DISPLAY DEVICE

• US 20110193836A1
• Filed: 01/26/2011
• Published: 08/11/2011
• Est. Priority Date: 02/05/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: UMEZAKI, Atsushi
• Granted Patent: US 8,638,322 B2
• Time in Patent Office: Days
• US Class Current: 345/205
• CPC Class Codes: G09G 2300/0439 Pixel structures
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes

Abstract

A display device in which partial driving can be performed with a simplified configuration of a circuit including a wiring. One of signal processing circuits includes a first transistor that controls the potential of its respective gate signal line, and a second transistor that outputs a start signal for the subsequent stage and a reset signal for the preceding stage. A signal for controlling whether the gate signal line is in an active state (a state where a selection signal is output) or a non-active state (a state where a selection signal is not output or a non-selection signal continues to be output) is input to the first transistor. A clock signal is input to the second transistor. Thus, the number of wirings necessary for operating the device is reduced.

Claims

1. A display device comprising:

a driver circuit comprising a first transistor and a second transistor; and

a pixel comprising a third transistor and a liquid crystal element,

wherein a first terminal of the first transistor is electrically connected to a first wiring, and a second terminal of the first transistor is electrically connected to a second wiring,

wherein a first terminal of the second transistor is electrically connected to a third wiring, a second terminal of the second transistor is electrically connected to a fourth wiring, and a gate of the second transistor is electrically connected to a gate of the first transistor, and

wherein a first terminal of the third transistor is electrically connected to a fifth wiring, a second terminal of the third transistor is electrically connected to one of electrodes of the liquid crystal element, and a gate of the third transistor is electrically connected to the fourth wiring.

2. The display device according to claim 1,

further comprising a protection circuit, and

wherein the protection circuit is electrically connected to the fourth wiring.

3. The display device according to claim 1,

wherein the driver circuit further comprises a fourth transistor, a fifth transistor, a sixth transistor, and an inverter circuit,

wherein a first terminal of the fourth transistor is electrically connected to a sixth wiring,

wherein a first terminal of the fifth transistor is electrically connected to a seventh wiring,

wherein a first terminal of the sixth transistor is electrically connected to a gate of the sixth transistor, and

wherein an input terminal of the inverter circuit is electrically connected to the gate of the first transistor, the gate of the second transistor, a second terminal of the fourth transistor, a second terminal of the fifth transistor, and a second terminal of the sixth transistor, and an output terminal of the inverter circuit is electrically connected to a gate of the fourth transistor.

4. The display device according to claim 1,

wherein a channel width of the first transistor is smaller than a channel width of the second transistor

9. The display device according to claim 1,

wherein the first to third transistors have the same conductivity type.

11. The display device according to claim 1,

wherein the display device is used for an electronic device selected from a group consisting of a mobile computer, a portable image reproducing device, a goggle-type display, a portable game machine, a projector, a television set, a portable television receiver, a camera, a computer, and a mobile phone.

13. The display device according to claim 1,

wherein each of the first to third transistors includes an oxide semiconductor layer which functions as a channel formation layer.

5. A display device comprising:

a first signal processing circuit portion having a first transistor, a second transistor, a third transistor, and a first circuit portion;

a second signal processing circuit portion having a fourth transistor, a fifth transistor, a sixth transistor, and a second circuit portion;

a third signal processing circuit portion having a seventh transistor, and a third circuit portion;

a first gate signal line;

a second gate signal line; and

a pixel comprising an eighth transistor and a liquid crystal element,

wherein the first circuit portion comprises;

a first output terminal electrically connected to a gate of the first transistor and a gate of the second transistor;

a second output terminal electrically connected to a gate of the third transistor; and

a first input terminal electrically connected to a first terminal of the fourth transistor,

wherein the second circuit portion comprises;

a first output terminal electrically connected to a gate of the fourth transistor and a gate of the fifth transistor;

a second output terminal electrically connected to a gate of the sixth transistor;

a first input terminal electrically connected to a first terminal of the first transistor; and

a second input terminal electrically connected to a first terminal of the seventh transistor,

wherein the third circuit portion comprises;

a first output terminal electrically connected to a gate of the seventh transistor; and

a first input terminal electrically connected to the first terminal of the fourth transistor,

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

wherein a first terminal of the third transistor is electrically connected to a first terminal of the sixth transistor,

wherein a first terminal of the second transistor and a second terminal of the third transistor are electrically connected to the first gate signal line,

wherein a first terminal of the fifth transistor and a second terminal of the sixth transistor are electrically connected to the second gate signal line, and

wherein a first terminal of the eighth transistor is electrically connected to one of electrodes of the liquid crystal element, and a gate of the eighth transistor is electrically connected to the second gate signal line.

6. The display device according to claim 5,

further comprising a protection circuit, and

wherein the protection circuit is electrically connected to the second gate signal line.

7. The display device according to claim 5,

wherein the second circuit portion comprises a ninth transistor, a tenth transistor, an eleventh transistor, and an inverter circuit, and

wherein the first output terminal of the second circuit portion is electrically connected to an input terminal of the inverter circuit, a first terminal of the ninth transistor, a first terminal of the tenth transistor, and a first terminal of the eleventh transistor,

wherein the second output terminal of the second circuit portion is electrically connected to an output terminal of the inverter circuit and a gate of the ninth transistor,

wherein the first input terminal of the second circuit portion is electrically connected to a second terminal of the eleventh transistor and a gate of the eleventh transistor, and

wherein the second input terminal of the second circuit portion is electrically connected to a gate of the tenth transistor.

8. The display device according to claim 5,

wherein a channel width of the first transistor is smaller than a channel width of the second transistor, and

wherein a channel width of the fourth transistor is smaller than a channel width of the fifth transistor.

10. The display device according to claim 5,

wherein the first to eighth transistors have the same conductivity type.

12. The display device according to claim 5,

wherein the display device is used for an electronic device selected from a group consisting of a mobile computer, a portable image reproducing device, a goggle-type display, a portable game machine, a projector, a television set, a portable television receiver, a camera, a computer, and a mobile phone.

14. The display device according to claim 5,

wherein each of the first to eighth transistors includes an oxide semiconductor layer which functions as a channel formation layer.