Method for driving semiconductor device
To provide a method for driving a semiconductor device, by which influence of variation in threshold voltage and mobility of transistors can be reduced. The semiconductor device includes an n-channel transistor, a switch for controlling electrical connection between a gate and a first terminal of the transistor, a capacitor electrically connected between the gate and a second terminal of the transistor, and a display element. The method has a first period for holding the sum of a voltage corresponding to the threshold voltage of the transistor and an image signal voltage in the capacitor; a second period for turning on the switch so that electric charge held in the capacitor in accordance with the sum of the image signal voltage and the threshold voltage is discharged through the transistor; and a third period for supplying a current to the display element through the transistor after the second period.
1. A light-emitting device,
wherein the light-emitting device has a function of correcting a threshold voltage and mobility of a transistor controlling a supply of a current to a light-emitting element according to a video signal,
wherein the transistor is formed using a single crystal substrate,
wherein the light-emitting device comprises a first switch controlling a conduction state between a wiring supplying the video signal and a gate of the transistor, a second switch controlling a conduction state between a wiring supplying the current flowing to the transistor and one of a source and a drain of the transistor, and a third switch controlling a conduction state between a wiring which is supplied with a potential and the other of the source and the drain of the transistor,
wherein an insulating layer is provided in an opening of the single crystal substrate,
wherein the other of the source and the drain of the transistor is electrically connected to the light-emitting element,
wherein the gate of the transistor is electrically connected to a capacitor,
wherein the transistor is connected to a plurality of capacitors, and
wherein a circuit comprising the light-emitting element comprises exactly four transistors.
2. The light-emitting device according to claim 1 , wherein the transistor is a p-channel transistor.
3. The light-emitting device according to claim 1 ,
wherein the plurality of capacitors is connected in series.
4. The light-emitting device according to claim 1 , wherein one electrode of the capacitor is formed from a same material as the source and the drain of the transistor.
5. A camera comprising the light-emitting device according to claim 1 .
6. The light-emitting device according to claim 1 , wherein the insulating layer is provided between two transistors.
7. A light-emitting device,
wherein the light-emitting device has a function of correcting a threshold voltage and mobility of a transistor controlling a supply of a current to a light-emitting element according to a video signal,
wherein the transistor is a p-channel transistor,
wherein the light-emitting device comprises a first switch controlling a conduction state between a wiring supplying the video signal and a gate of the transistor, a second switch controlling a conduction state between a wiring supplying the current flowing to the transistor and one of a source and a drain of the transistor, and a third switch controlling a conduction state between a wiring which is supplied with a potential and the other of the source and the drain of the transistor,
wherein the other of the source and the drain of the transistor is electrically connected to the light-emitting element,
wherein the transistor comprises a silicon oxide layer over the p-channel,
wherein the gate of the transistor comprises silicon,
wherein an insulating layer comprising silicon oxide is provided over the gate of the transistor,
wherein the gate of the transistor is electrically connected to a capacitor,
wherein one electrode of the capacitor is formed from a same material as the source and the drain of the transistor, and
wherein a circuit comprising the light-emitting element comprises exactly four transistors.
8. The light-emitting device according to claim 7 ,
wherein the capacitor comprises a plurality of capacitors connected in series.
9. A camera comprising the light-emitting device according to claim 7 .
10. A light-emitting device,
wherein the light-emitting device has a function of correcting a threshold voltage and mobility of a transistor controlling a supply of a current to a light-emitting element according to a video signal,
wherein the light-emitting device comprises a first switch controlling a conduction state between a wiring supplying the video signal and a gate of the transistor, a second switch controlling a conduction state between a wiring supplying the current flowing to the transistor and one of a source and a drain of the transistor, and a third switch controlling a conduction state between a wiring which is supplied with a potential and the other of the source and the drain of the transistor,
wherein a plurality of capacitors is provided, one of the plurality of capacitors being electrically connected to the gate of the transistor,
wherein the plurality of capacitors is connected in series,
wherein a circuit comprising the light-emitting element comprises exactly four transistors, and
wherein the other of the source and the drain of the transistor is directly connected to the light-emitting element.
11. A camera comprising the light-emitting device according to claim 10 .
12. The light-emitting device according to claim 10 , wherein an insulating layer is provided between two transistors in a single crystal silicon substrate.
13. The light-emitting device according to claim 10 ,
wherein the transistor comprises a silicon oxide layer below the gate,
wherein the gate of the transistor comprises silicon,
wherein an insulating layer comprising silicon oxide is provided over the gate of the transistor and
wherein a first conductive layer is provided in an opening of the insulating layer.