Backlight control method and device and liquid crystal display device

• US 10,670,914 B2
• Filed: 12/28/2017
• Issued: 06/02/2020
• Est. Priority Date: 02/28/2017
• Status: Active Grant

• Current Assignee: Hisense Visual Technology Co., Ltd. (Qingdao Huatong State-Owned Capital Operation (Group) Co., Ltd.)
• Original Assignee: Qingdao Hisense Electronics Co., Ltd. (Qingdao Huatong State-Owned Capital Operation (Group) Co., Ltd.)
• Inventors: Zhang, Yuxin
• Primary Examiner(s): Pardo, Thuy N
• Application Number:
  US15/857,595
• Publication Number:
  US 20180246375A1
• Time in Patent Office: 887 Days
• Field of Search: 345690, 345691, 345102, 345 77, 345 87, 345589, 345591, 345593
• CPC Class Codes: G02F 1/133601 for spatial active dimming
• CPC Class Codes: G02F 1/133602 Direct backlight
• CPC Class Codes: G09G 2310/0264 Details of driving circuits
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/36 using liquid crystals

Abstract

A backlight control method is provided. The method includes: determining, based on a global backlight brightness value, a backlight brightness interval in which the global backlight brightness value is located; determining, according to a correspondence between the backlight brightness interval and a backlight gain coefficient table, a backlight gain coefficient table corresponding to the backlight brightness interval, where the backlight gain coefficient table is configured to indicate a gain coefficient corresponding to a partition backlight brightness value; determining, according to a partition backlight brightness value of each of backlight partitions and the backlight gain coefficient table, a gain coefficient of each of the backlight partitions; and driving each of the backlight partitions according to the gain coefficient of each of the backlight partition and the partition backlight brightness value of each of the backlight partitions.

Claims

1. A backlight control method, comprising:

determining, based on a global backlight brightness value, a backlight brightness interval in which the global backlight brightness value is located;

determining, according to a correspondence between the backlight brightness interval and a backlight gain coefficient table, a backlight gain coefficient table corresponding to the backlight brightness interval, wherein the backlight gain coefficient table is configured to indicate a gain coefficient corresponding to a partition backlight brightness value;

determining, according to a partition backlight brightness value of each of backlight partitions and the backlight gain coefficient table, a gain coefficient of each of the backlight partitions; and

driving each of the backlight partitions according to the gain coefficient of each of the backlight partition and the partition backlight brightness value of each of the backlight partitions;

wherein a global backlight brightness value range is divided into a plurality of backlight brightness intervals, the plurality of backlight brightness intervals comprise a first backlight brightness interval and a second backlight brightness interval, and a minimum global backlight brightness value of the first backlight brightness interval is greater than a maximum global backlight brightness value of the second backlight brightness interval;

the first backlight brightness interval corresponds to a first backlight gain coefficient table;

the second backlight brightness interval corresponds to a second backlight gain coefficient table; and

in a first alternative mode,

a partition backlight brightness value range of the first backlight gain coefficient table and a partition backlight brightness value range of the second backlight gain coefficient table have an overlapped portion, and the backlight gain coefficient corresponding to the partition backlight brightness value in the overlapped portion, in the first backlight gain coefficient table, is greater than the backlight gain coefficient corresponding to the same partition backlight brightness value in the second backlight coefficient table;

in a second alternative mode,

the first backlight brightness interval and the second backlight brightness interval are adjacent at a first threshold value;

a partition backlight brightness value range of the first backlight gain coefficient table is a first backlight brightness interval;

a partition backlight brightness value range of the second backlight gain coefficient table is a second backlight brightness interval; and

the backlight gain coefficient corresponding to a first partition backlight brightness value nearest to the first threshold value in the first backlight gain coefficient table, is greater than the backlight gain coefficient corresponding to a second partition backlight brightness value nearest to the first threshold value in the second backlight gain coefficient table.

2. The method according to claim 1, wherein the global backlight brightness value is determined based on a global grayscale brightness value of an image or on a user input.

3. The method according to claim 1, wherein the determining, based on a global backlight brightness value, a backlight brightness interval in which the global backlight brightness value is located, comprises:

determining the backlight brightness interval in which the global backlight brightness value is located based on a comparison result between the global backlight brightness value and each of preset threshold values, wherein the backlight brightness interval in which the global backlight brightness value is located is indicated by two adjacent threshold values.

4. The method according to claim 1, wherein a partition backlight brightness value range of the backlight gain coefficient table is same as or greater than that of the backlight brightness interval corresponding to the backlight gain coefficient table.

5. The method according to claim 1, wherein in the backlight gain coefficient table, when a maximum partition backlight brightness value in the backlight gain coefficient table is less than a first backlight brightness value, the gain coefficient increases with an increase of the partition backlight value.

6. The method according to claim 1, wherein in the backlight gain coefficient table, when a first backlight brightness value is between a minimum backlight brightness value and a maximum backlight brightness value in the backlight gain coefficient table, the gain coefficient first increases and then decreases with an increase of the partition backlight brightness value.

7. The method according to claim 1, wherein in the backlight gain coefficient table, when a minimum partition backlight brightness value in the backlight gain coefficient table is greater than a first backlight brightness value, the gain coefficient decreases with an increase of the partition backlight brightness value.

8. The method according to claim 1, wherein the determining, according to a correspondence between a backlight brightness interval and a backlight gain coefficient table, a backlight gain coefficient table corresponding to the backlight brightness interval, comprises:

determining, according to a one-to-one correspondence between the backlight brightness interval and the backlight gain coefficient table, the backlight gain coefficient table corresponding to the backlight brightness interval.

9. A backlight control device, comprising a nonvolatile memory for storing instructions and a processor coupled to the memory, wherein the processor is configured to execute instructions stored in the memory and the processor is configured to:

determine, based on a global backlight brightness value, a backlight brightness interval in which the global backlight brightness value is located;

determine, according to a correspondence between the backlight brightness interval and a backlight gain coefficient table, a backlight gain coefficient table corresponding to the backlight brightness interval, wherein the backlight gain coefficient table is configured to indicate a gain coefficient corresponding to a partition backlight brightness value;

determine, according to a partition backlight brightness value of each of backlight partitions and the backlight gain coefficient table, a gain coefficient of each of the backlight partitions; and

drive each of the backlight partitions according to the gain coefficient of each of the backlight partitions and the partition backlight brightness value of each of the backlight partitions;

wherein a global backlight brightness value range is divided into a plurality of backlight brightness intervals, the plurality of backlight brightness intervals comprise a first backlight brightness interval and a second backlight brightness interval, and a minimum global backlight brightness value of the first backlight brightness interval is greater than a maximum global backlight brightness value of the second backlight brightness interval;

the first backlight brightness interval corresponds to a first backlight gain coefficient table;

the second backlight brightness interval corresponds to a second backlight gain coefficient table; and

in a first alternative mode,

a partition backlight brightness value range of the first backlight gain coefficient table and a partition backlight brightness value range of the second backlight gain coefficient table have an overlapped portion, and the backlight gain coefficient corresponding to the partition backlight brightness value in the overlapped portion, in the first backlight gain coefficient table, is greater than the backlight gain coefficient corresponding to the same partition backlight brightness value in the second backlight coefficient table;

in a second alternative mode,

the first backlight brightness interval and the second backlight brightness interval are adjacent at a first threshold value;

a partition backlight brightness value range of the first backlight gain coefficient table is a first backlight brightness interval;

a partition backlight brightness value range of the second backlight gain coefficient table is a second backlight brightness interval; and

the backlight gain coefficient corresponding to a first partition backlight brightness value nearest to the first threshold value in the first backlight gain coefficient table, is greater than the backlight gain coefficient corresponding to a second partition backlight brightness value nearest to the first threshold value in the second backlight gain coefficient table.

10. The device according to claim 9, wherein the global backlight brightness value is determined based on a global grayscale brightness value of an image or on a user input.

11. The device according to claim 9, wherein the processor is configured to determine the backlight brightness interval in which the global backlight brightness value is located based on a comparison result between the global backlight brightness value and each of preset threshold values, wherein the backlight brightness interval in which the global backlight brightness value is located is indicated by two adjacent threshold values.

12. The device according to claim 9, wherein a partition backlight brightness value range of the backlight gain coefficient table is same as or greater than that of the backlight brightness interval corresponding to the backlight gain coefficient table.

13. The device according to claim 9, wherein in the backlight gain coefficient table, when a maximum partition backlight brightness value in the backlight gain coefficient table is less than a first backlight brightness value, the gain coefficient increases with the an increase of partition backlight brightness value.

14. The device according to claim 9, wherein in the backlight gain coefficient table, when a first backlight brightness value is between a minimum backlight brightness value and a maximum backlight brightness value in the backlight gain coefficient table, the gain coefficient first increases and then decreases with an increase of the partition backlight brightness value.

15. The device according to claim 9, wherein in the backlight gain coefficient table, when a minimum partition backlight brightness value in the backlight gain coefficient table is greater than a first backlight brightness value, the gain coefficient decreases with an increase of the partition backlight brightness value.

16. A liquid crystal display device, comprising:

a backlight assembly, comprising backlight resources;

a liquid crystal panel;

a nonvolatile memory for storing instructions;

a processor coupled to the memory, wherein the processor is configured to execute the instructions stored in the memory and the processor is configured to;

determine, based on a global backlight brightness value, a backlight brightness interval in which the global backlight brightness value is located;

determine, according to a correspondence between the backlight brightness interval and a backlight gain coefficient table, a backlight gain coefficient table corresponding to the backlight brightness interval, wherein the backlight gain coefficient table is configured to indicate a gain coefficient corresponding to a partition backlight brightness value; and

determine, according to a partition backlight brightness value of each of backlight partitions and the backlight gain coefficient table, a gain coefficient of each of the backlight partitions; and

determine, according to the gain coefficient of each of the backlight partitions and the partition backlight brightness value of each of the backlight partition, a target backlight brightness value of each of the backlight partitions; and

a backlight driver configured to drive the backlight resource of each of the backlight partitions according to the target backlight brightness value of each of the backlight partitions;

wherein a global backlight brightness value range is divided into a plurality of backlight brightness intervals, the plurality of backlight brightness intervals comprise a first backlight brightness interval and a second backlight brightness interval, and a minimum global backlight brightness value of the first backlight brightness interval is greater than a maximum global backlight brightness value of the second backlight brightness interval;

the first backlight brightness interval corresponds to a first backlight gain coefficient table;

the second backlight brightness interval corresponds to a second backlight gain coefficient table; and

in a first alternative mode,

a partition backlight brightness value range of the first backlight gain coefficient table and a partition backlight brightness value range of the second backlight gain coefficient table have an overlapped portion, and the backlight gain coefficient corresponding to the partition backlight brightness value in the overlapped portion, in the first backlight gain coefficient table, is greater than the backlight gain coefficient corresponding to the same partition backlight brightness value in the second backlight coefficient table;

in a second alternative mode,

the first backlight brightness interval and the second backlight brightness interval are adjacent at a first threshold value;

a partition backlight brightness value range of the first backlight gain coefficient table is a first backlight brightness interval;

a partition backlight brightness value range of the second backlight gain coefficient table is a second backlight brightness interval; and

the backlight gain coefficient corresponding to a first partition backlight brightness value nearest to the first threshold value in the first backlight gain coefficient table, is greater than the backlight gain coefficient corresponding to a second partition backlight brightness value nearest to the first threshold value in the second backlight gain coefficient table.