| 摘要 |
PURPOSE:To facilitate the position alignment of each laser spot with high accuracy by providing one set of light emitting elements producing plural light emitting points on a semiconductor substrate, plural light guide use optical components corresponding to them and a required number of photodetectors. CONSTITUTION:Laser beams L1, L2 outputted from a semiconductor laser 12 in forward and reverse directions are led to objective lenses OL1, OL2 from half mirrors 14a, 14b respectively and form a multi-spot on a disk D. Moreover, the reflected light is made incident on photodetectors 15a - 15d via the half mirrors 14a, 14b and detected as a reproduction signal and a servo signal. Thus, it is possible to read the reproduction signal by using the laser beam L1 and to read servo information by using the other laser beam L2, and the position setting of the mutual beam spots is attained with high accuracy. |
