Digital touch signal area isolation shielding device and method

Abstract

The invention discloses a digital touch signal area isolating and shielding device and method. The device comprises a switching power supply module, a main control module, an analog switch module, an HDMI output unit, an application terminal connecting unit, a control key module and a serial port unit. The main control module is used for transmitting touch data and picture data of a user in a preset touch signal area in an unvarnished manner; the interception module is used for intercepting touch data of a user in a non-preset touch signal area and overlapping warning pictures; and the signal sending module is used for sending a corresponding level signal to the analog switch module when the continuous cumulative number of times of the user in the non-preset touch signal area exceeds a preset threshold number of times, or receiving a key signal of the control key module. The device carries out board-level isolation shielding on a non-preset touch signal area, a touch signal cannot be transmitted to an application terminal (a mainboard SOC end), and meanwhile, the device displays and overlaps an alarm picture.

Description

Technical Field

[0001] The present invention relates to the field of electronic terminal control, and in particular to a digital touch signal area isolation and shielding device and method. Background Art

[0002] With the widespread application of touch in the field of industrial control, more and more integrated terminal products are being developed in different application scenarios. Most processor platforms are equipped with touch input terminals. However, in industrial control scenarios, touching the prohibited touch area on the touch screen without the permission / authorization of the administrator can easily cause danger. Therefore, a digital touch signal area isolation and shielding device is urgently needed. Summary of the invention

[0003] The present invention provides a digital touch signal area isolation and shielding device and method, wherein the device performs board-level isolation and shielding on touch-dangerous / unauthorized touch areas. If the touch operation in the corresponding area is considered by the device to be an unauthorized user operation, the touch signal in the shielded area will not be transmitted to the SOC end of the terminal mainboard. At the same time, the device displays a superimposed prompt not to touch the dangerous / unauthorized touch area.

[0004] In a first aspect, the present invention provides a digital touch signal area isolation shielding device, comprising: a switching power supply module, a main control module, an analog switch module, an HDMI output unit, an application terminal connection unit, a control button module, and a serial port unit; wherein the main control module, the HDMI output unit, the application terminal connection unit, and the analog switch unit are all connected to the switching power supply module; the analog switch module, the HDMI output unit, the application terminal connection unit, the control button module, and the serial port unit are all connected to the main control module;

[0005] The switch power supply module is used to provide voltage to the main control module, the HDMI output unit, the application terminal connection unit, and the analog switch unit;

[0006] The main control module is used to transparently transmit the user's touch data and screen data in the preset touch signal area; to intercept the user's touch data in the non-preset touch signal area and superimpose a warning screen on the display screen; and to send a corresponding level signal to the analog switch module when the continuous cumulative number of times the user touches the non-preset touch signal area exceeds a preset threshold number, or when receiving a key signal from the control key module;

[0007] The analog switch module is used to receive the level signal sent by the main control module, so that the touch screen enters the full touch shielding state or the use state accordingly;

[0008] The HDMI output unit is used by the main control module to send the picture data sent by the application terminal to the display screen for display;

[0009] The application terminal connection unit is used for transmitting screen data and touch data between the main control module and the application terminal;

[0010] The control button module is used to clear the warning screen superimposed on the touch screen by pressing a button; and is used to restore the touch data transparent transmission between the touch screen and the application terminal;

[0011] The serial port unit is used to set a touch signal area, a non-touch signal range, and a preset threshold number of consecutive cumulative touches by a user in a non-preset touch signal area of ​​the touch screen.

[0012] Furthermore, the main control module is an FPGA chip GW5ANRT-15; wherein, pins 1-3 of the FPGA chip GW5ANRT-15 are connected to the switching power supply module, pin 4 is grounded, pin 5 is connected to the touch screen I2C clock signal I2C_SCL_TP, and pin 6 is connected to the analog switch module; pins 7-13 are connected to the HDMI port of the application terminal connection unit, pins 14-22 are connected to the HDMI output unit, pins 23 and 24 are connected to the I2C port of the application terminal connection unit, pin 25 is connected to the control button module, pins 26-28 are connected to the serial port unit, and pin 29 is connected to the analog switch module.

[0013] Furthermore, the analog switch module is AiP74LVC1G3157; wherein, pin 1 of the AiP74LVC1G3157 is connected to the data signal I2C_SDA_TP of the touch screen I2C, pins 3 and 5 are correspondingly connected to the switching power supply module, pin 2 is grounded, and pin 6 is connected to the GPIO control pin 29 of the FPGA chip GW5ANRT-15.

[0014] Furthermore, the control button module includes a switch S1 and a resistor R1; wherein one end of the resistor R1 is connected to the FPGA chip GW5ANRT-15, the other end of the resistor R1 is connected to one end of the switch S1, and the other end of the switch S1 is grounded.

[0015] Furthermore, a criterion for determining whether the touch data of the user on the touch screen is within the preset touch signal area is that + / - 4 pixels of the touch coordinates overlap with the non-preset touch signal area.

[0016] In a second aspect, the present invention provides a digital touch signal area isolation and shielding method, comprising:

[0017] S1: The administrator sets the touch signal area, non-touch signal range, and preset threshold number of consecutive cumulative touches of the user in the non-preset touch signal area of ​​the touch screen through the serial port unit, and the main control module receives the touch data of the user on the touch screen;

[0018] S2: The main control module determines whether the touch data of the user on the touch screen is within the preset touch signal area: if so, it proceeds to S3; if not, it intercepts the touch data and proceeds to S4;

[0019] S3: The main control module transparently transmits the user request to the application terminal through the application terminal connection unit, and sends the response return screen of the application terminal to the touch screen through the HDMI output unit for display, and returns to S1;

[0020] S4: The main control module determines whether the continuous cumulative number of times the user touches the non-preset touch signal area exceeds the preset threshold number: if not, enter S5; if yes, enter S6;

[0021] S5: The main control module actively superimposes the warning screen on the screen of the application terminal, and outputs the superimposed warning screen to the display screen through the HDMI output unit for display, and determines whether the control button module sends a signal: if so, clear the alarm screen and return to S1; if not, return to S4;

[0022] S6: The main control module switches the level signal through the analog switch module to make the touch screen enter the full touch shielding state, and determines whether the control button module sends a signal: if so, clear the alarm screen and send a level reset signal to the analog switch module, and enter S7; if not, keep the full touch shielding state and enter S6;

[0023] S7: The analog switch module performs a level reset after receiving the level reset signal from the main control module and returns to S1.

[0024] Beneficial Effects

[0025] The present invention proposes a digital touch signal area isolation and shielding device and method. The device performs board-level isolation and shielding on touch-dangerous / unauthorized touch areas. Touch signals in non-preset touch signal areas will not be transmitted to the SOC end of the terminal mainboard. At the same time, the device will display an alarm screen superposition to remind the user not to touch the dangerous / unauthorized touch area. When the number of consecutive cumulative touches by the user in the non-touch signal area exceeds a preset threshold, the analog switch module is activated to switch the I2C data line SDA of the touch screen from the touch data path to a normally high level, entering a full touch shielding state, and the touch data in this state cannot be obtained by FPGA, and there is no risk of data reversal. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a circuit diagram of a digital touch signal area isolation and shielding device provided by an embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of a preset touch signal area and a non-preset touch signal area in a touch screen provided by an embodiment of the present invention;

[0029] In the figure: U1: switching power supply module; U2: FPGA chip GW5ANRT-15; U3: analog switch module; J1: application terminal connection unit; J2: HDMI output unit; J3: serial port unit; S1: control button module. DETAILED DESCRIPTION

[0030] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0031] Example 1

[0032] like Figure 1 As shown, the present invention provides a digital touch signal area isolation and shielding device, including: a switching power supply module, a main control module, an analog switch module, an HDMI output unit, an application terminal connection unit, a control button module, and a serial port unit; wherein the main control module, the HDMI output unit, the application terminal connection unit, and the analog switch unit are all connected to the switching power supply module; the analog switch module, the HDMI output unit, the application terminal connection unit, the control button module, and the serial port unit are all connected to the main control module;

[0033] The switch power module is used to provide voltage for the main control module, HDMI output unit, application terminal connection unit, and analog switch unit. The switch power module in this embodiment can provide multiple voltage support, using an external 12V voltage to provide the main control module, HDMI output unit, application terminal connection unit, and analog switch unit with power support not limited to 3.3V, 1.8V, and 1.0V.

[0034] The main control module is used to transparently transmit the user's touch data and screen data in the preset touch signal area; to intercept the user's touch data in the non-preset touch signal area and superimpose a warning screen on the display screen; and to send a corresponding level signal to the analog switch module when the user's continuous cumulative number of touches in the non-preset touch signal area exceeds a preset threshold number, or when receiving a key signal from the control key module. The judgment standard for whether the user's touch data on the touch screen is in the preset touch signal area is that + / -4 pixels of the touch coordinates overlap with the non-preset touch signal area.

[0035] In the specific implementation, the main control FPGA chip GW5ANRT-15 (including but not limited to Gaoyun GW5ANRT-15) is used to implement the screen I2C interface of the touch screen and the SOC host-side I2C interface, such as Figure 2 As shown, the FPGA will preset the maximum touch resolution coordinates of the touch screen, screen_x_max and screen_y_max, as well as the starting coordinates of the danger fence, danger_x_max, danger_y_max, and the boundary coordinates of the danger fence, danger_x_max, danger_y_max, according to the user's requirements. The FPGA will obtain the coordinate points, user_touch_x and user_touch_y, reported by the touch screen in real time. When the touch area does not overlap with the set fence (i.e., the preset touch signal area), the FPGA will not intervene in the touch signal. When the touch area overlaps with the set area isolation fence area (i.e., the non-preset touch signal area), the main control FPGA chip will no longer transparently transmit the touch data to the SOC. Whether the touch screen actively reports data or the SOC requests data acquisition, the I2C (responsible for providing touch data to the SOC) implemented by the logic resources in the FPGA chip will not report the touch data to the SOC, and the linkage screen will display the superimposed part.

[0036] More specifically, the main control module is the FPGA chip GW5ANRT-15; wherein, pins 1-3 of the FPGA chip GW5ANRT-15 correspond to being connected to the switching power supply module, pin 4 is grounded, pin 5 is connected to the touch screen I2C clock signal I2C_SCL_TP, and pin 6 is connected to the analog switch module; pins 7-13 correspond to being connected to the HDMI port of the application terminal connection unit, pins 14-22 correspond to being connected to the HDMI output unit, pins 23 and 24 correspond to being connected to the I2C port of the application terminal connection unit, pin 25 is connected to the control button module, pins 26-28 correspond to being connected to the serial port unit, and pin 29 is connected to the analog switch module.

[0037] The analog switch module is used to receive the level signal sent by the main control module, so that the touch screen enters the full touch shielding state or the use state accordingly. The serial port unit is used to set the touch signal area, non-touch signal range, and the preset threshold number of continuous cumulative touches of the user in the non-preset touch signal area of ​​the touch screen.

[0038] During specific implementation, if the touch area overlaps with the isolation fence area multiple times (the threshold defined by "multiple times" can be configured by the serial port unit J3, and the default is 5 times), the device believes that the current operator is maliciously testing the judgment logic. The FPGA will control the two-to-one analog switch module AiP74LVC1G3157 of Zhongwei Aixin through GPIO to switch the I2C data line SDA of the touch screen from the touch data path to a normally high level and enter a full touch shielding state. In this state, the FPGA cannot read the touch data signal, thereby ensuring that the touch data of the device is not reversed.

[0039] Furthermore, the analog switch module is AiP74LVC1G3157; wherein, pin 1 of the AiP74LVC1G3157 is connected to the data signal I2C_SDA_TP of the touch screen I2C, pins 3 and 5 are correspondingly connected to the switching power supply module, pin 2 is grounded, and pin 6 is connected to the GPIO control pin 29 of the FPGA chip GW5ANRT-15.

[0040] The HDMI output unit is used by the main control module to send the picture data sent by the application terminal to the display screen for display.

[0041] The application terminal connection unit is used for transmitting screen data and touch data between the main control module and the application terminal (mainboard SOC end);

[0042] The control button module is used to clear the warning screen superimposed on the touch screen by pressing a button; and is used to restore the touch data transparent transmission between the touch screen and the application terminal.

[0043] During specific implementation, the FPGA chip (including but not limited to Gaoyun GW5ANRT-15, which requires video input and output and screen overlay, so the FPGA needs to have high-speed Transceivers / Serdes) transparently transmits HDMI's TMDS screen data, EDID data, and HotPlugDetect status when the touch screen does not touch the dangerous / unauthorized touch area. When the user touches the dangerous / unauthorized touch area (the touch area overlaps with the set area isolation fence area), the screen display overlay part will superimpose an alarm screen, such as "This area has been blocked, do not touch" and other similar prompts. When the touch area overlaps with the isolation fence area multiple times, the screen display overlay part will superimpose an alarm screen, such as "The full-screen touch signal has been blocked." When the superimposed prompts such as "This area has been blocked, do not touch" can be cleared by controlling the button module, and the physical I2C data communication of the touch screen is restored, the device will continue to transparently display the screen output by the SOC;

[0044] More specifically, the control button module includes a switch S1 and a resistor R1; wherein one end of the resistor R1 is connected to the FPGA chip GW5ANRT-15, the other end of the resistor R1 is connected to one end of the switch S1, and the other end of the switch S1 is grounded.

[0045] In specific implementation, the device obtains touch data through I2C_SCL_TP and I2C_SDA_TP:

[0046] When the user touches the preset touch signal area, that is, the touch area does not overlap with the set fence, the device transmits the touch data to the processor of the application terminal (through the application terminal connection unit) through I2C_SCL_SOC and I2C_SDA_SOC, and the HDMI signal of the application processor is transmitted to the HDMI output unit of the device, that is, the HDMI_OUT interface, through the application terminal connection unit of the device.

[0047] When the user touches the non-preset touch signal area connected to the device, that is, the touch area overlaps with the set area isolation fence area, the FPGA can obtain touch data, but will not report the touch data to the application terminal (mainboard SOC end). The HDMI signal of the application terminal processor passes through the application terminal connection unit of the device (i.e., I2C_HDMI_SOC interface), superimposing the "This area has been shielded, do not touch" screen content to the HDMI output unit of the device (i.e., HDMI_OUT interface). When the touch area overlaps with the isolation fence area multiple times, the I2C data line SDA of the touch screen switches from the touch data path to a normally high level, entering a full touch shielding state, and the touch data of this state cannot be obtained by the FPGA. The HDMI signal of the application processor passes through the application terminal connection unit of the device (i.e., I2C_HDMI_SOC interface), superimposing the "Full-screen touch signal has been shielded" screen content to the HDMI output unit of the device (i.e., HDMI_OUT interface).

[0048] When the touch screen is displaying an alarm screen, by pressing the touch status recovery button S1 in the control button module, the "this area has been blocked, do not touch" and "full screen touch signal has been blocked" states will be cleared, and the touch data will be restored to be transparently transmitted to the processor of the application terminal.

[0049] The specific circuit connection is as follows: Pin 1 of the switching power module U1 is connected to the 12V power input; Pins 4, 5, and 6 of the switching power module U1 are connected to Pins 1, 2, and 3 of the FPGA chip GW5ANRT-15 chip (U2) to provide the 3.3V, 1.8V, and 1.0V voltages required by the FPGA; Pin 5 of the GW5ANRT-15 chip (U2) is connected to the touch screen I2C clock signal I2C_SCL_TP, Pin 6 of the GW5ANRT-15 chip (U2) is connected to Pin 4 of the analog switch module AiP74LVC1G3157 (U3), Pins 23 and 24 of the GW5ANRT-15 chip (U2) are connected to the I2C port of the application terminal connection unit, Pins 7-13 of the GW5ANRT-15 chip (U2) are connected to the HDMI port of the application terminal connection unit; Pins 14-2 Pin 2 is connected to the HDMI output unit (i.e., the HDMI output port of the device); Pin 25 of the GW5ANRT-15 chip (U2) is connected to the series resistor R1 and the button S1 to the power supply GND, and the 26, 27, and 28 pins of the GW5ANRT-15 chip (U2) are connected to the 2, 3, and 5 pins of the DB9 serial port (i.e., the serial port unit); Pin 1 of the analog switch module AiP74LVC1G3157 (U3) is connected to the data signal I2C_SDA_TP of the touch screen I2C, Pins 3 and 5 of the analog switch module AiP74LVC1G3157 (U3) are connected to Pin 4 of the switch power module U1, Pin 2 of the analog switch AiP74LVC1G3157 (U3) is connected to Pin 7 of the switch power module U1, and Pin 6 of the analog switch AiP74LVC1G3157 (U3) is connected to the GPIO control pin 29 of the GW5ANRT-15 chip (U2).

[0050] Example 2

[0051] This embodiment provides a digital touch signal area isolation and shielding method, including:

[0052] S1: The administrator sets the touch signal area, non-touch signal range, and preset threshold number of consecutive cumulative touches of the user in the non-preset touch signal area of ​​the touch screen through the serial port unit, and the main control module receives the touch data of the user on the touch screen;

[0053] S2: The main control module determines whether the touch data of the user on the touch screen is within the preset touch signal area: if so, it proceeds to S3; if not, it intercepts the touch data and proceeds to S4;

[0054] S3: The main control module transparently transmits the user request to the application terminal through the application terminal connection unit, and sends the response return screen of the application terminal to the display screen through the HDMI output unit for display, and returns to S1;

[0055] S4: The main control module determines whether the continuous cumulative number of times the user touches the non-preset touch signal area exceeds the preset threshold number: if not, enter S5; if yes, enter S6;

[0056] S5: The main control module actively superimposes the warning screen on the screen of the application terminal, and outputs the superimposed warning screen to the touch screen through the HDMI output unit, and determines whether the control button module sends a signal: if so, clear the alarm screen and return to S1; if not, return to S4;

[0057] S6: The main control module switches the level signal through the analog switch module to make the touch screen enter the full touch shielding state, and determines whether the control button module sends a signal: if so, clear the alarm screen and send a level reset signal to the analog switch module, and enter S7; if not, keep the full touch shielding state and enter S6;

[0058] S7: The analog switch module performs a level reset after receiving the level reset signal from the main control module and returns to S1.

[0059] It should be understood that in the embodiments of the present invention, the processor may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The memory may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the type of device.

[0060] The readable storage medium is a computer-readable storage medium, which may be an internal storage unit of the controller described in any of the foregoing embodiments, such as a hard disk or memory of the controller. The readable storage medium may also be an external storage device of the controller, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the controller. Further, the readable storage medium may also include both an internal storage unit of the controller and an external storage device. The readable storage medium is used to store the computer program and other programs and data required by the controller. The readable storage medium may also be used to temporarily store data that has been output or is to be output.

[0061] Based on this understanding, the technical solution of the present invention, in essence or in other words, the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned readable storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., various media that can store program codes.

[0062] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0063] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A digital touch signal area isolation shielding device, characterized in that: include: Switching power supply module, main control module, analog switch module, HDMI output unit, application terminal connection unit, control button module, serial port unit; wherein the main control module, HDMI output unit, application terminal connection unit, and analog switch unit are all connected to the switching power supply module; the analog switch module, HDMI output unit, application terminal connection unit, control button module, and serial port unit are all connected to the main control module; The switch power supply module is used to provide voltage to the main control module, the HDMI output unit, the application terminal connection unit, and the analog switch unit; The main control module is used to transparently transmit the user's touch data and screen data in the preset touch signal area; to intercept the user's touch data in the non-preset touch signal area and superimpose a warning screen on the display screen; and to send a corresponding level signal to the analog switch module when the continuous cumulative number of times the user touches the non-preset touch signal area exceeds a preset threshold number, or when receiving a key signal from the control key module; The analog switch module is used to receive the level signal sent by the main control module, so that the touch screen enters the full touch shielding state or the use state accordingly; The HDMI output unit is used by the main control module to send the picture data sent by the application terminal to the display screen for display; The application terminal connection unit is used for transmitting screen data and touch data between the main control module and the application terminal; The control button module is used to clear the warning screen superimposed on the touch screen by pressing a button; and is used to restore the touch data transparent transmission between the touch screen and the application terminal; The serial port unit is used to set a touch signal area, a non-touch signal range, and a preset threshold number of consecutive cumulative touches by a user in a non-preset touch signal area of ​​the touch screen.

2. The digital touch signal area isolation and shielding device according to claim 1, characterized in that: The main control module is the FPGA chip GW5ANRT-15; wherein, pins 1-3 of the FPGA chip GW5ANRT-15 are connected to the switching power supply module, pin 4 is grounded, pin 5 is connected to the touch screen I2C clock signal I2C_SCL_TP, and pin 6 is connected to the analog switch module; pins 7-13 are connected to the HDMI port of the application terminal connection unit, pins 14-22 are connected to the HDMI output unit, pins 23 and 24 are connected to the I2C port of the application terminal connection unit, pin 25 is connected to the control button module, pins 26-28 are connected to the serial port unit, and pin 29 is connected to the analog switch module.

3. The digital touch signal area isolation and shielding device according to claim 2, characterized in that: The analog switch module is AiP74LVC1G3157; wherein, pin 1 of the AiP74LVC1G3157 is connected to the data signal I2C_SDA_TP of the touch screen I2C, pins 3 and 5 are correspondingly connected to the switch power supply module, pin 2 is grounded, and pin 6 is connected to the GPIO control pin 29 of the FPGA chip GW5ANRT-15.

4. The digital touch signal area isolation and shielding device according to claim 2, characterized in that: The control button module includes a switch S1 and a resistor R1; wherein one end of the resistor R1 is connected to the FPGA chip GW5ANRT-15, the other end of the resistor R1 is connected to one end of the switch S1, and the other end of the switch S1 is grounded.

5. The digital touch signal area isolation and shielding device according to claim 1, characterized in that: The judgment standard of whether the touch data of the user on the touch screen is in the preset touch signal area is that + / - 4 pixels of the touch coordinates overlap with the non-preset touch signal area.

6. A digital touch signal area isolation and shielding method based on the device according to any one of claims 1 to 5, characterized in that: include: S1: The administrator sets the touch signal area, non-touch signal range, and preset threshold number of consecutive cumulative touches of the user in the non-preset touch signal area of ​​the touch screen through the serial port unit, and the main control module receives the touch data of the user on the touch screen; S2: The main control module determines whether the touch data of the user on the touch screen is within the preset touch signal area: if so, it proceeds to S3; if not, it intercepts the touch data and proceeds to S4; S3: The main control module transparently transmits the user request to the application terminal through the application terminal connection unit, and sends the response return screen of the application terminal to the touch screen through the HDMI output unit for display, and returns to S1; S4: The main control module determines whether the continuous cumulative number of times the user touches the non-preset touch signal area exceeds the preset threshold number: if not, enter S5; if yes, enter S6; S5: The main control module actively superimposes the warning screen on the screen of the application terminal, and outputs the superimposed warning screen to the display screen through the HDMI output unit for display, and determines whether the control button module sends a signal: if so, clear the alarm screen and return to S1; if not, return to S4; S6: The main control module switches the level signal through the analog switch module to make the touch screen enter the full touch shielding state, and determines whether the control button module sends a signal: if so, clear the alarm screen and send a level reset signal to the analog switch module, and enter S7; if not, keep the full touch shielding state and enter S6; S7: The analog switch module performs a level reset after receiving the level reset signal from the main control module and returns to S1.

Images