Patent ID: 8913253

Claim:
An optical position detection apparatus optically detecting a position of a target object, comprising: a screen that is in a quadrangle shape having first through fourth sides, the target object being located next to the screen; a first light source unit that is located spaced apart from the first side of the screen and adjacent to one edge of the first side of the screen, the first light source unit emits a first detection light along the screen in a first direction; a second light source unit that is located spaced apart from the first side of the screen and adjacent to the other edge of the first side of the screen, the second light source unit emits a second detection light along the screen in the first direction, the first and second light source units being coaxially aligned parallel to the first side of the screen; a third light source unit that is located spaced apart from the first side of the screen and adjacent to the first light source unit, the third light source unit emits a third detection light along the screen in the first direction, the third light source unit being spaced further apart from the first side of the screen in the first direction than the first light source unit; a light receiving unit that is located spaced apart from the first side of the screen and adjacent to a center of the first side of the screen, the light receiving unit receives first through third reflected lights that result from respectively reflecting the first through third detection lights off the target object; a light source drive unit that alternatively drives the first light source unit, the second light source unit, and the third light source unit; and a position detection unit that detects the position of the target object first through third reflected lights that are received by the light receiving unit, wherein the light source drive unit sequentially turns the first and second light source units on and off to sequentially emit the first and second detection lights, and the light source drive unit sequentially turns the first and third light source units on and off to sequentially emit the first and third detection lights.