JPS61220843A - Ultraviolet rays irradiator - Google Patents

Abstract

PURPOSE:To reduce the temperature of the tube wall of high-pressure discharge lamps as well as equalize the distribution of the temperature by suppressing the occurrence of vortex flow on the surface of the lamps by providing flow ports to form air stream flowing along the surface of the high-pressure discharge lamp in a reflector. CONSTITUTION:As as high-pressure discharge lamp 1 is operated, a sucker is driven and gas with heat is sucked and discharged from an exhaust port 16. Cool air is flowed into an irradiation opening 3 and flows along the surface of a reflector 2 and the peripheral surface of the lamp 1 while cooling them. The cool air flows from a flow port 15 through an air port 24 into the reflector 2 and flows along the surface of the lamp 1 and also of a rear reflector 14. The occurrence of vortex flow on the downwind side of the lamp 1 can thus be suppressed by the air stream coming from the opening 3 and coming into the reflector 2 from the port 15 and the surface of the lamp 1 and the reflector 2 can be effectively cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ultraviolet irradiation device that irradiates ultraviolet rays using a high-pressure discharge lamp.

[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.

In this method, high-pressure discharge lamps that emit ultraviolet rays, such as high-pressure mercury lamps and metal halide lamps, also emit visible and infrared heat rays along with ultraviolet rays. The equipment itself, such as the reflector, the paint, ink, etc., and the substrate become hot, causing heat loss to the equipment and inhibiting the chemical reaction of ultraviolet curing. Therefore, a structure is generally adopted in which the gas around the high-pressure discharge lamp is exhausted and cool air is drawn into the device to remove heat within the device.

However, with such a structure, the windward side of the high-pressure discharge lamp surface is cooled by the cold air, but the vortex is generated on the leeward side, so the heat dissipation effect of the high-pressure discharge lamp surface is small. The temperature distribution on the surface of the high-pressure discharge lamp becomes uneven, and local heat loss occurs on the leeward side of the high-pressure discharge lamp.

Conventionally, as a means for preventing focal loss due to such eddy currents, a device described in, for example, Japanese Patent Publication No. 55-16281@ is known. This device prevents the generation of vortices by making the distance between the leeward side of the lamp surface and the cooling air suction part of the concave reflector less than 2/3 of the tube diameter of the lamp. However, because the lamp is placed close to the reflector, the temperature near the deepest part of the reflector increases, causing local IS due to thermal distortion.
In addition, if the lamp is arranged with a distance between the lamp and the cold air suction part of the reflector that is two-thirds or more of the tube diameter, a vortex will occur.

In addition, as a means to prevent the generation of other eddy currents,
There is an apparatus described in Japanese Patent No. 7-31298. In this device, eddy current elimination plates forming a ventilation path along the surface of the lamp are placed facing each other on the leeward side of the lamp, and the eddy current elimination plates prevent the generation of eddies. therefore,
In this case, it is necessary to use an eddy current elimination plate, and since the eddy current elimination plate is placed on the surface of the lamp, the temperature of the lamp surface increases due to secondary radiation from this eddy current elimination plate, which tends to cause burnout. , a fixed vortex is generated between the eddy current elimination plate and the reflecting mirror, the temperature near the deepest part of the reflecting mirror increases, and local abrasion occurs due to thermal strain.

[Problem that the invention seeks to solve]

As mentioned above, it is difficult to reliably suppress the generation of eddies, and the temperature of the reflector near the lamp increases, causing local damage due to thermal distortion. The heat dissipation effect of the lamp was very low, and there was a problem that the light output of the lamp decreased due to heat.

The present invention has been made in view of the above points, and is intended to suppress the eddy current generated on the surface of a high-pressure discharge lamp, reduce the tube wall temperature of the high-pressure discharge lamp, and improve the tube wall temperature distribution on the outer peripheral surface of the high-pressure discharge lamp. The object of the present invention is to provide an ultraviolet irradiation device that improves the uniformity of light output and improves the reduction in light output of a high-pressure discharge lamp.

[Means for solving problems]

The present invention comprises a rod-shaped high-pressure AM lamp 1, and a reflector 2 having a concave cross section with an illumination opening on the lower surface and accommodating the high-pressure discharge lamp 1. A lower reflector 14 is arranged, and a communication port 15 is formed separately from the lower reflector 14 and forms an airflow flowing along the surface of the high-pressure discharge lamp 1 between the lower reflector 14 and the lower reflector 14. and a lower reflector 13 disposed below.

[Effect]

According to the present invention, air is caused to flow along the surface of a high-pressure discharge lamp by means of a ventilation opening in a reflector.

〔Example〕

Next, one 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, a reflector 2 that is disposed opposite to the high-pressure discharge lamp 1 and has an enlarged opening on the front, and a housing that houses and holds the reflector 2 and has an open front and an irradiation opening 3. It is composed of 4.

The high-pressure discharge lamp 1 is comprised of, for example, a high-pressure mercury lamp, a metal halide lamp, or the like, and when the high-pressure discharge lamp 1 discharges, visible light, infrared light, and the like as well as ultraviolet rays are emitted.

The reflector 2 is made of borosilicate glass and has a base 11 formed into a quadratic curved surface. The refractive index layer and silica (S
A multilayer interference thin film 12 is formed by vapor deposition, in which 10ff to 60 layers of low refractive index layers made of magnesium fluoride (H(JFz), etc.) are alternately stacked. effectively reflects the ultraviolet rays having a wavelength of 200 to 400 nll emitted from the high pressure discharge lamp 1 to the irradiation aperture 3.
It allows infrared rays of 0 na+ or higher to pass through, and also allows some visible light rays to pass through.

The reflector 2 is composed of a front reflector 13 as a lower reflector disposed at the bottom and a rear reflector 14 as an upper reflector disposed in the upper part. , are arranged opposite to each other on both sides of the irradiation aperture 3, and
The rear reflector 14 is arranged so that its front end faces the outside of the rear end of the front reflector 13 and forms a communication opening 15 that communicates with the inside and outside of the reflector 2, and is arranged to face both of them. An exhaust port 16 is formed between the rear end portions of the rear reflector 12.

The housing 4 is formed into a rectangular parallelepiped shape, and the front end of the front reflector 13 and the rear end of the rear reflector 14 are attached to the holding parts 21 and 22 provided at the front end and the inner rear part of the housing 4, respectively. Retention is fixed.

Further, on the rear surface of this housing 4, an exhaust port 1 of the reflector 2 is provided.
6 are opened in communication with each other, and exhaust holes 23 are formed on both sides of the exhaust port 16 with a predetermined hole size and at predetermined intervals. Facing the communication hole 15 of the reflector 2,
A plurality of vent holes 24 communicating with the exhaust holes 23 are formed.

Further, at the rear of the housing 4, a frame body 27 is provided in an airtight state, and is provided with an intake port 26 that communicates with a suction device (not shown).

Next, the effect will be explained.

As the high-pressure discharge lamp 1 discharges, ultraviolet rays and infrared heat rays are emitted, and the ultraviolet rays emitted from the high-pressure discharge lamp 1 are irradiated directly from the irradiation opening 3 and reflected by the reflector 2, and are also reflected. The infrared rays directed towards the body 2 are transmitted through the reflector 2 and are partially absorbed inside the casing 4, and some are sucked and exhausted.

In addition, as the high-pressure discharge lamp 1 discharges, a suction device (not shown) is driven, and the exhaust port 16 is
The gas that has absorbed the heat generated by the high-pressure discharge lamp 1 in the space formed between the high-pressure discharge lamp 1 and the inside of the reflector 2 is sucked and exhausted from the exhaust hole 23 between the outside of the reflector 2 and the inside of the housing 4. Gas that has absorbed heat such as infrared rays that has passed through the reflector 2 in the space that constitutes the space is sucked and exhausted.

Along with the exhaust from the exhaust port 16, cold air (indicated by an arrow in FIG. 2, the same applies hereinafter) flows into the irradiation opening 3 and cools it along the circumferential surface of the high-pressure discharge lamp 1 and the surface of the reflector 2. At the same time, the air flows through the ventilation port 1 through the ventilation port 24.
5 into the inside of the reflector 2 and flows along the surface of the high-pressure discharge lamp 1 and the surface of the rear reflector 14. The high-pressure discharge lamp 1
The eddy current generated on the leeward side of the lamp is suppressed, and the surfaces of the high-pressure discharge lamp 1 and the reflector 2 are effectively cooled.

Further, due to the exhaust from the exhaust hole 23, cold air flows into the space formed by the reflector 2 and the housing 4 through the ventilation hole 24, and the reflector 2 and the housing 4 are cooled.

Further, as shown in FIG. 3, the reflector 2 is provided with ventilation holes 15 facing each other on both sides, and the outside of the reflector 2 is surrounded by a housing 4 having ventilation holes 24 opened on both sides. , one of the ventilation ports 24 may be configured to communicate with a suction device (not shown). In this case, the cold air (indicated by the arrow) flowing in from the other ventilation port 15 of the reflector 2 is connected to the high-pressure discharge. It flows along the surfaces of the lamp 1 and the reflector 2 and flows out from one of the ventilation ports 15 to one of the ventilation ports 24, and the cold air also flows from the irradiation opening 3 onto the surfaces of the high-pressure discharge lamp 1d3 and the reflector 2. It flows to one of the communication ports 15 along the line. The generation of vortices on the surface of the high-pressure discharge lamp 1 can be suppressed by the one-sided cooling air flowing from the other communication port 15 and the irradiation opening 3. Further, a part of the cold air flowing in through the other vent 24 flows along the rear side of the reflector 2 and flows out to the one vent 24.

In the above embodiment, the reflector 2 was formed by forming the multilayer interference thin film 12 on the borosilicate glass substrate 11.
A metal plate such as aluminum may also be used.

In addition, the reflector 2 includes a rear reflector 1 as shown in FIG.
4 may be formed from a metal plate 3o such as aluminum, and the front reflector 13 may be formed from a glass substrate 11 with a multilayer interference thin film 12 formed thereon.Furthermore, these may be formed from the opposite materials. .

Furthermore, as shown in FIG. 5, the reflector 2 has a rear reflector 14 formed of a metal plate 3o such as aluminum, one side of the front reflector 13 formed of a metal plate 3o, and the other formed of a glass substrate 1.
A multilayer interference thin film 12 may be formed on 1.

〔Effect of the invention〕

According to the present invention, since the reflector is provided with a ventilation port that forms an airflow flowing along the surface of the high-pressure discharge lamp, the airflow flowing from the ventilation port generates eddy currents that are likely to occur on the surface of the high-pressure discharge lamp. At the same time, it is possible to prevent a local temperature rise on the tube wall of the high-pressure discharge lamp, to make the temperature distribution of the tube wall of the high-pressure discharge lamp uniform, and to improve the decrease in the light output of the high-pressure discharge lamp. Furthermore, it is possible to reduce the temperature around the deepest part of the reflector near the high-pressure discharge lamp, and protect the reflector by preventing deformation and thermal deterioration.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the ultraviolet irradiation device of the present invention, FIG. 2 is a longitudinal cross-sectional view thereof, FIG. 3 is a longitudinal cross-sectional view showing another embodiment of the present invention, and FIGS. FIG. 5 is a sectional view showing other embodiments of the reflector. 1. High pressure discharge lamp, 2. Reflector, 3. Irradiation opening, 13. Lower reflector, 14. Upper reflector, 15. Ventilation opening.

Claims (1)

[Claims] (1) A rod-shaped high-pressure discharge lamp, and a reflector having an irradiation opening on the lower surface and a concave cross-section for accommodating the high-pressure discharge lamp; and a lower reflector, which is formed separately from the upper reflector and is disposed at the lower part thereof, and has an airflow opening between the upper reflector and the upper reflector to form an airflow that flows along the surface of the high-pressure discharge lamp. An ultraviolet irradiation device characterized by comprising a body.