Line scanning dispersion confocal measurement method and device in double peak signal mode

Abstract

The present invention provides a line scanning dispersion confocal measurement method and device of a double peak signal mode, which relates to the technical field of spectral confocal measurement; the method includes: forming multiple measurement spots on the object to be measured according to the light passing through the dispersion confocal component; placing the filter window at the center of the object to be measured, intercepting the center of the spot, and obtaining a single peak characteristic signal; continuously moving the filter window along the scanning direction until the single peak characteristic signal gradually sinks and the single peak splits into double peaks; intercepting the position of the spot guardrail, collecting the spectral power distribution signal of the measurement spot at the position of the spot guardrail and processing it to obtain a double peak characteristic signal; locating the peak characteristic of the double peak characteristic signal, and processing the peak characteristic signal to obtain a measurement result. The present invention offsets the filter window along the scanning direction to generate a double peak signal, obtains a more robust spectral power distribution signal, and thus improves the precision and accuracy of the output result.

Description

Technical Field

[0001] The present invention relates to the technical field of spectral confocal measurement, and in particular to a line scanning dispersion confocal measurement method and device in a double-peak signal mode. Background Art

[0002] Chromatic Confocal Microscope (CCM) has significant advantages such as large probe tolerance limit angle, small probe size, axial tomography capability, and fast response speed. It can achieve efficient scanning while maintaining high axial resolution and high radial resolution. It has broad application prospects in electronic manufacturing, aerospace, laser nuclear fusion, automobile, biology, IC manufacturing and other fields.

[0003] A common point scanning CCM optical configuration is a snapshot configuration, such as Figure 1 As shown, it includes two parts: the probe and the spectrum analysis. The specially designed dispersion lens group can produce linear chromatic aberration so that different wavelengths are focused at different axial positions; the confocal pinhole acts as a filter, and the focused wavelength returns without loss, while other wavelengths are severely lost, so that a single-peak spectral signal can be obtained. When the sample moves, the peak wavelength of the single-peak spectral signal changes accordingly. By analyzing the spectral power distribution (SPD) of the reflected light, the focused wavelength of the focused light can be obtained, and then the measured distance can be obtained. It can be seen that the focused wavelength of the focused light and the related SPD signal are crucial in CCM. The research focus of CCM is to reduce defocused light to distinguish SPD signals from focused light.

[0004] Point scanning CCM (PS-CCM) usually performs a two-dimensional scan in the sample and constructs the image in a point-by-point manner; PS-CCM has a slow frame rate and is easily affected by motion artifacts. Line scanning CCM (LS-CCM) usually integrates multiple PS paths into a single wide-field light path, scans the one-dimensional focal line in the sample, and generates images in a line-by-line manner; although LS-CCM can theoretically provide a higher frame rate, the SPD signal of LS-CCM has a serious peak feature degradation problem, making its precision and accuracy far lower than that of PS-CCM of the same specification.

[0005] In order to improve the scanning efficiency, extensive research has been conducted on the line scanning dispersive confocal technology at home and abroad in recent years. When the dispersive confocal sensing technology develops from the point scanning mode to the line scanning mode, the influence of the defocused light and the characteristic attenuation of the SPD signal become more and more serious, and it is no longer appropriate to improve the peak extraction accuracy by enhancing the focused light. On the one hand, this is due to the large field of view (FOV) design requirements of the dispersive lens group. The large field of view design requirements are to ensure the image quality of all measurement points on the scanning line. Coupled with the limitation of the F number, the dispersive lens group can only use a smaller aperture, which leads to a serious decline in the quality of the SPD signal. On the other hand, it is due to signal crosstalk from other measurement points. Signal crosstalk is mainly caused by the optical point diffusion phenomenon, and its existence will also reduce the image quality.

[0006] Therefore, as the scanning mode changes from point to line, it becomes increasingly difficult to eliminate the influence of scattered light and avoid the degradation of the peak characteristics of the SPD signal. Summary of the invention

[0007] The present invention provides a line scanning dispersion confocal measurement method and device in a double peak signal mode, which is used to solve the problem that the precision and accuracy of the measurement distance caused by the serious peak characteristic attenuation of the current LS-CCM is much lower than that of the PS-CCM of the same specification.

[0008] In a first aspect, the present invention provides a line scanning dispersion confocal measurement method in a double peak signal mode, the method comprising:

[0009] According to the light passing through the dispersive confocal component, a plurality of measuring spots are formed on the object to be measured;

[0010] Place the filter window at the center of the object to be tested, intercept the center of the light spot, and obtain a single-peak characteristic signal;

[0011] Continuously moving the filter window along the scanning direction until the single-peak characteristic signal gradually becomes concave and the single peak splits into two peaks; intercepting the light spot guardrail position, collecting the spectral power distribution signal of the measurement light spot at the light spot guardrail position and processing it to obtain a double-peak characteristic signal;

[0012] The peak characteristic is located on the double-peak characteristic signal, and the peak characteristic signal is processed to obtain a measurement result.

[0013] Furthermore, the moving distance is adjusted according to the signal strength of the spectral power distribution signal.

[0014] Further, the signal strength is determined according to a change in the full width at half maximum of the spectral power distribution signal.

[0015] Furthermore, the centroid method is used to locate the peak features.

[0016] Further, the peak characteristic signal is processed to obtain a measurement result including:

[0017] The bimodal characteristic signal is directly processed using the principal component analysis method to obtain an intermediate variable that is linearly mapped to the measurement result; the known intermediate variable is directly input into the linear mapping relationship to obtain the measurement result.

[0018] Furthermore, the intermediate variable is the chromaticity of the focused light.

[0019] Furthermore, the spectral power distribution signal of a single measurement light spot is obtained by:

[0020] Taking the current measuring spot as the origin, establish a coordinate system along the scanning direction and the measuring direction;

[0021] Measuring point The intensity is along the measurement direction x The superposition of the intensities of all crosstalk points.

[0022] Furthermore, the crosstalk superposition intensity is integrated along the measurement direction to obtain the measurement point Strength for:

[0023] ;

[0024] in, Indicates the distance The crosstalk superposition intensity.

[0025] Further, the dispersive confocal component includes a light source slit and a filter slit that are conjugately arranged;

[0026] In a second aspect, the present invention further provides a line scanning dispersive confocal measurement device in a double peak signal mode, comprising a light source component, a dispersive confocal lens component and a spectrum analysis component, for implementing the steps of any of the methods described above.

[0027] In general, the present invention provides a line scanning dispersion confocal measurement method and device in a double-peak signal mode. The technical solution conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0028] By utilizing the function of the conjugate slit, the filter window is offset along the scanning direction to generate a double-peak signal to obtain a more robust spectral power distribution signal, thereby improving the precision and accuracy of the final output result. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a common dispersion confocal measurement device in the prior art;

[0031] Figure 2 A schematic diagram of a line scanning dispersion confocal measurement method and device in a double-peak signal mode provided by the present invention;

[0032] Figure 3 It is a schematic diagram of a dispersive confocal component of a line scanning dispersive confocal measurement method and device of a double-peak signal mode provided by the present invention;

[0033] Figure 4 The present invention provides a method and device for measuring the point spread function of a line scanning dispersion confocal measurement of a double peak signal mode. Schematic diagram of the changes;

[0034] Figure 5 It is a schematic diagram of the principle of a double-peak signal obtained by moving a filter window of a line scanning dispersion confocal measurement method and device of a double-peak signal mode provided by the present invention;

[0035] Figure 6 It is a schematic diagram of the FWHM and signal intensity changes with the moving distance of the filter window of a line scanning dispersion confocal measurement method and device of a double-peak signal mode provided by the present invention;

[0036] Figure 7 It is a schematic diagram of the SPD signal intensity of a single measurement spot at different radial distances when there is no crosstalk in a line scanning dispersion confocal measurement method and device of a double-peak signal mode provided by the present invention;

[0037] Figure 8 It is a schematic diagram of the intensity superposition of crosstalk points of a line scanning dispersion confocal measurement method and device in a double-peak signal mode provided by the present invention;

[0038] Fig. 9 It is a schematic diagram of SPD signal processing using PCA output result as an intermediate variable of a line scanning dispersion confocal measurement method and device of a double-peak signal mode provided by the present invention;

[0039] Fig.10 It is a schematic diagram comparing a single-peak characteristic signal and a double-peak characteristic signal under the same configuration of a line scanning dispersion confocal measurement method and device of a double-peak signal mode provided by the present invention;

[0040] Fig.11 It is a precision test data and error schematic diagram of all measurement points of a line scanning dispersion confocal measurement method and device in a double-peak signal mode provided by the present invention;

[0041] Fig.12 It is a schematic diagram comparing the error distribution of a single-peak signal mode and a double-peak signal mode of a line scanning dispersion confocal measurement method and device for a double-peak signal mode provided by the present invention. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings and embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0043] It should be noted that, in the description of the embodiments of the present invention, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a method, step or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such method, step or device. In the absence of further restrictions, the elements defined by the sentence "include a ..." do not exclude the existence of other identical elements in the method, step or device including the elements.

[0044] The present invention provides a line scanning dispersion confocal measurement method of a double peak signal mode to solve the problem of peak feature degradation. By offsetting the filtering slit, two maximum half-peaks are obtained to make the full width smaller. Compared with the measurement method of the traditional single peak signal mode with the same hardware configuration, the feature positioning obtained by the line scanning dispersion confocal measurement method of the double peak signal mode is more robust and the measurement result is more accurate.

[0045] Specifically, if Figure 2 As shown, the method includes: forming multiple measuring spots on the object to be measured according to the light passing through the dispersive confocal component; placing the filter window at the center of the object to be measured, intercepting the center of the spot, and obtaining a single-peak characteristic signal; continuously moving the filter window along the scanning direction until the single-peak characteristic signal gradually sinks and the single peak splits into two peaks; intercepting the position of the spot guardrail, collecting the spectral power distribution signal of the measuring spot at the position of the spot guardrail and processing it to obtain a double-peak characteristic signal; locating the peak characteristic of the double-peak characteristic signal, and processing the peak characteristic signal to obtain a measurement result.

[0046] It should be noted that the traditional CCM uses a microlens array (MLA), a digital micromirror device (DMD) or a scanning galvanometer to reduce or avoid potential crosstalk between detection sensors. However, as the scanning mode changes from point to line, it becomes increasingly difficult to eliminate the influence of scattered light and avoid the degradation of the peak characteristics of the SPD signal. Therefore, the present invention no longer considers the enhancement of focused light, but can set a light source slit and a filter slit in the dispersive confocal component, and conjugately install the filter slit with the light source slit to allow the focused light to pass and block most of the scattered light. At the same time, the filter window is continuously moved along the scanning direction to split the single peak into a double peak, thereby obtaining a more robust peak characteristic, achieving more accurate peak positioning, and obtaining a measurement result.

[0047] like Figure 3 The figure shows a schematic diagram of a dispersive confocal component. According to the Fourier optics principle, the surface of the object being measured The light field distribution is:

[0048] ;

[0049] in, , represents the position of the light source slit; , represents the position of the surface of the object being measured; represents the three-dimensional point spread function (PSF) of the dispersion mirror group P1; , represents the projection matrix of the dispersion mirror group P1.

[0050] Taking into account the influence of reflection from the object under test, the light intensity distribution after reflection from the surface of the object under test is:

[0051] ;

[0052] in, is the amplitude reflectivity of the object measured by the reflection mode microscope. Since only the specular reflection is considered, .

[0053] Taking the intensity distribution of reflected light as the object, the light is incident on the dispersion mirror group P2 and finally reaches the filter slit surface .

[0054] Then the light field intensity distribution on the filter slit is: ;

[0055] in, Indicates the position of the filter slit surface; , represents the conjugate projection matrix of the dispersion mirror group P2.

[0056] The equivalent three-dimensional point spread function of the entire optical path is obtained based on the surface light intensity distribution of the object to be measured, the light intensity distribution after the surface reflection of the object to be measured, and the light field intensity distribution on the filter slit.

[0057] As an embodiment, the equivalent three-dimensional point spread function of the entire optical path is: .

[0058] In CCM, the distribution of the measurement spot of different wavelengths is linearly related to the axial distance; the linear relationship is only affected by the optical design of the dispersion lens group. Generally, the linearity or higher; therefore, the linear relationship between the distribution of the measurement spot at different wavelengths and the axial distance can be fitted by a quadratic polynomial, specifically: .

[0059] Point spread function with spectrum Changes such as Figure 4 As shown, the measurement spots on the filter slit surface at different wavelengths are given, wherein 500 nm is a focusing wavelength designed by the present invention. It can be seen that the intensity distribution changes between the measurement spots of different wavelengths and the corresponding one-dimensional intensity distribution within the measurement spot.

[0060] Place the filter window at the center of the object to be measured, intercept the center of the light spot, and obtain a single-peak characteristic signal; continuously move the filter window along the scanning direction until the single-peak characteristic signal gradually becomes concave and the single peak splits into two peaks; intercept the position of the light spot guardrail, collect the spectral power distribution signal of the measurement light spot at the position of the light spot guardrail and process it to obtain a double-peak characteristic signal.

[0061] It should be noted that the SPD signal mode can be changed by using the filter slit, changing the single-peak characteristic signal into a double-peak characteristic signal. The function of the filter window is to intercept the center of the light spot for subsequent spectrum analysis.

[0062] In the prior art, the filter window is generally placed in the center to obtain most of the focused light to intercept the center of the light spot and block the defocused light like a stop, resulting in a significant increase in the wavelength intensity share of the focused light in spectral analysis, thereby obtaining a single-peak characteristic signal of the SPD. However, when performing line scanning, the single-peak characteristic signal of the SPD from the dispersive confocal component will be significantly degraded.

[0063] In order to obtain a more robust SPD characteristic signal, such as Figure 5 As shown, the present invention continuously moves the filter window along the scanning direction until the single peak characteristic signal gradually sinks and the single peak splits into double peaks to obtain a double peak characteristic signal. At this time, the filter window no longer intercepts the center of the light spot, but intercepts the position of the light spot guardrail; at the position of the light spot guardrail, there are two SPD peak characteristics of significant intensity before and after the focused wavelength, which is a double peak characteristic signal.

[0064] It should be noted that in order to better split a single peak into a single peak, each wavelength is equivalent in SPD signal processing. The moving distance can be adjusted according to the signal strength of the spectral power distribution signal. The signal strength is determined according to the full width half height change of the spectral power distribution signal.

[0065] In other words, the full width at half maximum (FWHM) of the peak feature is used to measure the signal strength. The smaller the FWHM, the more prominent and robust the peak feature.

[0066] It should be noted that the bimodal feature can be located based on the centroid method, and the more prominent the peak feature is, the easier it is for the centroid method to locate the peak feature.

[0067] As a specific embodiment of the present invention, Figure 6 As shown, it is a schematic diagram of the change of FWHM and signal strength with the moving distance of the filter window; the signal strength decreases with the increase of the moving distance, the FWHM of the peak characteristic of the SPD signal first increases and then decreases, and the change of the half-height width of the SPD is a direct response to the change of its characteristics.

[0068] As the moving distance increases, the single-peak feature gradually becomes wider, and the FWHM continues to increase. When the moving distance is 21, the single-peak signal and the double-peak signal begin to transition, and there is a depression in the middle of the single peak, which gradually splits into two peaks; when the moving distance is 24, a double-peak feature is formed. However, when the moving distance continues to increase, the FWHM of the double-peak feature will be further reduced, and the signal strength will be excessively attenuated, which is not conducive to signal collection. Therefore, when the moving distance is about 24, the signal strength can be guaranteed to be sufficient and the feature is more prominent. In addition, the moving distance can be adjusted comprehensively according to factors such as optical component processing error, assembly alignment error, and FWHM.

[0069] When a single peak splits into two peaks, the moving distance is continuously adjusted to obtain an SPD signal with a stronger signal intensity; then the SPD signal of the measuring light spot is collected at the light spot guardrail position and processed to obtain a double-peak characteristic signal.

[0070] It should be noted that the SPD signal can be generated by a single measurement with crosstalk or without crosstalk, such as Figure 7 As shown, (ac) is the SPD signal intensity of a single measurement spot at different radial distances when there is no crosstalk; (df) is the SPD signal intensity of a single measurement spot at different radial distances when there is crosstalk.

[0071] As an embodiment, when there is crosstalk, the SPD signal of a single measuring light spot is obtained by: taking the current measuring light spot as the origin, establishing a coordinate system along the scanning direction and the measuring direction; measuring point The intensity is along the measurement direction The superposition of the intensities of all crosstalk points.

[0072] It should be noted that since the measurement spots are densest in the measurement direction, the point spread function of each measurement spot is the superposition of the point spread function of the current measurement spot and the adjacent measurement spot within the set range. Therefore, Figure 8 As shown, the measuring point The intensity is along the measurement direction The superposition of the intensities of all crosstalk points.

[0073] Preferably, the crosstalk superposition intensity is integrated along the measurement direction to obtain the measurement point Strength for:

[0074] ;

[0075] in, Indicates the distance The crosstalk superposition intensity.

[0076] As an embodiment of the present invention, processing the peak characteristic signal to obtain a measurement result includes: directly using the principal component analysis method to process the bimodal characteristic signal to obtain an intermediate variable that has a linear mapping relationship with the measurement result; directly inputting the known intermediate variable into the linear mapping relationship to obtain the measurement result.

[0077] From the perspective of signal processing, the signal analysis process from the SPD signal to the measured distance d is a principal component analysis (PCA) process of a multi-dimensional (spectral dimension) signal. In this process, the focused wavelength, as an intermediate variable for transmitting distance information, is the characteristic positioning result of the SPD signal and the input information of the λ-d mapping relationship. However, the focused wavelength does not have an obvious advantage in the transmission of distance information. Therefore, the present invention utilizes a method for solving the SPD signal without using a focused wavelength, and directly uses principal component analysis to process the SPD bimodal characteristic signal, so as to obtain an intermediate variable with a strong linear relationship with the measured distance.

[0078] As an embodiment of the present invention, the intermediate variable is the chromaticity of the focused light. Fig. 9 As shown, it is a polynomial mapping between the chromaticity of the focused light and the measurement, rather than a polynomial mapping between the focused wavelength and the measurement distance. The resulting error will be compensated in the polynomial fitting solution of the λ-d mapping relationship. Therefore, the focused wavelength is not the most suitable intermediate variable in the dispersion mirror group, which means that the focused wavelength as an intermediate variable is not irreplaceable.

[0079] It should be noted that the premise of the signal pattern change in the present invention is that the focused wavelength can be replaced as an intermediate variable; this is because if there is no focused wavelength as an intermediate variable, other types of features can be generated on the SPD signal and used as a more robust intermediate variable, thereby improving the accuracy of the final output result.

[0080] In order to verify the accuracy of the line scanning dispersion confocal measurement results of the double-peak signal mode of the present invention, the accuracy verification of the double-peak signal mode line scanning CCM was carried out.

[0081] On the other hand, the present invention also provides a line scanning dispersive confocal measurement device in a double-peak signal mode, comprising a light source component, a dispersive confocal lens component and a spectrum analysis component, for implementing the steps of any of the above methods.

[0082] As a specific embodiment of the present invention, the light source slit used in the measuring device can be 0.025*8 mm, the filter slit used can be 0.010*8 mm; the effective wavelength range can be 400-800 nm; the measurement line length can be 4-6 mm; the measurement range can be 4 mm; the working distance is greater than 200 mm; the maximum tolerance tilt angle of the measurement can be ±33°. The dispersion element in the dispersive confocal lens assembly can be an 800-line density reflection grating; the spectral signal receiver can be a camera, whose resolution in the spread spectrum direction determines the accuracy of the spectrum analysis, and the resolution in the measurement direction determines the number and distribution of points along the measurement line.

[0083] Within the measurement range, the motor is driven to move the plane mirror with a set step length. Every time it moves, the reading of the dual-frequency laser interferometer and the line scanning CCM signal are collected simultaneously, such as Fig.10 As shown, a single-peak characteristic signal and a double-peak characteristic signal are obtained under the same configuration. By comparison, it can be found that the full width at half maximum of the double-peak mode (cd) is significantly smaller than that of the single-peak mode (ab), which indicates that using the center of gravity method for feature positioning can obtain more robust results in the double-peak signal mode.

[0084] Since the illumination at the light source slit is uneven, the signal strength of the measurement light spots at both ends of the measurement direction is generally weak. Therefore, the method of the present invention further includes screening the multiple measurement light spots, and the screening includes: removing the measurement light spots at both ends of the measurement direction.

[0085] In order to compare the errors between different measurement points more reasonably and intuitively, the parameters M and to describe the error distribution, M represents the overall mean of the error, indicating the deviation of the center of the error distribution from 0 mm, reflecting the accuracy of the line scan CCM; represents the standard deviation of the error distribution, represents the possible range of the error distribution, and reflects the precision of the instrument. As a specific embodiment of the present invention, Fig.11 As shown in the figure, (a) is the accuracy measurement data after screening multiple measurement spots; (b) and (c) are the corresponding single-peak signal error and double-peak signal error, respectively. The point sequence dimension is the point sequence along the measurement line; the step sequence dimension is the number of steps of the drive motor; the distance and error are the readings from the line scan CCM and the error relative to the reference distance.

[0086] In addition, the present invention also compares the error distribution of the single-peak signal mode and the double-peak signal mode, such as Fig.12 As shown, it can be seen that the error value of the double-peak mode is significantly stable around 0 mm. In addition, the error value of the double-peak mode is much smaller than that of the single-peak mode, indicating that the measurement method in the double-peak signal mode has better accuracy and precision, which can improve the accuracy of the image sensor pixel (CCLS instrument) by 40%.

[0087] In summary, the present invention proposes a line scanning dispersion confocal measurement method and device for a double-peak signal mode, which utilizes the function of a conjugate slit to offset the filter window along the scanning direction to generate a double-peak signal, thereby enhancing the anti-crosstalk capability to obtain a more robust spectral power distribution signal, thereby improving the precision and accuracy of the final output result; under the same hardware configuration, the measurement accuracy of the measurement method of the double-peak signal mode is 40% higher than that of the measurement method of the single-peak signal mode.

[0088] It should be noted that, for the above-mentioned various embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0089] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0090] In the several embodiments provided in this application, it should be understood that the disclosed method or system can be implemented in other ways. For example, the above-described embodiments are only schematic, and the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0091] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0092] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0093] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the whole or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a memory, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application.

[0094] Those skilled in the art will appreciate that all or part of the various circuits in the above embodiments may be completed by entering a program to instruct related hardware, and the program may be stored in a computer-readable memory, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0095] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0096] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A line scanning dispersion confocal measurement method in a double peak signal mode, characterized in that: The method comprises: According to the light passing through the dispersive confocal component, a plurality of measuring spots are formed on the object to be measured; Place the filter window at the center of the object to be tested, intercept the center of the light spot, and obtain a single-peak characteristic signal; Continuously moving the filter window along the scanning direction until the single-peak characteristic signal gradually becomes concave and the single peak splits into two peaks; intercepting the light spot guardrail position, collecting the spectral power distribution signal of the measurement light spot at the light spot guardrail position and processing it to obtain a double-peak characteristic signal; Performing peak feature positioning on the double-peak characteristic signal, and processing the peak characteristic signal to obtain a measurement result; The spectral power distribution signal of a single measurement spot is obtained by: Taking the current measuring spot as the origin, establish a coordinate system along the scanning direction and the measuring direction; Measuring point The intensity is along the measurement direction The superposition of the intensities of all crosstalk points; integrating the crosstalk superposition intensity along the measurement direction to obtain the measurement point Strength for: ;in, Indicates the distance The crosstalk superposition intensity.

2. The line scanning dispersion confocal measurement method of a double peak signal mode according to claim 1, characterized in that: The moving distance is adjusted according to the signal strength of the spectral power distribution signal.

3. The line scanning dispersion confocal measurement method of a double peak signal mode according to claim 2, characterized in that: The signal strength is determined according to a full width half maximum change of the spectral power distribution signal.

4. The line scanning dispersion confocal measurement method of a double peak signal mode according to claim 1, characterized in that: The center of gravity method is used to locate the peak features.

5. The line scanning dispersion confocal measurement method of a double peak signal mode according to claim 1, characterized in that: Processing the peak characteristic signal to obtain a measurement result includes: The bimodal characteristic signal is directly processed using the principal component analysis method to obtain an intermediate variable that is linearly mapped to the measurement result; the known intermediate variable is directly input into the linear mapping relationship to obtain the measurement result.

6. The line scanning dispersion confocal measurement method of a double peak signal mode according to claim 5, characterized in that: The intermediate variable is the chromaticity of the focused light.

7. The line scanning dispersion confocal measurement method of a double peak signal mode according to claim 1, characterized in that: The dispersive confocal component comprises a light source slit and a filter slit which are conjugately arranged.

8. A line scanning dispersive confocal measurement device in a double peak signal mode, characterized in that: It comprises a light source component, a dispersive confocal lens component and a spectrum analysis component, and is used to implement the steps of the method as claimed in any one of claims 1 to 7.

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