US Patent 7223958 Device for and method of driving an electro-optical device

To provide an electro-optical device, such as a display or a printer head having a self-luminous element, in which a light-emitting state of a light-emitting element is detected. The electro-optical device comprises a plurality of pixel units arranged in a display region on a substrate in a predetermined pattern, each including a light-emitting element; a plate-like member disposed to overlap the display region and formed of a transparent medium for transmitting light emitted from the plurality of pixel units and internally reflecting a portion of the transmitted light; and light detection means for detecting light that is internally reflected and reaches at least one side of the display region through the inside of the plate-like member.