Drive Circuit, Driving Method, and Display Panel of a Display Panel

Abstract

The present application relates to a driving circuit, a driving method, and a display panel of a display panel. By sequentially determining the turn-on voltage and the conduction current, since there is a correlation between the turn-on voltage and the conduction current, and there is a relationship between the conduction current and the current flowing through the driving transistor, thus, the driving voltage determination module can accurately determine the driving voltage according to the turn-on voltage, achieving the effect that when the current flowing through the driving transistor becomes smaller, the driving voltage determination module increases the driving voltage based on the turn-on voltage, so that the current flowing through the driving transistor increases; conversely, when the current flowing through the driving transistor increases, the driving voltage determination module decreases the driving voltage based on the turn-on voltage, so that the current flowing through the driving transistor decreases. The circuit provided in this example achieves the effect of dynamically adjusting the driving voltage according to the current flowing through the driving transistor, avoiding the problem that the driving voltage adjustment is inaccurate due to obtaining the resistance value according to the thermistor to determine the temperature and then adjusting the driving voltage.

Description

Technical Field

[0001] This application relates to the technical field of display panels, and in particular, to a driving circuit, a driving method, and a display panel of a display panel. Background Art

[0002] A commonly used driving method for a liquid crystal display (LCD) is that a small number of gate drivers (gate driver less, GDL) on the display panel generate gate signals step by step to turn on the thin film transistors (TFTs) corresponding to the pixels, so as to realize the function of progressive scanning of the LCD. However, the conduction degree of the TFTs will be affected by temperature. Specifically, at low temperatures, the characteristics of the TFTs will shift, and the conduction characteristics will decrease, thereby affecting the switching characteristics and charging rate of the TFTs of the panel pixels. The decrease in the conduction ability of the TFTs at low temperatures results in the distortion of the gate signals generated by the GDL circuit at low temperatures, which may lead to a decrease in the charging ability of the panel pixels, abnormal pixel display, and even the situation where the pixels cannot be driven to display.

[0003] In the related art, the solution proposed to solve the above problems is to add a temperature compensation circuit on the driving board (PCBA). Through the thermistor arranged on the temperature compensation circuit, different ambient temperatures are sensed, and the resistance value of the thermistor changes with the change of the ambient temperature. Finally, different driving voltages (VGH voltages) are called according to the thermistor resistance value, so that a larger driving voltage (VGH) is input to the GDL at low temperatures to enhance the conduction ability of the GDL and output a normal square wave. At normal or high temperatures, a smaller VGH voltage is input to the GDL to ensure a normal output of the GDL (when the driving ability of the GDL is enhanced at high temperatures, if a larger VGH is still input, it will cause the risk of rising temperature of the panel WOA). However, since the thermistor is usually arranged on the PCB board of the panel, the material of the PCB board and its surrounding environment are different from the environment where the pixels are located. When the pixels are lit, the PCBA is affected by other components and the temperature rises, which affects the temperature of the thermistor, resulting in inaccurate driving voltage output according to the resistance value of the thermistor and causing abnormal pixel display. Summary of the Invention

[0004] This application provides a driving circuit, a driving method, and a display panel of a display panel, which can accurately output a driving voltage according to the ambient temperature, so as to solve the problem in the related art that the driving voltage output according to the resistance value of the thermistor is inaccurate, resulting in abnormal pixel display.

[0005] In a first aspect, the present application provides a driving circuit for a display panel. The driving circuit of the display panel includes: a driving current determination module, a turn-on voltage determination module, and a driving voltage determination module; an input end of the driving current determination module is connected to an output end of the driving voltage determination module, an output end of the driving current determination module is connected to an input end of the turn-on voltage determination module, an output end of the turn-on voltage determination module is connected to the driving voltage determination module, and the output end of the driving voltage determination module is further connected to at least one pixel driving circuit; the driving current determination module is configured to receive a current driving voltage output by the driving voltage determination module, and determine a conduction current based on the current driving voltage and a conduction current coefficient, where the conduction current coefficient is determined based on a conduction parameter of a driving transistor that drives a pixel to emit light in the pixel driving circuit; the turn-on voltage determination module is configured to receive the conduction current and determine a turn-on voltage based on the conduction current; the driving voltage determination module is configured to determine a driving voltage according to the turn-on voltage, and transmit the driving voltage as the current driving voltage to the pixel driving circuit and the driving current determination module respectively.

[0006] In some examples, the driving current determination module includes: a thin-film transistor, and the conduction parameter of the thin-film transistor is the same as that of the driving transistor that drives a pixel to emit light in the pixel driving circuit, where: a control end of the thin-film transistor is connected to the output end of the driving voltage determination module, an input end of the thin-film transistor is connected to the output end of the driving voltage determination module, and an output end of the thin-film transistor is connected to the input end of the turn-on voltage determination module.

[0007] In some examples, the turn-on voltage determination module includes: a voltage determination branch and a voltage output branch, where the output section of the voltage output branch and the input section of the voltage determination branch are connected in parallel to the output end of the driving current determination module, and the output end of the voltage output branch is connected to the driving voltage determination module; where the voltage determination branch is composed of a first grounding resistor.

[0008] In some examples of this embodiment, the driving circuit of the display panel is applied to a display panel. The display panel includes a display area and a non-display area, and the driving current determination module is disposed in the non-display area.

[0009] In some examples of this embodiment, the non-display area is provided with multiple rows of gate driver circuits arranged in sequence, and the driving current determination module is disposed after the last row of the gate driver circuits.

[0010] Second aspect, the present application provides a driving method for a display panel. The driving method for the display panel includes: obtaining a current driving voltage, and determining a conduction current based on the current driving voltage and a conduction current coefficient, where the conduction current coefficient is determined based on the current ambient temperature and the conduction parameters of a driving transistor that drives a pixel to emit light in a pixel driving circuit; determining a turn-on voltage according to the conduction current; determining a driving voltage according to the turn-on voltage, and transmitting the driving voltage as the current driving voltage to the pixel driving circuit.

[0011] In some examples, determining the driving voltage according to the turn-on voltage includes: determining a conduction impedance according to the turn-on voltage; obtaining an input voltage, and determining a driving current according to the input voltage and the conduction impedance; determining the driving voltage based on the driving current.

[0012] In some examples, determining the driving voltage according to the turn-on voltage includes: obtaining a correspondence between a preset voltage range and a driving voltage, where different driving voltages correspond to different voltage ranges; determining a target voltage region corresponding to the turn-on voltage, and determining the driving voltage according to the correspondence and the target voltage region.

[0013] Third aspect, the present application provides a display panel. The display panel includes pixels arranged in an array, each pixel corresponds to a pixel driving circuit, and at least one pixel driving circuit is connected to the driving circuit of the display panel as described in any one of the above.

[0014] In some examples, the display panel includes a display area and a non-display area. The pixels are arranged in the display area, and the driving circuit of the display panel is arranged in the non-display area.

[0015] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0016] In the solution provided by the embodiment of the present application, by sequentially determining the turn-on voltage and the conduction current, since there is an association relationship between the turn-on voltage and the conduction current, and there is a relationship between the conduction current and the current flowing through the driving transistor, thus, the driving voltage determination module can accurately determine the driving voltage according to the turn-on voltage, achieving the effect that when the current flowing through the driving transistor becomes smaller, the driving voltage determination module increases the driving voltage based on the turn-on voltage, so that the current flowing through the driving transistor increases; conversely, when the current flowing through the driving transistor increases, the driving voltage determination module decreases the driving voltage based on the turn-on voltage, so that the current flowing through the driving transistor decreases. The driving circuit of the display panel provided in this example achieves the effect of dynamically adjusting the driving voltage according to the current flowing through the driving transistor, avoiding the problem that the driving voltage adjustment is inaccurate due to obtaining the resistance value according to the thermistor to determine the temperature and then adjusting the driving voltage. Description of the Drawings

[0017] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments in accordance with the present invention, and are used together with the specification to explain the principles of the present invention.

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings required for use in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic diagram of the basic structure of a driving circuit for a display panel provided in Embodiment 1 of the present application;

[0020] Figure 2 It is another schematic diagram of the basic structure of a driving circuit for a display panel provided in Embodiment 1 of the present application;

[0021] Figure 3 It is another schematic diagram of the basic structure of a driving circuit for a display panel provided in Embodiment 1 of the present application;

[0022] Figure 4 It is still another schematic diagram of the basic structure of a driving circuit for a display panel provided in Embodiment 1 of the present application;

[0023] Figure 5 It is a schematic diagram of the basic flow of a driving method for a display panel provided in Embodiment 2 of the present application;

[0024] Figure 6 It is a schematic diagram of the basic structure of a display panel provided in Embodiment 3 of the present application;

[0025] Figure 7 It is a schematic diagram of the basic structure of a display panel provided in Embodiment 4 of the present application;

[0026] Figure 8 It is a schematic diagram of the basic structure of a driving circuit for a display panel provided in Embodiment 4 of the present application;

[0027] Figure 9 It is another schematic diagram of the basic structure of a driving circuit for a display panel provided in Embodiment 4 of the present application;

[0028] Explanation of reference numerals:

[0029] 1 - Driving current determination module; 2 - Turn - on voltage determination module; 3 - Driving voltage determination module; 41 - Display area; 42 - Non - display area; 421 - Gate driving area; 422 - Detection area; 43 - Pixel; 44 - Pixel driving circuit; 15 - External circuit board; 5 - Driving circuit of the display panel; M1 - Thin - film transistor; R1 - First ground resistor; R2 - Second ground resistor; Q1 - Triode; VGH - Driving voltage; Vin - Input voltage; PMIC - Power management integrated module. Detailed implementation manner

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0031] Embodiment 1

[0032] To solve the problem in the related art that the driving voltage output according to the resistance value of the thermistor is inaccurate, resulting in abnormal pixel display, please refer to Figure 1 , Figure 1 A driving circuit of a display panel provided by an embodiment of the present application, as Figure 1 shown, the driving circuit of the display panel includes: a driving current determination module 1, a turn - on voltage determination module 2, and a driving voltage determination module 3;

[0033] The input end of the driving current determination module 1 is connected to the output end of the driving voltage determination module 3, the output end of the driving current determination module 1 is connected to the input end of the turn - on voltage determination module 2, the output end of the turn - on voltage determination module 2 is connected to the driving voltage determination module 3, and the output end of the driving voltage determination module 3 is also connected to at least one pixel driving circuit;

[0034] The driving current determination module 1 is configured to receive the current driving voltage VGH output by the driving voltage determination module 3, and determine the conduction current based on the current driving voltage VGH and the conduction current coefficient, where the conduction current coefficient is determined based on the current ambient temperature and the conductive parameters of the driving transistor that drives the pixel to emit light in the pixel driving circuit;

[0035] The turn - on voltage determination module 2 is configured to receive the conduction current and determine the turn - on voltage based on the conduction current;

[0036] The driving voltage determination module 3 is configured to determine a driving voltage VGH according to the turn-on voltage, and transmit the driving voltage VGH as the current driving voltage VGH to the pixel driving circuit and the driving current determination module 1 respectively.

[0037] Among them, both the driving current determination module 1 and the pixel driving circuit receive the driving voltage VGH from the driving voltage determination module 3. Therefore, the driving current determination module 1 and the pixel driving circuit receive the same current driving voltage VGH. The above conduction current coefficient is determined based on the current ambient temperature and the conduction parameters of the driving transistor for driving the pixel to emit light. That is, the conduction current coefficient is related to the conduction of the driving transistor. When the current driving voltage VGH is the same and the conduction current coefficient is related to the conduction coefficient, the determined conduction current is related to the current flowing through the driving transistor. For example, the current flowing through the driving transistor is directly proportional to the conduction current. That is, the larger the current flowing through the driving transistor, the larger the conduction current; the smaller the current flowing through the driving transistor, the smaller the determined conduction current. For another example, the current flowing through the driving transistor is inversely proportional to the conduction current. In some examples, it may also be that the determined conduction current is equal to the current flowing through the driving transistor. Hereinafter, the case where the current flowing through the driving transistor is directly proportional to the conduction current will be described.

[0038] Among them, the turn-on voltage determination module 2 is configured to receive the conduction current and determine the turn-on voltage based on the conduction current. That is, the turn-on voltage is related to the conduction current. For example, the turn-on voltage is directly proportional to the conduction current. That is, the larger the conduction current, the larger the turn-on voltage; the smaller the conduction current, the smaller the turn-on voltage. For another example, the turn-on voltage is inversely proportional to the conduction current. Finally, the driving voltage determination module 3 determines the driving voltage VGH according to the turn-on voltage. Since the turn-on voltage is related to the conduction current and the conduction current is related to the current flowing through the driving transistor, the driving voltage determination module 3 can accurately determine the driving voltage VGH according to the turn-on voltage, achieving the effect that when the current flowing through the driving transistor becomes smaller, the driving voltage determination module 3 increases the driving voltage VGH based on the turn-on voltage, so that the current flowing through the driving transistor increases; conversely, when the current flowing through the driving transistor increases, the driving voltage determination module 3 decreases the driving voltage VGH based on the turn-on voltage, so that the current flowing through the driving transistor decreases. The driving voltage VGH determination circuit provided in this example achieves the effect of dynamically adjusting the driving voltage VGH according to the current flowing through the driving transistor, avoiding the problem that the driving voltage VGH adjustment is inaccurate due to obtaining the resistance value according to the thermistor to determine the temperature and adjusting the driving voltage VGH.

[0039] In some examples of this embodiment, such as Figure 2As shown, the drive current determination module 1 includes: a thin-film transistor M1, and the conductive parameters of the thin-film transistor M1 are the same as those of the drive transistor that drives the pixel to emit light in the pixel drive circuit, where:

[0040] The control terminal of the thin-film transistor M1 is connected to the output terminal of the drive voltage determination module 3, the input terminal of the thin-film transistor M1 is connected to the output terminal of the drive voltage determination module 3, and the output terminal of the thin-film transistor M1 is connected to the input terminal of the turn-on voltage determination module 2.

[0041] Among them, the conductive parameters of the thin-film transistor M1 are the same as those of the drive transistor, that is, the material, manufacturing process, etc. of the thin-film transistor M1 of the drive current determination module 1 are the same as those of the drive transistor, so that the drive current determination module 1 and the thin-film transistor are affected by temperature similarly; in some examples, at the same temperature, if the same drive voltage VGH is received, the current passing through the thin-film transistor M1 is the same as the current passing through the drive transistor; in some examples, the current passing through the thin-film transistor M1 and the current passing through the drive transistor have a correlation. For example, assuming that the drive voltage VGH is constant temperature, if the ambient temperature becomes low, the current passing through the drive transistor decreases, and the corresponding current passing through the thin-film transistor M1 also decreases; if the ambient temperature becomes high, the current passing through the drive transistor increases, and the corresponding current passing through the thin-film transistor M1 also increases.

[0042] It can be understood that the drive current determination module 1 provided in this embodiment is disposed on the display panel. Specifically, the display panel is divided into a display area and a non-display area. The display area is the area where pixels are set, and there are fewer gate driver less (GDL) circuits in the non-display area. The drive current determination module 1 of the display panel provided in this embodiment is also disposed in the non-display area;

[0043] In some examples, the non-display area is provided with multiple rows of gate driver circuits arranged in sequence, and the drive current determination module 1 of the display panel is disposed after the last row of the gate driver circuits. For example, if the non-display area of the display panel is provided with N rows of gate driver circuits arranged in sequence, then the drive current determination module 1 of the display panel is disposed after the Nth row of gate driver circuits. Other parts of the drive circuit of the display panel are disposed on the circuit board of the external circuit, such as areas like the printed circuit board S4 or the drive panel S6.

[0044] Continuing with the above example, the output terminal of the thin-film transistor M1 is connected to the output terminal of the driving voltage determination module 3, and the control terminal of the thin-film transistor M1 is also connected to the output terminal of the driving voltage determination module 3. When the control terminal and the input terminal of the thin-film transistor M1 receive the current driving voltage VGH output by the driving voltage determination module 3, the thin-film transistor M1 will be in the on state and output an on-current. It can be understood that the higher the current driving voltage VGH, the more current the driving transistor outputs, the higher the conduction degree of the thin-film transistor M1, and the higher the output on-current. Conversely, the lower the current driving voltage VGH, the less current the driving transistor outputs, the lower the conduction degree of the corresponding thin-film transistor M1, and the lower the output on-current.

[0045] It can be understood that this embodiment does not limit the thin-film transistor M1, nor does it limit the type of the thin-film transistor M1. The thin-film transistor M1 described in this embodiment can be a P-type thin-film transistor M1 (P-type thin-film-transistor, P-type TFT) or an N-type thin-film transistor M1 (N-type thin-film-transistor, N-type TFT). At the same time, the thin-film transistor M1 provided in this embodiment can be fabricated using low-temperature polycrystalline silicon (LTPS), amorphous silicon (a-Si), or amorphous indium gallium tin metal oxide (a-IGZO) thin-film transistor (TFT) manufacturing technology, but is not limited thereto. Similarly, this embodiment also does not limit the type of the driving transistor that drives the pixel to emit light in the pixel driving circuit.

[0046] In some examples of this embodiment, as Figure 2 shown, the turn-on voltage determination module 2 includes: a voltage determination branch and a voltage output branch. Among them, the input terminals of the voltage output branch and the voltage determination branch are connected in parallel to the output terminal of the driving current determination module 1, and the output terminal of the voltage output branch is connected to the driving voltage determination module 3. Among them, the voltage determination branch is composed of a first grounding resistor R1. As Figure 2As shown, the voltage determination branch is composed of a first grounding resistor R1. The resistance value of the first grounding resistor R1 is fixed. When the conduction current output by the drive current determination module 1 is fixed, the voltage at the output end of the drive current determination module 1 can be obtained according to the conduction current and the resistance value of the first grounding resistor R1. Specifically, the conduction current output by the drive current determination module 1 is denoted as I, and the resistance value of the first grounding resistor R1 is denoted as R. Then, the voltage U at the output end of the drive current determination module 1 = conduction current I * resistance R of the first grounding resistor R1. At this time, since the input segments of the voltage output branch and the voltage determination branch are connected in parallel at the output end of the drive current determination module 1, the voltage of the voltage output branch is also equal to conduction current I * resistance R of the first grounding resistor R1.

[0047] Continuing from the above example, according to the formula that the voltage U at the output end of the drive current determination module 1 = conduction current I * resistance R of the first grounding resistor R1, when the conduction current I decreases, the voltage U at the output end of the drive current determination module 1 naturally decreases; conversely, when the conduction current I increases, the voltage U at the output end of the drive current determination module 1 naturally increases.

[0048] It can be understood that the resistance value of the first grounding resistor R1 in this embodiment is not limited and can be flexibly set by relevant personnel according to actual usage requirements.

[0049] In some examples of this embodiment, as Figure 3 shown, the drive voltage determination module 3 includes: a triode Q1, a second grounding resistor R2, and a drive voltage VGH output branch. Among them, the control end of the triode Q1 is connected to the output end of the turn-on voltage determination module 2, the input end of the triode Q1 is connected to the input voltage Vin, the output end of the triode Q1 is connected to the second grounding resistor R2, the input end of the drive circuit output branch is connected in parallel with the second grounding resistor R2 at the output end of the triode Q1, and the output end of the drive circuit output branch is respectively connected to the pixel drive circuit and the input end of the drive current determination module 1.

[0050] It can be understood that the condition for the triode Q1 to conduct is Ue - Ub > 0.7V, where Ue is the voltage of the emitter, that is, the output terminal, and Ub is the voltage of the base, that is, the control terminal. According to the above formula, on the basis of satisfying Ue - Ub > 0.7V, the greater the voltage difference between Ue and Ub, the higher the conduction degree, and the smaller the impedance of the triode Q1; conversely, the smaller the voltage difference between Ue and Ub, the lower the conduction degree, and the higher the impedance of the triode Q1. Specifically, if the voltage output by the output terminal of the turn-on voltage determination module 2 is higher, the voltage received by the control terminal of the triode Q1 is greater, that is, Ub is greater. The greater Ub is, the smaller the difference between Ue and Ub, and finally the greater the impedance of the triode Q1; conversely, if the voltage output by the output terminal of the turn-on voltage determination module 2 is lower, the voltage received by the control terminal of the triode Q1 is lower. The smaller the voltage received by the control terminal of the triode Q1 is, that is, Ub is smaller. The smaller Ub is, the greater the difference between Ue and Ub, and finally the smaller the impedance of the triode Q1. The method for determining the conduction impedance according to Ue, Ub, and other parameters of the triode Q1 is not limited in this embodiment and can be flexibly set by relevant personnel. It is certain without doubt that the greater the turn-on voltage, the greater the conduction impedance, and the lower the turn-on voltage, the smaller the conduction impedance.

[0051] Continuing from the above example, since the triode Q1 and the second grounding resistor R2 together form a series circuit, and the current in the series circuit is the same everywhere and equal to the loop current. Therefore, the current passing through the triode Q1 can be determined according to the input voltage Vin, the impedance of the triode Q1, and the resistance value of the second grounding resistor R2. Specifically, the impedance of the triode Q1 is denoted as Rbe, the resistance value of the second grounding resistor R2 is denoted as R2, and the input voltage Vin is denoted as Vin. Then, at this time, the current passing through the triode Q1 is Vin / (Rbe + R2). After obtaining the current of the triode Q1, based on the resistance value of the second grounding resistor R2, the voltage at the output terminal of the triode Q1 can be obtained. Specifically: the voltage U at the output terminal of the triode Q1 = Vin / (Rbe + R2) * R2. Among them, since the input terminal of the output branch of the drive circuit is connected in parallel with the second grounding resistor R2 at the output terminal of the triode Q1, the drive voltage VGH output by the input terminal of the output branch of the drive circuit is also equal to Vin / (Rbe + R2) * R2.

[0052] For better understanding, the following will be described by taking the case where the current flowing through the driving transistor is directly proportional to the conduction current, the conduction current is directly proportional to the switching voltage, and the switching voltage is directly proportional to the driving voltage VGH as an example. Among them, the driving voltage determination module 3 outputs the current driving voltage VGH. If the current environment is in a low-temperature state, the conduction ability of the driving transistor decreases, the current flowing through the driving transistor decreases, and at this time the conduction current decreases proportionally. The conduction current transmitted by the driving current determination module 1 to the turn-on voltage determination module 2 decreases. The turn-on voltage determined by the turn-on voltage determination module 2 according to the conduction current decreases. When the turn-on voltage decreases, the impedance of the triode Q1 in the driving voltage determination module 3 decreases. Thus, the driving voltage VGH determined by the driving voltage determination module 3 increases, realizing an increase in the driving voltage VGH transmitted to the driving transistor in the pixel driving circuit, increasing the current flowing through the driving transistor, ensuring the normal display of the pixel, and avoiding the problem that in a low-temperature state, the conduction ability of the driving transistor decreases, and using the original driving voltage VGH results in too little current flowing through the driving transistor, leading to abnormal pixel display. At the same time, it avoids the problem that the driving voltage VGH is inaccurate according to the resistance value of the thermistor, resulting in abnormal pixel display; similarly, if the current environment is in a high-temperature state, the conduction ability of the driving transistor increases, the current flowing through the driving transistor increases, and at this time the conduction current increases proportionally. The conduction current transmitted by the driving current determination module 1 to the turn-on voltage determination module 2 increases. The turn-on voltage determined by the turn-on voltage determination module 2 according to the conduction current increases. When the turn-on voltage increases, the impedance of the triode Q1 in the driving voltage determination module 3 increases. Thus, the driving voltage VGH determined by the driving voltage determination module 3 decreases, reducing the driving voltage VGH transmitted to the driving transistor in the pixel driving circuit, reducing the current flowing through the driving transistor, ensuring the normal display of the pixel, and avoiding the problem that in a low-temperature state, the conduction ability of the driving transistor decreases, and using the original driving voltage VGH results in too much current flowing through the driving transistor, leading to abnormal pixel display. At the same time, it avoids the problem that the driving voltage VGH is inaccurate according to the resistance value of the thermistor, resulting in abnormal pixel display.

[0053] In some examples of this embodiment, such as Figure 4As shown in the figure, the driving voltage determination module 3 includes a power management integrated circuit (PMIC). The input terminal of the PMIC is connected to the output terminal of the turn-on voltage determination module 2, and the output terminal of the PMIC is respectively connected to the pixel driving circuit and the input terminal of the driving current determination module 1. Among them, the PMIC is used to output the driving voltage VGH according to the received turn-on voltage. Specifically, when the PMIC sets a reference voltage, when the received turn-on voltage is higher than the reference voltage, the output driving voltage VGH is decreased; when the received turn-on voltage is lower than the reference voltage, the output driving voltage VGH is increased.

[0054] Continuing with the above example, in some examples, the PMIC can also set multiple voltage ranges, and a corresponding driving voltage VGH is set for each voltage range. When the turn-on voltage falls into the corresponding voltage range, the PMIC outputs the corresponding driving voltage VGH. For example, the PMIC sets multiple voltage ranges. When the turn-on voltage is in the first voltage range, the PMIC outputs the first driving voltage VGH; when the turn-on voltage is in the second voltage range, the PMIC outputs the second driving voltage VGH, and so on. In this way, the problem of inaccurate driving voltage VGH caused by outputting the driving voltage VGH according to the resistance value of the thermistor and resulting in abnormal pixel display is avoided.

[0055] For the driving circuit of the display panel provided in this embodiment, by sequentially determining the turn-on voltage and the conduction current, since there is a correlation between the turn-on voltage and the conduction current, and there is a relationship between the conduction current and the current flowing through the driving transistor, thus, the driving voltage determination module can accurately determine the driving voltage according to the turn-on voltage. When the current flowing through the driving transistor becomes smaller, the driving voltage determination module increases the driving voltage based on the turn-on voltage, so that the current flowing through the driving transistor increases; conversely, when the current flowing through the driving transistor increases, the driving voltage determination module decreases the driving voltage based on the turn-on voltage, so that the current flowing through the driving transistor decreases. The driving circuit of the display panel provided in this example achieves the effect of dynamically adjusting the driving voltage according to the current flowing through the driving transistor, and avoids the problem of inaccurate driving voltage adjustment caused by obtaining the resistance value according to the thermistor to determine the temperature and then adjusting the driving voltage.

[0056] Embodiment 2

[0057] Based on the same concept, as Figure 5 shown in the figure, this embodiment provides a driving method for a display panel. The driving method for the display panel includes:

[0058] S101. Obtain the current driving voltage, and determine the conduction current based on the current driving voltage and the conduction current coefficient, where the conduction current coefficient is determined based on the current ambient temperature and the conduction parameters of the driving transistor that drives the pixel to emit light in the pixel driving circuit;

[0059] S102. Determine the turn-on voltage according to the conduction current;

[0060] S103. Determine the driving voltage according to the turn-on voltage, and transmit the driving voltage as the current driving voltage to the pixel driving circuit.

[0061] It can be understood that the driving method of the display panel provided in this embodiment can be applied to the driving circuit of the display panel as described above.

[0062] Among them, there is a correlation between the conduction current coefficient and the conductivity of the driving transistor. When the current driving voltage is the same and there is a correlation between the conduction current coefficient and the conductivity coefficient, the determined conduction current is correlated with the current flowing through the driving transistor; for example, the current flowing through the driving transistor is proportional to the conduction current, that is, the larger the current flowing through the driving transistor, the larger the conduction current, and the smaller the current flowing through the driving transistor, the smaller the determined conduction current; for another example, the current flowing through the driving transistor is inversely proportional to the conduction current. In some examples, it can also be that the determined conduction current is equal to the current flowing through the driving transistor. The following will be described with the current flowing through the driving transistor being proportional to the conduction current;

[0063] It can be understood that since the conduction current is proportional to the current flowing through the driving transistor, the magnitude of the conduction current can represent the magnitude of the current flowing through the driving transistor;

[0064] In some examples, determining the turn-on voltage according to the conduction current includes: determining the fixed resistance value of the first grounding resistor, and determining the turn-on voltage based on the fixed resistance value and the conduction current; specifically, record the conduction current as I and the resistance value of the first grounding resistor as R, then the turn-on voltage U = conduction current I * resistance R of the first grounding resistor. It can be understood that the turn-on voltage is proportional to the conduction current, that is, the larger the conduction current, the larger the turn-on voltage, and the smaller the conduction current, the smaller the turn-on voltage.

[0065] In some examples of this embodiment, determining the driving voltage according to the turn-on voltage includes: determining the conduction impedance according to the turn-on voltage; obtaining the input voltage, and determining the driving current according to the input voltage and the conduction impedance; determining the driving voltage based on the driving current. Among them, the above-mentioned conduction impedance is the conduction impedance of a triode. Since the condition for the triode to conduct is Ue - Ub > 0.7V, where Ue is the voltage of the emitter, that is, the output terminal, and Ub is the voltage of the base, that is, the control terminal. According to the above formula, on the basis of satisfying Ue - Ub > 0.7V, the greater the voltage difference between Ue and Ub, the higher the conduction degree, and the smaller the impedance of the triode; conversely, the smaller the voltage difference between Ue and Ub, the lower the conduction degree, and the higher the impedance of the triode.

[0066] Continuing with the above example, where the base of the triode is connected to the turn-on voltage. If the turn-on voltage is higher, the voltage received by the control terminal of the triode is greater, that is, Ub is greater. The greater Ub is, the smaller the difference between Ue and Ub, and finally the greater the impedance of the triode; conversely, if the turn-on voltage is lower, the voltage received by the control terminal of the triode is lower. The lower the voltage received by the control terminal of the triode, that is, Ub is smaller. The smaller Ub is, the greater the difference between Ue and Ub, and finally the smaller the impedance of the triode. The method for determining the conduction impedance according to Ue, Ub and other parameters of the triode is not limited in this embodiment and can be flexibly set by relevant personnel. It is certain beyond doubt that the greater the turn-on voltage, the greater the conduction impedance, and the lower the turn-on voltage, the smaller the conduction impedance.

[0067] Among them, after determining the conduction impedance, obtain the input voltage, and determine the driving current according to the input voltage and the conduction impedance. Specifically, for example, connect a second grounding resistor at the output terminal of the triode to form a series circuit together. The current in the series circuit is the same everywhere and equal to the loop current. Therefore, the current passing through the triode can be determined according to the input voltage, the impedance of the triode and the resistance value of the second grounding resistor. Specifically as follows, denote the impedance of the triode as Rbe, the resistance value of the second grounding resistor as R2, and the input voltage as Vin. Then, the current passing through the triode at this time is Vin / (Rbe + R2). After obtaining the current of the triode, based on the resistance value of the second grounding resistor, the voltage at the output terminal of the triode can be obtained. Specifically as follows: The voltage U at the output terminal of the triode = Vin / (Rbe + R2) * R2. Then, connect a driving circuit output branch in parallel at the output terminal of the triode, and use the voltage at the output terminal of the triode as the driving voltage output.

[0068] For better understanding, the following will take the relationships that the current flowing through the driving transistor is directly proportional to the conduction current, the conduction current is directly proportional to the switching voltage, and the switching voltage is directly proportional to the driving voltage as examples for illustration. Among them, in the current low-temperature environment, the conduction ability of the driving transistor decreases. Based on the current driving voltage, the current flowing through the driving transistor decreases, resulting in abnormal pixel display. At this time, the conduction current decreases proportionally. Since the conduction current decreases, the turn-on voltage that is directly proportional to the conduction current decreases. When the turn-on voltage decreases, the impedance of the triode decreases. Thus, the finally determined driving voltage increases, increasing the driving voltage transmitted to the driving transistor in the pixel driving circuit, making the current flowing through the driving transistor increase, ensuring normal pixel display, and avoiding the problem that in the low-temperature state, the conduction ability of the driving transistor decreases, and using the original driving voltage causes too little current to flow through the driving transistor, resulting in abnormal pixel display. At the same time, it avoids the problem that the driving voltage is inaccurate due to the driving voltage being output according to the resistance value of the thermistor, resulting in abnormal pixel display. Similarly, in the current high-temperature environment, the conduction ability of the driving transistor increases. Based on the current driving voltage, the current flowing through the driving transistor increases, resulting in abnormal pixel display. At this time, the conduction current increases proportionally. Since the conduction current increases, the turn-on voltage that is directly proportional to the conduction current increases. When the turn-on voltage increases, the impedance of the triode increases. Thus, the finally determined driving voltage decreases, reducing the driving voltage transmitted to the driving transistor in the pixel driving circuit, making the current flowing through the driving transistor decrease, ensuring normal pixel display, and avoiding the problem that in the low-temperature state, the conduction ability of the driving transistor decreases, and using the original driving voltage causes too much current to flow through the driving transistor, resulting in abnormal pixel display. At the same time, it avoids the problem that the driving voltage is inaccurate due to the driving voltage being output according to the resistance value of the thermistor, resulting in abnormal pixel display.

[0069] In some examples of this embodiment, determining the driving voltage according to the turn-on voltage includes: obtaining the correspondence between the preset voltage range and the driving voltage, where different driving voltages correspond to different voltage ranges; determining the target voltage region corresponding to the turn-on voltage, and determining the driving voltage according to the correspondence and the target voltage region.

[0070] Specifically, obtain the correspondence between the preset voltage range and the driving voltage. Among them, a corresponding driving voltage is set for each voltage range. When the turn-on voltage falls within the corresponding voltage range, the corresponding driving voltage is output according to the corresponding voltage range, thereby avoiding the problem that the driving voltage is inaccurate due to the driving voltage being output according to the resistance value of the thermistor, resulting in abnormal pixel display.

[0071] Among them, in the driving method of the display panel provided in this embodiment, by sequentially determining the turn-on voltage and the conduction current, since there is a correlation between the turn-on voltage and the conduction current, and there is a correlation between the conduction current and the current flowing through the driving transistor, the finally determined driving voltage is related to the current flowing through the driving transistor. Furthermore, when the current flowing through the driving transistor decreases, the driving voltage is increased based on the turn-on voltage, so that the current flowing through the driving transistor increases; conversely, when the current flowing through the driving transistor increases, the driving voltage is decreased based on the turn-on voltage, so that the current flowing through the driving transistor decreases. The driving method of the display panel provided in this example achieves the effect of dynamically and accurately adjusting the driving voltage according to the current flowing through the driving transistor, avoiding the problem that the driving voltage adjustment is inaccurate due to obtaining the resistance value according to the thermistor to determine the temperature and then adjusting the driving voltage.

[0072] Embodiment III

[0073] An embodiment of the present application provides a display panel, as Figure 6 shown, the display panel includes pixels 43 arranged in an array, each pixel 43 corresponds to a pixel driving circuit 44, and at least one pixel driving circuit 44 is connected to the driving circuit 5 of the display panel according to any one of the above embodiments.

[0074] In some examples, the display panel includes a display area 41 and a non-display area 42. The pixels 43 are arranged in the display area 41. The non-display area 42 of the display panel includes a gate driving area 421 and a detection area 422. A gate driver (gate driver less, GDL) circuit is provided in the gate driving area. A driving current determination module is provided in the detection area 422. That is, the driving current determination module in the driving circuit 5 of the display panel is arranged after the last row of the gate driver circuit, and other parts of the driving circuit of the display panel are arranged on the external circuit board 45.

[0075] Embodiment IV

[0076] To better understand the present invention, this example provides a more specific example for illustration: as Figure 7 shown, Figure 7 shown is a basic schematic diagram of a display panel provided by this solution. As Figure 7 shown, the display panel includes: a display area and a non-display area. Among them, a GDL driving circuit S1 is provided in the non-display area. The GDL driving circuit is used to generate GATE signals step by step. A driving circuit of the display panel is also provided in the non-display area. The driving circuit of the display panel is arranged as Figure 7Regions such as S4 / S6 shown; the display panel further includes: a driving chip S3, a printed circuit board S4 (Printed Circuit Board, PCB), a flexible printed circuit S5 (Flexible Flat Cable, FFC), and a driving panel S6. Among them, the driving panel S6 is connected to the flexible printed circuit S5, the flexible printed circuit S5 is connected to the printed circuit board S4, the printed circuit board S4 is connected to the display panel through the driving chip S3, and the driving chip S3 is disposed on the COF (chip on film).

[0077] As Figure 8 shown is a basic schematic diagram of a driving circuit of a display panel provided in this example. Among them, the thin-film transistor M1 is a detection MOS transistor made on the display panel, and M1 is disposed in the non-display area of the display panel. A GDL circuit is provided in the non-display area. The position of M1 can be any position in the GDL area on both sides of the panel. The position of M1 is preferably after the last effective GDL output module (refer to Figure 7 , that is, disposed in Figure 7 the S2 area in). The gate and drain of M1 are both VGH inputs of the GDL circuit. Among them, the position of the thin-film transistor M1 is in the S2 area, that is, the above-mentioned thin-film transistor M1 is disposed after the last GDL position and does not generate a gate drive signal to the display panel. The thin-film transistor M1 is only used to detect the VGH output by the gate driver circuit. Q1 is a PNP triode operating in the amplification region. Among them, the change in the voltage VT at the output end of M1 will cause the conduction impedance Vbe of the triode to change accordingly. The smaller VT is, the smaller the conduction impedance Vbe is, and vice versa.

[0078] In this application, by disposing the detection MOS transistor in the GDL area (gate drive circuit area) of the panel and after the last effective output module in the GDL area, the detection MOS transistor is connected to each stage of GDL. However, the detection MOS transistor is independent, that is, the detection MOS transistor does not participate in the work and signal transmission of each stage of GDL. The detection MOS transistor receives the same VGH as each stage of GDL circuit. Since there are many chips and traces on the external circuit, the heat generation is greater than that in the display panel and the GDL areas on both sides of the display panel. Therefore, the temperature in the display panel is more real than the temperature of the external circuit environment such as the external circuit board. At this time, the current detected by the detection MOS transistor can more accurately reflect the VGH required by the GDL circuit and the VGH required by the thin-film transistor in the panel pixel.

[0079] Among them, as Figure 8 shown, Figure 8 shown, R1 is the first grounding resistor of the external drive board and serves as a voltage-dividing resistor to generate VT. R2 is the second grounding resistor under the emitter of the triode;

[0080] Vin is the input voltage applied to the input terminal of the triode, and VGH can be generated through the second grounding resistor;

[0081] Specifically, when in a low-temperature state, the conduction ability of the driving transistor on the display panel decreases, and at the same time, the conduction ability of M1 decreases. At this time, the current in the circuit loop M1→R1→GND decreases. Since the resistance value of R1 remains fixed, the generated VT voltage decreases.

[0082] At this time, due to the decrease of VT, the conduction impedance of the triode Q1 decreases, and finally the output VGH increases. Specifically as follows:

[0083] VGH = R2 * Vin / (Rbe + R2);

[0084] Among them, in the above formula, Rbe is the conduction impedance of the triode, R2 is the resistance value of the second grounding resistor, and Vin is the input voltage.

[0085] When in a high-temperature state, the conduction ability of the driving transistor on the display panel increases, that is, the conduction ability of M1 increases. At this time, the current in the circuit loop M1→R1→GND increases. At this time, due to the increase of VT, the conduction impedance of the triode Q1 increases, and finally the output VGH decreases.

[0086] When VGH increases, the heat generation of the entire panel increases. However, the WOA (wire on Array) area is more likely to cause heat generation due to thinner traces. And when the temperature rises, VGH will further increase, which will lead to a further increase in the heat generation of the WOA area. And too high a temperature in the WOA area may cause abnormal display. Therefore, while adjusting and reducing VGH in this application, it can also reduce the temperature of the WOA area of the display panel, improve the tolerance and normal display of the display panel at high temperatures.

[0087] See Figure 9 , as Figure 9 shown is a basic schematic diagram of a driving circuit of a display panel provided by this example. Among them, as Figure 9 shown, in this example, the power management integrated module PMIC outputs the driving voltage VGH. Specifically, at different temperatures, the output VT is different. At this time, the PMIC has an internal algorithm, and the PMIC outputs different VGH according to different input VT. For example, when VT drops, the VGH output is increased.

[0088] The specific algorithm can be further expanded.

[0089] For example, first set a reference value and different temperature ranges, determine the corresponding stage according to the temperature range corresponding to VT, and determine VGH according to the stage where it is located. Specifically as follows:

[0090] When VT is in the first stage, the amplitude of increasing VGH is A * reference value;

[0091] When VT is in the second stage, the amplitude of increasing VGH is B * reference value, and B is less than A. Because a large VT indicates a high temperature at this time, a relatively small increase in VGH is required for compensation;

[0092] It can be extended sequentially...

[0093] In this example, a thin-film transistor M1 is designed on the panel. The thin-film transistor M1 receives the same driving voltage VGH as the current in the GDL area of the panel. By detecting the conduction current of this MOS transistor (i.e., the thin-film transistor M1), the conduction ability of the driving transistor inside the GDL module is judged. When the temperature is low, the conduction ability of the MOS transistor decreases, and the VGH voltage is increased to improve the GDL driving ability to avoid the distortion of the gate signal of the GDL circuit; when the temperature is high, the conduction ability increases, and the VGH voltage is decreased to reduce the GDL driving ability. Without affecting the driving of the GDL circuit, the temperature of the WOA area of the panel is reduced to avoid display abnormalities caused by too high a temperature in the WOA area. In this application, by setting the MOS transistor on the panel, the technical effects of accurately compensating the VGH driving voltage and dynamically reducing the temperature of the WOA area of the panel to improve the high-temperature tolerance of the panel are achieved. Specifically, by sequentially determining the turn-on voltage and the conduction current, since there is a correlation between the turn-on voltage and the conduction current, and there is a correlation between the conduction current and the current flowing through the driving transistor, the finally determined driving voltage is related to the current flowing through the driving transistor. Furthermore, when the current flowing through the driving transistor becomes smaller, the driving voltage is increased based on the turn-on voltage, so that the current flowing through the driving transistor increases; conversely, when the current flowing through the driving transistor increases, the driving voltage is decreased based on the turn-on voltage, so that the current flowing through the driving transistor decreases. The driving method of the display panel provided in this example achieves the effect of dynamically and accurately adjusting the driving voltage according to the current flowing through the driving transistor, and the circuit structure design is simple, avoiding the problem of inaccurate driving voltage adjustment caused by obtaining the resistance value according to the thermistor to determine the temperature and then adjusting the driving voltage.

[0094] Example Five

[0095] The embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the driving method of the display panel provided in any one of the foregoing method embodiments are implemented.

[0096] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0097] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A driving circuit for a display panel, characterized in that, The driving circuit of the display panel includes: a driving current determination module, a turn-on voltage determination module, and a driving voltage determination module; The input end of the driving current determination module is connected to the output end of the driving voltage determination module, the output end of the driving current determination module is connected to the input end of the turn-on voltage determination module, the output end of the turn-on voltage determination module is connected to the driving voltage determination module, and the output end of the driving voltage determination module is further connected to at least one pixel driving circuit; The driving current determination module is configured to receive the current driving voltage output by the driving voltage determination module, and determine a conduction current based on the current driving voltage and a conduction current coefficient, where the conduction current coefficient is determined based on the current ambient temperature and the conduction parameters of a driving transistor that drives a pixel to emit light in the pixel driving circuit; The turn-on voltage determination module is configured to receive the conduction current and determine a turn-on voltage based on the conduction current; The driving voltage determination module is configured to determine a driving voltage based on the turn-on voltage, and transmit the driving voltage as the current driving voltage to the pixel driving circuit and the driving current determination module respectively.

2. The circuit according to claim 1, wherein The driving current determination module includes: a thin-film transistor, and the conduction parameters of the thin-film transistor are the same as those of the driving transistor that drives a pixel to emit light in the pixel driving circuit, where: The control end of the thin-film transistor is connected to the output end of the driving voltage determination module, the input end of the thin-film transistor is connected to the output end of the driving voltage determination module, and the output end of the thin-film transistor is connected to the input end of the turn-on voltage determination module.

3. The circuit according to claim 1, characterized in that, The turn-on voltage determination module includes: a voltage determination branch and a voltage output branch, where the output section of the voltage output branch and the input section of the voltage determination branch are connected in parallel to the output end of the driving current determination module, and the output end of the voltage output branch is connected to the driving voltage determination module; Wherein, the voltage determination branch is composed of a first grounding resistor.

4. The circuit according to claim 2, wherein The driving voltage determination module includes: a triode, a second grounding resistor, and a driving voltage output branch, where the control end of the triode is connected to the output end of the turn-on voltage determination module, the input end of the triode is connected to an input voltage, the output end of the triode is connected to the second grounding resistor, the input end of the driving circuit output branch is connected in parallel to the output end of the triode with the second grounding resistor, and the output end of the driving circuit output branch is connected to the input ends of the pixel driving circuit and the driving current determination module respectively.

5. The circuit according to claim 2, wherein The driving voltage determination module includes: a power management integrated module, the input end of the power management integrated module is connected to the output end of the turn-on voltage determination module, and the output end of the power management integrated module is connected to the input ends of the pixel driving circuit and the driving current determination module respectively.

6. The circuit according to any one of claims 1-5, characterized in that, The driving circuit of the display panel is applied to a display panel, the display panel includes a display area and a non-display area, and the driving current determination module is disposed in the non-display area.

7. The circuit according to claim 6, wherein The non-display area is provided with multiple rows of gate driver circuits arranged in sequence, and the driving current determination module is arranged after the last row of the gate driver circuits.

8. A driving method for a display panel, characterized in that, The driving method of the display panel includes: Obtaining a current driving voltage, and determining a conduction current based on the current driving voltage and a conduction current coefficient, where the conduction current coefficient is determined based on the current ambient temperature and the conduction parameters of a driving transistor that drives a pixel to emit light in the pixel driving circuit; Determining a turn-on voltage according to the conduction current; Determining a driving voltage according to the turn-on voltage, and transmitting the driving voltage as the current driving voltage to the pixel driving circuit.

9. A display panel, characterized in that, The display panel includes pixels arranged in an array, each pixel corresponds to a pixel driving circuit, and at least one pixel driving circuit is connected to the driving circuit of the display panel according to any one of claims 1-5.

10. The display panel according to claim 9, wherein, The display panel includes a display area and a non-display area, the pixels are arranged in the display area, and the driving circuit of the display panel is arranged in the non-display area.

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