US Patent 7532209 Display apparatus and driving method thereof

A plurality of pairs of switch parts and current source circuits are disposed in each pixel. Switching of each of a plurality of the switch parts is controlled by a digital video signal. When the switch part is turned ON, by a current supplied from the current source circuit making a pair with the switch part, the light emitting element emits light. A current which is supplied from one current source circuit to the light emitting element is constant. A value of a current flowing through the light emitting element is comparable to a value of added currents which are supplied to the light emitting element from respective all current source circuits making pairs with the switch parts which are in the conductive states.