| 摘要 |
PURPOSE:To obtain an accurate reproduction scan locus by adding a control system to a tracking controller of 4-frequency pilot system in order to correct automatically the frequency variation of a pilot signal. CONSTITUTION:The output signals of the 1st and 2nd BPF23 and 24 are limited by the 1st and 2nd amplitude controllers 33 and 34 respectively, and the frequency variations of these output signals are detected by the 1st and 2nd FM wave detectors 35 and 36 respectively. Then these detection outputs are added together by an adder 37. Thus a tracking error signal of the scan direction of a video track is obtained independently of the tracking variation vertical to the scan direction of the video track. A time axis error signal thus obtained in the scan direction of the video track is amplified by the 2nd drive amplifier 38, and the output of the amplifier 38 is applied to the 2nd mobile actuator 39. Thus a reproduction head is shifted in the scan direction. |
