Detection method, system and correction method for transparent materials

Abstract

The present invention discloses a detection method, a system, and a correction method for a transparent material. The detection method includes: matching the correspondence between the number of peaks in the spectrograms at each position on the scanning line and the number of peaks corresponding to each defect type; identifying the defect types with the same number of peaks among the defect types; and the method adopted is to determine whether the change amount of the measurement height data corresponding to the second peak wavelength in the spectrograms at adjacent positions on the scanning line is within the allowable distance error range, so as to distinguish the defect types with the same number of peaks. The present invention can accurately identify the defect types at each position, and compensate the measurement height data corresponding to each peak wavelength in the spectrogram at the position where the defect type is located according to the defect type, so as to obtain the true measurement height data on the surface and inside of the transparent material, improve the accuracy of data detection on the surface and inside of the transparent material, and facilitate the accurate identification of the quality of the transparent material.

Description

Technical Field

[0001] The present invention belongs to the technical field of spectral confocal, and relates to a detection method, a system, and a correction method for transparent materials. Background Art

[0002] The line spectral confocal sensor is a high-precision, non-contact measurement technology, which is widely used in the fields of industrial automation, precision engineering, and scientific research. It can detect the thickness of transparent materials, and the thickness of transparent materials is directly related to the quality and performance of products. For example, it can detect the thickness of mobile phone screens, films, and transparent silica gels with high precision requirements.

[0003] When the line spectral confocal sensor detects the thickness of a single-layer transparent material, there are situations where there are no less than two peaks in the spectrogram at the detection position, and it is impossible to accurately determine the thickness of the transparent material and the type of defects existing inside the transparent material based on the peaks in the spectrogram. Due to the influence of internal defects of the transparent material, the height data of the transparent material detection deviates from its true data, and it is impossible to truly reflect the data information of internal defects and the surface topography data information of the transparent material. At the same time, it is impossible to perform targeted correction on the measured height data corresponding to different peak wavelengths according to different defect types, and it is impossible to accurately determine the coverage area corresponding to each defect type, thereby resulting in inaccuracies in the detection of internal and surface data of the transparent material, seriously affecting the quality detection accuracy of transparent materials with high precision requirements.

[0004] Therefore, in order to solve the above problems, the present invention provides a detection method, a system, and a correction method for transparent materials. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above problems existing in the prior art, and provides a detection method, a system, and a correction method for transparent materials.

[0006] To achieve the above technical purpose and reach the above technical effect, the present invention is realized through the following technical solutions:

[0007] A detection method for transparent materials, controlling a line spectral confocal sensor to continuously scan the transparent material along the line scan direction to obtain spectrograms at each position on the scan line, including:

[0008] Matching the correspondence between the number of peaks in the spectrograms at each position on the scan line and the number of peaks corresponding to each defect type to preliminarily determine the defect type of the transparent material at each position;

[0009] Identifying each defect type with the same number of peaks among the defect types;

[0010] The identification method for each defect type with the same number of wave peaks among the defect types is to determine whether the change amount of the measured height data corresponding to the second peak wavelength in the spectrogram at adjacent positions on the scan line is within the allowable distance error range, so as to distinguish the defect types at each position where the number of wave peaks is equal to the set number of wave peaks;

[0011] Among them, the defect types include bubbles inside the transparent material, non-transparent impurities, and grooves at the bottom;

[0012] The scan line is the line formed by the position coordinates on the upper surface of the transparent material covered by the line light source;

[0013] In the spectrogram, the peak wavelengths are numbered according to the order of light intensity. For the relationship between the peak wavelengths at any position, with the loss of light, in the same spectrogram, the light intensity corresponding to each peak decreases as the wavelength increases.

[0014] The identification method for each defect type with the same number of wave peaks among the defect types includes analyzing the light intensity ratio of the first peak wavelength and the second peak wavelength in the spectrogram at the same position on the scan line;

[0015] Determine the relationship between the light intensity ratio and the set threshold range to distinguish the defect types at each position where the number of wave peaks is equal to the set number of wave peaks.

[0016] The detection system for transparent materials includes: a defect identification module that extracts the number of wave peaks in the spectrogram at each position on the scan line and matches it with the number of wave peaks corresponding to each defect type to preliminarily determine the defect type of the transparent material at each position;

[0017] A data analysis module that determines whether the change amount of the measured height data corresponding to the second peak wavelength in the spectrogram at adjacent positions on the scan line is within the allowable distance error range to distinguish the defect types at each position where the number of wave peaks is equal to the set number of wave peaks. Among them, the scan line is the line formed by the position coordinates on the upper surface of the transparent material covered by the line light source.

[0018] The data analysis module includes analyzing the light intensity ratio of the first peak wavelength and the second peak wavelength in the spectrogram at the same position on the scan line;

[0019] Determine the relationship between the light intensity ratio and the set threshold range to distinguish the defect types at each position where the number of wave peaks is equal to the set number of wave peaks.

[0020] The correction method based on the defect type includes:

[0021] Extract the height data of the focused light of different wavelengths after dispersion by the dispersion lens group, for obtaining the height data of the convergence of the light of each wavelength along the optical axis direction in the propagation medium where the dispersion lens group is located;

[0022] Train the standard incident angles of the peak wavelengths at each position in the plane formed by the scanning line and the optical axis, so as to establish a mapping relationship between each wavelength and the standard incident angle, where the standard incident angle is the angle between the light ray and the normal line perpendicular to the upper surface of the standard sample when the light of different wavelengths is incident on the surface of the standard sample after passing through the dispersion lens group, when the optical axis of the line spectral confocal sensor is perpendicular to the upper surface of the standard sample;

[0023] Analyze the refractive index of the propagation medium through which the light ray of the peak wavelength passes during the convergence process, the incident angle of the wavelength, and the height data of the convergence of the wavelength along the optical axis direction in the propagation medium where the dispersion lens group is located, to obtain the measurement height compensation amount corresponding to the peak wavelength in the spectrogram at each position.

[0024] A computer-readable storage medium, the computer program, when the computer program is executed by a processor, implements the above correction method.

[0025] The beneficial effects of the present invention are:

[0026] (1) The present invention matches the number of wave peaks at each position with the number of wave peaks corresponding to each defect type to preliminarily determine the defect type of the transparent material, and further identifies the defect types with the same number of wave peaks in the defect type. By adopting two-level defect type identification, the defect type at each position can be accurately identified, providing a basis for later correcting the measurement height of each peak wavelength according to different defect types.

[0027] (2) The present invention analyzes the light intensity ratio corresponding to the first peak wavelength and the second peak wavelength in the same spectrogram to identify multiple defect types with the same number of wave peaks. In addition, by analyzing the change amount of the measurement height data corresponding to two adjacent second peak wavelengths in the scanning line direction, the same purpose of identifying multiple defect types with the same number of wave peaks is achieved, which can reduce the inaccuracy of defect type identification based only on the number of wave peaks and improve the accuracy of defect identification.

[0028] The present invention adaptively corrects the measured heights corresponding to different peak wavelengths at the same position under the defect type identified, and there are differences in the correction of the measured heights corresponding to the same peak wavelength under different defect types. Combining the defect type and the order in which the peaks appear in the spectrogram, compensates the measured height data corresponding to each peak wavelength, and obtains the true measured height data corresponding to each peak wavelength in the spectrogram under each defect type, reducing the error in the detection of height data, improving the accuracy of the detection of the measured height data corresponding to each peak wavelength, and eliminating the influence of the refractive index and internal defects of the transparent material on the measurement.

[0029] (4) The present invention compensates the measured height data corresponding to the peak wavelengths at the same position under each defect type in the transparent material, eliminates the interference of different defects on the measurement data. Through the compensated height data, not only can the thickness of the transparent material be obtained, but also the position, coverage area of each defect type in the transparent material, and the depth information of the defect type along the thickness direction of the transparent material can be obtained, realizing the accurate identification of the internal defect size of the transparent material, meeting the high-precision measurement requirements, providing reliable data for the quality inspection of the transparent material, and improving the accuracy of the quality inspection of the transparent material. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0031] Figure 1 is a flowchart of a detection method in the present invention;

[0032] Figure 2 is a flowchart of another detection method in the present invention;

[0033] Figure 3 is a schematic diagram of the detection and correction method in the present invention;

[0034] Figure 4 is a schematic diagram of the detection of bubbles in the present invention;

[0035] Figure 5 is a flowchart of the schematic diagram of the detection of the groove on the lower surface of the transparent material in the present invention;

[0036] Figure 6 is a schematic diagram of the detection of the critical width of bubbles in the present invention;

[0037] Figure 7 is a schematic diagram of the detection of less than the critical width of bubbles in the present invention;

[0038] Figure 8It is a schematic diagram for detecting non-transparent impurities in the present invention;

[0039] Figure 9 It is a schematic diagram for detecting the critical width of non-transparent impurities in the present invention. Specific embodiments

[0040] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0041] This application uses a line spectral confocal sensor to detect transparent materials. While obtaining the surface topography of the transparent materials, it is convenient to adjust the defects inside the transparent materials, meeting the detection requirements for transparent materials.

[0042] As Figure 1 shown, this embodiment first provides a method for detecting transparent materials, controlling the line spectral confocal sensor to continuously scan the transparent materials along the line scan direction to obtain spectrograms at various positions on the transparent materials, including:

[0043] Step 1: Match the correspondence between the number of wave peaks in the spectrograms at various positions on the scan line and the number of wave peaks corresponding to each defect type to preliminarily determine the defect type of the transparent materials at various positions;

[0044] When the object to be measured is at a certain position within the measurement range of the line spectral confocal sensor, only light of a specific wavelength is focused on the measured surface at this position. The light of the specific wavelength can be reflected back to the fiber coupler and enter the spectrometer because it meets the confocal condition, while the light of other wavelengths is out of focus on the surface of the object to be measured, and the distribution of the reflected light at the light source is much larger than the size that the spectrometer can receive. Therefore, most of the light cannot enter the spectrometer. By the wavelength value at the maximum light intensity in the spectrogram, the distance value corresponding to the target can be measured.

[0045] After the line light source in the line spectral confocal sensor passes through the dispersion lens group, the light is dispersed and converges into the plane formed by the scan line of the line spectral confocal sensor and the optical axis. When the line spectral confocal sensor scans the transparent materials along the line scan direction, spectrograms at various positions on the scan line are obtained, and there are at least two wave peaks in the spectrograms at various positions.

[0046] The transparent materials can be glass, transparent silica gel, transparent resin materials, transparent films, etc.

[0047] Extract the number of peaks in the spectrogram at any position on the transparent material, and judge the type of defect based on the number of peaks appearing in the spectrogram at the coordinate position. In the same spectrogram, the number of peaks is m. According to the order of the light intensities corresponding to each peak wavelength from large to small, the peak wavelengths are numbered as the first peak wavelength, the second peak wavelength... the m-th peak wavelength.

[0048] When the plane formed by the scanning line of the line spectral confocal sensor and the optical axis intersects with the bubble in the transparent material, in the spectrogram at the position where the measurement line parallel to the optical axis and passing through the bubble intersects with the upper surface of the transparent material, four peaks appear. The light rays corresponding to these four peak wavelengths converge to the intersection of the measurement line and the upper surface of the glass, the intersection of the measurement line and the upper surface of the bubble, the intersection of the measurement line and the lower surface of the bubble, and the intersection of the measurement line and the lower surface of the glass respectively. Among them, the measurement line is parallel to the optical axis and is located in the plane formed by the scanning line of the line spectral confocal sensor and the optical axis. Lights of different wavelengths converge to different heights on the measurement line.

[0049] When the plane formed by the scanning line of the line spectral confocal sensor and the optical axis intersects with the groove on the lower surface of the glass, in the spectrogram at the position where the measurement line parallel to the optical axis and passing through the groove intersects with the upper surface of the transparent material, three peaks appear. The light rays corresponding to the above three peak wavelengths converge to the intersection of the measurement line and the upper surface of the glass, the intersection of the measurement line and the groove on the lower surface of the glass, and the intersection of the measurement line and the surface of the stage supporting the glass respectively.

[0050] When the plane formed by the scanning line of the line spectral confocal sensor and the optical axis intersects with the non-transparent impurity in the transparent material, in the spectrogram at the position where the measurement line parallel to the optical axis and perpendicular to the transparent material intersects with the upper surface of the transparent material, three peaks or two peaks appear. If there are three peaks, the light rays corresponding to the three peak wavelengths converge to the intersection of the measurement line and the upper surface of the glass, the intersection of the measurement line and the non-transparent impurity, and the intersection of the measurement line and the lower surface of the glass respectively; if there are two peaks, the light rays corresponding to the two peak wavelengths converge to the intersection of the measurement line and the upper surface of the glass, the intersection of the measurement line and the non-transparent impurity.

[0051] When the plane formed by the scanning line of the line spectral confocal sensor and the optical axis intersects with both the bubble in the glass and the groove on the lower surface of the glass at the same time, in the spectrogram at the position where the measurement line parallel to the optical axis and passing through the bubble and the groove intersects with the upper surface of the transparent material, five peaks appear.

[0052] Step 2: Identify each type of defect with the same number of peaks among the types of defects.

[0053] Affected by the defect type, the number of peaks in the spectrogram at the same position may be the same, making it impossible to further distinguish the defect types with the same number of peaks. For example, in the cases of a groove on the lower surface of the glass and non-transparent impurities inside the glass, in the spectrogram at the position where the measurement line of any one of the two defect types intersects the upper surface of the glass, the number of peaks is equal to 3 in both cases.

[0054] The identification method for each defect type with the same number of peaks includes:

[0055] Judging whether the change amount of the measurement height data corresponding to the second peak wavelength in the spectrograms at adjacent positions on the scan line is within the allowable distance error range to distinguish the defect types at each position when the number of peaks is equal to the set number of peaks, where the set number of peaks is 3;

[0056] Among them, the defect types include bubbles inside the transparent material, non-transparent impurities, and grooves at the bottom;

[0057] The scan line is the line formed by the position coordinates on the upper surface of the transparent material covered by the line light source.

[0058] The detection system for the transparent material includes: a defect identification module that extracts the number of peaks in the spectrograms at each position on the scan line and matches it with the number of peaks corresponding to each defect type to preliminarily determine the defect type of the transparent material at each position;

[0059] A data analysis module that judges whether the change amount of the measurement height data corresponding to the second peak wavelength in the spectrograms at adjacent positions on the scan line is within the allowable distance error range to distinguish the defect types at each position when the number of peaks is equal to the set number of peaks, where the scan line is the line formed by the position coordinates on the upper surface of the transparent material covered by the line light source;

[0060] A data processing module that processes the refractive index of the propagation medium through which the light of each peak wavelength passes during the convergence process, the incident angle of the wavelength, and the height data of the wavelength converging along the optical axis direction in the propagation medium where the dispersion lens group is located to obtain the measurement height compensation amount corresponding to the peak wavelength in the spectrogram at each position.

[0061] Embodiment 1

[0062] For defect types with the same number of peaks, it is difficult to accurately identify the defect types only by the number of peaks. When the number of peaks in the spectrogram at each position in the transparent material is equal to the set number of peaks, further identify the defect type of the glass, such as Figure 2 As shown, the following method is adopted:

[0063] Step 1.1: Extract the light intensities I1 and I2 corresponding to the first peak wavelength and the second peak wavelength in the spectrogram at the same position.

[0064] Step 1.2: Analyze the light intensity ratio of the first peak wavelength and the second peak wavelength. The light intensity ratio is equal to the ratio between the light intensity corresponding to the second peak wavelength and the light intensity corresponding to the first peak wavelength, and the light intensity ratio I2 / I1 < 1.

[0065] Step 1.3: Determine whether the light intensity ratio is within the set threshold range. If it is within the set threshold range, the defect type at the convergence of the second peak wavelength is that there are non-transparent impurities inside the transparent material. If it is not within the set threshold range, the defect type at the convergence of the second peak wavelength is that there are grooves on the lower surface of the transparent material. By using the above method, the defect types with the same number of wave peaks can be further refined to identify the defect types.

[0066] Among them, the set threshold range is the numerical range interval formed by the ratio between the light intensity corresponding to the wavelength of the light converging to the surface of the non-transparent impurity and the light intensity corresponding to the first peak wavelength.

[0067] The non-transparent impurity hinders the refraction of the light converging to the surface of the non-transparent impurity, increasing the intensity of the reflected light. While there are grooves on the lower surface of the transparent material, causing part of the light converging to the grooves on the lower surface of the transparent material to be reflected and part to be refracted. Therefore, the light intensity ratio at the non-transparent impurity is greater than the light intensity ratio at the grooves on the lower surface of the transparent material.

[0068] Among them, the detection system for the transparent material includes: a defect identification module that extracts the number of wave peaks in the spectrogram at each position on the scan line and matches it with the number of wave peaks corresponding to each defect type to preliminarily determine the defect type of the transparent material at each position.

[0069] A data analysis module that analyzes the light intensity ratio of the first peak wavelength and the second peak wavelength in the spectrogram at the same position on the scan line; determines the relationship between the light intensity ratio and the set threshold range to distinguish the defect types at each position where the number of wave peaks is equal to the set number of wave peaks.

[0070] The data processing module processes the refractive index of the propagation medium through which the light of each peak wavelength passes during the convergence process, the incident angle of the wavelength, and the height data of the wavelength converging along the optical axis direction in the propagation medium where the dispersion lens group is located to obtain the measurement height compensation amount corresponding to the peak wavelength in the spectrogram at each position.

[0071] Example 2

[0072] Compared with Example 1, when the number of peaks in the spectrogram at each position in the transparent material is equal to the set number of peaks, the defect type at this position is identified. In this embodiment, another identification method is adopted to further identify the defect type of the glass, and the following method is used:

[0073] Obtain the number of peaks at each position on the scan line, and compensate the measurement height data corresponding to the second peak wavelength. Determine whether the change amount of the measurement height data corresponding to two adjacent second peak wavelengths on the scan line is within the allowable distance error range. If the change amount of the measurement height data corresponding to two adjacent second peak wavelengths along the scan line is within the allowable distance error range, it indicates that the detected glass defect type is a groove on the lower surface of the glass. If there is a change amount of the measurement height data corresponding to two adjacent second peak wavelengths along the scan line that is greater than the allowable distance error range, it indicates that the detected glass defect type is non-transparent impurities inside the glass.

[0074] During the process of distinguishing the defect type, when the plane formed by the scan line and the optical axis intersects with the non-transparent impurities inside the transparent material, the measurement height data corresponding to the second peak wavelength at each position on the scan line will undergo a jumpy mutation. If the defect type is a groove on the lower surface of the transparent material, the measurement height data corresponding to the second peak wavelength at each position on the scan line will change slowly and continuously.

[0075] Compensate the measurement distance corresponding to the second peak wavelength in the spectrogram to obtain the measurement height deviation △X2 corresponding to the second peak wavelength:

[0076] ;

[0077] The measurement height data corresponding to the compensated second peak wavelength: ;

[0078] Among them, represents the measurement height data corresponding to the second peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located; represents the measurement height data corresponding to the first peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located, and the first peak wavelength converges to the upper surface of the glass; and are both the measurement height data corresponding to the peak wavelength without height compensation; n1 and n2 respectively represent the refractive index of the propagation medium where the dispersion lens group is located and the refractive index of the glass; θ2 represents the standard incident angle of the wavelength λ2 converging to the upper surface of the glass bubble in the propagation medium with a refractive index of n1 where the dispersion lens group is located.

[0079] Example 3

[0080] Such asFigure 3 As shown, based on the defect types identified by the detection method for transparent materials, the defect types are corrected. The correction method includes:

[0081] Step S1: Extract the height data of the light focused at different wavelengths after being dispersed by the dispersive lens group, so as to obtain the measured height data of the light converging along the optical axis direction in the propagation medium where the dispersive lens group is located;

[0082] By adjusting the distance between the dispersive lens group and the upper surface of the transparent material, so that the light of different wavelengths converges to the upper surface of the transparent material, extract the first peak wavelength in the spectrogram, and establish the measured height data of the light of different wavelengths converging along the optical axis direction in the propagation medium where the dispersive lens group is located.

[0083] Select that the upper surface of the standard sample is perpendicular to the optical axis direction. There is no limitation on whether the standard sample is a transparent material or a non-transparent material. Place the lens in the line spectral confocal sensor system in a propagation medium. The lens is provided with a dispersive lens group. Adjust the distance between the lens and the standard sample, and screen the first peak wavelength in the spectrogram at this distance. By continuously adjusting the distance between the lens and the standard sample and the first peak wavelength in the spectrogram at this distance, establish the distances measured along the optical axis direction for each wavelength in the propagation medium.

[0084] Among them, the transparent material is selected as colorless transparent glass. The propagation medium where the dispersive lens group is located can be one of a gas environment and a liquid environment. The gas environment includes air or other gas environments with known refractive indices. The liquid environment includes water, oil, oil-water mixture, and other transparent liquid environments, so that the light dispersed by the dispersive lens group can detect the thickness of the transparent material after passing through the propagation medium where the dispersive lens group is located.

[0085] Step S2: Train the standard incident angles of the peak wavelengths at each position in the plane formed by the scanning line and the optical axis, so as to establish a mapping relationship between each wavelength and the standard incident angle. Among them, the standard incident angle is the angle between the light of different wavelengths and the normal line perpendicular to the upper surface of the standard sample when the light is incident on the surface of the standard sample after passing through the dispersive lens group. The optical axis of the line spectral confocal sensor is perpendicular to the upper surface of the standard sample;

[0086] According to the relationship between the numerical aperture NA and the incident angle θ: NA = nsinθ, where n is the refractive index in the propagation medium where the lens is located, and θ is the maximum incident angle between the light emitted from the optical axis and the optical axis. Since the numerical aperture of the lens is known, obtain the maximum incident angle between the light emitted from the optical axis and the optical axis. This maximum incident angle is the wavelength incident angle corresponding to the minimum measurement height. By adjusting the distance between the lens and the surface of the standard sample and the numerical aperture NA, the incident angles corresponding to each wavelength in the propagation medium where the lens is located can be established.

[0087] If a standard sample with the optical axis of the selected lens perpendicular to the upper surface of the standard sample is used, the incident angles of each wavelength obtained are the standard incident angles.

[0088] Step S3: Analyze the refractive index of the propagation medium through which the light of the peak wavelength passes during the convergence process, the incident angle of the wavelength, and the measured height data of the wavelength converging along the optical axis direction in the propagation medium where the dispersion lens group is located, so as to obtain the measurement height compensation amount corresponding to the peak wavelength in the spectrogram at each position.

[0089] In the propagation medium where the dispersion lens group is located, by adding the measurement height compensation amount corresponding to the peak wavelength in the spectrogram at each position to the height data of the peak wavelength converging along the optical axis direction in the propagation medium where the dispersion lens group is located, the true measurement height data corresponding to the peak wavelength in the spectrogram at each position on the transparent material in the propagation medium where the dispersion lens group is located is obtained.

[0090] Identify the defect types at each position on the scan line, and compensate the measured height data corresponding to the peak wavelength in the spectrogram at each position on the scan line, so as to obtain the true measurement height data corresponding to the peak wavelengths other than the first peak wavelength in the spectrogram at each position on the scan line.

[0091] Specifically, the compensation amounts of the measured height data corresponding to each peak wavelength at the same position are different, and are jointly affected by the defect type at that position and the order of the peak numbers at that position. The measured height data corresponding to the first peak wavelength in the spectrogram does not need to be compensated. The measured height data corresponding to the first peak wavelength is the distance from the lens of the line spectral confocal sensor to the upper surface of the transparent material. Only the measured height data corresponding to the other peak wavelengths in the spectrogram needs to be compensated to eliminate the situation that the measured height data corresponding to each peak wavelength without compensation is less than the true measurement height data due to the difference between the refractive index of the transparent material and the refractive index of the propagation medium where the dispersion lens group is located.

[0092] Affected by the height of the lens of the receiving line spectroscopic confocal sensor from the upper surface of the glass, the thickness of the glass, the types of defects in the glass, and the height of the location of each defect type in the glass, it is impossible to determine the wavelength of the light dispersed by the dispersion lens group converging to the upper surface of the glass, nor can it be determined which specific wavelength converges to the glass surface, the upper surface of the air bubble in the glass, the lower surface of the air bubble in the glass, the bottom of the glass, etc. Furthermore, it is impossible to compensate the measurement data corresponding to each wavelength in advance. Through the peak wavelengths in the spectrogram, according to the mapping relationship between different wavelengths and the measurement height data, the measurement height data of each peak wavelength converging in the air after passing through the dispersion lens group can be established, and the measurement height data corresponding to other peaks except the first peak can be compensated according to the number of peaks, reducing the measurement height error caused by the change in refractive index during the process of light traveling from air to glass, so as to accurately obtain the measurement height data corresponding to each peak.

[0093] Compensate the measurement height data corresponding to the peak wavelengths in the spectrogram at each position on the scan line. Among them, the compensation method for the measurement height data corresponding to each peak wavelength in the spectrogram at each position includes:

[0094] Step W1, determine the type of defect;

[0095] When the number of peaks in the spectrogram at each position on the scan line is the same, it is impossible to identify the type of defect only based on the number of peaks in the spectrogram. The method for determining the type of defect is to judge whether the number of peaks in the spectrogram at each position on the scan line is equal to the set number of peaks. If it is equal to the set number of peaks, analyze whether the light intensity change coefficient between adjacent peaks in the spectrogram at that position is within the allowable threshold error range to distinguish the types of defects at each position when the number of peaks is equal to the set number of peaks. Among them, the set number of peaks includes 3 peak numbers.

[0096] Step W2, extract the height data of each peak wavelength in the spectrogram at that position converging along the optical axis direction in the propagation medium where the dispersion lens group is located;

[0097] Step W3, extract the interference factors affecting the true measurement height data of the peak wavelength. The interference factors include the standard incident angle of the peak wavelength and the refractive index of the propagation medium through which the light of the peak wavelength converges to the defect type;

[0098] Step W4, analyze the measurement height deviation corresponding to the peak wavelength to obtain the measurement height data corresponding to the compensated peak wavelength.

[0099] The compensation amount for the measured distance data corresponding to the second peak wavelength in the spectrogram at each position is applicable to the compensation of the second peak wavelength when there are no defects inside the glass and for any defect type. The any defect type includes the presence of air bubbles inside the glass, grooves on the lower surface of the glass, and non-transparent impurities inside.

[0100] Specifically, compensate the measured distance data corresponding to the second peak wavelength in the spectrogram to obtain the measured height deviation △X2 corresponding to the second peak wavelength:

[0101] ;

[0102] The measured height data corresponding to the compensated second peak wavelength: ;

[0103] Among them, represents the measured height data corresponding to the second peak wavelength in the propagation medium with refractive index n1 where the dispersion lens group is located; represents the measured height data corresponding to the first peak wavelength in the propagation medium with refractive index n1 where the dispersion lens group is located, and the first peak wavelength converges to the upper surface of the glass; and are both the measured height data corresponding to the peak wavelength without height compensation; n1 and n2 respectively represent the refractive index of the propagation medium where the dispersion lens group is located and the refractive index of the glass; θ2 represents the standard incident angle of the wavelength λ2 converging to the upper surface of the glass air bubble in the propagation medium with refractive index n1 where the dispersion lens group is located.

[0104] As the glass defect type is different, the light rays converging to different positions on the glass change after passing through the propagation medium, which affects the compensation amount of the measured height data corresponding to the third peak wavelength. It is necessary to determine the defect type according to the number of wave peaks at each position, and then select the compensation amount matching the peak wavelength according to the defect type.

[0105] The light beam after the dispersion lens group enters the transparent material with a large refractive index from the propagation medium with a small refractive index, and light emission refraction occurs, making the converging position of the light rays with the same wavelength in the propagation medium with a small refractive index located directly above the light rays with the same wavelength in the transparent material with a large refractive index. Therefore, the measured height data of each wavelength light beam is affected by the propagation medium through which the light rays pass during the converging process.

[0106] Perform targeted compensation on the third peak wavelength and other peak wavelengths according to the defect type. Specifically:

[0107] Such as Figure 4As shown, when there are air bubbles in the glass, the number of peaks in the spectrogram at the position of the air bubbles is equal to 4, and the compensation amount of the measured height data corresponding to each peak wavelength in the spectrogram is analyzed.

[0108] The wavelength light converging on the upper surface of the air bubble corresponds to the second peak wavelength in the spectrogram. Compensate the measured height data corresponding to the second peak wavelength, adopt the compensation model of △X2, and obtain the measured height deviation △X2 corresponding to the second peak wavelength and the measured height data corresponding to the compensated second peak wavelength. .

[0109] When the measurement line passes through the air bubble, the wavelength light converging on the lower surface of the air bubble corresponds to the third peak wavelength in the spectrogram; or when the measurement line passes through the groove on the lower surface of the glass, the wavelength light converging on the stage supporting the glass corresponds to the third peak wavelength in the spectrogram. Compensate the measured height data corresponding to the third peak wavelength in the spectrogram to obtain the measured height deviation △X3 corresponding to the third peak wavelength and the compensated measured height data. :

[0110] ;

[0111] The measured height data corresponding to the compensated third peak wavelength: ;

[0112] Among them, L1 represents the distance between the intersection points of the measurement line and the upper surface of the glass and the upper surface of the air bubble respectively. ; θ3 represents the standard incident angle of the wavelength λ3 converging on the lower surface of the glass air bubble in the propagation medium with a refractive index of n1 where the dispersion lens group is located. represents the measured height data corresponding to the first peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located. represents the measured height data corresponding to the third peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located.

[0113] As Figure 5 shown, the compensation amount of the measured height data corresponding to the above-mentioned third peak wavelength and the compensated measured height data are applicable to the measured height data corresponding to the third peak wavelength in the spectrogram when there is a groove on the lower surface of the glass or there are air bubbles inside the glass. When there are air bubbles in the glass, the wavelength light converging on the lower surface of the air bubble corresponds to the third peak wavelength in the spectrogram; when there is a groove on the lower surface of the glass, the wavelength light converging on the stage supporting the glass below the groove corresponds to the third peak wavelength in the spectrogram.

[0114] The measured height data corresponding to the fourth peak wavelength in the spectrogram is also affected by the defect type, causing the propagation medium through which the converging light passes to change during the convergence process. Therefore, adaptive compensation and correction are performed on the fourth peak wavelength under different defect types.

[0115] Specifically: when the measurement line passes through the bubble, the wavelength light converging to the lower surface of the glass corresponds to the fourth peak wavelength in the spectrogram, and the measured distance corresponding to the fourth peak wavelength is compensated to obtain the measured height deviation △X4 corresponding to the fourth peak wavelength: ;

[0116] The measured height data corresponding to the compensated fourth peak wavelength: ;

[0117] Among them, L1 represents the distance between the intersection points of the measurement line with the upper surface of the glass and the upper surface of the bubble respectively, ; L3 represents the distance between the intersection points of the measurement line with the lower surface of the bubble and the lower surface of the glass respectively; θ4 represents the standard incident angle of the wavelength λ4 converging to the lower surface of the glass bubble in the propagation medium with a refractive index of n1 where the dispersion lens group is located; represents the measured height data corresponding to the first peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located; represents the measured height data corresponding to the fourth peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located; d represents the width of the bubble in the scanning line direction.

[0118] As Figure 8 shown, for non-transparent impurities in the glass, when the non-transparent impurities are smaller than the length of the scanning line, causing three peaks and two peaks to appear in the spectrogram at each position in the scanning line direction. When three peak wavelengths appear, the measured height data corresponding to the third peak wavelength in the spectrogram is compensated to obtain the measured height deviation △X3 corresponding to the third peak wavelength and the compensated measured height data :

[0119] ;

[0120] .

[0121] Among them, represents the measured height data corresponding to the first peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located; represents the measured height data corresponding to the third peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located; θ3 represents the standard incident angle of the wavelength λ3 converging to the lower surface of the glass bubble in the propagation medium with a refractive index of n1 where the dispersion lens group is located.

[0122] According to the coordinate data at each position on the scanning line, combined with the measured height data corresponding to each peak wavelength in the spectrogram at each position after compensation, point cloud data in a three-dimensional coordinate system is constructed. Through the point cloud data, the defect type, defect location, and coverage area in the glass can be identified to determine whether the glass quality meets the requirements.

[0123] For the compensated data, it is converted into point cloud data in three-dimensional coordinates, the glass morphology parameters and the type and coverage area of internal defects in the glass are constructed, and the glass quality is evaluated according to the type and coverage area of the defects to determine whether the glass meets the requirements.

[0124] Example 4

[0125] According to the above Example 3, the compensated measured height data corresponding to each peak wavelength in the spectrogram at each position on each scanning line along the line scan direction can be obtained, forming point cloud data in the glass surface and thickness directions. Affected by the bubble size, the compensation of the third peak wavelength at some positions in the scanning line direction deviates from its true measured height data, and the influence of the coverage area on the measurement accuracy needs to be considered.

[0126] When the bubble width d on the scanning line is greater than the bubble critical width S, the measurement height deviation corresponding to the third peak wavelength

[0127] ;

[0128] When the bubble width d on the scanning line is less than or equal to the bubble critical width S, the measurement height deviation corresponding to the third peak wavelength

[0129] ;

[0130] d represents the width of the bubble along the scanning line direction;

[0131] Among them, ;

[0132] When there are bubble defects in the glass, the measured height data corresponding to the third peak wavelength is affected by the bubble width. L1 represents the distance between the intersections of the measurement line with the upper surface of the glass and the upper surface of the bubble respectively; θ3 represents the standard incident angle of the wavelength λ3 converging to the lower surface of the glass bubble in the propagation medium with a refractive index of n1 where the dispersion lens group is located; represents the measured height data corresponding to the first peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located; represents the measured height data corresponding to the third peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located.

[0133] Example 5

[0134] In the process of determining the width and depth of the bubble, there are cases where the light corresponding to the fourth peak wavelength does not pass through the bubble and directly converges to the lower surface of the glass, and cases where the light of the fourth peak wavelength passes through the bubble and converges to the lower surface. Therefore, when the light corresponding to the first peak wavelength does not pass through the bubble and directly converges to the lower surface of the glass, the measured height data corresponding to the compensated fourth peak wavelength is greater than the true measured height data corresponding to the fourth peak wavelength.

[0135] Using the compensation amount of the fourth peak wavelength in Embodiment 3 and the measured height data corresponding to the compensated fourth peak wavelength, analyze the critical width W of the bubble when the measured height data corresponding to the compensated fourth peak wavelength is greater than the true measured height data corresponding to the fourth peak wavelength, as Figure 6 and 7 shown:

[0136] ;

[0137] where ; ; θ4 represents the standard incident angle of the wavelength λ4 converging to the lower surface of the glass bubble in the propagation medium with a refractive index of n1 where the dispersion lens group is located; △X3 is the measured height deviation corresponding to the third peak wavelength converging to the lower surface of the bubble when the measurement line penetrates the bubble.

[0138] When the bubble width on the scan line is greater than the critical width W of the bubble, at the position W / 2 from the bubble edge to the bubble center on the scan line, the light corresponding to the fourth peak wavelength does not pass through the bubble and directly converges to the lower surface of the glass, and the light of the fourth peak wavelength at other positions in the scan line direction passes through the bubble and converges to the lower surface of the glass.

[0139] Through the bubble width W, the bubble point cloud data obtained in Embodiment 4 can be processed to adjust the measured height data corresponding to the fourth peak wavelength in the spectrogram at each position within the range extending from the bubble edge to the bubble center by W / 2. The following formula is used for adjustment:

[0140] ;

[0141] The measured height data corresponding to the compensated fourth peak wavelength: .

[0142] By adjusting the point cloud data corresponding to the fourth peak wavelength at the position extending W / 2 from the bubble edge to the bubble center in the scanning line direction, and taking the difference between the adjusted fourth peak wavelength and the measured height data corresponding to the compensated third peak wavelength, the bubble height data at the position extending W / 2 from the bubble edge to the bubble center in the scanning line direction can be obtained, and the depth information of the bubble in the transparent material can be accurately obtained.

[0143] Example 6

[0144] When the line spectrum confocal sensor detects non-transparent impurities inside the glass, affected by the width of the transparent impurities, there may be three peaks or two peaks in the spectrogram at the positions of some non-transparent impurities along the scanning line direction. Specifically, when there are non-transparent impurities blocking in the glass and the non-transparent impurities block the incident light or reflected light converging to the bottom of the glass, there are only two peaks in the spectrogram at this position; when the non-transparent impurities in the glass do not block the incident light and reflected light converging to the bottom of the glass, there are three peaks in the spectrogram at this time. When the light converging to the bottom of the glass is not blocked by the non-transparent impurities, the critical width value W0 of the non-transparent impurities is as Figure 9 shown:

[0145]

[0146] Among them, represents the measured height data corresponding to the second peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located; △X2 represents the measured height deviation corresponding to the second peak wavelength; represents the measured height data corresponding to the third peak wavelength in the propagation medium with a refractive index of n1 where the dispersion lens group is located; △X3 is the measured height deviation corresponding to the third peak wavelength when the measurement line passes through the bubble and converges to the lower surface of the bubble; θ3 represents the standard incident angle of the wavelength λ3 converging to the lower surface of the glass bubble in the propagation medium with a refractive index of n1 where the dispersion lens group is located.

[0147] Based on the above critical width value of the non-transparent impurities that are not blocked, combined with the line scan distance L corresponding to the starting position coordinates and ending position coordinates of the non-transparent impurities in the scanning line direction, the true width data W1 = L - 2×W0 of the non-transparent impurities in the glass is analyzed, avoiding taking the line scan length with only two consecutive peaks in the spectrogram in the scanning line direction as the actual width of the non-transparent impurities, which makes the measured width of the non-transparent impurities greater than the true width of the non-transparent impurities, and improves the accuracy of the width measurement of the non-transparent impurities.

[0148] Example 7

[0149] The fourth aspect of the present invention further provides a computer-readable storage medium, including a computer program, and when the computer program is executed by a processor, the above detection method is implemented.

[0150] In practical applications, the computer-readable storage medium can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium can include: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, apparatus, or device.

[0151] The computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, in which computer-readable program code is carried. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium, and this computer-readable medium can send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device.

[0152] The program code contained on the computer-readable medium can be transmitted by any appropriate medium, including but not limited to wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0153] The computer program code for performing the operations of this application can be written in one or more programming languages or combinations thereof. The programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any kind of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (for example, by using an Internet service provider to connect through the Internet).

[0154] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0155] The above shows and describes 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 by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A method for detecting transparent materials, controlling a line spectrum confocal sensor to continuously scan the transparent material along a line scanning direction to obtain a spectrum diagram at each position on the scanning line, characterized in that: include: Match the corresponding relationship between the number of peaks in the spectrum at each position on the scan line and the number of peaks corresponding to each defect type, so as to preliminarily determine the defect type of the transparent material at each position; Identify defect types having the same number of peaks among the defect types; The method for identifying defect types with the same number of peaks in the defect types is to distinguish the defect types at each position with the number of peaks equal to the set number of peaks by judging whether the change in the measured height data corresponding to the second peak wavelength in the spectrum at adjacent positions on the scanning line is within the allowable distance error range; Among them, the defect types include bubbles inside the transparent material, non-transparent impurities and grooves at the bottom; The scanning line is a line formed by the position coordinates of the upper surface of the transparent material covered by the line light source; In the spectrum diagram, each peak wavelength is numbered in order of light intensity.

2. The method for detecting transparent materials according to claim 1, characterized in that: A method for identifying defect types with the same number of peaks in the defect types, including analyzing the light intensity ratio of the first peak wavelength and the second peak wavelength in the spectrum graph at the same position on the scan line; The relationship between the light intensity ratio and the set threshold range is determined to distinguish the defect type at each position where the number of peaks is equal to the set number of peaks.

3. A method for correcting a transparent material, characterized in that: The correction method is based on the defect type identified by the transparent material detection method according to claim 1 or 2, and includes: Extracting the focusing height data of light of different wavelengths after being dispersed by the dispersion lens group, so as to obtain the focusing height data of light of each wavelength along the optical axis in the propagation medium where the dispersion lens group is located; Training the standard incident angle of the peak wavelength at each position in the plane formed by the scanning line and the optical axis, so as to establish a mapping relationship between each wavelength and the standard incident angle, wherein the standard incident angle is the angle between the light and the normal perpendicular to the upper surface of the standard sample when light of different wavelengths is incident on the surface of the standard sample after passing through the dispersion lens group, and the optical axis of the line spectrum confocal sensor is perpendicular to the upper surface of the standard sample; The refractive index of the propagation medium through which the light of the peak wavelength passes during the convergence process, the incident angle of the wavelength, and the height data of the wavelength converged along the optical axis in the propagation medium where the dispersion lens group is located are analyzed to obtain the measured height compensation corresponding to the peak wavelength in the spectrum diagram at each position.

4. The correction method according to claim 3, characterized in that: The defect type at each position on the scanning line is identified, and the measured height corresponding to the peak wavelength in the spectrum at each position on the scanning line is compensated to obtain the real measured height data corresponding to the other peak wavelengths except the first peak wavelength in the spectrum at each position on the scanning line.

5. The correction method according to claim 4, characterized in that: Compensating the measured height corresponding to the peak wavelength in the spectrum at each position on the scan line, wherein the compensation method for the measured height corresponding to each peak wavelength in the spectrum at each position includes: Determine the defect type; Extracting the height data of each peak wavelength in the spectrum at the position where it converges along the optical axis in the propagation medium where the dispersion lens group is located; Extracting interference factors that affect the real measured height data of the peak wavelength, wherein the interference factors include a standard incident angle of the peak wavelength and a refractive index of a propagation medium through which light of the peak wavelength converges to a defect type; The measured height deviation corresponding to the peak wavelength is analyzed to obtain the measured height data corresponding to the compensated peak wavelength.

6. The correction method according to claim 5, characterized in that: When the defect type is non-transparent impurities, the method for correcting the defect coverage length on the scanning line includes: Extracting compensated measured height data corresponding to the second peak wavelength and the third peak wavelength at the same position in the scanning line direction and the incident angle of the third peak wavelength in the propagation medium where the dispersion lens group is located; Analyzing the critical width data of the non-transparent impurities at the position to determine the deviation of the coverage length of the non-transparent impurities in the scanning line direction; The coverage length of the corrected non-transparent impurities on the scan line is calculated to obtain the actual coverage length of the non-transparent impurities.

7. A transparent material detection system, which controls a line spectrum confocal sensor to continuously scan the transparent material along a line scanning direction to obtain a spectrum diagram at each position on the scanning line, characterized in that: include: The defect recognition module extracts the number of peaks in the spectrum at each position on the scan line and matches it with the number of peaks corresponding to each defect type to preliminarily determine the defect type of the transparent material at each position; wherein the defect type includes bubbles inside the transparent material, non-transparent impurities and grooves at the bottom; A data analysis module identifies defect types with the same number of peaks in the defect types, and determines whether a change in the measured height data corresponding to the second peak wavelength in the spectrum at adjacent positions on the scan line is within an allowable distance error range, so as to distinguish the defect types at each position where the number of peaks is equal to the set number of peaks, wherein the scan line is a line formed by the position coordinates of the upper surface of the transparent material covered by the line light source, and each peak wavelength is numbered in the spectrum according to the order of light intensity.

8. The transparent material detection system according to claim 7, characterized in that: The data analysis module includes analyzing the light intensity ratio of the first peak wavelength and the second peak wavelength in the spectrum graph at the same position on the scan line; The relationship between the light intensity ratio and the set threshold range is determined to distinguish the defect type at each position where the number of peaks is equal to the set number of peaks.

9. The transparent material detection system according to claim 7 or 8, characterized in that: Also included is a data processing module for correcting the measured height data corresponding to the peak wavelength at the location of the defect type in the transparent material; The data processing module processes the refractive index of the propagation medium through which the light of each peak wavelength passes during the convergence process, the incident angle of the wavelength, and the height data of the wavelength converged along the optical axis in the propagation medium where the dispersion lens group is located, so as to obtain the measured height compensation amount corresponding to the peak wavelength in the spectrum diagram at each position.

10. A computer-readable storage medium comprising a computer program, characterized in that: When the computer program is executed by a processor, the correction method according to any one of claims 3 to 6 is implemented.

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