JP2013077732A - Ultraviolet light irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet light irradiation device capable of suppressing intensity variation within a width of a line and also suppressing even intensity variation due to the distance variation to an object when irradiating a surface of the object linearly with ultraviolet light.SOLUTION: An ultraviolet light irradiation device 1 includes two substrates 3 on which a plurality of laser diodes 2 are mounted side by side. On one surface of the substrate 3, laser diodes 2 are mounted in columns along a length direction. The substrates 3 are arranged having their length directions in parallel. Ultraviolet light emitted from a laser diode 2 has its propagation direction controlled by a diffraction optical element 5 so that the emission range spreads only in the length directions of the substrates 3. The ultraviolet light emitted from the laser diode 2 is diffracted by the diffraction optical element 5 to form a linear irradiation region on a predetermined irradiation surface, and irradiation regions that the laser diodes 2 arranged on the respective substrates 3 form overlap with one another on the irradiation surfaces.

Description

  The present invention relates to an ultraviolet irradiation device that irradiates the surface of an object with ultraviolet rays in a line shape.

  Conventionally, ultraviolet curable inks and ultraviolet curable coatings have been used for printing and painting on various objects. An ultraviolet irradiation device is required to cure the ultraviolet curable ink and the ultraviolet curable paint. Here, the object of printing or painting is a sheet-like printing raw material made of paper or cloth, a building board made of cement, etc. In many cases, the surface to be printed or painted is constant. It has a width.

  Accordingly, by using an ultraviolet irradiation device that irradiates the surface of the object with ultraviolet rays in a line shape, the target and the ultraviolet irradiation device are relatively displaced along the surface of the object, so that the ultraviolet ray is applied to a required region of the object. The structure which irradiates is widely adopted. In general, the object is conveyed in a direction perpendicular to the direction having a constant width, and ultraviolet irradiation is performed so as to form a line that intersects the direction in which the object is conveyed in a plane along the surface of the object. The structure which arrange | positions an apparatus is employ | adopted.

  As a light source used for an ultraviolet irradiation device, there is a high-intensity ultraviolet lamp such as a xenon lamp. In recent years, a light emitting diode (hereinafter abbreviated as “LED”) is used as a light source for the purpose of reducing power consumption. It has been proposed to use (see, for example, Patent Document 1). The ultraviolet irradiation device using LEDs can irradiate the object in a line shape by arranging a plurality of LEDs in a direction intersecting the direction in which the object is conveyed along the surface of the object. It is configured.

JP 2011-146646 A

  By the way, it is considered that the curing of the ultraviolet curable ink or the ultraviolet curable coating is accelerated as the amount of light determined by the intensity of the irradiated ultraviolet ray and the irradiation time of the ultraviolet ray increases. Therefore, in order to increase the number of processes per unit time, it is required to increase the intensity of the ultraviolet rays irradiated to the object. Also, when the distance between the object and the ultraviolet irradiation device changes, for example, when the object is a building board used for the outer wall and the surface is uneven, the distance from the ultraviolet irradiation device on the surface of the object The conveyance speed of the object is limited by the amount of light irradiated to the region where the maximum is.

  From the above viewpoint, it is considered that the luminance of the light source used in the ultraviolet irradiation device should be high. However, in the current technology, it is not possible to increase the luminance to the extent that the ultraviolet ray irradiation device using the LED as the light source meets the above requirements. It's not easy.

  Further, as described above, in order to obtain a light amount for curing the ultraviolet curable ink or the ultraviolet curable paint, it is necessary to consider not only the luminance of the light source but also the time for irradiating the ultraviolet rays in the direction of conveying the object. Therefore, when the object is irradiated with ultraviolet rays in a line shape, the dimension of the line in the direction in which the object is conveyed (that is, the width dimension of the line-shaped irradiation region) must be taken into consideration. Further, in order to complete the curing of the ultraviolet curable ink or the ultraviolet curable paint while the object passes through the ultraviolet irradiation region, it is necessary to consider the width dimension of the line in the direction in which the object is conveyed.

  In an ultraviolet irradiation device using an ultraviolet lamp or LED as a light source, a linear irradiation region is formed using an optical element such as a lens. However, even if the distribution of ultraviolet rays emitted from the ultraviolet lamp or LED is controlled by an optical element, the intensity of ultraviolet rays is smaller in the peripheral portion than in the central portion within the width of the line. Therefore, the speed at which the object is conveyed is set in accordance with the strength of the peripheral part within the width of the line. This contributes to a decrease in the speed at which the object is conveyed.

  The present invention has been made in view of the above reasons, and in irradiating the surface of an object with ultraviolet rays in a line shape, while suppressing an intensity change within the width of the line, an intensity change due to a distance change with the object It is an object of the present invention to provide an ultraviolet irradiation device that can suppress the above.

  The ultraviolet irradiation apparatus of the present invention includes a plurality of substrates, a laser diode having a light emission wavelength in the ultraviolet region and arranged in a row for each substrate, and diffracting ultraviolet rays emitted from the laser diode. A diffractive optical element, the diffractive optical element has a function of diffracting ultraviolet rays in the direction in which the laser diodes are arranged on the substrate, the substrate is arranged so that the directions in which the laser diodes are arranged are parallel to each other, and It is characterized in that they are inclined with respect to each other in a plane perpendicular to the direction in which the laser diodes are arranged so that the ultraviolet rays emitted from the respective substrates overlap on one line.

  The ultraviolet irradiation device preferably further includes light emitting diodes arranged in a plurality of rows in a mounting substrate having a light emission wavelength in the ultraviolet region and different from the substrate.

  In this ultraviolet irradiation device, it is more desirable that a plurality of groups of laser diodes for forming the lines are arranged on a single substrate, and that the timing of turning on and off is different for each group.

  In this ultraviolet irradiation apparatus, it is more desirable that a plurality of groups of laser diodes for forming the lines are arranged on a single substrate, and that the emission wavelength differs for each group.

  In this ultraviolet irradiation apparatus, it is more desirable to further include a lens for controlling the spread range of ultraviolet rays emitted from the laser diode between the laser diode and the diffractive optical element.

  The present invention has an advantage that, when irradiating an object with ultraviolet rays in a line shape, it is possible to suppress an intensity change within the width of the line and to suppress an intensity change due to a distance change from the object.

A basic structure is shown, (a) is a top view, (b) is a side view. It is a perspective view which shows the laser diode used for the same as the above. (A) is a side view showing the arrangement of the laser diode and the diffractive optical element in the above, (b) is a side view showing the arrangement of the laser diode, the diffractive optical element and the lens in the above, and (c) is one laser. It is a figure which shows the irradiation range to the surface of the target object by a diode. It is operation | movement explanatory drawing regarding the one board | substrate used for the same as the above. (A) is a side view showing the light distribution of the laser diode used in the above, and (b) is a diagram showing the intensity distribution of ultraviolet rays at a predetermined distance in FIG. 3 is a side view illustrating an arrangement example in Embodiment 1. FIG. It is a figure which shows the intensity distribution of the ultraviolet-ray in the example of arrangement | positioning shown in FIG. FIG. 10 is a side view showing an arrangement example in Embodiment 2. It is a figure which shows the intensity distribution of the ultraviolet-ray in the example of arrangement | positioning shown in FIG. (A) is a side view which shows the light distribution of the light emitting diode used for the above, (b) is a figure which shows intensity distribution of the ultraviolet-ray at a predetermined distance about the figure (a). It is operation | movement explanatory drawing which shows the usage example same as the above. FIG. 10 is an operation explanatory diagram of the third embodiment.

  Below, the case where an ultraviolet irradiation device is used for a printing apparatus is demonstrated as an example. The printing device is configured to cure the ultraviolet curable ink by irradiating the printing raw material with ultraviolet rays from the ultraviolet irradiation device after printing on the sheet-like printing raw material such as paper or cloth with the ultraviolet curable ink. Is done.

(Basic configuration)
As shown in FIG. 1, the ultraviolet irradiation device 1 includes a plurality of strip-shaped substrates 3, and a plurality of laser diodes 2 are mounted side by side on one surface in the thickness direction for each substrate 3. Here, in order to explain the basic configuration, the case where there are two substrates 3 is taken as an example. Further, two or more rows of laser diodes 2 can be arranged on one substrate 3, but in the illustrated example, only one row of laser diodes 2 is arranged on one substrate 3.

  As shown in FIG. 2, the laser diode 2 includes a cylindrical package 21. A light emitting window 22 that emits ultraviolet rays is formed on one end surface of the package 21, and a terminal 23 projects from the other end surface of the package 21.

  A diffractive optical element 5 that controls the propagation direction of ultraviolet rays using diffraction is disposed at a portion of the laser diode 2 that faces the light emission window 22. The diffractive optical element 5 has a diffraction pattern formed so as to widen the radiation range of the ultraviolet light emitted from the laser diode 2 in one direction by diffracting the ultraviolet light emitted from the laser diode 2. Accordingly, the ultraviolet rays emitted from the laser diode 2 are spread in a fan shape like slit light by the diffractive optical element 5.

  The diffractive optical element 5 is arranged with the direction of the diffraction pattern determined so that the radiation range of ultraviolet rays emitted from the laser diode 2 is oriented along the longitudinal direction of the substrate 3. Therefore, the radiation range of ultraviolet rays emitted from the laser diode 2 (the range indicated by the broken line) extends mainly in the longitudinal direction of the substrate 3 (left-right direction in FIG. 3), as shown in FIG. Further, the radiation range of the ultraviolet rays emitted from the laser diode 3 hardly extends in the short direction of the substrate 3. Therefore, when the virtual irradiation surface 91 for irradiating ultraviolet rays is set in front of the diffractive optical element 5, the ultraviolet irradiation region 200 with respect to the irradiation surface 91 extends in the longitudinal direction of the substrate 3 as shown in FIG. The substrate 3 has a rectangular shape that hardly spreads in the short direction.

  Therefore, as shown in FIG. 4, when the arrangement pitch of the laser diodes 2 is set so as to overlap a part of the irradiation region 200 corresponding to each pair of laser diodes 2 adjacent in the longitudinal direction of the substrate 3, the irradiation surface 91 ( A line-shaped irradiation region 201 is formed in FIG. The arrangement pitch of the laser diodes 2 depends on design conditions such as the diffraction pattern of the diffractive optical element 5, but at least the adjacent laser diodes 2 can be arranged apart from each other. The arrangement pitch L2 of the laser diodes 2 can be set to, for example, about 1.5 to 2.5 times the dimension L1 of the single laser diode 2 in the longitudinal direction of the substrate 3. As a result, the number of laser diodes 2 required per unit length in the longitudinal direction of the substrate 3 is smaller than when a light emitting diode is used. Further, since the adjacent laser diodes 2 are separated from each other, the influence of heat generated by the other laser diodes 2 is suppressed. As shown in FIG. 4, a plurality of substrates 3 may be arranged in the longitudinal direction as necessary.

  As described above, the radiation range of the ultraviolet rays emitted from the laser diode 2 and diffracted by the diffractive optical element 5 does not widen greatly in the short direction of the substrate 3. In FIG. 5A, the spread of the radiation range is emphasized, but actually, the change of the irradiation region 200 is relatively small with respect to the change of the distance D1 from the laser diode 2. Further, as an attribute of the laser light emitted from the laser diode 2, the intensity change within the emission range is relatively small. That is, as shown in FIG. 5B, uniform intensity (illuminance) is obtained in the range of the irradiation region 200 in the short direction of the substrate 3.

  By the way, since the laser diode 2 used as the ultraviolet irradiation device 1 has a large output, it is necessary to take measures against heat dissipation. Therefore, the heat radiating member 4 is attached to the substrate 3 as shown in FIG. The illustrated heat radiating member 4 is configured to radiate heat using a coolant such as water, and the heat radiating member 4 is formed in a hollow shape having flow paths 44 and 45 through which the refrigerant passes. The substrate 3 is arranged on the upper surface of FIG. The upper surface of the heat radiating member 4 in FIG.1 (b) is provided with the center surface 43 of the center part in the left-right direction, and the two inclined surfaces 41 and 42 which continued to the left and right of the center surface 43, and went up in the direction away from each other. .

  Since the two substrates 3 are provided as described above, the substrate 3 is placed on each of the inclined surfaces 41 and 42, and both the substrates 3 are arranged so that their longitudinal directions are parallel to each other. Moreover, the board | substrate 3 and the thermal radiation member 4 are couple | bonded thermally. Since the two substrates 3 are arranged as described above, the line-shaped irradiation region 201 (see FIG. 4) formed on the desired irradiation surface 91 can be overlaid by the laser diode 2 provided on each substrate 3. Is possible. That is, by adjusting the inclination angle of the inclined surfaces 41 and 42 with respect to the desired irradiation surface 91 and the distance from the substrate 3 to the irradiation surface 91, the linear irradiation region 201 is formed on the irradiation surface 91 using the two substrates 3. Can be formed. In this configuration, since the ultraviolet rays are irradiated from the two substrates 3, if the other conditions are the same, the irradiation region 201 is 2 in comparison with the case where the ultraviolet rays are irradiated only by the single substrate 3. It becomes possible to irradiate ultraviolet rays with twice the intensity.

  In the above-described example, the propagation direction (light distribution) of the ultraviolet rays emitted from the laser diode 2 is controlled only by the diffractive optical element 5, but in addition to the diffractive optical element 5, as shown in FIG. A lens 51 may be provided. The lens 51 may be disposed between the laser diode 2 and the diffractive optical element 5. As the lens 51, for example, a collimating lens that emits incident light as parallel light and a lens for adjusting the width of a line formed in the irradiation region 201 can be used.

(Embodiment 1)
As an example of the basic configuration, the ultraviolet irradiation apparatus 1 using two substrates 3 is illustrated. However, in the following, as shown in FIG. 6, the case where four substrates 3 (31, 32, 33, 34) are used is used. This will be described as an example.

  The four substrates 31, 32, 33, and 34 are arranged so that the longitudinal directions thereof are parallel to each other, and the inclination angles with respect to the irradiation surface 91 (see FIG. 3) are different from each other in a plane orthogonal to the longitudinal direction of the substrate 3. It is arranged to let you. The inclination angle for each of the substrates 31, 32, 33, and 34 is set so that the linear irradiation areas 201 formed on the irradiation surface 91 for each of the substrates 31, 32, 33, and 34 coincide with each other and overlap each other. When the irradiation surface 91 is at the position indicated by reference numeral A1 in FIG. 6, irradiation of the substrates 31, 34 at both ends is performed in order to overlap the linear irradiation regions 201 formed by the substrates 31, 32, 33, 34. The inclination angle with respect to the surface 91 is set to be larger than the inclination angle with respect to the irradiation surface 91 of the central substrates 32 and 33.

  When the substrates 31, 32, 33, and 34 are arranged as shown in FIG. 6, the line-shaped irradiation areas 201 are overlapped at the position indicated by reference numeral A <b> 1, and as shown in FIG. The strength becomes almost constant at. On the other hand, at the position indicated by reference numeral B1 in FIG. 6 (positions closer to the substrates 31, 32, 33, and 34 than the position indicated by reference numeral A1), the radiation range of ultraviolet rays emitted from the respective substrates 31, 32, 33, and 34 is as follows. Overlapping areas and non-overlapping areas occur. In the region where the radiation ranges overlap, the intensity of the ultraviolet light increases, and in the region where the radiation ranges do not overlap, the ultraviolet light intensity decreases relatively. Accordingly, at the position indicated by reference numeral B1, the intensity of ultraviolet rays is not uniform in a plane orthogonal to the longitudinal direction of the substrate 3, as shown in FIG. 7B. FIG. 7B schematically shows the intensity of ultraviolet rays, and does not show the actual intensity distribution.

  In the configuration of the present embodiment, at the position where the intensity of the ultraviolet light becomes uniform (the position indicated by the symbol A1 in FIG. 6), the intensity of the ultraviolet light in the linear irradiation region 201 is four substrates 31, 32, 33. , 34 is the sum of ultraviolet rays. Therefore, it is possible to further increase the intensity of the ultraviolet light as compared with the basic configuration.

(Embodiment 2)
Although Embodiment 1 showed the example which uses only the laser diode 2 for a light source, this embodiment demonstrates the structural example used for a light source combining a light emitting diode.

  As shown in FIG. 8, the ultraviolet irradiation device 1 of the present embodiment is a strip-shaped mounting substrate 81, 82 on which a light emitting diode 6 having an emission wavelength in the ultraviolet region is mounted instead of the substrates 32, 33 of the first embodiment. Is provided.

  Like the laser diode 2, the light emitting diode 6 is used in combination with a diffractive optical element 7 that uses diffraction to control the propagation direction of ultraviolet rays. Similar to the diffractive optical element 5, the diffractive optical element 7 has a diffraction pattern formed so as to spread the ultraviolet rays emitted from the light emitting diode 6 in one direction. The light-emitting diodes 6 are arranged in a line along the longitudinal direction on one surface in the thickness direction of the mounting substrates 81 and 82, and the diffractive optical element 7 has a radiation range of ultraviolet rays radiated from the light-emitting diodes 6, The mounting boards 81 and 82 are arranged so as to extend in the longitudinal direction.

  This embodiment is based on the premise that the luminance of the light emitting diode 6 is lower than the luminance of the laser diode 2. Therefore, the distance at which the ultraviolet ray having the intensity required to cure the ultraviolet curable ink can be irradiated is shorter in the light emitting diode 6 than in the laser diode 2. That is, assuming that the maximum distance that can irradiate the ultraviolet light having the intensity required for curing the ultraviolet curable ink with respect to the light emitting diode 6 is D2 (see FIG. 10), the maximum distance that the laser diode 2 can be irradiated with the ultraviolet light with the same intensity is D2. Bigger than. Here, it is assumed that the distance D1 shown in FIG. 5 corresponds to the distance D2 (D2 <D1). Further, in the cross section orthogonal to the longitudinal direction of the mounting substrate 8, the irradiation region 202 when the provisional irradiation surface 92 is set at the position of the distance D 2 is the case where the irradiation surface 91 is set at the position of the distance D 1 in the laser diode 2. It is assumed that the area is wider than the irradiation area 201 of FIG. These assumptions can be said to be reasonable from the attributes of the laser diode 2 and the light emitting diode 6. Further, the intensity of the ultraviolet light emitted from the light emitting diode 6 does not become uniform in the irradiation region 202, and the intensity gradually decreases from the central portion of the irradiation region 202 toward both ends as shown in FIG. 10B. To do.

  In this embodiment, from the relationship between the light distribution of the ultraviolet rays from the laser diode 2 arranged on the substrates 31 and 34 and the ultraviolet rays from the light emitting diode 6 arranged on the mounting substrates 81 and 82, the irradiation surfaces 91 and 92 are reached. The change in the intensity of ultraviolet rays due to the distance is suppressed. That is, at the position where the linear irradiation area 201 (see FIG. 3) formed by the laser diode 2 overlaps (position A2 in FIG. 8), the intensity distribution of the irradiation area 201 is mainly based on the intensity of the ultraviolet rays from the laser diode 2. Is decided. Further, at the position where the ultraviolet rays from the light emitting diode 6 effectively contribute to the curing of the ultraviolet curable ink (position B2 in FIG. 8), the ultraviolet rays from the laser diode 2 and the ultraviolet rays from the light emitting diode 6 are combined and irradiated. The intensity distribution of the region 202 is determined. As a result, the intensity of the ultraviolet rays is not only substantially uniform at the position A2 as shown in FIG. 9 (a), but also the intensity of the ultraviolet rays is substantially uniform at the position B2 as shown in FIG. 9 (b). . In the plane orthogonal to the substrates 31 and 32, the ultraviolet irradiation region 202 at the position B2 is wider than the ultraviolet irradiation region 201 at the position A2.

  As described above, in the present embodiment, by using the laser diode 2 and the light emitting diode 6 in combination, the change in the intensity of the ultraviolet light with respect to the change in the distance to the irradiation surfaces 91 and 92 is suppressed.

  By the way, in the printing apparatus, as shown in FIG. 11, the structure which conveys the printing original fabric 9 which is the object which irradiates an ultraviolet ray along the impression cylinder 10 is known. For example, in a printing apparatus that performs offset printing, the printing original fabric 9 is transported along the impression cylinder 10, so the ultraviolet irradiation device 1 is disposed around the impression cylinder 10. Since no tension acts on the end portions 93 and 94 of the printing raw fabric 8, the end portions 93 and 94 tend to be lifted from the impression cylinder 10. Therefore, the end portions 93 and 94 of the printing original fabric 9 may pass through a position closer to the position where the line-shaped irradiation region 201 is formed only by the laser diode 2. In the configuration of the present embodiment, since the intensity of ultraviolet rays is compensated for by the light emitting diode 6 even at a position closer to the position indicated by reference numeral A2 (position indicated by reference numeral B2), the end portions 93, In 94, the intensity of ultraviolet rays can be made uniform. Further, even with the configuration of the first embodiment, since the intensity of the laser beam is high, it is possible to cope with a change in distance. In the present embodiment, the light emitting diode 6 is mounted on the mounting substrate 8 provided separately from the substrate 3 on which the laser diode 2 is disposed, but the light emitting diode 6 may be disposed on the same substrate 3 as the laser diode 2. Good. Other configurations and functions are the same as those of the first embodiment.

(Embodiment 3)
In the first embodiment, the same specifications are used for all the laser diodes 2 used as the light source of the ultraviolet irradiation device 1, and the same control is performed for all the laser diodes 2, but in this embodiment, the laser diode 2 is used. A description will be given of a case where different control is performed on the case 2 and a case where laser diodes 2 having different specifications are used in combination.

  Here, as shown in FIG. 12, a case where six laser diodes 2 are arranged on one substrate 3 will be described as an example. In addition, a plurality of groups of laser diodes 2 a and 2 b (two groups will be described in this embodiment) are arranged on one substrate 3. The first group of laser diodes 2 a and the second group of laser diodes 2 b are alternately arranged in the longitudinal direction of the substrate 3.

  The first group of laser diodes 2a and the second group of laser diodes 2b are controlled differently. Specifically, the state where the first group of laser diodes 2a is lit as shown in FIG. 12A and the state where the second group of laser diodes 2b are lit as shown in FIG. Replace with. Regardless of which of the first group of laser diodes 2a and the second group of laser diodes 2b is lit, the laser diodes 2a and 2b for each group are lit so that the irradiation region 201 is in a line shape. Sometimes the irradiation area 200 is arranged to be continuous.

  By alternately lighting the first group of laser diodes 2a and the second group of laser diodes 2b, a rest period in which no ultraviolet rays are emitted to one of the first group of laser diodes 2a and the second group of laser diodes 2b. Can be provided. Accordingly, it is possible to reduce the amount of heat generation as compared with the case where all the laser diodes 2a and 2b arranged on the substrate 3 are turned on all at once, and the change in the characteristics and the life of the laser diodes 2a and 2b are suppressed. . Further, since the laser diodes 2a and 2b of the first group and the second group are alternately turned on, the lifetime is approximately doubled compared to the case where the laser diodes 2a and 2b are turned on all at once.

  The first group of laser diodes 2a and the second group of laser diodes 2b may have different emission wavelengths instead of being alternately turned on. For example, the emission wavelength of the first group of laser diodes 2a is 365 nm, and the emission wavelength of the second group of laser diodes 2b is 385 nm. In this configuration, by turning on the first group of laser diodes 2a and the second group of laser diodes 2b at the same time, it becomes possible to simultaneously emit ultraviolet rays of different wavelengths from the ultraviolet irradiation device 1. For example, when the wavelength suitable for curing differs depending on the components and colors of the ultraviolet curable ink, the ultraviolet irradiating device 1 having this configuration is used to irradiate ultraviolet rays having a plurality of wavelengths according to the characteristics of the ultraviolet curable ink. Is possible.

  In this embodiment, an example in which two groups of laser diodes 2a and 2b are arranged on one substrate 3 is shown, but three or more groups of laser diodes may be arranged. Other configurations and functions are the same as the basic configuration.

  In each of the above-described embodiments, the diffractive optical elements 5 and 7 that form a rectangular irradiation region for each laser diode 2 are used. However, by using the diffractive optical elements 5 and 7 having different diffraction patterns, the laser diode 2 can be used. Each irradiation region can be formed in various shapes such as a square, a triangle, and a circle. It is also possible to use the diffractive optical elements 5 and 7 in which a diffraction pattern is formed so as to irradiate a spot on a local region. Further, the configuration example in which the diffractive optical element 5 is provided for each laser diode 2 has been described. However, a single sheet-like diffractive optical element that extends over the entire laser diode 2 disposed on the single substrate 3 is used. It is also possible.

  Further, in the above-described embodiment, the case where the ultraviolet irradiation device 1 is used for a printing device that prints on the printing original fabric 9 has been described. However, in other devices such as a device that applies an ultraviolet curable paint to a building board. Even if it exists, it is possible to employ | adopt the technique mentioned above.

DESCRIPTION OF SYMBOLS 1 Ultraviolet irradiation device 2 Laser diode 3 Substrate 5 Diffractive optical element 6 Light emitting diode 7 Diffractive optical element 51 Lens

Claims (5)

  A plurality of substrates; a laser diode having an emission wavelength in the ultraviolet region and arranged in a row for each of the substrates; and a diffractive optical element that diffracts ultraviolet rays emitted from the laser diode. The diffractive optical element has a function of diffracting ultraviolet rays in the direction in which the laser diodes are arranged on the substrate, and the substrate is arranged so that the directions in which the laser diodes are arranged are parallel to each other, and An ultraviolet irradiation device, wherein the ultraviolet rays emitted from the substrate are inclined with respect to each other in a plane perpendicular to the direction in which the laser diodes are arranged so that the ultraviolet rays emitted from one substrate overlap each other.   2. The ultraviolet irradiation apparatus according to claim 1, further comprising: a light emitting diode having a light emission wavelength in an ultraviolet region, and a plurality of light emitting diodes arranged in a row on a mounting substrate different from the substrate.   The ultraviolet irradiation apparatus according to claim 1, wherein the laser diodes of a plurality of groups forming the line are arranged on a single substrate, and the timing of turning on and off is different for each group.   4. The ultraviolet irradiation apparatus according to claim 1, wherein the laser diodes of a plurality of groups forming the line are arranged on a single substrate, and the emission wavelength is different for each group. 5.   The ultraviolet irradiation according to any one of claims 1 to 4, further comprising a lens that controls a spread range of ultraviolet rays radiated from the laser diode between the laser diode and the diffractive optical element. apparatus.

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