plans to start mass production of blue lasers for data replay devices such as DVD players, in April 2003.

Blue laserbeams have shorter wavelengths than red or infrared laserbeams, which are used in conventional CD and DVD players. The shorter the wavelength of light, the smaller the spot the laserbeam makes on the disc. Blue lasers will allow approximately five to six times as much data to be stored on and read from a disc.

The company has already developed a 405-nanometer wavelength blue laser. Its blue laser is based on a gallium nitride substrate, which means the optical noise created by a device can be decreased.

"The blue laser technology is a must, in order to develop DVDs that can be replayed or record more data," said Akihiko Ohiwa, a Sanyo spokesman.

The ability of vendors to develop electronics products based on blue lasers is hampered by patents held in the field by Nichia, which developed the first blue laser diodes, and is now engaged in a series of lawsuits over intellectual property rights in this field.

"Because those patents are not open, each vendor needs to develop its own technology," Ohiwa said.

Sanyo is planning to produce between one and two millon units a month.