In this patent suit, the United States District Court for the Western District of New York 1 held that United States Patent No. 4,853,266, entitled “Liquid Absorbing and Immobilizing Packet Containing a Material for Treating the Absorbed Liquid” (the ’266 patent), owned by Multiform Desiccants, Inc., was not infringed by the similar product sold by Medzam, Ltd. The district court entered judgment in favor of Medzam, did not decide the issue of patent validity, and denied Medzam’s request for attorney fees. Multiform appeals the judgment of non-infringement, and Medzam appeals the denial of attorney fees and the decision not to reach the issue of validity.
THE TECHNOLOGY
The invention described and claimed in the ’266 patent is a packet for use in controlling spilled liquids. In typical use the packet is placed in an outer shipping container that encloses an inner container holding a hazardous liquid such as medical waste or body fluids. Should the inner container break or leak, the released liquid encounters the packet in the outer container. The packet envelope, which is made of a soluble material, disintegrates and releases materials that absorb, immobilize, and treat the spilled liquid. The absorbing and immobilizing material is preferably sodium polyacrylate, a known absorbent that expands and gels on contact with liquid. The treating material may be a known disinfectant, scent, deodorizer, etc., depending on the intended use of the packet.
Medzam’s accused packet, called the Red-Z Zafety Pac, is designed and sold for the same uses as the Multiform packet. The Medzam envelope is made of porous material such as is used for tea bags, and contains the *1476 known absorbing and immobilizing material potassium polyacrylate and a disinfectant. When spilled liquid penetrates the porous envelope, the polyacrylate inside the envelope starts to absorb and expand. The expanding absorbent splits open the envelope, releasing its contents for further absorption.
LITERAL INFRINGEMENT
Patent infringement occurs when a device (or composition or method), that is literally covered by the claims or is equivalent to the claimed subject matter, is made, used, or sold, without the authorization of the patent holder, during the term of the patent.
See
35 U.S.C. § 271. The claims are concise statements of the subject matter for which the statutory right to exclude is secured by the grant of the patent. Since a full and complete understanding of the scope of the claims is requisite to determining whether the patent is infringed, technical terms or words of art or special usages in the claims, if in dispute, are construed or clarified by the court before the construed claims are applied to the accused device. On appellate review the Federal Circuit again construes the claims, determining
de novo
the correct construction.
See Markman v. Westview Instruments,
On occasion the issue of literal infringement may be resolved with the step of claim construction, for upon correct claim construction it may be apparent whether the accused device is within the claims.
See, e.g., Strattec Security Corp. v. Gen. Automotive Specialty,
Claims 1 and 6
In the ’266 patent the packet is claimed as a combination of the degradable envelope, the absorbing material, and the treating material. A second group of claims describes the envelope in terms of its function, in the form authorized by 35 U.S.C. § 112 ¶ 6; these claims are discussed post. Claims 1 and 6 are representative of the first group of claims:'
1. A packet for absorbing and immobilizing a liquid comprising an envelope which is degradable in said liquid, a first material in said envelope for absorbing and immobilizing said liquid, and a second material confined in said envelope for additionally treating said liquid which is absorbed and immobilized to nullify a specific undesirable quality thereof.
6. In an outer container having an inner container with liquid from which said liquid can leak, an absorbent packet located between said inner and outer containers for absorbing and immobilizing said liquid within said outer container in the event of leakage of said liquid from said inner container comprising an envelope which is degradable in said liquid, a first material in said envelope for absorbing and immobilizing said liquid, and a second material confined in said envelope for additionally treating said liquid which is absorbed and immobilized to nullify a specific undesirable quality thereof.
(Emphases added.) Medzam conceded that its packet contains all of the elements of claims 1 and 6 except the “degradable” envelope. Medzam argued that its envelope is not degradable, when that term is correctly construed, and thus that the claims are not infringed.
The disputed issue is the meaning of the term “degradable” in characterizing the claimed envelope. The district court defined this term with an eye to the accused envelope. The court held that the terms “degrade” and “degradable,” as used in the ’266 patent, mean that the envelope at least partially dissolves and thereby disintegrates in the liquid. The court held that this meaning of “degradable” does not include the mode of operation of the Medzam packet, wherein the envelope bursts open by expansion of the contents but the envelope itself does not dissolve and disintegrate by direct action of the liquid.
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Multiform states that this claim construction is incorrect, and that upon correct construction a finding of infringement is inevitable. Multiform argues that “degradable” must first be construed based on the ’266 patent documents, without reference to the accused device,
see Jurgens v. McKasy,
It is the person of ordinary skill in the field of the invention through whose eyes the claims are construed. Such person is deemed to read the words used, in the patent documents with an understanding of their meaning in the field, and to have knowledge of any special meaning and usage in the field. The inventor’s words that are used to, describe the invention — the inventor’s lexicography — must be understood and interpreted by the court as they would be understood and interpreted by a person in that field of technology. Thus the court starts the deci-sionmaking process by reviewing the same resources as would that person, viz., the patent specification and the prosecution history. These documents have legal as well as technological content, for they show not only the framework of the invention as viewed by the inventor, but also the issues of patenta-bility as viewed by the patent examiner. ■
During patent prosecution Multiform' submitted dictionary definitions of “degradable” from Webster’s New Collegiate Dictionary (1976), explaining the submission as follows:
The word “degrade” includes the definitions of “to deprive of standing or true function” and “to impair in respect of some physical property.” Thus when the envelope is dry and not degraded, its true function is to contain its contents. However, once it is exposed to liquid, it is deprived of its standing or true function and it has its physical property of containing its contents impaired.
Multiform states that this definition is comprehensive' of the degradation of the Medzam envelope that bursts apart and thus loses its true function, and is not limited to an envelope that degrades by dissolving. Multiform states that it is not necessary for the packet to disintegrate in order to degrade. Medzam responds that Multiform offered these definitions only after Multiform became aware of the Medzam packet, and that the definitions are at odds with the plain reading of the specification.
' Multiform argues that, in keeping with the rule that an inventor may be his own lexicographer, its definition of “degradable” must prevail. When the meaning of a term is sufficiently clear in the patent specification, that meaning shall apply.
See Intellicall, Inc. v. Phonometrics, Inc.,
Thus we review,
de novo,
the meaning of “degradable” in claims 1 and 6. We start with the specification.
See Slimfold Mfg. Co. v. Kinkead Industries, Inc.,
The district court concluded that the specification and the prosecution history do not support a meaning of “degradable” that would include an envelope that bursts open from inner pressure without any dissolution. The district court defined “degradable” in light of the mode of action of the accused device, a pragmatic expedient relevant to the issue in litigation. Thus the court held that Multiform’s dictionary definitions added during patent prosecution, although stating a broad definition of “degradable,” could not serve to enlarge the scope of the claims in order to cover the Medzam device. The district court did not accept Multiform’s position that the dictionary definitions provided during the prosecution simply clarified the inventor’s original usage of “degradable.” We agree with this analysis.
Courts must exercise caution lest dictionary definitions, usually the least controversial source of extrinsic evidence, be converted into technical terms of art having legal, not linguistic, significance. The best source for understanding a technical term is the specification from which it arose, informed, as needed, by the prosecution history. The evolution of restrictions in the claims, in the course of examination in the PTO, reveals how those closest to the patenting process— the inventor and the patent examiner— viewed the subject matter.
See Hoechst Celanese Corp. v. BP Chemicals Ltd.,
We conclude that the meaning of “degradable” in claims 1 and 6 (and the claims dependent thereon) is limited to the dissolution/degradation of the envelope as described in the specification. The court correctly excluded the meaning whereby the envelope “degrades” by bursting instead of dissolving, and correctly held that “degradable” means that there must be at least partial dissolution of the envelope. Upon this claim interpretation, the district court concluded that there could not be literal infringement of claims 1 and 6. We agree, for this claim interpretation eliminated the Medzam envelope, which bursts but does not dissolve, from the literal meaning and scope of the claims.
Claims 11 to 15
During pendency of the ’266 application claims 11-18 were added to describe the envelope in terms of its function, in accordance with the form authorized by 35 U.S.C. § 112 ¶ 6. 2 Claims 11-15, asserted against the Medzam packet, do not contain the word “degradable.” Claim 11 is representative:
*1479 11. A packet for absorbing and immobilizing a liquid comprising a first material which will absorb and immobilize said liquid, a second material for additionally treating said liquid which is absorbed and immobilized to nullify a specific undesirable quality of said liquid, and means for containing said first and second materials while said means are dry and for releasing said first and second materials on contact of said means with said liquid to thereby permit said first and second materials to absorb and immobilize and treat said liquid.
(Emphasis added.) In adding these “means-for” claims Multiform’s attorney wrote to the patent examiner that the word “degradable” was ambiguous in that it could be interpreted “as synonymous with ‘disintegrate,’ which is not necessary for the packet to function properly.” The attorney submitted the dictionary definitions that we discussed in connection with claims 1 and 6. Multiform argues that the grant of claims 11-15 makes clear that neither the applicant nor the examiner viewed the invention as limited to a dissolving, disintegrating envelope.
A claim containing a functional limitation written in means-for form is literally infringed when the accused device performs the function stated in the claim, by means of structure, material, or acts described in the specification or equivalents thereof.
See Texas Instruments, Inc. v. United States Int'l Trade Comm’n,
In determining whether there is literal infringement under § 112 ¶ 6, the first step in interpretation of the claim is determination of the meaning of the words used to describe the claimed function, if such meaning is in dispute. This claim interpretation is deemed to be a matter of law, and is reviewed
de novo
on appeal.
Markman,
The district court found that the function of containing and releasing the contents of the packet does not embrace all envelopes whose contents are released on contact with liquid. The court stressed the description of the envelope in the ’266 specification as made of “degradable starch paper,” “degradable in water and other liquids,” “able to dissolve,” and “practically entirely disintegrated,” in finding that the function of releasing the envelope contents must be performed by an envelope that disintegrates by dissolution. The court then found that since the Medzam envelope does not dissolve, it does not perform the function required by claims 11-15.
Multiform argues that the function of containing and releasing the contents of the envelope is plainly performed by the Medzam envelope, and that even if the Med-zam envelope’s structure and material are not the same as described in the ’266 specification, they are equivalent means of performing the same function. The district court found that the structure and material of Medzam’s porous envelope, which works by penetration of the liquid through the envelope fabric, are not equivalent to the starch paper described in the ’266 specification, which dissolves and disintegrates. The district court’s finding of non-infringement is reviewed for clear error.
Biodex Corp. v. Loredan Biomedical, Inc.,
Multiform invokes the doctrine of claim differentiation, which presumes that there is a difference in scope among the claims of a patent.
Tandon Corp. v. United States Int’l Trade Comm’n,
DOCTRINE OF EQUIVALENTS
Multiform argues that even on the district court’s interpretation of the claims, the Medzam packet inflinges under the doctrine of equivalents. The doctrine of equivalents, of common law origin, serves to prevent a “fraud on the patent.”
Graver Tank & Mfg. Co. v. Linde Air Products Co.,
Applying
Graver Tank
and
Warner-Jenkinson,
we review whether the Medzam porous envelope performs substantially the same function as that of the dissolving envelope of the ’266 patent and, if so, whether it is performed in substantially the same way to achieve substantially the same result.
Graver Tank,
Determination of infringement under the doctrine of equivalents occurs after the claims have been construed as a matter of law. The trier of fact, applying the claims as construed, finds whether the accused device, element by element, is equivalent to that which has been patented. The court also determines whether there is any estop-pel derived from the prosecution history that bars remedy even when there is technologic equivalency, for the patentee is precluded from reaching, under the doctrine of equivalents, subject matter that was disclaimed in order to obtain the patent.
The district court found that the Medzam envelope performs the function of releasing its contents in a substantially different way than does the envelope of the ’266 patent, in that the Medzam envelope is not soluble in and does not degrade in the liquid. Although Multiform argues that the Medzam packet functions in a way that is “consistent” with the ’266 invention, for the Med-zam porous envelope releases its contents upon contact with liquid, the district court found a porous envelope that bursts with inner pressure to be substantially different from a degradable envelope that dissolves. This finding has not been shown to be clearly erroneous.
Multiform argues that the interchangeability of the envelopes weighs heavily on the side of equivalency. Interchangeability is a significant factor in determination of equivalency. In
Warner-Jenkinson,
— U.S. at ---,
The district court’s finding of non-infringement under the doctrine of equivalents is not clearly erroneous, and must be affirmed.
VALIDITY
After the trial Medzam withdrew its antitrust, unfair competition, unfair trade practice, and tort-based counterclaims; no counterclaims remained. Although Medzam continued to assert patent invalidity as an affirmative defense to infringement, the district court stated, upon finding non-infringement, that it “need not reach the issue of whether Medzam has overcome the presumption of validity regarding the ’266 Patent.”
Although viewed by Medzam as a mere technicality, it is dispositive that Medzam did not file a counterclaim for a declaration of invalidity. The Supreme Court in
Cardinal Chem. Co. v. Morton Int’l, Inc.,
In
Cardinal Chemical
the Court held that the Federal Circuit, when reviewing infringement on appeal, should also review the issue of validity when that issue was raised by counterclaim or declaratory judgment and was decided by the trial court, as a matter of serving the public interest in valid patents. However, the Court suggested that appellate review was unnecessary when the issue of validity was raised only as an affirmative defense.
Thus we decline Medzam’s request for further proceedings on the issue of validity, even as we stress the useful general rule that trial courts should decide all litigated issues, in the interest of finality.
See Sinclair & Carroll Co. v. Interchemical Corp.,
ATTORNEY FEES
The district court’s denial of attorney fees under 35 U.S.C. § 285 is subject to reversal only if (1) the finding that this is not an exceptional ease is clearly erroneous and (2) the ensuing refusal of attorney fees is an abuse of discretion.
Findings of exceptional case have been based on a variety of factors; for ex
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ample, willful or intentional infringement, inequitable conduct before the Patent and Trademark Office, vexatious or unjustified litigation, or other misfeasant behavior.
See Rite-Hite Corp. v. Kelley Co., Inc.,
Medzam also argues that it was an act of bad faith for Multiform to add the “means-for” claims to the ’266 patent in an attempt to cover Medzam’s product. However, it is neither illegal nor bad faith for an applicant to amend the claims in view of a competitor’s product.
See Kingsdown Medical Consultants, Ltd. v. Hollister Inc.,
Medzam also states that Multiform committed inequitable conduct by presenting the patent examiner with misleading dictionary definitions during the prosecution of the ’266 patent. Medzam states that Multiform cited the dictionary definition of “degrade,” while failing to cite the dictionary definition of “degradable,” which Medzam says is inconsistent with “degrade.” Medzam states that intent to deceive can be inferred from this action. Although direct evidence of fraudulent intent is not easy to come by, inference without any probative evidence is insufficient to show culpable intent. As discussed in
Kingsdown,
the charge of inequitable conduct before the patent office had come to be attached to every patent prosecution, diverting the court from genuine issues and simply spawning satellite litigation.
See Kingsdown,
The district court correctly held that “Medzam has not shown by clear and convincing evidence that Multiform’s conduct before the PTO was inequitable.”
No costs.
AFFIRMED.
Notes
.
Multiform Desiccants, Inc. v. Medzam, Ltd.,
No. 91-CV-0095E(H),
. § 112 ¶ 6. An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.