In March 2002, the Federal Circuit sitting en banc decided the issue of “whether and under what circumstances a patentee can rely upon the doctrine of equivalents with respect to unclaimed subject matter disclosed in the specification.”
The Court decided 11-1, with four concurring opinions, that information disclosed in the specification, but not claimed could not be covered by the doctrine of equivalents. The Federal Circuit conceded at least one of its previous cases had been overruled, and the dissent argued the decision was inconsistent with binding U.S. Supreme Court precedent.
