To provide an optical disk device improving the deterioration of performance such as the increase of access time generated by the variance of the disk and the impossibility of data reproduction, by preventing too much or too little of the amplitude of a reproduced signal at the time right after the start of the AGC operation.
The device is furnished with an amplitude control means for controlling the reproducing signal produced by an optical head to the amplitude suitable for an information reproducing means, a waveform equalizing circuit 107 for equalizing the waveform of the reproduced signal, an amplitude detecting circuit 109 for measuring the amplitude of the equalized signal, and the information reproducing means for extracting the information from the equalized signal. In the amplitude control means, the gain fixing function for optionally fixing the gain of an AGC circuit 105 and a gain setting circuit 106 are furnished. The amplitude of the equalized signal, the gain of which is settled by this gain fixing function, is measured by the amplitude detecting circuit 109, then the gain value learning function is provided for adjusting the gain setting so as to become the amplitude of the equalized signal suitable for the information reproducing means while changing the setting to the gain setting circuit 106.
AKAGI TOSHIYA
KONISHI SHINICHI
