Ultraviolet irradiation device

Abstract

This ultraviolet irradiation device is provided with an irradiation unit (11) that irradiates ultraviolet light, and a control unit (13) that controls the irradiation unit (11) so as to repeatedly perform a first mode (M1) in which the irradiation unit (11) irradiates ultraviolet light such that the irradiation amount of ultraviolet light per unit area within a predetermined period is less than a reference irradiation amount, and a second mode (M2) in which the irradiation amount of ultraviolet light per unit area within a predetermined period is less than a reference irradiation amount. In the second mode (M2), the irradiation unit (11) is caused to irradiate ultraviolet light such that the irradiation amount of ultraviolet light per unit area within the predetermined period is equal to or greater than the reference irradiation amount.

Description

Technical Field

[0001] The present disclosure relates to an ultraviolet irradiation device. Background Art

[0002] Patent document 1 discloses an ultraviolet irradiation device. The ultraviolet irradiation device includes: a light source for irradiating a deep ultraviolet region onto an irradiated surface, and a drive circuit for controlling the operation of the light source. The drive circuit operates the light source intermittently in such a manner that the period of not irradiating the irradiation light does not exceed three days.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Publication No. 2020-202916 Summary of the invention

[0006] -Technical problem to be solved by the invention-

[0007] However, if the amount of irradiation light (ultraviolet light) is insufficient and the mold cannot be sufficiently sterilized during the ultraviolet light irradiation period, the mold may grow during the period when it is not irradiated with the irradiation light.

[0008] The purpose of the present disclosure is to provide an ultraviolet irradiation device that can inhibit the growth of fungi.

[0009] -Technical solutions for solving technical problems-

[0010] The ultraviolet irradiation device of the first aspect is used for sterilization. The ultraviolet irradiation device includes an irradiation unit 11 and a control unit 13, wherein the irradiation unit 11 irradiates ultraviolet rays, and the control unit 13 controls the irradiation unit 11 in a manner of repeatedly performing a first mode M1 and a second mode M2, wherein in the first mode M1, the irradiation unit 11 irradiates ultraviolet rays in a manner that the irradiation amount of ultraviolet rays per unit area within a specified period is less than a reference irradiation amount, and in the second mode M2, the irradiation unit 11 irradiates ultraviolet rays in a manner that the irradiation amount of ultraviolet rays per unit area within the specified period is greater than the reference irradiation amount.

[0011] In the first aspect, the growth of fungi can be suppressed.

[0012] According to a second aspect, in addition to the first aspect, in the first mode M1 , the irradiation unit 11 irradiates ultraviolet rays intermittently and multiple times.

[0013] In the second aspect, by reducing the operating time of the irradiation unit 11 , the life of the irradiation unit 11 can be extended.

[0014] According to a third aspect, in the first aspect, in the first mode M1 , the irradiation unit 11 continuously irradiates ultraviolet rays.

[0015] In the third aspect, the growth of mold can be stably suppressed in the first mode M1.

[0016] According to a fourth aspect, based on any one of the first to third aspects, when the peak wavelength of the ultraviolet rays is greater than or equal to 260 nm and less than or equal to 270 nm and the prescribed period is one day, the reference irradiation amount is 320 mJ / cm 2 , and the minimum value of the irradiation amount under the first mode M1 is 80mJ / cm 2 .

[0017] In the fourth aspect, the irradiation amount of ultraviolet rays that can effectively prevent the growth of mold can be determined in accordance with the peak wavelength of ultraviolet rays.

[0018] A fifth aspect is a method according to any one of the first to third aspects, wherein the peak wavelength of the ultraviolet rays is greater than or equal to 249 nm and less than or equal to 259 nm, and the predetermined period is one day, and the reference irradiation amount is 298 mJ / cm 2 , and the minimum value of the irradiation amount under the first mode M1 is 74mJ / cm 2 .

[0019] In the fifth aspect, the irradiation amount of ultraviolet rays that can effectively prevent the growth of mold can be determined in accordance with the peak wavelength of ultraviolet rays.

[0020] In the sixth aspect, based on any one of the first to third aspects, when the peak wavelength of the ultraviolet rays is greater than or equal to 275 nm and less than or equal to 285 nm and the prescribed period is one day, the reference irradiation amount is 496 mJ / cm 2 , and the minimum value of the irradiation amount under the first mode M1 is 124mJ / cm 2 .

[0021] In the sixth aspect, the irradiation amount of ultraviolet rays that can effectively prevent the growth of mold can be determined in accordance with the peak wavelength of ultraviolet rays.

[0022] According to a seventh aspect, in any one of the first to sixth aspects, an upper limit of a period Y from when the second mode M2 ​​is performed to when the second mode M2 ​​is performed next time is set based on the irradiation amount in the first mode M1.

[0023] In the seventh aspect, the timing of performing the second mode M2 ​​can be determined in consideration of the sterilization capability of ultraviolet rays at the irradiation level in the first mode M1 (how long the growth of mold can be suppressed).

[0024] In the eighth aspect, based on the fourth aspect, the period Y from the start of the second mode M2 ​​to the next second mode M2 ​​is less than Y1 hours, and when the exposure amount in one day under the first mode M1 is set to X, the Y1 hours is expressed by the following mathematical formula 1:

[0025] (Mathematical formula 1)

[0026] Y1=0.45X+33.

[0027] In the eighth aspect, the upper limit of the period Y from the start of the second mode M2 ​​to the next second mode M2 ​​can be set to Y1 hours.

[0028] In the ninth aspect, based on the fifth aspect, the period Y from the start of the second mode M2 ​​to the next second mode M2 ​​is less than Y2 hours, and when the exposure amount in one day under the first mode M1 is set to X, the Y2 hours is expressed by the following mathematical formula 2:

[0029] (Mathematical formula 2)

[0030] Y2=0.49X+33.

[0031] In the ninth aspect, the upper limit of the period Y from the start of the second mode M2 ​​to the next performance of the second mode M2 ​​can be set to Y2 hours.

[0032] In the tenth aspect, based on the sixth aspect, the period Y from the start of the second mode M2 ​​to the next second mode M2 ​​is less than Y3 hours, and when the exposure amount in one day under the first mode M1 is set to X, the Y3 hours is expressed by the following mathematical formula 3:

[0033] (Mathematical formula 3)

[0034] Y3=0.29X+33.

[0035] In the tenth aspect, the upper limit of the period Y from the start of the second mode M2 ​​to the next performance of the second mode M2 ​​can be set to Y3 hours.

[0036] In the eleventh aspect, based on any one of the first to third aspects, the reference irradiation amount is set based on corresponding information of the irradiation amount of ultraviolet rays irradiated on the fungi to be sterilized, the peak wavelength of the ultraviolet rays, and the mortality rate or inactivation rate of the fungi irradiated with the ultraviolet rays.

[0037] In the eleventh aspect, the reference irradiation amount can be set based on the corresponding information.

[0038] In the twelfth aspect, based on any one of the first to third aspects, when the peak wavelength of ultraviolet rays is greater than 260nm and less than 270nm, and the amount of ultraviolet rays per unit area during the specified period at which the mortality rate or inactivation rate of fungi after irradiation with ultraviolet rays is 90% is A, and when the amount of ultraviolet rays per unit area during the specified period at which the mortality rate or inactivation rate of fungi after irradiation with ultraviolet rays is B, the baseline irradiation amount is set to B, and the minimum value of the irradiation amount under the first mode M1 is set to A.

[0039] In the twelfth aspect, the reference irradiation amount and the minimum value of the irradiation amount in the first mode M1 can be set in consideration of the peak wavelength of the ultraviolet rays and the mortality rate or inactivation rate of fungi caused by the ultraviolet rays.

[0040] In the thirteenth aspect, based on the twelfth aspect, when the peak wavelength of ultraviolet light is greater than or equal to 260nm and less than or equal to 270nm, the period Y from the start of the second mode M2 ​​to the next execution of the second mode M2 ​​is set to less than Y4 hours, and when the irradiation amount in the first mode M1 is set to X, the Y4 hours is expressed by the following mathematical formula 4, where α and β are the irradiation amounts per unit area of ​​ultraviolet light with a peak wavelength of greater than or equal to 260nm and less than or equal to 270nm within a specified period, β is greater than α, and f (α) The time it takes to suppress the growth of fungi after exposure to ultraviolet light at a dose of α, f (β) It is the time it takes to suppress the growth of fungi after irradiating with ultraviolet light at a dose of β.

[0041] (Mathematical formula 4)

[0042] Y4=a·X+b

[0043] a={f (β) -f (α) / (β-α)}

[0044] b=f (α) -a·α.

[0045] In the thirteenth aspect, the period Y from the start of the second mode M2 ​​to the next execution of the second mode M2 ​​can be obtained by calculation.

[0046] A fourteenth aspect is based on the thirteenth aspect. When the peak wavelength of ultraviolet rays is greater than or equal to 249 nm and less than or equal to 259 nm, the reference irradiation amount is set to B / 1.08, and the minimum value of the irradiation amount in the first mode M1 is set to A / 1.08.

[0047] In the fourteenth aspect, the reference irradiation amount when the peak wavelength of ultraviolet rays is greater than or equal to 249 nm and less than or equal to 259 nm and the minimum irradiation amount in the first mode M1 can be set based on the mortality rate or inactivation rate of fungi caused by ultraviolet rays with a peak wavelength of 265 nm.

[0048] A fifteenth aspect is based on the fourteenth aspect. When the peak wavelength of ultraviolet rays is greater than or equal to 249 nm and less than or equal to 259 nm, and when the period Y from the start of the second mode M2 ​​to the next second mode M2 ​​is less than or equal to Y5 hours, the Y5 hours is expressed by the following mathematical formula 5:

[0049] (Mathematical formula 5)

[0050] Y5=a1·X+b1

[0051] a1={f (β / 1.08) -f (α / 1.08) / (β / 1.08-α / 1.08)}

[0052] b1=f (α / 1.08) -a·α / 1.08.

[0053] In the fifteenth aspect, the period Y from the start of the second mode M2 ​​to the next execution of the second mode M2 ​​can be obtained by calculation.

[0054] In the sixteenth aspect, based on any one of the thirteenth to fifteenth aspects, when the peak wavelength of ultraviolet rays is greater than 275nm and less than 285nm, the reference irradiation amount is set to B / 0.65, and the minimum value of the irradiation amount in the first mode M1 is set to A / 0.65.

[0055] In the sixteenth aspect, the reference irradiation amount when the peak wavelength of ultraviolet rays is greater than or equal to 275 nm and less than or equal to 285 nm and the minimum irradiation amount in the first mode M1 can be set based on the mortality rate or inactivation rate of fungi caused by ultraviolet rays with a peak wavelength of 265 nm.

[0056] In the seventeenth aspect, based on the sixteenth aspect, when the peak wavelength of ultraviolet rays is greater than or equal to 275 nm and less than or equal to 285 nm, and when the period Y from the start of the second mode M2 ​​to the next execution of the second mode M2 ​​is less than or equal to Y6 hours, the Y6 hours is expressed by the following mathematical formula 6:

[0057] (Mathematical formula 6)

[0058] Y6=a2·X+b2

[0059] a2={f (β / 0.65) -f (α / 0.65) / (β / 0.65-α / 0.65)}

[0060] b2=f (α / 0.65) -a·α / 0.65.

[0061] In the seventeenth aspect, the period Y from the start of the second mode M2 ​​to the next execution of the second mode M2 ​​can be obtained by calculation.

[0062] In the eighteenth aspect, based on any one of the first to third aspects, the fungi to be sterilized include Fusarium or Penicillium, the peak wavelength of the ultraviolet light is greater than 260nm and less than 270nm, and the prescribed period is one day, and the reference irradiation amount is 48mJ / cm 2 , and the minimum value of the irradiation amount under the first mode M1 is 12mJ / cm 2 .

[0063] In the eighteenth aspect, the reference irradiance and the lowest value of the irradiance in the first mode M1 can be set in accordance with the type of fungus.

[0064] In the nineteenth aspect, based on any one of the first to third aspects, the fungi to be sterilized include Cladosporium or Aspergillus, the peak wavelength of the ultraviolet light is greater than or equal to 260nm and less than or equal to 270nm, and the prescribed period is one day, and the reference irradiation amount is 327mJ / cm 2 , and the minimum value of the irradiation amount under the first mode M1 is 82mJ / cm 2 .

[0065] In the nineteenth aspect, the reference irradiation amount and the lowest value of the irradiation amount in the first mode M1 can be set in accordance with the type of fungus. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 is a schematic diagram showing an ultraviolet irradiation device;

[0067] Figure 2is a block diagram showing the structure of an ultraviolet irradiation device;

[0068] Figure 3 is a diagram showing an operating mode of a control unit;

[0069] Figure 4 This is a graph showing the relationship between the amount of ultraviolet radiation and the time that can suppress the growth of mold;

[0070] Figure 5 It is a diagram of the process of mold growth observed on an object;

[0071] Figure 6 It is a diagram of the process of mold growth observed on an object;

[0072] Figure 7 It is a diagram of the process of mold growth observed on an object;

[0073] Figure 8 It is a diagram of the process of mold growth observed on an object;

[0074] Fig. 9 is a diagram showing a first example of an ultraviolet irradiation pattern;

[0075] Fig.10 is a diagram showing a second example of an ultraviolet irradiation pattern;

[0076] Fig.11 is a diagram showing a third example of the ultraviolet irradiation pattern;

[0077] Fig.12 This is a graph showing the relationship between the amount of ultraviolet radiation and the time that can suppress the growth of mold;

[0078] Fig.13 This is a graph showing the relationship between the amount of ultraviolet radiation and the time that can suppress the growth of mold;

[0079] Fig.14 is a diagram showing corresponding information;

[0080] Fig.15 (a) is a diagram showing first related information; Fig.15 (b) is a diagram showing second related information;

[0081] Fig.16 It is a diagram showing sterilization information. DETAILED DESCRIPTION

[0082] The following is a detailed description of the embodiments of the present disclosure with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the embodiments shown below, and various changes can be made without departing from the technical concept of the present disclosure. Each of the accompanying drawings is a diagram for conceptually illustrating the present disclosure, so in order to facilitate understanding, the size, ratio or quantity may be exaggerated or simplified as needed.

[0083] (1) Overall structure

[0084] The ultraviolet irradiation device 1 according to the embodiment irradiates ultraviolet rays in order to prevent the growth of fungi such as mold. The ultraviolet irradiation device 1 is used, for example, for a device or object such as an air conditioner in which mold may grow. The ultraviolet irradiation device 1 is, for example, disposed near a water receiving tray of the air conditioner and irradiates ultraviolet rays toward the water receiving tray. The fungi in the present embodiment are, for example, fungi such as Cladosporium, Penicillium, Fusarium, Aspergillus, Alternaria, and Arthrosporium that can be removed by ultraviolet irradiation.

[0085] like Figure 1 and Figure 2 As shown, the ultraviolet irradiation device 1 includes an irradiation unit 11, a storage unit 12, and a control unit 13. The irradiation unit 11 irradiates ultraviolet rays. The irradiation unit 11 includes a light source, which is composed of, for example, a UVC-LED that emits light in the deep ultraviolet region. The irradiation unit 11 irradiates ultraviolet rays toward an object G. The object G is set in an environment where fungi such as molds are easy to reproduce. Figure 1 In the figure, as an example of the ultraviolet irradiation device 1, the device structure is illustrated when an agar culture medium is used as the object G and a test is performed to sterilize fungi grown on the object G. The storage unit 12 includes a main storage device (for example, a semiconductor memory) such as a flash memory, a ROM (Read Only Memory) and a RAM (Random Access Memory), and may also include an auxiliary storage device (for example, a hard disk drive, an SSD (Solid State Drive), an SD (Secure Digital) memory card, or a USB (Universal Serial Bus) flash memory). The storage unit 12 stores various computer programs executed by the control unit 13. The control unit 13 includes a processor such as a CPU and an MPU. The control unit 13 controls the various elements of the ultraviolet irradiation device 1 by executing the computer program stored in the storage unit 12.

[0086] (2) Operation of the control unit

[0087] like Figure 3As shown, the control unit 13 controls the irradiation unit 11 in such a manner that the first mode M1 and the second mode M2 ​​are performed alternately. Figure 3 As shown, the control unit 13 controls the irradiation unit 11 in a manner of repeatedly performing the first mode M1 and the second mode M2. The first mode M1 is an operation mode (inhibition mode) of the control unit 13 for inhibiting the growth of fungi such as mold. The second mode M2 ​​is an operation mode (sterilization mode) of the control unit 13 for killing bacteria.

[0088] In the first mode M1, ultraviolet rays are irradiated in such a manner that the amount of ultraviolet rays in a prescribed period (irradiation amount per unit area) is a first irradiation amount X. That is, in the first mode M1, ultraviolet rays are irradiated in such a manner that the amount of ultraviolet rays per unit area in the above prescribed period is less than a prescribed reference irradiation amount. In the second mode M2, ultraviolet rays are irradiated in such a manner that the amount of ultraviolet rays in the above prescribed period is a second irradiation amount Xa. That is, in the second mode M2, ultraviolet rays are irradiated in such a manner that the amount of ultraviolet rays per unit area in the above prescribed period is greater than the above reference irradiation amount. The first irradiation amount X and the second irradiation amount Xa represent the amount of ultraviolet rays per unit area in a prescribed period (DOSE amount, dosage). The second irradiation amount is greater than the first irradiation amount. In the present embodiment, in the first mode M1, ultraviolet rays are irradiated intermittently and multiple times by the irradiation unit 11.

[0089] (3) Effect

[0090] As described above, the control unit 13 controls the irradiation unit 11 in a manner of alternately performing the first mode M1 and the second mode M2. In the first mode M1, the irradiation unit 11 irradiates ultraviolet rays in a manner that the irradiation amount of ultraviolet rays per unit area in a prescribed period is the first irradiation amount, and in the second mode M2, the irradiation unit 11 irradiates ultraviolet rays in a manner that the irradiation amount of ultraviolet rays per unit area in the prescribed period is the second irradiation amount. The second irradiation amount is greater than the first irradiation amount. Thus, the following two processes can be alternately performed: in the first mode M1, a process of suppressing the growth of fungi using the first irradiation amount of ultraviolet rays with a relatively low amount and low output; and in the second mode M2, a process of killing bacteria using the second irradiation amount of ultraviolet rays with a relatively high output. As a result, even if the ultraviolet rays of the first irradiation amount with a low output become difficult to suppress the growth momentum of fungi over time in the first mode M1, it is possible to kill bacteria using the ultraviolet rays of the second irradiation amount with a high output after switching to the second mode M2, thereby weakening the growth momentum of fungi, and thus suppressing the growth of fungi.

[0091] Furthermore, by alternately performing the first mode M1 and the second mode M2, the state of irradiating high-power ultraviolet rays in the second mode M2 ​​is prevented from being always maintained. As a result, the power consumption of the irradiation unit 11 can be suppressed, and the life of the irradiation unit 11 can be extended.

[0092] In addition, by suppressing the power consumption of the irradiation unit 11 (LED), the heat dissipation of the irradiation unit 11 is suppressed, thereby eliminating the need for heat dissipation components (such as a heat sink provided on the LED substrate) for the irradiation unit 11, thereby reducing the number of components. In addition, since the LED substrate can be reduced, the degree of freedom in setting the irradiation unit 11 can be increased.

[0093] Furthermore, by alternately performing the first mode M1 and the second mode M2 ​​, the frequency of high-output ultraviolet irradiation in the second mode M2 ​​can be suppressed, and thus the amount of ultraviolet radiation received by the human body can be suppressed.

[0094] Furthermore, by alternately performing the first mode M1 and the second mode M2 ​​, it is possible to suppress the growth of mold, thereby reducing the load on the respiratory organs of the human body.

[0095] Furthermore, when the ultraviolet irradiation device 1 is installed in an air conditioner, by alternately performing the first mode M1 and the second mode M2 ​​, it is possible to prevent mold from growing inside the air conditioner, thereby reducing the frequency of cleaning parts such as the water tray inside the air conditioner.

[0096] Furthermore, when the ultraviolet irradiation device 1 is provided in an air conditioner, the frequency of high-output ultraviolet irradiation in the second mode M2 ​​can be suppressed by alternately performing the first mode M1 and the second mode M2, thereby suppressing the degradation of components inside the air conditioner due to high-output ultraviolet rays.

[0097] (4) First Example of First Irradiation Amount X and Second Irradiation Amount Xa (Peak Wavelength is 260 nm or More and 270 nm or Less)

[0098] Figure 4 Each point on the coordinates shown in FIG. 1 shows the results of an experiment that investigated the relationship between the amount of ultraviolet radiation and the time it takes to inhibit the growth of mold. In this experiment, an agar medium (reference Figure 1 ) irradiates ultraviolet light with a peak wavelength of 265nm. Figure 4 In the coordinate system shown, the horizontal axis represents the amount of ultraviolet radiation per unit area irradiated to the object G for one day (DOSE amount), and the vertical axis represents the time during which the growth of mold on the object G can be suppressed.

[0099] like Figure 4As shown in the test results F1 to F4, it can be confirmed that if the ultraviolet radiation dose per day is about 80mJ / cm 2 As described above, as the amount of ultraviolet irradiation increases, the time during which the growth of mold can be suppressed also increases, thereby effectively suppressing the growth of mold.

[0100] Figure 5 The first observation shows the state of the object G after zero to five days. In the first observation, the irradiation amount of ultraviolet light per day is 0 mJ / cm 2 、10mJ / cm 2 、40mJ / cm 2 、80mJ / cm 2 and 120mJ / cm 2 The object G is intermittently irradiated with ultraviolet rays in a manner of irradiation amount, and the state of the object G is observed. Figure 6 The state of the object G after six to ten days have passed when the above-mentioned first observation was performed is shown. Figure 7 The second observation shows the state of the object G after zero to five days. In the second observation, the irradiation amount of ultraviolet light per day is 160 mJ / cm 2 、240mJ / cm 2 and 320mJ / cm 2 The object G is intermittently irradiated with ultraviolet rays at an irradiation dose of 345.6 mJ / cm 2 The object G is continuously irradiated with ultraviolet rays in a manner and the state of the object G is observed. Figure 8 The state of the object G after six to ten days have passed when the second observation is performed is shown.

[0101] It should be noted that in Figures 5 to 8 In the first observation and the second observation shown, the object G is irradiated with ultraviolet rays having a peak wavelength of 265 nm.

[0102] Figures 5 to 8 Among the objects G shown, the object A1 outside the frame W indicates that the growth of mold is suppressed, and the object A2 inside the frame W indicates that the growth of mold is not suppressed.

[0103] like Figures 5 to 8 As shown in Figure 2, if the daily UV exposure is 320 mJ / cm 2 As a result, it can be confirmed that if the daily ultraviolet irradiation is 320 mJ / cm 2 The above can completely prevent the growth of mold and kill the mold.

[0104] In the first case, based on Figures 4 to 8 The test results shown in FIG. 1 show that when the peak wavelength of the irradiation unit 11 is between 260 nm and 270 nm, the first irradiation dose X of ultraviolet rays per day in the first mode M1 is set to 80 mJ / cm 2 Above and less than 320mJ / cm 2 (80≤X<320), the second irradiation amount Xa of ultraviolet rays per day in the second mode M2 ​​is set to 320 mJ / cm 2 That is, in the first example, the peak wavelength of ultraviolet rays is greater than 260 nm and less than 270 nm, the prescribed period is one day, and the reference irradiation amount is 320 mJ / cm 2 The minimum value of the above-mentioned irradiation amount (irradiation amount of ultraviolet rays per unit area within a specified period) in the first mode M1 is 80 mJ / cm 2 .

[0105] In the first example, the control unit 13 performs the first mode M1 and the second mode M2 ​​alternately. In the first mode M1, the ultraviolet rays of the first irradiation amount X with a low amount are used to suppress the growth of mold for a certain period of time. In the second mode M2, the ultraviolet rays of the second irradiation amount Xa with a high amount are used to kill the mold and weaken the momentum of the mold growth.

[0106] (5) Upper limit of the second mode interval

[0107] The second mode interval Y is described below. The second mode interval Y is a period from when the second mode starts to when the next second mode starts.

[0108] The first irradiation dose X of ultraviolet light in one day is set to 80 mJ / cm 2 Above and less than 320mJ / cm 2 In the case of Figures 5 to 8 As shown, at 80mJ / cm 2 Above and less than 320mJ / cm 2 Under the irradiation of 120mJ / cm 2 In the case of , mold began to grow on object G from the fourth day.

[0109] After the mold has grown, even if the mode is switched to the second mode M2 ​​and ultraviolet rays of the second irradiation amount Xa are irradiated, it is difficult to weaken the momentum of the mold growth.

[0110] In the first example, in order to switch from the first mode M1 to the second mode M2 ​​before mold propagation, an upper limit is set for the second mode interval Y.

[0111] In the first mode M1, at 80 mJ / cm 2 Above and less than 320mJ / cm 2 In the case of irradiating ultraviolet light with the first irradiation amount X, Figures 5 to 8 As shown, the date when mold starts to grow varies depending on the amount of ultraviolet radiation. Specifically, the greater the amount of radiation, the later the date when mold starts to grow. Therefore, the greater the first radiation amount X, the later the time when mold starts to grow, and thus the upper limit of the second mode interval Y is longer. In other words, the upper limit of the second mode interval Y represents the upper limit of the period during which the first mode M1 is performed once.

[0112] When the peak wavelength of ultraviolet light is greater than or equal to 260 nm and less than or equal to 270 nm, the upper limit of the second mode interval Y is, for example, Y1 hours (Y≤Y1). The upper limit of the second mode interval (the period from the start of the second mode M2 ​​to the next second mode M2) Y is set based on the amount of ultraviolet light irradiation per unit area during the above-mentioned prescribed period in the first mode M1. Y1 hours is expressed by the following mathematical formula 1. The following mathematical formula 1 expresses Figure 4 In the coordinate system shown, the vertical axis is Y1 hour and the horizontal axis is an approximate straight line V1 of the test results F1 to F4 at the first irradiation amount X. In other words, X is the irradiation amount of ultraviolet rays per unit area in a predetermined period (one day) in the first mode M1.

[0113] (Mathematical formula 1)

[0114] Y1=0.45X+33.

[0115] (6) Example of irradiation pattern

[0116] Fig. 9 The peak wavelength of the ultraviolet rays from the irradiation unit 11 is 265 nm, and the first irradiation amount X per day is set to 120 mJ / cm 2 The second irradiation dose Xa for one day is set to 320 mJ / cm 2 , the ultraviolet irradiation mode when the period of the first mode M1 is set to 72 hours. Fig. 9 In the irradiation mode shown, three treatments were performed in the first mode M1, and the total irradiation amount of ultraviolet light in each treatment was 120 mJ / cm 2 The ultraviolet rays are irradiated once a day in the second mode M2, and then the total irradiation amount of ultraviolet rays is 320mJ / cm 2 Expose to ultraviolet light for 1 hour.

[0117] Fig.10The peak wavelength of the ultraviolet rays from the irradiation unit 11 is 265 nm, and the first irradiation amount X per day is set to 240 mJ / cm 2 The second irradiation dose Xa for one day is set to 320 mJ / cm 2 , the ultraviolet irradiation mode when the period of the first mode M1 is set to 120 hours. Fig.10 In the irradiation mode shown, five treatments were performed in the first mode M1, and the total irradiation amount of ultraviolet rays in each treatment was 240 mJ / cm 2 The ultraviolet rays are irradiated once a day in the second mode M2, and then the total irradiation amount of ultraviolet rays is 320mJ / cm 2 Expose to ultraviolet light for 1 hour.

[0118] Fig.11 Shown in Fig.10 The UV irradiation pattern was performed under the same conditions as shown in the irradiation pattern. Fig.11 In the irradiation mode shown, in the first mode M1, the irradiation time and illumination are adjusted so that the total irradiation amount of ultraviolet rays per day is 240 mJ / cm 2 The method of irradiating ultraviolet light twice a day is similar to Fig.10 The illumination modes shown are different.

[0119] (7) Second Example of First Irradiation Amount X and Second Irradiation Amount Xa (Peak Wavelength is 249 nm or More and 259 nm or Less)

[0120] Fig.12 The test results shown used ultraviolet light with a peak wavelength of 254 nm, which is similar to Figure 4 The test results shown are different.

[0121] In the second example, if Fig.12 As shown in the test results F5 to F8, it can be confirmed that if the daily ultraviolet radiation dose is about 74mJ / cm 2 As described above, as the amount of ultraviolet irradiation increases, the time during which the growth of mold can be suppressed also increases, thereby effectively suppressing the growth of mold.

[0122] In the second example, ultraviolet light with a peak wavelength of 254 nm was irradiated as follows Figures 5 to 8 The experiment shown in the figure confirms that if the daily ultraviolet radiation dose is 298mJ / cm 2 The above can completely prevent the growth of mold and kill the mold.

[0123] Thus, in the second example, when the peak wavelength of the irradiation unit 11 is 249 nm or more and 259 nm or less, the first irradiation amount X of ultraviolet rays per day in the first mode M1 is set to 74 mJ / cm 2 Above and less than 298mJ / cm 2 (74≤X<298), the second irradiation amount Xa of ultraviolet rays per day in the second mode M2 ​​is set to 298 mJ / cm 2 That is, in the second example, the peak wavelength of ultraviolet rays is greater than 249 nm and less than 259 nm, the prescribed period is one day, and the reference irradiation amount is 298 mJ / cm 2 , and the minimum value of the above irradiation amount in the first mode M1 is 74mJ / cm 2 .

[0124] When the peak wavelength of ultraviolet light is greater than or equal to 249 nm and less than or equal to 259 nm, the upper limit of the period U from the start of the second mode M2 ​​to the next second mode M2 ​​is Y2 hours. Y2 hours is expressed by the following mathematical formula 2. Fig.12 In the coordinate system shown, the vertical axis is Y2 hours and the horizontal axis is an approximate straight line V2 of the test results F5 to F8 at the first irradiation amount X. In other words, X is the irradiation amount of ultraviolet rays per unit area in a predetermined period (one day) in the first mode M1.

[0125] (Mathematical formula 2)

[0126] Y2=0.49X+33.

[0127] (8) Third Example of First Irradiation Amount X and Second Irradiation Amount Xa (Peak Wavelength is 275 nm or More and 285 nm or Less)

[0128] Fig.13 The test results shown used ultraviolet light with a peak wavelength of 280 nm, which is similar to Figure 4 The test results shown are different.

[0129] In the third example, Fig.13 As shown in the test results F9 to F12, it can be confirmed that if the daily ultraviolet radiation dose is about 124mJ / cm 2 As described above, as the amount of ultraviolet irradiation increases, the time during which the growth of mold can be suppressed also increases, thereby effectively suppressing the growth of mold.

[0130] In the third example, ultraviolet light with a peak wavelength of 280 nm was irradiated as follows Figures 5 to 8 The experiment shown in the figure confirms that if the daily ultraviolet radiation dose is 496 mJ / cm2 The above can completely prevent the growth of mold and kill the mold.

[0131] Thus, in the third example, when the peak wavelength of the irradiation unit 11 is 275 nm or more and 285 nm or less, the first irradiation amount X of ultraviolet rays per day in the first mode M1 is set to 124 mJ / cm 2 Above and less than 496mJ / cm 2 (124≤X<496), the second irradiation amount Xa of ultraviolet rays per day in the second mode M2 ​​is set to 496 mJ / cm 2 That is, in the third example, the peak wavelength of ultraviolet light is greater than 275 nm and less than 285 nm, the prescribed period is one day, and the reference irradiation amount is 496 mJ / cm 2 , and the minimum value of the above irradiation amount in the first mode M1 is 124mJ / cm 2 .

[0132] When the peak wavelength of ultraviolet light is greater than or equal to 249 nm and less than or equal to 259 nm, the upper limit of the period U from the start of the second mode M2 ​​to the next second mode M2 ​​is, for example, Y3 hours. Y3 hours is expressed by the following mathematical formula 3. Fig.13 In the coordinate system shown, the vertical axis is Y3 hours and the horizontal axis is an approximate straight line V3 of the test results F9 to F12 at the first irradiation amount X. In other words, X is the irradiation amount of ultraviolet rays per unit area in a predetermined period (one day) in the first mode M1.

[0133] (Mathematical formula 3)

[0134] Y3=0.29X+33.

[0135] (9) Fourth Example of the First Irradiation Amount X and the Second Irradiation Amount Xa (Peak Wavelength is 260 nm or More and 270 nm or Less)

[0136] Fig.14 Corresponding information is shown. Corresponding information is information recorded in documents such as JIS Z8811 or information obtained through experiments. Corresponding information is information that corresponds the amount of ultraviolet light irradiated per unit area (DOSE amount) irradiated to the fungi to be sterilized within a specified period of time, the peak wavelength of ultraviolet light, and the mortality rate or inactivation rate of fungi irradiated with ultraviolet light.

[0137] In this embodiment, Fig.14In the correspondence information shown, the daily DOSE amount and the mortality rate of Cladosporium when Cladosporium is irradiated with ultraviolet light having a peak value of 265 nm are correlated.

[0138] In the fourth example, when the peak wavelength of ultraviolet rays is set to be greater than 260nm and less than 270nm, the first irradiation amount X in the specified period is set to be greater than A and less than B (A≤X<B), and the second irradiation amount Xa in the specified period is set to be greater than B (B≤Xa).

[0139] A is the amount of DOSE for a specified period of time when the fungi are irradiated with ultraviolet rays having a peak wavelength of 260 nm to 270 nm, so that the mortality rate or inactivation rate of the fungi is 90% to less than 99.99%. B is the amount of DOSE for a specified period of time when the fungi are irradiated with ultraviolet rays having a peak wavelength of 260 nm to 270 nm, so that the mortality rate or inactivation rate of the fungi is 99.99% or more.

[0140] exist Fig.14 The corresponding information shown is that 90% mortality is associated with 80 mJ / cm 2 Corresponding. Fig.14 The corresponding information shown is 99.99% mortality and 320mJ / cm 2 Therefore, in the fourth example, the first irradiation amount X for one day when the peak wavelength of ultraviolet rays is 260 nm or more and 270 nm or less is set to 80 mJ / cm 2 Above and less than 320mJ / cm 2 (80≤X<320), the second irradiation dose Xa for one day is set to 320mJ / cm 2 That is, the reference irradiation amount is set to 320 mJ / cm based on the corresponding information. 2 In the fourth example, when the peak wavelength of ultraviolet rays is greater than 260nm and less than 270nm, the ultraviolet irradiation amount per unit area during the above-mentioned prescribed period at which the mortality rate or inactivation rate of fungi after irradiation with ultraviolet rays is 90% is A, and the ultraviolet irradiation amount per unit area during the above-mentioned prescribed period at which the mortality rate or inactivation rate of fungi after irradiation with ultraviolet rays is 99.99% is B, the above-mentioned reference irradiation amount is set to B, and the minimum value of the above-mentioned irradiation amount in the first mode M1 is set to A.

[0141] In the fourth example, the second mode interval Y (see Figure 1 ) is represented by the following mathematical formula 4, that is, Y4 hours.

[0142] (Mathematical formula 4)

[0143] Y4=a·X+b

[0144] a in the above mathematical formula 4 is expressed by the following mathematical formula 5.

[0145] (Mathematical formula 5)

[0146] a={f (β) -f (α) / (β-α)}

[0147] b in the above mathematical formula 4 is expressed by the following mathematical formula 6.

[0148] (Mathematical formula 6)

[0149] b=f (α) -a·α.

[0150] α and β are the irradiation amounts of ultraviolet rays per unit area in a predetermined period. The peak wavelength of ultraviolet rays irradiated with the irradiation amounts α and β is 260 nm or more and 270 nm or less. β is greater than α (β>α). (α) It is the time that the growth of fungi can be suppressed after irradiation with ultraviolet light at an irradiation dose of α, and this time is obtained through experiments. (β) It is the time it takes to suppress the growth of fungi after irradiating with ultraviolet light at a dose of β. This time is obtained through experiments.

[0151] For example, the daily irradiation is 100 mJ / cm 2 (=α) After irradiation with ultraviolet light, the growth of fungi can be suppressed for 72 hours (=f (α) ), with a daily irradiation dose of 300 mJ / cm 2 (=β) After irradiation with ultraviolet light, the growth of fungi can be suppressed for 120 hours (=f (β) ). In this case, a={f (β) -f (α) / (β-α)}={120-72 / (300-100)}=0.24. In this case, b=f (α) -a·α=72-0.24×100=48. In this case, in the above formula 4, Y4=0.24X+48. In this case, for example, when the first irradiation amount X per day is 120 mJ / cm 2 When the first mode M1 and the second mode M2 ​​are performed alternately in a manner as follows, as the second mode interval Y (refer to Figure 1 )’s upper limit Y4 hours is 76.8 (=0.24×120+48) hours.

[0152] It should be noted that, for the above a and b, a plurality of DOSE amounts can be tested to observe the time for inhibiting the growth of mold, thereby preparing the following Figure 4 The slope of the approximate straight line is a, and the intercept is b.

[0153] (9) Fifth Example of the First Irradiation Amount X and the Second Irradiation Amount Xa (Peak Wavelength is 249 nm or More and 259 nm or Less)

[0154] Fig.15 (a) and Fig.15 (b) shows the related information. The related information is information that relatively specifies the sterilization effects of a plurality of ultraviolet rays having different peak wavelengths. The related information includes first related information and second related information.

[0155] Fig.15 (a) shows the first relevant information. The first relevant information is information recorded in documents such as JIS Z8811, or information obtained through experiments. In the first relevant information, the horizontal axis represents the peak wavelength of ultraviolet rays irradiated on fungi, and the vertical axis represents the relative value of the bactericidal effect. In the first relevant information, a plurality of ultraviolet rays with different peak wavelengths are matched with relative values ​​obtained by relatively stipulating the bactericidal effects brought by the ultraviolet rays. In the first relevant information of this embodiment, when the bactericidal effect brought by ultraviolet rays with a peak wavelength of 254nm is set to 1, the bactericidal effect brought by ultraviolet rays with a peak wavelength of 265nm is specified as 0.93, and the bactericidal effect brought by ultraviolet rays with a peak wavelength of 280nm is specified as 0.6.

[0156] Fig.15 (b) shows the second related information. The second related information is based on Fig.15 The second relevant information is information obtained by changing the reference ultraviolet light whose sterilization effect is set to 1 among a plurality of ultraviolet lights with different peak wavelengths on the basis of the first relevant information. In the present embodiment, in the first relevant information, the sterilization effect brought by the ultraviolet light with a peak wavelength of 254nm is set to 1, and the sterilization effect brought by the ultraviolet light with a peak wavelength of 265nm and the sterilization effect brought by the ultraviolet light with a peak wavelength of 280nm are respectively relatively specified. In the second relevant information, the relative values ​​of the sterilization effects of the ultraviolet lights with different peak wavelengths specified in the first relevant information are transformed in such a way that the sterilization effect brought by the ultraviolet light with a peak wavelength of 265nm is set to 1, thereby the sterilization effect brought by the ultraviolet light with a peak wavelength of 254nm is specified to 1.08, and the sterilization effect brought by the ultraviolet light with a peak wavelength of 280nm is specified to 0.65.

[0157] In the fifth example, the range of the first irradiation amount X, the range of the second irradiation amount Xa, and the second mode interval Y are relatively determined using A and B used in the fourth example (where the peak wavelength of ultraviolet rays is greater than 260nm and less than 270nm) through the relationship with the fourth example.

[0158] In the fifth example, when the peak wavelength of ultraviolet light is greater than or equal to 249 nm and less than or equal to 259 nm, the first irradiation amount X is set to be greater than or equal to A / 1.08 and less than or equal to B / 1.08 (A / 1.08≤X<B / 1.08), and the second irradiation amount Xa is set to be greater than or equal to B / 1.08 (B / 1.08≤Xa). That is, in the fifth example, when the peak wavelength of ultraviolet light is greater than or equal to 249 nm and less than or equal to 259 nm, the reference irradiation amount is set to B / 1.08, and the minimum value of the irradiation amount in the first mode M1 is set to A / 1.08.

[0159] In the fifth example, the second mode interval Y (see Figure 1 ) is represented by the following mathematical formula 7, that is, Y5 hours.

[0160] (Mathematical formula 7)

[0161] Y5=a1·X+b1

[0162] a1 in the above-mentioned mathematical formula 7 is expressed by the following mathematical formula 8.

[0163] (Mathematical formula 8)

[0164] a1={f (β / 1.08) -f (α / 1.08) / (β / 1.08-α / 1.08)}

[0165] b in the above equation 7 is represented by the following equation 9.

[0166] (Mathematical formula 9)

[0167] b1=f (α / 1.08) -a·α / 1.08.

[0168] The numerical value 1.08 used to obtain the range of the first irradiation amount X, the range of the second irradiation amount Xa, and the second mode interval Y when the peak wavelength of the ultraviolet rays is greater than or equal to 249 nm and less than or equal to 259 nm is obtained from Fig.15 The second related information shown in (b) is derived.

[0169] (10) Sixth Example of the First Irradiation Amount X and the Second Irradiation Amount Xa (Peak Wavelength is 275 nm or More and 285 nm or Less)

[0170] In the sixth example, the range of the first irradiation amount X, the range of the second irradiation amount Xa, and the second mode interval Y are relatively defined using A and B used in the fourth example (where the peak wavelength of ultraviolet rays is greater than 260nm and less than 270nm) through the relationship with the fourth example.

[0171] In the sixth example, when the peak wavelength of ultraviolet rays is greater than or equal to 275 nm and less than or equal to 285 nm, the first irradiation amount X is set to be greater than or equal to A / 0.65 and less than or equal to B / 0.65 (A / 0.65≤X<B / 0.65), and the second irradiation amount Xa is set to be greater than or equal to B / 0.65 (B / 0.65≤Xa). That is, in the sixth example, when the peak wavelength of ultraviolet rays is greater than or equal to 275 nm and less than or equal to 285 nm, the above-mentioned reference irradiation amount is set to B / 0.65, and the minimum value of the above-mentioned irradiation amount in the first mode M1 is set to A / 0.65.

[0172] In the sixth example, the second mode interval Y (see Figure 1 ) is represented by the following mathematical formula 10, that is, Y6 hours.

[0173] (Mathematical formula 10)

[0174] Y6=a2·X+b2

[0175] a2 in the above mathematical formula 10 is expressed by the following mathematical formula 11.

[0176] (Mathematical formula 11)

[0177] a2={f (β / 0.65) -f (α / 0.65) / (β / 0.65-α / 0.65)}

[0178] b2 in the above mathematical formula 10 is expressed by the following mathematical formula 12.

[0179] (Mathematical formula 12)

[0180] b2=f (α / 0.65) -a·α / 0.65.

[0181] The numerical value 0.65 used to obtain the range of the first irradiation amount X, the range of the second irradiation amount Xa, and the second mode interval Y when the peak wavelength of the ultraviolet rays is greater than 275nm and less than 285nm is obtained from Fig.15 The second related information shown in (b) is derived.

[0182] (11) Seventh Example of the First Irradiation Amount X and the Second Irradiation Amount Xa (Peak Wavelength is 260 nm or More and 270 nm or Less)

[0183] Fig.16 The sterilization information is shown. The sterilization information shows the range of DOSE amount per day when the mortality rate of fungi is greater than 90% and less than 99.99% after irradiation with ultraviolet rays having a peak wavelength of 265nm. In the present embodiment, the sterilization information of Fusarium, Cladosporium, Aspergillus, and Penicillium is shown. Regarding the range of DOSE amount shown in the sterilization information of each fungus, the minimum value indicates the DOSE amount when the mortality rate is 90%, and the maximum value indicates the DOSE amount when the mortality rate is 99.99%. For example, for Fusarium, 12mJ / cm 2 Indicates the DOSE dose when the mortality rate is 90%, 48mJ / cm 2 The amount of DOSE when the mortality rate is 99.99% is indicated. The sterilization information is information described in documents such as JIS Z8811 or information obtained through experiments.

[0184] In the seventh example, the first irradiation amount X and the second irradiation amount Xa are based on Fig.16 The first irradiation amount X and the second irradiation amount Xa are set according to the type of fungi to be sterilized by ultraviolet rays.

[0185] Below, use Fig.16 The related information shown describes the first irradiation amount X and the second irradiation amount Xa set according to the type of fungi to be sterilized by ultraviolet rays.

[0186] When Fusarium is the target of ultraviolet sterilization, the first irradiation dose X per day of ultraviolet rays with a peak wavelength of 260 nm to 270 nm is set to 12 mJ / cm 2 Above and less than 48mJ / cm 2 (12≤X<48), the second irradiation dose Xa for one day is set to 48mJ / cm 2 Above (48≤Xa).

[0187] When Penicillium is the target of ultraviolet sterilization, the first irradiation dose X per day of ultraviolet rays with a peak wavelength of 260 nm to 270 nm is set to 7 mJ / cm 2 Above and less than 28mJ / cm 2 (7≤X<28), the second irradiation dose Xa for one day is set to 28mJ / cm 2 Above (28≤Xa).

[0188] When Fusarium or Penicillium is the target of ultraviolet sterilization, the first irradiation dose X per day of ultraviolet rays with a peak wavelength of 260 nm to 270 nm is set to 12 mJ / cm 2 Above and less than 48mJ / cm 2 (12≤X<48), the second irradiation dose Xa for one day is set to 48mJ / cm 2 That is, when the fungi to be sterilized include Fusarium or Penicillium, the peak wavelength of ultraviolet light is between 260nm and 270nm, and the prescribed period is one day, the reference irradiation amount is 48mJ / cm 2 , and the minimum value of the above irradiation amount in the first mode M1 is 12mJ / cm 2 .

[0189] When Cladosporium is the target of ultraviolet sterilization, the first irradiation dose X per day of ultraviolet rays having a peak wavelength of 260 nm to 270 nm is set to 80 mJ / cm 2 Above and less than 320mJ / cm 2 (80≤X<320), the second irradiation dose Xa for one day is set to 320 mJ / cm 2 Above (320≤Xa).

[0190] When Aspergillus is the target of ultraviolet sterilization, the first irradiation dose X per day of ultraviolet rays having a peak wavelength of 260 nm to 270 nm is set to 82 mJ / cm 2 Above and less than 327mJ / cm 2 (82≤X<327), the second irradiation dose Xa for one day is set to 327mJ / cm 2 Above (327≤Xa).

[0191] When Cladosporium or Aspergillus is the target of ultraviolet sterilization, the first irradiation dose X per day of ultraviolet rays with a peak wavelength of 260 nm to 270 nm is set to 82 mJ / cm 2 Above and less than 327mJ / cm 2 (82≤X<327), the second irradiation dose Xa for one day is set to 327mJ / cm 2 That is, when the fungi to be sterilized include Cladosporium or Aspergillus, the peak wavelength of ultraviolet light is between 260 nm and 270 nm, and the prescribed period is one day, the reference irradiation amount is 327 mJ / cm 2 , and the minimum value of the above irradiation amount in the first mode M1 is 82mJ / cm 2 .

[0192] In the seventh example, the second mode M2 ​​is set using, for example, the above-mentioned equations 4, 5, and 6.

[0193] The above embodiments and variations are described, but it should be understood that various changes can be made to their forms and specific circumstances without departing from the spirit and scope of the claims (for example, the following (A)). In addition, the above embodiments, variations and other elements of the embodiments can be appropriately combined or replaced.

[0194] (A) Figure 1 As shown, in the first mode M1 of the present embodiment, the irradiation unit 11 irradiates ultraviolet rays intermittently and multiple times. However, the present invention is not limited thereto. In the first mode M1, the irradiation unit 11 may irradiate ultraviolet rays continuously without interruption.

[0195] The words "first", "second", "third", etc. mentioned above are only used to distinguish sentences containing the above words, and are not intended to limit the quantity or order of the sentences.

[0196] - Industrial Applicability -

[0197] In summary, the present disclosure is useful for an ultraviolet irradiation device.

[0198] - Explanation of symbols -

[0199] 1. Ultraviolet irradiation device

[0200] 11 Irradiation Department

[0201] 12 Storage

[0202] 13. Control Unit

[0203] G Object

Claims

1. An ultraviolet irradiation device for sterilization, characterized in that: The ultraviolet irradiation device comprises an irradiation unit (11) and a control unit (13). The irradiation unit (11) irradiates ultraviolet rays. The control unit (13) controls the irradiation unit (11) in a manner of repeatedly performing a first mode (M1) and a second mode (M2), wherein in the first mode (M1), the irradiation unit (11) irradiates ultraviolet rays in a manner such that the amount of ultraviolet rays per unit area within a specified period is less than a reference irradiation amount, and in the second mode (M2), the irradiation unit (11) irradiates ultraviolet rays in a manner such that the amount of ultraviolet rays per unit area within the specified period is greater than the reference irradiation amount.

2. The ultraviolet irradiation device according to claim 1, characterized in that: In the first mode (M1), the irradiation unit (11) irradiates ultraviolet rays intermittently and multiple times.

3. The ultraviolet irradiation device according to claim 1, characterized in that: In the first mode (M1), the irradiation section (11) continuously irradiates ultraviolet rays.

4. The ultraviolet irradiation device according to any one of claims 1 to 3, characterized in that: When the peak wavelength of the ultraviolet rays is 260 nm or more and 270 nm or less and the predetermined period is one day, the reference irradiation amount is 320 mJ / cm 2 , and the minimum value of the irradiation amount under the first mode (M1) is 80mJ / cm 2 .

5. The ultraviolet irradiation device according to any one of claims 1 to 3, characterized in that: When the peak wavelength of the ultraviolet rays is 249 nm or more and 259 nm or less and the predetermined period is one day, the reference irradiation amount is 298 mJ / cm 2 , and the minimum value of the irradiation amount under the first mode (M1) is 74mJ / cm 2 .

6. The ultraviolet irradiation device according to any one of claims 1 to 3, characterized in that: When the peak wavelength of the ultraviolet rays is 275 nm or more and 285 nm or less and the predetermined period is one day, the reference irradiation amount is 496 mJ / cm 2 , and the minimum value of the irradiation amount under the first mode (M1) is 124mJ / cm 2 .

7. The ultraviolet irradiation device according to any one of claims 1 to 6, characterized in that: An upper limit of a period (Y) from when the second mode (M2) is performed to when the second mode (M2) is performed next time is set based on the irradiation amount in the first mode (M1).

8. The ultraviolet irradiation device according to claim 4, characterized in that: The period (Y) from the start of the second mode (M2) to the next second mode (M2) is less than Y1 hours, When the radiation amount in one day in the first mode (M1) is set to X, the Y1 hour is expressed by the following mathematical formula 1: Mathematical formula 1 Y1=0.45X+33.

9. The ultraviolet irradiation device according to claim 5, characterized in that: The period (Y) from the start of the second mode (M2) to the next second mode (M2) is less than Y2 hours, When the radiation amount in one day in the first mode (M1) is set to X, the Y2 hours is expressed by the following mathematical formula 2: Mathematical formula 2 Y2=0.49X+33.

10. The ultraviolet irradiation device according to claim 6, characterized in that: The period (Y) from the start of the second mode (M2) to the next second mode (M2) is less than Y3 hours, When the radiation amount in one day in the first mode (M1) is set to X, the Y3 hours is expressed by the following mathematical formula 3: Mathematical formula 3 Y3=0.29X+33.

11. The ultraviolet irradiation device according to any one of claims 1 to 3, characterized in that: The reference irradiation amount is set based on correspondence information that associates the irradiation amount of ultraviolet rays irradiated on fungi to be sterilized, the peak wavelength of the ultraviolet rays, and the mortality rate or inactivation rate of fungi irradiated with the ultraviolet rays.

12. The ultraviolet irradiation device according to any one of claims 1 to 3, characterized in that: When the peak wavelength of ultraviolet light is between 260nm and 270nm, The amount of ultraviolet light irradiated per unit area during the predetermined period of time at which the mortality rate or inactivation rate of the fungi is 90% after the ultraviolet light is irradiated to the fungi is A, When the ultraviolet irradiation amount per unit area during the predetermined period is B and the mortality rate or inactivation rate of the fungi is 99.99%, The reference irradiation amount is set to B, and the lowest value of the irradiation amount in the first mode (M1) is set to A.

13. The ultraviolet irradiation device according to claim 12, characterized in that: When the peak wavelength of ultraviolet rays is 260 nm or more and 270 nm or less, Assume that the period (Y) from the start of the second mode (M2) to the next second mode (M2) is less than Y4 hours, When the irradiation amount in the first mode (M1) is set to X, the Y4 hours is expressed by the following mathematical formula 4: α and β are the irradiation amount per unit area of ​​ultraviolet rays with a peak wavelength of 260nm or more and 270nm or less within a specified period. The β is greater than the α, f (α) It is the time it takes to suppress the growth of fungi after irradiating with ultraviolet light at an irradiation dose of α. f (β) It is the time that the growth of fungi can be suppressed after irradiation with ultraviolet light at the irradiation dose of β. Mathematical formula 4 Y4=a·X+b a={f (β) -f (α) / (b-a)} b=f (α) -a·a.

14. The ultraviolet irradiation device according to claim 13, characterized in that: When the peak wavelength of ultraviolet light is 249 nm or more and 259 nm or less, The reference irradiation amount is set to B / 1.08, and the lowest value of the irradiation amount in the first mode (M1) is set to A / 1.

08.

15. The ultraviolet irradiation device according to claim 14, characterized in that: When the peak wavelength of ultraviolet light is 249 nm or more and 259 nm or less, When the period (Y) from the start of the second mode (M2) to the next second mode (M2) is Y5 hours or less, the Y5 hours is expressed by the following mathematical formula 5: Mathematical formula 5 Y5=a1·X+b1 a1={f (β / 1.08) -f (α / 1.08) / (β / 1.08-α / 1.08)} b1=f (α / 1.08) -a·α / 1.

08.

16. The ultraviolet irradiation device according to any one of claims 13 to 15, characterized in that: When the peak wavelength of ultraviolet rays is 275 nm or more and 285 nm or less, The reference irradiation amount is set to B / 0.65, and the lowest value of the irradiation amount in the first mode (M1) is set to A / 0.

65.

17. The ultraviolet irradiation device according to claim 16, characterized in that: When the peak wavelength of ultraviolet rays is 275 nm or more and 285 nm or less, When the period (Y) from the start of the second mode (M2) to the next second mode (M2) is Y6 hours or less, the Y6 hours is expressed by the following mathematical formula 6: Mathematical formula 6 Y6=a2·X+b2 a2={f (β / 0.65) -f (α / 0.65) / (β / 0.65-α / 0.65)} b2=f (α / 0.65) -a·α / 0.65。 18. The ultraviolet irradiation device according to any one of claims 1 to 3, characterized in that: The fungi to be sterilized include Fusarium and Penicillium. When the peak wavelength of the ultraviolet rays is 260 nm or more and 270 nm or less and the predetermined period is one day, the reference irradiation amount is 48 mJ / cm 2 , and the minimum value of the irradiation amount under the first mode (M1) is 12mJ / cm 2 .

19. The ultraviolet irradiation device according to any one of claims 1 to 3, characterized in that: The fungi to be sterilized include Cladosporium or Aspergillus, When the peak wavelength of the ultraviolet rays is 260 nm or more and 270 nm or less and the predetermined period is one day, the reference irradiation amount is 327 mJ / cm 2 , and the minimum value of the irradiation amount under the first mode (M1) is 82mJ / cm 2 .

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