Display panel, display driving method, and display device

Abstract

The present application discloses a display panel, a display driving method and a display device. The display panel includes: multiple rows of pixel driving circuits, and each pixel driving circuit includes: a driving transistor, with a first end connected to a first power supply line; a storage capacitor, with one end connected to the first power supply line and the other end connected to the gate of the driving transistor; a data loading transistor, with a first end connected to a data line, a second end connected to the first end of the driving transistor, and a gate connected to a scanning line; a light-emitting diode, with an anode connected to the second end of the driving transistor and a cathode connected to a second power supply line; during a refresh period, the data line provides a first voltage value, and the first voltage value belongs to a first voltage range; during a blanking period, the data line provides a second voltage value, and the second voltage value belongs to a second voltage range, and the second voltage range is a partial voltage value in the first voltage range. The embodiments of the present application reduce the amplitude of the voltage value jump provided by the data line when entering the blanking period during the refresh period, and reduce the crosstalk to the gate potential caused thereby, so as to eliminate the horizontal stripes.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and in particular, to a display panel, a display driving method, and a display device. Background Art

[0002] When the screen is at low brightness and low gray level, there are multiple bright and dark uneven horizontal stripes Mura. The light-emitting time of OLED within One Frame is usually referred to as EM Duty (Emission Duty, the proportion of light-emitting time). For example, as Figure 1 shown, when 4Pluse EM blanking is set, one frame is divided into 4 waveforms of high and low levels. When EM GOA (Gate On Array) is at a high level, Pixel does not emit light. When EM GOA is at a low level, Pixel emits light.

[0003] As Figure 2 shown, for a pixel compensation circuit including multiple TFTs, due to the large number of electronic components, a coupling capacitor C is formed between the data line inputting the Data voltage to the pixel compensation circuit and the Driver TFT (driving thin-film transistor T1). p As Figure 1 shown, when the low-level time of the 4 EM GOA coincides with the time of the Data voltage jump in the Blanking area (blanking period), due to the different settings of the blanking period and the refresh period, when entering the blanking period from the refresh period, the Data voltage value changes greatly, resulting in crosstalk to the gate potential of the Driver TFT (driving thin-film transistor). Due to the influence of the coupling capacitor C p , the current of the Driver TFT of the Pixel that emits light will be coupled, forming bright and dark different horizontal stripes, thus generating horizontal stripe Mura. Among them, when the Data voltage in the Blanking area is set to the high potential VGMP, the voltage at point Q is pulled up, resulting in a decrease in the DTFT (Driver TFT) current, and the brightness of the OLED-emitting Pixel is relatively low, showing dark stripes; when the Data voltage in the Blanking area is set to the high potential GND, the voltage at point Q is pulled down, resulting in an increase in the DTFT current, and the brightness of the OLED-emitting Pixel is relatively high, showing bright stripes. Therefore, it is necessary to improve the horizontal stripes caused by the Data voltage value jump when entering the blanking period from the refresh period. Summary of the Invention

[0004] Embodiments of the present application provide a display panel, a display driving method, and a display device. By setting a second voltage range during the blanking period based on a first voltage range during the refresh period, the amplitude of the voltage jump provided by the data line when entering the blanking period from the refresh period is reduced, and the crosstalk to the gate potential of the driving transistor during the voltage jump is reduced to eliminate the horizontal stripes.

[0005] In a first aspect, embodiments of the present application provide a display panel, including:

[0006] A plurality of rows of pixel driving circuits, and the pixel driving circuit includes:

[0007] A driving transistor, and a first end of the source-drain of the driving transistor is connected to a first power supply line;

[0008] A storage capacitor, one end of the storage capacitor is connected to the first power supply line, and the other end of the storage capacitor is connected to the gate of the driving transistor;

[0009] A data loading transistor, a first end of the source-drain of the data loading transistor is connected to a data line, a second end of the source-drain of the data loading transistor is connected to the first end of the source-drain of the driving transistor, and the gate of the data loading transistor is connected to a scan line;

[0010] A light-emitting diode, the anode of the light-emitting diode is connected to the second end of the source-drain of the driving transistor, and the cathode of the light-emitting diode is connected to a second power supply line;

[0011] Each frame of signal includes a refresh period and a blanking period. During the refresh period, the data line provides a first voltage value, and the first voltage value belongs to a first voltage range, and the first voltage range is a voltage change range corresponding to the gray scale allowable change range of the pixel driving circuit; during the blanking period, the data line provides a second voltage value, and the second voltage value belongs to a second voltage range, and the second voltage range is a partial voltage value in the first voltage range.

[0012] In some embodiments, the first voltage range and the second voltage range have the same intermediate value.

[0013] In some embodiments, the pixel driving circuit further includes an initialization transistor connected between the anode of the light-emitting diode and a third power supply line, and the voltage value of the third power supply line is less than the voltage value of the second power supply line.

[0014] In some embodiments, the display panel further includes an emission control circuit, the emission control circuit is connected to the plurality of rows of pixel driving circuits, the pixel driving circuit further includes a light-emitting control transistor connected in series between the driving transistor and the light-emitting diode, and the gates of the light-emitting control transistors are all connected to the light-emitting control signal sent by the emission control circuit.

[0015] In some embodiments, the light emission control signal is a pulse width modulation signal. During one pulse period of the light emission control signal, the emission control circuit inputs a turn-on signal to the pixel driving circuits of the adjacent first number of rows, and the emission control circuit inputs a turn-off signal to the pixel driving circuits of the adjacent second number of rows.

[0016] In some embodiments, the difference between the first number of rows and the second number of rows is less than or equal to a preset threshold.

[0017] In some embodiments, the pixel driving circuit further includes a voltage compensation transistor connected between the gate of the driving transistor and the second end of the source-drain of the driving transistor.

[0018] In a second aspect, the present application provides a display driving method, which is applied to the display panel described in any one of the above, and includes:

[0019] The pixel driving circuit obtains a scan signal provided by a scan line and a data signal provided by a data line. Each frame of signal includes a refresh period and a blanking period;

[0020] During the refresh period, the data signal is a first voltage value, and the pixel driving circuit drives the light emitting diode to emit light according to the scan signal and the first voltage value. The first voltage value belongs to a first voltage range, and the first voltage range is the voltage change range corresponding to the gray scale allowable change range of the pixel driving circuit;

[0021] During the blanking period, the data signal is adjusted from the first voltage value to a second voltage value, and the pixel driving circuit drives the light emitting diode to emit light according to the scan signal and the second voltage value. The second voltage value belongs to a second voltage range, and the second voltage range is a part of the voltage values in the first voltage range.

[0022] In one embodiment, after the pixel driving circuit obtains the scan signal provided by the scan line and the data signal provided by the data line, it further includes:

[0023] The emission control circuit sequentially sends a light emission control signal to each row of pixel driving circuits, and the light emission control signal is a pulse width modulation signal;

[0024] During one pulse period of the light emission control signal, the emission control circuit inputs a turn-on signal to the pixel driving circuits of the adjacent first number of rows, and the light emitting diodes in the pixel driving circuits of the first number of rows emit light;

[0025] The emission control circuit inputs a disconnection signal to the pixel driving circuit of the adjacent second row number, and the light-emitting diodes in the pixel driving circuit of the second row number do not emit light, and the difference between the first row number and the second row number is less than or equal to a preset threshold value.

[0026] In a third aspect, the present application provides a display device, and the display device includes the display panel described in any one of the above.

[0027] The display panel, the display driving method and the display device provided by the embodiments of the present application set the second voltage range during the blanking period based on the first voltage range during the refresh period, reduce the difference between the first voltage range and the second voltage range, and further reduce the amplitude of the voltage value jump provided by the data line when entering the blanking period from the refresh period, and reduce the crosstalk of the gate potential of the driving transistor when the voltage jumps, so as to eliminate the horizontal stripes. Description of the Drawings

[0028] The following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0029] Figure 1 It is the control timing diagram during 4Pluse EM blanking;

[0030] Figure 2 It is the circuit schematic diagram of the display driving unit of the present application;

[0031] Figure 3 It is the schematic diagram of the horizontal stripes on the display screen when the voltage difference between the blanking area voltage and the voltage setting information in the embodiment of the present application is large;

[0032] Figure 4 It is the schematic diagram of the display screen when the voltage difference between the blanking area voltage and the voltage setting information in the embodiment of the present application is small;

[0033] Figure 5 It is the driving signal timing diagram of the pixel driving circuit in the embodiment of the present application;

[0034] Figure 6 It is the flow schematic diagram of the display driving method in the embodiment of the present application. Detailed Embodiments

[0035] The following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0036] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0037] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" shall be construed broadly. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection or a connection capable of mutual communication; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0038] In the present application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0039] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0040] Since the display uses PWM (Pulse Width Modulation) dimming at low brightness, when the EM Pulse is at a low level and the Source potential jumps, the Q-point voltage of the TFT driving circuit of the Pixel is pulled down or up, resulting in an increase or decrease in the DTFT current, corresponding to a higher brightness of the OLED-emitting Pixel with bright stripes or a lower brightness with dark stripes. Therefore, the solution of this embodiment is used to improve the split-screen Mura that appears in the picture during low-brightness and low-gray-scale pulse-width modulation dimming, and to avoid abnormal display.

[0041] Please refer to Figure 2 , an embodiment of the present application provides a display panel. The display panel includes multiple rows of pixel driving circuits, and each row of pixel driving circuits is driven to light up row by row to achieve picture display.

[0042] The pixel driving circuit includes a driving transistor T1, a storage capacitor C1, a data loading transistor T2, and a light-emitting diode OLED. Among them, the first end of the source-drain of the driving transistor T1 is connected to the first power supply line VDD, one end of the storage capacitor C1 is connected to the first power supply line VDD, the other end of the storage capacitor C1 is connected to the gate of the driving transistor T1, the first end of the source-drain of the data loading transistor T2 is connected to the data line Data, the second end of the source-drain of the data loading transistor T2 is connected to the first end of the source-drain of the driving transistor T1, the gate of the data loading transistor T2 is connected to the scan line Scan(n), the anode of the light-emitting diode OLED is connected to the second end of the source-drain of the driving transistor T1, and the cathode of the light-emitting diode OLED is connected to the second power supply line VSS. The scan line Scan(n) provides a scan signal, and the data line Data provides a data signal. The pixel driving circuits are turned on row by row based on the scan signal, and at the same time, each pixel driving circuit drives the light-emitting diode OLED to emit light based on the data signal.

[0043] The pixel driving circuit drives the light-emitting diode OLED to display different brightness levels according to the magnitude of the voltage value input by the data line Data, thereby realizing a display screen with different gray-scale brightness levels. Therefore, based on the allowable change range of gray levels that the pixel driving circuit needs to achieve, the voltage value input by the data line Data has a corresponding voltage change range. When any voltage value within this voltage change range is input to the data line Data, the light-emitting diode OLED of the pixel driving circuit displays the corresponding gray-scale brightness level within the allowable change range of gray levels.

[0044] Among them, each frame signal of the to-be-displayed screen includes a refresh period and a blanking period. The refresh rate of the display determines the ratio of the refresh period to the blanking period in one frame signal. During the refresh period, when a certain gray-scale brightness level needs to be displayed, the data line Data provides a first voltage value to the pixel driving circuit, and the pixel driving circuit controls the light-emitting diode OLED to emit light with a corresponding intensity according to this first voltage value. Based on the different gray-scale brightness levels to be displayed, the corresponding first voltage values are different, but the first voltage value belongs to a first voltage range, and the first voltage range is the voltage change range corresponding to the allowable change range of gray levels of the pixel driving circuit.

[0045] During the blanking period, the data line Data provides a second voltage value to the pixel driving circuit, that is, when entering the blanking period from the refresh period, the voltage value provided by the data line Data jumps from the first voltage value to the second voltage value. The second voltage value belongs to a second voltage range. In order to avoid too large a change amplitude when the voltage value jumps from the first voltage value to the second voltage value, resulting in crosstalk coupling of the driving transistor T1 and causing horizontal stripes to appear, the second voltage range is set to a part of the voltage values in the first voltage range, and the second voltage range is set to the middle part of the first voltage range.

[0046] Preferably, the first voltage range and the second voltage range have the same intermediate value, that is, the intermediate value of the second voltage range is determined according to the intermediate value of the first voltage range, and then the second voltage range is obtained according to the intermediate value and the allowable fluctuation range. The allowable fluctuation range is the allowable voltage jump range during the blanking period. For example, if the first voltage range is 0 - 7V, the intermediate value is 3.5V, and the fluctuation range based on 3.5V is ±0.5V, then the second voltage range is determined to be 3 - 4V. As Figure 3 shown, a large difference between the first voltage range and the second voltage range results in obvious horizontal stripe phenomena on the display screen. As Figure 4 shown, a smaller difference between the first voltage range and the second voltage range visually eliminates the horizontal stripes.

[0047] In this embodiment, the second voltage range during the blanking period is set based on the first voltage range during the refresh period, reducing the amplitude of the voltage value jump provided by the data line Data when entering the blanking period from the refresh period, and reducing the crosstalk of the gate potential of the driving transistor T1 during the voltage jump to eliminate the horizontal stripes.

[0048] In one embodiment, the pixel driving circuit further includes an initialization transistor T7 connected between the anode of the organic light-emitting diode (OLED) and the third power supply line Vi. The voltage value of the third power supply line Vi is less than the voltage value of the second power supply line VSS to help turn off the OLED when it is not in use.

[0049] In one embodiment, the display panel further includes an emission control circuit. The emission control circuit is connected to a plurality of rows of pixel driving circuits, that is, the emission control circuit is connected to each pixel driving circuit. The pixel driving circuit further includes light-emitting control transistors T5 and T6 connected in series between the driving transistor T1 and the OLED. The gates of the light-emitting control transistors T5 and T6 are both connected to the light-emitting control signal sent by the emission control circuit.

[0050] When the light-emitting control signal is a turn-on signal and the scan signal is on, the OLED in the corresponding pixel driving circuit emits light. The intensity of the light emitted by the OLED depends on the voltage value of the data line Data. When the light-emitting control signal is a turn-off signal, even if the scan signal is on, the OLED in the corresponding pixel driving circuit does not emit light.

[0051] Among them, the light-emitting time within one frame is usually referred to as EM Duty (Emission Duty, the ratio of light-emitting time). The greater the ratio of light-emitting time, the stronger the display brightness of the corresponding screen. Therefore, the corresponding ratio of light-emitting time is determined based on the required brightness of the display screen.

[0052] In one embodiment, the light-emitting control signal is a pulse-width modulation signal. The light-emitting control signal within one frame includes multiple pulse periods. Since the turn-on signal and the turn-off signal are both continuous within one pulse period, correspondingly, for the adjacent first row number of pixel driving circuits, the emission control circuit inputs turn-on signals, that is, the OLEDs in the adjacent first row number of pixel driving circuits all emit light. Then, for the adjacent first row number of pixel driving circuits, the emission control circuit inputs turn-off signals, that is, the OLEDs in the adjacent second row number of pixel driving circuits all do not emit light.

[0053] In one embodiment, since the corresponding light-emitting time ratio is determined based on the required display screen brightness, the light-emitting time ratio is a determined value, that is, the time ratio of the on signal and the off signal within one pulse period is fixed. When the number of pulse periods included in one frame is larger, that is, when the number of pulse periods included in one frame is greater than or equal to the preset number of periods, correspondingly each pulse period is shorter, that is, the pixel driving circuits corresponding to the first row number and the second row number are fewer. The fewer the pixel driving circuits corresponding to the second row number, the fewer the non-light-emitting pixel driving circuits corresponding to each pulse period. When the non-light-emitting pixel driving circuits are fewer and not obvious compared with the light-emitting pixel driving circuits, that is, when the difference between the first row number and the second row number is less than or equal to the preset threshold, the non-light-emitting pixel driving circuits cannot be visually detected when the display screen displays a picture, so the horizontal stripes are eliminated. Among them, the preset number of periods and the preset threshold are set based on the display accuracy requirements of the display screen, and are not specifically limited in this embodiment. For example, the preset number of periods is set to 8, or 12, etc.

[0054] In one embodiment, the pixel driving circuit further includes a voltage compensation transistor connected between the gate of the driving transistor T1 and the second end of the source-drain of the driving transistor T1. The voltage compensation transistor includes a first transistor T3 and a second transistor T4. The gate of the first transistor T3 is connected to the scan signal. One end of the source-drain of the first transistor T3 is connected to the gate of the driving transistor T1, and the other end of the source-drain of the first transistor T3 is connected to the other end of the source-drain of the driving transistor T1. The gate of the second transistor T4 is connected to the previous-stage scan signal Scan(n - 1) of the above scan signal Scan(n). One end of the source-drain of the second transistor T4 is connected to the gate of the driving transistor T1, and the other end of the source-drain of the second transistor T4 is connected to the third power supply line Vi.

[0055] Figure 5 is the driving signal timing diagram of the pixel driving circuit according to the embodiment of the present application. Combining Figure 2 and Figure 3 , the pixel driving circuit performs a reset stage A1, a threshold voltage compensation stage A2, and a light-emitting stage A3 according to the previous-stage scan signal Scan(n - 1), the current row scan signal Scan(n), and the light-emitting control signal EM.

[0056] In the reset stage A1, the previous-stage scan signal Scan(n - 1) is at a low potential, causing the second transistor T4 to turn on; the current row scan signal Scan(n) is at a high potential, causing the data loading transistor T2, the first transistor T3, and the initialization transistor T7 to turn off; the light-emitting control signal EM is at a high potential, causing the light-emitting control transistors T5 and T6 to turn off. The node Q is reset to the initialization voltage Vi through the turned-on second transistor T4, that is, Vq = Vi, and the voltage at the other end of the storage capacitor C1 is the first voltage VDD.

[0057] In the threshold voltage compensation stage A2, the current row scan signal Scan(n) is at a low potential, turning on the data loading transistor T2, the first transistor T3, and the initialization transistor T7; the previous stage scan signal Scan(n - 1) is at a high potential, turning off the second transistor T4; the emission control signal EM is at a high potential, turning off the emission control transistors T5 and T6. At this time, the gate (the first node Q) and the drain of the driving transistor T1 are short-circuited, and the driving transistor T1 is equivalent to a diode structure. The data voltage Vdata is written into the source of the driving transistor T1 through the data loading transistor T2, and the potential of the gate (node Q) of the driving transistor T1 is charged to Vdata + Vth using this diode structure, that is, until the charging ends when Vg = Vdata + Vth and the driving transistor T1 turns off. At this time, the voltage at one end of the storage capacitor C1 is the potential Vdata + Vth of node Q, and the potential at the other end is still VDD. The initialization transistor T7 makes the anode potential of the light-emitting diode OLED the initialization voltage Vi. Vth is the threshold voltage of the driving transistor T1.

[0058] In the light-emitting stage A3, the emission control signal EM is at a low potential, turning on the emission control transistors T5 and T6; the previous stage scan signal Scan(n - 1) is at a high potential, turning off the second transistor T4; the current row scan signal Scan(n) is at a high potential, turning off the data loading transistor T2, the first transistor T3, and the initialization transistor T7. At this time, the storage capacitor C1 keeps the potential of the gate (node Q) of the driving transistor T1 at Vdata + Vth, and the emission control transistor T5 makes the potential of the source of the driving transistor T1 the constant voltage high potential VDD of Sn. Then, the gate-source voltage difference Vgs of the driving transistor T1 at this time is Vdata + Vth - VDD.

[0059] According to the current formula I = K(Vgs - Vth) for the current flowing through the light-emitting diode OLED 2 , where I is the current flowing through the light-emitting diode OLED, K is the intrinsic conductivity factor of the driving transistor T1, Vgs is the gate-source voltage difference of the driving thin-film transistor T1, and Vth is the threshold voltage of the driving transistor T1, it can be known that the current flowing through the light-emitting diode OLED is I = K(Vgs - Vth) 2 = K(Vdata + Vth - VDD - Vth)² = K(Vdata - VDD) 2 .

[0060] It can be seen from this that the current flowing through the light-emitting diode OLED has nothing to do with the threshold voltage of the driving transistor T1. Therefore, the pixel driving circuit provided by the embodiments of the present application can solve the problem of unstable current flowing through the light-emitting diode OLED caused by the threshold voltage drift of the driving thin-film transistor, making the light-emitting brightness of the light-emitting diode OLED uniform and improving the display effect of the picture.

[0061] However, it should be noted that the setting method of the voltage compensation transistor and the corresponding driving signal timing diagram in this embodiment are only illustrative examples for easy explanation, and should not be construed as being limited thereto.

[0062] In this embodiment, the second voltage range during the blanking period is set based on the first voltage range during the refresh period, the difference between the first voltage range and the second voltage range is reduced, and further the amplitude of the voltage jump provided by the data line Data when entering the blanking period from the refresh period is reduced, and the crosstalk to the gate potential of the driving transistor T1 during the voltage jump is reduced to eliminate the horizontal stripes.

[0063] In addition, when the low gray-scale picture is displayed, the light-emitting control signal is a pulse-width modulation signal. By adjusting the number of pulse periods included in the light-emitting control signal within one frame, the number of pixel driving circuit rows that do not emit light in each pulse period is reduced, the split-screen Mura that appears in the low-brightness and low-gray-scale pictures is improved, and abnormal display is avoided.

[0064] Please refer to Figure 6 , the embodiment of the present application provides a display driving method, which is applied to the display panel described in any of the above embodiments. The method includes steps S101 to S103, specifically as follows:

[0065] S101, the pixel driving circuit obtains the scanning signal provided by the scanning line and the data signal provided by the data line. Each frame of signal includes a refresh period and a blanking period.

[0066] S102, during the refresh period, the data signal is a first voltage value, and the pixel driving circuit drives the light-emitting diode OLED to emit light according to the scanning signal and the first voltage value. The first voltage value belongs to a first voltage range, and the first voltage range is the voltage change range corresponding to the gray-scale allowable change range of the pixel driving circuit.

[0067] S103, during the blanking period, the data signal is adjusted from the first voltage value to a second voltage value, and the pixel driving circuit drives the light-emitting diode OLED to emit light according to the scanning signal and the second voltage value. The second voltage value belongs to a second voltage range, and the second voltage range is a part of the voltage values in the first voltage range.

[0068] Specifically, the display screen is generally driven by a display driver integrated chip (IC). The driving method adopted for low gray scales is pulse-width modulation dimming, and the PAM (Pulse Amplitude Modulation) is adopted for high gray scales.

[0069] The pixel driving circuit obtains the scan signal provided by the scan line and the data signal provided by the data line, turns on the pixel driving circuit line by line based on the scan signal, and at the same time, each pixel driving circuit drives the light-emitting diode OLED to emit light based on the data signal.

[0070] Each frame signal of the picture to be displayed includes a refresh period and a blanking period. The refresh rate of the display determines the ratio of the refresh period to the blanking period in one frame signal. During the refresh period, when a certain gray-scale brightness needs to be displayed, the data line Data provides a first voltage value to the pixel driving circuit, and the pixel driving circuit controls the light-emitting diode OLED to emit light with a corresponding intensity according to the first voltage value. Based on the different gray-scale brightnesses to be displayed, the corresponding first voltage values are different, but the first voltage value belongs to the first voltage range. The pixel driving circuit drives the light-emitting diode OLED to display different brightnesses according to the magnitude of the voltage value input by the data line Data, thereby realizing the display of a display picture with different gray-scale brightnesses.

[0071] Therefore, based on the allowable change range of gray scale that the pixel driving circuit needs to achieve, the voltage value input by the data line Data has a corresponding voltage change range. When the data line Data inputs any voltage value within this voltage change range, the light-emitting diode OLED of the pixel driving circuit displays the corresponding gray-scale brightness within the allowable change range of gray scale. The first voltage range is the voltage change range corresponding to the allowable change range of gray scale of the pixel driving circuit.

[0072] During the blanking period, the data line Data provides a second voltage value to the pixel driving circuit, that is, when entering the blanking period from the refresh period, the voltage value provided by the data line Data jumps from the first voltage value to the second voltage value. The second voltage value belongs to the second voltage range. In order to avoid too large a change amplitude when the voltage value jumps from the first voltage value to the second voltage value, resulting in cross-talk coupling of the driving transistor T1 and causing horizontal stripes to appear, the second voltage range is set to a part of the voltage values in the first voltage range, and the second voltage range is set to the middle part of the first voltage range.

[0073] Preferably, the first voltage range and the second voltage range have the same middle value, that is, the middle value of the second voltage range is determined according to the middle value of the first voltage range, and then the second voltage range is obtained according to the middle value and the allowable fluctuation range. The allowable fluctuation range is the allowable voltage jump range during the blanking period. For example, if the first voltage range is 0 - 7V, the middle value is 3.5V, and the fluctuation range based on 3.5V is ±0.5V, then the second voltage range is determined to be 3 - 4V. As Figure 3 shown, a large difference between the first voltage range and the second voltage range results in obvious horizontal stripe phenomena on the display screen. As Figure 4 shown, a smaller difference between the first voltage range and the second voltage range visually eliminates the horizontal stripes.

[0074] In this embodiment, the second voltage range during the blanking period is set based on the first voltage range during the refresh period, reducing the amplitude of the voltage jump provided by the data line Data when entering the blanking period from the refresh period, and reducing the crosstalk of the gate potential of the driving transistor T1 during the voltage jump to eliminate the horizontal stripes.

[0075] In one embodiment, after step S101 where the pixel driving circuit obtains the scan signal provided by the scan line and the data signal provided by the data line, it further includes: S201, the emission control circuit sequentially sends the light emission control signal to each row of pixel driving circuits, and the light emission control signal is a pulse width modulation signal; S202, within one pulse period of the light emission control signal, the emission control circuit inputs an on signal to the pixel driving circuits of the adjacent first number of rows, and the light emitting diodes OLED in the pixel driving circuits of the first number of rows emit light; S203, the emission control circuit inputs an off signal to the pixel driving circuits of the adjacent second number of rows, and the light emitting diodes OLED in the pixel driving circuits of the second number of rows do not emit light, and the difference between the first number of rows and the second number of rows is less than or equal to a preset threshold.

[0076] Specifically, the emission control circuit sequentially sends the light emission control signal to each row of pixel driving circuits. When the light emission control signal is an on signal and the scan signal is on, the light emitting diodes OLED in the corresponding pixel driving circuits emit light, and the intensity of the light emission of the light emitting diodes OLED depends on the voltage value of the data line Data. When the light emission control signal is an off signal, even if the scan signal is on, the light emitting diodes OLED in the corresponding pixel driving circuits do not emit light.

[0077] Among them, the light emission time within one frame is usually called EM Duty (Emission Duty, light emission time ratio), and the larger the light emission time ratio, the stronger the screen display brightness corresponding to it. Therefore, in addition, the brightness parameter of the display can also be obtained, and the corresponding light emission time ratio can be determined according to the brightness parameter.

[0078] The light emission control signal is a pulse width modulation signal, and one frame of the light emission control signal includes multiple pulse periods. Since both the on signal and the off signal are continuous within one pulse period, correspondingly, for the pixel driving circuits of the adjacent first number of rows, the emission control circuit inputs on signals, that is, the light emitting diodes OLED in the pixel driving circuits of the adjacent first number of rows all emit light. Then, for the pixel driving circuits of the adjacent first number of rows, the emission control circuit inputs off signals, that is, the light emitting diodes OLED in the pixel driving circuits of the adjacent second number of rows all do not emit light.

[0079] Since the corresponding light-emitting time ratio is determined based on the required display screen brightness, the light-emitting time ratio is a determined value, that is, the time ratio of the on-signal and off-signal within one pulse period is fixed. When the number of pulse periods included in one frame is more, that is, when the number of pulse periods included in one frame is greater than or equal to the preset number of periods, correspondingly each pulse period is shorter, that is, the pixel driving circuits corresponding to the first row number and the second row number are fewer. The fewer the pixel driving circuits corresponding to the second row number, the fewer the non-light-emitting pixel driving circuits corresponding to each pulse period. When the non-light-emitting pixel driving circuits are fewer and not obvious compared with the light-emitting pixel driving circuits, that is, when the difference between the first row number and the second row number is less than or equal to the preset threshold, the non-light-emitting pixel driving circuits cannot be visually detected when the display screen displays the picture, so the horizontal stripes are eliminated. Among them, the preset number of periods and the preset threshold are set based on the display precision requirements of the display screen, and are not specifically limited in this embodiment. For example, the preset number of periods is set to 8, or 12, etc.

[0080] In addition, the more the number of pulse periods, the faster the change speed of the pixel driving circuits of the display screen, and correspondingly the higher the power consumption, resulting in an increase in cost. Therefore, the corresponding relationship between the power consumption information of the display screen and the number of pulse periods can be determined through experiments, etc., and then the power consumption parameter is obtained. Combining the power consumption parameter and the preset number of periods to determine the number of pulse periods included in one frame of the actual light-emitting control signal. While increasing the number of pulse periods per frame to ensure the elimination of horizontal stripes, try to select an appropriate power consumption. For example, the preset number of periods is set to 8, but considering the power consumption, the number of pulse periods is preferably 12. In addition, combining the number of pulse periods and determining the corresponding light-emitting time ratio according to the brightness parameter to obtain the light-emitting control signal.

[0081] In this embodiment, the light-emitting control signal for the low gray-scale picture is a pulse width modulation signal. By adjusting the number of pulse periods included in the light-emitting control signal within one frame, the number of rows of non-light-emitting pixel driving circuits in each pulse period is reduced, improving the split-screen Mura that appears in the low-brightness and low-gray-scale pictures and avoiding abnormal display.

[0082] An embodiment of the present application provides a display device, including the display panel described in any of the above embodiments.

[0083] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0084] In some embodiments of the present application, an electronic device is provided, including one or more processors; a memory; and one or more application programs, where one or more application programs are stored in the memory and are configured to be executed by the processor to perform the steps of the above display driving method. The steps of the display driving method here can be the steps of the display driving methods in the above various embodiments.

[0085] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0086] The above has introduced in detail a display driving method, device, electronic device and computer-readable storage medium provided by the embodiments of the present application. Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A display panel, characterized in that, Including multiple rows of pixel driving circuits, the pixel driving circuit includes: A driving transistor, with the first end of the source-drain of the driving transistor connected to the first power supply line; A storage capacitor, one end of the storage capacitor is connected to the first power supply line, and the other end of the storage capacitor is connected to the gate of the driving transistor; A data loading transistor, the first end of the source-drain of the data loading transistor is connected to the data line, the second end of the source-drain of the data loading transistor is connected to the first end of the source-drain of the driving transistor, and the gate of the data loading transistor is connected to the scan line; A light-emitting diode, the anode of the light-emitting diode is connected to the second end of the source-drain of the driving transistor, and the cathode of the light-emitting diode is connected to the second power supply line; Each frame includes a refresh period and a blanking period. During the refresh period, the data line provides a first voltage value, the first voltage value belongs to a first voltage range, and the first voltage range is the voltage change range corresponding to the gray-scale allowable change range of the pixel driving circuit; during the blanking period, the data line provides a second voltage value, the second voltage value belongs to a second voltage range, the second voltage range is included in the first voltage range, and the first voltage range and the second voltage range have the same intermediate value.

2. The display panel according to claim 1, characterized in that, The pixel driving circuit further includes an initialization transistor connected between the anode of the light-emitting diode and the third power supply line, and the voltage value of the third power supply line is less than the voltage value of the second power supply line.

3. The display panel according to claim 1, characterized in that, The display panel further includes an emission control circuit, the emission control circuit is connected to the multiple rows of pixel driving circuits, and the pixel driving circuit further includes a light-emitting control transistor connected in series between the driving transistor and the light-emitting diode, and the gates of the light-emitting control transistors are all connected to the light-emitting control signal sent by the emission control circuit.

4. The display panel according to claim 3, wherein The light-emitting control signal is a pulse-width modulation signal. Within one pulse period of the light-emitting control signal, the emission control circuit gives an on signal to the pixel driving circuits of the adjacent first number of rows, and the emission control circuit gives an off signal to the pixel driving circuits of the adjacent second number of rows.

5. The display panel according to claim 4, wherein The difference between the first number of rows and the second number of rows is less than or equal to a preset threshold.

6. The display panel according to claim 1, wherein The pixel driving circuit further includes a voltage compensation transistor connected between the gate of the driving transistor and the second end of the source-drain of the driving transistor.

7. A display driving method, applied to the display panel according to any one of claims 1 to 6, characterized in that, Including: The pixel driving circuit obtains the scan signal provided by the scan line and the data signal provided by the data line. Each frame includes a refresh period and a blanking period; During the refresh period, the data signal is the first voltage value, and the pixel driving circuit drives the light-emitting diode to emit light according to the scan signal and the first voltage value. The first voltage value belongs to a first voltage range, and the first voltage range is the voltage change range corresponding to the gray-scale allowable change range of the pixel driving circuit; During the blanking period, the data signal is adjusted from the first voltage value to the second voltage value, and the pixel driving circuit drives the light-emitting diode to emit light according to the scanning signal and the second voltage value. The second voltage value belongs to a second voltage range, the second voltage range is included in the first voltage range, and the first voltage range and the second voltage range have the same intermediate value.

8. The display driving method according to claim 7, wherein After the pixel driving circuit obtains the scanning signal provided by the scanning line and the data signal provided by the data line, it further includes: The emission control circuit sequentially sends the light emission control signal to each row of pixel driving circuits, and the light emission control signal is a pulse width modulation signal; Within one pulse period of the light emission control signal, the emission control circuit inputs a turn-on signal to the pixel driving circuits of the adjacent first number of rows, and the light-emitting diodes in the pixel driving circuits of the first number of rows emit light; The emission control circuit inputs a turn-off signal to the pixel driving circuits of the adjacent second number of rows, and the light-emitting diodes in the pixel driving circuits of the second number of rows do not emit light. The difference between the first number of rows and the second number of rows is less than or equal to a preset threshold.

9. A display device, characterized in that, The display device includes the display panel according to any one of claims 1 to 6.

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