O2 Micro Int’l Ltd. v. Beyond Innovation Tech. Co.
521 F.3d 1351 (Fed. Cir. 2008)
The Federal Circuit held that even where a claim term has an allegedly “well-understood definition,” if the parties dispute the term’s meaning or scope when used in the context of the patent, the court maintains a duty to resolve the dispute. In O2, the parties disputed the scope of the term “only if,” but the district court concluded that the term needs no construction because it had a “well-understood definition.” According to the Federal Circuit, however, the district court overlooked the fact that the parties disputed the scope of the term rather than the meaning of the words themselves. Therefore, the district court should have resolved the dispute before instructing the jury on its meaning.