Infrared touch frame circuit board, infrared touch frame and infrared touch screen

Abstract

This application provides an infrared touchpad frame circuit board, an infrared touch frame, and an infrared touchscreen. The infrared touch frame circuit board includes a main board and multiple slave boards. The main board includes a first signal amplification module, a signal filtering module, and a second signal amplification module. The slave boards include infrared signal receiving modules. The infrared signal receiving module includes an infrared signal receiving tube and a first amplification tube. This application improves the signal-to-noise ratio of the infrared received signal by filtering the amplified infrared signal from the first signal amplification module using the signal filtering module. Furthermore, the second signal amplification module further amplifies the filtered infrared received signal, increasing its intensity and improving its anti-interference capability. This improved signal-to-noise ratio and anti-interference capability enhance the accuracy of touch positioning.

Description

Technical Field

[0001] This application relates to the field of infrared touch control, such as an infrared touch frame circuit board, an infrared touch frame, and an infrared touch screen. Background Technology

[0002] With the development of electronic technology, infrared touch devices have been widely used in interactive flat panels due to their fast response speed and cost-effectiveness. Infrared touch devices consist of an infrared touch frame circuit board placed within each border of the infrared touch frame. Infrared emitting circuits and / or infrared receiving circuits are placed on these circuit boards. The infrared emitting circuits emit infrared signals, and the infrared receiving circuits receive these signals. After a series of processing steps by the signal processing circuit, the touch position is determined, and the corresponding touch operation is executed.

[0003] Because the infrared signal received by the infrared receiving circuit is a weak signal, the signal processing circuit in the related technology has weak anti-interference ability and low signal-to-noise ratio, which leads to the problem of inaccurate touch position determined based on the infrared receiving signal. Utility Model Content

[0004] To overcome the problems existing in related technologies, this application provides an infrared touch panel circuit board, an infrared touch frame, and an infrared touch screen, which can improve the anti-interference ability and signal-to-noise ratio of infrared received signals, thereby improving the accuracy of touch position.

[0005] According to a first aspect of the embodiments of this application, an infrared touch frame circuit board is provided, including a main board and a plurality of slave boards; the main board includes a first signal amplification module, a signal filtering module and a second signal amplification module, and the slave boards include an infrared signal receiving module; the infrared signal receiving module includes an infrared signal receiving tube and a first amplification tube;

[0006] The first end of the infrared signal receiving tube is used to receive an infrared signal receiving tube enable signal; the second end of the infrared signal receiving tube is connected to the signal input end of the first amplifying tube; the first connection end of the first amplifying tube is grounded; the second connection end of the first amplifying tube is connected to the first input end of the first signal amplification module; the second input end of the first signal amplification module is connected to a reference power supply; the output end of the first signal amplification module is connected to the input end of the signal filtering module; the output end of the signal filtering module is connected to the first input end of the second signal amplification module; the second input end of the second signal amplification module is used to receive a conduction impedance adjustment signal; the output end of the second signal amplification module is used to output the amplified infrared received signal.

[0007] This embodiment uses a signal filtering module to filter the infrared received signal amplified by the first signal amplification module, thereby improving the signal-to-noise ratio of the infrared received signal. Furthermore, the filtered infrared received signal is amplified again by a second signal amplification module, increasing the intensity of the infrared received signal and thus improving its anti-interference capability. Because of the improved signal-to-noise ratio and anti-interference capability of the infrared received signal, the accuracy of the touch position is improved.

[0008] According to a second aspect of the embodiments of this application, an infrared touch frame is provided, including the infrared touch circuit board described above.

[0009] According to a third aspect of the embodiments of this application, an infrared touch screen, a display screen, and the infrared touch frame described above are provided; the infrared touch frame surrounds the display screen.

[0010] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application.

[0011] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies 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.

[0013] Figure 1 This is a schematic diagram of the circuit structure of the infrared touch frame circuit board in the related technology of this application;

[0014] Figure 2 This is a schematic block diagram illustrating the structure of an infrared touch frame circuit board according to one embodiment of this application;

[0015] Figure 3 This is a schematic diagram of the circuit structure of an infrared touch frame circuit board according to one embodiment of this application;

[0016] Figure 4 This is a schematic block diagram illustrating the structure of an infrared touch frame circuit board according to another embodiment of this application;

[0017] Figure 5 This is a schematic diagram of the structure of an infrared touch frame according to one embodiment of this application;

[0018] Figure 6 This is a schematic diagram of the structure of an infrared touchscreen according to one embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in detail below with reference to the accompanying drawings. Wherein, when the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0020] It should be understood that the embodiments described below do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0021] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms "a" and "the" as used herein are also intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more. It should also be understood that the term "and / or" as used herein refers to and includes any or all possible combinations of one or more associated listed items, for example, A and / or B, which can represent: A alone, A and B together, and B alone; the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0022] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, this information should not be limited to these terms, and these terms are only used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Depending on the context, the word "if" as used in this application can be interpreted as "when," "when," or "in response to determination."

[0023] With the development of electronic technology, infrared touch devices are widely used in interactive flat panels due to their fast response speed and cost-effectiveness. Infrared touch devices consist of an infrared touch frame circuit board placed within each border of the infrared touch frame. Infrared emitting circuits and / or infrared receiving circuits are placed on the infrared touch frame circuit board. The infrared emitting circuits emit infrared signals, and the infrared receiving circuits receive the infrared signals. After processing the infrared signals, the touch position is determined, and the corresponding touch operation is executed.

[0024] Specifically, several infrared touch frame circuit boards are installed on the four edges of the infrared touch frame. Each infrared touch frame circuit board contains an infrared emitting circuit and / or an infrared receiving circuit. The infrared emitting circuit contains several infrared transmitters; the infrared receiving circuit contains several infrared receivers. The infrared transmitters emit infrared signals, and the infrared receivers receive infrared signals, thus forming a crisscrossing infrared detection network on the screen. When a user's finger or other object touches the screen, it blocks or reflects the passing infrared signals, causing a change in the infrared signals received by the infrared receivers. The touch point is then located based on the changed infrared signals.

[0025] Depending on their function and location, the infrared touch frame circuit boards on the infrared touch frame are divided into a main board and multiple slave boards. The main board and slave boards are connected by analog signal bus, digital signal bus and power signal bus.

[0026] The main board and slave board share a power signal bus to provide power signals, i.e., power to their respective connected infrared transmitters and receivers.

[0027] The motherboard sends control signals via a digital signal bus to control the operating status of the infrared transmitters and receivers on each slave board. The infrared receivers on the slave boards receive infrared light signals, convert them into analog electrical signals, and then load these analog electrical signals onto the analog signal bus before sending them back to the motherboard. The motherboard detects the analog electrical signals from each slave board on the analog signal bus and converts them into digital signals. The motherboard uses these digital signals to calculate the coordinates of the touched object, or it transmits these digital signals to a host computer (such as an Android motherboard or a Windows motherboard) for the host computer to calculate the coordinates of the touched object.

[0028] The slave board includes an infrared receiver selection circuit and an infrared receiving circuit. The infrared receiver selection circuit includes a shift register. The shift register includes multiple output terminals. The infrared receiving circuit contains several infrared receivers. According to the control signal sent by the master MCU, the shift register outputs an infrared receiver enable signal at the corresponding output terminal to control the corresponding infrared receiver to turn on. The turned-on infrared receiver receives the infrared light signal, converts the infrared light signal into an analog electrical signal, and then loads the analog electrical signal onto the analog signal bus and sends it back to the signal amplification circuit of the master board.

[0029] The motherboard contains a signal amplification module, an A / D sampling circuit, and a main MCU (Microcontroller Unit). The main MCU controls the activation or deactivation of each infrared transmitter and / or receiver via a digital control bus. The signal amplification module is connected to the analog signal bus; it detects and amplifies analog electrical signals from the bus. The A / D sampling circuit performs A / D sampling on the amplified analog electrical signals to obtain digital signals, which are then transmitted to the main MCU via a predefined protocol. The main MCU analyzes and processes the digital signals obtained from the A / D sampling to calculate the touch position.

[0030] In one embodiment, a shift register (not shown) and an infrared receiving circuit are provided on the slave board; the infrared receiving circuit includes several infrared receivers, several amplifying transistors, and several bias resistors. Please refer to [link to relevant documentation]. Figure 1 The infrared receiving circuit 11 is described exemplarily as including an infrared receiver PD1, an amplifier transistor Q1, and a bias resistor R1. The infrared receiver PD1 is a light signal receiving transistor; in one embodiment, the infrared receiver PD1 is a photodiode. The amplifier transistor Q1 is a transistor; in one embodiment, the amplifier transistor Q1 is an NPN transistor. V1 is an infrared receiver enable signal that controls the infrared receiver PD1 to be turned on or off.

[0031] The input of the shift register is connected to the main MCU of the motherboard via a digital signal bus to receive control signals. The output of the shift register is connected to the cathode of a photodiode PD1 to output an infrared receiver enable signal V1 according to the control signal. The anode of the photodiode PD1 is connected to the base of an NPN transistor Q1. The collector of the NPN transistor Q1 is connected to the power supply terminal VCC_R. The emitter of the NPN transistor Q1 is connected to the analog signal bus, which is then connected to the signal amplification module of the motherboard.

[0032] The signal amplification module includes a sampling resistor RH1, an operational amplifier U1C, a first capacitor C1, a first resistor RV1, a second resistor RK1, a feedback resistor RF1, and a feedback capacitor CJ1. The non-inverting input of operational amplifier U1C is connected to the first terminal of sampling resistor RH1 via the first capacitor C1. The first terminal of sampling resistor RH1 is connected to the emitter of NPN transistor Q1 via an analog signal bus, and the second terminal of sampling resistor RH1 is grounded. The non-inverting input of operational amplifier U1C is also connected to the reference power supply VREF via the first resistor RV1. The inverting input of operational amplifier U1C is connected to the reference power supply VREF via the second resistor RK1. The output of the operational amplifier is also connected to the inverting input of the operational amplifier via the parallel feedback resistor RF1 and the feedback capacitor CJ1. The output of the operational amplifier is connected to the A / D sampling circuit.

[0033] When photodiode PD1 receives the infrared receiver enable signal and turns on, it senses the infrared light signal and generates a photocurrent. The photocurrent is amplified by NPN transistor Q1 and then transmitted to the analog signal bus. The analog signal bus transmits the signal to the motherboard, where it is converted from current to voltage at the sampling resistor RH1 to obtain the infrared received signal. The infrared received signal is then sent to operational amplifier U1C for amplification and then input to the A / D sampling circuit for sampling.

[0034] In related technologies, the infrared received signal is still very weak after being amplified by the operational amplifier U1C. Therefore, the downstream signal processing circuit is required to have strong anti-interference capabilities. The signal-to-noise ratio and anti-interference capabilities of existing signal processing circuits still need to be improved.

[0035] This embodiment eliminates the reference power supply for the first amplification tube on each slave board, reducing noise interference introduced by the reference power supply wiring and improving the signal-to-noise ratio. By setting up a signal filtering module and a second signal amplification module, noise reduction and signal enhancement are performed on the infrared received signal, thereby improving the signal-to-noise ratio and anti-interference ability of the infrared received signal, and thus improving the accuracy of touch position.

[0036] The following will be combined with the appendix Figures 2 to 3 The infrared touch frame circuit board provided in the embodiments of this application will be described in detail.

[0037] Please see Figure 2 The infrared touch frame circuit board provided in this application embodiment includes a main board and multiple slave boards; the main board includes a first signal amplification module 2, a signal filtering module 3 and a second signal amplification module 4, and the slave boards include an infrared signal receiving module 1; the infrared signal receiving module 1 includes an infrared signal receiving tube PD1 and a first amplification tube Q1;

[0038] The first end of the infrared signal receiving tube PD1 is used to receive the infrared signal receiving tube enable signal; the second end of the infrared signal receiving tube PD1 is connected to the signal input end of the first amplifying tube Q1; the first connection end of the first amplifying tube Q1 is grounded; the second connection end of the first amplifying tube Q1 is connected to the first input end of the first signal amplification module 2; the second input end of the first signal amplification module 2 is connected to the reference power supply; the output end of the first signal amplification module 2 is connected to the input end of the signal filtering module 3; the output end of the signal filtering module 3 is connected to the first input end of the second signal amplification module 4; the second input end of the second signal amplification module 4 is used to receive the on-resistance adjustment signal; the output end of the second signal amplification module 4 is used to output the amplified infrared received signal.

[0039] Among them, the infrared signal receiving tube PD1 can be a photodiode or a photosensitive receiving tube, etc., which are devices that detect optical signals and perform photoelectric conversion, and the first amplifying tube Q1 can be a transistor or a field-effect transistor, etc., which are devices that have amplification functions.

[0040] The infrared signal receiver enable signal is used to enable the infrared signal receiver PD1 to work in reverse bias mode. When the infrared signal receiver PD1 receives infrared light emitted by the corresponding infrared signal transmitter, it will generate photocurrent.

[0041] The first signal amplification module 2 converts the photocurrent into a current-to-voltage signal to obtain an infrared received signal, and then amplifies the infrared received signal in the first stage to obtain a first-stage amplified infrared received signal. The signal filtering module 3 filters the first-stage amplified infrared received signal to obtain a filtered infrared received signal. The second signal amplification module 4 amplifies the filtered infrared received signal in the second stage to obtain a second-stage amplified infrared received signal.

[0042] The reference power supply provides a reference voltage signal. The higher the reference voltage signal, the less likely the voltage signal after the first stage amplification will saturate, and the better the circuit's anti-light performance. The on-resistance adjustment signal is used to adjust the signal amplification factor of the second signal amplification module.

[0043] In this embodiment, when the infrared signal receiver tube enable signal is high, the infrared signal receiver tube PD1 is selected. At this time, the infrared signal receiver tube PD1 operates in reverse bias mode. When the infrared signal receiver tube PD1 receives infrared light emitted by the corresponding infrared signal transmitter tube, it generates a photocurrent. The photocurrent is amplified by the first amplifier tube, then converted to voltage and amplified by the first signal amplification module 2 to obtain the first-stage amplified infrared received signal. The first-stage amplified infrared received signal is then filtered for noise by the signal filtering module 3 to obtain the filtered infrared received signal. The filtered infrared received signal is then amplified by the second signal amplification module 4 to obtain the second-stage amplified infrared received signal.

[0044] In this embodiment, the infrared received signal amplified by the first signal amplification module 2 is filtered by the signal filtering module 3, thereby improving the signal-to-noise ratio of the infrared received signal. Furthermore, the filtered infrared received signal is amplified again by the second signal amplification module 4, increasing the intensity of the infrared received signal and thus improving its anti-interference capability. Because the signal-to-noise ratio and anti-interference capability of the infrared received signal are improved, the accuracy of the touch position is enhanced.

[0045] In one embodiment, the first signal amplification module includes a sampling resistor and a first operational amplifier circuit;

[0046] The first end of the sampling resistor is the first input terminal of the first signal amplification module, the second end of the sampling resistor is connected to the first input terminal of the first operational amplifier circuit, the second input terminal of the first operational amplifier circuit is the second input terminal of the first signal amplification module, and the output terminal of the first operational amplifier circuit is the output terminal of the first signal amplification module.

[0047] In this embodiment, the sampling resistor is used to convert the photocurrent to a voltage to obtain an infrared received signal. The first operational amplifier circuit is used to amplify the infrared received signal in the first stage to obtain the amplified infrared received signal.

[0048] The embodiments of this application can realize the first stage amplification of the infrared received signal through the sampling resistor and the first operational amplifier circuit, thereby improving the anti-interference capability of the infrared received signal.

[0049] In one embodiment, see Figure 3 The first operational amplifier circuit includes a first operational amplifier U1C, a first resistor R3, a second resistor R5, a third resistor R4, and a first capacitor C3.

[0050] The inverting input terminal of the first operational amplifier U1C is the first input terminal of the first operational amplifier circuit, the non-inverting input terminal of the first operational amplifier U1C is the second input terminal of the first operational amplifier circuit, and the output terminal of the first operational amplifier U1C is the output terminal of the first operational amplifier circuit.

[0051] The first end of the first resistor R3 is connected to the inverting input terminal of the first operational amplifier U1C. The second end of the first resistor R3 is connected to the output terminal of the first operational amplifier U1C via the second resistor R5. The second end of the first resistor R3 is also grounded via the third resistor R4. The second end of the first resistor R3 is also grounded via the first capacitor C3.

[0052] In this embodiment, the signal amplification factor of the first operational amplifier U1C is determined by the first resistor R3, the second resistor R5, the third resistor R4, and the first capacitor C3. The first capacitor C3 and the third resistor R4 are connected in parallel, which effectively improves the AC signal amplification factor. The first-stage amplification factor of the infrared received signal is: β = R3 + R5 + R3*R5 / R4', where R4' is the equivalent impedance of the third resistor R4 and the first capacitor C3 connected in parallel.

[0053] In this embodiment, the first operational amplifier U1C, the first resistor R3, the second resistor R5, the third resistor R4, and the first capacitor C3 work together to achieve the first stage amplification of the infrared received signal, thereby improving the anti-interference capability of the infrared received signal.

[0054] In one embodiment, see Figure 3 The first operational amplifier circuit also includes a second capacitor C2;

[0055] The first end of the second capacitor C2 is connected to the inverting input of the first operational amplifier U1C, and the second end of the second capacitor C2 is connected to the second end of the first resistor R3.

[0056] In this embodiment, the second capacitor C2 is used to eliminate the self-oscillation of the first operational amplifier U1C, thereby improving the quality of the infrared received signal after the first stage amplification.

[0057] In one embodiment, see Figure 3 The signal filtering module includes a fourth resistor R6 and a third capacitor C4;

[0058] The first end of the third capacitor C4 is connected to the output end of the first signal amplification module, the second end of the third capacitor C4 is connected to the input end of the second signal amplification module, and the second end of the third capacitor C4 is also grounded via the fourth resistor R6.

[0059] In this embodiment, the fourth resistor R6 and the third capacitor C4 form a high-pass filter circuit to eliminate the DC signal and some low-frequency interference signals brought about by the first signal amplification module after the first stage amplification of the infrared received signal, thereby improving the quality of the infrared received signal after the first stage amplification.

[0060] In one embodiment, the second signal amplification module includes a second operational amplifier circuit and a switching transistor;

[0061] The first input terminal of the second operational amplifier circuit is the first input terminal of the second signal amplification module, the second input terminal of the second operational amplifier circuit is connected to the first connection terminal of the switching transistor, and the output terminal of the second operational amplifier circuit is the output terminal of the second signal amplification module.

[0062] The signal input terminal of the switching transistor is the second input terminal of the second signal amplification module, and the second connection terminal of the switching transistor is grounded.

[0063] In this embodiment, the second operational amplifier circuit is used to amplify the filtered infrared received signal in a second stage to obtain the amplified infrared received signal. The switching transistor can be a transistor or field-effect transistor, or other device with switching function, used to receive the on-resistance adjustment signal, change its own on-resistance, and realize the circuit on or off.

[0064] The embodiments of this application can realize the second stage amplification of the infrared received signal through the second operational amplifier circuit and the switching transistor, thereby further improving the anti-interference capability of the infrared received signal.

[0065] In one embodiment, see Figure 3 The second operational amplifier circuit includes a second operational amplifier U1D, a fifth resistor R7, a sixth resistor R8, a seventh resistor R9, and a fourth capacitor C5.

[0066] The first end of the fifth resistor R7 is the first input terminal of the second operational amplifier circuit, the second end of the fifth resistor R7 is connected to the non-inverting input terminal of the second operational amplifier U1D, the inverting input terminal of the second operational amplifier U1D is the second input terminal of the second operational amplifier circuit, and the output terminal of the second operational amplifier U1D is the output terminal of the second operational amplifier circuit.

[0067] The inverting input terminal of the second operational amplifier U1D is grounded via the sixth resistor R8. The output terminal of the second operational amplifier U1D is connected to the inverting input terminal of the second operational amplifier U1D via the seventh resistor R9. The output terminal of the second operational amplifier U1D is also connected to the inverting input terminal of the second operational amplifier U1D via the fourth capacitor C5.

[0068] In this embodiment, the signal amplification factor of the second operational amplifier U1D is determined by the fifth resistor R7, the sixth resistor R8, the seventh resistor R9, the fourth capacitor C5, and the on-resistance of the switching transistor. The sixth resistor R8 is used to improve the sensitivity to small-signal amplification.

[0069] In this embodiment, the second operational amplifier U1D, the fifth resistor R7, the sixth resistor R8, the seventh resistor R9, and the fourth capacitor C5 work together to achieve a second-stage amplification of the infrared received signal, thereby improving the anti-interference capability of the infrared received signal.

[0070] In one embodiment, see Figure 4 The motherboard also includes a signal holding module 5;

[0071] The output of the second signal amplification module 4 is transmitted through the signal holding module 5 to output the held infrared received signal.

[0072] The signal holding module can be an integrated chip or a logic circuit.

[0073] In this embodiment, the output terminal of the second signal amplification module 4 outputs the second-stage amplified infrared received signal to the signal holding module 5, and the signal holding module 5 can hold the second-stage amplified infrared received signal.

[0074] In this embodiment, the infrared received signal is held by a signal holding module, which facilitates subsequent sampling and processing of the infrared received signal.

[0075] In one embodiment, see Figure 3 The signal holding module 5 includes a switching element K1 and a fifth capacitor C6;

[0076] The input terminal of the switching element K1 is connected to the output terminal of the second signal amplification module. The driving terminal of the switching element K1 is used to receive the switching driving signal, and the output terminal of the switching element K1 is used to output the held infrared receiving signal.

[0077] The first terminal of the fifth capacitor C6 is connected to the output terminal of the switching element K1, and the second terminal of the fifth capacitor C6 is grounded.

[0078] Among them, the switching element K1 includes, but is not limited to, analog switches and digital switches, and the fifth capacitor C6 includes, but is not limited to, fixed capacitors and variable capacitors.

[0079] In this embodiment, when the circuit is in sampling state, the switch drive signal is high, the switch element K1 is turned on, and the fifth capacitor C6 is charged. When the circuit is in holding state, the switch drive signal is low, the switch element K1 is turned off, so that the output infrared received signal remains at the signal level value at the moment of disconnection.

[0080] In this embodiment, the second-stage amplified infrared received signal can be maintained for a certain period of time using the switching element K1 and the fifth capacitor C6.

[0081] In one embodiment, the main board further includes a main MCU; the main MCU includes a control signal output terminal; the slave board further includes a slave MCU and an infrared emitting circuit; the infrared emitting circuit includes a plurality of infrared emitting diodes; the slave MCU includes an input terminal and an output terminal; the input terminal of the slave MCU is connected to the control signal output terminal of the main MCU via an analog signal bus or a digital signal bus, for receiving control signals; the output terminal of the slave MCU is connected to the first terminal of at least one of the infrared signal receiving diodes, for outputting an enable signal for the infrared signal receiving diodes according to the control signal.

[0082] It is understandable that when the above solution is applied to the scenario where the infrared transmitter and infrared receiver (light signal receiving tube) are arranged alternately on the same side of the infrared touch frame, that is, when the infrared transmitter (light signal receiving tube) and infrared receiver are set on the slave board, the slave board controls the working state of the infrared transmitter through the MCU.

[0083] Before scanning begins, the main board sends scanning data to each slave board via the digital signal bus, controlling the infrared transmitters and receivers (optical signal receiving tubes). Each slave board shares the digital signal bus to acquire its own scanning data and controls its respective infrared transmitters and receivers (optical signal receiving tubes) to perform the scanning operation. The scanning data includes the position information of the infrared receivers (optical signal receiving tubes) and infrared transmitters connected to that slave board, as well as the corresponding scanning logic.

[0084] After scanning begins, the main board transmits synchronization signals to each slave board via a synchronization signal bus to control the corresponding slave board to perform scanning. The synchronization signal includes a control signal. In one embodiment, after receiving the synchronization signal from the main board, the slave board triggers the start of scanning based on the synchronization signal. The slave board reads its own stored scanning data and controls the operating status of the connected infrared receiver (optical signal receiving tube) and infrared transmitter according to the control signal in the synchronization signal. The synchronization signal bus can be an analog signal bus or a digital signal bus.

[0085] In this embodiment, when the infrared signal receiving tube of the slave board 21 receives the infrared signal receiving tube enable signal and is turned on, the infrared signal receiving tube senses the infrared light signal emitted by the infrared transmitter and generates photocurrent. After the photocurrent is amplified by the first amplifier tube, it is transmitted to the host board 22 via the analog signal bus. After current-to-voltage conversion on the sampling resistor RH1 of the host board 22, the infrared received signal is obtained.

[0086] This application embodiment controls the state of the infrared receiver (optical signal receiving tube) from the MCU, which avoids the need to deploy additional control devices on the slave board, reducing costs. Moreover, based on the powerful data processing capabilities of the slave MCU, precise timing control and synchronization control can be achieved.

[0087] Please see Figure 5 This is a schematic diagram of the structure of the infrared touch frame provided in the second embodiment of this application. The infrared touch frame 21 includes an infrared touch frame circuit board 22. The infrared touch frame circuit board of this embodiment has the structure of any of the above embodiments, and will not be described in detail here.

[0088] Please see Figure 6This is a schematic diagram of the structure of an infrared touchscreen provided in the third embodiment of this application. The infrared touchscreen includes a display screen 32 and an infrared touch frame 31; the infrared touch frame 31 surrounds the display screen 32. The infrared touchscreen can be used on various terminal devices. The display screen 32 can display screen content, while the infrared touch frame 31 has a touch positioning function, enabling the terminal device to have touch functionality. The infrared touch frame in this embodiment is the structure of any of the above embodiments, and will not be described in detail here.

[0089] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0090] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. An infrared touch frame circuit board, characterized in that, It includes a main board and multiple slave boards; the main board includes a first signal amplification module, a signal filtering module, and a second signal amplification module; the slave boards include an infrared signal receiving module; the infrared signal receiving module includes an infrared signal receiving tube and a first amplification tube; The first end of the infrared signal receiving tube is used to receive an infrared signal receiving tube enable signal; the second end of the infrared signal receiving tube is connected to the signal input end of the first amplifying tube; the first connection end of the first amplifying tube is grounded; the second connection end of the first amplifying tube is connected to the first input end of the first signal amplification module; the second input end of the first signal amplification module is connected to a reference power supply; the output end of the first signal amplification module is connected to the input end of the signal filtering module; the output end of the signal filtering module is connected to the first input end of the second signal amplification module; the second input end of the second signal amplification module is used to receive a conduction impedance adjustment signal; the output end of the second signal amplification module is used to output the amplified infrared received signal.

2. The infrared touch frame circuit board according to claim 1, characterized in that: The first signal amplification module includes a sampling resistor and a first operational amplifier circuit; The first end of the sampling resistor is the first input terminal of the first signal amplification module, the second end of the sampling resistor is connected to the first input terminal of the first operational amplifier circuit, the second input terminal of the first operational amplifier circuit is the second input terminal of the first signal amplification module, and the output terminal of the first operational amplifier circuit is the output terminal of the first signal amplification module.

3. The infrared touch frame circuit board according to claim 2, characterized in that: The first operational amplifier circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, and a first capacitor; The inverting input terminal of the first operational amplifier is the first input terminal of the first operational amplifier circuit, the non-inverting input terminal of the first operational amplifier is the second input terminal of the first operational amplifier circuit, and the output terminal of the first operational amplifier is the output terminal of the first operational amplifier circuit. The first end of the first resistor is connected to the inverting input of the first operational amplifier, the second end of the first resistor is connected to the output of the first operational amplifier via the second resistor, the second end of the first resistor is also grounded via the third resistor, and the second end of the first resistor is also grounded via the first capacitor.

4. The infrared touch frame circuit board according to claim 3, characterized in that: The first operational amplifier circuit also includes a second capacitor; The first end of the second capacitor is connected to the inverting input of the first operational amplifier, and the second end of the second capacitor is connected to the second end of the first resistor.

5. The infrared touch frame circuit board according to claim 1, characterized in that: The signal filtering module includes a fourth resistor and a third capacitor; The first end of the third capacitor is connected to the output end of the first signal amplification module, the second end of the third capacitor is connected to the input end of the second signal amplification module, and the second end of the third capacitor is also grounded via the fourth resistor.

6. The infrared touch frame circuit board according to claim 1, characterized in that: The second signal amplification module includes a second operational amplifier circuit and a switching transistor; The first input terminal of the second operational amplifier circuit is the first input terminal of the second signal amplification module, the second input terminal of the second operational amplifier circuit is connected to the first connection terminal of the switching transistor, and the output terminal of the second operational amplifier circuit is the output terminal of the second signal amplification module. The signal input terminal of the switching transistor is the second input terminal of the second signal amplification module, and the second connection terminal of the switching transistor is grounded.

7. The infrared touch frame circuit board according to claim 6, characterized in that: The second operational amplifier circuit includes a second operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, and a fourth capacitor; The first end of the fifth resistor is the first input terminal of the second operational amplifier circuit, the second end of the fifth resistor is connected to the non-inverting input terminal of the second operational amplifier, the inverting input terminal of the second operational amplifier is the second input terminal of the second operational amplifier circuit, and the output terminal of the second operational amplifier is the output terminal of the second operational amplifier circuit. The inverting input terminal of the second operational amplifier is grounded via the sixth resistor, the output terminal of the second operational amplifier is connected to the inverting input terminal of the second operational amplifier via the seventh resistor, and the output terminal of the second operational amplifier is also connected to the inverting input terminal of the second operational amplifier via the fourth capacitor.

8. The infrared touch frame circuit board according to claim 1, characterized in that: The motherboard also includes a signal holding module; The output of the second signal amplification module is transmitted through the signal holding module to output the held infrared received signal.

9. The infrared touch frame circuit board according to claim 8, characterized in that: The signal holding module includes a switching element and a fifth capacitor; The input terminal of the switching element is connected to the output terminal of the second signal amplification module, the driving terminal of the switching element is used to receive the switching driving signal, and the output terminal of the switching element is used to output the held infrared receiving signal. The first terminal of the fifth capacitor is connected to the output terminal of the switching element, and the second terminal of the fifth capacitor is grounded.

10. The infrared touch frame circuit board according to any one of claims 1 to 9, wherein: The main board also includes a main MCU; the main MCU includes a control signal output terminal; the slave board also includes a slave MCU and an infrared emitting circuit; the infrared emitting circuit includes several infrared emitting diodes; the slave MCU includes an input terminal and an output terminal; the input terminal of the slave MCU is connected to the control signal output terminal of the main MCU via an analog signal bus or a digital signal bus, for receiving control signals; The output terminal of the MCU is connected to the first terminal of at least one of the infrared signal receiving tubes, and is used to output an enable signal for the infrared signal receiving tubes according to the control signal.

11. An infrared touch frame, wherein, Includes the infrared touch frame circuit board as described in any one of claims 1 to 10.

12. An infrared touchscreen, characterized in that, The display screen and the infrared touch frame as described in claim 11; the infrared touch frame is disposed around the display screen.

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