Mark Selwyn, left, and Robert Greenspoon, right. Courtesy photos

The tech industry's court challenge to USPTO rules governing America Invents Act proceedings began ramping up Thursday before U.S. District Judge Edward Davila of the Northern District of California.

Davila presided over a two-hour-and-20-minute hearing into whether US Inventor and a group of patent owners could intervene in the case to present its own challenge to the rules.