| 摘要 |
When a signal is played back from a damaged portion of an optical disk, immediately after the reproduction of the signal from the damaged portion, a mirror signal can be obtained with a high degree of accuracy from conversion of a traverse signal into a binary signal. In a traverse-signal discriminating circuit, a traverse signal, a low-frequency component of a playback signal, is separated from the playback signal and then supplied to a hold circuit. In the hold circuit, the bottom of the traverse signal is held in order to produce a bottom hold signal. In a defect detecting circuit, in the meantime a defect in the playback signal, if any, is detected. If a defect is detected, the defect detecting circuit outputs a defect signal at an H level to a hold-voltage resetting circuit. The hold-voltage resetting circuit discharges a capacitor included in the hold circuit, halting the operation to hold the bottom of the traverse signal as long as the defect signal supplied thereto is set at the H level. <IMAGE> |
