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US-12626655-B2 - Organic light emitting diode (OLED) pixel circuit reducing weak light emission of light-emitting element in non-light emitting stage

US12626655B2US 12626655 B2US12626655 B2US 12626655B2US-12626655-B2

Abstract

A display panel and a display device are provided. The display panel includes a pixel circuit and a light-emitting element, and the pixel circuit provides a driving current for the light-emitting element. The display panel includes a power supply voltage terminal, and the power supply voltage terminal provides a power supply voltage signal for the pixel circuit. The display panel includes a light emission stage and a non-light emission stage. In the light emission stage, the power supply voltage terminal provides a first voltage V 1, and in the non-light emission stage, the power supply voltage terminal provides a second voltage V 2, V 1≠ V 2.

Inventors

  • Yingteng ZHAI

Assignees

  • TIANMA ADVANCED DISPLAY TECHNOLOGY INSTITUTE (XIAMEN) CO., LTD.

Dates

Publication Date
20260512
Application Date
20240628
Priority Date
20231229

Claims (15)

  1. 1 . A display panel, comprising: a pixel circuit; a light-emitting element; and a power supply voltage terminal; wherein the pixel circuit provides a driving current for the light-emitting element, and the power supply voltage terminal provides a power supply voltage signal for the pixel circuit; wherein the display panel comprises a light emission stage and a non-light emission stage, wherein in the light emission stage, the power supply voltage terminal provides a first voltage V 1 , and wherein in the non-light emission stage, the power supply voltage terminal provides a second voltage V 2 , wherein V 1 ≠V 2 ; and wherein the display panel comprises a first display mode and a second display mode, wherein a brightness of the display panel in the first display mode is less than a brightness of the display panel in the second display mode; wherein in the first display mode, the power supply voltage terminal provides the first voltage V 1 for a duration of T 1 in the light emission stage, and wherein in the second display mode, the power supply voltage terminal provides the first voltage V 1 for a duration of T 2 in the light emission stage, wherein T 1 <T 2 ; wherein the pixel circuit comprises an amplitude modulation module and a pulse width modulation module; wherein the amplitude modulation module is configured to control an amplitude of the driving current, and the pulse width modulation module is configured to output a pulse width modulation signal to control a duration of the driving current applied to the display panel; wherein in the first display mode and the second display mode, the pulse width modulation module outputs pulse width modulation signals with a same frequency; wherein in the first display mode, a duration of the power supply voltage terminal providing the first voltage V 1 within a pulse cycle of the pulse width modulation signal in the light emission stage is T 11 , and wherein in the second display mode, a duration of the power supply voltage terminal providing the first voltage V 1 within a pulse cycle of the pulse width modulation signal in the light emission stage is T 21 , wherein T 11 <T 21 .
  2. 2 . The display panel according to claim 1 , wherein the power supply voltage terminal comprises a first power supply voltage terminal; wherein the first power supply voltage terminal is coupled to the pixel circuit through the light-emitting element; wherein in the light emission stage, a first voltage provided by the first power supply voltage terminal is V 11 , and wherein in the non-light emission stage, a second voltage provided by the first power supply voltage terminal is V 21 ; wherein V 11 <V 21 .
  3. 3 . The display panel according to claim 2 , wherein in the first display mode, the first power supply voltage terminal provides the first voltage V 11 for a duration of T 12 in the light emission stage, and in the second display mode, the first power supply voltage terminal provides the first voltage V 11 for a duration of T 22 in the light emission stage, wherein T 12 <T 22 .
  4. 4 . The display panel according to claim 3 , wherein in the first display mode, a second voltage provided by the first power supply voltage terminal in the non-light emission stage is V 211 , and in the second display mode, a second voltage provided by the first power supply voltage terminal in the non-light emission stage is V 212 , wherein V 211 ≠V 212 .
  5. 5 . The display panel according to claim 4 , wherein V 211 <V 212 .
  6. 6 . The display panel according to claim 1 , wherein the power supply voltage terminal comprises a second power supply voltage terminal; wherein the second power supply voltage terminal is coupled to the light-emitting element through the pixel circuit; wherein in the light emission stage, a first voltage provided by the second power supply voltage terminal is V 12 , and wherein in the non-light emission stage, a second voltage provided by the second power supply voltage terminal is V 22 ; wherein V 12 >V 22 .
  7. 7 . The display panel according to claim 6 , wherein in the first display mode, the second power supply voltage terminal provides the first voltage V 12 for a duration of T 13 in the light emission stage, and in the second display mode, the second power supply voltage terminal provides the first voltage V 12 for a duration of T 23 in the light emission stage, wherein T 13 <T 23 .
  8. 8 . The display panel according to claim 7 , wherein in the first display mode, a second voltage provided by the second power supply voltage terminal in the non-light emission stage is V 221 , and in the second display mode, a second voltage provided by the second power supply voltage terminal in the non-light emission stage is V 222 , wherein V 221 ≠V 222 .
  9. 9 . The display panel according to claim 8 , wherein V 221 >V 222 .
  10. 10 . The display panel according to claim 1 , wherein the non-light emission stage comprises a plurality of non-light emission sub-stages; wherein the plurality of non-light emission sub-stages comprise at least a first non-light emission sub-stage and a second non-light emission sub-stage, wherein in the first non-light emission sub-stage, a second voltage provided by the power supply voltage terminal is V 23 , and wherein in the second non-light emission sub-stage, a second voltage provided by the power supply voltage terminal is V 24 , wherein V 23 ≠V 24 .
  11. 11 . The display panel according to claim 10 , wherein the display panel further satisfies at least one of the following: in the first display mode, a second voltage provided by the power supply voltage terminal in the first non-light emission sub-stage is V 231 , and a second voltage provided by the power supply voltage terminal in the second non-light emission sub-stage is V 241 , wherein V 231 ≠V 241 ; or in the second display mode, a second voltage provided by the power supply voltage terminal in the first non-light emission sub-stage is V 232 , and a second voltage provided by the power supply voltage terminal in the second non-light emission sub-stage is V 242 , wherein V 232 ≠V 242 .
  12. 12 . The display panel according to claim 1 , wherein the light-emitting element comprises a first light-emitting element and a second light-emitting element, the first light-emitting element and the second light-emitting element are electrically connected to a same pixel circuit, and the pixel circuit drives the first light-emitting element or the second light-emitting element to emit light.
  13. 13 . A display device, comprising a display panel, wherein the display panel comprises: a pixel circuit; a light-emitting element; and a power supply voltage terminal; wherein the pixel circuit provides a driving current for the light-emitting element, and the power supply voltage terminal provides a power supply voltage signal for the pixel circuit; wherein the display panel comprises a light emission stage and a non-light emission stage, wherein in the light emission stage, the power supply voltage terminal provides a first voltage V 1 , and wherein in the non-light emission stage, the power supply voltage terminal provides a second voltage V 2 , wherein V 1 ≠V 2 ; and wherein the display panel comprises a first display mode and a second display mode, wherein a brightness of the display panel in the first display mode is less than a brightness of the display panel in the second display mode; wherein in the first display mode, the power supply voltage terminal provides the first voltage V 1 for a duration of T 1 in the light emission stage, and wherein in the second display mode, the power supply voltage terminal provides the first voltage V 1 for a duration of T 2 in the light emission stage, wherein T 1 <T 2 ; wherein the pixel circuit comprises an amplitude modulation module and a pulse width modulation module; wherein the amplitude modulation module is configured to control an amplitude of the driving current, and the pulse width modulation module is configured to output a pulse width modulation signal to control a duration of the driving current applied to the display panel; wherein in the first display mode and the second display mode, the pulse width modulation module outputs pulse width modulation signals with a same frequency; wherein in the first display mode, a duration of the power supply voltage terminal providing the first voltage V 1 within a pulse cycle of the pulse width modulation signal in the light emission stage is T 11 , and wherein in the second display mode, a duration of the power supply voltage terminal providing the first voltage V 1 within a pulse cycle of the pulse width modulation signal in the light emission stage is T 21 , wherein T 11 <T 21 .
  14. 14 . A display panel, comprising: a pixel circuit; a light-emitting element; and a power supply voltage terminal; wherein the pixel circuit provides a driving current for the light-emitting element, and the power supply voltage terminal provides a power supply voltage signal for the pixel circuit; wherein the display panel comprises a light emission stage and a non-light emission stage, wherein in the light emission stage, the power supply voltage terminal provides a first voltage V 1 , and wherein in the non-light emission stage, the power supply voltage terminal provides a second voltage V 2 , wherein V 1 ≠V 2 ; and wherein the pixel circuit comprises an amplitude modulation module and a pulse width modulation module, wherein the amplitude modulation module is configured to control an amplitude of the driving current, and the pulse width modulation module is configured to output a pulse width modulation signal to control a duration of the driving current applied to the light-emitting element, wherein the display panel further satisfies one of the following: the amplitude modulation module comprises a first driving transistor, and an output terminal of the pulse width modulation module is electrically connected to a gate of the first driving transistor; the amplitude modulation module comprises a first driving transistor and a control transistor, and the control transistor is connected between the first driving transistor and the light-emitting element; and an output terminal of the pulse width modulation module is electrically connected to a gate of the control transistor; the amplitude modulation module comprises a first driving transistor, and the pixel circuit further comprises a connection capacitor, an output terminal of the pulse width modulation module is electrically connected to a first terminal of the connection capacitor, and a second terminal of the connection capacitor is electrically connected to a gate of the first driving transistor; the pulse width modulation module comprises a logic control unit and a voltage control unit, an output terminal of the logic control unit is electrically connected to a control terminal of the voltage control unit, the logic control unit is configured to output the pulse width modulation signal, and an output terminal of the voltage control unit is the power supply voltage terminal and is configured to output the first voltage V 1 in the light emission stage and output the second voltage V 2 in the non-light emission stage.
  15. 15 . The display panel according to claim 14 , wherein in a case where the pulse width modulation module comprises the logic control unit and the voltage control unit, the output terminal of the logic control unit is electrically connected to the control terminal of the voltage control unit, the logic control unit is configured to output the pulse width modulation signal, and the output terminal of the voltage control unit is the power supply voltage terminal and is configured to output the first voltage V 1 in the light emission stage and output the second voltage V 2 in the non-light emission stage, the voltage control unit comprises a multiplexer, wherein a first input terminal of the multiplexer is electrically connected to a first constant voltage terminal, a second input terminal of the multiplexer is electrically connected to a second constant voltage terminal, a control terminal of the multiplexer is electrically connected to the output terminal of the logic control unit, and an output terminal of the multiplexer is the power supply voltage terminal, and wherein the multiplexer is configured to: output a first voltage provided by the first constant voltage terminal in the light emission stage of the display panel and output a second voltage provided by the second constant voltage terminal in the non-light emission stage of the display panel according to the pulse width modulation signal.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Chinese patent application No. 202311868092.0 filed with the China National Intellectual Property Administration (CNIPA) on Dec. 29, 2023, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD Embodiments of the present disclosure relate to display technology, and in particular to a display panel and a display device. BACKGROUND With the development of display technology, the application of display panels is becoming more and more common, and users have more and more requirements for the display quality of display panels. In order to satisfy the driving requirements of high-resolution display panels, for example, micro light emitting diodes (micro LED) or organic light emitting diodes (OLED), a pixel circuit combining pulse amplitude modulation (PAM) and pulse width modulation (PWM) is used, and a hybrid driving method is used to control the driving current intensity and the duration of the driving current to control the light-emitting state of the light-emitting element. The pixel circuit includes multiple thin film transistors (TFT). Since TFT has a certain off-state leakage current, when TFT is turned off, the light-emitting element in the existing display panel structure still emits weak light, which affects the display effect. SUMMARY Embodiments of the present disclosure provide a display panel and a display device. In the display panel, the weak light emission of the light-emitting element in the non-light emission stage can be reduced or avoided by differentially designing the voltage values provided by the power supply voltage terminal in the light emission stage and the non-light emission stage, thereby improving the display effect. Embodiments of the present disclosure provide a display panel, and the display panel includes: a pixel circuit and a light-emitting element. The pixel circuit provides a driving current for the light-emitting element. The pixel circuit includes a power supply voltage terminal, and the power supply voltage terminal provides a power supply voltage signal for the pixel circuit. The display panel includes a light emission stage and a non-light emission stage, in the light emission stage, the power supply voltage terminal provides a first voltage V1, and in the non-light emission stage, the power supply voltage terminal provides a second voltage V2, where V1≠V2. Embodiments of the present disclosure provide a display device, which includes the display panel described in the first aspect. The display panel according to the embodiments of the present disclosure includes a pixel circuit and a light-emitting element, and the pixel circuit provides a driving current for the light-emitting element. The display panel includes a power supply voltage terminal, and the power supply voltage terminal provides a power supply voltage signal for the pixel circuit. The display panel includes a light emission stage and a non-light emission stage. In the light emission stage, the power supply voltage terminal provides a first voltage V1, and in the non-light emission stage, the power supply voltage terminal provides a second voltage V2, where V1≠V2. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic structural diagram of a display panel according to an embodiment of the present disclosure; FIG. 2 is a schematic structural diagram of another display panel according to an embodiment of the present disclosure; FIG. 3 is a schematic diagram of partial structure of the display panel shown in FIG. 1; FIG. 4 is a schematic diagram of partial structure of the display panel shown in FIG. 2; FIG. 5 is a schematic diagram of durations for which a power supply voltage terminal provides a first voltage in different display modes in a display panel according to an embodiment of the present disclosure; FIG. 6 is a schematic diagram of durations for which a power supply voltage terminal provides a first voltage in different display modes in a display panel according to an embodiment of the present disclosure; FIG. 7 is a schematic diagram of durations for which a first power supply voltage terminal provides a first voltage in different display modes in a display panel according to an embodiment of the present disclosure; FIG. 8 is a schematic diagram of durations for which a first power supply voltage terminal provides a first voltage in different display modes in a display panel according to an embodiment of the present disclosure; FIG. 9 is a schematic diagram of second voltages provided by a first power supply voltage terminal in different display modes in a display panel according to an embodiment of the present disclosure; FIG. 10 is a schematic diagram of durations for a second power supply voltage terminal to provide a first voltage in different display modes in a display panel according to an embodiment of the present disclosure; FIG. 11 is a schematic diagram of durations for a second