Patent ID: 8492719

Claim:
An optical position detection device that detects a position of a target object, comprising: a first detection light source unit that outputs a detection light from one side to the other side in a first direction; a second detection light source unit that is separated from the first detection light source unit along a second direction crossing the first direction, and outputs a detection light from the one side to the other side in the first direction; a light detection unit having sensitivity toward the other side in the first direction; a light source drive unit that drives the first detection light source unit and the second detection light source unit; a position detection unit that detects the position of the target object in the first direction and the position of the target object in the second direction based on received light results of the light detection unit when the light source drive unit turns on the first detection light source unit and the second detection light source unit in different periods from each other, a received light result of the light detection unit when the light source drive unit turns on the first detection light source unit and the second detection light source unit in the same period, or a result obtained by synthesizing the received light results of the light detection unit when the light source drive unit turns on the first detection light source unit and the second detection light source unit in the different periods from each other; and a reference light source that is held in the housing and outputs reference light entering the light detection unit not via an exterior part of the housing, wherein the position detection unit detects the position of the target object based on a result of a differential operation between the detection light source unit and the reference light source according to the received light result of the light detection unit; and the optical position detection device receives the reference light in the housing.