By: Mel R. Quintos
This issue of our IP Newsletter outlines three recent cases of the Court of Appeals for the Federal Circuit (C.A.F.C.), and the reasons given by the court in interpreting patent claim language under the doctrine of equivalents.
- Lucent Technologies, Inc. v. Gateway, Inc. (decided May 8, 2008). The claim language at issue in one of the patents (U.S. Patent No. 4,701,954) is the step of forming N pulses “for each successive time frame … by iteratively forming a sequence of pulses for said time frame, … each successive iteration including the steps of [steps 1-5].” The issue is whether each pulse is formed by: (1) performing each of steps 1-5, or (2) performing only step 5 and relying on the results of past steps 1-
In interpreting the claim language, the C.A.F.C. looked into the claim itself, and held that steps 1-5 must each be performed in forming each pulse because “[t]his court has consistently interpreted ‘including’ and ‘comprising’ to [mean] that the listed elements (i.e., method steps) are essential but other elements may be added.”