Ultraviolet-light-radiating device, and method for controlling ultraviolet-light-radiating device

Abstract

The present invention provides an ultraviolet-light-radiating device with which it is possible to stably radiate ultraviolet light even in low-air-pressure environments. To achieve the above, one representative ultraviolet-light-radiating device according to the present invention comprises a radiating unit that radiates ultraviolet light, a first detection unit that detects the strength of air insulation in the atmosphere in which the ultraviolet-light-radiating device is disposed, and a control unit that controls the radiating unit on the basis of the strength of air insulation that is detected by the first detection unit.

Description

Ultraviolet irradiation device and method for controlling ultraviolet irradiation device

[0001] The present invention relates to an ultraviolet irradiation device and a method for controlling an ultraviolet irradiation device.

[0002] With the global spread of COVID-19, there is an increasing demand for sterilization using ultraviolet lamps, and the demand for ultraviolet lamps is growing not only in medical settings but also in various living environments. Ultraviolet lamps exist that emit light at various wavelengths, but irradiation of the human body may have adverse effects. For this reason, in medical settings, ultraviolet light with wavelengths of 207 nm or more and 220 nm or less is used to perform sterilization while avoiding risks to the human body. Patent Document 1 describes a compact ultraviolet irradiation device that has a reduced impact on the human body.

[0003] Patent Document 1 discloses an ultraviolet irradiation device including "a lamp house having a light extraction surface formed on at least one surface; an excimer lamp housed in the lamp house and emitting ultraviolet light belonging to a first wavelength band having a main emission wavelength of 190 nm or more and 225 nm or less; a first electrode and a second electrode arranged in contact with the outer surface of the light-emitting tube of the excimer lamp; an optical filter arranged on the light extraction surface and substantially transmitting ultraviolet light in the first wavelength band and substantially reflecting ultraviolet light with a wavelength of 240 nm or more and 300 nm or less; and a reflective surface located outside the light-emitting tube of the excimer lamp as viewed in the axial direction of the light-emitting tube, inclined relative to the light extraction surface, and exhibiting reflectivity for ultraviolet light in the first wavelength band."

[0004] WO2021 / 070780

[0005] As the need for sterilization using ultraviolet lamps increases and the miniaturization of irradiation devices allows them to be used in a variety of environments, the use of ultraviolet irradiation devices will be attempted in environments that were previously unimaginable. For example, there is a growing need for sterilization using ultraviolet irradiation devices on international aircraft used by many passengers in order to prevent the spread of infection by COVID-19. However, the air pressure inside an aircraft can sometimes drop below that on the ground during flight, and the impact of such low air pressure on ultraviolet irradiation devices is not considered even in Patent Document 1. Therefore, an object of the present invention is to provide an ultraviolet irradiation device that can stably irradiate ultraviolet light even in a low-air pressure environment.

[0006] In order to solve the above problems, one representative ultraviolet irradiation device of the present invention comprises an irradiation unit that irradiates ultraviolet rays, a first detection unit that detects the gas insulation strength of the atmosphere in which the ultraviolet irradiation device is placed, and a control unit that controls the irradiation unit based on the gas insulation strength detected by the first detection unit.

[0007] According to the present invention, it is possible to provide an ultraviolet irradiation device that can stably irradiate ultraviolet rays even in a low-pressure environment. Problems, configurations, and effects other than those described above will become apparent from the description of the following embodiments.

[0008] 1 is a perspective view schematically showing the appearance of an ultraviolet irradiation device. FIG. 2 is a perspective view of FIG. 1 , with the main body casing and lid of a lamp house of the ultraviolet irradiation device disassembled. FIG. 3 is a perspective view schematically showing the structure of an electrode block and an excimer lamp provided in the ultraviolet irradiation device. FIG. 4 is a perspective view of FIG. 2 , with the excimer lamp further omitted. FIG. 5 is a diagram schematically showing the positional relationship between the excimer lamp and the electrode block. FIG. 1 shows an example of the configuration of an ultraviolet irradiation device according to a first embodiment. FIG. 2 is an example of the relationship between the air pressure measured by an air pressure sensor and the voltage output. FIG. 3 is a flowchart showing the operation of the ultraviolet irradiation device according to the first embodiment based on a first detection unit. FIG. 4 shows an example of air pressure fluctuations and the ON / OFF states of the drive signal and the ultraviolet irradiation device. FIG. 5 is a circuit diagram for implementing the ultraviolet irradiation device according to the first embodiment. FIG. 6 is a diagram showing an example of the configuration of an ultraviolet irradiation device according to a second embodiment. FIG. 7 is a flowchart showing the operation of the ultraviolet irradiation device according to the second embodiment based on a first detection unit and a second detection unit. 10 is a circuit diagram showing an example of fluctuations in atmospheric pressure, detection of a person, and ON / OFF states of a drive signal and an ultraviolet irradiation device according to a second embodiment.

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments. In addition, in the description of the drawings, identical parts are denoted by the same reference numerals. When there are multiple components having the same or similar functions, they may be described by using the same reference numerals with different subscripts. Furthermore, when it is not necessary to distinguish between these multiple components, the subscripts may be omitted. The position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] First, a conventional ultraviolet irradiation device will be described with reference to Figs. 1 to 6. Fig. 1 is a perspective view showing a typical appearance of the ultraviolet irradiation device. Fig. 2 is a perspective view showing the main body casing 2a and lid 2b of the lamp house 2 of the ultraviolet irradiation device disassembled from Fig. 1. Fig. 3 is a perspective view showing a typical structure of an electrode block and an excimer lamp provided in the ultraviolet irradiation device. Fig. 4 is a perspective view taken from a different perspective than Fig. 3.

[0011] In the following drawings, the explanation will be made with reference to an X-Y-Z coordinate system, in which the extraction direction of the ultraviolet light L1 is the X direction and the plane perpendicular to the X direction is the YZ plane. More specifically, as will be described later with reference to Figure 4 and subsequent drawings, the tube axis direction of the excimer lamp 3 is the Y direction, and the direction perpendicular to the X and Y directions is the Z direction. The X direction corresponds to the "first direction," the Y direction corresponds to the "second direction," and the Z direction corresponds to the "third direction."

[0012] As shown in Figures 2 and 3, the ultraviolet irradiation device includes a lamp house 2 having a light extraction surface 10 formed on one side. The lamp house 2 includes a main casing portion 2a and a lid portion 2b, and the main casing portion 2a houses an excimer lamp 3 and electrode blocks (11, 12). In this embodiment, an example will be described in which four excimer lamps 3 (3a, 3b, 3c, 3d) are housed in the lamp house 2 (see Figure 4), but the number of excimer lamps 3 may be one, two, three, five or more. The electrode blocks (11, 12) form electrodes for supplying power to each excimer lamp 3.

[0013] In this embodiment, as shown in FIG. 2, an optical filter 21 is provided in the area that forms the light extraction surface 10 of the lid portion 2b.

[0014] 3 and 4 are perspective views showing only the electrode blocks (11, 12) and the excimer lamps 3 (3a, 3b, 3c, 3d) with the main body casing 2a omitted from Fig. 2. Fig. 3 and Fig. 4 differ only in the viewing angle. Fig. 5 is a perspective view of Fig. 4 with the excimer lamp 3 further omitted.

[0015] As shown in Figures 3 and 4, the ultraviolet irradiation device 1000 of this embodiment includes four excimer lamps 3 (3a, 3b, 3c, 3d) spaced apart in the Z direction. Two electrode blocks (11, 12) are arranged so as to contact the outer surface of the arc tube of each excimer lamp 3. Hereinafter, the electrode block 11 will be referred to as the "first electrode block 11" and the electrode block 12 will be referred to as the "second electrode block 12" as appropriate. The electrode blocks here may be entirely made of conductive materials, or may be formed into a block shape by combining conductive and non-conductive materials.

[0016] The first electrode block 11 and the second electrode block 12 are disposed at positions spaced apart in the Y direction. As shown in Fig. 5, the first electrode block 11 may have a mounting area 11a on which the excimer lamp 3 is mounted, shaped to follow the curved outer surface of the arc tube of the excimer lamp 3, and a tapered surface 11b formed at a position spaced apart from the excimer lamp 3 in the Z direction and inclined with respect to the YZ plane. Similarly, the second electrode block 12 may have a mounting area 12a and a tapered surface 12b. This makes it easier for light emitted from the excimer lamp 3 to radiate in the X direction. (However, this device will function even without the tapered surface.)

[0017] The first electrode block 11 and the second electrode block 12 are made of a conductive material, preferably a material that is reflective to ultraviolet light L1 in the first wavelength band. As an example, the first electrode block 11 and the second electrode block 12 are both made of aluminum, an aluminum alloy, stainless steel, or the like. Alternatively, a structure in which a conductor such as aluminum, an aluminum alloy, or stainless steel is placed on a base made of ceramic may be used.

[0018] Fig. 6 is a diagram schematically showing the positional relationship between the excimer lamp 3 and the electrode blocks (11, 12), and corresponds to a schematic plan view of the excimer lamp 3 when viewed in the +Z direction. Note that Fig. 6 shows only the excimer lamp 3a, which is located furthest on the -Z side among the four excimer lamps 3 (3a, 3b, 3c, 3d), and omits the illustration of the other excimer lamps (3b, 3c, 3d), but as described above, the excimer lamps (3b, 3c, 3d) are also lined up in the +Z direction.

[0019] The excimer lamp 3 has an arc tube with its tube axis oriented in the Y direction, and the outer surface of the arc tube of the excimer lamp 3 is in contact with each of the electrode blocks (11, 12) at positions spaced apart in the Y direction. A light-emitting gas 3G is sealed in the arc tube of the excimer lamp 3. When a high-frequency AC voltage of, for example, about 10 kHz to 5 MHz is applied between the electrode blocks (11, 12), the voltage is applied to the light-emitting gas 3G via the arc tube of the excimer lamp 3. At this time, a discharge plasma is generated in the discharge space in which the light-emitting gas 3G is sealed, and atoms of the light-emitting gas 3G are excited to an excimer state, and excimer light emission occurs when these atoms transition to the ground state.

[0020] The light-emitting gas 3G is made of a material that emits ultraviolet light L1, the main emission wavelength of which is in the first wavelength band of 190 nm or more and 225 nm or less, during excimer light emission. Examples of the light-emitting gas 3G include KrCl, KrBr, and ArF. In addition to the above gas species, an inert gas such as argon (Ar) or neon (Ne) may also be mixed.

[0021] For example, when the light emitting gas 3G contains KrCl, the excimer lamp 3 emits ultraviolet light L1 having a main peak wavelength of about 222 nm. When the light emitting gas 3G contains KrBr, the excimer lamp 3 emits ultraviolet light L1 having a main peak wavelength of about 207 nm. When the light emitting gas 3G contains ArF, the excimer lamp 3 emits ultraviolet light L1 having a main peak wavelength of about 193 nm. The spectrum of ultraviolet light L1 emitted from the excimer lamp 3 when the light emitting gas 3G contains KrCl is as described above.

[0022] When the light-emitting gas 3G contains KrCl, the light output of the ultraviolet light L1 spectrum is concentrated near the main peak wavelength of 222 nm, but a very small amount of light output is also observed in the wavelength range of 240 nm or more, where there are concerns about its effects on the human body. For this reason, an optical filter 21 is provided in the area that constitutes the light extraction surface 10 in order to block light components in this wavelength range. By providing this configuration, the light-emitting tube can maintain insulation between the electrodes in a normal atmospheric pressure environment of 1 atmosphere, even when a high voltage of the kV level is applied during lighting.

[0023] As described above, conventional ultraviolet irradiation devices rely on air insulation between electrodes. However, since the insulating strength of air is proportional to the atmospheric pressure, air exhibits high insulating properties in an environment of 1 atmosphere, but as the atmospheric pressure decreases, the insulating strength also decreases. Specifically, insulation breakdown occurs when the atmospheric pressure drops below a certain level. In ultraviolet irradiation devices, a high voltage of the kV level is applied between the electrodes. Therefore, when the atmospheric pressure drops below a certain level, discharge that should occur within the excimer lamp may discharge directly between the electrodes without passing through the excimer lamp, causing excessive current to flow in the electrical circuit and causing malfunctions.

[0024] First Embodiment Therefore, a first embodiment of the present disclosure includes the following configuration to enable stable UV irradiation even in a low-pressure environment. In the following description, components identical or equivalent to those in the conventional UV irradiation device described above are designated by the same reference numerals, and their description will be simplified or omitted. First, the first embodiment will be described with reference to FIG. 7 . FIG. 7 is a diagram illustrating an example of the configuration of an UV irradiation device 1000 according to an embodiment of the present disclosure. The UV irradiation device 1000 is a device capable of stable UV irradiation even in a low-pressure environment. The UV irradiation device 1000 mainly includes an irradiation unit 1100, a first detection unit 1200, a pressure measurement unit 1300 connected to the first detection unit 1200, a setting unit 1400, a drive circuit 1500, and a control unit 1600. The irradiation unit 1100 is connected to the control unit 1600 and irradiates UV light based on the control of the control unit 1600. The first detection unit 1200 is connected to the setting unit 1400 and determines the atmospheric pressure of the surrounding atmosphere based on the threshold value set by the setting unit 1400 .

[0025] The irradiation unit 1100 is a light source that emits ultraviolet light in a specific wavelength range between 190 nm and 225 nm, and has a rated lamp power of several tens of watts, for example, 20 W or less.

[0026] The first electrode 1112 and the second electrode 1113 are formed of a conductive material, for example, a material that exhibits reflectivity to ultraviolet light in a specific wavelength range within a wavelength range of 190 nm to 225 nm. Examples of such materials include aluminum, aluminum alloys, and stainless steel alloys. The first electrode 1112 and the second electrode 1113 are made of a conductive material, but may be made of other materials as well. For example, aluminum, aluminum alloys, or stainless steel alloys may be placed on a ceramic base, forming a combination of conductive and non-conductive materials.

[0027] <First Detector> Next, the configuration of the first detector 1200 shown in FIG. 7 will be described. The first detector 1200 is a functional unit that detects the gas insulation strength of the atmosphere in which the ultraviolet irradiation device 1000 is placed. Specifically, the first detector 1200 is connected to the air pressure measurement unit 1300 and detects the gas insulation strength of the atmosphere in which the ultraviolet irradiation device 1000 is placed based on the air pressure measured by the air pressure measurement unit 1300. The first detector 1200 determines the magnitude of the ambient air pressure of the atmosphere and the threshold value by comparing the reference voltage, which can be adjusted to a voltage equivalent to 0.0 to 0.8 atmospheres using a volume resistor, for example, using a circuit configuration such as that shown in FIG. 11 (described later). The first detector may use other methods as long as it can compare the ambient air pressure of the atmosphere with the threshold value. For example, it may be possible to change the value of a fixed resistor.

[0028] The first detection unit 1200 detects whether the gas insulation strength of the atmosphere in which the ultraviolet irradiation device 1000 is placed is equal to or less than an arbitrarily set threshold value. The first detection unit 1200 calculates the atmospheric pressure of the atmosphere in which the ultraviolet irradiation device 1000 is placed based on the voltage value transmitted from the atmospheric pressure measurement unit 1300. The first detection unit 1200 is connected to the control unit 1600 and transmits the detection result.

[0029] <Atmospheric Pressure Measurement Unit> Next, the atmospheric pressure measurement unit will be described with reference to Fig. 8. A general atmospheric pressure sensor can be used as the atmospheric pressure measurement unit. Fig. 8 is a diagram showing the relationship between the atmospheric pressure measured by the atmospheric pressure sensor and the voltage output.

[0030] The atmospheric pressure measurement unit 1300 outputs the measurement result based on the measured atmospheric pressure as a voltage value, for example, between 0 and 5 V. For example, the atmospheric pressure measurement unit 1300 outputs a voltage value of 0 V at 0 atmospheres and 4.5 V at 1.32 atmospheres. Here, the output (voltage value) of the atmospheric pressure sensor of the atmospheric pressure measurement unit 1300 can be represented as a graph of a linear function that changes linearly between 0 atmospheres and 1.32 atmospheres, as shown in FIG.

[0031] The atmospheric pressure measurement unit 1300 transmits information on the output voltage value to the first detection unit 1200. Note that the structure of an atmospheric pressure sensor is well known, and therefore a detailed description of the structure will be omitted.

[0032] The setting unit 1400 arbitrarily sets a threshold value to an optimum value for applications other than aircraft cabins. The setting unit 1400 transmits the arbitrarily set threshold value to the first detection unit 1200.

[0033] The setting unit 1400 is, for example, a rotary switch. The setting unit 1400 can arbitrarily set the threshold by setting an arbitrary value set in the rotary switch. The setting unit 1400 is, for example, a numeric keypad for inputting an arbitrary value. The setting unit 1400 can set an arbitrary value as the threshold by inputting the arbitrary value.

[0034] The threshold value input to the setting unit 1400 may be in any unit as long as the first detection unit 1200 can determine the threshold value. For example, in this embodiment, the threshold value is set to 0.75 atmospheres, but the unit may be the gas insulation strength of the gas.

[0035] <Drive Circuit> Next, the drive circuit 1500 will be described. The drive circuit 1500 generates a drive signal that changes the irradiation of ultraviolet light at regular intervals to prevent the temperature of the irradiation unit 1100 from rising due to the irradiation of ultraviolet light. The drive circuit 1500 is connected to the control unit 1600. Specifically, the drive circuit 1500 generates an ON signal and an OFF signal that indicate the ON / OFF state of the ultraviolet irradiation device 1000 irradiating ultraviolet light.

[0036] In this embodiment, the drive circuit 1500 repeatedly generates the ON signal and the OFF signal at one-minute intervals, but other intervals may be used. For example, if the irradiating unit 1100 can prevent a temperature rise with a shorter stop time, the drive circuit 1500 may repeatedly generate the ON signal and the OFF signal at shorter intervals. For example, if the irradiating unit 1100 requires a longer stop time to prevent a temperature rise, the drive circuit 1500 may repeatedly generate the ON signal and the OFF signal at longer intervals.

[0037] In this embodiment, the drive circuit 1500 prevents the temperature of the irradiation unit 1100 from rising, but the temperature may be prevented from rising by other methods. For example, the temperature may be prevented from rising by a cooling circuit that cools the irradiation unit 1100.

[0038] <Control Unit> Next, the control unit 1600 will be described. The control unit 1600 is a functional unit that controls the irradiation unit 1100, and is connected to the irradiation unit 1100, the first detection unit 1200, and the drive circuit 1500. The control unit 1600 receives a detection result from the first detection unit 1200. The control unit 1600 receives a drive signal from the drive circuit 1500.

[0039] Furthermore, the control unit 1600 controls the irradiating unit 1100 to stop irradiating ultraviolet light when the gas insulating strength detected by the first detecting unit 1200 is lower than a threshold value, for example. Furthermore, the control unit 1600 controls the irradiating unit 1100 to irradiate ultraviolet light when the gas insulating strength detected by the first detecting unit 1200 is equal to or higher than a threshold value, for example.

[0040] The control unit 1600 also controls the irradiation unit 1100 to irradiate ultraviolet light based on, for example, an ON signal generated by the drive circuit 1500. The control unit 1600 also controls the irradiation unit 1100 to stop irradiating ultraviolet light based on, for example, an OFF signal generated by the drive circuit 1500.

[0041] Furthermore, when the instruction for ultraviolet irradiation based on the first detection unit 1200 differs from the instruction for ultraviolet irradiation based on the drive circuit 1500, the control unit 1600 irradiates ultraviolet rays only when the instructions from both the first detection unit 1200 and the drive circuit 1500 are to irradiate ultraviolet rays. For example, when the gas insulation strength detected by the first detection unit 1200 is lower than the threshold value and the drive circuit 1500 generates an ON signal, the control unit 1600 stops irradiating ultraviolet rays.

[0042] <Operation of Ultraviolet Irradiation Device> Next, the operation of the ultraviolet irradiation device 1000 in this embodiment will be described. Fig. 9 is a flowchart showing the operation of the ultraviolet irradiation device 1000 in this embodiment based on the first detection unit 1200. The process executed by the ultraviolet irradiation device 1000 will be described below with reference to the flowchart in Fig. 9.

[0043] First, the air pressure measurement unit 1300 measures the air pressure of the atmosphere in which the ultraviolet irradiation device 1000 is placed (S1001). Specifically, the air pressure measurement unit 1300 outputs a voltage value corresponding to the air pressure of the atmosphere in which the ultraviolet irradiation device 1000 is placed.

[0044] Next, the atmospheric pressure measurement unit 1300 transmits information on the measured atmospheric pressure to the first detection unit 1200 (S1002). Specifically, the atmospheric pressure measurement unit 1300 transmits information on the output voltage value to the first detection unit 1200.

[0045] Next, the control unit 1600 determines the state of ultraviolet irradiation (S1003). Specifically, the control unit 1600 determines whether the irradiation unit 1100 is irradiating ultraviolet rays. If ultraviolet rays are being irradiated, the process proceeds to step S1004. If ultraviolet rays are not being irradiated, the process proceeds to step S1006.

[0046] Next, the first detection unit 1200 determines whether the air pressure is lower than a threshold value (S1004). Specifically, the first detection unit 1200 calculates the air pressure corresponding to the voltage value received from the air pressure measurement unit 1300. The first detection unit 1200 determines whether the calculated pressure is lower than a set threshold value. The first detection unit 1200 transmits the determination result to the control unit 1600. If the calculated pressure is lower than the set threshold value, the process proceeds to step S1005; if the calculated pressure is equal to or greater than the set threshold value, the process returns to step S1001 and repeats the process.

[0047] Next, the control unit 1600 stops the irradiation of ultraviolet light (S1005). Specifically, the control unit 1600 stops the irradiation of ultraviolet light based on the determination result received from the first detection unit 1200, returns to step S1001, and repeats the process.

[0048] Next, the first detection unit 1200 determines whether the air pressure is equal to or greater than a threshold value (S1006). Specifically, the first detection unit 1200 calculates the air pressure corresponding to the voltage value received from the air pressure measurement unit 1300. The first detection unit 1200 determines whether the calculated pressure is equal to or greater than a set threshold value. The first detection unit 1200 transmits the determination result to the control unit 1600. If the calculated pressure is equal to or greater than the set threshold value, the process proceeds to step S1007; if the calculated pressure is less than the set threshold value, the process returns to step S1001 and repeats the process.

[0049] Next, the control unit 1600 irradiates ultraviolet light (S1007). Specifically, the control unit 1600 irradiates ultraviolet light based on the determination result received from the first detection unit 1200, and returns to step S1001 to repeat the process.

[0050] Next, referring to FIG. 10 , a specific example of the relationship between air pressure and ultraviolet irradiation when the above steps are adopted will be described. The upper graph (A) in FIG. 10 shows an example of fluctuations in air pressure. The middle graph (B) shows the status of the drive signal generated by the drive circuit 1500. The lower graph (C) shows the ON / OFF status of the ultraviolet irradiation device 1000. In the lower graph (C), when the drive signal from the drive circuit 1500 is an ON signal, the ultraviolet irradiation device is ON, and when the drive signal is an OFF signal, the ultraviolet irradiation device is OFF. The horizontal axis in each graph represents the time axis. As can be seen from this graph, the ultraviolet irradiation device 1000, in principle, repeatedly starts and stops irradiating ultraviolet light based on the drive signal generated by the drive circuit 1500.

[0051] The ultraviolet irradiation device 1000 is in an ON state when the drive signal is an ON signal and the atmospheric pressure is equal to or higher than a threshold, but is turned OFF once the atmospheric pressure falls below the threshold regardless of the state of the drive signal. When the atmospheric pressure returns to above the threshold and the drive signal generates an ON signal, the ultraviolet irradiation device 1000 also changes to return to ON. For example, a case where the ultraviolet irradiation device 1000 is installed on an aircraft will be described.

[0052] The aircraft equipped with the ultraviolet irradiation device 1000 waits on the ground and then takes off. After taking off, the aircraft flies in the sky and lands when it arrives at its destination. The aircraft repeats this series of operations.

[0053] On the ground, the pressure inside and outside an aircraft is about 1 atmosphere, but when flying in the sky, for example at an altitude of 10,000 m, the pressure inside the aircraft is about 0.8 atmospheres, but the pressure outside the aircraft drops to 0.2 atmospheres.

[0054] When the set threshold is 0.75 atmospheres, the ultraviolet irradiation device 1000 repeatedly starts and stops irradiating ultraviolet light based on the drive signal generated by the drive circuit 1500 .

[0055] In addition to the case where the drive circuit 1500 generates an OFF signal as a drive signal, the ultraviolet irradiation device 1000 may stop emitting ultraviolet rays in the following cases: for example, when the device controlling the air pressure in the aircraft malfunctions and the air pressure inside the aircraft temporarily drops below 0.8 atmospheres, or when an accident occurs in which a hole is created in the fuselage of the aircraft, causing air to leak.

[0056] In such a case, as shown in Figure 10, an event occurs in which the air pressure falls below the threshold. In such a case, there is a risk of dielectric breakdown occurring between the electrodes of the ultraviolet irradiation device, and therefore ultraviolet irradiation is stopped. Then, when control of the air pressure inside the aircraft is restored, that is, when the air pressure returns to or exceeds the threshold, ultraviolet irradiation is resumed.

[0057] As described above, the ultraviolet irradiation device 1000 of this embodiment can automatically stop and restart ultraviolet irradiation depending on the atmospheric pressure around the ultraviolet irradiation device 1000. This prevents abnormal discharge even if the gas insulation strength decreases with a drop in atmospheric pressure. In other words, the small ultraviolet irradiation device 1000 can be used stably even in places where the atmospheric pressure fluctuates during normal use.

[0058] As preventive measures against abnormal discharge, the following measures can be considered, but they have various problems as described below, and the method of this embodiment is therefore superior.

[0059] (Extending the Distance Between Electrodes) Preventive measures against abnormal discharge include, for example, increasing the distance between the electrodes. This increases the amount of air between the electrodes and improves insulation strength. However, this also increases the insulation distance for the excimer lamp 3, making it difficult for the excimer lamp 3 to start discharging, and in the worst case, causing the lamp to stop lighting. Furthermore, this measure requires a distance between the electrodes, which increases the size of the irradiation unit 1100 and, ultimately, the size of the ultraviolet irradiation device 1000.

[0060] (Filling with insulating material) One preventive measure against abnormal discharge is to fill the gap between the electrodes with an insulating material that has a higher insulating strength than air. The insulating material is, for example, Teflon, plastic, or vinyl, which exhibits electrical insulating properties. This increases the insulating strength. However, this measure requires the use of insulating material for all electrodes, which compromises the weight reduction.

[0061] (Introduction of a Protection Circuit) A preventive measure against abnormal discharge is, for example, to use a protection circuit such as a fuse. In this way, when abnormal discharge occurs, the fuse is activated to open the circuit, thereby preventing abnormal discharge from flowing to the entire ultraviolet irradiation device 1000.

[0062] Under this measure, if a fuse is activated, it must be replaced with a good one before it can be reused. Even in the case of a resettable fuse, a worker or other person must perform the reset operation on the fuse. Due to the way fuses work, an overcurrent must flow for a certain period of time before they activate, and during that time, an overcurrent greater than the design anticipates flows through the electronic components before and after the fuse. This places stress on electronic components other than the fuse, which can cause other failures.

[0063] (Abnormality monitoring device) As a preventive measure against abnormal discharge, for example, various sensors are installed. This makes it possible to stop the irradiation unit 1100 when abnormal discharge occurs. This measure requires a resident monitor to monitor the output of the various sensors, monitoring software to replace the monitor, and a communication network to transmit the sensor output to a server.

[0064] (Example) Next, an example of a circuit configuration for realizing an embodiment of the present disclosure will be described with reference to Fig. 11. Fig. 11 is a circuit diagram for implementing an ultraviolet irradiation device 1000.

[0065] The components included in the ultraviolet irradiation device 1000 are implemented using basic electronic components as shown in Fig. 11. The basic electronic components include, for example, an AND gate, a resistor, a diode, a comparator, etc. The ultraviolet irradiation device 1000 is configured by combining the basic electronic components.

[0066] For example, the first detection unit 1200 uses a comparator to compare the voltage value output from the atmospheric pressure measurement unit 1300 with the reference voltage output from the setting unit 1400. If the voltage value is greater than the reference voltage, the first detection unit 1200 outputs a logical value of 1, and if it is less than the reference voltage, the first detection unit 1200 outputs a logical value of 0.

[0067] The reference voltage is determined by changing the value of the volume resistor configured by the setting unit 1400 .

[0068] For example, when the drive circuit 1500 generates an ON signal, it outputs a logical value of 1, and when it generates an OFF signal, it outputs a logical value of 0.

[0069] When the logical value output from the first detection unit 1200 and the logical value output from the drive circuit 1500 are both 1, the control unit 1600 outputs a logical value of 1 from the AND gate.

[0070] The control unit 1600 outputs a logical value of 1 to the irradiation unit 1100 to irradiate ultraviolet light.

[0071] [Second Embodiment] An ultraviolet irradiation device 2000 according to a second embodiment differs from the first embodiment in that it has a function of stopping ultraviolet irradiation when a person is detected in addition to atmospheric pressure. Fig. 12 is a diagram showing an example of the configuration of an ultraviolet irradiation device 2000 according to an embodiment of the present disclosure. In the following description, components that are the same as or equivalent to those in the first embodiment described above are denoted by the same reference numerals, and their description will be simplified or omitted.

[0072] The ultraviolet irradiation device 2000 mainly includes an irradiation unit 1100, a first detection unit 1200, an air pressure measurement unit 1300 connected to the first detection unit 1200, a setting unit 1400, a drive circuit 1500, a control unit 2600, and a second detection unit 2700.

[0073] <Second detection unit> Next, the configuration of the second detection unit 2700 shown in Fig. 12 will be described. The second detection unit 2700 is a functional unit that detects people present in the location where the ultraviolet irradiation device 2000 is installed. Specifically, the second detection unit 2700 is connected to the control unit 2600, and detects people in the area detected by the second detection unit 2700.

[0074] The second detection unit 2700 detects a person present within a specific detection range. Here, the specific detection range detected by the second detection unit 2700 is, for example, a range into which ultraviolet light is irradiated by the ultraviolet irradiation device 2000. The second detection unit 2700 is, for example, a human presence sensor.

[0075] When the second detection unit 2700 detects a person present within the detection range, it transmits information about the detection of the person to the control unit 2600 .

[0076] <Control Unit> Next, the control unit 2600 will be described. The control unit 2600 is a functional unit that controls the irradiation unit 1100, and is connected to the irradiation unit 1100, the first detection unit 1200, the drive circuit 1500, and the second detection unit 2700. The control unit 2600 receives the detection result from the first detection unit 1200. The control unit 2600 receives a drive signal from the drive circuit 1500. The control unit 2600 receives the detection result from the second detection unit 2700.

[0077] Furthermore, the control unit 2600 controls the irradiating unit 1100 to stop irradiating ultraviolet light when the gas insulating strength detected by the first detecting unit 1200 is lower than a threshold value, for example. Furthermore, the control unit 2600 controls the irradiating unit 1100 to irradiate ultraviolet light when the gas insulating strength detected by the first detecting unit 1200 is equal to or higher than a threshold value, for example.

[0078] The control unit 2600 also controls the irradiation unit 1100 to irradiate ultraviolet light based on, for example, an ON signal generated by the drive circuit 1500. The control unit 2600 also controls the irradiation unit 1100 to stop irradiating ultraviolet light based on, for example, an OFF signal generated by the drive circuit 1500.

[0079] Furthermore, the control unit 2600 controls the irradiation unit 1100 to stop emitting ultraviolet light when the second detection unit 2700 detects a person, for example. Furthermore, the control unit 2600 controls the irradiation unit 1100 to irradiate ultraviolet light when the second detection unit 2700 does not detect a person, for example.

[0080] Furthermore, when the instruction for ultraviolet radiation based on the first detection unit 1200, the instruction for ultraviolet radiation based on the drive circuit 1500, and the instruction for ultraviolet radiation based on the second detection unit 2700 are different, the control unit 2600 irradiates ultraviolet radiation only when the instructions for ultraviolet radiation from all of the first detection unit 1200, the drive circuit 1500, and the second detection unit 2700 are ultraviolet radiation. For example, when the gas insulation strength detected by the first detection unit 1200 is lower than the threshold value and the second detection unit 2700 detects a person, the control unit 2600 stops ultraviolet radiation.

[0081] Next, the operation of the ultraviolet irradiation device 2000 in this embodiment will be described. Fig. 13 is a flowchart showing the operation of the ultraviolet irradiation device 2000 in this embodiment based on the first detection unit 1200 and the second detection unit 2700. The processing executed by the ultraviolet irradiation device 2000 will be described below with reference to the flowchart in Fig. 13. The flowchart in Fig. 13 starts when the ultraviolet irradiation device 2000 irradiates ultraviolet rays in an environment of 0.75 atmospheres or more.

[0082] First, the air pressure measurement unit 1300 measures the air pressure of the atmosphere in which the ultraviolet irradiation device 2000 is placed (S1101). Specifically, the air pressure measurement unit 1300 outputs a voltage value corresponding to the air pressure of the atmosphere in which the ultraviolet irradiation device 2000 is placed.

[0083] Next, the atmospheric pressure measurement unit 1300 transmits information on the measured atmospheric pressure to the first detection unit 1200 (S1102). Specifically, the atmospheric pressure measurement unit 1300 transmits information on the output voltage value to the first detection unit 1200.

[0084] Next, the first detection unit 1200 determines whether the air pressure is lower than a threshold value (S1103). Specifically, the first detection unit 1200 calculates the air pressure corresponding to the voltage value received from the air pressure measurement unit 1300. The first detection unit 1200 determines whether the calculated pressure is lower than a set threshold value. The first detection unit 1200 transmits the determination result to the control unit 2600. If the calculated pressure is lower than the set threshold value, the process proceeds to step S1105; if the calculated pressure is equal to or greater than the set threshold value, the process proceeds to step S1104.

[0085] Next, the second detection unit 2700 determines whether a person has been detected (S1104). Specifically, the second detection unit 2700 determines whether a person present in a specific detection range has been detected. If the second detection unit 2700 detects a person, it transmits the information to the control unit 2600.

[0086] Next, the control unit 2600 stops the irradiation of ultraviolet light (S1105). Specifically, the control unit 2600 stops the irradiation of ultraviolet light based on the determination results received from the first detection unit 1200 and the second detection unit 2700.

[0087] Next, referring to FIG. 14 , a specific example of the relationship between atmospheric pressure and ultraviolet irradiation when the above steps are adopted will be described. The upper graph (A) in FIG. 14 shows an example of fluctuations in atmospheric pressure. The middle graph (B) shows an example of fluctuations in human detection. The middle graph (C) shows the status of the drive signal generated by the drive circuit 1500. The lower graph (D) shows the ON / OFF status of the ultraviolet irradiation device. The horizontal axis in both graphs represents the time axis. In the lower graph (D), the ON signal indicates that the ultraviolet irradiation device is ON, and the OFF signal indicates that the ultraviolet irradiation device is OFF. As can be seen from this graph, the ultraviolet irradiation device 2000, in principle, repeatedly starts and stops irradiating ultraviolet light based on the drive signal generated by the drive circuit 1500.

[0088] The control unit 2600 controls the irradiation unit 1100 based on the information detected by the first detection unit 1200 and the information detected by the second detection unit 2700. The control unit 2600 stops the irradiation of ultraviolet rays when it receives either information that the first detection unit 1200 has detected that the gas insulation strength of the atmosphere in which the ultraviolet irradiation device 2000 is placed is equal to or less than an arbitrarily set threshold value, or information that the second detection unit 2700 has detected the presence of a person.

[0089] As can be seen from this graph, when the air pressure is above the threshold, the ultraviolet irradiation device is in the ON state, but once the air pressure falls below the threshold, the ultraviolet irradiation device is turned OFF, and when the air pressure returns to above the threshold, the ultraviolet irradiation device also changes to return to ON.

[0090] In addition, the ultraviolet irradiation device 2000 of this embodiment switches to the OFF state even when a person is detected, and switches back to the ON state when the air pressure returns to above the threshold and no person is detected. The ultraviolet irradiation device 2000 is in the ON state when the drive signal is an ON signal, the air pressure is above the threshold, and no person is detected, but switches to the OFF state once the air pressure falls below the threshold or when a person is detected, regardless of the state of the drive signal. The ultraviolet irradiation device 2000 switches back to the ON state when the air pressure returns to above the threshold, the drive signal generates an ON signal, and no person is detected.

[0091] (Example) Next, an example of a circuit configuration for realizing an embodiment of the present disclosure will be described with reference to Fig. 15. Fig. 15 is a circuit diagram for implementing an ultraviolet irradiation device 2000.

[0092] The components included in the ultraviolet irradiation device 2000 are implemented using basic electronic components as shown in Fig. 15. The basic electronic components include, for example, an AND gate, a resistor, a diode, a comparator, etc. The ultraviolet irradiation device 2000 is configured by combining the basic electronic components.

[0093] For example, the first detection unit 1200 uses a comparator to compare the voltage value output from the atmospheric pressure measurement unit 1300 with the reference voltage output from the setting unit 1400. If the voltage value is greater than the reference voltage, the first detection unit 1200 outputs a logical value of 1, and if it is less than the reference voltage, the first detection unit 1200 outputs a logical value of 0.

[0094] The reference voltage is determined by changing the value of the volume resistor in the setting section 1400 .

[0095] For example, when the drive circuit 1500 generates an ON signal, it outputs a logical value of 1, and when it generates an OFF signal, it outputs a logical value of 0.

[0096] For example, the second detection unit 2700 outputs a logical value of 1 if it does not detect a person, and outputs a logical value of 0 if it detects a person.

[0097] When the logical value output from the first detection unit 1200 and the logical value output from the drive circuit 1500 are both 1, the control unit 2600 outputs a logical value of 1 from the AND gate.

[0098] Furthermore, when the logical value output from this AND gate and the logical value output from the second detection unit 2700 are both 1, the control unit 2600 outputs a logical value of 1 from the AND gate.

[0099] When the logical values ​​output from the AND gates are both 1, the control unit 2600 outputs a logical value of 1 to cause the irradiation unit 1100 to irradiate ultraviolet light.

[0100] As described above, the ultraviolet irradiation device 2000 of this embodiment can automatically stop and resume ultraviolet irradiation by detecting a person in addition to the atmospheric pressure around the ultraviolet irradiation device 2000. This prevents ultraviolet rays from being irradiated onto a person even if the person is within the range of ultraviolet irradiation by the ultraviolet irradiation device 2000. In other words, the ultraviolet irradiation device 2000 can be used safely even in places where people are normally present.

[0101] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention.

[0102] 1000: ultraviolet irradiation device, 1100: irradiation unit, 1112: first electrode, 1113: second electrode, 1200: first detection unit, 1300: atmospheric pressure measurement unit, 1400: setting unit, 1500: drive circuit, 1600, 2600: control unit, 2700: second detection unit

Claims

1. An irradiation unit that irradiates ultraviolet light; A first detection unit that detects a gas insulation strength of an atmosphere in which the ultraviolet irradiation device is disposed; A control unit that controls the irradiation unit based on the gas insulation strength detected by the first detection unit; An air pressure measuring unit that measures the air pressure of an atmosphere in which the ultraviolet irradiation device is disposed, The first detection unit detects the gas insulation strength based on the air pressure measured by the air pressure measurement unit. Ultraviolet irradiation device.

2. The first detection unit transmits a detection result to the control unit when the detected gas insulation strength is smaller than a threshold value; The control unit stops the irradiation of the ultraviolet light based on the received detection result. The ultraviolet irradiation device according to claim 1 .

3. A setting unit for setting the threshold value of the gas insulation strength to an arbitrary value. The ultraviolet irradiation device according to claim 2 .

4. Equipped with a second detection unit that detects a person The ultraviolet irradiation device according to claim 1 .

5. The irradiation unit has a first electrode arranged in contact with the outer surface of the light emitting tube, and a second electrode arranged in contact with the outer surface of the light emitting tube at a position spaced apart from the first electrode in a direction parallel to the tube axis, and is characterized in that it irradiates ultraviolet light of a specific wavelength within a wavelength range of 190 nm to 225 nm. The ultraviolet irradiation device according to claim 1 .

6. The first detection unit is characterized in that the threshold value is 0.8 atmospheric pressure or less. The ultraviolet irradiation device according to claim 2 .

7. The first detection unit is characterized in that the threshold value is 0.75 atmospheres. The ultraviolet irradiation device according to claim 2 .

8. The ultraviolet irradiation device according to claim 1, Detect the gas insulation strength of the atmosphere in which the ultraviolet irradiation device is placed, The irradiation of ultraviolet light is controlled based on the detected gas insulation strength. A method for controlling an ultraviolet irradiation device.