Managing IP Quotes Ali Razai on U.S., China and European Approaches to Patent Litigation Estoppel

| Ali S. Razai

Knobbe Martens partner Ali Razai‘s participation in a panel at the recent 2022 AIPPI World Congress was covered by Managing IP. The article, “AIPPI 2022: Beware of estoppel when amending claims,” covered a session Razai participated in, which explored how the U.S., China and European countries approach prosecution history estoppel as a way to limit the application of the doctrine of equivalents during patent litigation.

Razai is quoted in the article as saying that in the United States, the intent of the patent owner is not relevant when determining prosecution history estoppel. He noted that instead, courts consider “whether competitors looking at the prosecution history would believe patent owners had given up certain materials.”

Razai is also quoted discussing the two ways to create prosecution history estoppel in the U.S. “Claim amendments are one,” he said. “If an applicant narrowed a claim after the USPTO said the scope was too broad, it couldn’t then use the doctrine of equivalents to assert the patent under the given-up scope,” he said. The other factor is argument-based estoppel, but only based on arguments made during U.S. prosecution. “Applicants’ prosecution histories in other jurisdictions wouldn’t lead to estoppel in the U.S.,” said Razai. But he pointed out that judges would likely be aware of the evidence, which could shape their views of cases. “Judges are human,” he said.

Read the full article here