The U.S. International Trade Commission (ITC) has announced that it is looking into possible patent infringement claims related to Blu-ray disc players and other similar products. The investigation is based on a complaint filed in February by Professor Emeritus Gertrude Neumark Rothschild of Columbia University, who is seeking to block imports into the U.S. of products that Rothschild claims are infringing her original patent.

The ITC is investigating 30 companies, including Sony Corporation, Hitachi, Toshiba, Samsung Group, Pioneer, Motorola, Sharp, Nokia, LG Electronics and Panasonic manufacturer, Matsushita. The ITC indicated that the products involved are short-wavelength, light-emitting diodes and laser diodes used in such electronics as handheld mobile devices, traffic lights and high-definition DVD players.

The diodes are used in products such as Motorola Razr mobile phones and Hitachi camcorders, and Sony’s Blu-ray disc player. Rothschild is the sole owner of the patent and conducted research in the 1980s and 1990s into the electrical and optical properties of so-called wide band-gap semiconductors that was key in the development of short-wavelength emitting (blue and violet) diodes.  Rothschild’s patent was issued by the U.S. Patent and Trademark Office in 1993.

Sony indicated that it had no comment because the investigation is ongoing.