Optical disk apparatus, signal processing apparatus, and playback control method for optical disk apparatus

Abstract

Use the addition amplifier N1 to add and amplify the signals A, B, C, and D of the recording information read from the optical disc to generate RF signals, and the off-track state detection signal obtained by detecting the RF signals by the detection circuit N5 is used to indicate the off-track state. During the repeated state of the track state and the on-track state, the DUTY detection part N8 measures the DUTY of the off-track state detection signal, and the sensitivity determination part N9 judges the detection sensitivity of the off-track state detection signal generated by the detection circuit N5 according to the result, and the detection sensitivity adjustment circuit N6 adjusts the detection sensitivity of the off-track state detection signal to the detection circuit N5 based on the determination result.

Description

field of invention [0001] The present invention relates to a signal processing technique in an optical disc device for reproducing recorded information from an optical disc such as a CD or a DVD. Background technique [0002] In recent years, optical disks such as CDs and DVDs, which are recording media of optical disk devices, have appeared cheap but poor in characteristics, and smooth playback of these disks has also become a requirement. [0003] A feature of this kind of cheap and inferior optical disk is that the RF signal read by the optical head on the pit surface of the optical disk includes not only the reflected light of the pit being read but also the reflected light of adjacent pits. [0004] Therefore, in the case where the optical head is not on the pit at the time of track jump or track lead-in, the RF signal including the reflected light of the adjacent pit has sufficient amplitude and is output, therefore, the result is that no RF signal is output due to the...

AI Technical Summary

Problems solved by technology

[0027] Therefore, in the poor optical disc that cannot normally output the off-track state detection signal, the servo control chip often misjudges the current position of the laser light due to the wrong count of the number of tracks, and cannot perform correct track jumping and track lead-in processing. cannot regenerate normally

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