On remand from the Supreme Court following its opinion in Teva Pharmaceuticals, the court affirmed all of the appealed claim constructions.  As to the construction for the term “voltage source means,” the district court, based on the expert’s and the inventor’s testimony, held that persons of ordinary skill in the art would have understood that the only possible structure that could have been described by the claim was a rectifier.  The Federal Circuit deferred to the district factual finding, based on extrinsic evidence, as it was not clearly erroneous.  In a tangential issue, regarding whether the defendant had waived its challenges to the claim constructions and the issue of invalidity for indefiniteness by raising them unsuccessfully in a summary judgment motion, but not at trial, the Court held that, for legal issues and issues decided only by the court and not a jury, such as claim construction and indefiniteness, there was no waiver, because the denial of summary judgment was not a finding that genuine issues of material exist, but rather a legal conclusion that the claims were not invalid or that a term has a certain construction.

Lighting Ballast Control LLC v. Philips Electronics North America Corporation, Case No. 2014-1014 (June 23, 2015); Opinion by: Reyna, joined by O’Malley and Lourie; Appealed From: District Court for the Northern District of Texas, O’Connor, J.  Read the full opinion here.

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