Patent ID: 8654101

Claim:
An electro-optical device comprising: a light guide plate that is configured to transmit therethrough light beams entering from a light incident face thereof and to emit the light beams from a light emitting face intersecting the light incident face; first multiple light sources for position detection that are arranged along the light incident face and that discharge position detection light beams toward the light incident face; a photosensor that detects at least some of position detection light beams reflected by an object to be detected among the position detection light beams emitted from the light emitting face; a light source control unit that switches between a first driving mode and a second driving mode, the first driving mode being a mode in which discharged light intensities of the first multiple light sources are gradually decreased toward one side of an arrangement direction of the first multiple light sources and in which emitted light intensities of the position detection light beams emitted from the light emitting face exhibit a first light emission distribution tilted toward the one side of the arrangement direction, the second driving mode being a mode in which discharged light intensities of the first multiple light sources are gradually decreased toward another side opposite to the one side of the arrangement direction and in which emitted light intensities of the position detection light beams emitted from the light emitting face exhibit a second light emission distribution tilted toward the other side of the arrangement direction; a position information derivation unit that derives position information regarding the object to be detected along the arrangement direction on the basis of output components of the photosensor respectively attributable to the first light emission distribution and the second light emission distribution; and an electro-optical panel that has a display area arranged so as to overlap in plan view the light emitting face of the light guide plate, the electro-optical an having first and second surface opposite to each other, wherein the light guide plate and the first multiple light sources are located at a side of the first surface of the electro-optical panel, and the photosensor is located at a side of the second surface of the electro-optical panel, and the position detection light beams reaches to the object through the electro-optical panel.