| 摘要 |
PURPOSE:To simplify the constitution by obtaining a skew jump pulse for correcting the arrangement of horizontal synchronism from a DOC pulse so as to eliminate the need for a skew jump detecting circuit. CONSTITUTION:A luminance signal via a high pass filter 4 is applied to a demodulator 6 and a DOC pulse detecting circuit 22. An output from heads 1, 2 is as shown in (a) and the DOC pulse b1 in this case is generated at a position as shown in (b). A DOC pulse b2 is eliminated from the DOC pulses b1, b2 detected by the DOC pulse detecting circuit 22 by passing them through a smoothing circuit 23, and the pulse b1 is shaped into a pulse (c). A switch 9 is driven by triggering a flip-flop 24 by this pulse (c). Thus, the luminance signal delayed by 0.5H via a delay circuit 8 and a straight signal not delayed are changed over and applied to a mixer 11 so as to arrange horizontal synchronizing signals. |
