LIQUID CRYSTAL DISPLAY DEVICE

• US 20090002586A1
• Filed: 05/06/2008
• Published: 01/01/2009
• 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
• Granted Patent: US 7,952,651 B2
• Time in Patent Office: Days
• 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 third switch;

a first resistor;

a second resistor;

a first liquid crystal element; and

a second liquid crystal element,

wherein each of the first liquid crystal element and the second liquid crystal element includes at least a pixel electrode, a common electrode, and a liquid crystal controlled by the pixel electrode and the common electrode;

wherein the pixel electrode of the first liquid crystal element is electrically connected to a first wiring through the first switch;

wherein the pixel electrode of the first liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element through the second switch and the first resistor; and

wherein the pixel electrode of the second liquid crystal element is electrically connected to a second wiring through the third switch and the second resistor.

2. The liquid crystal display device according to claim 1, wherein resistance of the second resistor is higher than that of the first resistor.

3. The liquid crystal display device according to claim 1, wherein a potential in accordance with the pixel is input to the first wiring.

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

a first switch;

a second switch;

a third switch;

a first resistor;

a second resistor;

a first liquid crystal element;

a second liquid crystal element;

a first storage capacitor; and

a second storage capacitor,

wherein each of the first liquid crystal element and the second liquid crystal element includes at least a pixel electrode, a common electrode, and a liquid crystal controlled by the pixel electrode and the common electrode;

wherein the pixel electrode of the first liquid crystal element is electrically connected to a first wiring through the first switch;

wherein the pixel electrode of the first liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element through the second switch and the first resistor;

wherein the pixel electrode of the second liquid crystal element is electrically connected to a second wiring through the third switch and the second resistor;

wherein the pixel electrode of the first liquid crystal element is electrically connected to the second wiring through the first storage capacitor; and

wherein the pixel electrode of the second liquid crystal element is electrically connected to the second wiring through the second storage capacitor.

5. The liquid crystal display device according to claim 4, wherein resistance of the second resistor is higher than that of the first resistor.

6. The liquid crystal display device according to claim 4, wherein a potential in accordance with the pixel is input to the first wiring.

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

a switch;

a first transistor;

a second transistor;

a first liquid crystal element;

a second liquid crystal element;

a first storage capacitor; and

a second storage capacitor,

wherein each of the first liquid crystal element and the second liquid crystal element includes at least a pixel electrode, a common electrode, and a liquid crystal controlled by the pixel electrode and the common electrode;

wherein the pixel electrode of the first liquid crystal element is electrically connected to a first wiring through the switch;

wherein the pixel electrode of the first liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element through the first transistor;

wherein the pixel electrode of the second liquid crystal element is electrically connected to a second wiring through the second transistor;

wherein the pixel electrode of the first liquid crystal element is electrically connected to the second wiring through the first storage capacitor; and

wherein the pixel electrode of the second liquid crystal element is electrically connected to the second wiring through the second storage capacitor.

8. The liquid crystal display device according to claim 7, wherein, when W represents a channel width of a transistor, and when L represents a channel length of a transistor, W/L of the second transistor is larger than W/L of the first transistor.

9. The liquid crystal display device according to claim 7, wherein the second transistor is a multi-gate transistor.

10. The liquid crystal display device according to claim 7, wherein the second transistor is electrically connected to the second wiring through a diode connected transistor.

11. The liquid crystal display device according to claim 7, wherein a potential in accordance with the pixel is input to the first wiring.

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

a first transistor;

a second transistor;

a third transistor;

a first liquid crystal element;

a second liquid crystal element;

a first storage capacitor; and

a second storage capacitor,

wherein each of the first liquid crystal element and the second liquid crystal element includes at least a pixel electrode, a common electrode, and a liquid crystal controlled by the pixel electrode and the common electrode;

wherein the pixel electrode of the first liquid crystal element is electrically connected to a first wiring through the third transistor;

wherein the pixel electrode of the first liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element through the first transistor;

wherein the pixel electrode of the second liquid crystal element is electrically connected to a second wiring through the second transistor;

wherein the pixel electrode of the first liquid crystal element is electrically connected to the second wiring through the first storage capacitor; and

wherein the pixel electrode of the second liquid crystal element is electrically connected to the second wiring through the second storage capacitor.

13. The liquid crystal display device according to claim 12, wherein, when W represents a channel width of a transistor, and when L represents a channel length of a transistor, W/L of the third transistor is smaller than W/L of the first transistor or the second transistor.

14. The liquid crystal display device according to claim 12, wherein, when W represents a channel width of a transistor, and when L represents a channel length of a transistor, W/L of the second transistor is larger than W/L of the first transistor.

15. The liquid crystal display device according to claim 12, wherein the second transistor is a multi-gate transistor.

16. The liquid crystal display device according to claim 12, wherein the second transistor is electrically connected to the second wiring through a diode connected transistor.

17. The liquid crystal display device according to claim 12, wherein a potential in accordance with the pixel is input to the first wiring.