A method and system for screening thickness measurement of transparent test objects using spectral confocal multi-peak screening

Abstract

This invention relates to the field of thickness measurement technology for transparent objects, and particularly to a method and system for screening and measuring the thickness of transparent objects using spectral confocal multi-peak screening. The method constructs a candidate response peak state set for the current measurement point, incorporates the confirmed interface layer sequence and layer spacing from the previous measurement point into the current measurement point to obtain a target response peak sequence, identifies abnormally close adjacent layers in the target response peak sequence, and calculates the change in the peak position of the current measurement point relative to the peak position of the corresponding layer at the previous measurement point based on the corrected target response peak sequence. When the change falls within a preset allowable range, the thickness is calculated. This invention avoids the loss of interface layers or misjudgment of peak sequence due to local merging of adjacent interface response peaks, improving the interface resolution capability in complex transparent structures such as ultrathin layers, adhesive layers, and micro-air gaps.

Description

Technical Field

[0001] This invention relates to the field of thickness measurement technology for transparent objects, specifically to a method and system for spectral confocal multi-peak screening thickness measurement of transparent objects. Background Technology

[0002] Spectral confocal measurement technology utilizes the characteristic that light of different wavelengths is focused at different positions along the axis to perform spectral analysis on the reflected echo of the measured surface, thereby obtaining interface position or distance information. For objects such as transparent sheets, optical cover plates, adhesive layer structures, and multilayer transparent laminates, since response peaks can be generated at both the front and back interfaces, thickness measurement can be achieved by the relative positional relationship between multiple interface response peaks.

[0003] However, in the continuous scanning thickness measurement of transparent objects, most existing methods still rely on the instantaneous peak value at a single measurement point as the main basis. That is, the target peak is directly selected from multiple response peaks at the current measurement point, and the thickness is calculated accordingly. This method can meet the measurement requirements when the interface response peaks can be stably separated. However, in the actual dynamic scanning process, as the measurement spot moves continuously along the scanning direction, the interface response between the previous and next measurement points will continue to change. The adjacent interface response peaks in weakly reflective interfaces, locally tilted areas, ultrathin layer areas, adhesive layer areas, or small air gap areas are prone to spacing compression, peak width broadening, and even local merging. This makes it easy for the layer correspondence to drift, peak sequence misjudgment, and peak merging misidentification to occur when the current measurement point is judged based on the peak value of a single point.

[0004] Furthermore, for multi-interface transparent structures, when two adjacent layers at a certain measurement point enter an abnormally close state, their corresponding response may exhibit a single composite peak, or although two peaks are still retained, the distance between the peaks has significantly contracted. In this case, if the existing single-point peak selection method is still directly used, the abnormally merged peak is easily mistakenly treated as a normal independent peak, resulting in the loss of interface layers, disordered layer order, and the continued propagation of erroneous results to subsequent measurement points, ultimately leading to sudden jumps in the thickness curve, local distortion, or even instability in the entire measurement result. Especially in continuous scanning scenarios, if the incorrect layer assignment of the current measurement point is not corrected in time, subsequent thickness calculations based on the erroneous layer will often amplify the error propagation range, reducing the continuity and reliability of the dynamic thickness measurement results of the transparent object. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a method and system for spectral confocal multi-peak screening thickness measurement of transparent objects. During continuous scanning, this method not only effectively extracts candidate response peaks from each measurement point but also combines the layer sequence and interlayer spacing of previous measurement points to match the layer attribution of the current measurement point. It promptly identifies adjacent layers in abnormally close states and performs restricted separation correction on composite responses in tandem or quasi-tandem states. This suppresses the influence of layer misjudgment and tandem distortion on the measurement results before thickness calculation, thereby improving the stability and accuracy of continuous thickness measurement of transparent objects.

[0006] This invention employs the following technical solution: a method for screening and measuring the thickness of a transparent test object using spectral confocal multi-peak screening, comprising:

[0007] Step S1: During the continuous thickness measurement of the transparent object, the spectral response curves of each measurement point are sequentially acquired along the scanning direction, and a continuous correspondence is established between the spectral response curves of each measurement point according to the sampling order. The peak position and peak width of all candidate response peaks of each measurement point are extracted to construct the candidate response peak state set of the current measurement point.

[0008] Step S2: Based on the candidate response peak state set, the interface layer order and layer spacing already confirmed at the previous measurement point are introduced into the current measurement point. Layer assignment matching is performed on each candidate response peak at the current measurement point to obtain the target response peak sequence, and the adjacent layers with abnormally close states in the target response peak sequence are identified.

[0009] Step S3: For the target response peak sequence in the abnormal proximity state, determine the object to be separated, establish a local separation window based on the determined object to be separated, obtain the local shape of the synthetic peak, perform fitting correction, and generate the corrected target response peak sequence.

[0010] Step S4: Based on the corrected target response peak sequence, determine the front boundary layer and the back boundary layer of the material segment to be tested, and calculate the change in the peak position corresponding to the current measuring point relative to the peak position corresponding to the previous measuring point; when the change falls within the preset allowable range, perform thickness calculation; otherwise, return to steps S2 to S3 and re-execute.

[0011] As a further description of the above technical solution: the method for extracting all candidate response peaks for each measurement point includes:

[0012] The local maxima are searched point by point along the wavelength coordinates of the standard spectral response curve of the current measurement point. The response structures that satisfy the condition that the local intensity is higher than the adjacent sampling points on both sides and the peak width reaches the preset lower limit are identified as candidate response peaks. After the search is completed, the set of all candidate response peaks corresponding to the current measurement point is obtained.

[0013] As a further description of the above technical solution: the peak position extraction method of the response peak includes:

[0014] For each candidate response peak in the current measurement point, with the peak vertex of the candidate response peak as the center, select two boundary points on the left and right sides of the peak vertex when the response intensity drops to half of the peak intensity, and determine the wavelength interval between the two boundary points as the analysis window. Perform continuous peak shape fitting on the response data within the analysis window, and take the wavelength position corresponding to the maximum value of the fitted curve as the peak position of the candidate response peak; when there is a plateau region at the local peak, take the center position of the plateau region as the peak position.

[0015] As a further description of the above technical solution: the peak width extraction method for the response peak includes:

[0016] Using the local valley positions on the left and right sides of the current candidate response peak as the left and right boundaries, a local baseline is established between the left and right boundaries; the fitted response intensity corresponding to the peak position of the candidate response peak is read, and the baseline response intensity corresponding to the peak position on the local baseline is read. The difference between the fitted response intensity and the baseline response intensity is determined as the net peak height of the candidate response peak.

[0017] The half-peak height intensity is determined based on the net peak height, and the half-peak height intensity is the sum of the reference response intensity corresponding to the local baseline at the peak position and half of the net peak height;

[0018] Search for the positions where the standard spectral response curve reaches the half-peak high intensity on the left and right sides of the candidate response peak, respectively, to obtain the left half-peak high intersection point and the right half-peak high intersection point. The difference between the wavelength corresponding to the left half-peak high intersection point and the wavelength corresponding to the right half-peak high intersection point is determined as the peak width of the candidate response peak.

[0019] As a further description of the above technical solution: the method for obtaining the target response peak sequence at the current measuring point includes:

[0020] Based on the target response peak sequence already confirmed at the previous measurement points, the peak distribution of each interface layer at the current measurement point is predicted to obtain the predicted peak position and the predicted interlayer spacing.

[0021] The candidate response peaks at the current measurement point are matched with the predicted peak positions and the predicted interlayer spacing, and the sequence of target response peaks corresponding to each interface layer at the current measurement point is determined based on the layer order relationship.

[0022] As a further description of the above technical solution: the method for predicting the peak distribution of each interface layer at the current measuring point includes:

[0023] Obtain the candidate response peak set for the current measurement point and the confirmed target response peak sequence for the previous measurement point; for each layer in the previous measurement point, read the peak position of its corresponding target response peak, and obtain the predicted peak position of the current measurement point based on the peak position difference of the corresponding target response peak between the previous measurement point and the two previous measurement points.

[0024] For two adjacent layers in the previous measurement point, calculate the peak position difference of their corresponding target response peaks to obtain the actual interlayer spacing of the previous measurement point. Based on the change in interlayer spacing between the previous measurement point and the two previous measurement points, obtain the predicted interlayer spacing of adjacent layers in the current measurement point.

[0025] As a further description of the above technical solution: the method for determining the target response peak sequence corresponding to each interface layer in the current measuring point based on the hierarchical order relationship includes:

[0026] For each candidate response peak in the current measurement point, calculate its peak position deviation relative to the predicted peak position of each layer. When the peak position deviation of a candidate response peak relative to a certain layer is not greater than the peak position deviation threshold, include the candidate response peak in the candidate peak set of that layer. Perform order-preserving matching on all layers to make the peak position of the candidate response peak assigned to the previous layer in the current measurement point smaller than the peak position of the candidate response peak assigned to the next layer. Use the minimum sum of peak position deviations of all assigned candidate response peaks as the matching criterion to determine the target response peak sequence of the current measurement point.

[0027] As a further description of the above technical solution: the method for identifying abnormally close adjacent layers in the target response peak sequence includes:

[0028] For any pair of adjacent layers in the target response peak sequence of the current measurement point, calculate the current actual layer spacing and compare the current actual layer spacing with the corresponding predicted layer spacing to obtain the layer spacing compression ratio. Read the peak width of the two adjacent target response peaks and calculate the peak width occupancy ratio. When a pair of adjacent layers simultaneously satisfies that the layer spacing compression ratio is not less than a preset compression threshold and the peak width occupancy ratio is not less than a preset broadening threshold, it is determined that the pair of adjacent layers is in an abnormally close state.

[0029] As a further description of the above technical solution: the method for determining the object to be separated includes:

[0030] Two adjacent layers in an abnormally close state are designated as the preceding layer and the following layer. The predicted peak positions corresponding to the preceding and following layers, as well as the corresponding predicted interlayer spacing, are simultaneously read from the previous measurement point. The composite response bands corresponding to these two adjacent layers at the current measurement point are also read. If the two adjacent layers at the current measurement point exhibit a single composite peak, the band containing that single composite peak is directly identified as the object to be separated. If the two adjacent layers at the current measurement point still exhibit two peaks, but the interlayer spacing compression ratio is not less than a preset compression threshold and the peak width occupancy ratio is not less than a preset broadening threshold, then the two peaks along with the bands between them are jointly identified as the object to be separated.

[0031] As a further description of the above technical solution: the method for obtaining the local morphology of the synthetic peak includes: based on the predicted peak position of the previous layer and the predicted peak position of the subsequent layer, determining a local separation window on the standard spectral response curve of the current measurement point, and extracting the response intensity distribution within the window as the local morphology of the synthetic peak.

[0032] As a further description of the above technical solution: the method for generating the corrected target response peak sequence includes:

[0033] The local morphology of the synthesized peak is constructed as a superposition model of the single-peak response of the front layer, the single-peak response of the back layer, and the background response;

[0034] Using the predicted peak position of the previous layer, the predicted peak position of the next layer, and the peak width of the target response peak of the previous measuring point as initial parameters, the superposition model is jointly fitted under the constraints of peak position deviation, minimum separation distance between peaks, and peak width range to obtain the independent peak position and independent peak width of the previous layer and the independent peak position and independent peak width of the next layer.

[0035] By using the independent peak positions and widths of the preceding and following layers, the original peak positions and widths corresponding to the preceding and following layers in the target response peak sequence of the current measuring point are replaced, and the corrected target response peak sequence is generated.

[0036] As a further description of the above technical solution: the method for calculating the thickness includes:

[0037] Read the peak positions of the preceding and following layers, and based on the pre-established peak-to-axial position calibration relationship of the dispersive confocal system, convert the preceding layer correction peak position into the preceding layer axial position and the following layer correction peak position into the following layer axial position; then, based on the axial interval between the preceding and following layer axial positions and the refractive index parameter corresponding to the current transparent material segment, calculate the actual thickness value of the current measuring point.

[0038] A spectral confocal multi-peak screening thickness measurement system for transparent test objects, used to implement the aforementioned spectral confocal multi-peak screening thickness measurement method for transparent test objects, the system comprising:

[0039] The spectral response acquisition module sequentially acquires the spectral response curves of each measuring point along the scanning direction during the continuous thickness measurement of the transparent test object. It establishes a continuous correspondence between the spectral response curves of each measuring point according to the sampling order, extracts the peak position and peak width of all candidate response peaks of each measuring point, and constructs the candidate response peak state set of the current measuring point.

[0040] The layer attribution matching module, based on the candidate response peak state set, introduces the interface layer order and layer spacing already confirmed at the previous measurement point into the current measurement point, performs layer attribution matching on each candidate response peak at the current measurement point, obtains the target response peak sequence, and identifies adjacent layers with abnormally close states in the target response peak sequence.

[0041] The overlapping peak separation correction module identifies the target to be separated from the target response peak sequence in an abnormally close state, establishes a local separation window based on the identified target to be separated, obtains the local morphology of the synthesized peak, performs fitting correction, and generates the corrected target response peak sequence.

[0042] The thickness calculation module determines the front and back boundary layers of the material segment under test based on the corrected target response peak sequence, and calculates the change in the peak position of the current measuring point relative to the peak position of the previous measuring point. When the change falls within the preset allowable range, the thickness is calculated; otherwise, it is sent back to the layer assignment matching module for re-execution.

[0043] The beneficial effects of this invention are as follows:

[0044] This invention first constructs a candidate response peak state set for each measurement point during continuous scanning, and then introduces the interface layer order and layer spacing already confirmed by the previous measurement point into the current measurement point to perform layer attribution matching. This makes the interface recognition of the current measurement point no longer rely on the instantaneous peak value judgment of a single measurement point, but is based on the layer transmission relationship and peak position constraint relationship between continuous measurement points. As a result, the continuous inheritance of layer numbering can be maintained during dynamic scanning, reducing the impact of weak peak fluctuations, local peak position drift and short-term loss of lock on interface recognition, and improving the stability of layer judgment for multi-interface transparent structures.

[0045] Furthermore, by identifying adjacent layers in an abnormally close state through the interlayer spacing compression ratio and peak width occupancy ratio, and based on this, the overlapping peak separation correction mechanism is invoked to perform local separation and restricted fitting of the composite response in the abnormal peak merging region. The recovered independent peak positions and peak widths are then rewritten back into the target response peak sequence. Through this processing, it is possible to avoid the loss of interface layers or misjudgment of peak sequence directly caused by the local merging of adjacent interface response peaks, so that the layer information in the abnormal region can still continue to be stably transmitted to subsequent measurement points, thereby improving the interface resolution capability in complex transparent structures such as ultrathin layers, adhesive layers, and tiny air gaps.

[0046] Finally, before calculating the thickness, the allowable range of peak position changes at the boundary layers of the material segment under test is further checked. If abnormal peak position changes occur, the data is sent back to the aforementioned layer assignment matching and separation correction steps for reprocessing, thus avoiding directly incorporating abnormal jump points into the thickness calculation. Therefore, this invention can simultaneously achieve layer position preservation, peak recovery, and abnormal feedback correction during continuous scanning thickness measurement, resulting in better continuity, accuracy, and resistance to jumps in the final thickness of transparent objects. It is suitable for dynamic high-precision thickness measurement scenarios involving transparent sheets, multilayer transparent laminates, optical cover plates, and adhesive layer structures. Attached Figure Description

[0047] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0048] Figure 1 This is a flowchart of a method for screening and measuring the thickness of a transparent test object using spectral confocal multi-peak screening, provided in Embodiment 1 of the present invention;

[0049] Figure 2 This is a flowchart of the peak width extraction method for the response peak provided in Embodiment 1 of the present invention;

[0050] Figure 3 This is a module connection diagram of a spectral confocal multi-peak screening thickness measurement system for a transparent test object provided in Embodiment 2 of the present invention. Detailed Implementation

[0051] To make the technical means, creative features, objectives, and effects of this invention readily understandable, the invention is further described below with reference to specific illustrations. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0052] Example 1

[0053] Please see Figures 1-2 This invention provides a technical solution: a method for screening and measuring the thickness of a transparent object using spectral confocal multi-peak screening, comprising...

[0054] Step S1: During the continuous thickness measurement of the transparent object, the spectral response curves of each measurement point are sequentially acquired along the scanning direction, and a continuous correspondence is established between the spectral response curves of each measurement point according to the sampling order. Based on this, the peak position and peak width of all candidate response peaks are extracted for each measurement point to construct the candidate response peak state set of the current measurement point.

[0055] In some implementation methods, the implementation steps include:

[0056] During the continuous thickness measurement of the transparent object, the measurement spot is driven to pass through each measurement point in sequence according to the preset scanning direction, and the spectral response curve of each measurement point is collected synchronously. The collection time, scanning position and spectral response curve data of each measurement point are bound and recorded. Then, the continuous measurement points are assigned numbers according to the sampling order, so that all measurement points form a continuous measurement point sequence with a sequential relationship. This completes the sequential organization of the spectral response curves of each measurement point, providing a unified temporal basis for the continuous analysis between adjacent measurement points.

[0057] For the original spectral response curves acquired at each measurement point, reference intensity normalization is performed to unify the response amplitude scale between different measurement points. Peak preservation and smoothing processing is then applied to the spectral response curves to suppress random fluctuations without weakening the true peak shape. After the above processing, the standard spectral response curve of the current measurement point is obtained, so that the curves between adjacent measurement points have consistent comparability.

[0058] The local maximum positions are searched point by point along the standard spectral response curve of the current measurement point along the wavelength coordinate. The response structures that satisfy the condition that the local intensity is higher than the adjacent sampling points on both sides and the peak width reaches the preset lower limit are identified as candidate response peaks. After the search is completed, the set of all candidate response peaks corresponding to the current measurement point is obtained.

[0059] It should be noted that the preset lower limit of the peak width is determined based on the wavelength sampling interval of the standard spectral response curve and the resolution of the spectral acquisition device. The preset lower limit of the peak width is not less than the wavelength width corresponding to three consecutive sampling points, and not less than the minimum spectral width that the spectral acquisition device can resolve. This eliminates spurious peaks formed by single-point jumps, random fluctuations between adjacent points, or narrow spikes below the instrument's resolution. After the search is completed, the set of all candidate response peaks corresponding to the current measurement point is obtained.

[0060] For each candidate response peak at the current measurement point, with the peak vertex as the center, select two boundary points on the left and right sides of the peak vertex where the response intensity drops to half of the peak intensity, and define the wavelength interval between these two boundary points as the analysis window. Perform continuous peak shape fitting on the response data within the analysis window, and take the wavelength position corresponding to the maximum value of the fitted curve as the peak position of the candidate response peak. When there is a plateau region at the local peak, take the center position of the symmetrical ends of the plateau region as the peak position. In this way, the peak position is no longer directly taken from a single discrete sampling point, but from the true center position determined by the local continuous curve, thereby improving the peak position resolution accuracy under multi-interface response conditions.

[0061] The continuous peak fitting of the response data within the analysis window involves using the wavelength values ​​of each sampling point within the analysis window as independent variables and the corresponding standard spectral response intensity as dependent variables. A quadratic polynomial, Gaussian function, or Lorentz function is used to fit the response data, resulting in a peak-shaped fitting curve that can continuously take values ​​between adjacent sampling points. After fitting, the location of the maximum value of the peak-shaped fitting curve within the analysis window is calculated, and the wavelength corresponding to this maximum value is determined as the peak position of the candidate response peak. Thus, the peak position is no longer limited to the location of discrete sampling points but can fall between adjacent sampling points. When using a quadratic polynomial fitting, the fitting function is P(λ) = aλ² + bλ + c, and when a < 0, the peak position λp = -b / 2a, where a, b, and c are the fitting coefficients of the fitting function, λ is the wavelength, and P(λ) is the standard spectral response intensity. When using a Gaussian function or Lorentz function fitting, the center wavelength parameter of the fitting function is determined as the peak position.

[0062] Using the local valley positions on the left and right sides of the current candidate response peak as the left and right boundaries, a local baseline is established between the left and right boundaries; the fitted response intensity corresponding to the peak position of the candidate response peak is read, and the baseline response intensity corresponding to the peak position on the local baseline is read. The difference between the fitted response intensity and the baseline response intensity is determined as the net peak height of the candidate response peak.

[0063] The half-peak height intensity is determined based on the net peak height, and the half-peak height intensity is the sum of the reference response intensity corresponding to the local baseline at the peak position and half of the net peak height;

[0064] Search for the positions where the standard spectral response curve reaches the half-peak high intensity on the left and right sides of the candidate response peak, respectively, to obtain the left half-peak high intersection point and the right half-peak high intersection point. The difference between the wavelength corresponding to the left half-peak high intersection point and the wavelength corresponding to the right half-peak high intersection point is determined as the peak width of the candidate response peak.

[0065] Through the above steps, the subsequent interface recognition no longer relies on the instantaneous peak value of a single measurement point, but is based on the dynamic response correlation between continuous measurement points.

[0066] Step S2: Based on the candidate response peak state set, the interface layer order and layer spacing confirmed by the previous measurement point are introduced into the current measurement point. Layer assignment matching is performed on each candidate response peak of the current measurement point to obtain the target response peak sequence with sequential layer meaning, and the adjacent layers with abnormally close states in the target response peak sequence are identified.

[0067] The methods for obtaining the target response peak sequence at the current measurement point include:

[0068] Based on the target response peak sequence already confirmed at the previous measurement points, the peak distribution of each interface layer at the current measurement point is predicted to obtain the predicted peak position and the predicted interlayer spacing.

[0069] The candidate response peaks at the current measurement point are matched with the predicted peak positions and the predicted interlayer spacing, and the sequence of target response peaks corresponding to each interface layer at the current measurement point is determined based on the layer order relationship.

[0070] In some implementation methods, the implementation steps include:

[0071] During the continuous scanning of the transparent test object, a reference measurement point where the candidate response peaks can be stably separated is selected. All candidate response peaks of the reference measurement point are arranged in order of increasing corresponding measurement depth, and layer numbers are assigned to the first layer, the second layer, and so on up to the Nth layer. The layer number, peak position, and peak width of each candidate response peak are associated and recorded to form an initial target response peak sequence.

[0072] Obtain the candidate response peak set for the current measurement point and the confirmed target response peak sequence for the previous measurement point; for each layer in the previous measurement point, read the peak position of its corresponding target response peak, and obtain the predicted peak position of the current measurement point based on the peak position difference of the corresponding target response peak between the previous measurement point and the two previous measurement points; for two adjacent layers in the previous measurement point, calculate the peak position difference of their corresponding target response peaks to obtain the actual interlayer spacing of the previous measurement point, and obtain the predicted interlayer spacing of adjacent layers in the current measurement point based on the change in interlayer spacing between the previous measurement point and the two previous measurement points.

[0073] It should be noted that when there is only one confirmed measuring point before the current measuring point, the predicted peak position is directly taken as the peak position of the layer corresponding to the previous measuring point, and the predicted interlayer spacing is directly taken as the actual interlayer spacing of the adjacent layer corresponding to the previous measuring point.

[0074] For each candidate response peak in the current measurement point, calculate its peak position deviation relative to the predicted peak position of each layer. That is, obtain the measured peak position of the candidate response peak after continuous peak shape fitting, and obtain the predicted peak position corresponding to each layer in advance. Subtract the measured peak position from the predicted peak position of each layer to obtain the peak position deviation of the predicted peak position of each layer.

[0075] When the peak position deviation of a candidate response peak relative to a certain stratum is not greater than the allowable peak position deviation threshold, the candidate response peak is included in the candidate peak set for that stratum. Order-preserving matching is performed on all strata to ensure that the peak position of the candidate response peak assigned to the previous stratum in the current measurement point is smaller than the peak position of the candidate response peak assigned to the subsequent stratum. The minimum sum of the peak position deviations of all assigned candidate response peaks is used as the matching criterion to determine the target response peak sequence of the current measurement point, so that each target response peak corresponds to a unique stratum number. The allowable peak position deviation threshold is obtained by statistically analyzing the peak position change of the same stratum between adjacent measurement points in the stable separation measurement point sample.

[0076] Methods for identifying abnormally close adjacent layers in the target response peak sequence include:

[0077] For any pair of adjacent layers in the target response peak sequence of the current measurement point, calculate their current actual interlayer spacing, and compare the current actual interlayer spacing with the corresponding predicted interlayer spacing to obtain the interlayer spacing compression ratio. The interlayer spacing compression ratio is used to characterize whether the distance between the current adjacent layers has significantly shrunk.

[0078] The method for obtaining the interlayer compression ratio is as follows: for any pair of adjacent layers in the target response peak sequence of the current measurement point, obtain the measured peak position of the target response peak of the kth layer and the measured peak position of the target response peak of the (k+1)th layer, and determine the absolute value of the wavelength difference between the two as the current actual interlayer spacing; obtain the predicted interlayer spacing corresponding to the adjacent layer, and subtract the actual interlayer spacing from the predicted interlayer spacing, and then divide the obtained difference by the predicted interlayer spacing to obtain the interlayer compression ratio.

[0079] It should be noted that the larger the interlayer compression ratio, the more significantly the actual interlayer spacing is shortened relative to the predicted interlayer spacing, the closer the two adjacent target response peaks are, and the higher the risk of peak overlap, layer response aliasing, or layer mismatch.

[0080] Read the peak width of two adjacent target response peaks and calculate the peak width occupancy ratio; when an adjacent layer pair simultaneously satisfies that the interlayer compression ratio is not less than a preset compression threshold and the peak width occupancy ratio is not less than a preset broadening threshold, it is determined that the adjacent layer pair is in an abnormally close state; wherein, the peak width occupancy ratio is used to characterize the degree of broadening of adjacent target response peaks relative to the degree of occupancy of the interlayer spacing.

[0081] The peak width-to-spacing ratio is calculated by obtaining the wavelength spacing between the peak positions of the two target response peaks and dividing the sum of the peak widths of the two target response peaks by the wavelength spacing to obtain the peak width-to-spacing ratio.

[0082] It should be noted that both the preset compression threshold and the preset broadening threshold are obtained from normal samples. The preset compression threshold is determined based on the statistical upper limit of the interlayer compression ratio between adjacent layers under normal conditions, and the preset broadening threshold is determined based on the statistical upper limit of the peak width occupancy ratio between adjacent target response peaks under normal conditions. The statistical upper limit can be the mean of multiple sets of normal sample calculations plus two to three times the standard deviation, or the 95th percentile of the normal sample calculation results.

[0083] In this embodiment, the layer determination of the current measurement point no longer relies on the instantaneous measurement result of a single point. Instead, it simultaneously uses the confirmed layer order of the previous measurement point, the distance between adjacent layers, and the peak position relationship of the candidate peaks of the current measurement point for constraint matching. This enables the continuous transmission of layer numbers during continuous scanning, reducing the impact of weak peak fluctuations, local peak merging, and short-term loss of lock on interface identification. At the same time, by identifying abnormal proximity states through the layer spacing compression ratio and peak width occupancy ratio, it is possible to detect the precursors or results of peak merging in advance before thickness calculation, avoiding the direct introduction of incorrect layers into subsequent thickness solutions. Therefore, it is beneficial to improve the layer stability, anomaly identification capability, and overall measurement reliability during the dynamic thickness measurement of transparent objects.

[0084] Step S3: For the target response peak sequence in the abnormal proximity state, determine the object to be separated, establish a local separation window based on the determined object to be separated, obtain the local morphology of the synthetic peak, and generate the corrected target response peak sequence.

[0085] In some implementations, the steps of determining the object to be separated include:

[0086] Two adjacent layers in an abnormally close state are designated as the preceding layer and the following layer. The predicted peak position corresponding to the preceding layer, the predicted peak position corresponding to the following layer, and the corresponding predicted interlayer spacing are read synchronously from the previous measurement point. The composite response bands corresponding to the two adjacent layers in the current measurement point are also read. If the two adjacent layers in the current measurement point have already shown a single composite peak, the band containing the single composite peak is directly identified as the object to be separated. If the two adjacent layers in the current measurement point still show two peaks, but the interlayer spacing compression ratio is not less than the preset compression threshold and the peak width occupancy ratio is not less than the preset broadening threshold, the two peaks together with the bands in between are identified as the objects to be separated.

[0087] A standard dual-interface transparent sample was used for pre-calibration. The actual distance between the two interfaces was gradually reduced, and the dispersive confocal response corresponding to each calibration thickness was measured. The minimum peak spacing corresponding to the algorithm being able to stably output two independent peak positions was recorded. This minimum peak spacing was determined as the minimum resolvable distance between layers. The stable output of two independent peak positions means that within a consecutive preset number of measurement points, the order of the two peak positions remains unchanged, and the peak position variation between adjacent measurement points does not exceed the allowable peak position deviation threshold. In the subsequent overlapping peak separation process, the separation results of the center positions of the preceding and following layers must not be less than the minimum resolvable distance between layers.

[0088] Methods for generating the corrected target response peak sequence include:

[0089] Based on the predicted peak positions corresponding to the previous and subsequent layers, a local separation window containing the composite response is determined on the standard spectral response curve of the current measurement point, and the response intensity distribution within the local separation window is extracted as the local morphology of the composite peak.

[0090] The local morphology of the synthesized peak is constructed as a superposition model of the single-peak response of the previous layer, the single-peak response of the next layer, and the local background response. The peak position corresponding to the predicted peak position of the previous layer, the predicted peak position corresponding to the next layer, and the peak width of the target response peak corresponding to the previous measurement point are used as initial parameters. Under the constraints of peak position deviation, minimum separation distance between peaks, and peak width range, the superposition model is jointly fitted to obtain the independent peak position and independent peak width after the recovery of the previous layer and the independent peak position and independent peak width after the recovery of the next layer.

[0091] The original peak positions and original peak widths corresponding to the front and rear layers in the target response peak sequence of the current measuring point are replaced by the restored independent peak positions, independent peak widths of the front and rear layers, and independent peak positions and independent peak widths of the rear layers, while keeping the original layer numbers of the front and rear layers unchanged, to generate the target response peak sequence after overlapping peak separation correction.

[0092] In some implementation methods, the implementation steps include:

[0093] Using the predicted peak positions corresponding to the previous and subsequent layers as the center, a local separation window is established on the standard spectral response curve of the current measurement point; the left boundary of the local separation window is the boundary after extending the predicted peak position corresponding to the previous layer to the left by a preset window width, and the right boundary is the boundary after extending the predicted peak position corresponding to the subsequent layer to the right by a preset window width, and the preset window width is one to two times the minimum resolvable spacing between layers;

[0094] When the response bands of the local separation window overlap with those of the adjacent non-abnormal layers, the midpoint between the anomalous layer and the adjacent non-abnormal layer is used as the cutoff boundary. All response intensity sampling points within the local separation window are extracted, and the response intensity distribution within the window is used as the local shape of the synthetic peak of the current measurement point to characterize the actual contour of the composite response.

[0095] It should be noted that the response intensity is the amplitude of the optical signal corresponding to each wavelength in the local separation window. The outline of the composite peak is described by these light intensity distributions so as to facilitate subsequent fitting and separation.

[0096] The obtained local morphology of the synthetic peak is considered as the superposition of the single-peak response of the preceding layer, the single-peak response of the following layer, and the local background response. The single-peak responses of the preceding and following layers are established using peak shape functions, preferably Gaussian single-peak functions, while the local background response is established using a linear baseline. The predicted peak position corresponding to the preceding layer is used as the initial center position of the single-peak response of the preceding layer, and the predicted peak position corresponding to the following layer is used as the initial center position of the single-peak response of the following layer. The peak width of the target response peak corresponding to the preceding layer at the previous measurement point is used as the initial peak width of the single-peak response of the preceding layer, and the peak width of the target response peak corresponding to the following layer at the previous measurement point is used as the initial peak width of the single-peak response of the following layer. The response intensity near each predicted center position in the local morphology of the synthetic peak at the current measurement point is used as the initial peak height of the corresponding single-peak response.

[0097] The following constraints are applied to the single-peak responses of the preceding and following strata: the center position of the preceding stratum must be smaller than that of the following stratum; the deviation of the center position of the preceding stratum from the corresponding predicted peak position must not exceed the allowable peak position deviation threshold; the deviation of the center position of the following stratum from the corresponding predicted peak position must not exceed the allowable peak position deviation threshold; the distance between the center positions of the preceding and following strata must not be less than the minimum resolvable distance between strata; the peak width of the single-peak response of the preceding stratum must not exceed three standard deviations above and below the mean peak width of the stable separated samples of the preceding stratum; the peak width of the single-peak response of the following stratum must not exceed three standard deviations above and below the mean peak width of the stable separated samples of the following stratum; the peak heights of both the single-peak responses of the preceding and following strata are positive; and the local background response remains continuous and monotonic within the local separation window. Through these constraints, the separation results conform to both the stratum continuity relationship obtained from the previous measurement point and the actual shape of the composite response at the current measurement point.

[0098] Under the above constraints, the parameters of the single-peak response of the preceding layer, the single-peak response of the following layer, and the local background response are jointly fitted to minimize the sum of squared residuals between the composite response obtained by superimposing the three and the local morphology of the obtained composite peak. After fitting, the center position of the single-peak response of the preceding layer is taken as the independent peak position after the recovery of the preceding layer, and the center position of the single-peak response of the following layer is taken as the independent peak position after the recovery of the following layer. The peak width of the single-peak response of the preceding layer is taken as the independent peak width after the recovery of the preceding layer, and the peak width of the single-peak response of the following layer is taken as the independent peak width after the recovery of the following layer.

[0099] The recovered independent peak positions and widths of the preceding layers are used to replace the composite response results corresponding to the preceding layers in the target response peak sequence of the current measuring point. Similarly, the recovered independent peak positions and widths of the following layers are used to replace the composite response results corresponding to the following layers in the target response peak sequence of the current measuring point, while keeping the original layer numbers unchanged. This generates the target response peak sequence after overlapping peak separation correction. The corrected target response peak sequence is then input into the subsequent measuring point processing, serving as the basis for the transmission of the predicted layer center position and predicted interlayer spacing for the next measuring point.

[0100] The peak position allowable deviation threshold is obtained by statistically analyzing the peak position variation between adjacent measurement points in the same layer of the stable separation measurement point sample; the normal peak width range is obtained by statistically analyzing the peak width distribution of the corresponding layer in the stable separation measurement point sample; the minimum resolvable spacing between layers is obtained by calibration using a standard dual-interface transparent sample; the width of the local separation window is preferably 1.5 times the minimum resolvable spacing between layers.

[0101] Step S4: Based on the corrected target response peak sequence, determine the front boundary layer and the back boundary layer of the material segment to be tested, and calculate the change in the peak position corresponding to the current measuring point relative to the peak position corresponding to the previous measuring point; when the change falls within the preset allowable range, perform thickness calculation; otherwise, return to steps S2 to S3 to re-execute the layer assignment matching and separation correction.

[0102] In some implementation methods, the implementation steps include:

[0103] Obtain the target response peak sequence of the current measuring point after separation and correction in step S3, read the corrected peak position corresponding to the front boundary layer and the corrected peak position corresponding to the back boundary layer from it, and then read the preceding peak position corresponding to the front boundary layer and the back boundary layer from the target response peak sequence of the previous measuring point that has been confirmed.

[0104] The changes in the peak position of the current measuring point relative to the peak position of the previous measuring point are calculated separately, as well as the changes in the peak position of the current measuring point relative to the peak position of the previous measuring point. The changes in the peak position of the current measuring point relative to the peak position of the previous measuring point are calculated separately. The changes in the peak position of the current measuring point are the absolute values ​​of the difference between the corrected peak position of the current measuring point and the peak position of the previous measuring point. The changes in the peak position of the current measuring point are the absolute values ​​of the difference between the corrected peak position of the current measuring point and the peak position of the previous measuring point. These are used to characterize the magnitude of the change in the stratigraphic position of the current measuring point relative to the previous measuring point.

[0105] The change in the front boundary layer is compared with the allowable range threshold for the change in the front boundary layer, and the change in the rear boundary layer is compared with the allowable range threshold for the change in the rear boundary layer. When the change in the front boundary layer is not greater than the allowable range threshold for the change in the front boundary layer, and the change in the rear boundary layer is not greater than the allowable range threshold for the change in the rear boundary layer, it is determined that the front and rear boundary layers of the current measuring point meet the thickness calculation conditions, and thickness calculation is allowed to proceed directly. When the change in the front boundary layer is greater than the allowable range threshold for the change in the front boundary layer, or the change in the rear boundary layer is greater than the allowable range threshold for the change in the rear boundary layer, it is determined that there is a risk of abnormal layer jump at the current measuring point, and thickness calculation is not performed directly.

[0106] The methods for obtaining the allowable range thresholds for front boundary layer level changes and rear boundary layer level changes include:

[0107] During continuous scanning of a transparent object, measurement points with stable peak separation and stable layer order are pre-selected as stable separation measurement point samples. The peak position change between adjacent measurement points in the same layer is statistically analyzed to obtain a sample set of peak position change in the previous layer and a sample set of peak position change in the subsequent layer. The mean and standard deviation of the sample set of peak position change in the previous layer are calculated, and the mean plus three times the standard deviation is used as the threshold of the allowable range of change in the previous layer. The mean and standard deviation of the sample set of peak position change in the subsequent layer are calculated, and the mean plus three times the standard deviation is used as the threshold of the allowable range of change in the subsequent layer.

[0108] It should be noted that the stable separation measurement point sample is preferably selected from a set of measurement points in which the peak spacing between candidate response peaks is greater than the minimum resolvable spacing between layers and the order of adjacent layers remains unchanged in multiple consecutive measurement points.

[0109] When direct entry into thickness calculation is allowed, the pre-layer correction peak position and the post-layer correction peak position are read. Based on the peak position to axial position calibration relationship pre-established by the dispersive confocal system, the pre-layer correction peak position is converted into the pre-layer axial position, and the post-layer correction peak position is converted into the post-layer axial position. Then, based on the axial interval between the pre-layer axial position and the post-layer axial position, combined with the refractive index parameter corresponding to the current transparent material segment, the actual thickness value of the current measuring point is calculated.

[0110] The calibration relationship between the peak position and the axial position is obtained by calibration using a standard step sample or a standard thickness sample; the actual thickness value can be obtained by dividing the difference between the axial position of the subsequent layer and the axial position of the preceding layer by the corresponding refractive index, or by obtaining the thickness conversion function obtained by calibration using a standard transparent sample.

[0111] Once all measurement points have been processed, the final thickness value corresponding to each measurement point is output according to the scanning direction, forming a continuous thickness result of the transparent object being measured.

[0112] The thickness conversion function can be obtained by calibrating multiple sets of standard transparent samples with known thicknesses to establish the correspondence between peak position difference and actual thickness.

[0113] Through the above steps, the interface identification, abnormal peak correction, and thickness calculation in the continuous thickness measurement process of transparent objects no longer rely on the instantaneous peak value determination of a single measurement point. Instead, they are based on the layer sequence transmission between continuous measurement points, peak position change constraints, abnormal proximity state identification, and restricted separation of overlapping peaks. This enables the maintenance of the corresponding stability of the layers before and after during dynamic scanning, suppresses layer loss and peak sequence misjudgment caused by peak merging, and corrects abnormal jump measurement points before thickness calculation, thereby improving the continuity, accuracy, and anti-jump capability of the thickness results of transparent objects.

[0114] Example 2

[0115] Please see Figure 3 This invention provides a technical solution: a spectral confocal multi-peak screening thickness measurement system for transparent test objects, used to implement the aforementioned spectral confocal multi-peak screening thickness measurement method for transparent test objects, the system comprising:

[0116] The spectral response acquisition module sequentially acquires the spectral response curves of each measuring point along the scanning direction during the continuous thickness measurement of the transparent test object. It establishes a continuous correspondence between the spectral response curves of each measuring point according to the sampling order, extracts the peak position and peak width of all candidate response peaks of each measuring point, and constructs the candidate response peak state set of the current measuring point.

[0117] The layer attribution matching module, based on the candidate response peak state set, introduces the interface layer order and layer spacing already confirmed at the previous measurement point into the current measurement point, performs layer attribution matching on each candidate response peak at the current measurement point, obtains the target response peak sequence, and identifies adjacent layers with abnormally close states in the target response peak sequence.

[0118] The overlapping peak separation correction module identifies the target to be separated from the target response peak sequence in an abnormally close state, establishes a local separation window based on the identified target to be separated, obtains the local morphology of the synthesized peak, performs fitting correction, and generates the corrected target response peak sequence.

[0119] The thickness calculation module determines the front and back boundary layers of the material segment under test based on the corrected target response peak sequence, and calculates the change in the peak position of the current measuring point relative to the peak position of the previous measuring point. When the change falls within the preset allowable range, the thickness is calculated; otherwise, it is sent back to the layer assignment matching module for re-execution.

[0120] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for screening and measuring the thickness of a transparent test object using spectral confocal multi-peak screening, characterized in that, include: Step S1: During the continuous thickness measurement of the transparent object, the spectral response curves of each measurement point are sequentially acquired along the scanning direction, and a continuous correspondence is established between the spectral response curves of each measurement point according to the sampling order. The peak position and peak width of all candidate response peaks of each measurement point are extracted to construct the candidate response peak state set of the current measurement point. Step S2: Based on the candidate response peak state set, the interface layer order and layer spacing already confirmed at the previous measurement point are introduced into the current measurement point. Layer assignment matching is performed on each candidate response peak at the current measurement point to obtain the target response peak sequence, and the adjacent layers with abnormally close states in the target response peak sequence are identified. Step S3: For the target response peak sequence in the abnormal proximity state, determine the object to be separated, establish a local separation window based on the determined object to be separated, obtain the local shape of the synthetic peak, perform fitting correction, and generate the corrected target response peak sequence. Step S4: Based on the corrected target response peak sequence, determine the front boundary layer and the back boundary layer of the material segment to be tested, and calculate the change in the peak position corresponding to the current measuring point relative to the peak position corresponding to the previous measuring point; when the change falls within the preset allowable range, perform thickness calculation; otherwise, return to steps S2 to S3 and re-execute.

2. The method for screening and measuring thickness of a transparent test object using spectral confocal multi-peak screening according to claim 1, characterized in that, The method for extracting all candidate response peaks for each measurement point includes: The local maxima are searched point by point along the wavelength coordinates of the standard spectral response curve of the current measurement point. The response structures that satisfy the condition that the local intensity is higher than the adjacent sampling points on both sides and the peak width reaches the preset lower limit are identified as candidate response peaks. After the search is completed, the set of all candidate response peaks corresponding to the current measurement point is obtained.

3. The method for screening and measuring thickness of a transparent test object using spectral confocal multi-peak screening according to claim 2, characterized in that, The method for extracting the peak position of the response peak includes: For each candidate response peak in the current measurement point, take the peak of the candidate response peak as the center, select two boundary points on the left and right sides of the peak peak where the response intensity drops to half of the peak intensity, and determine the wavelength interval between the two boundary points as the analysis window. Perform continuous peak shape fitting on the response data in the analysis window, and take the wavelength position corresponding to the maximum value of the fitted curve as the peak position of the candidate response peak. When a plateau region exists at the local peak, the center position symmetrically located at both ends of the plateau region is taken as the peak position.

4. The method for screening and measuring thickness of a transparent test object using spectral confocal multi-peak screening according to claim 3, characterized in that, The method for extracting the peak width of the response peak includes: Using the local valley positions on the left and right sides of the current candidate response peak as the left and right boundaries, a local baseline is established between the left and right boundaries; the fitted response intensity corresponding to the peak position of the candidate response peak is read, and the baseline response intensity corresponding to the peak position on the local baseline is read. The difference between the fitted response intensity and the baseline response intensity is determined as the net peak height of the candidate response peak. The half-peak height intensity is determined based on the net peak height, and the half-peak height intensity is the sum of the reference response intensity corresponding to the local baseline at the peak position and half of the net peak height; Search for the positions where the standard spectral response curve reaches the half-peak high intensity on the left and right sides of the candidate response peak, respectively, to obtain the left half-peak high intersection point and the right half-peak high intersection point. The difference between the wavelength corresponding to the left half-peak high intersection point and the wavelength corresponding to the right half-peak high intersection point is determined as the peak width of the candidate response peak.

5. The method for screening and measuring thickness of a transparent test object using spectral confocal multi-peak screening according to claim 1, characterized in that, The methods for obtaining the target response peak sequence at the current measurement point include: Based on the target response peak sequence already confirmed at the previous measurement points, the peak distribution of each interface layer at the current measurement point is predicted to obtain the predicted peak position and the predicted interlayer spacing. The candidate response peaks at the current measurement point are matched with the predicted peak positions and the predicted interlayer spacing, and the sequence of target response peaks corresponding to each interface layer at the current measurement point is determined based on the layer order relationship.

6. The method for screening and measuring thickness of a transparent test object using spectral confocal multi-peak screening according to claim 5, characterized in that, The method for predicting the peak distribution of each interface layer at the current measuring point includes: Obtain the candidate response peak set for the current measurement point and the confirmed target response peak sequence for the previous measurement point; for each layer in the previous measurement point, read the peak position of its corresponding target response peak, and obtain the predicted peak position of the current measurement point based on the peak position difference of the corresponding target response peak between the previous measurement point and the two previous measurement points. For two adjacent layers in the previous measurement point, calculate the peak position difference of their corresponding target response peaks to obtain the actual interlayer spacing of the previous measurement point. Based on the change in interlayer spacing between the previous measurement point and the two previous measurement points, obtain the predicted interlayer spacing of adjacent layers in the current measurement point.

7. The method for screening and measuring thickness of a transparent test object using spectral confocal multi-peak screening according to claim 5, characterized in that, The method for determining the target response peak sequence corresponding to each interface layer at the current measuring point based on the hierarchical order relationship includes: For each candidate response peak in the current measurement point, calculate its peak position deviation relative to the predicted peak position of each layer. When the peak position deviation of a candidate response peak relative to a certain layer is not greater than the peak position deviation threshold, include the candidate response peak in the candidate peak set of that layer. Perform order-preserving matching on all layers to make the peak position of the candidate response peak assigned to the previous layer in the current measurement point smaller than the peak position of the candidate response peak assigned to the next layer. Use the minimum sum of peak position deviations of all assigned candidate response peaks as the matching criterion to determine the target response peak sequence of the current measurement point.

8. The method for screening and measuring thickness of a transparent test object using spectral confocal multi-peak screening according to claim 1, characterized in that, Methods for identifying abnormally close adjacent layers in a target response peak sequence include: For any pair of adjacent layers in the target response peak sequence of the current measurement point, calculate the current actual layer spacing and compare the current actual layer spacing with the corresponding predicted layer spacing to obtain the layer spacing compression ratio. Read the peak width of the two adjacent target response peaks and calculate the peak width occupancy ratio. When a pair of adjacent layers simultaneously satisfies that the layer spacing compression ratio is not less than a preset compression threshold and the peak width occupancy ratio is not less than a preset broadening threshold, it is determined that the pair of adjacent layers is in an abnormally close state.

9. The method for screening and measuring thickness of a transparent test object using spectral confocal multi-peak screening according to claim 8, characterized in that, The method for determining the object to be separated includes: Two adjacent layers in an abnormally close state are designated as the preceding layer and the following layer. The predicted peak position corresponding to the preceding layer, the predicted peak position corresponding to the following layer, and the corresponding predicted interlayer spacing are read synchronously from the previous measurement point. The composite response bands corresponding to the two adjacent layers in the current measurement point are also read. If the two adjacent layers in the current measurement point have already shown a single composite peak, the band containing the single composite peak is directly identified as the object to be separated. If the two adjacent layers in the current measurement point still show two peaks, but the interlayer spacing compression ratio is not less than the preset compression threshold and the peak width occupancy ratio is not less than the preset broadening threshold, then the two peaks together with the bands in between are identified as the objects to be separated.

10. A method for screening and measuring the thickness of a transparent test object using spectral confocal multi-peak screening according to claim 1 or 9, characterized in that, The method for obtaining the local morphology of the synthetic peak includes: determining a local separation window on the standard spectral response curve of the current measurement point based on the predicted peak position of the previous layer and the predicted peak position of the subsequent layer, and extracting the response intensity distribution within the window as the local morphology of the synthetic peak.

11. The method for screening and measuring thickness of a transparent test object using spectral confocal multi-peak screening according to claim 10, characterized in that, The method for generating the corrected target response peak sequence includes: The local morphology of the synthesized peak is constructed as a superposition model of the single-peak response of the front layer, the single-peak response of the back layer, and the background response; Using the predicted peak position of the previous layer, the predicted peak position of the next layer, and the peak width of the target response peak of the previous measuring point as initial parameters, the superposition model is jointly fitted under the constraints of peak position deviation, minimum separation distance between peaks, and peak width range to obtain the independent peak position and independent peak width of the previous layer and the independent peak position and independent peak width of the next layer. By using the independent peak positions and widths of the preceding and following layers, the original peak positions and widths corresponding to the preceding and following layers in the target response peak sequence of the current measuring point are replaced, and the corrected target response peak sequence is generated.

12. The method for screening and measuring thickness of a transparent test object using spectral confocal multi-peak screening according to claim 1, characterized in that, The method for calculating the thickness includes: Read the peak positions of the preceding and following layers, and based on the pre-established peak-to-axial position calibration relationship of the dispersive confocal system, convert the preceding layer correction peak position into the preceding layer axial position and the following layer correction peak position into the following layer axial position; then, based on the axial interval between the preceding and following layer axial positions and the refractive index parameter corresponding to the current transparent material segment, calculate the actual thickness value of the current measuring point.

13. A spectral confocal multi-peak screening thickness measurement system for transparent test objects, used to implement the spectral confocal multi-peak screening thickness measurement method for transparent test objects according to any one of claims 1-12, characterized in that, The system includes: The spectral response acquisition module sequentially acquires the spectral response curves of each measuring point along the scanning direction during the continuous thickness measurement of the transparent test object. It establishes a continuous correspondence between the spectral response curves of each measuring point according to the sampling order, extracts the peak position and peak width of all candidate response peaks of each measuring point, and constructs the candidate response peak state set of the current measuring point. The layer attribution matching module, based on the candidate response peak state set, introduces the interface layer order and layer spacing already confirmed at the previous measurement point into the current measurement point, performs layer attribution matching on each candidate response peak at the current measurement point, obtains the target response peak sequence, and identifies adjacent layers with abnormally close states in the target response peak sequence. The overlapping peak separation correction module identifies the target to be separated from the target response peak sequence in an abnormally close state, establishes a local separation window based on the identified target to be separated, obtains the local morphology of the synthesized peak, performs fitting correction, and generates the corrected target response peak sequence. The thickness calculation module determines the front and back boundary layers of the material segment under test based on the corrected target response peak sequence, and calculates the change in the peak position of the current measuring point relative to the peak position of the previous measuring point. When the change falls within the preset allowable range, the thickness is calculated; otherwise, it is sent back to the layer assignment matching module for re-execution.

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