High-precision laser imaging and defect detection system based on line spectrum confocal

Abstract

The invention relates to the technical field of optical detection, in particular to a high-precision laser imaging and defect detection system based on line spectrum confocal. A light source module is used for emitting a light source light beam to a to-be-detected target; the beam shaping module is used for shaping the light source beam into a Gaussian spot by using a collimating optical element; the confocal measurement module is used for focusing Gaussian light spots to the surface of a to-be-measured target and forming a dispersion focal region in the Z-axis direction, so that different height positions of the surface of the to-be-measured target correspond to focus points with different wavelengths; the reflected light guiding module is used for collecting reflected light from the surface of a to-be-detected target, separating the reflected light from an incident light path and guiding the reflected light to a detection path; the photoelectric detection module is used for receiving reflected light in the detection path and recording spectral information corresponding to each spatial position; and the defect analysis module is used for calling a defect identification model to carry out defect type identification and area positioning on the to-be-detected target based on the collected spectral information. According to the invention, detection of tiny defects on the surface of a complex material can be realized.

Description

Technical Field

[0001] The present application relates to the field of optical detection technology, and in particular to a high-precision laser imaging and defect detection system based on line spectrum confocalization. Background Art

[0002] With the advancement of precision manufacturing, micro-nanofabrication, and new electronic packaging technologies, industrial products are placing higher demands on surface topography accuracy and defect detection capabilities. In typical applications such as display panels, wafer manufacturing, and microstructured devices, microscopic defects such as micron- and even submicron-level steps, scratches, pits, and foreign matter can significantly impact product performance. Therefore, there is an urgent need for 3D inspection technologies with high spatial resolution and high vertical accuracy to support high-quality evaluation of complex structures.

[0003] At present, the three-dimensional detection methods commonly used in the industrial field mainly include laser triangulation, structured light method and white light interferometry. Taking laser triangulation as an example, its basic principle is to infer the height information of the surface of the object being measured by the change in the position of laser projection and reflection at a known angle; the white light interferometry method relies on the phase change of the interference fringes to calculate the height difference. Although these technologies can achieve micron-level height measurement under most conditions, when faced with samples with high reflectivity, transparent layer coverage or strong changes in material absorbance, they are prone to problems such as decreased measurement accuracy, data loss or deterioration of signal-to-noise ratio. In addition, such systems often rely on axial scanning or complex structural adjustments. The system architecture required to achieve high-precision measurement is relatively complex, making it difficult to adapt to the requirements of high-speed production lines for compactness and rapid detection.

[0004] Line spectrum confocal technology is a high-precision three-dimensional imaging method based on the principle of dispersion focus displacement. Through the dispersion lens group, different wavelengths of light form a continuous focusing area in the Z-axis direction. The surface positions at different heights correspond one-to-one with the reflected wavelengths, thereby achieving height measurement from nanometers to micrometers. Compared with traditional confocal scanning, line spectrum confocal does not require mechanical axial scanning and has the advantages of non-contact, fast imaging, and strong anti-interference ability. It is especially suitable for high-precision defect identification under complex backgrounds. However, there is currently a lack of an integrated system solution specifically for industrial-grade defect detection needs that fully utilizes the advantages of line spectrum confocal technology. Therefore, how to build a laser detection system based on the line spectrum confocal principle that has both high-precision three-dimensional imaging and micro-defect identification capabilities has become a difficult problem that needs to be solved urgently in this field. Summary of the Invention

[0005] This application provides a high-precision laser imaging and defect detection system based on line spectrum confocal imaging, which achieves high-resolution and high-throughput detection of tiny defects on the surface of complex materials, significantly improving the automation and intelligence level of industrial inspection. This application provides the following technical solutions:

[0006] In a first aspect, the present application provides a high-precision laser imaging and defect detection system based on line spectrum confocal, the system comprising a light source module, a beam shaping module, a confocal measurement module, a reflected light guiding module, a photoelectric detection module, and a defect analysis module;

[0007] The light source module is used to emit a light beam to the target to be measured through a light source;

[0008] The beam shaping module is used to shape the light source beam into a Gaussian spot using a collimating optical element;

[0009] The confocal measurement module is used to focus the Gaussian spot onto the surface of the target to be measured using an objective lens group with dispersion characteristics, and form a dispersion focal area in the Z-axis direction, so that different height positions on the surface of the target to be measured correspond to focus points of different wavelengths;

[0010] The reflected light guiding module is used to collect reflected light from the surface of the target to be measured, separate the reflected light from the incident light path, and then guide it to the detection path;

[0011] The photoelectric detection module is used to receive the reflected light in the detection path and record the spectral information corresponding to each spatial position;

[0012] The defect analysis module is used to call the trained defect recognition model to perform defect type recognition and area positioning on the target to be tested based on the collected spectral information.

[0013] In a specific possible implementation scheme, the light source output end of the light source module adopts a fiber coupling structure, the light source is powered by a driving circuit to achieve stable constant current, and cooperates with a preset active temperature control module to suppress spectral drift.

[0014] In a specific embodiment, the beam shaping module is arranged after the light source module, and includes a first collimating lens, a spatial filtering component and a second collimating lens in sequence around the beam propagation path;

[0015] The first collimating lens is arranged after the light source output end, and is used to receive the divergent light beam generated by the light source module and convert the divergent light beam into approximately parallel collimated light; after the collimated light beam is output, it enters the spatial filtering component for wavefront shaping; the spatial filtering component includes a focusing lens and a pinhole filter. The focusing lens converges the light beam to the pinhole plane, allowing the central energy component in the light beam to pass through the pinhole. After the second collimating lens receives the light beam from the pinhole, it converts it into a far-field approximately parallel Gaussian beam according to the beam propagation angle and intensity distribution.

[0016] In one specific embodiment, the confocal measurement module is configured as a dispersive objective lens assembly, which includes several optical lenses with axial dispersion capabilities. The lens material combination forms a significantly wavelength-dependent refractive index distribution, with short-wavelength light focused at the proximal end of the optical axis and long-wavelength light focused at the distal end of the optical axis. The entire dispersion axis forms a continuous wavelength-coded focal scanning band. After the Gaussian beam output by the beam shaping module enters the confocal measurement module, it enters the objective lens assembly along the main optical axis and sequentially undergoes refractive transformation by each refractive element until it is focused within a dispersive focal range. The target to be measured is positioned within this dispersive focal range, with each surface position intersecting with a focal point of a different wavelength.

[0017] The confocal measurement module controls the scanning motion of the target to be measured on the XY plane, bringing each area of ​​the target surface into the focal range in sequence. During the scanning process, each illuminated point obtains a set of reflected spectral signals. By extracting the maximum wavelength intensity in the reflected light, the spatial position of that point in the Z-axis direction is inferred, completing the height reconstruction of the entire surface of the target.

[0018] In a specific embodiment, the reflected light guiding module is disposed after the confocal measurement module and arranged in the same direction as the main optical axis. After the target surface is focused and irradiated, light signals containing wavelength information are reflected at different positions. The reflected light returns to the confocal measurement module area along an optical path direction that approximately coincides with the incident light. The reflected light guiding module introduces a beam splitting structure to cause the reflected light to deviate from the original path near the incident path and be deflected into a lateral detection path.

[0019] When the shaped light beam passes through the beam splitting structure, it is transmitted into the confocal measurement module for the first time. The light beam reflected back from the target surface is reflected to a predetermined angle by the same beam splitting element in the return path, completing the optical path separation of the reflection path.

[0020] In a specific embodiment, the photoelectric detection module is arranged at the end of the reflected light path, directly receives the line spot reflection signal output by the reflected light channel, and synchronously records the main reflection wavelengths at different positions through a wavelength-sensitive photoelectric detection component;

[0021] The photoelectric detection module includes a focusing lens assembly, a spectral separation structure and a photodetector array. The focusing lens assembly is arranged at the exit of the reflected light path, and is used to re-converge the divergent light after deflection by the reflected light guiding module into a continuous line focus. The focused line light spot enters the spectral separation structure. The spectral separation structure is used to expand the composite reflected light containing multiple wavelength components into different bands, and spatially separate the different wavelength components to achieve spatial mapping of wavelengths; the light beam after spectral separation is irradiated on the photodetector array, and the photodetector array is arranged into a multi-channel receiving structure according to the dispersion direction, which is used to collect the reflection intensity of each wavelength channel in real time.

[0022] In a specific possible implementation scheme, the defect analysis module is arranged after the photoelectric detection module, automatically analyzes the collected spatial position and main reflection wavelength data, and outputs a structured defect determination result;

[0023] The defect analysis module includes a data preprocessing unit, a model inference unit and a result annotation unit; the data preprocessing unit is used to receive the original spectral data output by the photoelectric detection module and construct the multidimensional data tensor required for model input; the model inference unit is used to input the processed data tensor into the deployed defect recognition model for automatic analysis; the result annotation unit is used to align the defect type information output by the model with the spatial coordinate system of the target to be measured and generate a defect analysis report.

[0024] In a second aspect, the present application provides a high-precision laser imaging and defect detection method based on line spectrum confocal imaging, which adopts the following technical solutions:

[0025] A high-precision laser imaging and defect detection method based on line spectrum confocality, applied to the high-precision laser imaging and defect detection system based on line spectrum confocality as described in the first aspect, comprises:

[0026] The light source emits a light beam to the target to be measured through the light source;

[0027] shaping the light source beam into a Gaussian spot using a collimating optical element;

[0028] The Gaussian spot is focused onto the surface of the target to be measured using an objective lens group with dispersion characteristics, and a dispersion focal area is formed in the Z-axis direction, so that different height positions on the surface of the target to be measured correspond to focus points of different wavelengths;

[0029] Collecting reflected light from the surface of the target to be measured, separating the reflected light from the incident light path and guiding it to a detection path;

[0030] receiving reflected light in the detection path and recording spectral information corresponding to each spatial position;

[0031] Based on the collected spectral information, the trained defect recognition model is called to identify the defect type and locate the area of ​​the target to be tested.

[0032] In a third aspect, the present application provides an electronic device comprising a processor and a memory; a program is stored in the memory, and the program is loaded and executed by the processor to implement a high-precision laser imaging and defect detection method based on line spectrum confocality as described in the second aspect.

[0033] In a fourth aspect, the present application provides a computer-readable storage medium, in which a program is stored. When the program is executed by a processor, it is used to implement a high-precision laser imaging and defect detection method based on line spectrum confocality as described in the second aspect.

[0034] In summary, the beneficial effects of this application include at least:

[0035] (1) By constructing a confocal measurement module with a dispersion objective lens group as the core, a continuous dispersion focal range is formed in the Z-axis direction, so that the focal points of different wavelengths are spread out along the axial direction and correspond one-to-one with the target surface height. By extracting the main wavelength in the reflected light through the photoelectric detection module, the system can infer the precise position of each scanning point in the vertical direction, realizing non-contact height decoding without mechanical Z-axis scanning. This design overcomes the problem that traditional laser triangulation is limited by geometric structure and incident angle and difficult to achieve vertical measurement. It has Z-axis resolution capability from submicron to micron level and is suitable for high-precision three-dimensional imaging of micro-scale targets such as wafer bumps, stepped structures, and micro-packages.

[0036] (2) By introducing a defect analysis module at the end of the system, this application uses a pre-trained recognition model to automatically analyze the main reflection wavelength and its spatial distribution collected by the photoelectric detection module, identify abnormal spectral response characteristics, and then complete the identification and location of the defect type and defect area. Because the reflected light wavelength information is directly related to the target surface morphology and material reflection characteristics, the system can complete the rapid detection and intelligent classification of small defects such as surface foreign matter, pits, cracks, etc. without the need for additional spectral scanning or image segmentation, significantly improving the degree of detection automation and defect fault tolerance in complex backgrounds.

[0037] By configuring the light source module, the beam shaping module, the confocal measurement module, the reflected light guiding module, the photoelectric detection module and the defect analysis module in sequence around the target to be measured, a continuous and stable confocal detection path is constructed. Among them, the light source module and the beam shaping module cooperate to generate a collimated Gaussian spot; the confocal measurement module constructs a dispersion focal domain in the Z-axis direction through an objective group with dispersion characteristics, realizing the spatial matching of different heights and different wavelengths on the sample surface; the reflected light is collected by the photoelectric detection module after being guided by the guiding module out of the incident path, and finally the trained recognition model is called by the defect analysis module to intelligently analyze the spectral information. The structure integrates high-precision three-dimensional morphology acquisition and spectral information decoding in the same optical path system, solves the key problems such as step-by-step execution of three-dimensional imaging and defect recognition, difficult data alignment, low detection efficiency and other key problems in the prior art, realizes high-resolution and high-throughput detection of small defects on the surface of complex materials, and significantly improves the automation and intelligence level of industrial detection.

[0038] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, and can be implemented according to the content of the specification, the following will be described in detail with the preferred embodiments of the present application and with the help of the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is the structure block diagram of the high-precision laser imaging and defect detection system based on line spectrum confocal in the embodiment of the present application.

[0040] Figure 2 It is a use case diagram of the high-precision laser imaging system based on line spectrum confocal in the embodiment of the present application.

[0041] Figure 3 It is a flowchart of the high-precision laser imaging and defect detection method based on line spectrum confocal in the embodiment of the present application.

[0042] Figure 4 It is a block diagram of the electronic device for high-precision laser imaging and defect detection based on line spectrum confocal in the embodiment of the present application. DETAILED DESCRIPTION

[0043] The specific embodiments of the present application will be further described in detail below in combination with the drawings and examples. The following examples are used to illustrate the present application, but not to limit the scope of the present application.

[0044] REFERENCE Figure 1, is a block diagram of a high-precision laser imaging and defect detection system based on line spectrum confocality, provided by one embodiment of the present application. The system includes a light source module, a beam shaping module, a confocal measurement module, a reflected light guidance module, a photoelectric detection module, and a defect analysis module. These modules are connected in sequence to construct a complete line spectrum confocal detection path around the target to be measured. The light source module is used to emit a light beam to the target to be measured. The beam shaping module is used to shape the light beam into a Gaussian spot using a collimating optical element. The confocal measurement module is used to focus the Gaussian spot onto the surface of the target to be measured using an objective lens group with dispersion characteristics, and to form a dispersion focal zone in the Z-axis direction, so that different height positions on the target surface correspond to focal points of different wavelengths. The reflected light guidance module is used to collect reflected light from the target surface to be measured, separate the reflected light from the incident light path, and guide it to the detection path. The photoelectric detection module is used to receive the reflected light in the detection path and record the spectral information corresponding to each spatial position. The defect analysis module is used to call a trained defect recognition model based on the collected spectral information to identify the defect type and locate the area of ​​the target to be measured.

[0045] In the light source module, the light source module is used to emit a light source beam to the target to be measured through the light source, forming an incident light source of the line spectrum confocal system.

[0046] Optionally, the light source is preferably a wide-spectrum light source, specifically a supercontinuum laser or a broadband white light LED, to cover the continuous wavelength range from visible light to near-infrared bands, to ensure that different wavelengths of light in subsequent dispersion imaging can be focused on different axial height positions respectively. The output end of the light source can adopt a fiber coupling structure to improve the spatial stability and coupling efficiency of the light beam, which is suitable for long-term operation requirements in high-precision scenarios. In the actual arrangement, the light source is powered by a stable constant current through a driving circuit, and cooperates with an active temperature control module to suppress spectral drift, thereby ensuring the wavelength consistency and intensity stability of the output spectrum in the time dimension. According to the required spatial illumination range, the light source outlet can be connected to an imaging lens or a divergent conical mirror to meet the energy distribution requirements of the light beam during axial incidence, and provide good initial incidence conditions for subsequent beam shaping.

[0047] The beam shaping module uses collimating optics to shape the light source beam into a Gaussian spot, providing the confocal measurement module with an axially symmetric and energy-uniform incident illumination beam. This module, located after the light source module, comprises a first collimating lens, a spatial filter assembly, and a second collimating lens, arranged along the beam propagation path.

[0048] Firstly, a first collimating lens is arranged behind the light source exit end to receive the divergent light beam generated by the light source module and convert the divergent light beam into approximately parallel collimated light. The collimating lens forms a uniform and flat wavefront in the exit direction by reasonably designing the focal length and the incident angle. The collimating process requires that the optical axis be aligned to avoid imaging errors caused by the edge divergent light.

[0049] After the collimated light beam is output, it enters a spatial filtering assembly for wavefront shaping. The spatial filtering assembly includes a focusing lens and a pinhole filter. The focusing lens converges the light beam to the pinhole plane, so that the central energy component in the light beam passes through the pinhole, while the high-frequency spatial noise, non-ideal mode components and transverse intensity fluctuations are effectively blocked. The pinhole, as an optical confinement structure, is arranged at the focal point and has an aperture size matched with the spot size, so as to attenuate the non-Gaussian components and make the light beam after passing through have higher spatial coherence and transverse energy consistency. The light beam after spatial filtering belongs to near-field Gaussian distribution, but still has a certain divergence angle. To expand and collimate the light beam again, a second collimating lens is arranged. The second collimating lens receives the light beam from the pinhole and converts it into a far-field approximately parallel Gaussian light beam according to the propagation angle and intensity distribution of the light beam. Through the adjustment of the second collimating lens, a collimated light beam with low divergence angle and high spot symmetry is finally formed, which meets the requirements of the Z-axis dispersion focal domain for spot accuracy in the confocal measurement module.

[0050] In addition, as a preferred, in the shaping process, to ensure that the optical axis does not deviate, the first collimating lens, the spatial filtering assembly and the second collimating lens are arranged in the collinear optical track and precisely installed along the main optical axis of the system. The overall structure of the shaping module can be integrated on a stable optical bracket, the spacing between the components can be set by a fine adjustment device, and the optical axis alignment correction can be performed using a wavefront detector or an imaging target during the initial light adjustment stage of the system. The output end of the entire light beam shaping module is directly coupled with the incident end of the confocal measurement module to realize stable output of high-quality Gaussian spot.

[0051] In the confocal measurement module, the confocal measurement module is used to focus the light beam shaped into a Gaussian spot to the surface of the target to be measured by using an objective lens group having a dispersion characteristic, and form a dispersion focal domain in the Z-axis direction, so that the different height positions of the surface of the target to be measured correspond to the focal points of different wavelengths, and the height coding relationship under the line spectrum confocal path is constructed. The module is arranged behind the light beam shaping module and coaxially arranged with the main optical axis of the system, and an axial dispersion structure is constructed around the target surface.

[0052] The core of this module is the dispersive objective lens assembly, which consists of several optical lenses with axial dispersion. The lens material combination produces a significantly wavelength-dependent refractive index profile, ensuring that incident light of different wavelengths is focused to different axial positions within the objective lens assembly, thereby forming a continuous dispersive focal zone perpendicular to the target surface. Short-wavelength light (such as blue light) is focused near the optical axis, while long-wavelength light (such as red light) is focused far away. The entire dispersion axis forms a continuous, wavelength-coded focal sweep. The Gaussian beam output by the beam shaping module enters the confocal measurement module, then travels along the principal optical axis into the objective lens assembly. After undergoing refractive transformations by various refractive elements, it is focused into the dispersive focal zone above the sample. The target is positioned within this dispersive focal zone, with each surface location intersecting with a focal point of different wavelengths. Because the confocal structure generates a strong signal only for reflected light at the focal-matched position, the strongest wavelength component in the reflected light corresponds to the actual height of the target surface. The confocal measurement module uses a precision adjustment mechanism to control the scanning motion of the target on the XY plane, bringing each area of ​​the target surface into focus. During the scanning process, each illuminated point acquires a set of reflected spectral signals. The system then extracts the maximum wavelength intensity in the reflected light and infers the spatial position of that point along the Z axis, thereby completing high-precision height reconstruction of the entire target surface.

[0053] In order to maintain the focusing accuracy of the light beam in the dispersion focal range, the distance between the objective lens group and the target surface needs to be initially calibrated to ensure that the target to be measured is located within the axial effective range of the continuous dispersion focal range. In addition, the installation angle, focal length configuration and arrangement order of the objective lens group must ensure that the entire dispersion path is unfolded in a single direction along the main optical axis to avoid the generation of off-axis focus, which affects the height resolution accuracy. The output of the confocal measurement module is a set of raw height data consisting of spatial points arranged in a scanning order and the corresponding main reflection wavelength. This module and the reflected light guidance module jointly construct a complete incident-focusing-reflection channel, providing a preliminary pairing of spatial position and spectral response for subsequent detection.

[0054] The reflected light guidance module collects reflected light from the target surface, separates it from the incident light path, and guides it to the photoelectric detection path, providing a stable, separated, and directional reflected light channel for subsequent signal acquisition and height reconstruction. This module is located after the confocal measurement module, coaxially with the main optical axis. Its key function is to establish a reflected light path independent of the incident path, preventing the reflected signal from interfering with the incident light path and improving detection accuracy.

[0055] After the target surface is focused and illuminated, optical signals containing wavelength information are reflected from different locations. This reflected light returns to the confocal measurement module along an optical path that approximately coincides with the incident light. To effectively separate the reflected light path, the reflected light guidance module incorporates a beam splitting structure, which deflects the reflected light away from its original path near the incident path and into a lateral detection path. The beam splitting structure can utilize a polarizing beam splitter prism or a reflective beam splitter element, installed appropriately between the beam shaping module and the confocal measurement module, centered coaxially with the confocal channel.

[0056] During operation, the shaped light beam passes through the beamsplitting structure and is initially transmitted into the confocal measurement module. The beam reflected from the target surface is then reflected back by the same beamsplitting element to a predetermined angle on the return path, completing the optical path separation along the reflection path. This reflected light is then deflected and propagates along a new detection optical path, entering the subsequent photoelectric detection module.

[0057] To ensure the spatial energy concentration and wavelength fidelity of the reflected light, the beamsplitting elements in the reflected light guidance module must possess high transmittance and reflectivity control capabilities. The element's coating parameters, incident angle design, and mechanical stability collectively determine the degree to which it maintains the integrity of the light spot and the reflected light flux during the splitting process. Furthermore, to minimize stray light interference, the module's inner surface features a light-absorbing coating structure to suppress multiple reflections of non-target light. After entering the separation path, the reflected light continues through several lens groups or directional reflectors for guidance and shaping to match the receiving field of view and incident angle requirements of the subsequent photodetector. The entire reflection path structure must maintain axial stability to avoid beam decentering or scattering, ensuring accurate transmission of spectral information to the detector's receiving surface. The optical path layout, angle adjustment, and beamsplitting element performance of the entire reflected light guidance module work together to form a complete reflection channel system, laying the dual spatial and energy foundation for subsequent high-precision spectral acquisition.

[0058] The photoelectric detection module receives the reflected light guided by the reflected light guidance module and records the dominant reflected wavelength corresponding to each spatial position, thereby establishing a correspondence between the position and wavelength of the target surface to be measured. This module, located at the end of the reflected light path, directly receives the line spot reflection signal output by the reflected light channel and synchronously records the dominant reflected wavelength at different locations using a wavelength-sensitive photoelectric detection component.

[0059] The photodetection module comprises a focusing lens assembly, a spectral separation structure, and a photodetector array. Positioned at the exit of the reflected light path, the focusing lens assembly is used to converge the divergent light, deflected by the reflected light guidance module, into a continuous line focal point, facilitating spatial localization of the reflected light signals corresponding to different scanning positions. This lens assembly is required to possess excellent axial focusing capability and low aberration to avoid wavelength-to-space mapping errors caused by imaging offsets at different wavelengths.

[0060] The focused line spot enters the spectral separation structure, which is used to expand the composite reflected light containing multiple wavelength components into different wavelength bands and spatially separate the different wavelength components to achieve spatial wavelength mapping. This structure can use a diffraction grating or a high-precision dispersion prism to disperse the line spot in the vertical direction, so that each horizontal pixel position only receives the reflected signal of a specific wavelength range.

[0061] The spectrally separated beam is directed onto a photodetector array, arranged in a multi-channel receiving configuration along the dispersion direction. This array collects the reflected intensity of each wavelength channel in real time. The detector array is configured as a linear array along the scanning direction, with each detector element responding to the intensity of a specific wavelength of reflected light at a point on the target surface. This structure achieves a one-to-one mapping between scanning points and the dominant reflected wavelength, forming the basis for extracting basic height data.

[0062] The photoelectric detection module outputs data including the dominant wavelength value at each spatial location along the scan line, a wavelength intensity curve, and a synchronized acquisition timestamp. To ensure data integrity and response speed, the module integrates a signal acquisition circuit, an analog-to-digital converter, and a primary buffer unit. This synchronizes the readout and timing of the spectral data, preventing data interference or signal loss between different points.

[0063] The Defect Analysis Module uses the spectral information collected by the Photoelectric Detection Module to call upon a pre-trained defect recognition model to identify defect types and locate defect areas on the target. This module, located after the Photoelectric Detection Module and communicating with the system's data processing unit, automatically analyzes the collected spatial position and dominant reflection wavelength data, outputting structured defect determination results.

[0064] The defect analysis module consists of three parts: a data preprocessing unit, a model inference unit, and a result annotation unit. The data preprocessing unit receives the raw spectral data output by the photoelectric detection module and performs data format conversion, noise removal, and structural alignment. The raw data includes the spatial position sequence of scan lines, the dominant wavelength value corresponding to each position, the spectral curve, and synchronization time information. The processing unit performs channel normalization, dimension completion, and numerical standardization on this data based on the system-defined input tensor structure to construct the multidimensional data tensor required for model input.

[0065] The model inference unit is used to input processed data tensors into the deployed defect recognition model for automatic analysis. The recognition model is a neural network structure that has achieved parameter convergence during the training phase. This model is trained on a large number of typical defect datasets and is capable of outputting defect determination results based on a given input tensor. During the inference process, the model uses the input tensor as a basis to identify characteristic patterns such as abnormal distribution of reflected wavelengths, loss of spectral continuity, and localized energy loss, and maps these patterns into structured sets of defect type labels and spatial locations.

[0066] The result annotation unit aligns the defect type information output by the model with the spatial coordinate system of the target to be tested and generates a defect analysis report. This report includes fields such as the defect's spatial location index, classification label, and confidence score to support subsequent quality control or manual review processes. This unit also maps the recognition results to a 2D or 3D visualization interface for terminal display or system integration.

[0067] In summary, combined with Figure 2 By sequentially configuring the light source module, beam shaping module, confocal measurement module, reflected light guidance module, photoelectric detection module and defect analysis module around the target to be measured, a continuous and stable confocal detection path is constructed. Among them, the light source module and the beam shaping module cooperate to generate a collimated Gaussian spot; the confocal measurement module constructs a dispersion focal range in the Z-axis direction through an objective lens group with dispersion characteristics, realizing spatial matching of different heights and different wavelengths on the sample surface; the reflected light is collected by the photoelectric detection module after being separated from the incident path by the guidance module, and finally the defect analysis module calls the trained recognition model to perform intelligent analysis of the spectral information. This structure integrates high-precision three-dimensional morphology acquisition and spectral information decoding in the same optical path system, solving the key problems of existing technologies such as the need for step-by-step execution of three-dimensional imaging and defect recognition, difficult data alignment, and low detection efficiency. It realizes high-resolution and high-throughput detection of tiny defects on the surface of complex materials, significantly improving the automation and intelligence level of industrial detection.

[0068] Figure 3 This is a flow chart of a high-precision laser imaging and defect detection method based on line spectrum confocality provided by an embodiment of the present application. The method is applied to the above-mentioned high-precision laser imaging and defect detection system based on line spectrum confocality. The method includes at least the following steps:

[0069] A light source is used to emit a light beam to the target to be measured;

[0070] The light source beam is shaped into a Gaussian spot using a collimating optical element;

[0071] The Gaussian spot is focused onto the surface of the target by using an objective lens group with dispersion characteristics, and a dispersion focal area is formed in the Z-axis direction, so that different height positions of the target surface correspond to the focus points of different wavelengths.

[0072] Collect reflected light from the surface of the target to be measured, separate the reflected light from the incident light path and guide it to the detection path;

[0073] Receive the reflected light in the detection path and record the spectral information corresponding to each spatial position;

[0074] Based on the collected spectral information, the trained defect recognition model is called to identify the defect type and locate the area of ​​the target to be tested.

[0075] For relevant details, please refer to the above system embodiment.

[0076] Figure 4 4 is a block diagram of an electronic device provided in one embodiment of the present application. The device includes at least a processor 401 and a memory 402.

[0077] The processor 401 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 401 may be implemented in at least one hardware form of a DSP (Digital Signal Processing), an FPGA (Field-Programmable Gate Array), or a PLA (Programmable Logic Array). The processor 401 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 401 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 401 may also include an AI (Artificial Intelligence) processor, which is used to process computing operations related to machine learning.

[0078] Memory 402 may include one or more computer-readable storage media, which may be non-transitory. Memory 402 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory storage devices. In some embodiments, the non-transitory computer-readable storage medium in memory 402 is used to store at least one instruction, which is executed by processor 401 to implement the high-precision laser imaging and defect detection method based on line spectrum confocalization provided in the method embodiments of this application.

[0079] In some embodiments, the electronic device may optionally include a peripheral device interface and at least one peripheral device. The processor 401, memory 402, and peripheral device interface may be connected via a bus or signal lines. Each peripheral device may be connected to the peripheral device interface via a bus, signal lines, or circuit boards. Illustratively, the peripheral devices include, but are not limited to, a radio frequency circuit, a touchscreen display, an audio circuit, and a power supply.

[0080] Of course, the electronic device may also include fewer or more components, which is not limited in this embodiment.

[0081] Optionally, the present application also provides a computer-readable storage medium, in which a program is stored, and the program is loaded and executed by a processor to implement the high-precision laser imaging and defect detection method based on line spectrum confocality of the above method embodiment.

[0082] Optionally, the present application also provides a computer product, which includes a computer-readable storage medium, in which a program is stored. The program is loaded and executed by a processor to implement the high-precision laser imaging and defect detection method based on line spectrum confocality of the above-mentioned method embodiment.

[0083] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A high-precision laser imaging and defect detection system based on line spectrum confocal, characterized in that: The system includes a light source module, a beam shaping module, a confocal measurement module, a reflected light guiding module, a photoelectric detection module and a defect analysis module; The light source module is used to emit a light beam to the target to be measured through a light source; The beam shaping module is used to shape the light source beam into a Gaussian spot using a collimating optical element; The confocal measurement module is used to focus the Gaussian spot onto the surface of the target to be measured using an objective lens group with dispersion characteristics, and form a dispersion focal area in the Z-axis direction, so that different height positions on the surface of the target to be measured correspond to focus points of different wavelengths; The reflected light guiding module is used to collect reflected light from the surface of the target to be measured, separate the reflected light from the incident light path, and then guide it to the detection path; The photoelectric detection module is used to receive the reflected light in the detection path and record the spectral information corresponding to each spatial position; The defect analysis module is used to call the trained defect recognition model to perform defect type recognition and area positioning on the target to be tested based on the collected spectral information.

2. The high-precision laser imaging and defect detection system based on line spectrum confocal according to claim 1 is characterized in that: The light source output end of the light source module adopts a fiber coupling structure, the light source is powered by a driving circuit to achieve stable constant current, and cooperates with a preset active temperature control module to suppress spectral drift.

3. The high-precision laser imaging and defect detection system based on line spectrum confocal according to claim 1, characterized in that: The beam shaping module is arranged behind the light source module and includes a first collimating lens, a spatial filter component and a second collimating lens in sequence around the beam propagation path; The first collimating lens is arranged after the light source output end, and is used to receive the divergent light beam generated by the light source module and convert the divergent light beam into approximately parallel collimated light; after the collimated light beam is output, it enters the spatial filtering component for wavefront shaping; the spatial filtering component includes a focusing lens and a pinhole filter. The focusing lens converges the light beam to the pinhole plane, allowing the central energy component in the light beam to pass through the pinhole. After the second collimating lens receives the light beam from the pinhole, it converts it into a far-field approximately parallel Gaussian beam according to the beam propagation angle and intensity distribution.

4. The high-precision laser imaging and defect detection system based on line spectrum confocal according to claim 1, characterized in that: The confocal measurement module is composed of a dispersive objective lens group, which includes several optical lenses with axial dispersion capabilities. The lens material combination forms a refractive index distribution that is significantly wavelength-dependent. Short-wavelength light is focused at the proximal end of the optical axis, and long-wavelength light is focused at the distal end of the optical axis. The entire dispersion axis forms a continuous wavelength-coded focus scanning band. After the Gaussian beam output by the beam shaping module enters the confocal measurement module, it enters the objective lens group along the main optical axis and undergoes refractive transformation by each refractive element in sequence, and is focused into a dispersive focal range. The target to be measured is located within the dispersive focal range, and each position on the surface intersects with a focal point of different wavelengths. The confocal measurement module controls the scanning motion of the target to be measured on the XY plane, bringing each area of ​​the target surface into the focal range in sequence. During the scanning process, each illuminated point obtains a set of reflected spectral signals. By extracting the maximum wavelength intensity in the reflected light, the spatial position of that point in the Z-axis direction is inferred, completing the height reconstruction of the entire surface of the target.

5. The high-precision laser imaging and defect detection system based on line spectrum confocal according to claim 1, characterized in that: The reflected light guiding module is disposed after the confocal measurement module and arranged in the same direction as the main optical axis. After the target surface is focused and illuminated, light signals containing wavelength information are reflected at different positions. The reflected light returns to the confocal measurement module area along an optical path that approximately coincides with the incident light. The reflected light guiding module introduces a beam splitting structure to cause the reflected light to deviate from the original path near the incident path and be deflected to a lateral detection path. When the shaped light beam passes through the beam splitting structure, it is transmitted into the confocal measurement module for the first time. The light beam reflected back from the target surface is reflected to a predetermined angle by the same beam splitting element in the return path, completing the optical path separation of the reflection path.

6. The high-precision laser imaging and defect detection system based on line spectrum confocal according to claim 1, characterized in that: The photoelectric detection module is arranged at the end of the reflected light path, directly receives the line spot reflection signal output by the reflected light channel, and synchronously records the main reflection wavelengths at different positions through the wavelength-sensitive photoelectric detection component; The photoelectric detection module includes a focusing lens assembly, a spectral separation structure and a photodetector array. The focusing lens assembly is arranged at the exit of the reflected light path, and is used to re-converge the divergent light after deflection by the reflected light guiding module into a continuous line focus. The focused line light spot enters the spectral separation structure. The spectral separation structure is used to expand the composite reflected light containing multiple wavelength components into different bands, and spatially separate the different wavelength components to achieve spatial mapping of wavelengths; the light beam after spectral separation is irradiated on the photodetector array, and the photodetector array is arranged into a multi-channel receiving structure according to the dispersion direction, which is used to collect the reflection intensity of each wavelength channel in real time.

7. The high-precision laser imaging and defect detection system based on line spectrum confocal according to claim 1, characterized in that: The defect analysis module is arranged after the photoelectric detection module, automatically analyzes the collected spatial position and main reflection wavelength data, and outputs a structured defect determination result; The defect analysis module includes a data preprocessing unit, a model inference unit and a result annotation unit; the data preprocessing unit is used to receive the original spectral data output by the photoelectric detection module and construct the multidimensional data tensor required for model input; the model inference unit is used to input the processed data tensor into the deployed defect recognition model for automatic analysis; the result annotation unit is used to align the defect type information output by the model with the spatial coordinate system of the target to be measured and generate a defect analysis report.

8. A high-precision laser imaging and defect detection method based on line spectrum confocality, applied to the high-precision laser imaging and defect detection system based on line spectrum confocality as claimed in claims 1 to 7, characterized in that: include: A light source is used to emit a light beam to the target to be measured; shaping the light source beam into a Gaussian spot using a collimating optical element; The Gaussian spot is focused onto the surface of the target to be measured using an objective lens group with dispersion characteristics, and a dispersion focal area is formed in the Z-axis direction, so that different height positions on the surface of the target to be measured correspond to focus points of different wavelengths; Collecting reflected light from the surface of the target to be measured, separating the reflected light from the incident light path and guiding it to a detection path; receiving reflected light in the detection path and recording spectral information corresponding to each spatial position; Based on the collected spectral information, the trained defect recognition model is called to identify the defect type and locate the area of ​​the target to be tested.

9. An electronic device, characterized in that: The device includes a processor and a memory; a program is stored in the memory, and the program is loaded and executed by the processor to implement a high-precision laser imaging and defect detection method based on line spectrum confocality as described in claim 8.

10. A computer-readable storage medium, characterized in that The storage medium stores a program, which, when executed by the processor, is used to implement the high-precision laser imaging and defect detection method based on line spectrum confocality as described in claim 8.

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