Method and apparatus for scanning and imaging surface defects of a curved optical element

Abstract

The application provides a curved surface optical element surface defect scanning imaging method and device, the method comprises the following steps: determining the first scanning image quantity of the curved surface optical element along the meridian direction based on the edge latitude of the curved surface optical element and the spherical center angle corresponding to the imaging area of the scanning camera on the curved surface optical element; determining the second scanning image quantity of the curved surface optical element on each target parallel based on the spherical center angle and the latitude of each target parallel; obtaining a plurality of scanning images on the curved surface optical element based on the first scanning image quantity and the second scanning image quantity; and performing surface defect detection on the curved surface optical element based on the plurality of scanning images. The application can accurately obtain a plurality of scanning images on the curved surface optical element, and efficiently and accurately perform surface defect detection on the curved surface optical element based on the scanning images.

Description

Technical Field

[0001] This invention relates to the field of optical components technology, and in particular to a method and apparatus for scanning and imaging surface defects of curved optical components. Background Technology

[0002] Curved optical elements are optical components with curved shapes, widely used in various optical applications such as lasers, fiber optic communications, microscopes, and telescopes. After grinding and polishing, curved optical elements often have various defects (such as scratches, dents, cracks, chipped edges, and other surface defects). These defects not only reduce the user experience but can also affect the performance of the optical system.

[0003] Currently, surface defects in curved optical components are mostly detected manually by visual inspection. However, manual visual inspection is not only inefficient but also suffers from poor accuracy in subjective judgment. Therefore, how to efficiently and accurately detect defects on the surface of curved optical components has become an urgent problem to be solved. Summary of the Invention

[0004] This invention provides a method and apparatus for scanning and imaging surface defects of curved optical elements, which solves the problem of low efficiency and accuracy in detecting surface defects of curved optical elements in the prior art.

[0005] This invention provides a method for scanning and imaging surface defects of curved optical elements, comprising:

[0006] Based on the edge latitude of the curved optical element and the central angle of the imaging area of ​​the scanning camera on the curved optical element, the number of first scan images of the curved optical element along the meridian direction is determined.

[0007] Based on the central angle and the latitude of each target latitude line, the number of second scanned images of the curved optical element on each target latitude line is determined; the latitude of each target latitude line is determined based on the number of first scanned images and the edge latitude.

[0008] Based on the first number of scanned images and the second number of scanned images, multiple scanned images are obtained on the curved optical element; the multiple scanned images are used to detect surface defects on the curved optical element.

[0009] According to the present invention, a surface defect scanning imaging method for a curved optical element, wherein determining the number of first scan images of the curved optical element along the meridian direction based on the edge latitude of the curved optical element and the central angle corresponding to the imaging area of ​​the scanning camera on the curved optical element includes:

[0010] Based on the central angular interval and the central angular angle, an overlap coefficient is determined to characterize the overlap range between two adjacent imaging regions, wherein the central angular interval is used to characterize the central angular distance between the two adjacent imaging regions.

[0011] The number of the first scanned images is determined based on the overlap coefficient, the central angle, and the edge latitude.

[0012] According to the present invention, a surface defect scanning imaging method for a curved optical element, wherein determining the number of second scan images of the curved optical element on each target latitude line based on the central angle and the latitude of each target latitude line includes:

[0013] Based on the central angle, the central angle interval between two adjacent scanned images on each target latitude is determined;

[0014] The number of the second scanned images is determined based on the sphere center angle interval and the latitude of each target latitude line.

[0015] According to the present invention, a surface defect scanning imaging method for a curved optical element is provided, wherein acquiring multiple scanning images on the curved optical element based on a first number of scanning images and a second number of scanning images includes:

[0016] Based on the number of the first scanned images and the central angle, the latitude of the center point of each scanned image is determined;

[0017] Based on the number of the second scanned images, the central angle of the sphere, and the latitude of each target latitude line, the longitude of the center point of each scanned image is determined;

[0018] The plurality of scanned images are obtained based on the latitude of the center point of each scanned image and the longitude of the center point of each scanned image.

[0019] According to a surface defect scanning imaging method for curved optical elements provided by the present invention, the step of acquiring the plurality of scanning images based on the latitude of the center point of each scanning image and the longitude of the center point of each scanning image includes:

[0020] Based on the object distance of the scanning camera, the latitude of the center point of each scanned image, and the spherical radius of the curved optical element, the motion displacement of each translation axis on the scanning platform is determined when the scanning camera images at the latitude of the center point of each scanned image.

[0021] The rotation angle of each rotation axis on the scanning platform is determined based on the longitude of the center point of two adjacent scan images;

[0022] Based on the motion displacement of each translation axis and the rotation angle of each rotation axis, the position of the scanning camera is adjusted so that the scanning camera, after adjustment, can acquire the corresponding scanning image.

[0023] According to the present invention, a surface defect scanning imaging method for curved optical elements is provided, wherein the scanning platform is a five-axis motion platform, the five-axis motion platform includes a first translation axis, a second translation axis, a third translation axis, a first rotation axis, and a second rotation axis, the first translation axis and the second translation axis are horizontal translation axes and are perpendicular to each other, the third translation axis is a vertical translation axis, the first rotation axis is mounted on the platform formed by the first translation axis and the second translation axis, and the second rotation axis is fixed on the third translation axis.

[0024] The present invention also provides a surface defect scanning imaging device for curved optical elements, comprising:

[0025] The first determining unit is used to determine the number of first scan images of the curved optical element along the meridian direction based on the edge latitude of the curved optical element and the central angle corresponding to the imaging area of ​​the scanning camera on the curved optical element;

[0026] The second determining unit is used to determine the number of second scan images of the curved optical element on each target latitude line based on the central angle of the sphere and the latitude of each target latitude line; the latitude of each target latitude line is determined based on the number of first scan images and the edge latitude.

[0027] An image acquisition unit is used to acquire multiple scan images on the curved optical element based on the first number of scan images and the second number of scan images; the multiple scan images are used to detect surface defects on the curved optical element.

[0028] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the surface defect scanning imaging method for curved optical elements as described above.

[0029] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the surface defect scanning imaging method for curved optical elements as described above.

[0030] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the surface defect scanning imaging method for curved optical elements as described above.

[0031] The present invention provides a surface defect scanning imaging method and apparatus for curved optical elements. Based on the edge latitude and central angle of the curved optical element, the number of first scan images of the curved optical element along the meridian direction is determined. Based on the central angle and the latitude of each target latitude line, the number of second scan images of the curved optical element on each target latitude line is determined. Thus, multiple scan images on the curved optical element can be accurately obtained based on the number of first scan images and the number of second scan images, thereby enabling efficient and accurate surface defect detection of the curved optical element based on the scan images. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a schematic flowchart of the surface defect scanning imaging method for curved optical elements provided by the present invention;

[0034] Figure 2 This is a schematic diagram of the surface scanning path of the curved optical element provided by the present invention;

[0035] Figure 3 This is a schematic diagram of a scanned image along the meridian direction provided by the present invention;

[0036] Figure 4 This is a schematic diagram of a scanned image along the latitudinal direction provided by the present invention;

[0037] Figure 5 This is a schematic diagram of the scanning platform structure provided by the present invention;

[0038] Figure 6 This is a schematic diagram of the surface defect scanning imaging device for curved optical elements provided by the present invention;

[0039] Figure 7 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0041] Currently, surface defects of curved optical components (hereinafter referred to as "components") are mostly inspected manually by visual inspection. However, manual visual inspection is not only inefficient, but also has poor subjective judgment accuracy. Especially for large-aperture curved optical components with large radii of curvature and wide apertures, the manufacturing precision requirements are even higher.

[0042] In response, the present invention provides a method for scanning and imaging surface defects of curved optical elements. Figure 1 This is a schematic flowchart of the surface defect scanning imaging method for curved optical elements provided by the present invention, as shown below. Figure 1 As shown, the method includes the following steps:

[0043] Step 110: Based on the edge latitude of the curved optical element and the central angle of the imaging area of ​​the scanning camera on the curved optical element, determine the number of first scan images of the curved optical element along the meridian direction.

[0044] It should be noted that because the component has a large aperture and the scanning camera has a high resolution and a small field of view, complete imaging of the component surface requires imaging sub-aperture regions of the component at different locations. The imaging path for the component surface should cover all areas of the curved surface while minimizing the number of images taken. To simplify the image acquisition path design method, this invention adopts a method starting from the component center (I... 0,0 (To the edge, scanning along the latitude line.) Figure 2 As shown, the scanned image acquisition sequence is as follows: in This represents the m-th scanned image acquired at the nth latitude. The position of the scanned image is determined by the coordinates of its center point on the sphere of the element.

[0045] Here, the edge latitude of the component is used to characterize the degree of curvature of the component surface; the higher the edge latitude, the greater the curvature of the component surface. A scanning camera refers to a camera used to scan and photograph the surface of the component. Due to the high precision requirements of component detection, scanning cameras are typically high-resolution cameras paired with high-magnification lenses. The depth of field is relatively small, and the field of view is essentially fixed; that is, the imaging area of ​​the scanning camera on the component can be considered as a circular area of ​​fixed size on a sphere, with a corresponding central angle θ. The number of the first scan images refers to the number of imaging areas along the meridian direction. For example... Figure 2 As shown, with I 0,0 →I 1,0 Taking the meridian direction as an example, I 0,0 I 1,0 and I 2,0 These are the centers of the imaging areas along the meridian direction, meaning the number of the first scan images along the meridian direction is 3.

[0046] Considering that there must be no gaps between two adjacent imaging areas to ensure complete acquisition of the image of the component surface, the relationship between the spherical central angle interval (i.e., the spherical central angle distance between two adjacent imaging areas) and the spherical central angle can be determined. Since the surface of the component is spherical, the scanned images along the meridian direction are distributed in layers, and the distance between the center of the upper scanned image and the center of the component is smaller than the distance between the center of the lower scanned image and the center of the component.

[0047] Furthermore, the sphere center angle interval is the latitude difference between each layer of scanned images. Given the known center position of the element, the lower intersection latitude between the bottommost scanned images can be determined based on this latitude difference. To ensure that the bottommost scanned image completely covers the surface of the element, the lower intersection latitude is set greater than the edge latitude, thus obtaining the number of the first scanned images.

[0048] like Figure 2 As shown, with I 0,0 →I 1,0 Taking the meridian direction as an example, let's take I... 0,0 The scanned image centered on I is the topmost scanned image. 2,2 Centered scan images and with I 2,1 The scanned images centered on the element are both the lowest layer scanned images. When the latitude of the lower intersection point between these two lowest layer scanned images is greater than the edge latitude, the lowest layer scanned image can completely cover the surface of the element.

[0049] Step 120: Based on the central angle and the latitude of each target latitude line, determine the number of second scan images of the curved optical element on each target latitude line; the latitude of each target latitude line is determined based on the number of first scan images and the edge latitude.

[0050] Specifically, after determining the number of the first scan images, the corresponding scan images are evenly distributed along the meridian direction, and the dimension of the lower intersection point of the bottom scan image is greater than the edge latitude. Thus, the latitude of the corresponding scan image, i.e. the latitude of each target latitude line, can be determined.

[0051] After determining the latitude of each target latitude, the size of the circular region formed by the corresponding target latitude can be determined. Since the size of the circular region imaged by the scanning camera on a spherical surface is fixed, the number of second scan images on each target latitude can be determined, provided that there are no gaps between two adjacent scan images on each target latitude. It should be noted that the number of second scan images differs for target latitudes.

[0052] Step 130: Based on the number of first scan images and the number of second scan images, obtain multiple scan images on the curved optical element; the multiple scan images are used to detect surface defects on the curved optical element.

[0053] Specifically, after determining the number of first scan images and the number of second scan images, the longitude and latitude of the center point corresponding to each scan image can be determined. Then, based on the corresponding longitude and latitude of the center point, the position of the scanning camera can be adjusted to obtain the corresponding scan image.

[0054] The scanned images are used to characterize the semantic information of corresponding regions on the component surface, enabling surface defect detection. Optionally, each scanned image can be input into a pre-trained defect detection model, which extracts image features from each scanned image and determines whether a defect exists in the corresponding region based on these features, thus obtaining the detection result. The defect detection model can be trained based on sample component images and corresponding sample defect labels.

[0055] Therefore, the surface defect scanning imaging method for curved optical elements provided in this embodiment of the invention determines the number of first scan images of the curved optical element along the meridian direction based on the edge latitude and central angle of the curved optical element, and determines the number of second scan images of the curved optical element on each target latitude based on the central angle and the latitude of each target latitude. Thus, multiple scan images on the curved optical element can be accurately obtained based on the number of first scan images and the number of second scan images, thereby enabling efficient and accurate surface defect detection of the curved optical element based on the scan images.

[0056] Based on the above embodiments, step 110 includes:

[0057] Step 111: Based on the central angle interval and the central angle, determine the overlap coefficient used to characterize the overlap range between two adjacent imaging regions. The central angle interval is used to characterize the central angle distance between two adjacent imaging regions.

[0058] Step 112: Determine the number of first scan images based on the overlap coefficient, the central angle, and the edge latitude.

[0059] To reduce path planning complexity, the central angle interval between scanned images at different latitudes within the same longitude and between scanned images at different longitudes within the same latitude can be kept consistent; that is, the central angle interval can be set to Δθ. The value of Δθ is related to the central angle θ of the scanned area covered by a single scanned image; the larger θ is, the larger the central angle interval Δθ is.

[0060] Optionally, in this embodiment of the invention, an overlap coefficient k is used to construct the relationship between Δθ and θ, specifically as follows:

[0061] Δθ=kθ (1)

[0062] Here, k represents the overlap range between two adjacent imaging regions (i.e., scanned images). The smaller the k value, the larger the overlap range between two adjacent scanned images. To ensure that there are no gap regions between two adjacent images, such as... Figure 3 As shown, the upper layer image (I) in the figure 1,0 ,I 1,1 The lower intersection point between the two should be lower than the next layer image (I). 2,0 ,I 2,1 The upper intersection point between ) and . The spherical diameter of the factor aperture region d = Rθ, that is, d is directly proportional to θ, so I 2,0 The distance between A and I can be expressed as θ / 2. 1,0 with I 2,0 The distance between them can be expressed as Δθ, I 1,0 with I 2,1 The distance between them is the maximum distance between the diagonal scan images. When the maximum distance is greater than the sum of the radii of the two corresponding circular regions of the diagonal scan image (i.e., θ), a gap will be generated between the diagonal scan images. Therefore, the following geometric relationship can be obtained:

[0063]

[0064] Combining formulas (1) and (2), we can obtain:

[0065]

[0066] Based on the definition of Δθ, we can first determine the number and position of the first scanned images along the meridian direction, that is, determine the latitude value of each layer of images. Since the first scanned image is located at the apex of the sphere, i.e., the center of the sphere, and its corresponding latitude value α = 0, the latitude difference between each layer of scanned images is the central angular interval Δθ = kθ. For example... Figure 3 As shown, when the lowest layer image (I) 2,0 ,I 2,1 When the latitude of the lower intersection point between the two points is greater than the latitude of the element's edge, the imaging area can fully cover the element's surface. In this case:

[0067]

[0068] Where n is the number of the first scan images taken along the meridian direction, i.e., the number of image layers. nkθ is the latitude of the center of the lowest scan image layer. This is the latitude difference between the intersection point of the lowest scanned image and the image center. According to formula (4), we can obtain:

[0069]

[0070] in, This indicates rounding up to the nearest integer.

[0071] Based on any of the above embodiments, step 120 includes:

[0072] Step 121: Based on the central angle, determine the central angle interval between two adjacent scanned images on each target latitude line;

[0073] Step 122: Determine the number of second scan images based on the sphere center angle interval and the latitude of each target latitude line.

[0074] like Figure 4 As shown, P1 and P2 are at latitude α n The center of two adjacent scanned images (i.e., the latitude of the target latitude), and the longitude difference between two adjacent scanned images is Δθ. β R is the radius of the sphere, and r is the parallel α. n The radius of the circle enclosed by the circle, r, can be considered as the perpendicular distance from P1 or P2 to the optical axis of the element. The central angle interval between two adjacent scanned images is Δθ. Therefore, based on the spatial distance distance(P1,P2) between P1 and P2, the following system of equations can be obtained:

[0075]

[0076] Solving the system of equations (6), we obtain the longitude difference Δθ. β for:

[0077]

[0078] Therefore, the number of second scan images that need to be taken at the nth latitude (i.e., the target latitude) is m. n The following conditions must be met:

[0079] m n Δθ β ≥2π (8)

[0080] Substituting formula (7) into formula (8), we can obtain the solution:

[0081]

[0082] Based on any of the above embodiments, step 130 includes:

[0083] Step 131: Based on the number of the first scanned images and the central angle, determine the latitude of the center point of each scanned image;

[0084] Step 132: Based on the number of second scan images, the central angle, and the latitude of each target parallel, determine the longitude of the center point of each scan image;

[0085] Step 133: Based on the latitude of the center point of each scanned image and the longitude of the center point of each scanned image, obtain multiple scanned images.

[0086] Specifically, after determining the number of the first scanned images n and the central angle θ, the latitude α of the center point of each scanned image can be determined. i =ikθi=0…n.

[0087] In addition, the central angle θ and the latitude α of each target parallel are also considered. n The longitude difference Δθ between two adjacent scanned images is calculated using formula (7). β Furthermore, this is combined with the number of second scanned images m n The longitude β of the center point of each scanned image is obtained. i =(j-1)Δθ β j = 1…m n .

[0088] After determining the latitude and longitude of the center point of each scanned image, the position set P[α,β] of each scanned image can be obtained as follows:

[0089]

[0090] After determining the position of each scanned image, the position of the scanning camera can be adjusted according to the position of each scanned image, so that the scanning camera can capture multiple scanned images.

[0091] Based on any of the above embodiments, each scanning area is scanned to obtain a corresponding scanned image, including:

[0092] Based on the object distance of the scanning camera, the latitude of the center point of each scanning area, and the spherical radius of the curved optical element, the motion displacement of each translation axis on the scanning platform is determined when the scanning camera images at the latitude of the center point of each scanning area.

[0093] Based on the longitude of the center point of adjacent scanning areas, the rotation angle of each rotation axis on the scanning platform is determined;

[0094] Based on the motion displacement of each translation axis and the rotation angle of each rotation axis, the position of the scanning camera is adjusted so that the adjusted scanning camera can scan each scanning area and obtain the corresponding scanning image.

[0095] Taking a convex lens as an example, when the scanning platform moves along the meridian, the axes involved in the movement are the X-axis (translation axis), Z-axis (translation axis), and C-axis (rotation axis). Let R be the radius of the sphere, L be the object distance of the scanning camera, and α... i Let α be the latitude of the center point of the scanned image captured by the scanning camera. Let the point where the scanning camera takes a picture at latitude 0 be the origin. Then, the latitude of the scanning camera at α... i The motion displacement Δx1 along the X-axis, the motion displacement Δz1 along the Z-axis, and the rotation angle Δθ along the C-axis during imaging at latitude. C1 as follows:

[0096]

[0097] Correspondingly, when the element is a concave lens, the scanning camera has a moving displacement Δx2 of the X-axis, a moving displacement Δz2 of the Z-axis, and a rotation angle Δθ of the C-axis when imaging at the α i latitude, as follows: C2 As follows:

[0098]

[0099] Among them, when L > R, the scanning camera moves forward on the corresponding translation axis, and when L < R, the scanning camera moves backward on the corresponding translation axis.

[0100] When scanning along the latitude direction of the element, first align the optical axis of the element with the rotation axis A of the scanning platform. At this time, the rotation angle Δθ A of the rotation axis A is the longitude change value Δβ of the imaging center of the scanning camera on the surface of the element, that is:

[0101]

[0102] Based on any of the above embodiments, the scanning platform is a five-axis motion platform. The five-axis motion platform includes a first translation axis, a second translation axis, a third translation axis, a first rotation axis, and a second rotation axis. The first translation axis and the second translation axis are horizontal translation axes and are perpendicular to each other. The third translation axis is a vertical translation axis. The first rotation axis is installed on the platform formed by the first translation axis and the second translation axis, and the second rotation axis is fixed on the third translation axis.

[0103] As Figure 5 shown, the scanning platform is a five-axis motion platform, composed of three translation axes X - Y - Z and two rotation axes A - C. Among them, the X - Y axes are perpendicular to each other and are horizontal translation axes, and the Z axis is a vertical translation axis. The rotation axis A is fixed on the X - Y axis platform and is used to install the stage and the element holder for placing the element to be detected. The rotation axis C is fixed on the Z axis and is used to install the imaging system and the lighting system.

[0104] The surface defect scanning imaging device for a curved optical element provided by the present invention will be described below. The surface defect scanning imaging device for a curved optical element described below can be mutually referred to correspondingly with the surface defect scanning imaging method for a curved optical element described above.

[0105] Based on any of the above embodiments, the present invention further provides a surface defect scanning imaging device for a curved optical element. As Figure 6 shown, the device includes:

[0106] The first determining unit 610 is used to determine the number of first scan images of the curved optical element along the meridian direction based on the edge latitude of the curved optical element and the central angle of the imaging area of ​​the scanning camera on the curved optical element.

[0107] The second determining unit 620 is used to determine the number of second scan images of the curved optical element on each target latitude based on the central angle and the latitude of each target latitude; the latitude of each target latitude is determined based on the number of first scan images and the edge latitude.

[0108] The image acquisition unit 630 is used to acquire multiple scan images on the curved optical element based on the first number of scan images and the second number of scan images;

[0109] The defect detection unit 640 is used to detect surface defects in curved optical elements based on multiple scanned images.

[0110] Figure 7 This is a schematic diagram of the structure of the electronic device provided by the present invention, such as... Figure 7 As shown, the electronic device may include a processor 710, a memory 720, a communication interface 730, and a communication bus 740, wherein the processor 710, memory 720, and communication interface 730 communicate with each other through the communication bus 740. The processor 710 can call logical instructions in the memory 720 to execute a surface defect scanning imaging method for curved optical elements. This method includes: determining a first number of scanned images of the curved optical element along the meridian direction based on the edge latitude of the curved optical element and the central angle corresponding to the imaging area of ​​the scanning camera on the curved optical element; determining a second number of scanned images of the curved optical element on each target latitude line based on the central angle and the latitude of each target latitude line; the latitude of each target latitude line is determined based on the first number of scanned images and the edge latitude; acquiring multiple scanned images on the curved optical element based on the first number of scanned images and the second number of scanned images; the multiple scanned images are used to detect surface defects on the curved optical element.

[0111] Furthermore, the logical instructions in the aforementioned memory 720 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0112] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, wherein when the program instructions are executed by a computer, the computer is able to execute the surface defect scanning imaging method for curved optical elements provided by the above methods, the method comprising: determining a first number of scan images of the curved optical element along the meridian direction based on the edge latitude of the curved optical element and the central angle corresponding to the imaging area of ​​the scanning camera on the curved optical element; determining a second number of scan images of the curved optical element on each target latitude based on the central angle and the latitude of each target latitude; the latitude of each target latitude being determined based on the first number of scan images and the edge latitude; acquiring a plurality of scan images on the curved optical element based on the first number of scan images and the second number of scan images; the plurality of scan images being used to detect surface defects on the curved optical element.

[0113] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the surface defect scanning imaging method for the curved optical element provided above. The method includes: determining a first number of scanned images of the curved optical element along a meridian direction based on the edge latitude of the curved optical element and the central angle corresponding to the imaging area of ​​the scanning camera on the curved optical element; determining a second number of scanned images of the curved optical element on each target latitude line based on the central angle and the latitude of each target latitude line; the latitude of each target latitude line being determined based on the first number of scanned images and the edge latitude; acquiring a plurality of scanned images on the curved optical element based on the first number of scanned images and the second number of scanned images; the plurality of scanned images being used to detect surface defects on the curved optical element.

[0114] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units 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 modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0115] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0116] 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for scanning and imaging surface defects of curved optical elements, characterized in that, include: Based on the edge latitude of the curved optical element and the central angle of the imaging area of ​​the scanning camera on the curved optical element, the number of first scan images of the curved optical element along the meridian direction is determined. Based on the central angle and the latitude of each target latitude line, the number of second scan images of the curved optical element on each target latitude line is determined; The latitude of each target latitude is determined based on the number of the first scanned images and the edge latitude; Based on the first number of scanned images and the second number of scanned images, multiple scanned images are obtained on the curved optical element; the multiple scanned images are used to detect surface defects on the curved optical element. The determination of the number of first scan images of the curved optical element along the meridian direction, based on the edge latitude of the curved optical element and the central angle corresponding to the imaging area of ​​the scanning camera on the curved optical element, includes: Based on the central angular interval and the central angular angle, an overlap coefficient is determined to characterize the overlap range between two adjacent imaging regions, wherein the central angular interval is used to characterize the central angular distance between the two adjacent imaging regions. The number of the first scanned images is determined based on the overlap coefficient, the central angle, and the edge latitude.

2. The surface defect scanning imaging method for curved optical elements according to claim 1, characterized in that, The determination of the number of second scan images of the curved optical element on each target latitude line based on the central angle of the sphere and the latitude of each target latitude line includes: Based on the central angle, the central angle interval between two adjacent scanned images on each target latitude is determined; The number of the second scanned images is determined based on the sphere center angle interval and the latitude of each target latitude line.

3. The surface defect scanning imaging method for curved optical elements according to claim 1, characterized in that, The step of obtaining multiple scanned images on the curved optical element based on the first number of scanned images and the second number of scanned images includes: Based on the number of the first scanned images and the central angle, the latitude of the center point of each scanned image is determined; Based on the number of the second scanned images, the central angle of the sphere, and the latitude of each target latitude line, the longitude of the center point of each scanned image is determined; The plurality of scanned images are obtained based on the latitude of the center point of each scanned image and the longitude of the center point of each scanned image.

4. The surface defect scanning imaging method for curved optical elements according to claim 3, characterized in that, The process of obtaining the plurality of scanned images based on the latitude and longitude of the center point of each scanned image includes: Based on the object distance of the scanning camera, the latitude of the center point of each scanned image, and the spherical radius of the curved optical element, the motion displacement of each translation axis on the scanning platform is determined when the scanning camera images at the latitude of the center point of each scanned image. The rotation angle of each rotation axis on the scanning platform is determined based on the longitude of the center point of two adjacent scan images; Based on the motion displacement of each translation axis and the rotation angle of each rotation axis, the position of the scanning camera is adjusted so that the scanning camera, after adjustment, can acquire the corresponding scanning image.

5. The surface defect scanning imaging method for curved optical elements according to claim 4, characterized in that, The scanning platform is a five-axis motion platform, which includes a first translation axis, a second translation axis, a third translation axis, a first rotation axis, and a second rotation axis. The first translation axis and the second translation axis are horizontal translation axes and are perpendicular to each other. The third translation axis is a vertical translation axis. The first rotation axis is mounted on the platform formed by the first translation axis and the second translation axis, and the second rotation axis is fixed on the third translation axis.

6. A surface defect scanning imaging device for curved optical elements, characterized in that, include: The first determining unit is used to determine the number of first scan images of the curved optical element along the meridian direction based on the edge latitude of the curved optical element and the central angle corresponding to the imaging area of ​​the scanning camera on the curved optical element; The second determining unit is used to determine the number of second scan images of the curved optical element on each target latitude line based on the central angle of the sphere and the latitude of each target latitude line; The latitude of each target latitude is determined based on the number of the first scanned images and the edge latitude; An image acquisition unit is configured to acquire multiple scan images on the curved optical element based on the first number of scan images and the second number of scan images; the multiple scan images are used to detect surface defects on the curved optical element. The determination of the number of first scan images of the curved optical element along the meridian direction, based on the edge latitude of the curved optical element and the central angle corresponding to the imaging area of ​​the scanning camera on the curved optical element, includes: Based on the central angular interval and the central angular angle, an overlap coefficient is determined to characterize the overlap range between two adjacent imaging regions, wherein the central angular interval is used to characterize the central angular distance between the two adjacent imaging regions. The number of the first scanned images is determined based on the overlap coefficient, the central angle, and the edge latitude.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the surface defect scanning imaging method for curved optical elements as described in any one of claims 1 to 5.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the surface defect scanning imaging method for curved optical elements as described in any one of claims 1 to 5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the surface defect scanning imaging method for curved optical elements as described in any one of claims 1 to 5.

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