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U.S. Supreme Court Affirms the Rule That Patent Infringers Must Prove Invalidity Defense by Clear and Convincing Evidence

On June 14, 2011 by Schnader

The Supreme Court recently affirmed the long-standing rule that, in asserting patent invalidity under 35 U.S.C. § 282 as a defense to an infringement action, an alleged infringer must prove the patent invalid by clear and convincing evidence. This result was good news for patent owners, who faced the possibility that the Court would reduce the standard of proof for invalidating a patent. But there was good news for alleged infringers as well: in affirming the existing standard of proof, the Court stated its approval of a jury instruction that may make some patents easier to invalidate. This Alert discusses the recent decision.