DISTANCE-MEASURING APPARATUS

摘要

PROBLEM TO BE SOLVED: To highly accurately measure a distance with reducing influences of noises of light- receiving elements by providing a light-receiving means with two kinds of light-receiving elements one of which responds slower than the other and has a higher sensitivity than the other. SOLUTION: A light-projecting means 10 projects to an object to be measured a projection light F which is modulated by a modulation signal of a mixture of a pulse signal and a reference signal. A reflecting light R of the projection light F reflected by the object to be measured is received by a first light-receiving element 22 and a second light-receiving element 23 of a light-receiving means 11 independently and concurrently. A first measuring part 12 detects a time difference between a pulse signal component of a first receive signal of the reflecting light R detected by the first light-receiving element 22 and a pulse signal component of the projected light. A distance to the object to be measured is schematically calculated from the time difference. A second measuring part 13 detects a phase difference between a reference signal component of the second receive signal of the reflecting light R detected by the second light-receiving element 23 and a reference signal component of the projected light. Then, information on a distance within one phase difference to the object to be measured is calculated from the phase difference. A distance-calculating part 14 calculates a distance to the object 2 to be measured on the basis of the schematic calculation result of the first measuring part 12 and the distance information of the second calculating part 13.