Camera module and detection device having the same

Abstract

This application discloses a camera module and a detection device having the same. The camera module includes: a camera, including at least a lens; a ring light source disposed on the lens, the ring light source having a ring light-emitting surface; a light-shielding ring disposed on the inner ring of the ring light source, the ring light-emitting surface being located on the outer periphery of the light-shielding ring; and a second dimming element disposed on the inner ring of the light-shielding ring. The inner ring of the light-shielding ring near the lens end has a convex ring. In the front-rear direction, the convex ring is located between the second dimming element and the lens, and the convex ring can form a light-shielding structure on the front side of the lens. A first gap exists between the end face of the light-shielding ring near the lens end and the lens in the front-rear direction, so that a first light-shielding cavity is formed between the convex ring and the lens. The second dimming element can be adjusted relative to the light-shielding ring in the front-rear direction to form a dimming structure acting on the ring light-emitting surface and the lens. The second dimming element and the light-shielding ring enclose a second light-shielding cavity located on the front side of the convex ring.

Description

Technical Field

[0001] This application belongs to the technical field of appearance inspection equipment, specifically relating to a camera module and an inspection device having the same. Background Technology

[0002] After wafer fabrication, surface defect detection is required to ensure product quality. Current technology involves capturing images of the wafer using a camera module and then identifying surface defects using image analysis software. However, existing camera modules are susceptible to the effects of light sources and wafer reflections, resulting in poor image quality. Therefore, it is necessary to improve the existing technology to overcome these shortcomings. Summary of the Invention

[0003] Therefore, the technical problem to be solved by this application is to provide a camera module with good imaging effect and a detection device having it.

[0004] To address the aforementioned technical problems, this application provides a camera module, comprising: a camera, including at least a lens; a ring light source disposed on the lens, the inner ring of the ring light source having an annular light-emitting surface on its inner circumference at the end furthest from the lens; a light-shielding ring disposed on the inner circumference of the ring light source, the annular light-emitting surface located on the outer periphery of the light-shielding ring; and a second dimming element disposed on the inner circumference of the light-shielding ring and being annular in shape; wherein, the inner circumference of the light-shielding ring near the lens has a convex ring; in the front-rear direction, the convex ring is located on the outer periphery of the lens. Between the second dimming element and the lens, the convex ring can form a light-blocking structure on the front side of the lens; there is a first gap in the front-rear direction between the end face of the light-blocking ring near the lens and the lens, so that a first light-blocking cavity is formed between the convex ring and the lens; the second dimming element can adjust its position relative to the light-blocking ring in the front-rear direction to form a dimming structure acting on the annular light-emitting surface and the lens, and a second light-blocking cavity located on the front side of the convex ring is formed between the second dimming element and the light-blocking ring.

[0005] In some embodiments, a first adjustment structure is provided between the second dimming element and the light-shielding ring, and the first adjustment structure is used to adjust the position of the second dimming element in the front-rear direction; The first adjustment structure includes an oblong hole on the second dimming element and an adjustment bolt inserted into the oblong hole, wherein the light-shielding ring is provided with a hole that cooperates with the adjustment bolt, and the oblong hole extends in the front-back direction.

[0006] In some embodiments, the convex ring is fixed to the top of the light-shielding ring, and the distance between the top surface of the convex ring and the lens in the front-rear direction is the first spacing. The ring light source is mounted on the lens via a bracket. A second adjustment structure is provided between the bracket and the lens. The second adjustment structure can adjust the position of the bracket in the front and rear directions, thereby adjusting the size of the first gap.

[0007] In some embodiments, a second anti-reflective pad is provided on the top surface of the convex ring, and a first anti-reflective pad is provided on the bottom surface of the convex ring, wherein the inner diameter of the first anti-reflective pad is equal to the inner diameter of the convex ring, and the inner diameter of the second anti-reflective pad is smaller than the inner diameter of the convex ring.

[0008] In some embodiments, the bottom of the light-shielding ring is provided with at least one first dimming element, the first dimming element is located inside the annular light-emitting surface and outside the second dimming element, the first dimming element is configured to block part of the annular light-emitting surface in the circumferential direction of the annular light source, so that the annular light-emitting surface is a notched annular light-emitting surface, and a three-level blocking structure is formed between the convex ring, the second dimming element, and the first dimming element in a front-to-back upward direction; Wherein, the annular light-emitting surface is a first inclined surface, and in the direction from the annular light source to the lens, the annular light-emitting surface gradually approaches the optical axis of the lens, and the first dimming element has a second inclined surface that fits with the annular light-emitting surface, and the second inclined surface abuts and cooperates with the annular light-emitting surface. The bottom surface of the light-shielding ring is flush with the top surface of the annular light-emitting surface, or the bottom surface of the light-shielding ring is located between the top and bottom of the annular light-emitting surface and is closer to the top.

[0009] In some embodiments, the light-shielding ring has a first state in which it is rotatable relative to the annular light source and a second state in which it is fixed relative to the annular light source, and the light-shielding ring switches between the first state and the second state in response to an external operation.

[0010] In some embodiments, a mounting groove extending circumferentially is recessed on the outer ring of the light-shielding ring, and a set screw that mates with the mounting groove is provided on the annular light source. The annular light source is provided with a through hole for mounting the set screw, and the through hole penetrates the housing of the annular light source radially.

[0011] In some embodiments, the light-shielding ring, the convex ring, the second dimming element, and the annular light source are coaxially distributed, wherein an anti-reflective coating is provided on the outer surface of the second dimming element.

[0012] In some embodiments, the bracket includes a sleeve disposed on the outer ring of the lens and a mounting ring disposed at the bottom end of the sleeve, wherein the second adjustment structure is disposed between the sleeve and the lens, and the ring light source is disposed on the mounting ring.

[0013] This application also provides a detection device, which includes the camera module as described above.

[0014] The technical solution provided in this application has the following advantages: In this application, the convex ring restricts the range of light entering the lens, reduces the lens's aperture, and prevents light emitted from the annular light-emitting surface from directly hitting the lens. A first gap exists between the end face of the light-shielding ring near the lens and the lens in the front-to-back direction, forming a first light-shielding cavity between the convex ring and the lens. This first light-shielding cavity attenuates the light from the annular light source and stray light from the external environment, preventing stray light from interfering with imaging. Simultaneously, the first light-shielding cavity provides physical isolation between the annular light source and the lens, improving image contrast and sharpness, resulting in better imaging performance.

[0015] The second dimming element and the light-shielding ring form a second light-shielding cavity located in front of the convex ring. This second light-shielding cavity acts as a front barrier to the first light-shielding cavity, intercepting direct or reflected stray light emitted from the annular light-emitting surface in the first instant. After entering the second light-shielding cavity, the stray light undergoes multiple reflections within its walls, resulting in significant energy attenuation. Only a very small amount of stray light reaches the first light-shielding cavity, greatly reducing its stray light load and forming a two-stage stray light suppression structure. The second dimming element can be adjusted in position along the front-back direction, allowing dynamic adjustment of the axial dimension of the second light-shielding cavity. By changing the axial distance between the second dimming element and the convex ring, the stray light flux entering the lens and the effective imaging light intensity can be precisely controlled, adapting to the imaging needs of different workpieces and different inspection scenarios. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 A three-dimensional structural diagram of the camera module provided in this application; Figure 2 A schematic diagram of the camera module provided in this application in the upward viewing direction; Figure 3 for Figure 2 A schematic diagram of the decomposed structure; Figure 4 A cross-sectional structural diagram of the camera module provided in this application; Figure 5 This is a schematic diagram of the three-dimensional structure of the light-shielding ring; Figure 6 This is a schematic diagram of the three-dimensional structure of a ring-shaped light source. Detailed Implementation

[0018] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. The application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0020] In this application, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this application. Example 1

[0021] This application provides a camera module for defect detection on the outer surface of a wafer (not shown) in one application scenario. Of course, the camera module includes, but is not limited to, wafer inspection; it can also be used for defect detection in other products, such as mobile phone casings and battery tabs for new energy vehicles.

[0022] like Figures 1 to 4 As shown, the camera module includes a camera 210, which includes a body 212 and a lens 211 located on the front side of the body 212. The lens 211 of the camera 210 is equipped with a ring light source 220, such as... Figure 6 As shown, the inner ring of the ring light source 220, away from the lens 211, has a ring-shaped light-emitting surface 221. The function of the ring light source 220 is to provide uniform illumination for the wafer. The ring light source 220 projects light onto the wafer surface below, ensuring that the wafer surface has sufficient brightness, with the aim of providing sufficient incident light for camera imaging.

[0023] The annular light-emitting surface 221 is the first inclined surface. Along the direction from the annular light source 220 to the lens 211, the annular light-emitting surface 221 gradually approaches the optical axis of the lens 211. The inclined annular light-emitting surface 221 allows light to illuminate the wafer surface below at a preset oblique angle. For minute defects on the wafer surface such as scratches, particles, bumps, and lithographic patterns, the inclined light will create a significant contrast between light and dark at the defect location, making the defect more prominent in the image and improving detection accuracy. Furthermore, the inclined light-emitting design of the annular light-emitting surface 221 allows the light emission direction to avoid the field of view of the lens, preventing the light from directly illuminating the lens.

[0024] The camera module also includes a light-shielding ring 230 and a second dimming element 240. The light-shielding ring 230 is disposed on the inner ring of the ring light source 220, and the annular light-emitting surface 221 is located on the outer periphery of the light-shielding ring 230. The second dimming element 240 is annular and disposed on the inner ring of the light-shielding ring 230.

[0025] The light-shielding ring 230 has a raised ring 233 on its inner circumference near the lens 211. In the front-rear direction, the raised ring 233 is located between the second dimming element 240 and the lens 211, forming a light-shielding structure on the front side of the lens 211. The raised ring 233 restricts the range of light entering the lens 211, reduces the light-transmitting aperture of the lens 211, and also prevents light emitted from the annular light-emitting surface 221 from directly hitting the lens.

[0026] Furthermore, a first distance K exists between the end face of the light-shielding ring 230 near the lens 211 and the lens 211 in the front-to-back direction, forming a first light-shielding cavity between the convex ring 233 and the lens 211. This first light-shielding cavity attenuates the light from the ring light source 220 and stray light from the external environment, preventing stray light from interfering with imaging by entering the lens 211. Simultaneously, the first light-shielding cavity provides physical isolation between the ring light source 220 and the lens 211, improving image contrast and clarity, resulting in better imaging performance.

[0027] It is worth noting that in this application, the convex ring 233 can cooperate with the lower second dimming element 240 to form a multi-level stray light suppression structure, thereby achieving fine adjustment of the imaging light intensity. The aforementioned front and rear directions refer to the axial direction of the lens 211; the front corresponds to the lower direction in the attached figures, and the rear corresponds to the upper direction in the attached figures. For example, the ring light source 220 is located at the bottom of the lens 211, at the front end of the lens 211; the lens 211 is located above the ring light source 220, at the rear end of the ring light source 220.

[0028] The ring light source 220 is mounted on the lens 211 via a bracket 290. A second adjustment structure 291 is provided between the bracket 290 and the lens 211. The second adjustment structure 291 can adjust the position of the bracket 290 in the front-rear direction, thereby adjusting the size of the first gap K, thus realizing the dynamic adjustment of the axial dimension of the first light-shielding cavity. In this application, a convex ring 233 is fixed on the top of the light-shielding ring 230, and the distance between the top surface of the convex ring 233 and the lens 211 in the front-rear direction is the aforementioned first gap K.

[0029] The aforementioned dynamic adjustment can precisely control the stray light suppression intensity and effective light intake of the first light-shielding cavity, thereby adapting to the imaging requirements of different types of wafers and different detection scenarios; at the same time, it can compensate for the processing and assembly errors of the lens 211 and the light-shielding ring 230; and it can also work with the second dimming component 240 to form a multi-dimensional fine dimming system, thereby improving imaging contrast, brightness uniformity and detection accuracy.

[0030] like Figure 3 As shown, the bracket 290 includes a sleeve 2901 disposed on the outer ring of the lens 211 and a mounting ring 2902 disposed at the bottom end of the sleeve 2901. The second adjustment structure 291 is disposed between the sleeve 2901 and the lens 211, and the ring light source 220 is disposed on the mounting ring 2902.

[0031] The bracket 290 can use the lens 211 as a positioning reference to achieve coaxial installation of the ring light source 220 and the lens 211, ensuring illumination uniformity and imaging stability. In addition, the sleeve 2901 and the mounting ring 2902 can form a closed light-shielding space, which, together with the light-shielding ring 230 and the convex ring 233, further suppresses stray light from entering the lens 211 and improves image quality.

[0032] Preferably, the convex ring 233 and the light-shielding ring 230 are integrally formed without additional assembly, which simplifies the number of parts and assembly process, avoids the coaxiality error of the split structure, and helps to improve structural stability and processing consistency.

[0033] The top surface of the convex ring 233 is provided with a second anti-reflective pad 280, and the bottom surface of the convex ring 233 is provided with a first anti-reflective pad 270. The inner diameter of the first anti-reflective pad 270 is equal to the inner diameter of the convex ring 233, and the inner diameter of the second anti-reflective pad 280 is smaller than the inner diameter of the convex ring 233.

[0034] The second anti-reflective pad 280 has a smaller inner diameter and forms a shield on the top surface of the convex ring 233. The inner ring of the second anti-reflective pad 280 can serve as a physical limiting boundary for light entering the lens, precisely limiting the effective field of view of the lens, blocking stray light from entering the field of view, and further optimizing image quality.

[0035] The second anti-reflective pad 280 and the first anti-reflective pad 270 form an axial stepped structure. The second anti-reflective pad 280 is responsible for absorbing reflected light from the lens side, while the first anti-reflective pad 270 is responsible for extinction of light from the ring light source 220 side. The first anti-reflective pad 270 and the second anti-reflective pad 280 form a double extinction barrier along the optical axis, enabling multi-angle coverage and absorption of stray light from different directions and paths. Notably, both the outer surfaces of the first anti-reflective pad 270 and the second anti-reflective pad 280 are coated with an anti-reflective coating.

[0036] like Figure 5 As shown, the bottom of the inner ring of the convex ring 233 is provided with a chamfer 2331. If the chamfer 2331 is not provided, the bottom of the inner ring of the convex ring 233 is originally a right angle. The chamfer turns the right angle into a bevel, allowing stray light to be scattered obliquely into the second light-shielding cavity, thereby achieving the purpose of suppressing stray light.

[0037] In this application, the second dimming element 240 is adjustable in position relative to the light-shielding ring 230 in the front-rear direction to form a dimming structure acting on the annular light-emitting surface 221 and the lens 211. The second dimming element 240 and the light-shielding ring 230 form a second light-shielding cavity located in front of the convex ring 233, and an anti-reflective coating is provided on the outer surface of the second dimming element 240. The light-shielding ring 230, the convex ring 233, the second dimming element 240, and the annular light source 220 are coaxially distributed.

[0038] The aforementioned second light-shielding cavity serves as a front barrier for the first light-shielding cavity. The second light-shielding cavity can intercept direct or reflected stray light emitted from the annular light-emitting surface 221 in the first instant. Specifically, after the stray light enters the second light-shielding cavity, it is reflected multiple times between the cavity walls of the second light-shielding cavity, resulting in a significant energy attenuation. Only a very small amount of stray light can reach the first light-shielding cavity, greatly reducing the stray light load of the first light-shielding cavity and forming a two-stage stray light suppression structure.

[0039] The second dimming element 240 can be adjusted in position along the front-back direction, thereby dynamically adjusting the axial dimension of the second light-shielding cavity. By changing the axial distance between the second dimming element 240 and the convex ring 233, the amount of stray light entering the lens and the effective imaging light intensity can be precisely controlled to adapt to the imaging needs of different workpieces and different detection scenarios.

[0040] The second dimming element 240 has at least a first axial position where its bottom surface is flush with the top of the annular light-emitting surface 221, and a second axial position where its bottom surface is flush with the bottom of the annular light-emitting surface 221. When the second dimming element 240 is in the first axial position, it does not block the light path of the annular light-emitting surface 221, and it does not affect the brightness of the annular light-emitting surface 221. Although the second dimming element 240 does not affect the brightness of the annular light-emitting surface 221 when it is in the first axial position, it can act as an inner barrier to reduce or prevent light from the annular light source 220, reflected light from the external environment, etc., from entering the lens 211 or the precision components behind the lens 211, which helps to eliminate background stray light.

[0041] When the second dimming element 240 is located in the second axial position, the second dimming element 240 blocks part of the light path of the ring light source 220. At this time, the second dimming element 240 not only acts as an inner wall barrier, but also reduces the light output brightness of the ring light-emitting surface 221, suppresses overexposure at the wafer edge, and improves the imaging contrast and detection accuracy of the wafer.

[0042] The second dimming element 240 is movable between a first axial position and a second axial position. Notably, the second dimming element 240 also has multiple third axial positions between the first and second axial positions. In the third axial position, the bottom surface of the second dimming element 240 is located between the top and bottom of the annular light-emitting surface 221. The closer the bottom surface of the second dimming element 240 is to the bottom of the annular light-emitting surface 221, the greater its light-blocking ability.

[0043] In this application, a first adjustment structure 250 is provided between the second dimming element 240 and the light-shielding ring 230. The first adjustment structure 250 is used to adjust the position of the second dimming element 240 in the front-rear direction. The first adjustment structure 250 includes an oblong hole 251 on the second dimming element 240 and an adjusting bolt 252 inserted into the oblong hole 251. The light-shielding ring 230 has a hole 234 that mates with the adjusting bolt 252. The oblong hole 251 extends in the front-rear direction. When it is necessary to adjust the axial position of the second dimming element 240, the adjusting bolt 252 is loosened, the second dimming element 240 is moved to the desired position, and then the adjusting bolt 252 is tightened. The operation and use are convenient.

[0044] It is worth noting that the second adjustment structure 291 can be the same as the first adjustment structure 250, or other structures that can adjust the axial position of the bracket 290 can be selected.

[0045] The bottom surface of the light-shielding ring 230 is flush with the top surface of the annular light-emitting surface 221, or the bottom surface of the light-shielding ring 230 is located between the top and bottom of the annular light-emitting surface 221, and is closer to the top. When the bottom surface of the light-shielding ring 230 is located between the top and bottom of the annular light-emitting surface 221, the bottom of the light-shielding ring 230 can form an overall blockage of the light path of the annular light-emitting surface 221 in the circumferential direction. At this time, the bottom of the light-shielding ring 230 functions the same as the second dimming element 240.

[0046] Furthermore, such as Figure 5 As shown, the bottom of the light-shielding ring 230 is provided with at least one first dimming element 231. The first dimming element 231 is located inside the annular light-emitting surface 221 and outside the second dimming element 240. The first dimming element 231 is configured to block a portion of the annular light-emitting surface 221 in the circumferential direction of the annular light source 220, so that the annular light-emitting surface 221 is a notched annular light-emitting surface.

[0047] In this application, the first dimming element 231 and the second dimming element 240 can adjust the output brightness of the ring light source 220. The inner ring of the first dimming element 231 and the outer ring of the second dimming element 240 are located on the same circumference, so that there is no gap between them in the radial direction, forming a seamless geometric boundary and preventing light leakage from the seam. The convex ring 233, the second dimming element 240, and the first dimming element 231 form a multi-level adjustment structure in the front-back direction.

[0048] The first dimming element 231 is configured to partially block the annular light-emitting surface 221 of the ring light source 220 in the circumferential direction, so that the annular light-emitting surface 221 is a notched annular light-emitting surface. The second dimming element 240 is configured to partially block the annular light-emitting surface 221 of the ring light source 220 in the axial direction, thereby adjusting the height dimension of the annular light-emitting surface 221 in the axial direction. It is worth noting that in this application, "circumferential," "axial," and "radial" refer to the "circumferential," "axial," and "radial" directions of the ring light source 220 or the lens of the camera 210, wherein the aforementioned "axial" direction can be understood as the direction of the optical axis.

[0049] Specifically, the first dimming element 231 is an arc-shaped block, arranged circumferentially along the annular light-emitting surface 221. It can block a portion of the circumferential area of ​​the annular light-emitting surface 221, thereby adjusting the effective illumination range of the annular light-emitting surface 221. The first dimming element 231 is located on the bottom surface of the light-shielding ring 230. Below the bottom surface of the light-shielding ring 230 is an arc-shaped empty area on the same circumference as the first dimming element 231. Light emitted from the area of ​​the annular light-emitting surface 221 not blocked by the first dimming element 231 shines onto the wafer through the aforementioned empty area.

[0050] It is worth noting that the first dimming element 231 always blocks a portion of the circumferential area of ​​the annular light-emitting surface 221. Preferably, the first dimming element 231 and the light-shielding ring 230 are integrally formed. The first dimming element 231 and the light-shielding ring 230 are made of the same material, and both the first dimming element 231 and the light-shielding ring 230 have an anti-reflective coating on their outer surfaces.

[0051] In this application, both the first dimming element 231 and the second dimming element 240 are light-shielding dimming structures. They are coaxially nested along the optical axis of the lens 211. By blocking part of the light path of the annular light-emitting surface 221, the amount of light transmitted, the illumination range and stray light of the illumination light entering the lens 211 are controlled to optimize the imaging contrast and avoid edge image exposure of the wafer.

[0052] The first dimming element 231 and the second dimming element 240 work together to adjust the light output and light output area of ​​the ring light source 220 in both circumferential and axial directions, thereby improving the imaging contrast and detection accuracy of the wafer. The circumferential dimming of the first dimming element 231 and the axial dimming of the second dimming element 240 form a combination of switchable working states, which can realize independent or coordinated control of the illumination range and light transmission of the ring light source 220. This not only improves the imaging quality but also has strong scene adaptability and scalability.

[0053] The outer surfaces of the first dimming element 231 and the second dimming element 240 are provided with an anti-reflective coating, which can further improve the stray light absorption efficiency. The light-blocking areas of the first dimming element 231 and the second dimming element 240 are matched with the field of view of the lens 211, so as to minimize the incidence of invalid light while ensuring effective illumination.

[0054] Specifically, such as Figure 5 As shown, the first dimming element 231 has a second inclined surface 2311 that fits with the annular light-emitting surface 221. The second inclined surface 2311 abuts against the annular light-emitting surface 221, thereby achieving partial circumferential shading of the annular light-emitting surface 221.

[0055] Preferably, the top of the second inclined surface 2311 is flush with the top of the annular light-emitting surface 221, and the bottom surface of the second inclined surface 2311 is flush with the bottom of the annular light-emitting surface 221. Thus, the surface of the annular light-emitting surface 221 within the circumferential region defined by the second inclined surface 2311 is completely blocked. Alternatively, the top of the second inclined surface 2311 may be lower than the top of the annular light-emitting surface 221, and the bottom of the second inclined surface 2311 may be higher than the bottom of the annular light-emitting surface 221. Another option is that the top of the second inclined surface 2311 is lower than the top of the annular light-emitting surface 221, and the bottom of the second inclined surface 2311 is flush with the bottom of the annular light-emitting surface 221. Yet another option is that the top of the second inclined surface 2311 is higher than the top of the annular light-emitting surface 221, and the bottom of the second inclined surface 2311 is higher than the bottom of the annular light-emitting surface 221.

[0056] When the ring light source 220 is equipped with only one first dimming element 231, the central angle corresponding to the first dimming element 231 is smaller than the central angle corresponding to the remaining portion of the ring light-emitting surface 221. When the ring light source 220 is equipped with two or more first dimming elements 231, the sum of the central angles corresponding to the first dimming elements 231 is smaller than the sum of the central angles corresponding to the remaining portion of the ring light-emitting surface 221, thereby ensuring that the ring light source 220 has sufficient light-emitting area and preventing insufficient illumination brightness due to excessive obstruction, which would affect the imaging effect.

[0057] The light-shielding ring 230 has a first state in which it can rotate relative to the ring light source 220 and a second state in which it is fixed relative to the ring light source 220. The light-shielding ring 230 switches between the first state and the second state in response to an external operation. The aforementioned "external operation" refers to the user's action of manually rotating the light-shielding ring 230, causing the light-shielding ring 230 to rotate relative to the ring light source 220.

[0058] When the light-shielding ring 230 rotates, it drives the first dimming element 231 below it to rotate synchronously. That is to say, the position of the first dimming element 231 in the circumferential direction is adjustable. The operator can adjust the circumferential light-shielding area of ​​the first dimming element 231 according to actual usage needs to limit the effective lighting range to adapt to different application scenarios.

[0059] like Figure 5 As shown, a mounting groove 232 extending circumferentially is recessed on the outer ring of the light-shielding ring 230, and a set screw 260 that mates with the mounting groove 232 is provided on the ring light source 220. The ring light source 220 is provided with a through hole 222 for mounting the set screw 260, and the through hole 222 penetrates the housing of the ring light source 220 radially.

[0060] When it is necessary to adjust the position of the first dimming element 231 in the circumferential direction, loosen the set screw 260 but not completely disengage it from the mounting slot 232. At this time, the light-shielding ring 230 can rotate freely in the circumferential direction, thereby facilitating the adjustment of the position of the first dimming element 231 in the circumferential direction. After the position of the first dimming element 231 in the circumferential direction is determined, tighten the set screw 260 to restrict the degree of freedom of the light-shielding ring 230 in the circumferential direction, thus fixing the light-shielding ring 230 relative to the ring light source 220.

[0061] In this application, the bottom of the light-shielding ring 230 is provided with two first dimming elements 231, and the included angle between the two first dimming elements 231 in the circumferential direction is an acute angle. The central angle corresponding to the first dimming element 231 in the circumferential direction is also an acute angle. The sum of the central angle of the two first dimming elements 231 and the included angle between the two first dimming elements 231 is less than 180°, thereby ensuring that most of the light-emitting area of ​​the ring light source 220 remains open. The above arrangement can achieve local and directional stray light suppression without destroying the illumination uniformity of the ring light source 220, precisely weakening reflected light and glare in specific directions, while avoiding insufficient imaging brightness due to large-area light blocking. Example 2

[0062] This application also provides a detection device for surface quality detection of wafers, the detection device including the camera module described in Embodiment 1.

[0063] Obviously, the embodiments described above are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, those skilled in the art can make other variations or modifications without creative effort, and all such variations or modifications should fall within the scope of protection of this application.

Claims

1. A camera module, comprising: include: The camera (210) includes at least a lens (211); A ring light source (220) is disposed on the lens (211), and the inner ring of the ring light source (220) away from the lens (211) has a ring light-emitting surface (221). A light-shielding ring (230) is disposed on the inner ring of the ring light source (220), and the ring light-emitting surface (221) is located on the outer periphery of the light-shielding ring (230); The second dimming element (240) is disposed on the inner ring of the light-shielding ring (230) and is in the shape of a ring; The light-shielding ring (230) has a convex ring (233) on the inner ring near the end of the lens (211); in the front-to-back direction, the convex ring (233) is located between the second dimming element (240) and the lens (211), and the convex ring (233) can form a light-shielding structure on the front side of the lens (211); The end face of the light-shielding ring (230) near the lens (211) has a first gap in the front-to-back direction with the lens (211) so that a first light-shielding cavity is formed between the convex ring (233) and the lens (211); The second dimming element (240) can be adjusted in the front and rear directions relative to the light-shielding ring (230) to form a dimming structure acting on the annular light-emitting surface (221) and the lens (211). A second light-shielding cavity located in front of the convex ring (233) is formed between the second dimming element (240) and the light-shielding ring (230).

2. The camera module as described in claim 1, characterized in that, A first adjustment structure (250) is provided between the second dimming element (240) and the light-shielding ring (230), and the first adjustment structure (250) is used to adjust the position of the second dimming element (240) in the front and rear directions; The first adjustment structure (250) includes an oblong hole (251) provided on the second dimming component (240) and an adjustment bolt (252) inserted into the oblong hole (251). The light-shielding ring (230) is provided with a hole (234) that cooperates with the adjustment bolt (252). The oblong hole (251) extends in the front-back direction.

3. The camera module as described in claim 1, characterized in that, The convex ring (233) is fixed on the top of the light-shielding ring (230), and the distance between the top surface of the convex ring (233) and the lens (211) in the front and rear directions is the first spacing. The ring light source (220) is mounted on the lens (211) via a bracket (290). A second adjustment structure (291) is provided between the bracket (290) and the lens (211). The second adjustment structure (291) can adjust the position of the bracket (290) in the front and rear directions, thereby adjusting the size of the first gap.

4. The camera module as described in claim 1, characterized in that, The top surface of the convex ring (233) is provided with a second anti-reflective pad (280), and the bottom surface of the convex ring (233) is provided with a first anti-reflective pad (270). The inner diameter of the first anti-reflective pad (270) is equal to the inner diameter of the convex ring (233), and the inner diameter of the second anti-reflective pad (280) is smaller than the inner diameter of the convex ring (233).

5. The camera module as described in claim 1, characterized in that, The bottom of the light-shielding ring (230) is provided with at least one first dimming element (231). The first dimming element (231) is located inside the annular light-emitting surface (221) and outside the second dimming element (240). The first dimming element (231) is configured to block part of the annular light-emitting surface (221) in the circumferential direction of the annular light source (220) so that the annular light-emitting surface (221) is a notched annular light-emitting surface. A three-level blocking structure is formed between the convex ring (233), the second dimming element (240), and the first dimming element (231) in a front-to-back upward direction. Wherein, the annular light-emitting surface (221) is a first inclined surface. In the direction from the annular light source (220) to the lens (211), the annular light-emitting surface (221) gradually approaches the optical axis of the lens (211). The first dimming element (231) has a second inclined surface (2311) that fits with the annular light-emitting surface (221). The second inclined surface (2311) abuts against the annular light-emitting surface (221). The bottom surface of the light-shielding ring (230) is flush with the top surface of the annular light-emitting surface (221), or the bottom surface of the light-shielding ring (230) is located between the top and bottom of the annular light-emitting surface (221) and is distributed close to the top.

6. The camera module as described in claim 1, characterized in that, The light-shielding ring (230) has a first state in which it can rotate relative to the ring light source (220) and a second state in which it is fixed relative to the ring light source (220), and the light-shielding ring (230) switches between the first state and the second state in response to external operation.

7. The camera module as described in claim 1, characterized in that, The outer ring of the light-shielding ring (230) has a recessed mounting groove (232) extending circumferentially. The annular light source (220) is provided with a set screw (260) that mates with the mounting groove (232). The annular light source (220) is provided with a through hole (222) for mounting the set screw (260). The through hole (222) penetrates the housing of the annular light source (220) radially.

8. The camera module as described in claim 1, characterized in that, The light-shielding ring (230), the convex ring (233), the second dimming element (240), and the ring light source (220) are coaxially distributed, wherein the outer surface of the second dimming element (240) is provided with an anti-reflective coating.

9. The camera module as described in claim 3, characterized in that, The bracket (290) includes a sleeve (2901) disposed on the outer ring of the lens (211) and a mounting ring (2902) disposed at the bottom end of the sleeve (2901). The second adjustment structure (291) is disposed between the sleeve (2901) and the lens (211), and the ring light source (220) is disposed on the mounting ring (2902).

10. A detection device, characterized in that, Includes the camera module described in any one of claims 1 to 9.

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