10.4 Patent invalidity
Until 1980, U.S. district courts were the only institutions authorized to invalidate patents. They continue to play a central role in determining patent invalidity (see Section 10.5.3.1). In 1980, Congress augmented district court authority to review patents through patent reexamination at the USPTO (see Section 10.2.2.2). This process, however, proved cumbersome and slow, and hence was rarely used. The AIA established IPR, a robust and commonly used mechanism to challenge patent validity (see Section 10.2.2.4).