| 摘要 |
PROBLEM TO BE SOLVED: To obtain a control device by which a laser can be controlled to optimum laser light-emitting power always at low costs when information is recorded on, or reproduced from, an optical disk in a format by a CLV system by an optical-disk rotation control system other than the CLV system such as a CAV system or the like. SOLUTION: A modulation part 1 modulates the control signal of the laser driving current of a laser diode 12 by a laser drive part 2 according to information to be recorded on a recording medium. A laser beam which is output from the laser diode 12 is received by a photodetector 19. The laser beam is converted into an electric signal by a light receiving part 4. The frequency characteristic of an averaging part 5 is changed by a speed signal sig5 from a speed-signal generation part 9. The averaging part 5 averages the electric signal which is converted by the light receiving part 4. The laser driving current is changed according to the averaged electric signal. |
