| 摘要 |
PURPOSE:To enhance the degree of improvement of jitter and color phase irregularity, by sampling the horizontal synchronizing signal part of a chrominance subcarrier low band conversion NTSC signal to detect a periodic speed error of the time base error. CONSTITUTION:A sample holding circuit 18 samples the amplitude level of the horizontal synchronizing signal part or the color burst signal part of the chrominance subcarrier low band conversion NTSC signal, which is supplied from an FM demodulator 5 and includes a time base error, by the horizontal synchronizing signal from a synchronizing signal separator 6 or the burst gate pulse from a burst gate pulse generator 15 and holds the sampled result till the next sampling. Proper amplitude and frequency characteristic are given to the output signal of the circuit 18 by an arm stretcher driving circuit 8 to control an arm stretcher provided in a pickup 4. Thus, the direction of a stylus 3 is changed in the tangent direction of a signal track on a video disc 1 so that the frequency error becomes zero. |
