JP2018017564A - Illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination device which can prevent light from a light source from being emitted directly to a workpiece or a camera and can avoid entrance of foreign substances or deflection of a diffusion plate.SOLUTION: The illumination device includes: a substrate 3; a light source 2; a diffusion plate 5; and a through-hole 10 going through an outer surface 31 of the substrate 3 to an outer surface 51 of the diffusion plate 5, the through-hole 10 having a cylindrical member 11 with a light diffusion surface 11c in an inner periphery surface, and the cylindrical member being located at least from an inner surface 34 of the substrate 3 to an inner surface 54 of the diffusion plate 5. With the above configuration, it becomes possible to prevent light from the light source 2 from being emitted directly to a workpiece or a camera and avoid entrance of foreign substances or deflection of a diffusion plate.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an illuminating device used as illumination in product surface inspection or the like.

The thing of patent document 1 is known as an example of the illuminating device used as illumination in the surface inspection etc. of a product.
The lighting device includes a bottom plate provided with a light source, a plurality of side plates fixed to the bottom plate so as to surround the light source, and an end edge portion engaged with an attachment groove formed on an inner surface of the plurality of side plates. And a diffusion plate disposed in front of the light emission side of the light source.
The diffuser plate covers the entire opening of a substantially box-shaped casing formed by the bottom plate and the side plate, and diffuses and equalizes the light emitted from the light source to irradiate the product surface.

JP 2011-247779 A

By the way, there may be a case where a through hole is provided in a substantially central portion of the lighting device as described above. This is because a camera is arranged on the surface of the lighting device opposite to the surface on which the diffuser plate is provided, on the extension of the through-hole, and the reflected light of the light irradiated on the surface of the workpiece (product) is transmitted through the through-hole. It is for capturing with a camera through.
However, when the through-hole is provided in the illumination device, the light emitted from the light source passes directly through the through-hole as the direct light, in addition to the light emitted from the light source being diffused and uniformed by the diffusion plate and irradiated onto the work. Therefore, the irradiation light may become non-uniform.
Moreover, since the light emitted from the light source is reflected by the diffuser plate and directly enters the camera through the through hole, there is a possibility that accurate imaging cannot be performed.
Furthermore, there is a risk that foreign matter such as dust and dust may enter the lighting device from the through hole, and there is a possibility that the rigidity of the diffusion plate is lowered due to the presence of the through hole and the diffusion plate is bent.

  The present invention has been made in view of the above circumstances, and it is possible to prevent the light emitted from the light source from being directly applied to the work and the camera, and to prevent the intrusion of foreign matter and the bending of the diffusion plate. An object is to provide an apparatus.

In order to achieve the above object, an illuminating device of the present invention is an illuminating device including a substrate, a light source provided on the substrate, and a diffuser plate provided to face the light source.
A through-hole penetrating from a surface of the substrate opposite to the light source arrangement side to a surface of the diffusion plate opposite to the substrate side;
A cylindrical member provided with a light diffusing portion and provided at least between the opposing surfaces of the substrate and the diffusion plate of the through hole.

In the present invention, since the cylindrical member having the light diffusing portion is provided in the through hole, the light emitted from the light source is diffused by the light diffusing portion, and is diffused and uniformed by the diffusion plate to the work. Irradiated. Accordingly, it is possible to prevent light emitted from the light source from being directly irradiated to the work through the through hole or reflected by the diffuser and entering the camera as direct light through the through hole.
In addition, the light is diffused by the light diffusing part of the cylindrical member and irradiated onto the workpiece, thereby expanding the inspection range and irradiating the workpiece with diffused light from various directions to cancel out the unevenness of the inspection surface. Image acquisition becomes possible.

  In addition, since the space between the substrate of the through hole and the diffusion plate is blocked by the cylindrical member, it is possible to prevent foreign matter from entering the inside of the lighting device, and the diffusion plate is reinforced by the cylindrical member at both ends of the through hole. The rigidity is increased, and the diffusion plate can be prevented from bending.

  The said structure of this invention WHEREIN: The said light-diffusion part may be formed from the white coating surface formed by white-coating the internal peripheral surface of the said cylindrical member.

  According to such a structure, a light-diffusion part can be easily formed only by white-coating the internal peripheral surface of a cylindrical member.

In the configuration of the present invention, the cylindrical member includes a cylindrical main body, and a flange portion provided at one end of the main body,
The other end of the main body may be in contact with or embedded in one of the substrate and the diffusion plate, and the flange may be engaged with the other.

  According to such a configuration, the cylindrical member can be positioned in the through-hole in the circumferential direction and the axial direction and firmly fixed by engaging the flange portion with the other of the substrate and the diffusion plate. In addition, the flange part engages with the other of the substrate and the diffusion plate, and the other end part of the main body abuts or is embedded in one side, so that the through hole and the interior of the lighting device are securely blocked by the main body. Thus, it is possible to reliably prevent foreign matter from entering the lighting device.

  According to the present invention, it is possible to prevent the light emitted from the light source from being directly applied to the work and the camera, and to prevent the entry of foreign matter and the bending of the diffusion plate.

It is a perspective view of the illuminating device which concerns on the 1st Embodiment of this invention. It is a front view of an illuminating device. FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is an enlarged view of a B circle portion in FIG. 3. It is a perspective view of a cylindrical member. It is the partially cutaway perspective view of the principal part which looked at the illuminating device from diagonally upward. It is the partially notched perspective view of the principal part which looked at the illuminating device from diagonally downward. It is an expanded sectional view of the principal part of the illuminating device which concerns on the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
The illuminating device 1 according to the present embodiment is a surface illuminating device having a substantially rectangular flat light emitting surface used for a product inspection system or the like for inspecting surface defects or foreign matters of a product (work) flowing on a line.

  As shown in FIGS. 1 to 3, the illumination device 1 includes a bottom plate (substrate) 3 having a substantially rectangular plate shape on which a plurality of LEDs 2 as light sources are arranged, and four fixed to four sides of the bottom plate 3. A side plate 4 and a diffusion plate 5 having a substantially rectangular flat plate shape supported by the side plate 4 are provided. A power cable 6 for supplying power to the LED 2 extends from one side plate 4.

  The bottom plate 3 is an LED substrate on which a plurality of LEDs 2 are arranged, or a plurality of LEDs 2 are directly mounted thereon. The LEDs 2 are arranged in a matrix at regular intervals, for example, vertically and horizontally. Also. The bottom plate 3 is formed in a rectangular flat plate shape in which the side along the vertical direction in FIGS. 1 and 2 is a long side and the side along the horizontal direction is a short side. The upper and lower edge portions of the bottom plate 3 protrude in the vertical direction from the side plate 4, and a plurality of circular holes 3a are formed through the bottom plate 3 at predetermined intervals on the left and right sides.

The side plate 4 forms a rectangular bar shape having a long cross-sectional rectangle along each side of the bottom plate 3. In FIG. 2, the left and right side plates 4 are shorter than the vertical sides of the bottom plate 3, and the upper and lower side plates 4 are disposed between the left and right side plates, and their end surfaces are in contact with the end portions of the left and right side plates 4. In addition, it is fixed to the left and right side plates 4.
The bottom plate 3 is fixed to the side plate 4 by screwing screws 7 from the bottom plate 3 to the bottom surface of the side plate 4 as shown in FIGS.

As shown in FIG. 3, a mounting groove 41 having a U-shaped cross section that opens inward is formed along the longitudinal direction of the side plate 4 at a predetermined upper position on the inner surface of each side plate 4. The end edge portion of the diffusion plate 5 is fitted in. Thus, the diffusion plate 5 is provided to face the bottom plate 3 with the LED 2 interposed therebetween. A gap having a predetermined width is provided between the diffusion plate 5 and the bottom plate 3.
The diffusion plate 5 is fixed in front of the light emitting side of the LED 2, covers the entire opening of the casing having a substantially box shape formed by the bottom plate 3 and the side plate 4, and diffuses and equalizes the light emitted from the plurality of LEDs 2. Thus, it can be injected forward (upward in FIG. 3).

  In addition, a through-hole 10 that penetrates the lighting device 1 in the thickness direction is formed in the central portion of the lighting device 1. As shown in FIG. 4, the through hole 10 penetrates from the surface (outer surface) 31 on the side opposite to the LED 2 placement side of the bottom plate 3 to the surface (outer surface) 51 on the side opposite to the bottom plate 3 side of the diffusion plate 5. Is formed. Specifically, since a gap is provided between the bottom plate 3 and the diffusion plate 5, the through hole 10 has a through hole 32 formed in the bottom plate 3, and the diffusion plate 5 is coaxial with the through hole 32. The formed through-hole 52 and a hollow portion 10A located between the through-holes 32 and 52 are configured.

The inner diameter of the through hole 32 is smaller than the inner diameter of the through hole 52, so that the inner surface (opposing surface) 34 of the bottom plate 3 is disposed around the through hole 32 in addition to the main body 11 a of the cylindrical member 11 described later. An abutting surface 32a with which the end portion abuts is provided.
At the upper end portion of the through hole 52 (portion close to the outer surface 51 of the diffusing plate 5), an engaging portion 53 that engages a flange portion 11b of the cylindrical member 11 described later is formed. The engaging portion 53 is formed by sitting the diffusion plate 5 coaxially with the through-hole 52, and includes an annular flat surface portion 53a and a cylindrical surface 53b formed on the outer peripheral side of the flat surface portion 53a. ing.

A cylindrical member 11 is inserted into the through hole 10 as shown in FIGS. The cylindrical member 11 is formed of a transparent acrylic resin. As shown in FIG. 5, the cylindrical member 11a is provided integrally with the main body 11a at one end portion of the cylindrical main body 11a. And a flange portion 11b. The flange portion 11b is formed in a flat ring shape, and is provided coaxially with the main body 11a.
The inner peripheral surface of the cylindrical member 11 is a light diffusing portion composed of a white painted surface 11c to which white coating is applied. The white painted surface 11c is formed by spraying and painting a paint such as an acrylic lacquer paint on the inner peripheral surface of the cylindrical member 11.

  Further, the outer diameter of the main body 11 a is formed to be equal to or slightly smaller than the inner diameter of the through hole 52 formed in the diffusion plate 5. Further, the outer diameter of the flange portion 11 b is formed to be equal to or slightly smaller than the inner diameter of the cylindrical surface 53 b formed on the diffusion plate 5. Furthermore, the axial height dimension of the cylindrical member 11 is substantially equal to the distance between the outer surface 51 of the diffusion plate 5 and the inner surface 34 of the bottom plate 3.

The cylindrical member 11 having such a configuration is inserted into the through hole 10 from the outer surface 51 side of the diffusion plate 5, and the lower end portion (the other end portion) of the main body 11 a is brought into contact with the contact surface 32 a of the bottom plate 3. In addition, the flange portion 11 b is engaged with an engaging portion 53 formed on the diffusion plate 5. In this state, as shown in FIGS. 4 and 6, the upper surface of the flange portion 11 b is substantially flush with the outer surface 51 of the diffusion plate 5, and the outer peripheral surface and lower surface of the flange portion 11 b are cylindrical surfaces of the engaging portion 53. 53b and the flat portion 53a.
As shown in FIG. 7, the cylindrical member 11 inserted into the through hole 10 is illustrated from a counterbore portion 31 b formed on the outer surface (bottom surface) 31 of the bottom plate 3 and around the through hole 32. The screw not to be screwed is fixed to the through hole 10 by screwing it into the end face of the main body 11a.

  As described above, according to the present embodiment, the cylindrical member 11 having the light diffusion portion (painted surface 11 c) is provided in the through hole 10 provided in the lighting device 1, so that the light emitted from the LED 2 is The workpiece is irradiated with the light diffused by the coating surface 11 c and diffused and uniformed by the diffusion plate 5. Accordingly, it is possible to prevent the light emitted from the LED 2 from being directly irradiated to the work through the through hole 10 or reflected by the diffusion plate 5 and entering the camera as the direct light through the through hole 10.

Moreover, the light-diffusion part can be easily formed by painting the inner peripheral surface of the cylindrical member 11 with white.
In addition, the light is diffused by the light diffusing portion of the cylindrical member 11 and irradiated onto the workpiece, thereby expanding the inspection range and irradiating the workpiece with diffused light from various directions so that the inspection surface is uneven. It is also possible to obtain a canceled image).
Furthermore, by engaging the flange portion 11b of the cylindrical member 11 with the engaging portion 53 of the diffusion plate 5, the cylindrical member 11 can be positioned and fixed firmly in the circumferential direction and the axial direction in the through hole 10, The flange portion 11b of the cylindrical member 11 is engaged with the diffusion plate 5 and the other end portion of the main body 11a is in contact with the bottom plate 3 so that the diffusion plate 5 is reinforced by the cylindrical member 11 at both ends of the through hole 10. The rigidity can be increased. Therefore, the diffusion plate 5 can be prevented from bending.
Further, the flange portion 11 b is engaged with the engaging portion 53 of the diffusion plate 5, the other end portion of the main body 11 a is in contact with the inner surface 34 of the bottom plate 3, and the space between the bottom plate 3 of the through hole 10 and the diffusion plate 5 is a cylinder. Since it is blocked by the member 11, the through hole 10 and the inside of the lighting device 1 can be reliably blocked by the main body 11 a, and foreign matter can be reliably prevented from entering the inside of the lighting device 1.

(Second Embodiment)
FIG. 8 shows a second embodiment.
The main difference between the second embodiment shown in this figure and the first embodiment is the structure for attaching the cylindrical member 11 to the through-hole 10, so that this will be described in detail below. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

As shown in FIG. 8, in the present embodiment, the cylindrical member 11 is inserted into the through hole 10 from the outer surface 31 side of the bottom plate 3.
That is, first, the cylindrical member 11 has a larger diameter of the flange portion 11b than the cylindrical member 11 of the first embodiment. The inner diameter and the outer diameter of the main body 11a are equal to those in the first embodiment.

Further, a counterbore portion 55 is formed in the through hole 52 of the diffusion plate 5 by sitting the coaxially with the through hole 52, and the counterbore portion 55 has the other end of the main body 11a. The part (the upper end part in FIG. 8) is fitted. As a result, the other end of the main body 11 a is embedded in the inner surface 54 of the diffusion plate 5.
Further, an engaging portion 33 that engages with the flange portion 11 b of the cylindrical member 11 is formed at the lower end portion of the through hole 32 of the bottom plate 3 (the portion close to the outer surface 31 of the bottom plate 3). The engaging portion 33 is formed by sitting on the outer surface 31 of the bottom plate 3 coaxially with the through-hole 32, and includes an annular flat surface portion 33a and a cylindrical surface 33b formed on the outer peripheral side of the flat surface portion 33a. It is configured.

  And the cylindrical member 11 of such a structure is inserted in the through-hole 10 from the outer surface 31 side of the bottom plate 3, and the upper end part (other end part) of the main body 11a is fitted in the counterbore part 55 of the diffusion plate 5. Thus, the flange portion 11 b is engaged with the engagement portion 33 formed on the bottom plate 3 while being embedded in the inner surface 54 of the diffusion plate 5. In this state, the lower surface of the flange portion 11b is substantially flush with the outer surface 31 of the bottom plate 3, and the outer peripheral surface and upper surface of the flange portion 11b are in contact with the cylindrical surface 33b and the flat surface portion 33a of the engaging portion 33. A gap is provided between the other end of the main body 11 a and the bottom surface of the spot facing 55.

According to the present embodiment, the same effects as those of the first embodiment can be obtained, and the upper end portion of the main body 11a is embedded in the inner surface 54 of the diffusion plate 5. Therefore, the first embodiment Compared to the above, it is possible to firmly fix the cylindrical member 11 to the through hole 10 and more effectively prevent foreign matter from entering the lighting device 1 from the through hole 10.
Further, since the flange portion 11b of the cylindrical member 11 is engaged with the engaging portion 33 of the bottom plate 3 and the other end portion of the main body 11a is embedded in the inner surface 54 of the diffusion plate 5, the upper and lower end portions of the through hole 10 The diffusing plate 5 and the bottom plate 3 can be reinforced by the tubular member 11 in the periphery of the, thereby increasing the rigidity. Therefore, the diffusion plate 5 and the bottom plate 3 can be prevented from bending.

In the two embodiments described above, the other end portion of the main body 11a is brought into contact with or embedded in one of the bottom plate 3 and the diffusion plate 5 and the flange portion 11b is engaged in the other. May be provided at least between the inner surface 34 of the bottom plate 3 and the inner surface 54 of the diffusion plate 5. In this case, the flange portion 11b may not be formed on the main body 11a, or the flange portion 11b may be formed on both ends of the main body 11a.
In the two embodiments, the case where the illumination device of the present invention is applied to a surface illumination device has been described as an example. However, the illumination device of the present invention is applied to a ring illumination device having a flat ring-shaped diffusion plate. May be. Moreover, you may provide the white coating surface 11c not in the inner peripheral surface of the cylindrical member 11, but in an outer peripheral surface.

1 Illumination device 2 LED (light source)
3 Bottom plate (substrate)
31 outer surface 34 inner surface 5 diffuser plate 51 outer surface 54 inner surface 10 through-hole 11 cylindrical member 11a main body 11b flange portion 11c white coating surface 33, 53 engaging portion

Claims (3)

A lighting device comprising a substrate, a light source provided on the substrate, and a diffuser plate provided opposite to the light source,
A through-hole penetrating from a surface of the substrate opposite to the light source arrangement side to a surface of the diffusion plate opposite to the substrate side;
A lighting device comprising: a light diffusing portion; and a cylindrical member provided across at least the opposing surfaces of the substrate and the diffusion plate of the through hole.   The lighting device according to claim 1, wherein the light diffusing portion is formed of a white painted surface formed by white coating an inner peripheral surface of the cylindrical member. The cylindrical member includes a cylindrical main body and a flange portion provided at one end of the main body,
3. The lighting device according to claim 1, wherein the other end of the main body is in contact with or embedded in one of the substrate and the diffusion plate, and the flange is engaged with the other. .

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