| 摘要 |
PURPOSE:To simultaneously detect the relative dislocation and the inclination of an optical axis and an actuator part, and also, to execute the position detection of the actuator part without being influenced by a stray light, by splitting a laser beam, and making one light beam pulsative, in an actuator separating system. CONSTITUTION:A light beam of a semiconductor laser 31 is split into two beams by a beam splitter 32. A split light beam 34 is reflected by an optical disk through a beam splitter 33, and made incident on a bi-sected photodetector 6 through the splitter 33 again. On the other hand, the light 35 passes through a shutter 41 opened and closed by a signal from a shutter opening/closing pulse generator 40, brought to a pulsative luminous flux and made incident on a half mirror 36. Subsequently, said light is made incident on bi-sected photodetectors 37 and 38, the relative dislocation and the inclination of an optical axis 35 and an actuator part 13 are detected, and also, by a detecting output at the time when the shutter 41 is closed, the influence of a stray light can be eliminated. |
