Liquid crystal display device and method for improving color reproducibility thereof

• US 8,184,077 B2
• Filed: 10/23/2003
• Issued: 05/22/2012
• Est. Priority Date: 12/31/2002
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lee, Don-Gyou, Kil, Jung-Ho, Song, Ki-Yon
• Primary Examiner(s): Boddie, William
• Application Number:
  US10/691,312
• Publication Number:
  US 20040125063A1
• Time in Patent Office: 3,134 Days
• Field of Search: 345/89, 345589-590, 345600-602, 349/74, 382/167, 348/649
• US Class Current: 345/89
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607

Abstract

A liquid crystal display device and a method for improving a color reproducibility thereof, detects a gray scale value in applied image information that reduces a color reproducibility of a liquid crystal display device by measuring a gray scale level of a color displayed on a liquid crystal display panel while increasing the gray scale value of the color, and storing a maximum value of the gray scale level is displayable prior to reducing the color reproducibility. The applied image information is compensated to prevent reduction in the color reproducibility.

Claims

1. A liquid crystal display device, comprising:

a liquid crystal panel having a plurality of gate lines and data lines crossing each other, and having red (R), green (G) and blue (B) pixels arranged in a matrix pattern;

a light source transmitting light through the R, G, and B pixels creating red, green, and blue colors respectively;

a gate driving unit for applying scan signals to the gate lines;

a lookup table for storing gray scale values of image information including R, G and B data, where a gray scale value of a gray level of the B data that is lower than a gray level at which a color saturation is reduced, is stored as a gray scale value of gray levels that are higher than the gray level at which the color saturation is reduced,

wherein the lookup table includes a same initial gray scale value of at least one of the R and G data for all gray levels prior to a gray level at which the color saturation is reduced and the lookup table includes different gray scale values of the R and G data to mix with the B gray scale values from a gray level at which the color saturation is reduced to an uppermost gray level;

a data processing unit for compensating image information according to the gray scale values in the lookup table; and

a data driving unit for receiving the compensated image information and applying the compensated image information to the data lines.

2. The LCD device of claim 1, wherein the gray scale value of the gray levels of the B data prior to a gray level at which a color saturation is reduced is the same as the gray scale value of the gray levels from the gray level at which a color reproducibility is reduced to the uppermost gray level.

3. The LCD device of claim 1, wherein the B data has 64 gray levels.

4. The LCD device of claim 1, wherein the gray level at which a color saturation is reduced among the B data is a 52^nd gray level.

5. The LCD device of claim 1, wherein the gray level prior to a gray level where a color saturation is reduced among the B data is a 51^st gray level.

11. The liquid crystal display device of claim 1, wherein the lookup table includes the same initial gray scale value for both R and G data.

6. A method for improving a color reproducibility of a liquid crystal display (LCD) device, the method comprising:

detecting a gray scale value of a gray level at which a color saturation is reduced, and a gray scale value of a gray level that is lower than the gray level at which a color saturation is reduced, by measuring a color displayed on a liquid crystal panel with increasing gray scale values of B data among image information including R, G and B data;

storing the gray scale value of the gray level of the B data that is lower than the gray level at which a color saturation is reduced, as a gray scale value of gray level that are higher than the gray level at which a color saturation is reduced;

storing a same initial gray scale value of at least one of the R and G data for all gray levels prior to a gray level at which a color saturation is reduced and including different gray scale values of the R and G data to mix with the B gray scale values from a gray level at which the color saturation is reduced to an uppermost gray level;

compensating the image information according to the gray level and mixing the gray scale values of at least two of R, G, and B data; and

applying the compensated image information to data lines of the liquid crystal panel.

7. The method of claim 6, wherein the gray scale value of the gray level prior to the gray level at which a color saturation is reduced is same as the gray scale value of gray levels from the gray level at which a color saturation is reduced to the uppermost bit.

8. The method of claim 6, wherein the B data has 64 gray levels.

9. The method of claim 6, wherein the gray level at which a color saturation is reduced among the B data is a 52^nd gray level.

10. The method of claim 6, wherein the gray level prior to a gray level where a color saturation is reduced among the B data is a 51^st gray level.

12. The method of claim 6, wherein the same initial gray scale value is the same for both the R and G data.