Ultraviolet light irradiation device

Abstract

To provide an ultraviolet light irradiation device capable of irradiating a part of an object placed on a placement surface in a housing with ultraviolet rays with substantially uniform intensity.SOLUTION: An ultraviolet light irradiation device includes: a table 10 having a placement surface 25 on which an object is placed; a housing having a first side wall 13 connected to the placement surface and including an opening 20 through which a part of the object is exposed to the outside, and to which at least a part of the table is joined to cover the placement surface; and a plurality of light-emitting diodes 32 having a light-emitting surface that outputs ultraviolet rays toward the placement surface and arranged on an inner surface of the housing facing the placement surface from a first side wall side toward a second side wall side of the housing facing the first side wall in a state where the light-emitting surface is inclined with respect to the placement surface such that an angle on the opening side formed by the light-emitting surface and the placement surface is an acute angle.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] The present invention relates to an ultraviolet irradiation device. [Background technology]

[0002] Patent Document 1 describes an "ultraviolet irradiation device that irradiates ultraviolet rays onto gloves worn on hands for sterilization," while Patent Document 2 describes an "ultraviolet irradiation device that irradiates ultraviolet rays onto the treatment surface of a three-dimensional object." [Prior art document] [Patent documents] [Patent Document 1] Patent No. 5019628 [Patent Document 2] JP 2017-24362 A Summary of the Invention [Problem to be solved by the invention]

[0003] It is desirable to irradiate a portion of an object placed on a placement surface within a housing with ultraviolet light at a substantially uniform intensity. [Means for solving the problem]

[0004] In a first aspect of the present invention, there is provided an ultraviolet irradiation device comprising: a base having a mounting surface on which an object is placed; a housing connected to the mounting surface and having a first side wall including an opening that exposes a portion of the object to the outside, the housing having at least a portion joined to the base so as to cover the mounting surface; and a plurality of light-emitting diodes having a light-emitting surface that outputs ultraviolet light toward the mounting surface, the light-emitting surface being inclined with respect to the mounting surface so that the angle formed by the light-emitting surface and the mounting surface on the opening side is an acute angle, the light-emitting surface being arranged on an inner surface of the housing facing the first side wall from the first side wall side toward a second side wall side of the housing facing the first side wall.

[0005] The plurality of light emitting diodes may be arranged in a grid pattern.

[0006] In any one of the ultraviolet irradiation devices, the housing may have a mechanical structure that switches between a closed state in which the placement surface is covered with a part of the object exposed to the outside of the housing through the opening, and an open state in which the object can access the placement surface from the outside of the housing through a space other than the opening between the table and the housing.

[0007] In any one of the ultraviolet irradiation devices, the mechanical structure may be a structure that makes the housing detachable from the table.

[0008] In any one of the ultraviolet irradiation devices, the mechanical structure may be a hinge structure or a slide structure in which the first side wall opens and closes with respect to the main body of the housing.

[0009] In any one of the ultraviolet irradiation devices, the mechanical structure may be a hinge structure that connects a side wall other than the first side wall of the housing to the table and the housing opens and closes with respect to the table.

[0010] In any one of the ultraviolet irradiation devices, when the thickness of the first side wall is T, the diameter of the opening is D, the straight line connecting the opening and the light-emitting diode provided farthest distally from the opening among the plurality of light-emitting diodes, and the angle formed with the placement surface is φ, D < T×tanφ may be satisfied.

[0011] In any one of the ultraviolet irradiation devices, when the distance from the first side wall to the first light-emitting diode closest to the first side wall among the plurality of light-emitting diodes is A, the distance between the plurality of light-emitting diodes is P, and the distance from the first light-emitting diode to the placement surface is L, the angle may be an angle θ that satisfies θ ≤ 40 degrees and arctan((A + P / 3) / L) - 10 degrees ≤ θ ≤ arctan((A + P / 3) / L) + 10 degrees.

[0012] In any one of the ultraviolet irradiation devices, the distances A, P, and L arctan((A + P / 3) / L) ≤ 30 degrees may be satisfied.

[0013] In any of the ultraviolet irradiation devices, the plurality of light emitting diodes may irradiate ultraviolet light having a wavelength of 200 nm to 280 nm.

[0014] In any of the ultraviolet irradiation devices, the inner surface of the housing and the inner surface of the stand including the placement surface may be made of a material that transmits the ultraviolet light with a transmittance of less than 1%.

[0015] In any of the ultraviolet irradiation devices, the material may be an aluminum alloy, a magnesium alloy, or a titanium alloy, or an acrylic, polyethylene terephthalate (PET), polycarbonate (PC), or polyvinyl chloride (PVC) resin.

[0016] In any one of the ultraviolet irradiation devices, the table may have a fixing portion that fixes the object to the placement surface.

[0017] In any one of the ultraviolet irradiation devices, the fixing portion may be a magnet that is attached to the placement surface by magnetic force.

[0018] In any of the ultraviolet irradiation devices, the fixing part is a plate made of a material having a transmittance of 90% or more for transmitting the ultraviolet light, and the object may be fixed to the placement surface by sandwiching the object between the plate and the placement surface.

[0019] In any of the ultraviolet irradiation devices, the plate may be made of quartz glass.

[0020] Any of the ultraviolet irradiation devices may further include a control unit that controls light emission of each of the plurality of light-emitting diodes, and the control unit may cause at least one of the plurality of light-emitting diodes to emit light under conditions that are predetermined according to the size of the target object.

[0021] In any of the ultraviolet irradiation devices, the ultraviolet irradiation device may further include a control unit that controls light emission of each of the plurality of light-emitting diodes, and a detection unit that detects whether the housing is in the closed state or the open state. The control unit may not cause the plurality of light-emitting diodes to emit light when the housing is in the open state.

[0022] Any of the ultraviolet irradiation devices may further include an adjustment mechanism that supports the housing or the platform and is capable of adjusting the attitudes of the housing and the platform.

[0023] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also be inventions. [Brief explanation of the drawings]

[0024] [Figure 1A] FIG. 1 is a perspective view showing an example of the appearance of an ultraviolet irradiation device 100. [Figure 1B] FIG. 2 is an example of a cross-sectional view taken along line AA′ of FIG. 1A. [Figure 1C] FIG. 1B is an example of a cross-sectional view taken along line BB′ of FIG. 1A. [Figure 2] 1 is a plan view of the table 10 showing an example of a state in which an object 50 is placed on the placement surface 25 and fixed by a fixing part 60. FIG. [Figure 3] 10 is a plan view of another example of the table 10 in which the object 50 is placed on the placement surface 25 and fixed by the fixing portion 60. [Figure 4] 1 shows an example of a plurality of light-emitting diodes 32 arranged in a grid pattern, which irradiate ultraviolet light onto the mounting surface 25. [Figure 5] 5 is a schematic diagram showing an example of a plurality of light-emitting diodes 32 arranged as shown in FIG. 4, viewed from different angles. [Figure 6] 10 is a graph showing the change in illuminance near the opening 20 when the tilt angle θ is changed. [Figure 7] 10 is a graph showing the average intensity on the placement surface 25 when the tilt angle θ is changed. [Figure 8]10 shows the results of a simulation of the ultraviolet illuminance on the placement surface 25 when θ=31 degrees. [Figure 9] 10 shows the results of a simulation of the ultraviolet illuminance on the placement surface 25 when θ=40 degrees. [Figure 10] 10 shows the results of a simulation of the ultraviolet illuminance on the placement surface 25 when θ=0 degrees. [Figure 11] 10 shows the results of a simulation of the ultraviolet illuminance on the placement surface 25 when θ=50 degrees. [Figure 12] A schematic diagram of a movable arm 70 for placing the enclosure 11 on an object, including a target object 50, is shown. [Figure 13] FIG. 2 is a block diagram showing an example of the configuration of a control system in the ultraviolet irradiation device 100. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0026] The structure of the ultraviolet irradiation device 100 will be described with reference to FIGS. 1A to 1C. FIG. 1A is a perspective view showing an example of the appearance of the ultraviolet irradiation device 100. The ultraviolet irradiation device 100 shows a housing 11 joined to a base 10. In FIG. 1A, a cutting line A-A' is shown. FIG. 1B is an example of a cross-sectional view taken along A-A' in FIG. 1A. In FIG. 1B, the internal structure of the ultraviolet irradiation device 100 is shown. Also, in FIG. 1A, a cutting line B-B' is shown. FIG. 1C is an example of a cross-sectional view taken along B-B' in FIG. 1A.

[0027] The ultraviolet irradiation device 100 includes a table 10 having a mounting surface 25 on which an object 50 is placed, and a housing 11, at least a portion of which is joined to the table 10 so as to cover the mounting surface 25. The housing 11 includes a lid 12 facing the mounting surface 25, and a first side wall 13, a second side wall 14, a third side wall 15, and a fourth side wall 16 connected to the lid 12. An opening 20 is formed in the first side wall 13. A light-emitting diode 32 that irradiates the mounting surface 25 with ultraviolet light is provided on the inner surface of the lid 12. A heat sink 30 that cools the light-emitting diode 32 is provided on the outer surface of the lid 12, with at least a portion of the heat sink 30 exposed. Three heat sinks 30a, 30b, and 30c are shown in FIGS. 1A and 1B.

[0028] The ultraviolet irradiation device 100 is a device for irradiating ultraviolet rays onto an object 50 placed within a housing 11. The ultraviolet irradiation device 100 is capable of irradiating ultraviolet rays with a portion of the object 50 outside the irradiation range exposed to the outside of the housing 11 through the opening 20 by providing an opening 20 in the housing 11. The object 50 may be an object in which the cross-sectional area of ​​at least a portion of the portion irradiated with ultraviolet rays is larger than the cross-sectional area of ​​the opening 20. The object 50 may be a portion of an object, such as a plant leaf, a plant petal, or a plant fruit. The object 50 may be a portion of an object, such as the head of a spatula or a brush. The object 50 may be a flat portion of an object. As described below, the ultraviolet irradiation device 100 has such a structure that, when the object 50 is a portion of an object, ultraviolet rays can be irradiated to a desired area without cutting the entire object. Furthermore, the ultraviolet irradiation device 100 of this embodiment has a structure that can irradiate the target object 50 with ultraviolet rays almost uniformly up to the vicinity of the opening 20. In the following explanation, the configuration of such an ultraviolet irradiation device 100 will be described.

[0029] First, the appearance of the ultraviolet irradiation device 100 will be described. In the following description, a plane along the mounting surface 25 of the base 10 of the ultraviolet irradiation device 100 will be referred to as the XY plane. The X and Y axes are set as orthogonal axes on the XY plane. Furthermore, the Z axis is an axis orthogonal to the X and Y axes, and when at least a portion of the housing 11 is joined to the base 10 so as to cover the mounting surface 25, the side on which the housing 11 is provided is set as the positive direction. In this case, the XYZ coordinates are set in a direction such that the XYZ system forms a right-handed system (positive system). The definitions of the above-mentioned directions and the like are the same in other embodiments of this specification unless otherwise specified.

[0030] The housing 11 of this embodiment has a structure in which the outer surface of the base 10 and the outer surface of the housing 11 form a hexahedron. The surface of the base 10 on which the mounting surface 25 is provided has an approximately quadrilateral shape. Here, an approximately quadrilateral or rectangular shape refers to a shape consisting of four sides, including a square, a rectangle, a trapezoid, etc., and at least some of the corners may be cut out obliquely with respect to the sides, or at least some of the corners may be chamfered to include a curve.

[0031] The outer surface of the lid portion 12 facing the base 10 may have the same shape as the surface of the base 10 on which the mounting surface 25 is provided, or may have a different shape from the surface of the base 10 on which the mounting surface 25 is provided. The outer surface of the lid portion 12 in this embodiment has a substantially quadrilateral shape, similar to the surface of the base 10 on which the mounting surface 25 is provided.

[0032] The first side wall 13, the second side wall 14, the third side wall 15, and the fourth side wall 16 are side walls that hold the lid portion 12 against the base 10 when at least a portion of the housing 11 is joined to the base 10. The second side wall 14 faces the first side wall 13, and the fourth side wall 16 faces the third side wall 15. For example, when the outer surface of the lid portion 12 and the surface of the base 10 on which the mounting surface 25 is provided have the same shape and are parallelograms, the first side wall 13 and the second side wall 14 are parallel to each other, and the third side wall 15 and the fourth side wall 16 are also parallel to each other. In this embodiment, an example will be described in which the housing 11 is a substantially rectangular parallelepiped.

[0033] An opening 20 is formed in the first side wall 13. As a result, when the target object 50 is a part of an object, the part of the object can be placed inside the housing 11 through the opening 20 without cutting the irradiation target part from the other parts of the object, while leaving the other parts exposed to the outside of the housing 11. Therefore, the ultraviolet irradiation device 100 can irradiate only a part of the object as the target object 50 with ultraviolet light.

[0034] The opening 20 may be very small as long as it is large enough to pass through a connection portion of the object 50 to be irradiated with ultraviolet light and a portion other than the irradiation portion. This reduces leakage of ultraviolet light from the ultraviolet irradiation device 100, and prevents the user's body from being exposed to ultraviolet light. The cross-sectional area of ​​the connection portion may be smaller than the cross-sectional area of ​​the largest portion of the irradiation portion of the object 50 to be irradiated with ultraviolet light.

[0035] Heat sinks 30a to 30c are provided on the lid portion 12 for cooling the light emitting diodes 32 that emit ultraviolet light. Each of the heat sinks 30a to 30c is provided for one or more light emitting diodes to cool the light emitting diodes 32. In the following description of the embodiment, letters such as a, b, c, etc. may be used to distinguish and designate each of the multiple members provided, but the letters may also be omitted and the multiple members provided may be referred to collectively, for example, as heat sink 30.

[0036] Next, a description will be given of the internal structure of the ultraviolet irradiation device 100. Fig. 1B shows a cross-sectional view of the ultraviolet irradiation device 100 extending in the YZ direction.

[0037] The ultraviolet light irradiated by the ultraviolet irradiation device 100 of this embodiment may be ultraviolet light having a wavelength in the so-called ultraviolet C wave (UV-C) region. Therefore, the ultraviolet light irradiated by the ultraviolet irradiation device 100 may be ultraviolet light having a wavelength of 100 nm or more and less than 280 nm. In particular, the ultraviolet light irradiated by the ultraviolet irradiation device 100 of this embodiment may be ultraviolet light in the UV-C region having a wavelength of 200 nm to 280 nm.

[0038] Ultraviolet rays with wavelengths in the UV-C region overlap with wavelengths in the so-called deep ultraviolet (approximately 200 nm to less than approximately 350 nm) region. Ultraviolet rays with wavelengths in the deep ultraviolet region can be used for inactivating (particularly sterilizing) objects to be irradiated (e.g., bacteria / viruses in water, object surfaces, or the air), decomposing organic matter, denaturing proteins, hardening resins, or closing stomata in leaves of cut flowers and the like. In the following description of the embodiments, although not limited thereto, the use of ultraviolet rays emitted by the ultraviolet irradiation device 100 may be described using, as an example, stomatal closure in cut flower leaves. The ultraviolet irradiation device 100 irradiates cut flower leaves with deep ultraviolet rays to close the stomata, thereby suppressing water evaporation from the cut flowers.

[0039] However, the wavelength irradiated by the ultraviolet irradiation device 100 is not limited to this wavelength, and ultraviolet rays having a wavelength in the ultraviolet-B wave (UV-B) range or ultraviolet rays having a wavelength in the ultraviolet-A wave (UV-A) range may be used depending on the application. Ultraviolet rays having a wavelength in the UV-B range are ultraviolet rays having a wavelength of 280 nm or more and less than 320 nm, and ultraviolet rays having a wavelength in the ultraviolet-A wave (UV-A) range are ultraviolet rays having a wavelength of 320 nm or more and less than 400 nm.

[0040] Similarly, the wavelength of the electromagnetic waves irradiated by the ultraviolet irradiation device 100 may be shorter than the UV-C region and may include wavelengths between the UV-C region and the X-ray region (approximately 1 pm to 10 nm) as long as the electromagnetic waves include wavelengths in the ultraviolet region. In other words, the wavelength of the electromagnetic waves irradiated by the ultraviolet irradiation device 100 may be electromagnetic waves including wavelengths of 10 nm to 100 nm. In the following description, the ultraviolet irradiation device 100 may be described as a device that irradiates ultraviolet rays with wavelengths in the UV-C region.

[0041] By using the light-emitting diode 32 as the light source of the ultraviolet irradiation device 100, the overall size and weight of the ultraviolet irradiation device 100 can be reduced compared to when a light source such as an ultraviolet lamp is used. This makes the ultraviolet irradiation device 100 an easy-to-handle irradiator, and makes it easy for a user to carry the ultraviolet irradiation device 100 in one hand, for example.

[0042] Another advantage of using light-emitting diodes 32 as the light source of the ultraviolet irradiation device 100 is that they are a light source that can be easily turned on and off. Furthermore, light-emitting diodes are light sources that have a long service life and are resistant to deterioration, and are therefore suitable for applications in which ultraviolet light is irradiated for a short period of time on each object 50 (for example, on each leaf of a cut flower).

[0043] Another advantage of using light-emitting diodes 32 as the light source of the ultraviolet irradiation device 100 is that the installation area of ​​each light-emitting diode is not large, allowing for a high degree of freedom in light source placement. This allows for flexible design of the ultraviolet irradiator in the ultraviolet irradiation device 100 depending on the target object 50. The multiple light-emitting diodes 32 of this embodiment may irradiate ultraviolet light having a wavelength of 200 nm to 280 nm.

[0044] The plurality of light-emitting diodes 32 are provided for the heat sinks 30a, 30b, and 30c, respectively, to form light-emitting surfaces that output ultraviolet light toward the mounting surface 25. The plurality of light-emitting diodes 32 are arranged on the inner surface of the housing 11 facing the mounting surface 25, from the first side wall 13 side toward the second side wall 14 side, with the light-emitting surfaces inclined relative to the mounting surface 25 so that the angle formed between the light-emitting surfaces and the mounting surface 25 on the opening 20 side is an acute angle.

[0045] The light emitting diodes 32 are arranged in a grid pattern. Since Fig. 1B is a cross-sectional view taken along the line AA', light emitting diodes 32d, 32e, and 32f are depicted in Fig. 1B.

[0046] By tilting the light-emitting surface relative to the mounting surface 25, the ultraviolet irradiation device 100 can uniformly irradiate ultraviolet rays up to the vicinity of the opening 20. In this case, unlike the ultraviolet irradiation device in Patent Document 2, the ultraviolet irradiation device 100 does not have a structure for reflecting ultraviolet rays, such as a reflector. If a reflector is provided in the ultraviolet irradiation device and an opening is provided in the ultraviolet irradiation device, the reflector complicates the path of ultraviolet rays within the housing, making it difficult to design the device so that the reflected ultraviolet rays do not leak through the opening. Furthermore, if a reflector is provided in the ultraviolet irradiation device, the weight of the ultraviolet irradiation device increases, and if the reflector becomes dirty, this may increase the risk of performance degradation or the like. In this embodiment, ultraviolet rays can be uniformly irradiated up to the vicinity of the opening 20 without a reflector, making it possible to provide an ultraviolet irradiation device 100 that does not have these risks.

[0047] Here, by setting the angle at which the light-emitting surface is tilted relative to the mounting surface 25 within a predetermined range, the intensity of ultraviolet light can be made approximately uniform up to the vicinity of the opening 20. The distance from the first side wall 13 to the light-emitting diode 32d is defined as A, the distance between the light-emitting diodes 32d and 32e and the distance between the light-emitting diodes 32e and 32f is defined as P, and the distance from the light-emitting diode 32 to the mounting surface 25 is defined as L. In this case, the tilt angle may be an angle that satisfies θ≦40 degrees and arctan((A+P / 3) / L)−10 degrees≦θ≦arctan((A+P / 3) / L)+10 degrees. It has been confirmed by simulations described with reference to FIGS. 4 to 11 that when the tilt angle is set within this range, the illuminance near the opening 20 does not decrease to less than 95% of the maximum value.

[0048] Here, the distance A from the first side wall 13 to the light-emitting diode 32d is set to a size on the same order (A to L) as the distance L from the light-emitting diode 32 to the mounting surface 25. Therefore, for example, A is set to any value within the range of L / 10≦A≦2L. Since the light-emitting diode 32 emits ultraviolet light that spreads in the YZ directions from the position where the light-emitting diode 32 is disposed, setting A above a predetermined value makes it easier for the ultraviolet light to be irradiated with uniform illuminance up to the mounting surface 25 near the opening 20. For example, A is set to A=L / 4.

[0049] In this embodiment, the light-emitting diode 32d is the light-emitting diode among the plurality of light-emitting diodes 32 that is arranged closest to the first side wall 13. Here, the "distance to the light-emitting diode 32" may be the distance to the geometric center of the light-emitting diode 32.

[0050] Let the thickness of the first side wall 13 be T, the diameter of the opening 20 be D, and the angle formed by the straight line connecting the opening 20 and the light-emitting diode 32 that is provided farthest distally from the opening 20 among the plurality of light-emitting diodes 32 and the mounting surface 25 (for example, the XY plane) be φ. Then, D < T × tan φ is satisfied. Since the angle φ becomes smaller as the light-emitting diode 32 is farther distally from the opening 20, when D < T × tan φ is satisfied for the light-emitting diode 32 that is farthest distally from the opening 20, it becomes impossible to peek at all the light-emitting diodes 32 from the outside of the housing 11. By making the diameter of the opening 20 smaller and the thickness of the housing 11 thicker so as to satisfy this formula, it becomes impossible to peek at the ultraviolet light source from the outside of the housing 11, and leakage of ultraviolet light to the outside of the housing 11 can be prevented. Therefore, by providing the opening 20 with this size, even when the opening 20 is provided, it is possible to prevent the user's eyes from being exposed to ultraviolet light during the use of the ultraviolet irradiation device 100. In order to satisfy this value, by making the housing 11 thick (for example, T ≧ 3 mm), as will be described later, even when the housing 11 is made of resin, it is possible to give the housing 11 sufficient durability.

[0051] Next, the mechanical structure and material of the housing 11 will be described. The housing 11 has a structure in which the first side wall 13 opens and closes with respect to any one of the members (that is, the lid portion 12, the third side wall 15, and the fourth side wall 16) adjacent to the first side wall 13 in the housing 11. In other words, the housing 11 has a closed state in which the mounting surface 25 is covered with a part of the object 50 exposed through the opening 20. Further, the housing 11 has an open state in which the object 50 can access the mounting surface 25 from the outside of the housing 11 through the space other than the opening 20 between the base 10 and the housing 11. In this case, the housing 11 has a mechanical structure for switching between the open state and the closed state.

[0052] In this embodiment, the opening 20 is provided so as to follow the base 10 when the housing 11 is in the closed state. When the housing 11 is in the closed state, the placement surface 25 is disposed so as to extend from the first side wall 13 toward the inside of the housing 11. Therefore, the placement surface 25 is connected to the opening 20. As a result, when the housing 11 is in the closed state, with the object 50 placed on the placement surface 25, other parts of the object 50 can be exposed to the outside of the housing 11 through the opening 20, and a structure can be realized in which the object 50 does not interfere with the opening 20.

[0053] The mechanical structure for switching the housing 11 between the open state and the closed state may be a structure that allows the housing 11 to be attached to and detached from the base 10. As an example, when the housing 11 is in the open state, the cover portion 12, the first side wall 13, the second side wall 14, the third side wall 15, and the fourth side wall 16 of the housing 11 may be structured so that they can be removed as a cover from the base 10. In this case, when the housing 11 is in the closed state, each member of the housing 11 that is the cover may cover the base 10, and the cover may be locked to the base 10 by a locking member or the like.

[0054] The mechanical structure for switching the housing 11 between the open state and the closed state may be a hinge structure that connects a side wall (any of the second side wall 14, the third side wall 15, and the fourth side wall 16) other than the first side wall 13 of the housing 11 to the base 10, and allows the housing 11 to open and close relative to the base 10. In this case, a hinge is provided between any of the second side wall 14, the third side wall 15, and the fourth side wall 16 and the base 10. The lid 12, the first side wall 13, the second side wall 14, the third side wall 15, and the fourth side wall 16 of the housing 11 are structured to be rotatable relative to the base 10 around the hinge as a rotation axis. This rotation switches the housing 11 between the open state and the closed state.

[0055] The mechanical structure for switching the housing 11 between the open state and the closed state may be a structure in which the first side wall 13 is movable relative to other parts of the housing 11 (i.e., the lid portion 12, the second side wall 14, the third side wall 15, and the fourth side wall 16). In this case, since only the first side wall 13 is a mechanical structure that is movable relative to other parts of the housing 11, the parts of the housing 11 other than the first side wall 13 may be referred to as the "main body" of the housing 11.

[0056] The mechanical structure for switching the open state and closed state of the housing 11 may be a hinge structure in which the first side wall 13 opens and closes relative to the main body of the housing 11. In this case, a hinge is provided between the first side wall 13 and any one of the lid 12, the third side wall 15, and the fourth side wall 16. Such a hinge allows the first side wall 13 to rotate relative to the main body of the housing 11 around the hinge as a rotation axis.

[0057] The mechanical structure for switching the housing 11 between the open state and the closed state may be a sliding structure in which the first side wall 13 slides relative to the main body of the housing 11. In this case, the housing 11 supports the first side wall 13 so that it can slide along the boundary with at least one of the members of the housing 11 to which the first side wall 13 is adjacent (i.e., the cover portion 12, the third side wall 15, and the fourth side wall 16). Furthermore, when the housing 11 is a parallelepiped, the housing 11 may support the first side wall 13 so that it can slide along the third side wall 15 and the fourth side wall 16 opposite the third side wall 15.

[0058] The following describes the material of the housing 11. In the ultraviolet irradiation device 100 of this embodiment, the inner surface of the housing 11 and the inner surface of the table 10 including the mounting surface 25 are made of a material that transmits ultraviolet light with a transmittance of less than 1%.

[0059] Specifically, the inner surface of the housing 11 and the inner surface of the base 10, including the mounting surface 25, may be made of resin such as acrylic, polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl chloride (PVC), etc. These resins have the property of high transmittance for visible light (for example, 50% or more when the thickness is 3 mm or more) and low transmittance for ultraviolet light having a wavelength of 200 nm to 280 nm (for example, less than 1% when the thickness is 3 mm or more).

[0060] In this case, the housing 11 itself can be made of these resins. This allows the interior of the ultraviolet irradiation device 100 to be visually observed while the ultraviolet irradiation device 100 is irradiating ultraviolet rays, and also prevents ultraviolet rays from leaking from the ultraviolet irradiation device 100.

[0061] Alternatively, the inner surface of the housing 11 and the inner surface of the base 10, including the support surface 25, may be made of a lightweight metal such as an aluminum alloy, magnesium alloy, or titanium alloy that has been subjected to a surface treatment, such as black anodizing, magnesium conversion coating, or pickling, to reduce UV reflectance and increase UV absorption. When the housing 11 is made of metal, the mass of the housing 11 tends to be larger than when it is made of resin. Therefore, to reduce the overall weight of the ultraviolet irradiation device 100, a lightweight metal such as an aluminum alloy, magnesium alloy, or titanium alloy may be used. On the other hand, when the housing 11 is made of metal, it is easier to ensure strength and prevent UV leakage, even when the housing 11 is thin, compared to when it is made of resin. Therefore, when the housing 11 is made of metal, the housing 11 may be thinner than when it is made of resin.

[0062] When the housing 11 is made of metal, for example, the housing 11 is made of a material that is opaque to visible light. In such a case, a peephole may be provided in the second side wall 14 to visually check the state inside the housing 11. The light-emitting surfaces of the multiple light-emitting diodes 32 are inclined with respect to the mounting surface 25 so that the angle formed by the light-emitting surfaces and the mounting surface 25 on the opening 20 side is acute. Therefore, even when such a peephole is provided, ultraviolet light is prevented from leaking through the peephole. Furthermore, to prevent ultraviolet light from leaking, the peephole may be provided with a resin that has high transmittance for visible light and low transmittance for ultraviolet light.

[0063] Next, a description will be given of the arrangement of light emitting diodes 32 in the lid portion 12 shown in Fig. 1C. The ultraviolet irradiation device 100 includes light emitting diodes 32a to 32i.

[0064] Light-emitting diodes 32a, 32d, and 32g are provided to correspond to heat sink 30a, light-emitting diodes 32b, 32e, and 32h are provided to correspond to heat sink 30b, and light-emitting diodes 32c, 32f, and 32i are provided to correspond to heat sink 30c.

[0065] As shown in the figure, 3 × 3 light emitting diodes 32 are arranged in a grid pattern. In this embodiment, an example in which nine light emitting diodes 32 are arranged is shown, but the number of light emitting diodes 32 to be arranged may be any plural number and is not limited to nine.

[0066] Here, "grid-like" refers to a structure in which a plurality of light-emitting diodes 32 are arranged at intervals of a certain size for each degree of freedom in a two-dimensional plane. For example, a structure in which a plurality of light-emitting diodes 32 are arranged at intervals corresponding to a predetermined positive real number value a for the X coordinate and at intervals corresponding to a predetermined positive real number value b for the Y coordinate in a two-dimensional plane having an XY orthogonal coordinate system is an example of a structure arranged in a "grid-like" manner.

[0067] In this embodiment, the term "grid pattern" does not necessarily mean that the light-emitting diodes 32 are arranged at lattice points ((0,0), (1,0), (2,0), (3,0), ..., (0,1), (1,1), (2,1), ..., (0,2), (1,2), (2,2), ...) for each unit length along each axis of the XY coordinate system. The term "grid" may also include a configuration in which the light-emitting diodes 32 are arranged to form a rectangular lattice or a parallelogram lattice, or a configuration in which the light-emitting diodes 32 are arranged to form a hexagonal lattice by triangulating a surface. Furthermore, in terms of the degree of freedom of a two-dimensional plane, the light-emitting diodes 32 may be arranged at intervals of a certain size in a polar coordinate system. In this case, the light-emitting diodes 32 are arranged concentrically at certain diameters and angles. By arranging the light-emitting diodes 32 in a lattice pattern in this way, the ultraviolet irradiation device 100 can irradiate the entire mounting surface 25 with ultraviolet light at a predetermined illuminance or higher.

[0068] In the above description, it has been stated that T, D, and φ satisfy D < T × tan φ. In the above equation, φ is defined as the angle formed by the straight line connecting the light-emitting diode 32 provided farthest distally from the opening 20 and the mounting surface 25 (for example, the XY plane). In the embodiment of FIG. 1C, the light-emitting diodes 32 provided farthest distally from the opening 20 are the light-emitting diodes 32a and 32i. Since the angle φ is an acute angle, as the distance from the opening 20 to the light-emitting diode 32 increases, the angle φ decreases, and tan φ also shows a small value.

[0069] FIG. 2 is a plan view of the stage 10 showing an example of a state in which the object 50 is placed on the mounting surface 25 and fixed by the fixing portion 60. The ultraviolet irradiation device 100 includes the fixing portion 60, and the fixing portion 60 includes magnets 62a and 62b. In the figure, an example is shown in which the object 50 is a leaf for cut flowers to close the pores.

[0070] The fixing portion 60 fixes the object 50 to the mounting surface 25. The fixing portion 60 includes magnets 62a and 62b that adhere to the mounting surface 25 by magnetic force, and the corresponding portion of the stage 10 may include a ferromagnetic material. Alternatively, the fixing portion 60 may include a ferromagnetic material, and the corresponding portion of the stage 10 may include a ferromagnetic material. By adjusting the magnetic force between the fixing portion 60 and the stage 10, the fixing portion 60 can fix the object 50 to the mounting surface 25 without damaging the object 50.

[0071] The magnets 62a and 62b may be provided so as to occupy a narrow range within the fixing portion 60. The magnets 62a and 62b do not transmit ultraviolet rays. By providing the fixing portion 60 with a material that transmits ultraviolet rays (for example, quartz glass) and making the exclusive area of the magnets 62a and 62b small, the area on the mounting surface 25 where ultraviolet rays are not irradiated can be narrowed.

[0072] 3 is a plan view of the table 10 showing another example of a state in which the object 50 is placed on the mounting surface 25 and fixed by the fixing portion 60. In the figure, an example is shown in which the fixing portion 60 is a quartz glass plate. In the figure, the fixing portion 60 extends to cover the mounting surface 25. The fixing portion 60 may have any shape as long as it can fix the object 50, and is not limited to a shape that covers the entire mounting surface 25.

[0073] In this embodiment, the fixing portion 60 is a plate made of a material with a transmittance of 90% or more for transmitting ultraviolet light, and the object 50 is fixed to the mounting surface 25 by sandwiching the object 50 between the plate and the mounting surface 25. Examples of materials with a transmittance of 90% or more for deep ultraviolet light include quartz glass, crystal, and fluorite. From the viewpoints of ease of processing, availability in the market, price, etc., the plate of the fixing portion 60 may be made of quartz glass. By using quartz glass for the fixing portion 60, it is possible to minimize absorption of deep ultraviolet light by the fixing portion 60 while irradiating the mounting surface 25 with ultraviolet light in a substantially uniform manner.

[0074] Fig. 4 shows an example of a plurality of light-emitting diodes 32 arranged in a grid pattern that irradiates ultraviolet light onto the mounting surface 25. Fig. 4 shows an example in which the distance P between the light-emitting diodes 32d is 20 mm, the distance A from the first side wall 13 to the light-emitting diode 32d is P / 4 = 5 mm, and the size of the mounting surface 25 is 40 mm x 80 mm.

[0075] Fig. 5 is an example of a schematic diagram of the plurality of light-emitting diodes 32 arranged as in Fig. 4, viewed from a different angle. The diagram shows the plurality of light-emitting diodes 32 viewed from the positive side in the X direction.

[0076] The distance L from the light-emitting diode 32 to the placing surface 25 is set to L = 20 mm. In this case, Figures 6 to 10 show the results of a simulation of the illuminance of ultraviolet light on the placing surface 25 when the angle θ at which the light-emitting surface is inclined with respect to the placing surface 25 is varied under these conditions.

[0077] Figure 6 is a graph showing the change in illuminance near the opening 20 when the tilt angle θ is changed. Under the simulation conditions, arctan((A+P / 3) / L) is approximately 30 degrees. Range A is an angle range that satisfies arctan((A+P / 3) / L) - 10 degrees ≦ θ ≦ arctan((A+P / 3) / L) + 10 degrees.

[0078] According to the simulation results, the illuminance near the opening 20 is maximum when θ = arctan((A+P / 3) / L). When arctan((A+P / 3) / L) - 10 degrees ≦ θ ≦ arctan((A+P / 3) / L) + 10 degrees, the illuminance near the opening 20 remains at 95% or more of the maximum value.

[0079] FIG. 7 is a graph showing the average intensity on the support surface 25 when the tilt angle θ is varied. The average illuminance on the support surface 25 is maximum when θ = 0 degrees. The average illuminance gradually decreases as θ increases, but maintains 80% or more of the maximum value when θ = 40 degrees. Range B in the figure is the angle range where θ ≤ 40 degrees. Increasing θ beyond this range reduces the average intensity on the support surface 25, reducing the irradiation efficiency relative to the light output. In this way, when the support surface 25 is irradiated with ultraviolet light in a substantially uniform manner, it is possible to ensure that the illuminance near the opening is 95% or more of the maximum value when θ = arctan((A + P / 3) / L), and that the average illuminance is 80% or more of the maximum value when θ = 0 degrees.

[0080] Furthermore, in order for the entire range of arctan((A+P / 3) / L) -10 degrees ≦ θ ≦ arctan((A+P / 3) / L) + 10 degrees to overlap with the range of θ ≦ 40 degrees, arctan((A+P / 3) / L) ≦ 30 degrees is sufficient. By designing the distances A, P, and L to satisfy arctan((A+P / 3) / L) ≦ 30 degrees, it is possible to widen the setting range of the tilt angle that achieves high values ​​for both the illuminance near the opening 20 and the average illuminance on the mounting surface 25.

[0081] 8 shows the simulation results of the ultraviolet illuminance on the mounting surface 25 when θ=30 degrees. Under these simulation conditions, arctan((A+P / 3) / L)≈30.2, so θ=30 degrees is the angle at which the illuminance near the opening 20 reaches its maximum value within ranges A and B, where θ is an integer value.

[0082] In this case, the illuminance near the opening 20 can be kept at 95% or more of the maximum value, and the average illuminance on the mounting surface can also be kept at 90% or more compared to when θ = 0. The illuminance on the mounting surface 25 is maintained approximately uniform up to the vicinity of the opening 20.

[0083] FIG. 9 shows the results of a simulation of the ultraviolet illuminance on the placement surface 25 when θ = 40 degrees. In this simulation, the average illuminance on the placement surface is reduced to about 80% (approximately 83%) compared to when θ = 0, but remains above 80%. The illuminance near the opening 20 can remain above 95% compared to when θ = arctan((A + P / 3) / L). When θ is greater than this, the average illuminance on the placement surface may be less than 80%, or the illuminance near the opening 20 may be less than 95% compared to when θ = arctan((A + P / 3) / L).

[0084] 10 shows the results of a simulation of the ultraviolet illuminance on the mounting surface 25 when θ=0 degrees. In this case, the illuminance near the opening 20 is reduced to about 85% compared to when θ=arctan((A+P / 3) / L).

[0085] In this way, when θ is outside the range A, the illuminance of ultraviolet light near the opening 20 is less than 95% of that when θ=arctan((A+P / 3) / L).

[0086] FIG. 11 shows the results of a simulation of the ultraviolet irradiance on the support surface 25 when θ = 50 degrees. In this simulation, the average irradiance across the entire support surface 25 is reduced. The average irradiance across the support surface 25 is reduced to less than 80% (approximately 75%) compared to when θ = 0 degrees. In order to set the average irradiance on the support surface 25 to 80% or more when θ = 0 degrees and the irradiance near the opening 20 to 95% or more when θ = arctan((A + P / 3) / L), it is appropriate to set θ to arctan((A + P / 3) / L) - 10 degrees ≦ θ ≦ arctan((A + P / 3) / L) + 10 degrees and θ ≦ 40 degrees.

[0087] 12 is a schematic diagram of a movable arm 70 for installing the housing 11 on an object including the target object 50. The movable arm 70 includes a support portion 72 and a movable portion 74. In this embodiment, the ultraviolet irradiation device 100 is configured to include the movable arm 70.

[0088] The movable arm 70 supports the housing 11 or the base 10 and has a mechanism that can adjust the attitude of the housing 11 and the base 10. The movable arm 70 may be connected to the housing 11 or the base 10. The movable arm 70 is an example of an "adjustment mechanism" that supports the housing 11 or the base 10 and can adjust the attitude of the housing 11 and the base 10.

[0089] The support portion 72 supports the ultraviolet irradiation device 100 including the movable arm 70 at a location where the ultraviolet irradiation device 100 is installed. The support portion 72 functions as a stand that supports the movable portion 74.

[0090] The movable part 74 is made of a member that has flexibility that allows the attitude of the housing 11 or the base 10 to be adjusted, and that has rigidity that allows the housing 11 or the base 10 to be supported while maintaining the attitude of the housing 11 or the base 10 after the attitude of the housing 11 or the base 10 has been adjusted. For example, the movable part 74 is formed of a flexible pipe made of thin-walled metal with a continuous pleated shape.

[0091] 13 is a block diagram showing an example of the configuration of a control system in the ultraviolet irradiation device 100. The control system of the ultraviolet irradiation device 100 includes a plurality of light-emitting diodes 32, a detection unit 82, and a control unit 84. The control system may be provided within the ultraviolet irradiation device 100, and is installed on a printed circuit board provided within the ultraviolet irradiation device 100, for example.

[0092] The control unit 84 may be configured with a microprocessor such as a CPU or an MPU, a microcontroller such as an MCU, or the like. The control unit 84 controls the light emission of each of the plurality of light-emitting diodes 32. The control unit 84 causes at least one of the plurality of light-emitting diodes 32 to emit light under conditions determined in advance according to the size of the object 50. Specifically, when the object 50 occupies a portion of the placement surface 25, the control unit 84 may select a light-emitting diode 32 to be turned on so that ultraviolet light of a substantially uniform intensity is irradiated only onto an area of ​​the placement surface 25 including that portion. The control unit 84 is connected to the light-emitting diodes 32 to control the light emission of the plurality of light-emitting diodes 32. The setting of the plurality of light-emitting diodes 32 by the control unit 84 may be performed automatically by the control unit 84 according to the size of the object 50, or may be performed by adjusting the light-emitting range based on a user input, or a combination thereof.

[0093] The detection unit 82 detects whether the housing 11 is in the closed state or the open state. The detection unit 82 may mechanically or electrically detect whether the housing 11 is in the closed state or the open state. The detection unit 82 may be a switch that turns on or off when the housing 11 is in the closed state. The detection unit 82 may have a light-emitting unit such as a photodiode provided on either the base 10 or the housing 11, and a light-receiving unit provided on the other of the base 10 or the housing 11. When the housing 11 is in the closed state, the light-receiving unit may receive light emitted from the light-emitting unit, thereby detecting that the housing 11 is in the closed state. The control unit 84 may control whether the light-emitting diode 32 emits light depending on the detection result of the detection unit 82. Specifically, the control unit 84 may control the light-emitting diode 32 to emit light when the detection unit 82 detects that the housing 11 is in the closed state. On the other hand, the control unit 84 may control the light-emitting diode 32 not to emit light when the detection unit 82 detects that the housing 11 is in the open state. In this way, the combination of the detection unit 82 and the control unit 84 may function as a so-called interlock mechanism that causes the light-emitting diode 32 to emit light only when the housing 11 is in the closed state.

[0094] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0095] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0096] 10 units 11. Housing 12 Lid 13 First side wall 14 Second side wall 15 Third side wall 16 Fourth Side Wall 20 aperture 25 Placement surface 30 Heatsink 32 Light-emitting diode 50 Objects 60 Fixed part 62 Magnet 70 Movable Arm 72 Support part 74 Moving parts 82 Detection unit 84 Control Unit 100 Ultraviolet irradiation device

Claims

1. a platform having a placement surface on which an object is placed; a housing connected to the placement surface and having a first side wall including an opening for exposing a portion of the object to the outside, the housing having at least a portion joined to the platform so as to cover the placement surface; a plurality of light-emitting diodes each having a light-emitting surface that outputs ultraviolet light toward the placement surface, the light-emitting diodes being arranged on an inner surface of the housing facing the placement surface from the first side wall toward a second side wall of the housing facing the first side wall in a state in which the light-emitting surface is inclined with respect to the placement surface so that an angle formed by the light-emitting surface and the placement surface on the opening side is an acute angle; An ultraviolet irradiation device comprising:

2. The ultraviolet irradiation device according to claim 1 , wherein the plurality of light-emitting diodes are arranged in a grid pattern.

3. 2. The ultraviolet irradiation device according to claim 1, wherein the housing has a mechanical structure that switches between a closed state in which the housing covers the placement surface while a portion of the object is exposed to the outside of the housing through the opening, and an open state in which the object can access the placement surface from outside the housing through a space other than the opening between the base and the housing.

4. The ultraviolet irradiation device according to claim 3 , wherein the mechanical structure is a structure that allows the housing to be attached to and detached from the base.

5. The ultraviolet irradiation device according to claim 3 , wherein the mechanical structure is a hinge structure or a slide structure that allows the first side wall to open and close relative to the main body of the housing.

6. The ultraviolet irradiation device according to claim 3 , wherein the mechanical structure is a hinge structure that connects a side wall of the housing other than the first side wall to the base, and that allows the housing to open and close relative to the base.

7. When the thickness of the first side wall is T, the diameter of the opening is D, and the angle formed by the line connecting the opening and the light-emitting diode that is disposed farthest from the opening among the plurality of light-emitting diodes and the placement surface is φ, D<T×tanφ is satisfied. The ultraviolet irradiation device according to claim 1 .

8. When the distance from the first side wall to a first light-emitting diode among the plurality of light-emitting diodes that is closest to the first side wall is A, the distance between the plurality of light-emitting diodes is P, and the distance from the first light-emitting diode to the placement surface is L, The angle θ≦40 degrees, and arctan((A+P / 3) / L)-10 degrees ≦θ≦arctan((A+P / 3) / L)+10 degrees The ultraviolet irradiation device according to claim 1 , wherein the angle θ satisfies the following equation:

9. The distances A, P, and L are arctan((A+P / 3) / L)≦30 degrees; The ultraviolet irradiation device according to claim 8.

10. The ultraviolet irradiation device according to claim 1 , wherein the plurality of light-emitting diodes irradiate ultraviolet light having a wavelength of 200 nm to 280 nm.

11. 2. The ultraviolet irradiation device according to claim 1, wherein an inner surface of the housing and an inner surface of the base including the placement surface are made of a material that transmits the ultraviolet light with a transmittance of less than 1%.

12. 12. The ultraviolet irradiation device according to claim 11, wherein the material is an aluminum alloy, a magnesium alloy, or a titanium alloy, or an acrylic, polyethylene terephthalate (PET), polycarbonate (PC), or polyvinyl chloride (PVC) resin.

13. The ultraviolet irradiation device according to claim 1 , wherein the table has a fixing portion for fixing the object to the placement surface.

14. The ultraviolet irradiation device according to claim 13 , wherein the fixing portion is a magnet that is attached to the placement surface by magnetic force.

15. The ultraviolet irradiation device of claim 13, wherein the fixing portion is a plate made of a material having a transmittance of 90% or more for transmitting the ultraviolet light, and the object is fixed to the placement surface by sandwiching the object between the plate and the placement surface.

16. The ultraviolet irradiation device according to claim 15, wherein the plate is made of quartz glass.

17. a control unit for controlling light emission of each of the plurality of light-emitting diodes; 17. The ultraviolet irradiation device according to claim 1, wherein the control unit causes at least one of the plurality of light-emitting diodes to emit light under a condition that is predetermined according to a size of the object.

18. The ultraviolet irradiation device is a control unit that controls light emission of each of the plurality of light emitting diodes; a detection unit that detects whether the housing is in the closed state or the open state; Furthermore, The ultraviolet irradiation device according to claim 3 , wherein the control unit does not cause the plurality of light-emitting diodes to emit light when the housing is in the open state.

19. The ultraviolet irradiation device according to claim 1 , further comprising an adjustment mechanism that supports the housing or the platform and that can adjust the attitudes of the housing and the platform.

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