A driving circuit and a display panel

Abstract

The application provides a driving circuit and a display panel. The driving circuit comprises a temperature detection circuit, a temperature compensation detection circuit and a temperature compensation circuit. The temperature detection circuit comprises a thermistor. The temperature compensation detection circuit is connected to the temperature detection circuit. The temperature compensation detection circuit comprises a voltage detection circuit connected to the thermistor, which is used for detecting the voltage of the thermistor. An output circuit is connected to the output end of the voltage detection circuit and the temperature compensation detection circuit, which is used for outputting a control signal in a first state or a control signal in a second state based on the voltage of the thermistor. The control signal in the first state indicates that the temperature compensation circuit is enabled to output a gate driving voltage. The control signal in the second state indicates that the temperature compensation circuit is disabled. In this way, when temperature compensation is not needed, the temperature compensation circuit is prohibited to output the gate driving voltage, so that the instability of the gate driving voltage is avoided, and the display effect is improved.

Description

Technical Field

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

[0002] In the field of TFT-LCD (Thin Film Transistor Liquid Crystal Display), the threshold voltage (Vth) of a TFT shifts with temperature. At low temperatures, the carrier mobility of the semiconductor material decreases, causing the threshold voltage to exhibit the opposite trend (i.e., the lower the temperature, the lower the threshold voltage). If a room-temperature designed gate drive voltage (VGH) is still used, it cannot provide a sufficient gate-source voltage difference (VGH-Vth) for the TFT, resulting in insufficient TFT conduction and problems such as response delay and decreased display brightness.

[0003] Existing methods typically utilize PowerIC's temperature compensation function, employing thermistors with negative temperature coefficients (NTCs) to detect real-time temperature changes. As the thermistor's temperature rises, its resistance decreases, resulting in a lower voltage; conversely, lower temperatures increase resistance and thus, the voltage rises. Therefore, during temperature compensation, the set low-temperature and high-temperature voltage values ​​need to be processed by an analog-to-digital converter (ADC) to output the gate drive voltage. However, in practical applications, it has been found that when the thermistor voltage falls between the low-temperature and high-temperature voltages, the output gate drive voltage becomes unstable, affecting display quality. Summary of the Invention

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

[0005] To solve the above-mentioned 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 a thermistor to detect the voltage across the thermistor.

[0007] The output circuit connects the output terminals of the voltage detection circuit and the temperature compensation detection circuit. It is used to output a control signal for the first state or a control signal for the second state based on the voltage of the thermistor. The control signal for the first state enables the temperature compensation circuit to output the gate drive voltage, and the control signal for the second state enables the temperature compensation circuit to be turned off.

[0008] In one embodiment, the voltage detection circuit detects the voltage of the thermistor, including detecting the range of voltage changes or the rate of voltage change of the thermistor.

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

[0010] A first comparison unit, connected to a thermistor, is used to compare the voltage of the thermistor with a first reference voltage and a second reference voltage. In response to the thermistor voltage being greater than the first reference voltage, or in response to the thermistor voltage being less than the second reference voltage, the first comparison unit outputs a first detection signal, which instructs the output circuit to output a control signal for a first state. In response to the thermistor voltage being within the range of the first and second reference voltages, the first comparison unit outputs a second detection signal, which instructs the output circuit to output a control signal for 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 a thermistor to receive the voltage from the thermistor, and the other input terminal receives a 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 a thermistor to receive the voltage from the thermistor, and the other input terminal receives a second reference voltage; the second output unit is connected to the output terminal of the second operational amplifier unit.

[0014] In response to the thermistor voltage 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 for the first state.

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

[0016] In response to the thermistor voltage 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 turned off, and the output terminal of the temperature compensation detection circuit outputs the control signal of the second state.

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

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

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

[0020] A capacitor, with its first terminal connected to a thermistor;

[0021] The first resistor has its first terminal grounded.

[0022] The first comparator has its first input terminal connected to the second terminal of a capacitor, and its second input terminal connected to the second terminal of a first resistor.

[0023] The second resistor has its first end connected to the first input terminal of the first comparator and its second end connected to the output terminal of the first comparator.

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

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

[0026] The third resistor has its first terminal connected to a reference voltage source to receive the reference voltage.

[0027] The fourth resistor has its first end connected to a voltage detection circuit to receive a reference voltage, and its second end connected to the second end of the third resistor. Both the second ends of the fourth and third resistors are connected to the second comparison unit.

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

[0029] The second comparator is used to compare the first input voltage at the first input terminal with the second input voltage at the second input terminal. The comparison result of the first input voltage and the second input voltage represents the comparison result of 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] Where 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 reference voltage.

[0035] In one embodiment, in response to a reference voltage being greater than a threshold voltage, the output circuit outputs a control signal for a second state, which indicates that the temperature compensation circuit should be turned off.

[0036] In response to the reference voltage being less than the threshold voltage, the output circuit outputs a control signal for the first state, which enables the temperature compensation circuit.

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

[0038] The array consists of several pixel units; each pixel unit includes 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. The temperature compensation detection circuit includes:

[0040] A voltage detection circuit is connected to a thermistor to detect the voltage across the thermistor.

[0041] The output circuit connects the output terminals of the voltage detection circuit and the temperature compensation detection circuit, and is used to output a control signal for a first state or a control signal for a second state based on the voltage of the thermistor. The control signal for the first state enables the temperature compensation circuit to output a gate drive voltage to the driving transistor shown, and the control signal for the second state enables the temperature compensation circuit to be turned off.

[0042] The beneficial effects of this invention are as follows: Unlike existing technologies, the driving circuit provided by this 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. The temperature compensation detection circuit includes a voltage detection circuit connected to the thermistor for detecting the voltage of the thermistor; and an output circuit connected to the output terminals of the voltage detection circuit and the temperature compensation detection circuit for outputting a first-state control signal or a second-state control signal based on the thermistor voltage. The first-state control signal enables the temperature compensation circuit to output a gate drive voltage, and the second-state control signal enables the temperature compensation circuit to be turned off. Thus, it is possible to determine whether temperature compensation is needed based on the thermistor voltage, thereby selectively outputting the first-state control signal or the second-state control information to enable or disable the temperature compensation circuit. Specifically, this application can disable the temperature compensation circuit and prevent it from outputting a gate drive voltage when the thermistor voltage is between a low-temperature voltage and a high-temperature voltage and temperature compensation is not needed, thereby avoiding gate drive voltage instability and improving display performance. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0045] Figure 2 A schematic diagram of the structure of a first embodiment of the temperature compensation detection circuit in the driving circuit provided in this application;

[0046] Figure 3 for Figure 2 The illustrated embodiment shows a graph of the voltage of the thermistor versus the control signal.

[0047] Figure 4 A schematic diagram of the structure of a second embodiment of the temperature compensation detection circuit in the driving circuit provided in this application;

[0048] Figure 5 for Figure 4 The illustrated embodiment shows a graph of the voltage of the thermistor and the reference voltage.

[0049] Figure 6 for Figure 4 The illustrated embodiment is a graph showing the relationship between reference voltage and control signal;

[0050] Figure 7 This is a graph showing the relationship between the voltage and gate drive voltage of a real thermistor in the prior art;

[0051] Figure 8 This is a graph showing the relationship between the temperature of the thermistor and the gate drive voltage in the temperature compensation curve.

[0052] Figure 9 A schematic diagram of the structure of an embodiment of the display panel provided in this application.

[0053] Figure reference numerals: Drive circuit 10, Temperature compensation detection circuit 12, Temperature compensation circuit 13, Voltage detection circuit 121, Output circuit 122, Voltage VT of the 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 terminal P of temperature compensation detection circuit, Control signal u0, Threshold voltage providing unit 1223, Second comparator unit 1224, Capacitor C, First resistor R1, Second resistor R2, First comparator A3, Reference voltage u1, Reference voltage V ref The third resistor is R3, the fourth resistor is R4, the fifth resistor is R5, and the Zener diode is VD. Z Second comparator A4, display panel 20, array substrate 30. Detailed Implementation

[0054] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0055] In the following description, specific details such as particular system architectures, interfaces, and technologies are presented for illustrative purposes rather than for limiting purposes, in order to provide a thorough understanding of this application.

[0056] In this article, the term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, "more" in this article means two or more objects.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0058] Before providing a further detailed description of the embodiments of this application, the nouns and terms involved in the embodiments of this application will be explained, and the nouns and terms involved in the embodiments of this application shall be interpreted as follows.

[0059] Existing methods typically utilize PowerIC's temperature compensation function, employing a thermistor with a negative temperature coefficient to detect real-time temperature changes. As the thermistor's temperature increases, its resistance decreases, resulting in a lower voltage; conversely, as the temperature decreases, its resistance increases, leading to a higher voltage. Specifically, PowerIC's temperature compensation function must adhere to 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 temperature of the thermistor, and the vertical axis represents the gate drive voltage. 10℃ is the low-temperature boundary, and 35℃ is the high-temperature boundary. Specifically, when the thermistor temperature is below 10℃, compensation is required to ensure the corresponding output gate drive voltage VGH is 36V. When the thermistor temperature is above 35℃, compensation is also required to ensure the corresponding output gate drive voltage VGH is 28V. However, when the thermistor temperature is between 10℃ and 35℃, neither low-temperature nor high-temperature compensation is needed. In this case, the gate drive voltage VGH is unstable, as can be seen from the temperature compensation curve.

[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 represents the thermistor voltage, and the vertical axis represents the gate drive voltage VGH. When the thermistor is at a low temperature, its voltage is higher, for example, VT_LT, corresponding to an output gate drive voltage of VGH_LT. When the thermistor is at a high temperature, its voltage is lower, for example, VT_HT, corresponding to an output gate drive voltage of VGH_HT. When the thermistor voltage is between the low-temperature voltage VT_HT and VT_LT, the output gate drive voltage VGH becomes unstable and may also experience issues due to mode switching. Figure 7 The step-like fluctuations are shown. Although the gate drive voltage VGH will tend to stabilize as the temperature of the thermistor rises and stabilizes to a high temperature (above 35°C), the temperature rise takes a certain amount of time. During this time, the gate drive voltage VGH is unstable and is not the actual required voltage, which will cause abnormal display phenomena and affect the display effect.

[0061] In view of this, this application proposes a driving circuit that can determine whether temperature compensation is needed based on the voltage of a thermistor, thereby selectively outputting a control signal for a first state or control information for a second state to enable or disable the temperature compensation circuit. Specifically, this application can disable the temperature compensation circuit when the thermistor voltage is between a low-temperature voltage and a high-temperature voltage and temperature compensation is not needed, thus preventing the temperature compensation circuit from outputting a gate drive voltage, thereby avoiding gate drive voltage instability and improving display performance. To enable those skilled in the art to better understand the technical solution of this invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] See Figure 1 , Figure 1 This is a schematic diagram of an embodiment of the driving circuit provided in this 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. 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 output terminal P of the voltage detection circuit 121 and the temperature compensation detection circuit 12, and is used to output a first-state control signal or a second-state control signal based on the voltage VT of the thermistor RNTC. The first-state control signal enables the temperature compensation circuit 13 to output a gate drive voltage VGH, and the second-state control signal enables the temperature compensation circuit 13 to be turned off.

[0063] Specifically, such as Figure 1 As shown, the temperature detection circuit 11 is specifically formed by a thermistor RNTC and a resistor Ra connected in parallel, and then connected in series with a resistor Rb and grounded. Since the resistance of the thermistor RNTC changes with the ambient temperature, under a given constant current source, the resistance of the thermistor 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, for example, by a power management chip. The constant current source can be customized according to the actual application scenario, for example, it can be 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 a TFT shifts with temperature. At low temperatures, the carrier mobility of the semiconductor material decreases, causing the threshold voltage to exhibit the opposite trend (i.e., the lower the temperature, the lower the threshold voltage). If a room-temperature designed gate drive voltage (VGH) is still used, it cannot provide a sufficient gate-source voltage difference (VGH-Vth) for the TFT, resulting in insufficient TFT conduction and problems such as response delay and decreased display brightness. In this embodiment, the temperature detection circuit 11 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 compensation detection circuit 12 is connected to the temperature detection circuit 11, specifically to 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 output terminal P of the voltage detection circuit 121 and the temperature compensation detection circuit 12, and is used to output a first-state control signal or a second-state control signal based on the voltage VT of the thermistor RNTC. The first-state control signal enables the temperature compensation circuit 13 to output the gate drive voltage VGH, and the second-state control signal enables the temperature compensation circuit 13 to be turned off. It should be noted that the gate drive voltage VGH is the voltage after temperature compensation. When the temperature compensation circuit 13 outputs the gate drive voltage VGH after temperature compensation, 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 detects the voltage VT of the thermistor RNTC, including detecting the voltage change range of the thermistor RNTC voltage VT or the voltage change rate of the thermistor RNTC voltage VT.

[0067] In one embodiment, combined with Figure 2 and Figure 3When the voltage detection circuit 121 detects the voltage VT of the thermistor RNTC, including detecting the voltage change range of the thermistor RNTC voltage VT, the voltage detection circuit 121 includes a first comparison unit 123. The first comparison unit 123 is connected to the thermistor RNTC and is used 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 in response to the voltage VT of the thermistor RNTC being 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 for 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 for a second state. Wherein, 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. (Combined with...) 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 a thermistor RNTC to receive the voltage VT from the thermistor RNTC, and the other input terminal receives a first reference voltage VT_LT. A 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, connected to a series resistor Rd, is connected to the thermistor RNTC to receive the voltage VT from the thermistor RNTC; the inverting input terminal of the first operational amplifier unit A1, connected to a series resistor Rc, receives the first reference voltage VT_LT; and 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 a thermistor RNTC, receiving the voltage VT from RNTC. The other input terminal receives a 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 a series resistor Rf, which 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 a series resistor Re, which is connected to the thermistor RNTC, receiving the voltage VT from RNTC. 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 diode VD1 is connected to the output terminal of the first operational amplifier unit A1, and the cathode of diode VD1 is connected to the output terminal P of the temperature compensation detection circuit 12 and grounded through resistor Rg. The second output unit 1222 includes, for example, a diode VD2 and a resistor Rg. The anode of diode VD2 is connected to the output terminal of the second operational amplifier unit A2, and the cathode of diode VD2 is connected to the output terminal P of the temperature compensation detection circuit 12 and grounded through resistor Rg. It should be noted that the first output unit 1221 and the second output unit 1222 share a single resistor Rg.

[0072] In response to the thermistor RNTC's voltage VT being greater than the first reference voltage VT_LT, it is understandable that since the first reference voltage VT_LT is greater than the second reference voltage VT_HT, if VT > VT_LT, then VT must also > VT_HT. At this time, the first operational amplifier unit A1 outputs a high-level signal, diode VD1 is turned on, and the second operational amplifier unit A2 outputs a low-level signal, diode VD2 is turned off. The first output unit 1221 outputs a control signal for the first state, denoted as u0 in this embodiment. The control signal u0 for the first state 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 diode VD1 is turned on, the control signal u0 for the first state is in a high-level state, indicating that the temperature compensation circuit 13 is enabled and outputs a gate drive voltage VGH, which is the temperature-compensated voltage.

[0073] In response to the thermistor RNTC's voltage VT being less than the second reference voltage VT_HT, it's understandable 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, diode VD1 is cut off, and the second operational amplifier unit A2 outputs a high-level signal, diode VD2 is turned on. The second output unit 1222 outputs the first-state control signal u0, which is output through the output terminal P of the temperature compensation detection circuit 12. It should be noted that because the second operational amplifier unit A2 outputs a low-level signal and 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] When the voltage of the thermistor is within the range of the first reference voltage and the second reference voltage, i.e., 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 diodes VD1 and VD2 are turned off, and the output terminal 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] Understandably, 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; or, 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 low-level signals output by the first operational amplifier unit A1 and the second operational amplifier unit A2.

[0076] In this embodiment, when the detected VT voltage meets the condition VT_HT < VT < VT_LT, the output control signal u0 is low; when it meets the condition VT < VT_HT or VT > VT_LT, the output control signal u0 is high. In one embodiment, the control signal u0 can be connected to the GPIO port of the timing control circuit. The timing control circuit can turn on the temperature compensation enable switch when a high-level control signal u0 is detected and turn off the temperature compensation enable switch when a low-level control signal u0 is detected, thereby achieving the purpose of disabling temperature compensation when VT_HT < VT < VT_LT. After disabling temperature compensation, the temperature compensation circuit 13 will not output. Figure 7 The unstable gate drive voltage VGH shown is avoided to prevent instability in the output gate drive voltage VGH and improve the display effect. 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.

[0077] In one embodiment of this application, combined with Figure 7 and Figure 8 When the temperature of the 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, 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, for example, 36V). When the temperature of the 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, 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, for example, 28V).

[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 rate of change of the voltage VT of the thermistor RNTC, the voltage detection circuit 121 is used to determine the rate of change of the voltage VT of the thermistor RNTC, and outputs a reference voltage u1 based on the rate of change. The output circuit 122 is used to compare the reference voltage u1 with the threshold voltage UT, and outputs a control signal u0 for a first state or a control signal u0 for a second state 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 terminal of capacitor C is connected to a thermistor RNTC to receive voltage VT. The first terminal of the first resistor R1 is grounded. The first input terminal (inverting input -) of the first comparator A3 is connected to the second terminal of capacitor C. The second input terminal (non-inverting input +) of the first comparator A3 is connected to the second terminal of the first resistor R1. The first terminal of the second resistor R2 is connected to the first input terminal of the first comparator A3, and the second terminal of the second resistor R2 is connected to the output terminal 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 in the capacitor C is... C The current of the second resistor R2 Equal, that is Since the voltage at the inverting input terminal - is 0, the reference voltage u1 output by the first comparator A3 is as follows:

[0081]

[0082] in, This represents the rate of change of capacitance C with time t. It represents 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 derivative of the voltage VT with respect to time, and the derivative of the voltage VT with respect to time represents the rate of change of the voltage VT. Combined with... Figure 5 When the voltage VT rises linearly, the reference voltage u1 is a fixed negative voltage; when VT remains constant, the reference voltage u1 is 0; and when the voltage VT falls linearly, the reference voltage u1 is a fixed positive voltage. The amplitude of the reference voltage u1 represents the rate of voltage change.

[0084] See also Figure 4 The output circuit 122 includes a threshold voltage providing unit 1223 and a second comparison unit 1224. The threshold voltage providing unit 1223 provides a threshold voltage UT and includes a third resistor R3, a fourth resistor R4, and a reference voltage source. The first terminal 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 to receive 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 ends of both the fourth resistor R4 and the third resistor R3 are connected to the second comparison unit 1224.

[0085] The second comparison unit 1224 includes a second comparator A4, a fifth resistor R5, and a Zener diode VD. Z The first input terminal (inverting input -) 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 (non-inverting input +) of the second comparator A4 is connected in series with the fifth resistor R5 and grounded. The output terminal of the second comparator A4 is connected to the output terminal P of the temperature compensation detection circuit 12; Zener diode VD Z One end is connected to the first input terminal of the second comparator A4, and the Zener diode VD Z The other end is connected to the output 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 a control signal u0 for the second state, which indicates that the temperature compensation circuit 13 is turned off; in response to the reference voltage being less than the threshold voltage, the output circuit 122 outputs a control signal u0 for the first state, which indicates that the temperature compensation circuit 13 is enabled.

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

[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] Where 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 reference voltage.

[0094] Based on the above formula, it can be deduced that: if the first input voltage U_ is greater than 0, then the reference voltage u1 is greater than the threshold voltage UT; if the first input voltage U_ is less than 0, then the reference voltage u1 is less than the threshold voltage UT. Zener diode VD Z The control signal u0 output from the output terminal P of the temperature compensation detection circuit 12 can be stabilized, specifically as follows: 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 control signal u0 of the first state is output from the output terminal P. The control signal u0 of 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 control signal u0 of the second state is output from the output terminal P. The control signal u0 of 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] This embodiment allows for the determination of whether temperature compensation should be enabled based on the rate of change of voltage VT, preventing instability in the output gate drive voltage VGH and improving display performance. In one embodiment, to further enhance stability, the timing control circuit can also activate the temperature compensation enable switch only after detecting a high-level control signal u0 for a sustained period.

[0096] In one feasible embodiment of this application, the driving circuit simultaneously detects both the voltage change range and the voltage change rate of the thermistor. That is, it simultaneously includes the above-mentioned... Figure 2 (Detecting the voltage change range of the thermistor) and Figure 4 The temperature compensation detection circuit shown (detecting the voltage change rate of the thermistor) also includes a connection... Figure 2 and Figure 4 The selected output unit of the temperature compensation detection circuit shown receives... Figure 2 The temperature compensation detection circuit shown outputs control signals for the first and second states; and receives... Figure 4 The temperature compensation detection circuit shown outputs control signals for a first state and a second state. Specifically, if the control signals received by the selection output unit are in the same state, for example, if the selection output unit receives... Figure 2 Simultaneously with the output of the first state control signal from the temperature compensation detection circuit shown, it receives... Figure 4 The control signal for the first state output of the temperature compensation detection circuit shown in the diagram indicates that the output unit outputs an enable signal, enabling the temperature compensation circuit to output a gate drive voltage. For example, the output unit receives... Figure 2 Simultaneously with the control signal of the second state output by the temperature compensation detection circuit shown, it receives... Figure 4 The control signal for the second state output by the temperature compensation detection circuit shown in the diagram indicates that the selection output unit outputs a de-enable signal, thus shutting down the temperature compensation circuit. However, if the control signal states received by the selection output unit are inconsistent between the two outputs, for example, if the selection output unit receives... Figure 2 Simultaneously with the control signal of the first state output by the temperature compensation detection circuit shown, it receives... Figure 4 The control signal for the second state output by the temperature compensation detection circuit shown, or the selection output unit receiving... Figure 2 Simultaneously with the control signal of the second state output by the temperature compensation detection circuit shown, it receives... Figure 4 The control signal for the first state output of the temperature compensation detection circuit shown is used to disable the temperature compensation circuit by selecting the output unit to output a non-enable signal in order not to affect the display effect. By setting this strategy, the gate drive voltage can be controlled more precisely, keeping the gate drive voltage stable and improving the display effect.

[0097] Specifically, product manufacturing generally requires ensuring product consistency. Therefore, the temperature compensation circuit is usually always on to ensure the product can adapt to different environments, such as low or high temperatures, and adaptively compensate for temperature changes when entering such environments. However, when the voltage VT of the thermistor RNTC meets the condition VT_HT < VT < VT_LT, the gate drive voltage VGH will inevitably become unstable because the temperature compensation circuit must follow the temperature compensation curve. Adjusting the temperature compensation curve, however, will degrade 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. This application sets a voltage detection control mechanism, which can output a control signal to start the temperature compensation enable switch when temperature compensation is needed (i.e., when the voltage VT of the thermistor RNTC meets the condition that VT is less than VT_HT or VT is greater than VT_LT); and can output a control signal to turn off the temperature compensation enable switch when temperature compensation is not needed (i.e., when the voltage VT of the thermistor RNTC meets the condition that VT_HT < VT < VT_LT), thereby turning off the temperature compensation circuit. On the one hand, this avoids the instability of the output gate drive voltage VGH, and on the other hand, it ensures that the temperature-voltage relationship in the temperature compensation curve is followed during low and high temperature processes, thereby improving the display effect.

[0098] See Figure 9 , Figure 9 This is a schematic diagram of a display panel according to an embodiment of 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 turned on by the scan line, writing data voltage into the storage capacitor. During display, 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 temperature-compensated gate driving voltage. It can be understood that the temperature-compensated gate driving voltage is 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 can be understood that it does not necessarily come directly from the power management chip; for example, it may have undergone other processing during transmission, 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. The temperature compensation detection circuit includes a voltage detection circuit connected to the thermistor for detecting the voltage of the thermistor; and an output circuit connected to the output terminals of the voltage detection circuit and the temperature compensation detection circuit for outputting a first-state control signal or a second-state control signal based on the voltage of the thermistor. The first-state control signal enables the temperature compensation circuit to output a gate drive voltage to the driving transistor, and the second-state control signal enables the temperature compensation circuit to be turned off.

[0100] It is 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 again here.

[0101] The above are merely embodiments of the present invention and do not limit the scope of patent protection of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A drive circuit characterized by comprising: The application relates to a temperature compensation circuit, which 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 to the temperature detection circuit. The temperature compensation detection circuit comprises a voltage detection circuit connected to the thermistor and used 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 for outputting a first state control signal or a second state control signal based on the voltage of the thermistor, wherein the first state control signal indicates enabling the temperature compensation circuit to output a gate driving voltage, and the second state control signal indicates closing the temperature compensation circuit. When the voltage of the thermistor is within a first reference voltage and a second reference voltage range, the output circuit outputs the second state control signal; when the voltage of the thermistor is greater than the first reference voltage or the voltage of the thermistor is less than the second reference voltage, the output circuit outputs the first state control signal; and the first reference voltage is greater than the second reference voltage. The voltage detection circuit detects the voltage of the thermistor, including detecting a voltage variation range or a voltage variation rate of the thermistor.

2. The drive circuit according to claim 1, characterized in that, The voltage detection circuit comprises a first comparison unit connected to the thermistor and used for comparing the voltage of the thermistor with a first reference voltage and a second reference voltage.

3. The drive circuit according to claim 2, characterized in that, When the voltage of the thermistor is greater than the first reference voltage or the voltage of the thermistor is less than the second reference voltage, the first comparison unit outputs a first detection signal, which indicates that the output circuit outputs the first state control signal; and when the voltage of the thermistor is within the first reference voltage and the second reference voltage range, the first comparison unit outputs a second detection signal, which indicates that the output circuit outputs the second state control signal. The first reference voltage is greater than the second reference voltage. The first comparison unit comprises a first operational amplifier unit and a second operational amplifier unit, and the output circuit comprises a first output unit and a second output unit.

4. The drive circuit according to claim 3, characterized in that, One input end of the first operational amplifier unit is connected to the thermistor and receives the voltage of the thermistor, and the other input end receives the first reference voltage; the first output unit is connected to the output end of the first operational amplifier unit; one input end of the second operational amplifier unit is connected to the thermistor and receives the voltage of the thermistor, and the other input end receives the second reference voltage; and the second output unit is connected to the output end of the second operational amplifier unit. When the voltage of the thermistor is greater than the first reference voltage, the first operational amplifier unit outputs a high-level signal, and the second operational amplifier unit outputs a low-level signal, and the first output unit outputs the first state control signal. ​ 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, and the second operational amplifier unit outputs a high-level signal, and the second output unit outputs the control signal in the 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 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 the control signal in the second state.

5. The drive circuit according to claim 2, characterized by The voltage detection circuit is configured to determine a voltage change rate of the thermistor, and output a reference voltage based on the voltage change rate, wherein an 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 the control signal in the first state or the control signal in the second state based on a comparison result.

6. The drive circuit according to claim 5, characterized in that, The voltage detection circuit comprises: a capacitor, a first end of the capacitor being connected to the thermistor; a first resistor, a first end of the first resistor being grounded; a first comparator, a first input end of the first comparator being connected to a second end of the capacitor, and a second input end of the first comparator being connected to a second end of the first resistor; a second resistor, a first end of the second resistor being connected to a first input end of the first comparator, and a second end of the second resistor being connected to an output end of the first comparator.

7. The drive circuit according to claim 5, characterized by The output circuit comprises a threshold voltage providing unit and a second comparison unit. The threshold voltage providing unit is configured to provide the threshold voltage, and the threshold voltage providing unit comprises: a third resistor, a first end of the third resistor being connected to a reference voltage source to receive a reference voltage; a fourth resistor, a first end of the fourth resistor being connected to the voltage detection circuit to receive the reference voltage, a second end of the fourth resistor being connected to a second end of the third resistor, and the second end of the fourth resistor and the second end of the third resistor being connected to the second comparison unit; The second comparison unit comprises a second comparator, a fifth resistor and a voltage stabilizing tube, a first input end of the second comparator being 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 being connected to the fifth resistor and grounded in series, and an output end of the second comparator being connected to the output end of the temperature compensation detection circuit; one end of the voltage stabilizing tube being connected to the first input end of the second comparator, and the other end of the voltage stabilizing tube being connected to the output end of the second comparator. The second comparator is configured to compare a first input voltage at the first input end with a second input voltage at the second input end, and the comparison result of the first input voltage and the second input voltage represents a comparison result of the reference voltage and the threshold voltage.

8. The drive circuit according to claim 7, characterized in that, The first input voltage U is determined in the following manner: The threshold voltage UT is determined in the following manner: wherein R4 is a resistance value of the fourth resistor, R3 is a resistance value of the third resistor, u1 is the reference voltage, and Vref is the reference voltage.

9. The drive circuit according to any one of claims 5 to 8, characterized by 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 indicating 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 of a first state, the control signal of the first state indicating to enable the temperature compensation circuit.

10. A display panel, characterized by, The display panel comprises: 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 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 to the temperature detection circuit; wherein the temperature compensation detection circuit comprises: a voltage detection circuit connected to the thermistor, for detecting a voltage of the thermistor; an output circuit connected to an 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 to enable the temperature compensation circuit to output a gate driving voltage to the driving transistor, and the control signal of the second state indicating to turn off the temperature compensation circuit; wherein when the voltage of the thermistor is within a range of a first reference voltage and a second reference voltage, the output circuit outputs the control signal of the second state; when the voltage of the thermistor is greater than the first reference voltage or the voltage of the thermistor is less than the second reference voltage, the output circuit outputs the control signal of the first state; wherein the first reference voltage is greater than the second reference voltage.

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