JPH05262904A - Ultraviolet irradiation apparatus - Google Patents

Abstract

PURPOSE:To provide an ultraviolet irradiation apparatus capable of improving the irradiation efficiency of ultraviolet ray to the irradiation object in the case of increasing the output of a low-pressure mercury lamp. CONSTITUTION:The objective apparatus is provided with a low-pressure mercury lamp 11 emitting high-output ultraviolet ray and containing a luminescent tube 12 having flat cross section and with a reflection plate 24 having reflection planes 24a, 24b opposite to the flat face A of the luminescent tube 12 of the low-pressure mercury lamp 11. As an alternative, the ultraviolet ray emitted from a flat face of the luminescent tube 12 is reflected with a reflection plate 24 having the 1st reflection plane 24a and the 2nd reflection plane 24b perpendicular to the 1st plane and guided in the direction same as the direction of ultraviolet ray emitted from the other flat face B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet irradiation device for photochemical reaction, for example.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 10 to 12, as this type of ultraviolet irradiation device, a reflector 3 is provided along the side of a circular arc-shaped arc tube 2 of a mercury lamp 1 for generating ultraviolet rays.
It is known that an organic substance on the irradiation target 4 is optically cleaned, light-modified, or sterilized by the ultraviolet light emitted from the arc tube 2 and the ultraviolet light reflected from the reflection plate 3. ..

In this field, it is desired to develop a light source that efficiently radiates short-wavelength ultraviolet rays, and therefore the low-pressure mercury lamp 1 is used. This low-pressure mercury lamp 1
In the above, the arc tube 2 is formed of quartz glass or the like, which easily transmits ultraviolet rays, and efficiently emits light in the short wavelength ultraviolet region. In recent years, there has been an increasing demand for higher light output and higher density, and a high-output type low-pressure mercury lamp 1 has been developed.

[0004]

However, in the above-mentioned conventional ultraviolet irradiation device, since the arc tube 2 has a circular cross section, when the output of the low-pressure mercury lamp 1 is increased, the mercury in the arc tube 2 is increased. There is a drawback that the self-absorption of ultraviolet rays by the main vapor becomes remarkable and the irradiation efficiency of ultraviolet rays deteriorates. Moreover, as shown in FIG. 12, since the output of the ultraviolet rays emitted from the arc tube 2 is uniform in all directions, it is radiated from the arc tube 2 to the reflector 3 side, reflected by the reflector 3 and reflected again in the arc tube. There is a considerable amount of ultraviolet rays that reach the object to be irradiated 4 through the inside 2, and the ultraviolet rays are absorbed again in this line of light. Therefore, there is a problem that the higher the output, the lower the irradiation efficiency of the ultraviolet rays with respect to the irradiation object 4.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to irradiate ultraviolet rays which can improve the irradiation efficiency of ultraviolet rays to an object to be irradiated when the output of a low pressure mercury lamp is increased. To provide a device.

[0006]

In order to achieve the above object, the invention of claim 1 has a low-pressure mercury lamp for generating high-power ultraviolet light, which has an arc tube having a flat cross section, and this low-pressure mercury lamp. And a reflecting plate having a reflecting surface facing the flat surface of the arc tube.

Further, the invention of claim 2 has a low-pressure mercury lamp for generating high-power ultraviolet light, which has an arc tube formed to have a flat cross section, and one arc plane of one of the arc tubes of the low-pressure mercury lamp. The arc tube having first reflecting surfaces provided so as to face each other at an angle of 45 degrees, and provided so as to be substantially orthogonal to the first reflecting surfaces and reflecting from the first reflecting surfaces. A reflecting plate having a second reflecting surface for reflecting the light emitted from one of the planes of reflection in substantially the same direction as the direction of the light emitted from the other plane of the same arc tube. The low-pressure mercury lamp is not provided in the passage of the light reflected from the reflecting surface.

Further, the invention of claim 3 has a low-pressure mercury lamp for generating high-power ultraviolet light, which has an arc tube having a flat cross section, and one of the arc tubes of the low-pressure mercury lamp. It has first reflecting surfaces facing each other at an angle of 45 degrees and reflecting light emitted from one of the planes substantially in parallel with the plane, and is approximately 45 degrees with respect to the other plane of the arc tube. And a reflecting plate having a second reflecting surface that reflects light emitted from the other polarizing surface in the substantially same direction as the light reflected from the first reflecting surface. I am trying.

[0009]

In the invention of claim 1 configured as described above, since the cross section of the arc tube is formed in a flat shape, the distance between the flat surfaces of the cross section becomes short. For this reason, the rate of self-absorption of ultraviolet rays radiating in a direction orthogonal to the plane of polarization by the mercury-based vapor is extremely small. That is, the ultraviolet rays are efficiently emitted. Moreover, even if the direction of the reflecting surface is set so that the ultraviolet rays emitted from one of the planes return to the arc tube again, the absorption of the ultraviolet rays in the arc tube when passing through the arc tube again is extremely small. The intensity of the ultraviolet rays used for irradiation is improved.

Moreover, since ultraviolet rays of the same intensity in almost the same direction are radiated from the plane surface, the direction of the reflecting surface is set so that the reflected ultraviolet ray does not pass through the arc tube again. It can be effectively used without attenuating the generated ultraviolet rays. Therefore, it is possible to improve the irradiation efficiency of the ultraviolet rays to the irradiation target when the output of the low-pressure mercury lamp is increased.

According to the invention of claim 2, the ultraviolet rays emitted from one of the planes of the arc tube radiate from the other plane of the arc tube through the first reflecting surface and the second reflecting surface. It reflects in almost the same direction as the light. That is, the ultraviolet rays emitted from the other flat surface can directly irradiate the irradiation target, and the ultraviolet rays emitted from the one flat surface reach the irradiation object without passing through the arc tube. For this reason,
The ultraviolet rays are not absorbed by passing through the arc tube again. Therefore, in combination with the flatness of the arc tube, it is possible to improve the irradiation efficiency of the ultraviolet rays to the irradiation target when the output of the low-pressure mercury lamp is increased.

According to the third aspect of the present invention, both the light emitted from one of the planes of the arc tube and the light emitted from the other plane of the arc tube are reflected in substantially the same direction parallel to the plane.
Therefore, the ultraviolet rays are not absorbed by passing through the arc tube again. Therefore, in combination with the flatness of the arc tube, it is possible to improve the irradiation efficiency of the ultraviolet rays to the irradiation target when the output of the low-pressure mercury lamp is increased.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

First, a first embodiment will be described with reference to FIGS.

1 to 3, reference numeral 11 is a low-pressure mercury lamp for generating high-power ultraviolet light, which has an arc tube 12 having a flat cross section. The low-pressure mercury lamp 11 has been developed in response to the recent demand for higher output and higher density, and in the conventional cylindrical arc tube, the self-absorption of the mercury line becomes remarkable as the input is increased, and it becomes excessive. It overcomes the fact that the UV output decreases when the input is increased. That is, since the distance between the one flat surface A and the other flat surface B (distance in the minor axis direction) is short, self-absorption of the mercury line in the minor axis direction is extremely small.

Therefore, as shown in FIG. 10, the output of ultraviolet rays from the planes A and B becomes high in output and high in density,
The output of ultraviolet rays from the end face in the long axis direction becomes small.
With such a structure, in the case of ultraviolet rays having a wavelength of 254 nm, for example, in the conventional cylindrical arc tube, even if the current density (the discharge current divided by the cross-sectional area in the arc tube) is increased, the output of ultraviolet rays is rather increased. 1.6 to 3A due to decrease
Although it was possible to increase the current density up to about 8 / cm ^2, the current density can be increased up to about 8A / cm ² , and about 6A / cm ² is twice as high as the conventional one. UV output is now available.

The arc tube 12 is made of synthetic quartz glass having a high ultraviolet transmittance, and has a rectangular cross section with a length of 30 mm in the major axis direction and a length of 15 mm in the minor axis direction. It has been done. Also, this arc tube 1
2, the electrode storage portions 12a at both ends thereof are formed into a cylindrical shape having a diameter of 24 mm. The axial length of the electrode accommodating portion 12a is about 100 to 300 mm.

An anode 13 and a cathode 14 are housed in each electrode housing portion 12a, and the anode 13 and the cathode 1 are housed therein.
4 is fixed by a stem 15 that seals the electrode housing portion 12a. The anode 13 is formed by a circular two-layer coil. For example, a tungsten wire having a wire diameter of 1.2 mm is formed into a first-layer coil tightly wound with an outer diameter of 20 mm and a winding number of 8 turns. The second layer coil is rewound and formed.

The cathode 14 is made of a tungsten coil filament and is located on the back side of the anode 13. The reason why the cathode 14 is located at the back of the anode 13 is to protect the cathode 14 from fast electrons that enter the anode 13. Lead wire 1 is provided for each anode 13 and cathode 14.
6 is connected.

In the arc tube 12, a predetermined amount of mercury or amalgam and an argon gas for starting (13 to 267).
Pa) is enclosed, and an electrode part cooling means (not shown) is provided in each electrode housing part 12a. The low-pressure mercury lamp 11 configured as described above, as shown in FIG.
It is provided in the irradiation chamber 21.

The irradiation chamber 21 is formed of a material such as stainless steel having excellent heat resistance and oxidation resistance in a box shape, and is sealed with nitrogen gas inside, and the lower surface thereof is irradiated with ultraviolet rays. An irradiation window 22 for irradiating W is formed. The irradiation window 22 is hollowed out in a rectangular shape in a bottom view, and the irradiation window 22 is provided with a synthetic quartz glass plate 23 having a high ultraviolet transmittance to close the irradiation window 22.
Then, above the irradiation window 22, the other plane B is oriented parallel to the glass plate 23, and the other plane B is used to illuminate the irradiation window 22.
A low pressure mercury lamp 11 is provided so as to cover almost half of the low pressure mercury lamp 11.
4 are provided.

The reflecting plate 24 is a rectangular plate bent at a right angle along the center line thereof, and the inner surface bent at a right angle is the first reflecting surface 24a and the second reflecting surface 24.
It is b. This reflecting plate 24 has a first reflecting surface 24.
a covers the entire one flat surface A of the low-pressure mercury lamp 11 and is provided so as to face the flat surface A at an angle of 45 degrees, and the second reflecting surface 24b covers the low-pressure mercury lamp 11. It is provided so as to cover the portion of the irradiation window 22 other than that, and to face the glass plate 23 at an angle of 45 degrees. Further, as the irradiation target W, for example, an object to be cleaned such as a liquid crystal glass substrate, an aluminum substrate, a silicon substrate, or a resin substrate is provided.

In the ultraviolet irradiating device constructed as described above, a half-wave current component is caused to flow between the anode 13 on the one end side and the cathode 14 on the other end side to discharge between them, and then the anode on the other end side. A reverse half-wave current component is caused to flow between the cathode 13 and the cathode 14 on one end side to discharge during this period, and the discharge is alternately repeated in this way to continuously light up.

Due to such discharge, the vapor mainly containing mercury is excited at a low pressure, and as a result, the resonance line of mercury is 254 nm.
And emits light in various short wavelength ultraviolet regions of 185 nm. Since the arc tube 12 is formed flat,
The rate of self-absorption of ultraviolet rays in the direction orthogonal to the planes A and B is extremely small, and the intensity of ultraviolet rays emitted from the planes A and B is improved.

The ultraviolet rays emitted from the other plane B of the low-pressure mercury lamp 11 reach the object W to be irradiated through the irradiation window 22 as they are. The ultraviolet rays emitted from one of the planes A are the first reflection surface 24a and the second reflection surface 24b.
Is reflected in the same direction as the ultraviolet rays emitted from the other plane B, and reaches the irradiation target W through the irradiation window 22. Since the irradiation chamber 21 is filled with nitrogen gas, the ultraviolet rays in the irradiation chamber 21 are not absorbed by oxygen or ozone as when passing through the air, for example.

According to the ultraviolet irradiating device constructed as described above, since the arc tube 12 is formed in a flat shape, even if the low-pressure mercury lamp 11 has a high output, the ultraviolet ray self-absorption in the arc tube 12 is achieved. It can be kept extremely small. Moreover, the object W to be irradiated can be directly irradiated with the ultraviolet light emitted from the other plane B, and the object W can also be irradiated with the ultraviolet light emitted from the one plane A without passing through the arc tube 12. It is possible to emit UV light from the arc tube 1 again.
Attenuation can be prevented by passing through the inside of 2. Therefore, it is possible to improve the irradiation efficiency of the ultraviolet rays to the irradiation target when the low-pressure mercury lamp has a high output.

Although the irradiation chamber 21 is filled with nitrogen gas in the first embodiment, it is needless to say that other inert gas may be used instead of nitrogen gas. .. In addition, the low-pressure mercury lamp 11 and the reflector 24
Although the irradiation chamber 21 is provided so as to cover the above, it goes without saying that the irradiation chamber 21 may not be provided.

Next, a second embodiment of the present invention will be described with reference to FIG. However, elements common to those of the first embodiment shown in FIGS. 1 to 3 are designated by the same reference numerals, and the description thereof will be omitted. The difference between the second embodiment and the first embodiment is that the directions of the planes A and B of the arc tube 12 of the low-pressure mercury lamp 11 are different.

That is, the reflecting plate 24 is the first reflecting surface 2
4a and the second reflecting surface 24b are provided so that the boundary line between them coincides with the center line of the irradiation window 22, and the first reflecting surface 24
The a and the second reflecting surface 24b are provided so as to cover the entire upper side of the irradiation window 22 and face the glass 23 at an angle of 45 degrees.

In the low-pressure mercury lamp 11, the center position of one of the planes A and B of the arc tube 12 coincides with the boundary line between the first reflecting surface 24a and the second reflecting surface 24b. Further, the planes A and B are provided so as to be orthogonal to the glass plate 23. That is, one flat surface A faces the first reflecting surface 24a at an angle of 45 degrees, and the other flat surface B is located.
Faces the second reflecting surface 24b at an angle of 45 degrees.

In the ultraviolet irradiating device configured as described above, both the ultraviolet rays radiated from one of the planes A and B of the arc tube 12 are parallel to the planes A and B. The object W to be irradiated is reflected and irradiated.
Therefore, the ultraviolet rays reflected by the reflection plate 24 do not pass through the arc tube.

According to the ultraviolet irradiating device constructed as described above, neither the ultraviolet rays radiated from the one flat surface A nor the ultraviolet rays radiated from the other flat surface B pass through the arc tube 12 to be irradiated. Since W can be irradiated, the reflected ultraviolet rays can be prevented from being attenuated when passing through the inside of the arc tube 12. Therefore, in combination with the flattening of the arc tube 12, it is possible to improve the irradiation efficiency of the ultraviolet light to the irradiation target W when the low-pressure mercury lamp 11 has a high output.

Although the arc tube 12 is provided at the boundary position between the first reflecting surface 24a and the second reflecting surface 24b in the second embodiment, as shown in FIG. You may provide in the position shifted to the 1st reflective surface 24a side,
Although not shown, it goes without saying that they may be provided at positions shifted to the side of the second reflecting surface 24a. Further, as shown in FIGS. 6 and 7, the arc tube 12 is bent in a U shape.
May be arranged vertically. Further, as the arc tube 12, a more bent one such as an S shape or a W shape may be used, or a plurality of linear shapes may be used.

Next, a third embodiment of the present invention will be described with reference to FIG. However, elements common to the constituent elements shown in FIGS. 1 to 7 are designated by the same reference numerals, and description thereof will be omitted. Third
The embodiment is different from the first and second embodiments in that the irradiation chamber is not provided and the shape of the reflector is different.

That is, as shown in FIG. 8, the reflecting plate 31 is formed by two ellipses having different cross sections, and the first reflecting surface is formed by the end of the first ellipse C1 in the long axis direction. 31a is formed, and the second ellipse C2
Is formed on the reflective surface 31b. The positional relationship between the first ellipse C1 and the second ellipse C2 will be described using mathematical expressions.
First ellipse C1 ^{is, (x 2/100 2)} + (y 2/64 2) = 1 corresponds to ... (1), the second ellipse, (x ^{2/100 2)} + (y ² / 88 ² ) = 1 ... (2) (however, the directions of the coordinate axes are shown in FIG. 9).

Therefore, the distance O1F1 from the center O1 of the first ellipse C1 to one focus F1 is O1F1 = √ (100 ² −64 ² ) ... (3) = about 76.8. Further, the distance O2F2 from the center O2 of the second ellipse C2 to the one focus F2 is O2F2 = √ (100 ² −88 ² ) ... (4) = about 47.5. Therefore, the first ellipse C1 and the second ellipse C
When the two long axes are overlapped and the other focus F′1 of the first ellipse C1 and the other focus F′2 of the second ellipse C2 are overlapped, the first ellipse C1 and the second ellipse C2 are formed. Distance between centers O
1O2 becomes O1O2 = 76.8−47.5 = 29.3. That is, the first ellipse C1 and the second ellipse C2 shown in FIG. 8 are similar to those represented by the above mathematical formulas and numerical values.

The focal points F1 and F2 on one side are
A low pressure mercury lamp 11 is provided. As shown in FIG. 7, the low-pressure mercury lamp 11 is an arc tube 1 bent in a U shape.
2, the center of each arc tube 12 is made to coincide with each one of the focal points F1 and F2, and the one plane A and the other plane B are opposed to each other in parallel with the major axes of the ellipses C1 and C2. I am letting you.

In the ultraviolet irradiating device constructed as described above, the ultraviolet rays radiated from each of the planes A and B of the arc tube 12 located at one focal point F1 are reflected by the first reflecting surface 31a and the other side. Focus on F'1. Further, the ultraviolet rays emitted from each of the planes A and B of the arc tube 12 located at the one focus F2 are reflected by the second reflecting surface 31b and are collected at the other focus F′2. Then, the other focal points F′1 and F ′
Since 2 is at the same position, the intensity of the ultraviolet rays at the focal points F′1 and F′2 becomes extremely high.

In the ultraviolet irradiating device constructed as described above, both the ultraviolet rays emitted from the one flat surface A and the ultraviolet rays emitted from the other flat surface B are collected at almost one point without passing through the arc tube 12. Therefore, it is possible to collect light extremely efficiently. Moreover, since the low-pressure ultraviolet lamp 11 can emit high-power ultraviolet rays, it is possible to obtain the intensity of the collected ultraviolet rays which has never been obtained. Therefore, in the case of irradiating an object to be irradiated sent by a conveyor or the like with ultraviolet rays, the conveying speed of the conveyor can be made extremely high, and the effect of reducing the processing time is extremely large. Moreover, it is possible to obtain an unprecedented excellent modifying effect for modifying the surface of the object to be irradiated.

In the third embodiment described above, the arc tube 12 bent in a U shape is provided, but the arc tube 12 is further bent into a plurality of shapes such as an S shape or a W shape. Alternatively, a plurality of linear shapes may be used. However, it is necessary to provide a plurality of elliptical reflectors corresponding to the number of arc tubes 12. Further, it goes without saying that the arc tube 12 and the reflecting surface may be respectively provided. Further, although no irradiation chamber surrounding the reflection plate 31 is provided, the reflection plate 31 is surrounded by an irradiation chamber filled with an inert gas as shown in FIG. 1 so that ultraviolet rays are emitted from the irradiation window 22. Good.

[0041]

According to the first aspect of the present invention, since the arc tube has a flat cross section, ultraviolet rays radiating in a direction orthogonal to the plane are highly absorbed by the mercury-based vapor. Can be made smaller. That is, the radiation efficiency of ultraviolet rays from the low-pressure mercury lamp for generating high-power ultraviolet rays can be improved, and high-power ultraviolet rays can be emitted. Moreover, even if the direction of the reflecting surface is set so that the ultraviolet rays radiated from one of the planes are returned to the arc tube again, the absorption of the ultraviolet rays in the arc tube can be suppressed to be extremely small. It is possible to improve the intensity of ultraviolet rays for irradiating.

Further, since the ultraviolet rays of the same intensity in almost the same direction are emitted from the planes, the rays emitted from the planes are reflected so as not to pass through the arc tube again. Can be effectively used without attenuating. Therefore, it is possible to improve the irradiation efficiency of the ultraviolet rays to the irradiation target when the output of the low-pressure mercury lamp is increased.

According to the second aspect of the present invention, it is possible to irradiate the object to be irradiated with the ultraviolet rays radiated from the other flat surface as it is, and to pass the ultraviolet rays radiated from the one flat surface through the arc tube. Since it is possible to irradiate the irradiation target without irradiation, it is possible to prevent the ultraviolet rays from being attenuated when passing through the arc tube again. Therefore, by flattening the arc tube, the radiation efficiency of ultraviolet rays from the low-pressure mercury lamp is improved, and at the same time, it is possible to improve the irradiation efficiency of ultraviolet rays to the irradiation target when the low-pressure mercury lamp has a high output. it can.

According to the third aspect of the present invention, both the ultraviolet rays emitted from one of the planes of the arc tube and the ultraviolet rays emitted from the other plane of the arc tube can be applied to the irradiation object without passing through the inside of the arc tube. Therefore, it is possible to prevent the ultraviolet rays from being attenuated when passing through the arc tube again. Therefore, by flattening the arc tube, the radiation efficiency of ultraviolet rays from the low-pressure mercury lamp is improved, and at the same time, it is possible to improve the irradiation efficiency of ultraviolet rays to the irradiation target when the low-pressure mercury lamp has a high output. it can.

[Brief description of drawings]

FIG. 1 is a sectional view of an ultraviolet irradiation device shown as a first embodiment of the present invention.

FIG. 2 is a plan view showing a low-pressure mercury lamp of the ultraviolet irradiation device.

FIG. 3 is a side view of essential parts showing a low-pressure mercury lamp of the ultraviolet irradiation device.

FIG. 4 is a sectional view of an ultraviolet irradiation device shown as a second embodiment of the present invention.

FIG. 5 is a cross-sectional view showing another example of the ultraviolet irradiation device.

FIG. 6 is a sectional view showing another example of the ultraviolet irradiation device.

FIG. 7 is a sectional view of the low-pressure mercury lamp shown in the example shown in FIG. 6 of the same ultraviolet irradiation device.

FIG. 8 is a sectional view of an ultraviolet irradiation device shown as a third embodiment of the present invention.

FIG. 9 is an explanatory diagram showing light distribution of the arc tubes shown in the first to third embodiments of the present invention.

FIG. 10 is a sectional view of an ultraviolet irradiation device shown as a conventional example.

FIG. 11 is a plan view showing an arc tube of the ultraviolet irradiation device.

FIG. 12 is an explanatory view showing a light distribution of an arc tube of the ultraviolet irradiation device.

[Explanation of symbols]

11 High-Pressure Ultraviolet Light-Emitting Low-Pressure Mercury Lamp (Low-Pressure Mercury Lamp) 12 Arc Tubes 24, 31 Reflectors 24a, 31a First Reflective Surfaces 24b, 31b Second Reflective Surface A One Deflection Plane B The Other Deflection Plane

Claims (3)

[Claims] 1. A low-pressure mercury lamp for generating high-power ultraviolet light, comprising a light-emitting tube having a flat cross section, and a reflector having a reflecting surface facing a flat surface of the light-emitting tube of the low-pressure mercury lamp. An ultraviolet irradiation device characterized by the above. 2. A low-pressure mercury lamp for generating high-power ultraviolet light, which has an arc tube having a flat cross section, and is opposed to one of the flat surfaces of the arc tube of the low-pressure mercury lamp at an angle of approximately 45 degrees. Radiating from one of the planes of the arc tube which has the first reflecting surface provided in such a manner and is provided so as to be substantially orthogonal to the first reflecting surface and reflected from the first reflecting surface. A reflecting plate having a second reflecting surface for reflecting the emitted light in a direction substantially the same as the direction of the light emitted from the other deflecting surface of the same arc tube, and for reflecting the light reflected from the second reflecting surface. An ultraviolet irradiation device, wherein the low-pressure mercury lamp is not provided in a passage. 3. A low-pressure mercury lamp for generating high-power ultraviolet light, which has an arc tube having a flat cross-section, and is opposed to one of the flat surfaces of the arc tube of the low-pressure mercury lamp at an angle of about 45 degrees. , Having a first reflecting surface that reflects the light emitted from one of the planes of polarization substantially parallel to the plane of polarization,
A second member that opposes the other plane of the arc tube at an angle of approximately 45 degrees and reflects light emitted from the other plane in the same direction as the light reflected from the first reflecting surface. And a reflection plate having a reflection surface of 1.