Wireless transmission device based on laser

Abstract

The utility model relates to a wireless transmission device based on laser, which belongs to the technical field of transmission equipment and comprises a transmitting unit and a receiving unit, the transmitting unit comprises a first signal pickup circuit, a first signal amplification circuit and a second signal pickup circuit, the receiving unit comprises a photoelectric sensor, a second signal amplification circuit, a sound box, a waveform conversion circuit, an oscilloscope and a power supply module for supplying power to the whole device; each of the first signal amplification circuit and the second signal pickup circuit comprises a laser diode; according to the utility model, the first signal pick-up circuit and the second signal pick-up circuit are integrated, and voice and digital pulse signals can be processed at the same time. The transmitting unit realizes light intensity modulation of analog signals and on-off modulation of digital signals through switching of working states of triodes; the receiving unit can drive the sound box to restore voice through the photoelectric sensor and the waveform conversion circuit, and can visually display the waveform of the electric signal through the oscilloscope, so that a user can clearly observe the change process of the signal.

Description

Technical Field

[0001] This utility model belongs to the field of transmission equipment technology, and specifically relates to a laser-based wireless transmission device. Background Technology

[0002] With the rapid growth of the Internet of Things (IoT), smart devices, and data transmission demands, wireless communication technology is playing an increasingly important role in today's society. Whether it's smart homes, industrial automation, smart cities, or autonomous driving, all fields require efficient and stable wireless communication technology. Traditional wireless communication technologies, such as Bluetooth, Wi-Fi, and infrared communication, are widely used in people's daily lives. However, these technologies mostly rely on radio waves or infrared light for data transmission, which has some inherent drawbacks.

[0003] Specifically, radio wave communication technology is constrained by the scarcity of spectrum resources, especially in densely populated urban environments with numerous devices. Frequency congestion can lead to reduced communication speeds or signal interference, thus affecting user experience. Furthermore, radio waves are susceptible to electromagnetic interference, including natural phenomena such as lightning and cosmic rays, as well as electromagnetic noise generated by man-made wireless equipment and power lines, all of which reduce communication stability and security. While infrared communication technology offers good directionality, its transmission distance is limited, and it requires unobstructed transmission within line of sight, significantly restricting its application scenarios.

[0004] Meanwhile, laser-based free space optometry (FSO) technology has emerged, gradually becoming an important solution for short-range, high-speed communication due to its unique advantages. Laser communication features strong directionality, high bandwidth, strong resistance to electromagnetic interference, and good confidentiality. Its strong directionality makes communication signals difficult to steal or interfere with, resulting in superior security; high bandwidth means fast data transmission rates, meeting the demands of large-capacity, high-speed data transmission. Furthermore, laser communication also offers advantages such as low cost, low power consumption, and ease of miniaturization and integration.

[0005] However, existing laser communication devices still have some design shortcomings. Most traditional laser communication devices typically only support the transmission of a single type of signal, such as transmitting only voice signals or only digital data. In scenarios where multiple types of signals need to be transmitted simultaneously, multiple systems need to be configured, which not only increases the complexity and cost of the system, but also reduces the system's integration and flexibility. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies, such as traditional laser communication devices typically supporting only a single type of signal transmission. In scenarios requiring the simultaneous transmission of multiple types of signals, multiple systems need to be configured, which not only increases the complexity and cost of the system but also reduces its integration and flexibility. This invention provides a laser-based wireless transmission device to solve the problems existing in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A laser-based wireless transmission device includes a transmitting unit and a receiving unit. The transmitting unit includes a first signal pickup circuit, a first signal amplification circuit, and a second signal pickup circuit. The receiving unit includes a photoelectric sensor, a second signal amplification circuit, a speaker, a waveform conversion circuit, an oscilloscope, and a power module that powers the entire device.

[0009] Both the first signal amplification circuit and the second signal pickup circuit include a laser diode. The output of the first signal pickup circuit is wirelessly connected to the input of the photoelectric sensor through the laser diode in the first signal amplification circuit. The input of the second signal pickup circuit is connected to an external signal source. The output of the second signal pickup circuit is wirelessly connected to the input of the photoelectric sensor. The output of the photoelectric sensor is connected to the input of the speaker and the waveform conversion circuit through the second signal amplification circuit. The output of the waveform conversion circuit is connected to an oscilloscope.

[0010] Further improvements to this technical solution include a first signal pickup circuit comprising a resistor R1 and a microphone P1. The first end of the resistor R1 is connected to a 5V power supply, the second end of the resistor R1 is connected to the signal amplification circuit and the first end of the microphone P1, and the second end of the microphone P1 is grounded.

[0011] Further improvements to this technical solution include a first signal amplification circuit comprising a capacitor C1, a resistor R2, a transistor Q1, a variable resistor R3, a laser diode D1, and a resistor R4.

[0012] The first terminal of capacitor C1 is connected to the second terminal of resistor R1. The second terminal of capacitor C1 is connected to the first terminal of resistor R2 and the base of transistor Q1. The second terminal of resistor R2 is connected to the first terminal of variable resistor R3. The second terminal and the movable terminal of variable resistor R3 are both connected to a 5V power supply. The emitter of transistor Q1 is grounded. The collector of transistor Q1 is connected to the negative terminal of laser diode D1. The positive terminal of laser diode D1 is connected to a 5V power supply through resistor R4.

[0013] Further improvements to this technical solution include a second signal pickup circuit comprising resistor R5, resistor R6, transistor Q2, variable resistor R7, laser diode D2, and resistor R8.

[0014] The first end of resistor R5 is connected to an external digital audio source. The second end of resistor R5 is connected to the first end of resistor R6 and the base of transistor Q2. The second end of resistor R6 is connected to the first end of variable resistor R7. The second end and the movable end of variable resistor R7 are both connected to a 5V power supply. The emitter of transistor Q2 is grounded. The collector of transistor Q2 is connected to the negative terminal of laser diode D2. The positive terminal of laser diode D2 is connected to a 5V power supply through resistor R8.

[0015] Further improvements to this technical solution include a second signal amplification circuit comprising capacitor C2, resistor R9, transistor Q3, resistor R10, resistor R11, capacitor C3, resistor R12, resistor R13, and capacitor C4.

[0016] The first terminal of capacitor C2 is connected to the output terminal of the photoelectric sensor. The input terminal of the photoelectric sensor receives the light source emitted by laser diodes D1 and D2. The second terminal of capacitor C2 is connected to the first terminal of resistor R9, the base of transistor Q3, and the first terminal of resistor R10. The second terminal of resistor R9 is connected to a 5V power supply. The collector of transistor Q3 is connected to the first terminal of resistor R11 and the first terminal of capacitor C3. The second terminal of resistor R11 is connected to a 5V power supply. The second terminal of capacitor C3 is connected to the input terminal of the speaker and the waveform conversion circuit. The emitter of transistor Q3 is connected to the first terminal of resistor R13 and the first terminal of capacitor C4 through resistor R12. The second terminals of resistor R10, resistor R13, and capacitor C4 are all grounded.

[0017] Further improvements to this technical solution include a waveform conversion circuit comprising a variable resistor R14, a voltage comparator U1, a variable resistor R15, a diode D3, and a resistor R16.

[0018] The active terminal of variable resistor R14 and the inverting input terminal of voltage comparator U1 are both connected to the second terminal of capacitor C3. The first terminal of variable resistor R14 is connected to the 5V power supply, and the second terminal of variable resistor R14 is grounded. The non-inverting input terminal of voltage comparator U1 is connected to the active terminal of variable resistor R15. The first terminal of variable resistor R15 is connected to the 5V power supply, and the second terminal of variable resistor R15 is grounded. The output terminal of voltage comparator U1 is connected to the negative terminal of diode D3 and an oscilloscope. The positive terminal of diode D3 is connected to the 5V power supply through resistor R16.

[0019] Further improvements to this technical solution include a signal conversion module, the input of which is connected to the output of the voltage comparator U1, and the output of which is connected to an external host computer.

[0020] A further improvement to this technical solution is that the signal conversion module includes a signal conversion chip of model CH340T.

[0021] A further improvement to this technical solution is that the photoelectric sensor adopts the OP535 model.

[0022] The beneficial effects of this invention are that it integrates a first signal pickup circuit and a second signal pickup circuit, enabling simultaneous processing of voice and digital pulse signals. The transmitting unit achieves optical intensity modulation of analog signals and switching modulation of digital signals through transistor operating state switching (amplification / switching mode); the receiving unit, through a photoelectric sensor and waveform conversion circuit, can both drive the speaker to reproduce voice and visually display the waveform of electrical signals, including voice signals and digital data signals, on an oscilloscope, allowing users to clearly observe the signal change process. When encountering signal transmission problems, the oscilloscope can help technicians quickly locate the problem, such as signal distortion or noise interference, and then take corresponding measures to solve it.

[0023] Furthermore, the design principle of this utility model is reliable, the structure is simple, and it has a very wide range of application prospects.

[0024] It is evident that this utility model has outstanding substantive features and significant progress compared with the prior art, and the beneficial effects of its implementation are also obvious. Attached Figure Description

[0025] To more clearly illustrate the technical solution of this utility model, the drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic block diagram of the audio transmission device.

[0027] Figure 2 This is the schematic diagram of the first signal pickup circuit.

[0028] Figure 3 This is the schematic diagram of the first signal amplifier circuit.

[0029] Figure 4 This is the schematic diagram of the second signal pickup circuit.

[0030] Figure 5 This is the schematic diagram of the second signal amplifier circuit.

[0031] Figure 6 This is the schematic diagram of a waveform conversion circuit.

[0032] 110 is the first signal pickup circuit, 120 is the first signal amplification circuit, 130 is the second signal pickup circuit, 140 is the photoelectric sensor, 150 is the second signal amplification circuit, 160 is the speaker, 170 is the waveform conversion circuit, and 180 is the oscilloscope. Detailed Implementation

[0033] To make the objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0035] The key terms appearing in this utility model are explained below.

[0036] like Figure 1 As shown, this utility model provides a laser-based wireless transmission device, including a transmitting unit and a receiving unit. The transmitting unit includes a first signal pickup circuit, a first signal amplification circuit, and a second signal pickup circuit. The receiving unit includes a photoelectric sensor, a second signal amplification circuit, a speaker, a waveform conversion circuit, an oscilloscope, and a power supply module for the entire device. Both the first signal amplification circuit and the second signal pickup circuit include a laser diode. The output of the first signal pickup circuit is wirelessly connected to the input of the photoelectric sensor through the laser diode in the first signal amplification circuit. The input of the second signal pickup circuit is connected to an external signal source, and its output is wirelessly connected to the input of the photoelectric sensor. The output of the photoelectric sensor is connected to the speaker and the input of the waveform conversion circuit through the second signal amplification circuit. The output of the waveform conversion circuit is connected to the oscilloscope. The photoelectric sensor used is an OP535 model.

[0037] This invention supports the simultaneous transmission of audio signals and digital data, meeting diverse needs in various application scenarios. Using laser as the transmission medium offers advantages such as strong directionality, high bandwidth, and strong resistance to electromagnetic interference, ensuring high efficiency and stability in communication. The introduction of an oscilloscope allows technicians to observe and record signal waveforms in real time, providing strong support for signal analysis and debugging.

[0038] To ensure transmission quality, this invention incorporates the following design for the signal pickup circuit, signal amplification circuit, optical modulation circuit, and waveform conversion circuit:

[0039] like Figure 2 As shown, the first signal pickup circuit includes a resistor R1 and a microphone P1. The first end of the resistor R1 is connected to a 5V power supply, and the second end of the resistor R1 is connected to the signal amplification circuit and the first end of the microphone P1. The second end of the microphone P1 is grounded. The resistor R1 serves as a current limiter to prevent excessive current from damaging the microphone P1 and to ensure that the microphone can stably pick up sound signals under suitable operating conditions.

[0040] like Figure 3As shown, the first signal amplification circuit includes capacitor C1, resistor R2, transistor Q1, variable resistor R3, laser diode D1, and resistor R4. The first terminal of capacitor C1 is connected to the second terminal of resistor R1. The second terminal of capacitor C1 is connected to the first terminal of resistor R2 and the base of transistor Q1. The second terminal of resistor R2 is connected to the first terminal of variable resistor R3. The second terminal and movable terminal of variable resistor R3 are both connected to a 5V power supply. The emitter of transistor Q1 is grounded, and the collector of transistor Q1 is connected to the negative terminal of laser diode D1. The positive terminal of laser diode D1 is connected to the 5V power supply through resistor R4. Capacitor C1 acts as a DC-blocking and AC-passing capacitor, allowing the audio AC signal to smoothly enter the subsequent amplification stage while preventing DC interference. Resistor R2, in conjunction with variable resistor R3, provides a suitable bias voltage to the base of transistor Q1, ensuring that the transistor operates in the amplification region. Transistor Q1 amplifies the input audio signal, and then laser diode D1 converts the amplified electrical signal into an optical signal for long-distance, interference-resistant audio transmission using laser light. After the sound is acquired by the first signal pickup circuit, the first signal amplification circuit effectively amplifies the weak signal and converts it into an optical signal, ensuring the strength and quality of the audio signal during transmission. Furthermore, the variable resistor R3 provides the circuit with the ability to flexibly adjust the amplification factor. Different audio scenarios require different signal amplification factors. By adjusting the resistance of the variable resistor R3, the base bias current of the transistor Q1 can be changed, thereby adjusting the transistor's amplification factor. Technicians can adjust the circuit's amplification factor in real time according to the strength of the actual audio signal, ensuring that the output optical signal clearly carries the audio information without distortion due to over-amplification. The amplified electrical signal is converted into an optical signal and output through the laser diode D1. Utilizing the characteristics of laser transmission, the transmission stability and anti-interference capability of the audio signal are effectively improved. Compared to traditional electrical signal transmission, which is susceptible to electromagnetic interference, laser transmission can maintain signal integrity in complex electromagnetic environments, such as laboratories with dense electronic equipment. Even with significant wireless signal interference in the surrounding environment, the converted optical signal can still be transmitted stably, reducing audio stuttering and distortion, and ensuring that the wireless transmission device can work reliably in various complex scenarios.

[0041] like Figure 4As shown, the second signal pickup circuit includes resistors R5 and R6, transistor Q2, variable resistor R7, laser diode D2, and resistor R8. The first terminal of resistor R5 is connected to an external digital audio source. The second terminal of resistor R5 is connected to the first terminal of resistor R6 and the base of transistor Q2. The second terminal of resistor R6 is connected to the first terminal of variable resistor R7. Both the second terminal and the movable terminal of variable resistor R7 are connected to a 5V power supply. The emitter of transistor Q2 is grounded, and the collector of transistor Q2 is connected to the negative terminal of laser diode D2. The positive terminal of laser diode D2 is connected to the 5V power supply through resistor R8. Resistor R5 introduces the external signal source (e.g., a pulsed digital data signal) into the circuit. Resistors R6 and variable resistor R7 together provide a suitable bias voltage to the base of transistor Q2, ensuring that the transistor operates in the appropriate state. Transistor Q2 regulates the current according to the input pulse signal, thereby controlling the light intensity and frequency of laser diode D2, achieving efficient modulation of the digital electrical signal into an optical signal. Furthermore, the variable resistor R7 provides the circuit with the ability to flexibly adjust modulation parameters. Different external signal sources require varying modulation depths and precisions. By adjusting the value of R7, the base bias current of transistor Q2 can be changed, thereby adjusting the transistor's control over laser diode D2 and achieving fine-tuning of the optical modulation process. Technicians can adjust the modulation parameters in real time according to the characteristics of the actual external signal source and the transmission environment, ensuring that the output optical signal can accurately and stably carry digital audio information, improving the adaptability and reliability of digital audio transmission in different scenarios.

[0042] like Figure 5As shown, the second signal amplification circuit includes capacitor C2, resistor R9, transistor Q3, resistor R10, resistor R11, capacitor C3, resistor R12, resistor R13, and capacitor C4. The first end of capacitor C2 is connected to the output terminal of the photoelectric sensor, and the input terminal of the photoelectric sensor receives the light source emitted by laser diodes D1 and D2. The second end of capacitor C2 is connected to the first end of resistor R9, the base of transistor Q3, and the first end of resistor R10. The second end of resistor R9 is connected to a 5V power supply. The collector of transistor Q3 is connected to the first end of resistor R11 and the first end of capacitor C3. The second end of resistor R11 is connected to a 5V power supply. The second end of capacitor C3 is connected to the input terminal of the speaker and the waveform conversion circuit. The emitter of transistor Q3 is connected to the first end of resistor R13 and the first end of capacitor C4 through resistor R12. The second ends of resistor R10, resistor R13, and capacitor C4 are all grounded. In this circuit, capacitor C2 plays a crucial role in blocking DC and allowing AC, ensuring the AC signal carrying audio information smoothly enters the subsequent amplification stage while blocking DC interference. Resistors R9 and R10 provide a suitable bias voltage to the base of transistor Q3, enabling it to operate in a stable amplification region. Transistor Q3 amplifies the input signal, strengthening the weak photoelectric signal to a level sufficient to drive subsequent devices. Furthermore, components such as resistor R11 and capacitor C3 work together to precisely match and transmit the amplified signal. Resistor R11 limits current, protecting transistor Q3 and subsequent circuit components, and, in conjunction with capacitor C3, adjusts the amplitude and frequency characteristics of the output signal, ensuring the amplified audio signal meets the speaker's input requirements and is transmitted to the speaker without distortion or loss. Simultaneously, the second terminal of capacitor C3 is connected to a waveform conversion circuit, providing a suitable signal for the oscilloscope to monitor the audio signal waveform, allowing technicians to monitor the transmitted signal status in real time and ensuring accuracy throughout the entire process from signal acquisition to final playback.

[0043] This invention also adds a selection switch to the second terminal of capacitor C3 in the second signal amplification circuit. The two movable terminals of the selection switch are connected to the speaker and the waveform conversion circuit, respectively. When the device is working, if the first signal pickup circuit needs to work, the selection switch is switched to the speaker to form a loop; if the second signal pickup circuit needs to work, the selection switch is switched to the waveform conversion circuit to form a loop.

[0044] like Figure 6As shown, the waveform conversion circuit includes a variable resistor R14, a voltage comparator U1, a variable resistor R15, a diode D3, and a resistor R16. The movable terminal of the variable resistor R14 and the inverting input terminal of the voltage comparator U1 are both connected to the second terminal of the capacitor C3. The first terminal of the variable resistor R14 is connected to a 5V power supply, and the second terminal of the variable resistor R14 is grounded. The non-inverting input terminal of the voltage comparator U1 is connected to the movable terminal of the variable resistor R15. The first terminal of the variable resistor R15 is connected to a 5V power supply, and the second terminal of the variable resistor R15 is grounded. The output terminal of the voltage comparator U1 is connected to the cathode of the diode D3 and an oscilloscope. The anode of the diode D3 is connected to the 5V power supply through resistor R16. The variable resistor R14 can adjust the signal level input to the inverting input terminal of the voltage comparator U1; by changing its resistance value, the reference signal used for comparison can be flexibly adjusted. Voltage comparator U1 compares the signal at the inverting input with the reference level set by the variable resistor R15 at the non-inverting input, and outputs the corresponding signal according to the comparison result, thereby achieving precise trimming of the original signal waveform and ensuring the integrity and accuracy of the signal during transmission and processing.

[0045] In addition, the audio transmission device includes a signal conversion module. The input of the signal conversion module is connected to the output of the voltage comparator U1, and the output of the signal conversion module is connected to an external host computer. The signal conversion module includes a CH340T signal conversion chip. By incorporating this signal conversion module, with its input connected to the output of the voltage comparator U1 and its output connected to the external host computer, the audio transmission device successfully establishes an efficient communication bridge between the audio transmission device and the external host computer. The CH340T signal conversion chip in the signal conversion module can convert the specific format audio signal (USB to TTL serial port signal) output by the voltage comparator U1 into a signal format suitable for recognition and processing by the external host computer. In the intelligent conference room system, the audio signal acquired and processed by the audio transmission device, after conversion by the signal conversion module, can be smoothly transmitted to the host computer for storage, analysis, or further command control, achieving seamless integration of audio data between different devices and improving the overall system's collaborative efficiency.

[0046] The audio transmission device works as follows: Microphone P1 picks up human voice and converts it into a weak voltage signal (peak-to-peak range approximately -20mV to 20mV). This signal controls the base current of transistor Q1, which operates in amplification mode. The collector of transistor Q1 is connected to laser diode D1, and the current flowing through laser diode D1 is the collector current of transistor Q1. This current is controlled by the sound signal, causing the light intensity of laser diode D1 to change according to the strength of the sound signal. After receiving the laser signal, the photoelectric sensor generates a weak voltage signal (approximately 70 millivolts). This signal is amplified by a second signal amplification circuit into a voltage signal with a peak-to-peak value of several hundred millivolts, which then drives the speaker to emit sound. Microphone P1, under the stable 5V voltage provided by resistor R1 and current-limiting protection, collects the sound signal and outputs it to the signal amplification circuit via the second terminal of resistor R1. Here, capacitor C1 blocks DC and passes AC, and resistors R2 and variable resistor R3 provide appropriate bias for transistor Q1. The amplified signal drives laser diode D1 to convert the electrical signal into a light signal for emission. After receiving the signal, the OP535 photoelectric sensor converts it back into an electrical signal, which is then amplified again in the signal amplification circuit. Part of this signal drives the speaker to produce sound, while the other part enters the waveform conversion circuit. The signal output from the external signal source is connected to the second signal pickup circuit via resistor R5. Resistor R6, in conjunction with the variable resistor R7, causes transistor Q2 to control laser diode D2, modulating the input pulse signal into an optical signal for transmission. This signal is also received and converted by the OP535 photoelectric sensor, and the subsequent process is similar to audio transmission. In the waveform conversion circuit, variable resistor R14, voltage comparator U1, and variable resistor R15 shape and optimize the signal waveform. One optimized signal is used for monitoring by an oscilloscope, and the other is converted by the CH340T chip in the signal conversion module and transmitted to the host computer for in-depth processing and analysis, enhancing the device's synergy, stability, and applicability.

[0047] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A laser-based wireless transmission device, characterized in that, It includes a transmitting unit and a receiving unit. The transmitting unit includes a first signal pickup circuit, a first signal amplification circuit and a second signal pickup circuit. The receiving unit includes a photoelectric sensor, a second signal amplification circuit, a speaker, a waveform conversion circuit, an oscilloscope and a power supply module that powers the entire device. Both the first signal amplification circuit and the second signal pickup circuit include a laser diode. The output of the first signal pickup circuit is wirelessly connected to the input of the photoelectric sensor through the laser diode in the first signal amplification circuit. The input of the second signal pickup circuit is connected to an external signal source. The output of the second signal pickup circuit is wirelessly connected to the input of the photoelectric sensor. The output of the photoelectric sensor is connected to the input of the speaker and the waveform conversion circuit through the second signal amplification circuit. The output of the waveform conversion circuit is connected to an oscilloscope.

2. The laser-based wireless transmission device according to claim 1, characterized in that, The first signal pickup circuit includes a resistor R1 and a microphone P1. The first end of the resistor R1 is connected to a 5V power supply, and the second end of the resistor R1 is connected to the signal amplification circuit and the first end of the microphone P1. The second end of the microphone P1 is grounded.

3. The laser-based wireless transmission device according to claim 2, characterized in that, The first signal amplification circuit includes capacitor C1, resistor R2, transistor Q1, variable resistor R3, laser diode D1, and resistor R4; The first terminal of capacitor C1 is connected to the second terminal of resistor R1. The second terminal of capacitor C1 is connected to the first terminal of resistor R2 and the base of transistor Q1. The second terminal of resistor R2 is connected to the first terminal of variable resistor R3. The second terminal and the movable terminal of variable resistor R3 are both connected to a 5V power supply. The emitter of transistor Q1 is grounded. The collector of transistor Q1 is connected to the negative terminal of laser diode D1. The positive terminal of laser diode D1 is connected to a 5V power supply through resistor R4.

4. The laser-based wireless transmission device according to claim 3, characterized in that, The second signal pickup circuit includes resistor R5, resistor R6, transistor Q2, variable resistor R7, laser diode D2, and resistor R8; The first end of resistor R5 is connected to an external digital audio source. The second end of resistor R5 is connected to the first end of resistor R6 and the base of transistor Q2. The second end of resistor R6 is connected to the first end of variable resistor R7. The second end and the movable end of variable resistor R7 are both connected to a 5V power supply. The emitter of transistor Q2 is grounded. The collector of transistor Q2 is connected to the negative terminal of laser diode D2. The positive terminal of laser diode D2 is connected to a 5V power supply through resistor R8.

5. The laser-based wireless transmission device according to claim 4, characterized in that, The second signal amplification circuit includes capacitor C2, resistor R9, transistor Q3, resistor R10, resistor R11, capacitor C3, resistor R12, resistor R13 and capacitor C4. The first terminal of capacitor C2 is connected to the output terminal of the photoelectric sensor. The input terminal of the photoelectric sensor receives the light source emitted by laser diodes D1 and D2. The second terminal of capacitor C2 is connected to the first terminal of resistor R9, the base of transistor Q3, and the first terminal of resistor R10. The second terminal of resistor R9 is connected to a 5V power supply. The collector of transistor Q3 is connected to the first terminal of resistor R11 and the first terminal of capacitor C3. The second terminal of resistor R11 is connected to a 5V power supply. The second terminal of capacitor C3 is connected to the input terminal of the speaker and the waveform conversion circuit. The emitter of transistor Q3 is connected to the first terminal of resistor R13 and the first terminal of capacitor C4 through resistor R12. The second terminals of resistor R10, resistor R13, and capacitor C4 are all grounded.

6. The laser-based wireless transmission device according to claim 5, characterized in that, The waveform conversion circuit includes a variable resistor R14, a voltage comparator U1, a variable resistor R15, a diode D3, and a resistor R16; The active terminal of variable resistor R14 and the inverting input terminal of voltage comparator U1 are both connected to the second terminal of capacitor C3. The first terminal of variable resistor R14 is connected to the 5V power supply, and the second terminal of variable resistor R14 is grounded. The non-inverting input terminal of voltage comparator U1 is connected to the active terminal of variable resistor R15. The first terminal of variable resistor R15 is connected to the 5V power supply, and the second terminal of variable resistor R15 is grounded. The output terminal of voltage comparator U1 is connected to the negative terminal of diode D3 and an oscilloscope. The positive terminal of diode D3 is connected to the 5V power supply through resistor R16.

7. The laser-based wireless transmission device according to claim 6, characterized in that, It also includes a signal conversion module, whose input is connected to the output of voltage comparator U1, and whose output is connected to an external host computer.

8. The laser-based wireless transmission device according to claim 7, characterized in that, The signal conversion module includes a CH340T signal conversion chip.

9. The laser-based wireless transmission device according to claim 1, characterized in that, The photoelectric sensor used is the OP535 model.

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