented invention and what is an infringing equivalent.
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To reduce the uncertainty, Warner-Jenkinson acknowledged that
competitors may rely on the prosecution history, the public record of the
patent proceedings. In some cases the Patent and Trademark Office (PTO)
may have rejected an earlier version of the patent application on the
ground that a claim does not meet a statutory requirement for
patentability. 35 U. S. C. §132 (1994 ed., Supp. V). When the patentee
responds to the rejection by narrowing his claims, this prosecution
history estops him from later arguing that the subject matter covered by
the original, broader claim was nothing more than an equivalent.
Competitors may rely on the estoppel to ensure that their own devices will
not be found to infringe by equivalence.
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In the decision now under review the Court of Appeals for the Federal
Circuit held that by narrowing a claim to obtain a patent, the patentee
surrenders all equivalents to the amended claim element. Petitioner
asserts this holding departs from past precedent in two respects. First,
it applies estoppel to every amendment made to satisfy the requirements of
the Patent Act and not just to amendments made to avoid pre-emption by an
earlier invention, i.e., the prior art. Second, it holds that when
estoppel arises, it bars suit against every equivalent to the amended
claim element. The Court of Appeals acknowledged that this holding
departed from its own cases, which applied a flexible bar when considering
what claims of equivalence were estopped by the prosecution history.
Petitioner argues that by replacing the flexible bar with a complete bar
the Court of Appeals cast doubt on many existing patents that were amended
during the application process when the law, as it then stood, did not
apply so rigorous a standard.
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We granted certiorari to consider these questions.
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I.
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Petitioner Festo Corporation owns two patents for an improved magnetic
rodless cylinder, a piston-driven device that relies on magnets to move
objects in a conveying system. The device has many industrial uses and has
been employed in machinery as diverse as sewing equipment and the Thunder
Mountain ride at Disney World. Although the precise details of the
cylinder's operation are not essential here, the prosecution history must
be considered.
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Petitioner's patent applications, as often occurs, were amended during
the prosecution proceedings. The application for the first patent, the
Stoll Patent (U. S. Patent No. 4,354,125), was amended after the patent
examiner rejected the initial application because the exact method of
operation was unclear and some claims were made in an impermissible way.
(They were multiply dependent.) 35 U. S. C. §112 (1994 ed.). The inventor,
Dr. Stoll, submitted a new application designed to meet the examiner's
objections and also added certain references to prior art. 37 CFR §1.56
(2000). The second patent, the Carroll Patent (U. S. Patent No.
3,779,401), was also amended during a reexamination proceeding. The prior
art references were added to this amended application as well. Both
amended patents added a new limitation -- that the inventions contain a
pair of sealing rings, each having a lip on one side, which would prevent
impurities from getting on the piston assembly. The amended Stoll Patent
added the further limitation that the outer shell of the device, the
sleeve, be made of a magnetizable material.
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After Festo began selling its rodless cylinder, respondents (whom we
refer to as SMC) entered the market with a device similar, but not
identical, to the ones disclosed by Festo's patents. SMC's cylinder,
rather than using two one-way sealing rings, employs a single sealing ring
with a two-way lip. Furthermore, SMC's sleeve is made of a nonmagnetizable
alloy. SMC's device does not fall within the literal claims of either
patent, but petitioner contends that it is so similar that it infringes
under the doctrine of equivalents.
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SMC contends that Festo is estopped from making this argument because
of the prosecution history of its patents. The sealing rings and the
magnetized alloy in the Festo product were both disclosed for the first
time in the amended applications. In SMC's view, these amendments narrowed
the earlier applications, surrendering alternatives that are the very
points of difference in the competing devices -- the sealing rings and the
type of alloy used to make the sleeve. As Festo narrowed its claims in
these ways in order to obtain the patents, says SMC, Festo is now estopped
from saying that these features are immaterial and that SMC's device is an
equivalent of its own.
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The United States District Court for the District of Massachusetts
disagreed. It held that Festo's amendments were not made to avoid prior
art, and therefore the amendments were not the kind that give rise to
estoppel. A panel of the Court of Appeals for the Federal Circuit
affirmed. 72 F. 3d 857 (1995). We granted certiorari, vacated, and
remanded in light of our intervening decision in Warner-Jenkinson v.
Hilton Davis Chemical Co., 520 U. S. 17 (1997). After a decision by the
original panel on remand, 172 F. 3d 1361 (1999), the Court of Appeals
ordered rehearing en banc to address questions that had divided its judges
since our decision in Warner-Jenkinson. 187 F. 3d 1381
(1999).
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The en banc court reversed, holding that prosecution history estoppel
barred Festo from asserting that the accused device infringed its patents
under the doctrine of equivalents. 234 F. 3d 558 (2000). The court held,
with only one judge dissenting, that estoppel arises from any amendment
that narrows a claim to comply with the Patent Act, not only from
amendments made to avoid prior art. Id., at 566. More controversial in the
Court of Appeals was its further holding: When estoppel applies, it stands
as a complete bar against any claim of equivalence for the element that
was amended. Id., at 574-575. The court acknowledged that its own prior
case law did not go so far. Previous decisions had held that prosecution
history estoppel constituted a flexible bar, foreclosing some, but not
all, claims of equivalence, depending on the purpose of the amendment and
the alterations in the text. The court concluded, however, that its
precedents applying the flexible-bar rule should be overruled because this
case-by-case approach has proved unworkable. In the court's view a
complete-bar rule, under which estoppel bars all claims of equivalence to
the narrowed element, would promote certainty in the determination of
infringement cases.
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Four judges dissented from the decision to adopt a complete bar. Id.,
at 562. In four separate opinions, the dissenters argued that the
majority's decision to overrule precedent was contrary to Warner-Jenkinson
and would unsettle the expectations of many existing patentees. Judge
Michel, in his dissent, described in detail how the complete bar required
the Court of Appeals to disregard 8 older decisions of this Court, as well
as more than 50 of its own cases. 234 F. 3d, at 601-616.
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We granted certiorari. 533 U. S. 915 (2001).
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II.
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The patent laws "promote the Progress of Science and useful Arts" by
rewarding innovation with a temporary monopoly. U. S. Const., Art. I, §8,
cl. 8. The monopoly is a property right; and like any property right, its
boundaries should be clear. This clarity is essential to promote progress,
because it enables efficient investment in innovation. A patent holder
should know what he owns, and the public should know what he does not. For
this reason, the patent laws require inventors to describe their work in
"full, clear, concise, and exact terms," 35 U. S. C. §112, as part of the
delicate balance the law attempts to maintain between inventors, who rely
on the promise of the law to bring the invention forth, and the public,
which should be encouraged to pursue innovations, creations, and new ideas
beyond the inventor's exclusive rights. Bonito Boats, Inc. v. Thunder
Craft Boats, Inc., 489 U. S. 141, 150 (1989).
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Unfortunately, the nature of language makes it impossible to capture
the essence of a thing in a patent application. The inventor who chooses
to patent an invention and disclose it to the public, rather than exploit
it in secret, bears the risk that others will devote their efforts toward
exploiting the limits of the patent's language:
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"An invention exists most importantly as a tangible structure or a
series of drawings. A verbal portrayal is usually an afterthought written
to satisfy the requirements of patent law. This conversion of machine to
words allows for unintended idea gaps which cannot be satisfactorily
filled. Often the invention is novel and words do not exist to describe
it. The dictionary does not always keep abreast of the inventor. It
cannot. Things are not made for the sake of words, but words for things."
Autogiro Co. of America v. United States, 384 F. 2d 391, 397 (Ct. Cl.
1967).
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The language in the patent claims may not capture every nuance of the
invention or describe with complete precision the range of its novelty. If
patents were always interpreted by their literal terms, their value would
be greatly diminished. Unimportant and insubstantial substitutes for
certain elements could defeat the patent, and its value to inventors could
be destroyed by simple acts of copying. For this reason, the clearest rule
of patent interpretation, literalism, may conserve judicial resources but
is not necessarily the most efficient rule. The scope of a patent is not
limited to its literal terms but instead embraces all equivalents to the
claims described. See Winans v. Denmead, 15 How. 330, 347
(1854).
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It is true that the doctrine of equivalents renders the scope of
patents less certain. It may be difficult to determine what is, or is not,
an equivalent to a particular element of an invention. If competitors
cannot be certain about a patent's extent, they may be deterred from
engaging in legitimate manufactures outside its limits, or they may invest
by mistake in competing products that the patent secures. In addition the
uncertainty may lead to wasteful litigation between competitors, suits
that a rule of literalism might avoid. These concerns with the doctrine of
equivalents, however, are not new. Each time the Court has considered the
doctrine, it has acknowledged this uncertainty as the price of ensuring
the appropriate incentives for innovation, and it has affirmed the
doctrine over dissents that urged a more certain rule. When the Court in
Winans v. Denmead, supra, first adopted what has become the doctrine of
equivalents, it stated that "[t]he 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." Id., at 343. The dissent argued that
the Court had sacrificed the objective of "[f]ul[l]ness, clearness,
exactness, preciseness, and particularity, in the description of the
invention." Id., at 347 (opinion of Campbell, J.).
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The debate continued in Graver Tank & Mfg. Co. v. Linde Air
Products Co., 339 U. S. 605 (1950), where the Court reaffirmed the
doctrine. Graver Tank held that patent claims must protect the inventor
not only from those who produce devices falling within the literal claims
of the patent but also from copyists who "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." Id., at 607. Justice Black, in dissent,
objected that under the doctrine of equivalents a competitor "cannot rely
on what the language of a patent claims. He must be able, at the peril of
heavy infringement damages, to forecast how far a court relatively
unversed in a particular technological field will expand the claim's
language ... ." Id., at 617.
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Most recently, in Warner-Jenkinson, the Court reaffirmed that
equivalents remain a firmly entrenched part of the settled rights
protected by the patent. A unanimous opinion concluded that if the
doctrine is to be discarded, it is Congress and not the Court that should
do so:
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"[T]he lengthy history of the doctrine of equivalents strongly
supports adherence to our refusal in Graver Tank to find that the Patent
Act conflicts with that doctrine. Congress can legislate the doctrine of
equivalents out of existence any time it chooses. The various policy
arguments now made by both sides are thus best addressed to Congress, not
this Court." 520 U. S., at 28.
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III.
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Prosecution history estoppel requires that the claims of a patent be
interpreted in light of the proceedings in the PTO during the application
process. Estoppel is a "rule of patent construction" that ensures that
claims are interpreted by reference to those "that have been cancelled or
rejected." Schriber-Schroth Co. v. Cleveland Trust Co., 311 U. S. 211,
220-221 (1940). The doctrine of equivalents allows the patentee to claim
those insubstantial alterations that were not captured in drafting the
original patent claim but which could be created through trivial changes.
When, however, the patentee originally claimed the subject matter alleged
to infringe but then narrowed the claim in response to a rejection, he may
not argue that the surrendered territory comprised unforeseen subject
matter that should be deemed equivalent to the literal claims of the
issued patent. On the contrary, "[b]y the amendment [the patentee]
recognized and emphasized the difference between the two phrases[,] ...
and [t]he difference which [the patentee] thus disclaimed must be regarded
as material." Exhibit Supply Co. v. Ace Patents Corp., 315 U. S. 126,
136-137 (1942).
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A rejection indicates that the patent examiner does not believe the
original claim could be patented. While the patentee has the right to
appeal, his decision to forgo an appeal and submit an amended claim is
taken as a concession that the invention as patented does not reach as far
as the original claim. See Goodyear Dental Vulcanite Co. v. Davis, 102 U.
S. 222, 228 (1880) ("In view of [the amendment] there can be no doubt of
what [the patentee] understood he had patented, and that both he and the
commissioner regarded the patent to be for a manufacture made exclusively
of vulcanites by the detailed process"); Wang Laboratories, Inc. v.
Mitsubishi Electronics America, Inc., 103 F. 3d 1571, 1577-1578 (CA Fed.
1997) ("Prosecution history estoppel ... preclud[es] a patentee from
regaining, through litigation, coverage of subject matter relinquished
during prosecution of the application for the patent"). Were it otherwise,
the inventor might avoid the PTO's gatekeeping role and seek to recapture
in an infringement action the very subject matter surrendered as a
condition of receiving the patent.
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Prosecution history estoppel ensures that the doctrine of equivalents
remains tied to its underlying purpose. Where the original application
once embraced the purported equivalent but the patentee narrowed his
claims to obtain the patent or to protect its validity, the patentee
cannot assert that he lacked the words to describe the subject matter in
question. The doctrine of equivalents is premised on language's inability
to capture the essence of innovation, but a prior application describing
the precise element at issue undercuts that premise. In that instance the
prosecution history has established that the inventor turned his attention
to the subject matter in question, knew the words for both the broader and
narrower claim, and affirmatively chose the latter.
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A.
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The first question in this case concerns the kinds of amendments that
may give rise to estoppel. Petitioner argues that estoppel should arise
when amendments are intended to narrow the subject matter of the patented
invention, for instance, amendments to avoid prior art, but not when the
amendments are made to comply with requirements concerning the form of the
patent application. In Warner-Jenkinson we recognized that prosecution
history estoppel does not arise in every instance when a patent
application is amended. Our "prior cases have consistently applied
prosecution history estoppel only where claims have been amended for a
limited set of reasons," such as "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." 520 U. S., at
30-32. While we made clear that estoppel applies to amendments made for a
"substantial reason related to patentability," id., at 33, we did not
purport to define that term or to catalog every reason that might raise an
estoppel. Indeed, we stated that even if the amendment's purpose were
unrelated to patentability, the court might consider whether it was the
kind of reason that nonetheless might require resort to the estoppel
doctrine. Id., at 40-41.
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Petitioner is correct that estoppel has been discussed most often in
the context of amendments made to avoid the prior art. See Exhibit Supply
Co., supra, at 137; Keystone Driller Co. v. Northwest Engineering Corp.,
294 U. S. 42, 48 (1935). Amendment to accommodate prior art was the
emphasis, too, of our decision in Warner-Jenkinson, supra, at 30. It does
not follow, however, that amendments for other purposes will not give rise
to estoppel. Prosecution history may rebut the inference that a thing not
described was indescribable. That rationale does not cease simply because
the narrowing amendment, submitted to secure a patent, was for some
purpose other than avoiding prior art.
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We agree with the Court of Appeals that a narrowing amendment made to
satisfy any requirement of the Patent Act may give rise to an estoppel. As
that court explained, a number of statutory requirements must be satisfied
before a patent can issue. The claimed subject matter must be useful,
novel, and not obvious. 35 U. S. C. §§101-103 (1994 ed. and Supp. V). In
addition, the patent application must describe, enable, and set forth the
best mode of carrying out the invention. §112 (1994 ed.). These latter
requirements must be satisfied before issuance of the patent, for
exclusive patent rights are given in exchange for disclosing the invention
to the public. See Bonito Boats, 489 U. S., at 150-151. What is claimed by
the patent application must be the same as what is disclosed in the
specification; otherwise the patent should not issue. The patent also
should not issue if the other requirements of §112 are not satisfied, and
an applicant's failure to meet these requirements could lead to the issued
patent being held invalid in later litigation.
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Petitioner contends that amendments made to comply with §112 concern
the form of the application and not the subject matter of the invention.
The PTO might require the applicant to clarify an ambiguous term, to
improve the translation of a foreign word, or to rewrite a dependent claim
as an independent one. In these cases, petitioner argues, the applicant
has no intention of surrendering subject matter and should not be estopped
from challenging equivalent devices. While this may be true in some cases,
petitioner's argument conflates the patentee's reason for making the
amendment with the impact the amendment has on the subject
matter.
|
| [92] |
Estoppel arises when an amendment is made to secure the patent and the
amendment narrows the patent's scope. If a §112 amendment is truly
cosmetic, then it would not narrow the patent's scope or raise an
estoppel. On the other hand, if a §112 amendment is necessary and narrows
the patent's scope -- even if only for the purpose of better description
--estoppel may apply. A patentee who narrows a claim as a condition for
obtaining a patent disavows his claim to the broader subject matter,
whether the amendment was made to avoid the prior art or to comply with
§112. We must regard the patentee as having conceded an inability to claim
the broader subject matter or at least as having abandoned his right to
appeal a rejection. In either case estoppel may apply.
|
| [93] |
B.
|
| [94] |
Petitioner concedes that the limitations at issue -- the sealing rings
and the composition of the sleeve -- were made for reasons related to
§112, if not also to avoid the prior art. Our conclusion that prosecution
history estoppel arises when a claim is narrowed to comply with §112 gives
rise to the second question presented: Does the estoppel bar the inventor
from asserting infringement against any equivalent to the narrowed element
or might some equivalents still infringe? The Court of Appeals held that
prosecution history estoppel is a complete bar, and so the narrowed
element must be limited to its strict literal terms. Based upon its
experience the Court of Appeals decided that the flexible-bar rule is
unworkable because it leads to excessive uncertainty and burdens
legitimate innovation. For the reasons that follow, we disagree with the
decision to adopt the complete bar.
|
| [95] |
Though prosecution history estoppel can bar challenges to a wide range
of equivalents, its reach requires an examination of the subject matter
surrendered by the narrowing amendment. The complete bar avoids this
inquiry by establishing a per se rule; but that approach is inconsistent
with the purpose of applying the estoppel in the first place -- to hold
the inventor to the representations made during the application process
and to the inferences that may reasonably be drawn from the amendment. By
amending the application, the inventor is deemed to concede that the
patent does not extend as far as the original claim. It does not follow,
however, that the amended claim becomes so perfect in its description that
no one could devise an equivalent. After amendment, as before, language
remains an imperfect fit for invention. The narrowing amendment may
demonstrate what the claim is not; but it may still fail to capture
precisely what the claim is. There is no reason why a narrowing amendment
should be deemed to relinquish equivalents unforeseeable at the time of
the amendment and beyond a fair interpretation of what was surrendered.
Nor is there any call to foreclose claims of equivalence for aspects of
the invention that have only a peripheral relation to the reason the
amendment was submitted. The amendment does not show that the inventor
suddenly had more foresight in the drafting of claims than an inventor
whose application was granted without amendments having been submitted. It
shows only that he was familiar with the broader text and with the
difference between the two. As a result, there is no more reason for
holding the patentee to the literal terms of an amended claim than there
is for abolishing the doctrine of equivalents altogether and holding every
patentee to the literal terms of the patent.
|
| [96] |
This view of prosecution history estoppel is consistent with our
precedents and respectful of the real practice before the PTO. While this
Court has not weighed the merits of the complete bar against the flexible
bar in its prior cases, we have consistently applied the doctrine in a
flexible way, not a rigid one. We have considered what equivalents were
surrendered during the prosecution of the patent, rather than imposing a
complete bar that resorts to the very literalism the equivalents rule is
designed to overcome. E.g., Goodyear Dental Vulcanite Co., 102 U. S., at
230; Hurlbut v. Schillinger, 130 U. S. 456, 465 (1889).
|
| [97] |
The Court of Appeals ignored the guidance of Warner-Jenkinson, which
instructed that courts must be cautious before adopting changes that
disrupt the settled expectations of the inventing community. See 520 U.
S., at 28. In that case we made it clear that the doctrine of equivalents
and the rule of prosecution history estoppel are settled law. The
responsibility for changing them rests with Congress. Ibid. Fundamental
alterations in these rules risk destroying the legitimate expectations of
inventors in their property. The petitioner in Warner-Jenkinson requested
another bright-line rule that would have provided more certainty in
determining when estoppel applies but at the cost of disrupting the
expectations of countless existing patent holders. We rejected that
approach: "To 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." Id., at 32, n. 6; see also id., at 41
(Ginsburg, J., concurring) ("The new presumption, if applied woodenly,
might in some instances unfairly discount the expectations of a patentee
who had no notice at the time of patent prosecution that such a
presumption would apply"). As Warner-Jenkinson recognized, patent
prosecution occurs in the light of our case law. Inventors who amended
their claims under the previous regime had no reason to believe they were
conceding all equivalents. If they had known, they might have appealed the
rejection instead. There is no justification for applying a new and more
robust estoppel to those who relied on prior doctrine.
|
| [98] |
In Warner-Jenkinson we struck the appropriate balance by placing the
burden on the patentee to show that an amendment was not for purposes of
patentability:
|
| [99] |
"Where no explanation is established, however, the court should
presume that the patent application had a substantial reason related to
patentability for including the limiting element added by amendment. In
those circumstances, prosecution history estoppel would bar the
application of the doctrine of equivalents as to that element." Id., at
33.
|
| [100] |
When the patentee is unable to explain the reason for amendment,
estoppel not only applies but also "bar[s] the application of the doctrine
of equivalents as to that element." Ibid. These words do not mandate a
complete bar; they are limited to the circumstance where "no explanation
is established." They do provide, however, that when the court is unable
to determine the purpose underlying a narrowing amendment -- and hence a
rationale for limiting the estoppel to the surrender of particular
equivalents -- the court should presume that the patentee surrendered all
subject matter between the broader and the narrower
language.
|
| [101] |
Just as Warner-Jenkinson held that the patentee bears the burden of
proving that an amendment was not made for a reason that would give rise
to estoppel, we hold here that the patentee should bear the burden of
showing that the amendment does not surrender the particular equivalent in
question. This is the approach advocated by the United States, see Brief
for United States as Amicus Curiae 22-28, and we regard it to be sound.
The patentee, as the author of the claim language, may be expected to
draft claims encompassing readily known equivalents. A patentee's decision
to narrow his claims through amendment may be presumed to be a general
disclaimer of the territory between the original claim and the amended
claim. Exhibit Supply, 315 U. S., at 136-137 ("By the amendment [the
patentee] recognized and emphasized the difference between the two phrases
and proclaimed his abandonment of all that is embraced in that
difference"). There are some cases, however, where the amendment cannot
reasonably be viewed as surrendering a particular equivalent. The
equivalent may have been unforeseeable at the time of the application; the
rationale underlying the amendment may bear no more than a tangential
relation to the equivalent in question; or there may be some other reason
suggesting that the patentee could not reasonably be expected to have
described the insubstantial substitute in question. In those cases the
patentee can overcome the presumption that prosecution history estoppel
bars a finding of equivalence.
|
| [102] |
This presumption is not, then, just the complete bar by another name.
Rather, it reflects the fact that the interpretation of the patent must
begin with its literal claims, and the prosecution history is relevant to
construing those claims. When the patentee has chosen to narrow a claim,
courts may presume the amended text was composed with awareness of this
rule and that the territory surrendered is not an equivalent of the
territory claimed. In those instances, however, the patentee still might
rebut the presumption that estoppel bars a claim of equivalence. The
patentee must show that at the time of the amendment one skilled in the
art could not reasonably be expected to have drafted a claim that would
have literally encompassed the alleged equivalent.
|
| [103] |
IV.
|
| [104] |
On the record before us, we cannot say petitioner has rebutted the
presumptions that estoppel applies and that the equivalents at issue have
been surrendered. Petitioner concedes that the limitations at issue -- the
sealing rings and the composition of the sleeve -- were made in response
to a rejection for reasons under §112, if not also because of the prior
art references. As the amendments were made for a reason relating to
patentability, the question is not whether estoppel applies but what
territory the amendments surrendered. While estoppel does not effect a
complete bar, the question remains whether petitioner can demonstrate that
the narrowing amendments did not surrender the particular equivalents at
issue. On these questions, respondents may well prevail, for the sealing
rings and the composition of the sleeve both were noted expressly in the
prosecution history. These matters, however, should be determined in the
first instance by further proceedings in the Court of Appeals or the
District Court.
|
| [105] |
The judgment of the Federal Circuit is vacated, and the case is
remanded for further proceedings consistent with this
opinion.
|
| [106] |
It is so
ordered.
|