The action came a month after the Tokyo District Court ordered Japanese firm Nichia Corp. to pay a record 20 billion yen to the inventor of the revolutionary blue light-emitting diode (LED).

The latest patent suit was filed with the same court by former Toshiba engineer Fujio Masuoka, now a professor at the Research Institute of Electrical Communication at Japan's Tohoku University.

He claims Toshiba Corp. has gained 20 billion yen on the transfer of the patent rights to flash memory which he helped develop in the 1980s.

The flash memory chip is used to store data and applications inside cell phones, industrial equipment and portable memory cards.

Masuoka's filing argues his contribution to the invention was worth four billion yen and he is seeking partial payment of his share.

Toshiba's public relations office had no immediate comment on the lawsuit.

"We are aware of news reports about the legal action but we cannot comment before seeing the petition."

In other recent lawsuits on patent rights, the Tokyo High Court ordered electronics giant Hitachi Ltd. to pay 162 million yen to a former employee for the transfer of patent rights related to optical disc technologies, such as

On February 24, the court ordered seasoning maker Ajinomoto Co. to pay 189 million yen to a former worker for the transfer of patents on a production method for an artificial sweetener.

SPACE.WIRE