Driving circuit and display panel

Abstract

The invention provides a driving circuit and a display panel. The driving circuit provided by the invention comprises a temperature detection circuit, a temperature compensation detection circuit and a temperature compensation circuit, the temperature detection circuit comprises a thermistor, and the temperature compensation detection circuit is connected with the temperature detection circuit; the temperature compensation detection circuit comprises a voltage detection circuit which is connected with the thermistor and is used for detecting the voltage of the thermistor; the output circuit is connected with the output end of the voltage detection circuit and the output end of the temperature compensation detection circuit and used for outputting a control signal of a first state or a control signal of a second state based on the voltage of the thermistor, the control signal of the first state indicates that the temperature compensation circuit is enabled to output grid driving voltage, and the control signal of the second state indicates that the temperature compensation circuit is enabled to output grid driving voltage. And the control signal in the second state indicates to close the temperature compensation circuit. Therefore, when the temperature compensation is not needed, the temperature compensation circuit is forbidden to output the gate driving voltage, the instability of the gate driving voltage is avoided, and the display effect is improved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a driving circuit and a display panel. Background Art

[0002] In the field of TFT-LCD (thin-film transistor liquid crystal display), the threshold voltage (Vth) of the TFT will shift with temperature changes. At low temperatures, the carrier mobility of the semiconductor material decreases, causing the threshold voltage to show an opposite trend (i.e., the lower the temperature, the lower the threshold voltage). In this case, if the gate drive voltage (VGH) designed for normal temperature is still used, it will not provide a sufficient gate-source voltage difference (VGH-Vth) for the TFT, resulting in the TFT not being able to fully conduct, resulting in response delays and reduced display brightness.

[0003] Existing designs typically utilize the temperature compensation function of the PowerIC, setting a negative temperature coefficient thermistor to detect the thermistor's voltage as the temperature changes in real time. As the temperature of the thermistor increases, its resistance decreases, resulting in a decrease in voltage. Meanwhile, as the temperature decreases, its resistance increases, resulting in a corresponding increase in voltage. Therefore, when performing temperature compensation, the set low- and high-temperature voltages must be processed by an analog-to-digital converter (ADC) to ultimately output the gate drive voltage. However, in actual applications, when the thermistor voltage falls between the low- and high-temperature voltages, the output gate drive voltage becomes unstable, affecting display quality. Summary of the Invention

[0004] The present invention mainly provides a driving circuit and a display panel, which can improve the display effect.

[0005] To solve the above technical problems, the first technical solution adopted by the present invention is to provide a driving circuit, including: a temperature detection circuit, a temperature compensation detection circuit and a temperature compensation circuit; the temperature detection circuit includes a thermistor, and the temperature compensation detection circuit is connected to the temperature detection circuit; wherein the temperature compensation detection circuit includes:

[0006] A voltage detection circuit is connected to the thermistor and is used to detect the voltage of the thermistor;

[0007] The output circuit is connected to the output ends of the voltage detection circuit and the temperature compensation detection circuit, and is used to output a control signal of a first state or a control signal of a second state based on the voltage of the thermistor. The control signal of the first state indicates to enable the temperature compensation circuit to output the gate drive voltage, and the control signal of the second state indicates to turn off the temperature compensation circuit.

[0008] In one embodiment, the voltage detection circuit detecting the voltage of the thermistor includes detecting a voltage variation range or a voltage variation rate of the thermistor.

[0009] In one embodiment, the voltage detection circuit includes:

[0010] a first comparing unit, the first comparing unit being connected to the thermistor and being configured to compare a voltage of the thermistor with a first reference voltage and a second reference voltage; in response to the voltage of the thermistor being greater than the first reference voltage, or in response to the voltage of the thermistor being less than the second reference voltage, the first comparing unit outputting a first detection signal, the first detection signal instructing the output circuit to output a control signal of a first state; in response to the voltage of the thermistor being within a range of the first reference voltage and the second reference voltage, the first comparing unit outputting a second detection signal, the second detection signal instructing the output circuit to output a control signal of a second state;

[0011] The first reference voltage is greater than the second reference voltage.

[0012] In one embodiment, the first comparison unit includes: a first operational amplifier unit and a second operational amplifier unit; the output circuit includes: a first output unit and a second output unit;

[0013] One input terminal of the first operational amplifier unit is connected to the thermistor to receive the voltage of the thermistor, and the other input terminal receives the first reference voltage; the first output unit is connected to the output terminal of the first operational amplifier unit; one input terminal of the second operational amplifier unit is connected to the thermistor to receive the voltage of the thermistor, and the other input terminal receives the second reference voltage; the second output unit is connected to the output terminal of the second operational amplifier unit;

[0014] In response to the voltage of the thermistor being greater than the first reference voltage, the first operational amplifier unit outputs a high level signal, the second operational amplifier unit outputs a low level signal, and the first output unit outputs a control signal of a first state;

[0015] In response to the voltage of the thermistor being less than the second reference voltage, the first operational amplifier unit outputs a low-level signal, the second operational amplifier unit outputs a high-level signal, and the second output unit outputs a control signal of a first state;

[0016] In response to the voltage of the thermistor being within the range of the first reference voltage and the second reference voltage, the first operational amplifier unit and the second operational amplifier unit output low-level signals, the first output unit and the second output unit are cut off, and the output end of the temperature compensation detection circuit outputs a control signal of the second state.

[0017] In one embodiment, the voltage detection circuit is used to determine the rate of change of the voltage of the thermistor and output a reference voltage based on the rate of change of the voltage, wherein the amplitude of the reference voltage represents the rate of change of the voltage;

[0018] The output circuit is used to compare the reference voltage with the threshold voltage and output a control signal of a first state or a control signal of a second state based on the comparison result.

[0019] In one embodiment, the voltage detection circuit includes:

[0020] A capacitor, wherein a first end of the capacitor is connected to a thermistor;

[0021] a first resistor, wherein a first end of the first resistor is grounded;

[0022] a first comparator, wherein a first input terminal of the first comparator is connected to the second terminal of the capacitor, and a second input terminal of the first comparator is connected to the second terminal of the first resistor;

[0023] A second resistor, wherein a first end of the second resistor is connected to the first input end of the first comparator, and a second end of the second resistor is connected to the output end of the first comparator.

[0024] In one embodiment, the output circuit includes: a threshold voltage providing unit and a second comparing unit;

[0025] The threshold voltage providing unit is used to provide a threshold voltage, and the threshold voltage providing unit includes:

[0026] a third resistor, wherein a first end of the third resistor is connected to a reference voltage source and receives a reference voltage;

[0027] a fourth resistor, wherein a first end of the fourth resistor is connected to the voltage detection circuit and receives a reference voltage, a second end of the fourth resistor is connected to the second end of the third resistor, and the second end of the fourth resistor and the second end of the third resistor are both connected to the second comparing unit;

[0028] The second comparison unit includes a second comparator, a fifth resistor, and a voltage regulator; a first input end of the second comparator is connected to the second end of the fourth resistor and the second end of the third resistor, a second input end of the second comparator is connected in series with the fifth resistor and is grounded, and an output end of the second comparator is connected to the output end of the temperature compensation detection circuit; one end of the voltage regulator is connected to the first input end of the second comparator, and the other end of the voltage regulator is connected to the output end of the second comparator;

[0029] The second comparator is used to compare a first input voltage at the first input terminal with a second input voltage at the second input terminal, and a comparison result between the first input voltage and the second input voltage represents a comparison result between the reference voltage and the threshold voltage.

[0030] In one embodiment, the first input voltage U_ is determined as follows:

[0031]

[0032] The threshold voltage UT is determined as follows:

[0033]

[0034] Wherein, R4 is the resistance of the fourth resistor, R3 is the resistance of the third resistor, u1 is the reference voltage, and Vref is the base voltage.

[0035] In one embodiment, in response to the reference voltage being greater than the threshold voltage, the output circuit outputs a control signal of a second state, and the control signal of the second state instructs to turn off the temperature compensation circuit;

[0036] In response to the reference voltage being less than the threshold voltage, the output circuit outputs a control signal in a first state, where the control signal in the first state indicates enabling the temperature compensation circuit.

[0037] To solve the above technical problems, the second technical solution adopted by the present invention is to provide a display panel, the display panel comprising:

[0038] A plurality of pixel units are arranged in an array; each pixel unit comprises at least a driving transistor;

[0039] The driving circuit includes a temperature detection circuit, a temperature compensation detection circuit, and a temperature compensation circuit; the temperature detection circuit includes a thermistor, and the temperature compensation detection circuit is connected to the temperature detection circuit; wherein the temperature compensation detection circuit includes:

[0040] A voltage detection circuit is connected to the thermistor and is used to detect the voltage of the thermistor;

[0041] The output circuit is connected to the output ends of the voltage detection circuit and the temperature compensation detection circuit, and is used to output a control signal of a first state or a control signal of a second state based on the voltage of the thermistor. The control signal of the first state indicates to enable the temperature compensation circuit to output a gate drive voltage to the driving transistor shown, and the control signal of the second state indicates to turn off the temperature compensation circuit.

[0042] The beneficial effects of the present invention are as follows: different from the prior art, the driving circuit provided by the present invention includes: a temperature detection circuit, a temperature compensation detection circuit and a temperature compensation circuit; the temperature detection circuit includes a thermistor, and the temperature compensation detection circuit is connected to the temperature detection circuit; wherein the temperature compensation detection circuit includes: a voltage detection circuit connected to the thermistor for detecting the voltage of the thermistor; an output circuit connected to the output end of the voltage detection circuit and the temperature compensation detection circuit, for outputting a control signal of a first state or a control signal of a second state based on the voltage of the thermistor, the control signal of the first state indicating that the temperature compensation circuit is enabled to output a gate drive voltage, and the control signal of the second state indicating that the temperature compensation circuit is disabled. In this way, it is possible to determine whether temperature compensation is currently required based on the voltage of the thermistor, thereby selectively outputting the control signal of the first state or the control information of the second state to indicate whether the temperature compensation circuit is enabled or disabled. Specifically, the present application can disable the temperature compensation circuit and prohibit the temperature compensation circuit from outputting a gate drive voltage when the voltage of the thermistor is between the low temperature voltage and the high temperature voltage and no temperature compensation is required, thereby avoiding instability of the gate drive voltage and improving the display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 A schematic structural diagram of a first embodiment of a driving circuit provided in this application;

[0045] Figure 2 This is a structural diagram of a first embodiment of a temperature compensation detection circuit in a drive circuit provided by the present application;

[0046] Figure 3 for Figure 2 A graph showing the voltage across the thermistor and the control signal in the illustrated embodiment;

[0047] Figure 4 This is a structural diagram of a second embodiment of a temperature compensation detection circuit in a drive circuit provided by the present application;

[0048] Figure 5 for Figure 4 A graph showing a voltage across a thermistor and a reference voltage in the illustrated embodiment;

[0049] Figure 6 for Figure 4 A graph showing the relationship between the reference voltage and the control signal in the embodiment shown;

[0050] Figure 7 is a diagram showing the relationship between the actual thermistor voltage and the gate drive voltage in the prior art;

[0051] Figure 8 It is the relationship between thermistor temperature and gate drive voltage in the temperature compensation curve;

[0052] Figure 9 This is a schematic structural diagram of an embodiment of a display panel provided in this application.

[0053] Description of the accompanying symbols: driving circuit 10, temperature compensation detection circuit 12, temperature compensation circuit 13, voltage detection circuit 121, output circuit 122, voltage VT of thermistor, gate drive voltage VGH, temperature detection circuit 11, thermistor RNTC, resistor Ra, resistor Rb, resistor Rc, resistor Rd, resistor Re, resistor Rf, resistor Rg, first reference voltage VT_LT, second reference voltage VT_HT, first operational amplifier unit A1, second operational amplifier unit A2, first output unit 1221, second output unit 1222, diode VD1, diode VD2, output end P of temperature compensation detection circuit, control signal u0, threshold voltage providing unit 1223, second comparing unit 1224, capacitor C, first resistor R1, second resistor R2, first comparator A3, reference voltage u1, reference voltage V ref , the third resistor R3, the fourth resistor R4, the fifth resistor R5, the voltage regulator VD Z , second comparator A4, display panel 20, array substrate 30. DETAILED DESCRIPTION

[0054] The following describes the embodiments of the present application in detail with reference to the accompanying drawings.

[0055] In the following description, for the purpose of explanation rather than limitation, specific details such as specific system structures, interfaces, and technologies are provided to facilitate a thorough understanding of the present application.

[0056] The term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship. Furthermore, "many" in this document means two or more than two.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0058] Before further describing the embodiments of the present application in detail, the nouns and terms involved in the embodiments of the present application are explained. The nouns and terms involved in the embodiments of the present application are subject to the following interpretations.

[0059] The existing temperature compensation function of PowerIC is generally used to set a thermistor with a negative temperature coefficient to detect the voltage of the thermistor during real-time temperature changes. The higher the temperature of the thermistor, the smaller the resistance and the lower the voltage. The lower the temperature, the larger the resistance and the corresponding voltage will also increase. Specifically, the temperature compensation function of PowerIC needs to follow a pre-set temperature compensation curve, such as Figure 8 As shown, Figure 8 In the temperature compensation curve shown, the horizontal axis represents the thermistor temperature, and the vertical axis represents the gate drive voltage. In this temperature compensation curve, 10°C is the low temperature threshold, and 35°C is the high temperature threshold. Specifically, when the thermistor temperature is less than 10°C, compensation is required so that the corresponding output gate drive voltage VGH is 36V. When the thermistor temperature is greater than 35°C, compensation is required so that the corresponding output gate drive voltage VGH is 28V. However, when the thermistor temperature is between 10°C and 35°C, neither low temperature compensation nor high temperature compensation is required. At this time, the temperature compensation curve shows that the gate drive voltage VGH is unstable.

[0060] In the actual temperature compensation process, the relationship between the gate drive voltage VGH and the thermistor voltage is as follows: Figure 7 As shown, Figure 7 The horizontal axis is the voltage of the thermistor, and the vertical axis is the gate drive voltage VGH. When the temperature of the thermistor is low, its voltage is higher, for example, VT_LT, and the corresponding output gate drive voltage is VGH_LT. When the temperature of the thermistor is high, its voltage is lower, for example, VT_HT, and the corresponding output gate drive voltage is VGH_HT. When the voltage of the thermistor is between the low temperature voltage VT_HT and VT_LT, the output gate drive voltage VGH is unstable, and there will be some fluctuations due to mode conversion. Figure 7 The step-like fluctuations shown in the figure. Although the gate drive voltage VGH tends to stabilize as the thermistor temperature continues to rise and stabilizes to a high temperature (greater than 35°C), the temperature increase takes a certain amount of time. During this time, the gate drive voltage VGH is unstable and is not the actual required voltage. This will cause abnormal display images during this time, affecting the display effect.

[0061] In view of this, the present application proposes a driving circuit that can determine whether temperature compensation is currently required based on the voltage of the thermistor, thereby selectively outputting a control signal of a first state or control information of a second state to instruct to enable or disable the temperature compensation circuit. Specifically, the present application can disable the temperature compensation circuit when the voltage of the thermistor is between the low temperature voltage and the high temperature voltage and no temperature compensation is required, prohibiting the temperature compensation circuit from outputting a gate drive voltage, thereby avoiding gate drive voltage instability and improving display effects. In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0062] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of an embodiment of the driving circuit provided by the present application. The driving circuit 10 specifically includes: a temperature detection circuit 11, a temperature compensation detection circuit 12, and a temperature compensation circuit 13. The temperature detection circuit includes a thermistor RNTC, and the temperature compensation detection circuit 12 is connected to the temperature detection circuit 11; wherein, the temperature compensation detection circuit 12 includes: a voltage detection circuit 121 and an output circuit 122. The voltage detection circuit 121 is connected to the thermistor RNTC and is used to detect the voltage VT of the thermistor RNTC. The output circuit 122 is connected to the voltage detection circuit 121 and the output terminal P of the temperature compensation detection circuit 12, and is used to output a control signal of a first state or a control signal of a second state based on the voltage VT of the thermistor RNTC. The control signal of the first state indicates that the temperature compensation circuit 13 is enabled to output the gate drive voltage VGH, and the control signal of the second state indicates that the temperature compensation circuit 13 is disabled.

[0063] Specific as Figure 1 As shown, the temperature detection circuit 11 is specifically formed by a thermistor RNTC and a resistor Ra connected in parallel, which are then connected in series with a resistor Rb to ground. Since the resistance of the thermistor RNTC changes with the ambient temperature, given a constant current source, the thermistor's resistance changes with the ambient temperature, causing the voltage VT of the thermistor RNTC to change accordingly. Therefore, the corresponding ambient temperature can be indicated based on the voltage VT of the thermistor RNTC. In one embodiment, the constant current source can be provided by a power management chip, for example. The constant current source can be customized according to the actual application scenario, for example, 10μA, 20μA, 30μA, etc. In this embodiment, 20μA is used as the constant current source.

[0064] In a display panel, the threshold voltage (Vth) of the TFT shifts with temperature. At low temperatures, the carrier mobility of the semiconductor material decreases, causing the threshold voltage to exhibit an opposite trend (i.e., the lower the temperature, the lower the threshold voltage). If the gate drive voltage (VGH) designed for normal temperature is still used, it will not be possible to provide a sufficient gate-source voltage difference (VGH-Vth) for the TFT, resulting in the TFT not being able to fully conduct, causing problems such as response delays and decreased display brightness. The temperature detection circuit 11 in this embodiment can sense the ambient temperature through a thermistor RNTC, and indicate temperature changes through the voltage VT of the thermistor RNTC.

[0065] Furthermore, the temperature detection circuit 11 is connected via the temperature compensation detection circuit 12, specifically the thermistor RNTC in the temperature detection circuit 11. In one embodiment, the temperature compensation detection circuit 12 includes a voltage detection circuit 121 and an output circuit 122. The voltage detection circuit 121 is connected to the thermistor RNTC and is used to detect the voltage of the thermistor RNTC; the output circuit 122 is connected to the voltage detection circuit 121 and the output end P of the temperature compensation detection circuit 12, and is used to output a control signal of a first state or a control signal of a second state based on the voltage VT of the thermistor RNTC. The control signal of the first state indicates that the temperature compensation circuit 13 is enabled to output the gate drive voltage VGH, and the control signal of the second state indicates that the temperature compensation circuit 13 is turned off. It should be noted that the gate drive voltage VGH is the voltage after temperature compensation. When the temperature compensation circuit 13 performs temperature compensation and outputs the gate drive voltage VGH, it needs to be converted by an analog-to-digital converter before outputting the gate drive voltage VGH.

[0066] In one embodiment, the voltage detection circuit 121 detecting the voltage VT of the thermistor RNTC includes detecting a voltage variation range of the voltage VT of the thermistor RNTC or a voltage variation rate of the voltage VT of the thermistor RNTC.

[0067] In one embodiment, combining Figure 2 and Figure 3When the voltage detection circuit 121 detects the voltage VT of the thermistor RNTC and detects a voltage variation range of the voltage VT of the thermistor RNTC, the voltage detection circuit 121 includes a first comparison unit 123. The first comparison unit 123 is connected to the thermistor RNTC and is configured to compare the voltage VT of the thermistor RNTC with a first reference voltage VT_LT and a second reference voltage VT_HT. In response to the voltage VT of the thermistor RNTC being greater than the first reference voltage VT_LT or less than the second reference voltage VT_HT, the first comparison unit 123 outputs a first detection signal, which instructs the output circuit 122 to output a control signal in a first state. In response to the voltage VT of the thermistor RNTC being within the range of the first reference voltage VT_LT and the second reference voltage VT_HT, the first comparison unit 123 outputs a second detection signal, which instructs the output circuit 122 to output a control signal in a second state. The first reference voltage VT_LT is greater than the second reference voltage VT_HT. It should be noted that the first reference voltage VT_LT and the second reference voltage VT_HT are determined by the performance of the power management chip.

[0068] In one embodiment, the first comparison unit 123 may be, for example, a comparator. Specifically, the first comparison unit 123 may be, for example, a comparator including two operational amplifier units. Figure 2 The first comparison unit 123 includes: a first operational amplifier unit A1 and a second operational amplifier unit A2; the output circuit 122 includes: a first output unit 1221 and a second output unit 1222.

[0069] In one embodiment, one input terminal of the first operational amplifier unit A1 is connected to the thermistor RNTC and receives the voltage VT of the thermistor RNTC. The other input terminal receives the first reference voltage VT_LT. The first output unit 1221 is connected to the output terminal of the first operational amplifier unit A1. Specifically, the non-inverting input terminal of the first operational amplifier unit A1 is connected to the series resistor Rd via the resistor Rd and is connected to the thermistor RNTC via the resistor Rd and receives the voltage VT of the thermistor RNTC. The inverting input terminal of the first operational amplifier unit A1 is connected to the series resistor Rc via the resistor Rc and receives the first reference voltage VT_LT. The output terminal of the first operational amplifier unit A1 is connected to the first output unit 1221.

[0070] One input terminal of the second operational amplifier unit A2 is connected to the thermistor RNTC and receives the voltage VT of the thermistor RNTC. The other input terminal receives the second reference voltage VT_HT. The second output unit 1222 is connected to the output terminal of the second operational amplifier unit A2. Specifically, the non-inverting input terminal of the second operational amplifier unit A2 is connected to the series resistor Rf and receives the second reference voltage VT_HT through the resistor Rf. The inverting input terminal of the second operational amplifier unit A2 is connected to the series resistor Re and receives the voltage VT of the thermistor RNTC through the resistor Re. The output terminal of the first operational amplifier unit A1 is connected to the second output unit 1222.

[0071] Specifically, the first output unit 1221 includes, for example, a diode VD1 and a resistor Rg. The anode of the diode VD1 is connected to the output terminal of the first operational amplifier unit A1, and the cathode of the diode VD1 is connected to the output terminal P of the temperature compensation detection circuit 12 and is grounded via the resistor Rg. The second output unit 1222 includes, for example, a diode VD2 and a resistor Rg. The anode of the diode VD2 is connected to the output terminal of the second operational amplifier unit A2, and the cathode of the diode VD2 is connected to the output terminal P of the temperature compensation detection circuit 12 and is grounded via the resistor Rg. It should be noted that the first output unit 1221 and the second output unit 1222 share the same resistor Rg.

[0072] In response to the voltage VT of thermistor RNTC being greater than the first reference voltage VT_LT, it can be understood that since the first reference voltage VT_LT is greater than the second reference voltage VT_HT, if VT>VT_LT, then VT>VT_HT. At this time, the first operational amplifier unit A1 outputs a high-level signal, the diode VD1 is turned on, and the second operational amplifier unit A2 outputs a low-level signal, the diode VD2 is turned off, and the first output unit 1221 outputs a first-state control signal. In this embodiment, the control signal is denoted as u0. The first-state control signal u0 is output through the output terminal P of the temperature compensation detection circuit 12. It should be noted that since the first operational amplifier unit A1 outputs a high-level signal and the diode VD1 is turned on, the first-state control signal u0 is in a high-level state, indicating that the temperature compensation circuit 13 is enabled and outputs the gate drive voltage VGH, which is the temperature-compensated voltage.

[0073] In response to the voltage VT of thermistor RNTC being less than the second reference voltage VT_HT, it can be understood that since the first reference voltage VT_LT is greater than the second reference voltage VT_HT, if VT < VT_HT, then VT < VT_LT. At this time, the first operational amplifier unit A1 outputs a low-level signal, the diode VD1 is turned off, and the second operational amplifier unit A2 outputs a high-level signal, the diode VD2 is turned on, and the second output unit 1222 outputs the first-state control signal u0. The first-state control signal u0 is output through the output terminal P of the temperature compensation detection circuit 12. It should be noted that since the second operational amplifier unit A2 outputs a low-level signal and the diode VD2 is turned on, the first-state control signal u0 is a high-level signal, indicating that the temperature compensation circuit 13 is enabled and outputs the gate drive voltage VGH, which is the temperature-compensated voltage.

[0074] In response to the voltage of the thermistor being within the range of the first reference voltage and the second reference voltage, that is, VT_HT<VT<VT_LT, the first operational amplifier unit A1 and the second operational amplifier unit A2 output low-level signals, the first output unit 1221 and the second output unit 1222 are turned off, specifically, the diode VD1 and the diode VD2 are turned off, and the output end P of the temperature compensation detection circuit 12 outputs the control signal u0 of the second state. At this time, the control signal u0 of the second state is a low-level signal, indicating that the temperature compensation circuit 13 is turned off.

[0075] It is understood that the first detection signal includes a low-level signal output by the second operational amplifier unit A2 and a high-level signal output by the second operational amplifier unit A2; alternatively, the first detection signal includes a high-level signal output by the second operational amplifier unit A2 and a low-level signal output by the second operational amplifier unit A2. The second detection signal includes a low-level signal output by the first operational amplifier unit A1 and the second operational amplifier unit A2.

[0076] Through this embodiment, when the VT voltage is detected to meet VT_HT<VT<VT_LT, the output control signal u0 is low level, and when it meets VT<VT_HT or VT>VT_LT, the output control signal u0 is high level. In one embodiment, the control signal u0 can be connected to the GPIO port of the timing control circuit, and the timing control circuit can open the temperature compensation enable switch when the high level control signal u0 is detected, and close the temperature compensation enable switch when the low level control signal u0 is detected, thereby achieving the purpose of prohibiting temperature compensation when VT_HT<VT<VT_LT. After prohibiting temperature compensation, the temperature compensation circuit 13 will not output Figure 7 The unstable gate drive voltage VGH shown in FIG. 1 avoids the output gate drive voltage VGH from being unstable, thereby improving the display effect. In one embodiment, in order to improve stability, the timing control circuit may further turn on the temperature compensation enable switch after detecting a high-level control signal u0 for a period of time.

[0077] In one embodiment of the present application, Figure 7 and Figure 8 When the temperature of thermistor RNTC (i.e., the ambient temperature) is low, for example, less than 10°C, the thermistor RNTC will have a higher voltage. For example, the voltage of the thermistor RNTC will be greater than VT_LT. In this case, the temperature compensation circuit needs to be activated to control the gate drive voltage VGH to VGH_LT (VGH_LT is 36V, for example). When the temperature of thermistor RNTC (i.e., the ambient temperature) is high, for example, greater than 35°C, the thermistor RNTC will have a lower voltage. For example, the voltage of the thermistor RNTC will be less than VT_HT. In this case, the temperature compensation circuit needs to be activated to control the gate drive voltage VGH to VGH_HT (VGH_HT is 28V, for example).

[0078] In another embodiment, combined Figure 4 、 Figure 5 and Figure 6 When the voltage detection circuit 121 detects the voltage VT of the thermistor RNTC, including detecting the voltage change rate of the voltage VT of the thermistor RNTC, the voltage detection circuit 121 is configured to determine the voltage change rate of the thermistor RNTC voltage VT and output a reference voltage u1 based on the voltage change rate. The output circuit 122 is configured to compare the reference voltage u1 with the threshold voltage UT and output a first-state control signal u0 or a second-state control signal u0 based on the comparison result.

[0079] Specifically, the voltage detection circuit 121 includes: a capacitor C, a first resistor R1, a second resistor R2, and a first comparator A3. The first end of the capacitor C is connected to the thermistor RNTC and receives the voltage VT. The first end of the first resistor R1 is grounded. The first input end (inverting input end -) of the first comparator A3 is connected to the second end of the capacitor C. The second input end (non-inverting input end +) of the first comparator A3 is connected to the second end of the first resistor R1. The first end of the second resistor R2 is connected to the first input end of the first comparator A3. The second end of the second resistor R2 is connected to the output end of the first comparator A3.

[0080] In the voltage detection circuit 121, since the voltage VT is connected to the capacitor C, the voltage flowing into the inverting input terminal - of the first comparator A3 is 0, and the current i of the capacitor C is C and the current of the second resistor R2 Equal, that is Since the voltage at the inverting input terminal - is 0, the reference voltage u1 outputted by the output terminal of the first comparator A3 is as follows:

[0081]

[0082] in, represents the rate of change of capacitance C with time t, Indicates the rate of change of voltage VT with time t.

[0083] From the above formula, it can be seen that the reference voltage u1 is proportional to the differential of the voltage VT with respect to time, and the differential of the voltage VT with respect to time represents the voltage change rate of the voltage VT. Figure 5 When the voltage VT increases linearly, the reference voltage u1 is a fixed negative voltage. When VT remains unchanged, the reference voltage u1 is 0. When the voltage VT decreases linearly, the reference voltage u1 is a fixed positive voltage. The amplitude of the reference voltage u1 represents the rate of voltage change.

[0084] Continue to see Figure 4 The output circuit 122 includes a threshold voltage providing unit 1223 and a second comparing unit 1224. The threshold voltage providing unit 1223 is used to provide a threshold voltage UT. The threshold voltage providing unit 1223 includes: a third resistor R3, a fourth resistor R4 and a reference voltage source. The first end of the third resistor R3 is connected to the reference voltage source and receives the reference voltage V ref ; The first end of the fourth resistor R4 is connected to the voltage detection circuit 121 and receives the reference voltage u1, the second end of the fourth resistor R4 is connected to the second end of the third resistor R3, and the second end of the fourth resistor R4 and the second end of the third resistor R3 are both connected to the second comparison unit 1224.

[0085] The second comparison unit 1224 includes a second comparator A4, a fifth resistor R5 and a voltage regulator tube VD Z The first input terminal (i.e., the inverting input terminal -) of the second comparator A4 is connected to the second terminal of the fourth resistor R4 and the second terminal of the third resistor R3. The second input terminal (the non-inverting input terminal +) of the second comparator A4 is connected in series with the fifth resistor R5 and is grounded. The output terminal of the second comparator A4 is connected to the output terminal P of the temperature compensation detection circuit 12. The voltage regulator tube VD Z One end is connected to the first input end of the second comparator A4, and the voltage regulator tube VD Z The other end is connected to the output end of the second comparator A4.

[0086] The second comparator A4 is used to compare the first input voltage U_ at the first input terminal with the second input voltage U+ at the second input terminal. + The comparison result represents the comparison result between the reference voltage u1 and the threshold voltage UT. In response to the reference voltage u1 being greater than the threshold voltage UT, the output circuit 122 outputs the second-state control signal u0, which instructs to disable the temperature compensation circuit 13. In response to the reference voltage being less than the threshold voltage, the output circuit 122 outputs the first-state control signal u0, which instructs to enable the temperature compensation circuit 13.

[0087] Specifically, since the non-inverting input terminal + of the second comparator A4 is grounded via the fifth resistor R5, when the reference voltage u1 changes, if the first input voltage U_ at the first input terminal, i.e., the inverting input terminal -, is equal to the second input voltage U+ at the second input terminal, i.e., the non-inverting input terminal +, i.e., U_ - U+ - 0, then the control signal u0 will jump. At this time, the first input voltage U_ is determined as follows:

[0088]

[0089] The threshold voltage UT is determined as follows:

[0090]

[0091] It should be noted that when the first input voltage U_=0, the threshold voltage UT satisfies:

[0092]

[0093] Wherein, R4 is the resistance of the fourth resistor, R3 is the resistance of the third resistor, u1 is the reference voltage, and Vref is the base voltage.

[0094] Based on the above formula, it can be deduced that if the first input voltage U_ is greater than 0, the reference voltage u1 is greater than the threshold voltage UT, and if the first input voltage U_ is less than 0, the reference voltage u1 is less than the threshold voltage UT. Z The control signal u0 outputted from the output terminal P of the temperature compensation detection circuit 12 can be stabilized. Figure 6 As shown, when the reference voltage u1 is less than the threshold voltage UT When the reference voltage u1 is greater than the threshold voltage UT, the output terminal P outputs a control signal u0 of the first state. The control signal u0 output by the output terminal P in the first state is a positive voltage +Uz, that is, a high-level state, indicating that the temperature compensation circuit 13 is enabled and outputs the gate drive voltage VGH. When the reference voltage u1 is greater than the threshold voltage UT, the output terminal P outputs a control signal u0 of the second state. The control signal u0 output by the output terminal P in the second state is a negative voltage -Uz, that is, a low-level state, indicating that the temperature compensation circuit 13 is turned off.

[0095] Through this embodiment, the voltage change rate of voltage VT can be used to determine whether to enable temperature compensation, thereby preventing instability in the output gate drive voltage VGH and improving display quality. In one embodiment, to improve stability, the timing control circuit can also turn on the temperature compensation enable switch after detecting a high-level control signal u0 for a period of time.

[0096] In a feasible embodiment of the present application, the driving circuit simultaneously detects the voltage variation range of the thermistor and the voltage variation rate of the thermistor. Figure 2 (voltage variation range of thermistor) and Figure 4 (Detecting the voltage change rate of thermistor) as shown in the temperature compensation detection circuit, and also includes connecting Figure 2 and Figure 4 The output unit of the temperature compensation detection circuit shown in the figure is selected. The output unit receives Figure 2 The temperature compensation detection circuit shown outputs a control signal of a first state and a control signal of a second state; and receives Figure 4 The temperature compensation detection circuit shown in FIG1 outputs a first state control signal and a second state control signal. Specifically, if the control signal states of the two outputs received by the selection output unit are consistent, for example, the selection output unit receives Figure 2 The temperature compensation detection circuit shown in FIG1 outputs the first state control signal while receiving the Figure 4 The temperature compensation detection circuit outputs a control signal of the first state, and the output unit is selected to output an enable signal to enable the temperature compensation circuit to output a gate drive voltage. For another example, the output unit is selected to receive a signal. Figure 2 The temperature compensation detection circuit shown in FIG2 outputs the second state control signal while receiving the Figure 4 The temperature compensation detection circuit outputs the second state control signal, and the selection output unit outputs the non-enable signal to turn off the temperature compensation circuit. If the control signal states of the two outputs received by the selection output unit are inconsistent, for example, the selection output unit receives Figure 2 The temperature compensation detection circuit shown in FIG1 outputs the first state control signal while receiving the Figure 4 The temperature compensation detection circuit outputs the second state control signal, or the output unit receives the second state control signal. Figure 2 The temperature compensation detection circuit shown in FIG2 outputs the second state control signal while receiving the Figure 4 The temperature compensation detection circuit outputs a control signal in the first state. To avoid affecting the display effect, the output unit is selected to output a non-enable signal, turning off the temperature compensation circuit. By setting this strategy, the gate drive voltage can be more accurately controlled, keeping the gate drive voltage stable and improving the display effect.

[0097] Specifically, it is generally necessary to ensure the consistency of the product during product manufacturing, so the temperature compensation circuit of the product is generally always on. This is to ensure that the product can adapt to different environments, such as low temperature or high temperature environments, and to perform temperature compensation when entering low temperature or high temperature environments. When the voltage VT of the thermistor RNTC meets VT_HT<VT<VT_LT, because the temperature compensation circuit needs to follow the temperature compensation curve, it will inevitably cause the gate drive voltage VGH to be unstable. However, adjusting the temperature compensation curve will cause degradation in the display effect ( Figure 8 The temperature compensation curve shown is set according to the optimal display effect of the product), which reduces the display effect of the product. The present application sets a voltage detection control mechanism, which can output a control signal to start the temperature compensation enable switch when temperature compensation is required (that is, when the voltage VT of the thermistor RNTC meets VT less than VT_HT or VT greater than VT_LT); when temperature compensation is not required (that is, when the voltage VT of the thermistor RNTC meets VT_HT<VT<VT_LT), it can output a control signal to turn off the temperature compensation enable switch, thereby turning off the temperature compensation circuit. On the one hand, it avoids the instability of the output gate drive voltage VGH, and on the other hand, it can make the temperature-voltage relationship in the temperature compensation curve follow during low and high temperature processes, thereby improving the display effect.

[0098] See also Figure 9 , Figure 9 This is a structural diagram of an embodiment of a display panel provided by the present application. The display panel 20 includes: an array substrate 30 and a driving circuit 10. The array substrate 30 includes a plurality of pixel units arranged in an array; each pixel unit includes at least a driving transistor. Taking a conventional pixel unit as an example, it includes a driving transistor, a storage capacitor and a pixel electrode. The driving transistor is controlled by a scan line to turn on and writes the data voltage to the storage capacitor. When displaying, the storage capacitor discharges through the pixel electrode to control the liquid crystal flipping. It should be noted that when temperature compensation is performed, when the driving transistor is turned on, the control voltage input to the scan line corresponds to the gate drive voltage after temperature compensation. It is understandable that the gate drive voltage after temperature compensation will be transmitted to the timing control circuit for processing and then transmitted to the scan line. When temperature compensation is not performed, the control voltage input to the scan line comes from the power management chip. It is understandable that it may not come directly from the power management chip. For example, it may undergo other processing during the transmission process, such as passing through the timing control circuit, as long as it is not output by the temperature compensation circuit.

[0099] The driving circuit 10 includes a temperature detection circuit, a temperature compensation detection circuit and a temperature compensation circuit; the temperature detection circuit includes a thermistor, and the temperature compensation detection circuit is connected to the temperature detection circuit; wherein the temperature compensation detection circuit includes: a voltage detection circuit, connected to the thermistor, for detecting the voltage of the thermistor; an output circuit, connected to the output end of the voltage detection circuit and the temperature compensation detection circuit, for outputting a control signal of a first state or a control signal of a second state based on the voltage of the thermistor, the control signal of the first state indicates that the temperature compensation circuit is enabled to output a gate drive voltage to the driving transistor shown, and the control signal of the second state indicates that the temperature compensation circuit is turned off.

[0100] It can be understood that the driving circuit 10 in this embodiment can be the driving circuit of any of the above embodiments, and will not be described in detail here.

[0101] The above are merely embodiments of the present invention and are not intended to limit the scope of patent protection of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of the present invention.

Claims

1. A driving circuit, characterized in that: include: Temperature detection circuit, temperature compensation detection circuit and temperature compensation circuit; The temperature detection circuit includes a thermistor, and the temperature compensation detection circuit is connected to the temperature detection circuit; wherein the temperature compensation detection circuit includes: a voltage detection circuit, connected to the thermistor, for detecting the voltage of the thermistor; An output circuit is connected to the output ends of the voltage detection circuit and the temperature compensation detection circuit, and is used to output a control signal of a first state or a control signal of a second state based on the voltage of the thermistor, wherein the control signal of the first state indicates to enable the temperature compensation circuit to output a gate drive voltage, and the control signal of the second state indicates to turn off the temperature compensation circuit.

2. The driving circuit according to claim 1, wherein: The voltage detection circuit detecting the voltage of the thermistor includes detecting a voltage variation range or a voltage variation rate of the thermistor.

3. The driving circuit according to claim 2, wherein: The voltage detection circuit comprises: a first comparing unit, the first comparing unit being connected to the thermistor and being configured to compare a voltage of the thermistor with a first reference voltage and a second reference voltage, wherein in response to the voltage of the thermistor being greater than the first reference voltage or in response to the voltage of the thermistor being less than the second reference voltage, the first comparing unit outputs a first detection signal, the first detection signal instructing the output circuit to output a control signal of the first state; and in response to the voltage of the thermistor being within a range of the first reference voltage and the second reference voltage, the first comparing unit outputs a second detection signal, the second detection signal instructing the output circuit to output a control signal of the second state; The first reference voltage is greater than the second reference voltage.

4. The driving circuit according to claim 3, wherein: The first comparison unit includes: a first operational amplifier unit and a second operational amplifier unit; the output circuit includes: a first output unit and a second output unit; One input terminal of the first operational amplifier unit is connected to the thermistor to receive the voltage of the thermistor, and the other input terminal receives the first reference voltage; the first output unit is connected to the output terminal of the first operational amplifier unit; one input terminal of the second operational amplifier unit is connected to the thermistor to receive the voltage of the thermistor, and the other input terminal receives the second reference voltage; the second output unit is connected to the output terminal of the second operational amplifier unit; In response to the voltage of the thermistor being greater than the first reference voltage, the first operational amplifier unit outputs a high-level signal, the second operational amplifier unit outputs a low-level signal, and the first output unit outputs a control signal of the first state; In response to the voltage of the thermistor being less than the second reference voltage, the first operational amplifier unit outputs a low-level signal, the second operational amplifier unit outputs a high-level signal, and the second output unit outputs a control signal of the first state; In response to the voltage of the thermistor being within the range of a first reference voltage and a second reference voltage, the first operational amplifier unit and the second operational amplifier unit output a low-level signal, the first output unit and the second output unit are cut off, and the output end of the temperature compensation detection circuit outputs a control signal of the second state.

5. The driving circuit according to claim 2, wherein: The voltage detection circuit is used to determine the voltage change rate of the thermistor and output a reference voltage based on the voltage change rate, wherein the amplitude of the reference voltage represents the voltage change rate; The output circuit is configured to compare the reference voltage with a threshold voltage, and output a control signal of the first state or a control signal of the second state based on a comparison result.

6. The driving circuit according to claim 5, wherein: The voltage detection circuit comprises: a capacitor, a first end of the capacitor being connected to the thermistor; a first resistor, wherein a first end of the first resistor is grounded; a first comparator, wherein a first input terminal of the first comparator is connected to the second terminal of the capacitor, and a second input terminal of the first comparator is connected to the second terminal of the first resistor; a second resistor, wherein a first end of the second resistor is connected to the first input end of the first comparator, and a second end of the second resistor is connected to the output end of the first comparator.

7. The driving circuit according to claim 5, wherein: The output circuit includes: a threshold voltage providing unit and a second comparing unit; The threshold voltage providing unit is used to provide the threshold voltage, and the threshold voltage providing unit includes: a third resistor, wherein a first end of the third resistor is connected to a reference voltage source and receives a reference voltage; a fourth resistor, wherein a first end of the fourth resistor is connected to the voltage detection circuit and receives the reference voltage, a second end of the fourth resistor is connected to the second end of the third resistor, and the second end of the fourth resistor and the second end of the third resistor are both connected to the second comparing unit; The second comparison unit includes a second comparator, a fifth resistor, and a voltage regulator; a first input end of the second comparator is connected to the second end of the fourth resistor and the second end of the third resistor, a second input end of the second comparator is connected in series with the fifth resistor and is grounded, and an output end of the second comparator is connected to the output end of the temperature compensation detection circuit; one end of the voltage regulator is connected to the first input end of the second comparator, and the other end of the voltage regulator is connected to the output end of the second comparator; The second comparator is used to compare a first input voltage at the first input terminal with a second input voltage at the second input terminal, and a comparison result between the first input voltage and the second input voltage represents a comparison result between the reference voltage and the threshold voltage.

8. The driving circuit according to claim 7, wherein: The first input voltage U_ is determined by: The threshold voltage UT is determined as follows: Wherein, R4 is the resistance of the fourth resistor, R3 is the resistance of the third resistor, u1 is the reference voltage, and Vref is the base voltage.

9. The driving circuit according to any one of claims 5 to 8, characterized in that: In response to the reference voltage being greater than the threshold voltage, the output circuit outputs a control signal of a second state, the control signal of the second state instructing to turn off the temperature compensation circuit; In response to the reference voltage being less than the threshold voltage, the output circuit outputs a control signal in a first state, where the control signal in the first state indicates enabling the temperature compensation circuit.

10. A display panel, characterized in that: The display panel includes: A plurality of pixel units arranged in an array; each of the pixel units comprises at least a driving transistor; A driving circuit; the driving circuit includes a temperature detection circuit, a temperature compensation detection circuit, and a temperature compensation circuit; the temperature detection circuit includes a thermistor, and the temperature compensation detection circuit is connected to the temperature detection circuit; wherein the temperature compensation detection circuit includes: a voltage detection circuit, connected to the thermistor, for detecting the voltage of the thermistor; An output circuit is connected to the output ends of the voltage detection circuit and the temperature compensation detection circuit, and is used to output a control signal of a first state or a control signal of a second state based on the voltage of the thermistor, wherein the control signal of the first state indicates to enable the temperature compensation circuit to output a gate drive voltage to the driving transistor, and the control signal of the second state indicates to turn off the temperature compensation circuit.

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