LED maker Seoul Semiconductor Co Ltd. of Seoul, Korea, announced yesterday it has filed a unfair trade practices complaint with the US International Trade Commission (ITC) against rival Nichia Corp. of Tokyo, alleging that the company imported and sold gallium nitride (GaN) -based laser diode products that infringe Seoul Semiconductor's US Patent No. 5,321,713 ('713 patent). Seoul Semiconductor said it has invested more than $10 million in research and development of laser diode and LED related technologies by US-based universities and companies and as a result obtained rights to numerous patents. Seoul Semiconductor's US Patent No. 5,075,742 ('742) is also asserted in another pending lawsuit against Nichia for patent infringement through its sale of LEDs. That case was filed Nov. 6 and is pending in the US District Court for the Eastern District of Texas, Seoul Semiconductor said. The '742 patent covers technologies related to white, blue, green and ultraviolet LEDs and laser diodes. Seoul Semiconductor said it expects the ITC's investigation of Nichia will begin in January and the case will go to trial in the fall of 2008.