# US 12,183,291 B2 · Pixel driving circuit for display panel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,183,291 B2 - Document ID: US12183291B2 - Status: Granted - Kind: B2 - Application number: 18/078,853 - Filed: 2022-12-09 - Published: 2023-04-06 - Granted: 2024-12-31 - Earliest claimed: 2020-11-19 - Assignees: Lx Semicon Co., Ltd. - Applicants: LX Semicon Co., Ltd. - Inventors: Yong Jung Kwon; Sang Min Lee; Jong Hwi Park; Jung Bae Yun - Web page: https://patentgrep.com/patent/US12183291B2 ## CPC - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/3291: in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements - G09G 5/008: {Clock recovery} - G09G 2310/027: Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/0257: Reduction of after-image effects - G09G 2320/0626: for control of overall brightness - G09G 2320/0673: for control of gamma adjustment, e.g. selecting another gamma curve - G09G 2330/025: Reduction of instantaneous peaks of current - G09G 2330/028: Generation of voltages supplied to electrode drivers in a matrix display other than LCD - G09G 2330/04: Display protection - G09G 2330/045: Protection against panel overheating - 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 embodiment relates to a technology for driving a display device, and provides a technology in which a pixel driving device determines whether or not an overcurrent flows through a driving voltage line, and, if it is determined that an overcurrent flows therethrough, controls pixel data or an analog voltage output to a pixel so as to reduce a driving current. ## Claims ### Claim 1 A display device comprising: a first circuit connected to a main line; and a second circuit configured to output an analog voltage corresponding to pixel data included in image data, wherein the first and second circuits are included in a source driver, in response to a change of a signal level on the main line, a first voltage which is lower than or equal to a preset value, instead of the analog voltage corresponding to the pixel data, is outputted to data lines, and the first circuit is configured to: receive a packet including a clock signal through the main line; recover a clock from the clock signal; detect an abnormality using the recovered clock; and change the signal level based on the abnormality. ### Claim 2 (depends on 1) The display device of claim 1, wherein the first voltage corresponds to a grayscale value displaying black. ### Claim 3 (depends on 1) The display device of claim 1, wherein the preset value corresponds to a grayscale value displaying black. ### Claim 4 (depends on 1) The display device of claim 1, wherein the change of the signal level on the main line comprises changing from a high voltage level to a low voltage level. ### Claim 5 (depends on 1) The display device of claim 1, wherein the signal level on the main line is changed based on an abnormality in a clock or an abnormality in the image data. ### Claim 6 (depends on 1) The display device of claim 1, wherein in response to the change of the signal level on the main line, an output terminal of the second circuit is connected to a line corresponding to the first voltage. ### Claim 7 (depends on 1) The display device of claim 1, further comprising: a third circuit configured to change the pixel data to data corresponding to the first voltage, in response to the change of the signal level on the main line. ### Claim 8 (depends on 1) The display device of claim 1, wherein in response to the change of the signal level on the main line, the second circuit is configured to output the first voltage during a preset period, and the preset period is longer than a period corresponding to a frame. ### Claim 9 (depends on 1) The display device of claim 1, wherein the first circuit is configured to: transmit a signal having the changed signal level to a third circuit included in the source driver. ### Claim 10 (depends on 9) The display device of claim 9, wherein the source driver further comprises a latch circuit and a digital-to-analog (DAC) conversion circuit, the third circuit is configured to change the pixel data and transmit the changed pixel data to the latch circuit, the DAC conversion circuit is configured to convert the changed pixel data into an analog voltage and transmit, to the second circuit, the analog voltage, and the second circuit is configured to output the first voltage based on receiving the analog voltage. ### Claim 11 (depends on 9) The display device of claim 9, wherein the third circuit is configured to connect output terminals of the second circuit to a voltage source that is configured to output the first voltage, and the voltage source is different from the first, second, and third circuits. ### Claim 12 A method for driving a display device, the method comprising: obtaining, by a first circuit, image data comprising pixel data; outputting, by a second circuit, an analog voltage corresponding to the pixel data included in the image data; and in response to a change of a signal level on a main line, outputting a first voltage which is lower than or equal to a preset value, instead of the analog voltage corresponding to the pixel data, wherein the first and second circuits are included in a source driver, and the method further comprises: receiving, by the first circuit, a packet including a clock signal through the main line; recovering, by the first circuit, a clock from the clock signal; detecting, by the first circuit, an abnormality using the recovered clock; and changing, by the first circuit, the signal level based on detecting the abnormality. ### Claim 13 (depends on 12) The method of claim 12, wherein the preset value corresponds to a grayscale value displaying black. ### Claim 14 (depends on 12) The method of claim 12, wherein the signal level on the main line is changed based on an abnormality in a clock or an abnormality in the image data. ### Claim 15 (depends on 12) The method of claim 12, wherein the first voltage is outputted from a circuit connected to a line corresponding to the first voltage. ### Claim 16 (depends on 12) The method of claim 12, further comprising: changing the pixel data to data corresponding to the first voltage, in response to the change of the signal level on the main line. ### Claim 17 (depends on 12) The method of claim 12, comprising outputting the first voltage during a preset period, in response to the change of the signal level on the main line, wherein the preset period is longer than a period corresponding to a frame. ### Claim 18 (depends on 12) The method of claim 12, wherein the method further comprises: the first circuit transmitting a signal having the changed signal level to a third circuit included in the source driver. ### Claim 19 (depends on 18) The method of claim 18, wherein the source driver further comprises a latch circuit and a digital-to-analog (DAC) conversion circuit, and the method further comprises: the third circuit changing the pixel data and transmit the changed pixel data to the latch circuit, the DAC conversion circuit converting the changed pixel data into an analog voltage and transmit, to the second circuit, the analog voltage, and the second circuit outputting the first voltage based on receiving the analog voltage. ### Claim 20 (depends on 18) The method of claim 18, wherein the method further comprises connecting output terminals of the second circuit to a voltage source that is configured to output the first voltage, and the voltage source is different from the first, second, and third circuits.