# US 2021/0343249 A1 · Backlight adjustment circuit, backlight module and display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0343249 A1 - Document ID: US20210343249A1 - Status: Published application - Kind: A1 - Application number: 17/272,656 - Filed: 2018-12-21 - Published: 2021-11-04 - Earliest claimed: 2018-11-12 - Assignees: Hkc Corporation Limited - Applicants: Hkc Corporation Limited - Inventors: Wenxin LI; Xiaoyu HUANG - Web page: https://patentgrep.com/patent/US20210343249A1 ## CPC - G09G 3/3406: {Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336)} - G09G 3/342: {using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines} - G09G 3/3413: {Details of control of colour illumination sources} - G09G 3/36: using liquid crystals - H05B 45/14: using electrical feedback from LEDs or from LED modules - H05B 45/46: having LEDs disposed in parallel lines - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/0626: for control of overall brightness - 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) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract Disclosed is a backlight adjustment circuit including: a reference electrical information circuit, a feedback selection circuit, a main control circuit and at least two parallel light-emitting branches; where the reference electrical information circuit is connected to the main control circuit and is configured to provide reference electrical parameter information to the main control circuit; the feedback selection circuit is respectively connected to the main control circuit and the at least two light-emitting branches and is configured to provide the main control circuit with electrical information of each of the at least two light-emitting branches; and the main control circuit is connected to the at least two light-emitting branches and is configured to adjust a current magnitude of the each of the at least two light-emitting branches according to the reference electrical parameter information and the electrical information of the each of the at least two light-emitting branches. ## Claims ### Claim 1 A backlight adjustment circuit, comprising: a reference electrical information circuit, a feedback selection circuit, a main control circuit and at least two parallel light-emitting branches; wherein the reference electrical information circuit is connected to the main control circuit and is configured to provide reference electrical parameter information to the main control circuit; the feedback selection circuit is respectively connected to the main control circuit and the at least two light-emitting branches and is configured to provide the main control circuit with electrical information of each of the at least two light-emitting branches; and the main control circuit is connected to the at least two light-emitting branches and is configured to adjust a current magnitude of the each of the at least two light-emitting branches according to the reference electrical parameter information and the electrical information of the each of the at least two light-emitting branches. ### Claim 2 (depends on 1) The backlight adjustment circuit of claim 1, wherein the feedback selection circuit comprises a matrix circuit configured to gate the at least two light-emitting branches, and the matrix circuit comprises first transistors arranged in a matrix. ### Claim 3 (depends on 2) The backlight adjustment circuit of claim 2, wherein a number of rows of the matrix circuit corresponds to a number of the at least two light-emitting branches, the first transistors in each row are connected in series to form a row branch, an input terminal of the row branch is connected to a corresponding light-emitting branch, and an output terminal of the row branch is connected to a feedback receiving terminal of the main control circuit. ### Claim 4 (depends on 3) The backlight adjustment circuit of claim 3, wherein a number of columns of the matrix circuit corresponds to a logarithm of a number of the at least two light-emitting branches with a base of 2, and control terminals of the first transistors in each column are connected to a corresponding feedback control terminal of the main control circuit. ### Claim 5 (depends on 4) The backlight adjustment circuit of claim 4, wherein one of the at least two light-emitting branches comprises a current regulator and a light-emitting device, and the main control circuit comprises an electrical information comparator and a controller; the electrical information comparator is configured to compare the reference electrical parameter information and electrical information of the light-emitting device to obtain a comparison result; and the controller is configured to control the current regulator according to the comparison result to adjust brightness of the light-emitting device. ### Claim 6 (depends on 5) The backlight adjustment circuit of claim 5, wherein the light-emitting device comprises one or more light-emitting diodes connected in series. ### Claim 7 (depends on 5) The backlight adjustment circuit of claim 5, wherein the light-emitting device comprises one or more cold cathode fluorescent tubes connected in series. ### Claim 8 (depends on 6) The backlight adjustment circuit of claim 6, wherein the electrical information comparator comprises a voltage comparator; the reference electrical information circuit comprises a reference voltage circuit, and the reference electrical parameter information comprises reference voltage information. ### Claim 9 (depends on 6) The backlight adjustment circuit of claim 6, wherein the electrical information comparator comprises a current comparator; the reference electrical information circuit comprises a reference current circuit, and the reference electrical parameter information comprises reference current information. ### Claim 10 (depends on 8) The backlight adjustment circuit of claim 8, wherein the current regulator comprises a second transistor connected to the one or more light-emitting diodes, and the second transistor is controlled by the controller. ### Claim 11 (depends on 10) The backlight adjustment circuit of claim 10, wherein the second transistor comprises a field effect transistor. ### Claim 12 (depends on 11) The backlight adjustment circuit of claim 11, further comprising a memory configured to store the reference voltage information provided to the reference voltage circuit. ### Claim 13 (depends on 12) The backlight adjustment circuit of claim 12, wherein a voltage value provided by the reference voltage information is the same as a feedback voltage value when the at least two light-emitting branches work normally. ### Claim 14 (depends on 13) The backlight adjustment circuit of claim 13, wherein the one or more light-emitting diodes are connected with a resistor in series and grounded. ### Claim 15 (depends on 14) The backlight adjustment circuit of claim 14, wherein the feedback selection circuit is connected to a remote terminal of the resistor and is configured to collect voltage information on the resistor. ### Claim 16 A backlight module, comprising a backlight adjustment circuit and optical films, wherein the backlight adjustment circuit comprises a reference electrical information circuit, a feedback selection circuit, a main control circuit and at least two parallel light-emitting branches; wherein the reference electrical information circuit is connected to the main control circuit and is configured to provide reference electrical parameter information to the main control circuit; the feedback selection circuit is respectively connected to the main control circuit and the at least two light-emitting branches and is configured to provide the main control circuit with electrical information of each of the at least two light-emitting branches; and the main control circuit is connected to the at least two light-emitting branches and is configured to adjust a current magnitude of the each of the at least two light-emitting branches according to the reference electrical parameter information and the electrical information of the each of the at least two light-emitting branches. ### Claim 17 (depends on 16) The backlight module of claim 16, wherein the feedback selection circuit of the backlight adjustment circuit comprises a matrix circuit configured to gate the at least two light-emitting branches, and the matrix circuit comprises first transistors arranged in a matrix. ### Claim 18 (depends on 17) The backlight module of claim 17, wherein the matrix circuit of the backlight adjustment circuit is provided with a number of rows corresponding to a number of the at least two light-emitting branches, the first transistors in each row are connected in series to form a row branch, an input terminal of the row branch is connected to a corresponding light-emitting branch, and an output terminal of the row branch is connected to a feedback receiving terminal of the main control circuit. ### Claim 19 (depends on 18) The backlight module of claim 18, wherein a number of columns of the matrix circuit of the backlight adjustment circuit corresponds to a logarithm of a number of at least two light-emitting branches with a base of 2, and control terminals of the first transistors in each column are connected to a corresponding feedback control terminal of the main control circuit. ### Claim 20 (depends on 16) A display device, comprising a liquid crystal panel and the backlight module as recited in claim 16.