JP2005203481A - Ultraviolet ray irradiator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size and weight and to enable high-intensity irradiation on a narrow region. <P>SOLUTION: This ultraviolet ray irradiator 1 comprises a plurality of light emitting diodes 2 which are so arranged as to form one plane and are arranged at equal intervals on a concentric circle from a main optical axis of the device, collimate optical systems 3 in the same number as that of the light emitting diodes 2 which are arranged on the light emission side in correspondence with each the light emitting diodes 2, and one power supply housing 6 for holding the plurality of light emitting diodes 2 and the plurality of collimate optical systems 3. A stand may be arranged to hold the power supply housing 6 as well as to adjust the vertical position thereof. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ultraviolet irradiation device using a light emitting diode (hereinafter referred to as LED) that emits ultraviolet light as a light source.

  Conventionally, an ultraviolet irradiation device is used in backlight illumination, photocuring of ultraviolet curable resin, sterilization, cleaning, semiconductor manufacturing processes, and the like. As a light source of the ultraviolet irradiation device, a discharge lamp such as high pressure mercury, metal halide or xenon is mainly used.

  When the resin is cured using the light source of this type of discharge lamp, the following devices are required. That is, since the discharge lamp projects not only the ultraviolet region necessary for photocuring processing but also a wide spectrum light from the deep ultraviolet to the far infrared, the reflection mirror of the light source lamp is disclosed in Patent Document 1. As a result, it is necessary to use a cold mirror that transmits infrared light and reflects ultraviolet rays with high efficiency, and a band-pass filter (cold filter) that cuts visible light and unnecessary ultraviolet regions.

JP 5-156050 (abstract)

  In order to obtain predetermined ultraviolet rays, the conventional ultraviolet irradiation device requires the above-described device, that is, use of extra parts such as a cold mirror and a cold filter. For this problem, a countermeasure using an LED that emits ultraviolet rays that has recently appeared (hereinafter referred to as an ultraviolet LED) can be considered. If the ultraviolet LED is used, it is not necessary to use a member such as a cold mirror, and a reduction in size and weight can be achieved.

  However, the ultraviolet LED alone has a very low radiation intensity and is not sufficient as a light source. When an ultraviolet LED is employed as a light source for use in resin curing, a backlight, or other applications, it is necessary to increase the amount of irradiation light by arranging a large number of ultraviolet LEDs. When a large number of ultraviolet LEDs are simply arranged side by side in this way, the effective surface area of the light source becomes large and cannot be used in applications that require high intensity irradiation in a narrow area.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an ultraviolet irradiation device that can achieve a reduction in size and weight and can perform high-intensity irradiation in a narrow region.

  In order to solve the above-described problems, an ultraviolet irradiation device of the present invention includes a plurality of light emitting diodes that emit ultraviolet light, and a collimating optical system that is disposed on the light emission side corresponding to each light emitting diode. Yes.

  According to the present invention, it is possible to obtain an ultraviolet irradiation device that can achieve a reduction in size and weight and can perform high-intensity irradiation in a narrow region.

  According to another aspect of the present invention, there is provided a plurality of light emitting diodes that emit ultraviolet rays that are arranged so as to be equidistant from each other on a concentric circle from a main optical axis of the device. A number of collimating optical systems equal to the number of light emitting diodes arranged on the light emitting side corresponding to the diodes, a single light source casing holding a plurality of light emitting diodes and a plurality of collimating optical systems, and a light source casing And a stand that holds and adjusts the height position thereof. Note that the light source casing may also hold a single condensing optical system that bundles the plurality of collimated lights into one.

  According to the present invention, it is possible to obtain an ultraviolet irradiation device that can achieve a reduction in size and weight and can perform high-intensity irradiation in a narrow region. In addition, the light source housing makes it easy to handle the light source, and the ultraviolet light emitted from the height-adjustable stand is irradiated with ultraviolet light at an appropriate intensity, for example, an object coated with ultraviolet curable resin. Can be irradiated.

  Furthermore, the ultraviolet irradiation device according to another invention includes a single or a plurality of light emitting diodes that emit ultraviolet light, a collimating optical system disposed on the light emitting side corresponding to each light emitting diode, and light emitted from the collimating optical system. Condensing optical system that collects light, and a flexible light guide that enters the light collected by the condensing optical system, guides the incident light to the vicinity of the position of the work to be irradiated, and emits ultraviolet light in the work direction And have.

  By adopting the configuration of the present invention, it is possible to obtain an ultraviolet irradiation device that can achieve a reduction in size and weight and can perform high-intensity irradiation in a narrow region. In addition, the use of a light guide can alleviate restrictions on the installation conditions of the ultraviolet irradiation device.

  Furthermore, in another invention, in addition to the ultraviolet irradiation device of each of the above-described inventions, one lens is arranged as a collimating optical system or two lenses are arranged in series. With such a simple collimating optical system, sufficient light collecting characteristics can be obtained.

  Further, it is preferable that one or more lenses are arranged in series as the collimating optical system, and at least one of the lenses is an aspheric lens. By using an aspheric lens, the collimating optical system has a simple configuration, and highly accurate collimation is achieved.

  Further, it is preferable to change the irradiation light quantity by direct modulation of the drive current of the light emitting diode. When this configuration is adopted, a conventionally used filter for changing the amount of irradiation light becomes unnecessary.

  Furthermore, it is preferable that the light emitting diode has a maximum emitted wavelength in the range of 363 nm to 367 nm. If it does in this way, the ultraviolet curable resin currently widely used for the industrial use can be hardened most efficiently.

  In addition, it is preferable to arrange a single field lens that covers them immediately after the plurality of collimating optical systems to improve the light condensing characteristics to the workpiece irradiated with ultraviolet rays. In this configuration, since the light condensing characteristics are improved, the irradiation intensity to the workpiece is increased, and the work efficiency is improved.

  Further, it is preferable to arrange a diffuser plate that makes the irradiation intensity distribution uniform immediately after the field lens. When this configuration is adopted, the irradiation intensity distribution becomes uniform. For example, in the case of resin curing, there is no variation and a stable quality curing action can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the ultraviolet irradiation device which can achieve size reduction and weight reduction and can perform high intensity | strength irradiation to a narrow area | region can be obtained.

  Hereinafter, an ultraviolet irradiation device according to an embodiment of the present invention will be described with reference to the drawings. First, the ultraviolet irradiation device 1 according to the first embodiment will be described with reference to FIGS.

  This ultraviolet irradiation device 1 is mainly composed of a plurality of ultraviolet LEDs 2 arranged in a plane and a plurality of collimating lenses 3 arranged on the light emission side corresponding to each ultraviolet LED 2. Here, the numbers of the ultraviolet LEDs 2 and the collimating lenses 3 are the same, and are four in this embodiment. The collimating lens 3 serves as a collimating optical system. In this embodiment, the collimating lens 3 is a single plano-convex aspheric lens having a circular shape.

  The ultraviolet irradiation device 1 further includes a field composed of one circular convex flat lens arranged so as to cover (cover) all of the plurality of collimating lenses 3 on the light emission side of the collimating lens 3. It has the lens 4, the radiation fin 5 arrange | positioned at the back side of ultraviolet LED2, and the light source housing | casing 6 which hold | maintains the ultraviolet LED2 and the collimating lens 3 while covering. The field lens 4 forms a condensing optical system.

  The ultraviolet LED 2 is a compound semiconductor made of gallium nitride (GaN) that mainly emits a wavelength of 380 nm. As the ultraviolet LED 2, other compound semiconductors, diamond pn junction diamond, or the like can be adopted. Currently, UV curable resins widely used in industrial applications are cured most efficiently (quickly) and reliably with light having a wavelength of 365 nm. For this reason, it is more preferable to use an ultraviolet LED 2 having a wavelength of 365 nm.

  The ultraviolet LED 2 that emits a wavelength of 380 nm does not emit only a wavelength of 380 nm, but the wavelength of 380 nm is the largest, but ultraviolet rays having a wavelength around 380 nm are also emitted. Therefore, hereinafter, when the ultraviolet LED is specified, it is performed at the wavelength to be emitted, and the wavelength of the light indicates the one having the largest light amount in the wavelength distribution to be emitted. In addition, the wavelength half value width of ultraviolet LED2 of this embodiment is 15 nm.

  The ultraviolet LED 2 of this embodiment emits ultraviolet light having a wavelength of 380 nm, but as described above, the one having the optimum wavelength of 365 nm for resin curing may be used. When an ultraviolet LED that emits ultraviolet light having a wavelength of 365 nm is used for resin curing, it may be in the range of 363 to 367 nm. If it is ultraviolet LED of this range, the effect similar to 365-nm ultraviolet LED can be acquired. Moreover, when aiming at sterilization, it is good also as what radiate | emits the ultraviolet-ray in the range of 200-280 nm with a high sterilization effect. Further, the ultraviolet LED 2 may have a unique lens provided integrally with each ultraviolet LED 2.

  As described above, the collimating lens 3 is a single aspherical lens, and is disposed with the plane side directed toward the ultraviolet LED 2 and the aspherical shape side directed toward the output side. In this embodiment, an aspheric lens made of a quartz material is used. However, when the wavelength is 380 nm, a glass material such as BK7 may be used. In addition, the collimating optical system may be configured with a plurality of lenses in which two lenses, three lenses, or the like are arranged in series without forming the collimating optical system with one lens. When the collimating optical system is configured by one or two lenses, the collimating optical system has a simple configuration. In this case, when at least one lens is an aspherical lens, a desired accuracy can be obtained despite the simple configuration of the optical system.

  The field lens 4 is also called a field lens, and the collimated lens 2 condenses the collimated (parallelized) ultraviolet rays onto the irradiation surface 11 (see FIG. 3) at a predetermined distance from the field lens 4. Is. That is, as shown in FIG. 3, the optical axes 12 of the ultraviolet rays emitted from the ultraviolet LEDs 2 intersect at the irradiation surface 11. Note that the optical axis 13 of the entire optical system passes through the center of the field lens 4. When the ultraviolet rays are condensed, the irradiation density is increased, and when the resin is cured, the curing rate is increased.

  In this embodiment, the field lens 4 is arranged with the convex side facing the collimating lens 3 and the plane side facing the output side. The convex surface side is generally preferably an aspherical surface, but may be a spherical surface. The aspherical surface improves the light collecting characteristics, but the cost is cheaper when the spherical surface is used.

  The heat radiating fin 5 is composed of a circular bottom surface portion 14 and a plurality of linearly formed projection portions 15. Each of the ultraviolet LEDs 2 generates a small amount of heat, but if there are a plurality of, for example, four or more, the total amount of generated heat cannot be ignored. Further, as a general characteristic of the LED, since the operation at a high temperature causes a decrease in efficiency, the ultraviolet LED 2 is naturally conducted air-cooled by the radiation fin 5.

  The light source housing 6 includes a cylindrical cylindrical housing 21, an end surface housing 22 to which the heat radiating fin 5 is fixed and which covers one opening of the cylindrical housing 21, and an internal housing for holding the collimating lens 3. It is mainly composed of a body 23 and a holding housing 24 for holding the field lens 4.

  A columnar stand mounting support rod 31 is fixed to the peripheral surface of the cylindrical casing 21. A rectangular substrate 32 to which the ultraviolet LED 2 is attached and a support portion 33 of the internal housing 23 are fixed to a surface of the end surface housing 22 opposite to the mounting surface of the radiation fin 5. A holding body 34 that holds the collimating lens 3 is fixed to the support portion 33, and a holding member 35 is fixed to the holding body 34 so as to sandwich the outer peripheral plane portion of the collimating lens 3.

  The holding body 34 has a disk shape and has four through holes 36 corresponding to positions where the collimating lens 3 is disposed. Further, the holding member 35 is in a disk shape like the holding body 34 and has four through holes 37 at positions where the collimating lens 3 is arranged.

  In this embodiment, as shown in FIG. 2, the four ultraviolet LEDs 2 are arranged in a square shape at equal intervals. Moreover, it arrange | positions so that the center of ultraviolet LED2 and the center of the collimating lens 3 may correspond. Furthermore, in this embodiment, the field lens 4 is disposed so as to close the other opening of the cylindrical housing 21. In this embodiment, the distance in the optical axis direction between the collimating lens 3 and the field lens 4 is fixed, but may be variable.

In the ultraviolet irradiation device 1 of the first embodiment, the output wavelength is 380 nm as described above, and the wavelength half width is 15 nm. The minimum condensing region is a circle with a diameter of about 30 mm, and the ultraviolet intensity at that time is about 17 mW / cm ² . The power consumption of the ultraviolet irradiation device 1 is 10 W.

  Next, the ultraviolet irradiation device 41 according to the second embodiment will be described with reference to FIG. In addition, this ultraviolet irradiation device 41 attaches the ultraviolet irradiation device 1 which concerns on 1st Embodiment to the stand 42 as a light source module, The description about the part of the ultraviolet irradiation device 1 is abbreviate | omitted.

  The ultraviolet irradiation device 41 is a processing device used for curing a resin that is cured by irradiating ultraviolet rays (hereinafter referred to as an ultraviolet curable resin). The ultraviolet curable resin is generally used as an adhesive for a transparent body. After the ultraviolet curable resin is applied to a portion of the irradiated object (work) 43 to be bonded, the member is bonded by irradiating the applied portion with ultraviolet rays. As shown in FIG. 4, the work 43 is disposed on a work table 44. The ultraviolet irradiation device 41 can also be used when the ultraviolet curable resin is formed into a sheet and used for repair or as an adhesive.

  The stand 42 includes a first attachment portion 45 for attaching the support rod 31 for attaching the stand, a second attachment portion 48 for attaching the holding rod 47 holding the diffusion plate 46, and an external operation with a magnet disposed inside. It has a fixed function part 51 that can be attached to the base part 50 by allowing the magnetic force of the magnet to work with the base part 50 by operating the knob 49 or not.

  This stand 42 can adjust the height position from the workpiece | work 43 of the ultraviolet irradiation device 1 used as a light source module by moving the 1st attachment part 45 up and down. In addition, the height and position of the diffusion plate 46 from the work 43 can be adjusted by moving the second mounting portion 48 up and down, and the distance from the ultraviolet irradiation device 1 can be adjusted. The diffusion plate 46 improves the uniformity of the irradiation intensity distribution.

  In this ultraviolet irradiation device 41, the ultraviolet rays emitted from the ultraviolet LED 2 are collimated by the collimating lens 3, condensed by the field lens 4, and condensed (spotted) on the portion of the workpiece 43 to which the ultraviolet curable resin is applied. Apply the UV light. When the spotted ultraviolet rays do not hit the desired position of the workpiece 43, the height position of the ultraviolet irradiation device 1 as the light source module is adjusted by operating the first mounting portion 45, and the spotted ultraviolet rays are applied to the workpiece. It is made to touch 43 desired positions (= part to which the ultraviolet curable resin is applied).

  In the ultraviolet irradiation devices 1 and 41 according to the first and second embodiments described above, each ultraviolet LED 2 is used in spite of the small diameter of the collimating optical system (collimating lens 3) serving as a condenser lens. Therefore, by combining the large-diameter field lens 4 that covers the entire light source and these collimating optical systems, it is possible to efficiently collect light on the irradiation surface 11 and the work 43. It can be realized uniformly. Further, by further combining the diffusion plate 46, the uniformity of light collection is further improved.

  Further, the ultraviolet irradiation devices 1 and 41 are smaller and lighter and have a longer life than the conventional ultraviolet irradiation devices. Also, low heat is achieved. Further, since the collimating optical system corresponding to the ultraviolet LED 2 has a one-to-one correspondence, the high light collection efficiency and the irradiation surface 11 can be obtained even for a plurality of high-power ultraviolet LEDs having a large light emitting chip area. Further, a more uniform irradiation intensity distribution on the workpiece 43 is achieved.

  Next, an ultraviolet irradiation device 61 according to a third embodiment will be described with reference to FIG. FIG. 5 shows an optical system of the ultraviolet irradiation device 61.

  Although only one ultraviolet LED 2 is shown in FIG. 5, a plurality of ultraviolet LEDs 2 are arranged. Each ultraviolet LED 2 is provided with a unique condensing lens 62 similar to the conventional one. Immediately after viewing from the light traveling direction of the unique lens 62, only one collimating lens 3 serving as a collimating optical system is disposed so as to correspond to each ultraviolet LED 2. Immediately after the collimating lens 3, only one condensing lens 7 serving as a condensing optical system is disposed. The collimating lens 3 and the condenser lens 7 form an incident optical system 63. In addition, although the distance between the collimating lens 3 and the condensing lens 7 is fixed, it is good also as variable. Moreover, it is good also as one instead of arranging multiple ultraviolet LED2.

  The ultraviolet rays narrowed down by the incident optical system 63 are collected at the incident end 65 of the flexible light guide 64 disposed immediately after the condenser lens 7 and enter the light guide 64. In this embodiment, the light guide 64 is a liquid-sealed light guide having a core diameter of 8 mm. However, the core may have a different core diameter, or may be other than a liquid-sealed structure, for example, an optical fiber bundled with quartz fibers. . When a large amount of ultraviolet rays is to be taken in, a larger diameter is adopted, while when the light guide 64 requires mechanical flexibility, it is preferable to adopt a core having a core diameter of less than 8 mm.

  The ultraviolet rays that have passed through the light guide 64 while being guided by the light guide 64 are emitted from the emission end 66 of the light guide 64. The emitted ultraviolet light is collimated by a collimating lens 67 disposed immediately after the light emitting end 66 of the light guide 64, then condensed by the field lens 68, and irradiated onto the irradiation surface 11 serving as a work area. The collimating lens 67 and the condensing lens 68 disposed immediately after that form an emission optical system 69. Note that the distance between the collimating lens 67 and the condenser lens 68 is fixed in this embodiment, but may be variable.

  Note that the collimating optical system is not composed of one collimating lens 3 but may be composed of two or three or more lenses arranged in series, and at least one lens is an aspherical lens. It is preferable to do this. In addition, the number of collimating lenses 3 is not one, but the same number as the number of ultraviolet LEDs 2 corresponding to each one of the ultraviolet LEDs 2 as in the ultraviolet irradiation devices 1 and 41 according to the first and second embodiments. The collimating lens may be arranged. Further, the diffusing plate 46 may be disposed immediately after the condenser lens 68.

  The ultraviolet irradiation device 61 according to the third embodiment can be installed in a place where installation conditions are severe by adopting a flexible light guide 64. That is, at the manufacturing site or the like, the irradiated object as a workpiece is behind other objects, and the ultraviolet irradiation devices 1 and 41 often fail to appropriately irradiate the irradiated object with ultraviolet rays. If the irradiation device 61 is used, it becomes possible to appropriately irradiate the irradiated object with ultraviolet rays even in such a case. In other words, the ultraviolet irradiation device 61 can greatly relieve restrictions on installation conditions.

  As described above, the ultraviolet irradiation devices 1, 41, 61 according to the respective embodiments employ the highly efficient collimating optical system in the light source unit, and thereby efficiently radiate light (= ultraviolet rays) from the ultraviolet LED 2 in the subsequent optical system. Can be imported. Further, since it can be projected forward as a light beam with many components substantially parallel to the optical axis, there is little loss in the handling of light in the subsequent optical system, and it is suitable as an ultraviolet irradiation device for condensing purposes. Moreover, it becomes suitable also as a light source module for condensing use.

  Further, since the light source of the ultraviolet irradiation devices 1, 41, 61 is an LED, it is driven at a low voltage, and a high voltage as in the conventional ultraviolet light source power supply is not required, and the power supply itself is safer and simpler in configuration. As a result, the number of maintenance can be reduced as compared with the conventional ultraviolet irradiation device, and the workability of handling in the laboratory or work site is greatly improved.

  Furthermore, since the radiation from the ultraviolet LED 2 used in the ultraviolet irradiation devices 1, 41, 61 can be prevented from including unnecessary infrared and visible spectrums, various types of radiation as in the case of a conventional lamp device are available. No filter is required. In addition, since the LED is a semiconductor element, the intensity of the emitted light can be easily modulated by the injection current modulation. Therefore, by adding an irradiation mode that incorporates modulation control of the amount of irradiation of ultraviolet rays, Optimal irradiation can be performed. That is, the amount of irradiation light can be changed by direct modulation of the drive current of the ultraviolet LED 2. As the injection current modulation, changing the duty of the current on / off, changing either one or both of the minimum value and the maximum value of the current can be employed.

  As described above, each embodiment is a preferred embodiment of the present invention, but various modifications can be made without departing from the gist of the present invention. For example, although the number of the ultraviolet LEDs 2 is four, three may be arranged in a regular triangle shape, five may be arranged in a regular pentagon shape, or six or more. In addition, the ultraviolet LEDs 2 are arranged on the flat substrate 32 so that the surfaces formed by connecting the radiating portions form one complete plane. You may arrange | position so that a surface may be formed, or it may arrange | position so that a part of several ultraviolet LED2 may come before or after another in the optical axis 13 direction.

  The ultraviolet LED 2 has a maximum light quantity of 380 nm or 365 nm, but may be an ultraviolet LED that emits light in another ultraviolet region depending on the application. For example, an ultraviolet LED of 400 nm, 395 nm, and 370 nm may be used. When an ultraviolet LED having a wavelength close to visible light such as 380 nm is used, a part of emitted light can be visually confirmed, and the operability is improved.

  One field lens 4 is preferable, but two may be arranged in parallel, or three or more may be arranged in parallel. Also, two or more lenses may be arranged in series as the condensing optical system. In addition to the field lens 4, a Fresnel lens, a biconvex lens, or the like may be used as the condensing optical system.

  The ultraviolet irradiation devices 1, 41 and 61 are suitable for curing ultraviolet curable resins, but besides their uses, curing ultraviolet curable inks, backlight light sources, sterilization of water and other things, air cleaning, glass and other It can be used for other purposes such as washing of things, production of thermoplastic resin film, charge erasing, banknote recognition device, photochemical reaction, and other devices.

It is sectional drawing of the ultraviolet irradiation device which concerns on the 1st Embodiment of this invention, and is sectional drawing by the AA cutting line of FIG. It is the front view seen from the right side of FIG. It is a figure which shows the optical system of the ultraviolet irradiation device of FIG. It is a figure which shows the ultraviolet irradiation device which concerns on the 2nd Embodiment of this invention. It is a figure which shows the optical system of the ultraviolet irradiation device which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

1 UV irradiation device 2 UV LED (diode that emits UV)
3 Collimating lens (collimating optical system)
4 Field lens (condensing optical system)
DESCRIPTION OF SYMBOLS 5 Radiation fin 6 Light source housing 7 Condensing lens 41 Ultraviolet irradiation device 42 Stand 46 Diffusion plate 61 Ultraviolet irradiation device 64 Light guide

Claims (9)

A plurality of light emitting diodes emitting ultraviolet light;
A collimating optical system disposed on the light emitting side corresponding to each of the light emitting diodes; A plurality of light emitting diodes emitting ultraviolet rays arranged so as to form one plane and equidistant from each other on a concentric circle from the apparatus main optical axis;
The same number of collimating optical systems as the number of the light emitting diodes arranged on the light emitting side corresponding to each of the light emitting diodes;
One light source housing holding the plurality of light emitting diodes and the plurality of collimating optical systems;
A stand for holding the light source housing and adjusting its height position;
The ultraviolet irradiation device characterized by having. A single or a plurality of light emitting diodes emitting ultraviolet light;
A collimating optical system disposed on the light emitting side corresponding to each of the light emitting diodes;
A condensing optical system that condenses the light emitted from the collimating optical system;
A flexible light guide that guides the light collected by the condensing optical system to near the position of the workpiece to be irradiated with the incident light, and emits ultraviolet rays in the workpiece direction;
The ultraviolet irradiation device characterized by having.   4. The ultraviolet irradiation device according to claim 1, wherein one lens is arranged as the collimating optical system or two lenses are arranged in series.   4. The ultraviolet irradiation device according to claim 1, wherein one or a plurality of lenses are arranged in series as the collimating optical system, and at least one of the lenses is an aspheric lens. UV irradiation equipment.   4. The ultraviolet irradiation apparatus according to claim 1, wherein the irradiation light quantity is changed by direct modulation of a driving current of the light emitting diode.   4. The ultraviolet irradiation device according to claim 1, wherein the light emitting diode has a maximum emitted wavelength in a range of 363 nm to 367 nm.   4. The ultraviolet irradiation apparatus according to claim 1, wherein a single field lens that covers them is arranged immediately after the plurality of collimating optical systems, thereby improving the light condensing characteristics to the workpiece irradiated with ultraviolet rays. An ultraviolet irradiation device characterized by that.   9. The ultraviolet irradiation apparatus according to claim 8, wherein a diffusion plate for uniforming the irradiation intensity distribution is disposed immediately after the field lens.

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