| 摘要 |
PURPOSE:To record information on a recording medium with good efficiency and yield rate through preventing recording mistake in advance, by detecting that at least one error signal exceeds a fixed value in focus control and tracking control. CONSTITUTION:For example, an output of photodetectors 12a and 12c of a tracking controller is inputted to a differential amplifier 16 via amplifiers 14 and 15, and a tracking error signal being the output drives a tracking mirror via a phase compensation circuit 17, an amplifier 18 and a driving circuit 19. The tracking error signal from the amplifier 18 is inputted to comparators 20 and 21, and when the signal is greater than a set voltage V1 or smaller than -V2, the output signals of the comparators 20 and 21 go to high level. The high-level signal stops the recording of information via an OR circuit 22, and RS flip-flop circuit 23, a changeover switch 24, and a control circuit 25. Thus, recording can be done with efficiency and a good yield rate. |
