| 摘要 |
A semiconductor device with a transistor for supplying a current to a pixel comprising an EL element, that can supply an accurate current without the influence of variations even when a small signal current, is provided. A precharge voltage is supplied in advance for the current supply to a pixel and subsequently, the signal writing is completed quickly. The precharge voltage is outputted from a circuit for supplying voltage and current that supplies a current to a current source circuit for supplying a current to the pixel. As the precharge voltage, a gate voltage of a transistor for supplying a current to the current source circuit is supplied to the pixel. Optimum precharge voltage can be supplied in the case where W/L of a transistor in the pixel and W/L of a transistor for supplying current in the circuit for supplying voltage and current are approximately equivalent to each other. |
