Apparatus and method for controlling liquid crystal display brightness, and liquid crystal display device
First Claim
1. An apparatus for controlling liquid crystal display brightness, the apparatus comprising:
- a subarea image grayscale determining section configured to determine image grayscale values of subarea image data blocks corresponding to backlight subareas according to a received image signal;
a subarea backlight value pre-obtaining section configured to pre-obtain subarea backlight values corresponding to the subarea image data blocks according to the image grayscale values of the subarea image data blocks;
a subarea backlight value gain section configured to multiply the pre-obtained subarea backlight values with a preset backlight value gain coefficient to obtain gained backlight values of the backlight subareas, wherein the preset backlight value gain coefficient is more than 1;
a subarea backlight value adjusting section configured to obtain a subarea backlight value adjustment coefficient, and to further multiply the gained subarea backlight values with the corresponding backlight value adjustment coefficient to obtain adjusted subarea backlight values, wherein if the pre-obtained subarea backlight value or the gained subarea backlight value is below a first threshold, then the corresponding backlight value adjustment coefficient is less than 1, the subarea backlight value adjusting section comprising a local adjustment coefficient lookup table determining section configured to determine an adjustment coefficient lookup table corresponding to the subarea image data blocks, and a local backlight value adjusting section configured to search the determined adjustment coefficient lookup table for the subarea backlight value adjustment coefficient using the gained subarea backlight value of the subarea image data blocks;
a subarea backlight value outputting section configured to output the respective adjusted subarea backlight values to driver circuits of backlight sources in the corresponding backlight subareas to control the brightness of the backlight sources in the corresponding backlight subareas as a result of driving;
a local grayscale compensation coefficient lookup table determining section configured to determine a grayscale compensation coefficient lookup table corresponding to a cluster of the subarea image data blocks; and
a local image grayscale compensating section configured to determine a subarea image data block with the adjusted subarea backlight value below the first threshold, and to compensate for the grayscale value of each image pixel in the subarea image data block using a compensation coefficient found in the determined grayscale compensation coefficient lookup table, wherein the compensation coefficient is larger than 1.
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Accused Products
Abstract
An apparatus for controlling liquid crystal display brightness includes: a subarea image grayscale determining section configured to determine image grayscale values of subarea image data blocks corresponding to backlight subareas according to a received image signal; a subarea backlight value pre-obtaining section configured to pre-obtain subarea backlight values corresponding to the subarea image data blocks according to the image grayscale values of the subarea image data blocks; a subarea backlight value gain section configured to multiply the pre-obtained subarea backlight values with a preset backlight value gain coefficient to obtain gained backlight values of the backlight subareas, wherein the preset backlight value gain coefficient is more than 1; a subarea backlight value adjusting section configured to obtain a subarea backlight value adjustment coefficient, and to further multiply the gained subarea backlight values with the corresponding backlight value adjustment coefficient to obtain adjusted subarea backlight values, wherein if the pre-obtained subarea backlight value or the gained subarea backlight value is below a first threshold, then the corresponding backlight value adjustment coefficient is less than 1; and a subarea backlight value outputting section configured to output the respective adjusted subarea backlight values to driver circuits of backlight sources in the corresponding backlight subareas to control the brightness of the backlight sources in the corresponding backlight subareas as a result of driving.
38 Citations
16 Claims
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1. An apparatus for controlling liquid crystal display brightness, the apparatus comprising:
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a subarea image grayscale determining section configured to determine image grayscale values of subarea image data blocks corresponding to backlight subareas according to a received image signal; a subarea backlight value pre-obtaining section configured to pre-obtain subarea backlight values corresponding to the subarea image data blocks according to the image grayscale values of the subarea image data blocks; a subarea backlight value gain section configured to multiply the pre-obtained subarea backlight values with a preset backlight value gain coefficient to obtain gained backlight values of the backlight subareas, wherein the preset backlight value gain coefficient is more than 1; a subarea backlight value adjusting section configured to obtain a subarea backlight value adjustment coefficient, and to further multiply the gained subarea backlight values with the corresponding backlight value adjustment coefficient to obtain adjusted subarea backlight values, wherein if the pre-obtained subarea backlight value or the gained subarea backlight value is below a first threshold, then the corresponding backlight value adjustment coefficient is less than 1, the subarea backlight value adjusting section comprising a local adjustment coefficient lookup table determining section configured to determine an adjustment coefficient lookup table corresponding to the subarea image data blocks, and a local backlight value adjusting section configured to search the determined adjustment coefficient lookup table for the subarea backlight value adjustment coefficient using the gained subarea backlight value of the subarea image data blocks; a subarea backlight value outputting section configured to output the respective adjusted subarea backlight values to driver circuits of backlight sources in the corresponding backlight subareas to control the brightness of the backlight sources in the corresponding backlight subareas as a result of driving; a local grayscale compensation coefficient lookup table determining section configured to determine a grayscale compensation coefficient lookup table corresponding to a cluster of the subarea image data blocks; and a local image grayscale compensating section configured to determine a subarea image data block with the adjusted subarea backlight value below the first threshold, and to compensate for the grayscale value of each image pixel in the subarea image data block using a compensation coefficient found in the determined grayscale compensation coefficient lookup table, wherein the compensation coefficient is larger than 1. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A liquid crystal display device, comprising:
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a memory configured to store programs and various preset lookup table data; an apparatus for controlling liquid crystal display brightness configured to execute the programs in the memory, and to invoke the various lookup table data according to the executed programs;
to receive an image signal, to process the data, and to output the image data to a timing controller so that the timing controller generates a driver signal according to the image data to control a liquid crystal panel to display the image; and
to output subarea backlight values to a backlight processing unit according to the image signal;the backlight processing unit configured to determine duty ratios of corresponding PWM signals according to the respective subarea backlight values, and to output the duty ratios to a PWM driver unit; and the PWM driver unit configured to generate PWM control signals to control backlight sources in corresponding subareas; wherein the apparatus for controlling liquid crystal display brightness comprises; a subarea image grayscale determining section configured to determine image grayscale values of subarea image data blocks corresponding to backlight subareas according to a received image signal; a subarea backlight value pre-obtaining section configured to pre-obtain subarea backlight values corresponding to the subarea image data blocks according to the image grayscale values of the subarea image data blocks; a subarea backlight value gain section configured to multiply the pre-obtained subarea backlight values with a preset backlight value gain coefficient to obtain gained backlight values of the backlight subareas, wherein the preset backlight value gain coefficient is more than 1; a subarea backlight value adjusting section configured to obtain a subarea backlight value adjustment coefficient, and to further multiply the gained subarea backlight values with the corresponding backlight value adjustment coefficient to obtain adjusted subarea backlight values, wherein if the pre-obtained subarea backlight value or the gained subarea backlight value is below a first threshold, then the corresponding backlight value adjustment coefficient is less than 1, the subarea backlight value adjusting section comprising a local adjustment coefficient lookup table determining section configured to determine an adjustment coefficient lookup table corresponding to the subarea image data blocks, and a local backlight value adjusting section configured to search the determined adjustment coefficient lookup table for the subarea backlight value adjustment coefficient using the gained subarea backlight value of the subarea image data blocks; a subarea backlight value outputting section configured to output the respective subarea backlight values to driver circuits of backlight sources in the corresponding backlight subareas to control the brightness of the backlight sources in the corresponding backlight subareas as a result of driving; a local grayscale compensation coefficient lookup table determining section configured to determine a grayscale compensation coefficient lookup table corresponding to a cluster of the subarea image data blocks; and a local image grayscale compensating section configured to determine a subarea image data block with the adjusted subarea backlight value below the first threshold, and to compensate for the grayscale value of each image pixel in the subarea image data block using a compensation coefficient found in the determined grayscale compensation coefficient lookup table, wherein the compensation coefficient is larger than 1.
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10. A method for controlling liquid crystal display brightness, the method comprising:
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determining, by an apparatus for controlling liquid crystal display brightness, image grayscale values of subarea image data blocks corresponding to backlight subareas according to a received image signal, and pre-obtaining subarea backlight values corresponding to the subarea image data blocks according to the image grayscale values of the subarea image data blocks; multiplying, by the apparatus for controlling liquid crystal display brightness, the pre-obtained subarea backlight values with a preset backlight value gain coefficient to obtain gained subarea backlight values of the backlight subareas, wherein the preset backlight value gain coefficient is more than 1; obtaining, by the apparatus for controlling liquid crystal display brightness, a subarea backlight value adjustment coefficient by determining an adjustment coefficient lookup table corresponding to the subarea image data blocks and searching the determined adjustment coefficient lookup table for the subarea backlight value adjustment coefficient using the gained subarea backlight value of the subarea image data blocks, and further multiplying the gained subarea backlight values with the corresponding backlight value adjustment coefficient to obtain adjusted subarea backlight values, wherein if the pre-obtained subarea backlight value or the gained subarea backlight value is below a first threshold, then the corresponding backlight value adjustment coefficient is less than 1; outputting, by the apparatus for controlling liquid crystal display brightness, the respective adjusted subarea backlight values to driver circuits of backlight sources in the corresponding backlight subareas to control the brightness of the backlight sources in the corresponding backlight subareas as a result of driving; determining, by the apparatus for controlling liquid crystal display brightness, a grayscale compensation coefficient lookup table corresponding to a cluster of subarea image data blocks; and determining, by the apparatus for controlling liquid crystal display brightness, a subarea image data block with the adjusted subarea backlight value below the first threshold, and compensating for the grayscale value of each image pixel in the subarea image data block using a compensation coefficient found in the determined grayscale compensation coefficient lookup table, wherein the compensation coefficient is larger than 1. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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Specification