CN218006205U - Optical acquisition and amplification circuit and device - Google Patents

Abstract

An optical acquisition and amplification circuit and device are provided, which belong to the field of electronic technology. The optical acquisition and amplification circuit includes a photoelectric conversion module, a first-stage amplification module, a second-stage amplification module, an analog-to-digital conversion module, and a gain adjustment module; the output end of the photoelectric conversion module is connected to the input end of the first-stage amplification module. The output end of the amplification module is connected to the input end of the secondary amplification module, the output end of the secondary amplification module is connected to the input end of the analog-to-digital conversion module, and the output end of the analog-to-digital conversion module is used to connect to the micro control unit, The input end of the gain adjustment module is used to connect to the micro control unit, the control end of the gain adjustment module is connected to the control end of the secondary amplification module; the gain adjustment module is used to adjust the amplification gain of the secondary amplification module ; The low-pass filtering frequency of the secondary amplification module is lower than the low-pass filtering frequency of the primary amplification module. The effect of improving the reliability and applicability of optical inspection can be achieved.

Description

Optical acquisition and amplification circuit and device

technical field

The present application relates to the field of electronic technology, in particular, to an optical collection and amplification circuit and device.

Background technique

With the development of science and technology, various electronic devices have also entered people's work and life. For example, people often use some electronic equipment to perform optical inspection on some samples.

In related technologies, generally, when performing optical inspection on these samples, multiple different light sources are often used to irradiate these samples, and then the light reflected by these samples can be collected by corresponding electronic equipment, and the collected optical signals Converted into an electrical signal, since the light intensity reflected by the sample is generally relatively weak, it is necessary to set up a corresponding amplifier circuit in the electronic device to amplify the electrical signal, and then output the amplified electrical signal to the Microcontroller Unit (Microcontroller Unit) , referred to as MCU), for the MCU to identify these electrical signals and perform corresponding data processing.

However, the amplification circuit in the solution of the related art has the problem of poor amplification effect and cannot be applied to optical inspection under multi-channel light sources, which will lead to problems of poor reliability and applicability of optical inspection.

Utility model content

The purpose of this application is to provide an optical acquisition and amplification circuit, which can achieve the effect of improving the reliability and applicability of optical inspection.

The embodiment of the application is realized like this:

According to the first aspect of the embodiments of the present application, an optical acquisition and amplification circuit is provided, and the optical acquisition and amplification circuit includes a photoelectric conversion module, a primary amplification module, a secondary amplification module, an analog-to-digital conversion module, and a gain adjustment module;

The output end of the photoelectric conversion module is connected to the input end of the first-level amplification module, the output end of the first-level amplification module is connected to the input end of the second-level amplification module, and the output end of the second-level amplification module It is connected with the input end of the analog-to-digital conversion module, the output end of the analog-to-digital conversion module is used to connect the micro control unit, the input end of the gain adjustment module is used to connect the micro control unit, and the gain adjustment module The control terminal is connected to the control terminal of the secondary amplification module;

The photoelectric conversion module is used to collect the reflected light of the object to be detected, and output a current signal to the first-stage amplification module according to the reflected light;

The primary amplification module is used to convert the current signal into a voltage signal, filter and amplify the voltage signal, and output the amplified voltage signal to the secondary amplification module; the secondary amplification The module is used to filter and amplify the amplified voltage signal, and output an analog electrical signal matching the amplified voltage signal to the analog-to-digital conversion module; the analog-to-digital conversion module is used to convert the The analog electrical signal is converted into a digital electrical signal recognized by the micro control unit; the gain adjustment module is used to adjust the amplification gain of the secondary amplification module.

The low-pass filtering frequency of the secondary amplification module is lower than the low-pass filtering frequency of the primary amplification module.

Optionally, the primary amplification module includes a first operational amplifier, a first resistor, and a first capacitor;

The first end of the first resistor is respectively connected to the output end of the photoelectric conversion module and the inverting input end of the first operational amplifier, and the second end of the first resistor is respectively connected to the first operational amplifier The output terminal is connected to the input terminal of the secondary amplification module;

The positive power supply terminal of the first operational amplifier is used to input an operating voltage, and the positive phase input terminal and the negative power supply terminal of the first operational amplifier are grounded;

The first resistor and the first capacitor are connected in parallel.

Optionally, the primary amplification module further includes at least one second capacitor;

The first plate of each second capacitor is connected to the positive power supply terminal of the first operational amplifier, and the second plate of each second capacitor is grounded.

Optionally, the secondary amplification module includes a second operational amplifier and a second resistor;

The non-inverting input terminal of the second operational amplifier is connected to the output terminal of the first-stage amplification module, the inverting input terminal of the second operational amplifier is connected to the first terminal of the second resistor, and the second The second end of the resistor is grounded, and the output end of the second operational amplifier is connected to the input end of the analog-to-digital conversion module;

The gain adjustment module is also connected between the inverting input terminal and the output terminal of the second operational amplifier.

Optionally, the input end of the gain adjustment module is used to connect to the control end of the micro control unit, and the first end of the gain adjustment module is respectively connected to the negative phase input end of the second operational amplifier and the second operational amplifier. The first ends of the two resistors are connected, and the second end of the gain adjustment module is connected with the output end of the second operational amplifier.

Optionally, the gain adjustment module includes a first chip;

The first chip is used to adjust the amplification gain of the secondary amplification module by changing the resistance between the first terminal and the second terminal of the first chip.

Optionally, the optical acquisition and amplification circuit further includes a level conversion module;

The first input end, the second input end, and the third input end of the level conversion module are respectively connected to the control end of the micro control unit, and the first output end of the level conversion module is connected to the gain adjustment module The enabling end of the level conversion module is connected, the second output end of the level conversion module is connected to the input end of the gain adjustment module, and the second output end of the level conversion module is connected to the reset control end of the gain adjustment module ;

The level conversion module is used to convert the voltage level of the voltage output from the micro control unit to each input terminal of the level conversion module, and output the converted voltage from each output terminal of the level conversion module to the port corresponding to the gain adjustment module.

Optionally, the optical acquisition and amplification circuit further includes a filtering module;

The input end of the filtering module is connected to the output end of the first-stage amplification module, and the output end of the filtering module is connected to the input end of the second-stage amplification module.

Optionally, the filter module includes a third resistor and a third capacitor;

The first end of the third resistor is connected to the output end of the first-stage amplification module, and the second end of the third resistor is respectively connected to the input end of the second-stage amplification module and the first end of the third capacitor. The plates are connected, and the second plate of the third capacitor is grounded.

Another aspect of the embodiments of the present application provides an optical acquisition and amplification device, the optical acquisition and amplification device includes a power supply module, a micro control unit, and at least one optical acquisition and amplification circuit as described in the first aspect above;

The micro control unit is used to identify digital electrical signals to determine attribute information of the object to be detected, and output an electrical signal matching the attribute information.

The beneficial effects of the embodiments of the present application include:

In the optical acquisition and amplification circuit provided in the embodiment of the present application, when the object to be detected is irradiated by at least one light source, the light or light signal reflected by the object to be detected can be collected through the photoelectric conversion module, and the photoelectric conversion The module converts the collected light or optical signal into a current signal and outputs it to the input terminal of the first-stage amplification module, and then the first-stage amplification module converts the current signal into a voltage signal, and performs a broadband low-frequency signal on the voltage signal pass filtering, and preliminarily amplify the filtered voltage signal, and output the preliminarily amplified voltage signal to the secondary amplifying module, and then the gain adjustment module adjusts the gain of the secondary amplifying module under the control of the micro control unit. Amplification gain multiple, the secondary amplification module performs further broadband low-pass filtering and amplification on the initially amplified voltage signal according to the amplification gain multiple adjusted by the gain adjustment module, and then outputs the amplified voltage signal to the analog-to-digital conversion module, the analog-to-digital conversion module converts the amplified voltage signal from an analog signal into a digital signal that can be recognized by the micro-control unit, so that the micro-control unit can analyze and process the digital electrical signal accordingly.

It is worth noting that if the current signal output by the photoelectric conversion module is to be amplified ten thousand times, if only one stage of amplification circuit is used, the current signal needs to be amplified ten thousand times by this stage of amplification circuit. However, the optical acquisition In the amplification circuit, the first-level amplification module and the second-level amplification module are used to amplify the current signal, so that the magnification of 10,000 times can be achieved by superimposing the amplification factors of the first-level amplification module and the second-level amplification module. For example, after the primary amplification module converts the current signal into the voltage signal, it can amplify the voltage signal by one thousand times, and then the secondary amplification module can amplify the voltage signal after amplifying one thousand times by ten times .

That is to say, the individual amplification gain multiples of the first-stage amplifier module and the second-stage amplifier module can be reduced, and then the resistance values of the bias resistors of the first-stage amplifier module and the second-stage amplifier module can be reduced, so when the ambient temperature changes Under normal circumstances, since the resistance values of the bias resistors of the first-stage amplifier module and the second-stage amplifier module are relatively small, the bias resistors of the first-stage amplifier module and the second-stage amplifier module are less affected by temperature drift. The change range of the resistance value of the set resistor will be very small, so that the amplification effect of the photoelectric conversion module can be improved, and then the reliability of using the photoelectric conversion module for optical inspection can be improved.

In addition, since the amplification gain of the secondary amplification module can be adjusted through the gain adjustment module, when the object to be detected is inspected by using multiple different light sources, and the light intensity emitted by each light source is different, the By adjusting the amplification gain multiple of the secondary amplification module, the multiple of amplifying the current signal output by the photoelectric conversion module can be adjusted, and then the wavelength of the light source can be compensated by adjusting the multiple of amplifying the current signal output by the photoelectric conversion module. In this way, it can also ensure that the optical acquisition and amplification circuit can also generate correct analog electrical signals when performing optical inspections under multiple light sources, thereby ensuring that the optical acquisition and amplification circuit can be used in When performing optical inspection under multiple light sources, correct digital electrical signals can also be output to the micro control unit to ensure the applicability and reliability of optical inspection.

In this way, the effect of improving the reliability and applicability of optical inspection can be achieved.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, so It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

FIG. 1 is a schematic structural diagram of the first optical acquisition and amplification circuit provided by the embodiment of the present application;

FIG. 2 is a schematic structural diagram of a second optical collection and amplification circuit provided in an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a third optical collection and amplification circuit provided in an embodiment of the present application;

FIG. 4 is a schematic structural diagram of a fourth optical collection and amplification circuit provided in an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a fifth optical collection and amplification circuit provided by an embodiment of the present application;

FIG. 6 is a schematic structural diagram of a sixth optical collection and amplification circuit provided by an embodiment of the present application.

Reference signs:

100: Optical acquisition amplifier circuit, 101: Photoelectric conversion module, 102: Primary amplifier module, 103: Secondary amplifier module, 104: Analog-to-digital conversion module, 105: Gain adjustment module, 106: Micro control unit, 107: Level Conversion module, 108: filter module;

R1: first resistor, R2: second resistor, R3: third resistor, C1: first capacitor, C2: second capacitor, C3: third capacitor, U1: first operational amplifier, U2: second operational amplifier.

detailed description

In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of this application, not all of them. The components of the embodiments of the application generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship that is usually placed when the utility model product is used, and is only for the convenience of describing the application and simplifying the description, rather than indicating or Nothing to imply that a referenced device or element must have a particular orientation, be constructed, and operate in a particular orientation should therefore not be construed as limiting the application. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions, and should not be construed as indicating or implying relative importance.

In the description of this application, it should also be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, It can also be a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application in specific situations.

In related technologies, generally, when optically inspecting these samples, multiple different light sources are often used to irradiate these samples, and then the light reflected by these samples can be collected by corresponding electronic equipment, and the collected light The signal is converted into an electrical signal. Since the light intensity reflected by the sample is generally relatively weak, it is necessary to set up a corresponding amplifier circuit in the electronic device to amplify the electrical signal, and then output the amplified electrical signal to the microcontroller unit (Microcontroller Unit, referred to as MCU), for the MCU to identify these electrical signals and perform corresponding data processing.

However, the amplifying circuit in the related art is generally only a one-stage amplifying circuit, so when amplifying the electrical signal converted from an optical signal, it is necessary to set a resistor with a large resistance as a bias resistor, because the resistance of the resistor is very large Even if there is a small change in the ambient temperature, the resistance value of the resistor will change greatly under the influence of temperature drift. The amplification circuit in the solution of the related art has the problem of poor amplification effect, which will lead to the reliability of optical inspection. problem of poor sex.

In addition, when performing optical inspection, it is often necessary to use multiple different light sources to inspect the sample. Since the wavelength of each light source is different, and the power of the light source and the performance of the filter may also be different, therefore, each light source emits There are also differences in the intensity of the emitted light, and the solutions of the related art cannot adjust the amplification gain of the amplifier circuit to perform adaptive processing on the light of different light intensities. The problem of the optical inspection, that is, there is a problem that the applicability of the optical inspection is poor.

To this end, the embodiment of the present application provides an optical acquisition and amplification circuit, which includes a photoelectric conversion module, a primary amplification module, a secondary amplification module, an analog-to-digital conversion module, and a gain adjustment module. The output terminal of the photoelectric conversion module Connected to the input end of the primary amplification module, the output end of the primary amplification module is connected to the input end of the secondary amplification module, the output end of the secondary amplification module is connected to the input end of the analog-to-digital conversion module, the The output end of the analog-to-digital conversion module is used to connect to the micro control unit, the input end of the gain adjustment module is used to connect to the micro control unit, and the control end of the gain adjustment module is connected to the control end of the secondary amplification module. The effect of improving the reliability and applicability of optical inspection can be achieved.

The embodiment of the present application is described by taking an optical acquisition and amplification circuit applied in the medical field for optical inspection as an example. However, it does not mean that the embodiment of the present application can only be applied to the optical collection and amplification of optical inspection in the medical field.

The optical collection and amplification circuit provided by the embodiment of the present application will be explained in detail below.

FIG. 1 is a schematic structural diagram of an optical collection and amplification circuit provided by the present application. Referring to Fig. 1, an embodiment of the present application provides an optical acquisition and amplification circuit 100, the optical acquisition and amplification circuit 100 includes: a photoelectric conversion module 101, a primary amplification module 102, a secondary amplification module 103, an analog-to-digital conversion module 104 and a gain adjustment Module 105.

The output end of this photoelectric conversion module 101 is connected with the input end of this primary amplification module 102, the output end of this primary amplification module 102 is connected with the input end of this secondary amplification module 103, the output end of this secondary amplification module 103 Connected to the input end of the analog-to-digital conversion module 104, the output end of the analog-to-digital conversion module 104 is used to connect the micro control unit 106, the input end of the gain adjustment module 105 is used to connect the micro control unit 106, the gain adjustment module The control terminal of 105 is connected with the control terminal of the secondary amplification module 103 .

Wherein, the photoelectric conversion module 101 can be used to collect the reflected light of the object to be detected, and output a current signal to the primary amplification module 102 according to the reflected light.

The primary amplification module 102 can be used to convert the current signal into a voltage signal, filter and amplify the voltage signal, and output the amplified voltage signal to the secondary amplification module 103 .

The secondary amplification module 103 can be used to filter and amplify the amplified voltage signal, and output an analog electrical signal matching the amplified voltage signal to the analog-to-digital conversion module 104 .

The analog-to-digital conversion module 104 can be used to convert the analog electrical signal into a digital electrical signal recognized by the microcontroller unit 106 .

The gain adjustment module 105 can be used to adjust the amplification gain of the secondary amplification module 103 . The amplification gain multiple is used to indicate the ratio between the output voltage of the secondary amplification module 103 and the input voltage. Generally, the larger the amplification gain multiple, the greater the ratio between the output voltage of the secondary amplification module 103 and the input voltage. The larger the ratio.

Optionally, the low-pass filtering frequency of the secondary amplification module 103 is lower than the low-pass filtering frequency of the primary amplification module 102 .

Optionally, the photoelectric conversion module 101 may specifically refer to a photodetector that converts the reflected light signal of the object to be detected into a current signal, for example, the photoelectric conversion module 101 may be a photosensitive diode, that is, a photodiode.

The photoelectric conversion module 101 may be powered by a power supply or a power supply module, for example, a voltage may be applied to the photoelectric conversion module 101 by the power supply or a power supply module to drive the photoelectric conversion module 101 , which is not limited in this embodiment of the present application.

In addition, the power supply terminal of the primary amplification module 102 can also be connected to a power supply or a power supply module, so that the power supply or the power supply module supplies power to the primary amplification module 102 .

Optionally, the object to be inspected may be any object requiring optical inspection, or any object irradiated by an inspection light source, which is not limited in this embodiment of the present application.

The analog-to-digital conversion module 104 may be a device for converting an analog signal into a digital signal, and the analog-to-digital conversion module 104 may specifically include an analog-to-digital converter (Analog To Digital Converter, referred to as ADC), that is, an A/D converter .

The micro control unit 106 can be used to output a corresponding control signal to the input terminal of the gain adjustment module 105 , and then the amplification gain of the secondary amplification module 103 can be adjusted by adjusting the parameters of the gain adjustment module 105 .

The micro control unit 106 can also be used to receive the digital electrical signal sent by the analog-to-digital conversion module 104, and perform corresponding analysis and processing according to the digital electrical signal, which is not limited in this embodiment of the present application.

Exemplarily, the gain adjustment module 105 may include a first chip, and the first chip may be used to adjust the output of the secondary amplification module 103 by changing the resistance between the first end and the second end of the first chip. Magnification gain multiple. In this case, the microcontroller unit 106 may output a control signal to the first signal to adjust the resistance between the first terminal and the second terminal of the first chip.

For example, the first chip may be a four-channel digital potentiometer modeled as MCP4461-503E/ML, or any other chip capable of adjusting the output resistance, which is not limited in this embodiment of the present application.

It is worth noting that the working principle of the optical acquisition and amplification circuit 100 is: when the object to be detected is irradiated by at least one light source, the light or light signal reflected by the object to be detected can be collected through the photoelectric conversion module 101, And the light or light signal collected is converted into a current signal by the photoelectric conversion module 101 and output to the input end of the primary amplification module 102, and then the current signal is converted into a voltage signal by the primary amplification module 102, and Perform broadband low-pass filtering on the voltage signal, and preliminarily amplify the filtered voltage signal, and output the preliminarily amplified voltage signal to the secondary amplification module 103, and then the gain adjustment module 105 controls the micro-control unit Under the control of 106, the amplification gain multiple of the secondary amplification module 103 is adjusted, and the secondary amplification module 103 performs further broadband low-pass filtering and amplification on the initially amplified voltage signal according to the amplification gain multiple adjusted by the gain adjustment module 105, And the amplified voltage signal is output to the analog-to-digital conversion module 104, and the amplified voltage signal is converted from an analog signal to a digital signal that can be recognized by the micro-control unit 106 by the analog-to-digital conversion module 104 for the micro-control The unit 106 performs corresponding analysis and processing on the digital electrical signal.

It is worth noting that if the current signal output by the photoelectric conversion module 101 is to be amplified by ten thousand times, if only one stage of amplification circuit is used, the current signal needs to be amplified by one stage of amplification circuit by ten thousand times. However, the optical In the acquisition and amplification circuit 100, the primary amplification module 102 and the secondary amplification module 103 are used to amplify the current signal. In this way, the amplification factors of the primary amplification module 102 and the secondary amplification module 103 can be superimposed To achieve the purpose of magnifying 10,000 times, for example, after the primary amplification module 102 converts the current signal into the voltage signal, the voltage signal can be amplified by 1,000 times, and then the secondary amplification module 103 will amplify 1,000 times The subsequent voltage signal is then amplified ten times.

That is to say, the independent amplification gain multiples of the primary amplification module 102 and the secondary amplification module 103 can be reduced, and then the resistance value of the bias resistors of the primary amplification module 102 and the secondary amplification module 103 can be reduced, so in the environment When the temperature changes, since the resistance values of the bias resistors of the primary amplification module 102 and the secondary amplification module 103 are small, the bias resistors of the primary amplification module 102 and the secondary amplification module 103 are affected by temperature drift. The influence is relatively small, so the resistance value of the bias resistor changes in a small range, thus, the amplification effect of the photoelectric conversion module 101 can be improved, and the reliability of optical inspection using the photoelectric conversion module 101 can be improved.

In addition, since the amplification gain of the secondary amplification module 103 can be adjusted by the gain adjustment module 105, when multiple different light sources are used to inspect the object to be detected, and the light intensity emitted by each light source is different, It is possible to adjust the amplification factor of the current signal output by the photoelectric conversion module 101 by adjusting the amplification gain multiple of the secondary amplification module 103, and then adjust the amplification factor of the current signal output by the photoelectric conversion module 101. Compensate for the difference in light intensity caused by factors such as the wavelength and power of the light source. In this way, it can also ensure that the optical acquisition and amplification circuit can also generate correct analog electrical signals when performing optical inspections under multiple light sources, thereby ensuring that the optical The acquisition and amplification circuit can also output correct digital electrical signals to the micro control unit 106 when the optical inspection is performed under multiple light sources, so as to ensure the applicability and reliability of the optical inspection.

In this way, the effect of improving the reliability and applicability of optical inspection can be achieved.

In a possible implementation manner, referring to FIG. 2 on the basis of FIG. 1 , the primary amplification module 102 includes a first operational amplifier U1 , a first resistor R1 , and a first capacitor C1 .

The first terminal of the first resistor R1 is respectively connected to the output terminal of the photoelectric conversion module 101 and the inverting input terminal of the first operational amplifier U1, and the second terminal of the first resistor R1 is respectively connected to the first operational amplifier U1. The output terminal of is connected to the input terminal of the secondary amplification module 103 .

The positive power supply terminal of the first operational amplifier U1 is used for inputting an operating voltage, and the positive phase input terminal and the negative power supply terminal of the first operational amplifier U1 are grounded.

The first resistor R1 is connected in parallel with the first capacitor C1.

Optionally, the first operational amplifier U1 can be an amplifier of any specification. Generally, a dual amplifier of AD8606 or a single, dual, or quadruple amplifier of other models can be selected as the first operational amplifier U1. This embodiment of the present application does not limit it.

Optionally, the positive power terminal of the first operational amplifier U1 may be connected to the power supply or the power supply module, so that the power supply or the power supply module supplies power to the first operational amplifier U1, which is not limited in this embodiment of the present application.

Optionally, the first resistor R1 can be used as a bias resistor of the first operational amplifier U1.

The resistance value of the first resistor R1 can be set according to actual needs, for example, a resistor with a resistance value of 50 megohms (MΩ) can be selected as the first resistor R1, which is not limited in this embodiment of the present application. Generally, the resistance value of the first resistor R1 can be relatively large, but the resistance value of the first resistor R1 cannot be too large, so as to ensure that the resistance value of the first resistor R1 has a small change range when the ambient temperature changes, That is, the first resistor R1 can be reduced from being affected by temperature drift.

Optionally, the capacitance of the first capacitor C1 can be set relatively small, for example, a capacitor with a rated capacitance of 15 picofarads (pF) can be selected as the first capacitor C1.

In addition, the first capacitor C1 can be used as a filter capacitor. When the photoelectric conversion module 101 outputs a current signal to the input terminal of the primary amplification module 102, that is, the first terminal of the first resistor R1, then the first capacitor C1 begins to charge, and since the capacitor has a characteristic of having a small equivalent capacitive reactance to a specific frequency, the first capacitor C1 can allow the current of a specific frequency to pass, while blocking the current of other frequencies. In this way, the purpose of filtering out the current of a specific frequency can be achieved.

It is worth noting that the photoelectric conversion module 101 converts the collected light or light signal into a current signal and outputs it to the inverting input terminal of the first operational amplifier U1, the first terminal of the first resistor R1 and the first capacitor C1 In the case of , the first resistor R1 can convert the current signal into a voltage, and the output terminal of the first operational amplifier U1 is at the same point as the feedback sampling point of the first operational amplifier U1, then the first operational amplifier is formed U1 parallel voltage negative feedback. In this way, the primary amplification module 102 can convert the current signal into a voltage signal, and can also realize broadband low-pass filtering of the voltage signal, improve the stability of the amplification gain of the first operational amplifier U1, and reduce the The nonlinear distortion of the voltage signal after preliminary amplification can suppress interference and noise, and then the amplification effect of the first operational amplifier U1 on the current signal can be improved.

In a possible implementation manner, continuing to refer to FIG. 2 , the primary amplification module 102 further includes at least one second capacitor C2.

The first plate of each second capacitor C2 is connected to the positive power supply terminal of the first operational amplifier U1, and the second plate of each second capacitor C2 is grounded.

That is to say, each second capacitor C2 is connected in parallel.

It should be noted that since the positive power supply terminal of the first operational amplifier U1 is used to input the operating voltage, and the operating voltage may fluctuate, this may cause the first operational amplifier U1 to be in an unstable working state, thereby affecting the The problem of the amplification performance of the optical acquisition and amplification circuit 100 .

It should be noted that when the power supply or power supply module outputs electric energy to the positive power supply terminal of the first operational amplifier U1, the power supply or power supply module also outputs electric energy to each second capacitor C2, and the working principle of each second capacitor C2 is to act as a power supply Or when the voltage of the power supply module is higher than the voltage of the second capacitors C2, each second capacitor C2 is charged; when the voltage of the power supply or the power supply module is lower than the voltage of each second capacitor C2, each second capacitor C2 is discharged. In the process of charging and discharging each second capacitor C2, it can stabilize the working voltage input to the positive power supply terminal of the first operational amplifier U1, thereby ensuring that the first operational amplifier U1 can work stably, thereby ensuring that the optical acquisition The effect of the amplification performance of the amplification circuit 100.

In a possible implementation manner, referring to FIG. 3 on the basis of FIG. 2 , the secondary amplification module 103 includes a second operational amplifier U2 and a second resistor R2.

The non-inverting input terminal of the second operational amplifier U2 is connected to the output terminal of the primary amplification module 102, the inverting input terminal of the second operational amplifier U2 is connected to the first end of the second resistor R2, and the second resistor The second end of R2 is grounded, and the output end of the second operational amplifier U2 is connected to the input end of the analog-to-digital conversion module 104 .

The gain adjustment module 105 is also connected between the inverting input terminal and the output terminal of the second operational amplifier U2.

Specifically, the input end of the gain adjustment module 105 is used to connect to the control end of the microcontroller unit 106, and the first end of the gain adjustment module 105 is respectively connected to the negative phase input end of the second operational amplifier U2 and the second operational amplifier U2. The first end of the resistor R2 is connected, and the second end of the gain adjustment module 105 is connected to the output end of the second operational amplifier U2.

Optionally, the second operational amplifier U2 can be an amplifier of any specification. Generally, a dual amplifier of AD8606 or a single, dual, or quadruple amplifier of other models can be selected as the second operational amplifier U2, This embodiment of the present application does not limit it.

Optionally, the resistance value of the second resistor R2 can be small, for example, the resistance value of the second resistor R2 can be set to 1 kiloohm (kΩ), in addition, the temperature drift of the second resistor R2 is also small , generally only 0.1%. Generally, resistors with different resistance values can be used as the second resistor R2 according to actual requirements of the optical acquisition and amplification circuit 100 , which is not limited in this embodiment of the present application.

In addition, the second resistor R2 can be regarded as a bias resistor of the second operational amplifier U2.

It should be noted that, generally, a feedback resistor needs to be connected between the inverting input terminal and the output terminal of the second operational amplifier U2, so as to form a negative feedback circuit of the second operational amplifier U2 with the second resistor R2, specifically Specifically, the negative feedback circuit of the second operational amplifier U2 can be a series voltage negative feedback. In this way, not only can the voltage output by the second operational amplifier U2 be more stable, but also the amplification gain of the second operational amplifier U2 can be made more stable. Stable, and then the effect of improving the amplification performance of the second operational amplifier U2 can be achieved. In this way, the effect of improving the reliability of the optical inspection can be achieved.

However, in the embodiment of the present application, the gain adjustment module 105 is connected between the inverting input terminal and the output terminal of the second operational amplifier U2, that is to say, the gain adjustment module 105 may be equivalent to the second operational amplifier U2 the feedback resistor.

It is worth noting that, since the inverting input terminal and the output terminal of the second operational amplifier U2 are used to connect the gain adjustment module 105, the gain adjustment module 105 is equivalent to the feedback resistor of the second operational amplifier U2, and the gain adjustment module 105 can adjust the amplification gain of the secondary amplifier module 103 , then the amplification gain of the second operational amplifier U2 can be adjusted by adjusting the resistance of the gain adjustment module 105 . In this way, it is possible to change the amplifying factor of the current signal converted from the optical signal by the optical acquisition and amplification circuit 100, thereby achieving the effect of improving the applicability of the optical inspection.

In a possible implementation manner, the gain adjustment module 105 includes a first chip.

The first chip is used to adjust the amplification gain of the secondary amplification module 103 by changing the resistance between the first terminal and the second terminal of the first chip.

Specifically, the first terminal and the second terminal of the first chip can be respectively connected to the inverting input terminal and the output terminal of the second operational amplifier U2, so as to connect the first terminal and the second terminal of the first chip to into the optical acquisition amplifier circuit 100 to form the negative feedback circuit of the second operational amplifier U2, and then the output resistance between the first end and the second end of the first chip can be used as the feedback of the second operational amplifier U2 resistance.

Optionally, the microcontroller unit 106 is configured to output a control signal to the first chip to adjust the resistance between the first terminal and the second terminal of the first chip.

Optionally, the first chip may be any chip capable of adjusting the output resistance. For example, the first chip may be a four-channel digital potentiometer modeled as MCP4461-503E/ML.

It should be noted that the first chip may have multiple channels, and each channel corresponds to a first terminal and a second terminal. When the first chip is connected to the optical acquisition and amplification circuit 100, it may be the The first terminal and the second terminal corresponding to any group of channels of the first chip are respectively connected to the inverting input terminal and the output terminal of the second operational amplifier U2. In this way, the amplification gain of the second operational amplifier U2 can be adjusted by changing the resistance between the first terminal and the second terminal of the first chip.

In a possible implementation manner, on the basis of FIG. 3 , referring to FIG. 4 , the optical acquisition and amplification circuit 100 further includes a level conversion module 107 .

The first input end, the second input end, and the third input end of the level conversion module 107 are respectively connected to the control end of the micro control unit 106, and the first output end of the level conversion module 107 is connected to the gain adjustment module 105 The enabling end of the level conversion module 107 is connected to the input end of the gain adjustment module 105, and the second output end of the level conversion module 107 is connected to the reset control end of the gain adjustment module 105. .

The level conversion module 107 is used to convert the voltage level of the voltage output from the microcontroller unit 106 to each input terminal of the level conversion module 107, and output the converted voltage from each output terminal of the level conversion module 107 to the port corresponding to the gain adjustment module 105 .

It should be noted that since the level of the output voltage of each control terminal of the micro control unit 106 is different from the voltage level that can be identified by the enable terminal, input terminal and/or reset control terminal of the gain adjustment module 105, then the The level of the output voltage of each control terminal of the micro control unit 106 is correspondingly converted into a voltage level that can be recognized by each port of the gain adjustment module 105 , and then the converted voltage is output to the corresponding port of the gain adjustment module 105 . In this way, it can be ensured that the gain adjustment module 105 can accurately identify the control signals output by the micro control unit 106, and accurately perform corresponding actions according to each control signal.

For example, in the case where the gain adjustment module 105 is the above-mentioned four-channel digital potentiometer, the gain adjustment module 105 can output the control signal to the reset control terminal through the level conversion module 107 of the micro control unit 106 to set the first channel of each channel to The resistance between one end and the second end is adjusted to the initial resistance, and the control signal output to the enabling end by the level conversion module 107 from the micro-control unit 106 can also be entered into an enabling state, a power-off state or a dormant state, or The resistance value of the resistance between the first terminal and the second terminal of each channel can be controlled according to the control signal output from the micro control unit 106 to the input terminal of the gain adjustment module 105 through the level conversion module 107 .

In this way, the purpose of accurately controlling the amplification gain of the second operational amplifier U2 can be achieved by precisely controlling the gain adjustment module 105, thereby improving the reliability and adaptability of optical inspection using the optical collection and amplification circuit 100 .

In a possible implementation manner, on the basis of FIG. 4 , referring to FIG. 5 , the optical acquisition and amplification circuit 100 further includes a filtering module 108 .

The input end of the filtering module 108 is connected to the output end of the primary amplification module 102 , and the output end of the filtering module 108 is connected to the input end of the secondary amplification module 103 .

It should be noted that after the primary amplification module 102 performs broadband low-pass filtering on the voltage signal and initially amplifies the filtered voltage signal, the primary amplification module 102 needs to amplify the initially amplified voltage signal output to the secondary amplification module 103. Then, if there is nonlinear distortion or clutter in the voltage signal after the initial amplification, if the voltage signal after the initial amplification is directly amplified again through the secondary amplification module 103, it will result in the presence of The nonlinear distortion or clutter is also amplified, so that the error of the analog electrical signal finally output by the secondary amplification module 103 is relatively large.

It is worth noting that, by connecting the filtering module 108 between the output terminal of the primary amplification module 102 and the input terminal of the secondary amplification module 103, then the filtering module 108 can be used to filter the pre-amplified voltage signal Filtering is performed, so that the error of the analog electrical signal finally output by the secondary amplification module 103 is ensured to be small, thereby improving the reliability of the optical inspection by the optical collection and amplification circuit 100 .

In a possible implementation manner, referring to FIG. 6 on the basis of FIG. 5 , the filtering module 108 includes a third resistor R3 and a third capacitor C3.

The first end of the third resistor R3 is connected to the output end of the primary amplification module 102, and the second end of the third resistor R3 is respectively connected to the input end of the secondary amplification module 103 and the first end of the third capacitor C3. The plates are connected, and the second plate of the third capacitor C3 is grounded.

It is worth noting that, by using the third resistor R3 and the third capacitor C3 to filter the voltage signal after the preliminary amplification, it will ensure that the error of the analog electrical signal finally output by the secondary amplification module 103 is small, thereby improving The reliability of the optical inspection is performed by using the optical acquisition and amplification circuit 100 .

In a possible manner, the resistance value of the gain adjustment module 105 can be adjusted by the micro control unit 106 outputting a corresponding control signal to the input end of the gain adjustment module 105 .

It is also possible to adjust the resistance value of the gain adjustment module 105 by setting other mechanical structures or electrical structures on the gain adjustment module 105. In this case, the gain adjustment module 105 can be a sliding rheostat or other variable The resistance is not limited in this embodiment of the present application.

The embodiment of the present application also provides an optical collection and amplification device. The optical collection and amplification device includes a power supply module, a micro control unit 106 and at least one optical collection and amplification circuit 100 as in any of the above-mentioned embodiments.

The micro-control unit 106 is used to identify digital electrical signals to determine attribute information of the object to be detected, and output an electrical signal matching the attribute information.

Optionally, the power supply module can output voltages of 5V, 6V, 12V, 24V, 36V and/or any other possible levels. This embodiment of the present application does not limit it.

In a possible manner, in the case where the optical collection and amplification device includes two or more than two and less than four optical collection and amplification circuits 100, each optical collection and amplification circuit 100 can share the same gain adjustment module. In this case, the gain adjustment module can preferably use a four-channel digital potentiometer model MCP4461-503E/ML as the first chip in the gain adjustment module.

It is worth noting that since there are four groups of channels on the four-channel digital potentiometer model MCP4461-503E/ML, and each group of channels corresponds to a first terminal and a second terminal, then the corresponding first terminal of each group of channels can be One end and the second end are respectively connected between the inverting input end and the output end of the second operational amplifier U2 in each optical acquisition amplifier circuit 100, and then the model is MCP4461-503E/ML through the micro control unit 106 The four-channel digital potentiometer sends corresponding control signals to change the output resistance between the first end and the second end of each group of channels, that is, to change the second operational amplifier U2 connected to each optical acquisition amplifier circuit 100. Resistance between inverting input and output.

In this way, the effect of improving the reliability and applicability of the optical collection and amplification device can be achieved.

The above is only the specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the application, and should be covered Within the protection scope of this application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims (10)

1. An optical acquisition and amplification circuit, characterized in that, the optical acquisition and amplification circuit includes a photoelectric conversion module, a primary amplification module, a secondary amplification module, an analog-to-digital conversion module and a gain adjustment module; The output end of the photoelectric conversion module is connected to the input end of the first-level amplification module, the output end of the first-level amplification module is connected to the input end of the second-level amplification module, and the output end of the second-level amplification module It is connected with the input end of the analog-to-digital conversion module, the output end of the analog-to-digital conversion module is used to connect the micro control unit, the input end of the gain adjustment module is used to connect the micro control unit, and the gain adjustment module The control terminal is connected to the control terminal of the secondary amplification module; The photoelectric conversion module is used to collect the reflected light of the object to be detected, and output a current signal to the first-stage amplification module according to the reflected light; The primary amplification module is used to convert the current signal into a voltage signal, filter and amplify the voltage signal, and output the amplified voltage signal to the secondary amplification module; the secondary amplification The module is used to filter and amplify the amplified voltage signal, and output an analog electrical signal matching the amplified voltage signal to the analog-to-digital conversion module; the analog-to-digital conversion module is used to convert the The analog electrical signal is converted into a digital electrical signal recognized by the micro control unit; the gain adjustment module is used to adjust the amplification gain of the secondary amplification module; The low-pass filtering frequency of the secondary amplification module is lower than the low-pass filtering frequency of the primary amplification module. 2. The optical acquisition and amplification circuit according to claim 1, wherein the primary amplification module comprises a first operational amplifier, a first resistor, and a first capacitor; The first end of the first resistor is respectively connected to the output end of the photoelectric conversion module and the inverting input end of the first operational amplifier, and the second end of the first resistor is respectively connected to the first operational amplifier The output terminal is connected to the input terminal of the secondary amplification module; The positive power supply terminal of the first operational amplifier is used to input an operating voltage, and the positive phase input terminal and the negative power supply terminal of the first operational amplifier are grounded; The first resistor and the first capacitor are connected in parallel. 3. The optical acquisition and amplification circuit according to claim 2, wherein the primary amplification module further comprises at least one second capacitor; The first plate of each second capacitor is connected to the positive power supply terminal of the first operational amplifier, and the second plate of each second capacitor is grounded. 4. The optical acquisition and amplification circuit according to claim 1, wherein the secondary amplification module comprises a second operational amplifier and a second resistor; The non-inverting input terminal of the second operational amplifier is connected to the output terminal of the first-stage amplification module, the inverting input terminal of the second operational amplifier is connected to the first terminal of the second resistor, and the second The second end of the resistor is grounded, and the output end of the second operational amplifier is connected to the input end of the analog-to-digital conversion module; The gain adjustment module is also connected between the inverting input terminal and the output terminal of the second operational amplifier. 5. The optical acquisition and amplification circuit according to claim 4, wherein the input end of the gain adjustment module is used to connect the control end of the micro control unit, and the first end of the gain adjustment module is respectively connected to the The negative input terminal of the second operational amplifier is connected to the first terminal of the second resistor, and the second terminal of the gain adjustment module is connected to the output terminal of the second operational amplifier. 6. The optical acquisition and amplification circuit according to claim 5, wherein the gain adjustment module comprises a first chip; The first chip is used to adjust the amplification gain of the secondary amplification module by changing the resistance between the first terminal and the second terminal of the first chip. 7. The optical acquisition and amplification circuit according to claim 5, wherein the optical acquisition and amplification circuit also includes a level conversion module; The first input end, the second input end, and the third input end of the level conversion module are respectively connected to the control end of the micro control unit, and the first output end of the level conversion module is connected to the gain adjustment module The enabling end of the level conversion module is connected, the second output end of the level conversion module is connected to the input end of the gain adjustment module, and the second output end of the level conversion module is connected to the reset control end of the gain adjustment module ; The level conversion module is used to convert the voltage level of the voltage output from the micro control unit to each input terminal of the level conversion module, and output the converted voltage from each output terminal of the level conversion module to the port corresponding to the gain adjustment module. 8. The optical acquisition and amplification circuit according to any one of claims 1-7, wherein the optical acquisition and amplification circuit further comprises a filtering module; The input end of the filtering module is connected to the output end of the first-stage amplification module, and the output end of the filtering module is connected to the input end of the second-stage amplification module. 9. The optical acquisition and amplification circuit according to claim 8, wherein the filtering module comprises a third resistor and a third capacitor; The first end of the third resistor is connected to the output end of the first-stage amplification module, and the second end of the third resistor is respectively connected to the input end of the second-stage amplification module and the first end of the third capacitor. The plates are connected, and the second plate of the third capacitor is grounded. 10. An optical collection and amplification device, characterized in that the optical collection and amplification device comprises a power supply module, a micro control unit and at least one optical collection and amplification circuit according to any one of claims 1 to 9; The micro control unit is used to identify digital electrical signals to determine attribute information of the object to be detected, and output an electrical signal matching the attribute information.

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