| 摘要 |
<p>PURPOSE:To execute an accurate counting operation by detecting automatically the direction of rotation of a reel shaft and controlling the counting operation of a counter circuit, thereby switching the counting operation by a rewinding operation, etc. CONSTITUTION:Pulse signals are generated with the rotation of the reel shaft from a pulse signal generating circuit 17 provided with the photocoupler 8 of a counter device, and the pulses of pulse width of specified multiple and the pulses of pulse width of specified fraction are generated repeatedly corresponding to the direction of rotation. The pulse width from the circuit 17 is measured by a pulse width measuring circuit 18, and measured pulse width is stored in a register 21. The stored pulse width is compared with pulse width measured next by the circuit 18 by a pulse width comparator circuit 22. A counter circuit 24 that counts the pulses detected by the circuit 17 is controlled by output from the circuit 22. The counter is up counted at the time of reproducing and fast feeding operation, and down counted in case of rewinding. Thus counting operation is made accurate.</p> |
