Display panel and display apparatus

Abstract

A display panel (10) and a display apparatus (100). The display panel comprises a plurality of data lines (S), a plurality of scanning lines (G), and a plurality of pixel units (15) arranged in an array. Each pixel unit (15) comprises a drive module (151), an adjustment module (152) and a light-emitting module (153), wherein the adjustment module (152) and the light-emitting module (153) are electrically connected to the drive module (151), and the adjustment module (152) is used for receiving an adjustment signal in a compensation phase and adjusting, on the basis of the adjustment signal, a threshold voltage in the drive module (151) to be within a preset range; and the drive module (151) is used for driving, on the basis of a data signal, the light-emitting module (153) to emit light in a light-emitting phase. By means of the adjustment modules (152), the threshold voltages of the pixel units (15) are adjusted to be within the preset range, such that the luminance difference among the pixel units (15) can be effectively reduced, thereby improving the display effect.

Description

Display panel and display device

[0001] The present application claims priority to the Chinese patent application No. 2024113883270, filed on September 30, 2024, and entitled "Display panel and display device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of display, in particular to a display panel and a display device. BACKGROUND

[0003] Organic Light-Emitting Diode (OLED) display device has self-emission, low driving current, high luminous efficiency, short response time, high clarity and contrast, nearly 180° viewing angle, wide temperature range, flexible display and large-area full-color display, and many other advantages, and is considered by the industry as the most potential display device. However, since the light-emitting material of OLED is driven by current to emit light, when the size of the panel becomes larger and larger, in order to reduce the heat of the OLED large-size panel, the current driving the OLED light-emitting material needs to be as small as possible, at this time, the threshold voltage of the transistor controlling the driving current is likely to change, resulting in different driving currents flowing through the transistor when the same data voltage is controlled, thereby causing different OLED luminous intensities, and resulting in poor display effect of the display panel.

[0004] Therefore, how to adjust and compensate the threshold voltage change of the driving transistor to improve the display effect is a problem to be solved. SUMMARY

[0005] In view of the above technical problems, the present application provides a display panel and a display device capable of effectively adjusting the threshold voltage of a driving transistor.

[0006] The present application discloses a display panel, comprising a plurality of data lines, a plurality of scan lines and a plurality of pixel units arranged in an array, the pixel unit is configured to receive a scan signal from the scan line and receive a data signal from the data line under the control of the scan signal, and perform image display according to the data signal; the pixel unit comprises a driving module, an adjusting module and a light-emitting module, the adjusting module and the light-emitting module are electrically connected to the driving module, the adjusting module is configured to receive an adjusting signal and adjust the threshold voltage in the driving module to a preset range according to the adjusting signal, and the driving module is configured to drive the light-emitting module to emit light according to the data signal.

[0007] Optionally, the pixel unit further comprises a first signal receiving module, a second signal receiving module and a first node, the first signal receiving module is electrically connected to the data line, the scan line and the first node and is electrically connected to the first control end of the driving module through the first node, the first signal receiving module is used for receiving the data signal or the first reference signal from the data line under the control of the scan signal and transmitting to the first node; the second signal receiving module is electrically connected to the scan line and the reference voltage end and is used for receiving the second reference signal from the reference voltage end under the control of the scan signal and transmitting to the driving module, the first reference signal and the second reference signal are used for adjusting the threshold voltage of the driving module in cooperation with the adjusting module.

[0008] Optionally, the pixel unit further comprises a storage module and a second node, the second node is electrically connected to the adjusting module, the storage module and the second control end of the driving module, the adjusting signal comprises a first adjusting signal and a second adjusting signal; the adjusting module controls the driving voltage end to charge the second node to the first potential according to the first adjusting signal, the adjusting module controls the second node to discharge to the driving module through the adjusting module according to the second adjusting signal, when the potential of the second node drops to the second potential, the threshold voltage of the driving module is adjusted to a preset value, the storage module is used for storing charges to maintain the potential of the second node, and the preset value is the difference between the first reference signal and the second reference signal.

[0009] Optionally, the pixel unit further comprises a driving control module, the driving control module is electrically connected to the driving voltage end, the control signal end and the driving module, and is used for receiving the driving current from the driving voltage end and transmitting to the driving module under the control of the control signal, the driving module controls the driving current to drive the light emitting module to emit light according to the data signal.

[0010] Optionally, the pixel unit further comprises a third node, the adjusting module comprises a first switch tube and a second switch tube, the control end of the first switch tube is electrically connected to the first adjusting signal end, the first conductive end of the first switch tube is electrically connected to the driving voltage end, the second conductive end of the first switch tube is connected to the second node, the control end of the second switch tube is electrically connected to the second adjusting signal end, the first conductive end of the second switch tube is electrically connected to the second node, the second conductive end of the second switch tube is electrically connected to the third node and is electrically connected to the driving module through the third node; the first switch tube is turned on under the control of the first adjusting signal to control the driving voltage end to charge the second node to the first potential, and the second switch tube is used for being turned on under the control of the second adjusting signal to control the second node to be electrically connected to the third node and discharge to the driving module through the third node.

[0011] Optionally, the pixel unit further comprises a fourth node, and the driving module comprises a driving switch tube and a first capacitor, a first control terminal of the driving switch tube is electrically connected to the first node, a second control terminal of the driving switch tube is electrically connected to the second node, a first conductive terminal of the driving switch tube is electrically connected to the third node, a second conductive terminal of the driving switch tube is electrically connected to the fourth node and the light-emitting module through the fourth node, and the first capacitor is electrically connected between the first node and the fourth node, the driving switch tube is used for being turned on under the control of the first node and / or the second node, and the first capacitor is used for storing electric charges to maintain the voltage of the first node.

[0012] Optionally, the first signal receiving module comprises a third switch tube, the second signal receiving module comprises a fourth switch tube, and the storage module comprises a second capacitor, a control terminal of the third switch tube is electrically connected to the scanning line, a first conductive terminal of the third switch tube is electrically connected to the data line, a second conductive terminal of the third switch tube is electrically connected to the first node, the third switch tube is used for receiving the data signal or the first reference signal from the data line and transmitting to the first node under the control of the scanning signal; a control terminal of the fourth switch tube is electrically connected to the scanning line, a first terminal of the fourth switch tube is electrically connected to the reference voltage terminal, and a second terminal of the fourth switch tube is electrically connected to the fourth node, the fourth switch tube is used for receiving the second reference signal from the reference voltage terminal and transmitting to the fourth node under the control of the scanning signal; and the second capacitor is electrically connected between the second node and the fourth node, and is used for storing electric charges to maintain the voltage of the second node.

[0013] Optionally, the driving control module comprises a fifth switch tube, a control terminal of the fifth switch tube is electrically connected to the control signal terminal, a first conductive terminal of the fifth switch tube is electrically connected to the driving voltage terminal, and a second conductive terminal of the fifth switch tube is electrically connected to the first conductive terminal of the driving switch tube, the fifth switch tube is used for being turned on when the control signal is received, so as to control the driving current output by the driving voltage terminal to be transmitted to the driving switch tube; and the light-emitting module comprises a light-emitting element, an anode of the light-emitting element is electrically connected to the fourth node, and a cathode of the light-emitting element is electrically connected to the low-voltage terminal, the light-emitting element is used for receiving the driving current and emitting light according to the driving current.

[0014] Optionally, in the first time period, the first switch tube is turned on to control the second node to be charged to a first potential, the third switch tube and the fourth switch tube are turned on, the first node receives a first reference signal to rise to a first reference potential, and the fourth node receives a second reference signal to rise to a second reference potential; in the second time period, the driving switch tube is turned on, the second switch tube is turned on, the first switch tube is turned off, the fifth switch tube is turned off, and the second node is discharged to the driving switch tube through the second switch tube and the third node; when the driving switch tube is turned off, a threshold voltage of the driving switch tube is adjusted to a preset value, and at the same time, the second node is lowered from the first potential to the second potential, and the second capacitor is used to store charges to maintain the voltage of the second node; in the third time period, the second switch tube is turned off, and the data signal is transmitted to the first node through the third switch tube and stored in the first capacitor; in the fourth time period, the fifth switch tube is turned on, the data signal controls the driving switch tube to be turned on, and the driving switch tube receives a driving current from the fifth switch tube and controls the driving current to drive the light emitting element to emit light.

[0015] Optionally, the first time period and the second time period are performed in a non-display stage, and the third time period and the fourth time period are performed in an image display stage, wherein the non-display stage is a boot-up non-display stage.

[0016] Optionally, the first time period and the second time period are performed in a non-display stage, and the third time period and the fourth time period are performed in an image display stage, wherein the non-display stage is a vertical blanking stage; the vertical blanking stage is located between image display stages of adjacent two frames; the display panel performs the first time period and the second time period in the vertical blanking stage of each frame; or the display panel performs the first time period and the second time period once in the vertical blanking stage of each a frame, wherein a is an integer greater than 1.

[0017] Optionally, in each image display stage, the pixel unit sequentially performs the first time period, the second time period, the third time period and the fourth time period.

[0018] The embodiment of the present application further provides a display device, comprising a power module and the display panel, wherein the power module is used to provide driving power for the display panel to drive the display panel to perform image display.

[0019] Compared with the prior art, the present application adjusts the threshold voltage in the driving module to a preset range through the adjustment module, eliminates the difference in luminous intensity between adjacent pixel units caused by the different threshold voltages of the driving module, avoids the difference in brightness between adjacent pixel units, and effectively improves the display effect. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0021] Fig. 1 is a structural schematic diagram of a display device provided by an embodiment of the present application;

[0022] Fig. 2 is a planar layout schematic diagram of the display panel in Fig. 1;

[0023] Fig. 3 is an equivalent circuit schematic diagram of the pixel unit in Fig. 2;

[0024] Fig. 4 is a signal output timing diagram in Fig. 3;

[0025] Fig. 5 is a conduction curve change schematic diagram of the first switch tube in Fig. 3;

[0026] Fig. 6 is a signal output timing diagram of the first compensation mode;

[0027] Fig. 7 is a signal output timing diagram of the second compensation mode. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the present application, the following will make a more comprehensive description of the present application with reference to the related drawings. The drawings show the preferred embodiments of the present application. However, the present application can be implemented in many different forms, and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0029] The following description of each embodiment is made with reference to the additional drawings, which are used to illustrate the specific embodiments that the present application can be used to implement. The serial numbers of the components in this paper, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present application, unless otherwise specified, include direct and indirect connection (coupling). The direction terms mentioned in the present application, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only the direction of the attached drawings, therefore, the direction terms used are for better, clearer illustration and understanding of the present application, and are not indicative or implied that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the present application.

[0030] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection; it can be direct connection, or indirect connection through intermediate medium; it can be internal connection of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. It should be noted that the terms "first", "second" and the like in the description and claims of the present application and the accompanying drawings are used to distinguish different objects, and are not used to describe a specific order. In addition, the terms "including", "may include", "containing" or "may contain" used in the present application represent the existence of the corresponding functions, operations, elements, etc. disclosed, and do not limit other one or more functions, operations, elements, etc. In addition, the terms "including" or "containing" represent the existence of the corresponding features, numbers, steps, operations, elements, components or combinations thereof disclosed in the specification, and do not exclude the existence or addition of one or more other features, numbers, steps, operations, elements, components or combinations thereof, and are intended to cover non-exclusive inclusion. It should also be understood that the meaning of "at least one" described herein is one and more, for example, one, two or three, etc., and the meaning of "multiple" is at least two, for example, two or three, etc., unless otherwise explicitly specified. The terms "step 1", "step 2" and the like in the description and claims of the present application and the accompanying drawings are used to distinguish different objects, and are not used to describe a specific order.

[0031] In the field of display technology, a display device can generally include a display panel and a backlight assembly, wherein the display panel is mounted to the light exit side of the backlight assembly, and the backlight assembly is used to provide backlight to the display panel to adjust the display of different pictures by the display panel.

[0032] Please refer to FIG. 1, which is a structural schematic diagram of a display device 100 provided by the first embodiment of the present application. The display device 100 includes a display panel 10 and a power supply module 20, and the power supply module 20 is arranged on the back of the display panel 10, i.e. the non-display surface of the display panel 10. The power supply module 20 is used to provide driving current for the display panel 10 to display images.

[0033] Please refer to FIG. 2, which is a planar layout schematic diagram of the display panel in FIG. 1.

[0034] As shown in FIG. 2, the display panel 10 includes a plurality of matrix-arranged pixel units 15 disposed in a display area 10a of an array substrate 10c, m data lines S1-Sm and n scan lines G1-Gn, m and n are natural numbers greater than 1, and a timing control circuit 11, a data driving circuit 12 and a scan driving circuit 13 disposed in a non-display area of the array substrate 10c. The n scan lines G1-Gn extend along a first direction F1 and are insulated and arranged in parallel along a second direction F2, the m data lines S1-Sm extend along the second direction F2 and are insulated and arranged in parallel along the first direction F1, and the first direction F1 and the second direction F2 are perpendicular to each other.

[0035] The timing control circuit 11 is electrically connected to the data driving circuit 12 and the scan driving circuit 13, and is configured to control the timing of the data driving circuit 12 and the scan driving circuit 13, i.e., the timing control circuit 11 is configured to output corresponding timing control signals to the data driving circuit 12 and the scan driving circuit 13, respectively, to control the data driving circuit 12 to output data signals and the scan driving circuit 13 to output scan signals, and the pixel units 15 display images according to the scan signals receiving the data signals for image display.

[0036] The data driving circuit 12 is electrically connected to the m data lines S1-Sm, and is configured to transmit data signals (Data) to be displayed to the plurality of pixel units 15 in the form of data voltages through the m data lines S1-Sm.

[0037] The scan driving circuit 13 is electrically connected to the n scan lines G1-Gn, and is configured to output scan signals through the n scan lines G1-Gn to control when the pixel units 15 receive the data signals. In some embodiments, the scan driving circuit 13 can output scan signals from the scan lines G1, G2, …, Gn in a scan period according to the order of position arrangement to control the pixel units 15 to receive the data signals for image display, and of course, the scan signals can be output in other timing according to specific needs, which is not limited in the present application.

[0038] Referring to FIG. 3, FIG. 3 is a schematic circuit diagram of the pixel unit in FIG. 2.

[0039] As shown in FIG. 3, the pixel unit 15 includes a driving module 151, an adjusting module 152 and a light-emitting module 153, wherein the driving module 151 is electrically connected to the adjusting module 152 and the light-emitting module 153, the adjusting module 152 is configured to receive an adjusting signal and adjust a threshold voltage of the driving module 151 according to the adjusting signal to control the threshold voltage to be within a preset range, the driving module 151 is configured to receive a data signal and control the size of a driving current transmitted to the light-emitting module 153 according to the data signal, and the light-emitting module 153 emits light according to the received driving current.

[0040] By setting the adjusting module 152, the threshold voltage of the driving module 151 in the pixel unit 15 can be directly adjusted to a preset range, thus the threshold voltage of the driving module 151 in the adjacent pixel unit 15 can be adjusted in the same preset range, eliminating the difference in luminous intensity of the adjacent pixel units due to the different threshold voltage of the driving module 151, thereby avoiding the brightness difference between the adjacent pixel units 15, effectively improving the display effect.

[0041] In the embodiment, the pixel unit 15 further comprises a first signal receiving module 154, a second signal receiving module 155, a storage module 156, a driving control module 157, a first node N1, a second node N2, a third node N3 and a fourth node N4, wherein the first signal receiving module 154 is electrically connected to the data line S, the scan line G and the first node N1 and electrically connected to the first control end of the driving module 151 through the first node N1, the first signal receiving module 154 is used for receiving the scan signal and receiving the data signal or the first reference signal from the data line S under the control of the scan signal and transmitting the data signal or the first reference signal to the first node N1. Wherein, the first reference signal is used for adjusting the threshold voltage of the driving module 151 in cooperation with the adjusting module 152, and the data signal is used for providing to the driving module 151 in the image display stage, so that the driving module 151 drives the light emitting module 153 to emit light according to the data signal.

[0042] The second signal receiving module 155 is electrically connected to the scan line G, the reference voltage end VER and the fourth node N4, and is used for receiving the second reference signal from the reference voltage end VER under the control of the scan signal and transmitting the second reference signal to the fourth node N4 and transmitting the second reference signal to the driving module 151 through the fourth node N4. Wherein, the second reference signal is used for adjusting the threshold voltage in the driving module 151 in cooperation with the adjusting module 152.

[0043] The storage module 156 is electrically connected to the second node N2, and the second node N2 is also electrically connected to the adjusting module 152 and the second control end of the driving module 151, the adjusting signal comprises a first adjusting signal and a second adjusting signal, wherein the adjusting module 152 controls the driving voltage end to charge the second node N2 to the first potential according to the first adjusting signal, and controls the second node N2 to discharge to the driving module 151 through the adjusting module 152 according to the second adjusting signal, when the second node N2 decreases from the first potential to the second potential, the threshold voltage of the driving module 151 is adjusted to a preset value, the preset value is the difference between the first reference signal and the second reference signal, and the storage module 156 is used for storing the charge and maintaining the voltage of the second node N2.

[0044] The driving control module 157 is electrically connected to the driving voltage terminal VDD, the control signal terminal EM and the third node N3 and electrically connected to the driving module 151 through the third node N3, for receiving driving current from the driving voltage terminal VDD according to the control signal outputted by the control signal terminal EM and transmitting to the driving module 151 through the third node N3, and the driving module 151 controls the driving current to drive the light emitting module 153 to emit light according to the received data signal.

[0045] Referring to FIG. 3 and FIG. 4, FIG. 4 is a signal output timing diagram in FIG. 3.

[0046] As shown in FIG. 4, the first period t1 is an initialization stage, the adjusting module 152 controls the driving voltage terminal VDD to charge the second node N2 to the first potential, the first signal receiving module 154 inputs the first reference signal to the first node N1, and the second signal receiving module 155 inputs the second reference signal to the fourth node N4, wherein the second reference signal < VSS + Vel (Vel is the turn-on voltage of the light emitting module 153), that is, the voltage of the fourth node N4 is not enough to control the light emitting module 153 to emit light.

[0047] In the second period t2, the second period t2 is a compensation stage, the second node N2 is discharged to the driving module 151 through the adjusting module 152 and the third node N3, until the second node N2 stops discharging to the driving module 151, at this time, the second node N2 is decreased from the first potential to the second potential, and the storage module 156 is used to store the charge to maintain the voltage of the second node N2.

[0048] In the third period t3, the third period t3 is a data writing stage, the first signal receiving module 154 receives the data signal and transmits to the first node N1, at the same time, the second signal receiving module 155 still inputs the second reference signal to the fourth node N4 to control the fourth node N4 to maintain at the second reference voltage.

[0049] In the fourth period t4, the fourth period t4 is a light emitting stage, the driving control module 157 receives the driving current from the driving voltage terminal VDD and transmits to the driving module 151, and the driving module 151 controls the driving current to drive the light emitting module to emit light according to the data signal.

[0050] Specifically, the driving module 151 comprises a driving switch tube DT and a first capacitor C1. The first control end of the driving switch tube DT is electrically connected to the first node N1. The second control end of the driving switch tube DT is electrically connected to the second node N2. The first conductive end of the driving switch tube DT is electrically connected to the third node N3. The second conductive end of the driving switch tube DT is electrically connected to the fourth node N4 and the light emitting module 153 through the fourth node N4. That is, the driving switch tube DT is a double-gate transistor with a first control end and a second control end, wherein the first control end is a first gate and the second control end is a second gate. The first capacitor C1 is electrically connected between the first node N1 and the fourth node N4 of the driving switch tube DT. The driving switch tube DT is used to be turned on under the control of the first control end and / or the second control end to receive a driving current from the driving control module 157 and drive the light emitting module 153 to emit light according to the driving current.

[0051] The adjusting module 152 comprises a first switch tube T1 and a second switch tube T2. The control end of the first switch tube T1 is electrically connected to the first adjusting signal end K1. The first conductive end of the first switch tube T1 is electrically connected to the driving voltage end VDD. The second conductive end of the first switch tube T1 is connected to the second node N2. The control end of the second switch tube T2 is electrically connected to the second adjusting signal end K2. The first conductive end of the second switch tube T2 is electrically connected to the second node N2. The second conductive end of the second switch tube T2 is electrically connected to the third node N3 and the driving switch tube DT through the third node N3.

[0052] The first switch tube T1 is used to be turned on under the control of the first adjusting signal to control the driving voltage end VDD to charge the second node N2 to a first potential. The second switch tube T2 is used to be turned on under the control of the second adjusting signal to control the second node N2 to be electrically connected to the first conductive end of the driving switch tube DT through the third node N3. Since the second node N2 is also electrically connected to the second control end of the driving switch tube DT, when the second node N2 is at the first potential, the driving switch tube DT is turned on, so that the second node N2 forms a discharge path through the second switch tube T2, the third node N3 and the driving switch tube DT, so that the second node N2 can discharge to the driving switch tube DT.

[0053] The light emitting module 153 comprises a light emitting element E, which can be an organic light emitting diode. The anode of the light emitting element E is electrically connected to the third node N3. The cathode of the light emitting element E is electrically connected to the low voltage end VSS. The light emitting module 153 is driven according to the driving current transmitted by the driving switch tube DT.

[0054] The first signal receiving module 154 comprises a third switch tube T3, the second signal receiving module 155 comprises a fourth switch tube T4, the storage module 156 comprises a second capacitor C2, the control end of the third switch tube T3 is electrically connected to the scanning line G, the first conductive end of the third switch tube T3 is electrically connected to the data line S, and the second conductive end of the third switch tube T3 is electrically connected to the first node N1, for receiving the data signal or the first reference signal from the data line S under the control of the scanning signal and transmitting to the first node N1.

[0055] The control end of the fourth switch tube T4 is electrically connected to the scanning line G, the first end of the fourth switch tube T4 is electrically connected to the reference voltage end VER, and the second end of the fourth switch tube T4 is electrically connected to the fourth node N4, for receiving the second reference signal from the reference voltage end VER under the control of the scanning signal and transmitting to the fourth node N4.

[0056] The second capacitor C2 is electrically connected between the second node and the fourth node, and the second capacitor C2 is used for storing electric charges to maintain the voltage of the second node N2, or in other words, to maintain the voltage difference between the second node N2 and the fourth node N4.

[0057] The driving control module 157 comprises a fifth switch tube T5, the control end of the fifth switch tube T5 is electrically connected to the control signal end EM, the first conductive end of the fifth switch tube T5 is electrically connected to the driving voltage end VDD, and the second conductive end of the fifth switch tube T5 is electrically connected to the first conductive end of the driving switch tube DT, and the fifth switch tube T5 is used for turning on when receiving the control signal, to control the driving current output by the driving voltage end VDD to be transmitted to the driving switch tube DT.

[0058] As shown in FIG. 4, in the first time period t1, the first adjustment signal end K1 controls the first switch tube T1 to turn on, for controlling the driving voltage end VDD to charge the second node N2 to the first potential, that is, the voltage of the second node N2 is charged to VDD. At the same time, the scanning signal controls the third switch tube T3 and the fourth switch tube T4 to turn on, the third switch tube T3 receives the first reference voltage from the data line S and transmits to the first node N1, and the fourth switch tube T4 receives the second reference voltage from the reference voltage end VER and transmits to the fourth node N4. Wherein, the first reference voltage is greater than or equal to the second reference voltage, and VER < VSS + Vel, that is, the second reference voltage transmitted to the fourth node N4 is insufficient to drive the light emitting element E to emit light.

[0059] If the driving voltage terminal VDD initializes the second node N2 through the third node N3 and the second switch tube T2, and the third switch tube T3 is turned on to initialize the first node N1 and the fourth switch tube T4 is turned on to initialize the fourth node N4, at this time, the driving switch tube DT is in the conducting state, and there is a current flowing between the third node N3 and the fourth node N4, which causes the second node N2, the third node N3 and the fourth node N4 to fail to reach the preset initialization voltage, thereby affecting the adjustment of the threshold voltage, and it can also cause the voltage of the second node N2 to be much lower than VDD, further causing the compensation of the threshold voltage to fail. In the embodiment, the driving voltage terminal VDD only resets the second node N2 through the first switch tube T1, and in the first time period t1, the second switch tube T2 is in the cut-off state, that is, the second node N2 and the third node N3 are always in the electrically disconnected state, which effectively avoids the voltage change of the second node N2 and ensures the compensation effect of the threshold voltage.

[0060] In the second time period t2, the second switch tube T2 is turned on under the control of the second adjustment signal, and the driving switch tube DT is turned on under the control of the first node N1 and the second node N2, and the second node N2, the second switch tube T2, the third node N3 and the driving switch tube DT form a discharge path. As shown in FIG. 5, which is a schematic diagram of the conduction curve change of the driving switch tube in FIG. 3. Wherein, V TG_S is the voltage difference between the first control terminal and the second conductive terminal of the driving switch tube DT, that is, the voltage difference between the first gate and the source, that is, the voltage difference between the first node N1 and the fourth node N4; V MG_S is the voltage difference between the second control terminal and the second conductive terminal of the driving switch tube DT, that is, the voltage difference between the second gate and the source, that is, the voltage difference between the second node N2 and the fourth node N4. DS is the current flowing through the driving switch tube DT. The discharge process will be described in detail below according to the curve of V MG_S = 2.5V. In the initial stage of the second time period t2, V MG_S = 2.5V (V N2 -V N4 = 2.5V), V TG_S = 0V (V N1 -V N4 = 0V), at this time, I DS > 0, the driving switch tube DT is in the conducting state. As the second time period t2 proceeds, the second node N2 discharges to the fourth node N4 through the second switch tube T2 and the driving switch tube DT, so that the voltage of the second node N2 gradually decreases and the voltage of the fourth node N4 gradually increases, at this time, the voltage difference between the second node N2 and the fourth node N4 (that is, V MG_SThe voltage gradually decreases, and after the voltage at the second node N2 drops below the voltage at the fourth node N4, the voltage difference between the second node N2 and the fourth node N4 gradually increases again, i.e., V MG_S It gradually increases. In other words, the entire discharge process can be referenced to the arrow symbol on the vertical axis, V. TG_S Unchanged, while V MG_S First it gradually decreases and then gradually increases. During this process, I DS Gradually decrease. When the voltage at the second node N2 decreases to the preset voltage V... MG At that time, I DS This can be ignored, and at this point, the driving switch DT can be considered to be off. The critical voltage for the driving switch DT to turn on and off is the threshold voltage Vth, that is, when the voltage at the second node N2 or the second control terminal of the driving switch DT is the preset voltage Vth. MG At that time, the voltage difference (V) between the first control terminal and the source of the driving switch DT TG_S This is equal to the threshold voltage Vth that drives the switching transistor DT. In this embodiment, Vth = V TG_S =0. In other embodiments, the first time period t1 can make V TG_S (V N1 -V N4 Set to other values, because V in the second time period t2 TG_S While remaining unchanged, the threshold voltage Vth can also be other values. That is, the threshold voltage Vth can be set according to specific needs, and this application does not impose any restrictions on it.

[0061] During the third time period t3, the second adjustment signal controls the second switch T2 to turn off, the second capacitor C2 stores charge to maintain the voltage difference between the second node N2 and the fourth node N4, and the data line S outputs the data voltage V through the third switch T3. Data (Data signal) is sent to the first node N1. At this time, the reference voltage terminal VER provides a reference voltage to the fourth node N4. TG_S =V N1 -V N4 =V Data -V ER .

[0062] During the fourth time period t4, scan line G stops transmitting scan signals to control the third switch T3 and the fourth switch T4 to turn off, and the input voltage V written by data line S... Data The voltage is transmitted to the first node N1. The first capacitor C1 maintains the voltage of the first node N1. At the same time, the control signal terminal EM controls the fifth switch T5 to conduct, forming a path between the driving voltage terminal VDD and the low voltage terminal VSS. This drives the switching transistor DT and the light-emitting element E to divide the voltage, and the voltage of the fourth node N4 rises to V. E+VSS, to drive the light emitting element E to emit light, V E is the voltage for driving the light emitting element E to emit light. At the same time that the fourth node N4 rises, the first node N1 rises to V Data +V E +VSS-V ER , the second node N2 rises to V MG +V E +VSS-V ER , at which time the current I passing through the light emitting element is I = (k / 2)(V TG_S -Vth) 2 = (k / 2)[(1-α)(V Data -V ER- V th )] 2 , where, since the second stage has set V th to 0, I = (k / 2)[(1-α)(V Data -V ER )] 2 , where the first reference voltage written by the data line S in the initialization stage (the first time period t1) can be set as needed, and if the written voltage is Vx, then the final written voltage is V MG , under the control of the preset voltage V th , the threshold voltage V ER of the first switch tube is Vx-V th , that is, by adjusting the initialization written voltage Vx, the IDVG curve (FIG. 4) of the first switch tube T1 can be adjusted to be offset, so that the brightness adjustment can be achieved, that is, the brightness of the pixel unit can be compensated by controlling the initialization written voltage. Please refer to FIG. 6, which is a signal output timing diagram of the first compensation mode of the pixel unit in FIG. 3.

[0063] As shown in FIG. 6, when the display panel 10 executes the first compensation mode, in each frame of image display process, n scan lines sequentially output scan signals, while the first adjustment signal end K1, the second adjustment signal end K2 and the control signal end EM output signals according to the preset timing for adjusting the threshold voltage V th of the driving switch tube DT in the pixel unit 15, that is, compensating the threshold voltage V th , and then receiving data signals for image display, that is, the pixel unit 15 sequentially executes the process of the first time period t1 to the fourth time period t4 in each frame of image display process (display frame). In addition, the compensation and data writing are performed line by line.

[0064] Please refer to FIG. 7, which is a signal output timing diagram of the second compensation mode.

[0065] As shown in FIG. 7, in the second compensation mode, in the non-image display stage, the pixel unit 15 performs the first period t1 and the second period t2 for adjusting the threshold voltage of the driving switch tube DT, and in each frame image display stage, the pixel unit 15 performs the third period t3 and the fourth period t4 for receiving the data signal for image display. The non-image display stage can be the display panel 10 boot non-display stage and the vertical blanking stage between any two adjacent frames of images.

[0066] In the first period t1 and the second period t2 performed in the non-display stage, the compensation of the entire display panel pixel unit 15 can be controlled at the same time, that is, the entire compensation is performed. Or every a frames of images, the first period t1 and the second period t2 are performed in the vertical blanking stage, where a is an integer greater than or equal to 1, that is, the threshold voltage of the driving switch tube can be compensated after a plurality of continuous frames of image display. That is, the first period t1 and the second period t2 in the first compensation mode can be performed in the non-display stage, so as to complete the setting process of the threshold voltage of the driving switch tube DT. In this way, the two periods described above do not need to be performed in the display stage, and the third period t3 and the fourth period t4 are performed, so as to complete the data writing and light emitting processes.

[0067] The embodiment of the present application also has the effect of increasing the threshold voltage compensation range. The specific principle is as follows: from the foregoing current formula, I = (k / 2)(V TG_S -Vth) 2 After the compensation stage and the data writing stage, V TG_S = V Data -V ER , that is, V TG_S does not include Vth. For the traditional scheme in which the driving transistor is a single gate, after the compensation stage and the data writing stage, V TG_S = V Data + Vth-Vint, where Vint can be understood as a reference voltage similar to VER, and V TG_S (the voltage difference between the gate and the source) includes Vth. Due to the existence of Vth, the writing range of the data signal Data is squeezed, so the compensation range of Vth is limited to avoid affecting the range of Data. In the embodiment of the present application, V TG_S does not include Vth, so even if the range of Vth is set to be very large, the writing range of VData will not be squeezed. In addition, since the pixel unit 15 can be compensated in the non-display stage, the occupation of the display stage is reduced, and the threshold voltage of the driving module 151 can be adjusted and compensated in the case of a plurality of frames of images, so as to reduce the compensation time, increase the image display time of each frame, and effectively improve the image refresh rate.

[0068] It is to be understood that the application is not limited to the examples described above, which can be modified or adapted in several ways by those skilled in the art without departing from the scope of the present application, as defined by the following claims.

Claims

1. A display panel, comprising a plurality of data lines, a plurality of scan lines, and a plurality of pixel units arranged in an array, the pixel units configured to receive a scan signal from the scan lines and receive a data signal from the data lines under control of the scan signal, and perform image display according to the data signal; wherein, The pixel unit comprises a driving module, an adjusting module and a light-emitting module, the adjusting module and the light-emitting module are electrically connected to the driving module, the adjusting module is used for receiving an adjusting signal and adjusting a threshold voltage in the driving module to a preset range according to the adjusting signal, and the driving module is used for driving the light-emitting module to emit light according to the data signal.

2. The display panel of claim 1, wherein, The pixel unit further comprises a first signal receiving module, a second signal receiving module and a first node, the first signal receiving module is electrically connected to the data line, the scan line and the first node and is electrically connected to a first control end of the driving module through the first node, the first signal receiving module is used for receiving a data signal or a first reference signal from the data line and transmitting to the first node under the control of the scan signal; the second signal receiving module is electrically connected to the scan line and a reference voltage end and is used for receiving a second reference signal from the reference voltage end and transmitting to the driving module under the control of the scan signal, and the first reference signal and the second reference signal are used for adjusting the threshold voltage of the driving module in cooperation with the adjusting module.

3. The display panel of claim 2, wherein, The pixel unit further comprises a storage module and a second node, the second node is electrically connected to the adjusting module, the storage module and a second control end of the driving module, the adjusting signal comprises a first adjusting signal and a second adjusting signal; the adjusting module controls the driving voltage end to charge the second node to a first potential according to the first adjusting signal, the adjusting module controls the second node to discharge to the driving module through the adjusting module according to the second adjusting signal, when the potential of the second node drops to a second potential, the threshold voltage of the driving module is adjusted to the preset value, the storage module is used for storing charges to maintain the potential of the second node, and the preset value is the difference between the first reference signal and the second reference signal.

4. The display panel of claim 3, wherein, The pixel unit further comprises a driving control module, the driving control module is electrically connected to the driving voltage end, a control signal end and the driving module, and is used for receiving a driving current from the driving voltage end and transmitting to the driving module under the control of a control signal, and the driving module controls the driving current to drive the light-emitting module to emit light according to the data signal.

5. The display panel of claim 4, wherein, The pixel unit further comprises a third node, the adjusting module comprises a first switch tube and a second switch tube, a control end of the first switch tube is electrically connected to a first adjusting signal end, a first conductive end of the first switch tube is electrically connected to a driving voltage end, a second conductive end of the first switch tube is connected to a second node, a control end of the second switch tube is electrically connected to a second adjusting signal end, a first conductive end of the second switch tube is electrically connected to the second node, a second conductive end of the second switch tube is electrically connected to the third node and is electrically connected to the driving module through the third node. The first switch tube is turned on under control of a first adjustment signal to control the driving voltage terminal to charge the second node to a first potential, and the second switch tube is turned on under control of a second adjustment signal to control the second node to be electrically connected to the third node and discharge to the driving module through the third node.

6. The display panel of claim 5, wherein, The pixel unit further comprises a fourth node, and the driving module comprises a driving switch tube and a first capacitor. A first control terminal of the driving switch tube is electrically connected to the first node, a second control terminal of the driving switch tube is electrically connected to the second node, a first conductive terminal of the driving switch tube is electrically connected to the third node, a second conductive terminal of the driving switch tube is electrically connected to the fourth node and the light-emitting module through the fourth node, and the first capacitor is electrically connected between the first node and the fourth node of the driving switch tube. The driving switch tube is turned on under control of the first node and / or the second node, and the first capacitor is used to store electric charges to maintain the voltage of the first node.

7. The display panel of claim 6, wherein, The first signal receiving module comprises a third switch tube, the second signal receiving module comprises a fourth switch tube, and the storage module comprises a second capacitor. A control terminal of the third switch tube is electrically connected to the scanning line, a first conductive terminal of the third switch tube is electrically connected to the data line, and a second conductive terminal of the third switch tube is electrically connected to the first node, for receiving a data signal or a first reference signal from the data line and transmitting to the first node under control of the scanning signal. A control terminal of the fourth switch tube is electrically connected to the scanning line, a first terminal of the fourth switch tube is electrically connected to a reference voltage terminal, and a second terminal of the fourth switch tube is electrically connected to the fourth node, for receiving a second reference signal from the reference voltage terminal and transmitting to the fourth node under control of the scanning signal. The second capacitor is electrically connected between the second node and the fourth node, and is used to store electric charges to maintain the voltage of the second node.

8. The display panel of claim 7, wherein, The driving control module comprises a fifth switch tube. A control terminal of the fifth switch tube is electrically connected to a control signal terminal, a first conductive terminal of the fifth switch tube is electrically connected to a driving voltage terminal, and a second conductive terminal of the fifth switch tube is electrically connected to the first conductive terminal of the driving switch tube. The fifth switch tube is turned on when receiving the control signal to control the driving current output by the driving voltage terminal to be transmitted to the driving switch tube. The light-emitting module comprises a light-emitting element. An anode of the light-emitting element is electrically connected to the fourth node, and a cathode of the light-emitting element is electrically connected to a low-voltage terminal. The light-emitting element is used to receive the driving current and emit light according to the driving current.

9. The display panel of claim 8, wherein, In the first period, the first switch is turned on to control the second node to be charged to a first potential, the third switch and the fourth switch are turned on, the first node receives a first reference signal to rise to a first reference potential, and the fourth node receives a second reference signal to rise to a second reference potential; in the second period, the driving switch is turned on, the second switch is turned on, the first switch is turned off, the fifth switch is turned off, the second node is discharged to the driving switch through the second switch and the third node, when the driving switch is turned off, a threshold voltage of the driving switch is adjusted to a preset value, and at the same time, the second node is lowered from the first potential to the second potential, and the second capacitor is used to store charges to maintain the voltage of the second node; In the third period, the second switch is turned off, and the data signal is transmitted to the first node through the third switch and stored in the first capacitor; In the fourth period, the fifth switch is turned on, the data signal controls the driving switch to be turned on, and the driving switch receives the driving current from the fifth switch and controls the driving current to drive the light emitting element to emit light.

10. The display panel of claim 9, wherein, The first period and the second period are performed in a non-display stage, and the third period and the fourth period are performed in an image display stage, wherein the non-display stage is a power-on non-display stage.

11. The display panel of claim 9, wherein, The first period and the second period are performed in a non-display stage, and the third period and the fourth period are performed in an image display stage, wherein the non-display stage is a vertical blanking stage; the vertical blanking stage is located between the image display stages of two adjacent frames; the display panel performs the first period and the second period in the vertical blanking stage of each frame; or the display panel performs the first period and the second period once in the vertical blanking stage of every a frames, where a is an integer greater than 1.

12. The display panel of claim 9, wherein, In each image display stage, the pixel unit sequentially performs the first period, the second period, the third period and the fourth period.

13. A display device, wherein, The display panel comprises a power module and a display panel, and the power module is used to provide driving power for the display panel to drive the display panel to perform image display.

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