Planar coaxial lighting device and vision inspection system

Abstract

This utility model relates to the field of visual inspection technology, and more particularly to a planar coaxial lighting device and a visual inspection system. The planar coaxial lighting device includes a bracket and a light guide plate and a main light source strip connected to the bracket. The bracket can be connected to a camera, and the bracket does not obstruct the camera lens. The light guide plate is located in front of the lens, and the surface of the light guide plate is perpendicular to the shooting direction of the lens. The main light source strip is located on a first side of the light guide plate, and the main light source strip extends along the length of the first side. The light from the main light source strip is emitted towards the first side. The light guide plate is configured such that the light from the main light source strip is converted into surface light source light, and the surface light source light is emitted away from the lens. The visual inspection system includes a camera and the aforementioned planar coaxial lighting device, with the camera connected to the bracket of the planar coaxial lighting device. This planar coaxial lighting device and visual inspection system can improve light uniformity, improve image quality and inspection accuracy, and improve work efficiency.

Description

Technical Field

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

[0002] In the field of visual inspection, coaxial light sources are one of the most effective illumination solutions for surface defect detection of highly reflective planar objects (such as lithium battery electrodes, wafer surfaces, glass substrates, and metal nameplates). When traditional LED strips directly illuminate objects, the characteristics of LED point light sources easily lead to light spots and uneven brightness, affecting image quality and thus the accuracy of the inspection. Furthermore, in existing technologies, the camera and illumination device are installed independently, occupying a significant amount of space, and the illumination device requires separate adjustment to accommodate the camera lens. Utility Model Content

[0003] One objective of this invention is to provide a planar coaxial illumination device that can improve the uniformity of light, thereby improving image quality and detection accuracy, and can also simplify the debugging process and improve work efficiency.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A planar coaxial lighting device is provided, comprising:

[0006] A bracket that can be connected to a camera, and the bracket does not obstruct the lens of the camera;

[0007] A light guide plate is connected to the bracket and is located in front of the lens. The surface of the light guide plate is perpendicular to the shooting direction of the lens.

[0008] A main light source strip is connected to the bracket and located on the first side of the light guide plate. The main light source strip extends along the length of the first side and emits light towards the first side. The light guide plate is configured such that the light from the main light source strip is converted into surface light source light through the light guide plate, and the surface light source light is emitted away from the lens.

[0009] Optionally, the light guide plate has two first sides arranged opposite to each other, and two main light source strips are provided, with the two main light source strips located at the two first sides respectively, and the light from the two main light source strips emitting towards the two first sides respectively.

[0010] Optionally, the light from the main light source strip is emitted perpendicular to the first side.

[0011] Optionally, the bracket includes a first mounting base located on the first side, the first mounting base having a receiving groove on the side facing the first side, the receiving groove being deep along a direction perpendicular to the first side, the main light source strip and the first side being both located within the receiving groove, and a first heat dissipation protrusion protruding from the outer wall of the first mounting base.

[0012] Optionally, the planar coaxial lighting device further includes an auxiliary light strip connected to the bracket. The auxiliary light strip is located on the side of the light guide plate facing the lens and extends along the length of the first side. The light from the auxiliary light strip is directed toward the light guide plate and emitted at an acute angle to the surface of the light guide plate.

[0013] Optionally, the light from the auxiliary light strip is emitted at a 45-degree angle to the surface of the light guide plate.

[0014] Optionally, two auxiliary light strips are provided, and the two auxiliary light strips are spaced apart in a direction perpendicular to the first side, and the light-emitting surface of any one of the auxiliary light strips is inclined toward the other auxiliary light strip.

[0015] Optionally, the bracket includes a second mounting base located at the auxiliary light strip. The second mounting base has a receiving groove on the surface facing the light guide plate. The receiving groove extends longitudinally along a direction perpendicular to the surface of the auxiliary light strip. The auxiliary light strip is located within the receiving groove. A second heat dissipation protrusion is provided on the outer wall surface of the second mounting base.

[0016] Optionally, the planar coaxial lighting device further includes a first conductor, and a first interface terminal is soldered on the PCB board of the main light source strip. One end of the first conductor is connected to the first interface terminal, and the other end is connected to the power supply or the first lighting power transmission interface on the camera.

[0017] And / or, the planar coaxial lighting device further includes a second conductor, and a second interface terminal is soldered on the PCB board of the auxiliary light strip. One end of the second conductor is connected to the second interface terminal, and the other end is connected to the power supply or the second lighting power supply interface on the camera.

[0018] And / or, the main light source strip is an LED strip;

[0019] And / or, the auxiliary light strip is an LED light strip.

[0020] Another objective of this invention is to provide a visual inspection system that can improve the uniformity of light, thereby improving image quality and detection accuracy, and can also simplify the debugging process and improve work efficiency.

[0021] To achieve this objective, the present invention adopts the following technical solution:

[0022] A visual inspection system is provided, including a camera and the aforementioned planar coaxial illumination device, wherein the camera is connected to a bracket of the planar coaxial illumination device.

[0023] The beneficial effects of this utility model are:

[0024] This invention provides a planar coaxial lighting device, including a bracket, a light guide plate, and a main light source strip. The bracket can be connected to a camera without obstructing the camera lens. The light guide plate is connected to the bracket and located in front of the lens, with its surface perpendicular to the lens's shooting direction. The main light source strip is connected to the bracket and located on a first side of the light guide plate, extending along its length. The light from the main light source strip is emitted towards the first side. The light guide plate is configured to convert the light from the main light source strip into a surface light source, which is emitted away from the lens. By using the light guide plate, the light emitted from multiple point sources in the main light source strip is converted into a surface light source, resulting in more uniform light and eliminating light spots, thus improving image quality and detection accuracy. Furthermore, both the light guide plate and the main light source strip are fixed to the relative position of the camera via the bracket, eliminating the need to adjust the positional relationship between the camera and the planar coaxial lighting device, thus simplifying the adjustment process and improving work efficiency.

[0025] This invention also provides a visual inspection system, including a camera and the aforementioned planar coaxial illumination device, with the camera connected to a bracket of the planar coaxial illumination device. This visual inspection system can improve light uniformity, thereby improving image quality and inspection accuracy, and can also simplify the debugging process and improve work efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the planar coaxial lighting device provided in Embodiment 1 of this utility model;

[0027] Figure 2 This is a cross-sectional view of the planar coaxial lighting device provided in Embodiment 1 of this utility model;

[0028] Figure 3 This is a partially exploded structural diagram of the planar coaxial lighting device provided in Embodiment 1 of this utility model;

[0029] Figure 4 This is a schematic diagram of the planar coaxial lighting device provided in Embodiment 2 of this utility model;

[0030] Figure 5 This is a cross-sectional view of the planar coaxial lighting device provided in Embodiment 2 of this utility model.

[0031] In the picture:

[0032] 1. Bracket; 11. First mounting base; 111. Receiving groove; 112. First heat dissipation protrusion; 12. Second mounting base; 121. Receiving groove; 122. Second heat dissipation protrusion; 13. Connecting assembly;

[0033] 2. Light guide plate; 21. First side surface;

[0034] 3. Main light source strip; 4. Auxiliary light strip. Detailed Implementation

[0035] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining this utility model and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this utility model are shown in the drawings, not all of them.

[0036] In the description of this utility model, 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 fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections 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.

[0037] 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.

[0038] Example 1

[0039] In the field of visual inspection, coaxial light sources are one of the most effective illumination solutions for surface defect detection of highly reflective planar objects (such as lithium battery electrodes, wafer surfaces, glass substrates, and metal nameplates). When traditional LED strips directly illuminate objects, the characteristics of LED point light sources easily lead to light spots and uneven brightness, affecting image quality and thus the accuracy of the inspection. Furthermore, in existing technologies, the camera and illumination device are installed independently, occupying a significant amount of space, and the illumination device requires separate adjustment to accommodate the camera lens.

[0040] Therefore, this embodiment provides a planar coaxial illumination device to solve the above problems. The planar coaxial illumination device can improve the uniformity of light, thereby improving the imaging quality and the accuracy of detection, and can also simplify the debugging process and improve work efficiency.

[0041] like Figures 1-3 As shown, the planar coaxial lighting device of this embodiment includes a bracket 1, a light guide plate 2, and a main light source strip 3. The bracket 1 can be connected to a camera without obstructing the camera lens. The light guide plate 2 is connected to the bracket 1 and is located in front of the lens, with its surface perpendicular to the lens's shooting direction. The main light source strip 3 is connected to the bracket 1 and is located at the first side 21 of the light guide plate 2, extending along the length of the first side 21. The light from the main light source strip 3 is emitted towards the first side 21. The light guide plate 2 is configured such that the light from the main light source strip 3 is converted into surface light, and this surface light is emitted away from the lens.

[0042] The light emitted from the main light source strip 3 is converted into a surface light source by the light guide plate 2 and emitted towards the area being inspected. Only the light guide plate 2 is in front of the camera lens, and it does not obstruct the lens's view. This planar coaxial illumination device, by setting the light guide plate 2, converts the light emitted from the multiple point light sources of the main light source strip 3 into a surface light source, resulting in more uniform light and eliminating light spot problems, thereby improving image quality and detection accuracy. Furthermore, both the light guide plate 2 and the main light source strip 3 are mounted on the bracket 1, which is connected to the camera. The relative positions of the light guide plate 2 and the main light source strip 3 with the camera are fixed by the bracket 1, eliminating the need to adjust the positional relationship between the camera and the planar coaxial illumination device. This simplifies the adjustment process and improves work efficiency.

[0043] Optionally, the light guide plate 2 has two opposing first side surfaces 21, and two main light source strips 3 are provided, each located on one of the two first side surfaces 21, with the light emitted from each strip pointing towards the first side surfaces 21. Optionally, the two first side surfaces 21 are two opposing sides arranged along the width direction of the light guide plate 2, and the length direction of the first side surfaces 21 is the length direction of the light guide plate 2. Providing two main light source strips 3 can prevent the light emitted from the light guide plate 2 from having a tendency to decrease in intensity along a certain direction, thereby further ensuring the uniformity of the light emitted from the light guide plate 2 to the inspected area and improving the light intensity.

[0044] Optionally, the light from the main light source strip 3 is emitted perpendicular to the first side 21 to ensure optimal uniformity of the light emitted from the light guide plate 2.

[0045] Optionally, the bracket 1 includes a first mounting base 11 located on the first side 21. The first mounting base 11 has a receiving groove 111 on its surface facing the first side 21. The receiving groove 111 extends longitudinally in a direction perpendicular to the first side 21, and the main light source strip 3 and the first side 21 are both located within the receiving groove 111. Optionally, the main light source strip 3 is attached to the bottom of the receiving groove 111, and the first side 21 and part of the side of the light guide plate 2 are also inserted into the receiving groove 111, with a certain distance between the first side 21 and the light-emitting surface of the main light source strip 3. It is understood that, to accommodate the shape of the main light source strip 3 and the first side 21, the first mounting base 11 extends along the length direction of the light guide plate 2, and the receiving groove 111 is wider along the length direction of the light guide plate 2 and narrower along the thickness direction of the light guide plate 2.

[0046] To enhance the heat dissipation of the main light source strip 3, optionally, a first heat dissipation protrusion 112 is provided on the outer wall surface of the first mounting base 11. The heat of the main light source strip 3 can be transferred from the inner wall surface of the receiving groove 111 to the outer wall surface of the first mounting base 11, and the first heat dissipation protrusion 112 can increase the contact area with the outside world and enhance heat dissipation.

[0047] Optionally, the first heat dissipation protrusion 112 is disposed on the outer wall surface of the extension surface of the sidewall of the receiving groove 111. In this embodiment, the first heat dissipation protrusion 112 is disposed on the outer wall surface of the extension surface of the sidewall of the receiving groove 111 near the lens. The first heat dissipation protrusion 112 is a strip-shaped structure extending along the length direction of the light guide plate 2, and multiple strip-shaped structures are arranged in parallel and spaced along the width direction of the light guide plate 2 to further improve heat dissipation efficiency.

[0048] Optionally, the maximum height of the first heat dissipation protrusion 112 can be set to 4mm, the thickness of each protrusion can be set to 2mm, and the spacing between adjacent protrusions can be set to 2mm. Since the protrusions are integrated on the first mounting base 11, thermal resistance can be minimized.

[0049] Optionally, since there are two main light source strips 3, the bracket 1 has a first mounting base 11 on each side along the width direction of the light guide plate 2. The receiving grooves 111 on the two first mounting bases 11 are opened opposite each other. The two main light source strips 3 are respectively located in the receiving grooves 111 of the two first mounting bases 11. The two first side surfaces 21 and part of the side surfaces of the light guide plate 2 are also respectively inserted into the two receiving grooves 111.

[0050] Optionally, the bracket 1 further includes connecting components 13. Two connecting components 13 are located at opposite ends of the length of the light guide plate 2. One connecting component 13 is connected to one end of the two first mounting bases 11, and the other connecting component 13 is connected to the other end of the two first mounting bases 11. That is, the first mounting bases 11, connecting components 13, and so on are sequentially connected to form a ring-shaped component structure, with the light guide plate 2 embedded in the middle of the ring-shaped component structure. Optionally, the connecting components 13 are screwed to the first mounting bases 11.

[0051] Optionally, the connecting component 13 is screwed to the camera to form a detachable connection structure. The two connecting components 13 are screwed to both sides of the camera respectively to make the connection between the camera and the planar coaxial lighting device more secure.

[0052] Optionally, the bracket 1 is made of aluminum alloy, which can ensure structural strength, heat dissipation performance and light weight.

[0053] Optionally, the planar coaxial lighting device also includes a first conductor. A first interface terminal is soldered onto the PCB board of the main light source strip 3. One end of the first conductor is connected to the first interface terminal, and the other end is connected to the first lighting power supply interface on the power supply or camera to power the main light source strip 3. The first interface terminal is a standardized wiring terminal. Optionally, the first interface terminal adopts an XH2.0-4Pin wiring terminal.

[0054] Optionally, the main light source strip 3 is an LED strip, which consists of multiple LED beads spaced apart along its length. LED strips can reduce costs, improve product standardization, and offer advantages such as high brightness and thinness.

[0055] Example 2

[0056] This embodiment discloses a planar coaxial lighting device. The planar coaxial lighting device in this embodiment differs from the planar coaxial lighting device in Embodiment 1 in that: Figures 4 to 5As shown, the planar coaxial illumination device in this embodiment also includes an auxiliary light strip 4. The auxiliary light strip 4 is connected to the bracket 1 and is located on the side of the light guide plate 2 facing the lens. The auxiliary light strip 4 extends along the length of the first side surface 21, and the light from the auxiliary light strip 4 is directed towards the light guide plate 2 and emitted at an acute angle to the surface of the light guide plate 2. The auxiliary light strip 4 can further increase the light intensity emitted by the light guide plate 2 towards the inspected area, thereby improving the clarity of the photograph.

[0057] Optionally, the light from the auxiliary light strip 4 is emitted at a 45-degree angle to the surface of the light guide plate 2. Optionally, two auxiliary light strips 4 are provided, spaced apart along a direction perpendicular to the first side surface 21, with the emitting surface of one auxiliary light strip 4 tilted towards the other, i.e., the emitting surfaces of the two auxiliary light strips 4 are tilted relative to each other at a certain angle. Optionally, the two auxiliary light strips 4 are mirror-symmetrically arranged along the centerline of the width direction of the light guide plate 2, and the light from both auxiliary light strips 4 can point to the center of the inspected area, forming symmetrical cross illumination, effectively highlighting scratches, unevenness, and other features on the surface of the inspected area.

[0058] To accommodate the auxiliary light strip 4, the bracket 1 may optionally include a second mounting base 12 located at the auxiliary light strip 4. The second mounting base 12 has a receiving groove 121 on its surface facing the light guide plate 2. The receiving groove 121 extends longitudinally along a direction perpendicular to the surface of the auxiliary light strip 4, and the auxiliary light strip 4 is located within the receiving groove 121. Optionally, both ends of the second mounting base 12 are respectively connected to two connecting components 13 to form an integral bracket 1 with the ring-shaped component structure. Optionally, the second mounting base 12 is screwed to the connecting components 13.

[0059] Optionally, since there are two auxiliary light strips 4, there are correspondingly two second mounting bases 12. Each of the two second mounting bases 12 has a receiving groove 121, and the two auxiliary light strips 4 are respectively located in the receiving grooves 121 of the two second mounting bases 12. It can be seen that along the width direction of the light guide plate 2, one first mounting base 11 and one second mounting base 12 are located on one side of the lens, and the other first mounting base 11 and the other second mounting base 12 are located on the other side of the lens.

[0060] To enhance heat dissipation of the auxiliary light strip 4, optionally, a second heat dissipation protrusion 122 is provided on the outer wall surface of the second mounting base 12. The heat of the auxiliary light strip 4 can be transferred from the inner wall of the receiving groove 121 to the outer wall surface of the second mounting base 12, and the second heat dissipation protrusion 122 can increase the contact area with the outside world, thereby enhancing heat dissipation.

[0061] Optionally, the second heat dissipation protrusion 122 is disposed on the outer wall surface of the extension surface of the sidewall of the receiving groove 121. In this embodiment, the second heat dissipation protrusion 122 is disposed on the outer wall surface of the extension surface of the sidewall of the receiving groove 121 facing away from the lens. The second heat dissipation protrusion 122 is a strip-shaped structure extending along the length direction of the light guide plate 2, and multiple strip-shaped structures are arranged in parallel at intervals along a direction perpendicular to the plate surface of the auxiliary light strip 4 to further improve heat dissipation efficiency. That is, in this embodiment, the first heat dissipation protrusion 112 and the second heat dissipation protrusion 122 on the same side are both located in the space between the first mounting base 11 and the second mounting base 12, and the two protrude relative to each other at a certain angle. This design can make full use of the space between the first mounting base 11 and the second mounting base 12, and will not interfere with the installation of the lens or the shooting of the lens.

[0062] Optionally, the maximum height of the second heat dissipation protrusion 122 can be set to 4mm, the thickness of each protrusion can be set to 2mm, and the spacing between adjacent protrusions can be set to 2mm. Since the protrusions are integrated on the second mounting base 12, thermal resistance can be minimized.

[0063] Optionally, the planar coaxial lighting device also includes a second conductor. A second interface terminal is soldered onto the PCB board of the auxiliary light strip 4. One end of the second conductor is connected to the second interface terminal, and the other end is connected to the second lighting power supply interface on the power supply or camera to power the auxiliary light strip 4. The second interface terminal is a standardized wiring terminal; optionally, the second interface terminal uses an XH2.0-4Pin wiring terminal.

[0064] Optionally, the auxiliary light strip 4 is an LED light strip, which consists of multiple LED beads spaced apart along its length. LED light strips can reduce costs, improve product standardization, and have the characteristics of high brightness and thinness.

[0065] The camera of this planar coaxial lighting device can capture images illuminated by light emitted from the main light source strip 3 and auxiliary light strip 4, converted by the light guide plate 2. The final imaging effect is: surface defects are clearly distinguishable, and the image background is uniform and free of light spots. Actual measurements show that within the effective illumination area, the illumination uniformity can reach over 95%, far exceeding that of a single light strip at a 45-degree angle. The image background is clean and uniform, without light spots or areas of transition between light and dark. Three-dimensional defects such as scratches, indentations, and dents in the inspected area are highlighted, while two-dimensional features such as surface dirt, color differences, and printing defects are also clearly distinguishable. One planar coaxial lighting device covers the inspection tasks that traditionally require two independent lighting devices, and with higher image quality. Furthermore, the four light strips are independently controllable, allowing users to flexibly select the lighting mode according to different products and defect types.

[0066] This planar coaxial lighting device, by setting up a bracket 1 and embedding a main light source strip 3, an auxiliary light strip 4, and a light guide plate 2 on the bracket 1, can achieve light path conversion without increasing the light path height and overall volume, greatly improving space utilization. Compared with the traditional separate solution of main light source, independent supplementary light, and light guide plate 2, the overall installation volume can be reduced by 40%-50%, making it particularly suitable for precision testing equipment with multiple workstations side by side or limited space.

[0067] The ingenious heat dissipation structure on bracket 1 solves the heat dissipation problem under high-density integration of multiple light sources. Actual tests show that after four LED strips operate continuously at full power for 8 hours, the temperature of bracket 1 is 20°C lower than without optimized heat dissipation design. The lifespan of the LED strips is expected to be extended by more than 50%, and long-term consistency in testing is guaranteed.

[0068] Furthermore, by soldering standardized terminals onto the light strips, plug-and-play functionality is achieved, making them easy to use. The four-channel standardized 2.0mm interface facilitates all electrical connections for the four light strips, eliminating the need for technicians to distinguish the positive and negative terminals and trigger signals of the four wiring harnesses; they can simply plug and unplug. The wiring time for a single connection is reduced from the traditional 20-30 minutes (connecting four light strips separately) to less than 1 minute, significantly reducing assembly error rates and labor costs.

[0069] The camera, main light source strip 3, auxiliary light strip 4, and light guide plate 2 of this planar coaxial lighting device are all integrated on a compact bracket 1. The optical path is fixed in the design, and no complicated optical path debugging is required on site, which greatly reduces the difficulty of equipment deployment.

[0070] Apart from the above, the remaining structure of the planar coaxial lighting device provided in this embodiment is the same as that of the planar coaxial lighting device in Embodiment 1, and will not be described again here.

[0071] Example 3

[0072] This embodiment provides a visual inspection system, including a camera and a planar coaxial illumination device as described in Embodiment 1 or Embodiment 2, with the camera connected to a bracket 1 of the planar coaxial illumination device. This visual inspection system can improve light uniformity, thereby improving image quality and inspection accuracy, and can also simplify the debugging process and increase work efficiency.

[0073] 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 other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations 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. Flat coaxial illumination device, characterized in that include: A bracket (1) is capable of being connected to a camera, and the bracket (1) does not obstruct the lens of the camera; A light guide plate (2) is connected to the bracket (1). The light guide plate (2) is located in front of the lens, and the surface of the light guide plate (2) is perpendicular to the shooting direction of the lens. The main light source strip (3) is connected to the bracket (1). The main light source strip (3) is located on the first side (21) of the light guide plate (2) and extends along the length direction of the first side (21). The light from the main light source strip (3) is emitted towards the first side (21). The light guide plate (2) is configured such that the light from the main light source strip (3) is converted into surface light source light through the light guide plate (2) and the surface light source light is emitted away from the lens.

2. The planar coaxial illumination device of claim 1, wherein, The light guide plate (2) has two first side surfaces (21) arranged opposite to each other. There are two main light source strips (3). The two main light source strips (3) are located at the two first side surfaces (21) respectively, and the light from the two main light source strips (3) is emitted towards the two first side surfaces (21) respectively.

3. The planar coaxial illumination device of claim 1, wherein, The light from the main light source strip (3) is emitted perpendicular to the first side (21).

4. The planar coaxial illumination device of claim 1, wherein, The bracket (1) includes a first mounting base (11) located on the first side (21). The first mounting base (11) has a receiving groove (111) on the side facing the first side (21). The receiving groove (111) extends vertically in a direction perpendicular to the first side (21). The main light source strip (3) and the first side (21) are both located in the receiving groove (111). The outer wall of the first mounting base (11) has a first heat dissipation protrusion (112).

5. A planar coaxial illumination device according to any one of claims 1-4, characterized in that The planar coaxial lighting device also includes an auxiliary light strip (4), which is connected to the bracket (1). The auxiliary light strip (4) is located on the side of the light guide plate (2) facing the lens, and extends along the length direction of the first side (21). The light from the auxiliary light strip (4) is directed toward the light guide plate (2) and is emitted at an acute angle to the surface of the light guide plate (2).

6. The planar coaxial illumination device of claim 5, wherein, The light from the auxiliary light strip (4) is emitted at a 45-degree angle to the surface of the light guide plate (2).

7. The planar coaxial illumination device of claim 5, wherein, There are two auxiliary light strips (4), which are spaced apart in a direction perpendicular to the first side (21), and the light-emitting surface of any one of the auxiliary light strips (4) is tilted toward the other auxiliary light strip (4).

8. The planar coaxial illumination device of claim 5, wherein, The bracket (1) includes a second mounting base (12) located at the auxiliary light strip (4). The second mounting base (12) has a receiving groove (121) on the surface facing the light guide plate (2). The receiving groove (121) extends longitudinally along a direction perpendicular to the plate surface of the auxiliary light strip (4). The auxiliary light strip (4) is located in the receiving groove (121). The outer wall surface of the second mounting base (12) is provided with a second heat dissipation protrusion (122).

9. The planar coaxial illumination device of claim 5, wherein, The planar coaxial lighting device also includes a first conductor. The main light source bar (3) has a first interface terminal soldered on its PCB board. One end of the first conductor is connected to the first interface terminal, and the other end is connected to the power supply or the first lighting power transmission interface on the camera. And / or, the planar coaxial lighting device further includes a second conductor, and a second interface terminal is soldered on the PCB board of the auxiliary light strip (4). One end of the second conductor is connected to the second interface terminal, and the other end is connected to the power supply or the second lighting power supply interface on the camera. And / or, the main light source strip (3) is an LED strip; And / or, the auxiliary light strip (4) is an LED light strip.

10. A visual inspection system, characterized in that, Includes a camera and a planar coaxial lighting device as described in any one of claims 1-9, wherein the camera is connected to a bracket (1) of the planar coaxial lighting device.

Images