In recent years, one of the reasons for the ballooning cost of patent litigation is defense claims that patent holders deceived the Patent and Trademark Office, and so their patents are invalid because of inequitable conduct. On Tuesday the appeals court said enough is enough and raised the bar for misconduct allegations.

All of a sudden, everything's coming up Rambus in its long-running litigation against the chip industry. But Nvidia says it will keep on fighting.

In a first-of-its-kind mandamus decision issued Friday, the Federal Circuit ruled that a Delaware federal district court judge couldn't refuse to transfer a patent suit against a Silicon Valley company to California just because the defendant is incorporated in Delaware.