Sony, Nokia face US investigation

Sony Corp and Nokia Oyj are among 30 firms named in an inquiry by the United States International Trade Commission into allegations they violated a patent for technology used in electronics such as Blu-ray DVD players.

The investigation is based on a complaint filed by Gertrude Neumark Rothschild that seeks to block US imports of products she says infringe her patent for light-emitting diodes and laser diodes, according to a statement on Thursday on the commission Website.

Rothschild, a retired Columbia University professor, filed her complaint on February 20, Bloomberg News reported.

Rothschild made a "seminal breakthrough" in the production of blue, ultraviolet and white light, her lawyer Albert Jacobs of Dreier LLP said in New York last month. Blue and ultraviolet LEDs, which use less electricity than red LEDs, are used in computers, traffic lights, instrument panels and as the background color for mobile-phone screens.

The ITC is a federal agency that aims to protect the market from unfair trade practices, including patent infringement.