Patent Case Watch

Patent opinions from the Eastern District of Texas and the U.S. Court of Appeals for the Federal Circuit

Weekly Digest

Prosecution History Estoppel

Prosecution history estoppel prevents a patentee from recapturing through the doctrine of equivalents subject matter that was surrendered to obtain the patent. A narrowing amendment made for a reason related to patentability raises a presumption that everything between the original and amended claim was given up, and the patentee may rebut it only in narrow circumstances - for example where the equivalent was unforeseeable at the time. Argument-based estoppel arises from statements made to distinguish prior art even without an amendment. The opinions collected here address what was surrendered, whether the presumption applies, and the interaction between the prosecution record and an equivalents theory.

52 opinions and orders.