# US 12,008,968 B2 · Display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,008,968 B2 - Document ID: US12008968B2 - Status: Granted - Kind: B2 - Application number: 17/974,414 - Filed: 2022-10-26 - Published: 2023-07-06 - Granted: 2024-06-11 - Earliest claimed: 2021-12-31 - Assignees: LG Display Co., Ltd. - Applicants: LG Display Co., Ltd. - Inventors: MooKyoung Hong - Web page: https://patentgrep.com/patent/US12008968B2 ## CPC - 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 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/3266: Details of drivers for scan electrodes - G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing - G09G 2310/0251: Precharge or discharge of pixel before applying new pixel voltage - G09G 2310/0278: Details of driving circuits arranged to drive both scan and data electrodes - G09G 2310/0294: Details of sampling or holding circuits arranged for use in a driver for data electrodes - G09G 2310/08: Details of timing specific for flat panels, other than clock recovery - G09G 2320/0295: by monitoring each display pixel - G09G 2320/045: Compensation of drifts in the characteristics of light emitting or modulating elements - G09G 2320/0626: for control of overall brightness - G09G 2330/028: Generation of voltages supplied to electrode drivers in a matrix display other than LCD - 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 on which a plurality of pixels are disposed; a timing controller configured to receive Nth frame data and (N+1)th frame data and output a luminance control signal; and a power supply configured to output a reference voltage from a plurality of reference voltages each having a different level in response to the luminance control signal, in which output luminance of the plurality of pixels is determined according to the level of the reference voltage thereby maximizing an HDR effect. ## Claims ### Claim 1 A display device comprising: a display panel including a plurality of pixels; a timing controller configured to receive Nth frame data and (N+1)th frame data and output a luminance control signal based on the Nth frame data and the (N+1)th frame data; and a power supply configured to generate a plurality of reference voltages each having a different level and output a reference voltage from the plurality of reference voltages responsive to the luminance control signal, wherein output luminance of the plurality of pixels is determined according to a level of the outputted reference voltage, wherein N is a natural number of one or more, and wherein the timing controller comprises: a data sampler configured to extract (N+1)th sampling data by sampling the (N+1)th frame data; and a data comparator configured to compare the (N+1)th sampling data and the Nth frame data and output the luminance control signal based on a result of comparison. ### Claim 2 (depends on 1) The display device of claim 1, wherein the data comparator is configured to calculate a first average image level from the Nth frame data, calculate a second average image level from the (N+1)th sampling data, and output a difference between the first average image level and the second average image level as the luminance control signal. ### Claim 3 (depends on 1) The display device of claim 1, wherein the data comparator is configured to calculate a first average current luminance from the Nth frame data, calculate a second average current luminance from the (N+1)th sampling data, and output a difference between the first average current luminance and the second average current luminance as the luminance control signal. ### Claim 4 (depends on 1) The display device of claim 1, wherein the Nth frame data and the (N+1)th sampling data are simultaneously input to the data comparator. ### Claim 5 (depends on 1) The display device of claim 1, wherein the power supply includes a multiplexer configured to select one of the plurality of reference voltages responsive to the luminance control signal. ### Claim 6 (depends on 5) The display device of claim 5, wherein the power supply outputs the reference voltage having a lower level amongst the plurality of reference voltages as a level of the luminance control signal increases. ### Claim 7 (depends on 5) The display device of claim 5, wherein the power supply comprises: a first switch configured to select a first reference voltage from the plurality of reference voltages; a second switch configured to select a second reference voltage from the plurality of reference voltages; and a third switch configured to select a third reference voltage from the plurality of reference voltages, and wherein a level of the second reference voltage is less than a level of the first reference voltage, and a level of the third reference voltage is less than a level of the second reference voltage. ### Claim 8 (depends on 7) The display device of claim 7, wherein the third switch of the power supply is turned on and the first switch and the second switch are turned off responsive to the luminance control signal being at a third level, the second switch of the power supply is turned on and the first switch and the third switch are turned off responsive to the luminance control signal is at a second level that is less than the third level, and the first switch of the power supply is turned on and the second switch and the third switch are turned off responsive the luminance control signal is at a first level that is less than the third level and the second level. ### Claim 9 (depends on 1) The display device of claim 1, wherein each of the plurality of pixels comprises a driving transistor configured to apply a drive current to a light-emitting element, and wherein a data voltage is applied to a gate electrode of the driving transistor, and the outputted reference voltage is applied to a source electrode of the driving transistor. ### Claim 10 A display device comprising: a display panel including a plurality of pixels configured to display an image; a data driver configured to generate a data voltage of the image; a gate driver configured to generate a scan signal; a timing controller configured to receive first frame data and second frame data and output a luminance control signal based on the first frame data and the second frame data, wherein at least one of the plurality of pixel includes: a driving element including a first electrode of the driving element that is connected to a first node to which a power supply voltage is applied, a gate electrode of the driving element that is connected to a second node to which the data voltage is applied, and a second electrode of the driving element that is connected to a third node; a light emitting element including an anode electrode connected to the third node; a first switch element configured to supply the data voltage to the second node responsive to the scan signal being applied to the first switch element; and a second switch element connected to the third node, the second switch element configured to apply one of a plurality of reference voltages each having a different level to the third node, wherein an output luminance of the pixel is based on a level of the outputted reference voltage to the third node, wherein a reference voltage from the plurality of reference voltages is selected to apply to the third node based on the luminance control signal and wherein the timing controller comprises: a data sampler configured to sample the first frame data to extract sampling data from the first frame data; and a data comparator configured to compare the sampling data and the second frame data and output the luminance control signal based on a result of comparison. ### Claim 11 (depends on 10) The display device of claim 10, wherein the plurality of reference voltages include a first reference voltage having a first reference level which is a greatest level amongst the plurality of reference voltages, a second reference voltage having a second reference level that is less than the first reference level of the first reference voltage, and a third reference voltage having a third reference level that is less than the first reference level and the second reference level, wherein the first reference voltage is output responsive to the luminance control signal being at a first level, the second reference voltage is output responsive to the luminance control signal being at a second level that is greater than the first level, and the third reference voltage is output responsive to the luminance control signal being at a third level that is greater than the second level and the first level. ### Claim 12 (depends on 10) The display device of claim 10, wherein the data comparator is configured to calculate a first average image level from the second frame data, calculate a second average image level from the sampling data, and output a difference between the first average image level and the second average image level as the luminance control signal. ### Claim 13 (depends on 10) The display device of claim 10, wherein the data comparator is configured to calculate a first average current luminance from the second frame data, calculate a second average current luminance from the sampling data, and output a difference between the first average current luminance and the first average current luminance as the luminance control signal. ### Claim 14 A display device comprising: a display panel including a plurality of pixels; and a timing controller configured to simultaneously receive first frame data and second frame data, and output a luminance control signal based on a comparison of the first frame data and the second frame data that were simultaneously received, wherein an output luminance of the plurality of pixels is based on the luminance control signal, and wherein the timing controller comprises: a data sampler configured to sample the first frame data to extract sampling data from the first frame data; and a data comparator configured to compare the sampling data and the second frame data and output the luminance control signal based on a result of comparison. ### Claim 15 (depends on 14) The display device of claim 14, further comprising: a power supply configured to generate a plurality of reference voltages each having a different level and output a reference voltage from the plurality of reference voltages responsive to the luminance control signal, wherein the outputted reference voltage is applied to a node to which a driving and a light emitting element of at least one of the plurality of pixels is connected. ### Claim 16 (depends on 15) The display device of claim 15, wherein as a level of the luminance control signal increases one of the plurality of reference voltages having a lower level among the plurality of reference voltages is output. ### Claim 17 (depends on 14) The display device of claim 14, wherein second frame data is sampled frame data, and the data comparator is configured to compare the first frame data and the sampled second frame data by calculating a first average image level from the first frame data, calculate a second average image level from the sampled second frame data, and output a difference between the first average image level and the second average image level as the luminance control signal, or wherein the timing controller is configured to calculate a first average current luminance from the first frame data, calculate a second average current luminance from the sampled second frame data, and output a difference between the first average current luminance and the second average current luminance as the luminance control signal.