Liquid crystal display device

• US 8,199,267 B2
• Filed: 03/22/2011
• Issued: 06/12/2012
• Est. Priority Date: 05/17/2007
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime
• Primary Examiner(s): Wong, Tina
• Application Number:
  US13/053,323
• Publication Number:
  US 20110170029A1
• Time in Patent Office: 448 Days
• Field of Search: None
• US Class Current: 349/39
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• 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 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G02F 2202/10 semiconductor
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• 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 2300/0842 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 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• CPC Class Codes: G09G 2320/0238 Improving the black level
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• 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 2340/02 : Handling of images in compressed format, e.g. JPEG, MPEG
• 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 3/342 : using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3655 : Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
• 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: G09G 3/3688 : suitable for active matrices only

Abstract

The present invention has a pixel which includes a first switch, a second switch, a third switch, a first resistor, a second resistor, a first liquid crystal element, and a second liquid crystal element. A pixel electrode of the first liquid crystal element is electrically connected to a signal line through the first switch. The pixel electrode of the first liquid crystal element is electrically connected to a pixel electrode of the second liquid crystal element through the second switch and the first resistor. The pixel electrode of the second liquid crystal element is electrically connected to a Cs line through the third switch and the second resistor. A common electrode of the first liquid crystal element is electrically connected to a common electrode of the second liquid crystal element.

Claims

1. A liquid crystal display device including a pixel, the pixel comprising:

a first switch;

a second switch;

a first line configured to scan the first switch and the second switch;

a transistor;

a first capacitor wherein a first electrode of the first capacitor is electrically connected to a terminal of the first switch through the transistor;

a second line electrically connected to a second electrode of the first capacitor;

a second capacitor wherein a first electrode of the second capacitor is electrically connected to the terminal of the first switch and one of a source and a drain of the transistor, and a second electrode of the second capacitor is electrically connected to the second line;

a first liquid crystal element including a first pixel electrode electrically connected to the terminal of the first switch, wherein the first pixel electrode is electrically connected to the one of the source and the drain of the transistor through a first node; and

a second liquid crystal element including a second pixel electrode electrically connected to a terminal of the second switch through a second node,

wherein the first node is not overlapped with the second pixel electrode and the second node is not overlapped with the first pixel electrode.

2. The liquid crystal display device according to claim 1, wherein the second line is a Cs line.

3. The liquid crystal display device according to claim 1, wherein each of the first liquid crystal element and the second liquid crystal element includes a common electrode electrically connected to the second line.

4. The liquid crystal display device according to claim 1, wherein the first electrode of the first capacitor is connected to the other of the source and the drain of the transistor.

5. The liquid crystal display device according to claim 1, wherein the first line is configured to scan the transistor.

6. The liquid crystal display device according to claim 1, wherein the terminal of the first switch and the first node are included in a first wiring, and

wherein the terminal of the second switch and the second node are included in a second wiring.

7. The liquid crystal display device according to claim 1, wherein the second liquid crystal element is electrically connected to the first electrode of the first capacitor.

8. The liquid crystal display device according to claim 1, wherein each of the first electrodes of the first capacitor and the second capacitor is formed by a semiconductor material.

9. A liquid crystal display device including a pixel, the pixel comprising:

a first switch;

a second switch;

a first line configured to scan the first switch and the second switch;

a transistor;

a first capacitor wherein a first electrode of the first capacitor is electrically connected to a first terminal of the first switch through the transistor;

a second line electrically connected to a second electrode of the first capacitor;

a second capacitor wherein a first electrode of the second capacitor is electrically connected to the first terminal of the first switch and one of a source and a drain of the transistor, and a second electrode of the second capacitor is electrically connected to the second line;

a first liquid crystal element including a first pixel electrode electrically connected to the first terminal of the first switch, wherein the first pixel electrode is electrically connected to the one of the source and the drain of the transistor through a first node;

a second liquid crystal element including a second pixel electrode electrically connected to a first terminal of the second switch through a second node; and

a third line electrically connected to a second terminal of the first switch and a second terminal of the second switch,

wherein the first node is not overlapped with the second pixel electrode and the second node is not overlapped with the first pixel electrode.

10. The liquid crystal display device according to claim 9, wherein the second line is a Cs line.

11. The liquid crystal display device according to claim 9, wherein each of the first liquid crystal element and the second liquid crystal element includes a common electrode electrically connected to the second line.

12. The liquid crystal display device according to claim 9, wherein the first electrode of the first capacitor is connected to the other of the source and the drain of the transistor.

13. The liquid crystal display device according to claim 9, wherein the first line is configured to scan the transistor.

14. The liquid crystal display device according to claim 9, wherein the terminal of the first switch and the first node are included in a first wiring, and

wherein the terminal of the second switch and the second node are included in a second wiring.

15. The liquid crystal display device according to claim 9, wherein the second liquid crystal element is electrically connected to the first electrode of the first capacitor.

16. The liquid crystal display device according to claim 9, wherein each of the first electrodes of the first capacitor and the second capacitor is formed by a semiconductor material.

17. A liquid crystal display device including a pixel, the pixel comprising:

a first transistor;

a second transistor;

a first line configured to scan the first transistor and the second transistor;

a third transistor;

a first capacitor wherein a first electrode of the first capacitor is electrically connected to one of a source and a drain of the first transistor through the third transistor;

a second line electrically connected to a second electrode of the first capacitor;

a second capacitor wherein a first electrode of the second capacitor is electrically connected to the one of the source and the drain of the first transistor through a first node, and a second electrode of the second capacitor is electrically connected to the second line;

a first liquid crystal element including a first pixel electrode electrically connected to one of the source and the drain of the third transistor through the first node; and

a second liquid crystal element including a second pixel electrode electrically connected to one of a source and a drain of the second transistor through a second node,

wherein the first node is not overlapped with the second pixel electrode and the second node is not overlapped with the first pixel electrode.

18. The liquid crystal display device according to claim 17, wherein the second line is a Cs line.

19. The liquid crystal display device according to claim 17, wherein each of the first liquid crystal element and the second liquid crystal element includes a common electrode electrically connected to the second line.

20. The liquid crystal display device according to claim 17, wherein the first electrode of the first capacitor is connected to the other of the source and the drain of the third transistor.

21. The liquid crystal display device according to claim 17, wherein the first line is configured to scan the third transistor.

22. The liquid crystal display device according to claim 17, wherein the second liquid crystal element is electrically connected to the first electrode of the first capacitor, and

wherein the other of the source and the drain of the second transistor is connected to the second line.

23. The liquid crystal display device according to claim 17, wherein each of the first electrodes of the first capacitor and the second capacitor is formed by a semiconductor material.

24. A liquid crystal display device including a pixel, the pixel comprising:

a first transistor;

a second transistor;

a first line configured to scan the first transistor and the second transistor;

a third transistor;

a first capacitor wherein a first electrode of the first capacitor is electrically connected to one of a source and a drain of the first transistor through the third transistor;

a second line electrically connected to a second electrode of the first capacitor;

a second capacitor wherein a first electrode of the second capacitor is electrically connected to the one of the source and the drain of the first transistor through a first node, and a second electrode of the second capacitor is electrically connected to the second line;

a first liquid crystal element including a first pixel electrode electrically connected to one of the source and the drain of the third transistor through the first node; and

a second liquid crystal element including a second pixel electrode electrically connected to one of a source and a drain of the second transistor through a second node,

wherein the first node is not overlapped with the second pixel electrode and the second node is not overlapped with the first pixel electrode, and

wherein the second electrode of the second capacitor is overlapped with the first pixel electrode.

25. The liquid crystal display device according to claim 24, wherein the second line is a Cs line.

26. The liquid crystal display device according to claim 24, wherein each of the first liquid crystal element and the second liquid crystal element includes a common electrode electrically connected to the second line.

27. The liquid crystal display device according to claim 24, wherein the first electrode of the first capacitor is connected to the other of the source and the drain of the third transistor.

28. The liquid crystal display device according to claim 24, wherein the first line is configured to scan the third transistor.

29. The liquid crystal display device according to claim 24, wherein the second liquid crystal element is electrically connected to the first electrode of the first capacitor, and

wherein the other of the source and the drain of the second transistor is connected to the second line.

30. The liquid crystal display device according to claim 24, wherein each of the first electrodes of the first capacitor and the second capacitor is formed by a semiconductor material.