| 摘要 |
PURPOSE:To discriminate a track pitch for recording with simple constitution by detecting two recording modes having different track pitches on the basis of comparison of a tracking error signal obtained from plural reproduced frequency signals with a prescribed level. CONSTITUTION:A voltage comparator 45 converts a tracking error signal to a square signal 51 and supplies the signal 51 to a peak detecting circuit 53. The output of the circuit 53 is supplied to an adjusting circuit 55. The output voltage of the circuit 53 is gradually boosted from the time when the square signal 51 is turned from the low level to the high level on the basis of a time constant CR based upon a capacitor C and a resistor R constituting the circuit 53. When the voltage value reaches the threshold of a CMOS, the logical level of an output of a shaping circuit 55 is turned to the high level. If the signal level of an output terminal 57 to which the output signal of the circuit 55 is applied is turned to the high level, it is discriminated that the reproducing mode is different from a recording one.
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