| 摘要 |
In a display device using a light-emitting element or the like, the power consumption is reduced without reducing the display quality. A first operation and a second operation are carried out. In the first operation, a threshold voltage of a transistor is held in a capacitor. In the second operation, a signal potential corresponding to an image signal and the threshold voltage are added with the use of a capacitive coupling by the capacitor and are input to a gate of the transistor, so that a drain current of the transistor flows into a load element. The first operation is carried out once in a plurality of frames. A switch that determines whether the capacitor is electrically connected to a wiring to which a power supply potential is input is provided. A transistor in which a channel is formed in an oxide semiconductor layer is used as the switch. |
