Detection circuit, detection method, level conversion device and display device

Abstract

The present application provides a detection circuit, a detection method, a level conversion device and a display device. The detection circuit includes a temperature sensing module, which is used to obtain the temperature of a first branch, the first branch is an output branch of the level conversion module, the first branch is used to transmit a first signal, and the first signal is a working signal of a display panel; a control module, which is connected to the temperature sensing module, and the control module is used to generate a first control signal when the temperature detection result of the first branch exceeds the temperature critical value, and the first control signal is used to control the level conversion module not to output the first signal through the first branch. Since overcurrent will increase the temperature of the line, the embodiment of the present application determines whether to trigger overcurrent protection according to temperature changes, which helps to improve the accuracy of overcurrent detection.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a detection circuit, a detection method, a level conversion device and a display device. Background Art

[0002] Over current protection (OCP) is crucial for display products. When the traditional over current protection mechanism detects over current in the display product for multiple times in a row, it will control the working signal of the display product to stop outputting. However, the traditional over current protection mechanism has certain detection defects. For example, when over current occurs multiple times in a non-continuous manner, the over current protection cannot be triggered. Summary of the invention

[0003] The embodiments of the present application provide a detection circuit, a detection method, a level conversion device and a display device, which help to avoid the detection defects of traditional overcurrent protection mechanisms and help to improve the accuracy of overcurrent detection by judging whether there is an overcurrent phenomenon and whether the overcurrent protection mechanism is triggered according to temperature changes.

[0004] In a first aspect, an embodiment of the present application provides a detection circuit, comprising: a temperature sensing module, used to obtain the temperature of a first branch, the first branch being an output branch of a level conversion module, the first branch being used to transmit a first signal, the first signal being a working signal of a display panel; a control module, connected to the temperature sensing module, the control module being used to generate a first control signal when a temperature detection result of the first branch exceeds a temperature critical value, the first control signal being used to control the level conversion module not to output the first signal through the first branch.

[0005] As a possible implementation, the temperature sensing module includes a thermistor, which is connected in series with the first branch. The temperature sensing module is used to: detect the current value flowing through the thermistor, and transmit the current detection result of the thermistor to the control module; the control module is used to: generate the first control signal when the current detection result exceeds the current critical value, and the first control signal is used to control the level conversion module not to output the first signal through the first branch; wherein the current critical value is the current value flowing through the thermistor when the first branch is at a temperature corresponding to the temperature critical value.

[0006] As a possible implementation, the temperature sensing module includes a temperature sensor, the temperature sensor includes a detection circuit, and the temperature sensor is used to measure the temperature of a location where the detection circuit is located, wherein the area where the detection circuit is located covers the area where the first branch is located.

[0007] As a possible implementation manner, the first control signal is used to control the level conversion module to stop outputting the first signal, or the first control signal is used to control the level conversion module to output the first signal through a second branch.

[0008] As a possible implementation, the second branch includes a current limiting resistor and a first switch, the current limiting resistor is connected in series with the first switch, the first branch includes a second switch, the second branch is connected in parallel with the first branch, if the temperature detection result of the first branch exceeds the temperature critical value, the first control signal is used to control the first switch to be turned on, the second switch to be turned off, and the level conversion module to output the first signal through the second branch; if the temperature detection result of the first branch does not exceed the temperature critical value, the second switch is turned on, the first switch is turned off, and the level conversion module outputs the first signal through the first branch.

[0009] As a possible implementation method, the control module stores multiple temperature critical values, and the multiple temperature critical values ​​correspond one-to-one to multiple load ranges of the level conversion module. The control module is also used to: select the temperature critical value corresponding to the first branch from the multiple temperature critical values ​​based on the relationship between the value of the first signal and the multiple load ranges.

[0010] As a possible implementation manner, the thermistor is a negative temperature coefficient thermistor.

[0011] In second aspect, an embodiment of the present application provides a detection method for obtaining the temperature of a first branch, where the first branch is an output branch of a level conversion module, and the first branch is used to transmit a first signal, which is a working signal of a display panel; when the temperature detection result of the first branch exceeds a temperature critical value, a first control signal is generated, and the first control signal is used to control the level conversion module not to output the first signal through the first branch.

[0012] In a third aspect, an embodiment of the present application provides a level conversion device, including: a level conversion module; and a detection circuit as described in any one of the first aspects.

[0013] In a fourth aspect, an embodiment of the present application provides a display device, comprising a display panel; and a level conversion device as described in any one of the third aspects.

[0014] The embodiment of the present application can determine whether to trigger overcurrent protection based on temperature changes. Since overcurrent will increase the line temperature, and the temperature can be accumulated, it is possible to detect non-continuous overcurrent occurrences by judging whether there is overcurrent based on temperature, which helps to improve the accuracy of overcurrent detection, thereby helping to avoid the missed detection defects of traditional overcurrent protection mechanisms. In addition, since the embodiment of the present application does not need to count the number of overcurrents, it helps to reduce the computing power requirements of the overcurrent protection mechanism on the level conversion module. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0016] Figure 1 This is a schematic diagram of the triggering mechanism of an overcurrent protection method.

[0017] Figure 2 yes Figure 1 Schematic diagram of the principle of overcurrent protection method.

[0018] Figure 3 It is a schematic diagram of the principle of successful triggering of the overcurrent protection mechanism.

[0019] Figure 4 It is a schematic diagram of the principle of failure to trigger the overcurrent protection mechanism.

[0020] Figure 5 It is a flowchart of the overcurrent protection mechanism failing to be triggered.

[0021] Figure 6 It is a schematic diagram of the structure of the detection circuit provided in the embodiment of the present application.

[0022] Figure 7 Schematic diagram of a thermistor detection architecture provided in an embodiment of the present application.

[0023] Figure 8 Schematic diagram of a temperature sensor detection architecture provided in an embodiment of the present application.

[0024] Fig. 9 Schematic diagram of the thermistor protection mechanism architecture provided in an embodiment of the present application.

[0025] Fig.10 Schematic diagram of the temperature sensor protection mechanism architecture provided in an embodiment of the present application.

[0026] Fig.11It is a flowchart of a method for determining a critical current value provided in an embodiment of the present application.

[0027] Fig.12 Schematic diagram of the structure of the level conversion device provided in the embodiment of the present application.

[0028] Fig.13 It is a schematic diagram of the structure of the display device provided in an embodiment of the present application.

[0029] Fig.14 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0030] Fig.15 A schematic diagram of the process of the detection method provided in the embodiment of the present application. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0032] Display panels can include liquid crystal display (LCD), light-emitting diode (LED) display, mini light-emitting diode (mini LED) display, organic light-emitting diode (OLED) display, and quantum dot light-emitting diode, etc. As an important component of electronic products, display panels are widely used in industries such as televisions, monitors, and notebooks. For the sake of ease of description, display panels and products equipped with display panels are collectively referred to as display products in the following text.

[0033] When a display product is short-circuited, the high current and high temperature generated can easily make the display product unusable or even damaged. With the continuous development of the display industry, various technologies to improve display effects have emerged one after another. At the same time, more and more customers expect the size of display products to be as large as possible. Whether it is the technology to improve the display effect or the increase in product size, the overall power consumption of display products will become higher and higher. In this case, when a display product is short-circuited, a larger short-circuit current and a higher temperature will appear. Therefore, overcurrent protection is crucial for display products.

[0034] Generally, overcurrent protection refers to a protection measure that automatically starts when the current intensity in the circuit exceeds a predetermined safety value. Overcurrent protection is intended to prevent large currents and the high temperatures caused by large currents from damaging electrical components or causing fires.

[0035] There are many overcurrent protection methods used in display products. When the traditional overcurrent protection method detects overcurrent in the display product for multiple times, it will control the display product's working signal to stop output, thereby preventing overcurrent from damaging the display product. Figures 1 to 4 This paper introduces the traditional over-current protection method.

[0036] Figure 1 This is a schematic diagram of the triggering mechanism of an overcurrent protection method. Figure 1 The overcurrent protection method shown can detect various working signals in the display product. The various working signals may include, for example, a clock signal (also referred to as an HC signal), a frame start voltage (start pulse or start trigger voltage, STV), a gate high voltage (gate high voltage, VGH), a gate low voltage (gate low voltage, VGL), a reference voltage (voltage source and sink, VSS) (i.e., the ground in the circuit), and a control signal LC. The LC control signal is used to control the switching of the gate drive circuit.

[0037] Figure 1 The over-current protection triggering mechanism shown may include steps S0 to S401 .

[0038] In step S0, over-current detection is started.

[0039] Steps S101 to S105 are used to detect the currents of the STV, HC, VSS, LC and VGH signals in sequence.

[0040] In step S201, it is determined whether STV continuously overcurrents.

[0041] If STV continues to have overcurrent, the count value 1 increases by 1. If STV does not have overcurrent, the count value 1 remains unchanged.

[0042] In step S202a, it is determined whether the HC has overcurrent for 32 consecutive times.

[0043] If the HC has overcurrent for 32 consecutive times, the count value 2 is increased by 1, and step S202b is executed (the number of times the HC has overcurrent is set to 0). If the HC has not overcurrent for 32 consecutive times, the count value 2 remains unchanged.

[0044] In step S203, it is determined whether VSS has continuous overcurrent.

[0045] If overcurrent continues to appear in VSS, the count value 3 is increased by 1. If overcurrent does not appear in VSS, the count value 3 remains unchanged.

[0046] In step S204, it is determined whether overcurrent occurs continuously in the LC.

[0047] If overcurrent continues to appear in LC, the count value 4 is increased by 1. If overcurrent does not appear in LC, the count value 4 remains unchanged.

[0048] In step S205 , it is determined whether VGH continuously has overcurrent.

[0049] If VGH continues to have overcurrent, the count value 5 is increased by 1. If VGH does not have overcurrent, the count value 5 remains unchanged.

[0050] In step S301, it is determined whether an overcurrent occurs in a working signal for 32 consecutive frames.

[0051] The count values ​​corresponding to the multiple working signals (i.e., count values ​​1 to 5) are input into step S301 through an OR operation. That is to say, if one or more of the multiple working signals have overcurrent for 32 consecutive frames, step 401 is executed; if none of the multiple working signals have overcurrent for 32 consecutive frames, step S0 is executed.

[0052] In step S401, the output of all working signals is stopped.

[0053] It should be noted that, when it is detected that the working signal does not have an overcurrent, but the count value corresponding to the working signal is not 0, that is, the working signal has an overcurrent, but multiple overcurrents occur non-continuously, then the count value corresponding to the working signal is set to 0. When it is detected that the working signal has an overcurrent, and the count value corresponding to the working signal is 0, that is, the overcurrent occurs for the first time, then the count value corresponding to the working signal is set to 1.

[0054] Based on the above steps, it can be seen that the overcurrent protection mechanism needs to determine whether multiple working signals have overcurrent. Figure 2 The method of judging whether overcurrent occurs in the working signal is introduced.

[0055] Figure 2 yes Figure 1 Schematic diagram of the principle of overcurrent protection method. Figure 2 The voltage curve diagram of the clock signal and the current curve diagram of the clock signal are shown. Generally, each clock cycle may include two current detection times. Figure 2 The current detection time shown in includes t2. It can be seen that the current detection time is not the entire clock cycle. The current detection time does not include the time corresponding to the rising edge of the clock voltage and the falling edge of the clock voltage, such as t1. This is because the conduction moment usually occurs as follows Figure 2The current spike shown is the surge current, so no current detection is performed at t1 to avoid interference of the surge current on the overcurrent detection.

[0056] See also Figure 2 When the current of the clock signal exceeds the preset value for a period longer than the current detection time t2, it is considered that the clock signal has an overcurrent. If the current of the clock signal exceeds the preset value for a period less than the current detection time t2, it is considered that the clock signal has not an overcurrent, and the current exceeding the preset value is only a normal current fluctuation.

[0057] In actual use, the various working signals of the above-mentioned display products are provided by the level shifter (LS) module. As an implementation method, the LS module can detect the current of various working signals. When the detected overcurrent occurs multiple times in succession, it is considered that there is overcurrent in the display product, and the LS module stops outputting all working signals. For example, when the clock signal has overcurrent 32 times in succession and this phenomenon lasts for 32 frames, the LS triggers the overcurrent protection mechanism, that is, the LS shuts down the output of all working signals.

[0058] However, there are some problems with the traditional overcurrent protection mechanism.

[0059] For example, the detection mechanism of traditional overcurrent protection is relatively complex. Specifically, while the LS outputs the working signal, it needs to detect the current of multiple working signals and count the number of overcurrents, which requires a high computing power of the LS of the detection module.

[0060] For example, the traditional overcurrent protection mechanism has certain defects. Specifically, for the clock signal, if the number of consecutive overcurrents in the same frame is 32 times (such as Figure 3 As shown), the overcurrent protection mechanism is triggered; if the number of consecutive overcurrents in the same frame is 31 times (as shown Figure 4 As shown), the overcurrent protection mechanism cannot be triggered (as shown Figure 5 As an example, when the short-circuit point is not connected properly, or in other words, the short-circuit point is in a "not completely short-circuited" state, as the load changes, overcurrent may be detected multiple times in succession, but the number of overcurrent detections does not meet the set value, such as the 32 times mentioned above, and the overcurrent protection mechanism cannot be triggered. Figure 4 , Figure 5 In the situation shown, the internal wiring of the display product is still subjected to large current for a long time, and the high temperature generated by the large current may melt the circuit, resulting in display abnormality.

[0061] In order to solve the above problems, the embodiment of the present application provides a detection circuit that can determine whether to trigger overcurrent protection based on temperature changes. Since overcurrent will cause the line temperature to rise, and the temperature can be accumulated, it is possible to detect non-continuous overcurrent occurrences by judging whether there is overcurrent based on the temperature, which helps to improve the accuracy of overcurrent detection, thereby helping to avoid the missed detection defects of the traditional overcurrent protection mechanism. In addition, since the embodiment of the present application does not need to count the number of overcurrents, it helps to reduce the computing power requirements of the overcurrent protection mechanism on the level conversion module.

[0062] Combine the following Figure 6 The detection circuit 600 provided in the embodiment of the present application is introduced. Figure 6 The detection circuit 600 shown can be used to detect the working signals of one or more display products. For example, the detection circuit 600 can be used to detect the working signal output by the power management module of the display product. For another example, the detection circuit 600 can be used to detect the working signal output by the level conversion module of the display product.

[0063] The following text takes the detection circuit 600 used to detect the working signal output by the level conversion module of the display product as an example to introduce the method provided by the embodiment of the present application.

[0064] See also Figure 6 , the detection circuit 600 may include a temperature sensing module 610 and a control module 620 .

[0065] The temperature sensing module 610 can be used to obtain the temperature of the first branch. The first branch is used to transmit a first signal. The first signal can be a working signal of the display panel. For example, the first signal can be one or more of the clock signal (also referred to as HC signal), STV signal, VGH signal, VGL signal, VSS signal and LC signal mentioned above.

[0066] The first signal may include one or more signals, and accordingly, the first branch may include one or more branches. For example, the first signal includes a clock signal and an STV signal, and the first branch may include a branch for transmitting the clock signal and a branch for transmitting the STV signal.

[0067] The temperature of the line can reflect the current condition of the signal transmitted by the line, such as overcurrent. When the signal transmitted by the line has overcurrent, the temperature of the line will rise. Since temperature can be accumulated, when the signal transmitted by the line has overcurrent multiple times, or is in an overcurrent state for a long time, the temperature of the line will continue to rise. Based on this, the temperature sensing module 610 detects the temperature of the line (i.e., the first branch) carrying the first signal, that is, the temperature sensing module 610 can be used to detect the overcurrent condition of the first signal.

[0068] In some embodiments, the first branch may be an output branch of the level conversion module, and the first signal may be part or all of the output signal of the level conversion module. Since the output signal of the level conversion module is directly connected to the display panel, when the output signal of the level conversion module has an overcurrent, the probability of the display panel being damaged is higher. Therefore, compared with other signals indirectly connected to the display panel, it is more necessary to perform overcurrent detection on the first signal.

[0069] The detection circuit 600 may further include a control module 620 connected to the temperature sensing module 610. In some embodiments, the control module 620 may determine whether the first signal has an overcurrent condition based on the temperature detection result of the first branch. Exemplarily, the control module 620 may determine whether the first signal has an overcurrent condition based on a comparison result of the temperature detection result of the first branch and the temperature critical value. Since the current magnitude and temperature are positively correlated variables, when the temperature detection result of the first branch is greater than (or exceeds) the temperature critical value, it can be considered that the first signal has an overcurrent condition; when the temperature detection result of the first branch is less than or equal to (or does not exceed) the temperature critical value, it can be considered that the first signal does not have an overcurrent condition.

[0070] In some embodiments, the control module 620 may generate a first control signal when the temperature detection result of the first branch exceeds the temperature critical value. That is, the first control signal may be used to indicate that the temperature detection result of the first branch exceeds the temperature critical value. Exemplarily, the first control signal may be used to trigger overcurrent protection for the first signal. In the case where the first signal is the output signal of the level conversion module, the first control signal may be used to control the level conversion module not to output the first signal through the first branch. In this case, the control module 620 may transmit the first control signal to the level conversion module. If the level conversion module does not output the first signal through the first branch, the large current in the first branch may be cut off, thereby avoiding line fusing, or more line fusing, or even indicating that the product is scrapped.

[0071] The embodiment of the present application utilizes the fact that large current will cause temperature rise and the cumulative effect of temperature, and proposes a method for judging whether there is an overcurrent phenomenon and whether the overcurrent protection is triggered based on temperature changes. This method can detect the situation of non-continuous and multiple overcurrent occurrences, which helps to improve the accuracy of overcurrent detection, thereby helping to avoid the missed detection defects of traditional overcurrent protection mechanisms. In addition, the embodiment of the present application only detects the line temperature, and there is no need to perform operations such as counting the number of overcurrents of multiple signals, which helps to reduce the computing power requirements of the overcurrent protection mechanism on the level conversion module.

[0072] There are many methods for detecting the temperature of the first branch. Two temperature detection methods are given as examples below. It should be understood that the temperature of the first branch can also be detected by other methods, which is not limited in this application.

[0073] In some embodiments, the temperature detection of the first branch can be implemented by a thermistor. Since thermistors are relatively low in cost and do not require an additional control circuit, the temperature detection of the first branch by a thermistor is simple to implement and helps save costs.

[0074] Exemplarily, the temperature sensing module 610 may include a thermistor. The thermistor is connected in series with the first branch so that the thermistor can sense the temperature change in the first branch. When a short circuit occurs in the first branch and a large current is generated, the entire circuit of the first branch will generate heat under the action of heat conduction, that is, the temperature of the entire circuit of the first branch will also increase. Therefore, the thermistor can be connected in series at any position of the first branch. Optionally, the thermistor can be connected in series near the high-incidence point of short-circuit faults in the first branch according to historical fault information to improve the sensitivity of detection.

[0075] Typically, the resistance of a thermistor changes with temperature. As the resistance of the thermistor changes, the voltage across the thermistor and the voltage flowing through the thermistor will change. Based on this, the temperature change of the first branch can be detected by detecting the voltage across the thermistor and / or the current value flowing through the thermistor. Considering that the temperature sensing result is used to determine whether there is an overcurrent and the convenience of detection, as a possible implementation method, the temperature change of the first branch can be detected by detecting the current value flowing through the thermistor.

[0076] In some embodiments, the current detection result of the thermistor can be transmitted to the control module 620. The control module 620 can determine whether there is an overcurrent in the first branch and whether to trigger the overcurrent protection based on the comparison result of the current detection result of the thermistor and the current critical value. For example, when the current detection result of the thermistor exceeds the current critical value, it is considered that there is an overcurrent in the first branch; when the current detection result of the thermistor does not exceed the current critical value, it is considered that there is no overcurrent in the first branch. Exemplarily, when the current detection result of the thermistor exceeds the current critical value, a first control signal can be generated, wherein the first control signal can be used to control the level conversion module not to output the first signal through the first branch.

[0077] Optionally, the current critical value may be determined based on the temperature critical value mentioned above. For example, the current critical value may be the current value flowing through the thermistor when the first branch is at a temperature corresponding to the temperature critical value.

[0078] In some embodiments, the thermistor used in the temperature sensing module 610 can be a negative temperature coefficient thermistor, which helps to improve the accuracy of overcurrent judgment. This is because if the thermistor uses a positive temperature coefficient thermistor, the resistance of the thermistor will increase as the temperature rises. The increase in the resistance of the thermistor may inhibit the increase in current in the first branch, thereby affecting the accuracy of overcurrent judgment. In addition, under low temperature conditions, the resistance of the negative temperature coefficient thermistor is higher. In the event of a serious short circuit fault, the thermistor can suppress the large current at the moment of the short circuit, thereby avoiding the breakdown of the chip or device.

[0079] It should be noted that when a thermistor is used to obtain the temperature of the first branch, in order to avoid the influence of the thermistor on the load current under normal working conditions, the output current of the level conversion module can be adjusted according to the load requirements and the resistance value of the thermistor at low temperatures. For example, if the current in the first branch cannot reach the maximum current required by the load under normal working conditions, the current value of the first signal output by the level conversion module can be increased so that the current intensity of the first signal meets the load requirements.

[0080] Figure 7 Schematic diagram of a thermistor detection architecture provided in an embodiment of the present application. Figure 7 The detection architecture shown includes a display panel 710 , a detection circuit 720 (including a thermistor 720 a and a current detection module 720 b ), and a level conversion module 730 .

[0081] See also Figure 7 , the first signal is a clock signal (including CK1-CK8), the thermistor 720a includes 8 thermistors, which are respectively connected in series in the branches of the clock signals CK1-CK8 to detect the temperature of the branches. When the current detection module 720b detects that the current in the thermistor exceeds the current critical value, it generates a first control signal and transmits the first control signal to the level conversion module 730. Among them, the current detection module 720b can be the control module mentioned above.

[0082] In some embodiments, the current detection module 720 b and the level conversion module 730 may be integrated into one chip.

[0083] The above describes a method for detecting the temperature of the first branch based on a thermistor, and the following describes a method for detecting the temperature of the first branch based on a temperature sensor.

[0084] Since the temperature sensor can directly measure the temperature, using the temperature sensor to obtain the temperature of the first branch helps to improve the accuracy of the temperature detection result and is simple to implement.

[0085] Exemplarily, the temperature sensing module 610 may include a temperature sensor. As described above, when there is a short circuit in the first branch and a large current is generated, the entire circuit of the first branch will generate heat under the action of heat conduction, that is, the temperature of the entire circuit of the first branch will also increase accordingly. Therefore, the temperature sensor can be deployed near the first branch, or the detection circuit of the temperature sensor can be deployed near the first branch. For example, the detection circuit of the temperature sensor can be deployed at an adjacent position of the first branch, that is, the detection line and the line of the first branch are deployed adjacent to each other. For another example, the area where the detection line of the temperature sensor is located can cover the area where the first branch is located, such as the overlap of the detection line and the line of the first branch, which helps to further improve the accuracy of temperature detection.

[0086] Figure 8 Schematic diagram of a temperature sensor detection architecture provided in an embodiment of the present application. Figure 8 The detection architecture shown includes a display panel 810 , a detection circuit 820 (including a detection circuit 820 a and a temperature sensor 820 b ), and a level conversion module 830 .

[0087] See also Figure 8 , the detection circuit (including D1-D8) of the temperature sensor overlaps with the first branch line in the plane. When the temperature sensor 820b detects that the temperature in the first transmission branch exceeds the temperature threshold, a first control signal is generated and transmitted to the level conversion module 830. Among them, the control module mentioned above can be integrated in the temperature sensor 820b.

[0088] As mentioned above, when the temperature detection result of the first branch is greater than the temperature threshold, the level conversion module may not output the first signal through the first branch. There are many situations in which the level conversion module does not output the first signal through the first branch.

[0089] For example, the level conversion module does not output the first signal through the first branch, that is, the level conversion module stops outputting the first signal. If there is a short-circuit point in the first branch, then by stopping the output of the first signal, the current at the short-circuit point can be cut off, thereby avoiding further damage to the line, such as the fusing of other lines. If there is an overload in the first branch, then by stopping the output of the first signal, the overload current can be cut off, thereby reducing the load of the line. As the line load decreases, the temperature of the line also decreases, thereby avoiding the occurrence of faults such as line fusing.

[0090] For another example, the level conversion module does not output the first signal through the first branch, that is, the level conversion module outputs the first signal through other branches (such as the second branch). In this way, in the event of a short circuit, the first signal is transmitted through the second branch, which helps to avoid the fusing of the short-circuit point, ensure the normal display of the display product, and improve product performance. If there is a short-circuit point in the first branch, then outputting the first signal through other branches can make the transmission of the first signal avoid the short-circuit point, which helps the normal operation of the display product and improves the display reliability of the display product. If there is an overload in the first branch (not caused by increased load), then outputting the first signal through other branches can avoid faults in the first branch, such as poor contact, "short but not short" and other types of faults.

[0091] In other words, the first control signal can be used to control the level conversion module to stop outputting the first signal, or the first control signal can be used to control the level conversion module to output the first signal through the second branch.

[0092] In some embodiments, the first branch and the second branch are connected in parallel. To facilitate switching between the first branch and the second branch, the second branch may include a first switch, and the first branch may include a second switch. The first switch and / or the second switch may be any type of switch device, such as a triode, a metal-oxide-semiconductor field-effect transistor (MOSFET), etc.

[0093] In the case of overcurrent in the first signal, the fault point (such as a short circuit point) may be located at a location other than the first branch. Taking this into account, the second branch may also include a current limiting resistor to help avoid large currents from melting the short circuit point, thereby helping to further avoid damage to the display product caused by overcurrent. Optionally, the current limiting resistor may be connected in series with the first switch.

[0094] If the temperature detection result of the first branch exceeds the temperature critical value, the first control signal can be used to control the first switch to be turned on, the second switch to be turned off, and the level conversion module to output the first signal through the second branch. If the temperature detection result of the first branch does not exceed the temperature critical value, the second switch is turned on, the first switch is turned off, and the level conversion module outputs the first signal through the first branch.

[0095] Exemplarily, the first control signal may be a high level signal or a low level signal. Taking the first control signal being a high level signal as an example, the triggering mechanism of the overcurrent protection is introduced.

[0096] When the temperature detection result of the first branch exceeds the temperature critical value, the control module outputs a high level signal, i.e., a first control signal, to the level conversion module. After receiving the first control signal, the level conversion module may stop outputting the first signal, or may output the first signal through the second branch. For example, the level conversion module may control the first switch to be turned on and the second switch to be turned off based on the received high level signal, thereby outputting the first signal through the second branch.

[0097] When the level conversion module works normally, that is, when the level conversion module outputs the first signal through the first branch, the second switch is usually turned on and the first switch is turned off. When the temperature detection result of the first branch does not exceed the temperature critical value, the control module outputs a low-level signal to the level conversion module. After receiving the low-level signal, the level conversion module may not perform any processing, that is, the first switch may be kept in an off state, the second switch may be kept in an on state, and the first signal may continue to be output through the first branch.

[0098] It should be noted that the situation where the temperature detection result exceeds the temperature critical value mentioned here also includes the situation where the current detection result of the thermistor exceeds the current critical value mentioned above.

[0099] Fig. 9 Schematic diagram of the thermistor protection mechanism architecture provided in an embodiment of the present application. Fig. 9 The illustrated structure includes a display panel 910 , a detection circuit 920 (including a thermistor 920 a and a current detection module 920 b ), a level conversion module 930 , a plurality of first branches 940 , and a plurality of second branches 950 .

[0100] See also Fig. 9 , the first signal is a clock signal (including CK1-CK8), and the thermistor is connected in series in the branch of the clock signal CK1-CK8 to detect the temperature of the branch. The first branch 940 includes a second switch 941 and a thermistor, and the second branch 950 includes a first switch 951 and a current limiting resistor. Among them, the level conversion module 930 controls the conduction and disconnection of the first switch 951 and the second switch 941 through the second control signal.

[0101] When no short circuit occurs, the second control signal is at a low level, at which time the second switch in the first branch is turned on, the first switch in the second branch is turned off, and the level conversion module outputs the first signal through the first branch. When a short circuit occurs, the second control signal is at a high level, at which time the second switch in the first branch is turned off, the first switch in the second branch is turned on, and the level conversion module outputs the first signal through the second branch. Optionally, the first switch and the second switch can use different types of MOSFETs, and the conduction and disconnection of the first branch and the second branch can be controlled by one signal, with fewer control signals and simple implementation.

[0102] Fig.10 Schematic diagram of the temperature sensor protection mechanism architecture provided in an embodiment of the present application. Fig.10 The illustrated architecture includes a display panel 1010 , a detection circuit 1020 (including a detection circuit 1020 a (not shown) and a temperature sensor 1020 b ), a level conversion module 1030 , a plurality of first branches 1040 , and a plurality of second branches 1050 .

[0103] See also Fig.10 The first branch 1040 includes a second switch 1041, and the second branch 1050 includes a first switch 1051 and a current limiting resistor. The level conversion module 1030 controls the on and off of the first switch 1051 and the second switch 1041 through a second control signal.

[0104] When there is no short circuit, the second control signal is at a low level, at which time the second switch in the first branch is turned on, the first switch in the second branch is turned off, and the level conversion module outputs the first signal through the first branch. When there is a short circuit, the second control signal is at a high level, at which time the second switch in the first branch is turned off, the first switch in the second branch is turned on, and the level conversion module outputs the first signal through the second branch.

[0105] From the previous introduction, it can be seen that the temperature critical value is very important to the overcurrent protection mechanism. The following introduces the method for determining the temperature critical value.

[0106] In some embodiments, during the design process of the display product, a short-circuit state can be simulated, and the temperature of the first branch during the simulated short-circuit process can be measured. For example, the in-plane routing of the display product can be short-circuited by a laser, and then the display product can be powered on to put it in a working state, and finally the temperature of the short-circuit point can be measured. In this way, the relationship between the temperature of the short-circuit point and the short-circuit state can be obtained. For example, the temperature of the short-circuit point at time t1 is 40°C, the temperature of the short-circuit point at time t2 is 80°C, ..., the temperature of the short-circuit point at time tm is Tm, and the short-circuit point is blown. Considering a certain margin, the temperature of the short-circuit point at time tm-1 can be selected as the temperature critical value.

[0107] There may be a certain distance between the short-circuit point and the temperature sensing module. Although heat conduction exists on the same line, the temperature at different positions of the same line may be different. Therefore, in order to improve the accuracy of overcurrent protection, the relationship between the temperature at the temperature sensing module and the short-circuit state can be obtained in the simulated short-circuit state. For example, the temperature at the temperature sensing module at time t1 is 30°C, the temperature of the short-circuit point at the temperature sensing module at time t2 is 70°C, ..., the temperature of the short-circuit point at the temperature sensing module at time tn is Tn, and the short-circuit point is blown. Considering a certain margin, the temperature at the temperature sensing module at time tn-1 can be selected as the temperature critical value.

[0108] In the above case, if the distance between the position of the temperature sensing module and the position of the short-circuit point is different, the critical temperature value obtained may be different. At this time, the minimum value of the measured multiple critical temperature values ​​can be used as the critical temperature value finally used to improve the reliability of overcurrent protection detection. For example, when the distance between the short-circuit point and the temperature sensing module is the farthest, the short-circuit process can be simulated, and the obtained temperature critical value can be used as the temperature critical value finally used (i.e., the temperature critical value mentioned in the embodiment of the present application).

[0109] Since it is impossible to directly obtain the temperature of the thermistor, the temperature of the first branch is determined by measuring the current value flowing through the thermistor in the embodiment of the present application. In this case, the current critical value can be determined based on the current value flowing through the thermistor when the first branch is at a temperature corresponding to the temperature critical value. For example, the temperature critical value corresponding to the first branch is 90°C. In the above-mentioned simulated short circuit process, when the temperature of the first branch is 90°C, the current flowing through the thermistor is 100mA, then the current critical value can be 100mA.

[0110] In some embodiments, during the simulation of a short circuit, the temperature of the short-circuit point, the temperature of the thermistor, and the current flowing through the thermistor can be directly obtained. For example, a thermal imager can be used to measure the temperature data of the short-circuit point and the temperature data of the thermistor. Taking the current of 40mA when the first signal is working normally as an example, at t1, the short-circuit point temperature is 40°C, the thermistor is 25°C, and the current is 50mA; at t2, the short-circuit point temperature is 60°C, the thermistor is 30°C, and the current is 60mA; at t3, the short-circuit point temperature is 80°C, the thermistor is 40°C, and the current is 100mA; ...; at tx, the short-circuit point is blown, and the short-circuit point temperature is T0, the thermistor temperature is T1, and the current is 150mA. Considering a certain margin, the current critical value can be determined based on the data at tx-1. Taking the short-circuit point temperature of 100 degrees, the thermistor is 60°C, and the current is 80mA at tx-1 as an example, the critical current value can be a current of 80mA.

[0111] Fig.11It is a flowchart of a method for determining a critical current value provided in an embodiment of the present application. Fig.11 The method shown may include steps 1 to 7. Step 1, laser short-circuiting the first branch. Step 2, infrared measuring the temperature of the short-circuit point at different times. Step 3, infrared measuring the temperature of the thermistor at different times. Step 4, obtaining the current value flowing through the thermistor at different times. Step 5, confirming the temperature of the short-circuit point, the temperature of the thermistor and the current of the thermistor at the time of melting. Step 6, determining the critical current value. Step 7, setting the critical current value in the detection circuit.

[0112] The critical current value is usually written into the chip through code during the design process. For different products and different projects, the trace width and trace distance within the surface are different, so the critical current values ​​of different products may be different. Even in the same product, when the load increases (such as customer demand to improve picture quality), the current will increase synchronously, and the critical current value needs to be adjusted accordingly. In the traditional overcurrent protection mechanism, after the critical current value is determined, if it needs to be modified, the chip can only be replaced or the R&D personnel need to adjust the code.

[0113] In order to solve the above problems, the detection circuit can select a corresponding temperature critical value from a plurality of stored temperature critical values ​​according to different loads, which helps to improve the versatility and flexibility of the detection circuit. Exemplarily, a plurality of temperature critical values ​​can be stored in the control module, and the plurality of temperature critical values ​​correspond to a plurality of load ranges of the level conversion module one by one. The control module can select a temperature critical value corresponding to the first branch from a plurality of temperature critical values ​​according to the relationship between the value of the first signal and the plurality of load ranges. For example, the control module can store a temperature critical value A and a temperature critical value B, wherein the temperature critical value A is applicable to the case where the first signal is 50mA-100mA, and the temperature critical value B is applicable to the case where the first signal is 100mA-200mA. When the load is 80mA, the detection circuit can set A to the temperature critical value that triggers the overcurrent protection, and when the load is increased to 160mA, the detection circuit can set B to the temperature critical value that triggers the overcurrent protection.

[0114] Fig.12 Schematic diagram of the structure of the level conversion device provided in the embodiment of the present application. Fig.12 The level conversion device 1200 shown may include a level conversion module 1210 and the detection circuit 600 described above.

[0115] In some embodiments, part or all of the detection circuit 600 may be integrated into the same chip as the level conversion module 1210. For example, the control module 620 may be integrated into the same chip as the level conversion module 1210. For another example, the temperature sensor may be integrated into the same chip as the level conversion module 1210, and the detection circuit of the temperature sensor may be deployed outside the level conversion module 1210. For another example, the thermistor may be deployed outside the level conversion module.

[0116] Fig.13 1 is a schematic diagram of the structure of a display device provided in an embodiment of the present application. The display device 1300 includes a display panel 1310 and the level conversion device 1200 mentioned above. The display panel may be the LCD, OLED, etc. mentioned above.

[0117] Fig.14 The electronic device 1400 may include the display device 1300 described above. The electronic device 1400 may be, for example, a television, a computer monitor, a mobile phone, a tablet computer, a digital camera, and a dashboard.

[0118] The above describes the device embodiment of the present application in detail, and the following describes the method embodiment of the present application in detail. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment, so the part not described in detail can refer to the previous device embodiment.

[0119] Fig.15 The flowchart of the detection method provided in the embodiment of the present application is as follows: The detection method 1500 can be applied to overcurrent detection of the working signal of the display panel.

[0120] See also Fig.15 , the detection method 1500 may include step S1510 and step S1520.

[0121] S1510, obtaining a temperature of a first branch, wherein the first branch is an output branch of a level conversion module, and the first branch is used to transmit a first signal, and the first signal is a working signal of a display panel.

[0122] S1520: When the temperature detection result of the first branch exceeds the temperature critical value, generate a first control signal, wherein the first control signal is used to control the level conversion module not to output the first signal through the first branch.

[0123] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0124] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0125] In the embodiments provided in the present application, it should be understood that the disclosed devices / equipment and methods can be implemented in other ways. For example, the device / equipment embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0126] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0127] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0128] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0129] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0130] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A detection circuit, characterized in that: include: a temperature sensing module, used for acquiring the temperature of a first branch, where the first branch is an output branch of a level conversion module, and the first branch is used for transmitting a first signal, where the first signal is a working signal of a display panel; a control module connected to the temperature sensing module, wherein the control module is configured to generate a first control signal when the temperature detection result of the first branch exceeds a temperature critical value, wherein the first control signal is configured to control the level conversion module not to output the first signal through the first branch; The temperature sensing module includes a thermistor, which is connected in series with the first branch. The thermistor is a negative temperature coefficient thermistor. The temperature sensing module is specifically used for: Detecting a current value flowing through the thermistor, and transmitting a current detection result of the thermistor to the control module; The control module is specifically used for: When the current detection result exceeds a current critical value, the first control signal is generated, wherein the current critical value is a current value flowing through the thermistor when the first branch is at a temperature corresponding to the temperature critical value.

2. The detection circuit according to claim 1, characterized in that: The first control signal is used to control the level conversion module to stop outputting the first signal, or the first control signal is used to control the level conversion module to output the first signal through a second branch.

3. The detection circuit according to claim 2, characterized in that: The second branch includes a current limiting resistor and a first switch, the current limiting resistor is connected in series with the first switch, the first branch includes a second switch, and the second branch is connected in parallel with the first branch. If the temperature detection result of the first branch exceeds the temperature critical value, the first control signal is used to control the first switch to be turned on, the second switch to be turned off, and the level conversion module to output the first signal through the second branch; If the temperature detection result of the first branch does not exceed the temperature critical value, the second switch is turned on, the first switch is turned off, and the level conversion module outputs the first signal through the first branch.

4. The detection circuit according to claim 1, characterized in that: The control module stores a plurality of temperature critical values, and the plurality of temperature critical values ​​correspond to a plurality of load ranges of the level conversion module one by one. The control module is further used for: The temperature critical value corresponding to the first branch is selected from the multiple temperature critical values ​​according to the relationship between the value of the first signal and the multiple load ranges.

5. A detection method, characterized in that: include: Acquire the temperature of the first branch through the temperature sensing module, the first branch is the output branch of the level conversion module, the first branch is used to transmit a first signal, and the first signal is a working signal of the display panel; When the temperature detection result of the first branch exceeds the temperature critical value, a first control signal is generated, wherein the first control signal is used to control the level conversion module not to output the first signal through the first branch; Wherein, the temperature sensing module includes a thermistor, and the thermistor is a negative temperature coefficient thermistor; The obtaining the temperature of the first branch includes: detecting a current value flowing through the thermistor; The step of generating a first control signal when the temperature detection result of the first branch exceeds a temperature critical value comprises: The first control signal is generated when the current detection result exceeds a current critical value, where the current critical value is a current value flowing through the thermistor when the first branch is at a temperature corresponding to the temperature critical value.

6. A level conversion device, characterized in that: include: Level conversion module; as well as A detection circuit as claimed in any one of claims 1 to 4.

7. A display device, characterized in that: include: Display panel; as well as The level conversion device as claimed in claim 6.

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