Protection circuit, display device and detection method

Abstract

A protection circuit, a display screen and a detection method, comprising: a detection pin connected with a screen line; a micro power supply circuit connected with the detection pin and providing a first voltage for the detection pin; a comparison circuit comprising a first input end, a second input end and an output end, the first input end being connected with the detection pin, the second input end transmitting a reference voltage, the output end outputting a first level if the voltage of the first input end is greater than the reference voltage, otherwise outputting a second level, the reference voltage being less than the first voltage; and a power supply control circuit connected with the comparison circuit, the power supply control circuit being used for controlling the display screen and the power supply to be turned on if the output end outputs the first level, and the power supply control circuit being used for controlling the display screen and the power supply to be turned off if the output end outputs the second level. The embodiment of the application can solve the quality and safety problem of the electronic components being burned by the short circuit of the screen line obliquely inserted in the production operation.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular to a protection circuit, a display device, and a detection method. Background Technology

[0002] The low-cost TCONLESS solution has become the mainstream of screen design in the TV industry today. As a result, when factories are assembling TVs, the installation station for screen cables at the TCONLESS interface on the chassis board is prone to poor insertion of screen cables, which can cause electronic components to burn out upon power-up, reducing the timeliness of factory production and increasing potential hazards on the factory production line. Summary of the Invention

[0003] This application provides a protection circuit, a display device, and a detection method, which can solve the quality and safety problem of electronic components being burned out upon power-up due to short circuits caused by oblique insertion of screen cables during production operations.

[0004] In a first aspect, embodiments of this application provide a protection circuit applied to a display device, comprising:

[0005] A detection pin, which is connected to the screen cable;

[0006] A micro-current supply circuit is connected to the detection pin and provides a first voltage to the detection pin;

[0007] The comparator circuit includes a first input terminal, a second input terminal, and an output terminal. The first input terminal is connected to the detection pin, and the second input terminal transmits a reference voltage. If the voltage at the first input terminal is greater than the reference voltage, the output terminal of the comparator circuit outputs a first level; otherwise, the output terminal of the comparator circuit outputs a second level. The reference voltage is less than the first voltage.

[0008] A power supply control circuit is connected to the comparator circuit. If the output terminal of the comparator circuit outputs the first level, the power supply control circuit is used to control the display screen to be connected to the power supply; if the output terminal of the comparator circuit outputs the second level, the power supply control circuit is used to control the display screen to be disconnected from the power supply.

[0009] Optionally, the power supply control circuit includes a power input terminal, a screen power supply terminal, a screen power-on terminal, and a power supply control terminal. The power input terminal is used to connect to a power source, the screen power supply terminal is used to connect to the power supply pin of the display screen, the screen power-on terminal is used to receive a screen power-on signal, and the power supply control terminal is connected to the output terminal of the comparator circuit.

[0010] If the output terminal of the comparator circuit outputs the first level and the screen opening terminal receives the screen opening signal, then the power supply control circuit controls the power input terminal and the screen power supply terminal to be turned on.

[0011] If the output of the comparator circuit outputs the second level, then the power supply control circuit controls the power input terminal and the screen power supply terminal to disconnect.

[0012] Optionally, there are multiple detection pins, each connected to a plurality of comparison circuits, and the power supply control circuit includes:

[0013] The logic circuit has multiple input terminals, each of which is connected to the output terminal of a comparator circuit. The output terminal of the logic circuit is connected to the power supply control terminal. The logic circuit can perform an AND logic operation on the output levels of the multiple comparator circuits and then output the result.

[0014] Optionally, the power supply control circuit further includes a first switching transistor and a control sub-circuit. The input terminal of the first switching transistor is connected to the power input terminal, and the output terminal of the first switching transistor is connected to the screen power supply terminal. The screen opening terminal and the output terminal are connected to the control terminal of the first switching transistor through the control sub-circuit.

[0015] If the output terminal of the logic circuit also outputs the first level, and the screen opening terminal receives the screen opening signal, then the control sub-circuit provides a first signal to the control terminal of the first switch tube so that the input terminal and the output terminal of the first switch tube are turned on.

[0016] If the output of the logic circuit also outputs the second level, the control sub-circuit provides a second signal to the control terminal of the first switch transistor to disconnect the input and output terminals of the first switch transistor.

[0017] Optionally, the control sub-circuit includes a second switch, a third switch, and a fourth switch, wherein the control terminal of the second switch is connected to the screen opening terminal, and the output terminal of the second switch is grounded;

[0018] The input terminal of the third switch is connected to the output terminal of the logic circuit, the control terminal of the third switch is connected to the input terminal of the second switch through the first resistor, and the output terminal of the third switch is grounded through the second resistor.

[0019] The input terminal of the fourth switch is connected to the control terminal of the first switch, the output terminal of the fourth switch is grounded, and the control terminal of the fourth switch is connected to the output terminal of the third switch.

[0020] Optionally, the protection circuit further includes:

[0021] The indicator circuit includes an indicator switch, an alarm, and an indicator resistor. The control terminal of the indicator switch is connected to the output terminal of the logic circuit, the input terminal of the indicator switch is connected to the power supply terminal through the indicator resistor, the output terminal of the indicator switch is grounded, one end of the alarm is connected to the input terminal of the indicator switch, and the other end of the alarm is grounded.

[0022] Optionally, the micro-current supply circuit includes a battery, a current-limiting resistor, a first voltage-dividing resistor, a second voltage-dividing resistor, and a regulated reference source. The positive terminal of the battery is connected to the current-limiting resistor, the first voltage-dividing resistor, and the second voltage-dividing resistor in sequence and then grounded. The cathode of the regulated reference source is connected between the current-limiting resistor and the first voltage-dividing resistor. The anode of the regulated reference source is grounded. The reference pin of the regulated reference source is connected between the first voltage-dividing resistor and the second voltage-dividing resistor. The cathode of the regulated reference source outputs the first voltage.

[0023] Optionally, the micro-current supply circuit further includes a micro-current switch disposed between the battery and the current-limiting resistor.

[0024] Optionally, the detection pin is a power supply pin, and other pins adjacent to the power supply pin are low-level pins; or the detection pin is adjacent to a ground pin.

[0025] Secondly, embodiments of this application provide a display device, the display device comprising:

[0026] Display screen;

[0027] Circuit board;

[0028] A screen cable connects the display screen to the circuit board.

[0029] A protection circuit, as described in any of the preceding claims, is disposed on the display screen or the circuit board.

[0030] Thirdly, embodiments of this application provide a detection method applied to a display device, the method comprising:

[0031] Provide a first voltage to the detection pin;

[0032] After the detection pin is connected to the screen line, the voltage of the detection pin is compared with a reference voltage, and the reference voltage is less than the first voltage signal;

[0033] If the voltage of the detection pin is greater than the reference voltage and a screen-on signal is received, then power is supplied to the display screen.

[0034] If the voltage of the detection pin is less than the reference voltage, then no power is supplied to the display screen.

[0035] In the embodiments provided in this application, a first voltage is provided to the detection pin. After the detection pin is connected to the screen cable, the comparator circuit compares the voltage of the detection pin with a reference voltage. If the screen cable is properly connected to the connection interface, the voltage of the detection pin is the first voltage, which is greater than the reference voltage. The comparator circuit outputs a first level accordingly, and the power supply control circuit controls the normal power supply to the display screen. If the screen cable is inserted at an angle to the connection interface, the compression of the screen cable may cause the detection pin to contact an adjacent pin that is not provided with the first voltage, resulting in the voltage of the detection pin being pulled down. Alternatively, when inserted at an angle, the screen cable, as a conductor, may also conduct the detection pin to an adjacent pin that is not provided with the first voltage, thereby pulling down the voltage of the detection pin and causing the voltage of the detection pin to be less than the reference voltage. The comparator circuit outputs a second level accordingly, and the power supply control circuit controls the power supply not to the display screen, protecting the display screen from damage to its internal electronic components due to the angled insertion of the screen cable. This solves the quality and safety problem of short circuits caused by angled insertion of screen cables in production operations, which can lead to the burning out of electronic components upon power-on. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the protection circuit provided in an embodiment of this application;

[0038] Figure 2 A schematic diagram showing the distribution of detection pins provided in an embodiment of this application;

[0039] Figure 3 A schematic diagram of the microcurrent supply circuit provided in the embodiments of this application;

[0040] Figure 4 A schematic diagram of the comparison circuit provided in an embodiment of this application;

[0041] Figure 5 A circuit diagram of the power supply control circuit provided in an embodiment of this application;

[0042] Figure 6 Example diagrams of logic circuits and logic operations provided in embodiments of this application;

[0043] Figure 7 A schematic diagram of the indicator circuit provided in the embodiments of this application;

[0044] Figure 8 This is a schematic diagram of the structure of the display device provided in the embodiments of this application;

[0045] Figure 9 This is a schematic flowchart of the detection method provided in the embodiments of this application. Detailed Implementation

[0046] 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. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0047] This application provides a protection circuit 100, which is applied to a display device, such as a television, computer, or tablet computer. The display device may include a display screen, a circuit board, and the protection circuit. The display screen and the circuit board can be connected via a screen cable. The protection circuit 100 can be disposed on the display screen or on the circuit board. The protection circuit 100 includes a detection pin 110, a micro-current supply circuit 120, a comparison circuit 130, and a power supply control circuit 140. Please refer to... Figures 1 to 5 , Figure 1 A schematic diagram of the protection circuit provided in the embodiments of this application. Figure 2 This is a schematic diagram showing the distribution of the detection pins provided in an embodiment of this application. Figure 3 This is a schematic diagram of the microcurrent supply circuit provided in an embodiment of this application. Figure 4 This is a schematic diagram of the comparison circuit provided in an embodiment of this application. Figure 5 This is a schematic diagram of the power supply control circuit provided in an embodiment of this application.

[0048] The detection pin 110 is connected to the screen cable.

[0049] The micro-current supply circuit 120 is connected to the detection pin 110 and can provide a first voltage to the detection pin 110.

[0050] The comparator circuit 130 includes a first input terminal U1, a second input terminal U2, and an output terminal U3. The first input terminal U1 is connected to the detection pin 110, and the second input terminal U2 is connected to the reference voltage. If the voltage of the detection pin 110 is greater than the reference voltage, the output terminal U3 of the comparator circuit outputs a first level; otherwise, the output terminal U3 of the comparator circuit outputs a second level, and the reference voltage is less than the first voltage.

[0051] The power supply control circuit 140 is connected to the comparator circuit 130. If the output terminal U3 of the comparator circuit outputs the first level, the power supply control circuit 140 is used to control the display screen to be connected to the power supply; if the output terminal U3 of the comparator circuit outputs the second level, the power supply control circuit 140 is used to control the display screen to be disconnected from the power supply.

[0052] In the protection circuit 100, a first voltage is provided to the detection pin 110 of the connection interface. After the detection pin 110 is connected to the screen cable, the voltage of the detection pin 110 is compared with the reference voltage. If the screen cable is properly connected to the connection interface, the voltage of the detection pin 110 is the first voltage, which is greater than the reference voltage. The comparison circuit 130 outputs the first level accordingly, and the power supply control circuit 140 controls the normal power supply to the display screen. If the screen cable is inserted at an angle to the connection interface, the compression of the screen cable may cause the detection pin 110 to come into contact with an adjacent pin that is not provided with the first voltage, resulting in the voltage of the detection pin 110 being pulled down. Alternatively, when inserted at an angle, the screen cable, acting as a conductor, may also connect the detection pin 110 to an adjacent pin that is not provided with the first voltage, thereby pulling down the voltage of the detection pin 110. This would cause the voltage of the detection pin 110 to be less than the reference voltage, and the comparator circuit 130 would output the second level accordingly. In this case, the power supply control circuit 140 would control the power supply to the display screen to prevent damage to its internal electronic components due to the screen cable being inserted at an angle, thus solving the quality and safety problem of short circuits caused by screen cable insertion at an angle during production operations, which could lead to the burning of components upon power-up.

[0053] For example, please refer to Figure 5 The power supply control circuit 140 includes a power input terminal VDD, a screen power supply terminal PANNEL_VCC, a screen power-on terminal PANNEL_ON / OFF, and a power supply control terminal D1. The power input terminal VDD is used to connect to the power supply, the screen power supply terminal PANNEL_VCC is used to connect to the power supply pin of the display screen, the screen power-on terminal PANNEL_ON / OFF is used to receive the screen power-on signal, and the power supply control terminal D1 is connected to the output terminal U3 of the comparator circuit.

[0054] If the output terminal U3 of the comparator circuit outputs the first level and the screen power-on terminal PANNEL_ON / OFF receives the screen power-on signal, then the power supply control circuit 140 controls the power input terminal VDD and the screen power supply terminal PANNEL_VCC to be turned on; if the output terminal U3 of the comparator circuit outputs the second level, then the power supply control circuit 140 controls the power input terminal VDD and the screen power supply terminal PANNEL_VCC to be turned off.

[0055] For example, the display device also includes a screen cable, one end of which is connected to the display screen and the other end to a circuit board. A connection interface can be provided on the circuit board or display screen. The screen cable can be connected to the display screen or circuit board through the connection interface. A detection pin 110 can be provided at the connection interface. In this embodiment, whether the screen cable is inserted at an angle on the circuit board end or the screen cable is inserted at an angle on the display screen end, the power supply control circuit 140 will not supply power to the display screen to protect electronic components from damage due to the screen cable being inserted at an angle. To better understand the detection pin 110, the following example illustrates the detection pin 110. The detection pin 110 of the connection interface can be set as needed. There can be multiple detection pins 110, which are spaced apart at the connection interface so that when pins at different positions of the screen cable are inserted at an angle, they can all be detected. Please refer to... Figure 2 The display screen or circuit board connection interface may include two connection interfaces, left and right, and 12 detection pins 110 are provided on the left and right connection interfaces, and a first voltage is provided to each of the 12 detection pins 110, such as... Figure 2 As shown, the voltages of the 12 detection pins 110 are V_CHECK_1 to V_CHECK_12, respectively.

[0056] For example, the detection pin 110 can be a power supply pin, such as... Figure 2 The pins corresponding to V_CHECK_4, V_CHECK_5, and V_CHECK_6, etc., are supplied with a relatively low voltage (the first voltage) by the micro-current supply circuit 120. The value of the first voltage can be set as needed, such as 40mV, 50mV, 60mV, 100mV, etc. The screen cable includes the power connection line connected to the power pin, as well as the connection lines connecting to other pins adjacent to the power pin. If the screen cable is inserted at an angle into the connection interface, the power pin will connect to the connection line next to the power connection line in the screen cable. Since the display screen is not powered on during the screen cable assembly process, except for the detection pin 110 which provides the first voltage, the connection lines of other pins are generally in a low-level state, thus pulling the voltage of the power pin down, such as to 0V or less than 10mV. It should be noted that the power pin is chosen as the detection pin 110 because the voltage of the power pin is in the several volts range during normal operation. Even after the display screen is powered on, the power pin still has a relatively low residual first voltage, which will not affect the normal operation of the power pin.

[0057] In another example, the detection pin 110 can be adjacent to the ground pin, for example... Figure 2The pins corresponding to V_CHECK_1, V_CHECK_2, and V_CHECK_3 are specified. Specifically, the pin next to the ground pin is designated as detection pin 110, providing a first voltage. If the screen cable is inserted at an angle to the connection interface, detection pin 110 will connect to the connecting wire next to it in the screen cable that is connected to the ground pin, thus pulling the voltage of detection pin 110 low, such as to 0V or less than 10mV. It should be noted that, based on the existing screen cable wiring design, pins adjacent to the ground pin are generally not used for transmitting differential data. Therefore, even after the screen is powered on, the pins adjacent to the ground pin still have a relatively low residual first voltage, having minimal impact on data transmission in the screen cable.

[0058] It should be noted that the number of connection interfaces on the display screen or circuit board end used to connect to the screen cable can be set according to design requirements, such as 1 or 3, etc. The number of detection pins 110 can also be set as needed, such as 1, 8, 15, etc. This embodiment does not limit this.

[0059] Please refer to Figure 4 and Figure 6 , Figure 6 This is a schematic diagram of the logic circuits and logic operations provided in the embodiments of this application.

[0060] In this embodiment, if the connection interface has multiple detection pins 110, the multiple detection pins 110 are respectively connected to multiple comparator circuits 120. The power supply control circuit 140 may also include a logic circuit 150. Each of the multiple input terminals of the logic circuit 150 is connected to the output terminal U3 of a comparator circuit. The output terminal of the logic circuit 150 is connected to the power supply control terminal D1. The logic circuit 150 can perform an AND logic operation on the levels of the output terminals U3 of the multiple comparator circuits and then output the voltage. For example, the output terminal of the logic circuit 150 outputs a voltage of V_CHECK_BUS.

[0061] Specifically, the comparator circuit 120 includes a low-noise operational amplifier U, which includes a first input terminal U1, a second input terminal U2, and an output terminal U3. The first input terminal U1 is connected to a detection pin 110, and the second input terminal U2 is connected to a reference voltage, such as 25mV. The voltage V_CHECK_n at the detection pin 110 is compared with the reference voltage. If the voltage V_CHECK_n at the detection pin 110 is greater than the reference voltage, the output level V_CHECK_N_OP of the comparator circuit U3 is the first level; otherwise, the output level V_CHECK_N_OP of the comparator circuit U3 is the second level. For example, the first level is a high level, and the second level is a low level.

[0062] The outputs U3 of multiple comparator circuits are connected to logic circuit 150 for AND logic operations. For example, there are 12 detection pins 110, each connected to one of 12 comparator circuits 120. The outputs U3 of these 12 comparator circuits output 12 comparison results V_CHECK_1_OP to V_CHECK_12_OP, respectively. These outputs U3 are then input to logic circuit 150 for AND logic operations. For example,... Figure 6 As shown: A bitwise AND operation is performed on the two inputs of logic circuit 150, inputting V_CHECK_1_OP and V_CHECK_2_OP. This outputs one of the first intermediate operation results, V_CHECK_A_BUS. This process is repeated, resulting in six first intermediate operation results: V_CHECK_A_BUS, V_CHECK_B_BUS, V_CHECK_C_BUS, V_CHECK_D_BUS, V_CHECK_E_BUS, and V_CHECK_F_BUS. Then, a bitwise AND operation is performed on the other two inputs of logic circuit 150, inputting V_CHECK_A_BUS and V_CHECK_B_BUS. This outputs one of the second intermediate operation structures, V_CHECK_1_SI_NK. This process is repeated, resulting in three more second intermediate operation results: V_CHECK_1_SI_NK, V_CHECK_2_SI_NK, and V_CHECK_3_SI_NK. Next, V_CHECK_1_SI NK and V_CHECK_2_SI NK are input to the other two input terminals of logic circuit 150 and ANDed to output V_CHECK_A_SI NK; finally, V_CHECK_A_SI NK and V_CHECK_3_SI NK are input to the other two input terminals of logic circuit 150 and ANDed to output the final calculation result V_CHECK_BUS.

[0063] Understandably, if one of the detection pins 110 is pulled low due to the angled insertion, the output of the comparison circuit 120 will be ANDed by the logic circuit 150, resulting in a low voltage V_CHECK_BUS output from the logic circuit 150. Only when all detection pins 110 are at the first voltage will the voltage V_CHECK_BUS output from the logic circuit 150 be high.

[0064] It should be noted that if there is only one detection pin 110, then logic circuit 150 is not required to perform a logical AND calculation. Figure 4The output of the comparator circuit 120, U3, outputs V_CHECK_N_OP, which is directly connected to the power supply control terminal D1. That is, V_CHECK_N_OP is equivalent to V_CHECK_BUS.

[0065] In one embodiment, the voltages of multiple detection pins 110 can be first ANDed with the reference voltage and then input to the first input terminal U1 of the comparator circuit 120 for comparison. In this case, the output level of the output terminal U3 of the comparator circuit is V_CHECK_BUS. This embodiment does not limit this.

[0066] To better understand the power supply control circuit 140 of this embodiment, an example is given below. Please refer to... Figure 5 The power supply control circuit 140 also includes a first switching transistor T and a control sub-circuit D. The input terminal T1 of the first switching transistor is connected to the power input terminal VDD, which can provide the power supply voltage to drive the display screen, such as 12V or other voltages. The output terminal T2 of the first switching transistor T is connected to the screen power supply terminal PANNEL_VCC. The screen on terminal PANNEL_ON / OFF and the output terminal V_CHECK_BUS are connected to the control terminal T3 of the first switching transistor T through the control sub-circuit D. The screen on terminal PANNEL_ON / OFF can be connected to a processor, which sends signals to control the display screen to turn on or off.

[0067] Specifically, if the output terminal V_CHECK_BUS of logic circuit 150 outputs a first level and the screen-on terminal PANNEL_ON / OFF receives a screen-on signal, then the control sub-circuit D provides a first signal to the control terminal T3 of the first switch transistor T, so that the input terminal T1 and the output terminal T2 of the first switch transistor T are turned on; if the output terminal V_CHECK_BUS of logic circuit 150 outputs a second level, then the control sub-circuit D provides a second signal to the control terminal T3 of the first switch transistor T, so that the input terminal T1 and the output terminal T2 of the first switch transistor T are turned off. The first switch transistor T can conveniently control the power input terminal VDD and the screen power supply terminal PANNEL_VCC of the display screen to be turned on or off. The control sub-circuit D that controls the first switch transistor T is jointly controlled by the output terminal V_CHECK_BUS of the logic circuit 150 and the screen on terminal PANNEL_ON / OFF. The control sub-circuit D is a logic circuit, meaning that the first switch transistor T1 can only be turned on when both the output terminal V_CHECK_BUS of the logic circuit 150 and the screen on terminal PANNEL_ON / OFF meet the conditions (e.g., both are at a high level). If either the output terminal V_CHECK_BUS of the logic circuit 150 or the screen on terminal PANNEL_ON / OFF does not meet the conditions (e.g., one is at a low level), then the first switch transistor T will not be turned on.

[0068] The control sub-circuit D includes a second switch K, a third switch Q, and a fourth switch P. The control terminal K3 of the second switch K is connected to the PANNEL_ON / OFF terminal, and the output terminal K2 of the second switch K is grounded. The input terminal Q1 of the third switch Q is connected to the output terminal V_CHECK_BUS of the logic circuit 150. The control terminal Q3 of the third switch Q is connected to the input terminal K1 of the second switch K through the first resistor R1. The output terminal Q2 of the third switch Q is grounded through the second resistor R2. The input terminal P1 of the fourth switch P is connected to the control terminal T3 of the first switch T. The output terminal P2 of the fourth switch P is grounded. The control terminal P3 of the fourth switch P is connected to the output terminal Q2 of the third switch Q.

[0069] When the PANNEL_ON / OFF pin of the screen outputs a high level, the second switch K is turned on, pulling the voltage of the first resistor R1 low, thereby turning on the third switch Q. If the voltage V_CHECK_BUS output from the logic circuit 150 is high, the fourth switch P can be turned on, which in turn turns on the first switch T. Here, the first switch T is a MOSFET, the second switch K and the fourth switch P are NPN switches, and the third switch Q is a PNP switch.

[0070] The input terminal P1 of the fourth switch P is connected to the control terminal T3 of the first switch T through the third resistor R3. The input terminal P1 of the fourth switch P is also connected to the input terminal T1 of the first switch T3 through the fourth resistor.

[0071] To better understand the microcurrent supply circuit 120 in this embodiment, an example is given below. Please refer to... Figure 3 The micro-current supply circuit 120 includes a battery B, a current-limiting resistor R7, a first voltage-dividing resistor R8, a second voltage-dividing resistor R9, and a voltage regulator source V. The positive terminal of the battery B is connected to the current-limiting resistor R7, the first voltage-dividing resistor R8, and the second voltage-dividing resistor R9 in sequence and then grounded. The cathode V3 of the voltage regulator source V is connected between the current-limiting resistor R7 and the first voltage-dividing resistor R8. The anode V2 of the voltage regulator source V is grounded. The reference pin V1 of the voltage regulator source V is connected between the first voltage-dividing resistor R7 and the second voltage-dividing resistor R8. The cathode V3 of the voltage regulator source V outputs a first voltage, for example, 50mV.

[0072] For example, battery B can be a button cell battery.

[0073] For example, the microcurrent supply circuit 120 also includes a microcurrent switch L, which is disposed between the battery B and the current-limiting resistor R7.

[0074] Once the display screen is officially powered on, the micro-switch L can be turned off, which can reduce the consumption of battery B, extend the life of battery B, and also eliminate the impact of the micro-power supply circuit 120 on the display screen.

[0075] For example, the microcurrent supply circuit 120 also includes a filter capacitor C, one end of which is connected to the positive terminal of the battery B, and the other end is grounded.

[0076] Please refer to Figure 7 , Figure 7 The schematic diagram of the indicator circuit provided in this application embodiment shows that the protection circuit 100 further includes an indicator circuit 160. The indicator circuit includes an indicator switch G, an alarm F, and an indicator resistor R5. The control terminal G3 of the indicator switch G is connected to the output terminal V_CHECK_BUS of the logic circuit 150. The input terminal G1 of the indicator switch G is connected to the power supply terminal VDD through the indicator resistor R5. The output terminal G2 of the indicator switch G is grounded. One end of the alarm F is connected to the input terminal G1 of the indicator switch G, and the other end of the alarm F is grounded.

[0077] When the output terminal V_CHECK_BUS of logic circuit 150 outputs a high level, the indicator switch F is turned on, diverting the electrical signal provided by power supply terminal VDD to ground. The electrical signal provided by power supply terminal VDD will not pass through alarm F. When the output terminal V_CHECK_BUS of logic circuit 150 outputs a low level, the indicator switch G is turned off, and the electrical signal provided by power supply terminal VDD passes through alarm F, causing alarm F to start working. For example, alarm F can be an LED light, which can illuminate to indicate a misaligned screen cable. Alternatively, the alarm can be a tone converter (such as a buzzer), which can emit an alarm sound to indicate a misaligned screen cable.

[0078] In some examples, the control terminal G3 indicating the switching transistor G can be connected to the output terminal V_CHECK_BUS of the logic circuit 150 through the buffer resistor R6.

[0079] Please refer to Figure 8 , Figure 8 This is a schematic diagram of the structure of a display device provided in an embodiment of this application. The display device 10 includes a display screen 200, a circuit board 300, a screen cable 400, and a protection circuit 100. The circuit board 300 and the display screen 200 are connected by the screen cable 400. The protection circuit 100 can be disposed on either the circuit board 300 or the display screen 200. Figure 8For example, the protection circuit 100 is located on the display screen side. In this embodiment, whether the screen cable at the circuit board 300 end or the screen cable at the display screen 200 end is inserted at an angle, power is not supplied to the display screen 200 to protect the electronic components of the display screen 200 from damage due to the angled insertion of the screen cable. For a detailed description of the protection circuit 100 above, please refer to the above description; it will not be repeated here.

[0080] Please refer to Figure 9 , Figure 9 This is a flowchart illustrating the detection method provided in an embodiment of this application. The embodiment of this application provides a detection method applied to a display device, the method comprising:

[0081] In 101, a first voltage is provided to the detection pin;

[0082] For example, the display device may include a protection circuit, which may be located on the display screen or on a circuit board. For example, the protection circuit may have a dedicated micro-current supply circuit, which may have its own battery. The battery can provide a first voltage to the detection pin. For a detailed description of the specific protection circuit above, please refer to the description above; it will not be repeated here. In another example, the power supply circuit of the display device may also provide a first voltage to the detection pin.

[0083] The circuit board or display screen can be equipped with a connection interface. The screen cable is connected to the display screen or circuit board through the connection interface. The detection pin can be located on the connection interface. The number of detection pins can be one or more. The value of the first voltage can be set as needed, such as 40mV, 50mV, 60mV, 100mV, etc.

[0084] In 102, after the detection pin is connected to the screen line, the voltage of the detection pin is compared with the reference voltage, and the reference voltage is less than the first voltage signal;

[0085] In 103, if the voltage of the detection pin is greater than the reference voltage and a screen-on signal is received, then power is supplied to the display screen.

[0086] In 104, if the voltage of the detection pin is less than the reference voltage, the display screen is not powered.

[0087] For example, the reference voltage is less than the first voltage, such as 20mV, 25mV, or 30mV. Since the display screen is not powered on during the screen cable assembly process, the connection lines of other pins, except for the detection pin which provides the first voltage, are generally in a low-level state. If the connection interface is inserted at an angle to the screen cable, the compression of the screen cable may cause the detection pin to contact an adjacent pin that does not provide the first voltage, resulting in a pull-down of the detection pin's voltage. Alternatively, the screen cable, acting as a conductor, may also connect the detection pin to an adjacent pin that does not provide the first voltage, further pulling down the detection pin's voltage, such as to 0V or less than 10mV. Therefore, after the detection pin is connected to the screen cable, its voltage is compared with the reference voltage. If the screen cable is properly connected to the connection interface, the voltage of the detection pin is greater than the reference voltage, and a screen-on signal is received, thus powering the display screen. If the voltage of the detection pin is less than the reference voltage, it indicates that the screen cable is inserted at an angle, and power is not supplied to the display screen. For example, if there are multiple detection pins, a first voltage is provided to each detection pin; after the multiple detection pins are connected to the screen cable, the voltage of each detection pin is compared with a reference voltage. If the voltage of each detection pin is greater than the reference voltage and a screen-on signal is received, power is supplied to the display screen; if the voltage of any one of the detection pins is less than the reference voltage, power is not supplied to the display screen.

[0088] Therefore, the detection method in this embodiment can protect the display screen from damage to its internal electronic components due to the oblique insertion of the screen cable, thus solving the quality and safety problem of short circuits caused by oblique insertion of the screen cable during production operations, which leads to the burning of components upon power-up.

[0089] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed description of the protection circuit above, which will not be repeated here.

[0090] The protection circuit, display screen, and detection method provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A protection circuit applied to a display device, characterized in that, include: A detection pin, which is connected to the screen cable; A micro-current supply circuit, connected to the detection pin, is capable of providing a first voltage to the detection pin; The comparator circuit includes a first input terminal, a second input terminal, and an output terminal. The first input terminal is connected to the detection pin, and the second input terminal transmits a reference voltage. If the voltage at the first input terminal is greater than the reference voltage, the output terminal of the comparator circuit outputs a first level; otherwise, the output terminal of the comparator circuit outputs a second level. The reference voltage is less than the first voltage. A power supply control circuit is connected to the comparison circuit. If the output terminal of the comparison circuit outputs the first level, the power supply control circuit is used to control the display screen of the display device to be connected to the power supply. If the output terminal of the comparator circuit outputs the second level, then the power supply control circuit is used to control the display screen of the display device to disconnect from the power supply; The power supply control circuit includes a power input terminal, a screen power supply terminal, a screen power-on terminal, and a power supply control terminal. The power input terminal is used to connect to a power source, the screen power supply terminal is used to connect to the power supply pin of the display screen, the screen power-on terminal is used to receive a screen power-on signal, and the power supply control terminal is connected to the output terminal of the comparator circuit. If the output terminal of the comparator circuit outputs the first level and the screen opening terminal receives the screen opening signal, then the power supply control circuit controls the power input terminal and the screen power supply terminal to be turned on. If the output of the comparator circuit outputs the second level, then the power supply control circuit controls the power input terminal and the screen power supply terminal to disconnect. The detection pins are multiple, and the multiple detection pins are respectively connected to multiple comparison circuits. The power supply control circuit includes: A logic circuit, wherein each of the plurality of input terminals of the logic circuit is connected to the output terminal of a comparator circuit, and the output terminal of the logic circuit is connected to the power supply control terminal. The logic circuit is capable of performing an AND logic operation on the output levels of the plurality of comparator circuits and then outputting the result. The power supply control circuit further includes a first switching transistor and a control sub-circuit. The input terminal of the first switching transistor is connected to the power input terminal, and the output terminal of the first switching transistor is connected to the screen power supply terminal. The screen opening terminal and the output terminal are connected to the control terminal of the first switching transistor through the control sub-circuit. If the output terminal of the logic circuit also outputs the first level, and the screen opening terminal receives the screen opening signal, then the control sub-circuit provides a first signal to the control terminal of the first switch tube so that the input terminal and the output terminal of the first switch tube are turned on. If the output of the logic circuit also outputs the second level, then the control sub-circuit provides a second signal to the control terminal of the first switch transistor to disconnect the input and output terminals of the first switch transistor. The control sub-circuit includes a second switch, a third switch, and a fourth switch. The control terminal of the second switch is connected to the screen opening terminal, and the output terminal of the second switch is grounded. The input terminal of the third switch is connected to the output terminal of the logic circuit, the control terminal of the third switch is connected to the input terminal of the second switch through the first resistor, and the output terminal of the third switch is grounded through the second resistor. The input terminal of the fourth switch is connected to the control terminal of the first switch, the output terminal of the fourth switch is grounded, and the control terminal of the fourth switch is connected to the output terminal of the third switch. The detection pin is a power supply pin, and other pins adjacent to the power supply pin are low-level pins; or the detection pin is adjacent to a ground pin.

2. The protection circuit according to claim 1, characterized in that, The protection circuit also includes: The indicator circuit includes an indicator switch, an alarm, and an indicator resistor. The control terminal of the indicator switch is connected to the output terminal of the logic circuit, the input terminal of the indicator switch is connected to the power supply terminal through the indicator resistor, the output terminal of the indicator switch is grounded, one end of the alarm is connected to the input terminal of the indicator switch, and the other end of the alarm is grounded.

3. The protection circuit according to claim 1 or 2, characterized in that, The micro-current supply circuit includes a battery, a current-limiting resistor, a first voltage-dividing resistor, a second voltage-dividing resistor, and a voltage-regulating reference source. The positive terminal of the battery is connected to the current-limiting resistor, the first voltage-dividing resistor, and the second voltage-dividing resistor in sequence and then grounded. The cathode of the voltage-regulating reference source is connected between the current-limiting resistor and the first voltage-dividing resistor, the anode of the voltage-regulating reference source is grounded, the reference pin of the voltage-regulating reference source is connected between the first voltage-dividing resistor and the second voltage-dividing resistor, and the cathode of the voltage-regulating reference source outputs the first voltage.

4. The protection circuit according to claim 3, characterized in that, The micro-current supply circuit also includes a micro-current switch, which is disposed between the battery and the current-limiting resistor.

5. A display device, characterized in that, The display device includes: Display screen; Circuit board; A screen cable connects the display screen to the circuit board. A protection circuit, as described in any one of claims 1-4, wherein the protection circuit is disposed on the display screen or the circuit board.

6. A detection method, applied to the display device as described in claim 5, characterized in that, The method includes: Provide a first voltage to the detection pin; After the detection pin is connected to the screen cable, the voltage of the detection pin is compared with a reference voltage, and the reference voltage is less than the first voltage; If the voltage of the detection pin is greater than the reference voltage and a screen-on signal is received, then power is supplied to the display screen. If the voltage of the detection pin is less than the reference voltage, then no power is supplied to the display screen.

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