Patent ID: 8390793

Claim:
An optical ranging sensor comprising: a light emitting unit for projecting a light beam on an object to be measured, a light receiving unit on which reflected light resulting from reflection of the light beam from the object to be measured is incident and on which a light spot of the reflected light is formed, and a processing circuit unit for processing output signals from the light receiving unit and detecting a distance to the object to be measured, the light receiving unit including an effective light receiving part having a plurality of light receiving cells arranged in matrix form in a first direction in which a position of the light spot moves as the object to be measured moves along a direction of an optical axis of the light emitting unit, and in a second direction orthogonal to the first direction, and a size of the effective light receiving part in the second direction being not smaller than a radius of the light spot but not larger than a diameter thereof, wherein the effective light receiving part is composed of an area in the light receiving unit, and wherein areas except the effective light receiving part in the light receiving unit are blocked from functioning as light receiving parts for ranging.