Patent ID: 7973913

Claim:
A distance measurement apparatus, comprising: an emission unit for emitting stripe pattern light, whose intensity changes periodically, to a subject while shifting the phase of the pattern; an imaging unit which includes an image sensor having a plurality of light receiving elements, disposed two-dimensionally, for receiving reflected light of the stripe pattern light reflected from the subject and outputting a received light signal according to the amount of light received; an imaging control unit for controlling the emission unit and the imaging unit such that the stripe pattern light is emitted to the subject by shifting the phase of the pattern of the stripe pattern light by π/2 from a reference phase until the phase of the pattern light is shifted one cycle and the reflected light is received at the reference phase and at each of phases shifted by π/2, π, and 3π/2 from the reference phase; and a distance information calculation unit for calculating, with respect to each light receiving element, a phase difference between the stripe pattern light and the reflected light of the stripe pattern light from received light signals at four phases obtained by each light receiving element in relation to the one phase shifting cycle of the stripe pattern light, and calculating, with respect to each light receiving element, distance information representing a distance to the subject based on the phase difference, wherein the distance information calculation unit is a unit that calculates an absolute value of difference between a first added signal and a second added signal, the first added signal being a signal obtained by adding the received light signals at the reference phase and at the phase shifted by π from the reference phase, and the second added signal being a signal obtained by adding the received light signals at the phases shifted by π/2 and 3π/2 from the reference phase among the received light signals at four phases, and calculates the distance information only from a light receiving element having an absolute value smaller than a specific value.