| 摘要 |
<p>PURPOSE:To quickly and surely detect an accident by providing a revolution speed comparing means, and deciding a fact that a sticking accident of a tape is generated, when the detected speed of revolution exceeds a set value. CONSTITUTION:To a revolution speed comparing circuit 3, a reference frequency for giving the speed of revolution of a normal reel base 1 is set in advance at every tape running mode. When a tape is drawn out of a cassette half, a supply reel of the reel base 1 rotates in proportion to a draw-out speed. Subsequently, the speed of revolution is detected by a reel base revolution speed detector 2 and converted to a prescribed frequency signal, and sent to the circuit 3. The circuit 3 compares the reference frequency and the signal from the circuit 2, and when it exceeds a reference signal, it is decided that a tape is stuck to a drum. Next, a sticking detecting signal is sent out to a system controller, and by applying the brake to the reel base 1, a drum motor 9 is stopped. In such a way, an accident is detected quickly and exactly, and it is prevented that the tape is caught in the drum.</p> |
