Surface detection device for curved lens

Abstract

The surface detection device comprises a point light source, a lens bearing part and a first camera which are arranged in sequence, the first camera is provided with a telecentric lens, the lens bearing part is used for bearing the curved lens, a first distance is formed between the point light source and the lens bearing part, and a second distance is formed between the point light source and the lens bearing part. The first distance enables emergent light emitted by the point light source to become first parallel light after passing through the curved lens, the telecentric lens is used for receiving the first parallel light, and the first camera is used for generating surface imaging of the curved lens according to the first parallel light. The surface detection device has the advantages of clear imaging and high defect detection precision.

Description

Technical Field

[0001] The utility model relates to the field of surface detection of objects, in particular to a surface detection device for curved lenses. Background Art

[0002] In order to detect whether there are defects such as bad areas and bad pixels on surfaces such as lenses and mobile phone screens that affect use, optical means can be used to image these surfaces and judge the surface defects of the objects based on the generated images. Figure 1 This is a schematic diagram of the detection principle of a currently used screen detector. Figure 1 As shown, the screen to be tested 101 is placed between the light source 110 and the camera 120. The light source 110 provides parallel light through the telecentric lens 111. The irradiation direction of the parallel light is as shown in FIG. Figure 1 As shown by the parallel arrows in . The camera 120 also has a telecentric lens 121, which receives the parallel light, thereby generating a surface image of the screen 101 to be measured in the camera 120. The telecentric lens can ensure that the image magnification does not change with the change of the object distance within a certain object distance range, and therefore has been widely used in the fields of medical equipment, machine vision, image measurement, microscopy, etc. Compared with ordinary backlight sources, telecentric lenses have higher parallelism. The use of telecentric parallel light sources can eliminate the phenomenon of edge blur caused by diffuse reflection of the light source, obtain images with clear and sharp edges, and improve measurement accuracy. However, the volume of the telecentric lens is relatively large. Since telecentric lenses need to be set on both the light source 110 and the camera 120, the volume of the entire detector will be larger.

[0003] Figure 2 The following is a schematic diagram of the structure and detection principle of another inspection device for detecting surface defects. The inspection device includes a camera 210, a lens 220, a point light source 230, a beam splitter 240, and a reflector 250. Camera 210 includes a telecentric lens 211. Light emitted from point light source 230 passes through lens 220 and becomes parallel light. This parallel light changes direction after passing through beam splitter 240 and illuminates object 201. If object 201 is translucent, this parallel light passes through object 201, is reflected by reflector 250, and then passes through beam splitter 240 before entering camera 210, thereby obtaining a surface image of object 201.

[0004] Figure 2 The detection device shown includes only one telecentric lens. Figure 1This reduces the size of the screen inspection instrument. However, all of the above technical solutions are only suitable for detecting flat defects, ensuring that the light entering the telecentric lens is primarily parallel light. If the surface of the object to be inspected is curved, sufficient parallel light cannot enter the telecentric lens, thus losing its advantages and failing to obtain a clear image. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a surface detection device suitable for detecting surface defects of curved lenses.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is a surface detection device for a curved lens, comprising a point light source, a lens carrier and a first camera arranged in sequence, wherein the first camera has a telecentric lens, the lens carrier is used to carry the curved lens, and there is a first distance between the point light source and the lens carrier. The first distance allows the outgoing light emitted by the point light source to become a first parallel light after passing through the curved lens. The telecentric lens is used to receive the first parallel light, and the first camera is used to generate a surface imaging of the curved lens based on the first parallel light.

[0007] In one embodiment of the present application, the curved lens is a convex lens.

[0008] In one embodiment of the present application, the curved lens is a concave lens.

[0009] In one embodiment of the present application, a first lens is further included, which is arranged between the point light source and the lens carrier. There is a second distance between the point light source and the first lens. The outgoing light emitted by the point light source becomes the first parallel light after passing through the first lens and the curved lens.

[0010] In one embodiment of the present application, the first lens and the curved lens are combined to have a first focus on a side close to the point light source, and the point light source is located at the first focus.

[0011] In one embodiment of the present application, the first lens is a convex lens.

[0012] In one embodiment of the present application, the first lens is a liquid lens.

[0013] In one embodiment of the present application, when the curved lens is carried on the lens carrier, the point light source, the curved lens and the telecentric lens are coaxial.

[0014] In one embodiment of the present application, it also includes a beam splitter, a second lens and a second camera. The beam splitter is arranged between the lens carrier and the telecentric lens. The beam splitter is used to allow the first parallel light to pass through and at the same time reflect the first parallel light into second parallel light. The second lens and the second camera are arranged in sequence on the optical path of the second parallel light. After passing through the second lens, the second parallel light is captured and imaged by the second camera. The second camera is used to monitor the parallelism of the first parallel light.

[0015] In an embodiment of the present application, the second lens has a second focus on a side close to the second camera, and the second camera is located at the second focus.

[0016] The surface inspection device of the present application utilizes the inherent characteristics of curved lenses, using a point light source to generate a first parallel light beam. This allows for the formation of surface imaging of the curved lens through a telecentric lens, leveraging the inherent advantages of the telecentric lens to facilitate the acquisition of clear images, thereby helping to improve the accuracy of surface defect detection. The surface inspection device of the present application is suitable for surface defect detection on curved lenses, including convex and concave lenses, and offers high detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the following describes in detail the specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0018] Figure 1 This is a schematic diagram of the detection principle of a currently used screen detector;

[0019] Figure 2 It is a schematic diagram of the structure and detection principle of another detection device for detecting surface defects;

[0020] Figure 3 is a schematic diagram of an exemplary structure of a surface detection device according to an embodiment of the present application;

[0021] Figure 4 is a schematic diagram of an exemplary structure of a surface detection device according to another embodiment of the present application;

[0022] Figure 5 It is an exemplary structural diagram of a surface detection device according to another embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0024] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0025] As used in this application and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0026] In the description of this application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0027] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is solely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. Furthermore, while the terms used in this application are selected from commonly known and commonly used terms, some terms mentioned in this specification may have been selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant sections of this description. Furthermore, this application should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0028] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. However, the embodiments shown below are examples of surface detection devices for curved lenses that are used to concretize the technical ideas of the present invention, and the surface detection devices for curved lenses of the present invention are not specifically the following contents. Furthermore, in order to facilitate the understanding of the scope of the claims, this specification assigns numbers corresponding to the components shown in the embodiments to the components shown in the "Claims" and "Contents of the Utility Model" columns. However, the components shown in the claims are by no means specific to the components of the embodiments. In particular, the dimensions, materials, shapes, and relative configurations of the constituent components described in the embodiments, unless specifically described, are not intended to limit the scope of the present invention to these only, but are merely illustrative examples.

[0029] However, the dimensions or positional relationships of the components shown in the drawings are sometimes exaggerated for the purpose of clarifying the description. Furthermore, in the following description, for components that are identical or homogeneous, the same name or symbol will be used, and its detailed description will be omitted as appropriate. Furthermore, the various elements constituting the present invention may be in the form of multiple elements being constituted by the same component so that one component serves as multiple elements, or conversely, multiple components sharing the function of one component. In addition, the contents described in some embodiments and implementation methods may also be utilized in other embodiments, implementation methods, etc. In addition, in this specification, "on" is not limited to the case where it is formed in contact with the upper surface, but also includes the case where it is formed separately above, and is also used to include the meaning of the presence of an intervening layer between layers.

[0030] The surface detection device for curved lenses of the present application is suitable for detecting surface defects of any lens with a curved surface.

[0031] Figure 3 It is a schematic diagram of an exemplary structure of a surface detection device according to an embodiment of the present application. Figure 3 The surface detection device 300 may be presented from a top view or a front view. Figure 3 As shown, the surface detection device 300 of this embodiment includes a point light source 310, a lens carrier 302, and a first camera 330 arranged in sequence along a first direction D1, wherein the first camera 330 has a telecentric lens 331. The present application does not limit the specific structure of the telecentric lens 331, and a telecentric lens commonly used in the field can be used. The present application also does not limit the first direction D1. In actual products, the first direction D1 is determined by the placement direction of the surface detection device. It should be noted that the first direction D1 is parallel to the direction of the parallel light received by the telecentric lens 331.

[0032] like Figure 3 , the lens carrier 302 is used to carry the curved lens 301 to be measured. Figure 3 As shown, in this embodiment, the curved lens 301 is a convex lens. In other embodiments, the curved lens 301 may be a concave lens. This specification and the accompanying drawings use a convex lens as an example and are not intended to limit the curved lens 301 to a convex lens.

[0033] There is a first distance L1 between the point light source 310 and the lens carrier 302, such as Figure 3 As shown, the first distance L1 refers to the vertical distance between the light source 310 and the lens carrier 302 .

[0034] In some embodiments, the surface detection device 300 of this embodiment further includes a light source carrier 320, such as Figure 3As shown, the light source carrier 320 is used to carry the point light source 310. On the one hand, it can fix the point light source 310, and on the other hand, it can adjust the position of the point light source 310. By setting a suitable first distance L1, the outgoing light emitted by the point light source 310 becomes the first parallel light after passing through the curved lens 301. Figure 3 As shown by the radial arrows between the point light source 310 and the curved lens 301; the first parallel light is as shown in FIG. Figure 3 As shown by the parallel arrows between the curved lens 301 and the circular lens 331.

[0035] Furthermore, in some embodiments, the light source carrier 320 may include a first track 321 and a second track 322. The first track 321 extends along the second direction D2 and can be used to adjust the position of the point light source 310 in the second direction D2. The second track 322 extends along the first direction D1 and can be used to adjust the position of the point light source 310 in the first direction D1. The first direction D1 is perpendicular to the second direction D2.

[0036] Furthermore, in some embodiments, the detection device 300 includes a frame 340 , and the light source carrier 320 further includes an auxiliary track 323 disposed on the frame 340 for assisting in adjusting the position of the point light source 310 in the first direction D1 .

[0037] like Figure 3 As shown, the first camera 330 and the telecentric lens 331 are an integrated device. This application does not limit the specific structure, sensor type and imaging principle of the first camera 330. The sensor used can be a CCD, CMOS image sensor, etc.

[0038] The surface detection device 300 of the present application utilizes the characteristics of the object to be tested, that is, the curved lens 301 itself, so that the light entering the telecentric lens 331 is the first parallel light, and a clear image of the surface of the curved lens 301 can be obtained, which is conducive to the use of image processing methods to perform defect detection and improve detection accuracy.

[0039] Figure 4 FIG. 1 is a schematic diagram of an exemplary structure of a surface detection device according to another embodiment of the present application. Figure 4 As shown, the surface detection device 400 is Figure 3 The first lens 410 is added to the embodiment shown, and the other elements adopt the same Figure 3 The same reference numerals in the figure represent the same structure and will not be further described. Figure 4The first lens 410 is disposed between the point light source 310 and the lens carrier 302, and a second distance L2 is defined between the point light source 310 and the first lens 410. The second distance L2 represents a vertical distance between the point light source 310 and the first lens 410. Considering that the first lens 410 is a convex lens or a curved lens, the second distance L2 represents an average vertical distance or a shortest distance between the point light source 310 and the first lens 410.

[0040] like Figure 4 As shown, in this embodiment, the first lens 410 is a convex lens. According to these embodiments, the first lens 410 and the curved lens 301 are combined to have a first focal point F1 on the side close to the point light source 310. By adjusting the position of the point light source 310, the point light source 310 can be located at the first focal point F1, so that the outgoing light emitted by the point light source 310 can become a first parallel light after passing through the first lens 410 and the curved lens 301. Therefore, when the first lens 410 is selected as a convex lens, the position of the point light source 310 can be adjusted. However, if the first lens 410 is replaced with another convex lens, the position of the point light source 310 needs to be adjusted according to the position of the first focal point F1.

[0041] In some embodiments, the first lens 410 is a liquid lens. This liquid lens can be any liquid lens commonly used in the art, which has the characteristic of variable curvature, and its focal length can be changed by changing the curvature. According to these embodiments, the position of the first lens 410 and the first focal point F1 of the curved lens 301 can be changed by changing the focal length of the first lens 410. Therefore, in order to make the point light source 310 at the first focal point F1, it is sufficient to change the focal length of the first lens 410 without changing the position of the point light source 310. This makes it unnecessary to set a mechanism for adjusting the position of the point light source 310 in the surface detection device 400, and the structure is simple.

[0042] When the curved lens 301 to be tested is a concave lens, the generation of the first parallel light can be ensured by adding the first lens 410, so that the surface inspection device 400 is more suitable for detecting surface defects of concave lenses.

[0043] Figure 5 FIG. 1 is a schematic diagram of an exemplary structure of a surface detection device according to another embodiment of the present application. Figure 5 As shown, the surface detection device 500 is Figure 3 On the basis of the embodiment shown, a beam splitter 510, a second lens 520 and a second camera 530 are added, and the other components adopt the same Figure 3 The same reference numerals in the figure represent the same structure and will not be further described. Figure 5As shown, the beam splitter 510 is disposed between the lens carrier 302 and the telecentric lens 331. The beam splitter 510, also known as a semi-transparent mirror, has both reflective and transmissive properties. In some embodiments, the beam splitter 510 is a prism. In the surface inspection device 500 of the present application, the beam splitter 510 is configured to allow the first parallel light emitted from the curved lens 301 to pass through while reflecting the first parallel light as a second parallel light.

[0044] like Figure 5 As shown, the parallel arrows from the reflective surface 511 of the beam splitter 510 to the second lens 520 are used to represent the second parallel light. By adjusting the inclination angle of the reflective surface 511 of the beam splitter 510, the optical path direction of the second parallel light can be adjusted. Figure 5 In the embodiment, the direction of the second parallel light is perpendicular to the direction of the first parallel light. This application does not limit whether the directions of the two are perpendicular.

[0045] like Figure 5 As shown, the second lens 520 and the second camera 530 are sequentially arranged on the optical path of the second parallel light. After passing through the second lens 520, the second parallel light is captured by the second camera 530 and an image is formed. The second camera 530 is used to monitor the parallelism of the first parallel light. The second camera 530 can be a common camera. Based on the image formed by the second camera 530, the parallelism of the second parallel light can be evaluated, and thus the parallelism of the first parallel light can be evaluated.

[0046] In some embodiments, the second lens 520 has a second focal point F2 on the side closest to the second camera 530, and the second camera 530 is located at the second focal point F2. According to this embodiment, the image of the second parallel light beam in the second camera 530 is a clear circular dot, representing the image of a point light source. The parallelism of the first parallel light beam can be evaluated by performing image processing and analysis on the image captured by the second camera 530. It is understood that if the image captured by the second camera 530 is a clear circular dot, the parallelism of the first parallel light beam is high; if the image captured by the second camera 530 is blurred, the parallelism of the first parallel light beam is low.

[0047] according to Figure 5 The surface detection device 500 shown is further provided with a device for monitoring the parallelism of the first parallel light. When the parallelism of the first parallel light is found to be low, the position of the point light source 310 can be adjusted to improve the parallelism of the first parallel light.

[0048] Combine Figure 4 and Figure 5 , another surface detection device can be formed which includes both a first lens and a parallel light monitoring element. By using this surface detection device, when it is found that the parallelism of the first parallel light is low, the curvature of the liquid lens serving as the first lens can be adjusted to improve the parallelism of the first parallel light.

[0049] In the above-mentioned surface detection devices 300, 400, and 500, the present application does not limit the specific positions of the point light source 310, the curved lens 301, and the telecentric lens 331. The only condition to be met is that the telecentric lens 331 can obtain the first parallel light sufficient to generate an accurate image.

[0050] In some embodiments, when the lens carrier 302 carries the curved lens 301, the point light source 310, the curved lens 301 and the telecentric lens 331 are coaxial. Figure 3 According to these embodiments, it can be further ensured that the telecentric lens 331 can obtain sufficient first parallel light.

[0051] Although the above disclosure discusses some currently useful embodiments of the present invention through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the spirit and scope of the present invention. For example, although the system components described above can be implemented using hardware devices, they can also be implemented using software solutions, such as installing the described system on an existing server or mobile device.

[0052] Similarly, it should be noted that, in order to simplify the presentation of the present disclosure and thus facilitate understanding of one or more embodiments of the present disclosure, the foregoing descriptions of the embodiments of the present disclosure sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of the present disclosure requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0053] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of the scope of some embodiments of the present invention are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0054] Although the present invention has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present invention, and various equivalent changes or substitutions can be made without departing from the spirit of the present invention. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present invention, they will fall within the scope of the claims of this application.

Claims

1. A surface detection device for a curved lens, characterized in that: It includes a point light source, a lens carrier and a first camera arranged in sequence, wherein the first camera has a telecentric lens, the lens carrier is used to support a curved lens, there is a first distance between the point light source and the lens carrier, the first distance allows the outgoing light emitted by the point light source to become a first parallel light after passing through the curved lens, the telecentric lens is used to receive the first parallel light, and the first camera is used to generate a surface imaging of the curved lens based on the first parallel light.

2. The surface detection device according to claim 1, wherein The curved lens is a convex lens.

3. The surface detection device according to claim 1, wherein The curved lens is a concave lens.

4. The surface detection device according to claim 1, wherein It also includes a first lens, which is arranged between the point light source and the lens carrier. There is a second distance between the point light source and the first lens. The outgoing light emitted by the point light source becomes the first parallel light after passing through the first lens and the curved lens.

5. The surface detection device according to claim 4, wherein: The first lens and the curved lens are combined to have a first focus on a side close to the point light source, and the point light source is located at the first focus.

6. The surface detection device according to claim 4, wherein: The first lens is a convex lens.

7. The surface detection device according to claim 4, wherein: The first lens is a liquid lens.

8. The surface detection device according to claim 1, wherein: When the curved lens is carried on the lens carrier, the point light source, the curved lens and the telecentric lens are coaxial.

9. The surface detection device according to claim 1, wherein: It also includes a beam splitter, a second lens and a second camera. The beam splitter is arranged between the lens carrier and the telecentric lens. The beam splitter is used to allow the first parallel light to pass through and at the same time reflect the first parallel light into second parallel light. The second lens and the second camera are arranged in sequence on the optical path of the second parallel light. After passing through the second lens, the second parallel light is captured and imaged by the second camera. The second camera is used to monitor the parallelism of the first parallel light.

10. The surface detection device according to claim 9, wherein: The second lens has a second focus on a side close to the second camera, and the second camera is located at the second focus.

Images