A vision inspection apparatus and a uniformity illumination method for optimizing illumination

Abstract

The application provides an optimized visual detection device and a uniformity illumination method, which comprises a tube, a cylindrical reflector arranged in the tube, a ring-shaped lamp bead arranged at the top end of the cylindrical reflector, a multilayer transmittance diffusion cylinder sleeved on the outer periphery of the cylindrical reflector, the ring-shaped lamp bead emitting incident light above the multilayer transmittance diffusion cylinder, a spherical mirror arranged below the cylindrical reflector and the multilayer transmittance diffusion cylinder, and a lens arranged below the spherical mirror to form a closed space, wherein the multilayer transmittance diffusion cylinder comprises a plurality of diffusion rings arranged in sequence along the axial direction, and the light transmittance of the plurality of diffusion rings decreases layer by layer from bottom to top. The application effectively solves the problems of uneven illumination, strong light interference and insufficient brightness in the visual detection device by changing the light path design. The device improves the image brightness and uniformity, optimizes the light distribution and imaging quality, and makes the visual detection more accurate and efficient.

Description

Technical Field

[0001] This invention belongs to the field of visual inspection technology, and relates to a light reflection structure, particularly a visual inspection device for optimizing illumination and a method for achieving uniform illumination. Background Technology

[0002] In the field of machine vision, defect detection is particularly sensitive to the illumination of the surface to be inspected. Excessive or insufficient lighting can lead to overexposure or underexposure in the image, causing the target defect to be obscured by strong light or masked by dark light. When inspecting subtle defects on complex tubular or cylindrical surfaces, the incident light undergoes different optical effects in different areas of the target surface, resulting in inconsistent illumination levels across these areas.

[0003] In traditional spherical mirror imaging systems, illumination is achieved by a cylindrical light source formed by a ring-shaped LED with a specific divergence angle illuminating a cylindrical diffuser plate. This cylindrical light source is characterized by stronger light intensity at the upper end of the diffuser plate (closer to the LED) and weaker light intensity at the far end, with the overall luminous intensity gradually decreasing in the vertical direction. For a spherical mirror structure, within the imaging field of view on the pipe surface, the strong light area from the cylindrical light source creates a bright area due to strong incident light. Simultaneously, the uneven light intensity of the cylindrical diffuser plate creates varying degrees of incident light, resulting in areas of different illumination intensities along the longitudinal direction of the inspection surface. This leads to areas of moderate and dark illumination within the imaging range. The dark areas within the imaging range inevitably cause problems such as missed detections and low detection accuracy in visual inspection, severely impacting the detection results.

[0004] For example, Chinese patent document TW096129500 discloses a first annular ray guide that defines a rotation axis and has an annular entrance pupil. This annular entrance pupil is used to map incident radiation at an angle between 40 and 140 degrees to the rotation axis. The first annular ray guide has a first mapping surface relative to the entrance pupil. A second ray guide also defines the rotation axis and has a second mapping surface adjacent to the first mapping surface. This invention discloses the addition of different ray guides and their quality to form an optical channel. In one method, light is emitted from a light source at an angle between 40 and 140 degrees to the optical axis, and the emitted light is received in an entrance pupil arranged with ray guides. Then, the received radiation is guided to an exit pupil through the arrangement of ray guides in an average direction parallel to the optical axis, changing the direction of the radiation.

[0005] In the above technical solutions, although different ray guides are used to form uniform light within a certain range, their curved structure cannot be used in conjunction with ring-shaped lamp beads or cylindrical diffuser plates, meaning they cannot be applied to machine vision inspection equipment to achieve uniform illumination. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a visual inspection device for optimizing lighting and a method for achieving uniform lighting.

[0007] The objective of this invention can be achieved through the following technical solution: A visual inspection device for optimized lighting, comprising a tube, a cylindrical reflector disposed inside the tube, a ring-shaped LED bead fitted at the top of the cylindrical reflector, a multi-layer transmittance diffuser sleeve surrounding the cylindrical reflector, the ring-shaped LED bead emitting incident light above the multi-layer transmittance diffuser sleeve, a spherical mirror disposed at intervals below the cylindrical reflector and the multi-layer transmittance diffuser sleeve, and a lens disposed below the spherical mirror in the tube to form a closure, the multi-layer transmittance diffuser sleeve comprising a plurality of diffuser rings stacked sequentially along the axial direction, the light transmittance of the plurality of diffuser rings decreasing layer by layer from bottom to top.

[0008] Preferably, the multi-layer transmittance diffuser is provided with a total of 5 diffuser rings. The light transmittance of the 4 diffuser rings from bottom to top is 85%, 80%, 75%, and 70% respectively, and the light transmittance of the top diffuser ring is one of 50%, 40%, 30%, and 20%.

[0009] Preferably, the top surface of the spherical mirror facing the cylindrical reflector is a large curved surface, and the bottom surface of the spherical mirror facing the lens is a small curved surface; the distance between the spherical surface of the spherical mirror and the ring-shaped lamp bead is 35mm; the distance between the large curved surface of the spherical mirror and the bottom surface of the multilayer transmittance diffuser is 15mm.

[0010] Preferably, a conical reflector is fitted onto the upper part of the cylindrical reflector. The top opening of the conical reflector is a small diameter opening, and the bottom opening is a large diameter opening. The conical reflector has an inner conical wall and an outer conical wall. The light transmittance and reflectivity of the inner conical wall are lower than those of the outer conical wall.

[0011] Preferably, the incident angle of the inner peripheral wall of the cone is one of 40°, 30°, 20°, and 10°.

[0012] Preferably, an aperture is fitted around the outer periphery of the cylindrical reflector. The aperture is cylindrical, and its top end extends beyond the top of the annular LED bead and the cylindrical reflector.

[0013] Preferably, the length of the aperture is one of 12mm, 13mm, 14mm, 15mm, 16mm, and 17mm.

[0014] A uniform illumination method for a visual inspection device with optimized illumination, applied to the aforementioned visual inspection device with optimized illumination, the uniform illumination method comprising the following:

[0015] A1. The ring-shaped LED emits light, and the incident light passes through multiple layers of transmissivity diffuser tubes from top to bottom. As the transmissivity of the multiple diffuser rings increases from top to bottom, the incident light passes through diffuser rings with different transmissivity at each level. The light intensity in the medium is reduced in a stepwise manner, which gradually weakens the light intensity of the strong light segment formed in the multiple layers of transmissivity diffuser tubes, and finally reduces the degree of interference to the imaging area and improves the uniformity in the imaging field of view.

[0016] A2. The light rays pass through the hyperboloid mirror of the spherical mirror to form a deflected light path, and the incident light rays achieve longitudinal imaging inside the tube. At the same time, the spherical reflection is used to achieve imaging within a 360-degree field of view.

[0017] A uniform illumination method for a visual inspection device with optimized illumination, applied to the aforementioned visual inspection device with optimized illumination, the uniform illumination method comprising the following:

[0018] B1. The ring-shaped LED emits light, and the incident light passes through the reflective surfaces of the conical reflector at different tilt angles, causing the propagation path of the incident light to be deflected at different angles. Due to the high reflectivity of the inner wall of the cone, when it connects with the outer side of the strong light area, some of the strong light is reflected again by the surface, increasing the incident angle to illuminate the imaging area, reducing the interference caused by the strong light in the field of view, and improving the uniformity and brightness in the imaging field of view.

[0019] B2. The light rays pass through the hyperboloid mirror of the spherical mirror to form a deflected light path, and the incident light rays achieve longitudinal imaging inside the tube. At the same time, the spherical reflection is used to achieve imaging within a 360-degree field of view.

[0020] A uniform illumination method for a visual inspection device with optimized illumination, applied to the aforementioned visual inspection device with optimized illumination, the uniform illumination method comprising the following:

[0021] C1. The ring-shaped LED emits light, and the aperture immediately blocks and reflects the strong light from the ring-shaped LED, changing the deflection path of the incident light and avoiding interference from the strong incident light within the field of view, thereby improving the uniformity and brightness in the imaging field of view.

[0022] C2. The light rays pass through the hyperboloid mirror of the spherical mirror to form a deflected light path, and the incident light rays achieve longitudinal imaging inside the tube. At the same time, the spherical reflection is used to achieve imaging within a 360-degree field of view.

[0023] Compared with existing technologies, the visual inspection device and uniform lighting method for optimized lighting have the following advantages:

[0024] 1. Multi-layer Transmittance Diffuser Design: The design combines a multi-layer transmittance diffuser with a ring-shaped LED. By progressively reducing light intensity layer by layer, it effectively reduces uneven illumination during imaging. Through the gradually decreasing transmittance of each layer, the light intensity decreases as it propagates, avoiding the strong light bands common in traditional lighting structures and preventing interference from highlight areas. This optimized design not only improves illumination uniformity but also ensures relatively uniform illumination across the entire imaging area, enhancing image quality and enabling the detection system to more accurately identify minute surface defects, thus improving the accuracy and precision of defect detection.

[0025] 2. Conical Reflector Design: Utilizing the conical reflector and the different reflective properties of its inner and outer walls, light is more uniformly distributed when illuminating the imaging area. In particular, the design of the reflective surface and different incident angles redistributes light that was originally concentrated in areas of strong light, reducing excessive concentration in localized areas. Specifically, by guiding strong light to the outer edge of the imaging area, it avoids direct illumination of the center or important areas of the image, effectively improving the uniformity of illumination and reducing image distortion or excessive contrast caused by strong light. Simultaneously, secondary refraction and reflection effectively improve the brightness of dark areas in the image, making the overall image brighter and further enhancing the brightness and clarity within the field of view. Furthermore, the design, through multiple reflections and refractions, effectively utilizes light, improving illumination efficiency and reducing energy loss. This not only improves imaging quality but also offers significant energy efficiency advantages, helping to reduce energy consumption and extend the lifespan of the equipment.

[0026] 3. Aperture Design: The aperture structure is installed outside the cylindrical diffuser structure. This serves two purposes: firstly, it blocks the strong light areas created by the diffused light; secondly, it alters the light propagation path, changing the light from a small-angle, laterally diverging beam to a more longitudinal angle, thus collecting and utilizing the light without wasting it. Based on this method, while less light is emitted from the exposed area, more light is distributed in the edge areas, indirectly indicating improved illumination uniformity. Illuminance contrast ratio, standard deviation, and mean deviation all gradually decrease, indicating improved surface illumination uniformity.

[0027] 4. Wide Field of View and High-Efficiency Imaging: Combined with the spherical mirror design, this visual inspection device can form a 360-degree wide field of view within the tube, enabling the system to perform large-scale defect detection. The spherical mirror not only alters the propagation path of light but also achieves uniform imaging over a large field of view through spherical reflection. This characteristic allows the device to effectively cover a larger inspection area during visual inspection, improving inspection efficiency and reducing omissions caused by a narrow field of view.

[0028] 5. Compact Structure and High-Efficiency Integration: The device features a compact overall design, with the imaging system's width not exceeding 30mm, enabling efficient illumination and imaging within limited spaces. This miniaturized design is suitable for inspection environments requiring space saving or with restricted installation, enhancing the device's application range and flexibility. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0030] Figure 2 This is a structural diagram of the multilayer transmittance diffuser tube in Embodiment 1 of the present invention.

[0031] Figure 3 This is a simulation diagram of the illuminance based on a multilayer transmittance diffuser tube in Embodiment 1 of the present invention.

[0032] Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0033] Figure 5 This is a structural diagram of the conical reflector tube in Embodiment 2 of the present invention.

[0034] Figure 6 This is a simulation diagram of the reflection structure based on different angles in Embodiment 2 of the present invention.

[0035] Figure 7 This is a schematic diagram of the structure of Embodiment 3 of the present invention.

[0036] Figure 8 This is a simulation diagram of different shading distances based on a high-reflectivity aperture in Embodiment 3 of the present invention.

[0037] In the diagram, 1. Tube; 2. Incident light ray; 3. Multilayer transmittance diffuser; 4. Spherical mirror; 5. Cylindrical reflector; 6. Ring lamp bead; 7. Outer wall of cone; 8. Inner wall of cone; 9. Conical reflector; 10. Aperture. Detailed Implementation

[0038] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0039] Example 1

[0040] like Figure 1 and 2As shown, this optimized lighting visual inspection device includes a tube 1, a cylindrical reflector 5 inside the tube 1, a ring-shaped LED 6 fitted at the top of the cylindrical reflector 5, and a multi-layer transmissivity diffuser 3 surrounding the cylindrical reflector 5. The ring-shaped LED 6 emits incident light 2 above the multi-layer transmissivity diffuser 3. A spherical mirror 4 is spaced below the cylindrical reflector 5 and the multi-layer transmissivity diffuser 3. A lens is positioned below the spherical mirror 4 in the tube 1 to form a closed loop. The multi-layer transmissivity diffuser 3 includes several diffuser rings stacked sequentially along the axial direction, with the light transmittance of the diffuser rings decreasing layer by layer from bottom to top. The manufacturing principle of the multi-layer transmissivity diffuser 3, which forms different layers with different light transmittances, is as follows: the multi-layer transmissivity diffuser 3 is 3D printed using a light-transmitting material, and different fill rates are set for different layers, so that the light transmittance of the diffuser rings decreases layer by layer from top to bottom.

[0041] The ring-shaped LED 6 provides circular illumination as the lighting source for the imaging system itself. Its small size allows for columnar illumination of the surface. The spherical mirror 4 refracts the reflected light from the surface being inspected through the spherical mirror 4 at the bottom of the lens, allowing it to enter the camera's imaging panel. Utilizing the curved surface structure, the camera's unidirectional imaging mode is altered, enabling defect detection over a larger field of view. Within the cylindrical scene, the spherical mirror 4 forms the field of view, and the overall imaging unit's width does not exceed 30mm. The inner diameter of the multi-layer transmissivity diffuser 3 is slightly larger than the diameter of the cylindrical reflector 5, allowing the multi-layer transmissivity diffuser 3 to be directly fitted onto the reflective structure (cylindrical reflector 5).

[0042] Preferably, the multi-layer transmittance diffuser 3 has a total of 5 diffuser rings, all of which are of equal specifications, i.e., equal inner diameter, outer diameter, and thickness. The light transmittance of the four diffuser rings from bottom to top is 85%, 80%, 75%, and 70%, respectively, while the light transmittance of the top diffuser ring is one of 50%, 40%, 30%, and 20%.

[0043] like Figure 3 As shown, simulations were performed with light transmittance of the top diffuser ring at 50%, 40%, 30%, and 20%, respectively, and the simulated illuminance data is shown in Table 1.

[0044]

[0045] Table 1 Simulation results based on multilayer transmittance diffuser plates

[0046] Preferably, the top surface of the spherical mirror 4 facing the cylindrical reflector 5 is a large curved surface, and the bottom surface of the spherical mirror 4 facing the lens is a small curved surface; the distance between the spherical surface of the spherical mirror 4 and the ring lamp bead 6 is 35mm; the distance between the large curved surface of the spherical mirror 4 and the bottom surface of the multilayer transmittance diffuser tube 3 is 15mm.

[0047] A uniform illumination method for an optimized illumination visual inspection device, applied to the aforementioned optimized illumination visual inspection device, the uniform illumination method comprising the following:

[0048] A1. The ring-shaped LED 6 emits light, and the incident light 2 passes through multiple layers of transmissivity diffuser 3 from top to bottom. Because the transmissivity of the multiple diffuser rings increases layer by layer from top to bottom, the absorption rate of the light decreases. As the incident light 2 passes through diffuser rings with different transmissivity at each stage, the light intensity in the medium undergoes a step-like reduction phenomenon, gradually weakening the light intensity of the strong light segment formed in the multiple layers of transmissivity diffuser 3, ultimately reducing the degree of interference to the imaging area and improving the uniformity of the imaging field of view.

[0049] A2. The light rays pass through the hyperboloid mirror of the spherical mirror 4 to form a deflected light path. The incident light ray 2 achieves longitudinal imaging inside the tube 1, and at the same time, it uses spherical reflection to achieve imaging within a 360-degree field of view.

[0050] In this embodiment, a cylindrical diffuse structure is used as the research object. It is decomposed into several equal parts, and the light transmittance of different layers is changed. The transmittance of the diffuse ring is lowest near the ring-shaped LED bead 6, and highest far from the ring-shaped LED bead 6. The starting point is to reduce the light intensity in the originally strong light area by reducing the light transmittance. The incident light ray 2 formed from this area will reduce the incident light intensity in the originally strong light area, thereby reducing the illuminance of the originally bright area in the field of view and forming a larger medium illuminance range. Compared with the traditional lighting effect, the uniformity in the imaging field of view is improved, thereby improving the accuracy and precision of defect detection.

[0051] Example 2

[0052] like Figure 4 and 5 As shown, the visual inspection device for optimized lighting includes a tube 1, a cylindrical reflector 5 inside the tube 1, a ring-shaped lamp bead 6 fitted at the top of the cylindrical reflector 5, a diffuser sleeve around the outer periphery of the cylindrical reflector 5, and a conical reflector 9 fitted at the top of the diffuser sleeve. The top opening of the conical reflector 9 is a small diameter opening, and the bottom opening of the conical reflector 9 is a large diameter opening. The conical reflector 9 has an inner conical wall 8 and an outer conical wall 7. The light transmittance and reflectivity of the inner conical wall 8 are lower than those of the outer conical wall 7. The light transmittance is low because the surface properties of the inner conical wall 8 have high light reflectivity.

[0053] Preferably, the incident angle of the inner peripheral wall 8 of the cone is one of 40°, 30°, 20°, and 10°.

[0054] like Figure 6As shown, the reflection structure was simulated for the inner peripheral wall 8 of the cone at incident angles of 40°, 30°, 20° and 10°, and the illuminance data obtained from the simulation are shown in Table 2.

[0055]

[0056] Table 2 Simulation results of the reflection structure at different angles

[0057] Due to the effect of the internal reflection layer at different angles, the amount of light incident in the vertical direction is further increased compared to the previous method. This results in a significant improvement in brightness in darker areas of the image, and the overall uniformity is also optimized compared to the past.

[0058] A uniform illumination method for an optimized illumination visual inspection device, applied to the aforementioned optimized illumination visual inspection device, the uniform illumination method comprising the following:

[0059] B1. The ring-shaped lamp bead 6 emits light, and the incident light 2 passes through the reflective surfaces of the conical reflector 9 at different tilt angles, causing the propagation path of the incident light 2 to be deflected at different angles. Due to the high reflectivity of the inner wall 8 of the cone, when it connects with the outside of the strong light area, some of the strong light is reflected again by the surface, increasing the incident angle to illuminate the imaging area, reducing the interference caused by the strong light in the field of view, and improving the uniformity and brightness in the imaging field of view.

[0060] B2. The light rays pass through the hyperboloid mirror of the spherical mirror 4 to form a deflected light path. The incident light ray 2 achieves longitudinal imaging inside the tube 1, and at the same time, it uses spherical reflection to achieve imaging within a 360-degree field of view.

[0061] Furthermore, the increased angle of horizontal light rays causes light path deflection, which to some extent enhances the overall illumination in the field of view. The area of ​​high brightness in the field of view will increase due to the refraction of strong light; secondly, the area of ​​medium brightness will increase, while the area of ​​darkness will decrease because more light rays are entering the field of view.

[0062] This embodiment utilizes secondary refraction of light rays at different angles. The aim is to improve the processing of a portion of the incident light ray 2 in the original high-light region. Specifically, the original incident light direction is refracted again through the reflective layer designed in this paper, thereby shifting the high-light region in the field of view towards the vertical direction. Furthermore, due to the presence of the reflective layer, more scattered light from the diffuser is refracted into the field of view, enhancing the overall brightness.

[0063] Example 3

[0064] like Figure 7As shown, the visual inspection device for optimized lighting includes a tube 1, a cylindrical reflector 5 disposed inside the tube 1, an annular LED bead 6 fitted at the top of the cylindrical reflector 5, a diffuser tube fitted around the outer periphery of the cylindrical reflector 5, and an aperture 10 fitted around the outer periphery of the diffuser tube, blocking the upper half of the diffuser tube. The aperture 10 is cylindrical, and its top end extends beyond the top of the annular LED bead 6 and the top of the cylindrical reflector 5.

[0065] Preferably, the length of the aperture 10 is one of 12mm, 13mm, 14mm, 15mm, 16mm, and 17mm.

[0066] like Figure 8 As shown, optical simulations were performed on aperture 10 with lengths of 12mm, 13mm, 14mm, 15mm, 16mm, and 17mm. According to the illuminance distribution diagrams, when the light exit point is reduced, the brightness at the lower end of the field of view increases significantly. This is because the concentration of light leads to more downward scattering. The highest illuminance value in the strong light area is 1.13 × 10⁻⁶. -7 W / mm 2 Reduced to 4.67×10 -8 W / mm 2 This indicates that more light is shining around the perimeter of the area with strong light.

[0067] according to Figure 8 The illuminance data obtained from the simulation are shown in Table 3.

[0068]

[0069]

[0070] Table 3 Simulation results based on different shading distances of the high-reflectivity aperture.

[0071] The table above shows a decrease in average illuminance across the field of view. This means that while less light is emitted from the exposed areas, more light is distributed at the edges, indirectly indicating improved illumination uniformity. The illuminance contrast ratio, standard deviation, and mean deviation all gradually decrease, indicating improved surface illumination uniformity. Therefore, this method can increase the average illumination of the entire imaging area while also improving the illuminance in previously darker areas of the field of view.

[0072] A uniform illumination method for an optimized illumination visual inspection device, applied to the aforementioned optimized illumination visual inspection device, the uniform illumination method comprising the following:

[0073] C1. When the ring-shaped LED 6 emits light, the aperture 10 immediately blocks and reflects the strong light from the ring-shaped LED 6, changes the deflection path of the incident light 2, avoids interference from the strong incident light on the field of view, and improves the uniformity and brightness in the imaging field of view.

[0074] C2. The light rays pass through the hyperboloid mirror of the spherical mirror 4 to form a deflected light path. The incident light ray 2 achieves longitudinal imaging inside the tube 1, and at the same time, it uses spherical reflection to achieve imaging within a 360-degree field of view.

[0075] Traditional cylindrical diffused light structures can be approximated as a surface with a small divergence angle, meaning a significant amount of light does not enter the imaging field of view of the spherical mirror 4 below. In this embodiment, the aperture 10 primarily functions at the lower light exit, redirecting the light propagation direction downwards and concentrating the light. By changing the height of the aperture 10, the angle of the light exit is indirectly altered, directing the strong light from the exit towards the imaging center, while stronger scattered light illuminates the vertical sides. This results in a medium-bright-medium transition within the field of view, but because the light is fully illuminated within the field of view, the overall illuminance deviation is minimal.

[0076] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or substitute them in a similar manner, without departing from the spirit of the invention or exceeding its defined scope. Although the invention has been detailed and described in the accompanying drawings and foregoing description, such descriptions are considered illustrative or exemplary rather than restrictive. It should be understood that changes and modifications can be made by those skilled in the art within the scope of the following claims. Specifically, the invention covers additional embodiments having any combination of features from the different embodiments described above. With regard to the use of the expressions “general” or “substantially,” this patent application should be understood to disclose that the disclosure equally fully satisfies these features and values, i.e., without any of the foregoing characterizations as “general” or “substantially.”

[0077] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A visual inspection device for optimized lighting, comprising a tube, characterized in that, A cylindrical reflector is installed inside the tube, and a ring-shaped LED is fitted at the top of the cylindrical reflector. A multi-layered transmissivity diffuser is fitted around the outer periphery of the cylindrical reflector. The ring-shaped LED emits incident light above the multi-layered transmissivity diffuser. A spherical mirror is spaced apart below the cylindrical reflector and the multi-layered transmissivity diffuser. A lens is installed below the spherical mirror in the tube to form a closure. The multi-layered transmissivity diffuser includes several diffuser rings stacked sequentially along the axial direction, and the light transmittance of the diffuser rings decreases layer by layer from bottom to top.

2. The visual inspection device for optimized lighting as described in claim 1, characterized in that, The multi-layer transmittance diffuser tube is provided with a total of 5 diffuser rings. The light transmittance of the 4 diffuser rings from bottom to top is 85%, 80%, 75%, and 70% respectively, and the light transmittance of the top diffuser ring is one of 50%, 40%, 30%, and 20%.

3. The visual inspection device for optimized lighting as described in claim 1, characterized in that, The top surface of the spherical mirror facing the cylindrical reflector is a large curved surface, and the bottom surface of the spherical mirror facing the lens is a small curved surface; the distance between the spherical surface of the spherical mirror and the ring-shaped LED bead is 35mm; the distance between the large curved surface of the spherical mirror and the bottom surface of the multi-layer transmittance diffuser is 15mm.

4. The visual inspection device for optimized lighting as described in claim 1, characterized in that, A conical reflector is fitted onto the upper part of the cylindrical reflector. The top opening of the conical reflector is a small diameter opening, and the bottom opening is a large diameter opening. The conical reflector has an inner conical circumferential wall and an outer conical circumferential wall. The light transmittance and reflectivity of the inner conical circumferential wall are lower than those of the outer conical circumferential wall.

5. The visual inspection device for optimized lighting as described in claim 4, characterized in that, The incident angle of the inner circumference of the cone is one of 40°, 30°, 20°, or 10°.

6. The visual inspection device for optimized lighting as described in claim 1, characterized in that, An aperture is fitted around the outer periphery of the cylindrical reflector. The aperture is cylindrical, and its top end extends beyond the top of the annular LED and the cylindrical reflector.

7. The visual inspection device for optimized lighting as described in claim 6, characterized in that, The length of the aperture is one of 12mm, 13mm, 14mm, 15mm, 16mm, and 17mm.

8. A uniform illumination method for a visual inspection device with optimized illumination, applied to the visual inspection device with optimized illumination as described in any one of claims 1 to 3, characterized in that, The uniform illumination method includes the following: A1. The ring-shaped LED emits light, and the incident light passes through multiple layers of transmissivity diffuser tubes from top to bottom. As the transmissivity of the multiple diffuser rings increases from top to bottom, the incident light passes through diffuser rings with different transmissivity at each level. The light intensity in the medium is reduced in a stepwise manner, which gradually weakens the light intensity of the strong light segment formed in the multiple layers of transmissivity diffuser tubes, and finally reduces the degree of interference to the imaging area and improves the uniformity in the imaging field of view. A2. The light rays pass through the hyperboloid mirror of the spherical mirror to form a deflected light path, and the incident light rays achieve longitudinal imaging inside the tube. At the same time, the spherical reflection is used to achieve imaging within a 360-degree field of view.

9. A uniform illumination method for a visual inspection device with optimized illumination, applied to the visual inspection device with optimized illumination as described in claim 4 or 5, characterized in that, The uniform illumination method includes the following: B1. The ring-shaped LED emits light, and the incident light passes through the reflective surfaces of the conical reflector at different tilt angles, causing the propagation path of the incident light to be deflected at different angles. Due to the high reflectivity of the inner wall of the cone, when it connects with the outer side of the strong light area, some of the strong light is reflected again by the surface, increasing the incident angle to illuminate the imaging area, reducing the interference caused by the strong light in the field of view, and improving the uniformity and brightness in the imaging field of view. B2. The light rays pass through the hyperboloid mirror of the spherical mirror to form a deflected light path, and the incident light rays achieve longitudinal imaging inside the tube. At the same time, the spherical reflection is used to achieve imaging within a 360-degree field of view.

10. A uniform illumination method for a visual inspection device with optimized illumination, applied to the visual inspection device with optimized illumination as described in claim 6 or 7, characterized in that, The uniform illumination method includes the following: C1. The ring-shaped LED emits light, and the aperture immediately blocks and reflects the strong light from the ring-shaped LED, changing the deflection path of the incident light and avoiding interference from the strong incident light within the field of view, thereby improving the uniformity and brightness in the imaging field of view. C2. The light rays pass through the hyperboloid mirror of the spherical mirror to form a deflected light path, and the incident light rays achieve longitudinal imaging inside the tube. At the same time, the spherical reflection is used to achieve imaging within a 360-degree field of view.

Images