SUBCARRIER REPRODUCING CIRCUIT FOR TELEVISION RECEIVER,申请号JP19840253801-传众专利搜索

SUBCARRIER REPRODUCING CIRCUIT FOR TELEVISION RECEIVER

申请公布号：JPS60247391(A)

申请号：JP19840253801

申请日期：1984.11.30

申请公布日期：1985.12.07

申请人：

SONY KK

发明人：RONARUDO KUAN

分类号：H04N9/45

主分类号：H04N9/45

摘要：PURPOSE:To prevent the degradation of a picture without shortening a video band width by comparing the output of a variable frequency oscillator with the output of a fixed frequency oscillator and a color burst signal taken out from the video signal of a television receiver by an error detecting circuit and controlling the variable frequency oscillator in accordance with comparison results. CONSTITUTION:A capacitor 34 of a sample holding circuit is charged to a voltage corresponding to the error signal generated in the preceding vertical blanking period. A switch S3 is disconnected from the capacitor 34 during a vertical active field, and the electric charge of the capacitor 34 is not changed and remains till the next vertical blanking period because the input impedance of an amplifier 36 is very high. Consequently, an adding circuit adds the output of a phase detector 24 generated between vertical active fields and the output of the phase detector 24 generated in the vertical blanking period. A synthesized error signal in the output of the adding circuit locks the phase of a wide band oscillator 50 with the coming color burst signal. Consequently, wow and flutter of a recorder are corrected even if the phase or the frequency of the color burst signal are shifted considerably from 3.58MHz standard value.