JPS61158453A - Ultraviolet-ray irradiating device - Google Patents

Abstract

PURPOSE:To curb the temperature rise of the surface through irradiation with the ultraviolet rays only, with the infrared and visible rays eliminated by providing either the interior or the exterior of the outer tube of a double tubular body with a multi-layer interference film which admits the ultraviolet rays to go therethrough and reflects both the visible and infrared rays. CONSTITUTION:In the embodiment of the present invention, the infrared rays from a high- voltage discharge lamp 1 are absorbed with a fluid W within a double tubular body 2 while they pass therethrough, wherein the visible rays from the high-voltage discharge lamp are reflected from a multi-layer interference film formed on the outside peripheral surface of an outer tube 12 and successively go into the fluid W, within the double tubular body 2, where they are absorbed, further wherein part of the infrared rays passing through the fluid W without being absorbed are also reflected fro the multi-layer interference film 13, likewise with the visible rays, and then go into the fluid W wherein to be absorbed, whereby almost all infrared rays from the high-voltage discharge lamp are absorbed with the fluid within the double tubular body, with the remaining part thereof and the visible rays also absorbed with the fluid within said double tubular body through reflection from the multi-interference film with which the outer tube is provided, thereby it becomes practicable to curb from rising the temperature of the surface under irradiation with the ultraviolet rays almost totally devoid of the visible and infrared rays.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultraviolet irradiation device that reduces heating effect by removing visible light and infrared rays and emitting only ultraviolet rays.

[Conventional technology]

BACKGROUND ART In printing processes such as printed plywood, printed wiring boards, and newspaper printing, a method is known in which a substrate coated with ultraviolet-curable paint, ink, etc. is irradiated with ultraviolet rays to cure the paint, ink, etc. However, in such a method, e.g. a high-pressure mercury lamp that emits ultraviolet light,
High-pressure discharge lamps such as metal halide lamps emit visible light and infrared rays as well as ultraviolet rays, so irradiation with visible light and infrared rays applies high temperatures to paints, inks, etc. and the substrate, which inhibits the photochemical reaction of UV curing. Therefore, a means to eliminate the heating effect on the irradiated surface is generally adopted.

Conventionally, such means have been developed by arranging a double tube body having an inner tube and an outer tube around the outer periphery of a high-pressure discharge lamp, and circulating pure water between the inner tube and the outer tube to generate high pressure. There is a method in which infrared rays emitted from a discharge lamp are absorbed and removed by pure water, and ultraviolet rays that do not contain infrared rays are irradiated.

[Problem that the invention seeks to solve]

In the conventional ultraviolet irradiation device as described above, infrared rays are effectively removed by the absorption effect of pure water inside the double tube, but the wavelengths of the line spectrum of mercury emitted from the high-pressure discharge lamp are 435nn, 545nn+, and 578n1. The effect of absorbing and removing visible light such as UV rays is small, and therefore visible light is irradiated onto the irradiated surface along with ultraviolet rays, making it difficult to prevent the temperature of the irradiated surface from rising.

The present invention was made in view of the above-mentioned problems, and is an ultraviolet irradiation method that reduces the temperature rise of the irradiated surface by removing the infrared and visible regions from a high-pressure discharge lamp and irradiating only the ultraviolet region. The purpose is to provide a device.

[Means for solving problems]

The present invention provides a high-pressure discharge lamp 1 having an inner tube 11 and an outer tube 12 that transmit ultraviolet rays.
The outer tube 1 of this double tube body 2 is surrounded by an ultraviolet-transparent double tube body 2 in which a fluid W that transmits ultraviolet rays is circulated between.
A multilayer interference thin film 1i1 that transmits ultraviolet rays and reflects visible rays and infrared rays on at least one of the inner and outer surfaces of 2.
This is an ultraviolet irradiation device formed with No. 3.

[Effect]

The present invention absorbs infrared rays by the fluid inside the double tube surrounding the high pressure discharge lamp, and reflects part of the visible light and infrared rays by a multilayer interference thin film formed on the outer tube of the double tube. The ultraviolet rays are absorbed by the fluid inside the heavy tube and only the ultraviolet rays are irradiated onto the irradiated surface.

〔Example〕

Next, the configuration of an embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the ultraviolet irradiation device
A tubular high-pressure discharge lamp 1, an ultraviolet-transparent double tube body 2 surrounding this high-pressure discharge lamp, and this high-pressure discharge lamp 1.
and a pair of reflectors 3 that are disposed opposite to each other along the double tube body 2 and have an opening that expands toward the front, and a box-shaped frame that houses and holds the reflectors 3 and has an opening at the front to form an irradiation opening 4. body 5
It is composed of.

The high-pressure discharge lamp 1 is composed of, for example, a high-pressure mercury lamp, a metal halide lamp, etc., and when it discharges, it emits a line spectrum of mercury as shown in FIG. The mercury line spectrum in the area is emitted, and infrared rays are also emitted from the discharge and the high-temperature tube wall. The energy emitted by the discharge of this high-pressure discharge lamp 1 is approximately 50% in the ultraviolet region, approximately 35% in the visible region, and approximately 1% in the infrared region.
5%, and this radiation is directly emitted from the high-pressure discharge lamp 1, and furthermore, secondary infrared radiation emitted from various parts such as the tube wall is added to this radiation.

The double tube body 2 has an inner tube 11 and an outer tube 12 that surround the high-pressure discharge lamp 1 and are made of quartz glass or the like that transmits ultraviolet rays. water,
A fluid W that transmits ultraviolet rays, such as air, is circulated through a circulation device (not shown). Further, on the outer peripheral surface of the outer tube 12 of the double tube body 2, a high refractive index layer made of, for example, titanium oxide (TiOz), zirconium oxide (Zr0z), etc., and a layer of silica (5i02), magnesium fluoride (MgO2), etc.
A multilayer interference thin film 13 is formed by vapor deposition, in which 10 to 60 layers of low refractive index layers such as CIFg> are alternately laminated. The two-tube body 2 uses the fluid W to absorb and remove infrared rays emitted from the high-pressure discharge lamp 1. Furthermore, as shown in FIG.
m, 578 nm, etc. (wavelength 405 nm is reflected as necessary), and the reflected visible light is absorbed by the fluid W in the double tube body 2 and removed,
Ultraviolet wavelengths of 200 to 400 nm are transmitted.

The reflector 3 is formed of a metal plate such as aluminum and has a quadratic curved surface, and reflects the light emitted from the high-pressure discharge lamp 1 toward the irradiation opening 3.

The front and rear ends of the reflector 3 are fixed to the fixed ends 21 provided at the front and rear ends of the inner side of the frame 5,
The reflector 3 of the frame 5 is provided at the rear of the frame 5 and the reflector 3.
An exhaust hole 22 is formed through which the air in the space formed by the high-pressure discharge lamp 1 and the high-pressure discharge lamp 1 is sucked by a suction device.

Next, the operation of this embodiment will be explained.

As the high-pressure discharge lamp 1 discharges, spectra in the ultraviolet, visible and infrared regions are emitted, and while passing from the high-pressure discharge lamp 1 through the double tube body 2, infrared rays are emitted from the fluid inside the double tube body 2. The visible light is absorbed by W, and the visible light is absorbed by the outer tube 12.
It is reflected into the fluid W by the multilayer interference thin film 13 formed on the outer peripheral surface of the double tube body 2, and is absorbed by the fluid W inside the double tube body 2. Note that a part of the infrared rays that has passed through without being absorbed by the fluid W is reflected by the multilayer interference thin film 13 in the same way as visible light rays Fi1, and then absorbed by the fluid W.

In this way, the infrared rays emitted from the high-pressure discharge lamp 1 are absorbed and removed by the fluid W in the double tube body 2, and
The mercury line spectrum in the visible range is also reflected by the multilayer interference thin film 13 and absorbed and removed by the fluid W. Therefore, the radiant energy irradiated directly from the irradiation aperture 4 or reflected by the reflector 3 is mostly ultraviolet rays. Therefore, the mercury line spectrum in the infrared and visible regions is hardly irradiated.

In the above embodiment, the multilayer interference thin film 11A13 is formed by vapor deposition on the outer peripheral surface of the outer tube 12 of the double tube body 2, but the multilayer interference thin film 13 may be formed by vapor deposition on the inner surface of the outer tube 12. , and a multilayer interference thin film 1 deposited on this outer tube 12.
The vapor deposition formation range in step 3 is determined by the entire surface of the outer tube 12 or a part of the outer tube 12 depending on the width of the conveyor for conveying the object to be irradiated, the installation management temperature conditions, etc. It's okay.

Roughly speaking, by changing the film thickness, material, and number of layers of the multilayer interference thin film 13, the spectral transmittance of the mercury line spectrum transmitted through the multilayer interference thin film 13 can be arbitrarily varied.

〔Effect of the invention〕

According to the present invention, a high-pressure discharge lamp is surrounded by a double tube in which fluid is circulated, and a multilayer interference thin film is formed on at least one of the inner and outer surfaces of the outer tube of the double tube.
The infrared rays from the high-pressure discharge lamp are absorbed and removed by the fluid inside the double tube, and part of the visible light and infrared rays are reflected by the multilayer interference thin film formed on the outer tube and absorbed by the fluid inside the double tube. Therefore, it is possible to irradiate only ultraviolet rays that contain almost no visible light or infrared rays, which reduces the temperature of the irradiated surface, and allows photocuring of irradiated objects that are sensitive to heat. It can be carried out reliably without inhibiting the reaction, and by changing the spectral transmittance by changing the thickness, material, number of layers, etc. of the multilayer interference thin film, only the necessary mercury line spectrum can be irradiated onto the irradiated surface. It is something that can be done.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the ultraviolet irradiation device of the present invention, FIG. 2 is an enlarged view of the main parts, FIG. 3 is a spectral distribution diagram showing an example of discharge light emission from a high-pressure discharge lamp, and FIG. The figure is a spectral transmittance curve diagram of a multilayer interference thin film. 1...High pressure discharge lamp, 2...Double tube body, 11...Inner tube, 12...Outer tube, 13...Multilayer interference thin film, W...Fluid.

Claims (1)

[Claims] (1) A high-pressure discharge lamp, and an ultraviolet-transmitting double lamp that includes an inner tube and an outer tube that surround the high-pressure discharge lamp and that transmit ultraviolet rays, and a fluid that transmits ultraviolet rays is circulated between the inner tube and the outer tube. An ultraviolet irradiation device comprising a double tube body, and a multilayer interference thin film that transmits ultraviolet rays and reflects visible light and infrared rays is formed on at least one of the inner and outer surfaces of the outer tube of the double tube body. .