| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that conventionally an optical pickup device is prevented from gaining a small size and low cost, because of a large number of parts and adjustments, for installing independent photodetectors for a light beam to enter from each light-emitting part, in an optical pickup device having a plurality of light-emitting parts. SOLUTION: The device is equipped with semiconductor lasers 10a, 10b, an optical system for converging light from these lasers 10a, 10b to an optical disk 106, and a photodetector 109 that has photodetecting units 12a-12f and detects light beams reflected on the optical disk 106. Two photodetecting units 12c, 12d detect a part of each light beam from the two light-emitting parts of the semiconductor lasers 10a, 10b mounted on a laser light source 101. The same photodetecting units detect a part of each light beam from the two light- emitting parts, sharing the photodetecting units; hence, miniaturization of the photodetector and reduction in the number of circuits subsidiary to the photodetector are realized, and an inexpensive and smaller optical pickup device are realized. |
