Patent ID: 6621583
Filing Date: 2003-09-16
Classification: G01C,G01S

Abstract:
A distance-measuring apparatus comprising:a light projecting means for projecting pulses of light toward an object at a distance to be measured; light receiving means for receiving light of the light projected 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 receiving 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 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 the comparison; maximum second integration time selecting means for selecting one of a plurality of maximum second integration times, each second integration time being set as a process time of the second integration, according to a distance measurement condition; and detecting means for detecting the distance to the object, based on the signal outputted from said integrating means, after a lapse of the maximum second integration time selected.