# US 10,482,828 B2 · Method and apparatus for controlling backlight brightness, and liquid crystal display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,482,828 B2 - Document ID: US10482828B2 - Status: Granted - Kind: B2 - Application number: 15/449,888 - Filed: 2017-03-03 - Published: 2018-03-29 - Granted: 2019-11-19 - Earliest claimed: 2016-09-28 - Assignees: Hisense Electric Co., Ltd.; Hisense USA Corporation; Hisense International Co., Ltd. - Applicants: Hisense Electric Co., Ltd.; Hisense USA Corporation; Hisense International Co., Ltd. - Inventors: Yuxin Zhang - Web page: https://patentgrep.com/patent/US10482828B2 ## CPC - G09G 3/342: {using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines} - G09G 3/2007: {Display of intermediate tones} - G09G 3/3426: {the different display panel areas being distributed in two dimensions, e.g. matrix} - G09G 3/3648: {using an active matrix (G09G3/367 - G09G3/3696 take precedence)} - G09G 2310/08: Details of timing specific for flat panels, other than clock recovery - G09G 2320/064: by time modulation of the brightness of the illumination source - G09G 2320/0646: Modulation of illumination source brightness and image signal correlated to each other - G09G 2360/16: Calculation or use of calculated indices related to luminance levels in display data - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) ## Abstract The present application provides a method and an apparatus for controlling backlight brightness, and a liquid crystal display device. The method includes: determining, in an image to be displayed, an image block corresponding to each backlight partition of a plurality of backlight partitions, and determining an initial backlight value for each backlight partition; determining brightness distribution information for pixels in an image partition; determining a backlight adjusting curve corresponding to the image partition; and determining a backlight adjusting factor for a backlight partition corresponding to the image partition according to the initial backlight value of the backlight partition corresponding to the image partition and the backlight adjusting curve corresponding to the image partition, and determining a target backlight value for the backlight partition corresponding to the image partition according to the initial backlight value for the backlight partition and the corresponding backlight adjusting factor. ## Claims ### Claim 1 A method for controlling backlight brightness, comprising: determining, in an image to be displayed, an image block corresponding to a backlight partition of a plurality of backlight partitions, and determining an initial backlight value for the backlight partition according to grayscale values of pixels in the image block; determining brightness distribution information for pixels in the image block according to grayscale values of the pixels in the image block; determining that a backlight adjusting curve corresponding to the image block is of a reverse S-shaped curve type when the brightness distribution information indicates that number of pixels in the image block having grayscale values smaller than a first grayscale value is greater than a first threshold value, wherein the backlight adjusting curve of the reverse S-shaped curve type is configured to increase the initial backlight value to a target backlight value for the backlight partition corresponding to the image block when the initial backlight value is smaller than a first initial backlight value, and to decrease the initial backlight value to the target backlight value for the backlight partition corresponding to the image block when the initial backlight value is greater than a second initial backlight value; determining that the backlight adjusting curve corresponding to the image block is of a S-shaped curve type when the brightness distribution information indicates that number of pixels in the image block having grayscale values greater than a second grayscale value is greater than a second threshold value, wherein the backlight adjusting curve of the S-shaped curve type is configured to increase the initial backlight value to the target backlight value for the backlight partition corresponding to the image block when the initial backlight value is greater than a third initial backlight value, and to decrease the initial backlight value to the target backlight value for the backlight partition corresponding to the image block when the initial backlight value is smaller than a fourth initial backlight value; and determining a backlight adjusting factor for the backlight partition corresponding to the image block according to the initial backlight value of the backlight partition corresponding to the image block and the backlight adjusting curve corresponding to the image block, and determining the target backlight value for the backlight partition corresponding to the image block according to the initial backlight value for the backlight partition and the backlight adjusting factor. ### Claim 2 (depends on 1) The method according to claim 1 wherein the determining the initial backlight value for the backlight partition according to the grayscale values of the pixels in the image block comprises: determining the grayscale value for the image block corresponding to the backlight partition according to the grayscale values of the pixels in the image block corresponding to the backlight partition; and determining the initial backlight value for the backlight partition according to the grayscale value for the image block corresponding to the backlight partition, wherein the initial backlight value is proportional to the grayscale value for the image block corresponding to the backlight partition. ### Claim 3 (depends on 1) The method according to claim 1, wherein the image to be displayed comprises multiple image blocks; wherein before the determining the brightness distribution information for the pixels in the image block according to grayscale values of the pixels in the image block, the method further comprises: obtaining a division rule corresponding to a backlight assembly, wherein the division rule is configured to indicate a number of image blocks corresponding to the image to be displayed and numbers of backlight partitions corresponding to one image block respectively along a horizontal direction and a vertical direction, wherein the number of the backlight partitions corresponding to the image block along the horizontal direction is greater than one, or the number of the backlight partitions corresponding to the image block along the vertical direction is greater than one; and partitioning the image to be displayed to obtain the multiple image blocks according to the division rule. ### Claim 4 (depends on 1) The method according to claim 1, wherein the determining brightness distribution information for the pixels in the image block according to the grayscale values of the pixels in the image block comprises: generating a grayscale-histogram of numbers of pixels of the image block falling into a predetermined number of grayscale bins of a predetermined bin size; and determining the brightness distribution information according to the grayscale histogram. ### Claim 5 (depends on 1) The method according to claim 1, after the determining the target backlight value for the backlight partition corresponding to the image block according to the initial backlight value for the backlight partition and the corresponding backlight adjusting factor, further comprising: sending the target backlight value for the backlight partition corresponding to the image block to a corresponding driving circuit for the backlight partition corresponding to the image block, so that the corresponding driving circuit adjusts backlight source brightness for the backlight partition corresponding to the image block according to the target backlight value. ### Claim 6 (depends on 1) The method according to claim 1, wherein the image block corresponds to one backlight partition. ### Claim 7 (depends on 1) The method according to claim 1, wherein the image block corresponds to multiple backlight partitions. ### Claim 8 A method for controlling backlight brightness, comprising: determining, in an image to be displayed, an image block corresponding to a backlight partition of a plurality of backlight partitions, and determining an initial backlight value for each backlight partition according to grayscale values of pixels in the image block corresponding to the backlight partition; determining brightness distribution information for pixels in the image block according to grayscale values of the pixels in the image block; generating a peripheral enveloping curve for a grayscale histogram of numbers of pixels of the image block falling into a predetermined number of grayscale value bins with a predetermined bin size; determining a backlight adjusting curve corresponding to the image block according to a shape of the peripheral enveloping curve for the grayscale histogram; and determining a backlight adjusting factor for the backlight partition corresponding to the image block according to the initial backlight value of the backlight partition corresponding to the image block and the backlight adjusting curve corresponding to the image block, and determining a target backlight value for the backlight partition corresponding to the image block according to the initial backlight value for the backlight partition and the corresponding backlight adjusting factor. ### Claim 9 A liquid crystal display device, comprising a liquid crystal panel, a backlight assembly, and an apparatus for controlling backlight brightness, wherein the apparatus for controlling backlight brightness is configured to control backlight source brightness for backlight partitions in the backlight assembly, so that the backlight partitions in the backlight assembly illuminate the liquid crystal panel according to the corresponding backlight source brightness; and the apparatus for controlling backlight brightness comprises: a memory storing instructions; a processor coupled with the memory and configured to execute instructions stored in the memory, and the processor is configured to: determine, in an image to be displayed, an image block corresponding to a backlight partition of a plurality of backlight partitions, and determine an initial backlight value for the backlight partition according to grayscale values of pixels in the image block; determine brightness distribution information for pixels in the image block according to grayscale values of the pixels in the image block; determine that a backlight adjusting curve corresponding to the image block is of a reverse S-shaped curve type when the brightness distribution information indicates that number of pixels in the image block having grayscale values smaller than a first grayscale value is greater than a first threshold value, wherein the backlight adjusting curve of the reverse S-shaped curve type is configured to increase the initial backlight value to a target backlight value for the backlight partition corresponding to the image block when the initial backlight value is smaller than a first initial backlight value, and to decrease the initial backlight value to the target backlight value for the backlight partition corresponding to the image block when the initial backlight value is greater than a second initial backlight value; determine that the backlight adjusting curve corresponding to the image block is of a S-shaped curve type when the brightness distribution information indicates that number of pixels in the image block having grayscale values greater than a second grayscale value is greater than a second threshold value, wherein the backlight adjusting curve of the S-shaped curve type is configured to increase the initial backlight value to the target backlight value for the backlight partition corresponding to the image block when the initial backlight value is greater than a third initial backlight value, and to decrease the initial backlight value to the target backlight value for the backlight partition corresponding to the image block when the initial backlight value is smaller than a fourth initial backlight value; and determine a backlight adjusting factor for the backlight partition corresponding to the image block according to the initial backlight value of the backlight partition corresponding to the image block and the backlight adjusting curve corresponding to the image block, and determine the target backlight value for the backlight partition corresponding to the image block according to the initial backlight value for the backlight partition and the corresponding backlight adjusting factor. ### Claim 10 A liquid crystal display device, comprising a liquid crystal panel, a backlight assembly, and an apparatus for controlling backlight brightness, wherein the apparatus for controlling backlight brightness is configured to control backlight source brightness for backlight partitions in the backlight assembly, so that the backlight partitions in the backlight assembly illuminate the liquid crystal panel according to the corresponding backlight source brightness; and the apparatus for controlling backlight brightness comprises: a memory storing instructions; a processor coupled with the memory and configured to execute instructions stored in the memory, and the processor is configured to: determine, in an image to be displayed, an image block corresponding to each backlight partition of a plurality of backlight partitions, and determine an initial backlight value for each backlight partition according to grayscale values of pixels in the image block corresponding to the backlight partition; determine brightness distribution information for pixels in the image block according to grayscale values of the pixels in the image block; generate a peripheral enveloping curve for a grayscale histogram of numbers of pixels of the image block falling into a predetermined number of grayscale value bins with a predetermined bin size; determine the backlight adjusting curve corresponding to the image block according to a shape of the peripheral enveloping curve for the grayscale histogram; and determine a backlight adjusting factor for the backlight partition corresponding to the image block according to the initial backlight value of the backlight partition corresponding to the image block and the backlight adjusting curve corresponding to the image block, and determine a target backlight value for the backlight partition corresponding to the image block according to the initial backlight value for the backlight partition and the corresponding backlight adjusting factor.