Driving method and driving device of liquid crystal panel

• US 9,805,670 B2
• Filed: 08/12/2015
• Issued: 10/31/2017
• Est. Priority Date: 07/15/2015
• Status: Active Grant

• Current Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd. (TCL Technology Group Corp.)
• Original Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd. (TCL Technology Group Corp.)
• Inventors: Kang, Chih-tsung, Chen, Lixuan
• Primary Examiner(s): EURICE, MICHAEL
• Application Number:
  US14/781,136
• Publication Number:
  US 20170018238A1
• Time in Patent Office: 811 Days
• CPC Class Codes: G01J 3/463 Colour matching
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• 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 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• 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 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 2340/0428 Gradation resolution change
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/3607 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

Abstract

A driving method and a driving device of a liquid crystal panel are provided. Pixels in a liquid crystal panel are divided into groups, wherein each group includes two pixels; determining an original greyscale value of a first color sub-pixel and an original greyscale value of a second color sub-pixel of each pixel; acquiring two actual greyscale values for driving the first color sub-pixel and two actual greyscale values for driving the second color sub-pixel in each group. The actual greyscale value for driving the first color sub-pixel is determined for each pixel, among the two actual greyscale values for driving the first color sub-pixel in each group, and determining the actual greyscale value for driving the second color sub-pixel of each pixel, among the two actual greyscale values for driving the second color sub-pixel in each group, according to a position of each pixel in each group.

Claims

1. A driving method of a liquid crystal panel, comprising:

(A) dividing pixels in a liquid crystal panel into groups, wherein each group comprises two pixels, and two pixels in any group are two adjacent pixels in a predetermined direction;

(B) determining an original greyscale value of a first color sub-pixel and an original greyscale value of a second color sub-pixel of each pixel in each group;

(C) acquiring two actual greyscale values for driving the first color sub-pixel in each group according to at least one of the original greyscale values of the first color sub-pixel of two pixels in each group and acquiring two actual greyscale values for driving the second color sub-pixel in each group according to at least one of the original greyscale values of the second color sub-pixel of two pixels in each group by determining an index value according to at least one of the original greyscale values of the color sub-pixel of the two pixels in the group and looking up two actual greyscale values corresponding to the index value from a display look-up table of the color sub-pixel, wherein the table is acquired by

acquiring an actual brightness value of the color sub-pixel under a respective greyscale value within a greyscale value range of the liquid crystal panel separately in a case of front viewing and in a case of oblique viewing,

calculating a theoretical brightness value of the color sub-pixel under the respective greyscale value within the greyscale value range separately in the case of front viewing and in the case of oblique viewing using Lv(g)=Lv(g_max)′

×

(g/g_max)^γ

, wherein γ

is a predetermined gamma value, Lv(g) is the theoretical brightness value of the color sub-pixel under the greyscale value g in the case of viewing from an angle, and Lv(g_max)′

is the actual brightness values of the color sub-pixel under the maximum greyscale value g_max within the greyscale value range in the case of viewing from the angle, and wherein viewing from the angle defines one of front viewing or oblique viewing, and

determining two actual greyscale values meeting a predetermined condition and corresponding to each greyscale value within the greyscale value range which is taken as the index value, according to the acquired respective actual brightness value and the calculated respective theoretical brightness value, wherein any greyscale value g within the greyscale value range, which is taken as the index value, as well as two corresponding actual greyscale values g_H and g_L meet the following predetermined condition;

min y=[Lv_front(g)+Lv_front(g)−

Lv_front(g_H)′

−

Lv_front(g_L)′

]²+[Lv_oblique(g)+Lv_oblique(g)−

Lv_oblique(g_H)′

−

Lv_oblique(g_L)′

]²,

wherein Lv_front (g) and Lv_oblique (g) are the theoretical brightness value of the color sub-pixel under the greyscale value g separately in the case of front viewing and in the case of oblique viewing, Lv_front (g_H)′ and

Lv_oblique (g_H)′

are the actual brightness value of the color sub-pixel under the actual greyscale value g_H separately in the case of front viewing and in the case of oblique viewing, Lv_front (g_L)′ and

Lv_oblique (g_L)′

are the actual brightness value of the color sub-pixel under the actual greyscale value is g_L separately in the case of front viewing and in the case of obliquely viewing, and associating each index value with the determined two actual greyscale values; and

(D) determining the actual greyscale value for driving the first color sub-pixel of each pixel, among the two actual greyscale values for driving the first color sub-pixel in each group, and determining the actual greyscale value for driving the second color sub-pixel of each pixel, among the two actual greyscale values for driving the second color sub-pixel in each group, according to a position of each pixel in each group.

2. The driving method of claim 1, wherein step (D) comprises:

determining a larger one of the two actual greyscale values for driving the first color sub-pixel in each group as the actual greyscale value for driving the first color sub-pixel of one pixel of the two pixels, of which a sum of a row number and a column number is an even number, in each group;

determining a smaller one of the two actual greyscale values for driving the first color sub-pixel in each group as the actual greyscale value for driving the first color sub-pixel of one pixel of the two pixels, of which a sum of a row number and a column number is an odd number, in each group;

determining a larger one of the two actual greyscale values for driving the second color sub-pixel in each group as the actual greyscale value for driving the second color sub-pixel of one pixel of the two pixels, of which a sum of a row number and a column number is an odd number, in each group; and

determining a smaller one of the two actual greyscale values for driving the second color sub-pixel in each group as the actual greyscale value for driving the second color sub-pixel of one pixel of the two pixels, of which a sum of a row number and a column number is an even number, in each group.

3. The driving method of claim 1, wherein the predetermined direction is a lateral direction or a longitudinal direction.

4. The driving method of claim 1, wherein the step of determining the index value comprises:

taking the original greyscale value of the color sub-pixel of any one of the two pixels in the group as the index value.

5. The driving method of claim 1, wherein the step of determining the index value comprises:

taking an average value of the original greyscale values of the color sub-pixel of the two pixels in the group as the index value.

6. The driving method of claim 1, wherein the actual brightness value of the color sub-pixel under the respective greyscale value within the greyscale value range of the liquid crystal panel in the case of front viewing and in the case of obliquely viewing is acquired by measuring a gamma curve of the color sub-pixel separately in the case of front viewing and in the case of obliquely viewing.

7. A driving device of a liquid crystal panel, comprising:

a grouping unit configured to divide pixels in a liquid crystal panel into groups, wherein each group comprises two pixels, and two pixels in any group are two adjacent pixels in a predetermined direction;

an original greyscale value determination unit configured to determine an original greyscale value of a first color sub-pixel and an original greyscale value of a second color sub-pixel of each pixel in each group;

an actual greyscale value acquisition unit configured to sequentially acquire two actual greyscale values for driving the first color sub-pixel in each group according to at least one of the original greyscale values of the first color sub-pixel of two pixels in each group and acquire two actual greyscale values for driving the second color sub-pixel in each group according to at least one of the original greyscale values of the second color sub-pixel of two pixels in each group, wherein the actual greyscale value acquisition unit comprises;

an index value determination unit configured to determine an index value according to at least one of the original greyscale values of any color sub-pixel of the two pixels in any group,

a table creation unit configured to create a display look-up table of the color sub-pixel and comprising;

an actual brightness value acquisition unit configured to acquire an actual brightness value of the color sub-pixel under a respective greyscale value within a greyscale value range of the liquid crystal panel separately in a case of front viewing and in a case of oblique viewing,

a theoretical brightness value calculation unit configured to calculate a theoretical brightness value of the color sub-pixel under the respective greyscale value within the greyscale value range separately in the case of front viewing and in the case of oblique viewing based on Lv(g)=Lv(g_max)′

×

(g/g_max)^γ

, wherein γ

is a predetermined gamma value, Lv(g) is the theoretical brightness value of the color sub-pixel under the greyscale value g in the case of viewing from an angle, and Lv(g_max)′

is the actual brightness values of the color sub-pixel under the maximum greyscale value g_max within the greyscale value range in the case of viewing from the angle, and wherein viewing from the angle defines one of front viewing or oblique viewing,

a relationship determination unit configured to determine two actual greyscale values meeting a predetermined condition and corresponding to each greyscale value within the greyscale value range which is taken as the index value, according to the acquired respective actual brightness value and the calculated respective theoretical brightness value, such that

min y=[Lv_front(g)+Lv_front(g)−

Lv_front(g_H)′

−

Lv_front(g_L)′

]²+[Lv_oblique(g)+Lv_oblique(g)−

Lv_oblique(g_H)′

−

Lv_oblique(g_L)′

]²,

wherein Lv_front(g) and Lv_oblique(g) are the theoretical brightness value of the color sub-pixel under the greyscale value g separately in the case of front viewing and in the case of oblique viewing, Lv_front (g_H)′ and

Lv_oblique (g_H)′

are the actual brightness value of the color sub-pixel under the actual greyscale value g_H separately in the case of front viewing and in the case of oblique viewing, Lv_front (g_L)′ and

Lv_oblique (g_L)′

are the actual brightness value of the color sub-pixel under the actual greyscale value is g_L separately in the case of front viewing and in the case of oblique viewing, and

a creation unit configured to associate each index value with the determined actual greyscale values to define the display look-up table, and

a table look-up unit configured to look up two actual greyscale values corresponding to the index value from the display look-up table of the color sub-pixel, to acquire the two actual greyscale values for driving the color sub-pixel in the group; and

a driving determination unit configured to determine the actual greyscale value for driving the first color sub-pixel of each pixel, among the two actual greyscale values for driving the first color sub-pixel in each group, and to determine the actual greyscale value for driving the second color sub-pixel of each pixel, among the two actual greyscale values for driving the second color sub-pixel in each group, according to a position of each pixel in each group.

8. The driving device of claim 7, wherein the driving determination unit is configured to determine a larger one of the two actual greyscale values for driving the first color sub-pixel in each group as the actual greyscale value for driving the first color sub-pixel of one pixel of the two pixels, of which a sum of a row number and a column number is an even number, in each group;

and to determine a smaller one of the two actual greyscale values for driving the first color sub-pixel in each group as the actual greyscale value for driving the first color sub-pixel of one pixel of the two pixels, of which a sum of a row number and a column number is an odd number, in each group; and

to determine a larger one of the two actual greyscale values for driving the second color sub-pixel in each group as the actual greyscale value for driving the second color sub-pixel of one pixel of the two pixels, of which a sum of a row number and a column number is an odd number, in each group; and

to determine a smaller one of the two actual greyscale values for driving the second color sub-pixel in each group as the actual greyscale value for driving the second color sub-pixel of one pixel of the two pixels, of which a sum of a row number and a column number is an even number, in each group.

9. The driving device of claim 7, wherein the predetermined direction is a lateral direction or a longitudinal direction.

10. The driving device of claim 7, wherein the index value determination unit is configured to take the original greyscale value of the color sub-pixel of any one of the two pixels in the group as the index value.

11. The driving device of claim 7, wherein the index value determination unit is configured to take an average value of the original greyscale values of the color sub-pixel of the two pixels in the group as the index value.

12. The driving device of claim 7, wherein the actual brightness value acquisition unit is configured to acquire the actual brightness value of the color sub-pixel under the respective greyscale value within the greyscale value range of the liquid crystal panel in the case of front viewing and in the case of obliquely viewing by measuring a gamma curve of the color sub-pixel separately in the case of front viewing and in the case of obliquely viewing.