# US 10,373,550 B2 · Light emitting device and method of driving the light emitting device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,373,550 B2 - Document ID: US10373550B2 - Status: Granted - Kind: B2 - Application number: 16/027,892 - Filed: 2018-07-05 - Published: 2018-11-01 - Granted: 2019-08-06 - Earliest claimed: 2002-02-28 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Applicants: Semiconductor Energy Laboratory Co., Ltd. - Inventors: Mitsuaki Osame; Aya Anzai; Yoshifumi Tanada; Keisuke Miyagawa; Satoshi Seo; Shunpei Yamazaki - Web page: https://patentgrep.com/patent/US10373550B2 ## CPC - G09G 3/32: semiconductive, e.g. using light-emitting diodes [LED] - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/3258: with pixel circuitry controlling the voltage across the light-emitting element - G09G 3/3266: Details of drivers for scan electrodes - 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 - H10H 20/062: {Light-emitting semiconductor devices having field effect type light-emitting regions, e.g. light-emitting High-Electron Mobility Transistors} - G09G 2300/043: Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver - 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 2310/0251: Precharge or discharge of pixel before applying new pixel voltage - G09G 2310/0256: with the purpose of reversing the voltage across a light emitting or modulating element within a pixel - G09G 2310/027: Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters - G09G 2310/061: for resetting or blanking - G09G 2310/08: Details of timing specific for flat panels, other than clock recovery - G09G 2320/043: Preventing or counteracting the effects of ageing - G09G 2320/045: Compensation of drifts in the characteristics of light emitting or modulating elements - 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 ## Abstract A light emitting device that achieves long life, and which is capable of performing high duty drive, by suppressing initial light emitting element deterioration is provided. Reverse bias application to an EL element (109) is performed one row at a time by forming a reverse bias electric power source line (112) and a reverse bias TFT (108). Reverse bias application can therefore be performed in synchronous with operations for write-in of an image signal, light emission, erasure, and the like. Reverse bias application therefore becomes possible while maintaining a duty equivalent to that of a conventional driving method. ## Claims ### Claim 1 A light emitting device comprising: a first transistor, wherein a gate of the first transistor is electrically connected to a first gate signal line, and one of a source and a drain of the first transistor is electrically connected to a source signal line; a second transistor, wherein a gate of the second transistor is electrically connected to the other of the source and the drain of the first transistor, and one of a source and a drain of the second transistor is electrically connected to a first wiring; a third transistor, wherein a gate of the third transistor is electrically connected to a second gate signal line, one of a source and a drain of the third transistor is electrically connected to the other of the source and the drain of the second transistor; a fourth transistor, wherein one of a source and a drain of the fourth transistor is electrically connected to the other of the source and the drain of the third transistor, and the other of the source and the drain of the fourth transistor is electrically connected to a second wiring; and a light emitting element, wherein a first electrode of the light emitting element is electrically connected to the other of the source and the drain of the third transistor and the one of the source and the drain of the fourth transistor, wherein the source signal line and the first wiring extend in a first direction, wherein each of the first gate signal line and the second gate signal line intersects with the source signal line and the first wiring, and wherein at least the first transistor and the fourth transistor are n-channel transistors. ### Claim 2 (depends on 1) The light emitting device according to claim 1, wherein at least the third transistor and the fourth transistor are top-gate type transistors. ### Claim 3 (depends on 1) The light emitting device according to claim 1, wherein at least the second transistor and the third transistor have the same polarity type. ### Claim 4 (depends on 1) The light emitting device according to claim 1, wherein the first wiring is a power supply line. ### Claim 5 (depends on 1) A display module comprising the light emitting device according to claim 1 and an FPC. ### Claim 6 (depends on 1) An electronic device comprising: the light emitting device according to claim 1; an antenna; an audio output portion; an audio input portion, and an operation switch. ### Claim 7 A light emitting device comprising: a first transistor, wherein a gate of the first transistor is electrically connected to a first gate signal line, and one of a source and a drain of the first transistor is electrically connected to a source signal line; a second transistor, wherein a gate of the second transistor is electrically connected to the other of the source and the drain of the first transistor, and one of a source and a drain of the second transistor is electrically connected to a first wiring; a third transistor, wherein a gate of the third transistor is electrically connected to a second gate signal line, one of a source and a drain of the third transistor is electrically connected to the other of the source and the drain of the second transistor; a fourth transistor, wherein one of a source and a drain of the fourth transistor is electrically connected to the other of the source and the drain of the third transistor, and the other of the source and the drain of the fourth transistor is electrically connected to a second wiring; a light emitting element, wherein a first electrode of the light emitting element is electrically connected to the other of the source and the drain of the third transistor and the one of the source and the drain of the fourth transistor; and a capacitor, wherein a first electrode of the capacitor is electrically connected to the other of the source and the drain of the third transistor, the one of the source and the drain of the fourth transistor, and the first electrode of the light emitting element, wherein the source signal line and the first wiring extend in a first direction, wherein each of the first gate signal line and the second gate signal line intersects with the source signal line and the first wiring, and wherein at least the first transistor and the fourth transistor are n-channel transistors. ### Claim 8 (depends on 7) The light emitting device according to claim 7, wherein at least the third transistor and the fourth transistor are top-gate type transistors. ### Claim 9 (depends on 7) The light emitting device according to claim 7, wherein at least the second transistor and the third transistor have the same polarity type. ### Claim 10 (depends on 7) The light emitting device according to claim 7, wherein the first wiring is a power supply line. ### Claim 11 (depends on 7) A display module comprising the light emitting device according to claim 7 and an FPC. ### Claim 12 (depends on 7) An electronic device comprising: the light emitting device according to claim 7; an antenna; an audio output portion; an audio input portion, and an operation switch. ### Claim 13 A light emitting device comprising: a first transistor, wherein a gate of the first transistor is electrically connected to a first gate signal line, and one of a source and a drain of the first transistor is electrically connected to a source signal line; a second transistor, wherein a gate of the second transistor is electrically connected to the other of the source and the drain of the first transistor, and one of a source and a drain of the second transistor is electrically connected to a first wiring; a third transistor, wherein a gate of the third transistor is electrically connected to a second gate signal line, one of a source and a drain of the third transistor is electrically connected to the other of the source and the drain of the second transistor; a fourth transistor, wherein one of a source and a drain of the fourth transistor is electrically connected to the other of the source and the drain of the third transistor, and the other of the source and the drain of the fourth transistor is electrically connected to a second wiring; and a light emitting element, wherein a pixel electrode of the light emitting element is electrically connected to the other of the source and the drain of the third transistor and the one of the source and the drain of the fourth transistor, wherein the source signal line and the first wiring extend in a first direction, wherein the first gate signal line and the second gate signal line extend in a second direction perpendicular to the first direction, and wherein at least the first transistor and the fourth transistor are n-channel transistors. ### Claim 14 (depends on 13) The light emitting device according to claim 13, wherein at least the third transistor and the fourth transistor are top-gate type transistors. ### Claim 15 (depends on 13) The light emitting device according to claim 13, wherein at least the second transistor and the third transistor have the same polarity type. ### Claim 16 (depends on 13) The light emitting device according to claim 13, wherein the first wiring is a power supply line. ### Claim 17 (depends on 13) A display module comprising the light emitting device according to claim 13 and an FPC. ### Claim 18 (depends on 13) An electronic device comprising: the light emitting device according to claim 13; an antenna; an audio output portion; an audio input portion, and an operation switch.