Inter partes review
A US Patent Office procedure that lets anyone challenge an issued patent without going to court.
IPR arrived with the America Invents Act and has been available since September 2012. A challenger files a petition with the Patent Trial and Appeal Board (PTAB), citing printed prior art – earlier patents and publications – to show the invention was not new or was obvious. If the board institutes a trial, it must reach a final decision within a year.
Two differences from litigation make it dangerous for weak patents. The burden of proof is a preponderance of the evidence rather than clear and convincing evidence, and the deciders are technically trained patent judges, not a jury. Claims fell at such a rate that a former chief judge of the Federal Circuit called the board's panels "death squads". The Supreme Court upheld the scheme in Oil States (2018). For anyone sued by a patent troll, an IPR petition is often the cheapest counterpunch available.