In a previous post, I wrote about the U.S. International Trade Commission’s (ITC) investigation of six companies based in China and Taiwan, prompted by a complaint by retired Columbia University Professor and LED innovator Gertrude Neumark Rothschild.Â In the complaint, Rothschild asserted infringement of U.S. Patent No. 5,252,499Â (‘499 patent) relating to LED manufacturing methods.
The Notice of Investigation named Chi Mei Lighting Technology Corp., Tekcore Co. Ltd., Toyolite Technologies Corp., Tyntek Corp., Visual Photonics Epitaxy Co. and Xiamen Sanan Optoelectronics Technology (“Xiamen”).
The ITC recently let the investigation against Xiamen come to end when it ruled that it would not review the decision of an adminstrative law judge (ALJ) to end the investigation (xiamen_order.pdf).Â Â The ALJ’s decision followed Xiamen’s request to terminate the investigation in view ofÂ a proposed consent order.
In the consent order, Xiamen, without admitting infringement or validity of the ‘499 patent,Â agreed not to import LED and laser diode chips that allegedly infringe the ‘499 patent.Â The consent order also provided that it would be nullified if the ‘499 patent were to be held invalid or unenforceable in a final decision by any administrative or judicial body.
TheÂ ‘499 patentÂ is directed toÂ methods of making LEDs capable of emitting short wavelength (green or blue) light.Â TheÂ patent addresses the problem of “doping” wide band gap semiconductor materials, an essential step in creating adequate conductance for the materials to function as LEDs.Â Doping means adding impurities to a semiconductor to increase the number of free charge carriers.
Rothschild has aggressively asserted the ‘499 patent and U.S. Patent No. 4,904,618Â in recent years.Â Last year Rothschild filed a complaint in the ITC naming more than 25 respondents, including electronics giants Hitachi, LG, Matsushita, Motorola, Nokia, Samsung, Sony and Toshiba.Â Â At least eightÂ companies have taken licenses to her patents.