Liquid crystal display device

• US 10,012,880 B2
• Filed: 05/03/2017
• Issued: 07/03/2018
• Est. Priority Date: 05/18/2007
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime
• Primary Examiner(s): CHEN, WEN YING PATTY
• Application Number:
  US15/585,221
• Publication Number:
  US 20170235197A1
• Time in Patent Office: 426 Days
• Field of Search: 349 48
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/136295 Materials; Compositions; Manufacture processes
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• CPC Class Codes: G09G 2300/0447 for multi-domain technique to improve the viewing angle in a liquid crystal display, such as multi-vertical alignment [MVA]
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 2320/10 Special adaptations of display systems for operation with variable images
• CPC Class Codes: G09G 2320/106 Determination of movement vectors or equivalent parameters within the image
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 2340/16 : Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 3/2022 : using sub-frames
• CPC Class Codes: G09G 3/3233 : with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3648 : using an active matrix G09G3/367 - G09G3/3696 take precedence
• 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
• CPC Class Codes: H01L 27/12 : the substrate being other than a semiconductor body, e.g. an insulating body

Abstract

To improve viewing angle characteristics by varying voltage which is applied between liquid crystal elements. A liquid crystal display device in which one pixel is provided with three or more liquid crystal elements and the level of voltage which is applied is varied between the liquid crystal elements is varied. In order to vary the level of the voltage which is applied between the liquid crystal elements, an element which divides the applied voltage is provided. In order to vary the level of the applied voltage, a capacitor, a resistor, a transistor, or the like is used. Viewing angle characteristics can be improved by varying the level of the voltage which is applied between the liquid crystal elements.

Claims

1. A display device comprising a pixel portion, the pixel portion comprising:

a gate wiring;

a first source wiring and a second source wiring;

a first transistor, a second transistor, and a third transistor each comprising a gate, a first terminal, and a second terminal;

a first capacitor, a second capacitor, and a third capacitor each comprising a first terminal and a second terminal; and

a first liquid crystal element, a second liquid crystal element, and a third liquid crystal element each comprising a first terminal and a second terminal,

wherein the gate of the first transistor is directly connected to the gate wiring,

wherein the first terminal of the first transistor is directly connected to the first source wiring,

wherein the second terminal of the first transistor is directly connected to the first terminal of the first liquid crystal element,

wherein the second terminal of the first transistor is directly connected to the first terminal of the first capacitor,

wherein the gate of the second transistor is directly connected to the gate wiring,

wherein the first terminal of the second transistor is directly connected to the first source wiring,

wherein the second terminal of the second transistor is directly connected to the first terminal of the second liquid crystal element,

wherein the second terminal of the second transistor is directly connected to the first terminal of the second capacitor,

wherein the first transistor, the second transistor, and the third transistor are configured to be turned on simultaneously,

wherein the first terminal of the third transistor is directly connected to the second source wiring,

wherein the second terminal of the third transistor is directly connected to the first terminal of the third liquid crystal element,

wherein the second terminal of the third transistor is directly connected to the first terminal of the third capacitor,

wherein the first liquid crystal element, the second liquid crystal element, and the third liquid crystal element are in a same column, and

wherein the second terminal of the first capacitor is not directly connected to the second terminal of the third capacitor.

2. The display device according to claim 1, wherein the gate of the third transistor is directly connected to the gate wiring.

3. The display device according to claim 1, wherein the first liquid crystal element, the second liquid crystal element, and the third liquid crystal element are arranged in a line which is substantially parallel to the first source wiring.

4. The display device according to claim 1, wherein the second terminal of the first capacitor is electrically connected to the second terminal of the third capacitor.

5. The display device according to claim 1, wherein the first transistor, the second transistor, and the third transistor are in a same pixel.

6. A display module comprising:

the display device according to claim 1; and

a flexible printed circuit.

7. An electronic device comprising:

the display device according to claim 1; and

at least one of a battery, an antenna, a microphone, a speaker, a sensor, and a keyboard.

8. A display device comprising a pixel portion, the pixel portion comprising:

a gate wiring;

a first source wiring and a second source wiring;

a first transistor, a second transistor, and a third transistor each comprising a gate, a first terminal, and a second terminal;

a first capacitor, a second capacitor, and a third capacitor each comprising a first terminal and a second terminal; and

a first liquid crystal element, a second liquid crystal element, and a third liquid crystal element each comprising a first terminal and a second terminal,

wherein the gate of the first transistor is directly connected to the gate wiring,

wherein the first terminal of the first transistor is directly connected to the first source wiring,

wherein the second terminal of the first transistor is directly connected to the first terminal of the first liquid crystal element,

wherein the second terminal of the first transistor is directly connected to the first terminal of the first capacitor,

wherein the gate of the second transistor is directly connected to the gate wiring,

wherein the first terminal of the second transistor is directly connected to the first source wiring,

wherein the second terminal of the second transistor is directly connected to the first terminal of the second liquid crystal element,

wherein the second terminal of the second transistor is directly connected to the first terminal of the second capacitor,

wherein the first transistor, the second transistor, and the third transistor are configured to be turned on simultaneously,

wherein the first terminal of the third transistor is directly connected to the second source wiring,

wherein the second terminal of the third transistor is directly connected to the first terminal of the third liquid crystal element,

wherein the second terminal of the third transistor is directly connected to the first terminal of the third capacitor,

wherein the first liquid crystal element, the second liquid crystal element, and the third liquid crystal element are in a same column,

wherein the second terminal of the first capacitor is not directly connected to the second terminal of the third capacitor, and

wherein the second terminal of the second capacitor is directly connected to the second terminal of the third capacitor.

9. The display device according to claim 8, wherein the second terminal of the first capacitor is electrically connected to the second terminal of the third capacitor.

10. The display device according to claim 8, wherein the first transistor, the second transistor, and the third transistor are in a same pixel.

11. A display module comprising:

the display device according to claim 8; and

a flexible printed circuit.

12. An electronic device comprising:

the display device according to claim 8; and

at least one of a battery, an antenna, a microphone, a speaker, a sensor, and a keyboard.

13. A display device comprising a pixel portion, the pixel portion comprising:

a gate wiring;

a first source wiring and a second source wiring;

a first transistor, a second transistor, and a third transistor each comprising a gate, a first terminal, and a second terminal;

a first capacitor, a second capacitor, and a third capacitor each comprising a first terminal and a second terminal; and

a first liquid crystal element, a second liquid crystal element, and a third liquid crystal element each comprising a first terminal and a second terminal,

wherein the gate of the first transistor is directly connected to the gate wiring,

wherein the first terminal of the first transistor is directly connected to the first source wiring,

wherein the second terminal of the first transistor is directly connected to the first terminal of the first liquid crystal element,

wherein the first terminal of the first liquid crystal element is directly connected to the first terminal of the first capacitor through a first contact hole and a second contact hole,

wherein the gate of the second transistor is directly connected to the gate wiring,

wherein the first terminal of the second transistor is directly connected to the first source wiring,

wherein the second terminal of the second transistor is directly connected to the first terminal of the second liquid crystal element,

wherein the second terminal of the second transistor is directly connected to the first terminal of the second capacitor,

wherein the first transistor, the second transistor, and the third transistor are configured to be turned on simultaneously,

wherein the first terminal of the third transistor is directly connected to the second source wiring,

wherein the second terminal of the third transistor is directly connected to the first terminal of the third liquid crystal element,

wherein the second terminal of the third transistor is directly connected to the first terminal of the third capacitor,

wherein the first liquid crystal element, the second liquid crystal element, and the third liquid crystal element are in a same column, and

wherein the second terminal of the first capacitor is not directly connected to the second terminal of the third capacitor.

14. The display device according to claim 13, wherein the second terminal of the first capacitor is electrically connected to the second terminal of the third capacitor.

15. The display device according to claim 13, wherein the first transistor, the second transistor, and the third transistor are in a same pixel.

16. A display module comprising:

the display device according to claim 13; and

a flexible printed circuit.

17. An electronic device comprising:

the display device according to claim 13; and

at least one of a battery, an antenna, a microphone, a speaker, a sensor, and a keyboard.

18. A display device comprising a pixel portion, the pixel portion comprising:

a gate wiring;

a first source wiring and a second source wiring;

a first transistor, a second transistor, and a third transistor each comprising a gate, a first terminal, and a second terminal;

a first capacitor, a second capacitor, and a third capacitor each comprising a first terminal and a second terminal; and

a first liquid crystal element, a second liquid crystal element, and a third liquid crystal element each comprising a first terminal and a second terminal,

wherein the gate of the first transistor is directly connected to the gate wiring,

wherein the first terminal of the first transistor is directly connected to the first source wiring,

wherein the second terminal of the first transistor is directly connected to the first terminal of the first liquid crystal element,

wherein the second terminal of the first transistor is directly connected to the first terminal of the first capacitor,

wherein the gate of the second transistor is directly connected to the gate wiring,

wherein the first terminal of the second transistor is directly connected to the first source wiring,

wherein the second terminal of the second transistor is directly connected to the first terminal of the second liquid crystal element,

wherein the second terminal of the second transistor is directly connected to the first terminal of the second capacitor,

wherein the first transistor, the second transistor, and the third transistor are configured to be turned on simultaneously,

wherein the first terminal of the third transistor is directly connected to the second source wiring,

wherein the second terminal of the third transistor is directly connected to the first terminal of the third liquid crystal element,

wherein the second terminal of the third transistor is directly connected to the first terminal of the third capacitor,

wherein the first liquid crystal element, the second liquid crystal element, and the third liquid crystal element are in a same column,

wherein the second terminal of the first capacitor is not directly connected to the second terminal of the third capacitor, and

wherein the first transistor, the second transistor, and the third transistor comprise an oxide semiconductor material.

19. The display device according to claim 18, wherein the second terminal of the first capacitor is electrically connected to the second terminal of the third capacitor.

20. The display device according to claim 18, wherein the first transistor, the second transistor, and the third transistor are in a same pixel.

21. A display module comprising:

the display device according to claim 18; and

a flexible printed circuit.

22. An electronic device comprising:

the display device according to claim 18; and

at least one of a battery, an antenna, a microphone, a speaker, a sensor, and a keyboard.