The district court had made a summary judgment.

Summary judgment is appropriate only when there are no genuine issues of material fact and the moving party is entitled to judgment as a matter of law. See Fed. R. Civ. P. 56(c). “In determining whether there is a genuine issue of material fact, the evidence must be viewed in the light most favorable to the party opposing the motion, with doubts resolved in favor of the opponent.” Chiuminatta Concrete Concepts, Inc. v. Cardinal Indus., Inc., 145 F.3d 1303, 1307 (Fed. Cir. 1998). If there are no material facts in dispute precluding summary judgment, “our task is to determine whether the judgment granted is correct as a matter of law.” Marathon Oil Co. v. United States, 177 F.3d 1331, 1337 (Fed. Cir. 1999).

The CAFC recited the infringement analysis two-step.

A determination of infringement requires a two-step analysis. “First, the claim must be properly construed to determine its scope and meaning. Second, the claim as properly construed must be compared to the accused device or process.” Carroll Touch, Inc. v. Electro Mech. Sys., Inc., 15 F.3d 1573, 1576 (Fed. Cir. 1993). Claim construction is an issue of law, see Markman v. Westview Instruments, Inc., 52 F.3d 967, 970-71 (Fed. Cir. 1995) (en banc), aff'd, 517 U.S. 370 (1996), that we review de novo, see Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1456 (Fed. Cir. 1998) (en banc). Infringement, whether literal or under the doctrine of equivalents, is a question of fact. See Bai v. L & L Wings, Inc., 160 F.3d 1350, 1353 (Fed. Cir. 1998).

Claim Construction

The CAFC reiterated the priority stack for claim construction enunciated in Phillips v AWH, preferring intrinsic evidence to extrinsic. For intrinsic evidence, first consider the claim language, then specification (written description), then prosecution history.

“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.” Embrex, Inc., v. Serv. Eng’g Corp., 216 F.3d 1343, 1347 (Fed. Cir. 2000) (internal quotations and citation omitted). Interpreting the asserted claims entails a review of the intrinsic evidence, which consists of the claim language, the written description, and the prosecution history. See id.; Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996).

“[T]he specification is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term.” Phillips v. AWH Corp., No. 03-1269, 03-1286, 2005 U.S. App. LEXIS 13954, at *29 (Fed. Cir. Jul. 12, 2005) (en banc) (internal quotations omitted). “[T]he prosecution history can often inform the meaning of the claim language by demonstrating how the inventor understood the invention and whether the inventor limited the invention in the course of prosecution, making the claim scope narrower than it would otherwise be.” Id. at *36-37. Extrinsic evidence such as dictionaries also “may be considered if the court deems it helpful in determining the true meaning of the language used in the patent claims,” id. at *39 (internal quotations omitted), provided the court “attach[es] the appropriate weight . . . to those sources in light of the statutes and policies that inform patent law,” id. at *58.

In this particular case, the CAFC went through the usage of 'clear' in the claims, the specification, and the prosecution history; none being dispositive, on to the dictionary -

In construing the claims, the parties have cited several dictionaries. District courts are authorized “to rely on extrinsic evidence, which consists of all evidence external to the patent and prosecution history, including . . . dictionaries” as one of many claim construction tools. Phillips, 2005 U.S. App. LEXIS 13954, at *37 (internal citations omitted). The dictionary defines “clear” as “giving free passage to light or to the sight: easily seen through: not cloudy, turbid, or opaque.” Webster’s Third Int’l Dictionary 419 (1993). This definition lists “transparent” and “translucent” as synonyms. The definition also sets forth an express distinction between transparent and translucent: “transparent stresses complete absence of obstruction to vision” and “translucent applies to that which permits passage of light but bars clear and complete vision.” Id. The distinction between these synonyms cannot be ignored. See Int’l Rectifier Corp. v. IXYS Corp., 361 F.3d 1363, 1374 (2004) (holding that it was improper for the district court to adopt a definition that was attributed to a synonym of the disputed term while disregarding the distinction set forth in the usage note). Moreover, the distinction mirrors the distinction reflected in the written description and prosecution history between the unobstructed passage of light of the holder of the patented invention and the prior art structures that diffuse light. Here, the district court “attached appropriate weight” to the dictionary definitions in the context of the intrinsic evidence in reaching its construction of the claim term “clear.” Phillips, 2005 U.S. App. LEXIS 13954, at *58.

Finally, Terlep argues that to define “clear” so as to exclude “translucent” is to import a functional limitation into the claim. Terlep asserts that “clear plastic tubular holder” is merely a structural limitation and that the district court erred in importing a functional limitation into a structural term. However, Terlep fails to recognize that the construction properly adopted by the district court merely assigned meaning to the claim term “clear” and did not impermissibly import a functional limitation. Merck & Co. v. Teva Pharms. USA, Inc., 395 F.3d 1364, 1372 (Fed. Cir. 2005) (“A claim construction that gives meaning to all the terms of the claim is preferred over one that does not do so.”).

We conclude that the district court correctly construed the term “clear” to mean “transparent or having the property of transmitting light without appreciable scattering so that bodies lying beyond are seen clearly,” and that nothing in the claims or the written description warranted giving the term “clear” an expansive meaning that would cover “translucent” holders.

As to infringement -

“[F]or a court to find infringement, the plaintiff must show the presence of every element or its substantial equivalent in the accused device.” Wolverine World Wide, Inc. v. Nike, Inc., 38 F.3d 1192, 1199 (Fed. Cir. 1994); see also Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 40 (1997) (noting that because each limitation contained in a patent claim is material to defining the scope of the patented invention, a doctrine of equivalents analysis must be applied to individual claim limitations, not to the invention as a whole). “Application of the rule precluding use of the doctrine of equivalents to recapture claim scope surrendered during patent acquisition is a question of law.” KCJ Corp. v. Kinetics Concepts, Inc., 223 F.3d 1351, 1359 (Fed. Cir. 2000).

Festo loomed large in prosecution estoppel for limiting equivalence.

Under Festo, a narrowing amendment made to satisfy a requirement of the Patent Act may give rise to an estoppel. Id. at 736. Such a narrowing amendment creates a presumption that the patentee surrendered the territory between the original claims and the amended claims. Id. at 741. The patentee may rebut that presumption by showing that the alleged equivalent was unforeseeable at the time the amendment was made, that the alleged equivalent was tangential to the purpose of that amendment, or that there was some other reason suggesting that the patentee could not reasonably be expected to have described the insubstantial substitute in question. Id. at 740-41.

The primary consideration in determining when an amendment bears only a tangential relation to the equivalent in question is “whether the reason for the amendment is peripheral, or not directly relevant, to the alleged equivalent.” Insituform Techs., Inc. v. Cat Constr., Inc., 385 F.3d 1360, 1370 (Fed. Cir. 2004) (citing Festo Corp. v. Sheketsu Kinzoku Kogyo Kabushiki Co., Ltd., 344 F.3d 1359, 1365 (Fed. Cir. 2003) (en banc)).