| 摘要 |
PURPOSE:To reduce a space for the provision of an optical system, to miniatur ize it and to reduce the number of its assembling processes by selectively switching outputs from first and second arithmetic means and gaining a reproduc ing signal. CONSTITUTION:The data Do of a laser output is stored in the fixed data storing area of a ROM 55 in accordance with the kind of a disk 1 being used, the kind of the disk l is identified by a system controller 34 based on detecting signals Sx and Sy from detecting switches 53 and 54 and the laser output Do corresponding to its kind is read out. This data Do is transformed into an analog laser output signal So in the process by a D/A converter 60 and supplied to the laser driving circuit of a laser light source 71. The bias voltage of a laser driving circuit 31 is set at a voltage level corresponding to the laser output signal So, a driving current (i) corresponding to its set bias voltage is conducted to the laser light source 71 and an optical beam having an output corresponding to it is emitted. |
