Display

• US 8,319,791 B2
• Filed: 06/05/2006
• Issued: 11/27/2012
• Est. Priority Date: 10/03/2005
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ueki, Shun, Nakamura, Kozo, Taguchi, Tokio, Itou, Akiko
• Primary Examiner(s): Ma, Tize
• Assistant Examiner(s): He, Yingchun
• Application Number:
  US12/088,887
• Publication Number:
  US 20090273607A1
• Time in Patent Office: 2,367 Days
• Field of Search: 345589-605, 345 87- 88
• US Class Current: 345/613
• CPC Class Codes: G02F 2201/52 RGB geometrical arrangements
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/026 Control of mixing and/or overlay of colours in general G09G5/022 and G09G5/024 take precedence

Abstract

A display device has a pixel that is defined by a plurality of sub-pixels. The sub-pixels include a red sub-pixel representing red, a green sub-pixel representing green, a blue sub-pixel representing blue and a yellow sub-pixel representing yellow. When the pixel represents white, the luminance of the red sub-pixel is lower than its luminance corresponding to the highest gray scale level. In one embodiment, when the pixel represents white, the luminance of the red sub-pixel is preferably in the range of 25% to 96% of its luminance corresponding to the highest gray scale level. Also, the color temperature of white represented by the pixel is preferably higher than 4200 K, more preferably higher than 5000 K.

Claims

1. A display device comprising:

a pixel that is defined by a plurality of sub-pixels;

wherein

the sub-pixels include a red sub-pixel representing red, a green sub-pixel representing green, a blue sub-pixel representing blue, and a yellow sub-pixel representing yellow, and when the pixel represents white, the luminance of the red sub-pixel is lower than its luminance corresponding to a highest gray scale level; and

when the pixel represents white, a sum of the luminances of the red, the green, the blue, and the yellow sub-pixels is about 90% or more of a sum of the luminances of the red, the green, the blue, and the yellow sub-pixels at corresponding highest gray scale levels thereof.

2. The display device of claim 1, wherein the red sub-pixel has a dominant wavelength of about 597 nm to less than about 780 nm, the green sub-pixel has a dominant wavelength of about 488 nm to less than about 558 nm, the blue sub-pixel has a dominant wavelength of about 380 nm to less than about 488 nm, and the yellow sub-pixel has a dominant wavelength of about 558 nm to less than about 597 nm.

3. The display device of claim 1, wherein when the pixel represents white, the luminance of the red sub-pixel is about 96% or less of its luminance corresponding to the highest gray scale level.

4. The display device of claim 1, wherein when the pixel represents white, the luminance of the red sub-pixel is about 25% or more of its luminance corresponding to the highest gray scale level.

5. The display device of claim 1, wherein when the pixel represents white, the luminances of the green and yellow sub-pixels corresponds to a highest gray scale level thereof.

6. The display device of claim 1, wherein the color temperature of white represented by the pixel is higher than about 4200 K.

7. The display device of claim 6, wherein the color temperature of white represented by the pixel is equal to or higher than about 5000 K.

8. A display device comprising a pixel and conducting a display operation using a frame that includes a red subframe to make the pixel represent red, a green subframe to make the pixel represent green, a blue subframe to make the pixel represent blue, and a yellow subframe to make the pixel represent yellow;

wherein

when the pixel represents white in the frame, the luminance of the pixel in the red subframe is lower than its luminance corresponding to a highest gray scale level; and

when the pixel represents white in the frame, a sum of the luminances of the red, the green, the blue, and the yellow subframes is about 90% or more of a sum of the luminances of the red, the green, the blue, and the yellow subframes at corresponding highest gray scale levels thereof.