California
How Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. applies in California: state-specific rules, key cases, and bar exam notes for Patent Law.
California law adopts the principles established in Festo, particularly regarding the doctrine of equivalents. It emphasizes the flexibility of claim interpretation and how dependent claims can impact the scope of protection when amendments are made during prosecution.
In California, the doctrine of equivalents is applied in a manner consistent with the two-part Festo test, permitting the assertion of equivalents despite claim amendments unless the patentee has surrendered specific subject matter deliberately.
The court reinforced the Festo principles by stating that prosecution history estoppel restricts application of the doctrine of equivalents when an amendment was made to secure patentability.
This case clarified the burden on patentees to prove that the amendment was not made for the purpose of surrendering equivalents.
The court acknowledged the importance of the Festo standard in assessing whether a patentee had relinquished equivalent protections through amendments.
California's application of the Festo principles mirrors the federal approach in interpreting prosecution history estoppel and the doctrine of equivalents. However, California courts may occasionally emphasize informal discovery processes more than federal courts, which often rely strictly on formal prosecution history.
Festo and its implications on the doctrine of equivalents are notable topics on the California bar exam, especially within patent law sections.