JP2008130302A - Light irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light irradiation device which has an optical irradiator with a cooling air passage and is capable of improving treatment efficiency by increasing light irradiation amount to a treating object, and capable of obtaining sufficient cooling function without increasing greatly the amount of cooling air, and a light source lamp used for the same. <P>SOLUTION: The light irradiation device has an optical irradiator in which a light source lamp of rod shape with a circular cross-section is arranged with its tube axis in a state of coinciding with the position of a first focus of a reflection mirror of gutter shape having a reflection surface, and the light source lamp and the reflection mirror are cooled by cooling air at the time of lighting of the light source lamp. A cooling passage which is communicated with a space surrounded by the reflection mirror and circulates the cooling air is formed at the rear side of the light source to the light irradiation direction. An ultraviolet light diffusion reflection film made of alumina (Al<SB>2</SB>0<SB>3</SB>) which reflects the light emitted from the light source lamp is formed in the outer surface region opposed to the aperture of the cooling air passage of the light source lamp. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes, for example, a rod-shaped light source lamp and a reflection mirror that reflects light emitted from the light source lamp, and irradiates light to be processed with ultraviolet light, for example, a curing process or a modification process. It is related with the light irradiation apparatus which performs.

  Currently, using a light irradiation device equipped with a light source lamp that emits light including ultraviolet rays, for example, for protective films, adhesives, paints, inks, photoresists, resins, alignment films, etc. on the object to be treated Drying, melting or softening, and reforming are widely performed in various fields.

FIG. 9 is a cross-sectional view showing an outline of the configuration of an example of a conventional light irradiation apparatus, and FIG. 10 shows a cross section perpendicular to the tube axis of the light source lamp of the light irradiator constituting the light irradiation apparatus shown in FIG. It is sectional drawing.
This light irradiation apparatus includes a light irradiator 40 that irradiates light including ultraviolet rays. For example, the object to be processed (workpiece) conveyed by a conveyance mechanism (not shown) so as to pass through a position below the light irradiator 40. ) W is irradiated with ultraviolet rays.
The light irradiator 40 has a substantially box-shaped lamp house 41 in which an internal space is partitioned by a partition wall 42 and a wind tunnel 43 and a lamp arrangement space 44 are formed side by side. A rod-shaped light source lamp 50 is disposed in the lamp arrangement space 44 so as to extend in a direction orthogonal to the conveyance direction of the workpiece W and reflects light from the light source lamp 50. For example, a reflection mirror 55 having an ellipsoidal reflection surface is disposed so as to extend along the light source lamp 50 in a state where the position f1 of the first focal point coincides with the lamp center of the light source lamp 50.
In the partition wall 42 in the lamp house 41, for example, a plurality of through holes that communicate the wind tunnel 43 and the lamp arrangement space 44 are formed in a state of being aligned along the longitudinal direction of the light source lamp 50. Are formed integrally with the partition wall 42 so as to extend along the longitudinal direction of the light source lamp 50 at both side edge positions of the cooling air flow opening 45.
A duct 48 connected to the exhaust fan 49 and communicating with the internal space of the wind tunnel 43 is provided at the upper part of the lamp house 41.

  At the top of the reflection mirror 55, for example, an opening 56 made of a groove formed so as to extend along the light source lamp 50 is formed, and a nozzle portion 46 formed integrally with the partition wall 42 is formed in the opening 56. Thus, a cooling air passage 60 through which cooling air for cooling the light source lamp 50 and the reflection mirror 55 is circulated is formed.

In this light irradiation device, the light emitted from the light source lamp 50 is applied to the object W to be processed either directly or reflected by the reflection mirror 55. Specifically, the reflected light from the reflecting mirror 55 is once condensed at the position of the second focal point f2 of the reflecting mirror 55 and then spreads, and is further away from the second focal point f2 of the reflecting mirror 55 in the light irradiation direction. The entire object to be processed W is irradiated.
On the other hand, when the light source lamp 50 is turned on, the cooling fan is sucked into the lamp house 41 by operating the exhaust fan 49, and the light source lamp 50 and the reflection mirror 55 are cooled by this cooling air. The cooling air introduced into the air flows into the wind tunnel 43 through the nozzle portion 46 forming the cooling air passage 60 and is exhausted through the duct 48.
In the light irradiation device disclosed in Patent Document 1, for example, as shown in FIG. 11, the width of the cooling air passage 60 having the optimum size with the light source lamp 50 is set to the tube diameter of the light source lamp 50. For the purpose of setting, it is described that the nozzle 46 </ b> A forming the cooling air passage 60 is configured separately from the partition wall 42 in the lamp house 41.
JP-A-8-174567

  In general, the processing time in the light irradiation treatment using ultraviolet rays as described above greatly depends on the irradiation amount of ultraviolet rays, and the processing time can be shortened by setting the irradiation amount of ultraviolet rays in the light irradiation region to be large. Therefore, it is known that the processing efficiency can be improved, and it is desired to increase the irradiation amount of ultraviolet rays emitted from the light irradiator.

In the light irradiation device having the above-described configuration, the opening that forms the cooling air passage 60 for circulating the cooling air is used to prevent the light source lamp 50 and the reflection mirror 55 from being overheated when the light source lamp 50 is turned on. It is necessary to form the portion 56, and is formed, for example, on the top of the reflection mirror 55.
However, there is a problem that ultraviolet rays emitted from the light source lamp 50 toward the opening 56 of the reflection mirror 55 due to the presence of the opening 56 cannot be used effectively. In practice, the proportion of ultraviolet rays that are emitted in the direction of the opening 56 of the reflection mirror 55 and cannot be used effectively is about 20% of the total light emitted from the light source lamp 50, for example.

  To solve this problem, it is conceivable to increase the lamp input power of the light source lamp 50 as one means for increasing the amount of ultraviolet light applied to the workpiece W. However, the lamp input power is large. When the light source lamp 50 is used, the following problems are likely to occur. That is, the light emitted from the light source lamp 50 toward the opening 56 of the reflection mirror 55 is directly applied to the nozzle portion 46 or the nozzle 46A forming the cooling air passage 60 and heated. The 46 or the nozzle 46A is usually formed of, for example, aluminum for manufacturing reasons such as ease of processing and low cost, and thus is easily deformed when heated. Therefore, in order to prevent the nozzle portion 46 or the nozzle 46A from being deformed as it is heated, it is necessary to cool not only the light source lamp 50 and the reflection mirror 55 but also the nozzle portion 46 or the nozzle 46A. As a result, a cooling air with a larger air volume is required, and the energy consumption of the light irradiation device increases, and energy saving, which is one of the requirements for such a light irradiation device, is prevented.

The present invention has been made based on the circumstances as described above, and is a light provided with a light irradiator in which a cooling air passage for circulating a cooling air for cooling the light source lamp and the reflecting mirror is formed. It is an irradiation device that can increase the amount of light irradiated to the object to be processed, improve the processing efficiency, and has a sufficient cooling function without significantly increasing the amount of cooling air. An object is to provide a light irradiation apparatus that can be obtained.
Another object of the present invention is a light source lamp used in the light irradiating device, which can improve the utilization rate of light emitted from the light source lamp and increase the light irradiation amount on the light irradiation surface. And it aims at providing the light source lamp which can prevent reliably that the nozzle which forms the cooling air path of a light irradiation apparatus will be in an overheated state.

The light irradiator of the present invention is a light irradiator in which a rod-shaped light source lamp having a circular cross section is disposed in a state where its tube axis coincides with the position of the first focal point of a bowl-shaped reflecting mirror having a reflecting surface. A light irradiation device in which the light source lamp and the reflection mirror are cooled by cooling air when the light source lamp is turned on,
On the rear side of the light source lamp with respect to the light irradiation direction, there is formed a cooling air passage communicating with the space surrounded by the reflection mirror for circulating the cooling air,
The outer surface region facing the opening of the cooling air passage in the light source lamp is provided with an ultraviolet light scattering reflection film made of alumina (Al ₂ O ₃ ) that reflects light emitted from the light source lamp. And

Furthermore, the ultraviolet scattering reflection film is formed of alumina (Al ₂ O ₃ ) particles.

  The light irradiation apparatus of the present invention is a high-pressure mercury lamp in which the light source lamp mainly emits light having a wavelength of 254 nm, and the film thickness of the ultraviolet scattering reflection film is 100 μm or more.

  The light irradiation apparatus of the present invention is a high-pressure mercury lamp in which the light source lamp mainly emits light having a wavelength of 365 nm, and the film thickness of the ultraviolet scattering reflection film is 150 μm or more.

The light source lamp of the present invention is a light source lamp used in the above light irradiation device,
Cooling, comprising a rod-shaped envelope having a circular cross section and communicating with the space surrounded by the reflection mirror in the state of being disposed at the position of the first focal point of the bowl-shaped reflection mirror in the light irradiator An ultraviolet scattering reflection film made of alumina (Al ₂ O ₃ ) is provided on the outer surface region of the sealing body facing the opening of the cooling air passage for circulating the air.

In the light source lamp of the present invention, the cooling air passage formed to extend along the light source lamp at the top of the reflecting mirror is provided with a nozzle for setting the width with the light source lamp.
The ultraviolet light scattering reflection film is formed so as to extend along the tube axis over the entire light emitting region in the outer surface region of the angular range in which the nozzle is centered on the tube axis in the cross section perpendicular to the tube axis of the light source lamp. It is preferable to be configured.

The ultraviolet light scattering reflection film of the light source lamp is formed of alumina (Al ₂ O ₃ ) particles.

  The light source lamp of the present invention is a high-pressure mercury lamp that mainly emits light having a wavelength of 254 nm, wherein the ultraviolet scattering reflection film has a thickness of 100 μm or more.

  The light source lamp of the present invention is a high-pressure mercury lamp that mainly emits light having a wavelength of 365 nm, and the film thickness of the ultraviolet scattering reflection film is 150 μm or more.

  The light irradiation apparatus or the light source lamp of the present invention is characterized in that the ultraviolet scattering reflection film is formed by thermal spraying.

According to the light irradiation device of the present invention, as the light source lamp, by using an ultraviolet scattering reflection film formed in an appropriate range in the outer surface region of the envelope, the ultraviolet scattering reflection film, Since the light emitted from the light source lamp in the opening direction of the cooling air passage can be efficiently reflected without hindering the effective reflection area of the reflection mirror, the light irradiation amount on the light irradiation surface can be increased, The predetermined light irradiation process for the object to be processed can be performed with high processing efficiency.
In addition, in the configuration in which the nozzle for setting the width with the light source lamp is provided in the cooling air passage, light emitted in the opening direction of the cooling air passage is prevented from being directly irradiated to the nozzle. Therefore, it is possible to reliably prevent the nozzle from being overheated without increasing the amount of cooling air required, and energy saving can be achieved.

  According to the light source lamp of the present invention, when used in the light irradiation device, the light emitted in the opening direction of the cooling air passage is reflected by the ultraviolet scattering reflection film in relation to the effective reflection region by the reflection mirror. Therefore, it is possible to increase the amount of light irradiation on the light irradiation surface and to prevent the light from the light source lamp from being directly irradiated to the nozzle. As a result of reliably preventing the nozzle from being overheated without increasing the amount of cooling air required when the lamp is lit, light irradiation configured using the light source lamp Energy saving of the device can be achieved.

Hereinafter, the present invention will be described in detail with reference to the drawings.
1 is a cross-sectional view showing an outline of a configuration of an example of the light irradiation apparatus of the present invention, FIG. 2 is a perspective view showing an outline of a configuration of a light irradiator in the light irradiation apparatus shown in FIG. 1, and FIG. It is sectional drawing which shows a cross section perpendicular | vertical to the tube axis | shaft of a light source lamp of the light irradiation device shown in FIG.
This light irradiation apparatus comprises a light irradiator 10 that irradiates light including ultraviolet rays. A predetermined light irradiation process is performed by irradiating ultraviolet rays.

The light irradiator 10 has a light irradiation port 11A that opens downward, and is a substantially box in which an upper chamber that constitutes a wind tunnel 13 that is partitioned vertically by a partition wall 12 and a lower chamber that constitutes a lamp arrangement space 14 is formed. A mold-shaped lamp house 11 is provided, and a duct 17 connected to the exhaust fan 16 and communicating with the internal space of the wind tunnel 13 is provided at the upper part of the lamp house 11.
In the lamp arrangement space 14 in the lamp house 11, a rod-shaped light source lamp 20 is arranged in such a posture that its tube axis extends parallel to the light irradiation surface A.
In the partition wall 12 in the lamp house 11, for example, a plurality of through holes 15 </ b> A for communicating the wind tunnel 13 and the lamp arrangement space 14 are formed in a state of being arranged along the tube axis direction of the light source lamp 20. A portion 15 is formed, and a nozzle portion 18 made of, for example, aluminum that protrudes downward at both side edge positions of the cooling air circulation opening 15 is integrated with the partition wall 12 so as to extend along the tube axis direction of the light source lamp 20. Thus, a cooling air passage 19 is formed through which cooling air for cooling the light source lamp 20 and the reflecting mirror 30 drawn into the lamp house 11 by operating the exhaust fan 16 is circulated. Yes.
The nozzle unit 18 sets the width of the cooling air path formed between the light source lamp 20 (the distance from the light source lamp 20) so that the speed of the cooling air flowing around the light source lamp 20 is optimized. Is for.

In the lamp arrangement space 14, a bowl-shaped reflection mirror 30 having a length equal to or longer than the size of the light emitting region L (light emission length) of the light source lamp 20 and having an ellipsoidal reflecting surface is the first focal point. It is arranged in a state where the position of f1 coincides with the lamp center C constituting the light emitting part of the light source lamp 20.
At the top of the reflection mirror 30, for example, an opening 31 made of a groove formed so as to extend along the light source lamp 20 is formed, and an opening edge of the opening 31 is formed at the tip of the nozzle portion 18. The tip is supported by the opening edge of the light exit port 11A while being held by the reflecting mirror holding portion 18A.
A multilayer reflective film (not shown) made of tantalum oxide (Ta ₂ O ₅ ) and silicon dioxide (SiO ₂ ) is formed on the inner surface of the reflection mirror 30 by, for example, vapor deposition.
Specific configurations such as the thickness of each layer and the number of stacked layers in the multilayer reflective film can be appropriately set so that ultraviolet rays having a specific wavelength according to the processing purpose of the light irradiation device are efficiently reflected. For example, when used for the curing treatment of a photocurable resin, the thickness and the number of layers are set so that ultraviolet rays having a wavelength of 350 to 400 nm are efficiently reflected, and for example, an alignment film used for a liquid crystal panel is used. When used for the photo-alignment treatment, the thickness of each layer and the number of layers are set so that ultraviolet rays having a wavelength of 240 to 280 nm are efficiently reflected.

As shown in FIG. 4, the light source lamp 20 includes a sealed body 21 made of, for example, quartz glass whose both ends are sealed, and a pair of electrodes 22 are provided in the sealed body 21 at both end positions. For example, mercury, a rare gas, and halogen are enclosed, and a high-pressure mercury lamp that mainly emits light including ultraviolet rays having a wavelength of 254 nm is used. Alternatively, the light source lamp 20 is composed of a metal halide lamp that mainly emits light including ultraviolet light having a wavelength of 365 nm using the enclosed metal halide as a light emitting medium.
An umbrella-like wind shield member 23 for preventing a temperature drop by blowing cooling air to both end portions of the light source lamp 20 that are continuous with the light emitting region L is provided on the envelope facing the position where the electrode 22 is disposed. It is provided so as to cover the periphery of the surface portion.

The light source lamp 20 is formed at the opening of the nozzle portion 18 that forms the cooling air passage 19, in other words, at the top of the reflecting mirror 30, in a state where the light source lamp 20 is arranged at a predetermined position in the lamp house 11. An ultraviolet scattering reflection film 25 having a function of efficiently reflecting ultraviolet rays having a specific wavelength according to the processing purpose extends along the tube axis of the light source lamp 20 on the outer surface region of the sealing body 21 facing the opening 31. Is formed.
This ultraviolet scattering / reflecting film 25 is in a cross section perpendicular to the tube axis of the light source lamp 20, and an angle range θ region in which the reflection mirror holding portion 18 </ b> A in the nozzle portion 18 is centered on the tube axis (lamp center C) of the light source lamp 20. The angle range θ is, for example, 90 ° (see FIG. 3). With such a configuration, the effective reflection area of the reflection mirror 30 is not obstructed, and the light radiated in the direction of the opening 31 of the reflection mirror 30 is efficiently used by both the ultraviolet scattering reflection film 25 and the reflection mirror 30. Can reflect well.

Since the surface temperature of the envelope 21 of the light source lamp 20 is, for example, 600 to 800 ° C. when the ultraviolet light scattering / reflecting film 25 is lit, it is required to be made of a material having excellent heat resistance, for example. And alumina (Al ₂ O ₃ ) particles. The ultraviolet scattering reflection film 25 is formed of alumina fine particles having a particle diameter of 4 to 31 μm and has an uneven light scattering surface. For example, the ultraviolet scattering reflection film 25 has an opaque or ultraviolet scattering function with respect to ultraviolet rays having a wavelength of 254 nm and 365 nm. By using alumina particles as ultraviolet scattering particles, the reflectance of ultraviolet rays can be increased, the heat resistance of the ultraviolet scattering reflection film can be increased, and the ultraviolet scattering reflection film can be easily formed. it can. Here, the “particle diameter” refers to the width of a particle that maximizes the interval between parallel lines when a projected image of the particle is sandwiched between two parallel lines.

  Specifically, the ultraviolet scattering / reflecting film 25 has the following film thickness so that ultraviolet rays having a specific wavelength corresponding to the processing purpose of the light irradiation device are efficiently reflected. For example, when used for light distribution processing of a distribution film used in a liquid crystal panel, as will be described also by an experimental example described later, ultraviolet light having a wavelength of 254 nm emitted from the light source lamp 20 is efficiently reflected. The film thickness of the ultraviolet scattering reflection film 25 is set to 100 μm or more. For example, when used for the curing treatment of the photocurable resin, the film thickness of the ultraviolet scattering reflection film 25 is set to 150 μm or more so that the ultraviolet light having a wavelength of 365 nm emitted from the light source lamp 20 is efficiently reflected. .

Such an ultraviolet scattering reflection film 25 can be formed by, for example, a method such as thermal spraying, vapor deposition, or coating by a sol-gel method, but is particularly preferably formed by thermal spraying. That is, the fine particles of alumina supplied in the oxyhydrogen burner are sprayed onto the outer surface of the envelope together with the flame of the burner, and are laminated in several tens of layers, so that an ultraviolet ray having a desired film thickness is obtained. A scattering reflection film is formed. Although it is not certain, the cross section of the ultraviolet light scattering reflection film formed by thermal spraying is considered to be a scattering surface in which several tens of alumina fine particles are laminated and the surface is uneven as shown in FIG. In addition, the cross section of the ultraviolet scattering reflection film shown in FIG. 5 is a view for easy understanding.
Thermal spraying has the advantage that an ultraviolet scattering reflection film can be formed on the completed light source lamp. In other words, if an ultraviolet scattering reflection film is to be formed on the completed light source lamp by vapor deposition or the like, the light source lamp must be placed in an electric furnace in a high temperature atmosphere, avoiding an increase in the thermal load on the light source lamp. I can't. However, according to the thermal spraying, the completed light source lamp is not disposed in the electric furnace, so that the ultraviolet light scattering reflection film can be formed without applying an excessive thermal load to the light source lamp.

  An example of the spraying condition will be described. When the outer diameter of the envelope 21 of the light source lamp 20 is 26 mm to 27 mm and the wall thickness is in the range of 1.5 mm to 2.0 mm, 22 L (liter) ) / Min (min) of hydrogen and 28 L / min of oxygen, and the spray gun is moved along the tube axis of the light source lamp at 10 cm (centimeter) / sec (seconds), while the fine powder of alumina is used as the light source. Spray on the lamp.

  Although the ultraviolet scattering reflection film is preferably formed of alumina particles as described above, the shape of the alumina particles is not necessarily maintained. That is, a part of the alumina particles may be melted and combined with other adjacent alumina particles.

  In this light irradiator 10, the width of the nozzle portion 18 and the light source lamp 20, that is, the closest distance K between the light source lamp 20 and the reflection mirror holding portion 18A of the nozzle portion 18 is, for example, 4 to 5 mm. Thus, the cooling air can surely flow through the back side of the light source lamp 20.

In the light irradiation apparatus, for example, the object to be processed is in a direction orthogonal to the tube axis of the light source lamp 20 so as to pass through a position below the light irradiator 10 while maintaining a certain distance from the light source lamp 20. And a predetermined process is performed by the ultraviolet rays irradiated from the light irradiator 10. That is, when the light source lamp 20 is turned on, light including ultraviolet rays emitted from the light source lamp 20 is reflected directly or by the ultraviolet scattering / reflecting film 25 in the reflection mirror 30 and the light source lamp 20 through the light exit port 11A. Then, the object to be processed is irradiated. Here, the reflected light I1 reflected by the reflecting mirror 30 is once condensed on the second focal point f2 of the reflecting mirror 30, and further passes through the second focal point f2 and then spreads, and then the second focal point f2. Unlike the reflected light I 1 reflected by the reflecting mirror 30, the reflected light I 2 irradiated to the entire object to be processed located farther in the light irradiation direction than the reflected light by the ultraviolet scattering reflection film 25 is reflected. Without passing through the second focal point f2 of the mirror 30, for example, the light is irradiated to both sides of the center position of the light irradiation surface A (the position immediately below the light source lamp 20) (see FIG. 1).
On the other hand, the cooling air sucked through the light exit port 11 </ b> A by operating the exhaust fan 16 flows along the inner surface of the reflection mirror 30 and along the surface of the envelope 21 of the light source lamp 20. The reflection mirror 30 and the light source lamp 20 are cooled by flowing, and then the nozzle portion 18 is cooled as it flows into the wind tunnel 13 through the cooling air passage 19 formed by the nozzle portion 18. It is exhausted to the outside of the light irradiator 10 through the duct 17. Further, the reflection mirror 30 is also cooled from the back side by the cooling air sucked into the lamp arrangement space 14 through the through hole 11B formed in the opening edge portion of the light exit port 11A (see FIG. 3). ). Here, the air volume of the cooling air is, for example, 1.5 to 2 m ³ / min.

Thus, simply using a light source lamp in which an ultraviolet scattering reflection film is formed on the outer surface of the envelope, a light source lamp having no ultraviolet scattering reflection film is used for the amount of light irradiation on the light irradiation surface. It cannot be made larger than the light irradiation device. The reason for this is that the light reflected from the reflecting mirror and the reflected light from the UV scattering reflecting film are different from each other. This is because the light that can be reflected within the predetermined range in the case of being reflected by the ultraviolet scattering reflection film may be irradiated outside the range.
However, since the light source lamp 20 is formed by forming the ultraviolet scattering / reflecting film 25 in an appropriate range in the outer surface region of the envelope 21, according to the light irradiation device having the above-described configuration, Since the light reflected from the light source lamp 20 toward the opening 31 of the reflection mirror 30 can be efficiently reflected by the scattering reflection film 25 without obstructing the effective reflection area of the reflection mirror 30, the light irradiation surface A The amount of light irradiation in can be increased. Specifically, it is possible to obtain an illuminance distribution in which the illuminance level within a predetermined range including the position (center position) immediately below the light source lamp on the light irradiation surface A is increased (see, for example, FIG. 6). In practice, according to such an illuminance distribution, the entire object to be processed can be reliably covered, and a predetermined light irradiation process for the object to be processed can be performed with high processing efficiency.
In addition, since the light radiated in the direction of the opening 31 of the reflection mirror 30 is prevented from being directly applied to the nozzle portion 18 that forms the cooling air passage 19, the required amount of cooling air is required. Without increasing the amount, it is possible to prevent the nozzle portion 18 from being overheated and to save energy.

Hereinafter, experimental examples performed for confirming the effects of the present invention will be described.
<Experimental example 1>
A light irradiation apparatus according to the present invention was produced according to the configuration shown in FIG. The specific specification of this light irradiation apparatus is as follows.
The light source lamp is a high-pressure mercury lamp whose outer diameter is 26 mm, light emission length is 125 mm, rated power is 1.5 kW, and lamp input power is 120 W / cm. An ultraviolet scattering reflection film is formed on the outer surface area in the angle range of °.
The ultraviolet scattering reflection film is an ultraviolet scattering reflection film formed of alumina particles, and is formed by thermal spraying.
The reflecting mirror has an ellipsoidal reflecting surface, and the separation distance from the first focal point to the second focal point is about 120 mm.
The exhaust fan has a capacity that can be set so that the amount of air flowing through the light irradiator is 1.5 to 2 m ³ / min.
The lamp house and the nozzle part are made of aluminum, and the closest distance between the reflection mirror holding part of the nozzle part and the light source lamp is 4.5 mm.

  In addition, a comparative light irradiation having the same configuration as that of the light irradiation apparatus except that a high-pressure mercury lamp having the same specifications as the light source lamp is used except that it does not have an ultraviolet scattering reflection film. A device was made.

  About each of the light irradiation apparatus which concerns on this invention, and the light irradiation apparatus for a comparison, in the light irradiation surface installed in the position 400 mm away from the position of the 1st focus of a reflective mirror with respect to the light irradiation direction, center sensitivity is set to wavelength 365nm. The ultraviolet illuminance having The results are shown in FIG. The vertical axis in FIG. 6 indicates the magnitude of illuminance expressed as a relative value with reference to a comparative light irradiation apparatus, and the horizontal axis indicates the position immediately below the light source lamp (center position, 0 mm) from the lamp tube axis. The measurement position represented by the distance in the orthogonal direction is shown, the result of the light irradiation device according to the present invention is indicated by □, and the result of the comparative light irradiation device is indicated by Δ.

As is apparent from the results shown in FIG. 6, the magnitude of the illuminance at the center position (measurement position 0 mm), which is the position directly below the light source lamp, is largely different between the light irradiation apparatus according to the present invention and the comparison light irradiation apparatus. However, in the light irradiation apparatus according to the present invention, there is a portion with high illuminance on both sides of the center position in the illuminance distribution, and within the range of 600 mm on the left and right sides of the center position, the amount of ultraviolet irradiation (of the illuminance in FIG. It was confirmed that the integrated value was about 20% higher than that of the light irradiation device for comparison.
The reason is considered as follows. That is, the ultraviolet light scattering reflection film formed on the light source lamp is formed on the surface of the sealing body of the rod-shaped light source lamp having a circular cross section, and the cross section of the reflection surface of the ultraviolet light scattering reflection film is also circular. For example, assuming that light is emitted from the center of the light source lamp, the light is reflected in a direction opposite to 180 ° from the direction emitted by the ultraviolet light scattering reflection film.
However, the light emitting portion in an actual light source lamp has a certain thickness, and light is emitted from the surface of the light emitting portion having the thickness. That is, the position where the light is emitted is slightly deviated from the center of the lamp, and the light reflected by the ultraviolet scattering reflection film as shown as “reflected light I2 by the ultraviolet scattering reflection film” in FIG. It is reflected and slightly reflected from the center rather than the 180 ° opposite side. Therefore, it is considered that high illuminance portions are generated on both sides of the center position in the illuminance distribution.
As described above, according to the light irradiation apparatus according to the present invention, the light emitted in the direction of the cooling air path, which could not be effectively used with the comparative light irradiation apparatus, is converted into the ultraviolet light scattering reflection film. In addition, it was confirmed that the light can be effectively used by being reflected by a reflecting mirror, and the amount of light irradiation can be increased.
If the range in which the amount of light irradiation on the light irradiation surface can be increased is within the range of 600 mm from the center position to the left and right, the entire object to be processed can be practically covered, which is practically sufficient. Expected to be effective.

Moreover, when the temperature of the nozzle part at the time of lighting of a light source lamp was measured, in the light irradiation apparatus for a comparison, it was about 120-130 degreeC, but in the light irradiation apparatus which concerns on this invention, about It was about 100 degreeC, and it was confirmed that it is a temperature state 20 degreeC or more lower than the light irradiation apparatus for a comparison.
This is because, in the light irradiation device according to the present invention, the light emitted in the cooling air path direction is reflected by the ultraviolet scattering reflection film, emitted through the light emission port, and directly irradiated onto the nozzle portion. This is probably because the amount of light irradiation was reduced. Therefore, it is confirmed that the light irradiation device can be configured to have a sufficient cooling function without increasing the amount of cooling air required to prevent the nozzle portion from being overheated. It was.

Hereinafter, experimental examples performed for confirming the effect of the ultraviolet scattering reflection film formed of the alumina particles according to the present invention will be described.
<Experimental example 2>
In this experimental example, an experimental sample was formed by forming a reflective film formed of alumina particles by thermal spraying on a quartz glass flat plate. Four types of experimental samples were prepared which have the same quartz glass specifications but different UV scattering reflection film thicknesses. The specifications of the experimental sample are as follows.
[Sample for experiment]
Quartz glass: 35 mm x 35 mm, plate thickness 1 mm
Sample 1: 50 μm film thickness
Sample 2: Film thickness 100 μm
Sample 3: Film thickness 150 μm
Sample 4: 250 μm film thickness

FIG. 7 is a schematic diagram for explaining a measurement system for measuring the diffuse reflectance of the ultraviolet scattering reflection film formed on the sample. 61 is a light source lamp, 62 is an integrating sphere, 63 is a photodetector, and S is the above samples 1 to 4. The light source lamp 61 is a standard light source that emits ultraviolet rays having a predetermined wavelength.
As shown in FIG. 7, ultraviolet light having a wavelength of 254 nm or ultraviolet light having a wavelength of 365 nm emitted from the light source lamp is transmitted through the quartz glass of the sample S and reflected by the ultraviolet scattering reflection film of the sample S. It is scattered by being irradiated on the inner surface, and is irradiated toward the photodetector 63. By measuring the intensity of the ultraviolet rays scattered on the inner surface of the integrating sphere 62 with the photodetector 63, the diffuse reflectance of the ultraviolet scattering reflecting film is obtained for each of the samples 1 to 4 as compared with the sample without the sprayed film.

The experimental results of the second experimental example are shown in FIG. In FIG. 8, the vertical axis represents the diffuse reflectance (%) of the ultraviolet scattering reflection film, the horizontal axis represents the film thickness (μm) of the ultraviolet scattering reflection film, and the diffuse reflectance when irradiated with ultraviolet light having a wavelength of 254 nm. The relationship between the film thickness and the film thickness is indicated by Δ, and the relationship between the diffuse reflectance and the film thickness when irradiated with ultraviolet light having a wavelength of 365 nm is indicated by □.
From the results shown in FIG. 8, when the experimental sample 2 (film thickness 100 μm) is irradiated with ultraviolet light having a wavelength of 254 nm, the experimental sample 1 (film thickness 50 μm) is irradiated with ultraviolet light of the same wavelength. It was confirmed that the diffuse reflectance of the ultraviolet scattering reflection film was increased by about 20% compared to In addition, when the experimental sample 3 (film thickness 150 μm) and the experimental sample 4 (film thickness 250 μm) are irradiated with ultraviolet rays of the same wavelength, the diffuse reflectance is 50%, which is the same as the experimental sample 2 It was confirmed that there was.
Further, when ultraviolet rays having a wavelength of 365 nm are irradiated to the experimental samples 1 to 3, the diffuse reflectance increases as the film thickness of the ultraviolet scattering reflection film increases. It was confirmed that the diffuse reflectance of the ultraviolet scattering reflection film was higher by about 50% than 1. Further, when the experimental sample 4 was irradiated with ultraviolet rays having the same wavelength, it was confirmed that the diffuse reflectance was 60%, which was equivalent to the experimental sample 3.

  As described above, in order to efficiently reflect ultraviolet light having a wavelength of 254 nm, it is optimal that the ultraviolet scattering / reflecting film formed of alumina particles has a film thickness of 100 nm or more, and ultraviolet light having a wavelength of 365 nm is efficiently used. In order to reflect, it was confirmed that the film thickness is optimally 150 μm or more. Therefore, in the light irradiation apparatus of the present invention including the light source lamp formed with the reflection film formed of the alumina particles, the film thickness of the ultraviolet scattering reflection film is set as described above, so that the cooling air passage direction is set. It is expected that the radiated light can be effectively used by being reflected by the ultraviolet scattering reflection film and the reflection mirror, and the amount of light irradiation can be increased.

As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment, A various change can be added.
For example, in the above-described embodiment, the exhaust cooling method in which the cooling air is sucked into the lamp house by the exhaust fan has been described as an example. However, the cooling by which the cooling air is supplied into the lamp house through the cooling air passage is described. It may be of a system.
Further, in the light irradiation device of the present invention, the nozzle for setting the width with the light source lamp may be formed integrally with the partition wall of the lamp house of the light irradiator, or may be formed separately from the partition wall, Either may be sufficient.
Further, the reflecting mirror constituting the light irradiator may have a reflecting surface that is not an ellipsoid but a paraboloid.
Furthermore, in the light irradiation apparatus of the present invention, the reflection mirror constituting the light irradiator is combined with two mirrors having a length equal to or longer than the light emission length of the light source lamp and having a reflection surface. It may be a bowl. In this case, a cooling air path is formed between the two reflecting mirrors.
Further, the opening formed at the top of the reflecting mirror may be formed by a plurality of holes formed at positions spaced apart from each other along the light source lamp.

It is sectional drawing which shows the outline of a structure in an example of the light irradiation apparatus of this invention. It is a perspective view which shows the outline of a structure of the light irradiation device in the light irradiation apparatus shown in FIG. It is sectional drawing which shows a cross section perpendicular | vertical to the tube axis | shaft of a light source lamp of the light irradiation device shown in FIG. It is a top view which shows the outline of a structure in an example of the light source lamp of this invention. It is sectional drawing of the ultraviolet-ray scattering reflection film formed in the light source lamp of this invention. It is a graph which shows the illumination intensity distribution by the light irradiation apparatus based on this invention produced in Experimental example 1. FIG. It is the schematic for demonstrating the experiment example 2. FIG. It is a graph which shows the relationship between the diffuse reflectance by the experimental sample produced in Experimental example 2, and the film thickness of a ultraviolet-ray scattering reflection film. It is sectional drawing which shows the outline of a structure in an example of the conventional light irradiation apparatus. It is sectional drawing which shows a cross section perpendicular | vertical to the tube axis | shaft of a light source lamp of the light irradiator which comprises the light irradiation apparatus shown in FIG. It is a perspective view which shows the outline of the structure in the other example of the conventional light irradiation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light irradiator 11 Lamphouse 11A Light irradiation port 11B Through-hole 12 Bulkhead 13 Wind tunnel 14 Lamp arrangement space 15 Cooling air flow opening 15A Through-hole 16 Exhaust fan 17 Duct 18 Nozzle 18A Reflective mirror holder 19 Cooling air channel 20 Light source lamp 21 Enclosure 22 Electrode 23 Wind shield member 25 UV scattering reflection film 30 Reflection mirror 31 Aperture f1 First focus f2 Second focus I1 Reflected light by reflection mirror I2 Reflected light by ultraviolet scattering reflection film 40 Light irradiator 41 Lamp House 42 Bulkhead 43 Wind tunnel 44 Lamp placement space 45 Cooling air flow opening 46 Nozzle part 46A Nozzle 48 Duct 49 Exhaust fan 50 Light source lamp 55 Reflecting mirror 56 Opening part 60 Cooling air path W Object to be processed 61 Light source lamp 62 Integrating sphere 63 Detector S Sample

Claims (10)

A rod-shaped light source lamp having a circular cross section includes a light irradiator having a tube axis aligned with the position of the first focal point of a bowl-shaped reflection mirror having a reflecting surface. A light irradiation device in which the light source lamp and the reflection mirror are cooled by cooling air when lit,
On the rear side of the light source lamp with respect to the light irradiation direction, there is formed a cooling air passage communicating with the space surrounded by the reflection mirror for circulating the cooling air,
The outer surface region facing the opening of the cooling air passage in the light source lamp is provided with an ultraviolet light scattering reflection film made of alumina (Al ₂ O ₃ ) that reflects light emitted from the light source lamp. A light irradiation device. The light irradiation apparatus according to claim 1, wherein the ultraviolet scattering reflection film is formed of alumina (Al ₂ O ₃ ) particles.   2. The light irradiation apparatus according to claim 1, wherein the light source lamp is a high-pressure mercury lamp that mainly emits light having a wavelength of 254 nm, and the film thickness of the ultraviolet scattering reflection film is 100 μm or more.   2. The light irradiation apparatus according to claim 1, wherein the light source lamp is a metal halide lamp that mainly emits light having a wavelength of 365 nm, and the film thickness of the ultraviolet light scattering reflection film is 150 μm or more. A light source lamp used in the light irradiation device according to claim 1,
Cooling, comprising a rod-shaped envelope having a circular cross section and communicating with the space surrounded by the reflection mirror in the state of being disposed at the position of the first focal point of the bowl-shaped reflection mirror in the light irradiator A light source lamp, characterized in that an ultraviolet scattering reflection film made of alumina (Al ₂ O ₃ ) is formed on an outer surface region of a sealed body facing an opening of a cooling air passage for circulating air. In the cooling air passage formed to extend along the light source lamp at the top of the reflection mirror, a nozzle for setting the width with the light source lamp is provided,
The ultraviolet light scattering reflection film is formed to extend along the tube axis over the entire light emitting region in an outer surface region in an angular range in which a nozzle centering on the tube axis is viewed in a cross section perpendicular to the tube axis of the light source lamp. The light source lamp according to claim 5, wherein: The light source lamp according to claim 5 or 6, wherein the ultraviolet light scattering reflection film is formed of alumina (Al ₂ O ₃ ) particles.   The light source lamp according to claim 5 is a high-pressure mercury lamp that mainly emits light having a wavelength of 254 nm, wherein the film thickness of the ultraviolet scattering reflection film is 100 μm or more.   The light source lamp according to claim 5 is a metal halide lamp that mainly emits light with a wavelength of 365 nm, wherein the film thickness of the ultraviolet scattering reflection film is 150 μm or more.   The light irradiation device according to claim 1 or 4, or the light source lamp according to claim 5 to 9, wherein the ultraviolet scattering reflection film is formed by thermal spraying.

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