Washington
How Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. applies in Washington: state-specific rules, key cases, and bar exam notes for Patent Law.
Washington courts generally apply the doctrine of equivalents following Festo's principles, particularly focusing on the prosecution history and amendments during patent prosecution. The state emphasizes a balance between protecting patent rights and preventing unwarranted difficulties due to amendments.
In Washington, the doctrine of equivalents is limited by prosecution history estoppel, as shaped by Festo, which prohibits a patentee from recapturing subject matter surrendered during prosecution.
Held that arguments made during patent prosecution can limit the doctrine of equivalents, consistent with Festo's prosecution history estoppel.
Affirmed that amendments made for patentability may restrict the patentee’s ability to claim equivalent structures.
Reiterated that estoppel applies to prevent recapturing surrendered claims unless the patentee can show unforeseen circumstances.
Washington law aligns closely with the federal standard regarding prosecution history estoppel as dictated by Festo, adhering to the notion that claim amendments should be scrutinized carefully. Nevertheless, Washington courts may emphasize specific contextual factors present in local cases.
Understanding the impact of prosecution history and the doctrine of equivalents in Washington is critical for the patent law section of the Washington bar exam.