ArcelorMittal France v. AK Steel Corporation, No. 14-1189 (Fed. Cir. May 12, 2015)

From the Opinion

The passage below is extracted verbatim from the opening of the document. It has not been editorially summarized — consult the full opinion for the court's complete reasoning.

ArcelorMittal appeals from the decisions of the United States District Court for the District of Delaware granting summary judgment that U.S. Patent No. RE44,153E (the RE153 patent) is invalid because certain claims were broadened a fter two years of issuance in violation of 35 U.S.C. § 251.1 Because the district court was bound by our construction of the original claims and the reissue claims broadened that construction, we affirm the district court’s finding that claims 1 through 23 of the RE153 patent are invalid under § 251.