| 摘要 |
PROBLEM TO BE SOLVED: To obtain a compact and simple constitution by using a digital micromirror element(DMD) for a light projecting system, or the light projecting system and a light receiving system, controlling the reflection angle of the DMD and detecting the distances to plural points. SOLUTION: Light-receiving by a PSD(semiconductor position detecting element) 17 is performed by making an LED(light emitting diode) 15 emit light and project it toward the central position of a photographic image plane. A light receiving signal is processed by a PSD processing circuit 14 so as to detect a centroid position in light quantity distribution. Furthermore, the mirror of the DMD 16 is driven to be at a specified angle. The light is received by the PSD 17, and the centered position in the light quantity distribution of the PSD 17 is detected. Then, the centroid position of the received light is corrected in accordance with the angle of the DMD 16 at the time of projecting the light so as to obtain the corrected centroid position. Furthermore, a DMD control circuit 13 is driven to drive the mirror of the DMD 16 to be at the specified angle, the LED 15 projects the light, which is received by the PSD 17, and the centroid position in the light quantity distribution of the PSD 17 is detected. The centered of the received light is similarly corrected in accordance with the light projecting angle to obtain the corrected centroid position. The distance information on the centroid positions of three points is calculated. |
