# US 10,769,999 B2 · Display device and driving method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,769,999 B2 - Document ID: US10769999B2 - Status: Granted - Kind: B2 - Application number: 15/989,634 - Filed: 2018-05-25 - Published: 2019-04-18 - Granted: 2020-09-08 - Earliest claimed: 2017-10-16 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Hyung Jun Park; Yang Wan Kim; Byung Sun Kim; Su Jin Lee; Jae Yong Lee - Web page: https://patentgrep.com/patent/US10769999B2 ## CPC - G09G 3/3258: with pixel circuitry controlling the voltage across the light-emitting element - G09G 3/2003: {Display of colours (specific for liquid crystal displays G09G3/3607)} - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 2300/0452: Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components - G09G 2300/0809: Several active elements per pixel in active matrix panels - 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 2310/0262: The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes - G09G 2320/0242: Compensation of deficiencies in the appearance of colours - 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 first and second initialization voltage sources and first and second pixel circuits. The first initialization voltage source provides a first initialization voltage. The second initialization voltage source provides a second initialization voltage less than the first initialization voltage. The first pixel circuit includes a first organic light emitting diode. The second pixel circuit includes a second organic light emitting diode with an organic material having a band gap different from a band gap of an organic material in the first organic light emitting diode. The first pixel circuit is coupled to the first initialization voltage source and the second initialization voltage source. The second pixel circuit is coupled to a single initialization voltage source. ## Claims ### Claim 1 A display device, comprising: a first initialization voltage source to provide a first initialization voltage; a second initialization voltage source to provide a second initialization voltage less than the first initialization voltage; a first pixel circuit including a first organic light emitting diode and a first driving transistor; and a second pixel circuit including a second organic light emitting diode that includes an organic material having a band gap different from a band gap of an organic material in the first organic light emitting diode, wherein the first pixel circuit is coupled to the first initialization voltage source and the second initialization voltage source, the first initialization voltage is applied to a gate terminal of the first driving transistor, the second initialization voltage is applied to an anode of the first organic light emitting diode, and the second pixel circuit is coupled to a single initialization voltage source. ### Claim 2 (depends on 1) The display device as claimed in claim 1, wherein the second organic light emitting diode has a greater capacitance per unit area than the first organic light emitting diode. ### Claim 3 (depends on 1) The display device as claimed in claim 1, wherein an area of a light emitting surface of the second organic light emitting diode is less than an area of a light emitting surface of the first organic light emitting diode. ### Claim 4 (depends on 1) The display device as claimed in claim 1, wherein the single initialization voltage source is the first initialization voltage source. ### Claim 5 (depends on 4) The display device as claimed in claim 4, wherein: the first driving transistor has an end coupled to the anode of the first organic light emitting diode in an emission period, the second pixel circuit includes a second driving transistor having an end coupled to an anode of the second organic light emitting diode in an emission period, and the first initialization voltage source is coupled to the gate terminal of the first driving transistor and a gate terminal of the second driving transistor in a first initialization period. ### Claim 6 (depends on 5) The display device as claimed in claim 5, wherein: the second initialization voltage source is coupled to the anode of the first organic light emitting diode in a second initialization period, and the first initialization voltage source is coupled to the anode of the second organic light emitting diode in the second initialization period. ### Claim 7 (depends on 1) The display device as claimed in claim 1, wherein the single initialization voltage source is the second initialization voltage source. ### Claim 8 (depends on 7) The display device as claimed in claim 7, wherein the second initialization voltage source is coupled to the anode of the first organic light emitting diode and an anode of the second organic light emitting diode in a second initialization period that follows a first initialization period. ### Claim 9 (depends on 8) The display device as claimed in claim 8, wherein: the first pixel circuit includes the first driving transistor having an end coupled to the anode of the first organic light emitting diode in an emission period, the second pixel circuit includes a second driving transistor having an end coupled to the anode of the second organic light emitting diode in an emission period, the first initialization voltage source is coupled to the gate terminal of the first driving transistor in the first initialization period, and the second initialization voltage source is coupled to a gate terminal of the second driving transistor in the first initialization period. ### Claim 10 (depends on 9) The display device as claimed in claim 9, wherein the first initialization period is before the second initialization period. ### Claim 11 (depends on 1) The display device as claimed in claim 1, further comprising: a third initialization voltage source to provide a third initialization voltage having a voltage value different from voltage values of the first initialization voltage and the second initialization voltage, wherein the single initialization voltage source is the third initialization voltage source. ### Claim 12 (depends on 11) The display device as claimed in claim 11, wherein the third initialization voltage has a value between the first initialization voltage and the second initialization voltage. ### Claim 13 (depends on 12) The display device as claimed in claim 12, wherein: the second initialization voltage source is coupled to the anode of the first organic light emitting diode in a second initialization period, and the third initialization voltage source is coupled to an anode of the second organic light emitting diode in the second initialization period. ### Claim 14 (depends on 13) The display device as claimed in claim 13, wherein: the first pixel circuit includes the first driving transistor having an end coupled to the anode of the first organic light emitting diode in an emission period, the second pixel circuit includes a second driving transistor having an end coupled to the anode of the second organic light emitting diode in an emission period, the first initialization voltage source is coupled to the gate terminal of the first driving transistor in a first initialization period, and the third initialization voltage source is coupled to a gate terminal of the second driving transistor in the first initialization period. ### Claim 15 (depends on 1) The display device as claimed in claim 1, further comprising: a third pixel circuit coupled the first initialization voltage source and the second initialization voltage source, the third pixel circuit including a third organic light emitting diode including an organic material having a band gap different from bang gaps of the organic materials in the first organic light emitting diode and the second organic light emitting diode; a first data line; and a second data line different from the first data line, wherein the first pixel circuit and the third pixel circuit are coupled to the first data line and wherein the second pixel circuit is coupled to the second data line. ### Claim 16 (depends on 15) The display device as claimed in claim 15, wherein: the first organic light emitting diode is a red organic light emitting diode, the second organic light emitting diode is a green organic light emitting diode, and the third organic light emitting diode is a blue organic light emitting diode. ### Claim 17 (depends on 15) The display device as claimed in claim 15, wherein: the first organic light emitting diode is a red organic light emitting diode, the second organic light emitting diode is a blue organic light emitting diode, and the third organic light emitting diode is a green organic light emitting diode. ### Claim 18 (depends on 15) The display device as claimed in claim 15, wherein: the first organic light emitting diode is a blue organic light emitting diode, the second organic light emitting diode is a red organic light emitting diode, and the third organic light emitting diode is a green organic light emitting diode. ### Claim 19 (depends on 15) The display device as claimed in claim 15, wherein: the third pixel circuit includes a third driving transistor having an end coupled to an anode of the third organic light emitting diode in an emission period, the first initialization voltage source is coupled to a gate terminal of the third driving transistor in a first initialization period, and the second initialization voltage source is coupled to the anode of the third organic light emitting diode in a second initialization period. ### Claim 20 A method for driving a display device, the method comprising: in a first initialization period, applying a first initialization voltage to a gate terminal of a first driving transistor of a first pixel circuit and applying a single initialization voltage to a gate terminal of a second driving transistor of a second pixel circuit; in a second initialization period, applying a second initialization voltage less than the first initialization voltage to an anode of a first organic light emitting diode of the first pixel circuit and applying the single initialization voltage to an anode of a second organic light emitting diode of the second pixel circuit, which includes an organic material having a band gap different from a band gap of an organic material of the first organic light emitting diode; and in an emission period, allowing the first organic light emitting diode and the second organic light emitting diode to emit light. ### Claim 21 (depends on 20) The method as claimed in claim 20, wherein the single initialization voltage is equal to the first initialization voltage. ### Claim 22 (depends on 20) The method as claimed in claim 20, wherein the single initialization voltage is equal to the second initialization voltage. ### Claim 23 (depends on 20) The method as claimed in claim 20, wherein the single initialization voltage has a value different from values of the first initialization voltage and the second initialization voltage. ### Claim 24 (depends on 23) The method as claimed in claim 23, wherein the single initialization voltage has a value between the first initialization voltage and the second initialization voltage. ### Claim 25 (depends on 1) The display device as claimed in claim 1, wherein: the first pixel circuit is configured to apply the first initialization voltage and the second initialization voltage to the first organic light emitting diode. ### Claim 26 (depends on 25) The display device as claimed in claim 25, wherein: the second pixel circuit is configured to apply a single initialization voltage to the second organic light emitting diode. ### Claim 27 (depends on 15) The display device as claimed in claim 15, wherein: the third pixel circuit is configured to apply the first initialization voltage and the second initialization voltage to the third organic light emitting diode.