| 摘要 |
PURPOSE:To ensure the recording and reproduction of information by supplying an idling current to the degree not lighting the light source to the light source subjected to light control at the recording and reproduction of a recording medium so as to stabilize the lighting output of the light source. CONSTITUTION:Supplying power source, a contact 38a of a switch circuit 38 is thrown to the position of a fixed contact 38c and a transistor (TR) 33 is turned on. Then an idling current to a degree not stimulating the semiconductor laser 9 is supplied and the time during the initial setting of the device is used to stabilize the light emitting output. In reproducing the information recorded onto an optical disk, the TR 34 is turned on by a reproduction control circuit 35 and the semiconductor laser 9 is stimulated by the reproduced output. The laser beam generated from the laser 9 is radiated onto the optical disk, the recording information is reproduced and detected by a photodetector PD. The circuit 35 operates the TR 34 in response to the detection output of the photodetector PD to control that the stimulated light of the laser 9 is made constant. |
