IP Library › Granted Patent US 8,305,306
Granted Patent B2
US 8,305,306 · App. 13/097,140 · Granted Nov 6, 2012

Light-emitting device and driving method thereof

Assignee: Semiconductor Energy Laboratory Co., Ltd.
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 8,305,306
App. No.
13/097,140
Granted
Nov 6, 2012
Kind
B2
Abstract

In a light emitting device, luminance irregularities caused by fluctuation in threshold of TFTs for supplying a current to EL elements among pixels hinder the light emitting device from improving the image quality. A voltage equal to the threshold of a TFT 110 is held in capacitor means 111 in advance. When a video signal is inputted from a source signal line, the voltage held in the capacitor means is added to the signal, which is then applied to a gate electrode of the TFT 110 . Even when threshold is fluctuated among pixels, each threshold is held in the capacitor means 111 of each pixel, and therefore, influence of the threshold fluctuation can be removed. Since the threshold is stored in the capacitor means 111 alone and the voltage between two electrodes is not changed while a video signal is written, fluctuation in capacitance value has no influence.

Claims (194)

1. A semiconductor device comprising:

a first wiring;

a second wiring;

a third wiring;

a first switch,

a second switch,

a third switch,

a fourth switch,

a fifth switch,

a first capacitor;

a second capacitor; and

a transistor,

wherein a first terminal of the first switch is electrically connected to the first wiring;

wherein a second terminal of the first switch is electrically connected to a first terminal of the second switch,

wherein the first terminal of the second switch is electrically connected to a first terminal of the first capacitor,

wherein a second terminal of the second switch is electrically connected to a source of the transistor,

wherein a first terminal of the third switch is electrically connected to a second terminal of the first capacitor,

wherein a second terminal of the third switch is electrically connected to a first terminal of the fourth switch,

wherein the first terminal of the fourth switch is electrically connected to a drain of the transistor,

wherein a second terminal of the fourth switch is electrically connected to the second wiring,

wherein a first terminal of the fifth switch is electrically connected to the source of the transistor,

wherein a second terminal of the fifth switch is electrically connected to the third wiring,

wherein a gate of the transistor is electrically connected to a second terminal of the first capacitor,

wherein the source of the transistor is electrically connected to a load,

wherein a first terminal of the second capacitor is electrically connected to the second terminal of the first switch,

wherein a second terminal of the second capacitor is electrically connected to the source of the transistor,

wherein each of the first switch, the second switch, the third switch, the fourth switch and the fifth switch is configured to control conductive state and non-conductive state,

wherein the first wiring is configured to transmit an image signal voltage,

wherein the second wiring is configured to transmit a current flowing in the transistor,

wherein the third wiring is configured to transmit a predetermined voltage, and

wherein the transistor is configured to control a value of a current flowing in the load.

2. The semiconductor device according to claim 1 , wherein the transistor is an n-channel transistor.

3. The semiconductor device according to claim 1 , wherein the semiconductor device is applied to an electronic device.

4. The electronic device according to claim 3 , wherein the electronic device comprises an antenna and an audio output portion.

5. A semiconductor device comprising:

a first wiring;

a second wiring;

a third wiring;

a first switch,

a second switch,

a third switch,

a fourth switch,

a fifth switch,

a first capacitor;

a second capacitor; and

a transistor,

wherein a first terminal of the first switch is electrically connected to the first wiring;

wherein a second terminal of the first switch is electrically connected to a first of the second switch,

wherein the first terminal of the second switch is electrically connected to a first terminal of the first capacitor,

wherein a second terminal of the second switch is electrically connected to a source of the transistor,

wherein a first terminal of the third switch is electrically connected to a second terminal of the first capacitor,

wherein a second terminal of the third switch is electrically connected to a first terminal of the fourth switch,

wherein the first terminal of the fourth switch is electrically connected to a drain of the transistor,

wherein a second terminal of the fourth switch is electrically connected to the second wiring,

wherein a first terminal of the fifth switch is electrically connected to the source of the transistor,

wherein a second terminal of the fifth switch is electrically connected to the third wiring,

wherein a gate of the transistor is electrically connected to a second terminal of the first capacitor,

wherein the source of the transistor is electrically connected to a pixel electrode,

wherein a first terminal of the second capacitor is electrically connected to the second terminal of the first switch,

wherein a second terminal of the second capacitor is electrically connected to the source of the transistor,

wherein each of the first switch, the second switch, the third switch, the fourth switch and the fifth switch is configured to control conductive state and non-conductive state,

wherein the first wiring is configured to transmit an image signal voltage,

wherein the second wiring is configured to transmit a current flowing in the transistor,

wherein the third wiring is configured to transmit a predetermined voltage, and

wherein the transistor is configured to control a value of a current flowing in the pixel electrode.

6. The semiconductor device according to claim 5 , wherein the transistor is an n-channel transistor.

7. The semiconductor device according to claim 5 , wherein the semiconductor device is applied to an electronic device.

8. The electronic device according to claim 7 , wherein the electronic device comprises an antenna and an audio output portion.

9. A display device comprising:

a first wiring;

a second wiring;

a third wiring;

a first switch,

a second switch,

a third switch,

a fourth switch,

a fifth switch,

a first capacitor;

a second capacitor; and

a transistor,

wherein a first terminal of the first switch is electrically connected to the first wiring;

wherein a second terminal of the first switch is electrically connected to a first terminal of the second switch,

wherein the first terminal of the second switch is electrically connected to a first terminal of the first capacitor,

wherein a second terminal of the second switch is electrically connected to a source of the transistor,

wherein a first terminal of the third switch is electrically connected to a second terminal of the first capacitor,

wherein a second terminal of the third switch is electrically connected to a first terminal of the fourth switch,

wherein the first terminal of the fourth switch is electrically connected to a drain of the transistor,

wherein a second terminal of the fourth switch is electrically connected to the second wiring,

wherein a first terminal of the fifth switch is electrically connected to the source of the transistor,

wherein a second terminal of the fifth switch is electrically connected to the third wiring,

wherein a gate of the transistor is electrically connected to a second terminal of the first capacitor,

wherein the source of the transistor is electrically connected to a display element,

wherein a first terminal of the second capacitor is electrically connected to the second terminal of the first switch,

wherein a second terminal of the second capacitor is electrically connected to the source of the transistor,

wherein each of the first switch, the second switch, the third switch, the fourth switch and the fifth switch is configured to control conductive state and non-conductive state,

wherein the first wiring is configured to transmit an image signal voltage,

wherein the second wiring is configured to transmit a current flowing in the transistor,

wherein the third wiring is configured to transmit a predetermined voltage, and

wherein the transistor is configured to control a value of a current flowing in the display element.

10. The display device according to claim 9 , wherein the display element comprises a light emitting element.

11. The display device according to claim 9 , wherein the transistor is an n-channel transistor.

12. The display device according to claim 9 , wherein the display device is applied to an electronic device.

13. The electronic device according to claim 12 , wherein the electronic device comprises an antenna and an audio output portion.

14. A semiconductor device comprising:

a first wiring;

a second wiring;

a first switch,

a second switch,

a third switch,

a fourth switch,

a first capacitor;

a second capacitor; and

a transistor,

wherein a first tenninal of the first switch is electrically connected to the first wiring;

wherein a second terminal of the first switch is electrically connected to a first terminal of the second switch,

wherein the first terminal of the second switch is electrically connected to a first terminal of the first capacitor,

wherein a second terminal of the second switch is electrically connected to a source of the transistor,

wherein a first terminal of the third switch is electrically connected to a second terminal of the first capacitor,

wherein a second terminal of the third switch is electrically connected to a first terminal of the fourth switch,

wherein the first terminal of the fourth switch is electrically connected to a drain of the transistor,

wherein a second terminal of the fourth switch is electrically connected to the second wiring,

wherein a gate of the transistor is electrically connected to a second terminal of the first capacitor,

wherein the source of the transistor is electrically connected to a load,

wherein a first terminal of the second capacitor is electrically connected to the second terminal of the first switch,

wherein a second terminal of the second capacitor is electrically connected to the source of the transistor,

wherein each of the first switch, the second switch, the third switch and the fourth switch is configured to control conductive state and non-conductive state,

wherein the first wiring is configured to transmit an image signal voltage,

wherein the second wiring is configured to transmit a current flowing in the transistor, and

wherein the transistor is configured to control a value of a current flowing in the load.

15. The semiconductor device according to claim 14 , wherein the transistor is an n-channel transistor.

16. The semiconductor device according to claim 14 , wherein the semiconductor device is applied to an electronic device.

17. The electronic device according to claim 16 , wherein the electronic device comprises an antenna and an audio output portion.

18. A semiconductor device comprising:

a first wiring;

a second wiring;

a third wiring;

a first switch,

a second switch,

a third switch,

a fourth switch,

a fifth switch,

a first capacitor;

a second capacitor; and

a transistor,

wherein a first terminal of the first switch is electrically connected to the first wiring;

wherein a second terminal of the first switch is electrically connected to a first terminal of the second switch,

wherein the first terminal of the second switch is electrically connected to a first terminal of the first capacitor,

wherein a second terminal of the second switch is electrically connected to a source of the transistor,

wherein a first terminal of the third switch is electrically connected to a second terminal of the first capacitor,

wherein a first terminal of the fourth switch is electrically connected to a drain of the transistor,

wherein a second terminal of the fourth switch is electrically connected to the second wiring,

wherein a first terminal of the fifth switch is electrically connected to the source of the transistor,

wherein a second terminal of the fifth switch is electrically connected to the third wiring,

wherein a gate of the transistor is electrically connected to a second terminal of the first capacitor,

wherein the source of the transistor is electrically connected to a load,

wherein a first terminal of the second capacitor is electrically connected to the second terminal of the first switch,

wherein a second terminal of the second capacitor is electrically connected to the source of the transistor,

wherein each of the first switch, the second switch, the third switch, the fourth switch and the fifth switch is configured to control conductive state and non-conductive state,

wherein the first wiring is configured to transmit an image signal voltage,

wherein the second wiring is configured to transmit a current flowing in the transistor,

wherein the third wiring is configured to transmit a predetermined voltage, and

wherein the transistor is configured to control a value of a current flowing in the load.

19. The semiconductor device according to claim 18 , wherein the transistor is an n-channel transistor.

20. The semiconductor device according to claim 18 , wherein the semiconductor device is applied to an electronic device.

21. The electronic device according to claim 20 , wherein the electronic device comprises an antenna and an audio output portion.

22. A semiconductor device comprising:

a first wiring;

a second wiring;

a third wiring;

a first switch,

a second switch,

a third switch,

a fourth switch,

a fifth switch,

a first capacitor;

a second capacitor; and

a transistor,

wherein a first terminal of the first switch is electrically connected to the first wiring;

wherein a second terminal of the first switch is electrically connected to a first terminal of the second switch,

wherein the first terminal of the second switch is electrically connected to a first terminal of the first capacitor,

wherein a second terminal of the second switch is electrically connected to a source of the transistor,

wherein a first terminal of the third switch is electrically connected to a second terminal of the first capacitor,

wherein a second terminal of the third switch is electrically connected to a first terminal of the fourth switch,

wherein the first terminal of the fourth switch is electrically connected to a drain of the transistor,

wherein a second terminal of the fourth switch is electrically connected to the second wiring,

wherein a first terminal of the fifth switch is electrically connected to the source of the transistor,

wherein a second terminal of the fifth switch is electrically connected to the third wiring,

wherein a gate of the transistor is electrically connected to a second terminal of the first capacitor,

wherein the source of the transistor is electrically connected to a load,

wherein a first terminal of the second capacitor is electrically connected to the second terminal of the first switch,

wherein a second terminal of the second capacitor is electrically connected to the source of the transistor.

23. The semiconductor device according to claim 22 , wherein the transistor is an n-channel transistor.

24. The semiconductor device according to claim 22 , wherein the semiconductor device is applied to an electronic device.

25. The electronic device according to claim 24 , wherein the electronic device comprises an antenna and an audio output portion.

Priority Claims (1)
JP 2001-330050 · Oct 26, 2001 · national
Continuity (3)
Continuation 12271953 · Nov 17, 2008
Continuation 10279001 · Oct 24, 2002
Related Publication 20110205215A1 · Aug 25, 2011