Intellectual Property Law

Federal Circuit clarifies burdens of proof when priority to earlier application is contested

By McKee, Voorhees & Sease, P.L.C.

In a recent decision, the Federal Circuit affirmed a district court's determination that the asserted claims of a patent were not entitled to the effective filing date of the earliest application in a chain of four applications, and that as a result the claims were anticipated by intervening prior art.  The court explained its recent decision in PowerOasis, where the court seemed to put the burden of proof on the patentee when the issue was entitlement to an earlier effective priority date.  Rejecting this interpretation, the court stated:

Carefully read, however, PowerOasis says nothing more than, and should be understood to say, that once a challenger (the alleged infringer) has introduced sufficient evidence to put at issue whether there is prior art alleged to anticipate the claims being asserted, prior art that is dated earlier than the apparent effective date of the asserted patent claim, the patentee has the burden of going forward with evidence and argument to the contrary. As we noted earlier, it is a long-standing rule of patent law that, because an issued patent is by statute presumed valid, a challenger has the burden of persuasion to show by clear and convincing evidence that the contrary is true. That ultimate burden never shifts, however much the burden of going forward may jump from one party to another as the issues in the case are raised and developed.

This should eliminate much of the speculation and commentary regarding the burden of proof on validity issues that had appeared after the PowerOasis decision.

More detail of Tech. Licensing Corp. v. Videotek, Inc. after the jump.

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Full post as published by FileWrapper on November 11, 2008 (boomark / email).