| 摘要 |
<p>PURPOSE:To secure the automatic adaptation to alteration of the responsiveness of the recording start plus the length and speed of the tape by measuring and memorizing the cycle of the tape mark signals based on the clock signals. CONSTITUTION:The light given from light emitting diode 1 is reflected by reflective tape 3 on tape 2 and then detected by photo transistor 4 to be changed into the tape mark signals. The tape mark signal is then differentiated 6 to be changed into the input of the tape cycle measurement control circuit part. Here the time interval is measured between the first and second mark signals by counting the clock signals via counter 13, and this result is memorized in latch circuit 15. Then with application of recording start control signal K, the count value of circuit 15 is loaded to counter 16 to be subtracted by the clock signal. And when the count value becomes zero, the recording is stopped. In such way, the recording state can be secured instantaneously after measurement of the tape cycle. Furthermore, the memory data is renewed for adaptation when the length or speed of the tape is altered.</p> |
