Inspection lighting device manufacturing method

Abstract

To provide an illumination device for an inspection which imposes less restrictions on the types of light emitted from an LED and has a diffusion plate easily manufactured and having the optimum diffusion degree.SOLUTION: An illumination device 1 for an inspection includes: a housing 2; an LED substrate 3 arranged in the housing 2 and equipped with a large number of LEDs 31 for emitting ultraviolet light or visible light; and a diffusion plate 4 made of synthesis resin which can transmit ultraviolet light and visible light and having a large number of fine recesses and protrusions provided on a surface due to sand blast.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention is a method for irradiating an object with light from multiple LEDs in order to inspect the object. Examination The present invention relates to a method for manufacturing an inspection illumination device. [Background technology]

[0002] Conventionally, inspection devices have been used to inspect items (products) produced in factories by irradiating the items with light from multiple LEDs and photographing the images with a camera (visual inspection for defects, scratches, stains, foreign matter, etc.). Among these devices, there are ones that irradiate the items with light from multiple LEDs through a diffusion plate (for example, Patent Document 1 and Patent Document 2).

[0003] The inspection lighting device disclosed in Patent Document 1 transmits light from multiple LEDs through a diffusion plate and then reflects it off a reflecting section before irradiating it onto an object, while the inspection lighting device described in Patent Document 2 reflects light from multiple LEDs off a reflecting section before irradiating it onto an object, and also transmits light from multiple LEDs through a diffusion plate (light diffuser) and irradiates it directly onto the object.

[0004] The diffuser plate diffuses the light from multiple LEDs to make it uniform, while the greater the degree of light diffusion, the less light passes through the diffuser plate. In general, the type of light emitted by the LEDs and the degree of diffusion of the diffuser plate are selected according to the item to be inspected.

[0005] Diffusers are used in various fields, and in addition to those with a white paint applied to the surface to diffuse light, there are also those with a large number of fine irregularities on the surface. For example, in the light projection device described in Patent Document 3, glass fabricated by hardening a sol-gel solution and having a finely processed structure on the surface is used as a diffuser for visible light, ultraviolet light, infrared light, or laser. This finely processed structure is provided by replicating the surface structure from a master, or by mechanically fabricating it by etching, sandblasting, or brushing. In addition, in the imaging device described in Patent Document 4, glass or synthetic resin that has been subjected to embossing, etching, sandblasting, or polishing is used as a diffuser (light diffusing member) for light from fluorescent lamps, mercury lamps, etc. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. WO2012 / 005337 [Patent Document 2] JP 2014-235051 A [Patent Document 3] Special Publication No. 2002-523863 [Patent Document 4] JP 2017-215349 A Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, the inspection lighting device is generally a small-volume, high-variety product in which the type of light emitted by the LED and the degree of diffusion of the diffusion plate are selected according to the object to be inspected, so it is desirable that the diffusion plate is not so limited in the type of light emitted by the LED and can be easily manufactured with an optimal degree of diffusion. However, if glass is used for the diffusion plate as in Patent Document 3, it is easy to break, and it is not easy to provide a large number of fine irregularities on the surface. In addition, the diffusion plate as in Patent Document 4 is not compatible with ultraviolet light.

[0008] The present invention has been made in view of the above circumstances, and its object is to provide a lighting device suitable for small-lot, high-mix production in which the type of light emitted by the LED and the degree of diffusion by the diffusion plate are selectable. Test The present invention provides a method for manufacturing an inspection illumination device. [Means for solving the problem]

[0009] In order to achieve the above object, the method for manufacturing an inspection illumination device according to claim 1 is a method for manufacturing an inspection illumination device including a housing, an LED board on which a large number of LEDs are mounted, and a diffusion plate, the method comprising the steps of: Purple Expose to external light Multiple LEDs with different wavelengths are available. Irradiate visual light Multiple LEDs with different wavelengths Medium of wavelengths suited to the items to be inspected. Select the multiple LEDs In the common housing Furthermore, the surface is not sandblasted to create many fine irregularities, and the transmittance is higher than 90%. The above Ultraviolet light and The above On the surface of the synthetic resin plate that can transmit visible light, According to the item to be inspected The amount of the numerous fine irregularities is selected, and the numerous fine irregularities are provided by sandblasting to produce the diffusion plate. In the common housing The present invention relates to a method for manufacturing a small number of different types of illumination devices for inspection, the method being characterized in that:

[0010] Claim 2 The method for manufacturing an inspection illumination device according to the present invention includes the steps of: 1 In the method for manufacturing an inspection illumination device described in the above, the surface on which the numerous fine projections and recesses are provided is only one surface or one surface and the other surface of the diffusion plate.

[0011] Claim 3 The method for manufacturing an inspection illumination device according to the present invention includes the steps of: 2 In the method for manufacturing an inspection illumination device described in the above, the surface on which the numerous fine irregularities are provided is one side and the other side of the diffusion plate, and the amount of irregularities is changed between the one side and the other side of the diffusion plate. Effect of the Invention

[0012] The present invention Inspection The inspection lighting device manufacturing method is suitable for small-lot, high-mix production in which the type of light emitted by the LEDs and the degree of diffusion of the diffusion plate can be selected. [Brief description of the drawings]

[0013] [Figure 1] 1A and 1B show an inspection illumination device according to an embodiment of the present invention, where (a) is a cross-sectional view (a cross-sectional view taken along line AA in (b)), and (b) is a bottom view. [Diagram 2] 10A and 10B show another example of the inspection illumination device, in which (a) is a cross-sectional view (a cross-sectional view taken along line BB in (b)), and (b) is a bottom view. [Diagram 3] 4 is an explanatory diagram illustrating the state of light in the above-mentioned inspection illumination device in a cross-sectional view. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. An inspection illumination device 1 according to an embodiment of the present invention includes a housing 2, an LED substrate 3, and a diffusion plate 4, as shown in FIGS.

[0015] The housing 2 supports the LED substrate 3 and the diffusion plate 4, which will be described in detail later. The housing 2 is a roughly cylindrical body with a low height, and may be provided with a hollow hole 2a that penetrates in the vertical direction. The housing 2 is made of a metal material such as aluminum or copper, or a resin material.

[0016] The LED substrate 3 is disposed in the housing 2. The LED substrate 3 is equipped with a number of LEDs 31 that emit ultraviolet light (for example, light with wavelengths of 365 nm, 375 nm, 405 nm, etc.) or visible light (for example, light of red, green, blue, white, etc.). The LEDs 31 are arranged on a circle in Figs. 1(a) and (b), but as shown in Figs. 2(a) and (b), they can be arranged on a plurality of concentric circles (concentric circles in plan view) (two in the figure). The LED substrate 3 can be tilted obliquely so that the LEDs 31 radiate light obliquely downward. The LEDs 31 can be of a bullet type or a surface mount type. In Figs. 1(b) and 2(b), the LEDs 31 are arranged on the back side of the diffusion plate 4, and are therefore indicated by dashed lines. The LED substrate 3 may be a single piece in total, or a plurality of LEDs may be arranged to form a whole.

[0017] The diffusion plate 4 is made of a synthetic resin (e.g., an acrylic material) that can transmit ultraviolet light and visible light. Specifically, the diffusion plate 4 can transmit ultraviolet light and visible light with a transmittance higher than 90%, for example, unless the diffusion plate 4 has a large number of minute irregularities on its surface, as described below. The thickness of the diffusion plate 4 is not particularly limited, but can be, for example, 0.5 mm to 5 mm. The diffusion plate 4 can be a disk-shaped plate having a central hole 4a.

[0018] The surface of the diffusion plate 4 is provided with many fine projections and recesses by sandblasting using a sandblasting device. The amount of projections and recesses on the surface of the diffusion plate 4 is uniform without bias. The sandblasting device can easily change the amount of projections and recesses on the surface of the diffusion plate 4 by, for example, changing the amount of sand (abrasive) sprayed per unit time.

[0019] The surface of the diffusion plate 4 on which a large number of minute projections and recesses are provided may be only the one surface 4b of the diffusion plate 4, or may be the one surface 4b and the other surface 4c of the diffusion plate 4. It is also possible for the amount of projections and recesses to be different between the one surface 4b and the other surface 4c of the diffusion plate 4.

[0020] The degree of light diffusion is changed by changing the amount of unevenness on the surface (one surface 4b and the other surface 4c) of the diffusion plate 4. As the degree of light diffusion changes, the light transmittance also changes (for example, in the range of 30% to 90%).

[0021] In the inspection illumination device 1 described above, as shown in Fig. 3, ultraviolet light or visible light (schematically shown by dashed lines with arrows in Fig. 3) from the numerous LEDs 31 mounted on the LED board 3 is diffused and homogenized by the diffusion plate 4, passes through, and is irradiated onto the object M located below. Then, the reflected light (schematically shown by dashed lines with arrows in Fig. 3) from the object M passes through the central hole 4a of the diffusion plate 4 and the hollow hole 2a of the housing 2, and is incident on the camera C located above. In this way, the object M is photographed by the camera C and inspected.

[0022] In the inspection lighting device 1, the type of light (e.g., ultraviolet light or visible light (red, green, blue, white, etc.)) is selected by selecting the LEDs 31 to be used in accordance with the object to be inspected, and the degree of light diffusion is selected by selecting the amount of unevenness on the surface of the diffusion plate 4 provided by sandblasting. For example, the housing 2 can be shared, and the LEDs 31 can be arranged as shown in Figs. 1(a) and (b) to irradiate ultraviolet light and a predetermined diffusion plate 4 can be arranged, or the LEDs 31 can be arranged as shown in Figs. 2(a) and (b) to irradiate visible light and a predetermined diffusion plate 4 can be arranged.

[0023] The diffusion plate 4 of such an inspection lighting device 1 can transmit ultraviolet light and visible light, so there are few restrictions on the type of light emitted by the LEDs 31 and transmitted through the diffusion plate 4. In addition, since the diffusion plate 4 is made of synthetic resin, it is difficult to break, and it is easy to manufacture a diffusion plate with an optimal degree of diffusion by sandblasting. Therefore, the inspection lighting device 1 is suitable for small-volume, high-mix production in which the type of light emitted by the LEDs and the degree of diffusion of the diffusion plate can be selected.

[0024] Although the inspection illumination device according to the embodiment of the present invention has been described above, the present invention is not limited to the embodiment, and various design modifications are possible within the scope of the claims. For example, the inspection illumination device 1 is exemplified as one in which light from a number of LEDs 31 passes through a diffusion plate 4 and is directly irradiated onto an object, but the present invention is also applicable to one in which light from a number of LEDs passes through a diffusion plate and is then reflected by a reflection portion and irradiated onto an object. In addition, the structure or shape of the housing and the LED board can be modified as appropriate.

[0025] 1. Inspection lighting equipment 2. Housing 2a Housing Hole 3 LED board 31 LED 4 Diffuser 4a Center hole of the diffuser 4b One side of the diffuser 4c The other side of the diffuser C Camera M Goods

Claims

1. Housing and An LED board on which a large number of LEDs are mounted, the LED board being disposed within the housing; A diffusion plate; A method for manufacturing an inspection illumination device comprising: a plurality of LEDs having different wavelengths that irradiate ultraviolet light and a plurality of LEDs having different wavelengths that irradiate visible light, the plurality of LEDs having wavelengths that match the article to be inspected, are selected and placed in the common housing; and further, the plurality of LEDs are fabricated by sandblasting a synthetic resin plate having a surface that transmits the ultraviolet light and the visible light with a transmittance of more than 90% without having a plurality of fine irregularities formed on the surface by sandblasting, and the amount of the plurality of fine irregularities is selected to match the article to be inspected, and the plurality of fine irregularities are then formed on the surface by sandblasting, and the plurality of fine irregularities are then fabricated in the common housing.

2. 2. The method for manufacturing an inspection illumination device according to claim 1, A method for manufacturing an inspection illumination device, characterized in that the surface on which the numerous fine projections and recesses are provided is only one surface or one surface and another surface of the diffusion plate.

3. 3. The method for manufacturing an inspection illumination device according to claim 2, A method for manufacturing an inspection lighting device, characterized in that the surface on which the numerous fine irregularities are provided is one side and the other side of the diffusion plate, and the amount of irregularities is changed between the one side and the other side of the diffusion plate.

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