| 摘要 |
<p>PURPOSE:To eliminate any detection error and improve detection precision of a position of a body of rotation without increasing a current value allowed to flow in a reflection type photosensor by making a form in which the lengths of a light receiving part and a row direction thereof are longer than ones of rotation directions of a detection hole and a reflection part. CONSTITUTION:Because light emitted from a light emission part of a reflection type photosensor 3 is made incident on a reflection plate 1A and there is a form in which the lengths of row directions of the light emission part and a light receiving part of the sensor 3 are longer than ones of a detection hole 2A and a reflecting plate 1A, incident light enables reflection in a wide range on a path face. The light receiving part can receives a sufficient light quantity in the same case as a case where the reflection plate 1A is enlarged and detection is performed with the sensor 3 in a short time in the same case as another case where the reflecting plate 1A is lessened. Therefore precision of a position detector of a body of rotation can be improved without any increase of a current value allowed to flow in the sensor 3 and any detection error.</p> |
