| 摘要 |
PURPOSE:Not to cause a malfunction even if a flaw, etc. exist in an jumping point of a video disk record, by detecting a still state as a rotation stop of a tracking motor. CONSTITUTION:A rotation detecting pulse from a tracking motor is waveform- shaped by a pulse shaping circuit 13, and after that, it is inputted to a retriggerable monostable multivibrator 14. A metastable period of the monostable multivibrator concerned 14 is set so as to be much longer than a rotation detecting pulse period in case of a normal reverse reproduction. Therefore, a differentiating circuit 15 generates a positive pulse as soon as the monostable multivibrator 14 becomes a stable state. The positive pulse which has been generated is not synchronized with an output of a jumping position detecting circuit 7 but is applied to a jumping output generating circuit 8 as a forced jumping pulse. Accordingly, a tracking Miller executes the forced jumping of a scanning track at a position which is different from a prescribed jumping position, and gets out a still state. |
