Patents, Copyrights and Trademarks -- 2011



Microsoft Corp. v. i4i Ltd. Partnership   (U.S. Supreme Court)

How much evidence is required to invalidate a patent?

Most civil cases require a plaintiff to prove a claim by a preponderance of the evidence, that is, where the evidence shows the claim is more likely than not to be valid. In patent cases, the Federal Circuit has adopted a "clear and convincing evidence" requirement, a higher standard of proof making challenges to the validity of a patent somewhat more difficult. The Supreme Court agreed, finding that Congress prescribed the governing standard of proof. A patent that is "presumed valid" under the statute requires clear and convincing evidence that it is not valid in an infringement action.

The case involved a challenge by Microsoft of a patent award for $290 million in a case involving its popular Word program.