Liquid crystal display

• US 7,782,346 B2
• Filed: 09/29/2005
• Issued: 08/24/2010
• Est. Priority Date: 09/30/2004
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Akiyama, Hiroto
• Primary Examiner(s): Tran; Henry N
• Application Number:
  US11/576,402
• Publication Number:
  US 20080049052A1
• Time in Patent Office: 1,790 Days
• Field of Search: 345/50, 345/55, 345 87- 90, 345/93, 345694-696, 345/690, 349/73, 349/74, 349/77, 349 83- 85, 349/108, 349/109, 349/144
• US Class Current: 345/694
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/133742 for homeotropic alignment
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• 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 2201/40 Arrangements for improving the aperture ratio
• 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 2300/0876 Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A liquid crystal display device includes a plurality of pixels that are arranged in matrix so as to form a plurality of rows extending in an X direction and a plurality of columns extending in a Y direction. Each pixel includes a liquid crystal layer and a plurality of electrodes for applying a voltage to the liquid crystal layer, and is split into at least one bright subpixel, which has a luminance higher than a certain luminance produced by a display signal voltage supplied, and at least one dark subpixel that has a lower luminance than the certain luminance. The area of the at least one bright subpixel is smaller than that of the at least one dark subpixel. If the at least one bright subpixel and the at least one dark subpixel are arranged in the Y direction in each pixel, two closest pixels that belong to the same row to display the same color have geometric centroids with mutually different Y coordinates. The greatest difference between the Y coordinates of luminance centroids is equal to or smaller than a half of the length R_Y of the two pixels as measured in the Y direction.

Claims

1. A liquid crystal display device comprising a plurality of pixels that are arranged in matrix so as to form a plurality of rows extending in an X direction and a plurality of columns extending in a Y direction,

wherein each said pixel includes a liquid crystal layer and a plurality of electrodes for applying a voltage to the liquid crystal layer, and is split into at least one bright subpixel, which has a luminance higher than a certain luminance produced by a display signal voltage supplied, and at least one dark subpixel that has a lower luminance than the certain luminance, and

wherein the area of the at least one bright subpixel is smaller than that of the at least one dark subpixel, and

wherein if the at least one bright subpixel and the at least one dark subpixel are arranged in the Y direction in each said pixel, two closest pixels that belong to the same row to display the same color have geometric centroids with the same Y coordinate, the greatest difference between the Y coordinates of luminance centroids being equal to or smaller than a half of the length R_Y of the two pixels as measured in the Y direction, or

wherein if the at least one bright subpixel and the at least one dark subpixel are arranged in the X direction in each said pixel, two pixels that are adjacent to each other in the column direction have geometric centroids with the same X coordinate, the greatest difference between the X coordinates of luminance centroids being equal to or smaller than a half of the length R_X of the two pixels as measured in the X direction, and

wherein the luminance centroid of the at least one bright subpixel is different from the geometric centroid of the pixel.

2. The liquid crystal display device of claim 1, wherein the at least one bright subpixel that each said pixel has is the only bright subpixel of that pixel.

3. The liquid crystal display device of claim 1, wherein the luminance centroids of the bright subpixels of the two pixels have the same Y coordinate.

4. The liquid crystal display device of claim 1, wherein the Y coordinate of the luminance centroid of the only bright subpixel agrees with that of the geometric centroid of the pixel.

5. The liquid crystal display device of claim 1, wherein the area of the at least one dark subpixel is at least three times as large as that of the at least one bright subpixel.

6. A liquid crystal display device comprising a plurality of pixels that are arranged in matrix so as to form a plurality of rows extending in an X direction and a plurality of columns extending in a Y direction,

wherein each said pixel includes a liquid crystal layer and a plurality of electrodes for applying a voltage to the liquid crystal layer, and is split into at least one bright subpixel, which has a luminance higher than a certain luminance produced by a display signal voltage supplied, and at least one dark subpixel that has a lower luminance than the certain luminance, and

wherein the area of the at least one bright subpixel is smaller than that of the at least one dark subpixel, and

wherein if the at least one bright subpixel and the at least one dark subpixel are arranged in the Y direction in each said pixel, two closest pixels that belong to the same row to display the same color have geometric centroids with the same Y coordinate, the greatest difference between the Y coordinates of luminance centroids being equal to or smaller than a half of the length R_Y of the two pixels as measured in the Y direction, or

wherein if the at least one bright subpixel and the at least one dark subpixel are arranged in the X direction in each said pixel, two pixels that are adjacent to each other in the column direction have geometric centroids with the same X coordinate, the greatest difference between the X coordinates of luminance centroids being equal to or smaller than a half of the length R_X of the two pixels as measured in the X direction, and

wherein the luminance centroid of the at least one bright subpixel is different from that of the at least one dark subpixel.

7. The liquid crystal display device of claim 6, wherein the at least one bright subpixel that each said pixel has is the only bright subpixel of that pixel.

8. The liquid crystal display device of claim 6, wherein the luminance centroids of the bright subpixels of the two pixels have the same Y coordinate.

9. The liquid crystal display device of claim 7, wherein the Y coordinate of the luminance centroid of the only bright subpixel agrees with that of the geometric centroid of the pixel.

10. The liquid crystal display device of claim 6, wherein the area of the at least one dark subpixel is at least three times as large as that of the at least one bright subpixel.

11. A liquid crystal display device comprising a plurality of pixels that are arranged in matrix so as to form a plurality of rows extending in an X direction and a plurality of columns extending in a Y direction,

wherein each said pixel includes a liquid crystal layer and a plurality of electrodes for applying a voltage to the liquid crystal layer, and is split into at least one bright subpixel, which has a luminance higher than a certain luminance produced by a display signal voltage supplied, and at least one dark subpixel that has a lower luminance than the certain luminance, and

wherein the area of the at least one bright subpixel is smaller than that of the at least one dark subpixel, and

wherein if the at least one bright subpixel and the at least one dark subpixel are arranged in the Y direction in each said pixel, two closest pixels that belong to the same row to display the same color have geometric centroids with mutually different Y coordinates, the greatest difference between the Y coordinates of luminance centroids being equal to or smaller than a half of the length R_Y of the two pixels as measured in the Y direction, or

wherein if the at least one bright subpixel and the at least one dark subpixel are arranged in the X direction in each said pixel, two pixels that are adjacent to each other in the column direction have geometric centroids with mutually different X coordinates, the greatest difference between the X coordinates of luminance centroids being equal to or smaller than a half of the length R_X of the two pixels as measured in the X direction.

12. The liquid crystal display device of claim 11, wherein supposing the geometric centroid of one of the two closest pixels that belong to the same row to display the same color is defined as an origin, the Y coordinate of the luminance centroid of the bright subpixel of that pixel is positive, and

wherein supposing the geometric centroid of the other pixel is defined as an origin, the Y coordinate of the luminance centroid of the bright subpixel of that pixel is negative.

13. The liquid crystal display device of claim 11, wherein in every pixel belonging to the same column, the at least one bright subpixel and the at least one dark subpixel are arranged at the same locations of theirs.

14. The liquid crystal display device of claim 11, wherein the at least one bright subpixel that each said pixel has is the only bright subpixel of that pixel.

15. The liquid crystal display device of claim 14, wherein the at least one dark subpixel that each said pixel has is the only dark subpixel of that pixel.

16. The liquid crystal display device of claim 11, wherein the area of the at least one dark subpixel is at least three times as large as that of the at least one bright subpixel.

17. A liquid crystal display device comprising a plurality of pixels that are arranged in matrix so as to form a plurality of rows extending in an X direction and a plurality of columns extending in a Y direction,

wherein each said pixel includes a liquid crystal layer and a plurality of electrodes for applying a voltage to the liquid crystal layer, and is split into at least one bright subpixel, which has a luminance higher than a certain luminance produced by a display signal voltage supplied, and at least one dark subpixel that has a lower luminance than the certain luminance, and

wherein the area of the at least one bright subpixel is smaller than that of the at least one dark subpixel, and

wherein if the at least one bright subpixel and the at least one dark subpixel are arranged in the Y direction in each said pixel, two closest pixels that belong to the same row to display the same color have geometric centroids with mutually different Y coordinates, a difference between the Y coordinates of the luminance centroids of their respective bright subpixels being equal to or smaller than a half of the length R_Y of the two pixels as measured in the Y direction, or

wherein if the at least one bright subpixel and the at least one dark subpixel are arranged in the X direction in each said pixel, two pixels that are adjacent to each other in the column direction have geometric centroids with mutually different X coordinates, a difference between the X coordinates of the luminance centroids of their respective bright subpixels being equal to or smaller than a half of the length R_X of the two pixels as measured in the X direction.