| 摘要 |
PURPOSE:To prevent the offset of a returned light and a stray light by constituting a device so that the optical axis of a semiconductor laser is set oblique against the inclined surface of a prism, and a detector to detect the returned light from a disk is deviated from the prolongation line of the optical axis of the laser. CONSTITUTION:A laser light from the semiconductor laser 4 is made incident obliquely on the inclined surface 6 of the prism 5, and is reflected at the same angle, and is made incident on an optical disk, and the returned light comes incident obliquely to the inclined surface 6, and is received by the photodetector 2, installed obliquely against the inclined surface 6. Because the stray light, made incident in the inclined surface 6 at the beginning, is not received by the detector 2, and passes over, it can be prevented from offsetting the returned light from the disk. |
