Zenon Envtl., Inc. v. US Filter Corp.

United States Filter Corp. (“US Filter”) appeals from the final judgment of the United States District Court for the Southern District of California, following a bench trial, that the asserted claims of U.S. Patent 6,620,319 (“the ’319 patent”) are not invalid as anticipated under 35 U.S.C. § 102. Zenon Environmental, Inc. (“Zenon”) cross-appeals the district court’s grant of summary judgment that the accused products do not infringe the ’319 patent. Because we conclude that the district court erred in determining that the ’319 patent was entitled to the priority date of an earlier filed patent, and thus clearly erred in concluding that the ’319 patent was not anticipated by that patent, we reverse the court’s judgment of no invalidity and hold that patent to be invalid. In light of that conclusion, we need not reach Zenon’s cross-appeal seeking reversal of the district court’s grant of summary judgment of noninfringement.

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