| 摘要 |
PURPOSE:To ensure the proper value of a low level of laser light at write mode by providing a drive circuit making the low level of a modulation current of a laser diode proper. CONSTITUTION:A control circuit 19 at write mode, based on a signal detected by an ID information detection circuit 18, supplies an information signal 101 supplied from an input terminal 113, an operation signal 102 and a control signal 103 at a desired address to drive circuits 10, 11, a sample-and-holding circuit 8 and a gain switching circuit 13. On the other hand, while the signal 101 is sent, the circuit 10 controls to flow a modulation current 105 obtaining a prescribed lighting power to a laser diode 1. Then the circuit 11 controls that the current 106 adding a prescribed value to the current 105 in response to the signal 102 flows to the diode 1. Thus, the low level of the laser light modulated by recording information is ensured properly and proper write is executed. |
