Court rules in favor of Monolithic Power Systems in O2 Micro patent case

By Colleen Taylor, Contributing Editor -- Electronic News, 11/1/2007

Fabless semiconductor maker Monolithic Power Systems Inc. (MPS) announced late Wednesday that the U.S. District Court for the Northern District of California issued a final judgment and rulings that all of the patent claims asserted by O2 Micro International Ltd. against MPS and MPS's customer ASUSTeK Computer are invalid.

The court's ruling affirms a jury verdict entered on May 16, which found that none of the accused MPS CCFL inverter controllers literally infringes O2 Micro's patent No. 6,396,722 (the '722 patent). While two patent claims, number 12 and number 14, were found to infringe under the "doctrine of equivalents," the jury also found all asserted claims -- including claim 12 and 14 -- to be invalid.

The battle may not be over yet, however: MPS said it expects that O2 Micro may appeal the case to the U.S. Court of Appeals for the Federal Circuit.

This court case did not mark the first time the two companies have sparred over a patent. In 2005, a court in Northern California ruled in MPS' favor in a patent case and found that MPS did not infringe O2 Micro's '615 patent. The judge also denied O2 Micro's requests for an injunction and attorneys' fees and ruled that Monolithic did not act improperly in obtaining its patents.