A touch key based on modulated infrared light and a signal trigger recognition method

Abstract

The application discloses a touch key based on modulated infrared light and a signal triggering recognition method. In view of the problems of the existing mechanical touch key contact, such as easy oxidation, short service life, and many wire harnesses, and the problems of the existing optical touch key, such as easy interference from external light, adjacent light path crosstalk, and great influence of single point fault, the application adopts a matrix light path shielding principle to realize touch key positioning, and through the combination of infrared carrier modulation, time-sharing cyclic scanning, light beam angle limitation and a diffuse transmission light emitting mechanism with a redundant light source, the light interference problem is effectively solved. The application does not need mechanical contact, has a long service life, greatly reduces the cost of wire harnesses, has strong anti-interference ability, high recognition accuracy, redundancy design, high reliability, supports various signal outputs, and has strong adaptability.

Description

Technical Field

[0001] This invention belongs to the technical field of button devices, specifically relating to a touch button based on modulated infrared light and a signal triggering recognition method. Background Technology

[0002] With the development of electronic technology, touch buttons, as the most basic human-computer interaction device, are widely used in various electronic devices and control systems. Currently, touch buttons on the market are mainly divided into two categories: mechanical touch buttons and optical touch buttons.

[0003] Traditional mechanical touch buttons rely on the connection and disconnection of metal contacts to trigger signals. Their main drawbacks include:

[0004] (1) Contacts are easily damaged: Metal contacts are prone to oxidation and electrolytic corrosion after long-term use, resulting in poor contact or even abnormal adhesion. Their service life is usually only tens of thousands to hundreds of thousands of times.

[0005] (2) High wiring harness cost: Each touch button requires a separate connection wire. In the case of multiple touch buttons (such as the call panel in the elevator car of a high-rise building), a large number of wiring harnesses are required, which not only increases the material cost, but also increases the complexity of production and installation.

[0006] (3) Low connector reliability: Each touch button requires connectors at both ends, which can easily lead to problems such as loosening and poor contact;

[0007] (4) Complex material management: Different installation locations require cables of different lengths, resulting in a wide variety of material types and making management difficult.

[0008] To address the aforementioned drawbacks of mechanical touch buttons, optical touch buttons have emerged in recent years. Optical touch buttons operate on the principle of light path obstruction; when a finger or other object blocks the light path, the light-receiving element detects the change in light intensity, thus triggering a signal. Compared to mechanical touch buttons, optical touch buttons have no mechanical contacts, resulting in a longer lifespan, theoretically up to hundreds of millions of clicks.

[0009] However, existing optical touch buttons still have the following shortcomings:

[0010] (1) Susceptible to external light interference: There is a large amount of infrared light in nature (such as sunlight and lamp light), which is easily misreceived by light receiving components, leading to false triggering;

[0011] (2) Crosstalk between adjacent optical paths: Since infrared light has a certain divergence angle, the light emitted by one transmitting tube may be received by the adjacent receiving tube, resulting in signal identification error;

[0012] (3) Single point of failure has a great impact: Usually, a design of one transmitter tube corresponding to one receiver tube is adopted. Once a transmitter tube is damaged, the corresponding touch button will be unusable;

[0013] Light guide structure required: In order to reduce light interference, some optical touch buttons require complex structures such as light guide tubes or light shields, which increases manufacturing costs and process difficulty.

[0014] Prior art document CN102244514A discloses a touch button device with LEDs arranged in a ring around its inner side. This device has an LED strip arranged in a ring around the inner side of a frame, and a color light sensing element is disposed on the button substrate. A signal is triggered when a finger blocks the color light sensing element. While this solution achieves touch functionality without mechanical contacts, it still has the following problems:

[0015] Using a single-point light sensing method, each button requires an independent color light sensing element, which is still costly in multi-touch button scenarios; it does not solve the problems of external light interference and crosstalk between adjacent light paths, and is prone to malfunctions in strong light environments; it lacks redundancy design, and damage to a single light-emitting diode or color light sensing element will cause the corresponding button to malfunction.

[0016] In summary, existing touch button devices cannot simultaneously meet the requirements of long service life, low cost, high reliability, and strong anti-interference capability. Therefore, there is an urgent need to develop a new type of touch button to solve the above problems. Summary of the Invention

[0017] The main objective of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a touch button and signal trigger recognition method based on modulated infrared light. This method eliminates the need for mechanical contacts, has a long service life, and significantly reduces wiring harness costs. Furthermore, through a combination of various anti-interference technologies, it effectively solves the problems of external light interference and crosstalk between adjacent optical paths, and features a redundant design for high reliability.

[0018] To achieve the above objectives, the present invention adopts the following technical solution:

[0019] In a first aspect, the present invention provides a touch button based on modulated infrared light, comprising:

[0020] The button panel has multiple touch button areas arranged in a matrix.

[0021] The light emitting unit includes at least one infrared emitting tube for emitting infrared light;

[0022] The light receiving unit includes multiple infrared receiving tubes, which correspond one-to-one with the infrared emitting tubes to form multiple intersecting light paths. The intersection points of the light paths correspond one-to-one with the touch button areas.

[0023] The control unit is electrically connected to the optical emitting unit and the optical receiving unit respectively via a bus;

[0024] An anti-interference module is connected to the optical emitting unit;

[0025] The power supply unit is connected to the optical emitting unit, the optical receiving unit, and the control unit via wires.

[0026] The anti-interference module includes at least one of the following:

[0027] An infrared carrier modulation unit is used to modulate the infrared light emitted by the infrared emitting tube, so that the infrared receiving tube only responds to infrared light of a specific frequency.

[0028] The time-division cyclic scanning unit is used to control the infrared emitting tubes in the light emitting unit to emit infrared light sequentially in a time-division manner, and only one infrared emitting tube emits infrared light at any given time;

[0029] A beam angle limiting unit is disposed in the optical path of the infrared emitting tube and / or the infrared receiving tube to limit the emission and / or reception angle of infrared light;

[0030] The signal conversion unit is connected to the electrical and optical receiving units of the control unit, respectively;

[0031] When a certain touch button area is blocked, at least two corresponding intersecting light paths are blocked. The control unit identifies the pressed touch button area based on the signal output by the infrared receiver tube corresponding to the blocked light path.

[0032] As a preferred technical solution, the infrared carrier modulation unit includes:

[0033] A carrier generation circuit is used to generate a carrier signal at a preset frequency.

[0034] A modulation circuit is used to load the carrier signal onto the drive signal of the infrared emitting tube;

[0035] A demodulation circuit, connected to the infrared receiver tube, is used to demodulate a signal that matches the preset frequency from the signal output by the infrared receiver tube.

[0036] As a preferred technical solution, the infrared carrier modulation unit controls all infrared emitting tubes to emit infrared light of a preset frequency, all infrared receiving tubes respond to the infrared light of the same preset frequency, and the infrared emitting tubes emit infrared light of the same or different preset frequencies.

[0037] As a preferred technical solution, the time-division cyclic scanning unit controls the single emission duration of each infrared emitting tube to be 1 to 10 milliseconds, the emission interval between two adjacent infrared emitting tubes to be 0.1 to 1 millisecond, and the total time to complete one full scan does not exceed 50 milliseconds.

[0038] As a preferred technical solution, the beam angle limiting unit includes:

[0039] A light-shielding plate is disposed in front of the infrared emitting tube, and the light-shielding plate has emission slits that correspond one-to-one with the infrared emitting tubes.

[0040] A light-shielding plate is disposed in front of the infrared receiving tube, and the light-shielding plate has receiving slits that correspond one-to-one with the infrared receiving tubes.

[0041] The width of the transmitting slit and the receiving slit is 0.5 to 3 mm, used to limit the transmission and reception angles of infrared light to within ±5°.

[0042] As a preferred technical solution, when the anti-interference module is used as an infrared carrier modulation unit or a beam angle limiting unit, the light emitting unit further includes:

[0043] The diffuse transmission light guide strip is long and extends along the light path.

[0044] At least two infrared emitting diodes are respectively disposed at at least one end of the diffuse transmission light guide strip;

[0045] The diffuse light guide strip is used to homogenize the infrared light emitted by the at least two infrared emitting tubes and form a continuous surface light source along its length.

[0046] As a preferred technical solution, the diffuse transmission light guide strip is an acrylic light guide strip with a diffuse transmission microstructure formed on its surface.

[0047] As a preferred technical solution, the signal conversion unit is used to convert the touch button recognition signal output by the control unit into at least one of the following signal formats: RS485, RS232, CAN bus, GPIO.

[0048] Secondly, the present invention also provides a method for triggering and recognizing touch button signals based on modulated infrared light, including...

[0049] S1. Initialize the touch buttons and establish a matrix-like optical path with horizontal and vertical intersections;

[0050] S2. Activate the anti-interference mode, wherein the anti-interference mode includes at least one of the following:

[0051] The infrared light emitted by the infrared emitting tube is carrier-modulated so that the infrared receiving tube only responds to infrared light of a specific frequency.

[0052] The infrared emitting tubes are controlled to emit infrared light sequentially and at different times, with only one infrared emitting tube emitting infrared light at any given moment.

[0053] The emission and reception angles of infrared light are limited by a beam angle limiting unit;

[0054] S3. Real-time monitoring of the output signals of each infrared receiver tube;

[0055] S4. When a change in the output signal of the infrared receiver tube corresponding to at least two intersecting optical paths is detected, the corresponding intersection point is determined as the area of ​​the pressed touch button.

[0056] S5, outputs the corresponding touch button recognition signal.

[0057] As a preferred technical solution, step S2, the step of carrier modulation of the infrared light emitted by the infrared emitting tube, includes:

[0058] S21. Generate a carrier signal of a preset frequency;

[0059] S22. The carrier signal is loaded onto the drive signal of the infrared emitting tube;

[0060] S23. At the infrared receiver tube end, the received signal is demodulated, and only the signal that matches the preset frequency is retained;

[0061] In step S2, the step of controlling the infrared emitting tube to emit infrared light sequentially and in a time-division manner includes:

[0062] S24. Control the first infrared emitting tube to emit infrared light, and at the same time read only the signal of the corresponding first infrared receiving tube;

[0063] S25. Turn off the first infrared emitter and wait for the preset interval time;

[0064] S26. Control the next infrared emitting tube to emit infrared light, and at the same time read only the signal of the corresponding next infrared receiving tube;

[0065] S27. Repeat steps S24 to S26 above until all infrared emitting tubes complete one emission, forming one scanning cycle;

[0066] S28, continuously execute the scan cycle.

[0067] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0068] (1) Long service life: No mechanical contacts are required, and there are no problems such as contact oxidation or wear. The theoretical service life can reach hundreds of millions of times, which is far higher than that of traditional mechanical touch buttons.

[0069] (2) Low cost: The matrix optical path design, with M horizontal optical paths and N vertical optical paths, can realize the recognition of M×N touch buttons, which greatly reduces the number of transmitting tubes and receiving tubes. At the same time, it does not require a large number of wires, significantly reducing material costs and production and installation costs.

[0070] (3) Strong anti-interference capability: By combining any combination of three anti-interference technologies, namely infrared carrier modulation, time-division cyclic scanning and beam angle limitation, it can effectively filter external light interference and crosstalk between adjacent optical paths, and has a high recognition accuracy.

[0071] (4) High reliability: The diffuse transmission light guide strip design is adopted, and multiple emitters share one light guide strip. Even if some emitters are damaged, the system can still work normally, which has a redundancy design.

[0072] (5) Easy to install and maintain: The overall structure is simple and modular, making installation convenient; when a single component is damaged, only the corresponding component needs to be replaced, without replacing the entire panel, resulting in low maintenance costs. Attached Figure Description

[0073] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0074] Figure 1 This is a circuit diagram of a touch button based on modulated infrared light according to an embodiment of the present invention;

[0075] Figure 2 This is another circuit diagram of a touch button based on modulated infrared light according to an embodiment of the present invention;

[0076] Figure 3 This is a schematic diagram of the first optical path matrix according to an embodiment of the present invention;

[0077] Figure 4 This is a schematic diagram of the second optical path matrix according to an embodiment of the present invention;

[0078] Figure 5 This is a schematic diagram of the third optical path matrix according to an embodiment of the present invention;

[0079] Figure 6 This is a schematic diagram of the anti-interference module according to an embodiment of the present invention;

[0080] Figure 7This is a schematic diagram of the signal conversion unit structure according to an embodiment of the present invention;

[0081] Figure 8 This is a flowchart of a touch button signal triggering and recognition method based on modulated infrared light according to an embodiment of the present invention.

[0082] Numbering Explanation:

[0083] Keypad 1; Light emitting unit 2; Light receiving unit 3; Control unit 4; Anti-interference module 5; Signal conversion unit 6; Power supply unit 7; Diffuse transmission light guide strip 21; Infrared emitting tube 22; Infrared carrier modulation unit 51; Time-division cyclic scanning unit 52; Beam angle limiting unit 53; Carrier generation circuit 511; Modulation circuit 512; Demodulation circuit 513; Transmitter light shield 531; Receiver light shield 532; RS485 interface circuit 61; RS232 interface circuit 62; CAN bus interface circuit 63; GPIO interface circuit 64; Transmitter slit 5311; Receiver slit 5321. Detailed Implementation

[0084] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0085] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0086] Example 1.

[0087] Please see Figure 1 This embodiment provides a touch button based on modulated infrared light, including:

[0088] This embodiment provides a touch button based on modulated infrared light, such as... Figures 1 to 7 As shown, the system includes a keypad panel 1, a light emitting unit 2, a light receiving unit 3, a control unit 4, an anti-interference module 5, and a signal conversion unit 6.

[0089] like Figures 3 to 7As shown, the button panel 1 is made of transparent acrylic material, glass or other light-transmitting material, and its surface is printed with multiple touch button areas arranged in an N×N' matrix, such as a 6×3 matrix or a 3×6 matrix corresponding to the number keys 0-9, function keys and directional keys respectively.

[0090] The light emitting unit 2 includes multiple infrared emitting diodes arranged along the upper edge of the button panel 1; the light receiving unit includes multiple infrared receiving diodes, corresponding to the number of infrared emitting diodes. Taking a 6×3 matrix as an example, the diodes are arranged vertically along the left edge of the button panel 1. Figure 2 As shown, the infrared light emitted by infrared emitters D1-D6 forms 6 horizontal light paths, and infrared receivers S1-S6 receive the infrared light. The infrared light emitted by infrared emitters D7-D9 forms 3 vertical light paths, and infrared receivers S7-S9 receive the infrared light. The horizontal and vertical light paths intersect to form 18 intersection points, and each intersection point corresponds to a touch button area.

[0091] The control unit 4 uses an STM32F103C8T6 microcontroller, which is electrically connected to the light emitting unit 2 and the light receiving unit 3 respectively. It is used to control the emission of the infrared emitting tube and the signal reading of the infrared receiving tube, and to identify the pressed touch button area based on the received signal.

[0092] The anti-interference module 5 includes an infrared carrier modulation unit 51, a time-division cyclic scanning unit 52, and a beam angle limiting unit 53. At least one of the three anti-interference technologies can be used.

[0093] like Figure 1 and Figure 3 As shown, when the anti-interference module is an active module, it is connected to a power source and controlled via a CAN bus, such as when the anti-interference module 5 is an infrared carrier modulation unit 51 and a time-division cyclic scanning unit 52.

[0094] The infrared carrier modulation unit 51 includes a carrier generation circuit 511, a modulation circuit 512, and a demodulation circuit 513. The carrier generation circuit generates a 400kHz carrier signal, and the modulation circuit 511 loads this carrier signal onto the drive signal of the infrared emitting tube, causing the infrared emitting tube to emit 400kHz modulated infrared light. The demodulation circuit 513 is connected to the infrared receiving tube and uses a bandpass filter and a detector circuit to allow only the 400kHz signal to pass through, thereby filtering out external light interference of other frequencies.

[0095] The time-division cyclic scanning unit 52 is implemented by the internal timer of the control unit 4. The single emission duration of each infrared emitting tube is 5 milliseconds, and the emission interval between two adjacent infrared emitting tubes is 0.5 milliseconds. The total time to complete one full scan is (5 + 0.5) × 6 = 33 milliseconds, which is much shorter than the time it takes for a human finger to press down (usually 100-400 milliseconds). At any given time, only one infrared emitting tube emits infrared light, and the control unit 4 only reads the signal from the corresponding infrared receiving tube, thus completely eliminating crosstalk between adjacent optical paths.

[0096] like Figure 2 and Figure 4 As shown, when the anti-interference module is a passive module, the anti-interference module is controlled via the CAN bus, such as when the anti-interference module 5 is the beam angle limiting unit 53.

[0097] like Figure 4 As shown, the beam angle limiting unit 53 includes an emitting end light shield 531 and a receiving end light shield 532. The emitting end light shield 531 is disposed in front of the infrared emitting tube and has an emitting slit 5311 with a width of 1 mm. The receiving end light shield 532 is disposed in front of the infrared receiving tube and has a receiving slit 5321 with a width of 1 mm. By limiting the slits, the emission and reception angles of the infrared light are restricted to within ±3°. At this time, the receiving slit 521 restricts the light angle, preventing different receiving ends from mistakenly receiving each other's light, thus reducing light divergence and crosstalk at the source.

[0098] The signal conversion unit 6 includes an RS485 interface circuit 61, an RS232 interface circuit 62, a CAN bus interface circuit 63, and a GPIO interface circuit 64, which can convert the touch button recognition signal output by the control unit 4 into a variety of standard signal formats, making it convenient to connect to different control systems.

[0099] Power supply unit 7 is used to provide power to other power-consuming units.

[0100] The working process of this embodiment is as follows:

[0101] After the system is powered on, the control unit 4 initializes all peripherals and establishes a cross-matrix optical path;

[0102] S1. Start the infrared carrier modulation unit 51 and the time-division cyclic scanning unit 52, and the infrared emitting tube sequentially emits 400kHz modulated infrared light in a time-division manner.

[0103] S2, Control Unit 4 monitors the output signals of each infrared receiver tube in real time;

[0104] S3. When a user presses a certain touch button area, the corresponding horizontal and vertical light paths are blocked, and the corresponding infrared receiver tube output signal changes from high level to low level.

[0105] S4 and control unit 4 calculate the coordinates of the intersection point based on the numbers of the two blocked intersecting optical paths, thereby determining the area of ​​the pressed touch button.

[0106] S5 and control unit 4 send the touch button recognition signal to signal conversion unit 6, which converts it into the corresponding signal format and outputs it to the external control system.

[0107] Example 2.

[0108] The difference between this embodiment and Embodiment 1 is that the light emitting unit 2 adopts a diffuse transmission light guide strip design, such as... Figure 5 As shown. The light emitting unit 2 includes two diffuse transmission light guide strips 21, which extend along the transverse and longitudinal light path directions respectively; each diffuse transmission light guide strip 21 has at least two infrared emitting tubes 22 disposed inside.

[0109] The diffuse transmission light guide strip 21 is made of acrylic material, and its surface is laser-engraved to form a uniformly distributed diffuse transmission microstructure. After the infrared light emitted by the infrared emitting tube 22 enters the diffuse transmission light guide strip 21, it undergoes total internal reflection inside. When it encounters the diffuse transmission microstructure, it undergoes diffuse transmission, thereby forming a uniform continuous surface light source along the length of the light guide strip.

[0110] The advantages of this embodiment are:

[0111] (1) Multiple infrared emitting tubes share a single light guide strip. Even if one of the emitting tubes is damaged, the other emitting tube can still work normally. The system will not have a single point of failure, and the reliability is greatly improved.

[0112] (2) The continuous surface light source formed by the light guide strip has a more uniform optical path than the point light source, which improves the accuracy of signal recognition;

[0113] (3) It can reduce the number of transmitting tubes and further reduce costs.

[0114] When using the diffuse transmission light guide strip 21, it can be used in combination with the infrared carrier modulation unit 51 or the beam angle limiting unit 53. Combining the two can not only improve the stability of the system operation, but also make up for the defect that it is easily interfered with after diffuse reflection.

[0115] Example 3.

[0116] This embodiment provides a method for triggering and recognizing touch button signals based on modulated infrared light, such as... Figure 8 As shown, it includes the following steps:

[0117] S1. Initialize the touch buttons, configure the control unit's I / O ports, timers, and interrupts, and establish a cross-matrix optical path;

[0118] S2. Simultaneously activate three anti-interference modes:

[0119] Infrared carrier modulation mode: A 400kHz carrier signal is generated and loaded onto the drive signal of the infrared emitting tube. The signal is then demodulated at the receiving end, retaining only the 400kHz signal.

[0120] Time-sharing cyclic scanning mode: Controls 6 infrared emitters to emit sequentially in a time-sharing manner, with each emission lasting 5 milliseconds and an interval of 0.5 milliseconds, in a cyclic scanning process;

[0121] Beam angle limiting mode: The emission and reception angles of infrared light are limited to within ±3° through the slits at the transmitter and receiver.

[0122] S3. During each scanning cycle, read the output signals of the three infrared receivers sequentially and store them in the buffer area;

[0123] S4. Filter the signal in the buffer area. When the signal of two intersecting optical paths is low for two consecutive scanning cycles, determine the corresponding intersection point as the area of ​​the pressed touch button.

[0124] S5. The touch button recognition signal is output to the external control system through the signal conversion unit;

[0125] S6. Return to step S3 and continue monitoring the signal.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0127] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0128] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A touch button based on modulated infrared light, characterized in that, include: The button panel has multiple touch button areas arranged in a matrix. The light emitting unit includes at least one infrared emitting tube for emitting infrared light; The light receiving unit includes multiple infrared receiving tubes, which correspond one-to-one with the infrared emitting tubes to form multiple intersecting light paths. The intersection points of the light paths correspond one-to-one with the touch button areas. The control unit is electrically connected to the optical emitting unit and the optical receiving unit respectively via a bus; An anti-interference module is connected to the optical emitting unit; The power supply unit is connected to the optical emitting unit, the optical receiving unit, and the control unit via wires. The anti-interference module includes at least one of the following: An infrared carrier modulation unit is used to modulate the infrared light emitted by the infrared emitting tube, so that the infrared receiving tube only responds to infrared light of a specific frequency. The time-division cyclic scanning unit is used to control the infrared emitting tubes in the light emitting unit to emit infrared light sequentially in a time-division manner, and only one infrared emitting tube emits infrared light at any given time; A beam angle limiting unit is disposed in the optical path of the infrared emitting tube and / or the infrared receiving tube to limit the emission and / or reception angle of infrared light; The signal conversion unit is connected to the electrical and optical receiving units of the control unit, respectively; When a certain touch button area is blocked, at least two corresponding intersecting light paths are blocked. The control unit identifies the pressed touch button area based on the signal output by the infrared receiver tube corresponding to the blocked light path.

2. The touch button based on modulated infrared light according to claim 1, characterized in that, The infrared carrier modulation unit includes: A carrier generation circuit is used to generate a carrier signal at a preset frequency. A modulation circuit is used to load the carrier signal onto the drive signal of the infrared emitting tube; A demodulation circuit, connected to the infrared receiver tube, is used to demodulate a signal that matches the preset frequency from the signal output by the infrared receiver tube.

3. The touch button based on modulated infrared light according to claim 2, characterized in that, The infrared carrier modulation unit controls all infrared emitting tubes to emit infrared light at a preset frequency, and all infrared receiving tubes respond to the infrared light at the same preset frequency. The infrared emitting tubes emit infrared light at the same or different preset frequencies.

4. The touch button based on modulated infrared light according to claim 1, characterized in that, The time-division cyclic scanning unit controls the single emission duration of each infrared emitting tube to be 1 to 10 milliseconds, the emission interval between two adjacent infrared emitting tubes to be 0.1 to 1 millisecond, and the total time to complete one full scan does not exceed 50 milliseconds.

5. The touch button based on modulated infrared light according to claim 1, characterized in that, The beam angle limiting unit includes: A light-shielding plate is disposed in front of the infrared emitting tube, and the light-shielding plate has emission slits that correspond one-to-one with the infrared emitting tubes. A light-shielding plate is disposed in front of the infrared receiving tube, and the light-shielding plate has receiving slits that correspond one-to-one with the infrared receiving tubes. The width of the transmitting slit and the receiving slit is 0.5 to 3 mm, used to limit the transmission and reception angles of infrared light to within ±5°.

6. The touch button based on modulated infrared light according to claim 1, characterized in that, When the anti-interference module is used as an infrared carrier modulation unit or a beam angle limiting unit, the light emitting unit further includes: The diffuse transmission light guide strip is long and extends along the light path. At least two infrared emitting diodes are respectively disposed at at least one end of the diffuse transmission light guide strip; The diffuse light guide strip is used to homogenize the infrared light emitted by the at least two infrared emitting tubes and form a continuous surface light source along its length.

7. The touch button based on modulated infrared light according to claim 6, characterized in that, The diffuse transmission light guide strip is an acrylic light guide strip with a diffuse transmission microstructure formed on its surface.

8. The touch button based on modulated infrared light according to claim 1, characterized in that, The signal conversion unit is used to convert the touch button recognition signal output by the control unit into at least one of the following signal formats: RS485, RS232, CAN bus, GPIO.

9. A method for triggering and recognizing touch button signals based on modulated infrared light, characterized in that, Includes the following steps: S1. Initialize the touch buttons and establish a matrix-like optical path with horizontal and vertical intersections; S2. Activate the anti-interference mode, wherein the anti-interference mode includes at least one of the following: The infrared light emitted by the infrared emitting tube is carrier-modulated so that the infrared receiving tube only responds to infrared light of a specific frequency. The infrared emitting tubes are controlled to emit infrared light sequentially and at different times, with only one infrared emitting tube emitting infrared light at any given moment. The emission and reception angles of infrared light are limited by a beam angle limiting unit; S3. Real-time monitoring of the output signals of each infrared receiver tube; S4. When a change in the output signal of the infrared receiver tube corresponding to at least two intersecting optical paths is detected, the corresponding intersection point is determined as the area of ​​the pressed touch button. S5, outputs the corresponding touch button recognition signal.

10. The touch button signal triggering and recognition method based on modulated infrared light according to claim 9, characterized in that, In step S2, the step of carrier modulation of the infrared light emitted by the infrared emitting tube includes: S21. Generate a carrier signal of a preset frequency; S22. The carrier signal is loaded onto the drive signal of the infrared emitting tube; S23. At the infrared receiver tube end, the received signal is demodulated, and only the signal that matches the preset frequency is retained; In step S2, the step of controlling the infrared emitting tube to emit infrared light sequentially and in a time-division manner includes: S24. Control the first infrared emitting tube to emit infrared light, and at the same time read only the signal of the corresponding first infrared receiving tube; S25. Turn off the first infrared emitter and wait for the preset interval time; S26. Control the next infrared emitting tube to emit infrared light, and at the same time read only the signal of the corresponding next infrared receiving tube; S27. Repeat steps S24 to S26 above until all infrared emitting tubes complete one emission, forming one scanning cycle; S28, continuously execute the scan cycle.

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