| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect rotary action by reducing power consumption. SOLUTION: A signal Sdr is supplied to a transistor 63 from a control part 51 and a light emitting diode 11D is turned on and off to emit at 1st predetermined time intervals. Reel stands for supplying and taking up a tape are provided with reflecting bodies at predetermined intervals in the direction of rotation, and the light from a light emitting diode 61D can be made incident on a photo-transistor 61T by letting the reflecting bodies reflect the light, and also a time of incidence when the light can be made incident on the photo-transistor 61T and a time of non-incidence when the light cannot be made incident thereon are made longer than the 1st predetermined time. The photo-transistor 61T generates a sensor signal SS based on the light of incidence. The control part 51 detects the signal level of the sensor signal SS synchronizing with the time when the light emitting diode 61D is turned on, and the rotation of the reel is judged as stopped when the detected signal level is kept unchanged for a time longer than the time of incidence and the time of non-incidence.</p> |
