| 摘要 |
PURPOSE:To detect the position of an object by a simple mechanism irrespective of inclination of the object, by providing two pairs of light sources which are symmetrical with each other with a light-receiving element in the middle and are opposite to the object having non-irregulr-reflection surface, and driving each pair of the light sources by light whose phase are shifted by 90 deg.. CONSTITUTION:On positions which are symmetrically set on a straight line at equal intervals with a light-receiving element in the middle, 2 pairs of luminous elements 42, 43, 44 and 45 are arranged. The luminous elements 42 and 43 are driven in sine waves, and the luminous elements 44 and 45 are driven in cosine waves. A total of reflection lights on the surface of a non-irregular-reflectivity object i is detected by the light-receiving element. While power of the reflection lights becomes a sine wave with shifted position, this phase shift varies in accordance with distance from the object. By seeking phase shift from drive signals of the luminous elements 42 and 43 in this manner, a position of the object is detected. And therefore, an inclination of the objects surface i takes very little influence on the detected value. |
