# US 2024/0203344 A1 · Display device and method for driving same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0203344 A1 - Document ID: US20240203344A1 - Status: Published application - Kind: A1 - Application number: 17/909,861 - Filed: 2020-04-21 - Published: 2024-06-20 - Earliest claimed: 2020-04-21 - Assignees: Sharp Kabushiki Kaisha - Applicants: Sharp Kabushiki Kaisha - Inventors: Keiichi YAMAMOTO; Ryo YONEBAYASHI - Web page: https://patentgrep.com/patent/US20240203344A1 ## CPC - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/20: for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} - G09G 3/3225: using an active matrix - 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 2320/045: Compensation of drifts in the characteristics of light emitting or modulating elements - G09G 2330/021: Power management, e.g. power saving - 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 is implemented that can reduce power consumption over a known example while preventing occurrence of black floating. The voltage value of a low-level power supply voltage ELVSS provided to a pixel circuit is set to a higher value in a pause driving period than in a normal driving period. Upon writing a data voltage, an anode initialization period for initializing an anode voltage of an organic EL element is provided. In this regard, an anode initialization period in the pause driving period is made longer than an anode initialization period in the normal driving period. To implement this, for example, a write frequency of a data voltage is made lower in the pause driving period than in the normal driving period. ## Claims ### Claim 1 A driving method for a display device including a plurality of data signal lines each transmitting a data voltage; a plurality of scanning signal lines that intersect the plurality of data signal lines; a plurality of light-emission control lines that intersect the plurality of data signal lines; and a plurality of pixel circuits to which a high-level power supply voltage and a low-level power supply voltage are provided, the plurality of pixel circuits each including a display element that is driven by a current, wherein each of the plurality of pixel circuits includes: the display element having a first terminal and a second terminal to which the low-level power supply voltage is provided; a drive transistor having a control terminal, a first conductive terminal, and a second conductive terminal and provided in series with the display element; a capacitor having one terminal connected to the control terminal of the drive transistor, a light-emission control transistor having a control terminal connected to one of the plurality of light-emission control lines; a first conductive terminal connected to the second conductive terminal of the drive transistor; and a second conductive terminal connected to the first terminal of the display element; a first initialization transistor having a control terminal connected to one of the plurality of scanning signal lines; a first conductive terminal connected to the control terminal of the drive transistor; and a second conductive terminal to which an initialization voltage is provided; and a second initialization transistor having a control terminal connected to one of the plurality of scanning signal lines; a first conductive terminal connected to the first terminal of the display element; and a second conductive terminal to which the initialization voltage is provided, and the driving method comprises: a normal driving step of driving the plurality of data signal lines, the plurality of scanning signal lines, and the plurality of light-emission control lines such that the data voltage is written to the capacitor included in each of the plurality of pixel circuits every frame period; a pause driving step of driving the plurality of data signal lines, the plurality of scanning signal lines, and the plurality of light-emission control lines such that a data write period during which the data voltage is written to the capacitor included in each of the plurality of pixel circuits and a pause period during which the data voltage is not written to the capacitor included in each of the plurality of pixel circuits appear alternately; a low-level power supply voltage increasing step of increasing a voltage value of the low-level power supply voltage upon switching from a normal driving period during which the normal driving step is performed to a pause driving period during which the pause driving step is performed; and a low-level power supply voltage reducing step of reducing the voltage value of the low-level power supply voltage upon switching from the pause driving period to the normal driving period, upon writing the data voltage to the capacitor included in each of the plurality of pixel circuits, a first terminal initialization period during which the second initialization transistor is maintained in on state to initialize a voltage at the first terminal of the display element is provided, and the first terminal initialization period in the pause driving period is longer than the first terminal initialization period in the normal driving period. ### Claim 2 (depends on 1) The driving method according to claim 1, wherein a write frequency used upon writing the data voltage to the capacitor included in each of the plurality of pixel circuits during the pause driving period is lower than a write frequency used upon writing the data voltage to the capacitor included in each of the plurality of pixel circuits during the normal driving period. ### Claim 3 (depends on 2) The driving method according to claim 2, wherein a length of the data write period in the pause driving period is twice a length of the data write period in the normal driving period. ### Claim 4 (depends on 1) The driving method according to claim 1, wherein a write frequency used upon writing the data voltage to the capacitor included in each of the plurality of pixel circuits during the normal driving period is identical to a write frequency used upon writing the data voltage to the capacitor included in each of the plurality of pixel circuits during the pause driving period, and in the pause driving step, a data write period with a length obtained by adding an initialization extension period to one frame period in the normal driving period, and a pause period including a period with a length obtained by subtracting the initialization extension period from one frame period in the normal driving period, and a period with a length corresponding to N frame periods in the normal driving period appear alternately, the initialization extension period being a difference between the first terminal initialization period in the pause driving period and the first terminal initialization period in the normal driving period, and the N being an integer. ### Claim 5 (depends on 1) The driving method according to claim 1, wherein a voltage value of the initialization voltage and a voltage value of the low-level power supply voltage are set to equal values. ### Claim 6 (depends on 1) The driving method according to claim 1, wherein the display device includes a pixel driving unit configured to drive the plurality of data signal lines, the plurality of scanning signal lines, and the plurality of light-emission control lines, a voltage value of the data voltage corresponding to black is set to a higher value than a voltage value of the data voltage corresponding to white, and is set to a lower value in the pause driving period than in the normal driving period, as power supply voltages for operation of the pixel driving unit, a first power supply voltage of a high level and a second power supply voltage of a low level are provided to the pixel driving unit, and a voltage value of the first power supply voltage is set to a lower value in the pause driving period than in the normal driving period. ### Claim 7 (depends on 1) The driving method according to claim 1, wherein the first terminal initialization period is a part of a turn-off period during which the light-emission control transistor is maintained in off state. ### Claim 8 A display device including a plurality of pixel circuits to which a high-level power supply voltage and a low-level power supply voltage are provided, the plurality of pixel circuits each including a display element that is driven by a current, the display device comprising: a plurality of data signal lines each transmitting a data voltage; a plurality of scanning signal lines that intersect the plurality of data signal lines; a plurality of light-emission control lines that intersect the plurality of data signal lines; a pixel driving unit configured to drive the plurality of data signal lines, the plurality of scanning signal lines, and the plurality of light-emission control lines; and a low-level power supply voltage output unit configured to output the low-level power supply voltage, wherein each of the plurality of pixel circuits includes: the display element having a first terminal and a second terminal to which the low-level power supply voltage is provided; a drive transistor having a control terminal, a first conductive terminal, and a second conductive terminal and provided in series with the display element; a capacitor having one terminal connected to the control terminal of the drive transistor, a light-emission control transistor having a control terminal connected to one of the plurality of light-emission control lines; a first conductive terminal connected to the second conductive terminal of the drive transistor; and a second conductive terminal connected to the first terminal of the display element; a first initialization transistor having a control terminal connected to one of the plurality of scanning signal lines; a first conductive terminal connected to the control terminal of the drive transistor; and a second conductive terminal to which an initialization voltage is provided; and a second initialization transistor having a control terminal connected to one of the plurality of scanning signal lines; a first conductive terminal connected to the first terminal of the display element; and a second conductive terminal to which the initialization voltage is provided, the pixel driving unit drives, during a normal driving period, the plurality of data signal lines, the plurality of scanning signal lines, and the plurality of light-emission control lines such that the data voltage is written to the capacitor included in each of the plurality of pixel circuits every frame period, and drives, during a pause driving period, the plurality of data signal lines, the plurality of scanning signal lines, and the plurality of light-emission control lines such that a data write period during which the data voltage is written to the capacitor included in each of the plurality of pixel circuits and a pause period during which the data voltage is not written to the capacitor included in each of the plurality of pixel circuits appear alternately, during the pause driving period, the low-level power supply voltage output unit outputs the low-level power supply voltage having a higher voltage value than a voltage value in the normal driving period, upon writing the data voltage to the capacitor included in each of the plurality of pixel circuits, a first terminal initialization period during which the second initialization transistor is maintained in on state to initialize a voltage at the first terminal of the display element is provided, and the first terminal initialization period in the pause driving period is longer than the first terminal initialization period in the normal driving period. ### Claim 9 (depends on 8) The display device according to claim 8, wherein each of the plurality of pixel circuits further includes: a write control transistor having a control terminal connected to one of the plurality of scanning signal lines; a first conductive terminal connected to one of the plurality of data signal lines; and a second conductive terminal connected to the first conductive terminal of the drive transistor; a threshold voltage compensation transistor having a control terminal connected to one of the plurality of scanning signal lines; a first conductive terminal connected to the second conductive terminal of the drive transistor; and a second conductive terminal connected to the control terminal of the drive transistor; and a power supply control transistor having a control terminal connected to one of the plurality of light-emission control lines; a first conductive terminal to which the high-level power supply voltage is provided; and a second conductive terminal connected to the first conductive terminal of the drive transistor. ### Claim 10 (depends on 9) The display device according to claim 9, wherein the first initialization transistor, the second initialization transistor, and the threshold voltage compensation transistor are thin-film transistors having a channel layer made of an oxide semiconductor, the drive transistor, the light-emission control transistor, the write control transistor, and the power supply control transistor are thin-film transistors having a channel layer made of low temperature polysilicon, the plurality of scanning signal lines include a plurality of first scanning signal lines and a plurality of second scanning signal lines, the control terminal of the threshold voltage compensation transistor is connected to one of the plurality of first scanning signal lines, the control terminal of the write control transistor is connected to one of the plurality of second scanning signal lines, the control terminal of the first initialization transistor is connected to one of the plurality of first scanning signal lines, and the control terminal of the second initialization transistor is connected to one of the plurality of first scanning signal lines. ### Claim 11 (depends on 8) The display device according to claim 8, wherein a voltage value of the initialization voltage and a voltage value of the low-level power supply voltage are set to equal values, and the low-level power supply voltage outputted from the low-level power supply voltage output unit is provided as the initialization voltage to the second conductive terminals of the second initialization transistor.