| 摘要 |
PURPOSE:To prevent the destruction of information recorded in the optical recording medium by providing a second control means to stop the action of a first control means when the trouble of the first control means to control the optical output of an optical beam is detected. CONSTITUTION:Various failures of an optical output control circuit 15 are detected by a trouble detecting circuit 16, and when an abnormality is detected, a trouble detecting signal S4 is supplied to a relay circuit 17. The relay circuit 17 interrupts a voltage source E supplied only to a semiconductor laser oscillator 6, a photo diode 12 and the optical output control circuit 15 independent from other circuit out of a voltage source E0 supplied from the power source device, based on a trouble detecting signal S4. Thus, the light emission of a semiconductor laser 6 is stopped and it can be prevented that the information on the optical disk is destructed by the abnormal light emission of the semiconductor laser due to the trouble. |
