For over a century, the U.S. patent system has held a presumption of patent validity, based largely on the belief in the quality of the U.S. Patent Office examination system. There are several appellate processes to assert patent invalidity, including the patent reexam process, the federal district courts and the Court of Appeals for the Federal Circuit. Because of the presumption of validity in a patent, a standard that has been held since the time of the Civil War, and because of the adversarial nature of litigation, the bar for challenging patents in the courts has been to provide “clear and convincing” evidence. This standard has provided consistency in the U.S. patent system.
A group of patent critics, however, has argued that the bar to show patent invalidity with the “clear and convincing” standard is too high. This group, led by technology industry incumbents, has argued that the “preponderance of evidence” standard should be applied in the courts to invalidate patents, particularly if evidence is introduced after the Patent Office examination process.
The present essay critiques the view of the patent critics and argues that the “clear and convincing” standard evolved from a coherent and consistent patent jurisprudence that is important to maintain a healthy functioning patent system. The Patent Act of 1952 maintains that patents have a presumption of validity. The case law from 1874 to the present is consistent on this issue of requiring a higher bar to attack patents. Lowering the burden of proof to challenge patent validity would bias the patent system to the infringer and challenge the presumption of validity. This would have the effect of devaluing patents and harming incentives to innovate.
The argument is made that the infringer should have a duty to obtain an “opinion of counsel” to justify an assertion of patent invalidity. In the absence of such a requirement, the infringer has no good faith belief that the patent is invalid and, in fact, no defense from the assertion that the patent is not willfully infringed.
The adverse consequences of maintaining a lower standard of proof in patent validity cases are substantial, with infringers and Asian manufacturers as beneficiaries and pharmaceutical companies, universities, market entrants and innovators adversely affected. In combination with a set of recent judicial opinions unfavorable to patent holders, lowering the bar for asserting patent invalidity would provide a sea change in patent law that may hurt the U.S. economy.