Infrared touch device and infrared touch screen

Abstract

The embodiment of the utility model provides an infrared touch device and an infrared touch screen. The infrared touch device comprises a mainboard and a plurality of slave boards, the mainboard comprises a plurality of sampling resistors; the slave board comprises an infrared receiving circuit; the infrared receiving circuit comprises a plurality of optical signal receiving tubes and a plurality of amplifier tubes; the first end of each optical signal receiving tube is used for receiving an optical signal receiving tube enable signal; the second end of each optical signal receiving tube is connected to one sampling resistor of the mainboard through one amplifying tube, and the voltage difference between the first end and the second end of each optical signal receiving tube is equal to the voltage drop of the correspondingly connected amplifying tube. According to the embodiment of the invention, a bias resistor connected in parallel to the two ends of the optical signal receiving tube is removed, the interference current introduced by the bias resistor is reduced, and the amplifying tube can effectively amplify the signal, so that the signal-to-noise ratio is improved, and the accuracy of infrared touch detection is improved.

Description

[0001] This application claims priority to Chinese Patent Application No. 202422544348.9, filed on October 21, 2024, entitled "Infrared Touch Device and Infrared Touch Screen", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of infrared touch, and in particular to an infrared touch device and an infrared touch screen. Background Technology

[0003] With the development of electronic technology, infrared touch devices have been widely used in various display devices, such as interactive flat panels, due to their fast response speed and cost-effectiveness. The working principle of an infrared touch device involves placing infrared emitting circuits and / or infrared receiving circuits on each bezel. The infrared emitting circuits emit infrared signals, and the infrared receiving circuits receive these signals. After a series of stabilization adjustments and A / D (analog-to-digital converter) sampling processes, the signal processing circuit determines the touch position and executes the corresponding touch operation.

[0004] Therefore, the quality of the infrared received signal directly affects the accuracy of infrared touch detection. In related technologies, interference in the infrared received signal reduces the accuracy of infrared touch detection. Summary of the Invention

[0005] To overcome the problems existing in related technologies, this application provides an infrared touch device and an infrared touch screen, which reduces interference, improves the signal-to-noise ratio, and improves the accuracy of infrared touch detection.

[0006] According to a first aspect of the embodiments of this application, an infrared touch device is provided, comprising: a main board and a plurality of slave boards; the main board includes a plurality of sampling resistors; the slave boards include an infrared receiving circuit; the infrared receiving circuit includes a plurality of optical signal receiving tubes and a plurality of amplifying tubes; a first terminal of each optical signal receiving tube is used to receive an optical signal receiving tube enable signal; a second terminal of each optical signal receiving tube is connected to a sampling resistor of the main board via a amplifier tube; the voltage difference between the first terminal and the second terminal of each optical signal receiving tube is equal to the voltage drop of the correspondingly connected amplifier tube.

[0007] This application embodiment removes the bias resistor connected in parallel across the optical signal receiving tube, reducing the interference current introduced by the bias resistor. Furthermore, by making the voltage difference between the first and second ends of each optical signal receiving tube equal to the voltage drop of the corresponding connected amplifier tube, the amplifier tube can effectively amplify the signal, thereby improving the signal-to-noise ratio and the accuracy of infrared touch detection.

[0008] In an optional embodiment, several optical signal receiving tubes are arranged in an M-row N-column matrix, and the first end of the optical signal receiving tubes in the same row receives the same optical signal receiving tube enable signal, so as to reduce wiring complexity, simplify control, and reduce design costs.

[0009] In an optional embodiment, several optical signal receiving tubes are arranged in an M-row N-column matrix, and the second end of the amplifier tube corresponding to the optical signal receiving tube in the same column is connected to the same sampling resistor to simplify wiring, reduce the number of sampling resistors, and reduce costs.

[0010] In an optional embodiment, the motherboard further includes an MCU; the MCU includes a control signal output terminal; the slave board further includes an optical signal receiver selection circuit; the optical signal receiver selection circuit includes a shift register; the shift register includes an input terminal and multiple output terminals; the input terminal of the shift register is connected to the control signal output terminal of the MCU via an analog signal bus or a digital signal bus for receiving control signals; each output terminal of the shift register is connected to the first terminal of at least one optical signal receiver for outputting an optical signal receiver enable signal according to the control signal.

[0011] This application embodiment is based on a shift register to quickly perform data shifting operations according to control signals, thereby rapidly changing the working state of the optical signal receiving tube and improving the response speed of the optical signal receiving tube; moreover, since one shift register can control multiple optical signal receiving tubes, compared with a microcontroller, using a shift register can reduce the number of input / output ports required by the microcontroller and reduce costs.

[0012] In another optional embodiment, the motherboard further includes a master MCU; the master 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 emitters; 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 master 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 optical signal receiving tube for outputting an optical signal receiving tube enable signal according to the control signal.

[0013] This application controls the state of the 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.

[0014] In an optional embodiment, the signal input terminal of the amplifying tube is connected to the second terminal of the optical signal receiving tube; the first connection terminal of the amplifying tube is grounded; the second connection terminal of the amplifying tube is connected to the first terminal of the sampling resistor; and the second terminal of the sampling resistor is connected to the power supply terminal.

[0015] In this embodiment, the amplifier tubes are uniformly connected to the power supply terminal of the main board, eliminating the need to lay power supplies for each amplifier tube on the slave board. This avoids running power signal buses across each slave board, preventing interference introduced by wiring each amplifier tube, improving the signal-to-noise ratio, reducing wiring difficulty, and lowering design costs.

[0016] In an optional embodiment, the optical signal receiving tube is a photodiode; the first end of the optical signal receiving tube is the cathode of the photodiode; and the second end of the optical signal receiving tube is the anode of the photodiode.

[0017] The amplifying transistor is an NPN transistor; the signal input terminal of the amplifying transistor is the base of the NPN transistor; the first connection terminal of the amplifying transistor is the emitter of the NPN transistor; the second connection terminal of the amplifying transistor is the collector of the NPN transistor; or, the amplifying transistor is an N-type field-effect transistor; the signal input terminal of the amplifying transistor is the gate of the N-type field-effect transistor; the first connection terminal of the amplifying transistor is the source of the N-type field-effect transistor; the second connection terminal of the amplifying transistor is the drain of the N-type field-effect transistor.

[0018] This application embodiment uses a photodiode to match an NPN transistor or an N-type field-effect transistor. This allows for normal detection and amplification of infrared light signals, while avoiding the need to route power supplies for each amplifying transistor on the circuit board. This also avoids interference introduced by routing individual amplifying transistors, reduces wiring difficulty, and lowers design costs.

[0019] In an optional embodiment, the optical signal receiving tube is a photodiode; the first end of the optical signal receiving tube is the anode of the photodiode; and the second end of the optical signal receiving tube is the cathode of the photodiode.

[0020] The amplifying transistor is a PNP transistor; the signal input terminal of the amplifying transistor is the base of the PNP transistor; the first connection terminal of the amplifying transistor is the collector of the PNP transistor; the second connection terminal of the amplifying transistor is the emitter of the PNP transistor; or, the amplifying transistor is a P-type field-effect transistor; the signal input terminal of the amplifying transistor is the gate of the P-type field-effect transistor; the first connection terminal of the amplifying transistor is the drain of the P-type field-effect transistor; the second connection terminal of the amplifying transistor is the source of the P-type field-effect transistor.

[0021] This application embodiment uses a photodiode matched with a PNP transistor or a P-type field-effect transistor. This allows for normal detection and amplification of infrared light signals, while avoiding the need to route power supplies for each amplifying transistor on the circuit board. This also avoids interference introduced by routing each amplifying transistor, reduces wiring difficulty, and lowers design costs.

[0022] According to a second aspect of the present application, an infrared touch screen is provided, comprising: a display screen and any of the infrared touch devices described above; the infrared touch device is disposed around the display screen.

[0023] This application embodiment removes the bias resistor connected in parallel across the optical signal receiving tube, reducing the interference current introduced by the bias resistor. Furthermore, by making the voltage difference between the first and second ends of each optical signal receiving tube equal to the voltage drop of the corresponding connected amplifier tube, the amplifier tube can effectively amplify the signal, thereby improving the signal-to-noise ratio and the accuracy of infrared touch detection.

[0024] 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.

[0025] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the circuit structure of the infrared touch device in the related technology of this application;

[0028] Figure 2 This is a schematic block diagram illustrating the structure of an infrared touch device according to one embodiment of this application;

[0029] Figure 3 This is a schematic diagram of the circuit structure of an infrared touch device according to one embodiment of this application;

[0030] Figure 4 for Figure 3 A schematic diagram of the circuit structure of an infrared touch device when the intermediate amplifier tube is an NPN tube;

[0031] Figure 5 for Figure 3 A schematic diagram of the circuit structure of an infrared touch device when the intermediate amplifier tube is a PNP tube;

[0032] Figure 6 This is a schematic diagram of the circuit structure of an infrared touch device according to another embodiment of this application;

[0033] Figure 7 for Figure 6 A schematic diagram of the circuit structure of an infrared touch device when the intermediate amplifier tube is an NPN tube;

[0034] Figure 8 for Figure 6 A schematic diagram of the circuit structure of an infrared touch device when the intermediate amplifier tube is a PNP tube;

[0035] Figure 9 This is a schematic diagram of the structure of an infrared touchscreen according to one embodiment of this application. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further 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.

[0037] 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.

[0038] 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” used in this application 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” 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.

[0039] 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."

[0040] With the development of electronic technology, infrared touch devices have been widely used in various display devices, such as interactive flat panels, due to their fast response speed and cost-effectiveness. The working principle of an infrared touch device involves placing infrared emitting circuits and / or infrared receiving circuits on each bezel. The infrared emitting circuits emit infrared signals, and the infrared receiving circuits receive these signals. After a series of stabilization adjustments and A / D (analog-to-digital converter) sampling processes, the signal processing circuit determines the touch position and executes the corresponding touch operation.

[0041] Specifically, several infrared touch panels are installed on the four edges of the infrared touch device. Each infrared touch panel 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.

[0042] Depending on their function and location, the infrared touch panels on the infrared touch device are divided into a main board and multiple slave boards. The main board and slave boards are connected by an analog signal bus, a digital signal bus, and a power signal bus.

[0043] The main board and slave board share a power signal bus to provide power signals, i.e., power to the infrared transmitters and receivers connected to them respectively.

[0044] 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.

[0045] In related technologies, there are two main ways to set infrared transmitters and receivers on the four edges of an infrared touch device: one is to set the infrared transmitters and receivers on opposite sides of the infrared touch device; the other is to arrange the infrared transmitters and receivers alternately on the same side of the infrared touch device.

[0046] The following example, with the infrared transmitter and infrared receiver respectively located on opposite sides of the infrared touch device, will further illustrate the structure of the infrared touch device.

[0047] The motherboard contains a signal conditioning circuit, an A / D sampling circuit, and an MCU (Microcontroller Unit) connected in sequence. The MCU controls the activation or deactivation of each infrared transmitter and / or receiver via a digital control bus. The signal conditioning circuit is connected to the analog signal bus; it detects and amplifies the analog electrical signal from the bus. The A / D sampling circuit performs A / D sampling on the amplified analog electrical signal to obtain a digital signal, which is then transmitted to the MCU via a predefined protocol. The MCU analyzes and processes the digital signal obtained from the A / D sampling to calculate the touch position.

[0048] The infrared touch device has an infrared transmitter and an infrared receiver on opposite sides of the slave board. The slave board with the infrared receiver includes an infrared receiver selection circuit and an infrared receiving circuit. The infrared receiver selection circuit includes a shift register with multiple output terminals. The infrared receiving circuit has several infrared receivers. The shift register outputs an infrared receiver enable signal at the corresponding output terminal according to the control signal sent by the MCU 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 conditioning circuit of the host board.

[0049] For details, please refer to Figure 1 In the related technology, the slave board 11 is equipped with a shift register (not shown in the figure) and an infrared receiving circuit; the infrared receiving circuit includes an M row * N column infrared receiver PD1-PDmn, M * N bias resistors R1-Rmn, M * N amplifier tubes Q1-Qmn and M sampling resistors RH1-RHn.

[0050] The infrared receivers PD1-PDmn are optical signal receiving tubes, specifically photodiodes. The amplifier tubes Q1-Qmn are transistors, specifically NPN transistors. V1-Vm are the infrared receiver enable signals that control the infrared receiver to turn on or off; RH1-RHm are the received column signals.

[0051] The input of the shift register is connected to the MCU (not shown) on the motherboard 12 via a digital signal bus to receive control signals. The output of the shift register is connected to the cathode of a row of photodiodes to output an infrared receiver enable signal according to the control signal. The anode of each photodiode PD1-PDmn is connected to the base of an NPN transistor Q1-Qmn, the collector of each NPN transistor Q1-Qmn is connected to the power supply terminal VCC_R, and the emitter of each NPN transistor Q1-Qmn is connected to the analog signal bus, and then grounded via a sampling resistor on the motherboard 12 to RH1-RHn. A bias resistor R1-Rmn is connected in parallel across each photodiode PD1-PDmn.

[0052] When a row of photodiodes is turned on by receiving an infrared receiver enable signal, the photodiodes in that row sense the infrared light signal and generate a photocurrent. The photocurrent is amplified by an NPN transistor and then transmitted to the analog signal bus. The analog signal bus transmits the photocurrent to the motherboard 12, where it is converted from current to voltage at the sampling resistor to obtain the infrared received signal.

[0053] In related technologies, the bias resistor connected in parallel across the photodiode introduces interference current. This interference current is amplified and converted into an interference voltage signal across the sampling resistor, causing some interference to the real and effective infrared receiving signal. In addition, infrared touch devices are composed of multiple infrared touch panels. Each slave board used to receive infrared signals includes at least one infrared receiving circuit. The infrared receiving signal detected by the infrared receiving circuit is transmitted to the signal conditioning module via an analog signal bus. Each NPN transistor in the infrared receiving circuit requires a stable and clean power supply VCC_R. However, the power supply VCC_R on each NPN transistor is a single-point connection to the power signal bus, which means that the power signal bus must run through all infrared touch panels and be routed along with the distribution of each NPN transistor. This easily introduces noise interference, reduces the signal-to-noise ratio, and increases the difficulty of wiring on narrow and long infrared touch panels, thus increasing design costs.

[0054] This application embodiment avoids introducing interference current into the infrared receiving signal by removing the bias resistor. Furthermore, by redesigning the circuit, instead of routing a power supply for each amplifier tube on the slave board, the power supply terminal of each amplifier tube is uniformly connected to the power supply terminal of the main board, avoiding the passage of power signal buses on each slave board, thereby further reducing interference and improving the signal-to-noise ratio.

[0055] The following will be combined with the appendix Figures 2 to 8 This application provides a detailed description of the infrared touch device provided in the embodiments.

[0056] Please see Figure 2 The infrared touch device provided in this application includes: a main board 22 and multiple slave boards 21; the main board 22 includes several sampling resistors RH1-RHn; the slave boards 21 include an infrared receiving circuit; the infrared receiving circuit includes several optical signal receiving tubes PD1-PDmn and several amplifying tubes Q1-Qmn. The first terminal of each optical signal receiving tube is used to receive an optical signal receiving tube enable signal; the second terminal of each optical signal receiving tube is connected to a sampling resistor of the main board 22 via an amplifying tube, and the voltage difference between the first terminal and the second terminal of each optical signal receiving tube is equal to the voltage drop of the corresponding amplifying tube.

[0057] Among them, the optical signal receiving tube can be a photodiode or a photosensitive receiving tube, which are devices that detect optical signals and perform photoelectric conversion, and the amplifying tube can be a transistor or a field-effect transistor, which are devices that have amplification functions.

[0058] Please continue reading. Figure 2In an optional embodiment, several optical signal receiving tubes are arranged in an M-row N-column matrix. The first end of the optical signal receiving tubes in the same row receives the same optical signal receiving tube enable signal to reduce wiring complexity, simplify control, and reduce design costs. Here, M and N are both integers greater than 0, and M and N can be equal or unequal.

[0059] Please continue reading. Figure 2 In an optional embodiment, several optical signal receiving tubes are arranged in an M-row N-column matrix. The second end of the amplifier tube corresponding to the optical signal receiving tube in the same column is connected to the same sampling resistor to simplify wiring, reduce the number of sampling resistors, and reduce costs. Here, M and N are both integers greater than 0, and M and N can be equal or unequal.

[0060] In an optional embodiment, the motherboard further includes an MCU; the MCU includes a control signal output terminal; the slave board further includes an optical signal receiver selection circuit; the optical signal receiver selection circuit includes a shift register; the shift register includes an input terminal and multiple output terminals; the input terminal of the shift register is connected to the control signal output terminal of the MCU via an analog signal bus or a digital signal bus for receiving control signals; each output terminal of the shift register is connected to the first terminal of at least one optical signal receiver for outputting an optical signal receiver enable signal according to the control signal.

[0061] It is understood that the above solution is applicable to scenarios where the infrared transmitter and infrared receiver (light signal receiving tube) are respectively set on opposite sides of the infrared touch device, that is, only the infrared transmitter is set on the slave board, or only the infrared receiver (light signal receiving tube) is set on the slave board. For slave boards that only have infrared receivers (light signal receiving tubes), the above-mentioned light signal receiving tube selection circuit is set.

[0062] This application embodiment is based on a shift register to quickly perform data shifting operations according to control signals, thereby rapidly changing the working state of the optical signal receiving tube and improving the response speed of the optical signal receiving tube; moreover, since one shift register can control multiple optical signal receiving tubes, the number of input / output ports can be reduced, thus reducing costs.

[0063] In another optional embodiment, the motherboard further includes a master MCU; the master 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 emitters; 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 master 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 optical signal receiving tube for outputting an optical signal receiving tube enable signal according to the control signal.

[0064] It is understandable that when the above solution is applied to the scenario where infrared transmitters and infrared receivers (light signal receiving tubes) are arranged alternately on the same side of the infrared touch device, that is, when infrared transmitters and infrared receivers (light signal receiving tubes) are set on the slave board, the slave board controls the working state of the infrared transmitters through the MCU.

[0065] Before scanning begins, the main board sends scanning data to each slave board via the digital signal bus, controlling the infrared transmitters and receivers. Each slave board shares the digital signal bus to acquire its own scanning data and controls its respective infrared transmitter and receiver to perform the scanning operation based on that data. The scanning data includes the location information of the infrared receivers and transmitters connected to that slave board, as well as the corresponding scanning logic.

[0066] After scanning begins, the main board transmits synchronization signals to each slave board via the synchronization signal bus to control the corresponding slave board to perform scanning. The synchronization signal includes control signals. Specifically, 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 scan data and controls the working status of the connected infrared receivers (optical signal receiving tubes) and infrared transmitters according to the control signals in the synchronization signal. The synchronization signal bus can be an analog signal bus or a digital signal bus.

[0067] This application 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.

[0068] In this embodiment, when the optical signal receiving tube of the slave board 21 receives the optical signal receiving tube enable signal and is turned on, the optical signal receiving tube senses the infrared light signal emitted by the infrared transmitter and generates photocurrent. After the photocurrent is amplified by the amplifier tube, it is transmitted to the host board 22 via the analog signal bus. After current-to-voltage conversion on the sampling resistor of the host board 22, the infrared received signal is obtained.

[0069] This embodiment of the application removes the bias resistor connected in parallel across the optical signal receiving tube, avoiding interference current introduced by the bias resistor. Furthermore, by making the voltage difference between the first and second ends of each optical signal receiving tube equal to the voltage drop of the corresponding connected amplifier tube, the amplifier tube can effectively amplify the signal, thereby improving the signal-to-noise ratio and the accuracy of infrared touch detection.

[0070] Please see Figure 3In an optional embodiment, the signal input terminal of the amplifier tubes Q1-Qmn is connected to the second terminal of the optical signal receiving tubes PD1-PDmn; the first connection terminal of the amplifier tubes Q1-Qmn is connected to the power supply terminal VCC_R; the second connection terminal of the amplifier tubes Q1-Qmn is connected to the first terminal of the sampling resistors RH1-RHm; and the second terminal of the sampling resistors RH1-RHm is grounded to GND.

[0071] Optional, please refer to Figure 4 The optical signal receiving tubes PD1-PDmn are photodiodes; the first terminal of PD1-PDmn is the cathode of the photodiode; the second terminal of PD1-PDmn is the anode of the photodiode. The amplifying tubes Q1-Qmn are NPN transistors; the signal input terminal of PD1-PDmn is the base of the NPN transistor; the first connection terminal of Q1-Qmn is the collector of the NPN transistor; the second connection terminal of PD1-PDmn is the emitter of the NPN transistor.

[0072] Alternatively, the optical signal receiving tubes PD1-PDmn are photodiodes; the first terminal of the optical signal receiving tubes PD1-PDmn is the cathode of the photodiode; the second terminal of the optical signal receiving tubes PD1-PDmn is the anode of the photodiode. The amplifying tubes Q1-Qmn are N-channel field-effect transistors (N-FETs); the signal input terminal of the amplifying tubes Q1-Qmn is the gate of the N-FET; the first connection terminal of the amplifying tubes Q1-Qmn is the drain of the N-FET; the second connection terminal of the amplifying tubes Q1-Qmn is the source of the N-FET.

[0073] When the light signal receiving tube enable signal received from the cathode of the photodiode on the motherboard 21 is a low-level signal, the photodiode turns on. The photodiode senses the infrared light signal emitted by the infrared emitter and generates a photocurrent. The photocurrent flows into the signal input terminal of the amplifier tube (NPN transistor or N-type field-effect transistor), is amplified by the amplifier tube, and is transmitted to the analog signal bus. After current-to-voltage conversion at the sampling resistor on the motherboard 22, the infrared received signal is obtained.

[0074] Optional, please refer to Figure 5 The optical signal receiving tubes PD1-PDmn are photodiodes; the first terminal of PD1-PDmn is the anode of the photodiode; the second terminal of PD1-PDmn is the cathode of the photodiode. The amplifying tubes Q1-Qmn are PNP transistors; the signal input terminal of Q1-Qmn is the base of the PNP transistor; the first connection terminal of Q1-Qmn is the emitter of the PNP transistor; the second connection terminal of Q1-Qmn is the collector of the PNP transistor.

[0075] Alternatively, the optical signal receiving tubes PD1-PDmn are photodiodes; the first terminal of PD1-PDmn is the anode of the photodiode; the second terminal of PD1-PDmn is the cathode of the photodiode. The amplifying tubes Q1-Qmn are P-type field-effect transistors (P-FETs); the signal input terminal of Q1-Qmn is the gate of the P-FET; the first connection terminal of Q1-Qmn is the source of the P-FET; and the second connection terminal of Q1-Qmn is the drain of the N-type field-effect transistor.

[0076] When the light signal receiving tube enable signal received from the anode of the photodiode on the motherboard 21 is a high-level signal, the photodiode turns on. The photodiode senses the infrared light signal emitted by the infrared emitter and generates a photocurrent. The photocurrent flows into the signal input terminal of the amplifier tube (PNP or P-type field-effect transistor), is amplified by the amplifier tube, and is transmitted to the analog signal bus. After current-to-voltage conversion at the sampling resistor on the motherboard 22, the infrared received signal is obtained.

[0077] In another alternative embodiment, please refer to Figure 6 The signal input terminals of the amplifier tubes Q1-Qmn are connected to the second terminal of the optical signal receiving tube; the first connection terminal of the amplifier tubes Q1-Qmn is grounded to GND; the second connection terminal of the amplifier tubes Q1-Qmn is connected to the first terminal of the sampling resistors RH1-RHm; the second terminal of the sampling resistors RH1-RHm is connected to the power supply terminal VCC_R.

[0078] In this embodiment, the amplifier transistors Q1-Qmn are uniformly connected to the power supply terminal of the main board 22, eliminating the need to lay power supplies for each amplifier transistor Q1-Qmn on the slave board 21. This avoids running power signal buses across each slave board, preventing interference introduced by wiring each amplifier transistor, improving the signal-to-noise ratio, reducing wiring difficulty, and lowering design costs.

[0079] Optional, please refer to Figure 7 The optical signal receiving tubes PD1-PDmn are photodiodes; the first terminal of PD1-PDmn is the cathode of the photodiode; the second terminal of PD1-PDmn is the anode of the photodiode. The amplifier tubes Q1-Qmn are NPN transistors; the signal input terminal of Q1-Qmn is the base of the NPN transistor; the first connection terminal of Q1-Qmn is the emitter of the NPN transistor; the second connection terminal of Q1-Qmn is the collector of the NPN transistor.

[0080] Alternatively, the optical signal receiving tubes PD1-PDmn are photodiodes; the first terminal of PD1-PDmn is the anode of the photodiode; the second terminal of PD1-PDmn is the cathode of the photodiode. The amplifier tubes Q1-Qmn are N-channel field-effect transistors (N-FETs); the signal input terminal of Q1-Qmn is the gate of the N-FET; the first connection terminal of Q1-Qmn is the source of the N-FET; the second connection terminal of Q1-Qmn is the drain of the N-FET.

[0081] When the enable signal of the light signal receiving tube received from the anode on the motherboard 21 is a high-level signal, the photodiode turns on. The photodiode senses the infrared light signal emitted by the infrared emitter and generates a photocurrent. The photocurrent flows into the signal input terminal of the amplifier tube (NPN or N-type field-effect transistor). After being amplified by the amplifier tube, it is transmitted to the analog signal bus. After current-to-voltage conversion on the sampling resistor of the motherboard 22, the infrared received signal is obtained.

[0082] This application embodiment uses a photodiode to match an NPN transistor or an N-type field-effect transistor. This allows for normal detection and amplification of infrared light signals, while avoiding the need to route power supplies for each amplifying transistor on the circuit board. This also avoids interference introduced by routing individual amplifying transistors, reduces wiring difficulty, and lowers design costs.

[0083] Optional, please refer to Figure 8 The optical signal receiving tubes PD1-PDmn are photodiodes; the first terminal of PD1-PDmn is the anode of the photodiode; the second terminal of PD1-PDmn is the cathode of the photodiode. The amplifying tubes Q1-Qmn are PNP transistors; the signal input terminal of Q1-Qmn is the base of the PNP transistor; the first connection terminal of Q1-Qmn is the collector of the PNP transistor; the second connection terminal of Q1-Qmn is the emitter of the PNP transistor.

[0084] Alternatively, the optical signal receiving tubes PD1-PDmn are photodiodes; the first terminal of the optical signal receiving tube PD1-PDmn is the anode of the photodiode; the second terminal of the optical signal receiving tube PD1-PDmn is the cathode of the photodiode. The amplifying tubes Q1-Qmn are P-type field-effect transistors (P-FETs); the signal input terminal of the amplifying tubes Q1-Qmn is the gate of the P-FET; the first connection terminal of the amplifying tubes Q1-Qmn is the drain of the P-FET; the second connection terminal of the amplifying tubes Q1-Qmn is the source of the P-FET.

[0085] When the light signal receiving tube enable signal received from the anode of the photodiode on board 21 is a low-level signal, the photodiode turns on. The photodiode senses the infrared light signal emitted by the infrared emitter and generates a photocurrent. The photocurrent flows into the control terminal of the amplifier tube (PNP transistor or P-type field-effect transistor), is amplified by the amplifier tube, and is transmitted to the analog signal bus. After current-to-voltage conversion at the sampling resistor on the motherboard, the infrared received signal is obtained.

[0086] This application embodiment uses a photodiode matched with a PNP transistor or a P-type field-effect transistor. This allows for normal detection and amplification of infrared light signals, while avoiding the need to route power supplies for each amplifying transistor on the circuit board. This also avoids interference introduced by routing each amplifying transistor, reduces wiring difficulty, and lowers design costs.

[0087] Please see Figure 9 This is a schematic diagram of the structure of an infrared touchscreen provided in the second embodiment of this application. The infrared touchscreen includes a display screen 201 and an infrared touch device 202; the infrared touch device 202 is disposed around the display screen 201. The infrared touchscreen can be used on various terminal devices. The display screen 201 can display screen content, and the infrared touch device 202 has a touch positioning function, enabling the terminal device to have touch functionality. The infrared touch device 202 in this embodiment is the structure of any of the above embodiments, and will not be described in detail here.

[0088] 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.

[0089] 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 device, characterized by, include: The system comprises a main board and multiple slave boards; the main board includes several sampling resistors; each slave board includes an infrared receiving circuit; the infrared receiving circuit includes several optical signal receiving tubes and several amplifying tubes; the first terminal of each optical signal receiving tube is used to receive an optical signal receiving tube enable signal; the second terminal of each optical signal receiving tube is connected to one of the sampling resistors of the main board via one of the amplifying tubes; the voltage difference between the first and second terminals of each optical signal receiving tube is equal to the voltage drop of the corresponding amplifying tube.

2. The infrared touch device according to claim 1, characterized in that: The optical signal receiving tubes are arranged in an M-row N-column matrix, and the first end of the optical signal receiving tubes in the same row receives the same optical signal receiving tube enable signal; where M and N are both integers greater than 0.

3. The infrared touch device according to claim 1, characterized in that: Several optical signal receiving tubes are arranged in an M-row N-column matrix, and the second end of the amplifier tube corresponding to the optical signal receiving tube in the same column is connected to the same sampling resistor; where M and N are both integers greater than 0.

4. The infrared touch device according to claim 1, characterized in that: The main board also includes an MCU; the MCU includes a control signal output terminal; the slave board also includes an optical signal receiver selection circuit; the optical signal receiver selection circuit includes a shift register; the shift register includes an input terminal and multiple output terminals; the input terminal of the shift register is connected to the control signal output terminal of the MCU via a digital signal bus for receiving control signals; each output terminal of the shift register is connected to the first terminal of at least one optical signal receiver for outputting an optical signal receiver enable signal according to the control signal.

5. The infrared touch device according to claim 1, characterized in that: 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 emitters; 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 optical signal receiving tubes, and is used to output an optical signal receiving tube enable signal according to the control signal.

6. The infrared touch device according to any one of claims 1 to 5, characterized in that: The signal input terminal of the amplifier tube is connected to the second terminal of the optical signal receiving tube; the first connection terminal of the amplifier tube is grounded; the second connection terminal of the amplifier tube is connected to the first terminal of the sampling resistor; and the second terminal of the sampling resistor is connected to the power supply terminal.

7. The infrared touch device according to claim 6, characterized in that: The optical signal receiving tube is a photodiode; the first end of the optical signal receiving tube is the cathode of the photodiode; the second end of the optical signal receiving tube is the anode of the photodiode. The amplifying transistor is an NPN transistor; the signal input terminal of the amplifying transistor is the base of the NPN transistor; the first connection terminal of the amplifying transistor is the emitter of the NPN transistor; the second connection terminal of the amplifying transistor is the collector of the NPN transistor; or, the amplifying transistor is an N-type field-effect transistor; the signal input terminal of the amplifying transistor is the gate of the N-type field-effect transistor; the first connection terminal of the amplifying transistor is the source of the N-type field-effect transistor; the second connection terminal of the amplifying transistor is the drain of the N-type field-effect transistor.

8. The infrared touch device according to claim 6, characterized in that: The optical signal receiving tube is a photodiode; the first end of the optical signal receiving tube is the anode of the photodiode; the second end of the optical signal receiving tube is the cathode of the photodiode. The amplifying transistor is a PNP transistor; the signal input terminal of the amplifying transistor is the base of the PNP transistor; the first connection terminal of the amplifying transistor is the collector of the PNP transistor; the second connection terminal of the amplifying transistor is the emitter of the PNP transistor; or, the amplifying transistor is a P-type field-effect transistor; the signal input terminal of the amplifying transistor is the gate of the P-type field-effect transistor; the first connection terminal of the amplifying transistor is the drain of the P-type field-effect transistor; the second connection terminal of the amplifying transistor is the source of the P-type field-effect transistor.

9. An infrared touch screen, characterized by include: The display screen and the infrared touch device as described in any one of claims 1 to 8; The infrared touch device is positioned around the display screen.

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