JP2012124094A - Ultraviolet light radiation device - Google Patents

Abstract

An object of the present invention is to suppress a rise in lamp temperature while using a flat reflector that reflects ultraviolet rays.
An electrodeless lamp 12 in which a discharge medium capable of emitting ultraviolet rays based on microwaves generated by magnetrons 131 and 132 is enclosed in a lamp house 11. The magnetrons 131 and 132 and the electrodeless lamp 12 in the lamp house 11 are cooled using a cooling mechanism 20 mainly composed of a fan. The electrodeless lamp 12 is cooled by the cooling air of the cooling mechanism 20 that flows in through the gaps 24 a and 24 b of the flat reflectors 211 and 212. Cooling control members 25a and 25b for increasing the flow velocity of the cooling air flowing into the gaps 24a and 24b are formed on the reflectors 211 and 212, respectively. Accordingly, it is possible to realize a lamp temperature of 850 ° C. or less, which is an appropriate temperature for reliability, using the flat reflectors 211 and 212.
[Selection] Figure 5

Description

  The present invention relates to an ultraviolet irradiation apparatus used for printing-related ink drying, semiconductor-related fine exposure, liquid crystal-related adhesive curing, and the like.

  The conventional ultraviolet irradiation device emits ultraviolet rays by exciting an electrodeless lamp in which a discharge medium is sealed with microwaves, and irradiates an irradiated object using two curved reflectors. Since the electrodeless lamp generates heat when radiating ultraviolet rays, cooling is performed by applying cooling air from a cooling fan to the electrodeless lamp from a slot formed between two curved reflectors. (For example, Patent Document 1)

Special table 2003-531463 gazette

  The technique disclosed in Patent Document 1 uses a curved reflector and irradiates ultraviolet rays in a state of being condensed on an irradiated object. In this case, even if the positional relationship between the lamp and the reflector is shifted by, for example, about 0.3 mm vertically and horizontally from the optimum position, the uniformity decreases by 7% or more, so a liquid crystal dropping device that requires high uniformity is required. There is a problem that the light distribution control is difficult.

  Therefore, it is conceivable to use a flat reflector instead of the curved reflector. However, when a flat reflector is used, it is difficult to optically design a gap through which cooling air with a satisfactory flow rate is allowed to pass, and a lamp temperature of 850 ° C. or less, which is considered to be an appropriate temperature for reliability. It turned out that there was a problem that it was difficult to realize.

  An object of the present invention is to provide an ultraviolet irradiation device capable of suppressing a temperature rise of a lamp while using a flat reflector.

  In order to solve the above-described problems, an ultraviolet irradiation device of the present invention includes an electrodeless lamp that encloses a discharge medium and emits ultraviolet light by exciting the discharge medium with microwaves, and the ultraviolet light of the electrodeless lamp. A flat plate-like first and second reflecting plates to be irradiated to an irradiated body, a cooling mechanism for cooling air from the gap between the first and second reflecting plates and cooling the electrodeless lamp, and the gap And a cooling control member that is provided on the first and second reflectors that face each other and that gradually narrows the width of the gap from the inflow port through which the cooling air flows into the outflow port. It is characterized by that.

  According to the present invention, it is possible to suppress the temperature rise of the lamp while using the flat reflector and contribute to the extension of the lamp life.

It is a schematic block diagram for demonstrating one Embodiment regarding the ultraviolet irradiation device of this invention. It is the Ia-Ib sectional view taken on the line of FIG. It is a block diagram for demonstrating an example of the electrodeless lamp used in FIG. It is a perspective view which expands and shows the principal part of FIG. It is sectional drawing which expands and shows the principal part of FIG. It is explanatory drawing for demonstrating the lamp temperature by the reflecting plate of this invention and a comparative example. It is sectional drawing equivalent to FIG. 5 for demonstrating other embodiment regarding the ultraviolet irradiation device of this invention. It is principal part sectional drawing for demonstrating the modification of the intermediate member used with the ultraviolet irradiation device of this invention.

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

  FIG. 1 is a schematic configuration diagram for explaining an embodiment of the ultraviolet irradiation apparatus of the present invention.

  1 to 5 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 sectional view taken along line Ia-Ib in FIG. 1, and FIG. 4 is a configuration diagram for explaining an example of an electrodeless lamp used in FIG. 4, FIG. 4 is an enlarged perspective view showing a main part of FIG. 1, and FIG. 5 is a partially cutaway enlarged sectional view of the main part of FIG.

  1 and 2, reference numeral 11 denotes a lamp house made of, for example, stainless steel having a function of shielding microwaves. A so-called electrodeless lamp 12 having no electrode is disposed at the center lower part of the lamp house 11. It is. 131 and 132 are magnetrons that generate microwaves. Reference numeral 14 denotes a power supply for supplying electric power for driving the magnetrons 131 and 132. Reference numerals 151 and 152 denote waveguides that transmit the microwaves generated by the magnetrons 131 and 132 and transmitted from the antennas 161 and 162 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 an outer diameter of about 15 ± 1 mm and a length of about 240 mm, which transmits ultraviolet rays. In the light emitting space of the bulb 121, for example, an inert gas and a discharge medium for discharging with a microwave mainly composed of mercury and iron are enclosed. Support portions 122 and 123 that support the valve 121 are formed integrally with the valve 121 at both ends of the valve 121.

  In FIGS. 1 and 2 again, reference numeral 17 denotes a light receiving element that receives light emitted from the electrodeless lamp 12, and is covered with a cover made of a metal plate in which a metal wire is knitted or punched. It becomes. A light amount detector 18 outputs the light amount received by the light receiving element 17 as an analog voltage. Reference numeral 19 denotes a control unit that operates according to a program that controls the power supply 14 so that the light amount value detected by the light amount detector 18 becomes equal to the light amount value stored in advance. Specifically, when the light amount detection value output from the light amount detector 18 is smaller than a prestored value, the control unit 19 generates microwave energy generated by the magnetrons 131 and 132 with respect to the power source 14. Control is performed to increase the output voltage so as to increase the amount, and if the detected light amount is larger than the stored value, control is performed to decrease the output voltage so as to decrease the amount of microwave energy. Thereby, the amount of ultraviolet rays radiated from the electrodeless lamp 12 is made constant.

  Further, a cooling mechanism 20 mainly including a fan for cooling the electrodeless lamp 12 and the magnetrons 131 and 132 by supplying cooling air, for example, is provided inside the lamp house 11.

  As shown also in FIG. 4, on the back side of the electrodeless lamp 12, flat reflectors 211 and 212 sandwiching the electrodeless lamp 12 are arranged on the lower side so that, for example, the angle X with respect to the horizontal is 54 °. It is arranged in a state where the cross section has a letter C shape, that is, a narrow opening is formed on one end (upper) side and a wide opening is formed on the other end (lower) side. The reflectors 211 and 212 are, for example, 86 mm in length, 260 mm in width, and 3.3 mm in thickness. The electrodeless lamp 12 is also attached to the frame 22. An intermediate member 23 is disposed along the longitudinal direction of the reflecting plates 211 and 212 between the magnetrons 131 and 132 having a narrow interval, that is, between the reflecting plates 211 and 212 on the upper side. The intermediate member 23 has a width of 8 mm, a length of 250 mm, and a thickness of 4 mm, for example, which is difficult to absorb microwaves and has high heat resistance, such as ceramics, quartz, and Teflon (registered trademark). ing. Note that the distance between the center of the electrodeless lamp 12 and the lower end of the intermediate member 23 is, for example, 14 mm.

  As shown in FIG. 5, the reflectors 211 and 212 constitute first and second reflectors, and a gap 24 a is formed between one end of the intermediate member 23 and the reflector 211 facing the intermediate member 23. A gap 24 b is formed between the other end of the member 23 and the reflecting plate 212 facing the other end. A cooling control member 25a is attached to the reflecting portion 211 facing the gap 24a. The cooling control member 25a is a protrusion formed so as to protrude on the side facing the electrodeless lamp 12 at the upper end of the reflection portion 211 so as to gradually narrow the gap 24a toward the lower side (wide opening side). A cooling control member 25b similar to the cooling control member 25a is also attached to the reflecting portion 212 facing the gap 24a. That is, the width α1 of the air gaps 24a and 24b on the cooling mechanism 20 side and the width α2 of the air gaps 24a and 24b on the electrodeless lamp 12 side are configured in a relationship of α1> α2. In the present embodiment, the width α1 is 9 mm and the width α2 is 5 mm.

  Here, the reflection plates 211 and 212, the cooling control members 25a and 25b, and the intermediate member 23 are supported by the support members 41a and 41b. That is, the support member 41a, 41b has an oblique cutout formed so that the angle X with respect to the horizontal is 54 °, a triangular cutout formed so as to be continuous with the cutout, and a center A through-hole formed in the vicinity is provided, and the reflectors 211 and 212 are supported in the oblique notch, the cooling control members 25a and 25b are supported in the triangular notch, and the intermediate member 23 is supported in the through-hole. The lower ends of the reflectors 211 and 212 are attached to the frame 22 and the like via attachment means (not shown).

  A screen 26 constituting an irradiation window is provided in a part of the lamp house 11 between the reflection surface side of the reflection plates 211 and 212 and an irradiated body (not shown). The screen 26 has an opening, for example, by knitting a metal wire into a mesh shape or by punching a metal plate. Reference numeral 27 denotes a microwave cavity formed by the reflectors 211 and 212 and the screen 26.

  Here, when power is supplied from the power supply 14 to the magnetrons 131 and 132, the magnetrons 131 and 132 generate microwaves. The generated microwaves are transmitted from the antennas 161 and 162 to the electrodeless lamp 12 via the waveguides 151 and 152, respectively. The electrodeless lamp 12 emits ultraviolet light having a wavelength of 200 to 400 nm, for example, based on the discharge medium sealed in the light emitting space 121. Ultraviolet rays are radiated to the lower side of the lamp house 11 and irradiated to the irradiated object via the screen 26.

  As the lamp is turned on, the electrodeless lamp 12 generates heat and the lamp temperature rises. Therefore, the cooling air from the outside obtained by turning the fan of the cooling mechanism 20 is applied to the electrodeless lamp 12 via the reflectors 211 and 212 and the gaps 24a and 24b of the intermediate member 23, so that the lamp temperature can be lowered. .

  At this time, the gaps 24a and 24b have a relationship of α2 <α1 with respect to the width α1 on the outflow side with respect to the width α1 on the inflow side. The ability to cool will improve. As a result, it is possible to realize a lamp temperature of 850 ° C. or lower, which is considered to be an appropriate temperature for reliability.

  Further, as in the present embodiment, the upper ends of the reflectors 211 and 212 are positioned higher than the upper end of the intermediate member 23, and the cooling air is preliminarily accelerated before reaching the gaps 24a and 24b. Also good. At that time, by making the upper side inclined at a gentle angle with respect to the horizontal, that is, a wide angle, more cooling air can be taken into the gaps 24a and 24b. Further, the cooling air is effectively applied to the electrodeless lamp 12 by making the shape near the outlet of the cooling air, that is, the shape below the cooling members 25a and 25b so as to guide the cooling air toward the electrodeless lamp 12. Can be supplied automatically. As described above, the shapes of the upper and lower sides of the reflecting plates 211 and 212 may be changed stepwise or gradually.

  The intermediate member 23 contributes to increasing the cooling air speed by narrowing the gap between the reflectors 211 and 212 for optical design reasons. However, the intermediate member 23 is sufficient between the cooling control members 25a and 25b. It is not essential to obtain a space from which a cooling air can be obtained. Even when the intermediate member 23 is provided between the reflecting plates 211 and 212, the shape and the number thereof are not limited. For example, the width of the gaps 24a and 24b may be set to α2 <α1 by arranging the intermediate member 23 to be inclined in the direction of the reflectors 211 and 212 toward the lower side, or a plurality of the intermediate members 23 may be arranged. A space may also be formed between adjacent intermediate members.

  FIG. 6 is an explanatory diagram for explaining the lamp temperature by the reflector of the invention and the comparative example. FIG. 6 shows a state where the speed of the cooling air increases as the color becomes white.

6 (a) shows a curved reflector of the comparative example, FIG. 6 (b) shows a flat reflector of the comparative example, and FIG. 6 (c) has a cooling control member in the flat form of the present invention. The result of having measured the lamp temperature in a reflecting plate is shown. The measurement conditions were magnetron input power of 7.5 kW, lamp power of 6 kW, cooling air flow rate of 10 m ³ / min, and cooling air temperature of 25 ° C.

  That is, the lamp temperature when the curved reflector of FIG. 6A is used is 797 ° C., and there is no particular problem with the lamp life, but as described in the explanation of the problem, There is a problem that requires severe position management with the lamp.

  In the case of using only a flat reflector as shown in FIG. 6B, the management of the position of the reflector and the lamp is not necessary as compared with the curved reflector. However, from the viewpoint of optical design, since the gap between the intermediate member and the reflector cannot be narrowed, the flow velocity of the cooling air cannot be increased. For this reason, the lamp temperature becomes 879 ° C., and there is a problem that the temperature has a great influence on the lamp life.

  The lamp temperature when the outlet of the air gap formed in the intermediate member that takes in the cooling air and the cooling control member is narrower than the inlet using the flat reflector of FIG. 815 ° C. Although this was a slightly higher temperature than when a curved reflector was used, it was confirmed that a value sufficiently satisfying 850 ° C. or less, which is an appropriate temperature for reliability, was obtained.

  As described above, as a result of repeated investigations as a cause of the temperature rise due to the difference in the reflector shape, the gap end portion of the reflector plate, that is, the cooling air inlet to the lamp house is formed into a desired shape, and thus the shape of the reflector plate is affected. It was found that the lamp temperature can be controlled to an appropriate temperature. In the microwave ultraviolet irradiation module in which the cooling air flows into the lamp house from the gap between the two reflectors, a member is arranged at the center of the gap and the gap-side end of the two reflectors to generate the cooling air. By controlling the lamp temperature, the lamp temperature can be controlled without being influenced by the shape of the reflecting plate, so that a desired light distribution can be realized without causing early deterioration.

  In this embodiment, a cooling control member that gradually narrows the gap toward the electrodeless lamp side is arranged on a flat reflector facing the end face of the intermediate member, thereby reducing the lamp temperature while using the flat reflector. It becomes possible. This makes it possible to control the lamp temperature while using a flat reflector that allows the position of the irradiated object and the reflector to be somewhat rough, and obtains a desired light distribution without causing early deterioration of the lamp. be able to.

  FIG. 7 is a cross-sectional view corresponding to FIG. 5 for explaining another embodiment relating to the ultraviolet irradiation apparatus of the present invention. Parts having the same functions as those in the above embodiment will be described with the same reference numerals.

  In this embodiment, holding members 71a and 71b in which cooling control members 25a and 25b opposed to the gaps 24a and 24b are integrally formed are attached to one ends of the flat reflectors 211 and 212, respectively. is there. In this case, since the holding members 71a and 71b have both the cooling function of the electrodeless lamp 12 and the holding function of the reflection plates 211 and 212, the number of members can be reduced.

  8 (a) to 8 (c) are cross-sectional views of the main parts for explaining modifications of the ultraviolet irradiation device of the present invention.

  In the modification of FIG. 8A, the reflective film 81 is provided on the intermediate member 23 facing the electrodeless lamp 12. Thereby, it is possible to effectively use the upward light of the electrodeless lamp 12 opposite to the irradiated object.

  In the modification of FIG. 8B, a V-shaped projection 82 is formed on the surface of the intermediate member 23 facing the electrodeless lamp 12. In this case, since the amount of ultraviolet rays returning to the electrodeless lamp 12 by the protrusions 82 can be suppressed as much as possible, the generated ultraviolet rays can be used more effectively. Further, by changing the V-shaped angle, it is possible to adjust the wind speed of the cooling air, the direction of the wind after passing through the gaps 24a and 24b, and the like.

  In the modification of FIG. 8C, an embossed reflection mirror 83 is formed on the surface of the intermediate member 23 facing the electrodeless lamp 12. The reflection mirror 83 diffuses the ultraviolet rays from the electrodeless lamp 12 and further irradiates the irradiated object side with the reflectors 211 and 212, thereby improving the illuminance and the uniformity.

  Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. For example, the electrodeless lamp may be replaced with a linear light source such as a low-pressure ultraviolet lamp or a metal halide lamp. Further, the cooling control members 25a and 25b are formed integrally with the reflection plates 211 and 212 by using a mold or the like, or formed separately from the reflection plates 211 and 212, for example, using a thermosetting adhesive. Or you may make it. Further, the support of the reflecting plates 211 and 212 may be attached to both ends of the frame 22 by using, for example, a heat resistant adhesive. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

11 Lamp house 12 Electrodeless lamp 131, 132 Magnetron 14 Power supply 151, 152 Waveguide 161, 162 Antenna 20 Cooling mechanism 211, 212 Reflector 22 Frame 23 Intermediate member 24a, 24b Air gap 25a, 25b Cooling control member 26 Screen 27 Micro Wave cavity portions 41a and 41b Support members 71a and 71b Holding portion 81 Reflecting film 82 Projection 83 Reflecting mirror

Claims (2)

An electrodeless lamp that encloses a discharge medium and emits ultraviolet light by exciting the discharge medium with microwaves;
Flat plate-like first and second reflectors for irradiating the irradiated body with ultraviolet rays of the electrodeless lamp;
A cooling mechanism for flowing cooling air from the gap between the first and second reflectors and cooling the electrodeless lamp;
A cooling control member that is provided on the first and second reflectors facing the gap and that gradually reduces the width of the gap from the inlet through which the cooling air flows to the outlet through which the cooling air flows. An ultraviolet irradiation device characterized by comprising. A flat plate-like first and second reflectors arranged in a U-shape so as to form a narrow opening on one end side and a wide opening on the other end side;
A linear light source disposed in a space formed by the first and second reflectors;
A cooling mechanism for flowing cooling air into the space from the narrow opening side and cooling the electrodeless lamp,
An intermediate member disposed in the vicinity of the narrow opening and forming two gaps between the end portions of the first and second reflectors;
UV irradiation, comprising: the cooling control member provided at the end of the first and second reflectors on the narrow opening side and narrowing the width of the gap toward the wide opening. apparatus.