# US 12,217,681 B2 · Display device including compensation for current difference between circuit boards, and method of driving the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,217,681 B2 - Document ID: US12217681B2 - Status: Granted - Kind: B2 - Application number: 18/382,942 - Filed: 2023-10-23 - Published: 2024-07-25 - Granted: 2025-02-04 - Earliest claimed: 2023-01-25 - Assignees: LG Display Co., Ltd. - Applicants: LG Display Co., Ltd. - Inventors: Dong Ju Kim; Won Yong Jang - Web page: https://patentgrep.com/patent/US12217681B2 ## CPC - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/2096: {Details of the interface to the display terminal specific for a flat panel (suitable for both CRT and flat panel G09G5/006; specific for a CRT G09G1/167)} - G09G 2320/02: Improving the quality of display appearance - G09G 2330/08: Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared - G09G 2330/12: Test circuits or failure detection circuits included in a display system, as permanent part thereof - 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 A display device includes a display panel configured to display images, a plurality of circuit boards connected to one side of the display panel, a cable electrically connecting at least two of the plurality of circuit boards, voltage lines disposed on the cable, the plurality of circuit boards, and the display panel, a deviation compensation circuit configured to sense voltages transmitted through a circuit board on one side and a circuit board on the other side connected by the cable among the plurality of circuit boards and to output a signal based on the sensed voltages, and a variable circuit configured to compensate for a current difference between the circuit board on one side and the circuit board on the other side based on the signal output from the deviation compensation circuit. ## Claims ### Claim 1 A method of driving a display device including a display panel configured to display images; a first circuit board including a timing controller; a plurality of second circuit boards arranged along one side of the display panel; at least one first cable electrically connecting the first and second circuit boards; a plurality of third circuit boards arranged along the one side of the display panel and connecting the display panel to the plurality of second circuit boards; voltage lines extending on the third circuit boards, the second circuit boards and the at least one first cable and to transmit a voltage signal from the timing controller to the display panel for driving the display panel; a deviation compensation circuit; and a variable circuit, the method comprising: sensing, via the deviation compensation circuit, sense a voltage transmitted through the voltage line on a first one of the plurality of second circuit boards and a voltage transmitted through the voltage line on a second one of the plurality of second circuit boards adjacent to the first one of the plurality of second circuit boards; and compensating, via the variable circuit, for a current difference between the first one and the second one of the plurality of second circuit boards, wherein the deviation compensation circuit is disposed on one of the first one and the second one of the plurality of second circuit boards. ### Claim 2 (depends on 1) The method of claim 1, wherein the compensating for the current difference comprises controlling at least one transistor or at least one resistor included in the variable circuit based on the signal. ### Claim 3 (depends on 2) The method of claim 2, wherein the compensating for the current difference comprises: controlling the at least one resistor to vary resistance values of the voltage lines, or controlling the at least one transistor to vary an amount of current flowing through the voltage lines or to block the current flowing through the voltage lines. ### Claim 4 A display device comprising: a display panel configured to display images; a first circuit board including a timing controller; a plurality of second circuit boards arranged along one side of the display panel; at least one first cable electrically connecting the first and second circuit boards; a plurality of third circuit boards arranged along the one side of the display panel and connecting the display panel to the plurality of second circuit boards; voltage lines extending on the third circuit boards, the second circuit boards and the at least one first cable and to transmit a voltage signal from the timing controller to the display panel for driving the display panel; a deviation compensation circuit configured to sense a voltage transmitted through the voltage line on a first one of the plurality of second circuit boards and a voltage transmitted through the voltage line on a second one of the plurality of second circuit boards adjacent to the first one of the plurality of second circuit boards; and a variable circuit configured to compensate for a current difference between the first one and the second one of the plurality of second circuit boards, wherein the deviation compensation circuit is disposed on one of the first one and the second one of the plurality of second circuit boards. ### Claim 5 (depends on 4) The display device of claim 4, wherein the variable circuit includes at least one variable resistor configured to vary resistance values of the voltage lines. ### Claim 6 (depends on 4) The display device of claim 4, wherein the variable circuit includes at least one transistor configured to vary an amount of current flowing through the voltage lines. ### Claim 7 (depends on 6) The display device of claim 6, wherein the deviation compensation circuit outputs a signal for controlling an on/off duty ratio of the at least one transistor. ### Claim 8 (depends on 4) The display device of claim 4, wherein the variable circuit is disposed between voltage lines formed in a display area of the display panel. ### Claim 9 (depends on 8) The display device of claim 8, wherein the variable circuit includes at least one transistor configured to block a current flowing through the voltage lines formed in the display area of the display panel. ### Claim 10 (depends on 9) The display device of claim 9, wherein the deviation compensation circuit outputs a signal for controlling on/off of each of the at least one transistor. ### Claim 11 (depends on 9) The display device of claim 9, wherein the deviation compensation circuit outputs at least one signal for independently controlling on/off of the at least one transistor. ### Claim 12 (depends on 4) The display device of claim 4, wherein the variable circuit is disposed on at least one of the first and the second circuit boards. ### Claim 13 (depends on 1) The display device of claim 1, wherein the deviation compensation circuit includes: a first input terminal connected to the voltage line disposed on the first one of the plurality of second circuit boards; a second input terminal connected to the voltage line disposed on the second one of the plurality of second circuit boards; and an output terminal connected to the variable circuit.