| 摘要 |
PURPOSE:To prevent deterioration in a reproducing information signal and to detect and eliminate jitters with respect to main information accurately by eliminating a deviation of a timewise continuous sub signal reproduced in accompany with a main information signal from a prescribed frequency. CONSTITUTION:A reproduced 4f signal is sent to a tracking error compensating circuit and a jitter eliminating circuit, where the frequency of the 4f signal changed at each field is discriminated (9). An output of a VCO 16 is subjected to frequency division 10-13, the result is selected sequentially by a switch SW and fed to a phase detector 14, where the phase with the reproduced 4f signal is compared, and its phase error voltage is sent to the VCO 16 via an LPF 15. Each multiple frequency signal of the reproduced 4f signal is given to a comparator 17 from the VCO 16 through the loop as a reproduced reference signal, which is compared with a reference signal from the oscillator 1. The deviation component in the error voltage as the result of comparison is eliminated by an elimination circuit 18, an error voltage corresponding to the jitter only is fed to an AP system circuit 19 to apply jitter correction continuously during reproduction of signal. |
