Lack of Knowledge That A Patent Is Valid Is NOT A Defense To Patent Infringement

The U.S. Supreme Court ruled today, in a case of first impression, that a purported infringer's lack of knowledge that a patent is valid is not a defense to an induced infringement claim. In today's case of Commil USA v. Cisco Systems, the Supreme Court pointed out that an issued patent is presumed to be valid, and that a claim for infringement of an issued patent is a strict liability claim. As such, whether or not an infringer believes that the issued patent is invalid, the good faith believe in invalidity is not a defense. And the defendant infringer cannot introduce evidence of good faith belief of invalidity.