Patent ID: 8259309
Filing Date: 2012-09-04
Classification: G01B,G06F

Abstract:
1. An optical position detection apparatus for optically detecting a position of a target object in a detection area, comprising: position detection light sources that emit position detection light irradiated onto the target object; a light guide plate that receives the position detection light therein and emits the received position detection light onto the detection area to form an intensity distribution of a light emission quantity of the position detection light in the detection area; a light detector having light receiving portions arranged facing toward the detection area to receive the position detection light that is reflected by the target object; and a signal processing portion that detects the position of the target object based on the intensity distribution of the light emission quantity in the detection area, wherein the light guide plate includes light incident portions for receiving the position detection light and side portions except for the light incident portions are provided on outer periphery side portions of the light guide plate when the light guide plate is seen in a plan view, a light emission surface that emits the position detection light incident from the light incident portions toward the detection area is provided on a plane portion of the light guide plate when the light guide plate is seen in a plan view, and at least a portion of the side portions is an anti-reflection surface that prevents reflection of the position detection light in the light guide plate.