The opinion of the court was delivered by: Wayne R. Andersen District Judge
MEMORANDUM OPINION AND ORDER
This case is before the court for construction of disputed claim language in U.S. Patent No. 5,468,545 (the "'545 Patent").
This case involves a patent for treated, flame resistant cotton blended fabrics. "[C]otton fabrics used for clothing are comfortable to wear, generally because of the cotton fabrics' ability to breathe, their flexibility, and the generally good feel the fabrics have when placed against the skin." (Defs.' Claim Construction at 2). "A disadvantage of using 100% cotton fabric for industrial clothing applications, however, is that cotton fabric is not inherently flame resistant, and flame resistant clothing is essential for certain industrial users . . . ." Id. "Flame resistance is achieved by impregnating the cotton yarn with a pre-polymer containing phosphorous, and then polymerizing the pre-polymer, leaving the cotton impregnated with a phosphorous polymer." (Pls.' Claim Construction at 6). Including non-flame-retardant thermoplastic fibers, such as nylon, in the fabric provides a much longer wear life than 100% cotton materials, but non-flame-retardant thermoplastic fibers do not "wet," which means they do not become impregnated with flame-retarding polymer. Id. at 5-6. Because these thermoplastic fibers may burn, "the flame retardant capability of the cotton must extend to attenuate the burning tendency of the non-cotton fibers." Id. at 6. A simple solution is to increase the amount of polymer in the cotton, but the resulting fabric becomes stiff and uncomfortable. Id. "Goals of the '545 Patent include a long wear life product with sufficient phosphorous-containing polymer to retard the burning of both cotton and the non-flame-retardant thermoplastic fibers, yet leave the fabric soft." Id.
The '545 Patent was originally issued on November 21, 1995, and was subsequently confirmed by two reexaminations by the United States Patent and Trademark Office ("PTO") on July 17, 2007 and February 19, 2008. (Dkt. No. 1521-1).
Itex, Inc., ("Itex") and MF&H Textiles, Inc. ("MF&H," collectively "Plaintiffs") filed the instant lawsuit on October 21, 2005. Plaintiffs' complaint alleged that Westex, Inc. ("Westex") was infringing on the '545 Patent by making or selling certain flame retardant cotton blended fabrics. Other defendants have also been added to the lawsuit, including King America Finishing, Inc. ("King America"), Western Pierce Dyers & Finishers, Inc. ("Western"), Workrite Uniform Company Inc. ("Workrite"), VF Imagewear, Inc. ("VF"), Cintas Corporation ("Cintas"), Unifirst Corporation ("Unifirst"), G&K Services ("G&K"), Aramark Uniform & Career Apparel, LLC ("Aramark"), and Greenwood Mills, Inc. ("Greenwood," collectively with Westex, "Defendants").
On February 29, 2008, Plaintiffs initiated a second lawsuit in the Northern District of Illinois also involving alleged infringement of the '545 Patent (08 CV 1224). On February 12, 2009, the Honorable Morton Denlow entered an order consolidating the two cases for the purposes of claim construction and related discovery. (Dkt. No. 119).
The '545 Patent has six claims, with Claim 1 being the only independent claim, and the only one at issue for the purpose of claim construction. The parties filed extensive briefs on claim construction, and the court held a Markman hearing on December 21, 2009.
The first step in a patent infringement case is to interpret and construe the patent claims, "which define the scope of the patentee's rights under the patent." Markman v. Westview Instruments, Inc., 52 F.3d 967, 970 (Fed. Cir. 1995). The construction of a patent's claims is a question of law to be determined by the court. Id. at 970-71.
"The construction of claims is simply a way of elaborating the normally terse claim language in order to understand and explain, but not to change, the scope of the claims." Terlep v. Brinkman Corp., 418 F.3d 1379, 1382 (Fed. Cir. 2005) (quoting Embrex, Inc. v. Serv. Eng'g Corp., 216 F.3d 1343, 1347 (Fed. Cir. 2000)). "The words of a claim are generally given their ordinary and customary meaning as understood by a person of ordinary skill in the art in question at the time of the invention." Kara Technology Inc. v. Stamps.com Inc., 582 F.3d 1341, 1345 (Fed. Cir. 2009) (citing Phillips v. AWH Corp., 415 F.3d 1303, 1312-13 (Fed. Cir. 2005)).
In addition to studying the words of the claim, a court may also look to the patent specification, Phillips, 415 F.3d at 1315, the prosecution history, Vanderlande Indus. Nederland BV v. I.T.C., 366 F.3d 1311, 1318 (Fed. Cir. 2004), and extrinsic evidence, Phillips, 415 F.3d at 1317-18.
With respect to the specification, the Federal Circuit has explained, "[A]lthough the specification often describes very specific embodiments of the invention, we have repeatedly warned against confining the claims to those embodiments." Kara, 582 F.3d at 1345 (citing Phillips, 415 F.3d at 1323). "In particular, we have expressly rejected the contention that if a patent describes only a single embodiment, the claims of the patent must be construed as being limited to that embodiment." Kara, 582 F.3d at 1345 (citing Phillips, 415 F.3d at 1323).
The complete language of Claim 1, broken into segments for ease of analysis, is as follows:
1 - Wash resistant durable fabrics, including woven fabrics comprising:
a) 50 to 95% cotton fibers; 5-30% non-flame-retardant thermoplastic fibers in which warp yarns for woven fabrics are comprised of 50 to 95% cotton and 5 to 30% non-flame-retardant thermoplastic fibers;
b) said fibers being uniformly treated with a durable flame retardant of a prepolymer of urea and tetrakis (hydroxymethyl) phosphonium salt which has been applied, ammoniated and oxidized in a manner such that
c) after exposure to five washes and twenty-four hours emersion in boiling water
i) the cotton fabrics burn less than 15 cm (6") at cut edges and
ii) retain at least 2.0% and no more than 3.0% phosphorous by weight of fabric.
('545 Patent, col. 8, lns. 29-44). The following sections address each segment of Claim 1.
I. Part 1 -- "Wash Resistant Durable Fabrics"
A. Relevant Claim Language
The relevant language for this section is as follows: "Wash resistant durable fabrics, including woven fabrics comprising." ('545 Patent, col. 8, lns. 29-30).
Plaintiffs and Defendants are in agreement that this language does not require construction.
The court concludes that this language does not require construction.
II. Part a) -- "50 to 95% ...