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IPR Proceedings: Extrinsic or Intrinsic Evidence for Claim Construction?, PTAB Litigation Blog

January 2018

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In district courts’ claim construction analyses, intrinsic evidence is of paramount importance. Although extrinsic evidence "may be useful to the court," it is considered “less significant” than the claim language, specification, and prosecution history making up the intrinsic record. Phillips v. AWH Corp., 415 F.3d 1303, 1317 (Fed. Cir. 2005). Further, when "an analysis of the intrinsic evidence alone will resolve any ambiguity in a disputed claim term[,] . . . it is improper to rely on extrinsic evidence." Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1583 (Fed. Cir. 1996).

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