JP7117148B2 - UV irradiation device - Google Patents

Description

The present invention relates to an ultraviolet irradiation device used, for example, in a water sterilization device.

Ultraviolet light can kill or kill bacteria by acting on the nucleic acids that are the cytoplasm of the bacteria. The output of an ultraviolet irradiation lamp that emits ultraviolet light gradually decreases as the usage time increases.

Therefore, the power output of the UV irradiation lamp will decrease with time of use below that required to obtain the desired bacterial kill rate. Therefore, when the output of the ultraviolet irradiation lamp falls below a certain reference output, it is necessary to replace the ultraviolet irradiation lamp.

Therefore, the in-use water treatment device that can monitor the output change of the ultraviolet irradiation lamp by irradiating the fluorescent dye part with ultraviolet light and converting it into visible light and visually observing the change in the intensity of the visible light is patented. It is disclosed in Document 1.

Patent No. 4358780

However, the fluorescent dye portion of the in-use water treatment device of Patent Document 1 generates heat when converting ultraviolet light into visible light. Here, there is a suitable temperature range for efficiently sterilizing water. Therefore, when the water temperature rises due to the heat generated by the fluorescent dye portion, there is a problem that the sterilization efficiency decreases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ultraviolet irradiating device capable of visually recognizing the output state of an ultraviolet irradiating lamp without using a phosphor dye portion.

In order to achieve the above-mentioned object, the ultraviolet irradiation device of the present invention contains a light-emitting lamp that emits irradiation light including visible light and ultraviolet light, and a conduit through which the light-emitting lamp and fluid flow and transmit the irradiation light. a cover member having a housing space and having a through hole penetrating between the inside and the outside of the housing space; a blocking member that closes the through hole and has a property of being transparent to the visible light; characterized by having

1 is a plan view of an ultraviolet irradiation device according to Example 1. FIG. FIG. 2 is a cross-sectional view of the ultraviolet irradiation device taken along line AA of FIG. 1; 2 is a plan view of the closure member of FIG. 1; FIG. Figure 2 is a side view of the closure member of Figure 1; 4 is a graph showing emission spectra of ultraviolet light emitting lamps. 5 is an enlarged graph of a specific wavelength range of FIG. 4; 4 is a graph showing an emission spectrum observed outside an ultraviolet irradiation device; 4 is a graph showing an emission spectrum observed outside an ultraviolet irradiation device; It is a graph which shows the relationship between an ultraviolet light illumination intensity ratio and a visible light illumination intensity ratio. 1. It is the graph which showed the thickness of the closure member of FIG. 1, and the relationship of visible light illuminance ratio. 1. It is the graph which showed the thickness of the closure member of FIG. 1, and the relationship of visible light illuminance ratio. FIG. 8 is a plan view of an ultraviolet irradiation device according to Example 2; Figure 12 is a plan view of the closure member of Figure 11; Figure 12 is a side view of the closure member of Figure 11; It is a top view of the closure member which concerns on the ultraviolet irradiation device of a modification. It is a side view of the closure member which concerns on the ultraviolet irradiation device of a modification. FIG. 11 is a plan view of an ultraviolet irradiation device according to Example 3; FIG. 15 is a cross-sectional view of the ultraviolet irradiation device taken along line BB of FIG. 14; FIG. 15 is a cross-sectional view of the ultraviolet irradiation device taken along line CC of FIG. 14;

Preferred embodiments of the present invention are described in detail below. In the following description and accompanying drawings, substantially the same or equivalent parts are denoted by the same reference numerals.

FIG. 1 shows a plan view of a water sterilization device 100 as an ultraviolet irradiation device that is an embodiment of the present invention. As shown in FIG. 1, the water sterilizer 100 is a device that irradiates water with ultraviolet light to kill bacteria contained in the water, that is, sterilize the water.

The ultraviolet light emitting lamp 20 emits irradiation light including visible light and ultraviolet light. For example, a xenon flash lamp, an arc discharge lamp, a mercury lamp, or the like can be used as the ultraviolet light emitting lamp 20 . The ultraviolet light emitting lamp 20 is formed in a substantially cylindrical shape. The ultraviolet light emitting lamp 20 is connected to the power supply through the connector CN.

A water pipe P serving as a conduit through which water flows and through which the irradiation light emitted by the ultraviolet light emitting lamp 20 is transmitted is formed in a cylindrical shape along the longitudinal direction of the ultraviolet light emitting lamp 20 . The water conduit P is made of, for example, quartz glass, synthetic quartz, fused quartz, synthetic sapphire, or the like.

The cover member 30 is formed in a substantially rectangular parallelepiped tubular shape. The cover member 30 is made of a material that does not transmit ultraviolet light. Materials that do not transmit ultraviolet light include, for example, ABS (Acrylonitrile Butadiene Styrene) resin. The cover member 30 has an accommodation space (not shown) in which the ultraviolet light emitting lamp 20 and the water pipe P are accommodated.

FIG. 2 shows a cross-section of the water sterilizer 100 along line AA of FIG. As shown in FIG. 2, the cover member 30 is composed of two half-split pipe members 30a and 30b. The two pipe members 30a and 30b are fixed to each other by bolting.

The housing space 31 of the cover member 30 is formed to have a curved surface so that the irradiation light transmitted through the water pipe P is irradiated to the water pipe P again. Specifically, the housing space 31 is recessed in an arc shape. A reflecting member that reflects ultraviolet light may be provided on the inner peripheral surface of the housing space 31 . A metal such as aluminum can be used for the reflecting member. By providing the reflecting member, the irradiation light transmitted through the water pipe P can be reflected toward the water pipe P more efficiently.

In addition, at one end of the housing space 31 in the direction in which water flows in the water pipe P, a first support portion (not shown) is formed to fit and support one end of the water pipe P and one end of the ultraviolet light emitting lamp. It is At the other end of the accommodation space 31 in the direction in which the water flows in the water pipe P, there is a second support (not shown) that fits and supports the other end of the water pipe P and the other end of the ultraviolet light emitting lamp. formed. Therefore, the ultraviolet light emitting lamp 20 and the water pipe P are supported within the accommodation space 31 by the first support and the second support.

Further, the cover member 30 has a through hole 32 penetrating between the inside and the outside of the housing space 31 . Therefore, part of the irradiation light emitted from the ultraviolet light emitting lamp 20 is incident on the through hole 32 . The opening end of the through hole 32 on the accommodation space 31 side is formed so as to narrow toward the outside of the accommodation space 31 .

The inner wall of the through hole 32 has a concave portion 33 that is recessed in a direction perpendicular to the direction of penetration of the through hole 32 . The recess 33 of the through-hole 32 is provided with a closing member 40 that closes the through-hole 32 and has transparency to visible light.

3A shows a plan view of the closure member 40. FIG. 3B shows a side view of the closure member 40. FIG. As shown in FIGS. 3A and 3B, the closing member 40 is formed in a disc shape and includes a base portion 41 as a protrusion that fits into the recess 33 and a disc-like protrusion that protrudes from the base portion 41. 42 and . The protruding portion 42 is shorter than the base portion 41 in the width direction of the through hole 32 and is formed to have the same width as the through hole 32 .

In other words, the closing member 40 has a first region A and a second region B having different thicknesses in the direction of penetration of the through hole 32 . The first region A is formed thicker than the second region B in the through-hole direction of the through hole 32 .

Therefore, by inserting the projecting portion 42 of the closing member 40 into the through hole 32 and pressing the base portion 41 toward the outside of the accommodation space 31 while pressing the base portion 41 against the opening end of the through hole 32 , the base portion 41 fits into the recess portion 33 . mated. At this time, since the open end is narrowed, the frictional resistance against the closing member 40 is reduced. Therefore, it is possible to easily fix the closing member 40 to the recess 33 .

The blocking member 40 has an absorption property for ultraviolet light. The closing member 40 is, for example, silicone rubber. The blocking member 40 contains at least one of an ultraviolet absorber and an ultraviolet scattering material.

Examples of ultraviolet absorbers include octyl methoxycinnamate, dimethoxybenzylidenedioxoimidazolidinepropionate, octyl diethylaminohydroxybenzoylbenzoate, t-butylmethoxydibenzoylmethane, octyltriazone, and 2-ethylhexyl paramethoxycinnamate. etc.

Examples of UV scattering agents include zinc oxide and titanium oxide.

Also, the closing member 40 has a color corresponding to the visible light included in the irradiation light, such as red and green. The blocking member 40 may be made of a material other than silicone rubber as long as it contains at least one of an ultraviolet absorber and an ultraviolet scattering material. , an inorganic material such as glass.

FIG. 4 shows the emission spectrum of the ultraviolet light emitting lamp 20. As shown in FIG. The ultraviolet light emitting lamp 20 has, for example, a peak near 254 nm in the ultraviolet region and peaks near 320, 370, 410, 430, and 545 nm (green) in the visible region. The relative intensity is a numerical value proportional to the intensity of light detected by the detector.

FIG. 5 is an enlarged view of the spectrum at 600-800 nm of FIG. As shown in FIG. 5, the ultraviolet light emitting lamp 20 used in this embodiment has a peak near 770 nm.

Thus, the ultraviolet light emitting lamp 20 used in this embodiment has a peak at around 254 nm in the ultraviolet region, and at least around 545 nm (green) and 770 nm (red) in the visible region. is doing.

FIG. 6 shows an emission spectrum observed near the through-hole 32 outside the accommodation space 31 when the closing member 40 having green is attached to the water sterilizer 100 .

As shown in FIG. 6, the peak near 254 nm is hardly detected outside the housing space 31, while the peak near 545 nm is detected. Therefore, most of the ultraviolet light emitted by the ultraviolet light emitting lamp 20 is blocked by the blocking member 40 and is not emitted to the outside of the housing space 31 . On the other hand, visible light contained in the irradiation light emitted by the ultraviolet light emitting lamp 20 passes through the closing member 40 and is emitted to the outside of the housing space 31 .

FIG. 7 shows an emission spectrum observed near the through-hole 32 outside the accommodation space 31 when the closing member 40 having red color is attached to the water sterilizer 100 .

As shown in FIG. 7, almost no peak near 254 nm is detected outside the housing space 31 . On the other hand, a peak near 770 nm is detected. Therefore, most of the ultraviolet light emitted by the ultraviolet light emitting lamp 20 is absorbed by the closing member 40 and is not emitted to the outside of the housing space 31 . On the other hand, visible light contained in the irradiation light emitted by the ultraviolet light emitting lamp 20 passes through the closing member 40 and is emitted to the outside of the housing space 31 .

FIG. 8 shows the relationship between the ultraviolet light illuminance ratio and the visible light illuminance ratio. The ultraviolet light illuminance ratio represents the ratio of the illuminance of ultraviolet light contained in the irradiation light emitted by the ultraviolet light emitting lamp 20 . Specifically, it represents the ratio of the illuminance of the ultraviolet light according to the lighting time, with the illuminance of the ultraviolet light at the start of lighting of the ultraviolet light emitting lamp 20 as a reference. Also, the visible light illuminance ratio is based on the illuminance of the visible light at the start of lighting of the ultraviolet light emitting lamp 20, and represents the ratio of the illuminance of the visible light according to the lighting time.

A solid line in the figure indicates an approximated curve. Here, when "x" is the visible light illuminance ratio and "y" is the ultraviolet light illuminance ratio, the approximate curve can be expressed as follows.

y = 1.019 ^{x 0.5786}

As shown in FIG. 8, according to this approximate curve, the ultraviolet light illuminance ratio decreases as the visible light illuminance ratio decreases. For example, the ultraviolet light illuminance ratio is 50% when the visible light illuminance ratio is 30%. Thus, by observing the visible light illuminance ratio, the ultraviolet light illuminance ratio can be observed.

In addition, the case where the ultraviolet light illumination ratio of the ultraviolet light emitting lamp 20 is defined as 50% as a reference will be described. Therefore, if it is possible to observe when the visible light illuminance ratio is 30%, it is possible to observe the reference of the ultraviolet light illuminance ratio. Note that this criterion can be changed arbitrarily by the user.

Here, if the illuminance of visible light is 0.1 lx or less, it cannot be visually observed. Therefore, in order to visually observe the reference of the ultraviolet light illuminance ratio, it is preferable to set the illuminance of visible light to 0.1 lx or less when the ultraviolet light illuminance ratio reaches the reference.

FIG. 9 shows the relationship between the length of the blocking member 40 (green) in the formation direction of the through hole 32, that is, the thickness of the blocking member 40, and the visible light illuminance when the ultraviolet light emitting lamp 20 is operated at an applied voltage of 24V. ing. In addition, the solid line in the drawing indicates an approximated curve. Here, when "x" is the thickness of the closing member 40 and "y" is the visible light illuminance ratio, the approximate curve can be expressed as follows.

y=59.012x- ^3.138

As shown in FIG. 9, when the blocking member 40 has a thickness of 2 mm, the visible light illuminance is 8 lx. That is, when the visible light illuminance ratio is 30%, the visible light illuminance is 2 lx or more, and it is difficult to visually observe the reference of the ultraviolet light illuminance ratio.

Moreover, when the thickness of the closing member 40 is 8 mm, the visible light illuminance is 0.1 lx. That is, even if the ultraviolet light illuminance ratio is equal to or higher than the standard, the visible light illuminance is 0.1 lx or less, so it is difficult to visually observe the standard of the ultraviolet light illuminance ratio.

When the blocking member 40 has a thickness of 5.2 mm, the visible light illuminance is 0.33 lx. That is, since the visible light illuminance is 0.1 lx when the ultraviolet light illuminance ratio is the reference, the reference can be visually observed.

FIG. 10 shows the relationship between the length of the blocking member 40 (red) in the direction in which the through hole 32 is formed, that is, the thickness of the blocking member 40, and the illuminance of visible light when the ultraviolet light emitting lamp 20 is operated at an applied voltage of 24V. showing. In addition, the solid line in the drawing indicates an approximated curve. Here, when "x" is the thickness of the closing member 40 and "y" is the visible light illuminance ratio, the approximate curve can be expressed as follows.

y = 5.169x ^-1.354

As shown in FIG. 10, when the blocking member 40 has a thickness of 2 mm, the visible light illuminance is 2 lx. That is, when the visible light illuminance ratio is 30%, the visible light illuminance is 0.6 lx or more, and it is difficult to visually observe the reference.

When the blocking member 40 has a thickness of 7.6 mm, the visible light illuminance is 0.33 lx. That is, since the visible light illuminance is 0.1 lx when the ultraviolet light illuminance ratio is the reference, the reference can be visually observed.

As described above, according to the ultraviolet irradiation device 100 of the present embodiment, changes in the output of ultraviolet light are detected based on the correlation between the output of visible light and the output of ultraviolet light contained in the irradiation light. It can be observed by intensity change.

Therefore, the ultraviolet irradiation device 100 of the present embodiment does not convert the ultraviolet light into visible light, and the output state of the ultraviolet light from the ultraviolet light emitting lamp 20 can be visually recognized by the change in the intensity of the visible light contained in the irradiated light. can be done. That is, the ultraviolet irradiation device 100 of the present embodiment does not generate heat when converting ultraviolet light into visible light, so that the sterilization efficiency is not lowered. Therefore, the user can visually recognize the output state of the ultraviolet light emitting lamp 20 that emits ultraviolet light, for example, the replacement life, simply by visually observing the intensity change of the visible light.

Specifically, the user can see the lighting of the projecting portion 42 until the ultraviolet light illumination intensity ratio of the irradiated light reaches the standard. When the ultraviolet illumination intensity ratio of the irradiated light reaches the standard, the user can visually see that the projecting portion 42 is turned off. By observing such a change in the output state by turning off the blocking member 40, the user can visually confirm that the ultraviolet light illumination ratio has reached the standard.

A water sterilizer 100 according to a second embodiment will be described. The water sterilizer 100 according to Example 2 differs from the water sterilizer 100 of Example 1 in the shape of the closing member 40 . Other configurations are the same as those of the water sterilizer 100 of the first embodiment.

FIG. 11 shows a plan view of the water sterilizer 100 according to the second embodiment. As shown in FIG. 11 , the base portion 41 and the protruding portion 42 of the closing member 40 are visible from the outside of the housing space 31 .

12A shows a plan view of the closure member 40. FIG. 12B shows a side view of the closure member 40. FIG. As shown in FIGS. 12A and 12B, the protruding portion 42 is formed so that the width direction of the through hole 32 is shorter than the base portion 41 and shorter than the width of the through hole 32 .

Here, there may be individual differences in the intensity of visible light that can be visually observed. For example, for a user who has a sensitive retina to visible light and can observe relatively weak light, when the ultraviolet light illumination ratio reaches the reference output, the projecting portion 42 is turned off and the base portion 41 is turned off. It can be seen that only the is illuminated. By observing such a change in the output state of the ultraviolet light emitting lamp 20 by turning off the closing member 40, it is possible to visually confirm that the ultraviolet light illuminance ratio has reached the standard.

On the other hand, for a person whose retina has a relatively weak response to visible light and is difficult to detect faint light, both the projecting portion 42 and the base portion 41 may is off. By observing such a change in the output state of the ultraviolet light emitting lamp 20 by turning off the closing member 40, it is possible to visually confirm that the ultraviolet light illuminance ratio has reached the standard.

As described above, according to the water sterilizer 100 according to the present embodiment, the user can visually confirm that the ultraviolet light illumination ratio has reached the standard regardless of individual differences in visible light intensity.

The first area A and the second area B may have different colors. By configuring the closing member 40 in this way, the base portion 41 is lit in a color different from that of the projecting portion 42, so that the user can easily visually confirm that the ultraviolet light illumination ratio has reached the standard. .

Further, not only when the entire first region A has a color different from that of the second region B, but also when part of the first region A has a color different from that of the second region B. good. For example, the base portion 41 and the projecting portion 42 may have different colors.

[Variation]
In Examples 1 and 2, the closing member 40 is composed of the base portion 41 and the projecting portion 42 . The protruding portion 42 may be formed in a stepped shape such that the length in the width direction of the through hole 32 becomes shorter in the protruding direction.

FIG. 13A is a plan view of the closing member 40 of the water sterilizer 100 according to the modification. FIG. 13B is a side view of the water sterilizer 100 according to the modification. As shown in FIGS. 13A and 13B, the protruding portion 42 is formed in a stepped shape in which the length in the width direction of the through hole 32 becomes shorter toward the protruding direction. Specifically, the protruding portion 42 includes a first protruding portion 42a protruding from the base portion 41 and a second protruding portion 42b protruding from the first protruding portion 42a. have.

The first protruding portion 42 a is shorter in the width direction of the through hole 32 than the base portion 41 and shorter than the width direction of the through hole 32 . The second protruding portion 42b is formed to be shorter than the through hole 32 in the width direction and shorter in the width direction of the through hole 32 than the first protruding portion 42a.

The first projecting portion 42a and the second projecting portion 42b may have different colors. In other words, the projecting portion 42 may have different colors depending on the length of the through-hole 32 in the through-hole direction when viewed from the outside of the housing space 31 .

By configuring the blocking member 40 in this way, the user can see that the first projecting portion 42a is lit in a color different from that of the second projecting portion 42b. It becomes easier to recognize that

For example, the user can visually confirm that both the first projecting portion 42a and the second projecting portion 42b are lit when the ultraviolet illumination ratio is sufficiently higher than the reference. In addition, the user can visually confirm that only the first projecting portion 42a is lit when the ultraviolet light illumination ratio is close to the reference. Furthermore, in a state where the ultraviolet light illumination intensity ratio is the reference, it can be visually observed that both the first projecting portion 42a and the second projecting portion 42b are turned off.

As described above, according to the water sterilization apparatus 100 of this modified example, the user can visually observe the change in the output state of the ultraviolet light emitting lamp 20 step by step. Therefore, it is possible for the user to estimate an appropriate time to replace the ultraviolet light emitting lamp 20 .

A water sterilizer 100 according to Example 3 will be described. The water sterilizer 100 according to Example 3 differs from the water sterilizer 100 of Example 1 in that a plurality of through holes 32 and closing members 40 are provided. Other configurations are the same as those of the water sterilizer 100 of the first embodiment.

FIG. 14 shows a plan view of the water sterilizer 100 according to the third embodiment. As shown in FIG. 14, the cover member 30 is provided with two through holes 32a and 32b. A plurality of closing members 40 are provided according to the number of through holes.

Specifically, one through-hole 32a is provided with a closing member 40a that closes the through-hole 32a. The other through hole 32b is provided with a closing member 40b that closes the through hole 32b.

FIG. 15A shows a cross-section of the water sterilizer 100 along line BB of FIG. FIG. 15B shows a cross-section of the water sterilizer 100 along line CC of FIG. As shown in FIGS. 15A and 15B, each of the closing members 40a and 40b has a different thickness in the through-hole 32 penetration direction. Specifically, the blocking member 40a blocking the through-hole 32a is thicker in the through-hole 32 direction than the blocking member 40b blocking the through-hole 32b.

As described above, according to the water sterilizer 100 according to the present embodiment, by appropriately adjusting the thickness of the blocking members 40a and 40b, the user can control the ultraviolet light illuminance regardless of individual differences in visible light intensity. It becomes possible to visually observe that the ratio has reached the criterion. Specifically, a user who can observe relatively weak light visually confirms that the blocking member 40a is turned off and only the blocking member 40b is turned on when the ultraviolet light illuminance ratio reaches the reference output. can. By observing such a change in the output state of the ultraviolet light emitting lamp 20 by turning off the closing member 40a, it is possible to visually confirm that the ultraviolet light illuminance ratio has reached the standard.

Also, a person who has difficulty detecting weak light can visually confirm that both the blocking member 40a and the blocking member 40b are turned off when the ultraviolet light illuminance ratio of the irradiated light reaches the reference output. By observing such a change in the output state of the ultraviolet light emitting lamp 20 by turning off the closing members 40a and 40b, it is possible to visually confirm that the ultraviolet light illuminance ratio has reached the standard.

Each of the closing members 40a and 40b may have different colors. Since each of the blocking members 40a and 40b has a different color from each other in this manner, it is possible to easily visually check whether the blocking members 40a and 40b are turned on and off.

100 water sterilizer 20 ultraviolet light emitting lamp 30 cover member 31 accommodation space 32 through hole 33 recess 40 closing member 41 base 42 projection

Claims (8)

a light-emitting lamp that emits illuminating light including visible light and ultraviolet light;
a cover member having a housing space for housing a conduit through which the light-emitting lamp and the fluid flow and through which the irradiation light is transmitted, and having a through hole penetrating between the inside and the outside of the housing space;
a closing member that closes the through hole and has a property of being transparent to the visible light;
The closing member has a first region and a second region having different thicknesses in the direction of penetration of the through hole, and the first region and the second region have different colors. An ultraviolet irradiation device characterized by: A plurality of the through holes are provided in the cover member,
A plurality of the closing members are provided according to the number of the through holes,
2. The ultraviolet irradiation device according to claim 1 , wherein each of said blocking members has a different thickness in the direction of penetration of said through-hole. a light-emitting lamp that emits illuminating light including visible light and ultraviolet light;
a cover member having a housing space for housing a conduit through which the light-emitting lamp and the fluid flow and through which the irradiation light is transmitted, and having a through hole penetrating between the inside and the outside of the housing space;
a closing member that closes the through hole and has a property of being transparent to the visible light;
A plurality of the through holes are provided in the cover member,
A plurality of the closing members are provided according to the number of the through holes,
Each of the closing members has a different thickness in the direction of penetration of the through hole,
The ultraviolet irradiation device, wherein each of the blocking members has a color different from each other. the inner wall of the through hole has a recess that is recessed in a direction perpendicular to the direction of penetration of the through hole,
4. The ultraviolet irradiation device according to any one of claims 1 to 3 , wherein the closing member has a convex portion that fits into the concave portion. 5. The ultraviolet irradiation device according to any one of claims 1 to 4 , wherein an open end of the through hole on the accommodation space side is formed so as to narrow toward the outside. 6. The ultraviolet irradiation device according to any one of claims 1 to 5 , wherein the blocking member is an elastic body and has a color corresponding to the visible light contained in the irradiation light. a light-emitting lamp that emits illuminating light including visible light and ultraviolet light;
a conduit through which a fluid flows and through which the illuminating light is transmitted;
a cover member having a housing space for housing the light-emitting lamp and the conduit, and a through hole penetrating between the inside and the outside of the housing space;
and a blocking member that blocks the through hole and has a property of being transparent to the visible light,
The closing member has a first region and a second region having different thicknesses in the penetration direction of the through hole, and the first region penetrates the through hole more than the second region. A base portion and a protruding portion that protrudes from the base portion in the direction of penetration of the through hole so that the thickness in the direction is formed thick,
The inner wall of the through-hole has a concave portion that is depressed in a direction perpendicular to the through-hole direction,
the blocking member includes at least one of an ultraviolet absorber and an ultraviolet scattering material, and has absorbability for ultraviolet light emitted from the light emitting lamp;
and having a color corresponding to the visible light contained in the irradiation light,
The closing member has the projecting portion inserted into the through hole and the base portion fitted into the recess so that the base portion and the projecting portion can be seen.
An ultraviolet irradiation device characterized by: The closing member is
When the visible light illuminance ratio is plotted on the horizontal axis and the ultraviolet light illuminance ratio is plotted on the vertical axis, the ultraviolet light illuminance ratio decreases as the visible light illuminance ratio decreases, and
When the thickness of the blocking member is plotted on the horizontal axis and the illuminance of visible light is plotted on the vertical axis, the illuminance of the visible light decreases as the thickness of the blocking member increases.
The ultraviolet irradiation device according to any one of claims 1 to 7, characterized in that:

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