| 摘要 |
PURPOSE:To correct a time base error which is generated steadily on every turn of a rotary head device by calculating a phase error which is generated repeatedly on every turn of the rotary head device and feeding it back negatively to a voltage-controlled oscillator which constitutes a phase locked loop. CONSTITUTION:The voltage-controlled oscillator(VCO) 21 is brought under feedback control based upon the phase error output of the phase comparator 24 of a PLL circuit 5 which generates clock pulses for writing a digitized playback signal in a memory to correct the time base, and residual phase error data is calculated by an arithmetic processing circuit 32 based on the phase error output of the phase comparator 24 by utilizing the frame correlation of the time base error containing a high frequency component originating from the impact error, etc., of an input playback signal from the rotary head device; and this data is converted into analog data, which is fed back negatively to the VCO 21 of the PLL circuit 6. Consequently, the time base error due to an impact error, etc., generated steadily on every turn of the rotary analog device is corrected.
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