SEMICONDUCTOR DEVICE AND LIGHT EMITTING DEVICE

摘要

A semiconductor device and a light emitting device are provided to prevent brightness reduction by preventing voltage variations between gate and source of a driving thin film transistor. A gate electrode of a first transistor(404) is electrically connected to a first gate signal line(402). A first electrode of the first transistor is electrically connected to a first wire(401). A second electrode of the first transistor is electrically connected to a first electrode of a second transistor(407). A gate electrode of the second transistor is electrically connected to a second signal line(403). A gate electrode of a third transistor(405) is electrically connected to the first electrode of the first transistor. A first electrode of the third transistor is electrically connected to a second wire(409). A capacitor(408) is connected between the gate and second electrodes of the third transistor. A first electrode of a fourth transistor(406) is electrically connected to a second electrode of the third transistor. A second electrode of the fourth transistor is electrically connected to a third wire(412).