# US 12,223,863 B2 · Display panel and display device including the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,223,863 B2 - Document ID: US12223863B2 - Status: Granted - Kind: B2 - Application number: 17/903,468 - Filed: 2022-09-06 - Published: 2023-04-27 - Granted: 2025-02-11 - Earliest claimed: 2021-10-27 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Hai-Jung In - Web page: https://patentgrep.com/patent/US12223863B2 ## CPC - G09G 3/006: {Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays (testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309)} - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/32: semiconductive, e.g. using light-emitting diodes [LED] - 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 2300/0852: being a dynamic memory with more than 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 2310/0278: Details of driving circuits arranged to drive both scan and data electrodes - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - 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 panel includes a pixel connected to a scan line and a data line, and a lighting test circuit which provides a lighting test voltage to the pixel through the data line. The lighting test circuit includes a first test transistor including a first electrode which receives the lighting test voltage, a second electrode and a gate electrode which receives a first test control signal, and a second test transistor including a first electrode connected to the second electrode of the first test transistor, a second electrode connected to the data line and a gate electrode which receives a second test control signal. ## Claims ### Claim 1 A display panel, comprising: a pixel connected to a scan line and a data line; and a lighting test circuit which provides a lighting test voltage to the pixel through the data line, wherein the lighting test circuit includes: a first test transistor including a first electrode which receives the lighting test voltage, a second electrode, and a gate electrode which receives a first test control signal; and a second test transistor including a first electrode connected to the second electrode of the first test transistor, a second electrode connected to the data line, and a gate electrode which receives a second test control signal, wherein the image display period includes a plurality of frame periods that each include a data write period in which the data voltage is written to the data line and a data porch period in which the data voltage is not written to the data line, and wherein during the data write period only one of the first test control signal and the second test control signal has a high voltage and during at least a portion of the data porch period both the first test control signal and the second test control signal simultaneously have a low voltage. ### Claim 2 (depends on 1) The display panel of claim 1, wherein each of the first test transistor and the second test transistor is an N-type transistor. ### Claim 3 (depends on 2) The display panel of claim 2, wherein each of the first test control signal and the second test control signal has a low voltage and a high voltage which are alternating with each other in an image display period in which a data voltage is provided to the pixel through the data line, and wherein at least one selected from the first test control signal and the second test control signal has the low voltage at all time points in the image display period. ### Claim 4 (depends on 3) The display panel of claim 3, and wherein each of the first test control signal and the second test control signal is switched from the low voltage to the high voltage or from the high voltage to the low voltage in the data porch period. ### Claim 5 (depends on 3) The display panel of claim 3, wherein each of the first test control signal and the second test control signal is switched from the low voltage to the high voltage or from the high voltage to the low voltage every one frame period in the image display period. ### Claim 6 (depends on 3) The display panel of claim 3, wherein each of the first test control signal and the second test control signal is switched from the low voltage to the high voltage or from the high voltage to the low voltage every plurality of frame periods in the image display period. ### Claim 7 (depends on 2) The display panel of claim 2, wherein each of the first test control signal and the second test control signal has a constant high voltage in a lighting test period in which the lighting test voltage is provided to the pixel through the data line. ### Claim 8 (depends on 1) The display panel of claim 1, wherein each of the first test transistor and the second test transistor is one of an oxide semiconductor transistor and an amorphous silicon transistor. ### Claim 9 A display device, comprising: a pixel connected to a scan line and a data line; a scan driver which provides a scan signal to the pixel through the scan line; a data driver which provides a data voltage to the pixel through the data line; and a lighting test circuit which provides a lighting test voltage to the pixel through the data line, wherein the lighting test circuit includes: a first test transistor including a first electrode which receives the lighting test voltage, a second electrode, and a gate electrode which receives a first test control signal; and a second test transistor including a first electrode connected to the second electrode of the first test transistor, a second electrode connected to the data line, and a gate electrode which receives a second test control signal, wherein the image display period includes a plurality of frame periods that each include a data write period in which the data voltage is written to the data line and a data porch period in which the data voltage is not written to the data line, and wherein during the data write period only one of the first test control signal and the second test control signal has a high voltage and during at least a portion of the data porch period both the first test control signal and the second test control signal simultaneously have a low voltage data. ### Claim 10 (depends on 9) The display device of claim 9, wherein each of the first test transistor and the second test transistor is an N-type transistor. ### Claim 11 (depends on 10) The display device of claim 10, wherein each of the first test control signal and the second test control signal has a low voltage and a high voltage which are alternating with each other in an image display period in which the data voltage is provided to the pixel through the data line, and wherein at least one selected from the first test control signal and the second test control signal has the low voltage at all time points in the image display period. ### Claim 12 (depends on 11) The display device of claim 11, wherein each selected from the first test control signal and the second test control signal is switched from the low voltage to the high voltage or from the high voltage to the low voltage in the data porch period. ### Claim 13 (depends on 11) The display device of claim 11, wherein each of the first test control signal and the second test control signal is switched from the low voltage to the high voltage or from the high voltage to the low voltage every one frame period in the image display period. ### Claim 14 (depends on 11) The display device of claim 11, wherein each of the first test control signal and the second test control signal is switched from the low voltage to the high voltage or from the high voltage to the low voltage every plurality of frame periods in the image display period. ### Claim 15 (depends on 10) The display device of claim 10, wherein each of the first test control signal and the second test control signal has a constant high voltage in a lighting test period in which the lighting test voltage is provided to the pixel through the data line.