US Supreme Court Refuses to Modify ‘Clear and Convincing’ Standard of Proof for Validity Challenges

June 13, 2011
The U.S. Supreme Court issued its much-anticipated decision in Microsoft Corp. v. i4i Limited Partnership and affirmed, without hesitation, that patent invalidity must be proven by clear and convincing evidence. Still, the Supreme Court’s seemingly straight-forward opinion invited patent challengers to request—and for lower courts to “most often” grant—jury instructions on the effect of new evidence not previously before the Patent Office. This practice may potentially weaken the presumption of validity for a patent.