Ultraviolet irradiation device and method for controlling ultraviolet irradiation 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

[Technical field]

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

[0002] As the COVID-19 infection continues to spread globally, 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. There are ultraviolet lamps that emit light at a variety of wavelengths, but some of them can have adverse effects on the human body when irradiated with ultraviolet light. For this reason, in medical settings, ultraviolet light with wavelengths between 207 nm and 220 nm is used to sterilize the body while avoiding risks. Patent Document 1 describes a small-sized ultraviolet irradiation device that has a reduced impact on the human body.

[0003] Patent Document 1 discloses an ultraviolet irradiation device comprising "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 when viewed from the axial direction of the light-emitting tube, inclined with respect to the light extraction surface, and exhibiting reflectivity for ultraviolet light in the first wavelength band." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2021 / 070780 Summary of the Invention [Problem to be solved by the invention]

[0005] As the need for sterilization using ultraviolet lamps increases and the miniaturization of irradiation devices makes it possible to use ultraviolet irradiation devices in a variety of environments, trials will be conducted on the use of ultraviolet irradiation devices in environments that were not previously envisioned. For example, there is an increasing 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 become lower than that on the ground during flight, and Patent Document 1 does not consider the effect of such low air pressure on the ultraviolet irradiation device. Therefore, an object of the present invention is to provide an ultraviolet irradiation device that can stably irradiate ultraviolet rays even in a low pressure environment. [Means for solving the problem]

[0006] In order to solve the above problems, one representative ultraviolet irradiation device of the present invention includes 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. Effect of the Invention

[0007] According to the present invention, it is possible to provide an ultraviolet irradiation device capable of stably irradiating 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. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view showing a schematic appearance of an ultraviolet irradiation device. [Diagram 2] 2 is an exploded perspective view of a main casing and a lid of a lamp house of the ultraviolet irradiation device shown in FIG. 1. [Diagram 3] FIG. 2 is a perspective view showing a schematic structure of an electrode block and an excimer lamp provided in the ultraviolet irradiation device. [Figure 4] FIG. 4 is a perspective view taken from a different viewpoint than FIG. 3 . [Diagram 5] 5 is a perspective view of FIG. 4 in which the excimer lamp is further omitted. [Figure 6] FIG. 2 is a diagram showing a schematic positional relationship between an excimer lamp and an electrode block. [Figure 7] FIG. 1 is a diagram showing an example of the configuration of an ultraviolet irradiation device according to a first embodiment. [Figure 8] 5 is a diagram showing an example of the relationship between the air pressure measured by the air pressure sensor and the voltage outputted. FIG. [Figure 9] 5 is a flowchart showing an operation of the ultraviolet irradiating device according to the first embodiment based on a first detection unit. [Figure 10] An example of fluctuations in air pressure and the ON / OFF status of the drive signal and the ultraviolet irradiation device. [Figure 11] FIG. 2 is a circuit diagram illustrating the ultraviolet ray irradiation device according to the first embodiment. [Figure 12] FIG. 13 is a diagram showing an example of the configuration of an ultraviolet irradiating device according to a second embodiment. [Figure 13] 10 is a flowchart showing the operation of an ultraviolet irradiating device according to a second embodiment based on a first detection unit and a second detection unit. [Figure 14] A diagram showing an example of fluctuations in air pressure, detection of a person, and the ON / OFF status of the drive signal and the UV irradiation device. [Figure 15] FIG. 11 is a circuit diagram illustrating an ultraviolet ray irradiation device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment. In addition, in the description of the drawings, the same 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, or when there is no need to distinguish between these multiple components, the subscripts may be omitted. In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. 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. Fig. 1 is a perspective view showing a typical appearance of an ultraviolet irradiation device. Fig. 2 is a perspective view showing a main body casing 2a and a cover 2b of a 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 showing a different viewpoint from Fig. 3.

[0011] In the following drawings, the description will be given with reference to an XYZ coordinate system in which the direction in which ultraviolet light L1 is extracted 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 the drawings from FIG. 4 onwards, 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 Figs. 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 an excimer lamp 3 and electrode blocks (11, 12) are housed in the main casing portion 2a. 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 Fig. 4), but the number of excimer lamps 3 may be one, two, three, or 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 a region that constitutes 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. The only difference between FIG. 3 and FIG. 4 is the viewing angle. FIG. 5 is a perspective view showing FIG. 4 with the excimer lamp 3 further omitted.

[0015] As shown in Fig. 3 and Fig. 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 all be made of conductors, or may be formed into a block shape by combining conductors and non-conductors.

[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, which has a shape that conforms to the curved surface of the 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 to radiate light emitted from the excimer lamp 3 in the X direction. (However, this device will function even if it does not have a 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, stainless steel, or the like is placed on a base made of ceramics may be used.

[0018] Fig. 6 is a diagram showing a schematic positional relationship between the excimer lamps 3 and the electrode blocks (11, 12), and corresponds to a schematic plan view of the excimer lamps 3 when viewed in the +Z direction. Note that in Fig. 6, of the four excimer lamps 3 (3a, 3b, 3c, 3d), only the excimer lamp 3a located furthest on the -Z side is shown, and the other excimer lamps (3b, 3c, 3d) are not shown, 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 whose tube axis direction is in the Y direction, and the outer surface of the arc tube of the excimer lamp 3 is in contact with each electrode block (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 the 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 that has a main emission wavelength in the first wavelength band of 190 nm or more and 225 nm or less during excimer emission. As an example, the light emitting gas 3G includes KrCl, KrBr, and ArF. In addition to the above gas species, inert gases such as argon (Ar) and neon (Ne) may be mixed.

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

[0022] When the luminescent gas 3G contains KrCl, the light output in the spectrum of the ultraviolet light L1 is concentrated in the vicinity of the main peak wavelength of 222 nm, but a very small amount of light output is also observed in the wavelength band of 240 nm or more, where there are concerns about effects on the human body. For this reason, an optical filter 21 is provided in the area constituting the light extraction surface 10 for the purpose of blocking light components in this wavelength band. With this configuration, the arc tube can maintain insulation between the electrodes in a normal atmospheric pressure environment of 1 atmosphere, even when a high voltage of kV level is applied during lighting.

[0023] As mentioned above, conventional ultraviolet irradiation devices use air insulation between electrodes. However, since the insulation strength of air is proportional to the air pressure, it shows high insulation in an environment of 1 atmosphere, but the insulation strength decreases as the air pressure decreases. Specifically, when the atmospheric pressure falls below a certain level, insulation breakdown occurs. In ultraviolet irradiation devices, a high voltage of the kV level is applied between the electrodes, so when the atmospheric pressure falls below a certain level, the discharge that should take place within the excimer lamp may actually take place directly between the electrodes without passing through the excimer lamp, causing excessive electricity to flow in the electrical circuit and resulting in malfunctions.

[0024] [First embodiment] Therefore, in the first embodiment of the present disclosure, the following configuration is provided so as to enable stable irradiation of ultraviolet light even in a low pressure environment. In the following description, the same or equivalent components as those in the conventional ultraviolet irradiation device described above are denoted by the same reference numerals, and the description thereof will be simplified or omitted. First, the first embodiment will be described with reference to FIG. FIG. 7 is a diagram showing an example of the configuration of an ultraviolet irradiation device 1000 according to an embodiment of the present disclosure. The ultraviolet irradiation device 1000 is a device that can stably irradiate ultraviolet rays even in a low pressure environment. The ultraviolet irradiation device 1000 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, and a control unit 1600. The irradiation unit 1100 is connected to the control unit 1600, and irradiates ultraviolet 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 irradiating unit 1100 is a light source that emits ultraviolet light in a specific wavelength range that falls within the wavelength range of 190 nm to 225 nm. The irradiating unit 1100 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 the wavelength range of 190 nm to 225 nm. Such materials include, for example, 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. For example, they may be made of a conductive material and a non-conductive material by placing aluminum, an aluminum alloy, or a stainless steel alloy on a ceramic base.

[0027] <First detection section> Next, the configuration of the first detection unit 1200 shown in FIG. 7 will be described. The first detection unit 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 detection unit 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 detection unit 1200, for example, by using a circuit configuration as shown in FIG. 11 described later, determines the magnitude of the ambient air pressure and the threshold value by comparing with a reference voltage that can be adjusted to a voltage equivalent to 0.0 to 0.8 atmospheres using a volume resistor. The first detection unit may use other methods as long as it can compare the magnitude of the ambient air pressure with the threshold value, for example, by changing 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 irradiating device 1000 is placed is equal to or lower than an arbitrarily set threshold value. The first detection unit 1200 calculates the atmospheric pressure of the atmosphere in which the ultraviolet irradiating device 1000 is placed, based on the voltage value transmitted from the atmospheric pressure measuring unit 1300 . The first detection unit 1200 is connected to the control unit 1600 and transmits the detection result.

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

[0030] The atmospheric pressure measuring unit 1300 outputs the measurement result based on the measured atmospheric pressure, for example, as a voltage value of 0 to 5 V. For example, the atmospheric pressure measuring unit 1300 outputs a voltage value of 0 V at 0 atmospheric pressure and 4.5 V at 1.32 atmospheric pressure. 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 as shown in FIG. 8 between 0 atmospheric pressure and 1.32 atmospheric pressure.

[0031] The atmospheric pressure measurement unit 1300 transmits information on the output voltage value to the first detection unit 1200. Incidentally, the structure of the air pressure sensor is well known, so a detailed description of the configuration will be omitted.

[0032] <Settings section> The setting unit 1400 arbitrarily sets the threshold value in order to set an optimal 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 set an arbitrary value in the rotary switch, thereby arbitrarily setting the threshold value. The setting unit 1400 is, for example, a numeric keypad for inputting an arbitrary value. By inputting an arbitrary value, the setting unit 1400 can set the input value as the threshold 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 0.75 atmospheres, but it may be a unit of gas insulation strength of gas.

[0035] <Drive circuit> Next, a description will be given of the driving circuit 1500. The driving circuit 1500 generates a driving signal that changes the irradiation of ultraviolet light at regular intervals in order to prevent a temperature rise in the irradiation unit 1100 due to the irradiation of ultraviolet light. The driving circuit 1500 is connected to a control unit 1600. Specifically, the drive circuit 1500 generates an ON signal or an OFF signal indicating the ON or OFF state of the ultraviolet irradiation device 1000 irradiating ultraviolet rays.

[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 increasing, but the temperature increase may be prevented by other methods. For example, this may be prevented by using 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, for example, when the gas insulation strength detected by the first detection unit 1200 is smaller than a threshold value, the control unit 1600 controls the irradiation unit 1100 to stop emitting ultraviolet light. Furthermore, for example, when the gas insulation strength detected by the first detection unit 1200 is equal to or greater than a threshold value, the control unit 1600 controls the irradiation unit 1100 to irradiate ultraviolet light.

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

[0041] Furthermore, when the instruction content for ultraviolet light irradiation based on the first detection unit 1200 differs from the instruction content for ultraviolet light irradiation based on the drive circuit 1500, the control unit 1600 irradiates ultraviolet light only when the instruction content of both the first detection unit 1200 and the drive circuit 1500 is to irradiate ultraviolet light. For example, when the gas insulation strength detected by the first detector 1200 is smaller than the threshold value and the drive circuit 1500 generates an ON signal, the irradiation of ultraviolet light is stopped.

[0042] <Ultraviolet ray irradiation device operation> 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 irradiating 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 of FIG.

[0043] First, the air pressure measurement unit 1300 measures the air pressure of the atmosphere in which the ultraviolet irradiating 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 irradiating 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 light irradiation (S1003). Specifically, the control unit 1600 determines whether or not the irradiation unit 1100 is irradiating ultraviolet light. If the irradiation unit 1100 is irradiating ultraviolet light, the process proceeds to step S1004, and if the irradiation unit 1100 is not irradiating ultraviolet light, 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 smaller than a set threshold value. The first detection unit 1200 transmits the determination result to the control unit 1600. If it is smaller than the set threshold, the process proceeds to step S1005, and if it is equal to or greater than the set threshold, 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 higher 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. The first detection unit 1200 transmits the determination result to the control unit 1600. If it is equal to or greater than the set threshold, the process proceeds to step S1007, and if it is less than the set threshold, 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, with reference to FIG. 10, a specific example of the relationship between atmospheric pressure and ultraviolet radiation when the above-mentioned steps are adopted will be described. The top graph (A) in Fig. 10 shows an example of fluctuations in air pressure. The middle graph (B) shows the state of the drive signal generated by the drive circuit 1500. The bottom graph (C) shows the ON / OFF state of the ultraviolet irradiation device 1000. In the bottom graph (C), when the drive signal of 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 indicates the time axis. As can be seen from this graph, the ultraviolet irradiation device 1000 in principle repeats the start and stop of ultraviolet irradiation 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 air pressure is equal to or higher than a threshold, but is in an OFF state once the air pressure falls below the threshold regardless of the state of the drive signal. When the air pressure returns to above the threshold again 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 in 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 a series of operations.

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

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

[0055] Examples of cases in which the ultraviolet irradiation device 1000 stops irradiating ultraviolet rays other than when the drive circuit 1500 generates an OFF signal as a drive signal include when a device controlling the air pressure in the aircraft breaks down 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, the atmospheric pressure may become lower than the threshold value as shown in Fig. 10. In such a case, there is a risk of dielectric breakdown occurring between the electrodes of the ultraviolet irradiation device, and therefore irradiation of ultraviolet rays is stopped. Then, when control of the air pressure inside the aircraft is restored, that is, when the air pressure reaches or exceeds the threshold value, irradiation of ultraviolet rays is resumed.

[0057] In this way, according to the ultraviolet irradiation device 1000 of the present embodiment, irradiation of ultraviolet rays can be automatically stopped and automatically resumed depending on the atmospheric pressure conditions around the ultraviolet irradiation device 1000. This makes it possible to prevent abnormal discharge even if the gas insulation strength decreases with a drop in atmospheric pressure. In other words, the small-sized ultraviolet irradiation device 1000 can be used stably even in places where the atmospheric pressure fluctuates in normal use.

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

[0059] (Extending the distance between electrodes) As a preventative measure against abnormal discharge, for example, the electrodes are arranged so as to be spaced apart from each other. This increases the amount of air between the electrodes and improves the insulation strength. However, Similarly, the insulation distance of the excimer lamp 3 becomes long, making it difficult for the excimer lamp 3 to start discharging, and in the worst case, causing the excimer lamp 3 to stop lighting. Furthermore, this measure requires a distance between the electrodes, which increases the size of the irradiation unit 1100 and therefore the size of the ultraviolet irradiation device 1000.

[0060] (Insulating material filling) As a preventive measure against abnormal discharge, for example, an insulating material having a higher insulation strength than air is filled between the electrodes. The insulating material is, for example, Teflon, plastic, or vinyl insulating material that exhibits electrical insulating properties. This can increase the insulating strength. This measure requires the use of insulating materials for all electrodes, which compromises the weight reduction.

[0061] (Introduction of protection circuit) As a preventative measure against abnormal discharge, for example, a protection circuit such as a fuse is used. With this, when abnormal discharge occurs, the fuse is activated to open the circuit, and it is possible to prevent the 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 if the fuse is resettable, a worker must reset the fuse. Due to the way fuses work, they need to be subjected to an overcurrent for a certain period of time before they activate, and during that time the electronic components before and after the fuse will carry an overcurrent greater than the design anticipated. This can cause stress on other electronic components besides the fuse, which can lead to other failures.

[0063] (Abnormality monitoring device) As a preventive measure against abnormal discharge, for example, various sensors are installed, which allows the irradiation unit 1100 to be stopped when abnormal discharge occurs. This measure requires the presence of monitors on-site to monitor the output of various sensors, monitoring software to replace the monitors, and a communications network to transmit the sensor output to a server.

[0064] (Example) Next, an example of a circuit configuration for implementing an embodiment of the present disclosure will be described with reference to FIG. FIG. 11 is a circuit diagram for implementing the 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 are, for example, an AND gate, a resistor, a diode, a comparator, and the like. The ultraviolet irradiation device 1000 is constructed by combining 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, it outputs a logical value of 1, and if it is less, it outputs a logical value of 0.

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

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

[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 so as to cause the irradiation unit 1100 to irradiate ultraviolet light.

[0071] [Second embodiment] The ultraviolet irradiating device 2000 of the second embodiment differs from the first embodiment in that it has a function of stopping ultraviolet irradiating when a person is detected in addition to the air 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 given the same reference numerals, and descriptions thereof 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 a person 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 a person 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 in which the ultraviolet irradiation device 2000 irradiates ultraviolet rays. The second detection unit 2700 is, for example, a human sensor.

[0075] When the second detection unit 2700 detects a person present within the detection range, the second detection unit 2700 transmits information indicating that the person has been detected 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 a 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 a detection result from the second detection unit 2700.

[0077] Furthermore, for example, when the gas insulation strength detected by the first detection unit 1200 is smaller than a threshold value, the control unit 2600 controls the irradiation unit 1100 to stop irradiating ultraviolet rays. Furthermore, for example, when the gas insulation strength detected by the first detection unit 1200 is equal to or greater than a threshold value, the control unit 2600 controls the irradiation unit 1100 to irradiate ultraviolet light.

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

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

[0080] Furthermore, when the instruction content for ultraviolet light irradiation based on the first detection unit 1200, the instruction content for ultraviolet light irradiation based on the drive circuit 1500, and the instruction content for ultraviolet light irradiation based on the second detection unit 2700 are different, the control unit 2600 irradiates ultraviolet light only when the instruction content for ultraviolet light irradiation from all of the first detection unit 1200, the drive circuit 1500, and the second detection unit 2700 is to irradiate ultraviolet light. For example, when the gas insulation strength detected by the first detection unit 1200 is smaller than the threshold value and the second detection unit 2700 detects a person, irradiation of ultraviolet rays is stopped.

[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 irradiating device 2000 in this embodiment based on the first detecting section 1200 and the second detecting section 2700. As shown in FIG. Hereinafter, the process executed by the ultraviolet irradiation device 2000 will be described with reference to the flowchart of Fig. 13. The flowchart of Fig. 13 starts when the ultraviolet irradiation device 2000 irradiates ultraviolet rays in an environment of 0.75 atmospheric pressure or higher.

[0082] First, the air pressure measurement unit 1300 measures the air pressure of the atmosphere in which the ultraviolet irradiating 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 irradiating 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 smaller than a set threshold value. The first detection unit 1200 transmits the determination result to the control unit 2600. If it is smaller than the set threshold, the process proceeds to step S1105, and if it is equal to or greater than the set threshold, 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 is present in a specific detection range. If the second detection unit 2700 detects a person, the second detection unit 2700 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, with reference to FIG. 14, a specific example of the relationship between atmospheric pressure and ultraviolet radiation when the above-mentioned steps are adopted will be described. The top graph (A) in Figure 14 shows an example of fluctuations in air pressure. The middle graph (B) shows an example of fluctuations in human detection. The middle graph (C) shows the state of the drive signal generated by the drive circuit 1500. The bottom graph (D) shows the ON / OFF state of the ultraviolet irradiation device. The horizontal axis in both graphs indicates the time axis. In the bottom graph (D), when there is an ON signal, the ultraviolet irradiation device is ON, and when there is an OFF signal, the ultraviolet irradiation device is OFF. As can be seen from this graph, the ultraviolet ray irradiation device 2000 in principle repeats the start and stop of irradiation of ultraviolet rays 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 irradiating 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 below 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 ON, 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 ON again.

[0090] In addition to this, in the ultraviolet irradiation device 2000 of this embodiment, even if a person is detected, the ultraviolet irradiation device is turned OFF, and when the air pressure returns to above the threshold value and no person is detected, the ultraviolet irradiation device is turned ON again. 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 turns OFF once the air pressure falls below the threshold or when a person is detected, regardless of the state of the drive signal. When the air pressure returns to or exceeds the threshold value, the drive signal generates an ON signal, and no human presence is detected, the ultraviolet irradiation device 2000 also changes to return to ON.

[0091] (Example) Next, an example of a circuit configuration for implementing an embodiment of the present disclosure will be described with reference to FIG. FIG. 15 is a circuit diagram for implementing the 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 are, for example, an AND gate, a resistor, a diode, a comparator, and the like. The ultraviolet irradiation device 2000 is constructed by combining 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, it outputs a logical value of 1, and if it is less, it outputs a logical value of 0.

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

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

[0096] For example, the second detection section 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 so as to cause the irradiation unit 1100 to irradiate ultraviolet light.

[0100] In this way, according to the ultraviolet irradiation device 2000 of the present embodiment, the irradiation of ultraviolet rays can be automatically stopped and automatically resumed by detecting a person in addition to the atmospheric pressure conditions around the ultraviolet irradiation device 2000. This makes it possible to prevent ultraviolet rays from being irradiated onto people even if they are within the range irradiated with ultraviolet rays by the ultraviolet irradiation device 2000. In other words, the ultraviolet irradiation device 2000 can be used safely even in places where people would be present in normal use.

[0101] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention. [Explanation of symbols]

[0102] 1000: ultraviolet irradiation device, 1100: irradiation unit, 1112: first electrode, 1113: second electrode, 1200: first detection unit, 1300: air pressure measurement unit, 1400: setting unit, 1500: driving 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.

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