United States District Courts, M.D. North Carolina
MEMORANDUM OPINION AND ORDER
THOMAS D. SCHROEDER, District Judge.
These consolidated patent cases turn on the parties' disputed construction of the term "intumescent" appearing in the claims of U.S. Patent Nos. 8, 796, 162 ('162 Patent and 8, 501, 639 ('639 Patent held by Plaintiff Precision Fabrics Group, Inc. ("PFG"). PFG alleges that Defendant Tietex International, Ltd. ("Tietex") is infringing the patents, and Tietex has denied infringement and asserted various counterclaims. PFG also moves to strike the declaration of Tietex's expert in support of the latter's construction of the term at issue. (Doc. 38.) The court held a claim construction hearing on December 23, 2014. For the reasons stated herein, the court adopts the claim construction advanced by PFG.
The '162 and '639 patents are both for inventions relating to lightweight fabric that is flame retardant and "intumescent." (Doc. 47-2 at 3 ('162 Patent) col. 1, ll. 15-23; Doc. 37-1 at 2 ('639 Patent) col. 1, ll. 17-24.) The fabric is single-layer, non-woven, and stitch-bonded; this "substrate" is treated with a finish comprising an "intumescent, flame retardant coating." ('162 Patent col. 12, ll. 7-14; '639 Patent col. 12, ll. 47-50). Being lightweight and thermally protective, the invention is suitable for various applications, including furniture, vehicle components, and building components. ('162 Patent col. 1, ll. 15-23; '639 Patent col. 1, ll. 17-24). As PFG presented at the hearing, an asserted advantage of its invention is that, because the intumescent swells and chars upon exposure to flame, it not only retards flame but forms a protective thermal barrier over the holes of the stitch-bonded fabric.
According to the allegations of PFG's amended complaint, Tietex manufactures a fabric with "a single layer of a non-woven, stitch-bonded substrate treated with an intumescent substance, " infringing both the '162 and '639 patents. (Doc. 27 (Am. Compl.) ¶¶ 14-26.) Tietex denies infringement and asserts counterclaims for a declaration that it has not infringed either of PFG's patents, that both of PFG's patents are invalid, and that neither is enforceable; and for unfair competition and abuse of process.
Pursuant to Local Patent Rule 104.3, the parties have filed a joint claim construction statement, agreeing on the meaning of several terms, including the following:
a "flame retardant" is "[a] substance that can suppress, reduce, or delay combustion and/or propagation of flame when a substrate is exposed to heat or flame"; and
a "finish" is "[a] substance that is applied to a substrate."
(Doc. 24 (Joint Claim Construction Statement) at 1.)
The parties ask the court to construe only the claim term "intumescent." (Id. at 2-3.) To define this term, Tietex relies in part on the expert opinion of Dr. Charles A. Wilkie, presented in the form of his declaration. (Joint Claim Construction Statement at 6; Doc. 24-2.) PFG has moved to strike the declaration and to preclude Dr. Wilkie's testimony. (Doc. 38.) However, since Tietex did not present Dr. Wilkie at the claim construction hearing, preclusion is unnecessary, leaving only the motion to strike.
The parties have each filed a claim construction brief, and the motion to strike Dr. Wilkie's declaration has been fully briefed. Following the claim construction hearing on December 23, 2014, these matters are now ripe for resolution.
A. Legal Standard
Claim construction is a question of law to be determined by the court. Markman v. Westview Instruments, Inc., 517 U.S. 370, 389-91 (1996). The claims of a patent are what define the invention itself, Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (en banc), and are to be given the meaning they "would have to a person of ordinary skill in the art in question, " id. at 1313.
A person of ordinary skill in the art "is deemed to read the claim term not only in the context of the particular claim in which the disputed term appears, but in the context of the entire patent, including the specification." Id . The patent's own specifications and claims are intrinsic evidence of what the patent's terms mean. The specification is not just "always highly relevant" to claim construction; rather, it is usually dispositive, being "the single best guide to the meaning of a disputed term." Id. at 1315 (quoting Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)); see also 35 U.S.C. § 112(a) ("The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention."). The patent's specification may rely on the ordinary meaning of a term, but it may also "reveal a special definition given to a claim term by the patentee that differs from the meaning it would otherwise possess. In such cases, the inventor's lexicography governs." Phillips, 415 F.3d at 1316. Also relevant as intrinsic evidence is the patent's prosecution history: the record of the proceedings before the Patent and Trademark Office, which includes the prior art cited during the examination of the patent. Id. at 1317. Although not always clear, the prosecution history can be helpful in understanding whether the inventor has intentionally narrowed the scope of a claim. Id.
Courts may also consider evidence extrinsic to the patent itself. Although sometimes probative of a claim's meaning, extrinsic evidence is "less significant" and "less reliable" than intrinsic evidence. Id . (quoting C.R. Bard, Inc. v. U.S. Surgical Corp., 388 F.3d 858, 862 (Fed. Cir. 2004)). Several types of evidence fall into the category of extrinsic evidence, each with its own limitations. Dictionaries and treatises can be helpful aids in understanding "the way in which one of skill in the art might use the claim terms, " id. at 1318, although no dictionary definition can "contradict any definition found in or ascertained by a reading of the patent documents, " id. at 1322-23 (quoting Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1584 n.6 (Fed. Cir. 1996)). The opinions of experts can also be helpful in understanding how one with ordinary skill in the art would understand a term, but they are less useful when they are just "conclusory, unsupported" definitions, or when they contradict the intrinsic evidence. Id. at 1318. Expert testimony must be viewed with caution because it is evidence "generated at the time of and for the purpose of litigation and thus can suffer from bias that is not present in intrinsic evidence." Id . Moreover, this bias "can be exacerbated if the expert is not one of skill in the relevant art or if the expert's opinion is offered in a form that is not subject to cross-examination." Id.
When a court considers all probative evidence of a claim's meaning, as the Federal Circuit has stated, there is "no magic formula or catechism for conducting claim construction." Id. at 1324. What counts is that the court "attach the appropriate weight" to the evidence from the various sources, ...