High-precision single-wavelength weak light intensity signal detection device

Abstract

The utility model designs a high-precision single-wavelength weak light intensity signal detection device. The high-precision single-wavelength weak light intensity signal detection device comprises a light intensity signal wavelength selection module, a weak signal high-precision amplification module and a power supply module. The light intensity signal wavelength selection module of the utility model is composed of a light inlet universal interface and a special film-coated filter lens. The weak signal high-precision amplification module is composed of a composite amplification circuit, a bias adjustment circuit, a phase adjustment circuit and a low-pass filter circuit. According to the utility model, an active high-speed precision operational amplifier is used in the signal detection circuit; therefore, the matched power supply module independently supplies power to a chip in the circuit so as to ensure the accuracy of an output result, and the power supply module consists of a rectifying circuit and a voltage stabilizing circuit and can convert power frequency alternating current into stable direct current required by an active device. The high-precision single-wavelength weak light intensity signal detection device can realize effective high-precision light intensity detection on a weak light signal with a specific single wavelength.

Description

Technical Field

[0001] This utility model relates to the field of detection technology, and in particular to a high-precision single-wavelength weak light intensity signal detection device. Background Technology

[0002] Weak signal detection technology aims to extract weak target signals from a strong noise background, with noise suppression and signal enhancement being its core components. Traditional methods are based on time-frequency analysis (such as lock-in amplifiers compressing noise bandwidth through phase-sensitive detection) and statistical averaging (sampling integration method improving signal-to-noise ratio through multiple sampling). Key hardware components of this technology include low-noise preamplifiers and narrowband filtering modules, and it is widely used in defect detection (detection of defect location feature signals), biomedicine (fluorescence detection), and environmental monitoring (trace gas analysis). Currently, this technology faces challenges such as the susceptibility of detection devices to environmental influences and electromagnetic interference, and relatively low accuracy of detection results. Utility Model Content

[0003] In view of this, the present invention provides a high-precision single-wavelength weak light intensity signal detection device, which can achieve distortion-free transimpedance amplification with high signal-to-noise ratio, low offset, and high gain bandwidth for single-wavelength weak light intensity signals, and zero-signal bias in-phase signal conditioning output, while resisting electromagnetic interference. The detection device provided by the present invention is easy to install, has universal interfaces, and provides reliable results.

[0004] This utility model provides the following technical solution:

[0005] In a first aspect, a high-precision single-wavelength weak light intensity signal detection device is provided. The detection device includes a light intensity signal wavelength selection module assembly housing, an anti-electromagnetic interference assembly housing, and a power supply module assembly housing.

[0006] The optical intensity signal wavelength selection module housing is located on one side of the electromagnetic interference protection housing, and the power supply module housing is located above the electromagnetic interference protection housing.

[0007] The light intensity signal wavelength selection module has a light intensity signal inlet on one side of its housing, and a special coated filter lens is installed inside.

[0008] The electromagnetic interference resistant assembly housing has a signal output interface on one side, and contains a composite amplifier circuit, a bias adjustment circuit, a phase adjustment circuit, a low-pass filter circuit, and a signal output interface.

[0009] The power supply module housing contains a rectifier circuit and a voltage regulator circuit.

[0010] A light intensity signal wavelength selection module, including a mounting housing and components disposed thereon and inside thereof:

[0011] The light intensity signal inlet is a universal lens interface, which can be connected to the matching lens or directly facing the object being measured;

[0012] Specially coated filter lenses are used to filter the wavelength of incoming light signals.

[0013] Preferably, the special coated filter lens allows light signals of a specific wavelength to pass through while blocking light signals of other wavelengths.

[0014] In a second aspect, a high-precision amplification module for weak signals is provided, comprising an electromagnetic interference-resistant mounting housing and components disposed thereon and inside thereof.

[0015] The composite amplifier circuit effectively amplifies weak light intensity signals;

[0016] The bias adjustment circuit is used to adjust the bias of weak light intensity signals.

[0017] Phase adjustment circuit for adjusting the phase of weak light intensity signals;

[0018] A low-pass filter circuit is used to filter out high-frequency noise from weak light intensity signals.

[0019] The signal output interface outputs the detected analog signal.

[0020] Preferably, the composite amplifier circuit performs distortion-free transimpedance amplification of weak light intensity signals with high signal-to-noise ratio, low offset, and high gain bandwidth.

[0021] Preferably, the bias adjustment circuit adjusts the dark current of the photoelectric sensor and the cumulative bias of the operational amplifier in the circuit, and the circuit has an inverting output.

[0022] Preferably, the phase adjustment circuit adjusts the inverted output of the bias adjustment circuit so that the output signal is in phase with the original signal.

[0023] Preferably, the low-pass filter circuit is a Butterworth second-order low-pass filter, which effectively filters out high-frequency noise in the output signal.

[0024] In a third aspect, a power supply module is provided, including a mounting housing and components disposed thereon and inside therein:

[0025] The rectifier circuit converts the 220V AC voltage source to a DC voltage source.

[0026] A voltage regulator circuit converts a DC voltage source with large ripple into a DC voltage source with higher stability.

[0027] Preferably, the rectifier circuit uses a transformer to convert the 220V AC power to dual-channel 6V AC power, and then uses a rectifier bridge to convert the dual-channel AC voltage source into a DC voltage source.

[0028] Preferably, the voltage regulator circuit uses a linear voltage regulator chip to effectively suppress the ripple signal of the DC voltage source, resulting in a high degree of stability in the output voltage.

[0029] The high-precision single-wavelength weak light intensity signal detection device of this utility model has a universal lens interface for its weak light intensity signal inlet. It can be directly connected with conventional matching lenses or the optical path system of the object being measured, making it highly applicable. Furthermore, the special coated filter lens of this device can achieve nanometer-level wavelength differentiation and highly flexible light intensity signal wavelength selection.

[0030] The high-precision single-wavelength weak light intensity signal detection device of this utility model uses a photodiode to convert the weak light intensity signal into a current signal. Then, the weak photocurrent signal is amplified by a composite amplification circuit with high signal-to-noise ratio, low offset, and high gain bandwidth without distortion transimpedance, converting it into a 0-5 V voltage signal. Next, the output voltage signal is conditioned by bias adjustment and phase adjustment circuits to eliminate the dark current of the photodiode and the phase bias effect caused by the accumulation of active devices. Finally, a second-order Butterworth low-pass filter is used to filter out high-frequency noise in the output signal.

[0031] The high-precision single-wavelength weak light intensity signal detection device of this utility model uses multiple active operational amplifiers in its detection circuit. Therefore, it is equipped with a power supply module to individually power the chips in the circuit to ensure the accuracy of the output results. The power supply module consists of two parts: a rectifier circuit and a voltage regulator circuit, which can convert the power frequency AC power into the stable DC power required by the active devices. Attached Figure Description

[0032] To more clearly illustrate the technical solution of this utility model, the accompanying drawings used in the embodiments are briefly described below.

[0033] Figure 1 This is a schematic diagram of the overall structure of the device provided in the embodiment of the present utility model;

[0034] Figure 2 A schematic diagram of a composite amplifier circuit provided for an embodiment of this utility model;

[0035] Figure 3 The schematic diagram of the bias adjustment and phase adjustment circuit provided in the embodiment of this utility model;

[0036] Figure 4 A schematic diagram of a low-pass filter circuit provided in an embodiment of this utility model;

[0037] Figure 5 The schematic diagram of the rectifier circuit and voltage regulator circuit provided for the embodiments of this utility model.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1-Light intensity signal wavelength selection module housing; 11-Light intensity signal inlet; 12-Special coated filter lens; 2-Anti-electromagnetic interference housing; 21-Composite amplifier circuit; 22-Bias adjustment circuit; 23-Phase adjustment circuit; 24-Low-pass filter circuit; 25-Signal output interface; 3-Power supply module housing; 31-Rectifier circuit; 32-Voltage regulator circuit. Detailed Implementation

[0040] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0041] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention.

[0042] The high-precision single-wavelength weak light intensity signal detection device will now be described in detail with reference to the accompanying drawings.

[0043] Example: See Figure 1 As shown, the high-precision single-wavelength weak light intensity signal detection device described in this embodiment includes an assembly housing 1, a light intensity signal inlet 11 disposed on and inside the housing, and a special coated filter lens 12. In this embodiment, the light intensity signal inlet 11 is typically a C-Mount standard lens interface, which connects to a matching lens or is directly facing the object being measured. In other embodiments, the interface type can be customized and replaced according to requirements.

[0044] The special coated filter lens 12 allows light signals of a specific wavelength to pass through while blocking light signals of other wavelengths. In this embodiment, the customized special coated filter lens group can achieve nanometer-level wavelength differentiation and highly flexible selection of light intensity signal wavelengths. In other embodiments, the customized special coated filter lens group is determined by the specific detection scenario and detection requirements.

[0045] See Figure 1As shown, the high-precision single-wavelength weak light intensity signal detection device described in this embodiment includes an anti-electromagnetic interference designed mounting housing 2, and a composite amplifier circuit 21, a bias adjustment circuit 22, a phase adjustment circuit 23, a low-pass filter circuit 24, and a signal output interface 25 disposed on and inside the housing. In this embodiment, the circuit schematic of the composite amplifier circuit 21 is shown below. Figure 2 As shown, this composite amplifier circuit amplifies the weak electrical signal generated by the photodiode's response to molten pool radiation in reverse-biased photoconductive mode through two stages. The first stage operational amplifier, OP07, is a precision operational amplifier, while the second stage operational amplifier, AD8065, is a high-speed operational amplifier. Combining OP07 and AD8065 leverages their respective advantages to meet the detection requirements of high signal-to-noise ratio, low offset, high gain bandwidth, and distortion-free transimpedance amplification. In other embodiments, the circuit design and component models can be customized and replaced according to specific detection needs.

[0046] The bias adjustment circuit 22 and phase adjustment circuit 23 condition the output voltage signal to eliminate the dark current of the photodiode and the phase bias effect caused by the accumulation of active devices. In this embodiment, the circuit schematics of the bias adjustment circuit 22 and phase adjustment circuit 23 are shown below. Figure 3 As shown, Figure 3 (a) Adjust the initial bias of the circuit using a potentiometer. Figure 3 (b) The gain of the inverting amplifier is adjusted using a potentiometer to ensure that the amplitude range of the circuit output signal meets expectations. In other embodiments, the circuit design and component models can also be customized and changed according to specific testing requirements.

[0047] The low-pass filter circuit 24 filters out high-frequency noise in the output signal. In this embodiment, the circuit schematic of the low-pass filter circuit 24 is shown below. Figure 4 As shown, this circuit is a Butterworth second-order active low-pass filter circuit, which can reduce high-frequency noise present in photodiodes during use, thereby reducing glitches and spikes in the output signal and obtaining a smoother output waveform curve. In other embodiments, the circuit design and component models can also be customized and replaced according to specific testing requirements.

[0048] See Figure 1 As shown, the high-precision single-wavelength weak light intensity signal detection device described in this embodiment includes an assembly housing 3 and a rectifier circuit 31 and a voltage regulator circuit 32 disposed on and inside the housing. In this embodiment, the circuit diagrams of the rectifier circuit 31 and the voltage regulator circuit 32 are shown below. Figure 5 As shown, the rectifier circuit is as follows Figure 5As shown in (a), L represents the live wire and N represents the neutral wire. The rectifier circuit uses a center-shaft transformer to convert the AC220V power frequency to a dual-channel AC6V power frequency voltage source, and then uses a rectifier bridge to convert the dual-channel AC voltage source into positive and negative DC voltage sources. Although capacitors and inductors are added to the rectifier circuit to reduce the output voltage ripple as much as possible, the output DC voltage ripple is still relatively large, making it unsuitable for direct use as a power supply for the detection device. Therefore, a linear regulator circuit is added to obtain a DC voltage source with higher linearity. Its circuit principle is as follows: Figure 5 As shown in (b), the linear voltage regulator chip can withstand a voltage drop of approximately 2 V, and its output voltage has high stability. In other embodiments, the circuit design and component models can also be customized and replaced according to specific testing requirements.

[0049] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A high-precision single-wavelength weak light intensity signal detection device, characterized in that, The detection device includes a light intensity signal wavelength selection module assembly shell (1), an anti-electromagnetic interference assembly shell (2), and a power supply module assembly shell (3), the light intensity signal wavelength selection module assembly shell (1) is arranged on one side of the anti-electromagnetic interference assembly shell (2), and the power supply module assembly shell (3) is arranged above the anti-electromagnetic interference assembly shell (2); One side of the light intensity signal wavelength selection module assembly shell (1) is provided with a light intensity signal light inlet (11), and the inside is provided with a special coated filter lens (12); One side of the anti-electromagnetic interference assembly shell (2) is provided with a signal output interface (25), and the inside is provided with a composite amplification circuit (21), a bias adjustment circuit (22), a phase adjustment circuit (23), a low-pass filter circuit (24) and the signal output interface (25); The inside of the power supply module assembly shell (3) is provided with a rectifier circuit (31) and a voltage stabilizing circuit (32).

2. The high-precision single-wavelength weak light intensity signal detection device according to claim 1, wherein the light intensity signal light inlet (11) is connected with a matching lens or directly faces the measured object; The special coated filter lens (12) performs wavelength screening on the incoming light signal.

3. The high-precision single-wavelength weak light intensity signal detection device according to claim 1, wherein the composite amplification circuit (21) performs non-distortion transimpedance amplification with high signal-to-noise ratio, low offset and high gain bandwidth on the weak light intensity signal; The bias adjustment circuit (22) adjusts the dark current of the photoelectric sensor and the cumulative bias of the operational amplifier in the circuit, and the circuit is a non-inverting output; The phase adjustment circuit (23) adjusts the non-inverting output result of the bias adjustment circuit so that the output signal is consistent in phase with the original signal, The low-pass filter circuit (24) is a Butterworth second-order low-pass filter, which effectively filters out high-frequency noise in the output signal, The signal output interface (25) outputs the detected analog signal.

4. The high-precision single-wavelength weak light intensity signal detection device according to claim 1, wherein the rectifier circuit (31) uses a transformer to convert a power frequency 220V alternating current into a double-channel power frequency 6V alternating current, and then converts the double-channel alternating voltage source into a direct current voltage source through a rectifier bridge, The voltage stabilizing circuit (32) uses a linear voltage stabilizing chip to effectively suppress the ripple signal of the direct current voltage source, and the output voltage has high stability. ​ ​ ​

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