| 摘要 |
<P>PROBLEM TO BE SOLVED: To precisely control the output of a semiconductor laser chip by efficiently using the light outputted by the laser chip. <P>SOLUTION: The optical pickup device 20 includes a light source 21, a photosensor 22, a light condenser 23, and a control 24. On the photosensor 22, the light condenser 23 condenses the light outputted by the light source 21 but not used for recording or reproduction. Since the photosensor 22 can receive both the light directly outputted by the light source 21 but not used for information recording or reproduction and the light condensed by the condenser 23, the amount of the light is increased to control the output light, and the control precision can be improved. Further, the efficiency can be improved for the light by using the light outputted by the light source 21 but not used for information recording or reproduction for the purpose of controlling the light amount without reducing the amount of the unused light. <P>COPYRIGHT: (C)2004,JPO |
