Visual inspection device

Abstract

This utility model belongs to the field of visual inspection technology and discloses a visual inspection device. The visual inspection device includes a first housing assembly, a camera, and a first illumination assembly. The camera is mounted on the upper side of the first housing assembly, and a first mounting cavity is formed inside the first housing assembly. The first housing has a first light-receiving hole located on the upper side of the first mounting cavity, and the camera lens faces the first light-receiving hole. The first illumination assembly includes a first light source, a first condenser rod, a Fresnel lens group, and a semi-reflective and semi-transparent assembly, all installed in the first mounting cavity and arranged sequentially and at intervals along a second direction. The semi-reflective and semi-transparent assembly is located below the first light-receiving hole, allowing light reflected from the workpiece to pass through the semi-reflective and semi-transparent assembly and enter the first light-receiving hole. The first housing assembly also has a second light-receiving hole located below the semi-reflective and semi-transparent assembly. This visual inspection device can reduce the occurrence of light spots, improve light propagation efficiency, and simplify optical path design when inspecting highly reflective surfaces.

Description

Technical Field

[0001] This utility model relates to the field of visual inspection technology, and in particular to a visual inspection device. Background Technology

[0002] In the field of machine vision inspection, eliminating light spot interference caused by strong reflection is a core technical challenge for defect detection on highly reflective surfaces (such as mirrored metals, polished plastics, glass, and wafers). Existing illumination solutions for highly reflective surfaces have the following shortcomings in practical applications:

[0003] 1. Problems with traditional coaxial light source spot: For highly reflective surfaces, the vertical illumination of traditional coaxial light will still produce strong specular reflection, forming localized overly bright spots in the image, which will obscure the true defect information of the area.

[0004] 2. Low luminous efficacy of beam-splitter coaxial light source: The design of a semi-reflective, semi-transparent beam splitter results in significant light loss. To achieve sufficient brightness, the LED power needs to be greatly increased, leading to high heat generation.

[0005] 3. Complex optical path design and large size: Traditional coaxial light sources require complex beam splitter groups and optical path folding structures, resulting in bulky light source modules that are difficult to integrate into space-constrained testing stations.

[0006] Therefore, there is an urgent need to design a visual inspection device to solve the above problems. Utility Model Content

[0007] The purpose of this invention is to provide a visual inspection device that can reduce the occurrence of light spots, improve light propagation efficiency, and simplify optical path design when inspecting highly reflective surfaces.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] Visual inspection device, including:

[0010] A first housing assembly and a camera, wherein the first housing assembly extends along a first direction, the camera is mounted on the upper side of the first housing assembly, a first mounting cavity is formed inside the first housing assembly, and a first light-receiving hole is opened in the first housing assembly extending along the first direction and located on the upper side of the first mounting cavity, and the lens of the camera faces the first light-receiving hole.

[0011] The first illumination assembly includes a first light source, a first focusing rod, a Fresnel lens group, and a semi-reflective and semi-transparent assembly, all installed in the first mounting cavity and arranged sequentially at intervals along the second direction. The light emitted by the first light source passes sequentially through the first focusing rod and the Fresnel lens group and enters the semi-reflective and semi-transparent assembly, where it is refracted downwards toward the object to be tested. The semi-reflective and semi-transparent assembly is located below the first light receiving hole, allowing light reflected from the object to be tested to pass through the semi-reflective and semi-transparent assembly and enter the first light receiving hole. The first housing assembly also has a second light receiving hole located below the semi-reflective and semi-transparent assembly, and the second direction is perpendicular to the first direction.

[0012] As an optional solution, the aforementioned semi-reflective and semi-transparent component includes two prisms with right-angled triangular cross-sections. A semi-reflective and semi-transparent film is attached to one side of the inclined surface of the two prisms, and the inclined surfaces of the two prisms abut against each other to form a quadrangular prism, which is installed below the aforementioned first light-receiving aperture.

[0013] As an optional solution, the aforementioned semi-reflective / semi-transparent component includes:

[0014] A semi-reflective mirror is mounted on the first housing assembly and located below the first light-receiving aperture. The cross-section of the semi-reflective mirror forms a 45° angle with the second direction.

[0015] The protective element is transparent and is installed on the first housing assembly and located below the semi-reflective lens.

[0016] As an optional solution, the aforementioned first housing assembly includes:

[0017] A first housing, on the upper side of which the camera is mounted, and a first mounting cavity is formed inside the first housing. A first light-receiving hole is opened on the upper side of the first mounting cavity, and a second light-receiving hole is opened on the lower side of the first mounting cavity.

[0018] As an alternative, the first housing is provided with a plurality of first heat dissipation fins.

[0019] As an optional solution, the aforementioned visual inspection device further includes an auxiliary lighting module, which comprises:

[0020] The adapter and the second housing assembly are connected to the first housing assembly via the adapter. The second housing assembly is located beside the first housing assembly and extends along the first direction, from one end close to the first housing assembly to one end away from the first housing assembly. The second housing assembly is inclined upward, and the inclination direction is defined as the U direction. A second mounting cavity is formed inside the second housing assembly, and a light-emitting hole is opened on the side of the second mounting cavity facing the first housing assembly.

[0021] The second lighting assembly includes a second light source, a second focusing rod, and a diffuser plate arranged sequentially at intervals along the U direction, with the diffuser plate positioned close to the light-emitting hole.

[0022] As an alternative, the angle between the second direction and the U direction is α, where 20°≤α≤30°.

[0023] As an optional solution, the aforementioned first light source is constructed with two first standard power interfaces.

[0024] As an optional solution, the access end of the aforementioned second light source is equipped with a second standard power interface.

[0025] As an alternative, the second housing assembly includes a second housing, which is connected to the adapter, and the second housing has a plurality of second heat dissipation fins on its outer surface.

[0026] The beneficial effects of this utility model are:

[0027] This invention provides a visual inspection device. A first light source emits relatively divergent light, which is then focused by a first condenser rod. The condenser rod is made of high-transmittance optical glass or PMMA material, which focuses the large-angle divergent light from the first light source, improving light energy utilization. The light then passes through a Fresnel lens group. One side of the Fresnel lens group is smooth, while the other side is engraved with concentric circles of increasing size. In cross-section, its surface consists of a series of serrated grooves, which convert the incident light into parallel light rays, simultaneously losing its original directionality and becoming diffusely reflected parallel light. After passing through a semi-reflective component, the light is further homogenized and its angle adjusted, resulting in uniformly diffused, vertically downward-facing light rays that illuminate the object being measured in an extremely soft manner. The reflected light from the object's surface passes vertically upward through a second light-receiving aperture and the semi-reflective component. Some of the light rays pass through the first light-receiving aperture in a straight line without refraction and enter the camera, forming an image. In other words, the light illuminating the object is parallel to the light reflected to the camera, reducing light distortion and preventing image blurring. Since the incident light is diffuse reflection, the specular reflection effect is greatly suppressed, and there are no strong light spots in the image. At the same time, the use of a condenser rod and Fresnel lens group greatly simplifies the optical path design of the first illumination component. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the visual inspection device provided in Embodiment 1 of this utility model;

[0029] Figure 2 This is a cross-sectional view of the visual inspection device provided in Embodiment 1 of this utility model;

[0030] Figure 3 This is a schematic diagram of the structure of the first light source provided in Embodiment 1 of this utility model;

[0031] Figure 4 This is a cross-sectional view of the visual inspection device provided in Embodiment 2 of this utility model.

[0032] In the picture:

[0033] 10. First housing assembly; 11. First housing; 111. First light-receiving hole; 112. Second light-receiving hole; 13. First heat dissipation fin; 14. First mounting cavity;

[0034] 20. First illumination assembly; 21. First light source; 211. First standard power interface; 22. First condenser bar; 23. Fresnel lens group; 24. Semi-reflective and semi-transparent assembly; 241. Prism; 242. Semi-reflective and semi-transparent mirror; 243. Protective component;

[0035] 30. Auxiliary lighting module; 31. Adapter; 32. Second housing assembly; 321. Second housing; 324. Light emission hole; 325. Second heat dissipation fins;

[0036] 33. Second lighting component; 331. Second light source; 332. Second focusing rod; 333. Diffuser plate. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0038] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0039] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0040] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0041] Example 1

[0042] This embodiment provides a visual inspection device that, when inspecting highly reflective surfaces, can reduce the occurrence of light spots, improve light propagation efficiency, and simplify optical path design. For example... Figure 1 and Figure 2 As shown, the visual inspection device includes a first housing assembly 10, a camera (not shown in the figure), and a first illumination assembly 20. The first housing assembly 10 extends along a first direction (the X direction in the figure is the first direction, which is in the horizontal plane after installation). The camera is mounted on the upper side of the first housing assembly 10. A first mounting cavity 14 is formed inside the first housing assembly 10. A first light-receiving hole 111 extends along the first direction and is located on the upper side of the first mounting cavity 14. The lens of the camera faces the first light-receiving hole 111. The first illumination assembly 20 includes components all mounted in the first mounting cavity 14 and extending along a second direction (the Y direction in the figure is the second direction). After installation, the first light source 21, the first light-collecting rod 22, the Fresnel lens group 23, and the semi-reflective and semi-transparent component 24 are arranged in sequence at intervals in the second direction (which is in the horizontal plane and perpendicular to the first direction). The light emitted by the first light source 21 passes through the first light-collecting rod 22 and the Fresnel lens group 23 and enters the semi-reflective and semi-transparent component 24, where it is refracted downward toward the object to be tested. The semi-reflective and semi-transparent component 24 is located below the first light-receiving hole 111. The light reflected from the object to be tested can pass through the semi-reflective and semi-transparent component 24 and enter the first light-receiving hole 111. The first housing component 10 also has a second light-receiving hole 112, which is located below the semi-reflective and semi-transparent component 24.

[0043] In the aforementioned visual inspection device, the first light source 21 emits relatively divergent light. This light is then focused by the first focusing rod 22, which uses high-transmittance optical glass or PMMA material to concentrate the large-angle divergent light from the first light source 21, thus improving light energy utilization. The light then passes through a Fresnel lens group 23, one side of which is a smooth surface, and the other side is engraved with concentric circles of varying sizes. In cross-section, its surface is composed of a series of sawtooth grooves, which convert the incident light into parallel light rays and cause it to lose its original directionality, becoming diffusely reflected parallel light. After passing through a semi-reflective component 24, the light is further homogenized and the angle is adjusted, resulting in uniformly diffused, vertically downward light rays that illuminate the object being tested in an extremely soft manner, reducing the generation of light spots. The reflected light from the object's surface passes vertically upwards through the second light-receiving aperture 112 and the semi-reflective component 24. Some of this light enters the camera in a straight line through the first light-receiving aperture 111 without refraction, forming an image. In other words, the light illuminating the object is parallel to the light reflected to the camera, reducing light distortion and preventing image blurring. Because the incident light is diffusely reflected, specular reflection is significantly suppressed, resulting in no strong light spots in the image. Furthermore, the use of the first condenser rod 22 and the Fresnel lens group 23 greatly simplifies the optical path design of the first illumination component 20.

[0044] It should be noted that this visual inspection device is designed for use with macro cameras, hence its elongated and slender design. Macro cameras have a very small working distance, as low as 7mm and typically 15mm. To accommodate the camera's imaging capabilities, the light source needs to be very thin while maintaining sufficient brightness. The elongated light source is also designed to match the length of the macro camera.

[0045] In this embodiment, the semi-reflective and semi-transparent assembly 24 includes a semi-reflective lens 242 and a protective member 243. The semi-reflective lens 242 is mounted on the first housing assembly 10 and located below the first light-receiving aperture 111. The cross-section of the semi-reflective lens 242 forms a 45° angle with the second direction. The protective member 243 is transparent and is mounted on the first housing assembly 10 and located below the semi-reflective lens 242. The semi-reflective lens 242 allows some light to be vertically reflected onto the object to be tested below, while the light reflected from the object to be tested can be transmitted in a straight line through the semi-reflective lens 242 into the camera. At the same time, the protective member 243 can block the second light-receiving aperture 112, preventing dirt from affecting the reflection and transmission path of the semi-reflective lens 242.

[0046] Optionally, both the first light-receiving aperture 111 and the second light-receiving aperture 112 are elongated and extend along the first direction, so as to be used in conjunction with the camera of the macro camera.

[0047] Optionally, such as Figure 2As shown, the first housing assembly 10 includes a first housing 11, a camera is mounted on the upper side of the first housing 11, a first mounting cavity 14 is formed inside the first housing 11, a first light-receiving hole 111 is formed on the upper side of the first mounting cavity 14, and a second light-receiving hole 112 is formed on the lower side of the first mounting cavity 14. Optionally, the first housing 11 can be detachable to facilitate the installation of various parts within the first mounting cavity 14.

[0048] Furthermore, the shape of the first mounting cavity 14 is adapted to the shapes of the components of the first lighting assembly 20. Specifically, the first focusing rod 22 is columnar, an arc-shaped groove is provided on the upper side of the first mounting cavity 14, and a rectangular groove is provided on the lower side of the first mounting cavity 14. The first focusing rod 22 is simultaneously accommodated in the arc-shaped groove and the rectangular groove. The semi-reflective lens 242 is set at 45°. The first mounting cavity 14 is formed with a first inclined surface corresponding to the position of the semi-reflective lens 242. The first inclined surface abuts against the top of the semi-reflective lens 242. At the same time, a second inclined surface is formed on the lower side of the first mounting cavity 14. The second inclined surface abuts against the bottom of the semi-reflective lens 242. A blocking edge is formed on the side of the first inclined surface. The blocking edge and the second inclined surface are located on both sides of the first inclined surface to prevent the semi-reflective lens 242 from rotating.

[0049] Optionally, the first housing is constructed with multiple first heat dissipation fins 13. This allows the heat generated by the first light source 21 to be dissipated into the air in a timely manner, extending the service life of the first light source 21.

[0050] Optionally, such as Figure 3 As shown, the first light source 21 has two first standard power interfaces 211, which are standard 2mm pitch pin interfaces. Each interface contains multiple pins, providing independent power supply and control channels for the first light source 21. The pin definitions are standardized, and it features a reverse insertion protection design. The first housing 11 has clearance holes, and the first standard power interfaces 211 pass through the corresponding clearance holes.

[0051] Optionally, such as Figure 1 and Figure 2As shown, the visual inspection device also includes an auxiliary lighting module 30. The auxiliary lighting module 30 includes a connector 31, a second housing assembly 32, and a second lighting assembly 33. The second housing assembly 32 is connected to the first housing assembly 10 via the connector 31. The second housing assembly 32 is located beside the first housing assembly 10 and extends along a first direction, from one end close to the first housing assembly 10 to one end away from the first housing assembly 10. The second housing assembly 32 is inclined upward, and the inclination direction is defined as the U direction. A second mounting cavity is formed inside the second housing assembly 32, and a light-emitting hole 324 is opened on the side of the second mounting cavity facing the first housing assembly 10. The second lighting assembly 33 includes a second light source 331, a second focusing rod 332, and a diffuser plate 333 arranged sequentially along the U direction. The diffuser plate 333 is disposed close to the light-emitting hole 324. With the above settings, the auxiliary lighting module 30 is located to the side of the camera, providing supplementary illumination at an angle. The light paths of both light sources are designed to ensure that the light entering the camera illuminates the object at a near-vertical angle, making it easier to display defects and scratches on mirrored metal, glass, wafers, lenses, and highly reflective surfaces. At the same time, the diffuser plate 333 introduced in the second lighting component 33 will turn the point light source into a line light source. For macro cameras, the light can be more concentrated on the object being measured, allowing macro cameras to better identify objects.

[0052] Of course, the first light source 21 and the second light source 331 can also be used independently. Using the second light source 331 independently is suitable for scenarios that require diffuse side lighting to highlight features.

[0053] Optionally, such as Figure 2 As shown, the angle between the second direction and the U direction is α, where 20°≤α≤30°. For example, the value of α can be 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, or 30°, with 25° being preferred.

[0054] Optionally, such as Figure 2 As shown, the second housing assembly 32 includes a second housing 321, which is connected to the adapter 31. A second mounting cavity is formed within the second housing 321. This allows for the limiting of the second focusing rod 332 and the diffuser plate 333 in a direction perpendicular to the U direction. The limiting groove of the second mounting cavity is similar to the limiting structure in the first mounting cavity 14, and will not be described further here.

[0055] Optionally, such as Figure 2 As shown, the outer side of the second housing assembly 32, i.e., the outer side of the second housing 321, has multiple second heat dissipation fins 325. These fins can dissipate the heat from the second light source 331 to the outside in a timely manner.

[0056] Optionally, the second light source 331 has two second standard power interfaces, both of which are standard 2mm pitch pin interfaces. Each interface contains multiple pins, providing independent power and control channels for the second light source 331. The pin definitions are standardized, and it features a reverse insertion protection design. The structure of the second standard power interface can refer to the form of the first standard power interface 211, which is not shown in the figure.

[0057] Example 2

[0058] This embodiment is largely the same in structure as Embodiment 1, and the similarities will not be repeated. The differences are as follows: Figure 4 As shown, the semi-reflective and semi-transparent assembly 24 includes two triangular prisms 241. The cross-section of each triangular prism 241 is a right-angled triangle. A semi-reflective and semi-transparent film is attached to one side of the inclined surface of each prism 241, and the inclined surfaces of the two prisms 241 abut against each other to form a quadrangular prism, which is installed below the first light-receiving aperture 111. The function of the semi-reflective and semi-transparent film is similar to that of the semi-reflective and semi-transparent lens 242, both of which can realize the function of partial reflection and partial transmission of light. The stacking of two triangular prisms 241 ensures that the angle of the semi-reflective and semi-transparent film is precisely controlled at 45°, and the film is clamped together, resulting in better dust prevention.

[0059] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A vision inspection apparatus characterized by, include: A first housing assembly (10) and a camera, the first housing assembly (10) extending along a first direction, the camera being mounted on the upper side of the first housing assembly (10), a first mounting cavity (14) being formed inside the first housing assembly (10), the first housing assembly (10) having a first light-receiving hole (111) extending along the first direction and located on the upper side of the first mounting cavity (14), the lens of the camera facing the first light-receiving hole (111). The first illumination assembly (20) includes a first light source (21), a first focusing rod (22), a Fresnel lens group (23), and a semi-reflective and semi-transparent assembly (24), all installed in the first mounting cavity (14) and arranged sequentially at intervals along the second direction. The light emitted by the first light source (21) passes sequentially through the first focusing rod (22) and the Fresnel lens group (23) and enters the semi-reflective and semi-transparent assembly (24), where it is refracted downward toward the object to be tested. The semi-reflective and semi-transparent assembly (24) is located below the first light receiving hole (111). The light reflected from the object to be tested can pass through the semi-reflective and semi-transparent assembly (24) and enter the first light receiving hole (111). The first housing assembly (10) also has a second light receiving hole (112), which is located below the semi-reflective and semi-transparent assembly (24). The second direction is perpendicular to the first direction.

2. The vision inspection apparatus of claim 1, wherein The semi-reflective and semi-transparent component (24) includes two prisms (241). The cross-section of the prisms (241) is a right triangle. A semi-reflective and semi-transparent film is attached to one side of the inclined surface of the two prisms (241). The inclined surfaces of the two prisms (241) abut each other to form a quadrangular prism. The quadrangular prism is installed on the lower side of the first light receiving hole (111).

3. The vision inspection apparatus of claim 1, wherein The semi-reflective and semi-transparent component (24) includes: A semi-reflective mirror (242) is mounted on the first housing assembly (10) and located below the first light receiving hole (111). The cross section of the semi-reflective mirror (242) forms a 45° angle with the second direction. The protective element (243) is transparent and is installed on the first housing assembly (10) and located below the semi-reflective lens (242).

4. The vision inspection apparatus of claim 1, wherein The first housing assembly (10) includes: A first housing (11) is provided with a camera mounted on its upper side. A first mounting cavity (14) is formed inside the first housing (11). A first light-receiving hole (111) is located on the upper side of the first mounting cavity (14), and a second light-receiving hole (112) is located on the lower side of the first mounting cavity (14).

5. The vision inspection apparatus of claim 4, wherein The first housing (11) has a plurality of first heat dissipation fins (13).

6. The vision inspection apparatus according to any one of claims 1 to 5, characterized in that, The visual inspection device further includes an auxiliary lighting module (30), which includes: The adapter (31) and the second housing assembly (32) are connected to the first housing assembly (10) via the adapter (31). The second housing assembly (32) is located beside the first housing assembly (10) and extends along the first direction from one end close to the first housing assembly (10) to one end away from the first housing assembly (10). The second housing assembly (32) is inclined upward, and the inclination direction is defined as the U direction. A second mounting cavity is formed inside the second housing assembly (32). A light-emitting hole (324) is opened on the side of the second mounting cavity facing the first housing assembly (10). The second lighting assembly (33) includes a second light source (331), a second light-concentrating rod (332) and a diffuser plate (333) arranged sequentially at intervals along the U direction, with the diffuser plate (333) positioned close to the light-emitting hole (324).

7. The vision inspection apparatus of claim 6, wherein The angle between the second direction and the U direction is α, where 20°≤α≤30°.

8. The vision inspection apparatus of claim 6, wherein The first light source (21) is constructed with two first standard power interfaces (211).

9. The vision inspection apparatus of claim 6, wherein, The second light source (331) has a second standard power interface at its access end.

10. The vision inspection apparatus of claim 6, wherein The second housing assembly (32) includes a second housing (321), which is connected to the adapter (31), and the second housing (321) has a plurality of second heat dissipation fins (325) on its exterior.

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