JP2011091007A - Electrodeless lamp and ultraviolet irradiation device - Google Patents

Abstract

An object of the present invention is to improve the luminous efficiency in the 350 to 380 nm region by raising the tube wall load at the portion corresponding to the valley of the standing wave formed by the microwave irradiated to the electrodeless lamp to raise the coldest part temperature. .
When an electrodeless lamp emits ultraviolet light having a wavelength of 350 to 380 nm based on microwave irradiation, the diameter of the central portion of the arc tube of the electrodeless lamp is 45 with respect to other arc tube diameters. % To 75%, and the thickness B within the range of 5 mm from the end sealing portions 151 and 152 is increased by 200% or more with respect to the arc tube thickness of 1 mm. The thickness C in the range of 5 mm to 10 mm from the sealing portions 151 and 152 was increased to 100% or more with respect to the arc tube thickness of 1 mm. By adopting a shape suitable for the standing wave generated in the arc tube, the tube wall load can be increased and the luminous efficiency can be improved.
[Selection] Figure 1

Description

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

  Conventionally, as a discharge lamp for generating ultraviolet rays, an electrodeless discharge lamp by a microwave power feeding method using a discharge by a microwave has been considered. Metal halide lamps that contain iron, which is an ultraviolet light emitting metal, can emit ultraviolet light with a wavelength of 350 to 380 nm, and can be used to synthesize chemical substances by surface hardening treatment or photochemical reaction on surfaces coated with paint, ink, resin, paint, etc. It is used for the manufacture of semiconductors and liquid crystal panels having processes such as treatment, and water treatment for sterilization using ultraviolet rays. In such an ultraviolet irradiation device, a magnetron is arranged in the same casing and radiated from the magnetron to an electrodeless lamp. (For example, Patent Document 1)

Special table 2003-510773 gazette

  Although the technique of the above-mentioned Patent Document 1 conventionally shows strong light emission by iron at 350 to 380 nm in an iron metal halide lamp, a discharge is formed based on a standing wave in a microwave-fed electrodeless lamp. There was a problem that the coldest part occurred in the wave valley, and the luminous efficiency of iron was lowered.

  An object of the present invention is to provide an electrodeless lamp in which the emission efficiency of a microwave-fed electrodeless lamp that emits light in a wavelength region of 350 to 380 nm is further increased, and an ultraviolet irradiation device using the lamp.

  In order to solve the above-described problems, an electrodeless lamp according to the present invention includes at least a rare gas and a discharge medium such as mercury or iron serving as a discharge medium in a light emission space of a quartz glass arc tube having a substantially cylindrical shape. In a microwave-fed electrodeless lamp in which discharge is generated by microwaves radiated from a magnetron, the central tube diameter of the arc tube ranges from 45% to 75% with respect to the tube diameter of the arc tube The wall thickness within a range of 5 mm from the end seal portion of the arc tube is more than twice the thickness of the arc tube, and 5-10 mm from the end seal portion of the arc tube. The wall thickness within the range is 1.01 times or more the wall thickness of the arc tube.

  The ultraviolet irradiation device according to the present invention comprises: an electrodeless lamp according to claim 1 that emits ultraviolet light in which a discharge medium is enclosed; a lamp house that houses the electrodeless lamp and is capable of irradiating ultraviolet light to the outside; In order to limit the irradiation area of the ultraviolet rays irradiated from the lamp house, the apparatus includes an ultraviolet cut filter installed below the ultraviolet irradiation surface.

  According to the present invention, by increasing the tube wall load in the portion corresponding to the valley of the standing wave formed by the microwave irradiated to the electrodeless lamp and raising the temperature of the coldest part, in the wavelength range of 350 to 380 nm Luminous efficiency can be improved.

It is a perspective view showing the whole composition for explaining one embodiment about the electrodeless lamp of this invention. It is sectional drawing of FIG. It is explanatory drawing for demonstrating the standing wave in the electrodeless lamp made to light based on a microwave. It is explanatory drawing for demonstrating the relationship between the diameter of the arc tube of the coldest part in the center part of an arc tube, and temperature. It is explanatory drawing for demonstrating the relationship between the thickness in the edge part sealing part of an arc_tube | light_emitting_tube, and temperature. It is explanatory drawing for demonstrating the spectral distribution of the electrodeless lamp of this invention, and the past. It is explanatory drawing for demonstrating the light emission ratio of this invention and the former in the wavelength range of 350-380 nm. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram for explaining an embodiment relating to an ultraviolet irradiation device of the present invention. It is sectional drawing of the I-I 'line | wire of FIG.

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

  FIG. 1 and FIG. 2 are perspective views showing an overall configuration, and FIG. 2 is a cross-sectional view of FIG. 1, for explaining an embodiment of the electrodeless lamp of the present invention.

  1 and 2, reference numeral 100 denotes an electrodeless lamp, and 11 of the electrodeless lamp 100 is a cylindrical arc tube having a length of about 240 mm and a tube diameter φ of 11 mm made of quartz glass that transmits ultraviolet light. is there. The arc tube 11 is formed such that the central portion 12 is thinner than both end portions 13 and 14 thereof. For example, the tube diameter φa (= φ) of both end portions 13 and 14 is 11 mm, the tube diameter φb of the central portion 12 is 6.6 mm which is 60% of the tube diameter φa, the wall thickness m is 1 mm, and the light emission length L is 138 mm. It constitutes an airtight container with a single tube of the degree.

  Further, in the discharge space 16 of the arc tube 11, 60 torr of argon gas and a discharge medium such as mercury or iron are enclosed. At both ends of the arc tube 11, support portions 171 and 172 that support the arc tube 11 are formed integrally with the arc tube 11. The electrodeless lamp 100 can emit a discharge medium by irradiating microwaves.

  Here, a standing wave in a microwave electrodeless lamp will be described with reference to FIG. As shown by broken lines in FIG. 3, standing wave valleys Va to Vc are generated at both ends and the center of the electrodeless lamp 100 in the longitudinal direction. In each portion of the standing wave valleys Va to Vc, the electromagnetic energy is lower than that of the peak portions Ma and Mb, so that the generated temperature is also low.

  FIG. 4 is for explaining the relationship between the diameter of the arc tube at the coldest part in the central portion 12 of the arc tube 11 and the temperature.

  As shown in FIG. 4, the tube diameter φb at the central portion 12 of the arc tube 11 is made smaller than the tube diameter φ of the arc tube 11, so that the temperature of the arc tube 11 rises. If the tube diameter φ is reduced, the temperature also rises. However, if the tube diameter φ is increased too much and the temperature is raised, damage such as cracking of the arc tube 11 is caused.

  FIG. 5 is for explaining the relationship between the wall thickness t1 and the temperature at the end sealing portions 151 and 152 of the arc tube 11.

  In FIG. 5, the temperature of the arc tube 11 at the end sealing portions 151 and 152 when the thickness at t1 is the same as the thickness m of the other part of the arc tube 11 that is 1 mm is about 520 degrees. . The thickness is increased to about 540 degrees at a thickness twice as large as the wall thickness m, about 550 degrees at 3 times, about 570 degrees at 4 times, and about 590 degrees at 5 times.

  FIG. 6 is an explanatory diagram for explaining the comparison of spectral distribution between the electrodeless lamp of the present invention and the conventional one.

  In the electrodeless lamp 100 of the present invention, the tube diameter φa of the both side portions 13 and 14 of the arc tube 11 is 11 mm, the tube diameter φb of the central portion 12 is 5.5 mm which is 50% of the tube diameter φa, and the end seals are made. The wall thickness t1 at 5 mm from the stop portions 151 and 152 was 2 mm, and the wall thickness t2 at 10 mm was 1 mm. In the conventional electrodeless lamp, the thickness at t1 and t2 is 1 mm, and the central portion 12 of the arc tube 11 is a straight.

  As is apparent from FIG. 6, it was found that the amount of ultraviolet light in the required wavelength range of 350 to 380 nm increases. In FIG. 7, the light emission ratio of FIG. 6 in the wavelength region of 350 to 380 nm is represented by a numerical value. As can be seen from FIG. 7, the present invention aims to increase the amount of light by about 1.7 times compared to the conventional case. Can do.

  In the electrodeless lamp 100 of the present invention, the tube diameter φb of the central portion 12 is reduced to 45% to 70% with respect to the outer tube of the arc tube 11, and is within a range of 5 mm from the end sealing portions 151 and 152. When the wall thickness t1 is 2 times or more and the wall thickness t2 within a range of 10 mm from the end sealing portions 151 and 152 is 1.01 or more, the temperature rises due to the valley portion of the standing wave. It was found that we can plan.

  In this embodiment, the temperature of the coldest part was increased by increasing the tube wall load at the end sealing part, which is the valley part of the standing wave formed by microwaves, and the arc tube central part. Thus, the light emission efficiency in the wavelength region of 350 to 380 nm can be improved.

  8 and 9 are diagrams for explaining a lighting device for lighting an electrodeless lamp according to the present invention. FIG. 8 is a system configuration diagram, and FIG. 9 is a cross-sectional view taken along line I-I 'of FIG.

  81 of the ultraviolet irradiation device 200 is a lamp house made of, for example, stainless steel having a function of shielding microwaves, and this lamp house 81 is not provided with an electrode at the lower central portion, as described in FIGS. The electrodeless lamp 100 of the invention is attached to a part of the side surface of the lamp house 81.

  Reference numeral 82 denotes a magnetron that generates a microwave of 2.45 GHz, for example, and power is supplied to the magnetron 82 from a power supply 83. Reference numeral 84 denotes a waveguide that transmits the microwave generated by the magnetron 82 from the antenna 85 and transmits the microwave to the electrodeless lamp 100.

  An air inlet 86 is provided on the upper surface of the lamp house 11 so that air as a cooling medium blown from the blower 87 is taken into the lamp house 81. A duct (not shown) is provided between the blower 87 and the intake port 86 so as to take in air sent from the blower 87.

  On the back side of the electrodeless lamp 100, a reflection plate 88 for condensing or diffusing irradiated ultraviolet light is installed. In addition, an RF screen 89 constituting an irradiation window is provided in a part of the lamp house 81 on the front surface of the reflection plate 88. The RF screen 89 is made of metal and has an opening, blocks microwaves, and allows ultraviolet light and air to pass through. The RF screen 89 is formed, for example, by knitting a metal wire into a mesh shape or by forming a metal plate by punching. The opposite surface of the RF screen 89 facing the electrodeless lamp 100 is an ultraviolet irradiation surface.

  In this manner, the electrodeless lamp 100 excited by the microwave of the magnetron 82 emits ultraviolet light and can irradiate an irradiation object (not shown) through the RF screen 89.

  In this embodiment, the portion with a low temperature distribution in the longitudinal direction of the electrodeless lamp 100 is eliminated as much as possible, thereby realizing the irradiation of ultraviolet rays with improved luminous efficiency in the wavelength range of 350 to 380 nm emitted by the electrodeless lamp 100. can do.

DESCRIPTION OF SYMBOLS 100 Electrodeless lamp 11 Arc tube 12 Central part 13,14 Both ends 151,152 End sealing part 16 Discharge space 171,172 Support part 200 Ultraviolet irradiation device 81 Lamp house 82 Magnetron 83 Power supply 84 Waveguide 85 Antenna 86 Intake Mouth 87 blower 88 reflector 89 RF screen

Claims (2)

A discharge gas is generated by microwaves radiated from a magnetron, in which at least a rare gas, a mercury as a discharge medium, and a discharge medium such as iron are enclosed in an emission space of a quartz glass arc tube having a substantially cylindrical shape. In the wave feed type electrodeless lamp,
The tube diameter of the arc tube is reduced in the range of 45% to 75% with respect to the tube diameter of the arc tube, and the thickness within the range of 5 mm from the end sealing portion of the arc tube is That the wall thickness within the range of 5 to 10 mm from the end sealing portion of the arc tube is more than 1.01 times the wall thickness of the arc tube, more than twice the wall thickness of the arc tube. A featured electrodeless lamp. The electrodeless lamp according to claim 1, which 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;
An ultraviolet irradiation device comprising: an ultraviolet cut filter installed under the ultraviolet irradiation surface in order to limit an irradiation area of ultraviolet rays irradiated from the lamp house.

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