JP7587199B2 - Ultraviolet irradiation equipment - Google Patents

Description

An embodiment of the present invention relates to an ultraviolet irradiation device.

There are ultraviolet irradiation devices that irradiate an object with ultraviolet light for purposes such as curing ultraviolet-curable resins, surface modification, and sterilization. Discharge lamps such as mercury arc lamps, metal halide lamps, and xenon lamps are used as light sources to generate ultraviolet light. In recent years, ultraviolet light-emitting diodes (Ultraviolet Light Emitting Diodes) have come to be used instead of discharge lamps in order to save energy and extend life.

However, the ultraviolet light emitted from the ultraviolet light-emitting diode has a narrower band (narrower wavelength range) than the ultraviolet light emitted from the discharge lamp. Therefore, depending on the components of the object to be irradiated with ultraviolet light, the time required for processing (for example, the time until the ultraviolet curing resin hardens) may be longer.
Therefore, there has been a demand for the development of an ultraviolet irradiation device that can shorten the time required for processing.

JP 2011-25170 A

The problem that this invention aims to solve is to provide an ultraviolet irradiation device that can shorten the time required for processing.

The ultraviolet irradiation device according to the embodiment irradiates ultraviolet rays to a moving object. The ultraviolet irradiation device includes a first irradiation unit having a plurality of light sources each having a first light-emitting element capable of irradiating ultraviolet rays having a first peak wavelength; and at least one second irradiation unit having a second light-emitting element capable of irradiating ultraviolet rays having a second peak wavelength shorter than the first peak wavelength. The ultraviolet rays having the first peak wavelength irradiated from the first light-emitting element provided in each of the plurality of light sources are simultaneously irradiated to approximately the same irradiation position on the object, and the distance between the center of the emission surface of the first light-emitting element provided in each of the plurality of light sources and the irradiation position on the object is approximately the same. The distance between the center of the emission surface of the second light-emitting element and the irradiation position on the object of the ultraviolet rays irradiated from the second light-emitting element is smaller than the distance between the center of the emission surface of the first light-emitting element and the irradiation position on the object of the ultraviolet rays irradiated from the first light-emitting element. The first peak wavelength is 350 nm or more and 450 nm or less, and the integrated light amount of the ultraviolet light having the first peak wavelength is 1000 mJ/ ^cm2 or more. The second peak wavelength is 300 nm or more and less than 350 nm, and the integrated light amount of the ultraviolet light having the second peak wavelength is 3.5 mJ/ ^cm2 or more .

According to an embodiment of the present invention, it is possible to provide an ultraviolet irradiation device that can shorten the time required for processing.

1 is a schematic perspective view illustrating an ultraviolet irradiation device according to an embodiment of the present invention; 11 is a schematic side view for illustrating the first irradiation unit. FIG. 1 is a schematic perspective view for illustrating a first irradiation unit. FIG. FIG. 3 is a schematic cross-sectional view of part A in FIG. 2 . 5 is a schematic cross-sectional view of the first irradiation unit in FIG. 4 taken along line BB. 13 is a schematic side view for illustrating the second irradiation unit. FIG. 13 is a schematic perspective view for illustrating a second irradiation unit. FIG. FIG. 4 is a schematic cross-sectional view of a second irradiation unit. 9 is a schematic cross-sectional view of the second irradiation unit in FIG. 8 taken along line CC. 13 is a schematic side view illustrating a base according to another embodiment. FIG. 11 is a table illustrating the effect of an ultraviolet irradiation device.

Hereinafter, an embodiment will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.
The ultraviolet irradiation device 100 according to the present embodiment can irradiate ultraviolet rays onto a moving object 200. There is no particular limitation on the method of moving the object 200, and for example, the object 200 may be moved using a conveyor or an XY table, or the object 200 may be moved using a rotating roller or the like.

Although there is no particular limitation on the use of the ultraviolet irradiation device 100, it is preferable to use it for curing the object 200. For example, the ultraviolet irradiation device 100 can be used for curing ink, adhesive, paint, etc., containing ultraviolet curable resin.
Therefore, in the following, as an example, a case will be described in which the ultraviolet irradiation device 100 cures an object 200 containing an ultraviolet curable resin.

FIG. 1 is a schematic perspective view illustrating an ultraviolet irradiation device 100 according to the present embodiment.
In FIG. 1, in order to avoid complication, the holding portion 3a of the lens unit 3 is omitted.
As shown in FIG. 1, the ultraviolet irradiation device 100 can be provided with a first irradiation unit 1, a second irradiation unit 10, a bracket 20, a power source 30, and a controller 40.

Generally, UV-curable resins contain monomers, oligomers (prepolymers), photopolymerization initiators, and additives. When UV-curable resins are irradiated with UV rays, the photopolymerization initiators generate ions, and these ions polymerize with the monomers and oligomers (combine to form chains or networks). This type of reaction is called a photopolymerization reaction, and the UV-curable resin hardens as a result of the photopolymerization reaction.

In this case, the reaction sensitivity of the photopolymerization initiator generally increases as the wavelength of the irradiated ultraviolet light becomes shorter, so that the curing time (time required for processing) of the ultraviolet curing resin can be shortened by using a light emitting element that irradiates ultraviolet light with a shorter peak wavelength.
However, it is considered that if the wavelength of the irradiated ultraviolet light is longer, the amount of ultraviolet light that reaches the inside of the object 200 increases. Therefore, it is preferable that the object 200 is irradiated with ultraviolet light having a different peak wavelength.

The luminous efficiency of a light-emitting element varies depending on the peak wavelength of the ultraviolet light it generates. In general, the luminous efficiency of a light-emitting element decreases as the peak wavelength of the ultraviolet light it generates becomes shorter. In general, the price of a light-emitting element increases as the peak wavelength of the ultraviolet light it generates becomes shorter.

Therefore, if all the light-emitting elements provided in the ultraviolet irradiation device 100 were light-emitting elements with a shorter peak wavelength, a large number of light-emitting elements with low light-emitting efficiency and high cost would be required, which would increase manufacturing costs and lead to an increase in the size of the ultraviolet irradiation device 100. Also, as mentioned above, the light-emitting efficiency of a light-emitting element decreases as the peak wavelength of the ultraviolet light generated becomes shorter, so if light-emitting elements with long and short peak wavelengths are mounted on the same board, the illuminance of the ultraviolet light with a short peak wavelength may be insufficient, and the board and therefore the ultraviolet irradiation device 100 may become larger.

The ultraviolet irradiation device 100 is provided with a first irradiation unit 1 and a second irradiation unit 10. For example, the first irradiation unit 1 can be configured to irradiate the object 200 with ultraviolet light having a peak wavelength (corresponding to an example of a first peak wavelength) of 350 nm or more and 450 nm or less. The second irradiation unit 10 can be configured to irradiate ultraviolet light having a peak wavelength (corresponding to an example of a second peak wavelength) of 300 nm or more and less than 350 nm, preferably 300 nm or more and 330 nm or less.

(First Irradiation Unit 1)
FIG. 2 is a schematic side view for illustrating the first irradiation unit 1. As shown in FIG.
FIG. 3 is a schematic perspective view for illustrating the first irradiation unit 1. As shown in FIG.
FIG. 4 is a schematic cross-sectional view of part A in FIG.
FIG. 5 is a schematic cross-sectional view of the first irradiation unit 1 taken along line BB in FIG.
As shown in FIGS. 2 and 3, the first illumination unit 1 may include a light source 2, a lens unit 3, and a base 4.

A plurality of light sources 2 may be provided. For example, as shown in FIG. 2, at least one light source 2 may be provided on both sides of the central axis 1a of the first irradiation unit 1. For example, one light source 2 may be provided on the central axis 1a, and at least one light source 2 may be provided on both sides of the central axis 1a. The plurality of light sources 2 may be arranged side by side in a direction intersecting the direction in which the substrate 2a extends.

As shown in FIG. 3, the light source 2 can have a substrate 2a and a plurality of light-emitting elements 2b (corresponding to an example of a first light-emitting element).
The substrate 2a has a plate-like shape and extends in one direction. The planar shape of the substrate 2a can be, for example, rectangular. The substrate 2a can be attached to the surface 4a of the base 4 using a fastening member such as a screw. It is also possible to provide a recess in the surface 4a of the base 4 and provide the substrate 2a inside the recess. In this way, it is possible to easily align the base 4 and the light source 2, and furthermore, to easily align the light source 2 and the lens unit 3.

A wiring pattern can be provided on one surface of the substrate 2a. A plurality of light-emitting elements 2b can be mounted on the wiring pattern. The plurality of light-emitting elements 2b can be connected in series by the wiring pattern. A pair of connection terminals 2a1 can be provided on the wiring pattern. The pair of connection terminals 2a1 are electrically connected to a power source 30 provided outside the first irradiation unit 1 via wiring.

A protective film can also be provided to cover the wiring pattern. In this case, the protective film can function as a reflective film by using a white protective film (e.g., white resist) or a protective film containing light-scattering particles such as titanium oxide.

The material of the substrate 2a is preferably resistant to ultraviolet light and has high thermal conductivity. The material of the substrate 2a can be, for example, ceramics such as aluminum oxide. The substrate 2a can also be a metal plate with the surface covered with an inorganic material (metal core substrate). If the material of the substrate 2a is ceramics or the substrate 2a is a metal core substrate, it is possible to obtain resistance to ultraviolet light and high heat dissipation.

The multiple light-emitting elements 2b can be provided on the surface of the substrate 2a. The multiple light-emitting elements 2b can be arranged in a line in the direction in which the substrate 2a extends. In the light source 2 illustrated in FIG. 3, the multiple light-emitting elements 2b are arranged in a line, but the multiple light-emitting elements 2b may be arranged in multiple rows. The pitch dimension of the multiple light-emitting elements 2b (the distance between the light-emitting elements 2b) may be constant or may be different.

If the pitch dimension of the plurality of light emitting elements 2b is constant, it is possible to prevent uneven illumination.
On the other hand, depending on the application of the ultraviolet irradiation device 100, it may be preferable to have the pitch dimensions of the multiple light-emitting elements 2b different from each other. For example, it may be preferable to make the illuminance of the ultraviolet light irradiated from the central region of the light source 2 greater than that of the ultraviolet light irradiated from the peripheral region. Conversely, it may be preferable to make the illuminance of the ultraviolet light irradiated from the peripheral region of the light source 2 greater than that of the ultraviolet light irradiated from the central region. In such a case, the number of light-emitting elements 2b provided in the region where the illuminance of the irradiated ultraviolet light is increased can be increased, and the pitch dimension of the light-emitting elements 2b can be shortened.

The light-emitting element 2b is not particularly limited as long as it is an element capable of emitting ultraviolet light, and may be, for example, a light-emitting diode or a laser diode capable of emitting ultraviolet light.
For example, the light emitting element 2b can emit ultraviolet light having a peak wavelength of 350 nm or more and 450 nm or less.

The light-emitting element 2b can be, for example, a surface-mount type light-emitting element such as a PLCC (Plastic Leaded Chip Carrier) type. The light-emitting element 2b can also be, for example, a light-emitting element having a lead wire such as a bullet type. The light-emitting element 2b illustrated in FIG. 3 is a surface-mount type light-emitting element.

The light-emitting element 2b can also be mounted by COB (Chip On Board). When the light-emitting element 2b is mounted by COB, the chip-shaped light-emitting element 2b, wiring electrically connecting the light-emitting element 2b to the wiring pattern, a frame-shaped member surrounding the light-emitting element 2b and the wiring, and a sealing portion provided inside the frame-shaped member can be provided on the substrate 2a. In this case, the frame-shaped member can have the function of defining the formation range of the sealing portion and the function of a reflector. Note that it is also possible to provide only the sealing portion without providing a frame-shaped member. When providing only the sealing portion, a dome-shaped sealing portion is provided on the substrate 2a. The sealing portion can be formed, for example, from silicone resin.

As shown in FIGS. 1 and 2, the lens unit 3 can be provided on the side of the base 4 where the light source 2 is provided.
The lens unit 3 can have a holder 3a and a lens 3b.

The holding portions 3a are plate-shaped and can be provided in pairs. The pair of holding portions 3a can be provided on the outer side of the surface 4a of the base 4 in the direction in which the substrate 2a extends. The pair of holding portions 3a face each other in the direction in which the substrate 2a extends. The pair of holding portions 3a can be attached to the base 4 using fastening members such as screws. The pair of holding portions 3a can be formed from a metal such as aluminum.

The lens 3b can be provided between a pair of holding parts 3a. The end of the lens 3b in the direction in which the substrate 2a extends can be fixed to the holding part 3a. One lens 3b can be provided for each of the multiple light sources 2. The lens 3b focuses the ultraviolet light emitted from the light source 2 at the irradiation position.

The lens 3b can be, for example, a cylindrical lens extending in the extension direction of the substrate 2a. Although the example shows a case where one lens 3b is provided for each of the multiple light sources 2, multiple lenses 3b may be integrated. The shape of the lens 3b can be changed as appropriate depending on the application of the ultraviolet irradiation device 100. For example, the lens 3b shown in FIG. 2 is a concave-convex lens (meniscus lens), but it may also be a plano-convex lens or a biconvex lens.

Lens 3b can also be a fly-array lens. When lens 3b is a fly-array lens, a lens can be provided for each of the multiple light-emitting elements 2b provided in light source 2.

The material of lens 3b may be any material that is transparent to ultraviolet light and has resistance to ultraviolet light. The material of lens 3b may be, for example, quartz glass, silicone resin, acrylic resin, etc.

The base 4 can have the function of holding the multiple light sources 2 and the function of cooling the multiple light sources 2. The base 4 is block-shaped and can be made of a metal with high thermal conductivity. The base 4 can be made of a metal such as aluminum, for example.

As shown in Figures 4 and 5, a flow path 4b for flowing a coolant such as water can be provided inside the base 4. For example, a flow path 4b can be provided for each of a plurality of light sources 2. In this case, the center of the corresponding flow path 4b can be provided on an extension of the optical axis of the light-emitting element 2b. In this way, the distance between the light-emitting element 2b and the flow path 4b can be shortened, making it easier to cool the light-emitting element 2b.

The flow path 4b can also have a shape that extends in the same direction as the row of the multiple light-emitting elements 2b. In this way, it is possible to prevent uneven cooling of the multiple light-emitting elements 2b.

The flow paths 4b and the adjacent flow paths 4b can be connected inside the base 4, or can be connected to a pipe joint 4c via a pipe as shown in Figures 2, 4, and 5. In addition, a pipe joint 4c1 for supplying a refrigerant and a pipe joint 4c2 for discharging the supplied refrigerant can be connected to the flow paths 4b.
The base 4 may also be provided with heat dissipation fins or the like.

The base 4 has a plurality of surfaces 4a on which one substrate 2a is provided. As shown in FIG. 2, when the base 4 is viewed from the direction in which the substrate 2a extends, the centers of the plurality of surfaces 4a can be provided on the circumference of an installation circle 5. The installation circle 5 can be a virtual circle centered on a point where the optical axes of the plurality of light sources 2 (light-emitting elements 2b) intersect. More specifically, the installation circle 5 can be a virtual circle centered on a point where a line segment connecting the center of the emission surface of the light-emitting element 2b provided in one light source 2 and the ultraviolet irradiation position 200a intersects with a line segment connecting the center of the emission surface of the light-emitting element 2b provided in the other light source 2 and the ultraviolet irradiation position 200a.

The radius of the installation circle 5 can be changed as appropriate depending on the purpose and size of the ultraviolet irradiation device 100, the illuminance of the ultraviolet light emitted from the light-emitting element 2b, etc.

In addition, if the angle between the optical axes (the angle between the line segments) described above is the installation angle θp, the installation angle θp can be the same or different. In the case of the first irradiation unit 1 illustrated in FIG. 2, the installation angle θp is the same.

If ultraviolet light is incident from a direction perpendicular to the surface 200b of the object 200, it is possible to reduce the amount of ultraviolet light reflected by the surface 200b of the object 200. In this case, if the installation angle θp is reduced, it is possible to reduce the angle θ1 between the central axis 1a of the first irradiation unit 1 and the optical axis of the light source 2 provided on the outermost side. Therefore, it is possible to suppress the ultraviolet light irradiated from the light source 2 provided on the outermost side from being reflected by the surface 200b of the object 200.
For example, the installation angle θp can be about 24°, and the angle θ1 can be about 60°. Note that the installation angle θp and the angle θ1 can be appropriately changed depending on the size, number, etc. of the light source 2.

In addition, the smaller the angle between the central axis 1a of the first irradiation unit 1 and the optical axis of the light source 2, the less likely the irradiated ultraviolet light is reflected by the surface 200b of the object 200. Therefore, it is preferable to provide the light source 2 (light-emitting element 2b) on or near the central axis 1a.

(Second Irradiation Unit 10)
At least one second irradiation unit 10 can be provided. For example, as shown in FIG. 1, at least one second irradiation unit 10 can be provided upstream of the first irradiation unit 1 in the moving direction of the object 200. In addition, at least one second irradiation unit 10 can be provided downstream of the first irradiation unit 1, or upstream and downstream of the first irradiation unit 1 in the moving direction of the object 200. That is, at least one second irradiation unit 10 can be provided at least on either the upstream or downstream side of the first irradiation unit 1 in the moving direction of the object 200.

FIG. 6 is a schematic side view for illustrating the second irradiation unit 10. As shown in FIG.
FIG. 7 is a schematic perspective view for illustrating the second irradiation unit 10. As shown in FIG.
FIG. 8 is a schematic cross-sectional view of the second irradiation unit 10. As shown in FIG.
Fig. 9 is a schematic cross-sectional view of the second irradiation unit 10 taken along line CC in Fig. 8. As shown in Figs. 6 and 7, the second irradiation unit 10 can be provided with a light source 12 and a base 14.

As shown in FIG. 7, the light source 12 can have a substrate 12a and a plurality of light-emitting elements 12b (corresponding to an example of second light-emitting elements).
The substrate 12a has a plate-like shape and extends in one direction. The planar shape of the substrate 12a can be, for example, rectangular. The substrate 12a can be attached to the surface 14a of the base 14 using a fastening member such as a screw. It is also possible to provide a recess in the surface 14a of the base 14 and provide the substrate 12a inside the recess. In this way, the positioning of the base 14 and the light source 12 can be easily performed.

A wiring pattern can be provided on one surface of the substrate 12a. A plurality of light-emitting elements 12b can be mounted on the wiring pattern. The plurality of light-emitting elements 12b can be connected in series by the wiring pattern. A pair of connection terminals 12a1 can be provided on the wiring pattern. The pair of connection terminals 12a1 are electrically connected to a power source 30 provided outside the second irradiation unit 10 via wiring.

A protective film can also be provided to cover the wiring pattern. In this case, the protective film can function as a reflective film by using a white protective film (e.g., white resist) or a protective film containing light-scattering particles such as titanium oxide.

The material of the substrate 12a is preferably resistant to ultraviolet light and has high thermal conductivity. The material of the substrate 12a can be, for example, the same as the material of the substrate 2a described above.

The multiple light-emitting elements 12b can be provided on the surface of the substrate 12a. The multiple light-emitting elements 12b can be arranged in a line in the direction in which the substrate 12a extends. In the light source 12 illustrated in FIG. 7, the multiple light-emitting elements 12b are arranged in a line, but the multiple light-emitting elements 12b may be arranged in multiple rows. The pitch dimension of the multiple light-emitting elements 12b (the distance between the light-emitting elements 12b) may be constant or may be different.

If the pitch dimension of the plurality of light emitting elements 12b is constant, the occurrence of uneven illumination can be suppressed.
On the other hand, depending on the application of the ultraviolet irradiation device 100, it may be preferable to have the pitch dimensions of the multiple light-emitting elements 12b different from each other. For example, it may be preferable to make the illuminance of the ultraviolet light irradiated from the central region of the light source 12 greater than that of the ultraviolet light irradiated from the peripheral region. Conversely, it may be preferable to make the illuminance of the ultraviolet light irradiated from the peripheral region of the light source 12 greater than that of the ultraviolet light irradiated from the central region. In such a case, the number of light-emitting elements 12b provided in the region where the illuminance of the irradiated ultraviolet light is increased can be increased, and the pitch dimension of the light-emitting elements 12b can be shortened.

The light emitting element 12b is not particularly limited as long as it is an element capable of emitting ultraviolet light, and may be, for example, a light emitting diode or a laser diode capable of emitting ultraviolet light.
The light emitting element 12b can irradiate ultraviolet light having a peak wavelength of 300 nm or more and less than 350 nm, preferably having a peak wavelength of 300 nm or more and 330 nm or less.

As with the light-emitting element 2b described above, the light-emitting element 12b can be a surface-mount type light-emitting element, a bullet-shaped light-emitting element having lead wires, or a chip-shaped light-emitting element mounted by COB. When using a chip-shaped light-emitting element, wiring that electrically connects the light-emitting element 12b to the wiring pattern, a frame-shaped member that surrounds the light-emitting element 12b and the wiring, and a sealing part provided inside the frame-shaped member can be appropriately provided.

The base 14 can have the function of holding the light source 12 and the function of cooling the light source 2. The base 14 is block-shaped and can be made of a metal with high thermal conductivity. The base 14 can be made of a metal such as aluminum, for example.

As shown in Figures 8 and 9, a flow path 14b for flowing a coolant such as water can be provided inside the base 14. In this case, the center of the flow path 14b can be located on an extension of the optical axis of the light-emitting element 12b. In this way, the distance between the light-emitting element 12b and the flow path 14b can be shortened, making it easier to cool the light-emitting element 12b.

Furthermore, the flow paths 14b may have a shape that extends in the same direction as the row of the light emitting elements 12b, thereby making it possible to prevent uneven cooling of the light emitting elements 12b.
A pipe joint 14c1 for supplying a refrigerant and a pipe joint 14c2 for discharging the supplied refrigerant can be connected to the flow path 14b.
The base 14 may also be provided with heat dissipation fins or the like.

FIG. 10 is a schematic side view illustrating a base 14d according to another embodiment.
In cases where the installation space for the ultraviolet irradiation device 100 is narrow, it is preferable to reduce the distance between the first irradiation unit 1 and the second irradiation unit 10. In such cases, as shown in Fig. 10, a base 14d can be formed integrally with the base 4. If the base 14d is formed integrally with the base 4, the ultraviolet irradiation device 100 can be made smaller, so that the ultraviolet irradiation device 100 can be provided even in a narrow installation space.

Here, if ultraviolet light is incident from a direction perpendicular to the surface 200b of the object 200, the amount of ultraviolet light reflected by the surface 200b of the object 200 can be reduced. Therefore, it is preferable that the surface 14a of the base 14 on which the light source 12 is provided is approximately parallel to the surface 200b of the object 200.

As mentioned above, the light-emitting efficiency of a light-emitting element decreases as the peak wavelength of the ultraviolet light it generates becomes shorter. Therefore, the light-emitting efficiency of light-emitting element 12b is lower than that of light-emitting element 2b. In this case, if the number of expensive light-emitting elements 12b is increased to obtain the required illuminance, this will result in an increase in the size of the light source 12 and an increase in manufacturing costs.

The ultraviolet irradiation device 100 is provided with a first irradiation unit 1 having a light-emitting element 2b, and a second irradiation unit 10 having a light-emitting element 12b that irradiates ultraviolet light with a shorter peak wavelength than that of the light-emitting element 2b. Therefore, it is easy to make the distance between the center of the emission surface of the light-emitting element 12b and the irradiation position of the ultraviolet light irradiated from the light-emitting element 12b on the object 200 smaller than the distance between the center of the emission surface of the light-emitting element 2b and the irradiation position of the ultraviolet light irradiated from the light-emitting element 2b on the object 200. In other words, since the distance between the emission surface of the light-emitting element 12b and the object 200 is reduced, the illuminance of the ultraviolet light irradiated from the light-emitting element 12b can be increased. Therefore, even if the luminous efficiency of the light-emitting element 12b is lower than that of the light-emitting element 2b, it is easy to obtain the required illuminance.

For example, the distance between the center of the emission surface of the light-emitting element 12b and the ultraviolet irradiation position 200a can be 10 mm or less. For example, the distance between the center of the emission surface of the light-emitting element 2b and the ultraviolet irradiation position 200a can be 80 mm or less.

In addition, a rotating roller or the like for moving the object 200 may be provided near the second irradiation unit 10. In such a case, a lens unit may be further provided as in the case of the first irradiation unit 1 described above. If a lens unit is provided, the irradiated ultraviolet light can be condensed, so the distance between the emission surface of the light-emitting element 12b and the surface 200b of the object 200 can be increased. This makes it easier to install the second irradiation unit 10. However, if the distance between the emission surface of the light-emitting element 12b and the surface 200b of the object 200 is reduced and the lens unit is omitted, the manufacturing cost can be reduced.

(Bracket 20)
The bracket 20 can be provided with the first irradiation unit 1 and the second irradiation unit 10. In this case, as shown in FIG. 1, the first irradiation unit 1 and the second irradiation unit 10 can be provided on one bracket 20, or a bracket can be provided for each of the first irradiation unit 1 and the second irradiation unit 10. If the first irradiation unit 1 and the second irradiation unit 10 are provided on one bracket 20, it is possible to reduce the size and manufacturing costs. If a bracket is provided for each of the first irradiation unit 1 and the second irradiation unit 10, it is possible to increase the degree of freedom regarding the installation of the first irradiation unit 1 and the second irradiation unit 10.

The material, shape, size, etc. of the bracket 20 can be changed appropriately depending on the number, shape, size, arrangement, etc. of the first irradiation units 1 and the second irradiation units 10.
The bracket 20 can be attached to, for example, a housing of a device for moving the object 200. When the first irradiation unit 1 and the second irradiation unit 10 are attached to a housing of a device for moving the object 200, the bracket 20 can be omitted.

(Power supply 30)
The power source 30 can be electrically connected to the first irradiation unit 1 and the second irradiation unit 10. The power source 30 supplies a predetermined power to the light source 2 (light-emitting element 2b) of the first irradiation unit 1 and the light source 12 (light-emitting element 12b) of the second irradiation unit 10. The power source 30 can be, for example, a DC power source. The DC power source can be provided with a rectifier circuit, a converter, a switch, and the like. The rectifier circuit is electrically connected to the AC power source. The rectifier circuit can, for example, full-wave rectify the AC voltage applied by the AC power source. The rectifier circuit can have, for example, a diode bridge, and the like. The converter converts the voltage full-wave rectified by the rectifier circuit into a predetermined DC voltage. The converter can have, for example, a switching circuit. The switch can switch between applying power to the light source 2 (light-emitting element 2b) and the light source 12 (light-emitting element 12b) and stopping the application of power.

(Controller 40)
The controller 40 may have, for example, a calculation element such as a CPU (Central Processing Unit) and a storage element such as a semiconductor memory. The controller 40 may be, for example, a computer. The storage element may store a control program that controls the operation of each element provided in the ultraviolet irradiation device 100. The calculation element may control the operation of each element provided in the ultraviolet irradiation device 100 using the control program stored in the storage element, data input by an operator, and the like.

For example, the controller 40 can control the power source 30 to simultaneously irradiate ultraviolet light from the light source 2 of the first irradiation unit 1 and the light source 12 of the second irradiation unit 10. If the distance between the light source 2 and the light source 12 is large, it is also possible to irradiate ultraviolet light from the upstream light source, and then irradiate ultraviolet light from the downstream light source. In this case, the irradiation timing can be appropriately determined based on the distance between the light source 2 and the light source 12, the moving speed of the object 200, etc.

FIG. 11 is a table illustrating the effect of the ultraviolet irradiation device 100.
The comparative example is a case where only the first irradiation unit 1 is provided. In this case, the peak wavelength of the irradiated ultraviolet light is 385 nm, and the integrated light amount is 1600 mJ/ ^cm2 .

The peak wavelength of the ultraviolet light irradiated from the first irradiation unit 1 provided in the ultraviolet irradiation device 100 is 385 nm, and the accumulated light amount is 1600 mJ/ ^cm2 . The peak wavelength of the ultraviolet light irradiated from the second irradiation unit 10 provided in the ultraviolet irradiation device 100 is 310 nm, and the accumulated light amount is 4.7 mJ/ ^cm2 .

As can be seen from FIG. 11, the ultraviolet irradiation device 100 can harden the object 200 even if the moving speed of the object 200 is increased by about 33% compared to the comparative example. This means that the time required for processing can be reduced by about 33%.

According to the findings of the present inventors, when the peak wavelength of the ultraviolet ray irradiated from the first irradiation unit 1 is set to 350 nm or more and 450 nm or less, it is preferable to set the integrated light amount to 1000 mJ/ ^cm2 or more. When the peak wavelength of the ultraviolet ray irradiated from the second irradiation unit 10 is set to 300 nm or more and less than 350 nm (preferably 300 nm or more and 330 nm or less), it is preferable to set the integrated light amount to 3.5 mJ/ ^cm2 or more.

Although several embodiments of the present invention have been illustrated above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. These embodiments and their variations are included within the scope and gist of the invention, as well as within the scope of the invention and its equivalents described in the claims. Furthermore, the above-mentioned embodiments can be implemented in combination with each other.

1 First irradiation unit, 1a Central axis, 2 Light source, 2a Substrate, 2b Light emitting element, 3 Lens unit, 4 Base, 10 Second irradiation unit, 12 Light source, 12a Substrate, 12b Light emitting element, 14 Base, 40 Controller, 100 UV irradiation device, 200 Object, 200a Irradiation position, 200b Surface

Claims (4)

An ultraviolet irradiation device that irradiates ultraviolet rays onto a moving object,
a first irradiation unit including a plurality of light sources each having a first light-emitting element capable of emitting ultraviolet light having a first peak wavelength;
at least one second irradiation unit having a second light-emitting element capable of emitting ultraviolet light having a second peak wavelength shorter than the first peak wavelength;
Equipped with
the ultraviolet rays having the first peak wavelength irradiated from the first light-emitting elements provided in each of the plurality of light sources are simultaneously irradiated to substantially the same irradiation position on the object,
a distance between a center of an emission surface of the first light-emitting element provided in each of the plurality of light sources and the irradiation position on the object is substantially the same;
a distance between a center of an emission surface of the second light-emitting element and an irradiation position of the ultraviolet light irradiated from the second light-emitting element on the object is smaller than a distance between a center of an emission surface of the first light-emitting element and an irradiation position of the ultraviolet light irradiated from the first light-emitting element on the object;
the first peak wavelength is 350 nm or more and 450 nm or less,
The integrated light amount of the ultraviolet light having the first peak wavelength is 1000 mJ/ ^cm2 or more,
The second peak wavelength is equal to or greater than 300 nm and less than 350 nm,
An ultraviolet irradiation device, wherein an integrated light amount of the ultraviolet light having the second peak wavelength is 3.5 mJ/ ^cm2 or more. The ultraviolet irradiation device according to claim 1, wherein at least one of the second irradiation units is provided at least either upstream or downstream of the first irradiation unit in the moving direction of the object. The ultraviolet irradiation device according to claim 1 or 2, wherein one of the plurality of light sources is provided on the central axis of the first irradiation unit. The ultraviolet irradiation device according to claim 1 or 2, wherein the plurality of light sources are provided at positions symmetrical with respect to the central axis of the first irradiation unit.

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