Shadowless light source and detection device

Abstract

The utility model relates to the technical field of detection light sources, and discloses a shadowless light source and a detection device.The shadowless light source comprises a plane coaxial light source which comprises a light guide plate and light bars arranged on the periphery of the light guide plate, and a light reflecting layer is arranged on the back face of the light guide plate and composed of a plurality of arc-shaped protruding points; the arc-shaped salient points reflect light rays emitted by the light bar, so that the light rays are emitted from the front surface of the light guide plate; the hemispherical shell is arranged on the light emitting side of the plane coaxial light source, and the edge of the hemispherical shell is connected with the plane coaxial light source in a sealed mode; a diffuse reflection coating is arranged on the inner shell face of the hemispherical shell, the hemispherical shell is provided with a material passing groove allowing a workpiece to enter a detection station, and the material passing groove is located under the plane coaxial light source. According to the shadowless light source and the detection device disclosed by the utility model, the camera can better detect the surface defects of the workpiece.

Description

Technical Field

[0001] This utility model relates to the field of detection light source technology, and in particular to a shadowless light source and detection device. Background Technology

[0002] Machine vision refers to a technology that uses machines to replace human eyes for measurement and judgment. In a machine vision system, image quality determines the accuracy of visual inspection. When the image quality is good and the image features are obvious, the accuracy of machine vision inspection can be effectively guaranteed. To obtain a good image, it is necessary to select a suitable light source.

[0003] Commonly used light sources include point light sources, ring light sources, strip light sources, coaxial light sources, etc. These light sources illuminate the surface of the workpiece directly from the top side. Since the workpiece surface may have depressions or protrusions, when conventional light sources illuminate the workpiece from the top side, the image captured by the camera is prone to overexposure or underexposure, especially the edges of the workpiece contour, which are prone to overexposure and are not conducive to highlighting the surface defects of the workpiece.

[0004] Therefore, it is necessary to design a shadowless light source and detection device so that the camera can better detect surface defects of the workpiece.

[0005] The above information is provided as background information only to aid in understanding this disclosure and does not constitute an assertion or admission that any of the above content can be used as prior art relative to this disclosure. Utility Model Content

[0006] This invention provides a shadowless light source and a detection device to enable cameras to better detect surface defects in workpieces.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A shadowless light source, comprising:

[0009] A planar coaxial light source includes a light guide plate and light strips arranged around the light guide plate. A light reflective layer is provided on the back of the light guide plate. The light reflective layer is composed of several arc-shaped protrusions. The arc-shaped protrusions reflect the light emitted by the light strips, so that the light is emitted from the front of the light guide plate.

[0010] A hemispherical shell is disposed on the light-emitting side of the planar coaxial light source, and its edge is sealed to the planar coaxial light source; the inner shell surface of the hemispherical shell is provided with a diffuse reflection coating, and the hemispherical shell is provided with a material passage for the workpiece to enter the inspection station, the material passage being located directly below the planar coaxial light source.

[0011] Optionally, the planar coaxial light source further includes a housing, and both the light guide plate and the light strip are installed in the housing;

[0012] The bottom of the housing is provided with an assembly groove for positioning the hemispherical shell, and the edge of the hemispherical shell extends out to form an annular edge that presses against the bottom wall of the assembly groove.

[0013] A fixing hole is provided on the annular edge, and a fastener passes through the fixing hole and is threaded into the housing.

[0014] Optionally, the planar coaxial light source further includes a support ring for mounting in the housing to position and support the light guide plate;

[0015] The support ring includes an annular body and four strip-shaped positioning protrusions disposed on the annular body. The annular body and the strip-shaped positioning protrusions form a positioning groove, and the top of the light guide plate is positioned and inserted into the positioning groove.

[0016] Optionally, the planar coaxial light source further includes a clamping ring for pressing the planar coaxial light source, the clamping ring pressing on the top of the light guide plate and being detachably connected to the support ring.

[0017] Optionally, the arc-shaped protrusion has an arc-shaped reflective surface, which reflects the light from the light bar into the light guide plate.

[0018] Optionally, the device further includes a fastening ring for pressing against the annular edge;

[0019] The fasteners sequentially pass through the fastening ring and the annular edge and are threaded into the housing.

[0020] Optionally, the support ring is further provided with a mounting groove for positioning the light strip.

[0021] Optionally, the housing is a plastic housing.

[0022] Optionally, a light-absorbing layer is provided on the wall of the material conveying trough.

[0023] A detection device comprising a shadowless light source as described in any of the preceding claims.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The shadowless light source provided by this utility model has light from the light bar entering the light guide plate reflected by the arc-shaped protrusion, so that the light shines downward onto the surface of the workpiece entering the feed trough or onto the diffuse reflection coating on the inner wall of the hemispherical shell. The diffuse reflection coating reflects the light to the outer periphery of the workpiece, thereby avoiding shadows on the workpiece surface and effectively reducing overexposure or underexposure, better highlighting the surface defects of the workpiece, and enabling the camera to directly photograph and inspect the workpiece from the top side of the light guide plate.

[0026] This invention has other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and the following detailed description, which together serve to explain the particular principles of this invention. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is an exploded view of the shadowless light source provided in this embodiment of the utility model;

[0029] Figure 2 This is a bottom-view schematic diagram of the shadowless light source provided in this embodiment of the utility model;

[0030] Figure 3 It is the workpiece plus Figure 2 A schematic diagram of the AA cross-sectional structure of the shadowless light source in the image;

[0031] Figure 4 This is a three-dimensional structural schematic diagram of the shadowless light source provided in this embodiment of the utility model;

[0032] Figure 5 This is a three-dimensional structural diagram of another downward-facing shadowless light source provided in an embodiment of this utility model;

[0033] Figure 6 This is a three-dimensional structural schematic diagram of the support ring provided in an embodiment of this utility model.

[0034] Reference numerals: 1. Planar coaxial light source; 11. Light guide plate; 12. Light strip; 13. Housing; 1301. Assembly groove; 14. Support ring; 1401. Positioning groove; 1402. Mounting groove; 141. Annular body; 142. Strip-shaped positioning protrusion; 15. Pressing ring; 2. Hemispherical shell; 201. Material passage groove; 21. Annular edge; 3. Fastening ring. Detailed Implementation

[0035] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0036] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0037] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0038] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0039] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0040] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0041] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0042] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0043] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0044] Example 1

[0045] In view of the aforementioned defects in existing shadowless light sources, the applicant, based on years of rich practical experience and professional knowledge in the design and manufacture of such products, and in conjunction with the application of theoretical principles, actively conducted research and innovation in order to create a technology that can solve the defects in the existing technology and make the shadowless light source more practical. After continuous research, design, and repeated prototype production and improvement, this utility model with real practical value has finally been created.

[0046] Please refer to Figures 1 to 6This utility model embodiment provides a shadowless light source, including: a planar coaxial light source 1, including a light guide plate 11 and light strips 12 disposed around the light guide plate 11. A light reflection layer is disposed on the back of the light guide plate 11. The light reflection layer is composed of several arc-shaped protrusions. The arc-shaped protrusions reflect the light emitted by the light strips 12, so that the light is emitted from the front of the light guide plate 11; a hemispherical shell 2, disposed on the light-emitting side of the planar coaxial light source 1, and its edge is sealed to the planar coaxial light source 1; the inner shell surface of the hemispherical shell 2 is provided with a diffuse reflection coating, and the hemispherical shell 2 has a material passage 201 for the workpiece to enter the inspection station. The material passage 201 is located directly below the planar coaxial light source 1.

[0047] In this embodiment, the shadowless light source, the light from the light strip 12 entering the light guide plate 11 is reflected by the arc-shaped protrusion, so that the light shines downward onto the surface of the workpiece entering the feed trough 201 or onto the diffuse reflection coating on the inner wall of the hemispherical shell 2. The diffuse reflection coating reflects the light to the outer periphery of the workpiece, thereby avoiding local shadows on the workpiece surface and effectively reducing overexposure or underexposure, better highlighting the surface defects of the workpiece, and enabling the camera to directly photograph and inspect the workpiece from the top side of the light guide plate 11.

[0048] It should also be noted that the planar coaxial light source 1 in this embodiment is existing technology, and the light guide plate 11 is a transparent plate, so the camera can directly take pictures of the workpiece on the top of the light guide plate 11. The focus of protection in this embodiment is the combined structure of the planar coaxial light source 1 and the hemispherical shell 2, as well as the specific structure of the hemispherical shell 2.

[0049] Optionally, the planar coaxial light source 1 also includes a housing 13, which serves to support the light guide plate 11 and the light strip 12, and both the light guide plate 11 and the light strip 12 are installed in the housing 13; the bottom of the housing 13 is provided with an assembly groove 1301 for positioning the hemispherical shell 2, and the edge of the hemispherical shell 2 extends out to form an annular edge 21 that presses against the bottom wall of the assembly groove 1301; a fixing hole is provided on the annular edge 21, and a fastener passes through the fixing hole and is threadedly connected to the housing 13.

[0050] Specifically, the hemispherical shell 2 can be directly positioned and installed into the assembly groove 1301, and then fastened with fasteners, which simplifies the installation process and makes the positioning of the hemispherical shell 2 more accurate. Generally, the fasteners are bolts.

[0051] Optionally, the planar coaxial light source 1 further includes a support ring 14 for mounting in the housing 13 to position and support the light guide plate 11. The support ring 14 includes an annular body 141 and four strip-shaped positioning protrusions 142 disposed on the annular body 141. The annular body 141 and the strip-shaped positioning protrusions 142 form a positioning groove 1401, into which the top of the light guide plate 11 is positioned and inserted. Specifically, the four strip-shaped positioning protrusions 142 are provided on the top surface of the annular body 141, thereby forming a positioning groove 1401 that can position the light guide plate 11, making the installation of the light guide plate 11 simpler and more accurate.

[0052] Optionally, the planar coaxial light source 1 further includes a clamping ring 15 for pressing the planar coaxial light source 1. The clamping ring 15 presses against the top of the light guide plate 11 and is detachably connected to the support ring 14. When it is necessary to replace the light guide plate 11, the clamping ring 15 can be removed first, then the light guide plate 11 to be replaced can be removed, then the new light guide plate 11 can be installed, and finally the clamping ring 15 can be reinstalled on the support ring 14, so that the clamping ring 15 presses the light guide plate 11.

[0053] Optionally, the arc-shaped protrusion has an arc-shaped reflective surface that reflects the light emanating from the light strip 12 into the light guide plate 11.

[0054] Optionally, a fastening ring 3 is also included for pressing against the annular edge 21; the fastener passes sequentially through the fastening ring 3 and the annular edge 21 and is threadedly connected to the housing 13. The fastening ring 3 presses against the annular edge 21, thereby improving the fixation effect of the hemispherical shell 2 and enhancing the fixation stability of the hemispherical shell 2.

[0055] Optionally, the support ring 14 is also provided with a mounting groove 1402 for positioning the light strip 12. This allows the light strip 12 to be installed in a more accurate position. The positioning groove 1401 and the mounting groove 1402 are provided to make the relative position between the light strip 12 and the light guide plate 11 more stable.

[0056] Optionally, the housing 13 is a plastic housing.

[0057] Optionally, a light-absorbing layer is provided on the wall of the feed trough 201.

[0058] Example 2

[0059] This embodiment discloses a detection device, including a shadowless light source as described in Embodiment 1.

[0060] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. A shadowless light source, characterized in that, include: The planar coaxial light source (1) includes a light guide plate (11) and light strips (12) arranged around the light guide plate (11). A light reflection layer is provided on the back of the light guide plate (11). The light reflection layer is composed of several arc-shaped protrusions. The arc-shaped protrusions reflect the light emitted by the light strips (12), so that the light is emitted from the front of the light guide plate (11). A hemispherical shell (2) is disposed on the light-emitting side of the planar coaxial light source (1), and its edge is sealed to the planar coaxial light source (1); the inner shell surface of the hemispherical shell (2) is provided with a diffuse reflection coating, and the hemispherical shell (2) is provided with a material passage (201) for the workpiece to enter the inspection station, and the material passage (201) is located directly below the planar coaxial light source (1).

2. The shadowless light source according to claim 1, characterized in that, The planar coaxial light source (1) also includes a housing (13), and the light guide plate (11) and the lamp strip (12) are both installed in the housing (13); The bottom of the housing (13) is provided with an assembly groove (1301) for positioning the hemispherical shell (2), and the edge of the hemispherical shell (2) extends out to form an annular edge (21) that presses against the bottom wall of the assembly groove (1301). A fixing hole is provided on the annular edge (21), and a fastener passes through the fixing hole and is threadedly connected to the housing (13).

3. The shadowless light source according to claim 2, characterized in that, The planar coaxial light source (1) also includes a support ring (14) for mounting in the housing (13) to position and support the light guide plate (11); The support ring (14) includes an annular body (141) and four strip-shaped positioning protrusions (142) disposed on the annular body (141). The annular body (141) and the strip-shaped positioning protrusions (142) form a positioning groove (1401). The top of the light guide plate (11) is positioned and inserted into the positioning groove (1401).

4. The shadowless light source according to claim 3, characterized in that, The planar coaxial light source (1) also includes a clamping ring (15) for pressing the planar coaxial light source (1), the clamping ring (15) is pressed on the top of the light guide plate (11) and is detachably connected to the support ring (14).

5. The shadowless light source according to claim 1, characterized in that, The arc-shaped protrusion has an arc-shaped reflective surface, which reflects the light emanating from the light strip (12) into the light guide plate (11).

6. The shadowless light source according to claim 2, characterized in that, It also includes a fastening ring (3) for pressing against the annular edge (21); The fasteners sequentially pass through the fastening ring (3) and the annular edge (21) and are threadedly connected to the housing (13).

7. The shadowless light source according to claim 3, characterized in that, The support ring (14) is also provided with a mounting groove (1402) for positioning the light strip (12).

8. The shadowless light source according to claim 2, characterized in that, The shell (13) is a plastic shell.

9. The shadowless light source according to claim 2, characterized in that, The feed trough (201) has a light-absorbing layer on its wall.

10. A detection device, characterized in that, It includes a shadowless light source as described in any one of claims 1 to 9.

Images