| 摘要 |
PROBLEM TO BE SOLVED: To optimize the intensity of laser beam at the time of the reproducing by considering an equalizer coefficient of the equalizer eliminating the waveform interference of a reproduced signal. SOLUTION: A specified signal is recorded on a magneto-optical recording medium 10, and the magneto-optical recording medium 10 is irradiated by the laser beam, the intensity of which is changed, from an optical head 30 to reproduce the recorded signal, and the waveform interference is eliminated by changing the equalizer coefficient of the equalizer 95 when each waveform interference of the signal reproduced by changing the intensity of the laser beam is eliminated. Then, by a control circuit 102, the optimum equalizer coefficients for each intensity of the laser beam such as lowering the error rate are decided by using the number of errors detected with a PRML(partial response maximum likelihood) 96, and the optimum intensity of laser beam is decided by using the decided optimum equalizer coefficient. The equalizer 95 and a laser driving circuit 103 are controlled by the control circuit 102 so as to reproduce the signal by using the decided optimum intensity of laser beam and the optimum equalizer coefficient at this intensity.
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