Bold Declarations in Specification can Limit Claims

In a rare win for Blackberry-maker Research in Motion, the U.S. Court of Appeals for the Federal Circuit, affirming the district court, disavowed the doctrine of claim differentiation in favor of a "very important" claim limitation in the specification. Inpro Licensing, S.A.R.L. v. T-Mobile USA, Inc., Research in Motion Limited and Research in Motion Corporation (collectively "RIM"), Case No. 05-1233 (Fed. Cir. May 11, 2006) (Newman, C.J.).

Inpro accused RIM of infringing its patent for a credit-card-sized personal digital assistant that communicates with a host computer. Inpro appealed the district court’s interpretation of three claim terms, including the term "host interface." The district court had interpreted "host interface" as "a direct parallel bus interface." Inpro conceded that if the district court’s interpretation of "host interface" was correct, infringement would not lie.