Detection system and detection method

Abstract

The invention relates to the technical field of semiconductor front channel detection, discloses a dark field detection system and method, and particularly relates to a detection system and a detection method. A calibration image of a bearing object is collected through an image sensor, whether the position of the image sensor has deviation or not is determined based on the spatial change relation between the calibration image and a pre-collected standard image, and the position of the image sensor is adjusted to a target position. An image sensor arranged on the basis of the target position is used for collecting images of the multiple components in the detection system, and the spatial positions of the multiple components are adjusted through the collected images. Compared with the prior art, the embodiment of the invention can solve the technical problems that the camera needs to be reassembled for observation in the processes of stability test, light path debugging and the like of the detection system in the prior art, and the camera is disassembled and assembled for many times and is complicated to debug.

Description

Technical Field

[0001] This application relates to the field of semiconductor front-end inspection technology, specifically a dark field inspection system and method. Background Technology

[0002] A scattering signal collection device in laser scattering wafer inspection equipment includes an ellipsoidal mirror and a photomultiplier tube. During operation, both the photomultiplier tube and the laser incident position must be aligned with the center of the ellipsoidal bowl. The center of the ellipsoidal bowl is typically captured using a temporary camera. The center of a marker plate is aligned with the center of the ellipsoidal bowl within the temporary camera, and the position of the temporary camera is recorded. Subsequently, the photomultiplier tube is used to replace the temporary camera, and its position is then fine-tuned. However, because the camera needs to be reinstalled for observation during stability testing and optical path debugging, repeated camera reinstallation and disassembly are cumbersome and complex. Furthermore, after the inspection equipment is accepted, the temporary camera cannot be disassembled and reinstalled, making re-inspection difficult. Summary of the Invention

[0003] In order to address the technological gaps existing in the prior art, embodiments of this application are provided.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows: In a first aspect, a detection system is provided, comprising: a stage for placing a carrier; an incident light source for projecting an incident light spot onto the surface of the carrier and forming a scattered light beam via the surface of the carrier; an ellipsoidal mirror and a reflector disposed within the ellipsoidal mirror, the ellipsoidal mirror being placed above the carrier for collecting the scattered light beam and reflecting the scattered light beam to a detector assembly, the reflector being for collecting the scattered light beam and reflecting the scattered light beam to form a reflected light beam, the reflected light beam propagating through an optical channel opened on the ellipsoidal mirror; an image sensor disposed on the propagation path of the reflected light beam and performing imaging based on the reflected light beam to obtain a real-time image containing the light spot and the carrier; and a controller electrically connected to the incident light source and adjusting the spatial position of the incident light source based on the positional deviation between the light spot and the carrier in the real-time image.

[0005] In another possible implementation, a coaxial light source coaxially disposed with the image sensor is further included to generate an incident light beam and project it onto the carrier via the light channel, and reflect it through the carrier to form a reflected light signal. The reflected light signal is transmitted to the image sensor via the reflector to form an image, thereby obtaining a calibration image containing the carrier and the bottom contour of the ellipsoidal mirror.

[0006] In another possible implementation, the controller is electrically connected to the ellipsoid and adjusts the spatial position of the ellipsoid based on the relative positional deviation between the bottom contour of the ellipsoid and the carrier in the real-time image.

[0007] In another possible implementation, the carrier includes the object to be tested or a calibration plate having multiple calibration points.

[0008] In another possible implementation, the carrier includes a calibration plate having a plurality of calibration points.

[0009] Another possible implementation includes a memory containing the standard spatial positional relationships of the calibration board.

[0010] In another possible implementation, the controller is connected to the memory, the image sensor, and the coaxial light source, and adjusts the spatial position of the image sensor and the coaxial light source based on the deviation between the real-time spatial position relationship of the carrier in the real-time image and the standard spatial position relationship.

[0011] Secondly, a detection method is provided, the method comprising: projecting an incident light spot onto the surface of a carrier, and forming a scattered light beam through the surface of the carrier; the carrier is a calibration plate, and the calibration plate is provided with multiple feature points; reflecting the scattered light beam to form a reflected light beam, and performing imaging based on the reflected light beam to obtain a real-time image containing the incident light spot and the carrier; acquiring the positional deviation between the incident light spot and the carrier in the real-time image, and adjusting the spatial position of the incident light source based on the positional deviation until the center of the incident light spot coincides with the center of the carrier.

[0012] In another possible implementation, the method further includes: generating an incident light beam projected forward relative to the carrier and reflecting it through the carrier to form a reflected light signal; performing imaging based on the reflected light signal to obtain a calibration image containing the carrier and the bottom contour of the ellipsoidal mirror; and adjusting the spatial position of the ellipsoidal mirror based on the relative positional deviation between the bottom contour of the ellipsoidal mirror and the carrier in the real-time image.

[0013] In another possible implementation, the method further includes: generating an incident light beam projected forward relative to the carrier and forming a reflected light signal via reflection from the carrier; performing imaging based on the reflected light signal to obtain a calibration image containing the carrier and the bottom contour of the ellipsoidal mirror; extracting the deviation between the feature point positions of the calibration plate in the calibration image and the feature point positions in the standard image, and adjusting the spatial positions of the image sensor and the coaxial light source to the standard position based on the deviation.

[0014] The embodiments of the present invention bring the following beneficial effects: In the technical solution provided by this application embodiment, a calibration image of the carrier is acquired by an image sensor. The position of the image sensor is determined based on its spatial variation relationship with a pre-acquired standard image to check for deviations. The position of the image sensor is then adjusted to the target position. Based on the target position, the image sensor acquires images of multiple components within the detection system, and the spatial positions of these components are adjusted using the acquired images. Compared to existing technologies, this application embodiment solves the technical problem in existing technologies where the camera needs to be reinstalled for observation during stability testing and optical path debugging of the detection system, resulting in complex camera disassembly and assembly and debugging.

[0015] Other features and advantages of this disclosure will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0016] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] The methods, systems, and / or procedures shown in the accompanying drawings will be further described with reference to exemplary embodiments. These exemplary embodiments will be described in detail with reference to the drawings. These exemplary embodiments are non-limiting exemplary embodiments, wherein example figures represent similar mechanisms in the various views of the drawings.

[0019] Figure 1 This is a schematic diagram of the first detection system.

[0020] Figure 2 This is a schematic diagram of the first detection method.

[0021] Figure 3 This is a schematic diagram of the second type of detection system.

[0022] Figure 4 This is a schematic diagram of the second detection method.

[0023] Figure 5 This is a schematic diagram of the third type of detection system.

[0024] Figure 6 This is a schematic diagram of the third detection method.

[0025] Figure 7 This is a schematic diagram of perspective transformation.

[0026] Figure 8 This is a schematic diagram of a readable medium structure. Detailed Implementation

[0027] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0028] In the detailed description below, numerous specific details are illustrated with examples to provide a comprehensive understanding of the relevant guidance. However, it will be apparent to those skilled in the art that this application can be practiced without these details. In other instances, well-known methods, procedures, systems, components, and / or circuits have been described at a relatively high level without detail to avoid unnecessarily obscuring aspects of this application.

[0029] This application uses flowcharts to illustrate the execution process performed by a system according to embodiments of this application. It should be clearly understood that the execution processes in the flowcharts may not be executed sequentially. Instead, these execution processes may be executed in reverse order or simultaneously. Additionally, at least one other execution process may be added to the flowchart. One or more execution processes may be deleted from the flowchart.

[0030] Before providing a further detailed description of the embodiments of the present invention, the nouns and terms involved in the embodiments of the present invention will be explained, and the nouns and terms involved in the embodiments of the present invention shall be interpreted as follows.

[0031] As the substrate for chips, wafers are susceptible to defects on their surface, which can lead to chip failure, reduced yield, and increased manufacturing costs. Therefore, a common practice is to perform wafer surface defect detection before or during chip fabrication. Wafer surface defect detection refers to detecting the presence and location of defects such as grooves, particles, and scratches on the wafer surface.

[0032] This application provides a detection system for dark-field detection. The test object is a wafer. In this embodiment, "wafer" generally refers to a substrate formed of semiconductor or non-semiconductor materials. Examples include (but are not limited to) single-crystal silicon, gallium arsenide, gallium nitride, and indium phosphide. Such substrates are typically found and / or processed in semiconductor manufacturing facilities. In some cases, the wafer may contain only the substrate (i.e., a bare wafer). Alternatively, the wafer may contain one or more layers of different materials formed on the substrate. The one or more layers formed on the wafer may be "patterned" or "unpatterned." For example, the wafer may contain multiple bare wafers with repeatable pattern features.

[0033] For the precision inspection application scenario in this embodiment, the positions of several key components in the system need to be stable and accurate. Generally, the main components required for dark-field inspection include an incident light assembly and an ellipsoidal mirror. The incident light assembly projects an incident light spot onto the surface of the wafer to be inspected, and the ellipsoidal mirror collects the scattered light formed on the surface of the wafer based on the incident light spot through reflection and focusing, forming scattered light with a specific propagation path. The focused scattered light is collected by a detector assembly positioned along the propagation path, thereby forming optical features of the scattered light.

[0034] In this design, the positions of the incident light component and the ellipsoidal mirror in space remain unchanged. To achieve a complete scan of the wafer surface under test, a motion mechanism drives the wafer to perform an elliptical motion to complete the overall scan. This can be understood as the positions of the incident light spot formed on the wafer by the incident light component and the ellipsoidal mirror not changing during the detection process. Furthermore, the positions of the incident light spot and the ellipsoidal mirror should also ensure that their centers coincide.

[0035] Therefore, existing technologies require adjustment of the positions of the incident light spot and the ellipsoid during detection startup, especially for the initial startup, to avoid positional deviations caused by installation errors and external factors, thereby improving overall detection accuracy.

[0036] In existing technologies, the above-mentioned processing typically involves disassembling the detector and replacing it with a camera. This is because the detector's incident surface is parallel to the wafer under test, and the center of the detector's incident surface coincides with the center of the focal plane. Therefore, by replacing the detector with a camera, the camera acquires images within the current field of view. Based on the relative positions of the ellipsoid and the incident light spot in the image, as well as their respective relative positions within the image, it is determined whether the incident light spot and the ellipsoid deviate from the requirements.

[0037] This can be understood as follows: using the detector's position as the reference position in existing technology, and replacing the detector with a camera, the center of the camera is used as a surrogate reference position. The positional relationship between the ellipsoidal mirror, the incident light spot, and this surrogate reference position is used to determine whether there is a deviation between the two and the degree of deviation.

[0038] Furthermore, to ensure more accurate determination of deviations and their degree, a calibration board is typically included in this system. This calibration board can replace the wafer under test, making the deviation representation more intuitive. The calibration board usually features a grid or other positional parameters for differentiation. When using the calibration board, its center is first aligned with the camera center. The calibration board has a center point, and the camera also has a center imaging point; aligning them ensures more precise placement of the calibration board.

[0039] For a system that places a calibration plate, the camera acquires images within the current field of view, determines the positional relationship between the ellipsoid, the incident light spot, and the center of the calibration plate in the image, determines whether there is a deviation between the ellipsoid and the incident light spot and the degree of deviation, and adjusts the spatial position of the ellipsoid and the incident component accordingly based on the degree of deviation.

[0040] The incident light spot and the center of the calibration plate should be coincident or contained within each other; this relationship is relatively easy to express in the image. However, the relationship between the ellipsoidal mirror and the center of the calibration plate requires processing the acquired image. Generally, the pixel distance between the edge point of the ellipsoidal mirror in the image and the center of the calibration plate is determined, and spatial distance mapping is performed based on this pixel distance. This mapping process can be implemented using existing image processing methods, which will not be elaborated upon in this embodiment.

[0041] While the aforementioned system can effectively adjust the spatial positions of the various ellipsoidal mirrors and incident components within the monitoring system, it relies on the configuration of replaceable cameras. The cameras are configured to replace the detectors, and then replaced with detectors after debugging. Repeated camera disassembly and replacement can introduce systematic errors, which increase with the frequency of replacement. This can lead to detector position deviations, reducing overall detection accuracy and increasing debugging costs.

[0042] Therefore, in order to solve the problem of complex system adjustment in existing detection systems, embodiments of this application provide a detection system, see below. Figure 1The detection system 10 includes an incident light source 11, a stage 12, an ellipsoidal mirror 13, a reflector 14, and an image sensor 15. The incident light source and the ellipsoidal mirror form the basic optical path system of the detection system. The incident light source projects an incident light beam onto the carrier 20 on the stage, forming an incident light spot on the carrier. The incident light beam is then scattered through the surface of the carrier. The ellipsoidal mirror is positioned above the stage and has an entrance and an exit point arranged in an ellipsoidal structure. The scattered light beam enters through the entrance and undergoes multiple reflections by the ellipsoidal mirror to form a reflected light beam, which exits through the exit point and is received by the detector assembly positioned above the ellipsoidal mirror.

[0043] Unlike existing technologies, in this embodiment, a reflector is provided inside the ellipsoidal mirror to collect the scattered light beam formed by the scattering of the surface of the carrier and reflect it to form a reflected light beam. An optical channel is provided on the ellipsoidal mirror to transmit this reflected light beam, and an image sensor is provided at this reflected light beam propagation channel to receive this reflected light beam.

[0044] The image sensor uses this reflected light beam to obtain a real-time image containing the incident light spot and the object. This embodiment can be understood as follows: the detection system has an independent reflected light path, formed based on the scattered light beam from the incident light spot. This reflected light path is led out through an ellipsoidal mirror to achieve imaging of the current incident light spot and the object. The final imaging result includes the incident light spot and the object, as well as their relative positional relationship.

[0045] Furthermore, the relative positional relationship between the incident light spot and the carrier reflects the spatial position of the incident light source. Moreover, the detection system requires the incident light spot to be centered on the carrier. Therefore, in this embodiment, by determining the positional deviation between the incident light spot and the center point of the carrier in the acquired image, the spatial position deviation corresponding to the current incident light source can be determined, thereby achieving adjustment of the incident light source.

[0046] The adjustment of the incident light source includes manual adjustment and automatic adjustment. In this embodiment, automatic adjustment is preferred to achieve precise adjustment and control.

[0047] Specifically, the detection system in this embodiment also includes a controller 16, which is electrically connected to the incident light source and the image sensor. The controller is used to receive the image acquired by the image sensor and adjust the spatial position of the incident light source based on the positional deviation between the incident light source and the carrier in the image.

[0048] Furthermore, in this embodiment, the carrier includes either the object to be tested (i.e., the wafer to be tested) or the calibration plate. The positional deviation between the incident light spot and the carrier is either the deviation between the incident light spot and the center of the wafer to be tested, or the deviation between the incident light spot and the center of the calibration plate. Since determining the deviation is simpler than calibrating the specific center point of the calibration plate, the calibration plate is preferred as the carrier in this embodiment. The calibration plate in this embodiment includes not only a center point but also several other feature points.

[0049] It is worth noting that, when the reflector is placed inside the ellipsoidal mirror, to avoid interference with the collection of scattered light beams during detection by the detection system, the reflector in this embodiment is configured in the region where the scattering angle of the scattered light beam is less than 20°. That is, the reflector only reflects scattered light beams with a scattering angle of less than 20°, thus not affecting the detector's collection of scattered light at other scattering angles.

[0050] In summary, the detection system provided in this embodiment includes a reflector along the propagation path of the scattered light beam. This reflector reflects the scattered light beam to form a real-time image containing the incident light spot and the carrier. By adjusting the spatial position of the incident light source based on the offset between the incident light spot and the center point of the carrier in the real-time image, real-time detection and adjustment of the incident light source are achieved. Compared to existing technologies, the system's debugging costs are reduced by repeatedly disassembling and reassembling the image sensor.

[0051] Among them, see Figure 2 In this embodiment, a detection method is configured in the detection system to achieve the above-mentioned effect. This method includes: Step S21. Project an incident light spot onto the surface of the carrier and form a scattered light beam through the surface of the carrier.

[0052] Step S22. The scattered beam is reflected to form a reflected beam, and an image containing the incident light spot and the carrier is obtained based on the reflected beam.

[0053] Step S23. Obtain the positional deviation between the incident light spot and the carrier in the real-time image, and adjust the spatial position of the incident light source based on the positional deviation until the incident light spot coincides with the center of the carrier.

[0054] In the detection system of this embodiment, the calibration plate is fixed on the support platform and will not drift due to changes in the external physical environment, while the incident light spot is a non-moving component. Therefore, under normal circumstances, the error is caused by the movement of the incident light spot, and the result of the movement of the incident light spot is reflected in the image as a deviation between the center point of the incident light spot and the calibration plate.

[0055] The deviation between the incident light spot and the center point of the calibration plate in the image can be obtained by acquiring the corresponding pixel coordinates and mapping the pixel coordinates to physical coordinates. This can be achieved using existing technologies and will not be elaborated further in this embodiment.

[0056] In another possible implementation, for the detection scenario in this embodiment, the ellipsoidal mirror is used to collect scattered light and transmit it to the detector. Therefore, the spatial placement of the ellipsoidal mirror has a significant impact on the collection of scattered light signals. Thus, generally, the position of the ellipsoidal mirror needs to be calibrated and adjusted before the detection system operates, ensuring that the center of the ellipsoidal mirror coincides with the center of the calibration plate.

[0057] Therefore, this embodiment also provides a detection system to address this problem. For details about this detection system, please refer to [link / reference needed]. Figure 3 As shown, based on Figure 1 The corresponding detection system also includes a coaxial light source 17, coaxially aligned with the image sensor. This coaxial light source generates an incident light beam, which is projected onto the carrier via an optical channel and reflected by the carrier to form a reflected light signal. The reflected light signal is transmitted to the image sensor via a reflector for imaging, resulting in a calibration image containing the carrier and the bottom contour of the ellipsoidal mirror. The carrier is preferably a calibration plate, which has at least one center point and multiple feature points.

[0058] This can be understood as adjusting the spatial position of the ellipsoid mirror by comparing its spatial position with that of the calibration plate to determine if the ellipsoid mirror has a deviation relative to the calibration plate. Furthermore, images of the ellipsoid mirror and the calibration plate are acquired, and the ellipsoid mirror is adjusted based on the deviation between the center position of the ellipsoid mirror and the center position of the calibration plate.

[0059] Specifically, the outline of the ellipsoidal mirror is first segmented to obtain its contour. Since the outline of the ellipsoidal mirror in the image is represented by an ellipse, the center point of the ellipsoidal mirror is the center of the ellipse. This process can be performed using existing image processing methods, and will not be elaborated further in this embodiment.

[0060] Therefore, in this embodiment, the calibration image acquired by the image sensor is first decomposed into the coordinates of the ellipsoidal mirror center point and the calibration plate center point. Then, the offset between the ellipsoidal mirror and the calibration plate is determined based on the decomposed coordinates. Then, the ellipsoidal mirror is adjusted according to this offset. Adjustments are made to ensure that the center of the ellipsoid mirror coincides with the center of the calibration plate, thus forming a standard spatial relationship detection system.

[0061] In this embodiment, please refer again. Figure 3 Furthermore, optical devices can be provided for optimizing the incident beam and the reflected beam path. These optical devices include a second reflecting mirror 18 disposed on the incident beam. The second reflecting mirror reflects the incident beam along the first propagation path to form a second propagation path, which is then transmitted to the reflecting mirror, forming an incident beam projected positively relative to the calibration plate. By providing the second reflecting mirror, the propagation path of the incident beam can be improved, and corresponding optical functional devices can be configured along the relatively long propagation path. The configuration of these optical functional devices can be tailored to specific scenarios and will not be elaborated upon in this embodiment.

[0062] For further details, please refer to [link / reference]. Figure 4 In this embodiment, a detection method is configured in the detection system to adjust the spatial position of the ellipsoidal mirror. This method includes: Step S41. Generate an incident light beam projected in the direction of the carrier, and form a reflected light signal through reflection by the carrier.

[0063] In this embodiment, a calibration plate is preferentially selected as the carrier, which includes at least one center point and multiple feature points. The forward-projected incident light beam is achieved in this embodiment using a coaxial light source and a reflector.

[0064] Step S42. Based on the reflected light signal, perform imaging to obtain a calibration image containing the carrier and the bottom contour of the ellipsoidal mirror.

[0065] Step S43. Adjust the spatial position of the ellipsoid mirror based on the relative positional deviation between the bottom contour of the ellipsoid mirror and the support in the real-time image.

[0066] In another possible implementation, the adjustment described in this embodiment is based on the premise that the image sensor and coaxial light source are in standard positions. Since the detection system experiences significant fluctuations during transport, these fluctuations can cause the image sensor and coaxial light source to move. If the positions of the image sensor and coaxial light source are inherently deviated, the acquired image cannot be used for correction of other optical components. Therefore, to ensure the overall accuracy of the detection equipment, an adjustment mechanism can be implemented to perform secondary calibration and correction of the image sensor and coaxial light source positions after the detection equipment has been running for a certain period.

[0067] This correction mechanism involves acquiring a standard image of the calibration plate in a standard position, which records the spatial positions of multiple feature points on the calibration plate. Then, this standard image is compared with the spatial positions of multiple feature points in a real-time image acquired by the image sensor. Because the connection between the calibration plate and the support platform is relatively stable, the calibration plate generally does not experience positional deviations due to external vibrations. Therefore, changes in the spatial position of the calibration plate image can determine whether there is a deviation between the image sensor and the coaxial light source.

[0068] In this embodiment, the acquisition of standard images of the calibration board in the standard position is achieved by setting up a temporary camera 19. For details, please refer to... Figure 5 A detection system is provided, in which a temporary camera, including a temporary image sensor and a temporary coaxial light source, is positioned at a standard location. Further, in this embodiment, the standard location is the placement location of the detector assembly. The standard image is acquired by replacing the detector assembly with a temporary camera. The temporary camera, positioned at the standard location, generates an incident light beam projected directly towards the calibration plate. The reflected light beam, generated based on the support, is then received, thereby acquiring a standard image containing the calibration plate.

[0069] The temporary camera is used only for standard images. That is, for this detection system, replacing the detector component with a temporary camera only occurs in the scene where the standard image is obtained. Generally, the standard image only needs to be acquired once and stored in the standard image memory 30. When needed, the image can be retrieved from the memory without requiring multiple installations and removals of the temporary camera.

[0070] In this embodiment, the controller is connected to the memory, the image sensor, and the coaxial light source. The controller retrieves a standard image from the memory and compares the standard spatial position relationship of the calibration board in the standard image with the spatial position relationship of the calibration board in the real-time image obtained by the image sensor to determine the deviation between the two. Then, the controller adjusts the spatial position of the image sensor and the coaxial light source based on the deviation.

[0071] For further details, please refer to [link / reference]. Figure 6 This embodiment also provides a detection method for adjusting the aforementioned deviation, which includes: Step S61. Generate an incident light beam projected in the direction of the carrier, and form a reflected light signal by reflection from the carrier.

[0072] In this embodiment, the incident light beam is emitted from a second coaxial light source in a temporary camera positioned at a standard location, which is also the placement position of the detector assembly. The detector placement position is adjusted based on the distribution of the received reflected light intensity signal, so that it is at the position with the maximum received light intensity; this is the standard position of the detector placement.

[0073] Then, the detector assembly is replaced with a temporary camera, and the temporary interplanetary spacecraft adjusts its position to acquire an image of the calibration plate, which becomes the standard image. The position adjustment of the detector assembly can be achieved using existing technologies and will not be elaborated upon in this embodiment.

[0074] Step S62. Based on the reflected light signal, perform imaging to obtain a calibration image containing the carrier and the bottom contour of the ellipsoidal mirror.

[0075] The image sensor acquires calibration images of the current support and the bottom contour of the ellipsoidal mirror based on the incident beam generated by the coaxial light source. The support is a calibration plate, which has a center point and multiple feature points.

[0076] Step S63. Extract the deviation between the feature point positions of the calibration plate in the calibration image and the feature point positions in the standard image, and adjust the spatial positions of the image sensor and the coaxial light source to the standard positions based on the deviation.

[0077] To determine the position of the calibration plate in the calibration image and the standard image, two sub-images of the calibration plate are obtained. Then, feature point matching is performed on the sub-images. Based on the matched feature points, the spatial transformation relationship between the two sub-images is determined, and the corresponding positional offset is determined based on this spatial transformation relationship. This can be understood as follows: a point in any sub-image can be transformed through perspective to obtain the corresponding position in the other sub-image. For more information on this perspective transformation relationship, please refer to [reference needed]. Figure 7 As shown.

[0078] In this embodiment, the feature point matching process uses feature operators in the prior art to obtain feature points and descriptors for each feature point in the calibration image and the standard image, and determines the feature point pairs in the two images by descriptor matching.

[0079] To determine the spatial transformation relationship between two images based on feature point pairs, in this embodiment, the transformation of the current position relative to the standard position is calculated by setting a homography transformation matrix, which is further refined into rotational change, left-right change, and front-back change. Based on the changes obtained above, the current position of the first camera is calibrated accordingly.

[0080] This homography matrix can be further decomposed into a rotation matrix and a translation vector. The positional changes of the image sensor can be determined by solving the homography matrix.

[0081] Specifically, for an image to rotate counterclockwise around a given origin by a certain angle, the analytical expression can be used as follows: , Where x and y represent the coordinates of any point before rotation, and This represents the coordinates of this point after rotation. Let be the rotation angle. Expressing it as a matrix is: For image translation, it is expressed by the following formula: , ,in Let x represent the translation of any point in the x and y directions. Since translation cannot be represented using matrix multiplication, homogeneous coordinates are introduced in this embodiment for matrix transformation.

[0082] In summary, the image transformation in this embodiment can be represented by the following formula: .

[0083] For each pair of matching points in the two images above: And can be further transformed into: , For each set of matching points in the two images, two sets of equations can be obtained, from which the homography matrix of this application can be derived. There are six degrees of freedom. Therefore, in this embodiment, a unique solution for the homography matrix is ​​obtained by acquiring three sets of non-collinear matching points.

[0084] In this embodiment, by obtaining the spatial transformation relationship between the calibration image and the standard image, the spatial transformation relationship between the current position of the image sensor and the standard position is determined, and the current position of the image sensor is corrected to the target position based on this spatial transformation relationship.

[0085] In summary, the detection system and method provided in this application embodiment utilize an image sensor to acquire calibration images of the carrier. The position of the image sensor is determined based on its spatial variation relationship with a pre-acquired standard image, and the sensor's position is adjusted to a target position. Based on this target position, the image sensor acquires images of multiple components within the detection system, and the spatial positions of these components are adjusted using the acquired images. Compared to existing technologies, this application embodiment solves the technical problem of existing technologies requiring repeated camera reassembly and adjustment during stability testing and optical path debugging, resulting in complex camera disassembly and reassembly processes.

[0086] See Figure 8 The present invention also provides a readable medium 80, which stores computer-readable instructions 801, including instructions for performing the aforementioned detection method.

[0087] The functions and technical effects of the readable medium 80 provided in the embodiments of the present invention can be referred to the technical effects of the calibration method in the foregoing embodiments, and will not be repeated here.

[0088] It should be noted that, in the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and / or methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of units / modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or modules may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0089] The units / modules described as separate components may or may not be physically separate. The components shown as units / modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units / modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0090] Furthermore, in the various embodiments of the present invention, the functional units / modules can be integrated into one processing unit / module, or each unit / module can exist physically separately, or two or more units / modules can be integrated into one unit / module. The integrated unit / module described above can be implemented in hardware or in the form of hardware plus software functional units / modules.

[0091] The integrated unit / module implemented as a software functional unit / module described above can be stored in a computer-readable storage medium. The software functional unit, stored in a storage medium, includes several instructions to cause one or more processors of a computer device (which may be a personal computer, server, or network device, etc.) to execute some steps of the methods described in the various embodiments of the present invention.

[0092] The integrated unit / module implemented as a software functional unit / module described above can be stored in a computer-readable storage medium. The software functional unit, stored in a storage medium, includes several instructions to cause one or more processors of a computer device (which may be a personal computer, server, or network device, etc.) to execute some steps of the methods described in the various embodiments of the present invention.

[0093] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A detection system, characterized in that, include: A platform, used to hold and support objects; An incident light source is used to project an incident light spot onto the surface of the carrier and form a scattered light beam through the surface of the carrier; An ellipsoidal mirror and a reflector disposed within the ellipsoidal mirror, the ellipsoidal mirror being placed above the carrier for collecting the scattered light beam and reflecting the scattered light beam to the detector assembly, the reflector being used to collect the scattered light beam and reflect the scattered light beam to form a reflected light beam, the reflected light beam propagating through an optical channel opened on the ellipsoidal mirror; An image sensor is positioned on the propagation path of the reflected light beam and performs imaging based on the reflected light beam to obtain a real-time image containing the incident light spot and the carrier. The controller is electrically connected to the incident light source and adjusts the spatial position of the incident light source based on the positional deviation between the light spot and the carrier in the real-time image.

2. The detection system according to claim 1, characterized in that, It also includes a coaxial light source coaxially arranged with the image sensor to generate an incident light beam and project it onto the carrier through the light channel. The reflected light signal is generated by the reflection of the carrier and transmitted to the image sensor through the reflector to form an image, thereby obtaining a calibration image containing the carrier and the bottom contour of the ellipsoidal mirror.

3. The detection system according to claim 2, characterized in that, The controller is electrically connected to the ellipsoidal mirror and adjusts the spatial position of the ellipsoidal mirror based on the relative positional deviation between the bottom contour of the ellipsoidal mirror and the support in the real-time image.

4. The detection system according to any one of claims 1-3, characterized in that, The carrier includes the object to be tested or a calibration plate, and the calibration plate is provided with multiple calibration points; each calibration point includes at least one center point.

5. The detection system according to any one of claims 2-3, characterized in that, The carrier includes a calibration plate, on which multiple calibration points are provided; the multiple calibration points include at least one center point and multiple auxiliary points symmetrically arranged around the center point.

6. The detection system according to claim 5, characterized in that, It also includes a temporary camera, which is set at a standard position to acquire reflected light, and acquires a standard image containing the object to be detected or the carrier based on the reflected light, and stores the standard image in a memory.

7. The detection system according to claim 6, characterized in that, The controller is connected to the memory, the image sensor, and the coaxial light source, and adjusts the spatial position of the image sensor and the coaxial light source based on the deviation between the real-time spatial position relationship of the carrier in the real-time image and the standard spatial position relationship.

8. A detection method, characterized in that, The method includes: An incident light spot is projected onto the surface of a carrier, and a scattered light beam is formed through the surface of the carrier; the carrier is a calibration plate, and the calibration plate is provided with multiple feature points; The scattered light beam is reflected to form a reflected light beam, and an image containing the incident light spot and the carrier is obtained based on the reflected light beam. The positional deviation between the incident light spot and the carrier in the real-time image is obtained, and the spatial position of the incident light source is adjusted based on the positional deviation until the incident light spot coincides with the center of the carrier.

9. The detection method according to claim 8, characterized in that, The method further includes: An incident light beam is generated that is projected in the direction of the support, and a reflected light signal is formed by the reflection of the support. Imaging is performed based on the reflected light signal to obtain a calibration image containing the outline of the carrier and the bottom of the ellipsoidal mirror; The spatial position of the ellipsoid is adjusted based on the relative positional deviation between the bottom contour of the ellipsoid and the support in the real-time image.

10. The detection method according to claim 8, characterized in that, The method further includes: An incident light beam is generated that is projected in the direction of the support, and a reflected light signal is formed by the reflection of the support. Imaging is performed based on the reflected light signal to obtain a calibration image containing the outline of the carrier and the bottom of the ellipsoidal mirror; The deviation between the feature point positions of the calibration plate in the calibration image and the feature point positions in the standard image is extracted, and the spatial positions of the image sensor and the coaxial light source are adjusted to the standard positions based on the deviation.

Images