Elbex Video v. Sensormatic Electronics (CAFC 2007-1097)

The claim in question was a means-plus-function claim, invoking 35 U.S.C. § 112, ¶ 6.

“First, the court must determine the claimed function.” Applied Med. Res. Corp. v. U.S. Surgical Corp., 448 F.3d 1324, 1332 (Fed. Cir. 2006). Once the function has been identified, we turn to the specification to determine which structures disclosed in the specification perform that function. Id.

Prosecution estoppel requires a "clear and unmistakable" disclaimer.

Claim terms are entitled to a “heavy presumption” that they carry their ordinary and customary meaning to those skilled in the art in light of the claim term’s usage in the patent specification. See Superguide Corp. v. DirectTV Enters. Inc., 358 F.3d 870, 874 (Fed. Cir. 2004); Omega Eng’g, Inc. v. Raytek Corp., 334 F.3d 1314, 1323 (Fed. Cir. 2003). However, when a patent applicant surrendered claim scope during prosecution before the PTO, the ordinary and customary meaning of a claim term may not apply. This doctrine of prosecution disclaimer has been “adopted . . . as a fundamental precept in our claim construction jurisprudence.” Omega Eng’g, 334 F.3d at 1323 (citing cases). Prosecution disclaimer “promotes the public notice function of the intrinsic evidence and protects the public’s reliance on definitive statements made during prosecution.” Id. at 1324. This doctrine does not apply “where the alleged disavowal is ambiguous;” the disavowal must “be both clear and unmistakable” to one of ordinary skill in the art. Id. at 1326; Seachange Int’l, Inc. v. C-COR Inc., 413 F.3d 1361, 1373 (Fed. Cir. 2005) (“A disclaimer must be clear and unambiguous.”); Rambus Inc. v. Infineon Techs. AG, 318 F.3d 1081, 1089-91 (Fed. Cir. 2003) (finding no clear disclaimer because the statement made was ”facially inaccurate” in light of the remainder of the prosecution history); Biotec Biologische Naturverpackugen GmbH & Co. KG v. Biocorp, Inc., 249 F.3d 1341, 1348 (Fed. Cir. 2001) (finding no clear disclaimer because “a person of reasonable intelligence would not be misled into relying on the erroneous statement, for it is contrary not only to the plain language of the claims and the specification, but also to other statements in the same prosecution document”); Hockerson-Halberstadt, Inc. v. Avia Group Int’l, Inc., 222 F.3d 951, 956-57 (Fed. Cir. 2000) (finding disavowal because “reasonable competitor . . . would have no reason to believe that a mistake was made”); Desper Prods., Inc. v. QSound Labs., Inc., 157 F.3d 1325, 1334-36 (Fed. Cir. 1998) (concluding prosecution statements were clear and unmistakable disclaimer because they were entirely consistent with written description and knowledge of those skilled in the art).

Two on the panel, DYK and Moore, didn't agree with the district court.

First, the statement in the prosecution history is unsupported by even a shred of evidence from the specification.

Second, read in isolation, the statement in the prosecution history could be argued to be a disclaimer. When the prosecution history as a whole is considered, the inventor’s response to the PTO is not as clear. Because of the potential for such ambiguities, we have recognized that “because the prosecution history represents an ongoing negotiation between the PTO and the applicant . . . it often lacks the clarity of the specification and thus is less useful for claim construction purposes.” Phillips v. AWH Corp., 415 F.3d 1303, 1317 (Fed. Cir. 2005).

Two paragraphs after the supposed disclaimer, an apparent statement not in accord with the alleged estoppel.

This statement, unlike the alleged disclaimer, is fully supported by the written description and provides further indication that the earlier statement in the same document was not a clear and unmistakable surrender.

Looking at the big picture, and the import of the alleged disclaimer -

Third, reading the specification and remainder of the intrinsic record as a whole would lead those skilled in the art to the conclusion that the inventor’s statement... was not a clear and unmistakable surrender of claim scope... This prosecution statement if taken literally would result in an inoperable system.

Sitting district court judge Cote found the evidence "clear and unambiguous" that the relevant prosecution statement "was a strategic choice and an unmistakable surrender of claim scope."

Affirmed in part, reversed in part; remanded.