Opinion ID: 211752
Heading Depth: 3
Heading Rank: 2

Heading: Waiver and Estoppel—Choice of Law

Text: 33 Because waiver and estoppel are the only available grounds on which to affirm the district court's construction, we first consider whether Ericsson waived, or is estopped from asserting, any of its claim construction arguments based on its actions before the district court. Waiver is a procedural issue, but if one views the issue more narrowly as waiver of a claim construction argument, rather than the more general waiver of an appellate argument, it seems indisputably unique to patent law. In our estimation, the narrower of these two views is more appropriate. This court does not appear to have addressed explicitly the choice of law issue presented here, but numerous Federal Circuit cases have discussed waiver of claim construction arguments, citing Federal Circuit law without so much as mentioning regional circuit law. See, e.g., Gaus v. Conair Corp., 363 F.3d 1284, 1287-88 (Fed.Cir.2004); Interactive Gift Express, Inc. v. Compuserve Inc., 256 F.3d at 1346, 1344-47 (Fed.Cir. 2001); Key Pharms. v. Hercon Labs. Corp., 161 F.3d 709, 714-16 (Fed.Cir.1998); Sage Prods., Inc. v. Devon Indus., 126 F.3d 1420, 1426 (Fed.Cir.1997). Also, we have held that waiver of claims and defenses in a settlement agreement, where the underlying substance of these arguments. . . is intimately related with the substance of enforcement of a patent right[,] is a matter of Federal Circuit law. Flex-Foot, Inc. v. CRP, Inc., 238 F.3d 1362, 1365 (Fed.Cir.2001). Because the ability to make claim construction arguments on appeal is intimately bound up with patent enforcement, we hold that Federal Circuit law controls waiver in the context of claim construction arguments.