Patent ID: 6501085
Filing Date: 2002-12-31
Classification: G01C,G01S,G02B

Abstract:
A distance-measuring apparatus comprising:light projecting means for projecting pulses of light toward an object at a distanced to be measured; light detecting means for detecting light of said light projected toward and reflected from the object, at a photoreceptive position on a position sensing device according to the distance to the object and outputting a signal according to the photoreceptive position; arithmetic means for carrying out an arithmetic operation based on the signal outputted from said light detecting means and outputting an output ratio signal according to the distance to the object; integrating means comprising an integrating capacitor, said integrating means carrying out a first integration in which the signal outputted from said arithmetic means is integrated by discharging/charging said integrating capacitor according to the signal output from said arithmetic means and, thereafter, carrying out a second integration by charging/discharging said integrating capacitor with a constant current, said integrating means comparing a voltage of said integrating capacitor with a reference voltage during the second integration and outputting a comparison result signal according to a result of the comparison; and detecting means for detecting the distance to the object, based on the signal output from said integrating means, wherein said integrating means comprises a plurality current sources having different output currents and said integrating means carries out the first integration with one of said current sources to discharge/charge the integrating capacitor to a maximum in detection of the distance to the object.