CN-122024609-A - Display device and display driving method

Abstract

The application relates to a display device and a display driving method. The present disclosure may provide a display device including a display panel including a plurality of sub-pixels including a light emitting element and a driving transistor, a power management circuit providing a pixel driving voltage to the plurality of sub-pixels, a light emitting current sensor detecting a change in a light emitting current flowing through the light emitting element in a light emitting current detection section, and a controller controlling the power management circuit according to a detection result of the light emitting current sensor.

Inventors

• Yin Zaijing
• YU DONGJUN

Assignees

• 乐金显示有限公司

Dates

Publication Date

20260512

Application Date

20250908

Priority Date

20241111

Claims (20)

1. 1. A display device, the display device comprising: A display panel including a sub-pixel including a light emitting element and a driving transistor connected to the light emitting element; A power management circuit configured to supply a pixel high potential voltage, a pixel low potential voltage, and a reference voltage to the sub-pixel, the power management circuit being further configured to change the pixel low potential voltage or the reference voltage in a light emission current detection section; a light-emitting current sensor configured to detect a change in light-emitting current flowing through the light-emitting element in the light-emitting current detection section, and And a controller configured to control the pixel low potential voltage based on a detection result of the light emission current sensor.
2. 2. The display device according to claim 1, wherein the light emission current detection section is located in at least one of: A power-on interval during which power is applied to the display panel; A blanking interval in a display driving period in which an image is displayed on the display panel, and And a power-off section during which the power to the display panel is cut off.
3. 3. The display device according to claim 1, wherein in the light emission current detection section, a data voltage at an off level is applied so that the driving transistor maintains an off state.
4. 4. The display device according to claim 1, wherein the pixel high potential voltage is supplied to a first electrode of the driving transistor, wherein the reference voltage is supplied to a second electrode of the driving transistor and an anode of the light emitting element through a sense transistor included in the sub-pixel, and wherein the pixel low potential voltage is supplied to a cathode of the light emitting element.
5. 5. The display device according to claim 4, wherein in the light-emission current detection section, the power management circuit holds the pixel high potential voltage and the reference voltage at zero volts, and changes the pixel low potential voltage to three or more different levels.
6. 6. The display device according to claim 5, wherein the pixel low potential voltage varies within a range that a deviation from the reference voltage is larger than a threshold voltage of the light-emitting element.
7. 7. The display device of claim 5, wherein the three or more different levels have the same voltage interval.
8. 8. The display device according to claim 4, wherein the power management circuit determines a level of the compensated pixel low potential voltage based on a deviation between an initial pixel low potential voltage when a light emission current of a maximum gray level flows and a present pixel low potential voltage when the light emission current of the maximum gray level flows, and supplies the compensated pixel low potential voltage to the display panel in a subsequent display section.
9. 9. The display device according to claim 4, wherein the power management circuit simultaneously changes the pixel high potential voltage based on a deviation between an initial pixel low potential voltage when a light emission current of a maximum gray level flows and a present pixel low potential voltage when the light emission current of the maximum gray level flows.
10. 10. The display device of claim 1, wherein the controller further comprises a temperature sensor configured to detect a temperature of the display panel, and The controller determines a current offset of the light emitting current based on the temperature of the display panel detected by the temperature sensor.
11. 11. The display device according to claim 1, wherein in the light-emission current detection section, the power management circuit holds the pixel high potential voltage and the pixel low potential voltage at zero volts, and changes the reference voltage to three or more different levels.
12. 12. The display device of claim 1, wherein the light emitting current sensor is located in the power management circuit.
13. 13. The display device according to claim 1, wherein when the light emission current detection section is included in a blanking section in a display driving period in which an image is displayed on the display panel, the controller controls the data voltage for each gray level by reflecting the gray level of the image displayed through the display panel in the display driving period.
14. 14. The display device according to claim 1, wherein the controller controls the power management circuit by reflecting accumulated stress according to a data voltage for the sub-pixel.
15. 15. The display device according to claim 1, wherein the detection result is a difference voltage between an initial pixel low potential voltage and a detected pixel low potential voltage corresponding to the initial pixel low potential voltage, and Wherein the pixel low potential voltage is changed according to the difference voltage.
16. 16. A display driving method for driving a display panel including a plurality of sub-pixels each including a light emitting element and a driving transistor, the display driving method comprising the steps of: Determining a fixed first pixel driving voltage and a variable second pixel driving voltage; Turning off the driving transistor using the fixed first pixel driving voltage; Detecting a light emitting current flowing through the light emitting element by changing the variable second pixel driving voltage to three or more different levels; determining a current-voltage characteristic of the light emitting element based on the light emitting current; determining a compensated driving voltage using a maximum gray level of the light emitting current, and The driving voltage of the display panel is changed to the compensated driving voltage.
17. 17. The display driving method according to claim 16, further comprising the step of: And determining a current offset of the light emitting current according to the temperature of the display panel.
18. 18. The display driving method according to claim 16, further comprising the step of controlling a data voltage for each gray level supplied to the display panel by reflecting the gray level of the image displayed through the display panel in the display driving period when the interval for detecting the light emitting current is included in a blanking interval in a display driving period in which the image is displayed on the display panel.
19. 19. The display driving method of claim 18, wherein the data voltage for each gray level is determined by: Where VdataN is a data voltage for each gray level, vdata1 is a data voltage applied in a frame to detect the light emitting current, cdep is a capacitance formed between a source electrode and a gate electrode of the driving transistor, cox is a capacitance formed between a source electrode and a body of the driving transistor, vsN is a source voltage applied to the source electrode of the driving transistor reflecting the gray level, and Vshift is an offset voltage according to a change in a current-voltage curve of the light emitting element.
20. 20. The display driving method according to claim 16, wherein the compensation for the brightness of the display panel includes reflecting accumulated stress according to the data voltages for the plurality of sub-pixels.

Description

Display device and display driving method Technical Field Embodiments of the present disclosure relate to a display device and a display driving method, and more particularly, for example, but not limited to, to a display device and a display driving method capable of compensating for a luminance variation according to a variation of a characteristic value of a light emitting element. Background With the development of information technology, the market for display devices as a user-to-information connection medium is growing. Accordingly, the use of various display devices such as Organic Light Emitting Displays (OLEDs), quantum Dot Displays (QDDs), liquid Crystal Displays (LCDs), and Plasma Display Panels (PDPs) has increased. The display device includes a display panel in which a plurality of sub-pixels are arranged, and various driving circuits such as a data driving circuit and a gate driving circuit for driving the display panel. In a display panel of a display device, transistors, various electrodes, various signal lines, and the like are formed on a glass substrate, and a driving circuit which may be implemented as an integrated circuit is mounted on a printed circuit and electrically connected to the display panel through the printed circuit. However, such a conventional structure is suitable for a large-sized display device, but is not suitable for a small-sized display device. Further, many different electronic devices requiring a small display device, such as a Virtual Reality (VR) device and an Augmented Reality (AR) device, are emerging, and thus a micro display device having a very small display panel has been proposed. The description provided in the background section is not admitted to be prior art solely by virtue of its mention in or association with the background section. The background section may include information describing one or more aspects of the subject technology. Disclosure of Invention The inventors of the present disclosure newly recognize that these display devices are formed with semiconductor chips in the form of Integrated Circuits (ICs) on a silicon substrate (silicon semiconductor substrate), and in many cases, display panels in the display devices and various driving circuits are integrally formed. In this way, since the display device implementing virtual reality uses the silicon substrate, the light-emitting current flowing through the light-emitting element may fluctuate due to degradation of the light-emitting element and a change in characteristics of the driving transistor, resulting in degradation of luminance. Accordingly, the inventors of the present disclosure have invented a display device and a display driving method capable of compensating for a change in a characteristic value caused by a light emitting element by detecting a light emitting current flowing through the light emitting element. Embodiments of the present disclosure may provide a display device and a display driving method capable of accurately detecting and compensating for a change in a light emitting current by changing a pixel low potential voltage applied to a cathode of a light emitting element. Further, embodiments of the present disclosure may provide a display device and a display driving method capable of detecting and compensating for a change in a light emitting current of an entire area or a partial area of a display panel. Embodiments of the present disclosure may provide a display device and a display driving method capable of accurately detecting and compensating for a change in a light emitting current by changing a reference voltage supplied to a reference voltage line. Additional features and aspects of the disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the inventive concepts provided herein. Other features and aspects of the inventive concept may be realized and attained by the structure particularly pointed out in the written disclosure (or derived therefrom) and the appended claims and drawings. To achieve these and other aspects of the inventive concept, as embodied and broadly described herein, embodiments of the present disclosure may provide a display device including a display panel including a plurality of sub-pixels including a light emitting element and a driving transistor, a power management circuit providing a pixel driving voltage to the plurality of sub-pixels, a light emitting current sensor detecting a change in a light emitting current flowing through the light emitting element in a light emitting current detection section, and a controller controlling the power management circuit according to a detection result of the light emitting current sensor. In another aspect, embodiments of the present disclosure may provide a display driving method for driving a display panel including a plurality of sub-pixels, each sub-pixel including a light emitting