JP2008227062A - Ultraviolet ray irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size and to expand the life of an ultraviolet ray irradiation device. <P>SOLUTION: The ultraviolet ray irradiation device 100 comprises a semiconductor laser 12, a light guide 30, a wavelength conversion element 22, and a condensing lens 26. The semiconductor laser 12 emits laser light 102 in a visible light region. The light guide 30 transmits the laser light 102 to the wavelength conversion element 22. The wavelength conversion element 22 converts at least part of the laser light 102 into ultraviolet laser light 104. The condensing lens 26 condenses the ultraviolet laser light 104 and casts it on a target object. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ultraviolet irradiation device used when, for example, an ultraviolet curable resin is cured.

  An ultraviolet curable resin is a resin that cures from a liquid to a solid by irradiating light with a wavelength in the ultraviolet region, and since the curing time is short and the handling of the resin is relatively easy, It is used in a wide range of fields such as resist film formation.

Conventionally, as an ultraviolet irradiation means for curing this ultraviolet curable resin, an ultraviolet irradiation apparatus using a high-pressure mercury lamp or a mercury xenon lamp as a light source is generally used (see, for example, Patent Document 1). In such an ultraviolet irradiation device, light emitted from a light source is transmitted to a head portion through a light guide in which quartz fibers are bundled, and ultraviolet rays are irradiated from the head portion.
JP 2006-12486 A

  However, high-pressure mercury lamps and mercury-xenon lamps generate a large amount of heat, so a large cooling mechanism is required and the apparatus becomes large. In addition, high-pressure mercury lamps and mercury xenon lamps need to be constantly lit to stabilize light emission, so that energy consumption is large and lamp life is short.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ultraviolet irradiation device that is small in size and has an improved device life.

  In order to solve the above problems, an ultraviolet irradiation device according to an aspect of the present invention includes a semiconductor laser that emits laser light, a wavelength conversion element that converts laser light from the semiconductor laser into laser light in the ultraviolet region, and wavelength conversion. Condensing means for condensing the laser light from the element.

  According to this aspect, since a heat generation amount is relatively small by using a semiconductor laser as a light source, a very large cooling mechanism is not necessary, and the apparatus can be miniaturized. In addition, a semiconductor laser originally has a longer life than a high-pressure mercury lamp or a mercury xenon lamp and can stabilize light emission in a short time. Therefore, it is only necessary to emit light when irradiation is necessary. Therefore, the life of the apparatus can be improved.

  You may further provide the light guide which guides the laser beam from a semiconductor laser to a wavelength conversion element. In this case, since the head unit that emits ultraviolet rays can be reduced in size, the apparatus can be handled easily.

  The light guide may be composed of a plastic optical fiber or a multicomponent optical fiber. In this case, the apparatus can be configured at low cost.

  You may further provide the infrared light source which radiate | emits infrared light, and the multiplexing means to multiplex the infrared light from an infrared light source, and the laser beam from a semiconductor laser. Some UV curable adhesives require a high temperature environment as a curing condition. By comprising in this way, an ultraviolet curable adhesive can be heated with infrared light, and a curing reaction can be performed suitably.

  The semiconductor laser may emit laser light in the visible light region. As a semiconductor laser in the visible light region, since a high-power semiconductor laser has been put into practical use, the irradiation power of the apparatus can be increased. Further, the laser beam in the visible light region can be used as a marker for the user to visually recognize the ultraviolet irradiation region.

The wavelength conversion element may be formed of a nonlinear optical crystal that generates a second harmonic or a third harmonic with respect to incident light. Nonlinear optical crystal, BBO, LBO, CLBO, may be any of LB _4. Since these nonlinear optical crystals have high transparency with respect to ultraviolet rays, wavelength conversion can be suitably performed.

  It should be noted that any combination of the above-described constituent elements and a representation of the present invention converted between a method, an apparatus, a system, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the ultraviolet irradiation device which was small and improved the apparatus lifetime can be provided.

  FIG. 1 is a diagram showing a configuration of an ultraviolet irradiation apparatus according to an embodiment of the present invention. FIG. 1 shows a state in which the ultraviolet curable adhesive 50 applied on the parts A and B is irradiated with ultraviolet rays. The ultraviolet irradiation device 100 includes a main body unit 10, a head unit 20, and a light guide 30.

  The main body 10 includes a semiconductor laser 12 and a coupling lens 14. The semiconductor laser 12 emits laser light 102 having a wavelength in the visible light region. Here, as an example, it is assumed that laser light 102 having a wavelength of 650 nm is emitted. The coupling lens 14 is a lens for coupling the laser light 102 emitted from the semiconductor laser 12 to the light guide 30. Although FIG. 1 illustrates a coupling optical system using one coupling lens 14, the coupling optical system may be configured using a curved mirror and a plurality of lenses. Although not shown, the main body 10 further includes a power supply device for supplying current to the semiconductor laser 12, a cooling device for the semiconductor laser 12, and the like.

  The light guide 30 has a function of guiding the laser beam 102 emitted from the semiconductor laser 12 to the head unit 20. By providing the light guide 30, it is not necessary to provide a light source in the head unit 20, so that the head unit 20 becomes small and the apparatus can be easily handled.

  The light guide 30 is formed of a single optical fiber. As the optical fiber, a suitable fiber is selected according to the wavelength of the semiconductor laser 12 and the application. In the ultraviolet irradiation apparatus 100 according to the present embodiment, since the semiconductor laser 12 having a wavelength of 650 nm is used, a quartz optical fiber, a plastic optical fiber, a multicomponent optical fiber, or the like can be used as the optical fiber. It is preferable to select an optical fiber suitable for characteristics such as the wavelength and output of the light source. By using an inexpensive plastic optical fiber or multicomponent optical fiber as compared with a quartz optical fiber, the apparatus can be configured at a low cost. Furthermore, since the plastic optical fiber has high bending durability, there is an advantage that the apparatus can be easily handled.

The head unit 20 includes a wavelength conversion element 22, a wavelength selective mirror 24, and a condenser lens 26. The wavelength conversion element 22 converts at least a part of the laser light 102 guided by the light guide 30 into the ultraviolet laser light 104 in the ultraviolet region. The wavelength conversion element 22 is formed of a nonlinear optical crystal that generates second harmonics with respect to incident light. As such nonlinear optical crystals for second harmonic generation, BBO (β-BaB ₂ O ₄ ), LBO (LiB ₃ O ₅ ), CLBO (CsLiB ₆ O ₁₀ ), and LB4 (LiB ₄ O ₇ ) are used. It can be illustrated. These nonlinear optical crystals are known to be suitable for generating ultraviolet rays because of their high transparency to ultraviolet rays. In the ultraviolet irradiation apparatus 100 according to the present embodiment, at least a part of the laser light 102 from the semiconductor laser 12 is converted into the ultraviolet laser light 104 having a wavelength of 325 nm by the wavelength conversion element 22.

  The wavelength selective mirror 24 is provided in order to efficiently perform wavelength conversion by the wavelength conversion element 22. The wavelength selective mirror 24 is configured to transmit only light having a wavelength in the ultraviolet region and reflect light having other wavelengths. In the present embodiment, a partial reflection film is formed on the end face of the wavelength conversion element 22 on the light guide 30 side, and the reflection film and the wavelength selective mirror 24 constitute an optical resonator. As described above, it is known that by using the optical resonator, the fundamental wave intensity inside the wavelength conversion element 22 can be increased and high-efficiency conversion can be performed. The condensing lens 26 condenses the ultraviolet laser beam 104 transmitted through the wavelength selective mirror 24 and irradiates the ultraviolet curable adhesive 50.

  The operation of the ultraviolet irradiation device 100 configured as described above will be described. Laser light 102 emitted from the semiconductor laser 12 enters the light guide 30 through the coupling lens 14. The laser beam 102 transmitted through the light guide 30 is at least partially converted into the ultraviolet laser beam 104 by the wavelength conversion element 22. The ultraviolet laser beam 104 that has passed through the wavelength selective mirror 24 is applied to the ultraviolet curable adhesive 50 through the condenser lens 26. As a result, the ultraviolet curable adhesive 50 is cured from a liquid to a solid, and the parts A and B can be bonded.

  According to the ultraviolet irradiation device 100 configured as described above, since the heat generation amount is relatively small by using the semiconductor laser 12 as a light source, a very large cooling mechanism is not necessary, and the device can be miniaturized. The semiconductor laser 12 originally has a longer life than a high-pressure mercury lamp and a mercury xenon lamp, and can stabilize light emission in a short time. Therefore, it is only necessary to emit light when irradiation is necessary. Therefore, the lifetime of the semiconductor laser 12 is extended, and as a result, the lifetime of the ultraviolet irradiation device 100 can be improved.

  In an ultraviolet irradiation apparatus using a conventional high-pressure mercury lamp or mercury xenon lamp, an expensive quartz fiber has to be used as a light guide in order to transmit light in the ultraviolet region. According to the ultraviolet irradiation device 100 according to the present embodiment, since the laser light 102 transmitted by the light guide 30 is laser light in the visible light region, various optical fibers can be selected according to the purpose. It is. For example, by configuring the light guide 30 with quartz fiber, it is possible to configure the ultraviolet irradiation device 100 with improved light utilization efficiency. Moreover, the ultraviolet irradiation apparatus 100 can be comprised cheaply by comprising the light guide 30 with a plastic optical fiber or a multi-component optical fiber. In addition, since a high-power semiconductor laser has already been put to practical use for the semiconductor laser in the visible light region, it is possible to increase the irradiation power of the apparatus.

  In addition, conventional high-pressure mercury lamps and mercury xenon lamps emit light with an unnecessary wavelength in addition to light with a wavelength in the necessary ultraviolet region, and the light with this unnecessary wavelength damages an object. Was the cause of strain and residual stress. According to the ultraviolet irradiation device 100 according to the present embodiment, since only the ultraviolet laser beam 104 can be irradiated, such a problem can be avoided.

  FIG. 2 is a diagram illustrating another configuration example of the ultraviolet irradiation device. In FIG. 2, the same or corresponding components as those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted as appropriate. In FIG. 2, the ultraviolet curable adhesive 60 applied on the parts A and B is an ultraviolet curable adhesive that requires a high temperature environment as a curing condition.

  The ultraviolet irradiation apparatus 200 according to the present embodiment is mainly different from the ultraviolet irradiation apparatus 100 shown in FIG. The main body 210 of the ultraviolet irradiation device 200 includes a semiconductor laser 12, collimator lenses 28 and 32, a prism 34, a coupling lens 14, and an infrared semiconductor laser 36.

  The collimator lens 28 converts the laser beam 102 having a wavelength of 650 nm from the semiconductor laser 12 into parallel light. The infrared semiconductor laser 36 emits infrared laser light 106 in the infrared region. The infrared semiconductor laser 36 may be an infrared LED or a red LED. The collimator lens 32 converts the infrared laser beam 106 into parallel light. The prism 34 combines the parallel light of the laser light 102 from the collimator lens 28 and the parallel light of the infrared laser light 106 from the collimator lens 32. The coupling lens 14 couples the combined laser beam 108 combined by the prism 34 to the light guide 30.

  The wavelength selective mirror 24 of the head unit 220 is preferably configured to transmit not only light having a wavelength in the ultraviolet region but also light having a wavelength in the infrared region.

  The operation of the ultraviolet irradiation apparatus 200 shown in FIG. 2 will be described. The laser beam 102 from the semiconductor laser 12 and the infrared semiconductor laser 36 to the infrared laser beam 106 are combined by the prism 34 and incident on the light guide 30 as a combined laser beam 108. Of the combined laser beam 108 transmitted by the light guide 30, at least a part of the laser beam 102 is converted into an ultraviolet laser beam by the wavelength conversion element 22. The combined laser beam 110 of the ultraviolet laser beam and the infrared laser beam transmitted through the wavelength selective mirror 24 is condensed by the condenser lens 26 and irradiated to the ultraviolet curable adhesive 60. Since the ultraviolet curable adhesive 60 is heated by infrared laser light, the ultraviolet curable adhesive 60 can be suitably cured.

  FIG. 3 is a diagram showing still another configuration of the ultraviolet irradiation device. The ultraviolet irradiation device 300 illustrated in FIG. 3 includes a main body portion 310, a cable 314, and a head portion 320. The ultraviolet irradiation apparatus 300 is different from the above-described ultraviolet irradiation apparatus in that the head unit 320 includes the semiconductor laser 12 that is a light source.

  The main body 310 includes a current control unit 312 that controls the drive current of the semiconductor laser 12. The drive current output by the current control unit 312 is supplied to the semiconductor laser 12 via the cable 314.

  The head unit 320 includes the semiconductor laser 12, the wavelength conversion element 22, the wavelength selective mirror 24, and the condenser lens 26. The semiconductor laser 12 emits laser light 102 having a wavelength of 650 nm. At least a part of the laser beam 102 emitted from the semiconductor laser 12 is converted into the ultraviolet laser beam 104 by the wavelength conversion element 22. The ultraviolet laser beam 104 that has passed through the wavelength selective mirror 24 is collected by the condenser lens 26 and irradiated onto the ultraviolet curable adhesive 50.

  According to the ultraviolet irradiation device 300 configured as described above, since the head unit 320 includes the semiconductor laser 12 that is a light source, a light guide for transmitting light becomes unnecessary, and thus the device can be configured at low cost. . Further, since the cable 314 has higher bending durability than the light guide made of optical fiber, the device can be handled easily.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and various modifications can be made to combinations of the respective constituent elements. Those skilled in the art will appreciate that such modifications are also within the scope of the present invention.

  For example, in the above-described embodiment, a semiconductor laser having a wavelength of 650 nm is used as the semiconductor laser 12, but a semiconductor laser having another wavelength may be used. Further, third harmonic generation of the wavelength conversion element 22 may be used. For example, ultraviolet laser light having a wavelength of 350 nm can be output by generating third harmonics of laser light having a wavelength of 1050 nm.

  Further, in the ultraviolet irradiation device 100 of FIG. 1, the wavelength selective mirror 24 is configured to selectively transmit only ultraviolet light, but may be configured to transmit part of the laser light in the visible light region. In this case, the laser light in the visible light region transmitted through the wavelength selective mirror 24 can be used as a marker for the user to visually recognize the ultraviolet irradiation region.

It is a figure which shows the structure of the ultraviolet irradiation device which concerns on embodiment of this invention. It is a figure which shows another structural example of an ultraviolet irradiation device. It is a figure which shows another structure of an ultraviolet irradiation device.

Explanation of symbols

  10, 210, 310 Main body part, 12 Semiconductor laser, 14 Coupling lens, 16 Wavelength conversion element, 20, 220, 320 Head part, 22 Wavelength conversion element, 24 Wavelength selective mirror, 26 Condensing lens, 28, 32 Collimator Lens, 30 light guide, 34 prism, 36 infrared semiconductor laser, 50, 60 UV curable adhesive, 100, 200, 300 UV irradiation device, 312 current control unit, 314 cable.

Claims (7)

A semiconductor laser that emits laser light;
A wavelength conversion element that converts laser light from the semiconductor laser into laser light in the ultraviolet region;
Condensing means for condensing the laser light from the wavelength conversion element;
An ultraviolet irradiation device comprising:   The ultraviolet irradiation apparatus according to claim 1, further comprising a light guide for guiding laser light from the semiconductor laser to the wavelength conversion element.   The ultraviolet light irradiation apparatus according to claim 2, wherein the light guide is made of a plastic optical fiber or a multicomponent optical fiber.   2. An infrared light source that emits infrared light; and a multiplexing unit that combines infrared light from the infrared light source and laser light from the semiconductor laser. 4. The ultraviolet irradiation device according to any one of 3 above.   The ultraviolet irradiation apparatus according to claim 1, wherein the semiconductor laser emits laser light in a visible light region.   6. The ultraviolet irradiation according to claim 1, wherein the wavelength conversion element is formed of a nonlinear optical crystal that generates a second harmonic or a third harmonic with respect to incident light. apparatus.   The ultraviolet irradiation apparatus according to claim 6, wherein the nonlinear optical crystal is any one of BBO, LBO, CLBO, and LB4.

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