| 摘要 |
<p>PURPOSE:To ensure the tape retrieval by giving the control to the pass of the pseudo featuring the duration proportional to the no signal duration longer than the fixed time via the pulse train of the interval corresponding to the tape running speed. CONSTITUTION:Pulse row generation means 7 generates the pulse train formed by the pulses featuring the interval proportional to the tape speed in coupling to the reel or the like. With this pulse's rear edge, mono-multi 8 is triggered. As multi 8 can be triggered again, it generates the high-level output if the pulse interval becomes short for the pulse train when the tape speed increases. Thus FF10 is set via NOR gate 9, and the output generated is made to pass through NAND gate 13 to which the no signal detection pulse of the duration proportional to the no signal duration longer than the fixed time. And the pseudo detection pulse at the decrement time of the tape speed does not pass. As a result, the reverse control is given to the quick winding direction via the necessary no signal detection pulse, and thus the tape is stopped at the fixed leading position with no malfunction.</p> |
