Light source device and irradiation device

Abstract

This light source device comprises: a first light source unit including one or more kinds of semiconductor light sources, the first light source unit emitting first ultraviolet rays; a second light source unit including one or more kinds of semiconductor light sources, the second light source unit emitting second ultraviolet rays that are different from the first ultraviolet rays in at least one of central wavelength and optical spectrum; a light tunnel that guides each of the first ultraviolet rays and the second ultraviolet rays; and a mixing optical system provided inside the light tunnel, the mixing optical system mixing the first ultraviolet rays and the second ultraviolet rays to obtain third ultraviolet rays. The inner surface of the light tunnel is a reflective surface that reflects the first ultraviolet rays, the second ultraviolet rays, and the third ultraviolet rays. The third ultraviolet rays mixed by the mixing optical system are emitted from the light tunnel.

Description

Light source device and irradiation device

[0001] The present disclosure relates to a light source device and an illumination device.

[0002] Light source devices equipped with ultraviolet discharge lamps such as high-pressure mercury lamps and metal halide lamps are known. These types of light source devices are widely used in various devices, such as lightfastness testers for testing the lightfastness of objects, photocuring devices for photocuring photocurable resins, and ultraviolet light source devices installed in printing machines for curing ultraviolet-curable inks. Meanwhile, in recent years, in the technical field to which light source devices belong, mercury-containing discharge lamps have been replaced with LEDs (light-emitting diodes) for purposes such as reducing environmental impact. However, because the spectral spectrum of an ultraviolet discharge lamp is a continuous spectrum over a relatively wide wavelength range, it may be difficult to replace the ultraviolet discharge lamp with a single type of ultraviolet LED. Therefore, a light source device that can be used to replace an ultraviolet discharge lamp needs to be configured to include multiple types of ultraviolet LEDs with different center wavelengths and emit a mixture of ultraviolet LEDs to obtain a continuous spectrum over a desired wavelength range.

[0003] Patent Document 1 discloses a technique for mixing light from different light sources using a beam splitter, and Patent Document 2 discloses a technique for mixing light from different light sources using a dichroic mirror.

[0004] JP 2021-96998 A JP 2010-263218 A

[0005] However, in the conventional technology, the illuminance and spectral uniformity within the irradiation area where the mixed ultraviolet light is irradiated are not taken into consideration.

[0006] The present disclosure aims to provide a light source device and an illumination device that can improve the illuminance and spectral uniformity within an illumination area.

[0007] A light source device according to one aspect of the present disclosure comprises a first light source unit including one or more types of semiconductor light sources and emitting first ultraviolet light; a second light source unit including one or more types of semiconductor light sources and emitting second ultraviolet light having a center wavelength different from that of the first ultraviolet light; a light tunnel that guides each of the first ultraviolet light and the second ultraviolet light; and a mixing optical system that is provided inside the light tunnel and combines the first ultraviolet light and the second ultraviolet light to obtain third ultraviolet light, wherein the inner surface of the light tunnel is a reflective surface that reflects the first ultraviolet light, the second ultraviolet light, and the third ultraviolet light, and the third ultraviolet light mixed by the mixing optical system is emitted from the light tunnel.

[0008] According to one aspect of the present disclosure, the illuminance and spectral uniformity within the illuminated area can be improved.

[0009] 5 is a perspective view schematically showing an example of the configuration of a light source device according to a first embodiment of the present disclosure; FIG. 6 is a cross-sectional view schematically showing an example of the internal configuration of a light source device; FIG. 7 is a view showing an example of ultraviolet LEDs provided in each of a first light source unit and a second light source unit; FIG. 8 is a plan view showing an example of an LED substrate provided in a second light source unit; FIG. 9 is a view showing the positions of measurement points of the spectral spectrum in the irradiation area; FIG. 10 is a view showing measurement results of the spectral spectrum at each measurement point shown in FIG. 5; FIG. 11 is a view showing measurement points of illuminance measurement in the irradiation area and illuminance measured values ​​at those measurement points; FIG. 12 is a view showing the conformity of the third ultraviolet ray to the wavelength range regulations of JIS; FIG. 13 is a perspective view schematically showing an example of the configuration of a light source device according to a second embodiment of the present disclosure; FIG. 14 is a cross-sectional view schematically showing an example of the internal configuration of a light source device; FIG. 15 is a view showing the transmission characteristics and reflection characteristics of a dichroic mirror; FIG. 16 is a plan view showing an example of two LED substrates provided in a first light source unit; FIG. 17 is a view showing measurement results of the spectral spectrum at each measurement point in the irradiation area; FIG. 18 is a view showing measurement points of illuminance measurement in the irradiation area and illuminance measured values ​​at those measurement points; FIG. 19 is a view showing the conformity of the third ultraviolet ray to the wavelength range regulations of JIS; FIG. 1 is a perspective view of the external configuration of the irradiation device as viewed from below. FIG. 2 is an exploded perspective view of the irradiation device. FIG. 3 is a longitudinal sectional view of a light source device according to a third embodiment. FIG. 4 is a plan view of the irradiation device as viewed from the bottom. FIG. 5 is a perspective view of the irradiation device as viewed from the bottom. FIG. 6 is an assembly view of the partition unit and the light tunnel. FIG. 7 is a perspective view of the irradiation device as viewed from the top. FIG. 8 is a plan view of an LED board group. FIG. 9 is a view showing a modified example of the arrangement of the LED board group. FIG. 10 is a view showing a modified example of the irradiation device according to the third embodiment. FIG. 11 is a view showing other modified examples of the irradiation device according to the third embodiment.

[0010] Preferred embodiments of the present disclosure will be described below with reference to the drawings. The dimensions and scale of each part in the drawings may differ from the actual dimensions and scale, and some parts may be shown schematically to facilitate understanding. Furthermore, unless otherwise specified in the following description to the effect that the present disclosure is limited, the scope of the present disclosure is not limited to the embodiments described below. The scope of the present disclosure includes equivalents of the embodiments.

[0011] 1. First Embodiment FIG. 1 is a perspective view schematically illustrating an example of the configuration of a light source device 1A according to this embodiment. FIG. 2 is a cross-sectional view schematically illustrating an example of the internal configuration of the light source device 1A. The light source device 1A is an apparatus that can be incorporated into various devices, such as light resistance testing devices, photocuring devices, and semiconductor processing devices, and used as an alternative light source to ultraviolet discharge lamps. As shown in FIGS. 1 and 2, the light source device 1A of this embodiment includes a first light source unit 10-1 that emits first ultraviolet rays L1, a second light source unit 10-2 that emits second ultraviolet rays L2 that differ from the first ultraviolet rays L1 in at least one of the central wavelength and the optical spectrum, a light tunnel 30 that guides each of the first ultraviolet rays L1 and the second ultraviolet rays L2, and a mixing optical system 40 that is provided inside the light tunnel 30 and mixes the first ultraviolet rays L1 and the second ultraviolet rays L2. The third ultraviolet rays L3 mixed by the mixing optical system 40 are irradiated from the light tunnel 30 toward a stage A. On stage A, an appropriate irradiation object to be irradiated with the third ultraviolet light L3 is placed.

[0012] The light source device 1A of this embodiment includes a first cooling unit 50-1 that cools the first light source unit 10-1 and a second cooling unit 50-2 that cools the second light source unit 10-2. The first cooling unit 50-1 and the second cooling unit 50-2 include one or more types of appropriate cooling means, such as a heat sink, an air-cooled fan, or a water cooler. Although not shown, the light source device 1A also includes a light source control device that controls the on / off and dimming of the first light source unit 10-1 and the second light source unit 10-2, and a cooling control device that controls the operation of the first cooling unit 50-1 and the second cooling unit 50-2.

[0013] FIG. 3 is a diagram showing an example of ultraviolet LEDs provided in each of the first light source unit 10-1 and the second light source unit 10-2. In order to approximate the spectral spectrum of an alternative ultraviolet discharge lamp, the first light source unit 10-1 and the second light source unit 10-2 of the light source device 1A each include one or more types of ultraviolet LEDs that differ from each other in at least one of their central wavelengths and spectral spectra. The ultraviolet LED is an example of a "semiconductor light source" in the present disclosure. Existing accelerated weathering test devices that use a metal halide lamp as a light source irradiate an object with light emitted from the metal halide lamp and transmitted through a filter. The light source device 1A of this embodiment achieves the spectral spectrum of light transmitted through a filter in existing accelerated weathering test devices by mixing light emitted from multiple LEDs with different peak wavelengths. Specifically, to reproduce this spectrum, as shown in FIG. 3 , the first light source unit 10-1 includes two types of ultraviolet LEDs, a first ultraviolet LED and a second ultraviolet LED, and the second light source unit 10-2 includes four types of ultraviolet LEDs, a third ultraviolet LED, a fourth ultraviolet LED, a fifth ultraviolet LED, and a sixth ultraviolet LED. In this embodiment, the first to sixth ultraviolet LEDs are LEDs with different center wavelengths. That is, as shown in FIG. 3 , the center wavelengths of the first ultraviolet LED, the second ultraviolet LED, the third ultraviolet LED, the fourth ultraviolet LED, the fifth ultraviolet LED, and the sixth ultraviolet LED are 325 nm, 340 nm, 365 nm, 375 nm, 385 nm, and 405 nm, respectively. The ultraviolet rays from the six types of ultraviolet LEDs with different center wavelengths are mixed by the mixing optical system 40 to form the third ultraviolet light L3, so that the spectrum of the third ultraviolet light L3 becomes a continuous spectrum with a relatively wide wavelength range. In addition, the number of each of the six types of ultraviolet LEDs and the forward current are determined so that the spectrum of the third ultraviolet light L3 approximates the spectrum of light from a metal halide lamp that has passed through a filter in an existing accelerated weather resistance test device.

[0014] 4 is a plan view showing an example of the LED substrate 100 provided in the second light source unit 10-2. The LED substrate 100 includes four types of ultraviolet LEDs, the third to sixth ultraviolet LEDs, provided in the second light source unit 10-2, and a mounting substrate 110 on which these ultraviolet LEDs are mounted. The mounting substrate 110 is a printed circuit board that is generally rectangular in plan view. Each ultraviolet LED is mounted within a central region 110R located approximately in the center of the mounting substrate 110. Within this central region 110R, each type of ultraviolet LED is widely dispersed and arranged so that the ultraviolet LEDs are point-symmetrical about the center of the central region.

[0015] 1, the first light source unit 10-1 includes two LED substrates 100. One of the two LED substrates 100 has a first ultraviolet LED arranged in a central region 110R, and the other LED substrate 100 has a second ultraviolet LED arranged in the central region 110R.

[0016] In this embodiment, the central region 110R is rectangular with sides of approximately 25 mm, and ultraviolet light from each type of ultraviolet LED is emitted from substantially the entire surface of the central region 110R. Furthermore, in this embodiment, the first through sixth ultraviolet LEDs are all packaged LEDs, which are light sources that do not themselves include optical elements such as lenses. Each ultraviolet LED emits ultraviolet light at a relatively wide radiation angle (e.g., 120 degrees), resulting in a relatively wide radiation angle of the ultraviolet light emitted from the LED substrate 100. The radiation angle is assumed to be an appropriate angle between 15 degrees and 180 degrees. Note that some or all of the one or more types of LEDs included in each of the first light source unit 10-1 and the second light source unit 10-2 may include optical elements, or may be SMD (Surface Mount Device) type, COB (Chip On Board) type, or shell-type LEDs.

[0017] Returning to FIG. 2 , the mixing optical system 40 of this embodiment includes a beam splitter 400. The beam splitter 400 of this embodiment is a plate-type optical element. The beam splitter 400 has optical characteristics of a transmittance of 70% and a reflectance of 30% when the incident angle of incident light is 45 degrees. The beam splitter 400 is disposed at an intersection Ba between the first optical axis K1 of the first ultraviolet ray L1 and the second optical axis K2 of the second ultraviolet ray L2, at a right angle, and is tilted at 45 degrees with respect to the first optical axis K1 and the second optical axis K2. The beam splitter 400 mixes the light component of the first ultraviolet ray L1 that has passed through the beam splitter 400 with the light component of the second ultraviolet ray L2 that has been reflected by the beam splitter 400, thereby obtaining the third ultraviolet ray L3.

[0018] 2, the light tunnel 30 is a hollow cylindrical body 300 that extends linearly and has an exit port 300Q at one end 300T1 through which the third ultraviolet ray L3 is emitted. A first inlet 300M1 that introduces one of the first ultraviolet ray L1 and the second ultraviolet ray L2 is opened at the other end 300T2 of the cylindrical body 300. A second inlet 300M2 that introduces the other of the first ultraviolet ray L1 and the second ultraviolet ray L2 is opened on the side surface of the cylindrical body 300.

[0019] In this embodiment, the first light source unit 10-1 is disposed in the first inlet 300M1, and the first ultraviolet ray L1 is introduced through the first inlet 300M1. Meanwhile, the second light source unit 10-2 is disposed in a sub-cylinder 300S extending from the second inlet 300M2, and the second ultraviolet ray L2 is introduced through the second inlet 300M2. In this configuration, the first light source unit 10-1 is installed so that the first optical axis K1 of the first ultraviolet ray L1 roughly coincides with the central axis of the cylinder 300. The second light source unit 10-2 is installed so that the second optical axis K2 of the second ultraviolet ray L2 is perpendicular to the central axis of the cylinder 300. Then, as described above, a beam splitter 400 is installed inside the cylinder 300 at the intersection Ba of the first optical axis K1 and the second optical axis K2, and the third ultraviolet ray L3 travels from the beam splitter 400 toward the exit 300Q.

[0020] In this embodiment, in order to make the distance from intersection Ba to first inlet 300M1 and the distance from intersection Ba to second inlet 300M2 approximately equal, a secondary cylinder 300S extending from the side surface of cylinder 300 in a direction perpendicular to the central axis of cylinder 300 is installed at second inlet 300M2. Second light source unit 10-2 is disposed at the end of this secondary cylinder 300S. The cross-sectional shape and cross-sectional dimensions of secondary cylinder 300 are approximately the same as those of cylinder 300.

[0021] In this embodiment, the cross-sectional shapes of the cylinder 300 and the sub-cylinder 300S, as well as the opening shapes of the first inlet 300M1, the second inlet 300M2, and the outlet 300Q, are all square. The inner dimensions of the cylinder 300 and the sub-cylinder 300S are each approximately 50 mm on a side, and the distance from the first inlet 300M1 to the outlet 300Q is 160.5 mm. The distance from the intersection Ba to the first inlet 300M1 is 65.5 mm, and the distance from the intersection Ba to the installation position of the second light source unit 10-2 on the sub-cylinder 300S is also 65.5 mm. The light exit 300Q is a square with sides of 50 mm, the same as the inner dimensions of the cylindrical body 300, and an irradiation area D of predetermined dimensions and a predetermined shape with the first optical axis K1 as its center E is defined at a position 5 mm away from the light exit 300Q. In this embodiment, the irradiation area D is defined as a square range with sides of 25 mm.

[0022] The shape and dimensions of the cylinder 300 and the sub-cylinder 300S, as well as the shape and dimensions of the first inlet 300M1, the second inlet 300M2, and the outlet 300Q are set appropriately depending on, for example, the desired shape, dimensions, and illuminance of the irradiation area D.

[0023] In the light tunnel 30 of this embodiment, the cylindrical body 300 and the sub-cylindrical body 300S are each formed using a plate material primarily made of a highly reflective material such as aluminum, and the inner surface 30A of the light tunnel 30 is a reflective surface that reflects ultraviolet rays with high reflectivity. Meanwhile, as described above, the first light source unit 10-1 and the second light source unit 10-2 each emit the first ultraviolet rays L1 and the second ultraviolet rays L2 at a relatively large radiation angle (e.g., 120 degrees or more). Therefore, inside the light tunnel 30, as indicated by the dashed arrows C1 in FIG. 2, the first ultraviolet rays L1, the second ultraviolet rays L2, and the third ultraviolet rays L3 each travel while being multiplexedly reflected by the inner surface 30A. As a result, the third ultraviolet rays L3 are a sufficiently mixed ultraviolet light from each of the six types of ultraviolet LEDs provided in the first light source unit 10-1 and the second light source unit 10-2. Irradiating the irradiation area D with the third ultraviolet light L3 improves the illuminance and spectral uniformity in the irradiation area D. Note that the dashed arrow C1 shown in Fig. 2 conceptually illustrates the state of reflection and does not represent the actual trajectory of the light ray.

[0024] Next, the measurement results of the illuminance and the optical spectrum in the irradiation area D will be described.

[0025] FIG. 5 is a diagram showing the positions of measurement points of the optical spectrum in the irradiation area D. FIG. 6 is a diagram showing measurement results of the optical spectrum at each measurement point shown in FIG. 5. As described above, the irradiation area D in this embodiment is a square with sides of 25 mm. As shown in FIG. 5, measurement points, from the first measurement point DP1 to the fifth measurement point DP5, are set in this irradiation area D. The first measurement point DP1, the second measurement point DP2, the third measurement point DP3, the fourth measurement point DP4, and the fifth measurement point DP5 correspond to the center, the vicinity of the upper left corner, the vicinity of the lower left corner, the vicinity of the lower right corner, and the vicinity of the upper right corner of the irradiation area D, respectively. Note that in FIG. 5, the circles surrounding each measurement point indicate the light receiving range of the spectroscopic sensor.

[0026] 6, the relative intensities of the optical spectra measured at the first measurement point DP1 to the fifth measurement point DP5 are all approximately equal. This indicates that the optical spectrum is uniform in the irradiation area D.

[0027] FIG. 7 shows the measurement points for illuminance measurement in the irradiation area D and the illuminance measurement values ​​at those measurement points. As shown in the figure, the sixth measurement point DP6 to the fourteenth measurement point DP14 are set as measurement points for illuminance measurement in the irradiation area D. The sixth measurement point DP6 to the fourteenth measurement point DP14 correspond to the center, upper left corner, center of the left side, lower left corner, center of the top side, center of the bottom side, upper right corner, center of the right side, and lower right corner of the irradiation area D, respectively. From the illuminance measurement values ​​at each of the sixth measurement point DP6 to the fourteenth measurement point DP14, the uniformity in the irradiation area D is determined to be 90% or higher. When the illuminance measurement values ​​in FIG. 7 are estimated using the formula (uniformity = MIN value / MAX value × 100), the uniformity is approximately 93%, indicating high illuminance uniformity.

[0028] 8 is a diagram showing the conformance of the third ultraviolet ray L3 to the wavelength range specifications of JIS (Japanese Industrial Standards). The wavelength range specifications are those of JIS A 1501A, "Accelerated Weathering Test Method for Resin Doors and Windows Using Metal Halide Lamps." As shown in the figure, all of the first to fifth measurement points DP1 to DP5 conform to the JIS wavelength range specifications.

[0029] As described above, the light source device 1A of this embodiment includes a first light source unit 10-1 that includes two types of ultraviolet LEDs and emits a first ultraviolet ray L1, a second light source unit 10-2 that includes four types of ultraviolet LEDs and emits a second ultraviolet ray L2 that differs from the first ultraviolet ray L1 in at least one of its central wavelength and optical spectrum, a light tunnel 30 that guides each of the first ultraviolet ray L1 and the second ultraviolet ray L2, and a mixing optical system 40 that is provided inside the light tunnel 30 and mixes the first ultraviolet ray L1 and the second ultraviolet ray L2 to obtain a third ultraviolet ray. The inner surface 30A of the light tunnel 30 is a reflective surface that reflects the first ultraviolet ray L1, the second ultraviolet ray L2, and the third ultraviolet ray L3, and the third ultraviolet ray L3 mixed by the mixing optical system 40 is emitted from the light tunnel 30.

[0030] According to this configuration, the third ultraviolet light L3 is obtained by mixing ultraviolet light from a total of six types of ultraviolet LEDs. Therefore, the spectrum of the third ultraviolet light L3 is a continuous spectrum, similar to that of an ultraviolet discharge lamp, and has optical characteristics that make it suitable as an alternative light source to an ultraviolet discharge lamp. In particular, the light source device 1A does not contain mercury like a mercury discharge lamp, which contributes to reducing environmental impact. Furthermore, because the light source device 1A uses a semiconductor light source such as an ultraviolet LED as a light source, it has a relatively long life compared to a discharge lamp, reducing the frequency of maintenance work such as replacing the discharge lamp. Furthermore, because the light source is divided into two light sources, the first light source unit 10-1 and the second light source unit 10-2, even if the number of ultraviolet LEDs installed increases depending on the required illuminance, the installation area for the ultraviolet LEDs in each light source unit can be secured, preventing the device from becoming larger. Furthermore, by dividing the light source into the first light source unit 10-1 and the second light source unit 10-2, the cooling capacity required for the cooling units (first cooling unit 50-1, second cooling unit 50-2) that cool the individual light source units can be reduced, thereby suppressing the size and cost of the cooling units. In addition, the first ultraviolet light L1, second ultraviolet light L2, and third ultraviolet light L3 are mixed together due to reflection on the inner surface 30A of the light tunnel 30, thereby improving the uniformity of the illuminance and spectrum in the irradiation area D.

[0031] In the light source device 1A of this embodiment, the first light source unit 10-1 and the second light source unit 10-2 respectively emit the first ultraviolet ray L1 and the second ultraviolet ray L2 at an emission angle that causes multiple reflections on the inner surface 30A of the light tunnel 30.

[0032] With this configuration, multiple reflections of the first ultraviolet ray L1, the second ultraviolet ray L2, and the third ultraviolet ray L3 are induced on the inner surface 30A of the light tunnel 30, thereby further improving the uniformity of the illuminance and the spectral distribution in the irradiation area D.

[0033] 2. Second Embodiment In the first embodiment, a light source device 1A was described in which the mixing optical system 40 includes a beam splitter 400. In this embodiment, a light source device 1B will be described in which the mixing optical system 40 includes a dichroic mirror 410. In the description of the second embodiment, the elements described in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

[0034] Fig. 9 is a perspective view schematically illustrating an example of the configuration of a light source device 1B according to this embodiment. Fig. 10 is a cross-sectional view schematically illustrating an example of the internal configuration of the light source device 1B. As shown in Figs. 9 and 10 , in the light source device 1B, the dichroic mirror 410, which serves as an example of the mixing optical system 40, is provided inside the light tunnel 30. Similar to the beam splitter 400 of the first embodiment, the dichroic mirror 410 is disposed at an intersection Ba between the first optical axis K1 of the first ultraviolet ray L1 and the second optical axis K2 of the second ultraviolet ray L2, at an orthogonal intersection, and in a position tilted at 45 degrees with respect to the first optical axis K1 and the second optical axis K2.

[0035] FIG. 11 is a diagram showing the transmission and reflection characteristics of the dichroic mirror 410 of this embodiment. The dichroic mirror 410 has a design incident angle of 45 degrees for transmission and reflection, and as shown in FIG. 11 , has the property of reflecting ultraviolet light in a wavelength band of approximately 356 nm or less and transmitting ultraviolet light in a wavelength band of approximately 356 nm or more. Meanwhile, as shown in FIG. 3 above, the first light source unit 10-1 is provided with an ultraviolet LED having a center wavelength of 340 nm or less, and the first light source unit 10-1 is optimally configured as a light source utilizing the reflection of the dichroic mirror 410. Furthermore, the second light source unit 10-2 is provided with an ultraviolet LED having a center wavelength of 365 nm or more, and the second light source unit 10-2 is optimally configured as a light source utilizing the transmission of the dichroic mirror 410.

[0036] Therefore, by making the second ultraviolet ray L2 of the second light source unit 10-2 incident on the first surface 410P1 that receives transmitted light and making the first ultraviolet ray L1 of the first light source unit 10-1 incident on the second surface 410P2 that receives reflected light, loss due to the dichroic mirror 410 is reduced and the third ultraviolet ray L3 can be obtained efficiently.

[0037] In this embodiment, the second inlet 300M2 formed on the side of the light tunnel 30 is not provided with the second light source unit 10-2, but with the first light source unit 10-1, which emits the first ultraviolet light L1, which has a shorter wavelength than the second ultraviolet light L2 of the second light source unit 10-2. That is, the dichroic mirror 410 is installed so that its second surface 410P2 faces the side of the light tunnel 30 and also faces the outlet 300Q. Furthermore, in the light tunnel 30 of this embodiment, the secondary cylinder 300S is not provided at the second inlet 300M2, and the first light source unit 10-1 is installed directly at the second inlet 300M2. Therefore, the distance from the first light source unit 10-1 to the outlet 300Q (irradiation area D) is shorter than the distance from the second light source unit 10-2 to the outlet 300Q (irradiation area D).

[0038] Generally, semiconductor light sources such as LEDs have lower light-emitting efficiency as the wavelength of the light they emit becomes shorter, and therefore consume more power to obtain a certain amount of light. In contrast, with this light source device 1B, the first light source unit 10-1, which has a shorter wavelength, is positioned closer to the irradiation area D than the second light source unit 10-2, so that the desired amount of first ultraviolet light L1 can be obtained with less power, thereby achieving a highly efficient light source device 1B.

[0039] 12 is a plan view showing an example of two LED substrates 100 provided in the first light source unit 10-1. As described above, each of the two LED substrates 100 has a central region 110R, with a plurality of first ultraviolet LEDs arranged in one central region 110R and a plurality of second ultraviolet LEDs arranged in the other central region 110R. Furthermore, as shown in FIG. 12, the LED substrate 100 of this embodiment is provided with reflectors 120 on both sides of the central region 110R, which reflect the second ultraviolet light L2 emitted by the second light source unit 10-2 and the first ultraviolet light L1 emitted by the first light source unit 10-1. The reflectors 120 are an example of a "reflector" in the present disclosure and are, for example, metal plates such as aluminum. Because the dichroic mirror 410 has a relatively high transmittance, a portion of the second ultraviolet ray L2 that passes through the dichroic mirror 410 is incident on the LED substrate 100 of the first light source unit 10-1, as shown by the dashed arrow C2 in Fig. 10. This second ultraviolet ray L2 is then reflected by the reflector 120, and is emitted from the outlet 300Q as the third ultraviolet ray L3, thereby reducing loss of the second ultraviolet ray L2. The addition of the first ultraviolet ray L1 further increases the efficiency of the light source device 1B.

[0040] Furthermore, even if a portion of the second ultraviolet light L2 that has passed through the dichroic mirror 410 enters the second inlet 300M2 where the first light source unit 10-1 is disposed, because the secondary cylinder 300S is not provided, the second ultraviolet light L2 does not enter the secondary cylinder 300S but is instead reflected by the reflector 120 provided at the second inlet 300M2. This prevents a decrease in uniformity in the irradiation area D due to a portion of the second ultraviolet light L2 entering the secondary cylinder 300S or being absorbed by the LED substrate 100 of the first light source unit 10-1, thereby maintaining uniformity of illuminance. Note that, in addition to providing the reflector 120, a similar effect can be achieved by using a resist with high reflectivity against ultraviolet light on the LED substrate 100. Although not shown in FIG. 4, a reflector such as the reflector 120 may be provided on the second light source unit 10-2.

[0041] Next, we will explain the measurement results of the illuminance and optical spectrum in the irradiation area D. Note that the following measurements were performed by reducing the forward current of the third to sixth ultraviolet LEDs provided in the second light source unit 10-2 to half that of the first embodiment (to be more precise, 350 mA).

[0042] 13 is a diagram showing the measurement results of the optical spectrum at each measurement point in the irradiation area D. The positions of each measurement point are the same as in the first embodiment. As shown in the figure, in the light source device 1B of this embodiment, as in the light source device 1A of the first embodiment, the relative intensities of the optical spectrum measured at each of the first measurement point DP1 to the fifth measurement point DP5 are all approximately equal. This shows that the optical spectrum is uniform in the irradiation area D.

[0043] FIG. 14 shows the measurement points for illuminance measurement in the irradiation area D and the illuminance measurement values ​​at those measurement points. In the light source device 1B of this embodiment, as in the light source device 1A of the first embodiment, the illuminance measurement values ​​at each of the sixth measurement point DP6 to the fourteenth measurement point DP14 indicate that the uniformity in the irradiation area D is 90% or higher. When the illuminance measurement values ​​in FIG. 14 are estimated using the formula (uniformity = MIN value / MAX value × 100), the uniformity is approximately 93%, indicating high illuminance uniformity. Furthermore, even when the forward currents of the third to sixth ultraviolet LEDs in the second light source unit 10-2 are lower than in the first embodiment, the illuminance measurement values ​​equivalent to those in the first embodiment are obtained at each of the sixth measurement point DP6 to the fourteenth measurement point DP14, indicating high efficiency.

[0044] 15 is a diagram showing the conformity of the third ultraviolet ray to the JIS wavelength range specification. Similar to the first embodiment, this wavelength range specification is the specification for JIS A 1501A "Method for accelerated weather resistance testing of resin fittings using metal halide lamps." As shown in the figure, this embodiment, like the first embodiment, also conforms to the JIS wavelength range specification at all of the first to fifth measurement points DP1 to DP5.

[0045] Furthermore, the inventors performed measurements on the configuration of light source device 1B by shortening the overall length of cylindrical body 300 (i.e., the distance from first inlet 300M1 to outlet 300Q). In this case, the distance from intersection Ba (second inlet 300M2) to outlet 300Q was also shortened. As a result of these measurements, the inventors found that the uniformity of the optical spectrum in irradiation area D and the conformance to the JIS wavelength range regulations were not affected even when the overall length of cylindrical body 300 was shortened, regardless of whether the overall length of cylindrical body 300 was 140.5 mm (the distance between intersection Ba and outlet 300Q was 75 mm), 120.5 mm (the distance between intersection Ba and outlet 300Q was 55 mm), 100.5 mm (the distance between intersection Ba and outlet 300Q was 35 mm), or 51 mm (the distance between intersection Ba and outlet 300Q was 25 mm).

[0046] On the other hand, when the overall length is shortened, the uniformity of the illuminance is affected due to differences in the placement positions of the first light source unit 10-1 and the second light source unit 10-2 as viewed from the irradiation area D and an increase in the direct light component that reaches the irradiation area D without being reflected by the inner surface 30A of the light tunnel 30, but it was found that a uniformity of 90% or more can be obtained at any overall length.

[0047] As described above, the light source device 1B of this embodiment has the same effects as the light source device 1A of the first embodiment.

[0048] In addition, in the light source device 1B of this embodiment, of the first light source unit 10-1 and the second light source unit 10-2, the light source unit that emits ultraviolet light with a shorter wavelength (i.e., the first light source unit 10-1) is arranged at the second inlet 300M2.

[0049] With this configuration, the first light source unit 10-1, which has a shorter wavelength, is positioned closer to the irradiation area D than the second light source unit 10-2, so that the desired amount of light from the first ultraviolet ray L1 can be obtained with less power, thereby realizing a highly efficient light source device 1B.

[0050] In the light source device 1B of this embodiment, of the first light source unit 10-1 and the second light source unit 10-2, the light source unit that is arranged at the second inlet 300M2 (i.e., the first light source unit 10-1) is provided with a reflector 120 that reflects ultraviolet light emitted by the other light source unit (i.e., the second light source unit 10-2).

[0051] This configuration prevents a decrease in uniformity in the illumination area D, thereby maintaining uniformity in illuminance. Furthermore, the illuminance in the illumination area D can be increased, resulting in a more efficient light source device 1B.

[0052] In the light source device 1B of this embodiment, the mixing optical system 40 includes a dichroic mirror 410 .

[0053] With this configuration, even when the mixing optical system 40 is equipped with a dichroic mirror 410 having a relatively high transmittance, a light source device 1B can be obtained that maintains uniformity of illuminance and suppresses a decrease in efficiency of the light source device 1B.

[0054] 3. Third Embodiment In this embodiment, an illumination device 1000 will be described. The illumination device 1000 includes components of a plurality of light source devices 1A according to the first embodiment or a plurality of light source devices 1B according to the second embodiment, and achieves uniformity of illuminance and spectral distribution equivalent to that of the light source devices 1A and 1B while expanding the area of ​​the illumination area D compared to the light source devices 1A and 1B alone.

[0055] The irradiation device 1000 will be described in detail below. In this embodiment, an irradiation device 1000 including components of a plurality of light source devices 1B according to the second embodiment will be described. In addition, in the description of this embodiment, the components described in the first embodiment or the second embodiment will be assigned the same reference numerals, and the description thereof will be omitted.

[0056] FIG. 16 is a perspective view of the irradiation device 1000 according to this embodiment, viewed from above. FIG. 17 is a perspective view of the exterior configuration of the irradiation device 1000, viewed from below. FIG. 18 is an exploded perspective view of the irradiation device 1000. As shown in FIGS. 16 and 17 , the irradiation device 1000 includes a cylindrical external housing 2. As shown in FIG. 18 , a light source device 1C is provided inside the external housing 2. In this embodiment, the cross-sectional shape of the external housing 2 is rectangular, but other shapes are also possible. The external housing 2 is made of a highly rigid plate material, such as an alloy. As shown in FIG. 17 , a bottom plate 3 is attached to the bottom surface 2A of the external housing 2. This bottom plate 3 has an exit opening 3A for emitting the third ultraviolet light L3. As shown in FIG. 16 , the top surface 2B of the external housing 2 is open, allowing air and the wiring of the LED board to flow between the inside and outside of the external housing 2. Further, a grip portion 5 is provided on the side surface of the external housing 2 so that the external housing 2 can be gripped by an operator during transportation.

[0057] 19 is a longitudinal cross-sectional view of a light source device 1C according to the present embodiment. As shown in Fig. 19, like the light source device 1A according to the first embodiment and the light source device 1B according to the second embodiment, the light source device 1C includes a first light source unit 10-1 that emits a first ultraviolet ray L1, a second light source unit 10-2 that emits a second ultraviolet ray L2 that differs from the first ultraviolet ray L1 in at least one of the central wavelength and the optical spectrum, a light tunnel 30 that guides each of the first ultraviolet ray L1 and the second ultraviolet ray L2, and a mixing optical system 40 that is provided inside the light tunnel 30 and mixes the first ultraviolet ray L1 and the second ultraviolet ray L2, and irradiates the third ultraviolet ray L3 mixed by the mixing optical system 40 from the light tunnel 30.

[0058] Furthermore, like light source device 1B according to the second embodiment, light source device 1C according to the present embodiment includes a dichroic mirror 410 as an example of mixing optical system 40. In addition, like light source device 1B according to the second embodiment, light source device 1C has first light source unit 10-1 disposed in second inlet 300M2 provided on the side of light tunnel 30, and second light source unit 10-2 disposed in first inlet 300M1 provided at end 300T2 of light tunnel 30. A window plate 4 is disposed at the other end 300T1 of light tunnel 30, and window plate 4 is made of a material that is transparent to at least the wavelength of third ultraviolet light L3, such as quartz glass.

[0059] FIG. 20 is a plan view of the illumination device 1000 as viewed from the bottom, and FIG. 21 is a perspective view of the illumination device 1000 as viewed from the bottom. Note that the bottom plate 3 of the illumination device 1000 and the window plate 4 of the light source device 1C are omitted in FIGS. 20 and 21 . As shown in FIGS. 20 and 21 , the light tunnel 30 of the light source device 1C is partitioned into multiple (four in this embodiment) cylindrical bodies 300 by partition units 60 each consisting of multiple reflectors 61. Each cylindrical body 300 in this embodiment has the same configuration as the cylindrical body 300 in the first and second embodiments. That is, each cylindrical body 300 has a cylindrical shape with a constant cross-sectional area and cross-sectional shape in the axial direction, and the cross-sectional shape is rectangular. Note that the cross-sectional shape of the cylindrical body 300 is not limited to a rectangular shape. Furthermore, the multiple cylindrical bodies 300 included in the light tunnel 30 have the same cross-sectional area, but may also have different cross-sectional areas or cross-sectional shapes.

[0060] As shown in FIG. 19 , in the irradiation device 1000, second ultraviolet light L2 is introduced into each of the multiple cylindrical bodies 300 from a second light source unit 10-2 arranged at a first inlet 300M1. The irradiation device 1000 also includes a first light source unit 10-1 and a dichroic mirror 410 for each cylindrical body 300. A second inlet 300M2 opens on the side of the light tunnel 30 for each cylindrical body 300. The first light source unit 10-1 is arranged at the second inlet 300M2 of each cylindrical body 300. The first ultraviolet light L1 of the first light source unit 10-1 is introduced from the second inlet 300M2 of each cylindrical body 300. Inside each cylindrical body 300, the first ultraviolet light L1 is mixed with the second ultraviolet light L2 by passing through the dichroic mirror 410 while undergoing multiple reflections. The third ultraviolet light L3 obtained by mixing, the first ultraviolet light L1, and the second ultraviolet light L2 are multiple-reflected and reach the end 300T1 before being emitted to the outside. Therefore, the illuminance and spectral distribution are uniform in all areas irradiated by the third ultraviolet light L3 of each cylindrical body 300. These areas are adjacent to each other to form the irradiation area D of the irradiation device 1000, so the area of ​​the irradiation area D can be expanded while maintaining uniformity in the illuminance and spectral distribution.

[0061] In addition, by dividing the interior of the light tunnel 30 into multiple cylinders 300, the cross-sectional area of ​​each cylinder 300 is reduced, increasing the number of times the first ultraviolet light L1, the second ultraviolet light L2, and the third ultraviolet light L3 are multiple-reflected inside each cylinder 300. Therefore, the overall length of the light tunnel 30 can be shortened while maintaining the uniformity of the illuminance and spectral distribution in the irradiation area D.

[0062] Next, details of the illumination device 1000 will be described. As described above, the light source device 1C includes a partition unit 60 inside the light tunnel 30 that divides the interior into a plurality of cylindrical bodies 300. In this embodiment, parts of the partition unit 60 are fixed to each other and the partition unit 60 is fixed to the light tunnel 30 using an insertion structure between members rather than fastening members such as screws or bolts.

[0063] 22 is an assembly diagram of the partition unit 60 and the light tunnel 30. As shown in the figure, the partition unit 60 includes two rectangular reflectors 61. Each of the reflectors 61 has an insertion slit 62 that extends along the central axis of the reflector 61 to the center 61O of the reflector 61. By inserting the two reflectors 61 into each other's insertion slits 62, the partition unit 60 that divides the light tunnel 30 into four cylinders 300 is assembled using an insertion structure.

[0064] The light tunnel 30 also includes two reflectors 31, 31 that are bent into an L-shape in plan view. These two reflectors 31, 31 are fastened together in a facing position to assemble the hollow light tunnel 30 with a rectangular cross section. The fastening structure of the reflectors 31, 31 is detailed as follows: the edge 31A of each of the two reflectors 31, 31 is provided with a bent piece 32 that is bent outward into an L-shape and a contact piece 33 that contacts the bent piece 32 of the other reflector 31. The bent piece 32 of one reflector 31 and the contact piece 33 of the other reflector 31 are then firmly fastened together by fastening means such as bolts or screws.

[0065] Furthermore, a plurality of insertion pieces 63 are formed on the edge 61A of the reflectors 61, 61 that make up the partition unit 60. Meanwhile, in the light tunnel 30, insertion holes 34 into which the insertion pieces 63 of the partition unit 60 are inserted are also formed in the surfaces of the two reflectors 31, 31. Then, by fastening the two reflectors 31, 31 together with the partition unit 60 sandwiched between them so that the insertion pieces 63 of the partition unit 60 are inserted into the insertion holes 34 of the reflectors 31, 31, the partition unit 60 is fixed to the light tunnel 30 by the insertion structure.

[0066] In this way, by using a plug-in structure rather than fastening members such as screws or bolts to fix each reflector 61 of the partition unit 60 to each other and to fix the partition unit 60 to the light tunnel 30, low-reflection areas due to the fastening members are not included on the inner surface of any of the cylindrical bodies 300 of the light tunnel 30, and loss during multiple reflection of the first ultraviolet light L1, the second ultraviolet light L2, and the third ultraviolet light L3 is reduced.

[0067] In this embodiment, the dichroic mirror 410 is fixed to each cylinder 300 with an adhesive. In this configuration, a flange may be provided on the edge of the dichroic mirror 410, and the flange may be fixed to the reflectors 31, 31 of the light tunnel 30 or the reflectors 61, 61 of the partition unit 60 using an insert structure.

[0068] In addition, in this embodiment, the above-mentioned light tunnel 30 is fixed by fastening a fixing piece 70 to the abutment piece 33 for fastening the reflectors 31, 31 together, and then fastening this fixing piece 70 to the external housing 2, as shown in Figure 18 above.

[0069] Here, similar to the light source device 1A of the first embodiment and the light source device 1B of the second embodiment, the irradiation device 1000 includes a first cooling unit 50-1 that cools the first light source unit 10-1 and a second cooling unit 50-2 that cools the second light source unit 10-2, as shown in FIG. 18 . In this embodiment, the first light source unit 10-1 is fixed to the first cooling unit 50-1, and the second light source unit 10-2 is fixed to the second cooling unit 50-2. Both the first cooling unit 50-1 and the second cooling unit 50-2 are fixed to the external housing 2, not the light tunnel 30. Therefore, the weights of the first cooling unit 50-1, the second cooling unit 50-2, and the first light source unit 10-1 and the second light source unit 10-2 are not applied to the light tunnel 30. This prevents bending and damage to the light tunnel 30 and the partition unit 60, even when a low-rigidity material such as aluminum plate is used for the reflectors 31, 31 of the light tunnel 30 and the reflectors 61, 61 of the partition unit 60. Furthermore, since there is no need to increase the rigidity of the light tunnel 30 by using, for example, the partition unit 60, the plate thickness of each of the reflectors 61, 61 of the partition unit 60 can be made thin, and the effect on the illuminance and spectral spectrum of shadows cast in the irradiation area D by the plate thickness of each of the reflectors 61, 61 can be reduced.

[0070] In this embodiment, a water-cooled unit is used for the first cooling unit 50-1, and an air-cooled unit is used for the second cooling unit 50-2. More specifically, as shown in FIG. 18 , the first cooling unit 50-1 includes a water-cooled heat sink 501A through which cooling water circulates, an inlet port 501B for introducing cooling water into the water-cooled heat sink 501A, and a drain port 501C for draining the cooling water from the water-cooled heat sink 501A. The first light source unit 10-1 is fixed to the water-cooled heat sink 501A. The water-cooled heat sink 501A is provided with a plurality of support columns 501D. The first cooling unit 50-1 is fixed to the external housing 2 by fixing each support column 501D to a first support plate 80 fixed to a side surface of the external housing 2.

[0071] 23 is a perspective view of the irradiation device 1000 as viewed from above. Note that the second support plate 81 included in the irradiation device 1000 is omitted in this figure. As shown in FIG. 18, the second cooling unit 50-2 includes one or more (two in this embodiment) air-cooled heat sinks 502A each having a large number of heat dissipation fins, and an axial fan 502B that blows cooling air onto the air-cooled heat sink 502A. In the second cooling unit 50-2, as shown in FIGS. 18 and 23, the air-cooled heat sink 502A is fixed to the external housing 2 by a support rod 502C, and as shown in FIG. 18, the axial fan 502B is fixed to the second support plate 81 fixed to the upper surface 2B of the external housing 2, thereby fixing the second cooling unit 50-2 to the external housing 2.

[0072] As described in the second embodiment, the first light source unit 10-1 includes LEDs that emit ultraviolet light with a shorter wavelength than the second light source unit 10-2, and therefore consumes more power and generates more heat. Furthermore, the first light source unit 10-1 of this embodiment emits the second ultraviolet light L2 to be introduced into each of the multiple cylindrical bodies 300. Therefore, the number and density of ultraviolet LEDs are greater than those of the first light source unit 10-1 of the first and second embodiments, and heat generation is also significantly increased. In contrast, in this embodiment, the first light source unit 10-1 is cooled using a water-cooling system, which can achieve higher cooling performance than an air-cooling system. Therefore, even if the first light source unit 10-1 generates a large amount of heat, it can be sufficiently cooled, and a decrease in the efficiency of the first light source unit 10-1 due to heat generation is suppressed.

[0073] On the other hand, in this embodiment, the second light source unit 10-2 has a plurality of LED substrate groups 100G, as shown in Figure 20, and each LED substrate group 100G corresponds one-to-one to one of the plurality of cylindrical bodies 300, and the second ultraviolet light L2 emitted from the corresponding one LED substrate group 100G is introduced into one cylindrical body 300.

[0074] FIG. 24 is a plan view of an LED substrate group 100G. One LED substrate group 100G includes multiple (six in this embodiment) LED substrates 101. Each LED substrate 101 has a fastening hole 101H formed in its surface, and fastening members such as screws are inserted through the hole 101H to fasten the LED substrate 101 to the base plate 102 ( FIG. 20 ). By applying thermally conductive grease or sandwiching a thermally conductive sheet between the LED substrate 101 and the base plate 102, heat generated by the LEDs can be dissipated to an air-cooled heat sink. One LED substrate group 100G corresponds to the LED substrate 100 of the first and second embodiments and, like the LED substrate 100, includes four types of ultraviolet LEDs: a third ultraviolet LED, a fourth ultraviolet LED, a fifth ultraviolet LED, and a sixth ultraviolet LED. The ultraviolet LEDs may be arranged appropriately on the LED substrate 100.

[0075] The LED substrates 101 have the same shape and dimensions in a plan view (i.e., congruent shapes), and the LED substrates 101 of this embodiment include a rectangular portion 103 and an engaging portion 104. The rectangular portion 103 is a portion of the LED substrate 101 that is rectangular in a plan view.

[0076] On the other hand, the engaging portion 104 is a portion that is continuous with one side of the rectangular portion 103. The shape of this engaging portion 104 in a plan view is line-symmetrical with respect to the center line 101C of the LED substrate 101, and is shaped to form a receiving portion δ, which is a gap having a shape corresponding to the outline of the engaging portion 104, between the engaging portion 104 of another horizontally adjacent LED substrate 101. In Fig. 24, the shape of the receiving portion δ is indicated by a double-chain line.

[0077] By providing each LED board 101 with the rectangular portion 103, it is possible to arrange a plurality of LED boards 101 side by side with almost no gaps between them, and the light-emitting region of the second light source unit 10-2 can be easily expanded in the horizontal direction. Also, by engaging the engaging portion 104 of another LED board 101 in an upside-down position with each receiving portion δ formed by two horizontally arranged LED boards 101, the light-emitting region of the second light source unit 10-2 can be easily expanded in the vertical direction.

[0078] Here, the engaging portion 104 in this embodiment includes a protrusion 104A and a shoulder 104B. The shoulder 104B, in plan view, is inclined at a predetermined angle α (α = 30 degrees in this embodiment) from the rectangular portion 103 to the protrusion 104A with respect to the center line 101C. The protrusion 104A also has a V-shaped shape in plan view, with two sides 104A1 inclined at the same angle α as the shoulder 104B. By providing each LED board 101 with such an engaging portion 104, the arrangement of the LED boards 101 can be increased. Specifically, depending on how the engaging portions 104 of the multiple LED boards 101 are engaged with each other, two upside-down LED boards 101 can be arranged vertically in a straight line, as shown in Arrangement A of FIG. 25 , or multiple LED boards 101 can be arranged in a star pattern, as shown in Arrangement B of FIG. 25 .

[0079] As explained above, the light source device 1C of this embodiment includes a partition unit 60 that partitions the interior of the light tunnel 30 into a plurality of cylindrical bodies 300. With this configuration, the illuminance and spectral distribution are uniform in the areas irradiated by the individual cylindrical bodies 300, and by these areas being adjacent to each other to form an irradiation area D, the area of ​​the irradiation area D is expanded, while the illuminance is higher than that of the light source device 1B of the second embodiment and the uniformity of the spectral distribution is maintained. The irradiation device 1000 including this light source device 1C has an illuminance (approximately 150 mW / cm) that is approximately three times that of the light source device 1B. ２ ) to be achieved.

[0080] In addition, by dividing the interior of the light tunnel 30 into multiple cylinders 300, the cross-sectional area of ​​each cylinder 300 is reduced, increasing the number of times the first ultraviolet light L1, the second ultraviolet light L2, and the third ultraviolet light L3 are multiple-reflected inside each cylinder 300. This makes it possible to shorten the overall length of the light tunnel 30 while maintaining the uniformity of the illuminance and spectral distribution in the irradiation area D.

[0081] In the light source device 1C of this embodiment, the partition unit 60 includes a plurality of reflectors 61, which are fixed to one another by an insert structure. With this configuration, no low-reflection areas due to fastening members are included on the inner surface of any of the cylindrical bodies 300, and loss of the first ultraviolet ray L1, the second ultraviolet ray L2, and the third ultraviolet ray L3 due to multiple reflections can be reduced.

[0082] The illumination device 1000 of this embodiment includes a light source device 1C, a first cooling unit 50-1 that cools the first light source unit 10-1, a second cooling unit 50-2 that cools the second light source unit 10-2, and an external housing 2 that houses the light source device 1C, with the first cooling unit 50-1 and the second cooling unit 50-2 fixed to the external housing 2. This configuration prevents the light tunnel 30 and the partition unit 60 from bending or being damaged, even when a low-rigidity material such as aluminum plate is used for the reflectors 31, 31 of the light tunnel 30 and the reflectors 61, 61 of the partition unit 60. Furthermore, since there is no need to increase the rigidity of the light tunnel 30 using the partition unit 60, the thickness of each reflector 61, 61 of the partition unit 60 can be made thinner, thereby reducing the impact of shadows cast in the illumination area D by the thickness of each reflector 61, 61 on the illuminance and spectral spectrum.

[0083] In the third embodiment, the illumination device 1000 includes a plurality of light source devices 1A, a plurality of light source devices 1B, or a plurality of light source devices 1C, and the surface area of ​​the illumination area D may be expanded by storing the plurality of light source devices 1A, a plurality of light source devices 1B, or a plurality of light source devices 1C in the external housing 2 with their light tunnels 30 connected in a contacting state.

[0084] Furthermore, the illumination device 1000 may include elements of multiple light source devices 1A according to the first embodiment, instead of the light source device 1B according to the second embodiment. In this case, for example, as shown in FIG. 26 , an illumination device 1000A may be configured in which multiple (two in the illustrated example) light source devices 1A are arranged side by side and the light tunnels 30 of the light source devices 1A are connected in a state of contact with each other. Furthermore, as shown in FIG. 27 , for example, an illumination device 1000B may be configured in which a pair of light source devices 1A are arranged opposite each other and the light tunnels 30 of the light source devices 1A are connected in a state of contact with each other. Furthermore, the illumination device 1000A and the illumination device 1000B may include an external housing 2, each light source device 1A is housed in the external housing 2, and the first cooling unit 50-1 and the second cooling unit 50-2 may be fixed to the external housing 2.

[0085] 4. Modifications Examples of modifications that can be added to each of the above-described embodiments are given below. Two or more of the following examples may be arbitrarily selected and combined as long as they are not mutually contradictory.

[0086] The light source control device may adjust the brightness of each type of ultraviolet LED included in the first light source unit 10-1 and the second light source unit 10-2, thereby dynamically changing the relative intensity of the spectrum of the third ultraviolet light L3.

[0087] A light source system may be configured that illuminates a larger illumination area D by arranging multiple light source devices 1A or multiple light source devices 1B side by side. The illumination area D may also be enlarged by increasing the cross-sectional size of the light tunnel 30 of the light source device 1A or light source device 1B.

[0088] In each of the first light source unit 10-1 and the second light source unit 10-2, a configuration may be adopted in which a larger number of ultraviolet LEDs are mounted densely on the LED substrate 100, thereby obtaining a higher illuminance.

[0089] The ultraviolet LEDs included in each of the first light source unit 10-1 and the second light source unit 10-2 may be bare chip type instead of package type. In this case, a substrate on which the bare chip type ultraviolet LEDs are mounted may be used as the LED substrate 100.

[0090] The wavelength range of the semiconductor light sources included in each of the first light source unit 10-1 and the second light source unit 10-2 is not limited to the range of 325 nm to 405 nm described in the first and second embodiments. That is, the wavelength range of the semiconductor light sources may be in the UV-C range of less than 300 nm, the visible light range, or the infrared range.

[0091] 1A...light source device, 1B...light source device, 1C...light source device, 10-1...first light source unit, 2...external housing, 10-2...second light source unit, 50-1...first cooling unit, 50-2...second cooling unit, 30...light tunnel, 30A...inner surface, 40...mixing optical system, 60...compartment unit, 61...reflector, 100...LED substrate, 110...mounting substrate, 110R...central region, 120...reflector, 300...cylinder, 300M1...first inlet, 300M2...second inlet, 300Q...exit port, 400...beam splitter, 410...dichroic mirror, 1000...irradiation device, D...irradiation area, K1...first optical axis, K2...second optical axis, L1...first ultraviolet ray, L2...second ultraviolet ray, L3...third ultraviolet ray.

Claims

1. A light source device comprising: a first light source unit including one or more types of semiconductor light sources and emitting a first ultraviolet ray; a second light source unit including one or more types of semiconductor light sources and emitting a second ultraviolet ray having a central wavelength and at least one of a spectral spectrum different from that of the first ultraviolet ray; a light tunnel for guiding each of the first ultraviolet ray and the second ultraviolet ray; and a mixing optical system provided inside the light tunnel for mixing the first ultraviolet ray and the second ultraviolet ray to obtain a third ultraviolet ray, wherein the inner surface of the light tunnel is a reflective surface that reflects the first ultraviolet ray, the second ultraviolet ray, and the third ultraviolet ray, and the light tunnel is configured to emit the third ultraviolet ray mixed by the mixing optical system.

2. The light source device described in claim 1, wherein the first light source unit emits the first ultraviolet light within a range of radiation angles at which multiple reflections occur on the inner surface of the light tunnel, and the second light source unit emits the second ultraviolet light within a range of radiation angles at which multiple reflections occur on the inner surface of the light tunnel.

3. The light source device according to claim 1, wherein the light tunnel includes a hollow cylinder extending linearly, one end of the cylinder has an exit port for emitting the third ultraviolet ray, the other end of the cylinder has a first inlet port for introducing one of the first ultraviolet ray and the second ultraviolet ray, a side of the cylinder has a second inlet port for introducing the other of the first ultraviolet ray and the second ultraviolet ray, and one of the first light source unit and the second light source unit that emits ultraviolet ray with a shorter wavelength is disposed at the second inlet.

4. The light source device according to claim 1, further comprising a partition unit that partitions the inside of the light tunnel into a plurality of cylinders.

5. A light source device comprising: a first light source unit including one or more types of semiconductor light sources and emitting a first ultraviolet ray; a light tunnel; and a partition unit that partitions the interior of the light tunnel into a plurality of cylinders, wherein for each of the plurality of cylinders, a second light source unit including one or more types of semiconductor light sources and emitting a second ultraviolet ray having a shorter wavelength than the first ultraviolet ray; and a mixing optical system that is provided inside the cylinder and mixes the first ultraviolet ray and the second ultraviolet ray to obtain a third ultraviolet ray, wherein an inner surface of the light tunnel is a reflective surface that reflects the first ultraviolet ray, the second ultraviolet ray, and the third ultraviolet ray, and wherein the light tunnel is configured to emit the third ultraviolet ray mixed by the mixing optical system, wherein a second inlet opens on a side surface of the light tunnel for each of the plurality of cylinders, and wherein the second light source unit corresponding to each of the plurality of cylinders is disposed in the second inlet of each of the plurality of cylinders.

6. The light source device according to claim 4 or 5, wherein the partition unit comprises a plurality of reflectors, and the plurality of reflectors are fixed to each other by an insert structure.

7. A light source device as described in claim 3, wherein of the first light source unit and the second light source unit, the light source unit arranged at the second inlet is provided with a reflecting portion that reflects ultraviolet light emitted by the other light source unit.

8. A light source device according to claim 1, wherein the mixing optical system comprises a dichroic mirror.

9. An irradiation device comprising: a light source device according to any one of claims 1 to 4; a first cooling unit for cooling the first light source unit; a second cooling unit for cooling the second light source unit; and an external housing for housing the light source device, wherein the first cooling unit and the second cooling unit are fixed to the external housing.

10. An illumination device comprising: a plurality of light source devices according to any one of claims 1 to 4; and an external housing that houses the plurality of light source devices with their light tunnels connected to each other.

Images