In asserting patent invalidity as a defense to an infringement action, an alleged infringer must contend with §282 of the Patent Act of 1952 (Act), under which “[a] patent shall be presumed valid” and “[t]he burden of establishing invalidity… shall rest on the party asserting” it. Since 1984, the Federal Circuit has read §282 to require a defendant seeking to overcome the presumption to persuade the factfinder of its invalidity defense by clear and convincing evidence.
Respondents (collectively, i4i) hold the patent at issue, which claims an improved method for editing computer documents. After i4i sued petitioner Microsoft Corp. for willful infringement of that patent, Microsoft counterclaimed and sought a declaration that the patent was invalid under §102(b)’s on-sale bar, which precludes patent protection for any “invention” that was “on sale in this country” more than one year prior to the filing of a patent application. The parties agreed that, more than a year before filing its patent application, i4i had sold a software program known as S4 in the United States, but they disagreed over whether that software embodied the invention claimed in i4i’s patent. Relying on the undisputed fact that the S4 software was never presented to the Patent and Trademark Office (PTO) during its examination of the patent application, Microsoft objected to i4i’s proposed jury instruction that the invalidity defense must be proved by clear and convincing evidence. The District Court nevertheless gave that instruction, rejecting Microsoft’s alternative instruction proposing a preponderance of the evidence standard. The jury found that Microsoft willfully infringed the i4i patent and had failed to prove the patent’s invalidity. The Federal Circuit affirmed, relying on its settled interpretation of §282.
