摘要 |
A rotation detector wherein a rotary disk formed with slits in the circumferential direction thereof at predetermined regular intervals and connected to a driving source is disposed between a light emitting element and a light receiving element, and the light sensed by the light receiving element is intermittenlly interrupted by rotation of the rotary disk, whereby rotation of the driving source is detected. One of the rotation detectors is of such an arrangement that a parallel circuit is constituted by a resistor and a series circuit including a feedback resistor and a switching element, and this parallel circuit connects a power source and a light emitting element. Additionally, another of the rotational detectors is of such an arrangement that a comparator, in which a reference level is set, is used to compare outputs from a light emitting element with the reference level. As the result, misdetection occurring when the quantity of light sensed by a light receiving element is as low as one half and misdetection caused by external factors mixed in from the power source system and the like.
|