| 摘要 |
PURPOSE:To obtain high distance detecting capacity with a simple circuit construction, by scanning with a light-shielding member over an incident surface of a pair of light-receiving elements connected in such a way that photoelectric outputs balance each other and detecting a time point where output polarities of the pair change. CONSTITUTION:A ray of light of a luminous element 2 is concentrated into a beam-shape by an irradiating lens 3 and irradiated onto an object 1. A reflected ray 5 from the object 1 is collected with a light-receiving lens 6 and generates a light spot 15 on light-receiving element pair 71, 72 after passing through a light-transmitting slit of a light-shielding member 8. The pair 71, 72 are connected in such a way that these outputs balance each other. The light-transmitting slit is accompanied with a deviation of position in each longitudinal direction of the basic line and consequently, a portion differentiated by spot image intensity distribution is irradiated. There, by scanning the light- shielding member 8 and detecting the time point where the output polarities of element pair 71, 72, a distance up to the object 1 can be detected. |
