Method of Setting Grayscale Value of Liquid Crystal Panel and Liquid Crystal Display

Patent metadata

Field	Value
Publication number	US-2016247296-A1
Application number	US-201414387019-A
Country	US
Kind code	A1
Filing date	Aug 22, 2014
Priority date	Aug 18, 2014
Publication date	Aug 25, 2016
Grant date	—

Abstract

A method of setting a grayscale value of a liquid crystal panel, each pixel unit in the liquid crystal panel comprises a main pixel M and a sub pixel S, having an area ratio between the main and sub pixels. The method includes acquiring an actual brightness value of each grayscale of the liquid crystal panel under a front view and a squint angle; dividing the actual brightness values based on the area ratio, and establishing a relationship between the grayscale and the actual brightness; calculating a theoretical brightness value of each grayscale; setting a grayscale combination input to the main pixel M and the sub pixel S, so a sum of difference values between actual and theoretical brightness would be the smallest under the front and squint angles; repeating the previous step for all grayscales of the liquid crystal panel. A liquid crystal display is also disclosed.

First claim

1 . A method of setting a grayscale value of a liquid crystal panel, the liquid crystal panel comprises a plurality of pixel units, each pixel unit comprising a main pixel M and a sub pixel S, an area ratio between the main pixel M and the sub pixel S being a:b, wherein the method comprises:
S101, acquiring an actual brightness value Lvα of each grayscale G of the liquid crystal panel under a front view angle α; S102, acquiring an actual brightness value Lvβ of each grayscale G of the liquid crystal panel under a squint angle β; S103, dividing the actual brightness values Lvα and Lvβ based on the area ratio between the main pixel M and the sub pixel S according to relationships:
LvMα:LvSα=a:b, LvMα+LvSα=Lvα;
LvMβ:LvSβ=a:b, LvMβ+LvSβ=Lvβ;
thereby acquiring the actual brightness values LvMα and LvMβ of each grayscale G of the main pixel M under the front view angle αand the squint angle β; acquiring the actual brightness values LvSα and LvSβ of each grayscale G of the sub pixel S under the front view angle αand the squint angle β; S104, based on the actual brightness values Lvα(max) and Lvβ(max) of a maximum grayscale max acquired in steps S101 and S102, and in conjunction with formulae

gamma
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(
γ
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=

2.2
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and
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(

G
max

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γ

=

LvG

Lv
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(
max
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,

calculating and acquiring theoretical brightness values LvGα and LvGβ of each grayscale G of the liquid crystal panel under the front view angle α and the squint angle β;
S105, regarding one of grayscales Gx of the pixel unit, assuming that the grayscales input to the main pixel M and the sub pixel S are Gmx and Gsx respectively, then obtaining the actual brightness values LvMxα, LvMxβ, LvSxα and LvSxβ according to a result of step S103, and obtaining the theoretical brightness values LvGxα and LvGxβ according to a result of step S104; calculating relationships:
Δ1= LvMxα+LvSxα−LvGxα;

Δ2= LvMxβ+LvSxβ−LvGxβ;

y=Δ 2 +Δ2 2 ;

wherein grayscales Gmx and Gsx obtained when a minimum of y is calculated are set as the grayscales input to the main pixel M and the sub pixel S respectively when the pixel unit is in the grayscale Gx; and
S106, regarding each grayscale G of the pixel unit, repeating step S105 so as to obtain the grayscales input to the main pixel M and the sub pixel S respectively for all grayscales of the liquid crystal panel.

2 . The method according to claim 1 , wherein the front view angle α is 0°, while the squint angle β is 30˜80°.

3 . The method according to claim 2 , wherein the squint angle β is 60°.

4 . The method according to claim 1 , wherein the liquid crystal panel comprises 256 grayscales (from 0 to 255), and the maximum grayscale max is 255 grayscale.

5 . The method according to claim 1 , wherein the acquiring of the actual brightness value Lvα of each grayscale G of the liquid crystal panel under the front view angle α comprises:
acquiring a gamma curve of the liquid crystal panel under the front view angle α; and
determining the actual brightness value Lvα according to the gamma curve.

6 . The method according to claim 1 , wherein the acquiring of the actual brightness value Lvβ of each grayscale G of the liquid crystal panel under the squint angle β comprises:
acquiring a gamma curve of the liquid crystal panel under the squint angle β; and
determining the actual brightness value Lvβ according to the gamma curve.

7 . The method according to claim 1 , wherein after completing step S106, a relation curve Gm−Lv between the grayscale and brightness of the main pixel M and a relation curve Gs−Lv between the grayscale and brightness of the sub pixel S are obtained, and singular points appeared in the curve Gm−Lv and the curve Gs−Lv are processed by using a locally weighted scatter plot smoothing method.

8 . The method according to claim 1 , wherein after completing step S106, a relation curve Gm−Lv between the grayscale and brightness of the main pixel M and a relation curve Gs−Lv between the grayscale and brightness of the sub pixel S are obtained, and singular points appeared in the curve Gm−Lv and the curve Gs−Lv by using a power function fitting method.

9 . The method according to claim 8 , wherein an expression of the power function is:
f=m*x̂n+k.

10 . A liquid crystal display, comprising a backlight module and a liquid crystal panel facing each other; the backlight module providing display light source to the liquid crystal panel so as to allow the liquid crystal panel to display image; the liquid crystal panel comprising a plurality of pixel units, each pixel unit comprising a main pixel M and a sub pixel S; an area ratio between the main pixel M and the sub pixel S being a:b, wherein a method of setting a grayscale of the liquid crystal panel comprises:
S101, acquiring an actual brightness value Lvα of each grayscale G of the liquid crystal panel under a front view angle α; S102, acquiring an actual brightness value Lvβ of each grayscale G of the liquid crystal panel under a squint angle β; S103, dividing the actual brightness values Lvα and Lvβ based on the area ratio between the main pixel M and the sub pixel S according to relationships:
LvMα:LvSα=a:b, LvMα+LvSα=Lvα;
LvMβ:LvSβ=a:b, LvMβ+LvSβ=Lvβ;
thereby acquiring the actual brightness values LvMα and LvMβ of each grayscale G of the main pixel M under the front view angle α and the squint angle β; acquiring the actual brightness values LvSα and LvSβ of each grayscale G of the sub pixel S under the front view angle α and the squint angle β; S104, based on the actual brightness values Lvα(max) and Lvβ(max) of a maximum grayscale max acquired in steps S101 and S102, and in conjunction with formulae

gamma


(
γ
)

=

2.2



and




(

G
max

Assignees

• Shenzhen China Star Optoelect

Inventors

• Chen Lixuan

Classifications

• G06T11/10 Primary

  Texturing; Colouring; Generation of textures or colours (retouching, inpainting or scratch removal G06T5/77) · CPC title

• G09G5/02

  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)} · CPC title

• G09G2320/0673

  for control of gamma adjustment, e.g. selecting another gamma curve · CPC title

• G09G2320/028

  by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction · CPC title

• G09G3/3607

  for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels (display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127) · CPC title