Liquid crystal display apparatus and method of driving the same

Patent metadata

Field	Value
Publication number	US-9767737-B2
Application number	US-201514816738-A
Country	US
Kind code	B2
Filing date	Aug 3, 2015
Priority date	Dec 1, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A liquid crystal display apparatus includes a backlight configured to emit red light, green light, and blue light for forming an image, a liquid crystal panel including a plurality of pixels through which light components supplied by the backlight respectively pass, configured to control transmittances of the plurality of pixels to form an image, and a backlight controller configured to control respective intensities of the red light, the green light, and the blue light emitted by the backlight. The backlight controller is configured to compensate for a black color coordinate value generated with respect to a predetermined color by controlling the backlight such that a second red light intensity and a second green light intensity are larger than a first red light intensity and a first green light intensity and a second blue light intensity are smaller than a first blue light intensity. A black color coordinate value may be made correspond to a white color coordinate value.

First claim

What is claimed is:

1. A liquid crystal display apparatus comprising:
a backlight configured to emit red light, green light, and blue light for forming an image;
a liquid crystal panel including a plurality of pixels through which light components supplied by the backlight respectively pass, configured to control transmittances of the plurality of pixels to form an image; and
a backlight controller configured to control respective intensities of the red light, the green light, and the blue light emitted by the backlight,
wherein the backlight controller is configured to compensate for a black color coordinate value generated with respect to a predetermined color by controlling the backlight such that a second red light intensity and a second green light intensity are larger than a first red light intensity and a first green light intensity and a second blue light intensity are smaller than a first blue light intensity.

2. The liquid crystal display apparatus of claim 1 , wherein the backlight controller is configured to control the backlight so that any change of a white color coordinate value and the compensated black color coordinate value generated with respect to the predetermined color remain within a predetermined range.

3. The liquid crystal display apparatus of claim 2 , further comprising a data driver configured to control data voltages applied to the plurality of pixels and control transmittances of the plurality of pixels,
the data driver is configured to control the data voltages so that a color coordinate value having an intermediate grayscale with respect to the predetermined color corresponds to the white color coordinate value.

4. The liquid crystal display apparatus of claim 2 , further comprising a memory configured to store color coordinates.

5. The liquid crystal display apparatus of claim 4 , further comprising a color measuring unit configured to measure the change of the white color coordinate value with respect to the color coordinates stored in the memory.

6. The, liquid crystal display apparatus of claim 5 , further comprising a processor configured to control the color measuring unit to measure the change of the white color coordinate value.

7. The liquid crystal display apparatus of claim 6 , the processor controlling the liquid crystal panel, the backlight controller, and the memory.

8. The liquid crystal display apparatus of claim 1 , wherein the backlight comprises a red light-emitting diode configured to emit the red light, a green light-emitting diode configured to emit the green light, and a blue light-emitting diode configured to emit the blue light.

9. The liquid crystal display apparatus of claim 8 , wherein the backlight controller is configured to control currents applied to the red light-emitting diode, the green light-emitting diode, and the blue light-emitting diode to control the intensity of the red light, the intensity of the green light, and the intensity of the blue light.

10. A liquid crystal display apparatus comprising:
a liquid crystal panel including a plurality of pixels; and
a backlight configured to emit light toward the liquid crystal panel,
wherein each of the plurality of pixels comprises a liquid crystal layer and red, green, and blue color filters configured to filter light that passes through the liquid crystal layer and transmit red, green, and blue light components, and
transmittance of the blue color filter is smaller than that of the green color filter and that of the red color filter.

11. The liquid crystal display apparatus of claim 10 , wherein the transmittances of the blue color filter, the green color filter, and the red c r filter are determined so that any change in a color coordinate value of a predetermined color remain within a predetermined range during a change from a black color coordinate value to a white color coordinate value.

12. The liquid crystal display apparatus of claim 11 , wherein the liquid crystal panel further comprises a data driver configured to control data voltages applied to the plurality of pixels and control transmittances of the plurality of pixels,
the data driver is configured to control the data voltages so that a color coordinate value generated when an intermediate grayscale is formed with respect to the predetermined color corresponds to the white color coordinate value.

13. The liquid crystal display apparatus of claim 10 , wherein the blue color filter is thicker than the green color filter and thicker than the red color filter.

14. A method of driving a liquid crystal display apparatus having a backlight configured to emit red light, green light, and blue light for forming an image, a liquid crystal panel including a plurality of pixels through which light components supplied by the backlight respectively pass, configured to control transmittances of the plurality of pixels to form an image, and a backlight controller configured to control respective intensities of the red light, the green light, and the blue light emitted by the backlight, wherein the backlight controller is configured to compensate for a black color coordinate value generated with respect to a predetermined color by controlling the backlight such that a second red light intensity and a second green intensity are larger than a first red light intensity and a first green light intensity and a second blue light intensity is smaller than a first blue light intensity, the method comprising:
measuring a white color coordinate value;
comparing a black color coordinate value stored in a memory with the white color coordinate value to calculate a compensation signal; and
adjusting the black color coordinate value based on the compensation signal until the black color coordinate value corresponds to the white color coordinate value.

15. The method of claim 14 , further comprising, adjusting a color coordinate value until the color coordinate value having an intermediate grayscale corresponding to the white color coordinate value.

16. The method of claim 14 , wherein the compensation signal is calculated by detecting a first red light intensity, a first green light intensity, and a first blue light intensity at a black color coordinate value, making a second red light intensity and a second green light intensity larger than the first red light intensity and the first green light intensity at the black color coordinate value, and making a second blue light intensity smaller than the first blue light intensity at the black color coordinate value.

Assignees

• Samsung Display Co Ltd

Inventors

• Son Jongho
• Lee Kyunghee
• Jeong Kangseob
• Park Joonhyung
• Oh Keunchan

Classifications

• G09G2320/0666

  for control of colour parameters, e.g. colour temperature · CPC title

• G02B6/0068

  Arrangements of plural sources, e.g. multi-colour light sources · CPC title

• G02B6/0073

  Light emitting diode [LED] · CPC title

• G09G3/2003

  Display of colours (specific for liquid crystal displays G09G3/3607) · CPC title

• G09G2320/0242

  Compensation of deficiencies in the appearance of colours · CPC title