Patent ID: 8816960
Filing Date: 2014-08-26
Classification: G01J,G06F

Abstract:
1. A light detector comprising: a light receiving device that has a central optical axis and first and second directions perpendicular thereto, the light receiving device detecting incident light; and a holder that includes first and second folder members that sandwich the light receiving device in the first direction, the first and second holder members include first and second bases and first and second light shields, respectively, wherein the light receiving device has a directional characteristic of light sensitivity in which a first position located along the optical axis has a highest sensitivity and a second position angled from the first position in the second direction has a low sensitivity, and the sensitivity lowers and the angle becomes larger, each of the first and second bases has a rectangular shape in which longitudinal sides extend in the second direction, a first thickness of the first base is larger than a second thickness of the second base, the light receiving device is provided on the second base next to the longitudinal side of the second base, and a portion of the longitudinal side of the first base that corresponds to the light receiving device has a recess that opens the central optical axis of the light receiving device toward a light incident side, the first and second light shields continuously and respectively project from the longitudinal sides of the first and second bases toward the light incident side, each of the first and second light shields has a semi-circular shape, a third thickness of the first light shield is smaller than the first thickness so that the light receiving device detects the incident light, and a fourth thickness of the second light shield is the same as the second thickness, and top surfaces of the first base and the first light shield are co-planar, the third thickness gradually decreases from a first tip closest to the light incident side of the first light shield toward ends of the first light shield connected to the first base, and the light receiving device receives the incident light that passes through a gap between the first and second light shields.