| 摘要 |
PURPOSE:To increase sensitivity to dust and scratches stuck to a disk and the defect on a recording medium and to prevent an error at the time of reproduction. CONSTITUTION:A switch 6 is opened by means of a verifying mode signal from a controller 7 at the time of ordinary reproduction and closed by means of the verifying mode signal at the time of verifying. The gain of a signal IA is made smaller at the time of verifying compared with that of the ordinary reproduction, the gains of two channels are forcedly made to cause unbalance and a minute defect is detected. |
