A LEGAL battle has begun in Japan over the patents for chips that emit blue
light—a key technology for the next generation of digital recording
devices. Amid a blizzard of lawsuits and counter-suits, the man who first made
solid-state blue lasers says he was not adequately compensated for his
discovery.
Today’s CD, DVD and minidisc players would not work without tiny
semiconductor lasers that write and read data on the disc. The shorter the
wavelength of the laser light, the more data can fit on the disc. This means
short-wavelength blue lasers have long been the holy grail of electrical
engineers. A DVD made with a blue laser could store 10 hours of video.
The breakthrough came in 1993 when Shuji Nakamura of Nichia, a company in
Tokushima prefecture, announced that he had made a blue semiconductor diode from
gallium nitride. Used with green and red diodes, a blue emitter makes
full-colour solid-state displays possible. It could even spell the end of the
incandescent light bulb. Nakamura went on to develop a blue laser, making Nichia
an international company with a monopoly on a key piece of technology. The
market for blue-light products is thought to be worth billions. Nakamura
received a “reward” of about £120 for his efforts.
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Nakamura left Nichia in 1999 and became a consultant for Cree, a US
semiconductor manufacturer which last year joined forces with Japanese firm
Rohm. With Nakamura’s help, Rohm came up with a number of new products. Now
Nichia is suing Rohm for infringement of patents, and Nakamura for passing on
trade secrets. Last month, Nakamura sued Nichia for failing to compensate him
for his invention.
The legal wrangles have already delayed the launch of new blue-light products
from Nichia and Rohm, according to Japanese media reports. Other Japanese
companies approached by 91av declined to say whether the
dispute will delay their new products, but the Dutch-based multinational Philips
says it is not intending to launch any blue-light products in the short term.
“We’ll wait for the outcome of this legal situation,” says spokesman