| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain discrimination of a color frame only by having to reproduce one frame of control pulses, to be hardly affected by a remanent signal by means of overwrite and to surely and easily detect change in a duty ratio of the control pulse. SOLUTION: A recording CTL(control) duty ratio generating circuit 17 generates a control pulse whose duty ratio is switched cyclicly in the order of 70%, 50%, 65%, 55% for each frame recording period or a control pulse whose duty ratio is switched cyclicly in the order of 70%, 55%, 65%, 50% for each frame recording period. The control pulse extracted from the recording CTL duty ratio generating circuit 17 is fed to a fixed control head 22 through a recording amplifier 20 and a switch 21 and then recorded on a magnetic tape 27.</p> |
