Patent Validity: U.S. Supreme Court Grants Microsoft's Petition for a Writ of Certiorari

The U.S. Supreme Court has granted Microsoft’s petition for a writ of certiorari seeking review of the stand of proof required to prove a patent invalid.  Under current U.S. law, invalidity of a patent must be proven by “clear and convincing” evidence.  The clear and convincing standard is a higher standard than the most commonly used standard in civil cases: “preponderance of the evidence,” which is often discussed as “more likely than not” or considered to require proof just beyond 50%.  Patent infringement, as opposed to invalidity, is determined by the “preponderance of the evidence” standard.  The “beyond a reasonable doubt” standard, used in criminal cases, is a higher standard than “clear and convincing” evidence, and “clear and convincing” is generally considered to be somewhere between “preponderance of the evidence” and “beyond a reasonable doubt.”