Protection circuit, goa driving circuit and display panel

Abstract

The protection circuit, GOA driving circuit and display panel provided by the application, the first switch unit includes a first end, a second end and a third end, the first end is electrically connected with the signal input end, and the third end is electrically connected with the to-be-input signal unit; the second switch unit includes a fourth end, a fifth end and a sixth end, the fourth end is electrically connected with the second end, and the sixth end is grounded; the first voltage input unit is electrically connected with the second end and the fourth end, the first voltage input unit is used for providing a first voltage, and the first voltage is greater than the cutoff voltage of the first switch unit; the adjusting unit is electrically connected with the fifth end, the adjusting unit is configured to make the voltage of the fifth end less than the cutoff voltage of the second switch unit when the monitored temperature is within a preset temperature range, and the adjusting unit is configured to make the voltage of the fifth end greater than or equal to the cutoff voltage of the second switch unit when the temperature is greater than an upper limit value of the preset temperature range, thereby reducing the risk of safety hazards caused by continuous temperature rise.

Description

Protection circuit, GOA drive circuit and display panel Technical Field

[0001] This application relates to the field of display technology, specifically to a protection circuit, a GOA driving circuit, and a display panel. Background Technology

[0002] Currently, the panel industry uses the overcurrent protection (OCP) function of level shifter (LS) chips to achieve overcurrent protection. However, the accuracy of LS chips in monitoring current and time is not high. Therefore, there may be situations where the panel is not turned off because the load current is within the monitoring error range of the LS chip, but the temperature rises. This can lead to a continuous rise in temperature and create safety hazards. Summary of the Invention

[0003] This application provides a protection circuit, a GOA driving circuit, and a display panel that can reduce the safety risks caused by continuous temperature rise.

[0004] In a first aspect, an embodiment of this application provides a protection circuit applied to a display panel, the protection circuit comprising:

[0005] The signal input terminal is used to receive input signals.

[0006] A first switching unit includes a first terminal, a second terminal, and a third terminal. The first terminal is electrically connected to the signal input terminal, and the third terminal is electrically connected to the signal unit to be input. When the voltage difference between the second terminal and the third terminal is greater than or equal to the cutoff voltage of the first switching unit, the first terminal and the third terminal are electrically connected, and when the voltage difference between the second terminal and the third terminal is less than the cutoff voltage of the first switching unit, the first terminal and the third terminal are electrically disconnected.

[0007] The second switching unit includes a fourth terminal, a fifth terminal, and a sixth terminal. The fourth terminal is electrically connected to the second terminal, and the sixth terminal is grounded or configured to be at a low voltage. When the voltage difference between the fifth terminal and the sixth terminal is greater than or equal to the cutoff voltage of the second switching unit, the fourth terminal and the sixth terminal are electrically connected, and the first terminal and the third terminal of the first switching unit are electrically disconnected. When the voltage difference between the fifth terminal and the sixth terminal is less than the cutoff voltage of the second switching unit, the second switching unit is electrically disconnected.

[0008] A first voltage input unit is electrically connected to the second terminal and the fourth terminal. The first voltage input unit provides a first voltage, the difference between the first voltage and the voltage at the third terminal being greater than or equal to the cutoff voltage of the first switching unit. The first voltage input unit is used to input the first voltage to the second terminal of the first switching unit when the fourth terminal of the second switching unit is electrically disconnected from the sixth terminal.

[0009] An adjustment unit is electrically connected to the fifth terminal. The adjustment unit is configured to make the voltage difference between the fifth terminal and the sixth terminal less than the cutoff voltage of the second switching unit when the monitored temperature is within a preset temperature range, and to make the voltage difference between the fifth terminal and the sixth terminal greater than or equal to the cutoff voltage of the second switching unit when the monitored temperature is greater than the upper limit of the preset temperature range.

[0010] Optionally, the regulating unit includes a second voltage input unit and a thermistor. The second voltage input unit is electrically connected to one end of the thermistor, and the other end of the thermistor is electrically connected to the fifth terminal of the second switching unit. The thermistor is configured to, when the monitored temperature is within the preset temperature range, cause the regulating unit to provide a voltage difference between the fifth terminal and the sixth terminal that is less than the cutoff voltage of the second switching unit. The thermistor is also configured to, when the monitored temperature is within the preset temperature range, cause the regulating unit to provide a voltage difference between the fifth terminal and the sixth terminal that is greater than or equal to the cutoff voltage of the second switching unit.

[0011] Optionally, the adjustment unit further includes a voltage divider resistor, one end of which is electrically connected to the other end of the thermistor, and the other end of which is electrically connected to the sixth terminal of the second switching unit.

[0012] Optionally, the voltage divider resistor includes a first voltage divider resistor and a second voltage divider resistor. One end of the first voltage divider resistor is electrically connected to the other end of the thermistor. The other end of the first voltage divider resistor is electrically connected to one end of the second voltage divider resistor and to the third end of the first switching unit. The other end of the second voltage divider resistor is electrically connected to the sixth end of the second switching unit.

[0013] Optionally, the voltage at the fifth terminal is: V2qb = [(R3 + R4) / R2 + R3 + R4] V1, wherein R3 is the resistance value of the first voltage divider resistor, R4 is the resistance value of the second voltage divider resistor, R2 is the resistance value of the thermistor, and V1 is the voltage provided by the second voltage input unit.

[0014] Optionally, the protection circuit further includes a protection resistor, one end of which is electrically connected to one end of the first voltage input unit, and the other end of which is electrically connected to the second end and the fourth end.

[0015] Optionally, the preset temperature range is [-10℃, 45℃], and / or the cutoff voltage of the second switching unit is 0.7V.

[0016] Secondly, an embodiment of this application provides a GOA driving circuit, including a first signal line, a GOA unit, and the protection circuit. The first signal line is electrically connected to the signal input terminal of the protection circuit and is used to provide a clock signal. The GOA unit is the input signal unit.

[0017] Thirdly, an embodiment of this application provides a display panel including a plurality of the aforementioned GOA driving circuits, wherein the plurality of GOA driving circuits are arranged along a column direction, and at least one of the GOA driving circuits includes the protection circuit.

[0018] Optionally, the display panel further includes multiple data lines, and the first voltage input unit is also electrically connected to the data lines, and the first voltage input unit is also used to provide data voltage to the data lines.

[0019] The protection circuit, GOA driving circuit, and display panel provided in this application are designed with a first switching unit including a first terminal, a second terminal, and a third terminal. The first terminal is electrically connected to the signal input terminal, and the third terminal is electrically connected to the signal unit to be input. The first terminal and the third terminal are electrically connected when the voltage at the second terminal is greater than or equal to the cutoff voltage of the first switching unit, and electrically disconnected when the voltage at the second terminal is less than the cutoff voltage of the first switching unit. The second switching unit includes a fourth terminal, a fifth terminal, and a sixth terminal. The fourth terminal is electrically connected to the second terminal, and the sixth terminal is grounded. The fourth terminal and the sixth terminal are electrically connected when the voltage at the fifth terminal is greater than or equal to the cutoff voltage of the second switching unit, and the first terminal and the third terminal of the first switching unit are electrically disconnected when the voltage at the fifth terminal is greater than or equal to the cutoff voltage of the second switching unit. The circuit is electrically disconnected when the voltage is less than the cutoff voltage of the second switching unit; the first voltage input unit is electrically connected to the second and fourth terminals, and is used to provide a first voltage, which is greater than the cutoff voltage of the first switching unit. The first voltage input unit is used to input the first voltage to the second terminal of the first switching unit when the fourth and sixth terminals of the second switching unit are electrically disconnected; the regulating unit is electrically connected to the fifth terminal, and is configured such that when the monitored temperature is within a preset temperature range, the voltage at the fifth terminal is less than the cutoff voltage of the second switching unit, and when the regulating unit is greater than the upper limit of the preset temperature range, the voltage at the fifth terminal is greater than or equal to the cutoff voltage of the second switching unit, thereby reducing the risk of safety hazards caused by continuous temperature rise. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 is a circuit diagram of the protection circuit provided in an embodiment of this application;

[0022] Figure 2 is a circuit diagram of the adjustment unit in the protection circuit provided in the embodiment of this application, which includes a second voltage input unit and a temperature-sensitive resistor;

[0023] Figure 3 is a circuit diagram showing that the adjustment unit in the protection circuit provided in the embodiment of this application also includes a voltage divider resistor;

[0024] Figure 4 is a circuit diagram of the protection circuit provided in the embodiment of this application, which includes a first voltage divider resistor and a second voltage divider resistor.

[0025] Figure 5 is a circuit diagram of the protection circuit provided in an embodiment of this application, including a protection resistor;

[0026] Figure 6 is a schematic diagram of the GOA driving circuit provided in an embodiment of this application;

[0027] Figure 7 is a timing diagram of the GOA unit in the GOA driving circuit provided in the embodiment of this application;

[0028] Figure 8 is a schematic diagram of the structure of the display panel provided in an embodiment of this application.

[0029] Label Explanation:

[0030] Display panel 1000; Protection circuit 10; GOA drive circuit 100; Signal input terminal 11; First switch unit Q1; Second switch unit Q2; First voltage input unit 12; Adjustment unit 13; Input signal unit 20; Second voltage input unit 131; Thermistor R2; Voltage divider resistor R0; First voltage divider resistor R3; Second voltage divider resistor R4; Protection resistor R1; First signal line 30; GOA unit 40; Reset signal line Output N-1; First switch M1; Second switch M2; Initial signal line Output N-1; Third switch M3; Fourth switch M4; Parasitic capacitance C; Output signal line Output N. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. The reference to "embodiment" or "implementation" herein means that a specific feature, structure, or characteristic described in connection with an embodiment or implementation can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0033] In general technology, overcurrent protection is achieved using the overcurrent protection (OCP) function of a level shifter (LS) chip. The principle is as follows: when the LS chip detects a large load current inside the panel, according to its specific judgment mechanism, the LS chip pulls all its outputs (STV, RST reset signal, CLK signal, etc.) to a high impedance state, and all LS chip outputs are at a low potential, thereby achieving the purpose of shutting down the panel. However, there are situations where the load current connected to the LS chip is within the LS chip's monitoring error range, but the temperature rises. For example, a short circuit occurs in the circuit near the GOA drive circuit, causing the temperature to rise, while no large current is generated in the GOA drive circuit. Therefore, when the panel heats up due to the load current being within the LS chip's monitoring error range, it may not be shut down because the load current is within the LS chip's monitoring error range. In other words, the LS chip cannot monitor both the large load current inside the panel and the rising temperature in the surrounding environment when the load current is within the LS chip's monitoring error range, resulting in a continuous temperature rise and creating a safety hazard.

[0034] Please refer to Figure 1. This application provides a protection circuit 10 for reducing the safety risks caused by continuous temperature rise in a display panel 1000. The protection circuit 10 includes a signal input terminal 11, a first switching unit Q1, a second switching unit Q2, a first voltage input unit 12, and an adjustment unit 13.

[0035] Optionally, the protection circuit 10 can be applied to the GOA driving circuit 100. Further, the protection circuit 10 monitors the current of the GOA driving circuit 100 and the surrounding temperature. GOA is short for Gate Driven on Array. The GOA driving circuit 100 is an array-on-a-substrate gate driver integrated circuit, also known as an ASG (Amorphous Silicon Gate), which enables the progressive scan driving function of the liquid crystal panel. In traditional active-matrix liquid crystal displays, the line scan signal is implemented by an external integrated circuit (G-COF). Using GOA driving, the line scan driving circuit is fabricated using the same process as thin-film transistors (TFTs) based on only a few control signals provided by the external circuit, thus achieving the progressive scan driving function.

[0036] Of course, in other embodiments, the protection circuit 10 can also be used for other load circuits.

[0037] Signal input terminal 11 is used to receive input signals. These input signals include, but are not limited to, control signals. When protection circuit 10 is applied to GOA drive circuit 100, the input signals include, but are not limited to, CLK signals.

[0038] Referring to Figure 1, the first switching unit Q1 includes a first terminal c1, a second terminal b1, and a third terminal e1. The first terminal c1 is electrically connected to the signal input terminal 11 and is used to receive input signals. The third terminal e1 is electrically connected to the input signal unit 20. When the protection circuit 10 is applied to the GOA drive circuit 100, the input signal unit 20 includes, but is not limited to, a GOA unit, etc. Specific examples of GOA units will be given later.

[0039] When the voltage difference between the second terminal b1 and the third terminal e1 is greater than or equal to the cutoff voltage of the first switching unit Q1, the first terminal c1 and the third terminal e1 are electrically connected; when the voltage difference between the second terminal b1 and the third terminal e1 is less than the cutoff voltage of the first switching unit Q1, the first terminal c1 and the third terminal e1 are electrically disconnected.

[0040] Optionally, the first switching unit Q1 is a transistor. A transistor is a semiconductor device that controls current, amplifying weak signals into larger amplitude electrical signals, and is also used as a contactless switch. The first terminal c1 is the collector of the first switching unit Q1, the second terminal b1 is the base of the first switching unit Q1, and the third terminal e1 is the emitter of the first switching unit Q1. The cutoff voltage of the first switching unit Q1 refers to the voltage between its base and emitter; when this voltage is less than the cutoff voltage, the transistor is in the off state and does not conduct current. The cutoff voltage of the transistor is mainly related to its structure and material parameters.

[0041] The first switching unit Q1 is, but is not limited to, an NPN transistor or a PNP transistor. For an NPN transistor, the cutoff voltage is approximately between 0.6V and 0.7V, and for a PNP transistor, the cutoff voltage is also approximately between 0.6V and 0.7V. This application is not limited to a specific value for the cutoff voltage, which may vary depending on the specific process and design, but is generally between 0.2V and 0.7V. This embodiment uses a cutoff voltage of 0.7V for the first switching unit Q1 as an example.

[0042] Of course, in other embodiments, the first switching unit Q1 may also be at least one of MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), transistor, etc., to realize the function of turning on or off the signal input terminal 11 and the input signal unit 20.

[0043] The second switching unit Q2 includes a fourth terminal c2, a fifth terminal b2, and a sixth terminal e2. The fourth terminal c2 is electrically connected to the second terminal b1. The sixth terminal e2 is grounded or configured to a low level. Optionally, the low level is less than the cutoff voltage of the first switching unit Q1, for example, 0.7V. In this embodiment, the sixth terminal e2 is electrically connected to a reference ground (ground). When the voltage difference between the fifth terminal b2 and the sixth terminal e2 is greater than or equal to the cutoff voltage of the second switching unit Q2, the fourth terminal c2 and the sixth terminal e2 are electrically connected, and the first terminal c1 and the third terminal e1 of the first switching unit Q1 are electrically disconnected; and when the voltage difference between the fifth terminal b2 and the sixth terminal e2 is less than the cutoff voltage of the second switching unit Q2, the fourth terminal c2 and the sixth terminal e2 are electrically disconnected.

[0044] Optionally, the second switching unit Q2 is a transistor. The fourth terminal c2 is the collector of the second switching unit Q2, the fifth terminal b2 is the base of the second switching unit Q2, and the sixth terminal e2 is the emitter of the second switching unit Q2. The cutoff voltage of the second switching unit Q2 refers to the voltage between its base and emitter, at which point the transistor is in the off state and does not conduct current. The cutoff voltage of the transistor is mainly related to its structure and material parameters.

[0045] The second switching unit Q2 is, but is not limited to, an NPN transistor or a PNP transistor. For an NPN transistor, the cutoff voltage is approximately between 0.6V and 0.7V, and for a PNP transistor, the cutoff voltage is also approximately between 0.6V and 0.7V. This application is not limited to a specific value for the cutoff voltage, which may vary depending on the specific process and design, but is generally between 0.2V and 0.7V. This embodiment uses a cutoff voltage of 0.7V for the second switching unit Q2 as an example.

[0046] Of course, in other embodiments, the second switching unit Q2 may also be at least one of MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), transistor, etc., to realize the function of turning on or off the signal input terminal 11 and the input signal unit 20.

[0047] Referring to Figure 1, the first voltage input unit 12 is electrically connected to the second terminal b1 and the fourth terminal c2. The first voltage input unit 12 is used to provide a first voltage VGH. The difference between the first voltage VGH and the voltage at the third terminal e1 is greater than or equal to the cutoff voltage of the first switching unit Q1. The first voltage input unit 12 is used to input the first voltage VGH to the second terminal b1 of the first switching unit Q1 when the fourth terminal c2 of the second switching unit Q2 is electrically disconnected from the sixth terminal e2 (i.e., the second switching unit Q2 is in the cutoff state). The voltage difference between the base and collector of the first switching unit Q1 is greater than or equal to the cutoff voltage of the first switching unit Q1, and the first switching unit Q1 is in the on state (i.e., the first terminal c1 and the third terminal e1 are electrically connected).

[0048] Optionally, when the second switch unit Q2 is in the on state, the fourth terminal c2 and the sixth terminal e2 are electrically connected, and the fourth terminal c2 is electrically connected to the second terminal b1, and the sixth terminal e2 is electrically connected to a low level or ground. Therefore, the second terminal b1 is at a low level or ground. The voltage difference between the second terminal b1 and the third terminal e1 is less than the cutoff voltage of the first switch unit Q1. Therefore, the first switch unit Q1 is in the off state (i.e., the first terminal c1 and the third terminal e1 are electrically disconnected).

[0049] Referring to Figure 1, the regulating unit 13 is electrically connected to the fifth terminal b2. The regulating unit 13 is configured to ensure that, when the monitored temperature is within a preset temperature range, the voltage difference between the fifth terminal b2 and the sixth terminal e2 is less than the cutoff voltage of the second switching unit Q2. Specifically, the regulating unit 13 is used to regulate the voltage of the fifth terminal b2, thereby ensuring that the voltage difference between the fifth terminal b2 and the sixth terminal e2 is less than the cutoff voltage of the second switching unit Q2.

[0050] Optionally, the sixth terminal e2 is grounded, and the cutoff voltage of the second switching unit Q2 is 0.7V. The adjustment unit 13 is configured to adjust the voltage of the fifth terminal b2 to be less than 0.7V when the monitored temperature is within a preset temperature range. At this time, the second switching unit Q2 is in the off state. As mentioned above, the first voltage input unit 12 provides the first voltage VGH to the third terminal e1, and the first switching unit Q1 is in the on state, so that the input signal of the signal input terminal 11 can be transmitted to the input signal unit 20. That is, when the monitored temperature is within the preset temperature range, the protection circuit 10 does not block the input signal unit 20 from receiving the input signal (CLK), that is, the GOA drive circuit 100 can work normally when the monitored temperature is within the preset temperature range.

[0051] The adjustment unit 13 is configured to, when the monitored temperature exceeds the upper limit of the preset temperature range, make the voltage difference between the fifth terminal b2 and the sixth terminal e2 greater than or equal to the cutoff voltage of the second switching unit Q2. At this time, the second switching unit Q2 is turned on. As mentioned above, the second terminal b1 is grounded through the second switching unit Q2, and the first switching unit Q1 is in the off state. Consequently, the signal input terminal 11 is disconnected from the signal input unit 20, meaning the GOA unit cannot receive the CLK signal. The GOA driving circuit 100 stops working when the monitored temperature exceeds the upper limit of the preset temperature range, and the display panel 1000 is turned off to avoid safety hazards caused by excessively high temperatures or continued temperature increases.

[0052] Optionally, the preset temperature range is [-10℃~45℃], with the upper limit of the preset temperature range being 45℃ and the lower limit being -10℃.

[0053] Optionally, when the input signal current at signal input terminal 11 is too large, the monitored temperature rises. Furthermore, when the current in other wires in the GOA drive circuit 100 is too large, the monitored temperature also rises. In other words, the protection circuit 10 provided in this embodiment not only monitors nearby electrically connected wires, but also monitors situations where the current in nearby unconnected wires is too large.

[0054] The protection circuit 10, GOA driving circuit 100, and display panel 1000 provided in this application are designed such that the first switching unit Q1 includes a first terminal c1, a second terminal b1, and a third terminal e1. The first terminal c1 is electrically connected to the signal input terminal 11, and the third terminal e1 is electrically connected to the signal input unit 20. The first terminal c1 and the third terminal e1 are electrically connected when the voltage at the second terminal b1 is greater than or equal to the cutoff voltage of the first switching unit Q1, and electrically disconnected when the voltage at the second terminal b1 is less than the cutoff voltage of the first switching unit Q1. The second switching unit Q2 includes a fourth terminal c2, a fifth terminal b2, and a sixth terminal e2. The fourth terminal c2 is electrically connected to the second terminal b1, and the sixth terminal e2 is grounded. The fourth terminal c2 and the sixth terminal e2 are electrically connected when the voltage at the fifth terminal b2 is greater than or equal to the cutoff voltage of the second switching unit Q2, and the first terminal c1 and the third terminal e1 of the first switching unit Q1 are electrically disconnected. When the voltage at the fifth terminal b2 is less than the cutoff voltage of the second switching unit Q2, the circuit is electrically disconnected. The first voltage input unit 12 is electrically connected to the second terminal b1 and the fourth terminal c2. The first voltage input unit 12 is used to provide a first voltage VGH, which is greater than the cutoff voltage of the first switching unit Q1. When the fourth terminal c2 and the sixth terminal e2 of the second switching unit Q2 are electrically disconnected, the first voltage input unit 12 is used to input the first voltage VGH to the second terminal b1 of the first switching unit Q1. The adjustment unit 13 is electrically connected to the fifth terminal b2. The adjustment unit 13 is configured to make the voltage at the fifth terminal b2 greater than or equal to the cutoff voltage of the second switching unit Q2 when the monitored temperature is within a preset temperature range and when the voltage at the fifth terminal b2 is less than the cutoff voltage of the second switching unit Q2, and when the adjustment unit 13 is greater than the upper limit of the preset temperature range, thereby reducing the risk of safety hazards caused by continuous temperature rise.

[0055] Optionally, the protection circuit 10 provided in this application embodiment is located in the GOA driving circuit 100. The GOA driving circuit 100 is formed by the same process as thin film transistor (TFT). Therefore, the protection circuit 10 is a circuit in the panel and does not need to be controlled by the chip. It directly performs temperature monitoring in the area where the GOA driving circuit 100 is located, and performs current monitoring in and near the GOA driving circuit 100.

[0056] Optionally, the protection circuit 10 provided in this application embodiment can be fabricated using the same process as that used for thin-film transistors (TFTs).

[0057] Optionally, as shown in Figure 2, the adjustment unit 13 includes a second voltage input unit 131 and a thermistor R2.

[0058] Referring to Figure 2, the second voltage input unit 131 is used to provide a second voltage V1. The second voltage V1 is greater than the cutoff voltage of the second switching unit Q2.

[0059] Referring to Figure 2, the second voltage input unit 131 is electrically connected to one end of the thermistor R2, and the other end of the thermistor R2 is electrically connected to the fifth terminal b2 of the second switching unit Q2. The thermistor R2 is used to adjust its resistance value according to the monitored temperature, thereby changing the voltage at the fifth terminal b2 of the second switching unit Q2, so that the second switching unit Q2 is in a cutoff state or a conduction state.

[0060] A thermistor R2 is a resistive device whose resistance changes with different temperatures. More specifically, the thermistor R2 is a device that detects changes in resistivity caused by temperature variations in a material.

[0061] The temperature-sensitive resistor R2 is configured to, when the monitored temperature is within the preset temperature range, cause the regulating unit 13 to provide a voltage difference between the fifth terminal b2 and the sixth terminal e2 that is less than the cutoff voltage of the second switching unit Q2.

[0062] The temperature-sensitive resistor R2 is configured such that when the monitored temperature is greater than the upper limit of the preset temperature range, the voltage difference provided by the adjustment unit 13 between the fifth terminal b2 and the sixth terminal e2 is greater than or equal to the cutoff voltage of the second switching unit Q2.

[0063] Optionally, by designing the resistance of the temperature-sensitive resistor R2 to change with temperature, or by selecting a temperature-sensitive resistor R2 with suitable parameters, the resistance of the temperature-sensitive resistor R2 within a preset temperature range [-10℃~45℃] is kept within a preset resistance range, thereby ensuring that the voltage at the fifth terminal b2 is within a preset voltage range, for example, less than 0.7V, thus keeping the second switching unit Q2 in the off state and the first switching unit Q1 in the on state. Conversely, at temperatures exceeding the upper limit of the preset temperature range [-10℃~45℃], the resistance of the temperature-sensitive resistor R2 is kept outside the preset resistance range, thereby keeping the voltage at the fifth terminal b2 outside the preset voltage range, for example, greater than or equal to 0.7V, thus keeping the second switching unit Q2 in the on state and the first switching unit Q1 in the off state.

[0064] This embodiment of the application designs an adjustment unit 13 including a second voltage input unit 131 and a thermistor R2. The second voltage input unit 131 provides a second voltage V1 greater than the cutoff voltage of the second switching unit Q2. The thermistor R2 is configured to, when the monitored temperature is within the preset temperature range, cause the adjustment unit 13 to provide a voltage difference between the fifth terminal b2 and the sixth terminal e2 that is less than the cutoff voltage of the second switching unit Q2. It is also configured to, when the monitored temperature is greater than the upper limit of the preset temperature range, cause the adjustment unit 13 to provide a voltage difference between the fifth terminal b2 and the sixth terminal e2 that is greater than or equal to the cutoff voltage of the second switching unit Q2, thereby achieving the monitoring temperature within the preset temperature range. When the second switch unit Q2 is in the off state and the first switch unit Q1 is in the on state, the protection circuit 10 does not block the input signal unit 20 from receiving the input signal (CLK), that is, the GOA drive circuit 100 can work normally when the monitored temperature is within the preset temperature range; it also realizes that when the monitored temperature is greater than the upper limit of the preset temperature range, the second switch unit Q2 is in the on state and the first switch unit Q1 is in the off state, the signal input terminal 11 is disconnected from the input signal unit 20, that is, the GOA unit cannot receive the CLK signal, the GOA drive circuit 100 stops working when the monitored temperature is greater than the upper limit of the preset temperature range, and the display panel 1000 is turned off to avoid safety hazards caused by excessive temperature or continued temperature rise.

[0065] Optionally, referring to Figure 3, the adjustment unit 13 further includes a voltage divider resistor R0. One end of the voltage divider resistor R0 is electrically connected to the other end of the thermistor R2, and the other end of the voltage divider resistor R0 is electrically connected to the sixth terminal e2 of the second switching unit Q2.

[0066] Optionally, the sixth terminal e2 is grounded, and the voltage divider resistor R0 is used together with the thermistor R2 to share the first voltage VGH provided by the first voltage input unit 12.

[0067] In this embodiment, the voltage divider resistor R0 and the temperature-sensitive resistor R2 are designed to share the first voltage VGH provided by the first voltage input unit 12, so as to better control the voltage of the fifth terminal b2 to be less than or greater than or equal to the cutoff voltage of the second switching unit Q2, avoid the voltage of the fifth terminal b2 from suddenly increasing or decreasing, and reduce or increase the voltage of the fifth terminal b2 within a small range.

[0068] Optionally, referring to Figure 4, the voltage divider resistor R0 includes a first voltage divider resistor R3 and a second voltage divider resistor R4. One end of the first voltage divider resistor R3 is electrically connected to the other end of the thermistor R2. The other end of the first voltage divider resistor R3 is electrically connected to one end of the second voltage divider resistor R4 and to the third terminal e1 of the first switching unit Q1. The other end of the second voltage divider resistor R4 is electrically connected to the sixth terminal e2 of the second switching unit Q2.

[0069] Optionally, the voltage at the fifth terminal b2 is: V2qb = [(R3 + R4) / (R2 + R3 + R4)] V1. Wherein, R3 is the resistance value of the first voltage divider resistor R3. R4 is the resistance value of the second voltage divider resistor R4. R2 is the resistance value of the thermistor R2. V1 is the second voltage V1 provided by the second voltage input unit 131.

[0070] The resistance value of the temperature-sensitive resistor R2 is selected such that within the preset temperature range, the resistance value of the temperature-sensitive resistor R2 makes Vq2b < 0.7V. At this time, the second switch unit Q2 is turned off, the first switch unit Q1 is turned on, and the input signal is normally input to the input signal unit 20.

[0071] When the input load current suddenly increases beyond the threshold current and the temperature has not yet had time to rise, since the other end of the first voltage divider resistor R3 is electrically connected to one end of the second voltage divider resistor R4 and the third terminal e1 of the first switching unit Q1, the current in the first voltage divider resistor R3 and the second voltage divider resistor R4 increases, thereby increasing the voltage at the fifth terminal b2. For example, when the voltage Vq2b at the fifth terminal b2 is ≥ 0.7V, the second switching unit Q2 is turned on, the first switching unit Q1 is turned off, the input signal is interrupted, and the overcurrent protection is triggered.

[0072] When the input load current suddenly increases beyond the threshold current and the temperature rises, the current in the first voltage divider resistor R3 and the second voltage divider resistor R4 increases, as the other end of the first voltage divider resistor R3 is electrically connected to one end of the second voltage divider resistor R4 and the third terminal e1 of the first switching unit Q1. This increases the voltage at the fifth terminal b2. Simultaneously, the temperature near the thermistor R2 rises, causing its resistance to decrease, which also increases the voltage at the fifth terminal b2. When the voltage at the fifth terminal b2, Vq2b, is ≥ 0.7V, the second switching unit Q2 turns on, and the first switching unit Q1 turns off. At this point, the input signal stops being input to the signal waiting unit 20, triggering overcurrent and overtemperature protection. The overcurrent and overtemperature protection continues until the temperature in the GOA drive circuit 100 drops to a preset temperature range, increasing the impedance of the thermistor R2, causing Vq2b < 0.7V. At this point, the second switching unit Q2 turns off, the first switching unit Q1 turns on, and the input signal is input to the signal waiting unit 20 normally again.

[0073] When the temperature near the thermistor R2 rises while the input load current of the GOA drive circuit 100 does not increase, the impedance of the thermistor R2 decreases, and the value of V2qb increases until V2qb ≥ 0.7V. Consequently, the second switching unit Q2 turns on, and the first switching unit Q1 turns off. At this time, the input signal stops being input to the signal waiting unit 20. Until the temperature near the thermistor R2 drops to a preset temperature range, the impedance of the thermistor R2 increases, causing Vq2b < 0.7V. At this time, the second switching unit Q2 turns off, the first switching unit Q1 turns on, and the input signal is input normally to the signal waiting unit 20 again.

[0074] Further, referring to Figure 5, the protection circuit 10 also includes a protection resistor R1. One end of the protection resistor R1 is electrically connected to one end of the first voltage input unit 12, and the other end of the protection resistor R1 is electrically connected to the second terminal b1 and the fourth terminal c2. The protection resistor R1 is used to buffer the signal strength output by the first voltage input unit 12 (e.g., voltage division or current division), to prevent the output signal strength of the first voltage input unit 12 from being too large, which could cause an impact on the devices after the protection resistor R1.

[0075] Referring to Figure 6, the GOA driving circuit 100 provided in this application further includes a first signal line 30, a GOA unit 40, and the aforementioned protection circuit 10. The first signal line 30 is electrically connected to the signal input terminal 11 of the protection circuit 10. The first signal line 30 is used to provide a CLK signal. The GOA unit 40 is the input signal unit 20. Optionally, a first switch unit Q1 is disposed on the first signal line 30. The first switch unit Q1 controls the conduction or disconnection of the first signal line 30, thereby controlling whether the CLK signal is input to the GOA unit 40.

[0076] Please refer to Figure 6. The GOA unit 40 includes the reset signal line Output N-1 electrically connected to the previous row GOA unit 40, the first switch M1, the second switch M2, the initial signal line Output N-1 electrically connected to the next row GOA unit 40, the third switch M3, the fourth switch M4, the parasitic capacitance C, the output signal line Output N (gate line) electrically connected to the gate in the pixel unit, and the low potential line VSS.

[0077] The reset signal line Output N-1 is electrically connected to the gate M12 and the first terminal M11 of the first switch M1. The second terminal M13 of the first switch M1 is electrically connected to the first terminal M21 of the second switch M2, the gate M32 of the third switch M3, and the first terminal C1 of the parasitic capacitance C. The gate M22 of the second switch M2 is electrically connected to the initial signal line Output N-1 and the gate M42 of the fourth switch M4. The second terminal M23 of the second switch M2 is electrically connected to the low-potential line VSS. The first terminal M31 of the third switch M3 is electrically connected to the third terminal e1 of the first switch unit Q1. The second terminal M33 of the third switch M3 is electrically connected to the first terminal M41 of the fourth switch M4. The second terminal M43 of the fourth switch M4 is electrically connected to the low-potential line VSS. The second terminal C2 of the parasitic capacitance C is electrically connected to the output signal line Output N (gate line).

[0078] Point PU is the gate M32 of the third switch M3 (pull-up point) that controls the output signal line Output N to output a high level. Point PD is the gate M42 of the fourth switch M4 (pull-down point) that controls the output signal line Output N to output a low level. The first switch M1 pre-charges the parasitic capacitance C; that is, the input of the pulse signal in the previous row's reset signal line Output N-1 turns on the first switch M1. Then, the PU point (connected to one end of the parasitic capacitor C) is pre-charged. The pulse signal of the next row is used as the reset signal input to the PD point, causing the second switch M2 and the fourth switch M4 to turn on. The turned-on second switch M2 discharges the PU point (one end of the parasitic capacitor C is connected to the low potential line VSS). The turned-on fourth switch M4 discharges the output signal line Output N (the other end of the parasitic capacitor C is connected to the low potential line VSS). Therefore, functionally, a GOA unit 40 can be further divided into several functional sub-units. Among them, the first switch M1 constitutes the "charging unit". The second switch M2 and the fourth switch M4 constitute the "reset unit". The third switch M3 constitutes the "output unit". The working timing of the GOA unit 40 of the 4TIC is shown in Figure 7. The analysis is as follows:

[0079] Step 1: Before the output signal of the previous stage GOA unit 40 arrives, although the CLK signal line has a high potential input to the source of the third switch M3, the PU point is at a low potential, the third switch M3 is in the off state, and at this time the output signal line Output N does not output a high potential.

[0080] Step 2: The reset line of the previous stage GOA unit 40 provides the input signal for this stage GOA unit 40. After the first switch M1 is turned on and the PU point potential rises to V11, the third switch M3 is also turned on. However, since the CLK signal connected to the source of the third switch M3 (the first terminal M11) is still at a low potential at this time, the output signal line Output N of the GOA unit 40 still does not output a high potential, as shown in stage 1 of Figure 7.

[0081] Step 3: At this moment, the CLK signal outputs a high potential. Under the capacitive coupling of the gate M32 and the source parasitic capacitor C of the third switch M3, the potential of the PU point is also pulled up synchronously, that is, the potential of the PU point is raised to V12. At this time, the conduction capability of the third switch M3 is also greatly increased, and the output current is generated, causing the output signal line Output N to output a high potential, as shown in stage 2 of Figure 7.

[0082] Step 4: Because the current GOA unit 40's output signal line Output N is the input signal for the next-stage GOA unit 40, the next stage is also pre-charging during the output signal line Output N's output. As the CLK signal potential changes from high to low, the next stage's high-potential output signal line Output N is input to the current stage as a reset signal, making the PD point high. Then, the second switch M2 and the fourth switch M4 are turned on, connecting the parasitic capacitor C to the low potential of the low-potential line VSS for discharge. The output signal line Output N is also connected to the low potential, turning off the TFT (pixel thin-film transistor) of that row. See stage 3 in Figure 7.

[0083] Optionally, referring to Figure 8, this application also provides a display panel 1000. The display panel 1000 can be applied to, but is not limited to, mobile phones, televisions, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, automotive displays (e.g., odometer displays), navigators, cockpit controllers and / or displays, camera view displays (e.g., displays for rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, etc.

[0084] The display panel 1000 provided in this application includes the GOA driving circuit 100 described in any of the above embodiments. The display panel 1000 includes a plurality of the aforementioned GOA driving circuits 100. The GOA driving circuits 100 are located in the peripheral wiring area of ​​the display panel 1000. Each GOA driving circuit 100 corresponds to a row of pixel units. The plurality of GOA driving circuits 100 are arranged along a column direction. At least one of the GOA driving circuits 100 includes the protection circuit 10. Optionally, each GOA driving circuit 100 is provided with a protection circuit 10 to provide over-temperature and over-current protection for each GOA driving circuit 100. The display panel 1000 includes, but is not limited to, a TFT-LCD panel.

[0085] The display panel 1000 also includes multiple data lines. These data lines are used to electrically connect the source or drain of the pixel units of the display panel 1000. The data lines provide data voltage to the pixel units. The first voltage input unit 12 is also electrically connected to the data lines. The first voltage input unit 12 is also used to provide data voltage to the data lines. In other words, the first voltage VGH can be a data voltage, meaning that the data voltage can not only be used to drive the pixel units but also serve as over-temperature and over-current protection, achieving multiple uses with a single component, reducing the layout of components or wiring, saving space, and reducing manufacturing processes and costs.

[0086] This application provides a protection circuit 10, a GOA driving circuit 100, and a display panel 1000 that improves the overcurrent and overtemperature trigger protection inside the display panel 1000. The circuit design inside the display panel 1000 is optimized and modified without changing any signals input to the panel. While not reducing the quality of the display panel 1000 (transmittance, contrast, color coordinates, etc.), it achieves precise control of overcurrent and overtemperature protection inside the display panel 1000. The signal is turned off by controlling the output of the GOA driving circuit 100. The improvement effect can be achieved by only modifying the circuit design inside the display panel 1000.

[0087] The above are some embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A protection circuit, characterized in that, The protection circuit, applied to a display panel, includes: a signal input terminal for receiving input signals; a first switching unit, comprising a first terminal, a second terminal, and a third terminal, wherein the first terminal is electrically connected to the signal input terminal, and the third terminal is electrically connected to a unit receiving the input signal; the first terminal and the third terminal are electrically connected when the voltage difference between the second terminal and the third terminal is greater than or equal to the cutoff voltage of the first switching unit, and are electrically disconnected when the voltage difference between the second terminal and the third terminal is less than the cutoff voltage of the first switching unit; and a second switching unit, comprising a fourth terminal, a fifth terminal, and a sixth terminal, wherein the fourth terminal... The second terminal is electrically connected, the sixth terminal is grounded or configured to a low voltage, the fourth terminal is electrically connected to the sixth terminal when the voltage difference between the fifth terminal and the sixth terminal is greater than or equal to the cutoff voltage of the second switching unit, and the first terminal and the third terminal of the first switching unit are electrically disconnected, and the fourth terminal and the sixth terminal are electrically disconnected when the voltage difference between the fifth terminal and the sixth terminal is less than the cutoff voltage of the second switching unit; a first voltage input unit is electrically connected to the second terminal and the fourth terminal, the first voltage input unit is used to provide a first voltage, the difference between the first voltage and the voltage of the third terminal is greater than or equal to the voltage of the fifth terminal; The system includes a cutoff voltage for a switching unit, a first voltage input unit for inputting the first voltage to the second terminal of the first switching unit when the fourth terminal of the second switching unit is electrically disconnected from the sixth terminal; and an adjustment unit, the adjustment unit including a second voltage input unit and a thermistor, the second voltage input unit for providing a second voltage, the second voltage being greater than the cutoff voltage of the second switching unit, the second voltage input unit being electrically connected to one end of the thermistor, the other end of the thermistor being electrically connected to the fifth terminal of the second switching unit, the thermistor being used to adjust its resistance according to the monitored temperature, the thermistor being configured to adjust the resistance value according to the monitored temperature being within a preset temperature range. The regulating unit provides voltage to the fifth terminal and the sixth terminal such that the voltage difference is less than the cutoff voltage of the second switching unit, the second switching unit is in the off state, the first voltage input unit provides a first voltage to the third terminal, the first switching unit is in the on state, and the temperature-sensitive resistor is configured such that when the monitored temperature is greater than the upper limit of the preset temperature range, the regulating unit provides voltage to the fifth terminal and the sixth terminal such that the voltage difference is greater than or equal to the cutoff voltage of the second switching unit, the second switching unit is on, the second terminal is grounded through the second switching unit, the first switching unit is in the off state, and the signal input terminal is disconnected from the signal unit to be input.

2. The protection circuit as described in claim 1, characterized in that, The adjustment unit further includes a voltage divider resistor, one end of which is electrically connected to the other end of the thermistor, and the other end of which is electrically connected to the sixth terminal of the second switching unit.

3. The protection circuit as described in claim 2, characterized in that, The voltage divider resistor includes a first voltage divider resistor and a second voltage divider resistor. One end of the first voltage divider resistor is electrically connected to the other end of the thermistor. The other end of the first voltage divider resistor is electrically connected to one end of the second voltage divider resistor and to the third end of the first switching unit. The other end of the second voltage divider resistor is electrically connected to the sixth end of the second switching unit.

4. The protection circuit as described in claim 3, characterized in that, The voltage at the fifth terminal is: V2qb = [(R3 + R4) / (R2 + R3 + R4)] V1, wherein R3 is the resistance value of the first voltage divider resistor, R4 is the resistance value of the second voltage divider resistor, R2 is the resistance value of the thermistor, and V1 is the second voltage provided by the second voltage input unit.

5. The protection circuit as described in any one of claims 1 to 4, characterized in that, The protection circuit further includes a protection resistor, one end of which is electrically connected to one end of the first voltage input unit, and the other end of which is electrically connected to the second end and the fourth end.

6. The protection circuit as described in any one of claims 1 to 4, characterized in that, The preset temperature range is [-10℃, 45℃], and / or the cutoff voltage of the second switching unit is 0.7V.

7. A GOA driving circuit, characterized in that, It includes a first signal line, a GOA unit, and a protection circuit as described in any one of claims 1 to 6. The first signal line is electrically connected to the signal input terminal of the protection circuit and is used to provide a clock signal. The GOA unit is the input signal unit.

8. A display panel, characterized in that, It includes multiple GOA driving circuits as described in claim 7, the multiple GOA driving circuits are arranged along the column direction, and at least one of the GOA driving circuits includes the protection circuit.

9. The display panel as described in claim 8, characterized in that, The display panel also includes multiple data lines, and the first voltage input unit is electrically connected to the data lines. The first voltage input unit is also used to provide data voltage to the data lines.

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