Dimming method, dimming screen, liquid crystal display device and computer readable storage medium

Patent metadata

Field	Value
Publication number	US-11217186-B2
Application number	US-201916611444-A
Country	US
Kind code	B2
Filing date	Apr 4, 2019
Priority date	Apr 16, 2018
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

The present disclosure provides a dimming method for an LCD device. The LCD device includes a dimming screen and a display screen. The dimming screen is divided into N×M dimming areas, and the display screen is also divided into N×M display areas. N and M are respectively positive integers greater than or equal to 1. The dimming areas correspond to the display areas in a one-to-one relationship. The dimming method includes determining a regional eigenvalue of each of the dimming areas according to image data, determining a dimming brightness of each of the dimming areas according to each regional eigenvalue, and dimming each of the dimming areas according to each dimming brightness. The present disclosure also provides a dimming screen for use in the dimming method and an LCD device using the dimming method.

First claim

What is claimed is:

1. A dimming method for an LCD device, the LCD device comprising a light source, a dimming screen and a display screen, wherein the dimming screen is divided into N×M dimming areas, wherein the display screen is divided into N×M display areas, wherein N and M are positive integers greater than or equal to 1, and wherein the dimming areas correspond to the display areas in a one-to-one relationship, the dimming method comprising:
determining a maximum or an average value of gray scale in each of the dimming areas respectively as a regional eigenvalue of each of the dimming areas according to image data;
determining a dimming brightness of each of the dimming areas according to the regional eigenvalue of corresponding ones of the dimming areas; and
dimming each of the dimming areas according to the dimming brightness of the corresponding ones of the dimming areas;
determining a target brightness of each of the display areas according to the image data and a correspondence between a gray scale and the target brightness;
determining a transmittance of each of the display areas according to the target brightness of corresponding ones of the display areas and a corresponding dimming brightness of the corresponding ones of the dimming areas;
determining a target gray scale of each of the display areas according to the transmittance of the corresponding ones of the display areas and a correspondence between a gray scale and the transmittance of the corresponding ones of the display areas; and
making compensation according to the target gray scale of each of the display areas,
wherein the dimming screen is between the light source and the display screen, so that light from the light source illuminates the dimming screen and then reaches the display screen after the dimming of the dimming screen,
wherein the dimming area and the display area are respectively configured as a single pixel.

2. The dimming method according to claim 1 , further comprising:
correcting the dimming brightness of each of the dimming areas by boundary smoothing filtering.

3. The dimming method according to claim 2 , wherein correcting the dimming brightness of each of the dimming areas by boundary smoothing filtering comprises:
configuring a Gaussian smoothing filter to perform the boundary smoothing filtering.

4. The dimming method according to claim 1 , wherein determining the dimming brightness of each of the dimming areas according to the regional eigenvalue of the corresponding ones of the dimming areas comprises:
determining whether the regional eigenvalue is less than a threshold;
when the regional eigenvalue is not less than the threshold, configuring the corresponding dimming brightness with a maximum brightness; and
when the regional eigenvalue is less than the threshold, determining the corresponding dimming brightness in direct proportion to the regional eigenvalue.

5. The dimming method according to claim 1 , wherein the target brightness is determined by the following formula:

L

n
⁢
e
⁢
w

=

(

x

2
⁢
5
⁢
5

)

G
⁢
a
⁢
m
⁢
m
⁢
a

⁢

g
⁡

(

L

2
⁢
5
⁢
5

-

n
⁢
e
⁢
w

-

L

0
-

n
⁢
e
⁢
w

)

+

L

0
-

n
⁢
e
⁢
w

,

and
wherein L new is the target brightness, x is the gray scale, Gamma is a curvature coefficient of the gray scale and the target brightness, L 255-new is a maximum brightness of the display screen after dimming, L 0-new is a minimum brightness of the display screen after dimming, and g is a proportional coefficient.

6. The dimming method according to claim 1 , wherein the transmittance is determined by the following formula:

η
=

L

n
⁢
e
⁢
w

L

L
⁢
C
⁢
D
⁢
1

,

and
wherein η is the transmittance, L new is the target brightness, and L LCD1 is the dimming brightness corresponding to the target brightness.

7. A non-transitory computer readable storage medium, on which a computer program is stored, the computer program, when executed by a processor, realizing the dimming method according to claim 1 .

8. An LCD device comprising a light source, a dimming screen and a display screen, wherein the dimming screen is between the light source and the display screen, so that light from the light source illuminates on the dimming screen a

Assignees

• Boe Technology Group Co Ltd

Inventors

• Xi Yanhui
• Bi Yuxin
• Dai Bin
• Zhang Xiaomang
• Shi Lingyun

Classifications

• G09G3/3426 Primary

  the different display panel areas being distributed in two dimensions, e.g. matrix · CPC title

• G09G2320/0646

  Modulation of illumination source brightness and image signal correlated to each other · CPC title

• G09G2320/0686

  with two or more screen areas displaying information with different brightness or colours · CPC title

• G09G2360/16

  Calculation or use of calculated indices related to luminance levels in display data · CPC title

• G09G3/342 Primary

  using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines · CPC title