Patent attributes
Luminance variation due to change of current through a light-emitting element caused by change in environmental temperature is suppressed. Current through a first light-emitting element in a pixel portion is controlled by a monitor circuit. The monitor circuit includes a second light-emitting element, a transistor, a resistor, and an amplifier circuit. An anode of the second light-emitting element is connected to a source of the transistor. A cathode of the second light-emitting element is connected to the resistor and a first input terminal of the amplifier circuit. A second input terminal of the amplifier circuit is connected to a second power supply line. An output terminal of the amplifier circuit is connected to a gate of the transistor. The drain of the transistor is connected to a third power supply line. The transistor and the resistor each include an oxide semiconductor film.
