# US 2023/0274685 A1 · Display device for reducing deterioration of light-emitting elements > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0274685 A1 - Document ID: US20230274685A1 - Status: Published application - Kind: A1 - Application number: 17/965,534 - Filed: 2022-10-13 - Published: 2023-08-31 - Earliest claimed: 2022-02-25 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., LTD. - Inventors: Jin Won JANG; Seung Won KUK - Web page: https://patentgrep.com/patent/US20230274685A1 ## CPC - 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 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 2300/0426: Layout of electrodes and connections - G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing - G09G 2300/0842: forming a memory circuit, e.g. a dynamic memory with one capacitor - G09G 2310/08: Details of timing specific for flat panels, other than clock recovery - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/043: Preventing or counteracting the effects of ageing - G09G 2330/021: Power management, e.g. power saving - G09G 2330/028: Generation of voltages supplied to electrode drivers in a matrix display other than LCD - G09G 2360/148: the light being detected by light detection means within each pixel - G09G 2360/16: Calculation or use of calculated indices related to luminance levels in display data - H10H 20/857: Interconnections, e.g. lead-frames, bond wires or solder balls - H10W 90/00: Package configurations - 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) - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A display device comprises pixels arranged along rows and columns, and including light-emitting elements, a first transistor for supplying a driving current to the light-emitting elements, a second transistor for supplying a data voltage to a first node at a gate electrode of the first transistor, a third transistor for electrically connecting a second node, which is at a first electrode of the light-emitting elements, and a sensing line, and a fourth transistor for electrically connecting a third node, which is at a second electrode of the light-emitting elements, and the sensing line, and a display driver for driving the pixels, for sensing voltages of the second node and the third node to calculate a driving voltage across the light-emitting elements, and for compensating for the data voltage in case that the driving voltage exceeds a reference voltage. ## Claims ### Claim 1 A display device comprising: pixels arranged along rows and columns, and comprising: light-emitting elements; a first transistor for supplying a driving current to the light-emitting elements; a second transistor for supplying a data voltage to a first node at a gate electrode of the first transistor upon receiving a scan write signal of a gate high level during a first period; a third transistor for electrically connecting a second node, which is at a first electrode, and a sensing line upon receiving a first scan sensing signal of a gate high level during the first period and during a second period after the first period; and a fourth transistor for electrically connecting a third node, which is at a second electrode, and the sensing line upon receiving a second scan sensing signal of a gate high level during a third period after the second period; and a display driver for driving the pixels, for sensing voltages of the second node and the third node to calculate a driving voltage across the light-emitting elements, and for compensating for the data voltage in case that the driving voltage exceeds a reference voltage. ### Claim 2 (depends on 1) The display device of claim 1, wherein the display driver is configured to determine compensation data based on a preset lookup table when the driving voltage exceeds the reference voltage. ### Claim 3 (depends on 2) The display device of claim 2, wherein the display driver is configured to receive digital video data, is configured to generate the data voltage, and is configured to generate a compensated data voltage by applying the compensation data to the digital video data. ### Claim 4 (depends on 3) The display device of claim 3, wherein the compensated data voltage is lower than the data voltage before being compensated. ### Claim 5 (depends on 1) The display device of claim 1, wherein the light-emitting elements are connected in parallel between the second node and the third node, and wherein a magnitude of a current flowing to one of the light-emitting elements increases as a number of light-emitting elements among the light-emitting elements, to which a collective current flows, decreases. ### Claim 6 (depends on 1) The display device of claim 1, wherein the display driver is configured to drive the pixels based on a vertical synchronization signal having a low level and a high level during one frame period, and wherein the display driver is configured to calculate driving voltages of pixels in some rows among the pixels during a rest period in which the vertical synchronization signal has the low level, wherein the rest period comprises the first period, the second period, and the third period. ### Claim 7 (canceled) ### Claim 8 (depends on 1) The display device of claim 1, wherein the first electrode comprises: a first portion extending in a first direction; and a second portion branching from the first portion, and extending in a second direction crossing the first direction, and wherein the second electrode comprises: a first portion extending in the first direction; a second portion branching from one side of the first portion, and extending toward one side of the second portion of the first electrode; and a third portion branching from another side of the first portion, and extending toward another side of the second portion of the first electrode. ### Claim 9 (depends on 8) The display device of claim 8, wherein the light-emitting elements comprise: a first semiconductor layer comprising at least one semiconductor material doped with a p-type dopant, and electrically connected to the second portion of the first electrode; and a second semiconductor layer comprising at least one semiconductor material doped with an n-type dopant, and electrically connected to the second portion and the third portion of the second electrode. ### Claim 10 (depends on 8) The display device of claim 8, wherein the driving current is configured to be supplied to the second portion of the first electrode, to be divided into the light-emitting elements, and to flow to the second portion and the third portion of the second electrode. ### Claim 11 A display device comprising: pixels arranged along rows and columns, and comprising: light-emitting elements; a first transistor for supplying a driving current to the light-emitting elements; a second transistor for supplying a data voltage to a first node at a gate electrode of the first transistor; a third transistor for electrically connecting a second node, which is at a source electrode of the first transistor, and a sensing line; a fourth transistor electrically connecting a third node and the sensing line; and a fifth transistor electrically connecting a fourth node and the sensing line; and a display driver for driving the pixels, for sensing voltages of the second to the fourth nodes to calculate a first driving voltage between the second and third nodes, for calculating a second driving voltage between the third and fourth nodes, and for compensating for the data voltage when at least one of the first and second driving voltages exceeds a reference voltage. ### Claim 12 (depends on 11) The display device of claim 11, wherein the display driver is configured to determine compensation data based on a preset lookup table when at least one of the first and second driving voltages exceeds the reference voltage. ### Claim 13 (depends on 12) The display device of claim 12, wherein the display driver is configured to receive digital video data, to generate the data voltage, and to generate a compensated data voltage by applying the compensation data to the digital video data. ### Claim 14 (depends on 13) The display device of claim 13, wherein the compensated data voltage is lower than the data voltage before being compensated. ### Claim 15 (depends on 11) The display device of claim 11, wherein some of the light-emitting elements are connected in parallel between the second and third nodes, and others of the light-emitting elements are connected in parallel between the third and fourth nodes, and wherein a magnitude of a current flowing to one of the light-emitting elements increases as a number of the light-emitting elements, to which a collective current flows, decreases. ### Claim 16 (depends on 11) The display device of claim 11, wherein the display driver is configured to drive the pixels based on a vertical synchronization signal having a low level and a high level during one frame period, and is configured to calculate first and second driving voltages of pixels in some rows among the pixels during a rest period in which the vertical synchronization signal has the low level. ### Claim 17 (depends on 16) The display device of claim 16, wherein the second transistor is configured to receive a scan write signal of a gate high level during a first period of the rest period, wherein the third transistor is configured to receive a first scan sensing signal of a gate high level during the first period of the rest period and a second period after the first period, wherein the fourth transistor is configured to receive a second scan sensing signal of a gate high level during a third period after the second period of the rest period, and wherein the fifth transistor is configured to receive a third scan sensing signal of a gate high level during a fourth period after the third period of the rest period. ### Claim 18 (depends on 11) The display device of claim 11, further comprising a first electrode at the second node, and a second electrode at the third node, wherein the first electrode comprises: a first portion extending in a first direction; and a second portion branching from the first portion, and extending in a second direction crossing the first direction, and wherein the second electrode comprises: a first portion extending in the first direction; a second portion branching from one side of the first portion, and extending toward one side of the second portion of the first electrode; and a third portion branching from another side of the first portion, and extending toward another side of the second portion of the first electrode. ### Claim 19 (depends on 18) The display device of claim 18, wherein the light-emitting elements comprise: a first semiconductor layer comprising at least one semiconductor material doped with a p-type dopant, and electrically connected to the second portion of the first electrode; and a second semiconductor layer comprising at least one semiconductor material doped with an n-type dopant, and electrically connected to the second portion and the third portion of the second electrode. ### Claim 20 (depends on 18) The display device of claim 18, wherein the driving current is configured to be supplied to the second portion of the first electrode, to be divided into the light-emitting elements, and to flow to the second portion and the third portion of the second electrode.