WO2024084797A1 - Sink with sterilization function, sink sterilization method - Google Patents

Abstract

Provided is a sink with a sterilization function that maintains the clean state of the sink and minimizes irradiation of ultraviolet light to the human body, and a method for sterilizing the sink.　The sink is provided with a bowl, a faucet that discharges water into the bowl, a drain hole provided on the inner bottom surface of the bowl, an ultraviolet light source that emits ultraviolet light of which the main emission wavelength belongs to a wavelength band of 200 nm or more and less than 240 nm toward the inner surface of the bowl, a first detection unit that detects whether the bowl is in use, and a lighting control unit that controls the ultraviolet light source on the basis of the detection signal outputted from the first detection unit. When the first detection unit detects that the bowl is in use, the lighting control unit executes a sterilization mode in which ultraviolet light is irradiated toward the inner surface of the bowl.

Description

Sink with sterilization function and sterilization method for sink

The present invention relates to a sink with a sterilization function and a method for sterilizing a sink.

　Conventionally, sinks that irradiate the inner surface of the bowl and the area around the drain with ultraviolet light to keep the sink in the kitchen, washstand, toilet, etc. clean are known. For example, the following Patent Document 1 describes a sink equipped with an LED that emits ultraviolet light for sterilization toward the drain.

In addition, the wavelength of ultraviolet light currently used for sterilization is still mainly 254 nm. This is because ultraviolet light with a wavelength of around 260 nm is known to have a high sterilizing and inactivating effect on bacteria and pathogens.

JP 2001-112855 A

For example, sinks installed in hospitals may be provided for washing towels used in the treatment and care of patients. In such sinks, bacteria, viruses, etc. (hereinafter sometimes simply referred to as "bacteria, etc.") attached to the towels may not be completely discharged with the water and may remain on the inner surface of the bowl. This may result in the bacteria, etc. remaining on the inner surface of the bowl gradually infecting many people via the people who use the sink. For this reason, there is a strong demand to maintain a clean environment for sinks installed in environments where utmost attention must be paid to hygiene, such as hospitals.

　Possible methods for sterilizing sinks include sterilization methods using chemicals such as alcohol or hypochlorous acid. However, it is known that spore-forming bacteria such as Bacillus cereus can be sterilized by irradiation with ultraviolet light, but are difficult to sterilize with alcohol. Furthermore, sterilization methods using chemicals containing hypochlorous acid, which are also effective against spore-forming bacteria, are difficult to actively adopt, for example, when sinks or drain pipes are made of metal, as there is a risk of these materials corroding. For this reason, sterilization using ultraviolet light has attracted attention.

When ultraviolet light with a wavelength of 254 nm is irradiated onto the human body, it reaches the nuclei of human cells and kills the cells that make up the skin, making it harmful to the human body. For this reason, sterilization devices that irradiate ultraviolet light with 254 nm are installed solely for the purpose of sterilizing the inner surface of the bowl and the area around the drain, and when constructing such a device, it is necessary to devise a way to irradiate the sink while preventing the human body from being irradiated.

In recent years, research and verification into the effects of ultraviolet light on the human body has progressed, and it has been confirmed that ultraviolet light is easily absorbed by the surface layer of the skin and the corneal epithelium, and that the shorter the wavelength, the greater the safety. In particular, it has been confirmed that ultraviolet light with a wavelength of less than 240 nm poses little risk of affecting the human body.

In addition, sterilization using ultraviolet light in a wavelength range that has little effect on the human body has attracted particular attention in the wake of the recent coronavirus infection epidemic, and it is expected that this method will be introduced not only in hospitals, but also in sinks and other facilities installed in private homes and facilities with frequent human traffic.

However, although ultraviolet light having a wavelength of 200 nm or more and less than 240 nm has a much smaller effect on the human body than ultraviolet light having a wavelength of around 260 nm, a regulated value is set for the cumulative dose of irradiation on the human body for safety reasons. At the time of filing the present application, it is recommended that the cumulative dose of ultraviolet light irradiated on the human body be within the regulated value (tolerable limit value) set by ACGIH (American Conference of Governmental Industrial Hygienists). For example, the tolerable limit value of the cumulative dose of ultraviolet light having a wavelength of 222 nm per day (8 hours) is set to 22 mJ/ ^cm2 .
The numerical values of the permissible limit values in this specification are current numerical values and may be changed in the future. In addition, not limited to the above, from the viewpoint of ensuring safety, it is desirable to set a predetermined upper limit value for the cumulative irradiation amount of ultraviolet light irradiated to the human body.

Therefore, in sinks where sterilization is performed by irradiating ultraviolet light, even if the ultraviolet light used is in a wavelength range that has little effect on the human body, it is desirable to irradiate the inner surface of the bowl and the area around the drain with ultraviolet light while taking measures to avoid irradiating the human body with ultraviolet light as much as possible.

In view of the above problems, the present invention aims to provide a sink with a sterilization function that maintains the clean state of the sink while suppressing exposure of the human body to ultraviolet light, and a method for sterilizing the sink.

The sterilizing sink of the present invention is
A bowl and
A faucet that discharges water toward the bowl;
A drain hole provided on the inner bottom surface of the bowl;
An ultraviolet light source that emits ultraviolet light having a main emission wavelength belonging to a wavelength band of 200 nm or more and less than 240 nm toward the inner surface of the bowl;
A first detection unit that detects whether the bowl is in use;
a lighting control unit that controls the ultraviolet light source based on a detection signal output from the first detection unit,
The lighting control unit is characterized in that when the first detection unit detects that the bowl is not in use, it executes a sterilization treatment mode in which the ultraviolet light is irradiated toward the inner surface of the bowl.

In the sink,
The lighting control unit may be configured to execute an in-use mode in which, when the first detection unit detects that the bowl is in use, the ultraviolet light source is turned off or the ultraviolet light is irradiated with an integrated irradiation amount per unit time that is lower than in the sterilization processing mode.

In this specification, the term "main emission wavelength" refers to a wavelength λi in a wavelength range Z(λi) that shows an integrated intensity of 40% or more of the total integrated intensity in the emission spectrum when a wavelength range Z(λ) of ±10 nm from a certain wavelength λ is defined on the emission spectrum.

In this specification, "the bowl is in use" refers to a state in which a person holds out their hand towards the bowl and is waiting for water to be dispensed from the faucet, a state in which a person is touching the faucet to make water dispense, a state in which water is being dispensed from the faucet, or a state in which water is being drained from the drain. The first detection unit is composed of, for example, a sensor that detects that a hand has been held out towards the bowl, a sensor that detects that a person is touching the faucet, a sensor that detects the presence of water flow on the inner surface of the bowl, or a combination of these.

In addition, in this specification, the "cumulative dose per unit time" is defined as the time until a predetermined cumulative dose is reached during the execution period of each processing mode. Specifically, for example, if the predetermined cumulative dose is 5 mJ/ ^cm2 , the unit time is the time from the start of the mode until the cumulative dose on the inner surface of the bowl reaches 5 mJ/ ^cm2 .

The sterilization mode is a mode in which bacteria and the like present on the inner surface of the bowl are sterilized intensively, and the cumulative irradiation amount on the inner surface of the bowl is relatively high. Note that the sterilization mode may be a mode in which ultraviolet light is irradiated toward the inner surface of the bowl when the bowl is not in use, and switching to the sterilization mode is not limited to adjusting the cumulative irradiation amount.
For example, when the first detector detects that the bowl is not in use, a shutter may open and ultraviolet light may be emitted toward the inner surface of the bowl.

When the bowl is in use, there is a very high possibility that a person, or a part of the human body such as a hand or arm, is present in the vicinity of the bowl where the sterilization process is being carried out by irradiating it with ultraviolet light. Even in such a case, if irradiation with ultraviolet light at a relatively high cumulative dose per unit time continues, a person washing their hands at the sink or cleaning around the bowl may be exposed to an amount of ultraviolet light that exceeds the above-mentioned permissible limit while they are working.

The above configuration allows irradiation of ultraviolet light with a high cumulative dose per unit time for sterilization to occur only while it is detected that the bowl is not in use. This significantly reduces the risk that the person using the bowl will be irradiated with an amount of ultraviolet light that exceeds the allowable limit while the bowl is in use.

In the sink,
A timer is provided to measure the time during which the sterilization processing mode is executed,
After the sterilization treatment mode has been continuously executed for a predetermined time, the lighting control unit may be configured to execute a preventive treatment mode in which the ultraviolet light irradiated to the inner surface of the bowl has an integrated irradiation amount per unit time of the ultraviolet light that is lower than that in the sterilization treatment mode.

After a sufficient period of exposure to UV light, the bowl will remain clean until the sink is used again or until a long period of time has passed that causes bacteria to rise from the drain. Also, exposure to UV light for long periods of time can cause deterioration of the materials that make up the sink, although the deterioration is very slight compared to chemicals that contain hypochlorous acid, etc.

Furthermore, if the sterilization mode is constantly running while it is detected that the bowl is not in use, and there is a worker performing some kind of work around the bowl, even though he or she is not using the bowl, there is a risk that the worker will continue to be exposed to ultraviolet light leaking from the bowl or ultraviolet light reflected by the surface of the bowl.

With the above configuration, once irradiation of the ultraviolet light, which is expected to be sufficient to sterilize the inner surface of the bowl, is completed, irradiation of the components that make up the sink and people around the bowl is suppressed. In addition, this configuration also reduces the power supplied to the ultraviolet light source, which contributes to reducing power consumption and extending the life of the ultraviolet light source.

The sink above is
A second detection unit that detects whether or not a human body is present around the bowl,
The lighting control unit may be configured to execute a human approach mode in which, when the second detection unit detects the presence of a human body while the sterilization processing mode is being executed, the ultraviolet light is irradiated to the inner surface of the bowl at a cumulative irradiation amount per unit time that is lower than that in the sterilization processing mode.

In this specification, "around the bowl" refers to the space that is no more than 1.5 m away from the bowl.

As mentioned above, there may be workers performing some tasks around the bowl, even if they are not using it.

With the above configuration, even if ultraviolet light is irradiated onto people around the bowl or those who have passed around the bowl, the irradiated ultraviolet light will have a lower illuminance than in the sterilization mode. This makes it possible to realize a sink with improved safety.

In the sink,
The first detection unit may be a human presence sensor that detects a human body present between the faucet and the bowl.

In the sink,
The first detection unit may be a flow sensor that detects the discharge of water from the faucet or the inflow of water into the drain.

The sink above is
The first detection unit and the second detection unit may be optical human presence sensors, and may use different wavelength bands of light for detection.

If multiple optical motion sensors that use overlapping wavelength bands of light for detection are placed within each other's detection areas, the light emitted by one motion sensor may be received by the other motion sensor, resulting in a false detection that a person is present within the detection area even when no person is actually present.

With the above configuration, multiple human sensors react to each other, avoiding false detections as described above.

In the sink,
The ultraviolet light source may be positioned at a distance of 1.5 m or less from the inner bottom surface of the bowl.

The illuminance of the ultraviolet light in the irradiation area decreases as the distance between the ultraviolet light source and the irradiation area increases. In other words, if the ultraviolet light source is too far away from the irradiation area, the illuminance on the surface of the irradiated object may not be sufficient for sterilization. In particular, it is preferable to irradiate the inside bottom surface of the sink, the drain outlet from which bacteria may come out of the drain pipe, and the inside of the drain pipe connected to the drain outlet with ultraviolet light of an illuminance sufficient for sterilization.

In addition, since the main body of spore-forming bacteria is protected by the spores, sterilization of spore-forming bacteria requires irradiation with ultraviolet light at an illuminance sufficient to destroy the spores. For this reason, when spore-forming bacteria are to be sterilized, it is preferable to place the ultraviolet light source as close as possible to the area to be sterilized.

With the above configuration, ultraviolet light with a relatively high illuminance is irradiated onto the inner bottom surface of the bowl, the drain outlet, and the inner wall surface of the drain pipe connected to the drain outlet, so bacteria and the like present on the inner bottom surface of the bowl and in the drain pipe can be sterilized more reliably.

The sink above is
An irradiation area changing mechanism may be provided that changes the position of the ultraviolet light source and changes the irradiation area of the ultraviolet light on the inner surface of the bowl.

In addition, the sink is
An optical element may be provided that changes the direction of travel or blocks at least a portion of the ultraviolet light generated from the ultraviolet light source and changes the irradiation area of the ultraviolet light on the inner surface of the bowl.

For example, in order to irradiate ultraviolet light over a wide area, it is possible to provide a member that diffuses and transmits ultraviolet light. However, diffusing the ultraviolet light emitted from the ultraviolet light source may result in a decrease in illuminance per unit area in the ultraviolet light irradiation area, or ultraviolet light may be unnecessarily irradiated onto the space surrounding the bowl.

In addition, if a very large sink is required, it is possible to enlarge the ultraviolet light source depending on the size of the sink, but this is not realistic due to issues such as controlling the irradiation area and the power required to turn on the light.

The above configuration makes it possible to realize a sink that can sterilize the entire inner surface of the bowl evenly, regardless of the shape or size of the bowl.

In the above sink configuration,
The ultraviolet light source may be configured to change the irradiation area of the ultraviolet light on the inner surface of the bowl, while the drain outlet is included in the irradiation area of the ultraviolet light.

In addition, in the sink,
The ultraviolet light source may be fixed in a state in which it irradiates the ultraviolet light onto an area including the drain outlet.

The sink above is
A waterproof cover may be provided to cover the entire ultraviolet light source.

The above configuration prevents the ultraviolet light source from getting wet from splashed water. This prevents water from adhering to the ultraviolet light source while it is turned on, causing it to go out or become damaged. Note that "covering the entire ultraviolet light source" here means that the configuration is such that water droplets that splash when people wash their hands, for example, do not penetrate into the interior, and includes not only cases where the ultraviolet light source is completely sealed, but also cases where there are gaps that allow outside air to enter and exit.

The method for sterilizing a sink of the present invention comprises the steps of:
A method for irradiating an inner surface of a bowl of a sink with ultraviolet light having a main emission wavelength in a wavelength band of 200 nm or more and less than 240 nm, comprising:
a sterilization treatment step of irradiating the inner surface of the bowl with the ultraviolet light;
a first determination step for determining whether the bowl is in use;
The method is characterized in that it includes an in-use step in which, when it is determined in the first judgment step that the bowl is in use, the irradiation of the ultraviolet light is stopped, or the ultraviolet light is irradiated with an integrated irradiation amount per unit time that is lower than that of the sterilization treatment step.

The sterilization method includes the steps of:
The method may include an in-use step of stopping the irradiation of the ultraviolet light when it is determined in the first judgment step that the bowl is in use, or irradiating the ultraviolet light with an integrated irradiation amount per unit time that is lower than that of the sterilization treatment step.

The sterilization method includes the steps of:
The first determination step may include a preventive treatment step in which, if it is determined that the bowl has not been in use for a predetermined period of time, an ultraviolet light irradiation amount per unit time is lower than that of the sterilization treatment step.

The sterilization method includes the steps of:
a second determination step of determining whether or not a person is approaching the bowl during the execution of the sterilization treatment step;
The second judgment process may include a human approach treatment process in which, when it is determined that a person is approaching the bowl, an ultraviolet light treatment process is performed in which an integrated irradiation amount per unit time is lower than that of the sterilization treatment process.

The subject product of the present invention does not cause erythema or keratitis on the skin or eyes of humans or animals, and can provide the germicidal and virus inactivation capabilities inherent to ultraviolet light. In particular, unlike conventional ultraviolet light sources, it can be used in manned environments, and by installing it in manned environments indoors and outdoors, it can irradiate the entire environment, suppressing and sterilizing viruses in the air and on the surfaces of materials installed in the environment.

This corresponds to Goal 3 of the UN-led Sustainable Development Goals (SDGs) "Ensure healthy lives and promote well-being for all at all ages" and also contributes significantly to Target 3.3 "By 2030, end the epidemics of AIDS, tuberculosis, malaria and neglected tropical diseases, and combat hepatitis, water-borne and other communicable diseases."

The above configuration realizes a sink with a sterilization function that maintains the clean state of the sink while suppressing exposure of the human body to ultraviolet light, and a sterilization method for the sink.

1 is a diagram illustrating a schematic configuration of an embodiment of a sink. FIG. 2 is a side cross-sectional view of the sink of FIG. 1 . FIG. 2 is a side cross-sectional view of the drain pipe and its surroundings in FIG. 1 . FIG. 2 is a perspective view illustrating an example of the appearance of a light source device. FIG. 2 is a perspective view showing an example of the appearance of a light source device, in which an ultraviolet light source disposed inside a cover member is shown by a dashed line. 11 is a flowchart of a control executed by an embodiment of a sink. 13 is a diagram illustrating a configuration of another embodiment of a sink. FIG. 8 is an enlarged view of the light source device of FIG. 7 . FIG. 11 is a schematic side cross-sectional view of the drain pipe and its surroundings in another embodiment of the sink.

The sink with sterilization function and the sterilization method for the sink of the present invention will be described below with reference to the drawings. Note that the following drawings of the sink with sterilization function are all schematic illustrations, and the dimensional ratios and numbers in the drawings do not necessarily match the actual dimensional ratios and numbers.

[Configuration of this embodiment]
Fig. 1 is a diagram showing a schematic configuration of one embodiment of a sink 1. Fig. 2 is a side cross-sectional view of the sink 1 in Fig. 1, and Fig. 3 is a side cross-sectional view of the drain pipe 11d and its surroundings in Fig. 1. As shown in Figs. 1 and 2, this embodiment of the sink 1 includes a plurality of light source devices 10, a bowl 11, a faucet 12, a lighting control unit 13, and a water discharge control unit 14.

The bowl 11 in this embodiment is made of stainless steel and has a recessed portion having a roughly rectangular parallelepiped shape that receives water discharged from the faucet 12. As shown in FIG. 1, the bowl 11 has a drain port 11c on the inner bottom surface 11b that is connected to a drain pipe 11d. The material and shape of the bowl 11 are optional.

As shown in Figures 1 and 2, a human presence sensor S1 corresponding to the first detection unit and a human presence sensor S2 corresponding to the second detection unit are arranged on one surface of the inner surface 11a of the bowl 11. The human presence sensor S1 is an optical sensor that detects whether or not a person is holding out their hand towards the bowl 11, that is, whether or not the bowl 11 is in use. The human presence sensor S2 is an optical sensor that detects whether or not a person is present around the bowl 11.

The components constituting the first and second detection units do not have to be human sensors, and may be, for example, a face recognition system that detects a person's face in a space photographed by a camera. If the system can distinguish and detect whether a person is using the bowl 11 or whether the bowl 11 is not being used but a person is present near the bowl 11, the system may function as both the first and second detection units on its own.

The human presence sensors (S1, S2) used in this embodiment use different wavelength bands of light for detection to prevent erroneous detection. Note that if the human presence sensors (S1, S2) are placed far enough apart that erroneous detection does not occur, the wavelength bands used for detection may overlap or match. In addition, the placement positions of the human presence sensors (S1, S2) shown in Figures 1 and 2 are merely examples, and are adjusted as appropriate depending on the configuration of the sink 1 and the specifications of the sensors.

When the human presence sensor S1 detects that a person is holding out their hand towards the bowl 11, i.e., that the bowl 11 is in use, it outputs a detection signal d1 to the lighting control unit 13 and the water discharge control unit 14. Then, when the human presence sensor S1 detects that the person withdraws their hand from the bowl 11, i.e., that the bowl 11 is not in use, it stops outputting the detection signal d1.

When the human presence sensor S2 detects the presence of a person around the bowl 11, it outputs a detection signal d2 to the lighting control unit 13. Then, when there is no person around the bowl 11, the human presence sensor S2 stops outputting the detection signal d2.

As shown in FIG. 2, the lighting control unit 13 controls the power supplied to the light source device 10 based on the detection signal d1 and the detection signal d2 input from each of the human sensors (S1, S2). The lighting control unit 13 also includes a timer 13a that measures the time that the various modes described below are continuously executed. Note that if the lighting control unit 13 is configured not to switch modes depending on the passage of time, the timer 13a does not have to be included.

When a detection signal d1 is input from the human presence sensor S1, the water discharge control unit 14 controls the water faucet 12 to discharge water. In this embodiment, the water discharge control unit 14 is connected to the human presence sensor S1 in the same way as the lighting control unit 13, but the water discharge control unit 14 may be connected to a sensor other than the human presence sensor S1 to which the lighting control unit 13 is connected.

FIG. 4 is a perspective view showing an example of the appearance of the light source device 10. FIG. 5 is a perspective view showing an example of the appearance of the light source device 10, in which the ultraviolet light source 30 arranged inside the cover member 20 is illustrated by a dashed line. As shown in FIGS. 4 and 5, the light source device 10 includes a cover member 20 consisting of a lid portion 20a and a main body portion 20b, and an ultraviolet light source 30 housed within the cover member 20, which emits ultraviolet light L1 whose main emission wavelength belongs to a wavelength band of 200 nm or more and less than 240 nm.

In reality, a power supply line is connected to the cover member 20 to supply power from the lighting control unit 13, but for convenience of illustration, the power supply line is omitted in Figures 4 and 5. The power supply line is wired inside the cover member 20 to prevent it from getting wet, and is wired so that it is hidden by the bowl 11 and cannot be seen when it is installed on the sink 1.

The light source device 10 of this embodiment is installed at a position where the distance A1 between the center of the drain outlet 11c on the surface along the inner bottom surface 11b and the light source device 10 is 50 cm, as shown in FIG. 2. This distance A1 is preferably 1 m or less, and more preferably 80 cm or less, so that the ultraviolet light L1 emitted from the light source device 10 has an illuminance sufficient to sterilize the inner bottom surface 11b of the bowl 11, including spore-forming bacteria.

As shown in FIG. 4, the lid portion 20a constituting the cover member 20 is provided with a light exit window 20c for extracting the ultraviolet light L1 emitted from the ultraviolet light source 30 to the outside. In this embodiment, the material of the light exit window 20c is quartz glass, but any material other than quartz glass may be used as long as it is a material through which the ultraviolet light L1 can pass. For example, ceramic materials such as borosilicate glass, sapphire, magnesium fluoride, calcium fluoride, lithium fluoride, and barium fluoride, and resin materials such as silicone resin and fluororesin may be used. Note that the cover member 20 in this embodiment is a member that fixes and supports the ultraviolet light source 30 at a predetermined position on the sink 1, and is also a waterproof cover that covers the entire ultraviolet light source 30.

If the light source device 10 is positioned far enough away from the bowl 11 and waterproofing is not necessary, the cover member 20 may be configured such that, for example, the light exit window 20c is simply an opening and does not function as a waterproof cover.

In this embodiment, the light exit window 20c is configured with an optical filter that transmits ultraviolet light with a wavelength in the range of 200 nm or more and less than 240 nm, and suppresses the intensity of at least ultraviolet light with a wavelength of 240 nm or more and less than 280 nm. The optical filter provided in this embodiment is a dielectric multilayer film formed on the main surface of the light exit window 20c. If the ultraviolet light source 30 is a light source that emits almost no ultraviolet light with a wavelength of 240 nm or more and less than 280 nm, and measures for light in this wavelength range are not necessary, an optical filter does not have to be provided.

The ultraviolet light source 30 in this embodiment is an excimer lamp equipped with multiple arc tubes 31 and a pair of electrodes (32a, 32b), as shown by the dashed lines in FIG. 5. The arc tube 31 is a straight tube in which krypton (Kr) and chlorine (Cl) gases are sealed as luminous gases. The ultraviolet light source 30 in this embodiment emits ultraviolet light with a main emission wavelength of 222 nm when a predetermined voltage is applied between the electrodes (32a, 32b).

The ultraviolet light source 30 may be an excimer lamp that has krypton (Kr) and bromine (Br) gas sealed inside the tube as the light emitting gas and emits ultraviolet light with a main emission wavelength of 207 nm when a predetermined voltage is applied between the electrodes (32a, 32b), or may be a solid-state light source such as an LED. The number of light emitting tubes 31 and the number of solid-state light sources such as LEDs can be set to any number depending on the purpose and mode of use.

[Control method]
Fig. 6 is a flow chart of the control executed by the present embodiment of the sink 1. Hereinafter, the control executed by the lighting control unit 13 will be described with reference to Fig. 6. Note that the control method described below is merely an example, and the conditions and order for executing each mode (each process) are not limited to the conditions and order described below, and are appropriately changed according to the usage mode. In addition, for convenience of explanation, the following explanation is based on the premise that no person is present around the bowl 11 when the power is turned on and control starts.

When the power is turned on and control starts, a sterilization mode is executed in which ultraviolet light is irradiated toward the inner surface (11a, 11b) of the bowl (step ST1). This step ST1 corresponds to the sterilization process in the sterilization method.

When step ST1 is started, the timer 13a measures the time during which the sterilization mode is continuously executed, and determines whether 30 minutes have passed since the sterilization mode was started (step ST2). Note that this time is adjusted appropriately depending on the shape and size of the bowl 11 and the location and environment in which the sink 1 is installed.

When it is detected (determined) in step ST2 that the sterilization processing mode has been executed for a predetermined time, a decision is made as to whether or not to continue the processing operation (step ST3). If the processing operation is to be continued, the next operation is started directly, and if the control operation is not to be continued, the control ends when the sterilization processing is completed.

If it is decided in step ST3 that the processing operation is to be continued, the lighting control unit 13 executes the preventive processing mode (step ST4). This step ST4 corresponds to the preventive processing step in the sterilization processing method. In the preventive processing mode (preventive processing step), ultraviolet light is irradiated with a lower cumulative irradiation amount per unit time than in the sterilization processing mode (sterilization processing step).

In this embodiment, in the sterilization mode (sterilization process), the lighting control unit 13 controls the power supplied to the light source device 10 so that the cumulative irradiation amount of the ultraviolet light L1 on the inner bottom surface 11b of the bowl 11 is 30 mJ/ ^cm2 or more. In the sterilization mode, the cumulative irradiation amount of the ultraviolet light L1 on the inner bottom surface 11b of the bowl 11 is preferably 5 mJ/cm2 or ^more , and more preferably 15 mJ/ ^cm2 or more, from the viewpoint of performing a sufficient sterilization process. In the preventive treatment mode (preventive treatment process), the lighting control unit 13 controls the power supplied to the light source device 10 so that the cumulative irradiation amount per unit time of the ultraviolet light L1 on the inner bottom surface 11b of the bowl 11 is 70% or less of the cumulative irradiation amount per unit time in the sterilization treatment mode. In other words, the preventive treatment mode (preventive treatment process) is a mode in which the cumulative irradiation amount per unit time is controlled to be lower than that in the sterilization treatment mode (sterilization treatment process).

The cumulative amount of irradiation per unit time can be adjusted not only by lowering the illuminance value, but also, for example, by changing the ON/OFF duty ratio of intermittent operation. Note that intermittent operation here is used to include not only repeated turning on and off, but also repeated switching between high-intensity lighting and low-intensity lighting. It is also possible that one mode is a continuous lighting operation and the other mode is an intermittent operation.

If the human presence sensor S2 does not detect the presence of a person around the bowl 11 while the preventive treatment mode is being executed, the lighting control unit 13 continues step ST4 (step ST5). This step ST5 corresponds to the second determination step in the sterilization treatment method.

If the human presence sensor S2 detects the presence of a person around the bowl 11 in step ST5, the lighting control unit 13 executes the human approach mode (step ST6). This step ST6 corresponds to the human approach processing step in the sterilization processing method. In the human approach mode (human approach processing step), the lighting control unit 13 controls the power supplied to the light source device 10 so that the cumulative irradiation amount per unit time of the ultraviolet light L1 on the inner bottom surface 11b of the bowl 11 is 50% or less of the cumulative irradiation amount per unit time in the sterilization processing mode. In other words, the human approach mode (human approach processing step) is a mode in which the cumulative irradiation amount per unit time is controlled to be lower than the sterilization processing mode (sterilization processing step). Furthermore, the human approach mode (human approach processing step) may be controlled to be lower than the illuminance value in the preventive processing mode (preventive processing step).

In addition, from the viewpoint of safety, it is preferable that the lighting control unit 13 is configured to transition to the human approach mode (step ST6) even if the human presence sensor S2 detects the presence of a person around the bowl 11 while the sterilization processing mode is being executed. However, as another possible measure, a method can be considered in which visible light is emitted, music is played, or a buzzer is sounded to keep people away while the sterilization processing mode is being executed.

If the human presence sensor S1 does not detect that a person is holding out a finger in step ST6, the lighting control unit 13 performs the judgment in step ST5 again (step ST7). This step ST7 corresponds to the first judgment step in the sterilization processing method.

If the human presence sensor S1 detects that a person is holding out a finger in step ST6, the lighting control unit 13 executes an in-use mode in which ultraviolet light is irradiated with a lower cumulative dose per unit time than in the sterilization processing mode (step ST8). This step ST8 corresponds to the in-use process in the sterilization processing method. Note that, if the human presence sensor S1 detects that a person is holding out a finger in step ST6, the water discharge control unit 14 starts discharging water. Note that the in-use mode may be a mode in which the ultraviolet light source 30 is turned off.

While step ST8 is being executed, while the human presence sensor S1 detects that a person is holding out their fingers, the lighting control unit 13 continues step ST8 (step ST9). If the human presence sensor S1 no longer detects that a person is holding out their fingers while step ST8 is being executed, the lighting control unit 13 causes the water discharge control unit 14 to stop discharging water, and returns to step ST1. The lighting control unit 13 then repeatedly executes the operations from ST1 to ST9 described above until control is terminated.

With the above configuration, irradiation with ultraviolet light, which has a high cumulative irradiation amount per unit time for sterilization processing, is performed only while it is detected that the bowl 11 is not being used by a person. Therefore, while the bowl 11 is in use, the risk of a person using the bowl 11 being irradiated with an amount of ultraviolet light L1 that exceeds the allowable limit is significantly reduced.

In addition, in the sink 1 of this embodiment, a human presence sensor S2 is provided as the second detection unit, but in cases where, for example, the intensity of the ultraviolet light L1 emitted from the light source device 10 in the sterilization processing mode and preventive processing mode is relatively low and there is no concern about the impact on people around the bowl 11, the second detection unit does not have to be provided.

[Another embodiment]
Another embodiment will be described below.

<1> Fig. 7 is a schematic diagram showing another embodiment of the sink 1, and Fig. 8 is an enlarged view of the light source device 10 of Fig. 7. As shown in Fig. 8, the light source device 10 of this embodiment has an irradiation area changing mechanism 21 for changing the direction in which the ultraviolet light L1 is emitted and changing the irradiation area on the inner surface (11a, 11b) of the bowl 11. The irradiation area changing mechanism 21 has a first rotation part 21a that rotates the light source device 10 around the axis Rx of the support rod 22 that supports the light source device 10, and a second rotation part 21b that rotates the light source device 10 around an axis Ry that is perpendicular to the axis Rx on a plane parallel to the horizontal plane.

With the above configuration, one light source device 10 can irradiate the entire inner surface (11a, 11b) of the bowl 11 with ultraviolet light L1. The irradiation area changing mechanism 21 may be configured so that the sink 1 is equipped with a drive control unit and is automatically controlled, or it may be configured so that the direction is changed manually by a person.

In addition, as a configuration for changing the irradiation area on the inner surface (11a, 11b) of the bowl 11, the light source device 10 may be equipped with optical components such as a lens that controls the direction of travel of the ultraviolet light L1 emitted from the light exit window 20c, or a shutter that adjusts the aperture to block some of the ultraviolet light.

<2> Figure 9 is a schematic side cross-sectional view of the drain pipe 11d and its surroundings in another embodiment of the sink 1. As shown in Figure 9, the sink 1 may be provided with a flow sensor S3 on the inside of the drain pipe 11d for detecting the flow of water discharged from the drain outlet 11c.

For example, if a person is not washing their hands but instead pours water from a basin used to wash towels into the bowl 11, the human sensor S1 will not be able to detect that the person has put out their hand, and there is a possibility that the person pouring the water will be irradiated with ultraviolet light of relatively high illuminance.

The above configuration makes it possible to more reliably prevent people from being accidentally exposed to relatively high-intensity ultraviolet light.

The method for detecting whether the bowl 11 is in use is selected according to the structure of the sink 1 or the environment or location in which the sink 1 is installed. For example, if the sink 1 does not have a water discharge control unit 14 and the faucet 12 is configured so that water is discharged by a person turning a valve, a flow sensor may be provided in the faucet 12 or a pressure sensor may be provided on the valve.

〈3〉 The light source device 10 may be configured to be stored in the sink 1 when not in use. For example, in the configuration of the sink 1 shown in FIG. 1, the light source device 10 may be configured to automatically retract into the wall of the sink 1 after irradiation of the ultraviolet light L1 is completed.

<4> The light source device 10 may be configured such that, when the human presence sensor S1 corresponding to the first detection unit detects that the bowl 11 is not in use, the shutter opens and starts emitting ultraviolet light toward the inner surface of the bowl. With this configuration, when the first detection unit detects that the bowl 11 is not in use, a sterilization processing mode is executed in which ultraviolet light is irradiated toward the inner surface of the bowl 11.

<5> The configuration of the sink 1 described above is merely an example, and the present invention is not limited to the configurations shown in the figures.

LIST OF SYMBOLS 1: Sink 10: Light source device 11: Bowl 11a: Inner surface 11b: Inner bottom surface 11c: Drain 11d: Drain pipe 12: Faucet 13: Lighting control unit 13a: Timer 14: Water discharge control unit 20: Cover member 20a: Lid portion 20b: Main body portion 20c: Light exit window 21: Irradiation area change mechanism 21a: First rotation portion 21b: Second rotation portion 22: Support rod 30: Ultraviolet light source 31: Light emitting tube 32a, 32b: Electrodes L1: Ultraviolet light S1, S2: Human presence sensor S3: Flow sensor

Claims (15)

A bowl and
A faucet that discharges water toward the bowl;
A drain hole provided on the inner bottom surface of the bowl;
An ultraviolet light source that emits ultraviolet light having a main emission wavelength belonging to a wavelength band of 200 nm or more and less than 240 nm toward the inner surface of the bowl;
A first detection unit that detects whether the bowl is in use;
a lighting control unit that controls the ultraviolet light source based on a detection signal output from the first detection unit,
A sink with a sterilization function, characterized in that when the first detection unit detects that the bowl is not in use, the lighting control unit executes a sterilization treatment mode in which the ultraviolet light is irradiated toward the inner surface of the bowl. The sink with sterilization function according to claim 1, characterized in that, when the first detection unit detects that the bowl is in use, the lighting control unit turns off the ultraviolet light source or executes an in-use mode in which the ultraviolet light is irradiated with a lower cumulative irradiation amount per unit time than in the sterilization processing mode. A timer is provided to measure the time during which the sterilization processing mode is executed,
The sink with sterilization function described in claim 1, characterized in that after the sterilization treatment mode is continuously executed for a predetermined time, the lighting control unit executes a preventive treatment mode in which the ultraviolet light irradiated to the inner surface of the bowl is irradiated with a lower cumulative irradiation amount per unit time of the ultraviolet light than in the sterilization treatment mode. A second detection unit that detects whether or not a human body is present around the bowl,
The sink with sterilization function described in claim 1, characterized in that when the second detection unit detects the presence of a human body while the sterilization treatment mode is being executed, the lighting control unit executes a human approach mode in which the integrated irradiation amount of the ultraviolet light per unit time irradiated onto the inner surface of the bowl is lower than that in the sterilization treatment mode. The sink with sterilization function according to claim 1, characterized in that the first detection unit is a human presence sensor that detects a human body present between the faucet and the bowl. The sink with sterilization function according to claim 1, characterized in that the first detection unit is a flow sensor that detects the discharge of water from the faucet or the inflow of water into the drain. The sink with sterilization function according to claim 4, characterized in that the first detection unit and the second detection unit are optical human sensors, and the wavelength bands of light used for detection are different. The sink with sterilization function according to claim 1, characterized in that the ultraviolet light source is positioned at a distance of 1.5 m or less from the inner bottom surface of the bowl. The sink with sterilization function according to claim 1, characterized in that it is provided with an irradiation area changing mechanism that changes the position of the ultraviolet light source and changes the irradiation area of the ultraviolet light on the inner surface of the bowl. The sink with sterilization function according to claim 1, characterized in that it is provided with an optical element that changes the direction of travel or blocks at least a portion of the ultraviolet light generated by the ultraviolet light source, and changes the irradiation area of the ultraviolet light on the inner surface of the bowl. The sink with sterilization function according to claim 1, characterized in that it is provided with a waterproof cover that entirely covers the ultraviolet light source. A method for irradiating an inner surface of a bowl of a sink with ultraviolet light having a main emission wavelength in a wavelength band of 200 nm or more and less than 240 nm, comprising:
a first determination step for determining whether the bowl is in use;
A sink sterilization method characterized by including a sterilization treatment step of irradiating the inner surface of the bowl with ultraviolet light when it is determined in the first judgment step that the bowl is in an unused state. The sink sterilization method according to claim 12, further comprising an in-use step of stopping the irradiation of the ultraviolet light or irradiating the ultraviolet light with a lower cumulative irradiation amount per unit time than in the sterilization step when the first determination step determines that the bowl is in use. The sink sterilization method according to claim 12, further comprising a preventive treatment step of irradiating the ultraviolet light with a lower cumulative dose per unit time than the sterilization treatment step when it is determined in the first determination step that the bowl has not been in use for a predetermined time. a second determination step of determining whether or not a person is approaching the bowl during the execution of the sterilization treatment step;
The sink sterilization method according to claim 12 or 13, characterized in that when it is determined in the second judgment step that a person is approaching around the bowl, a person approach processing step is included in which the ultraviolet light is irradiated with an integrated irradiation amount per unit time that is lower than that of the sterilization processing step.