IT’S an invention worth billions of dollars. But with the blue light-emitting diode already more than 10 years old, the row over who deserves the credit rumbles on. Last week, the company at the centre of the controversy told its side of the story.
Light-emitting diodes were invented in the 1960s, when it was found that semiconductors could be made to emit visible light. Green and red LEDs quickly became common, but it wasn’t until 1993 that the first blue LED was created by Nichia of Japan.
With the three primary colours now available, this opened the way to full-colour displays, solid-state white light, as well as blue lasers writing to high-capacity recordable DVDs. The market for all types of LED is estimated to be worth $6 billion a year.
Advertisement
In 1999, however, Nichia employee Shuji Nakamura suddenly quit the company, after long claiming he had single-handedly invented the blue LED. Nakamura, who is now a researcher at the University of California in Santa Barbara, sued the firm for compensation, claiming to have received just $200 for his work on the invention.
In January 2004, the Tokyo District Court calculated Nichia will have made $1.2 billion profit from the invention by 2010 and awarded Nakamura the $190 million he had asked for. But Nichia successfully appealed the case, and this January the Tokyo High Court found the firm was responsible for 95 per cent of the original invention. The court forced a compromise that ended when Nakamura reluctantly accepted only $7.6 million. Now the company has revealed details of its case, at a press conference on 11 May.
Nichia argued that the original patents Nakamura worked on were virtually obsolete and are no longer used by Nichia or the four companies to which it licenses its blue-LED technology. It also argued that Nakamura did not work alone on the LED project, and was receiving a salary of $190,000 when he quit at age 45, as well as $150,000 from stock options.
Nichia said it equipped the lab Nakamura used and had sent him to Florida for training in metal organic chemical vapour deposition, a key production technology that makes gallium nitride blue LEDs possible – and which was recommended by an adviser to Nichia, not Nakamura. Nichia also said it bore all the risk in developing and commercialising the technology.
