# US 10,872,563 B2 · Display apparatus and method of driving display panel using the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,872,563 B2 - Document ID: US10872563B2 - Status: Granted - Kind: B2 - Application number: 16/360,918 - Filed: 2019-03-21 - Published: 2019-11-07 - Granted: 2020-12-22 - Earliest claimed: 2018-05-03 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Sehyuk Park; Hyo Jin Lee; Hui Nam - Web page: https://patentgrep.com/patent/US10872563B2 ## CPC - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/2018: {by time modulation using two or more time intervals} - G09G 3/3266: Details of drivers for scan electrodes - G09G 3/3275: Details of drivers for data electrodes - 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 2300/0861: with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes - G09G 2310/08: Details of timing specific for flat panels, other than clock recovery - G09G 2320/0238: Improving the black level - G09G 2320/0247: Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes - G09G 2320/0646: Modulation of illumination source brightness and image signal correlated to each other - G09G 2320/10: Special adaptations of display systems for operation with variable images - G09G 2330/021: Power management, e.g. power saving - G09G 2340/0435: Change or adaptation of the frame rate of the video stream - 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 apparatus includes a display panel, a gate driver, a data driver, and an emission driver. The display panel includes a pixel. The pixel includes a switching element of a first type and a switching element of a second type different from the first type. The gate driver is configured to output a gate signal to the display panel. The data driver is configured to output a data voltage to the display panel. The emission driver is configured to output an emission signal. The emission signal comprises a length of an emission off duration of a writing frame in which data is written to the pixel and a length of an emission off duration of a holding frame in which the data written to the pixel is maintained in a low frequency driving mode. The length of the emission off duration of the holding frame is different from the length of the emission off duration of the writing frame in the low frequency driving mode. ## Claims ### Claim 1 A display apparatus comprising: a display panel comprising a pixel, the pixel comprising: a switching element of a first type; and a switching element of a second type different from the first type; a gate driver configured to output a gate signal to the display panel; a data driver configured to output a data voltage to the display panel; and an emission driver configured to output an emission signal, the emission signal comprising: a length of an emission off duration of a writing frame in which data is written to the pixel; and a length of an emission off duration of a holding frame in which the data written to the pixel is maintained in a low frequency driving mode, the length of the emission off duration of the holding frame being different from the length of the emission off duration of the writing frame in the low frequency driving mode, wherein the length of the emission off duration of the writing frame is greater than the length of the emission off duration of the holding frame in the low frequency driving mode. ### Claim 2 (depends on 1) The display apparatus of claim 1, wherein: in a normal driving mode, the display panel is configured to be driven in a frequency greater than a frequency of the low frequency driving mode; the normal driving mode only comprises writing frames, the writing frames comprising the writing frame; a length of the emission off duration of the writing frame in the low frequency driving mode is substantially the same as a length of the emission off duration of the writing frame in the normal driving mode; and the length of the emission off duration of the holding frame in the low frequency driving mode is less than the length of the emission off duration of the writing frame in the normal driving mode. ### Claim 3 (depends on 2) The display apparatus of claim 2, wherein the length of the emission off duration of the holding frame in the low frequency driving mode is adjusted to vary according to grayscales of an input image. ### Claim 4 (depends on 2) The display apparatus of claim 2, wherein the length of the emission off duration of the holding frame in the low frequency driving mode is adjusted to vary according to the frequency of the low frequency driving mode. ### Claim 5 (depends on 1) The display apparatus of claim 1, wherein: in a normal driving mode, the display panel is configured to be driven in a frequency greater than a frequency of the low frequency driving mode; the normal driving mode only comprises writing frames, the writing frames comprising the writing frame; a length of the emission off duration of the writing frame in the low frequency driving mode is greater than a length of the emission off duration of the writing frame in the normal driving mode; and the length of the emission off duration of the holding frame in the low frequency driving mode is substantially the same as the length of the emission off duration of the writing frame in the normal driving mode. ### Claim 6 (depends on 5) The display apparatus of claim 5, wherein the length of the emission off duration of the writing frame in the low frequency driving mode is adjusted to vary according to grayscales of an input image. ### Claim 7 (depends on 5) The display apparatus of claim 5, wherein the length of the emission off duration of the writing frame in the low frequency driving mode is adjusted to vary according to the frequency of the low frequency driving mode. ### Claim 8 (depends on 1) The display apparatus of claim 1, wherein: in a normal driving mode, the display panel is configured to be driven in a frequency greater than a frequency of the low frequency driving mode; the normal driving mode only comprises writing frames, the writing frames comprising the writing frame; a length of the emission off duration of the writing frame in the low frequency driving mode is greater than a length of the emission off duration of the writing frame in the normal driving mode; and the length of the emission off duration of the holding frame in the low frequency driving mode is less than the length of the emission off duration of the writing frame in the normal driving mode. ### Claim 9 (depends on 8) The display apparatus of claim 8, wherein: the length of the emission off duration of the writing frame in the low frequency driving mode is adjusted to vary according to grayscales of an input image; and the length of the emission off duration of the holding frame in the low frequency driving mode is adjusted to vary according to the grayscales of the input image. ### Claim 10 (depends on 8) The display apparatus of claim 8, wherein: the length of the emission off duration of the writing frame in the low frequency driving mode is adjusted to vary according to the frequency of the low frequency driving mode; and the length of the emission off duration of the holding frame in the low frequency driving mode is adjusted to vary according to the frequency of the low frequency driving mode. ### Claim 11 (depends on 1) The display apparatus of claim 1, wherein: the switching element of the first type is a polysilicon thin film transistor; and the switching element of the second type is an oxide thin film transistor. ### Claim 12 (depends on 11) The display apparatus of claim 11, wherein: the switching element of the first type is a P-type transistor; and the switching element of the second type is an N-type transistor. ### Claim 13 (depends on 11) The display apparatus of claim 11, wherein the pixel comprises: a first pixel switching element comprising a control electrode connected to a first node, an input electrode connected to a second node, and an output electrode connected to a third node; a second pixel switching element comprising a control electrode configured to receive a first data write gate signal, an input electrode configured to receive the data voltage, and an output electrode connected to the second node; a third pixel switching element comprising a control electrode configured to receive a second data write gate signal, an input electrode connected to the first node, and an output electrode connected to the third node; a fourth pixel switching element comprising a control electrode configured to receive a data initialization gate signal, an input electrode configured to receive an initialization voltage; and an output electrode connected to the first node; a fifth pixel switching element comprising a control electrode configured to receive the emission signal, an input electrode configured to receive a high power voltage; and an output electrode connected to the second node; a sixth pixel switching element comprising a control electrode configured to receive the emission signal, an input electrode connected to the third node, and an output electrode connected to an anode electrode of an organic light emitting element; a seventh pixel switching element comprising a control electrode configured to receive an organic light emitting element initialization gate signal, an input electrode configured to receive the initialization voltage, and an output electrode connected to the anode electrode of the organic light emitting element; a storage capacitor comprising a first electrode configured to receive the high power voltage and a second electrode connected to the first node; and the organic light emitting element comprising the anode electrode connected to the output electrode of the sixth switching element and a cathode electrode configured to receive a low power voltage. ### Claim 14 (depends on 13) The display apparatus of claim 13, wherein: the first pixel switching element, the second pixel switching element, the fifth pixel switching element, and the sixth pixel switching element are polysilicon thin film transistors; and the third pixel switching element, the fourth pixel switching element, and the seventh pixel switching element are oxide thin film transistors. ### Claim 15 (depends on 14) The display apparatus of claim 14, wherein the control electrode of the third pixel switching element is connected to the control electrode of the seventh pixel switching element. ### Claim 16 (depends on 13) The display apparatus of claim 13, wherein: the first pixel switching element, the second pixel switching element, the fifth pixel switching element, the sixth pixel switching element, and the seventh pixel switching element are polysilicon thin film transistors; and the third pixel switching element and the fourth pixel switching element are oxide thin film transistors. ### Claim 17 (depends on 16) The display apparatus of claim 16, wherein the control electrode of the second pixel switching element is connected to the control electrode of the seventh pixel switching element. ### Claim 18 (depends on 13) The display apparatus of claim 13, wherein: the second data writing gate signal and the data initialization gate signal have a first frequency; and the first data writing gate signal, the emission signal, and the organic light emitting element initialization gate signal have a second frequency greater than the first frequency. ### Claim 19 A method of driving a display panel, the method comprising: outputting a first data writing gate signal to a display panel; outputting a second data writing gate signal to the display panel simultaneously with the first data writing gate signal; outputting a data voltage to the display panel; and outputting an emission signal to the display panel, wherein the display panel comprises a pixel, the pixel comprising: a switching element of a first type; and a switching element of a second type different from the first type, wherein the emission signal comprises: a length of an emission off duration of a writing frame in which data is written to the pixel; and a length of an emission off duration of a holding frame in which the data written to the pixel is maintained in a low frequency driving mode, and wherein the length of the emission off duration of the writing frame is greater than the length of the emission off duration of the holding frame in the low frequency driving mode. ### Claim 20 (depends on 19) The method of claim 19, wherein the length of the emission off duration of the writing frame or the length of the emission off duration of the holding frame in the low frequency driving mode is adjusted to vary according to grayscales of an input image. ### Claim 21 (depends on 19) The method of claim 19, wherein the length of the emission off duration of the writing frame or the length of the emission off duration of the holding frame in the low frequency driving mode is adjusted to vary according to the frequency of the low frequency driving mode.