Fluid sterilization device

Abstract

The present invention provides a fluid sterilization device that irradiates a fluid with the required amount of ultraviolet light. [Solution] The fluid sterilization device includes a first photoelectric element, a first photoelectric element for emitted light, and a first photoelectric element for reflected light, a photoelectric element for transmitted light arranged opposite them, a chamber having an interior through which a fluid located inside can pass, a first light-transmitting member arranged between the first photoelectric element, the first photoelectric element for emitted light, the first photoelectric element for reflected light, and the interior of the chamber, and a control unit having a processor that receives a first reflected light reception signal from the first photoelectric element that receives ultraviolet light emitted from the first photoelectric element and reflected by the first light-transmitting member, a first emitted light reception signal from the first photoelectric element that receives a portion of the ultraviolet light emitted from the first photoelectric element, and a first transmitted light reception signal from the photoelectric element that receives ultraviolet light emitted from the first photoelectric element and transmitted through the first light-transmitting member and the fluid, and controls the emission of ultraviolet light by the first photoelectric element.

Description

Technical Field

[0001] The present disclosure relates to a fluid sterilization device.

Background Art

[0002] Conventionally, a fluid sterilization device using an ultraviolet LED (Ultraviolet-Light Emitting Diode) has been known. For example, Patent Document 1 discloses a fluid sterilization device including a solid electromagnetic radiation source, a reaction chamber arranged such that the fluid inside is exposed to the electromagnetic radiation of ultraviolet light irradiated from the solid electromagnetic radiation source, and an electromagnetic radiation sensor such as a photoelectric element that is arranged at a distance from the solid electromagnetic radiation source and detects the electromagnetic radiation emitted from the solid electromagnetic radiation source and reflected by at least one surface.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An embodiment according to the present disclosure aims to provide a fluid sterilization device that irradiates a fluid with a required amount of ultraviolet radiation.

Means for Solving the Problems

[0005] A fluid sterilization apparatus according to one embodiment of the present disclosure comprises a first photoelectric element, a first photoelectric element for emitted light, and a first photoelectric element for reflected light; a photoelectric element for transmitted light arranged opposite to the first photoelectric element, the first photoelectric element for emitted light, and the first photoelectric element for reflected light; a chamber disposed between the first photoelectric element, the first photoelectric element for emitted light, and the first photoelectric element for reflected light and the photoelectric element for transmitted light, having an interior through which a fluid irradiated with ultraviolet light emitted from the first photoelectric element can pass; and the chamber. The device comprises a first light-transmitting member disposed between the interiors of the first photoelectric element, and a control unit having a processor that receives a first reflected light reception signal from a first reflected light photoelectric element that receives ultraviolet light emitted from the first photoelectric element and reflected by the first light-transmitting member, a first emitted light reception signal from a first emitted light photoelectric element that receives a portion of the ultraviolet light emitted from the first photoelectric element, and a first transmitted light reception signal from a first transmitted light photoelectric element that receives ultraviolet light emitted from the first photoelectric element and transmitted through the first light-transmitting member and the fluid, and controls the emission of ultraviolet light by the first photoelectric element.

[0006] A fluid sterilization apparatus according to one embodiment of the present disclosure comprises one or more first photoelectric elements, a first photoelectric element for emitted light, and a first photoelectric element for reflected light, and one or more second photoelectric elements, a second photoelectric element for emitted light, and a second photoelectric element for reflected light, arranged to face the one or more first photoelectric elements, the first photoelectric element for emitted light, and the first photoelectric element for reflected light, and the one or more second photoelectric elements, A chamber disposed between a second photoelectric element for emitted light and a second photoelectric element for reflected light, having an interior through which a fluid irradiated with ultraviolet light emitted from one or more first photoelectric elements can pass; a first light-transmitting member disposed between the one or more first photoelectric elements, the first photoelectric element for emitted light and the first photoelectric element for reflected light and the interior of the chamber; and the one or more second photoelectric elements, the second photoelectric element for emitted light and the second photoelectric element for reflected light and the interior of the chamber A second light-transmitting member is positioned between the interior elements, and the one or more first photoelectric elements emit ultraviolet light, and the first photoelectric element for emitted light, the first photoelectric element for reflected light, the one or more second photoelectric elements, the second photoelectric element for emitted light and the second photoelectric element for reflected light do not emit ultraviolet light, and the one or more second photoelectric elements emit ultraviolet light, and the one or more first photoelectric elements, the first photoelectric element for emitted light, the first photoelectric element for reflected light, the second photoelectric element for emitted light and The system includes a control unit having a processor for alternately switching between state I and state I, wherein in state I, the first reflected light photoelectric element receives ultraviolet light emitted from one or more first photoelectric elements and reflected by the first light-transmitting member and outputs a first reflected light reception signal, and the first emitted light photoelectric element receives a portion of the ultraviolet light emitted from one or more first photoelectric elements and outputs a first emitted light reception signal.The second reflected light photoelectric element receives ultraviolet light emitted from the one or more first photoelectric elements and transmitted through the first light-transmitting member, the fluid, and the second light-transmitting member, and outputs a first transmitted light reception signal. The processor controls the emission of ultraviolet light by the one or more first photoelectric elements based on the first reflected light reception signal, the first emitted light reception signal, and the first transmitted light reception signal. In state II, the second reflected light photoelectric element receives ultraviolet light emitted from the one or more second photoelectric elements and reflected by the second light-transmitting member, and outputs a second reflected light signal. The first photoelectric element outputs an emitted light receiving signal, the second emitted light photoelectric element receives a portion of the ultraviolet light emitted from the one or more second photoelectric elements and outputs a second emitted light receiving signal, the first reflected light photoelectric element receives the ultraviolet light emitted from the one or more second photoelectric elements that has passed through the second light-transmitting member, the fluid, and the first light-transmitting member and outputs a second transmitted light receiving signal, and the processor controls the emission of ultraviolet light by the one or more second photoelectric elements based on the second reflected light receiving signal, the second emitted light receiving signal, and the second transmitted light receiving signal.

[0007] A fluid sterilization apparatus according to one embodiment of the present disclosure comprises a first photoelectric element, a third photoelectric element, a first photoelectric element for emitting light, and a third photoelectric element for emitting light, and a second photoelectric element, a fourth photoelectric element, a second photoelectric element for emitting light, and a fourth photoelectric element for emitting light arranged to face the first photoelectric element, the third photoelectric element, the first photoelectric element for emitting light, and the third photoelectric element for emitting light, and a second photoelectric element, a fourth photoelectric element, a second photoelectric element for emitting light, and a fourth photoelectric element for emitting light A chamber positioned between the first photoelectric element and having an interior that allows a fluid to pass through which ultraviolet light emitted from the first photoelectric element is irradiated; a first light-transmitting member positioned between the first photoelectric element, the third photoelectric element, the first light-emitting photoelectric element, and the third light-emitting photoelectric element and the interior of the chamber; a second light-transmitting member positioned between the second photoelectric element, the fourth photoelectric element, the second light-emitting photoelectric element, and the fourth light-emitting photoelectric element and the interior of the chamber; the first photoelectric element emits ultraviolet light, and the third photoelectric element, the first light-emitting photoelectric element, and the third A first state in which the light-emitting photoelectric element, the second photoelectric element, the fourth photoelectric element, the second light-emitting photoelectric element and the fourth light-emitting photoelectric element each do not emit ultraviolet light; a second state in which the third photoelectric element emits ultraviolet light and the first photoelectric element, the first light-emitting photoelectric element, the third light-emitting photoelectric element, the second photoelectric element, the fourth photoelectric element, the second light-emitting photoelectric element and the fourth light-emitting photoelectric element each do not emit ultraviolet light; and a second state in which the second photoelectric element emits ultraviolet light and the first photoelectric element, the third photoelectric element, the first light-emitting photoelectric element, the first light-emitting photoelectric element The device comprises a control unit having a processor for sequentially switching between a third state in which the third light-emitting photoelectric element, the fourth photoelectric element, the second light-emitting photoelectric element, and the fourth light-emitting photoelectric element each do not emit ultraviolet light, and a fourth state in which the fourth photoelectric element emits ultraviolet light and the first photoelectric element, the third photoelectric element, the first light-emitting photoelectric element, the third light-emitting photoelectric element, the second photoelectric element, the second light-emitting photoelectric element, and the fourth light-emitting photoelectric element each do not emit ultraviolet light, wherein in the first state, the third photoelectric element,The first photoelectric element receives ultraviolet light emitted from the first photoelectric element and reflected by the first light-transmitting member, and outputs a third reflected light reception signal. The first photoelectric element for emitted light receives a portion of the ultraviolet light emitted from the first photoelectric element and outputs a first emitted light reception signal. The second or fourth photoelectric element receives ultraviolet light emitted from the first photoelectric element and transmitted through the first light-transmitting member, the fluid, and the second light-transmitting member, and outputs a first transmitted light reception signal. The processor, based on the third reflected light reception signal, the first emitted light reception signal, and the first transmitted light reception signal, 1. Control the emission of ultraviolet light by a photoelectric element. In the second state, the first photoelectric element receives ultraviolet light emitted from the third photoelectric element and reflected by the first light-transmitting member, and outputs a first reflected light reception signal. The third photoelectric element for emitted light receives a portion of the ultraviolet light emitted from the third photoelectric element and outputs a third emitted light reception signal. The second or fourth photoelectric element receives ultraviolet light emitted from the third photoelectric element and transmitted through the first light-transmitting member, the fluid, and the second light-transmitting member, and outputs a third transmitted light reception signal. The processor controls the emission of ultraviolet light by the first Based on the reflected light received signal, the third emitted light received signal, and the third transmitted light received signal, the emission of ultraviolet light by the third photoelectric element is controlled. In the third state, the fourth photoelectric element receives the ultraviolet light emitted from the second photoelectric element and reflected by the second light-transmitting member, and outputs a fourth reflected light received signal. The second emitted light photoelectric element receives a portion of the ultraviolet light emitted from the second photoelectric element and outputs a second emitted light received signal. The first or third photoelectric element receives the ultraviolet light emitted from the second photoelectric element and transmits it to the second light-transmitting member, the fluid, and the first light-transmitting member. The transmitted ultraviolet light is received and a second transmitted light reception signal is output. The processor controls the emission of ultraviolet light by the second photoelectric element based on the fourth reflected light reception signal, the second emitted light reception signal, and the second transmitted light reception signal. In the fourth state, the second photoelectric element receives ultraviolet light emitted from the fourth photoelectric element and reflected by the second light-transmitting member and outputs a second reflected light reception signal. The fourth emitted light photoelectric element receives a portion of the ultraviolet light emitted from the fourth photoelectric element and outputs a fourth emitted light reception signal. The first photoelectric element or the third photoelectric element,The fourth photoelectric element receives ultraviolet light emitted from it, which has passed through the second light-transmitting member, the fluid, and the first light-transmitting member, and outputs a fourth transmitted light reception signal. The processor controls the emission of ultraviolet light by the fourth photoelectric element based on the second reflected light reception signal, the fourth emitted light reception signal, and the fourth transmitted light reception signal. [Effects of the Invention]

[0008] According to the embodiments of this disclosure, a fluid sterilization device can be provided that irradiates a fluid with a required amount of ultraviolet radiation. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram showing the overall configuration of the fluid sterilization apparatus according to the first embodiment. [Figure 2] This is a schematic cross-sectional view showing the configuration around the chamber of the fluid sterilization device according to the first embodiment. [Figure 3] This is a schematic top view showing the configuration around the first photoelectric element in the fluid sterilization device according to the first embodiment. [Figure 4] This is a schematic bottom view of a light-receiving sensor unit in a fluid sterilization device according to the first embodiment. [Figure 5] This is a block diagram showing the overall configuration of the fluid sterilization apparatus according to the second embodiment. [Figure 6] This is a schematic cross-sectional view showing state I of the fluid sterilization apparatus according to the second embodiment. [Figure 7] This is a schematic cross-sectional view showing state II of the fluid sterilization apparatus according to the second embodiment. [Figure 8] This is a schematic top view showing the configuration around the first photoelectric element in the fluid sterilization device according to the second embodiment. [Figure 9] This is a block diagram showing the overall configuration of a fluid sterilization apparatus according to the third embodiment. [Figure 10] This is a schematic cross-sectional view showing the configuration around the chamber of the fluid sterilization device according to the third embodiment. [Figure 11]This is a schematic cross-sectional view showing the first state of the fluid sterilization device according to the third embodiment. [Figure 12] This is a schematic cross-sectional view showing the second state of the fluid sterilization device according to the third embodiment. [Figure 13] This is a schematic cross-sectional view showing the third state of the fluid sterilization device according to the third embodiment. [Figure 14] This is a schematic cross-sectional view showing the fourth state of the fluid sterilization apparatus according to the third embodiment. [Figure 15] This is a schematic top view showing the configuration of the first photoelectric element and the area surrounding the third photoelectric element in the fluid sterilization device according to the third embodiment. [Figure 16] This is a block diagram showing the overall configuration of the fluid sterilization apparatus according to the fourth embodiment. [Figure 17] This is a schematic cross-sectional view showing the configuration around the chamber of the fluid sterilization device according to the fourth embodiment. [Modes for carrying out the invention]

[0010] The embodiments of this disclosure will be described below with reference to the drawings. Since each drawing schematically shows an embodiment of this disclosure, the scale, spacing, or positional relationship of each component may be exaggerated, or some components may be omitted from the illustration. In some cases, an end view showing only the cut surface may be used as a cross-sectional view.

[0011] In the following description, components having substantially the same function are denoted by a common reference numeral, and the description thereof may be omitted. Also, terms indicating a specific direction or position (e.g., "up", "down", and other terms including these terms) are merely used for the sake of clarity to indicate the relative direction or position in the referenced drawings. If the relative direction or position relationship by terms such as "up", "down", etc. in the referenced drawings is the same, in drawings other than the present disclosure, actual products, etc., they do not have to be arranged in the same way as in the referenced drawings. In this specification, the side from which the most light is emitted from the first photoelectric element included in the fluid sterilization device according to the embodiment of the present disclosure is referred to as "up", and the side opposite to "up" through the first photoelectric element is referred to as "down". Also, "opposite" means facing each other, but is not limited to facing directly. It includes a case where one is inside a cone having a semi-line perpendicular to one arrangement surface and passing through the center of gravity of one as the axis of symmetry and the center of gravity as the apex, and the apex angle in the plane including the axis of symmetry is 90°. The photoelectric element may include, for example, one or more light-emitting diodes, solar cells, photodiodes, laser diodes, other photoelectric elements, and combinations thereof. The reflected light may include light reflected at a certain interface, light that has passed through any path after being reflected at a certain interface, etc. Note that the reflected light includes at least one of specularly reflected light and diffusely reflected light. The reflected light reception signal refers to a signal from a photoelectric element that has directly or indirectly received the reflected light. "Indirectly receiving the reflected light" means that the photoelectric element receives the reflected light through an optical member such as a light guide plate, an optical fiber, a prism, a lens, etc. On the other hand, "directly receiving the reflected light" means that the photoelectric element receives the reflected light without passing through the above optical member.

[0012] In this specification, the positional relationship expressed as "up" includes cases where they are in contact and cases where they are not in contact but are located above. "Arranging" is not limited to cases of direct contact and also includes cases of arranging indirectly, for example, through other members.

[0013] In this specification or the claims, when there are multiple components and they need to be distinguished and expressed separately, "first", "second", etc. may be appended to the heads of the components for distinction. Also, there may be cases where the objects of distinction in this specification and the claims are different.

[0014] [First Embodiment] <Configuration of the Fluid Sterilization Device According to the First Embodiment of the Present Disclosure> Referring to FIGS. 1 to 4, the configuration of the fluid sterilization device according to the first embodiment of the present disclosure will be described. FIG. 1 is a block diagram showing the overall configuration of the fluid sterilization device 100 according to the first embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view showing the configuration around the chamber 30 of the fluid sterilization device 100. FIG. 3 is a schematic top view showing the configuration around the first photoelectric element of the fluid sterilization device 100. FIG. 4 is a schematic bottom view of the light receiving sensor unit 20 of the fluid sterilization device 100.

[0015] (Overall Configuration) As shown in FIGS. 1 and 2, the fluid sterilization device 100 includes a first light source 10-1, a light receiving sensor unit 20, a chamber 30, and a control unit 50. Also, in the example shown in FIGS. 1 and 2, the fluid sterilization device 100 includes a user interface unit 60, the first light source 10-1 includes a first light transmissive member 40-1, and the light receiving sensor unit 20 includes a light transmissive member 70 for transmitted light. Note that FIG. 2 shows a cross-section of the fluid sterilization device 100 including the first light source 10-1, the light receiving sensor unit 20, and the chamber 30.

[0016] The fluid sterilization device 100 sterilizes bacteria or viruses in the fluid F by irradiating ultraviolet light from the first light source 10-1 onto the fluid F located inside the chamber 30. The fluid sterilization device 100 can reduce the number of bacteria or viruses in the fluid F after irradiation compared to before irradiation.

[0017] The first light source 10-1 includes, in addition to the first light-transmitting member 40-1, a first photoelectric element 11-1, a first photoelectric element for emitted light 12-1, and a first photoelectric element for reflected light 13-1. The light-receiving sensor unit 20 includes a photoelectric element 21 for transmitted light. The photoelectric element 21 for transmitted light is positioned to face the first photoelectric element 11-1, the first photoelectric element for emitted light 12-1, and the first photoelectric element for reflected light 13-1.

[0018] Chamber 30 has an interior through which a fluid F irradiated with ultraviolet light emitted from the first photoelectric element 11-1 can pass. The fluid F located inside chamber 30 is positioned between the first photoelectric element 11-1, the first photoelectric element for emitted light 12-1, the first photoelectric element for reflected light 13-1, and the photoelectric element for transmitted light 21. The fluid F located inside chamber 30 is irradiated with ultraviolet light emitted from the first photoelectric element 11-1.

[0019] The first light-transmitting member 40-1 is positioned between the first photoelectric element 11-1, the first photoelectric element for emitted light 12-1, and the first photoelectric element for reflected light 13-1 and the inside of the chamber 30.

[0020] The light-transmitting member 70 is positioned between the light-transmitting photoelectric element 21 and the inside of the chamber 30.

[0021] The control unit 50 includes a processor 53 that receives a first reflected light reception signal, a first emitted light reception signal, and a first transmitted light reception signal, and controls the emission of ultraviolet light by the first photoelectric element 11-1. The first reflected light reception signal is an electrical signal from the first reflected light photoelectric element 13-1 that receives ultraviolet light emitted from the first photoelectric element 11-1 and reflected by the first light-transmitting member 40-1. The first emitted light reception signal is an electrical signal from the first emitted light photoelectric element 12-1 that receives a portion of the ultraviolet light emitted from the first photoelectric element 11-1. The first transmitted light reception signal is an electrical signal from the transmitted light photoelectric element 21 that receives ultraviolet light emitted from the first photoelectric element 11-1 and transmitted through the first light-transmitting member 40-1 and the fluid F. The electrical signals from the photoelectric elements, such as the first reflected light photoelectric element 13-1, the first emitted light photoelectric element 12-1, and the transmitted light photoelectric element 21, are analog current signals or analog voltage signals.

[0022] In typical fluid sterilization systems, a predetermined amount of ultraviolet (UV) radiation is required for the fluid to be sterilized, as required by standards such as NSF / ANSI 55-2024. The UV radiation dose is the total amount of energy irradiated by UV light, expressed as the product of illuminance and irradiation time. On the other hand, the lifespan of the light source in a typical fluid sterilization system decreases as the drive current increases, depending on the light output of the light source, which is proportional to the illuminance. As the light source approaches the end of its lifespan, the drive current increases, and the frequency of maintenance such as dirt removal increases. If dirt is not properly removed, the light source will fail, requiring maintenance such as replacement of the light source. In other words, the maintainability of the fluid sterilization system decreases. Therefore, in order to maintain sterilization performance without reducing maintainability, it is necessary to stably irradiate the fluid with UV light at the illuminance required to obtain the predetermined UV radiation dose. The drive current required to obtain illuminance beyond what is necessary should be limited.

[0023] A common method for irradiating a fluid with the required amount of ultraviolet light is to receive the ultraviolet light emitted from a light source with a light-receiving sensor and use feedback control to adjust the drive current of the light source, provided the fluid flow rate is nearly constant. This is because the time the fluid is irradiated with ultraviolet light in the chamber is inversely proportional to the flow rate. In typical fluid sterilization devices, dirt such as slime, mold, and limescale may adhere to the inner walls of the chamber. If the above-mentioned dirt adheres to a light-transmitting member placed between the fluid in the chamber and the light source, the dirt may absorb or scatter the ultraviolet light from the light source, potentially reducing the amount of ultraviolet light irradiated to the fluid. Furthermore, if the above-mentioned dirt adheres to a light-transmitting member placed between the fluid in the chamber and the light-receiving sensor, the dirt may absorb or scatter the ultraviolet light received by the light-receiving sensor, reducing the accuracy of the feedback control of the ultraviolet irradiation amount and potentially preventing the fluid from being stably irradiated with the required amount of ultraviolet light.

[0024] The control unit 50 of the fluid sterilization apparatus 100 according to the first embodiment of this disclosure includes a processor 53 that receives a first emitted light receiving signal which includes information on the light output emitted by the first photoelectric element 11-1. The control unit 50 also includes a processor 53 that receives a first reflected light receiving signal which includes the effects of light absorption or scattering by at least one of the first light-transmitting member 40-1 and dirt adhering to the first light-transmitting member 40-1. Furthermore, the control unit 50 includes a processor 53 that receives a first transmitted light receiving signal which includes the effects of light absorption or scattering by at least one of the first light-transmitting member 40-1, dirt adhering to the first light-transmitting member 40-1, fluid F, light-transmitting member 70 for transmitted light, and dirt adhering to the light-transmitting member 70 for transmitted light.

[0025] The control unit 50 includes a processor 53 that receives a first reflected light receiving signal, a first emitted light receiving signal, and a first transmitted light receiving signal to reduce the influence of dirt adhering to the first light-transmitting member 40-1 and the light-transmitting member 70 for transmitted light, respectively, and controls the emission of ultraviolet light from the first photoelectric element 11-1. For example, the control unit 50 included in the fluid sterilization device 100 includes a processor 53 that adjusts the drive current supplied to the first photoelectric element 11-1 so that the amount of ultraviolet light irradiated from the first photoelectric element 11-1 to the fluid F falls within a predetermined range. This predetermined range is, for example, within ±5%, preferably within ±3%, and more preferably within ±1% of the specification regarding the amount of ultraviolet light irradiated.

[0026] The fluid sterilization device 100 can irradiate the fluid with the required amount of ultraviolet light by controlling the emission of ultraviolet light from the first photoelectric element 11-1, while reducing the influence of dirt adhering to the first light-transmitting member 40-1 and the light-transmitting member 70 for transmitted light, respectively. As a result, the fluid sterilization device 100 can improve maintainability while maintaining sterilization performance. Irradiating the fluid with the required amount of ultraviolet light means, for example, keeping the illuminance of ultraviolet light constant to a fluid F with a constant flow rate, thereby keeping the amount of ultraviolet light constant. "A constant amount of ultraviolet light" includes the fact that the amount of ultraviolet light is within ±5%, preferably within ±3%, and more preferably within ±1% of the specification regarding the amount of ultraviolet light. Further details of the operation and effects of the fluid sterilization device 100 will be described later in the explanation of the operation and effects of the fluid sterilization device 100.

[0027] The following explanation describes an example where the fluid is a liquid. However, the fluid may be a gas. Furthermore, this describes a fluid sterilization device 100 where the fluid flow rate is constant.

[0028] (1st light source 10-1) In the example shown in Figures 2 and 3, the first light source 10-1 includes a first substrate 14-1, a first light-emitting unit 15-1 disposed on the first substrate 14-1, a first light-transmitting member 40-1, and a first frame 16-1 that supports the first substrate 14-1 and the first light-transmitting member 40-1. The first light source 10-1 also includes a first sealing member 17-1 disposed between the chamber 30 and the first frame 16-1, and a first fixing member 18-1 that fixes the first light source 10-1 to the chamber 30.

[0029] In the example shown in Figure 3, the first substrate 14-1 has a substantially circular outer edge shape when viewed from above. The first frame 16-1 has a circular annular shape when viewed from above, and the first substrate 14-1 is placed in the inner space. However, the first substrate 14-1 may have an outer edge shape such as substantially rectangular, substantially elliptical, or substantially polygonal when viewed from above. The first frame 16-1 may have a rectangular annular shape when viewed from above, and the first substrate 14-1 is placed in the inner space. For the material of the first frame 16-1, for example, metal such as SUS or engineering plastic can be used.

[0030] The first light source 10-1 may have a plurality of first light-emitting units 15-1. Furthermore, the first light source 10-1 may include a first light-emitting unit 15-1 that includes a first photoelectric element 12-1 for emitting first light, and a first light-emitting unit 15-1 that does not include the first photoelectric element 12-1 for emitting first light.

[0031] The first light source 10-1 can be removed from the fluid sterilization device 100. Removing the first light source 10-1 from the fluid sterilization device 100 makes it easier to remove dirt adhering to the first light-transmitting member 40-1, or to replace the first substrate 14-1 on which the first light-emitting unit 15-1 is mounted. The first light source 10-1 has a first sealing member 17-1, which ensures watertightness between it and the inside of the chamber 30.

[0032] The first fixing member 18-1 has a female threaded portion formed on its inner surface. The female threaded portion of the first fixing member 18-1 is screwed into a male threaded portion formed in the chamber 30 in a portion corresponding to the female threaded portion. By screwing in and tightening the first fixing member 18-1 and pressing the first frame 16-1 against the chamber 30, the first light source 10-1 can be attached and fixed to the chamber 30. The first fixing member 18-1 can also be removed from the chamber 30 by loosening the screw connection between the female threaded portion of the first fixing member 18-1 and the male threaded portion of the chamber 30. By removing the first fixing member 18-1 from the chamber 30, the first light source 10-1 can be removed from the chamber 30. However, the configuration and method for attaching and detaching the first light source 10-1 to and from the fluid sterilization device 100 are not limited to those described above and can be modified as appropriate.

[0033] The first light-transmitting member 40-1 may not be included in the first light source 10-1 and may be provided separately. If the first light-transmitting member 40-1 is provided separately from the first light source 10-1, and maintenance such as cleaning or replacement is performed on the first light-transmitting member 40-1, the first light-transmitting member 40-1 can be removed from the fluid sterilization device 100 separately from the first light source 10-1, or together with the first light source 10-1, and the first light-transmitting member 40-1 can be maintained separately from the first light source 10-1.

[0034] (First photoelectric element 11-1) The first photoelectric element 11-1 is an element that emits ultraviolet light having a bactericidal or inactivating effect on bacteria or viruses contained in the fluid F. The first photoelectric element 11-1 is, for example, a UV-LED (Ultraviolet-Light Emitting Diode) chip. However, the first photoelectric element 11-1 may be a UV-LD (Ultraviolet-Laser Diode) chip. The first photoelectric element 11-1 is positioned opposite the first light-transmitting member 40-1.

[0035] The peak wavelength of ultraviolet light emitted by the first photoelectric element 11-1 is, for example, between 200 nm and 400 nm. The first photoelectric element 11-1 consists of, for example, a translucent growth substrate, a multilayer film of a group III nitride mixed crystal semiconductor, and positive and negative electrodes. The first photoelectric element 11-1 has an n-side semiconductor layer electrically connected to the negative electrode, a p-side semiconductor layer electrically connected to the positive electrode, and an active layer between them. The first photoelectric element 11-1 may be electrically connected to the internal electrode terminals of the first housing 151-1 of the first light-emitting unit 15-1 by wires, or it may be electrically connected to the internal electrode terminals of the first housing 151-1 by flip-chip connection. One or more first photoelectric elements 11-1 can be arranged inside one first housing 151-1.

[0036] (Photoelectric element for first emitted light 12-1) The first photoelectric element 12-1 for emitted light directly or indirectly receives a portion of the ultraviolet light emitted from the first photoelectric element 11-1 and outputs a first emitted light reception signal to the control unit 50 corresponding to the illuminance of the received ultraviolet light. The first emitted light reception signal is either a received photocurrent or a received photovoltage. The first emitted light reception signal includes information about the light output emitted by the first photoelectric element 11-1.

[0037] "Direct light reception" means that the first photoelectric element 12-1 receives a portion of the ultraviolet light emitted from the first photoelectric element 11-1 without passing through any other components. "Indirect light reception" means that the first photoelectric element 12-1 receives a portion of the light that has been emitted from the first photoelectric element 11-1 and then reflected by components other than the first photoelectric element 12-1, such as the first cover member 152-1. In the example shown in Figure 2, the first photoelectric element 12-1 directly receives a portion of the ultraviolet light emitted from the first photoelectric element 11-1, and indirectly receives the remaining portion of the ultraviolet light emitted from the first photoelectric element 11-1 via the first cover member 152-1.

[0038] A photodiode made of Si, SiC, or GaN can be used as the first photoelectric element 12-1 for emitting light. In this case, the bias voltage applied to the photodiode can be appropriately selected as zero bias or reverse bias. At least one first photoelectric element 12-1 for emitting light can be arranged in one first housing 151-1.

[0039] (First reflected light photoelectric element 13-1) The first reflected light photoelectric element 13-1 is an element that receives ultraviolet light reflected by the first light-transmitting member 40-1 from the ultraviolet light emitted from the first light-emitting unit 15-1, and outputs a first reflected light reception signal to the control unit 50 according to the illuminance of the received ultraviolet light. For example, the first reflected light photoelectric element 13-1 receives ultraviolet light reflected at the interface between the first light-transmitting member 40-1 and the fluid F from the ultraviolet light emitted from the first light-emitting unit 15-1. The first reflected light reception signal is a received photocurrent or a received photovoltage. The first reflected light reception signal includes the effects of light absorption or scattering by at least one of the first lid member 152-1, the first light-transmitting member 40-1, and dirt adhering to the first light-transmitting member 40-1.

[0040] A photodiode made of Si, SiC, or GaN can be used as the first reflected light photoelectric element 13-1. In this case, the bias voltage applied to the photodiode can be appropriately selected as zero bias or reverse bias. The first reflected light photoelectric element 13-1 is positioned opposite the first light-transmitting member 40-1.

[0041] If the space in which the first reflected light photoelectric element 13-1 is located is airtight, either a photodiode with a housing or a photodiode chip can be used for the first reflected light photoelectric element 13-1. If the space in which the first reflected light photoelectric element 13-1 is located is not airtight, from the viewpoint of reliability, it is more preferable to use a photodiode with a housing that makes it easier to ensure airtightness for the first reflected light photoelectric element 13-1.

[0042] (First board 14-1) The first substrate 14-1 is a wiring board having an insulating substrate, a region to which the first light-emitting unit 15-1 is connected, a region to which the first reflected light photoelectric element 13-1 is connected, and predetermined wiring connected to these regions. In the example shown in Figure 2, the region to which the first light-emitting unit 15-1 is connected and the region to which the first reflected light photoelectric element 13-1 is connected face-to-face with the first light-transmitting member 40-1, and the first photoelectric element 11-1 and the first reflected light photoelectric element 13-1 are each positioned facing face-to-face with the first light-transmitting member 40-1. When the first substrate 14-1 has wiring to which a plurality of first light-emitting units 15-1 are connected, the plurality of first light-emitting units 15-1 may be connected in series, in parallel, or in a combination of series and parallel connections.

[0043] A detachable connection terminal may be provided on at least one of the first surface of the first substrate 14-1 on the side where the fluid F is located and the second surface opposite the first surface, for electrically connecting the external wiring to the wiring on the first substrate 14-1. The first substrate 14-1 may include a substrate having a region to which the first light-emitting unit 15-1 is connected, and a substrate having a region to which the first reflected light photoelectric element 13-1 is connected. In addition, the first substrate 14-1 may have an annular wall in a top view, and the region to which the first light-emitting unit 15-1 is connected and the region to which the first reflected light photoelectric element 13-1 is connected may be provided on the inner surface of the wall that does not directly face the first light-transmitting member 40-1.

[0044] The first substrate 14-1 can be easily removed from the first frame 16-1 by, for example, being fixed to the first frame 16-1 by screws, clips, or the like.

[0045] (First light-emitting unit 15-1) In the example shown in Figure 2, the first light-emitting unit 15-1 includes a first photoelectric element 11-1 and a first photoelectric element for emitting light 12-1, as well as a first housing 151-1 and a first cover member 152-1.

[0046] (First housing 151-1 and first lid member 152-1) The first cover member 152-1 is positioned opposite the first photoelectric element 11-1 and between the first photoelectric element 11-1 and the first light-transmitting member 40-1, reflecting a portion of the ultraviolet light emitted from the first photoelectric element 11-1 and transmitting all or part of the remaining light. The first light-emitting photoelectric element 12-1 receives a portion of the ultraviolet light reflected by the first cover member 152-1.

[0047] The first housing 151-1 houses the first photoelectric element 11-1 and the first photoelectric element for emitting light 12-1, and supports the first cover member 152-1.

[0048] The first housing 151-1 and the first lid member 152-1 hermetically seal the first photoelectric element 11-1 and the first light-emitting photoelectric element 12-1 from the outside of the first light-emitting unit 15-1. The first housing 151-1 and the first lid member 152-1 can be made of ceramic material, a ceramic package including a composite material of metal and ceramic, or a CAN package. In the example shown in Figure 3, the first housing 151-1 and the first lid member 152-1 each have a substantially rectangular outer edge shape when viewed from above. However, the first housing 151-1 and the first lid member 152-1 may each have a substantially circular, substantially elliptical, or substantially polygonal outer edge shape when viewed from above.

[0049] The first housing 151-1 includes external electrode terminals electrically connected to the wiring of the first substrate 14-1, internal electrode terminals electrically connected to the first photoelectric element 11-1, internal electrode terminals electrically connected to the first photoelectric element for emitting light 12-1, and a conductive member that electrically connects the external electrode terminals and the internal electrode terminals. For the material of the first housing 151-1, for example, a composite material of metal and ceramics can be used.

[0050] The first lid member 152-1 includes a light-transmitting material. Preferably, the light-transmitting surface of the first lid member 152-1 transmits 60% or more of the ultraviolet light emitted by the first photoelectric element 11-1. The first lid member 152-1 transmits a portion of the ultraviolet light emitted from the first photoelectric element 11-1 and reflects all or part of the remaining portion.

[0051] The first lid member 152-1 includes a window portion that transmits a portion of the ultraviolet light emitted from the first photoelectric element 11-1, and a support portion that supports the window portion and is joined to the first housing 151-1. The window portion of the first lid member 152-1 may be equipped with an optical thin film (AR coating) that increases the transmittance of ultraviolet light emitted from the first photoelectric element 11-1. The first lid member 152-1 may also have an optical element function such as a lens function.

[0052] The material for the window portion of the first lid member 152-1 can be an inorganic material consisting of at least one selected from the group consisting of quartz glass, borosilicate glass, calcium fluoride glass, aluminoborsilicate glass, oxynitride glass, chalcogenide glass, and sapphire. The window portion included in the first lid member 152-1 may be joined to the support portion included in the first lid member 152-1 using low-melting-point glass mainly composed of lead and oxygen.

[0053] In the examples shown in Figures 2 and 3, the first cover member 152-1 includes the first light intensity adjusting member 153-1. The first light intensity adjusting member 153-1 is positioned opposite the first light-emitting photoelectric element 12-1. More specifically, the first light intensity adjusting member 153-1 is provided on the side of the first cover member 152-1 where the first photoelectric element 11-1 is located, in a position that does not overlap with the first photoelectric element 11-1 when viewed from above. The first light intensity adjusting member 153-1 has a substantially rectangular outer edge shape when viewed from above. However, the first light intensity adjusting member 153-1 may have a shape that is substantially square, substantially circular, substantially elliptical, or annular when viewed from above.

[0054] The first light intensity adjustment member 153-1 reduces the amount of light incident on the first photoelectric element 12-1 housed in the first housing 151-1 from outside the first housing 151-1, and also reflects ultraviolet light emitted from the first photoelectric element 11-1. The first light intensity adjustment member 153-1 reduces the decrease in the accuracy of light intensity control of ultraviolet light emitted from the first photoelectric element 11-1 due to light from outside the first light-emitting unit 15-1.

[0055] The first light intensity adjusting member 153-1 is, for example, a multilayer film with a two-layer structure consisting of an aluminum layer or a metallic chromium layer and a chromium oxide layer, or a dielectric multilayer film.

[0056] (First light-transmitting member 40-1) The first light-transmitting member 40-1 may be a flat plate-shaped member having light-transmitting properties. Preferably, the light-transmitting properties of the first light-transmitting member 40-1 are such that it transmits 60% or more of the ultraviolet light emitted by the first photoelectric element 11-1. The first light-transmitting member 40-1 may include shapes other than flat surfaces, such as curved surfaces, in at least a part of it. The first light-transmitting member 40-1 may include lenses, prisms, light guide structures, etc. From the viewpoint of making it easier to remove dirt adhering to the first light-transmitting member 40-1, it is preferable that the surface of the first light-transmitting member 40-1 in contact with the fluid F is flat.

[0057] In the example shown in Figure 2, the first light-transmitting member 40-1 is positioned between the first substrate 14-1, the first light-emitting unit 15-1, and the first photoelectric element for reflected light 13-1 and the inside of the chamber 30. The placement of the first light-transmitting member 40-1 prevents the fluid F from contacting the first substrate 14-1, the first light-emitting unit 15-1, and the first photoelectric element for reflected light 13-1.

[0058] The first light-transmitting member 40-1 transmits a portion of the ultraviolet light emitted from the first light-emitting unit 15-1 and reflects all or part of the remaining portion. The material of the first light-transmitting member 40-1 can be an inorganic material consisting of at least one selected from the group consisting of quartz glass, borosilicate glass, calcium fluoride glass, aluminoborosilicate glass, oxynitride glass, chalcogenide glass, crystal, and sapphire. Furthermore, the first light-transmitting member 40-1 may be equipped with an optical thin film on its light-transmitting surface to adjust its transmittance and reflectance.

[0059] (Light receiving sensor unit 20) In the example shown in Figure 2, the light-receiving sensor unit 20 includes a light-transmitting substrate 22, a light-transmitting housing 211 positioned below the light-transmitting substrate 22, and a light-transmitting cover member 212 positioned between the light-transmitting photoelectric element 21 and the light-transmitting member 70. The light-receiving sensor unit 20 also includes a light-transmitting member 70, a light-transmitting frame 213 supporting the light-transmitting substrate 22 and the light-transmitting member 70, a light-transmitting sealing member 214 positioned between the chamber 30 and the light-transmitting frame 213, and a light-transmitting fixing member 215 for fixing the light-receiving sensor unit 20 to the chamber 30. The light-transmitting photoelectric element 21 is housed in the light-transmitting housing 211.

[0060] In the example shown in Figure 4, the light-transmitting substrate 22 has a substantially circular outer edge shape when viewed from below. The light-transmitting frame 213 has a circular annular shape when viewed from below, and the light-transmitting substrate 22 is placed in the inner space. However, the light-transmitting substrate 22 may have an outer edge shape such as substantially rectangular, substantially elliptical, or substantially polygonal when viewed from below. The light-transmitting frame 213 may have a rectangular annular shape when viewed from below, and the light-transmitting substrate 22 may be placed in the inner space.

[0061] The light-receiving sensor unit 20 can be removed from the fluid sterilization device 100. Removing the light-receiving sensor unit 20 from the fluid sterilization device 100 makes it easier to remove dirt adhering to the light-transmitting member 70 for transmitted light, or to replace the light-transmitting substrate 22 on which the light-transmitting photoelectric element 21 for transmitted light is mounted. The light-receiving sensor unit 20 has a light-transmitting sealing member 214, which ensures watertightness between it and the inside of the chamber 30.

[0062] The light transmission fixing member 215 has a female threaded portion formed on its inner surface. The female threaded portion of the light transmission fixing member 215 is screwed into a male threaded portion formed in the chamber 30 in a portion corresponding to the female threaded portion. By screwing in and tightening the light transmission fixing member 215 and pressing the light transmission frame 213 against the chamber 30, the light receiving sensor unit 20 can be attached and fixed to the chamber 30. The light transmission fixing member 215 can also be removed from the chamber 30 by loosening the screw connection between the female threaded portion of the light transmission fixing member 215 and the male threaded portion of the chamber 30. By removing the light transmission fixing member 215 from the chamber 30, the light receiving sensor unit 20 can be removed from the chamber 30. However, the configuration and method for attaching and detaching the light receiving sensor unit 20 to and from the fluid sterilization device 100 are not limited to those described above and can be modified as appropriate.

[0063] The light-transmitting member 70 may not be included in the light-receiving sensor unit 20 and may be provided separately. If the light-transmitting member 70 is provided separately from the light-receiving sensor unit 20, and maintenance such as cleaning or replacement is performed on the light-transmitting member 70, the light-transmitting member 70 can be removed from the fluid sterilization device 100 separately from the light-receiving sensor unit 20, or together with the light-receiving sensor unit 20, and the light-transmitting member 70 can be maintained separately from the light-receiving sensor unit 20.

[0064] (Photoelectric element for transmitted light 21) The transmitted light photoelectric element 21 is an element that receives a portion of the ultraviolet light emitted from the first photoelectric element 11-1 and transmitted through the first lid member 152-1, the first light-transmitting member 40-1, the fluid F located inside the chamber 30, the transmitted light-transmitting member 70, and the transmitted light lid member 212. The transmitted light photoelectric element 21 outputs a first transmitted light reception signal to the control unit 50 according to the illuminance of the received ultraviolet light. The first transmitted light reception signal is either a received photocurrent or a received photovoltage. The first transmitted light reception signal includes the effects of light absorption or scattering by at least one of the first lid member 152-1, the first light-transmitting member 40-1, dirt adhering to the first light-transmitting member 40-1, the fluid F, the transmitted light-transmitting member 70, and the transmitted light lid member 212. A photodiode such as Si, SiC, or GaN can be used for the transmitted light photoelectric element 21. In this case, the bias voltage applied to the photodiode is selected as appropriate, either zero bias or reverse bias.

[0065] (Transmitted light housing 211 and transmitted light cover member 212) The light-transmitting cover member 212 is positioned opposite the light-transmitting photoelectric element 21 and between the light-transmitting photoelectric element 21 and the light-transmitting member 70, allowing a portion of the ultraviolet light emitted from the first photoelectric element 11-1 to pass through. The light-transmitting photoelectric element 21 receives the ultraviolet light emitted from the first photoelectric element 11-1 and transmitted through the light-transmitting cover member 212.

[0066] The light-transmitting housing 211 houses the light-transmitting photoelectric element 21 and supports the light-transmitting cover member 212.

[0067] The light-transmitting housing 211 and the light-transmitting cover member 212 hermetically seal the light-transmitting photoelectric element 21 housed in the light-transmitting housing 211 from the outside of the light-transmitting housing 211 and the light-transmitting cover member 212. The light-transmitting housing 211 and the light-transmitting cover member 212 can be made of ceramic material, a ceramic package including a composite material of metal and ceramic, or a CAN package.

[0068] In the example shown in Figure 4, the light-transmitting housing 211 and the light-transmitting cover member 212 each have a roughly rectangular outer edge shape when viewed from below. The light-transmitting housing 211 and the light-transmitting cover member 212 can also have a roughly circular, roughly elliptical, or roughly polygonal shape when viewed from below. Since the light-transmitting housing 211 and the light-transmitting cover member 212 overlap when viewed from below, the reference numerals for the light-transmitting housing 211 and the light-transmitting cover member 212 are shown together in Figure 4. Reference numerals may also be shown together in subsequent figures for the same purpose.

[0069] The light-transmitting housing 211 includes external electrode terminals electrically connected to the wiring of the light-transmitting substrate 22, internal electrode terminals electrically connected to the light-transmitting photoelectric element 21, and a conductive member that electrically connects the external electrode terminals and the internal electrode terminals. For the material of the light-transmitting housing 211, for example, a composite material of metal and ceramics can be used.

[0070] The light-transmitting cover member 212 includes a light-transmitting material. Preferably, the light-transmitting surface of the light-transmitting cover member 212 transmits 60% or more of the ultraviolet light emitted by the first photoelectric element 11-1.

[0071] The light-transmitting cover member 212 includes a window portion that transmits a portion of the ultraviolet light emitted from the first photoelectric element 11-1, and a support portion that supports the window portion and is joined to the light-transmitting housing 211. The window portion of the light-transmitting cover member 212 may be equipped with an optical thin film (AR coating) that increases the transmittance of ultraviolet light emitted from the first photoelectric element 11-1. The light-transmitting cover member 212 may also have an optical element function such as a lens function.

[0072] The material for the window portion included in the light-transmitting cover member 212 can be an inorganic material consisting of at least one selected from the group consisting of quartz glass, borosilicate glass, calcium fluoride glass, aluminoborsilicate glass, oxynitride glass, chalcogenide glass, and sapphire. The window portion included in the light-transmitting cover member 212 may be joined to the support portion included in the light-transmitting cover member 212 using low-melting-point glass mainly composed of lead oxide.

[0073] (Transmitted light substrate 22) The light-transmitting substrate 22 is a wiring board having an insulating substrate, a region to which the light-receiving sensor unit 20 is connected, and predetermined wiring connected to that region.

[0074] A detachable connection terminal may be provided on at least one of the first surface of the light-transmitting substrate 22 on the side where the fluid F is located and on the second surface opposite the first surface, for electrically connecting the external wiring and the wiring below the light-transmitting substrate 22. The light-transmitting substrate 22 may also have an annular wall when viewed from below, and an area to which the light-receiving sensor unit 20 is connected may be provided on the inner surface enclosed by the wall. The light-transmitting substrate 22 can be easily removed from the light-transmitting frame 213 by fixing it to the light-transmitting frame 213, for example, by screws, clips, etc.

[0075] (Transparent member 70 for transmitted light) The light-transmitting member 70 is a flat plate-shaped member that has light-transmitting properties. Preferably, the light-transmitting member 70 transmits 60% or more of the ultraviolet light emitted by the first photoelectric element 11-1. The light-transmitting member 70 may include shapes other than flat surfaces, such as curved surfaces, in at least a part of it. The light-transmitting member 70 may include lenses, prisms, light guide structures, etc. From the viewpoint of making it easier to remove dirt adhering to the light-transmitting member 70, it is preferable that the surface of the first light-transmitting member 40-1 that is in contact with the fluid F is flat.

[0076] In the example shown in Figure 2, the light-transmitting member 70 is positioned between the light-transmitting substrate 22, the light-transmitting housing 211, and the light-transmitting lid member 212 and the inside of the chamber 30. The placement of the light-transmitting member 70 prevents the fluid F from coming into contact with the light-transmitting substrate 22, the light-transmitting housing 211, and the light-transmitting lid member 212.

[0077] The light-transmitting member 70 emits ultraviolet light from the first light-emitting unit 15-1, transmits a portion of the ultraviolet light that has passed through the first light-transmitting member 40-1 and the fluid F, and reflects the other portion. The material of the light-transmitting member 70 can be an inorganic material consisting of at least one selected from the group consisting of quartz glass, borosilicate glass, calcium fluoride glass, aluminoborsilicate glass, oxynitride glass, chalcogenide glass, crystal, and sapphire. In addition, the light-transmitting member 70 may be equipped with an optical thin film on its light-transmitting surface to adjust its transmittance and reflectance.

[0078] (Chamber 30) Chamber 30 includes a fluid inlet 31 for fluid F and a fluid outlet 32 ​​for fluid F. Chamber 30 is part of the flow path. The arrow Fi shown in Figure 2 represents the fluid F flowing in from the inlet 31. The arrow Fo represents the fluid F flowing out from the outlet 32. The boundary between chamber 30 and fluid F includes the inner wall of chamber 30, the first light-transmitting member 40-1, and the light-transmitting member 70 for transmitted light. The inner wall of chamber 30 may be coated with a PTFE film, an aluminum film, or an optical thin film to increase the reflectivity of ultraviolet light.

[0079] (Control unit 50) In the example shown in Figure 1, the control unit 50 includes a power supply 51 that supplies a drive current to the first photoelectric element 11-1, and a storage unit 52 that stores at least the initial value of the first transmitted light received signal. The control unit 50 also includes a processor 53 that receives the first reflected light received signal, the first emitted light received signal, and the first transmitted light received signal, performs signal processing, and adjusts the drive current of the first photoelectric element 11-1.

[0080] The memory unit 52 can store the initial value of the first emitted light received signal, the initial value of the first reflected light received signal, and the initial value of the first transmitted light received signal. The initial value of the first emitted light received signal is, for example, the magnitude of the first emitted light received signal when no dirt is attached to the first light-transmitting member 40-1. The initial value of the first reflected light received signal is, for example, the magnitude of the first reflected light received signal when no dirt is attached to the first light-transmitting member 40-1. The initial value of the first transmitted light received signal is, for example, the magnitude of the first transmitted light received signal when no dirt is attached to the first light-transmitting member 40-1 and the light-transmitting member 70 for transmitted light.

[0081] The processor 53 can perform various processes to realize the functions of the fluid sterilization device 100 by executing instruction codes stored in memory using electronic circuits. The processor 53 is, for example, a CPU (Central Processing Unit). However, the processor 53 may be an electronic circuit other than a CPU, such as an FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit) designed for special applications.

[0082] The control unit 50 can output information regarding the status of the fluid sterilization device 100 to the user interface unit 60. For example, the information regarding the status of the fluid sterilization device 100 includes a first error signal indicating that the first light-transmitting member 40-1 or the light-transmitting member 70 for transmitted light is dirty, and a second error signal indicating deterioration of the first photoelectric element 11-1.

[0083] (User Interface Unit 60) The user interface unit 60 is a unit that receives input from the operator of the fluid sterilization device 100 and outputs information or signals that the operator can recognize. The user interface unit 60 is communicated with the control unit 50.

[0084] In the example shown in Figure 1, the user interface unit 60 includes a display 61 that displays information such as text messages, and an indicator lamp 62 and a buzzer 63 that notify information regarding the status of the fluid sterilization device 100.

[0085] The user interface unit 60 receives a first error signal or a second error signal output from the control unit 50 and can illuminate the indicator lamp 62, sound the buzzer 63, or display a warning message on the display 61.

[0086] <Operation and effects of the fluid sterilization device 100> Next, the operation of the fluid sterilization device 100 and its effects other than those described above will be explained.

[0087] In the fluid sterilization device 100, the illuminance of ultraviolet light received by the light receiving sensor unit 20 depends on the condition of the first lid member 152-1, the first light-transmitting member 40-1, the dirt adhering to the first light-transmitting member 40-1, the fluid F, the dirt adhering to the light-transmitting member 70, the light-transmitting member 70, and the light-transmitting lid member 212. Furthermore, the amount of ultraviolet irradiation irradiated onto the fluid F depends on the condition of the first lid member 152-1, the first light-transmitting member 40-1, and the dirt adhering to the first light-transmitting member 40-1. In the fluid sterilization device 100, if dirt adheres to and accumulates on the first light-transmitting member 40-1 and the light-transmitting member 70, it may not be possible to secure the predetermined amount of ultraviolet irradiation necessary to sterilize the fluid F.

[0088] Furthermore, if a certain type of dirt adheres to and accumulates on the first light-transmitting member 40-1 or the light-transmitting member 70 for transmitted light, the magnitude of the first transmitted light received signal output from the light-transmitting photoelectric element 21 may decrease, even if the amount of ultraviolet irradiation irradiated onto the fluid F remains constant. In this case, increasing the drive current supplied to the first light source 10-1 can restore the magnitude of the first transmitted light received signal to the level before the dirt adhered and accumulated. However, since this irradiates the fluid F with an amount of ultraviolet irradiation exceeding the amount necessary to sterilize the fluid F, the lifespan of the first light source 10-1 may be shortened unnecessarily depending on the drive current supplied to the first light source 10-1.

[0089] Furthermore, if another type of dirt adheres to and accumulates on the first light-transmitting member 40-1 or the light-transmitting member 70 for transmitted light, the magnitude of the first transmitted light received signal may increase even if the amount of ultraviolet irradiation irradiated onto the fluid F remains constant. In this case, reducing the drive current supplied to the first light source 10-1 can return the magnitude of the first transmitted light received signal to the level before the dirt adhered and accumulated. However, since the amount of ultraviolet irradiation irradiated onto the fluid F becomes less than the amount of ultraviolet irradiation necessary to sterilize the fluid F, the sterilization performance cannot be maintained. Therefore, it becomes necessary to remove the dirt adhering to the light-transmitting member 70 for transmitted light, or to adjust the amplification factor of the first transmitted light received signal, etc.

[0090] In addition, the magnitude of the first transmitted light received signal may decrease due to the degradation of the first photoelectric element 11-1. In this case, the first photoelectric element 11-1 will need to be replaced.

[0091] As described above, in the fluid sterilization device 100, factors that cause the magnitude of the first transmitted light received signal to decrease include the state of contamination adhering to the first light-transmitting member 40-1 or the light-transmitting member 70 for transmitted light, and the state of deterioration of the first photoelectric element 11-1. However, it is not possible to determine from the first transmitted light received signal alone whether the decrease in the magnitude of the first transmitted light received signal is due to the state of contamination adhering to the first light-transmitting member 40-1 or the light-transmitting member 70, or the state of deterioration of the first photoelectric element 11-1. Therefore, by receiving only the first transmitted light received signal, the fluid sterilization device may not be able to properly control the emission of ultraviolet light from the first photoelectric element, and may not be able to keep the amount of ultraviolet light irradiated onto the fluid F constant.

[0092] Here, the first light-transmitting member 40-1 and the light-transmitting member 70 for transmitted light are connected to the same chamber 30 and come into contact with the same fluid F. Therefore, the type and thickness of the dirt adhering to the first light-transmitting member 40-1 and the light-transmitting member 70 for transmitted light are considered to be approximately the same. From this, the fluid sterilization device 100 can control the emission of ultraviolet light by the first photoelectric element 11-1 in response to the first reflected light receiving signal, the first emitted light receiving signal, and the first transmitted light receiving signal, thereby keeping the amount of ultraviolet light irradiated onto the fluid F constant.

[0093] The operation of the fluid sterilization device 100 for irradiating fluid F with a predetermined amount of ultraviolet light at a constant rate will be explained in more detail.

[0094] First, when the first light-transmitting member 40-1 is free of dirt, the fluid sterilization device 100 supplies a drive current from the power supply 51 of the control unit 50 to the first photoelectric element 11-1 to irradiate the fluid F with a predetermined amount of ultraviolet light. The fluid sterilization device 100 stores the magnitude of the first reflected light received signal obtained at this time as the initial value of the first reflected light received signal in the storage unit 52. The fluid sterilization device 100 also stores the magnitude of the first emitted light received signal obtained at this time as the initial value of the first emitted light received signal in the storage unit 52. Furthermore, the fluid sterilization device 100 stores the magnitude of the first transmitted light received signal obtained at this time as the initial value of the first transmitted light received signal in the storage unit 52.

[0095] Next, if the fluid sterilization device 100 is operated continuously, dirt will accumulate on the first light-transmitting member 40-1.

[0096] Here, there are two cases in which the refractive index of the dirt adhering to the first light-transmitting member 40-1 is higher than the refractive index of the first light-transmitting member 40-1, and cases in which the refractive index of the dirt is lower than that of the first light-transmitting member 40-1.

[0097] If the refractive index of the dirt adhering to the first light-transmitting member 40-1 is higher than the refractive index of the first light-transmitting member 40-1, the magnitude of the first reflected light received signal will be greater than the initial value of the first reflected light received signal, even if the magnitude of the first emitted light received signal is approximately the same as the initial value of the first emitted light received signal. Furthermore, the magnitude of the first transmitted light received signal will be smaller than the initial value of the first transmitted light received signal. This is because the adhesion of dirt to the first light-transmitting member 40-1 and the light-transmitting member 70 for transmitted light results in higher reflectivity and lower transmittance with respect to ultraviolet light at the interface between the first light-transmitting member 40-1 and the dirt, and at the interface between the light-transmitting member 70 for transmitted light and the dirt.

[0098] On the other hand, if the refractive index of the dirt adhering to the first light-transmitting member 40-1 is lower than that of the first light-transmitting member 40-1, even if the magnitude of the first emitted light received signal is approximately the same as the initial value of the first emitted light received signal, the magnitude of the first reflected light received signal will be smaller than the initial value of the first reflected light received signal. Furthermore, the magnitude of the first transmitted light received signal will be larger than the initial value of the first transmitted light received signal. This is because, at the interface between the first light-transmitting member 40-1 and the dirt, and at the interface between the light-transmitting member 70 for transmitted light and the dirt, the reflectance becomes lower and the transmittance becomes higher with respect to ultraviolet light.

[0099] Next, the fluid sterilization device 100 supplies a drive current to the first photoelectric element 11-1 from the power supply 51 of the control unit 50, and the processor 53 calculates the ultraviolet light transmittance at the interface between the first light-transmitting member 40-1 and the dirt from the magnitudes of the first reflected light received signal and the first emitted light received signal. The fluid sterilization device 100 also calculates the ultraviolet light absorption rate by the fluid F, etc., from the magnitude of the first transmitted light received signal using the processor 53. Based on the calculation results of the ultraviolet light transmittance at the interface between the first light-transmitting member 40-1 and the dirt, and the ultraviolet light absorption rate by the fluid F, etc., the fluid sterilization device 100 adjusts the drive current supplied to the first photoelectric element 11-1 from the power supply 51. This allows the fluid sterilization device 100 to keep the amount of ultraviolet light irradiated onto the fluid F constant.

[0100] Subsequently, in order to keep the amount of ultraviolet irradiation to the fluid F constant, as the absorption of ultraviolet light due to the adhesion and accumulation of dirt increases, the light output of the first photoelectric element 11-1 increases monotonically, and the magnitude of the first emitted light received signal also increases monotonically. In addition, the magnitude of the first reflected light received signal increases or decreases from the start of operation of the fluid sterilization device 100, and then increases monotonically in proportion to the magnitude of the first emitted light received signal. On the other hand, the magnitude of the first transmitted light received signal also decreases monotonically. If the absolute value of the difference between the magnitude of the first transmitted light received signal and the initial value of the first transmitted light received signal is significant and exceeds a predetermined transmitted light threshold, then the adhesion and accumulation of dirt is significant, and the drive current of the first photoelectric element 11-1 increases. Continuing to operate the fluid sterilization device 100 in this state will significantly deplete the lifespan of the first photoelectric element 11-1. In this case, the control unit 50 outputs a first error signal to the user interface unit 60 via the processor 53.

[0101] Furthermore, as the fluid sterilization device 100 continues to operate, the first photoelectric element 11-1 deteriorates, and the drive current required to irradiate the fluid F with a predetermined amount of ultraviolet light necessary to sterilize the fluid F increases. If the magnitude of the drive current of the first photoelectric element 11-1 exceeds the maximum rated drive current value of the first photoelectric element 11-1, the first photoelectric element 11-1 may suddenly fail. Therefore, it is necessary to set a predetermined current threshold for drive currents below the maximum rated drive current value of the first photoelectric element 11-1 to prevent sudden failure of the fluid sterilization device 100.

[0102] On the other hand, as described above, as the absorption of ultraviolet light due to the adhesion and accumulation of dirt increases, the drive current of the first photoelectric element 11-1 increases. In this case, after the dirt is removed, the drive current of the first photoelectric element 11-1 decreases compared to before the dirt was removed, so replacement of the first photoelectric element 11-1 is unnecessary.

[0103] Therefore, if the absolute value of the difference between the magnitude of the first transmitted light received signal and the initial value of the first transmitted light received signal does not exceed a predetermined transmitted light threshold, and the magnitude of the drive current supplied to the first photoelectric element 11-1 exceeds a predetermined current threshold, the control unit 50 outputs a second error signal to the user interface unit 60 via the processor 53 in order to prevent a sudden failure of the fluid sterilization device 100.

[0104] As described above, the fluid sterilization device 100 can maintain a constant amount of ultraviolet irradiation applied to the fluid F. Furthermore, it can improve maintainability by indicating the appropriate maintenance timing for the fluid sterilization device 100, and prevent sudden malfunctions of the fluid sterilization device 100.

[0105] In the first embodiment of this disclosure, the storage unit 52 can store at least the initial value of the first transmitted light receiving signal. The control unit 50 can output a first error signal if the absolute value of the difference between the magnitude of the first transmitted light receiving signal and the magnitude of the initial value of the first transmitted light receiving signal exceeds a predetermined transmitted light threshold. Upon receiving the first error signal, the user interface unit 60 lights up the indicator lamp 62 and sounds the buzzer 63 to indicate that dirt is adhering to the first light-transmitting member 40-1. Alternatively, the user interface unit 60 displays a text message on the display 61 indicating that dirt is adhering to the first light-transmitting member 40-1. This allows the fluid sterilization device 100 to notify the operator of the fluid sterilization device 100 that dirt is adhering to the first light-transmitting member 40-1 and prompt the operator to clean the first light-transmitting member 40-1. By prompting cleaning at an appropriate time, the maintainability of the fluid sterilization device 100 can be improved.

[0106] The memory unit 52 can store the initial value of the first transmitted light receiving signal, a predetermined current threshold for the drive current, and a predetermined transmitted light threshold. The control unit 50 can output a second error signal regarding the deterioration of the first photoelectric element 11-1 if the absolute value of the difference between the magnitude of the first transmitted light receiving signal and the magnitude of the initial value of the first transmitted light receiving signal does not exceed the transmitted light threshold, and the magnitude of the drive current supplied to the first photoelectric element 11-1 exceeds the current threshold. Upon receiving the second error signal, the user interface unit 60 lights up the indicator lamp 62 and sounds the buzzer 63 to indicate that the first photoelectric element 11-1 is in a deteriorated state. Alternatively, the user interface unit 60 displays a text message on the display 61 indicating that the first photoelectric element 11-1 is in a deteriorated state. This allows the fluid sterilization device 100 to notify its operator that the first photoelectric element 11-1 is deteriorating and prompt them to replace the first photoelectric element 11-1. By prompting replacement at the appropriate time, the maintainability of the fluid sterilization device 100 can be improved.

[0107] The first photoelectric element 12-1 for emitting light can receive ultraviolet light emitted from the first photoelectric element 11-1 and reflected by the first lid member 152-1. As a result, the first photoelectric element 12-1 for emitting light can output a first emitted light reception signal to the control unit 50 regarding the light output of ultraviolet light emitted by the first photoelectric element 11-1, without being affected by dirt such as the first light-transmitting member 40-1. The fluid sterilization device 100 can obtain information regarding the lifespan of the first photoelectric element 11-1 based on the first emitted light reception signal.

[0108] The first lid member 152-1 includes a first light intensity adjustment member 153-1, which can be positioned opposite the first light-emitting photoelectric element 12-1. The first light intensity adjustment member 153-1 reduces the incidence of light from outside the first housing 151-1 onto the first light-emitting photoelectric element 12-1, thereby reducing noise in the first light-emitting and receiving signal. As a result, the fluid sterilization device 100 can improve the accuracy of controlling the light output of ultraviolet light emitted from the first photoelectric element 11-1 based on the first light-emitting and receiving signal.

[0109] The fluid sterilization device 100 may have a first housing 151-1 that houses the first photoelectric element 11-1 and the first photoelectric element for emitting light 12-1 and supports the first lid member 152-1. This configuration improves the airtightness of the space in which the first photoelectric element 11-1 and the first photoelectric element for emitting light 12-1 are arranged, thereby reducing the deterioration of the first photoelectric element 11-1 and the first photoelectric element for emitting light 12-1.

[0110] The first photoelectric element 11-1 and the first reflected light photoelectric element 13-1 can each be positioned opposite the first light-transmitting member 40-1. As a result, the first reflected light photoelectric element 13-1 can receive ultraviolet light emitted from the first photoelectric element 11-1 and reflected at the interface between the first light-transmitting member 40-1 and the fluid F, and output a first reflected light reception signal to the control unit 50. The fluid sterilization device 100 can acquire information regarding contamination of the first light-transmitting member 40-1 based on the first reflected light reception signal, etc.

[0111] In the first embodiment of this disclosure, the first light source 10-1 (light source) includes a first photoelectric element 11-1 (first light-emitting element) and a first photoelectric element for emitted light 12-1 (first light-receiving element for emitted light) that receives a portion of the ultraviolet light (light) from the first photoelectric element 11-1. The first light source 10-1 also includes a first light-transmitting member 40-1 that reflects a portion of the ultraviolet light from the first photoelectric element 11-1 and a first photoelectric element for reflected light 13-1 (first light-receiving element for reflected light) that receives a portion of the ultraviolet light reflected by the first light-transmitting member 40-1.

[0112] The first light source 10-1 may further have a first cover member 152-1, and the first light-emitting photoelectric element 12-1 may receive ultraviolet light emitted from the first photoelectric element 11-1 and reflected by the first cover member 152-1. The first cover member 152-1 includes a first light intensity adjusting member 153-1, and the first light intensity adjusting member 153-1 may be positioned opposite the first light-emitting photoelectric element 12-1.

[0113] The first light source 10-1 can control the emission of ultraviolet light from the first photoelectric element 11-1 by using the light received signal from the first light-emitting photoelectric element 12-1 and the light received signal from the first light-reflecting photoelectric element 13-1, thereby reducing the influence of dirt adhering to the first light-transmitting member 40-1. For example, the first light source 10-1 can control the emission from the first photoelectric element 11-1 by adjusting the drive current supplied to the first photoelectric element 11-1, so that the amount of ultraviolet irradiation stays within a predetermined range. The first light source 10-1 can keep the amount of ultraviolet irradiation constant by controlling the emission of ultraviolet light from the first photoelectric element 11-1, thereby reducing the influence of dirt adhering to the first light-transmitting member 40-1.

[0114] In a first embodiment of this disclosure, the light source device includes a first photoelectric element 11-1, a first photoelectric element for emitted light 12-1, and a first photoelectric element for reflected light 13-1, and a first light-transmitting member 40-1 positioned opposite the first photoelectric element 11-1, the first photoelectric element for emitted light 12-1, and the first photoelectric element for reflected light 13-1. The light source device also includes a control unit 50 that receives a first reflected light reception signal from the first photoelectric element 13-1, which receives light (ultraviolet light) emitted from the first photoelectric element 11-1 and reflected by the first light-transmitting member 40-1, and a first emitted light reception signal from the first photoelectric element 12-1, which receives a portion of the ultraviolet light emitted from the first photoelectric element 11-1, and controls the emission of light by the first photoelectric element 11-1.

[0115] The above light source device can control the emission of ultraviolet light from the first photoelectric element 11-1 by reducing the effect of dirt adhering to the first light-transmitting member 40-1 and by using the first emitted light receiving signal and the first reflected light receiving signal. For example, the above light source device can control the ultraviolet light emitted from the first photoelectric element 11-1 by adjusting the drive current supplied to the first photoelectric element 11-1 so that the amount of ultraviolet irradiation falls within a predetermined range. The first light source 10-1 can keep the amount of ultraviolet irradiation constant by controlling the emission of ultraviolet light from the first photoelectric element 11-1 by reducing the effect of dirt adhering to the first light-transmitting member 40-1.

[0116] From the viewpoint of extending the lifespan of the first photoelectric element 11-1, it is preferable to irradiate the fluid sterilization device 100 with ultraviolet light as described above. Specifically, in the initial stages of using the fluid sterilization device 100, a drive current is supplied to the first photoelectric element 11-1 so that the fluid sterilization device 100 irradiates a predetermined amount of ultraviolet light necessary to sterilize the fluid F. Subsequently, as the usage period of the fluid sterilization device 100 increases, the drive current supplied to the first photoelectric element 11-1 is gradually increased so that the fluid sterilization device 100 irradiates a predetermined amount of ultraviolet light.

[0117] [Second Embodiment] Next, a fluid sterilization apparatus according to a second embodiment of this disclosure will be described. Note that names and reference numerals identical to those used in the previously described embodiments indicate the same or identical components or configurations, and detailed explanations will be omitted as appropriate. This also applies to the embodiments described hereafter.

[0118] <Configuration of the fluid sterilization apparatus according to the second embodiment of this disclosure> The configuration of the fluid sterilization apparatus according to the second embodiment of this disclosure will be described with reference to Figures 5 to 8. Figure 5 is a block diagram showing the overall configuration of the fluid sterilization apparatus 100a according to the second embodiment of this disclosure. Figure 6 is a schematic cross-sectional view showing state I of the fluid sterilization apparatus 100a. Figure 7 is a schematic cross-sectional view showing state II of the fluid sterilization apparatus 100a. Figure 8 is a schematic top view showing the configuration around the first photoelectric element 11-1A and the first photoelectric element 11-1B of the fluid sterilization apparatus 100a.

[0119] (Overall structure) As shown in Figures 5 to 7, the fluid sterilization device 100a includes a first light source 10-1a, a chamber 30, a second light source 10-2, and a control unit 50a. The first light source 10-1a includes a first light-transmitting member 40-1. The second light source 10-2 includes a second light-transmitting member 40-2. Figures 6 and 7 show a cross-section of the fluid sterilization device 100a including the first light source 10-1a, the chamber 30, and the second light source 10-2.

[0120] The fluid sterilization device 100a may have one or more first photoelectric elements and one or more second photoelectric elements. Furthermore, the fluid sterilization device 100a may have one or more first photoelectric elements for emitted light and one or more second photoelectric elements for emitted light. The configuration of each of the one or more first photoelectric elements and the one or more second photoelectric elements can be the same as that of the first photoelectric element 11-1. The configuration of each of the one or more first photoelectric elements and the one or more second photoelectric elements can be the same as that of the first photoelectric element 12-1.

[0121] The first light source 10-1a includes a first photoelectric element 11-1A, a first photoelectric element 11-1B, a first photoelectric element for emitted light 12-1, and a first photoelectric element for reflected light 13-1. The second light source 10-2 includes a second photoelectric element 11-2A, a second photoelectric element 11-2B, a second photoelectric element for emitted light 12-2, and a second photoelectric element for reflected light 13-2. The first light source 10-1a and the second light source 10-2 are arranged opposite each other.

[0122] The control unit 50a of the fluid sterilization device 100a includes a processor 53 that alternately switches between state I, in which the first light source 10-1a emits ultraviolet light and the second light source 10-2 does not emit ultraviolet light, and state II, in which the second light source 10-2 emits ultraviolet light and the first light source 10-1a does not emit ultraviolet light. Figure 5 shows the case when the control unit 50a is in state I. In state I, the second reflected light photoelectric element 13-2 functions as a transmitted light photoelectric element and emits a first transmitted light received signal. Based on the first reflected light received signal, the first emitted light received signal, and the first transmitted light received signal, the control unit 50a controls the emission of ultraviolet light by the first photoelectric element 11-1A and the first photoelectric element 11-1B. In state II, the first reflected light photoelectric element 13-1 functions as a transmitted light photoelectric element and emits a second transmitted light received signal. The control unit 50a controls the emission of ultraviolet light by the second photoelectric element 11-2A and the second photoelectric element 11-2B based on the second reflected light received signal, the second emitted light received signal, and the second transmitted light received signal.

[0123] The fluid sterilization device 100a differs from the fluid sterilization device 100 according to the first embodiment of this disclosure in the points described above.

[0124] Here, the junction temperature of the first or second photoelectric element rises when the first or second photoelectric element begins to emit ultraviolet light, and decreases when the first or second photoelectric element stops emitting ultraviolet light, returning to the temperature before it began emitting ultraviolet light. The fluid sterilization device 100a alternately emits ultraviolet light from the first light source 10-1a and the second light source 10-2, and does not emit ultraviolet light from any light sources other than those emitting ultraviolet light. As a result, the fluid sterilization device 100a can reduce the rise in the junction temperature of the first photoelectric element 11-1A, the first photoelectric element 11-1B, the second photoelectric element 11-2A, and the second photoelectric element 11-2B. As a result, the lifespan of the first photoelectric element 11-1A, the first photoelectric element 11-1B, the second photoelectric element 11-2A, and the second photoelectric element 11-2B is extended, and the replacement cycle of the first photoelectric element 11-1A, the first photoelectric element 11-1B, the second photoelectric element 11-2A, and the second photoelectric element 11-2B is extended.

[0125] In the second embodiment of this disclosure, the maintainability of the fluid sterilization device 100a can be improved by having a long replacement cycle for the first photoelectric element 11-1A, the first photoelectric element 11-1B, the second photoelectric element 11-2A, and the second photoelectric element 11-2B. Furthermore, in the second embodiment of this disclosure, the number of parts in the fluid sterilization device 100a can be reduced, simplifying the configuration and reducing costs by making the first reflected light photoelectric element 13-1 and the second reflected light photoelectric element 13-2, which are not functioning as reflected light photoelectric elements, function as transmitted light photoelectric elements.

[0126] The fluid sterilization device 100a will be described in more detail below.

[0127] (1st light source 10-1a) In the example shown in Figures 6 and 7, the first light source 10-1a includes a first photoelectric element 11-1A, a first photoelectric element 11-1B, a first photoelectric element for emitted light 12-1, and a first photoelectric element for reflected light 13-1. The first light source 10-1a also includes a first light-emitting unit 15-1A, a first reflected light housing 131-1, and a first reflected light cover member 132-1, all of which are arranged on a first substrate 14-1.

[0128] The first photoelectric element 11-1A and the first photoelectric element 11-1B are connected in parallel.

[0129] The first light-emitting unit 15-1A includes a first housing 151-1A and a first cover member 152-1A. The first housing 151-1A houses the first photoelectric element 11-1A, the first photoelectric element 11-1B, and the first photoelectric element for emitting light 12-1, and supports the first cover member 152-1A.

[0130] The first cover member 152-1A is positioned between the first photoelectric element 11-1A, the first photoelectric element 11-1B, and the first photoelectric element for emitting light 12-1 and the first light-transmitting member 40-1, facing the first photoelectric element 11-1A, the first photoelectric element 11-1B, and the first photoelectric element for emitting light 12-1. The first cover member 152-1A transmits a portion of the ultraviolet light emitted from the first photoelectric element 11-1A. The first cover member 152-1A includes a first light intensity adjustment member 153-1A. The first light intensity adjustment member 153-1A is positioned facing the first photoelectric element for emitting light 12-1.

[0131] The configurations of the first light-emitting unit 15-1A and the second light-emitting unit 15-2A can be the same as those of the first light-emitting unit 15-1.

[0132] The first reflected light housing 131-1 houses the first reflected light photoelectric element 13-1 and supports the first reflected light cover member 132-1. The first reflected light cover member 132-1 is positioned opposite the first reflected light photoelectric element 13-1 and between the first reflected light photoelectric element 13-1 and the first light-transmitting member 40-1. The first reflected light cover member 132-1 transmits a portion of the ultraviolet light emitted from the first photoelectric element 11-1A, the first photoelectric element 11-1B, the second photoelectric element 11-2A, or the second photoelectric element 11-2B. The configuration of the first reflected light housing 131-1 can be the same as that of the transmitted light housing 211. The configuration of the first reflected light cover member 132-1 can be the same as that of the transmitted light cover member 212.

[0133] In the example shown in Figure 8, the first substrate 14-1 has a substantially circular outer edge shape when viewed from above. The first frame 16-1 has a circular annular shape when viewed from above, and the first substrate 14-1 is placed in the inner space. However, the first substrate 14-1 may have an outer edge shape such as a substantially rectangular, substantially elliptical, or substantially polygonal shape when viewed from above. The first frame 16-1 may have a rectangular annular shape when viewed from above, and the first substrate 14-1 may be placed in the inner space.

[0134] The first housing 151-1A and the first lid member 152-1A hermetically seal the first photoelectric element 11-1A, the first photoelectric element 11-1B, and the first photoelectric element for emitted light 12-1 from the outside of the first light-emitting unit 15-1A. The configuration of the first housing 151-1A can be the same as that of the first housing 151-1. The configuration of the first lid member 152-1A can be the same as that of the first lid member 152-1. In the example shown in Figure 8, the first housing 151-1A and the first lid member 152-1A each have a substantially rectangular outer edge shape when viewed from above. However, the first housing 151-1A and the first lid member 152-1A may each have a substantially circular, substantially elliptical, or substantially polygonal outer edge shape when viewed from above.

[0135] (First light-transmitting member 40-1) The first light-transmitting member 40-1 is positioned between the first photoelectric element 11-1A, the first photoelectric element 11-1B, the first photoelectric element for emitted light 12-1, and the first photoelectric element for reflected light 13-1, and the inside of the chamber 30.

[0136] The first light source 10-1a can be removed from the fluid sterilization device 100a, similar to the first light source 10-1. Removing the first light source 10-1a from the fluid sterilization device 100a makes it easier to remove dirt adhering to the first light-transmitting member 40-1, or to replace the first substrate 14-1 on which the first light-emitting unit 15-1A and the first reflective light housing 131-1 are mounted.

[0137] (Second light source 10-2) In the example shown in Figures 6 and 7, the second light source 10-2 includes a second photoelectric element 11-2A, a second photoelectric element 11-2B, a second photoelectric element for emitted light 12-2, and a second photoelectric element for reflected light 13-2. The second light source 10-2 also includes a second substrate 14-2, a second light-emitting unit 15-2A positioned below the second substrate 14-2, a second housing for reflected light 131-2, and a second cover member 132-2 for reflected light. Furthermore, the second light source 10-2 has a second frame 16-2 that supports the second substrate 14-2 and the second light-transmitting member 40-2, a second sealing member 17-2 positioned between the chamber 30 and the second frame 16-2, and a second fixing member 18-2 that fixes the second light source 10-2 to the chamber 30.

[0138] The second photoelectric element 11-2A and the second photoelectric element 11-2B are connected in parallel.

[0139] The second photoelectric element 11-2A, the second photoelectric element 11-2B, the second photoelectric element for emitted light 12-2, and the second photoelectric element for reflected light 13-2 are arranged to face the first photoelectric element 11-1A, the first photoelectric element 11-1B, the first photoelectric element for emitted light 12-1, and the first photoelectric element for reflected light 13-1.

[0140] The second light-emitting unit 15-2A includes a second housing 151-2A and a second cover member 152-2A. The second housing 151-2A houses the second photoelectric element 11-2A, the second photoelectric element 11-2B, and the second photoelectric element for emitting light 12-2, and is a member that supports the second cover member 152-2A. The second cover member 152-2A is positioned opposite the second photoelectric element 11-2A and the second photoelectric element for emitting light 12-2, and is positioned between the second photoelectric element 11-2A, the second photoelectric element 11-2B, and the second photoelectric element for emitting light 12-2 and the second light-transmitting member 40-2. The second cover member 152-2A transmits a portion of the ultraviolet light emitted from the second photoelectric element 11-2A. The second cover member 152-2A includes a second light intensity adjustment member 153-2A. The second light intensity adjusting member 153-2A is positioned opposite the second photoelectric element 12-2 for emitted light.

[0141] The second reflected light housing 131-2 houses the second reflected light photoelectric element 13-2 and supports the second reflected light cover member 132-2. The second reflected light cover member 132-2 is positioned opposite the second reflected light photoelectric element 13-2 and between the second reflected light photoelectric element 13-2 and the second light-transmitting member 40-2. The second reflected light cover member 132-2 transmits a portion of the ultraviolet light emitted from the first photoelectric element 11-1A, the first photoelectric element 11-1B, the second photoelectric element 11-2A, or the second photoelectric element 11-2B.

[0142] The configuration of the second substrate 14-2 can be the same as that of the first substrate 14-1. The configuration of the second frame 16-2 can be the same as that of the first frame 16-1. The configuration of the second housing 151-2A can be the same as that of the first housing 151-1A. The configuration of the second lid member 152-2A can be the same as that of the first lid member 152-1A.

[0143] (Second light-transmitting member 40-2) The second light-transmitting member 40-2 is positioned between the second photoelectric element 11-2A, the second photoelectric element 11-2B, the second photoelectric element for emitted light 12-2, and the second photoelectric element for reflected light 13-2, and the inside of the chamber 30.

[0144] The second light source 10-2 can be removed from the fluid sterilization device 100a. Removing the second light source 10-2 from the fluid sterilization device 100a makes it easier to remove dirt adhering to the second light-transmitting member 40-2, or to replace the second substrate 14-2 on which the second light-emitting unit 15-2A and the second light-reflecting housing 131-2 are mounted. The second light source 10-2 is watertight with the inside of the chamber 30 using the second sealing member 17-2.

[0145] The second fixing member 18-2 has a female threaded portion formed on its inner surface. The female threaded portion of the second fixing member 18-2 is screwed into a male threaded portion formed in the chamber 30 in a portion corresponding to the female threaded portion. By screwing in and tightening the second fixing member 18-2 and pressing the second frame 16-2 against the chamber 30, the second light source 10-2 can be attached and fixed to the chamber 30. The second fixing member 18-2 can also be removed from the chamber 30 by loosening the screw connection between the female threaded portion of the second fixing member 18-2 and the male threaded portion of the chamber 30. By removing the second fixing member 18-2 from the chamber 30, the second light source 10-2 can be removed from the chamber 30.

[0146] (Chamber 30) The fluid F located inside the chamber 30 is positioned between the first photoelectric element 11-1A, the first photoelectric element 11-1B, the first photoelectric element for emitted light 12-1, and the first photoelectric element for reflected light 13-1, and the second photoelectric element 11-2A, the second photoelectric element 11-2B, the second photoelectric element for emitted light 12-2, and the second photoelectric element for reflected light 13-2. The fluid F located inside the chamber 30 is irradiated with ultraviolet light emitted from the first photoelectric element 11-1A and the first photoelectric element 11-1B, or the second photoelectric element 11-2A and the second photoelectric element 11-2B.

[0147] (Control unit 50a) The control unit 50a includes a processor 53 used to alternately switch between state I and state II. The processor 53 included in the control unit 50a can alternately switch between state I and state II by alternately switching the drive current supplied to either the first light source 10-1a (first photoelectric element 11-1A and first photoelectric element 11-1B) or the second light source 10-2 (second photoelectric element 11-2A and second photoelectric element 11-2B).

[0148] (State I) State I is a state in which the first photoelectric element 11-1A and the first photoelectric element 11-1B emit ultraviolet light, and the first photoelectric element for emitted light 12-1, the first photoelectric element for reflected light 13-1, the second photoelectric element 11-2A, the second photoelectric element 11-2B, the second photoelectric element for emitted light 12-2, and the second photoelectric element for reflected light 13-2 do not emit ultraviolet light.

[0149] In the example shown in Figures 5 and 6, in state I, the first reflected light photoelectric element 13-1 receives ultraviolet light emitted from the first photoelectric elements 11-1A and 11-1B and reflected by the first light-transmitting member 40-1, and outputs a first reflected light reception signal. The first emitted light photoelectric element 12-1 receives a portion of the ultraviolet light emitted from the first photoelectric elements 11-1A and 11-1B and outputs a first emitted light reception signal. Furthermore, the second reflected light photoelectric element 13-2 receives ultraviolet light emitted from the first photoelectric elements 11-1A and 11-1B and transmitted through the first light-transmitting member 40-1, the fluid F, and the second light-transmitting member 40-2, and outputs a first transmitted light reception signal. In addition, the control unit 50a controls the emission of ultraviolet light from the first photoelectric element 11-1A and the first photoelectric element 11-1B based on the first reflected light receiving signal, the first emitted light receiving signal, and the first transmitted light receiving signal.

[0150] For example, the control unit 50a receives the first reflected light reception signal, the first emitted light reception signal, and the first transmitted light reception signal from the processor 53, performs signal processing, and adjusts the drive current of the first photoelectric element 11-1A and the first photoelectric element 11-1B. This allows control of the emission of ultraviolet light by the first photoelectric element 11-1A and the first photoelectric element 11-1B.

[0151] The first emitted light received signal includes information about the light output emitted by the first photoelectric element 11-1A and the first photoelectric element 11-1B, respectively. The first emitted light received signal is not affected by dirt or fluid F adhering to the second light-transmitting member 40-2 and the second light-transmitting member 40-2. The first reflected light received signal includes the effects of light absorption or scattering by at least one of the first lid member 152-1A, the first light-transmitting member 40-1, and the dirt adhering to the first light-transmitting member 40-1. The first transmitted light received signal includes the effects of light absorption or scattering by at least one of the first lid member 152-1A, the first light-transmitting member 40-1, the dirt adhering to the first light-transmitting member 40-1, the fluid F, the dirt adhering to the second light-transmitting member 40-2, and the second light-transmitting member 40-2.

[0152] (State II) State II is a state in which the second photoelectric element 11-2A and the second photoelectric element 11-2B emit ultraviolet light, while the first photoelectric element 11-1A, the first photoelectric element 11-1B, the first photoelectric element for emitted light 12-1, the first photoelectric element for reflected light 13-1, the second photoelectric element for emitted light 12-2, and the second photoelectric element for reflected light 13-2 do not emit ultraviolet light.

[0153] In the example shown in Figure 7, in state II, the second reflected light photoelectric element 13-2 receives ultraviolet light emitted from the second photoelectric elements 11-2A and 11-2B and reflected by the second light-transmitting member 40-2, and outputs a second reflected light reception signal. The second emitted light photoelectric element 12-2 receives a portion of the ultraviolet light emitted from the second photoelectric elements 11-2A and 11-2B and outputs a second emitted light reception signal. Furthermore, the first reflected light photoelectric element 13-1 receives ultraviolet light emitted from the second photoelectric elements 11-2A and 11-2B and transmitted through the second light-transmitting member 40-2, the fluid F, and the first light-transmitting member 40-1, and outputs a second transmitted light reception signal. In addition, the control unit 50a controls the emission of ultraviolet light from the second photoelectric element 11-2A and the second photoelectric element 11-2B based on the second reflected light receiving signal, the second emitted light receiving signal, and the second transmitted light receiving signal.

[0154] For example, the control unit 50a receives the second reflected light reception signal, the second emitted light reception signal, and the second transmitted light reception signal via the processor 53, performs signal processing, and adjusts the drive current of the second photoelectric element 11-2A and the second photoelectric element 11-2B. This allows control of the emission of ultraviolet light by the second photoelectric element 11-2A and the second photoelectric element 11-2B.

[0155] The second emitted light received signal includes information on the light output emitted by the second photoelectric element 11-2A and the second photoelectric element 11-2B, respectively. The second emitted light received signal is not affected by the first light-transmitting member 40-1, dirt or fluid F adhering to the first light-transmitting member 40-1, etc. The second reflected light received signal includes the effect of light absorption or scattering, etc., by at least one of the second lid member 152-2A, the second light-transmitting member 40-2, and dirt adhering to the second light-transmitting member 40-2. The second transmitted light received signal includes the effect of light absorption or scattering, etc., by at least one of the second lid member 152-2A, the first light-transmitting member 40-1, dirt adhering to the first light-transmitting member 40-1, fluid F, dirt adhering to the second light-transmitting member 40-2, and the second light-transmitting member 40-2.

[0156] In a second embodiment of this disclosure, the storage unit 52 can store at least the initial value of the first transmitted light receiving signal and the initial value of the second transmitted light receiving signal. When the first light-transmitting member 40-1 and the second light-transmitting member 40-2 are free of dirt, the fluid sterilization device 100a supplies a drive current from the power supply 51 of the control unit 50 to the first photoelectric elements 11-1A and 11-1B to provide a predetermined amount of ultraviolet irradiation to the fluid F. The fluid sterilization device 100a stores the magnitude of the first transmitted light receiving signal obtained at this time as the initial value of the first transmitted light receiving signal in the storage unit 52. Also in this state, the fluid sterilization device 100a supplies a drive current from the power supply 51 to the second photoelectric elements 11-2A and 11-2B to provide a predetermined amount of ultraviolet irradiation to the fluid F, and stores the magnitude of the second transmitted light receiving signal obtained at this time as the initial value of the second transmitted light receiving signal in the storage unit 52.

[0157] In state I, when the control unit 50a outputs a first error signal and a second error signal, the operation of the fluid sterilization device 100a is the same as the operation of the fluid sterilization device 100 in the first embodiment. In state II, when the control unit 50a outputs a first error signal and a second error signal, the operation of the fluid sterilization device 100a is the same as the operation of the fluid sterilization device 100 in the first embodiment, except that the first emitted light received signal is replaced by the second emitted light received signal, the first reflected light received signal is replaced by the second reflected light received signal, and the first transmitted light received signal is replaced by the second transmitted light received signal.

[0158] <Effects and Effects of Fluid Sterilization Device 100a> Next, we will explain the effects and benefits of the fluid sterilization device 100a other than those described above.

[0159] In the second embodiment of this disclosure, the first photoelectric element 11-1A and the first photoelectric element 11-1B are connected in parallel, and the second photoelectric element 11-2A and the second photoelectric element 11-2B are connected in parallel. This allows multiple first photoelectric elements and multiple second photoelectric elements to be driven in parallel. Furthermore, it is possible to easily control the emission of ultraviolet light from the first photoelectric elements and multiple second photoelectric elements. Moreover, by emitting ultraviolet light from each of the multiple first photoelectric elements and multiple second photoelectric elements, the amount of ultraviolet light irradiated from the first light source 10-1a and the second light source 10-2 in the fluid sterilization device 100a can be increased.

[0160] Other effects of the fluid sterilization device 100a according to the second embodiment of this disclosure are the same as those of the fluid sterilization device 100 described in the first embodiment of this disclosure.

[0161] [Third Embodiment] Next, a fluid sterilization apparatus according to a third embodiment of this disclosure will be described.

[0162] <Configuration of the fluid sterilization apparatus according to the third embodiment of this disclosure> The configuration of the fluid sterilization apparatus according to the third embodiment of this disclosure will be described with reference to Figures 9 to 15. Figure 9 is a block diagram showing the overall configuration of the fluid sterilization apparatus 100b according to the third embodiment of this disclosure. Figure 10 is a schematic cross-sectional view showing the configuration around the chamber 30 of the fluid sterilization apparatus 100b. Figure 11 is a schematic cross-sectional view showing the first state of the fluid sterilization apparatus 100b. Figure 12 is a schematic cross-sectional view showing the second state of the fluid sterilization apparatus 100b. Figure 13 is a schematic cross-sectional view showing the third state of the fluid sterilization apparatus 100b. Figure 14 is a schematic cross-sectional view showing the fourth state of the fluid sterilization apparatus 100b. Figure 15 is a schematic top view showing the configuration around the first photoelectric element 11-1 and the third photoelectric element 11-3 of the fluid sterilization apparatus 100b.

[0163] (Overall structure) As shown in Figures 9 and 10, the fluid sterilization device 100b includes a first light source 10-1b, a chamber 30, a second light source 10-2b, and a control unit 50b. The first light source 10-1b includes a first light-transmitting member 40-1. The second light source 10-2b includes a second light-transmitting member 40-2. Figure 10 shows a cross-section of the fluid sterilization device 100b including the first light source 10-1b, the chamber 30, and the second light source 10-2b. This is also true for Figures 11 to 14.

[0164] The first light source 10-1b includes a first photoelectric element 11-1, a first photoelectric element for emitted light 12-1, a third photoelectric element 11-3, and a third photoelectric element for emitted light 12-3. The second light source 10-2b includes a second photoelectric element 11-2, a second photoelectric element for emitted light 12-2, a fourth photoelectric element 11-4, and a fourth photoelectric element for emitted light 12-4. The first light source 10-1b and the second light source 10-2b are arranged opposite each other.

[0165] The fluid sterilization device 100b switches between the first, second, third, and fourth states one by one in sequence using the control unit 50b. The first state is when the first photoelectric element 11-1 emits ultraviolet light, and no other photoelectric elements emit ultraviolet light. The second state is when the third photoelectric element 11-3 emits ultraviolet light, and no other photoelectric elements emit ultraviolet light. The third state is when the second photoelectric element 11-2 emits ultraviolet light, and no other photoelectric elements emit ultraviolet light. The fourth state is when the fourth photoelectric element 11-4 emits ultraviolet light, and no other photoelectric elements emit ultraviolet light.

[0166] In the first state, the third photoelectric element 11-3 outputs a third reflected light reception signal. The first photoelectric element 12-1 for emitted light outputs a first emitted light reception signal. The second photoelectric element 11-2 or the fourth photoelectric element 11-4 outputs a first transmitted light reception signal. The control unit 50b controls the emission of ultraviolet light by the first photoelectric element 11-1 based on the third reflected light reception signal, the first emitted light reception signal, and the first transmitted light reception signal.

[0167] In the second state, the first photoelectric element 11-1 outputs a first reflected light reception signal. The third photoelectric element 12-3 for emitted light outputs a third emitted light reception signal. The second photoelectric element 11-2 or the fourth photoelectric element 11-4 outputs a third transmitted light reception signal. The control unit 50b controls the emission of ultraviolet light by the third photoelectric element 11-3 based on the first reflected light reception signal, the third emitted light reception signal, and the third transmitted light reception signal.

[0168] In the third state, the fourth photoelectric element 11-4 outputs a fourth reflected light reception signal. The second photoelectric element 12-2 for emitted light outputs a second emitted light reception signal. The first photoelectric element 11-1 or the third photoelectric element 11-3 outputs a second transmitted light reception signal. The control unit 50b controls the emission of ultraviolet light by the second photoelectric element 11-2 based on the fourth reflected light reception signal, the second emitted light reception signal, and the second transmitted light reception signal.

[0169] In the fourth state, the second photoelectric element 11-2 outputs a second reflected light reception signal. The fourth photoelectric element 12-4 for emitted light outputs a fourth emitted light reception signal. The first photoelectric element 11-1 or the third photoelectric element 11-3 outputs a fourth transmitted light reception signal. The control unit 50b controls the emission of ultraviolet light by the fourth photoelectric element 11-4 based on the second reflected light reception signal, the fourth emitted light reception signal, and the fourth transmitted light reception signal.

[0170] The fluid sterilization device 100b emits ultraviolet light one by one from each photoelectric element, starting from the first photoelectric element 11-1 in the first state, from the second photoelectric element 11-2 in the third state, from the third photoelectric element 11-3 in the second state, and from the fourth photoelectric element 11-4 in the fourth state. In each state, no ultraviolet light is emitted from any photoelectric elements other than the one emitting ultraviolet light. As a result, the fluid sterilization device 100b can reduce the rise in junction temperature of the first photoelectric element 11-1, the second photoelectric element 11-2, the third photoelectric element 11-3, and the fourth photoelectric element 11-4. As a result, the lifespan of the first photoelectric element 11-1, the second photoelectric element 11-2, the third photoelectric element 11-3, and the fourth photoelectric element 11-4 is extended, and the replacement cycle for the first photoelectric element 11-1, the second photoelectric element 11-2, the third photoelectric element 11-3, and the fourth photoelectric element 11-4 is extended. The extended replacement cycle for the first photoelectric element 11-1, the second photoelectric element 11-2, the third photoelectric element 11-3, and the fourth photoelectric element 11-4 improves the maintainability of the fluid sterilization device 100b in the third embodiment of this disclosure. Furthermore, by having the first photoelectric element 11-1, the second photoelectric element 11-2, the third photoelectric element 11-3, and the fourth photoelectric element 11-4 each function as photoelectric elements for transmitted light, the number of parts in the fluid sterilization device 100b can be reduced, simplifying the configuration and reducing costs in the third embodiment of this disclosure. The order in which the first, second, third, and fourth states are switched is arbitrary.

[0171] The fluid sterilization device 100b differs from the fluid sterilization device 100 according to the first embodiment of this disclosure in the points described above.

[0172] The fluid sterilization device 100b will be described in more detail below.

[0173] (1st light source 10-1b) In the examples shown in Figures 10 to 15, the first light source 10-1b includes a first photoelectric element 11-1, a first photoelectric element for emitted light 12-1, a third photoelectric element 11-3, and a third photoelectric element for emitted light 12-3. The first light source 10-1b also includes a first light-emitting unit 15-1 and a third light-emitting unit 15-3 arranged on a first substrate 14-1.

[0174] The third light-emitting unit 15-3 includes a third housing 151-3 and a third cover member 152-3. The third photoelectric element 11-3 and the third photoelectric element for emitting light 12-3 are housed in the third housing 151-3. The third housing 151-3 supports the third cover member 152-3. The third photoelectric element 11-3 and the third photoelectric element for emitting light 12-3 are hermetically sealed by the third housing 151-3 and the third cover member 152-3.

[0175] The third cover member 152-3 is positioned between the third photoelectric element 11-3 and the third photoelectric element 12-3 and the first light-transmitting member 40-1, facing the third photoelectric element 11-3 and the third photoelectric element 12-3 for emitting light. The third cover member 152-3 transmits a portion of the ultraviolet light emitted from the third photoelectric element 11-3. The third cover member 152-3 includes a third light intensity adjustment member 153-3. The third light intensity adjustment member 153-3 is positioned facing the third photoelectric element 12-3 for emitting light.

[0176] The configuration of the third housing 151-3 can be the same as that of the first housing 151-1. The configuration of the third lid member 152-3 can be the same as that of the first lid member 152-1.

[0177] The configuration of the third photoelectric element 11-3 can be the same as that of the first photoelectric element 11-1. The configuration of the third photoelectric element for emitted light 12-3 can be the same as that of the first photoelectric element for emitted light 12-1. Furthermore, the configuration of the third light-emitting unit 15-3 can be the same as that of the first light-emitting unit 15-1.

[0178] (First light-transmitting member 40-1) The first light-transmitting member 40-1 is positioned between the first photoelectric element 11-1, the third photoelectric element 11-3, the first light-emitting photoelectric element 12-1, and the third light-emitting photoelectric element 12-3 and the inside of the chamber 30.

[0179] (Second light source 10-2b) In the example shown in Figure 10, the second light source 10-2b includes a second photoelectric element 11-2, a second photoelectric element for emitted light 12-2, a fourth photoelectric element 11-4, and a fourth photoelectric element for emitted light 12-4. The second light source 10-2b also includes a second light-emitting unit 15-2 and a fourth light-emitting unit 15-4, which are positioned below the second substrate 14-2.

[0180] The second light-emitting unit 15-2 includes a second housing 151-2 and a second cover member 152-2. The second photoelectric element 11-2 and the second photoelectric element for emitting light 12-2 are housed in the second housing 151-2. The second housing 151-2 supports the second cover member 152-2. The second photoelectric element 11-2 and the second photoelectric element for emitting light 12-2 are hermetically sealed by the second housing 151-2 and the second cover member 152-2.

[0181] The fourth light-emitting unit 15-4 includes a fourth housing 151-4 and a fourth cover member 152-4. The fourth photoelectric element 11-4 and the fourth photoelectric element for emitting light 12-4 are housed in the fourth housing 151-4. The fourth housing 151-4 supports the fourth cover member 152-4. The fourth photoelectric element 11-4 and the fourth photoelectric element for emitting light 12-4 are hermetically sealed by the fourth housing 151-4 and the fourth cover member 152-4.

[0182] The second photoelectric element 11-2, the second photoelectric element for emitted light 12-2, the fourth photoelectric element 11-4, and the fourth photoelectric element for emitted light 12-4 are arranged to face the first photoelectric element 11-1, the first photoelectric element for emitted light 12-1, the third photoelectric element 11-3, and the third photoelectric element for emitted light 12-3.

[0183] The second light source 10-2b can be removed from the fluid sterilization device 100b, similar to the second light source 10-2. Removing the second light source 10-2b from the fluid sterilization device 100b makes it easier to remove dirt adhering to the second light-transmitting member 40-2, or to replace the second substrate 14-2 on which the second light-emitting unit 15-2 and the fourth light-emitting unit 15-4 are mounted.

[0184] The second cover member 152-2 is positioned between the second photoelectric element 11-2 and the second photoelectric element 12-2 for emitting light and the second light-transmitting member 40-2, facing the second photoelectric element 11-2 and the second photoelectric element 12-2 for emitting light. The second cover member 152-2 transmits a portion of the ultraviolet light emitted from the second photoelectric element 11-2. The second cover member 152-2 includes a second light intensity adjusting member 153-2. The second light intensity adjusting member 153-2 is positioned facing the second photoelectric element 12-2 for emitting light.

[0185] The fourth cover member 152-4 is positioned between the fourth photoelectric element 11-4 and the fourth photoelectric element 12-4 and the second light-transmitting member 40-2, facing the fourth photoelectric element 11-4 and the fourth photoelectric element 12-4 for emitting light. The fourth cover member 152-4 transmits a portion of the ultraviolet light emitted from the fourth photoelectric element 11-4. The fourth cover member 152-4 includes a fourth light intensity adjustment member 153-4. The fourth light intensity adjustment member 153-4 is positioned facing the fourth photoelectric element 12-4 for emitting light.

[0186] The configuration of the second housing 151-2 can be the same as that of the first housing 151-1. The configuration of the second lid member 152-2 can be the same as that of the first lid member 152-1.

[0187] The configuration of the second photoelectric element 11-2 can be the same as that of the first photoelectric element 11-1. The configuration of the second photoelectric element for emitted light 12-2 can be the same as that of the first photoelectric element for emitted light 12-1. In addition, the configuration of the second light-emitting unit 15-2 can be the same as that of the first light-emitting unit 15-1.

[0188] The configuration of the fourth housing 151-4 can be the same as that of the first housing 151-1. The configuration of the fourth lid member 152-4 can be the same as that of the first lid member 152-1.

[0189] The configuration of the fourth photoelectric element 11-4 can be the same as that of the first photoelectric element 11-1. The configuration of the fourth photoelectric element for emitted light 12-4 can be the same as that of the first photoelectric element for emitted light 12-1. Furthermore, the configuration of the fourth light-emitting unit 15-4 can be the same as that of the first light-emitting unit 15-1.

[0190] (Second light-transmitting member 40-2) The second light-transmitting member 40-2 is positioned between the second photoelectric element 11-2, the fourth photoelectric element 11-4, the second light-emitting photoelectric element 12-2, and the fourth light-emitting photoelectric element 12-4 and the inside of the chamber 30.

[0191] (Chamber 30) The fluid F located inside the chamber 30 is positioned between the first photoelectric element 11-1, the third photoelectric element 11-3, the first light-emitting photoelectric element 12-1 and the third light-emitting photoelectric element 12-3, and the second photoelectric element 11-2, the fourth photoelectric element 11-4, the second light-emitting photoelectric element 12-2 and the fourth light-emitting photoelectric element 12-4. The fluid F located inside the chamber 30 is irradiated with ultraviolet light emitted from the first photoelectric element 11-1, the third photoelectric element 11-3, the second photoelectric element 11-2 and the fourth photoelectric element 11-4.

[0192] (Control unit 50b) The control unit 50b is used to switch between the first, second, third, and fourth states one by one in sequence. In the example shown in Figure 9, the control unit 50b includes a forward-bias power supply 51A and a reverse-bias power supply 51B. Note that the third state is illustrated in the example shown in Figure 9.

[0193] The control unit 50b switches the drive current supplied from the forward bias power supply 51A to one of the first photoelectric element 11-1, the second photoelectric element 11-2, the third photoelectric element 11-3, or the fourth photoelectric element 11-4. This allows the control unit 50b to switch between the first, second, third, and fourth states one by one in sequence. The control unit 50b also applies a reverse bias to the first photoelectric element 11-1, the second photoelectric element 11-2, the third photoelectric element 11-3, and the fourth photoelectric element 11-4 from the reverse bias power supply 51B. This allows the control unit 50b to make the reverse-biased photoelectric elements function as photodetectors.

[0194] (First state) The first state is one in which the first photoelectric element 11-1 emits ultraviolet light, and the third photoelectric element 11-3, the first light-emitting photoelectric element 12-1, the third light-emitting photoelectric element 12-3, the second photoelectric element 11-2, the fourth photoelectric element 11-4, the second light-emitting photoelectric element 12-2, and the fourth light-emitting photoelectric element 12-4 do not emit ultraviolet light.

[0195] In the example shown in Figure 11, in the first state, the third photoelectric element 11-3 receives ultraviolet light emitted from the first photoelectric element 11-1 and reflected by the first light-transmitting member 40-1, and outputs a third reflected light reception signal. The first emitted light photoelectric element 12-1 receives a portion of the ultraviolet light emitted from the first photoelectric element 11-1 and outputs a first emitted light reception signal. The second photoelectric element 11-2 or the fourth photoelectric element 11-4 receives ultraviolet light emitted from the first photoelectric element 11-1 and transmitted through the first light-transmitting member 40-1, the fluid F, and the second light-transmitting member 40-2, and outputs a first transmitted light reception signal. Furthermore, at least one of the second photoelectric element 11-2 and the fourth photoelectric element 11-4 can receive ultraviolet light emitted from the first photoelectric element 11-1 and transmitted through the first light-transmitting member 40-1, the fluid F, and the second light-transmitting member 40-2, and output a first transmitted light reception signal. The control unit 50b controls the emission of ultraviolet light by the first photoelectric element 11-1 based on the third reflected light reception signal, the first emitted light reception signal, and the first transmitted light reception signal.

[0196] (Second state) The second state is one in which the third photoelectric element 11-3 emits ultraviolet light, and the first photoelectric element 11-1, the first photoelectric element for emitting light 12-1, the third photoelectric element for emitting light 12-3, the second photoelectric element 11-2, the fourth photoelectric element 11-4, the second photoelectric element for emitting light 12-2, and the fourth photoelectric element for emitting light 12-4 do not emit ultraviolet light.

[0197] In the example shown in Figure 12, in the second state, the first photoelectric element 11-1 receives ultraviolet light emitted from the third photoelectric element 11-3 and reflected by the first light-transmitting member 40-1, and outputs a first reflected light reception signal. The third photoelectric element for emitted light 12-3 receives a portion of the ultraviolet light emitted from the third photoelectric element 11-3 and outputs a third emitted light reception signal. The second photoelectric element 11-2 or the fourth photoelectric element 11-4 receives ultraviolet light emitted from the third photoelectric element 11-3 and transmitted through the first light-transmitting member 40-1, the fluid F, and the second light-transmitting member 40-2, and outputs a third transmitted light reception signal. Furthermore, at least one of the second photoelectric element 11-2 and the fourth photoelectric element 11-4 can receive ultraviolet light emitted from the third photoelectric element 11-3 and transmitted through the first light-transmitting member 40-1, the fluid F, and the second light-transmitting member 40-2, and output a third transmitted light reception signal. The control unit 50b controls the emission of ultraviolet light by the third photoelectric element 11-3 based on the first reflected light reception signal, the third emitted light reception signal, and the third transmitted light reception signal.

[0198] (Third state) The third state is one in which the second photoelectric element 11-2 emits ultraviolet light, and the first photoelectric element 11-1, the third photoelectric element 11-3, the first photoelectric element for emitting light 12-1, the third photoelectric element for emitting light 12-3, the fourth photoelectric element 11-4, the second photoelectric element for emitting light 12-2, and the fourth photoelectric element for emitting light 12-4 do not emit ultraviolet light.

[0199] In the example shown in Figure 13, in the third state, the fourth photoelectric element 11-4 receives ultraviolet light emitted from the second photoelectric element 11-2 and reflected by the second light-transmitting member 40-2, and outputs a fourth reflected light reception signal. The second photoelectric element for emitted light 12-2 receives a portion of the ultraviolet light emitted from the second photoelectric element 11-2 and outputs a second emitted light reception signal. The first photoelectric element 11-1 or the third photoelectric element 11-3 receives ultraviolet light emitted from the second photoelectric element 11-2 and transmitted through the second light-transmitting member 40-2, the fluid F, and the first light-transmitting member 40-1, and outputs a second transmitted light reception signal. Furthermore, at least one of the first photoelectric element 11-1 and the third photoelectric element 11-3 can receive ultraviolet light emitted from the second photoelectric element 11-2 and transmitted through the second light-transmitting member 40-2, the fluid F, and the first light-transmitting member 40-1, and output a second transmitted light reception signal. The control unit 50b controls the emission of ultraviolet light by the second photoelectric element 11-2 based on the fourth reflected light reception signal, the second emitted light reception signal, and the second transmitted light reception signal.

[0200] (Fourth state) The fourth state is one in which the fourth photoelectric element 11-4 emits ultraviolet light, and the first photoelectric element 11-1, the third photoelectric element 11-3, the first photoelectric element for emitting light 12-1, the third photoelectric element for emitting light 12-3, the second photoelectric element 11-2, the second photoelectric element for emitting light 12-2, and the fourth photoelectric element for emitting light 12-4 do not emit ultraviolet light.

[0201] In the example shown in Figure 14, in the fourth state, the second photoelectric element 11-2 receives ultraviolet light emitted from the fourth photoelectric element 11-4 and reflected by the second light-transmitting member 40-2, and outputs a second reflected light reception signal. The fourth photoelectric element for emitted light 12-4 receives a portion of the ultraviolet light emitted from the fourth photoelectric element 11-4 and outputs a fourth emitted light reception signal. The first photoelectric element 11-1 or the third photoelectric element 11-3 receives ultraviolet light emitted from the fourth photoelectric element 11-4 and transmitted through the second light-transmitting member 40-2, the fluid F, and the first light-transmitting member 40-1, and outputs a fourth transmitted light reception signal. Furthermore, at least one of the first photoelectric element 11-1 and the third photoelectric element 11-3 can receive ultraviolet light emitted from the fourth photoelectric element 11-4 and transmitted through the second light-transmitting member 40-2, the fluid F, and the first light-transmitting member 40-1, and output a fourth transmitted light reception signal. The control unit 50b controls the emission of ultraviolet light by the fourth photoelectric element 11-4 based on the second reflected light reception signal, the fourth emitted light reception signal, and the fourth transmitted light reception signal.

[0202] The first emitted light received signal includes information about the light output emitted by the first photoelectric element 11-1. The second emitted light received signal includes information about the light output emitted by the second photoelectric element 11-2. The third emitted light received signal includes information about the light output emitted by the third photoelectric element 11-3. The fourth emitted light received signal includes information about the light output emitted by the fourth photoelectric element 11-4. The first emitted light received signal, the second emitted light received signal, the third emitted light received signal, and the fourth emitted light received signal are not affected by the first light-transmitting member 40-1, dirt adhering to the first light-transmitting member 40-1, the second light-transmitting member 40-2, dirt adhering to the second light-transmitting member 40-2, or fluid F, etc.

[0203] The first reflected light received signal and the third reflected light received signal include the effects of light absorption or scattering, etc., due to at least one of the dirt adhering to the first lid member 152-1, the third lid member 152-3, the first light-transmitting member 40-1, and the first light-transmitting member 40-1. The second reflected light received signal and the fourth reflected light received signal include the effects of light absorption or scattering, etc., due to at least one of the dirt adhering to the second lid member 152-2, the fourth lid member 152-4, the second light-transmitting member 40-2, and the second light-transmitting member 40-2.

[0204] The first transmitted light received signal includes the effects of light absorption or scattering by at least one of the following: the first lid member 152-1, the first light-transmitting member 40-1, dirt adhering to the first light-transmitting member 40-1, fluid F, dirt adhering to the second light-transmitting member 40-2, the second light-transmitting member 40-2, the second lid member 152-2, and the fourth lid member 152-4. The second transmitted light received signal includes the effects of light absorption or scattering by the second lid member 152-2, the first light-transmitting member 40-1, dirt adhering to the first light-transmitting member 40-1, fluid F, dirt adhering to the second light-transmitting member 40-2, and at least one of the following: the second light-transmitting member 40-2, the first lid member 152-1, and the third lid member 152-3. The third transmitted light received signal includes the effects of light absorption or scattering by at least one of the third lid member 152-3, the first light-transmitting member 40-1, dirt adhering to the first light-transmitting member 40-1, fluid F, dirt adhering to the second light-transmitting member 40-2, the second light-transmitting member 40-2, the second lid member 152-2, and the fourth lid member 152-4. The fourth transmitted light received signal includes the effects of light absorption or scattering by the fourth lid member 152-4, the first light-transmitting member 40-1, dirt adhering to the first light-transmitting member 40-1, fluid F, dirt adhering to the second light-transmitting member 40-2, and at least one of the second light-transmitting member 40-2, the first lid member 152-1, and the third lid member 152-3.

[0205] In a third embodiment of this disclosure, the storage unit 52 can store at least the initial value of the first transmitted light receiving signal, the initial value of the second transmitted light receiving signal, the initial value of the third transmitted light receiving signal, and the initial value of the fourth transmitted light receiving signal. When the first light-transmitting member 40-1 and the second light-transmitting member 40-2 are free of dirt, the fluid sterilization device 100b supplies a drive current from the forward bias power supply 51A of the control unit 50 to the first photoelectric element 11-1 to provide a predetermined amount of ultraviolet irradiation to the fluid F. The fluid sterilization device 100b stores the magnitude of the first transmitted light receiving signal obtained at this time as the initial value of the first transmitted light receiving signal in the storage unit 52. Also in this state, the fluid sterilization device 100b supplies a drive current from the forward bias power supply 51A to the second photoelectric element 11-2 to provide a predetermined amount of ultraviolet irradiation to the fluid F, and stores the magnitude of the second transmitted light receiving signal obtained at this time as the initial value of the second transmitted light receiving signal in the storage unit 52. Furthermore, in this state, the fluid sterilization device 100b supplies a drive current from the forward bias power supply 51A to the third photoelectric element 11-3 to provide a predetermined amount of ultraviolet irradiation to the fluid F, and stores the magnitude of the third transmitted light received signal obtained at this time as the initial value of the third transmitted light received signal in the storage unit 52. Furthermore, in this state, the fluid sterilization device 100b supplies a drive current from the forward bias power supply 51A to the fourth photoelectric element 11-4 to provide a predetermined amount of ultraviolet irradiation to the fluid F, and stores the magnitude of the fourth transmitted light received signal obtained at this time as the initial value of the fourth transmitted light received signal in the storage unit 52.

[0206] In the first state, when the control unit 50b outputs a first error signal and a second error signal, the operation of the fluid sterilization device 100b is the same as the operation of the fluid sterilization device 100 in the first embodiment, except that the first reflected light receiving signal is replaced by a third reflected light receiving signal. In the second state, when the control unit 50b outputs a first error signal and a second error signal, the operation of the fluid sterilization device 100b is the same as the operation of the fluid sterilization device 100 in the first embodiment, except that the first emitted light receiving signal is replaced by a third emitted light receiving signal, and the first transmitted light receiving signal is replaced by a third transmitted light receiving signal. In the third state, when the control unit 50b outputs a first error signal and a second error signal, the operation of the fluid sterilization device 100b is the same as the operation of the fluid sterilization device 100 in the first embodiment, except that the first emitted light receiving signal is replaced by the second emitted light receiving signal, the first reflected light receiving signal is replaced by the fourth reflected light receiving signal, and the first transmitted light receiving signal is replaced by the second transmitted light receiving signal. In the fourth state, when the control unit 50b outputs a first error signal and a second error signal, the operation of the fluid sterilization device 100b is the same as the operation of the fluid sterilization device 100 in the first embodiment, except that the first emitted light receiving signal is replaced by the fourth emitted light receiving signal, the first reflected light receiving signal is replaced by the second reflected light receiving signal, and the first transmitted light receiving signal is replaced by the fourth transmitted light receiving signal.

[0207] <Effects and Effects of Fluid Sterilization Device 100b> Other effects of the fluid sterilization device 100b are the same as those of the fluid sterilization device 100 described in the first embodiment of this disclosure.

[0208] [Fourth Embodiment] Next, a fluid sterilization apparatus according to the fourth embodiment of this disclosure will be described.

[0209] Figure 16 is a block diagram showing the overall configuration of the fluid sterilization device 100c according to the fourth embodiment. Figure 17 is a schematic cross-sectional view showing the configuration around the chamber 30 of the fluid sterilization device 100c.

[0210] The fourth embodiment differs from the first embodiment in that the fluid sterilization device 100c further includes a flow meter 80, and the processor 53 further receives a flow signal from the flow meter 80 and controls the emission of ultraviolet light by the first photoelectric element 11-1.

[0211] If the fluid flow rate fluctuates, the fluid sterilization device 100c may further include a flow meter 80 to obtain a predetermined amount of ultraviolet light irradiation to the fluid to be sterilized, as shown in Figures 16 and 17. Furthermore, the fluid sterilization device 100c can receive a flow rate signal from the flow meter 80 and control the illuminance of the ultraviolet light irradiated from the first light source 10-1 using a control unit 50.

[0212] In the example shown in Figure 17, the flow meter 80 is located at the inlet 31 of the chamber 30. The flow meter 80 measures the flow rate of the fluid flowing into the chamber 30 and outputs a flow rate signal to the control unit 50. The processor 53 receives the first reflected light received signal, the first emitted light received signal, the first transmitted light received signal, and the flow rate signal from the flow meter 80, and controls the emission of ultraviolet light from the first photoelectric element 11-1. For example, the processor 53 can control the emission of ultraviolet light from the first photoelectric element 11-1 so that the illuminance of the ultraviolet light irradiated from the first light source 10-1 increases as the flow rate signal indicates a faster fluid velocity.

[0213] For example, an ultrasonic flow meter can be used as the flow meter 80. However, other types of flow meters, such as volumetric flow meters and differential pressure flow meters, may also be used as the flow meter 80. The flow meter 80 is not limited to being placed at the inlet 31, but may also be placed at the outlet 32, or at both the inlet 31 and the outlet 32. The number of flow meters 80 is not limited to one, but may be multiple.

[0214] As shown in Figure 17, the first substrate 14-1 may further include a temperature sensor 19-1 near the area to which the first light-emitting unit 15-1 is connected. In this case, when the control unit 50 controls the irradiation of ultraviolet light by the first photoelectric element 11-1, the processor 53 included in the control unit 50 receives a temperature signal from the temperature sensor. The processor 53 included in the control unit 50 can use this temperature signal to control the emission of ultraviolet light by the first photoelectric element 11-1.

[0215] The examples shown in Figures 16 and 17 illustrate an example in which the fourth embodiment is combined with the first embodiment. However, the fourth embodiment can also be combined with the second or third embodiment.

[0216] Although preferred embodiments have been described in detail above, the invention is not limited to the embodiments described above, and various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0217] The ordinal numbers, quantities, and other figures used in the description of the embodiments are all illustrative to specifically illustrate the technology of this disclosure, and this disclosure is not limited to the illustrative figures. Furthermore, the connection relationships between the components are illustrative to specifically illustrate the technology of this disclosure, and are not limited to the connection relationships that realize the functions of this disclosure.

[0218] The fluid sterilization apparatus of this disclosure can irradiate a fluid with a required amount of ultraviolet radiation, and is therefore suitably used in apparatuses for sterilizing water or air, etc. Furthermore, the light source and light source apparatus of this disclosure can irradiate a fluid with a required amount of ultraviolet radiation, and are therefore suitably used in exposure apparatuses that use ultraviolet light, printing apparatuses such as inkjet printers, sterilization apparatuses, bonding apparatuses, etc. Moreover, the light source and light source apparatus of this disclosure can irradiate a fluid with a required amount of ultraviolet radiation while reducing the influence of contamination of light-transmitting members such as glass plates, and are therefore particularly preferable for use in fluid sterilization apparatuses.

[0219] The aspects of this disclosure may include, for example, the following: <Item 1> A first photoelectric element, a first photoelectric element for emitted light, and a first photoelectric element for reflected light; a photoelectric element for transmitted light arranged to face the first photoelectric element, the first photoelectric element for emitted light, and the first photoelectric element for reflected light; a chamber arranged between the first photoelectric element, the first photoelectric element for emitted light, and the first photoelectric element for reflected light and the photoelectric element for transmitted light, having an interior through which a fluid irradiated with ultraviolet light emitted from the first photoelectric element can pass; and a first photoelectric element arranged between the first photoelectric element, the first photoelectric element for emitted light, and the first photoelectric element for reflected light and the interior of the chamber. The fluid sterilization device comprises a light-transmitting member, a control unit having a processor that controls the emission of ultraviolet light by the first photoelectric element, based on a first reflected light reception signal from a first reflected light photoelectric element that receives ultraviolet light emitted from the first photoelectric element and reflected by the first light-transmitting member, a first emitted light reception signal from a first emitted light photoelectric element that receives a portion of the ultraviolet light emitted from the first photoelectric element, and a first transmitted light reception signal from a first transmitted light photoelectric element that receives ultraviolet light emitted from the first photoelectric element and transmitted through the first light-transmitting member and the fluid. <Item 2> The fluid sterilization apparatus according to Item 1, wherein the first photoelectric element emits ultraviolet light in accordance with the supplied drive current, and the processor controls the amount of ultraviolet light irradiated from the first photoelectric element to the fluid to fall within a predetermined range by adjusting the drive current supplied to the first photoelectric element. <Item 3> The control unit has a storage unit that stores at least an initial value of a first transmitted light receiving signal and a predetermined transmitted light threshold, and the processor outputs a first error signal when the absolute value of the difference between the magnitude of the first transmitted light receiving signal and the magnitude of the initial value of the first transmitted light receiving signal exceeds the transmitted light threshold, the fluid sterilization apparatus according to Item 2. <Item 4> The fluid sterilization apparatus according to Item 3, wherein the memory unit further stores a predetermined current threshold for the drive current, and the processor outputs a second error signal relating to the degradation of the first photoelectric element when the absolute value of the difference between the magnitude of the first transmitted light receiving signal and the magnitude of the initial value of the first transmitted light receiving signal does not exceed the transmitted light threshold, and the magnitude of the drive current supplied to the first photoelectric element exceeds the current threshold. <Item 5> A fluid sterilization device according to any one of items 1 to 4, wherein the device has a first lid member positioned opposite the first photoelectric element and between the first photoelectric element and the first light-transmitting member, and which transmits a portion of the ultraviolet light emitted from the first photoelectric element, and the first light-emitting photoelectric element receives the ultraviolet light emitted from the first photoelectric element and reflected by the first lid member. <Clause 6> A fluid sterilization device according to any one of Clauses 1 to 4, wherein the device has a first cover member that is positioned opposite the first photoelectric element and between the first photoelectric element and the first light-transmitting member, and transmits a portion of the ultraviolet light emitted from the first photoelectric element, the first cover member includes a first light intensity adjusting member, and the first light intensity adjusting member is positioned opposite the first photoelectric element for emitting light. <Item 7> A fluid sterilization device according to item 5 or item 6, comprising a first housing that houses the first photoelectric element and the first photoelectric element for emitting light and supports the first lid member. <Clause 8> The fluid sterilization apparatus according to any one of Clauses 1 to 7, wherein the first photoelectric element and the first reflected light photoelectric element are each arranged facing the first light-transmitting member. <Item 9> One or more first photoelectric elements, a first photoelectric element for emitted light and a first photoelectric element for reflected light, one or more second photoelectric elements, a second photoelectric element for emitted light and a second photoelectric element for reflected light arranged to face the one or more first photoelectric elements, the first photoelectric element for emitted light and the first photoelectric element for reflected light, and a flow that is irradiated with ultraviolet light emitted from the one or more first photoelectric elements A chamber having an interior through which a body can pass; a first light-transmitting member disposed between the one or more first photoelectric elements, the first photoelectric element for emitted light, and the first photoelectric element for reflected light and the interior of the chamber; a second light-transmitting member disposed between the one or more second photoelectric elements, the second photoelectric element for emitted light, and the second photoelectric element for reflected light and the first photoelectric element for emitted light, the first photoelectric element for reflected light, the one or more second photoelectric elements, the second photoelectric element for emitted light, and the second photoelectric element for reflected light The control unit has a processor for alternately switching between a state I in which the photoelectric element does not emit ultraviolet light, and a state II in which the one or more second photoelectric elements emit ultraviolet light, and the one or more first photoelectric elements, the first photoelectric element for emitted light, the first photoelectric element for reflected light, the second photoelectric element for emitted light, and the second photoelectric element for reflected light do not emit ultraviolet light, wherein in state I, the first photoelectric element for reflected light receives ultraviolet light emitted from the one or more first photoelectric elements and reflected by the first light-transmitting member and outputs a first reflected light reception signal, and the 1. An outgoing photoelectric element receives a portion of the ultraviolet light emitted from the one or more first photoelectric elements and outputs a first outgoing light reception signal. The second reflected light photoelectric element receives the ultraviolet light emitted from the one or more first photoelectric elements that has passed through the first light-transmitting member, the fluid, and the second light-transmitting member and outputs a first transmitted light reception signal. The processor controls the emission of ultraviolet light by the one or more first photoelectric elements based on the first reflected light reception signal, the first outgoing light reception signal, and the first transmitted light reception signal. In state II, the second reflected light photoelectric element...This fluid sterilization device includes a system in which one or more second photoelectric elements emit ultraviolet light, which is reflected by the second light-transmitting member, is received and a second reflected light received signal is output; the second emitted light photoelectric element receives a portion of the ultraviolet light emitted from one or more second photoelectric elements and outputs a second emitted light received signal; the first reflected light photoelectric element receives ultraviolet light emitted from one or more second photoelectric elements that has passed through the second light-transmitting member, the fluid, and the first light-transmitting member and outputs a second transmitted light received signal; and the processor controls the emission of ultraviolet light by one or more second photoelectric elements based on the second reflected light received signal, the second emitted light received signal, and the second transmitted light received signal. <Clause 10> The fluid sterilization apparatus according to Clause 9, wherein the one or more first photoelectric elements are two or more first photoelectric elements, and the two or more first photoelectric elements are connected in parallel, and the one or more second photoelectric elements are two or more second photoelectric elements, and the two or more second photoelectric elements are connected in parallel. <Item 11> The fluid sterilization apparatus according to item 9 or item 10, wherein the one or more first photoelectric elements and the one or more second photoelectric elements emit ultraviolet light in accordance with the drive current supplied to the one or more first photoelectric elements and the one or more second photoelectric elements, and the processor controls the amount of ultraviolet light irradiated from the one or more first photoelectric elements or the one or more second photoelectric elements to the fluid to fall within a predetermined range by adjusting the drive current supplied to the one or more first photoelectric elements or the one or more second photoelectric elements. <Clause 12> The control unit has a storage unit that stores at least a first transmitted light receiving signal initial value, a second transmitted light receiving signal initial value, and a predetermined transmitted light threshold, and the processor outputs a first error signal when the absolute value of the difference between the magnitude of the first transmitted light receiving signal and the magnitude of the first transmitted light receiving signal initial value or the absolute value of the difference between the magnitude of the second transmitted light receiving signal and the magnitude of the second transmitted light receiving signal initial value exceeds the transmitted light threshold, the fluid sterilization apparatus according to Clause 11. <Clause 13> The fluid sterilization apparatus according to Clause 12, wherein the memory unit further stores a predetermined current threshold for the drive current, and the processor outputs a second error signal relating to the deterioration of the one or more first photoelectric elements or the one or more second photoelectric elements when the absolute value of the difference between the magnitude of the first transmitted light receiving signal and the magnitude of the initial value of the first transmitted light receiving signal does not exceed the transmitted light threshold and the magnitude of the drive current supplied to the one or more first photoelectric elements exceeds the current threshold, or when the absolute value of the difference between the magnitude of the second transmitted light receiving signal and the magnitude of the initial value of the second transmitted light receiving signal does not exceed the transmitted light threshold and the magnitude of the drive current supplied to the one or more second photoelectric elements exceeds the current threshold. <Clause 14> A fluid sterilization device according to any one of Clauses 9 to 13, comprising: a first lid member positioned opposite the one or more first photoelectric elements and the first photoelectric element for emitting light, between the one or more first photoelectric elements and the first photoelectric element for emitting light and the first light-transmitting member, and transmitting a portion of the ultraviolet light emitted from the one or more first photoelectric elements; and a second lid member positioned opposite the one or more second photoelectric elements and the second photoelectric element for emitting light, between the one or more second photoelectric elements and the second light-transmitting member, and transmitting a portion of the ultraviolet light emitted from the one or more second photoelectric elements, wherein the first lid member includes a first light intensity adjusting member, the first light intensity adjusting member is positioned opposite the first photoelectric element for emitting light, and the second lid member includes a second light intensity adjusting member, the second light intensity adjusting member is positioned opposite the second photoelectric element for emitting light. <Item 15> The fluid sterilization apparatus according to item 14, comprising: a first housing that houses the one or more first photoelectric elements and the first photoelectric element for emitting light and supports the first lid member; and a second housing that houses the one or more second photoelectric elements and the second photoelectric element for emitting light and supports the second lid member. <Item 16> A first photoelectric element, a third photoelectric element, a first photoelectric element for emitting light, and a third photoelectric element for emitting light; a second photoelectric element, a fourth photoelectric element, a second photoelectric element for emitting light, and a fourth photoelectric element for emitting light, arranged to face the first photoelectric element, the third photoelectric element, the first photoelectric element for emitting light, and the third photoelectric element for emitting light; and a device arranged between the first photoelectric element, the third photoelectric element, the first photoelectric element for emitting light, and the third photoelectric element for emitting light and the second photoelectric element, the fourth photoelectric element, the second photoelectric element for emitting light, and the fourth photoelectric element for emitting light, which emits purple light from the first photoelectric element. A chamber having an interior through which a fluid irradiated with ambient light can pass; a first light-transmitting member disposed between the first photoelectric element, the third photoelectric element, the first light-emitting photoelectric element, and the third light-emitting photoelectric element and the interior of the chamber; a second light-transmitting member disposed between the second photoelectric element, the fourth photoelectric element, the second light-emitting photoelectric element, and the fourth light-emitting photoelectric element and the interior of the chamber; the first photoelectric element emits ultraviolet light, and the third photoelectric element, the first light-emitting photoelectric element, the third light-emitting photoelectric element, the second photoelectric element, the fourth photoelectric element, the A first state in which the second light-emitting photoelectric element and the fourth light-emitting photoelectric element do not emit ultraviolet light, a second state in which the third photoelectric element emits ultraviolet light and the first photoelectric element, the first light-emitting photoelectric element, the third light-emitting photoelectric element, the second photoelectric element, the fourth photoelectric element, the second light-emitting photoelectric element and the fourth light-emitting photoelectric element do not emit ultraviolet light, and the second photoelectric element emits ultraviolet light and the first photoelectric element, the third photoelectric element, the first light-emitting photoelectric element, the third light-emitting photoelectric element, the fourth photoelectric element, the second light-emitting photoelectric element and The device includes a control unit having a processor for sequentially switching between a third state in which the fourth photoelectric element for emitting light does not emit ultraviolet light, and a fourth state in which the fourth photoelectric element emits ultraviolet light, and the first photoelectric element, the third photoelectric element, the first photoelectric element for emitting light, the third photoelectric element for emitting light, the second photoelectric element, the second photoelectric element for emitting light, and the fourth photoelectric element for emitting light does not emit ultraviolet light, and in the first state, the third photoelectric element receives ultraviolet light emitted from the first photoelectric element and reflected by the first light-transmitting member,The third reflected light receiving signal is output, the first emitted light photoelectric element receives a portion of the ultraviolet light emitted from the first photoelectric element and outputs a first emitted light receiving signal, the second or fourth photoelectric element receives the ultraviolet light emitted from the first photoelectric element that has passed through the first light-transmitting member, the fluid and the second light-transmitting member and outputs a first transmitted light receiving signal, the processor controls the emission of ultraviolet light by the first photoelectric element based on the third reflected light receiving signal, the first emitted light receiving signal and the first transmitted light receiving signal, and in the second state, the first photoelectric element, The third photoelectric element receives ultraviolet light emitted from the third photoelectric element and reflected by the first light-transmitting member, and outputs a first reflected light reception signal. The third photoelectric element receives a portion of the ultraviolet light emitted from the third photoelectric element and outputs a third emitted light reception signal. The second or fourth photoelectric element receives ultraviolet light emitted from the third photoelectric element and transmitted through the first light-transmitting member, the fluid, and the second light-transmitting member, and outputs a third transmitted light reception signal. Based on the first reflected light reception signal, the third emitted light reception signal, and the third transmitted light reception signal, the processor... The emission of ultraviolet light is controlled by the following: In the third state, the fourth photoelectric element receives ultraviolet light emitted from the second photoelectric element and reflected by the second light-transmitting member, and outputs a fourth reflected light reception signal; the second light-emitting photoelectric element receives a portion of the ultraviolet light emitted from the second photoelectric element, and outputs a second light-emitting light reception signal; the first photoelectric element or the third photoelectric element receives ultraviolet light emitted from the second photoelectric element and transmitted through the second light-transmitting member, the fluid, and the first light-transmitting member, and outputs a second transmitted light reception signal; and the processor receives the fourth reflected light reception signal, and the previous Based on the second emitted light receiving signal and the second transmitted light receiving signal, the emission of ultraviolet light by the second photoelectric element is controlled, and in the fourth state, the second photoelectric element receives ultraviolet light emitted from the fourth photoelectric element and reflected by the second light-transmitting member, and outputs a second reflected light receiving signal, the fourth emitted light photoelectric element receives a portion of the ultraviolet light emitted from the fourth photoelectric element, and outputs a fourth emitted light receiving signal, and the first photoelectric element or the third photoelectric element receives ultraviolet light emitted from the fourth photoelectric element and transmitted through the second light-transmitting member, the fluid, and the first light-transmitting member,This fluid sterilization device outputs a fourth transmitted light receiving signal, and the processor controls the emission of ultraviolet light from the fourth photoelectric element based on the second reflected light receiving signal, the fourth emitted light receiving signal, and the fourth transmitted light receiving signal. <Clause 17> The fluid sterilization apparatus according to Clause 16, wherein the first photoelectric element, the second photoelectric element, the third photoelectric element and the fourth photoelectric element emit ultraviolet light in accordance with the drive current supplied to the first photoelectric element, the second photoelectric element, the third photoelectric element and the fourth photoelectric element, and the processor controls the amount of ultraviolet light irradiated from the first photoelectric element, the second photoelectric element, the third photoelectric element or the fourth photoelectric element to the fluid to fall within a predetermined range by adjusting the drive current supplied to the first photoelectric element, the second photoelectric element, the third photoelectric element or the fourth photoelectric element. <Clause 18> The control unit has a storage unit that stores at least a first transmitted light receiving signal initial value, a third transmitted light receiving signal initial value, a second transmitted light receiving signal initial value, a fourth transmitted light receiving signal initial value, and a predetermined transmitted light threshold, and the processor outputs a first error signal when the absolute value of the difference between the magnitude of the first transmitted light receiving signal and the magnitude of the first transmitted light receiving signal initial value, the absolute value of the difference between the magnitude of the third transmitted light receiving signal and the magnitude of the third transmitted light receiving signal initial value, the absolute value of the difference between the magnitude of the second transmitted light receiving signal and the magnitude of the second transmitted light receiving signal initial value, or the absolute value of the difference between the magnitude of the fourth transmitted light receiving signal and the magnitude of the fourth transmitted light receiving signal initial value exceeds the transmitted light threshold, thus the fluid sterilization apparatus described in Clause 17. <Item 19> The memory unit further stores a predetermined current threshold for the drive current, and the processor, if the absolute value of the difference between the magnitude of the first transmitted light received signal and the magnitude of the initial value of the first transmitted light received signal does not exceed the transmitted light threshold, and the drive current supplied to the first photoelectric element exceeds the current threshold, then the processor, if the absolute value of the difference between the magnitude of the third transmitted light received signal and the magnitude of the initial value of the third transmitted light received signal does not exceed the transmitted light threshold, and the drive current supplied to the third photoelectric element exceeds the current threshold, then the magnitude of the second transmitted light received signal and the The fluid sterilization apparatus according to paragraph 18 outputs a second error signal relating to the deterioration of the first photoelectric element, the second photoelectric element, the third photoelectric element, or the fourth photoelectric element when the absolute value of the difference between the magnitude of the transmitted light received signal and the initial value of the fourth transmitted light received signal does not exceed the transmitted light threshold and the drive current supplied to the second photoelectric element exceeds the current threshold, or when the absolute value of the difference between the magnitude of the fourth transmitted light received signal and the initial value of the fourth transmitted light received signal does not exceed the transmitted light threshold and the drive current supplied to the fourth photoelectric element exceeds the current threshold. <Item 20> A first cover member is positioned opposite the first photoelectric element and between the first photoelectric element and the first light-transmitting member, and transmits a portion of the ultraviolet light emitted from the first photoelectric element; a second cover member is positioned opposite the second photoelectric element and between the second photoelectric element and the second light-transmitting member, and transmits a portion of the ultraviolet light emitted from the second photoelectric element; a third cover member is positioned opposite the third photoelectric element and between the third photoelectric element and the first light-transmitting member, and transmits a portion of the ultraviolet light emitted from the third photoelectric element; and a fourth cover member is positioned opposite the fourth photoelectric element and between the fourth photoelectric element and the second light-transmitting member, and the fourth The fluid sterilization apparatus according to item 16, further comprising a fourth lid member that transmits a portion of the ultraviolet light emitted from a photoelectric element, wherein the first lid member includes a first light intensity adjusting member, the first light intensity adjusting member is positioned opposite the first light-emitting photoelectric element, the second lid member includes a second light intensity adjusting member, the second light intensity adjusting member is positioned opposite the second light-emitting photoelectric element, the third lid member includes a third light intensity adjusting member, the third light intensity adjusting member is positioned opposite the third light-emitting photoelectric element, and the fourth lid member includes a fourth light intensity adjusting member, the fourth light intensity adjusting member is positioned opposite the fourth light-emitting photoelectric element. <Clause 21> A fluid sterilization apparatus according to any one of Clauses 1 to 20, further comprising a flow meter, wherein the processor further receives a flow signal from the flow meter and controls the emission of ultraviolet light by the first photoelectric element. <Section 22> A fluid sterilization method using a fluid sterilization device, wherein the fluid sterilization device irradiates a fluid located inside a chamber positioned between a first photoelectric element and a transmissive light photoelectric element positioned opposite the first photoelectric element with ultraviolet light emitted by the first photoelectric element; a first reflected light photoelectric element receives ultraviolet light reflected by a first light-transmitting member positioned between the fluid and the first photoelectric element and outputs a first reflected light reception signal; a first emitted light photoelectric element receives a portion of the ultraviolet light emitted from the first photoelectric element and outputs a first emitted light reception signal; a transmissive light photoelectric element receives ultraviolet light emitted from the first photoelectric element that has passed through the first light-transmitting member and the fluid and outputs a first transmitted light reception signal; and a control unit that receives the first reflected light reception signal, the first emitted light reception signal, and the first transmitted light reception signal controls the emission of ultraviolet light from the first photoelectric element. <Item 23> A light source comprising: a first light-emitting element; a first light-receiving element for emitted light that receives a portion of the light from the first light-emitting element; a first light-transmitting member that reflects a portion of the light from the first light-emitting element; and a first light-receiving element for reflected light that receives a portion of the light reflected by the first light-transmitting member. <Clause 24> The light source according to Clause 23, comprising a housing that houses the first light-emitting element and the first light-receiving element for emitted light, and a lid member joined to the housing that reflects a portion of the light from the first light-emitting element and transmits a portion of it, wherein the lid member has a light intensity adjusting member that covers the first light-receiving element for emitted light. <Item 25> A light source device comprising: a first photoelectric element, a first photoelectric element for emitted light, and a first photoelectric element for reflected light; a first light-transmitting member disposed opposite to the first photoelectric element, the first photoelectric element for emitted light, and the first photoelectric element for reflected light; and a control unit that receives a first reflected light reception signal from the first photoelectric element which has received light emitted from the first photoelectric element and reflected by the first light-transmitting member, and a first emitted light reception signal from the first photoelectric element which has received a portion of the light emitted from the first photoelectric element, and controls the emission of light by the first photoelectric element. <Clause 26> The light source device according to Clause 25, further comprising a photoelectric element for transmitted light that receives light emitted from the first photoelectric element and transmitted through the first light-transmitting member and outputs a first transmitted light reception signal, wherein the control unit controls the emission of light from the first photoelectric element based on the first reflected light reception signal, the first emitted light reception signal, and the first transmitted light reception signal. <Clause 27> A method of irradiating light using a light source device, wherein the light source device comprises a first photoelectric element, a first photoelectric element for emitting light, and a first photoelectric element for refracting light; a first light-transmitting member positioned opposite the first photoelectric element, the first photoelectric element for emitting light, and the first photoelectric element for refracting light; a photoelectric element for transmitting light that receives light emitted from the first photoelectric element and transmitted through the first light-transmitting member and outputs a first light-transmitting signal; and a control unit, wherein the control unit receives a first light-refracting signal from the first photoelectric element that receives light emitted from the first photoelectric element and reflected by the first light-transmitting member, a first light-emitting signal from the first photoelectric element that receives a portion of the light emitted from the first photoelectric element, and the first light-transmitting signal, and controls the emission of light by the first photoelectric element. [Explanation of Symbols]

[0220] 10-1, 10-1a, 10-1b, 10-1b 1st light source 10-2, 10-2b 2nd light source 11-1, 11-1A, 11-1B First Photoelectric Element 11-2, 11-2A, 11-2B Second Photoelectric Element 11-3 Third Photoelectric Element 11-4 Fourth Photoelectric Element 12-1 Photoelectric element for first emitted light 12-2 Photoelectric element for second emitted light 12-3 Photoelectric element for third emitted light 12-4 Photoelectric element for fourth emitted light 13-1 First reflected light photoelectric element 13-2 Second reflected light photoelectric element 14-1 First circuit board 14-2 Second board 15-1, 15-1A First light-emitting unit 15-2, 15-2A Second light-emitting unit 15-3 Third Light-Emitting Unit 15-4 Fourth Light-Emitting Unit 16-1 Frame 1 16-2 Second Frame 17-1 First sealing member 17-2 Second sealing member 18-1 First fixing member 18-2 Second fixing member 19-1 Temperature sensor 20 Light receiving sensor unit 21 Photoelectric element for transmitted light 22 Transmitted light substrate 30 Chambers 31 Inlet 32 Outlet 40-1 First light-transmitting member 40-2 Second light-transmitting member 50, 50a, 50b control units 51 Power supply 51A forward bias power supply 51B Reverse Bias Power Supply 52 Storage section 53 processors 60 User Interface Units 61 displays 62 Indicator Lamps 63 Buzzer 70 Translucent material for transmitted light 80 flow meter 100, 100a, 100b, 100c fluid sterilizer 131-1 Housing for first reflected light 131-2 Housing for second reflected light 132-1 First reflective light cover member 132-2 Second Reflected Light Cover Member 151-1, 151-1A First enclosure 151-2, 151-2A Second enclosure 151-3 Third cabinet 151-4 Cabinet No. 4 152-1, 152-1A First lid member 152-2, 152-2A 2nd lid member 152-3 Third lid member 152-4 Fourth lid member 153-1, 153-1A First light intensity adjustment member 153-2, 153-2A 2nd light amount adjustment member 153-3 Third light intensity adjustment member 153-4 Fourth light intensity adjustment member 211 Light-transmitting housing 212 Cover member for transmitted light 213 Frame for transmitted light 214 Sealing member for transmitted light 215 Light-transmitting fixing member F fluid Fi, Fo arrow

Claims

1. A first photoelectric element, a first photoelectric element for emitted light, and a first photoelectric element for reflected light, A photoelectric element for transmitted light is arranged to face the first photoelectric element, the first photoelectric element for emitted light, and the first photoelectric element for reflected light, A chamber is positioned between the first photoelectric element, the first photoelectric element for emitted light, and the first photoelectric element for reflected light, and has an interior through which a fluid irradiated with ultraviolet light emitted from the first photoelectric element can pass; A first light-transmitting member is disposed between the first photoelectric element, the first photoelectric element for emitted light, and the first photoelectric element for reflected light and the interior of the chamber, A first reflected light reception signal from the first reflected light photoelectric element that receives ultraviolet light emitted from the first photoelectric element and reflected by the first light-transmitting member, A first emitted light received signal from the first emitted light photoelectric element, which receives a portion of the ultraviolet light emitted from the first photoelectric element, and A fluid sterilization device comprising: a control unit having a processor that receives a first transmitted light reception signal from a transmitted light photoelectric element that receives ultraviolet light emitted from the first photoelectric element and transmitted through the first light-transmitting member and the fluid, and controls the emission of ultraviolet light by the first photoelectric element.

2. The first photoelectric element emits ultraviolet light in accordance with the supplied drive current, The aforementioned processor, The fluid sterilization apparatus according to claim 1, wherein the amount of ultraviolet irradiation from the first photoelectric element to the fluid is controlled to fall within a predetermined range by adjusting the drive current supplied to the first photoelectric element.

3. The control unit is It has a storage unit that stores at least the initial value of the first transmitted light received signal and a predetermined transmitted light threshold, The fluid sterilization apparatus according to claim 2, wherein the processor outputs a first error signal when the absolute value of the difference between the magnitude of the first transmitted light receiving signal and the magnitude of the initial value of the first transmitted light receiving signal exceeds the transmitted light threshold.

4. The memory unit further stores a predetermined current threshold value relating to the drive current, The fluid sterilization apparatus according to claim 3, wherein the processor outputs a second error signal relating to the degradation of the first photoelectric element when the absolute value of the difference between the magnitude of the first transmitted light received signal and the magnitude of the initial value of the first transmitted light received signal does not exceed the transmitted light threshold, and the magnitude of the drive current supplied to the first photoelectric element exceeds the current threshold.

5. The first photoelectric element is positioned opposite the first photoelectric element and between the first photoelectric element and the first light-transmitting member, and has a first cover member that transmits a portion of the ultraviolet light emitted from the first photoelectric element. The fluid sterilization apparatus according to claim 1, wherein the first photoelectric element for emitting light receives ultraviolet light emitted from the first photoelectric element and reflected by the first lid member.

6. The first photoelectric element is positioned opposite the first photoelectric element and between the first photoelectric element and the first light-transmitting member, and has a first cover member that transmits a portion of the ultraviolet light emitted from the first photoelectric element. The fluid sterilization apparatus according to claim 1, wherein the first lid member includes a first light intensity adjusting member, and the first light intensity adjusting member is positioned opposite the first photoelectric element for emitting light.

7. The fluid sterilization apparatus according to claim 5 or claim 6, comprising a first housing that houses the first photoelectric element and the first photoelectric element for emitting light and supports the first lid member.

8. The fluid sterilization apparatus according to claim 1, wherein the first photoelectric element and the first photoelectric element for reflected light are each arranged facing the first light-transmitting member.

9. One or more first photoelectric elements, a first photoelectric element for emitted light, and a first photoelectric element for reflected light, The one or more first photoelectric elements, the first photoelectric element for emitted light, and the first photoelectric element for reflected light are arranged opposite to the one or more first photoelectric elements, the first photoelectric element for emitted light, and the first photoelectric element for reflected light, A chamber is disposed between the one or more first photoelectric elements, the first photoelectric element for emitted light, and the first photoelectric element for reflected light, and the one or more second photoelectric elements, the second photoelectric element for emitted light, and the second photoelectric element for reflected light, and has an interior through which a fluid irradiated with ultraviolet light emitted from the one or more first photoelectric elements can pass. The first light-transmitting member is disposed between the one or more first photoelectric elements, the first photoelectric element for emitted light, and the first photoelectric element for reflected light and the interior of the chamber, The one or more second photoelectric elements, the second photoelectric element for emitted light, and the second photoelectric element for reflected light, and the second light-transmitting member disposed between the inside of the chamber, The system includes a control unit having a processor for alternately switching between a state I in which the one or more first photoelectric elements emit ultraviolet light and the first photoelectric element for emitted light, the first photoelectric element for reflected light, the one or more second photoelectric elements, the second photoelectric element for emitted light, and the second photoelectric element for reflected light do not emit ultraviolet light, and a state II in which the one or more second photoelectric elements emit ultraviolet light and the one or more first photoelectric elements, the first photoelectric element for emitted light, the first photoelectric element for reflected light, the second photoelectric element for emitted light, and the second photoelectric element for reflected light do not emit ultraviolet light. In state I, The first reflected light photoelectric element receives ultraviolet light emitted from the one or more first photoelectric elements and reflected by the first light-transmitting member, and outputs a first reflected light reception signal. The first photoelectric element for emitting light receives a portion of the ultraviolet light emitted from the one or more first photoelectric elements and outputs a first emitting light reception signal. The second reflected light photoelectric element receives ultraviolet light emitted from the one or more first photoelectric elements and transmitted through the first light-transmitting member, the fluid, and the second light-transmitting member, and outputs a first transmitted light reception signal. The processor controls the emission of ultraviolet light from the one or more first photoelectric elements based on the first reflected light receiving signal, the first emitted light receiving signal, and the first transmitted light receiving signal. In state II, The second reflected light photoelectric element receives ultraviolet light emitted from the one or more second photoelectric elements and reflected by the second light-transmitting member, and outputs a second reflected light reception signal. The second photoelectric element for emitted light receives a portion of the ultraviolet light emitted from the one or more second photoelectric elements and outputs a second emitted light reception signal. The first reflected light photoelectric element receives ultraviolet light emitted from the one or more second photoelectric elements and transmitted through the second light-transmitting member, the fluid, and the first light-transmitting member, and outputs a second transmitted light reception signal. A fluid sterilization device in which the processor controls the emission of ultraviolet light from one or more second photoelectric elements based on the second reflected light receiving signal, the second emitted light receiving signal, and the second transmitted light receiving signal.

10. The one or more first photoelectric elements are two or more first photoelectric elements. Two or more of the first photoelectric elements are connected in parallel, The aforementioned one or more second photoelectric elements are two or more of the aforementioned second photoelectric elements. The fluid sterilization apparatus according to claim 9, wherein two or more of the second photoelectric elements are connected in parallel.

11. The one or more first photoelectric elements and the one or more second photoelectric elements emit ultraviolet light in accordance with the drive current supplied to the one or more first photoelectric elements and the one or more second photoelectric elements. The aforementioned processor, The fluid sterilization apparatus according to claim 9, wherein the amount of ultraviolet irradiation from the one or more first photoelectric elements or the one or more second photoelectric elements to the fluid is controlled to fall within a predetermined range by adjusting the drive current supplied to the one or more first photoelectric elements or the one or more second photoelectric elements.

12. The control unit is It has a storage unit that stores at least the initial value of the first transmitted light received signal, the initial value of the second transmitted light received signal, and a predetermined transmitted light threshold, The fluid sterilization apparatus according to claim 11, wherein the processor outputs a first error signal when the absolute value of the difference between the magnitude of the first transmitted light receiving signal and the magnitude of the initial value of the first transmitted light receiving signal, or the absolute value of the difference between the magnitude of the second transmitted light receiving signal and the magnitude of the initial value of the second transmitted light receiving signal, exceeds the transmitted light threshold.

13. The memory unit further stores a predetermined current threshold value relating to the drive current, The aforementioned processor, The fluid sterilization apparatus according to claim 12, wherein a second error signal relating to the deterioration of one or more first photoelectric elements or one or more second photoelectric elements is output when the absolute value of the difference between the magnitude of the first transmitted light received signal and the magnitude of the initial value of the first transmitted light received signal does not exceed the transmitted light threshold, and the magnitude of the drive current supplied to the one or more first photoelectric elements exceeds the current threshold, or when the absolute value of the difference between the magnitude of the second transmitted light received signal and the magnitude of the initial value of the second transmitted light received signal does not exceed the transmitted light threshold, and the magnitude of the drive current supplied to the one or more second photoelectric elements exceeds the current threshold.

14. A first cover member is positioned opposite the one or more first photoelectric elements and the first light-emitting photoelectric element, between the one or more first photoelectric elements and the first light-emitting photoelectric element and the first light-transmitting member, and transmits a portion of the ultraviolet light emitted from the one or more first photoelectric elements. The device comprises one or more second photoelectric elements and a second photoelectric element for emitting light, and positioned between the one or more second photoelectric elements and the second photoelectric element for emitting light and the second light-transmitting member, and having a second cover member that transmits a portion of the ultraviolet light emitted from the one or more second photoelectric elements. The first cover member includes the first light intensity adjusting member, The first light intensity adjusting member is positioned opposite the first photoelectric element for emitted light, The second cover member includes a second light intensity adjusting member, The fluid sterilization apparatus according to claim 9, wherein the second light intensity adjusting member is arranged opposite to the second photoelectric element for emitting light.

15. A first housing that houses the one or more first photoelectric elements and the first photoelectric element for emitting light and supports the first lid member, The fluid sterilization apparatus according to claim 14, comprising: one or more second photoelectric elements and a second housing that houses the second photoelectric element for emitting light and supports the second lid member.

16. A first photoelectric element, a third photoelectric element, a first photoelectric element for emitted light, and a third photoelectric element for emitted light, The first photoelectric element, the third photoelectric element, the first photoelectric element for emitting light, and the third photoelectric element for emitting light are arranged opposite each other, and the second photoelectric element, the fourth photoelectric element, the second photoelectric element for emitting light, and the fourth photoelectric element for emitting light are arranged opposite each other. A chamber is positioned between the first photoelectric element, the third photoelectric element, the first photoelectric element for emitting light, and the third photoelectric element for emitting light, and the second photoelectric element, the fourth photoelectric element, the second photoelectric element for emitting light, and the fourth photoelectric element for emitting light, and has an interior through which a fluid irradiated with ultraviolet light emitted from the first photoelectric element can pass. A first light-transmitting member disposed between the first photoelectric element, the third photoelectric element, the first photoelectric element for emitting light, and the third photoelectric element for emitting light and the interior of the chamber, The second photoelectric element, the fourth photoelectric element, the second photoelectric element for emitting light, and the second light-transmitting member disposed between the fourth photoelectric element for emitting light and the interior of the chamber, A first state in which the first photoelectric element emits ultraviolet light, and the third photoelectric element, the first photoelectric element for emitting light, the third photoelectric element for emitting light, the second photoelectric element, the fourth photoelectric element, the second photoelectric element for emitting light, and the fourth photoelectric element for emitting light each do not emit ultraviolet light, A second state in which the third photoelectric element emits ultraviolet light, and the first photoelectric element, the first photoelectric element for emitting light, the third photoelectric element for emitting light, the second photoelectric element, the fourth photoelectric element, the second photoelectric element for emitting light, and the fourth photoelectric element for emitting light each do not emit ultraviolet light. A third state in which the second photoelectric element emits ultraviolet light, and the first photoelectric element, the third photoelectric element, the first photoelectric element for emitting light, the third photoelectric element for emitting light, the fourth photoelectric element, the second photoelectric element for emitting light, and the fourth photoelectric element for emitting light each do not emit ultraviolet light. The system includes a control unit having a processor for sequentially switching between a fourth state in which the fourth photoelectric element emits ultraviolet light, and the first photoelectric element, the third photoelectric element, the first photoelectric element for emitting light, the third photoelectric element for emitting light, the second photoelectric element, the second photoelectric element for emitting light, and the fourth photoelectric element for emitting light, one by one. In the first state, The third photoelectric element receives ultraviolet light emitted from the first photoelectric element and reflected by the first light-transmitting member, and outputs a third reflected light reception signal. The first photoelectric element for emitting light receives a portion of the ultraviolet light emitted from the first photoelectric element and outputs a first light emission reception signal. The second photoelectric element or the fourth photoelectric element receives ultraviolet light emitted from the first photoelectric element and transmitted through the first light-transmitting member, the fluid, and the second light-transmitting member, and outputs a first transmitted light reception signal. The processor controls the emission of ultraviolet light from the first photoelectric element based on the third reflected light receiving signal, the first emitted light receiving signal, and the first transmitted light receiving signal. In the second state described above, The first photoelectric element receives ultraviolet light emitted from the third photoelectric element and reflected by the first light-transmitting member, and outputs a first reflected light reception signal. The third photoelectric element for emitting light receives a portion of the ultraviolet light emitted from the third photoelectric element and outputs a third light emission reception signal. The second photoelectric element or the fourth photoelectric element receives ultraviolet light emitted from the third photoelectric element and transmitted through the first light-transmitting member, the fluid, and the second light-transmitting member, and outputs a third transmitted light reception signal. The processor controls the emission of ultraviolet light by the third photoelectric element based on the first reflected light receiving signal, the third emitted light receiving signal, and the third transmitted light receiving signal. In state 3 above, The fourth photoelectric element receives ultraviolet light emitted from the second photoelectric element and reflected by the second light-transmitting member, and outputs a fourth reflected light reception signal. The second photoelectric element for emitted light receives a portion of the ultraviolet light emitted from the second photoelectric element and outputs a second emitted light reception signal. The first photoelectric element or the third photoelectric element receives ultraviolet light emitted from the second photoelectric element and transmitted through the second light-transmitting member, the fluid, and the first light-transmitting member, and outputs a second transmitted light reception signal. The processor controls the emission of ultraviolet light by the second photoelectric element based on the fourth reflected light receiving signal, the second emitted light receiving signal, and the second transmitted light receiving signal. In the fourth state, The second photoelectric element receives ultraviolet light emitted from the fourth photoelectric element and reflected by the second light-transmitting member, and outputs a second reflected light reception signal. The fourth photoelectric element for emitting light receives a portion of the ultraviolet light emitted from the fourth photoelectric element and outputs a fourth light emission reception signal. The first photoelectric element or the third photoelectric element receives ultraviolet light emitted from the fourth photoelectric element and transmitted through the second light-transmitting member, the fluid, and the first light-transmitting member, and outputs a fourth transmitted light reception signal. A fluid sterilization device in which the processor controls the emission of ultraviolet light by the fourth photoelectric element based on the second reflected light receiving signal, the fourth emitted light receiving signal, and the fourth transmitted light receiving signal.

17. The first photoelectric element, the second photoelectric element, the third photoelectric element, and the fourth photoelectric element emit ultraviolet light in accordance with the drive current supplied to the first photoelectric element, the second photoelectric element, the third photoelectric element, and the fourth photoelectric element. The aforementioned processor, The fluid sterilization apparatus according to claim 16, wherein the amount of ultraviolet irradiation from the first photoelectric element, the second photoelectric element, the third photoelectric element, or the fourth photoelectric element to the fluid is controlled to fall within a predetermined range by adjusting the drive current supplied to the first photoelectric element, the second photoelectric element, the third photoelectric element, or the fourth photoelectric element.

18. The control unit is It has a storage unit that stores at least the initial value of the first transmitted light received signal, the initial value of the third transmitted light received signal, the initial value of the second transmitted light received signal, the initial value of the fourth transmitted light received signal, and a predetermined transmitted light threshold. The fluid sterilization apparatus according to claim 17, wherein the processor outputs a first error signal when the absolute value of the difference between the magnitude of the first transmitted light receiving signal and the magnitude of the initial value of the first transmitted light receiving signal, the absolute value of the difference between the magnitude of the third transmitted light receiving signal and the magnitude of the initial value of the third transmitted light receiving signal, the absolute value of the difference between the magnitude of the second transmitted light receiving signal and the magnitude of the initial value of the second transmitted light receiving signal, or the absolute value of the difference between the magnitude of the fourth transmitted light receiving signal and the magnitude of the initial value of the fourth transmitted light receiving signal exceeds the transmitted light threshold.

19. The memory unit further stores a predetermined current threshold value relating to the drive current, The aforementioned processor, The fluid sterilization apparatus according to claim 18, which outputs a second error signal relating to the deterioration of the first photoelectric element, the second photoelectric element, the third photoelectric element, or the fourth photoelectric element if the absolute value of the difference between the magnitude of the first transmitted light received signal and the magnitude of the initial value of the first transmitted light received signal does not exceed the transmitted light threshold and the drive current supplied to the first photoelectric element exceeds the current threshold; if the absolute value of the difference between the magnitude of the third transmitted light received signal and the magnitude of the initial value of the third transmitted light received signal does not exceed the transmitted light threshold and the drive current supplied to the third photoelectric element exceeds the current threshold; or if the absolute value of the difference between the magnitude of the second transmitted light received signal and the magnitude of the initial value of the second transmitted light received signal does not exceed the transmitted light threshold and the drive current supplied to the second photoelectric element exceeds the current threshold; or if the absolute value of the difference between the magnitude of the fourth transmitted light received signal and the magnitude of the initial value of the fourth transmitted light received signal does not exceed the transmitted light threshold and the drive current supplied to the fourth photoelectric element exceeds the current threshold.

20. The aforementioned fluid sterilization device is A first cover member is positioned opposite the first photoelectric element and between the first photoelectric element and the first light-transmitting member, and transmits a portion of the ultraviolet light emitted from the first photoelectric element. A second cover member is positioned opposite the second photoelectric element and between the second photoelectric element and the second light-transmitting member, and transmits a portion of the ultraviolet light emitted from the second photoelectric element. A third cover member is positioned opposite the third photoelectric element and between the third photoelectric element and the first light-transmitting member, and transmits a portion of the ultraviolet light emitted from the third photoelectric element. The device includes a fourth cover member positioned opposite the fourth photoelectric element and between the fourth photoelectric element and the second light-transmitting member, which transmits a portion of the ultraviolet light emitted from the fourth photoelectric element, The first cover member includes the first light intensity adjusting member, The first light intensity adjusting member is positioned opposite the first photoelectric element for emitted light, The second cover member includes a second light intensity adjusting member, The second light intensity adjusting member is positioned opposite the second photoelectric element for emitted light, The third cover member includes a third light intensity adjusting member, The third light intensity adjusting member is positioned opposite the third photoelectric element for light emission, The fourth cover member includes a fourth light intensity adjusting member, The fluid sterilization apparatus according to claim 16, wherein the fourth light intensity adjusting member is arranged opposite to the fourth photoelectric element for emitting light.

21. It further has a flow meter, The fluid sterilization apparatus according to claim 1, claim 9, or claim 16, wherein the processor further receives a flow rate signal from the flow meter and controls the emission of ultraviolet light by the first photoelectric element.

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