| 摘要 |
PURPOSE:To most suitably control the laser beam power of a magneto-optical disk recording and reproducing device according to the surrounding temperature and the recording pattern. CONSTITUTION:A part of the emitting light of laser beam is sampled at first and second timings and within a range wherein the output power is changed linearly to the driving current, the upper and lower limits of the output power level of the laser beam are held in sample-hold circuits 3a and 3B. The full scale of a D/A converter 9 is set so that the laser beam is controlled within the range between the upper and lower limits. |
