| 摘要 |
<p>PURPOSE:To avoid the waste of the tape as well as to ensure an observation in detail when some change occurs by detecting the difference in the vertical correlation of the video signals and then controlling the transfer speed of the recording medium based on the difference of the vertical correlation. CONSTITUTION:The video signals are supplied through input terminal 11 to be processed, and for example the video signals equivalent to one frame are drawn out with every 1000 frames to be supplied to recording head Hr. At the same time, reproduction head Hp is provided at the position distant by 180 away from head Hr to reproduce the recorded video signals. The reproduced signals are supplied to subtractor circuit 30 to obtain the difference to the input video signals. When detector circuit 31 detects that the difference is under the fixed level, the video signals are drawn out every 1000 frames; while if the difference signal is over the fixed level, switches 16 and 26 are changed over to draw out all frames. Thus the tape speed is increased.</p> |
