| 摘要 |
PURPOSE: To stably reproduce recorded information with high reliability by detecting the relative linear velocity of a laser light beans to an optical disk recording medium and controlling the intensity of the laser beam when the recorded information is reproduced according to the detected relative linear velocity. CONSTITUTION: The optical disk recording medium 1 is rotated at a fixed number of revolution by a spindle motor 2. The optical disk recording medium l is irradiated by a reproducing laser light beam through a convergence lens. Then, track address information recorded beforehand on the optical disk recording medium 1 as a phase pit or the track address information written as the information is read out. Further, the optimum value of a reproducing laser light intensity is set in a linear velocity operation circuit 8 based on the data corresponding to a disk number of revolution from the drive circuit 3 of the spindle motor 2 rotating the optical disk recording medium 1 to be sent to a laser drive circuit 5. |
