| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the size and cost of an optical pickup device for recording, reproducing or erasing information to or from two kinds of optical information media varying in track pitches. <P>SOLUTION: The optical pickup device is provided with a two-wavelength semiconductor laser device 1 which is formed with a semiconductor laser chip to generate a light beam of a wavelength λ1 and a semiconductor laser chip to generate a light beam of a wavelength λ2 made into one chip or is arranged with these chips in proximity to each other, and a diffraction grating 2 which has one diffraction period Λ to branch the light beam of the wavelength λ1 or the light beam of the wavelength λ2 generated by the two-wavelength semiconductor laser device 1 to the main beam and the sub-beam. The device is so formed that the optical information media varying in the track pitches are subjected to recording or reproducing of the information and the tracking control accompanying the same. <P>COPYRIGHT: (C)2004,JPO |
