JP2010199045A - Ultraviolet irradiation device - Google Patents

Abstract

An ultraviolet ray that has been transmitted through a filter that transmits ultraviolet rays has an optimum wavelength range and illuminance value.
A filter in which an electrodeless ultraviolet lamp 12 in which a discharge medium is enclosed is housed and an irradiation area of ultraviolet rays irradiated from a lamp house 11 capable of irradiating ultraviolet rays to the outside is disposed below the ultraviolet irradiation surface. The irradiated object is irradiated through 23. The irradiation surface of the lamp house 11 with respect to the length of the electrodeless lamp 12 and the filter 23 installed below the irradiation surface of the lamp house 11 so that the ultraviolet light after passing through the filter 23 has an optimum wavelength range and illuminance value. The distance was set according to the incident angle.
[Selection] Figure 1

Description

  The present invention relates to an ultraviolet irradiation device using an electrodeless lamp that emits ultraviolet rays by being excited by microwaves.

  Microwave-fed electrodeless lamp-mounted ultraviolet irradiation devices have been used for various industrial purposes. Mainly used for printing-related ink drying, semiconductor-related fine exposure, and liquid crystal-related adhesive curing.

  In a conventional ultraviolet irradiation apparatus equipped with such a microwave power supply type electrodeless lamp, a multilayer filter is provided between the electrodeless lamp and the irradiated object in order to irradiate only the wavelength range necessary for the ultraviolet reaction of the irradiated object. It is installed in between to limit the irradiation wavelength range to the irradiated object. (For example, Patent Document 1)

Japanese Unexamined Patent Publication No. 9-113881 (page 5, FIG. 1)

  In the technique disclosed in Patent Document 1, the cut wavelength range of the filter is shifted depending on the angle of incidence of ultraviolet rays on the multilayer filter. For this reason, there existed a problem that it was not able to irradiate the wavelength range optimal to the to-be-irradiated body with the influence power distribution characteristic efficiently.

  An object of the present invention is to provide an ultraviolet irradiation apparatus in which ultraviolet rays after passing through a filter have an optimum wavelength range and illuminance value.

  In order to solve the above-described problems, an ultraviolet irradiation device of the present invention includes an electrodeless lamp that emits ultraviolet light in which a discharge medium is sealed, and a lamp that houses the electrodeless lamp and that can irradiate ultraviolet rays to the outside. An ultraviolet cut filter installed under the ultraviolet irradiation surface to limit the irradiation area of the ultraviolet light emitted from the lamp house, and the wavelength region and the illuminance value in which the ultraviolet light after passing through the filter is optimal The distance between the lamp house irradiation surface and the filter installed below the lamp house irradiation surface with respect to the lamp length is set by an incident angle.

  According to this invention, it becomes possible to irradiate efficiently the wavelength range and illuminance required for the irradiated object.

It is a system configuration diagram for explaining one embodiment about the ultraviolet irradiation device of this invention. It is sectional drawing of the I-I 'line | wire of FIG. It is a block diagram for demonstrating an example of the electrodeless lamp used for FIG. In order to explain the operation of the present invention, it is an explanatory view schematically showing a main part from the configuration of FIG. It is explanatory drawing for demonstrating an example of the transmittance | permeability with respect to the incident angle of the filter used by this invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  1 to 3 are diagrams for explaining an embodiment of the ultraviolet irradiation apparatus of the present invention, FIG. 1 is a system configuration diagram, FIG. 2 is a cross-sectional view taken along line II ′ of FIG. 1, and FIG. It is a block diagram for demonstrating an example of the electrodeless lamp used for.

  First, in FIG. 1 and FIG. 2, 11 is a lamp house made of, for example, stainless steel having a function of shielding microwaves, and a so-called electrodeless lamp 12 having no electrode at the center lower part of the lamp house 11 is provided. It is attached to a part of the side surface of the lamp house 11. Reference numeral 13 denotes a magnetron that generates a microwave of 2.45 GHz, for example, and power is supplied to the magnetron 13 from a power supply 14. Reference numeral 15 denotes a waveguide that transmits the microwave generated by the magnetron 13 from the antenna 16 and transmits it to the electrodeless lamp 12.

  Here, a configuration example of the electrodeless lamp 12 will be described with reference to FIG. Reference numeral 121 denotes a cylindrical bulb having a length of about 240 mm made of quartz glass that transmits ultraviolet light. The valve 121 has a taper formed so that the central portion 122 is thinner than both end portions 123 and 124. The outer diameter of both end portions 123 and 124 is, for example, about 17 mm, and the outer diameter of the central portion 122 is 10 mm. Degree. An inert gas and a discharge medium such as mercury or iron are enclosed in the light emitting space 125 of the bulb 121. Support portions 126 and 127 for supporting the valve 121 are formed integrally with the valve 121 at both ends of the valve 121. The electrodeless lamp 12 can emit light from the discharge medium by irradiating microwaves.

  1 and 2 again, an air inlet 17 is provided on the upper surface of the lamp house 11, and air that is a cooling medium blown from the blower 18 is taken into the lamp house 11. A duct (not shown) is provided between the blower 18 and the intake port 17 so as to take in air sent from the blower 18.

  On the back side of the electrodeless lamp 12, a reflecting plate 19 for condensing or diffusing the irradiated ultraviolet light is installed. Further, an RF screen 20 constituting an irradiation window is provided on a part of the lamp house 11 on the front surface of the reflection plate 19. The RF screen 20 is made of metal and has an opening, blocks microwaves, and allows ultraviolet light and air to pass through. For example, the RF screen 20 is formed by knitting metal wires into a mesh shape or by punching a metal plate to have an opening.

  The opposite surface of the RF screen 20 facing the electrodeless lamp 12 is an ultraviolet irradiation surface 21.

  An exhaust duct 22 is disposed in close contact with the lower portion of the lamp house 11. The duct 22 has a box-like shape, and openings 221 and 222 having the same shape and the same size as the RF screen 20 are respectively formed on the upper surface plate and the lower surface plate where the RF screen 20 is located. Further, the duct 22 has an exhaust port 224 formed through a vent hole 223. For example, a multilayer filter 23 is attached to the opening 222 so as to block air flow and allow ultraviolet light to pass therethrough.

  The magnetron 13 and the electrodeless lamp 12 blow air from the blower 18 for blowing into the air inlet 17 and the lamp house 11 and exhaust the air through the air outlet 224 of the duct 22 for cooling. The series of air flows is a cooling mechanism. Is configured.

  Here, when the magnetron 13 is being driven, air is blown from the blower 18 and taken into the lamp house 11 through the air inlet 17. The taken-in air is exhausted from the exhaust port 224 of the duct 22 through the magnetron 13, the electrodeless lamp 12, the RF screen 20, and the duct 22 as indicated by the wavy arrow in FIG. 1.

  At this time, the electrodeless lamp 12 excited by the microwave of the magnetron 13 emits ultraviolet light and can irradiate an irradiation object (not shown) through the RF screen 20 and the filter 23.

  FIG. 4 is an explanatory view schematically showing the main part from the configuration of FIG. 1 in order to explain the operation of the present invention. FIG. 5 is an explanatory diagram for explaining an example of transmittance with respect to an incident angle of ultraviolet rays passing through a filter.

  In FIG. 4, the lamp length is a (mm), the distance from the electrodeless lamp 12 to the irradiation surface 21 is b (mm), and the distance from the irradiation surface 21 to the filter 23 surface is c (mm). When the angle (incident angle) when the ultraviolet rays radiated from the one end 128 of the light emitting unit are incident on the one end 231 of the filter 23 located on the opposite side of the one end 128 of the electrodeless lamp 12 is θ, it is installed. When the incident angle is limited by the cut wavelength band shift characteristic of the filter 23, the distance b + c (mm) from the electrodeless lamp 12 to the filter 23 with respect to the lamp length a (mm) is tan θ = a / b + c (where, (0 ° ≦ θ ≦ 90 °). For example, when the incident angle is 45 ° and the lamp length is 100 mm, b + c is 100 mm from the above equation.

  Further, b + c (mm) can be freely varied in the range of b and c> 0. However, the microwave power supply type electrodeless lamp device has a structure in which the cooling air and ultraviolet rays of the magnetron 13 and the electrodeless lamp 12 are irradiated from the irradiation surface 21. For this reason, a certain space is required for the irradiation surface 21 and the filter 23. Therefore, for the distance c (mm) from the irradiation surface to the filter 23, it is necessary to ensure a value based on the thermal characteristics and pressure characteristics of the filter 23.

  By the way, considering the efficiency of the reaction of the irradiated object with respect to ultraviolet rays, a transmittance of 80% or more is preferable. For this reason, in the case of FIG. 5 showing an example of the filtering characteristics of the filter 23, the incident angle (tan θ) when it is set to 330 nm or more, for example, is 40 ° or less at most. In this case, the distance b + c when a is 100 mm is about 119 mm.

  As described above, since the transmittance and wavelength characteristics of the filter 23 to be used are known in advance, the distance from the electrodeless lamp 12 to the filter 23 should be set to a condition for obtaining an optimum wavelength region and illuminance value. Can do.

  In this embodiment, it is possible to irradiate ultraviolet rays under optimum conditions for the irradiated object from the wavelength and incident angle of the ultraviolet rays desired from the filter characteristics.

DESCRIPTION OF SYMBOLS 11 Lamp house 12 Electrodeless lamp 13 Magnetron 14 Power supply 15 Waveguide 16 Antenna 19 Reflector 20 RF screen 21 Irradiation surface 23 Filter

Claims (3)

An electrodeless lamp that emits ultraviolet light in which a discharge medium is enclosed;
A lamp house that houses the electrodeless lamp and that can be irradiated with ultraviolet rays to the outside;
In order to limit the irradiation area of the ultraviolet light irradiated from the lamp house, an ultraviolet cut filter installed under the ultraviolet irradiation surface,
That the ultraviolet ray after passing through the filter has an optimal wavelength range and illuminance value, is set by the distance between the lamp house irradiation surface and the filter installed under the lamp house irradiation surface with respect to the lamp length, and the incident angle. A featured ultraviolet irradiation device.   The length of the electrodeless lamp is a, the distance from the electrodeless lamp to the irradiation surface is b, the distance from the irradiation surface to the filter surface is c, and ultraviolet rays emitted from one end of the electrodeless lamp are When the incident angle is limited by the cut wavelength band shift characteristic of the installed filter, where θ is the incident angle when entering one end of the filter opposite to one end of the electrode lamp, the lamp for the lamp length a The ultraviolet irradiation apparatus according to claim 1, wherein the distance b + c from the filter to the filter is set under the condition of tan θ = a / b + c (where 0 ° ≦ θ ≦ 90 °).   The ultraviolet irradiation apparatus according to claim 1, wherein the incident angle is limited to a state in which the transmittance of the filter is maintained at 80% or more.

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