CAFC: Operability of 102(g) prior invention

z4 Technologies v. Microsoft Corp. (Fed. Cir. 2007)

z4 was one of the first plaintiffs to test the revived notion that an injunction for patent infringement is a form of equitable relief.  After a jury verdict of infringement, the E.D. Texas court awarded over $100M in damages, but refused to enter a permanent injunction to stop infringement of z4’s anti software piracy patent.

Microsoft appealed (z4 did not appeal the denial of injunctive relief).

Prior Invention: Although rarely invoked, 35 USC 102(g) embodies the heart of the American first-to-invent system. 102(g) allows a small category of secret activities to serve as invalidating prior art when another party shows that it was the first to conceive of an invention and then ‘exercised reasonable diligence’ in reducing to practice. 

Microsoft argued on appeal that its “BP 98” software was invented first. According to the appellate panel, Microsoft’s claim fails because the BP 98 software did not actually work. (Or at least that such evidence was sufficient for the jury verdict).

Decision affirmed.