| 摘要 |
PURPOSE:To satisfactorily reproduce a disk in a high recording density disk having a narrow track pitch by mounting three semiconductor laser chips so that the direction of each laser output is same for each inside surface of both wall parts and an inside surface of a bottom part of a heat sink. CONSTITUTION:Three semiconductor laser chips 1-3 are mounted to a heat sink 4 consisting of a bottom part 41 and two wall parts 42, 43 provided vertically from the bottom part. Then, a chip 1 is mounted to the inside surface of the bottom part 41 of the heat sink 4, also, laser chips 2, 3 are mounted to the inside surfaces of the wall parts 42, 43 of the heat sink 4 respectively. Thereby, beam cross sections of laser beams LB2, LB3 emitted from each end surface of chips 2, 3 are in a direction perpendicular to each other. Therefore, the direction of a major axis of the laser beam LB1 can be made in the orthogonal direction to a track, and the directions of major axes of the laser beams LB2, LB3 can be made same as the track direction. |
