Ultraviolet light irradiation device and freshness preservation device

Abstract

To provide an ultraviolet light irradiation device capable of obtaining appropriate ultraviolet irradiation performance. [Solution] The ultraviolet light irradiation device of the embodiment comprises a housing, a partition plate, an ultraviolet light source, and a fan. The housing has an irradiation window, and the internal cavity of the housing opens to the outside through an intake port and an exhaust port. The partition plate divides the internal cavity into a first space where the irradiation window is located and a second space where the intake port and exhaust port are located, and the first space and the second space are in communication through ventilation holes in the partition plate. The ultraviolet light source located in the first space can irradiate ultraviolet light to the outside through the irradiation window. The fan located in the second space operates to draw air from the intake port through the second space and the ventilation holes into the first space.

Description

Technical Field

[0005] ,

[0001] Embodiments of the present invention relate to an ultraviolet light irradiation device and a freshness maintaining device.

Background Art

[0002] An ultraviolet light irradiation device is installed near a transport unit that transports food or the like as a transport target, and the ultraviolet light from the ultraviolet light source of the ultraviolet light irradiation device is irradiated onto the transport target being transported, thereby maintaining the freshness of the transport target. A freshness maintaining device has been developed. In an ultraviolet light irradiation device used in such a freshness maintaining device, an ultraviolet light source is provided inside a housing, and an irradiation window through which light can pass is formed in the housing. Then, the ultraviolet light emitted from the ultraviolet light source to the outside of the housing through the irradiation window is irradiated onto a transport target such as food.

[0003] As described above, in an ultraviolet light irradiation device used in a freshness maintaining device, it is required not to significantly reduce the ultraviolet irradiation performance during use and maintenance. For example, from the viewpoint of performing cleaning as maintenance, it is required to ensure high waterproof performance and suppress a decrease in ultraviolet irradiation performance due to water intrusion into the housing. Also, by appropriately cooling the ultraviolet light source disposed inside the housing, it is required not to significantly reduce the ultraviolet irradiation performance during use.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide an ultraviolet light irradiation device capable of obtaining appropriate ultraviolet irradiation performance, and a freshness maintaining device including the ultraviolet light irradiation device.

Means for Solving the Problems

[0006] According to the embodiment, the ultraviolet light irradiation device comprises a housing, a partition plate, an ultraviolet light source, and a fan. The housing has an irradiation window through which light can pass, and the internal cavity of the housing opens to the outside at an intake port and an exhaust port, respectively. The partition plate divides the internal cavity of the housing into a first space where the irradiation window is located and a second space where the intake port and exhaust port are located, and ventilation holes are formed in the partition plate to connect the first space and the second space. The ultraviolet light source is placed in the first space and can irradiate ultraviolet light to the outside of the housing through the irradiation window. The fan is placed in the second space and, when operating, causes air to flow from the intake port through the second space and the ventilation holes into the first space. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an ultraviolet light irradiation device capable of obtaining appropriate ultraviolet irradiation performance, and a freshness preservation device equipped with the ultraviolet light irradiation device. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing an example of an ultraviolet light irradiation device according to an embodiment. [Figure 2] Figure 2 is a perspective view showing the ultraviolet light irradiation device of Figure 1, cut in a cross-section perpendicular or nearly perpendicular to the depth direction. [Figure 3] Figure 3 is a perspective view showing the ultraviolet light irradiation device of Figure 1, cut in a cross-section perpendicular or nearly perpendicular to the lateral direction. [Figure 4] Figure 4 is a cross-sectional view of the ultraviolet light irradiation device shown in Figure 1, taken in a section perpendicular or nearly perpendicular to the depth direction. [Figure 5] Figure 5 is a schematic cross-sectional view showing the configuration of the louver unit located at the air intake and its vicinity in an example ultraviolet light irradiation device shown in Figures 1 to 4. [Figure 6] Figure 6 is a schematic diagram showing the temperature measurement results in verification related to the embodiment, etc. [Figure 7] Figure 7 is a cross-sectional view showing an example of a freshness preservation device according to the embodiment, with a cross-section perpendicular or substantially perpendicular to the conveying direction in the conveying section. [Figure 8] Figure 8 is a cross-sectional view showing an example of the freshness preservation device shown in Figure 7, along the direction of transport in the transport section. [Figure 9] Figure 9 is a cross-sectional view showing an example of a freshness preservation device according to a modified example, taken along the conveying direction in the conveying section. [Figure 10] Figure 10 is a schematic diagram showing an example of a freshness preservation device relating to a different modification from the modification shown in Figure 9. [Figure 11] Figure 11 is a schematic diagram showing an example of a freshness preservation device relating to a modified version of Figure 9 and another modified version of Figure 10. [Modes for carrying out the invention]

[0009] The ultraviolet light irradiation device (1) of the embodiment comprises a housing (2), a partition plate (23), an ultraviolet light source (27), and a fan (31). The housing (2) is provided with an irradiation window (13) through which light can pass, and the internal cavity (7) of the housing (2) opens to the outside at an intake port (17) and an exhaust port (18), respectively. The partition plate (23) divides the internal cavity (7) of the housing (2) into a first space (25) where the irradiation window (13) is located and a second space (26) where the intake port (17) and exhaust port (18) are located, and ventilation holes (51) are formed in the partition plate (23) that connect the first space (25) and the second space (26). The ultraviolet light source (27) is positioned in the first space (25) and can irradiate the outside of the housing (2) with ultraviolet light through the irradiation window (13). The fan (31) is positioned in the second space (26) and, when operating, causes air to flow from the intake port (17) through the second space (26) and the ventilation hole (51) into the first space (25). This ensures high waterproof performance in the ultraviolet light irradiation device (1), making it possible to obtain appropriate ultraviolet irradiation performance. In addition, the ultraviolet light source (27) can be cooled, making it possible to obtain appropriate ultraviolet irradiation performance.

[0010] In the ultraviolet light irradiation device (1) of the embodiment, the ultraviolet light source (27) includes an ultraviolet light lamp (28) that extends along the longitudinal direction, and the ultraviolet light lamp (28) is positioned in the first space (25) with its longitudinal end (E1) adjacent to the ventilation hole (51). As a result, when the ultraviolet light source (27) is emitting ultraviolet light, the end (E1), which is at a lower temperature than the rest of the ultraviolet light lamp (28), is properly cooled. Therefore, the ultraviolet light lamp (28) performs its light emission operation properly, and ultraviolet light is properly emitted from the ultraviolet light lamp (28), making it possible to obtain appropriate ultraviolet irradiation performance.

[0011] The ultraviolet light irradiation device (1) of the embodiment further includes a louver plate (57), which is positioned in the second space (26) near the ventilation holes (51) and opposite the intake port (17). When air flowing into the second space (26) from the intake port (17) collides with the louver plate (57), the louver plate (57) causes the collided air to flow into the first space (25) through the ventilation holes (51). With this configuration, air flows into the first space (25) through the ventilation holes (51) more reliably. As a result, the ultraviolet light source (27) positioned in the first space (25) is cooled more appropriately.

[0012] In the ultraviolet light irradiation device (1) of this embodiment, the louver plate (57) is positioned in the second space (26) at an angle to the opening surface of the ventilation hole (51) to the second space (26). This allows air to flow more reliably into the first space (25) through the ventilation hole (51), and the ultraviolet light source (27) positioned in the first space (25) is cooled more effectively.

[0013] The ultraviolet light irradiation device (1) of the embodiment further includes a power supply unit (30). The power supply unit (30) is disposed in the second space (26) and converts external power and supplies it to the ultraviolet light source (27) and the fan (31). With such a configuration, the power supply unit (30) is disposed in the second space (26) partitioned from the first space (25) where the ultraviolet light source (27) is located. Therefore, the influence of the ultraviolet light from the ultraviolet light source (27) on the power supply unit (30) is appropriately reduced.

[0014] The ultraviolet light irradiation device (1) of the embodiment has a waterproof performance of IPX5 or higher in terms of the IPX rating. Therefore, in the ultraviolet light irradiation device (1), a high waterproof performance is ensured.

[0015] The freshness maintaining device (60) of the embodiment includes a transport unit (61) in addition to the above-described ultraviolet light irradiation device (1). The transport unit (61) transports the transport object (62), and the ultraviolet light from the ultraviolet light source (27) of the ultraviolet light irradiation device (1) is irradiated through the irradiation window (13) onto the transport object (62) being transported by the transport unit (61). Thereby, using the ultraviolet light irradiation device (1), it becomes possible to remove mold, bacteria, etc. in foods and the like that become the transport object (62), and it becomes possible to maintain freshness.

[0016] Hereinafter, the embodiment will be described with reference to the drawings.

[0017] FIG. 1 is a perspective view showing an example of the ultraviolet light irradiation device 1 according to the embodiment. As shown in FIG. 1, the ultraviolet light irradiation device 1 includes a housing 2 that forms an exterior. In the ultraviolet light irradiation device 1 and the housing 2, a depth direction (directions indicated by arrows X1 and X), a lateral direction (directions indicated by arrows Y1 and Y2) that intersects (is orthogonal or substantially orthogonal) to the depth direction, and a height direction (directions indicated by arrows Z1 and Z2) that intersects (is orthogonal or substantially orthogonal) to both the depth direction and the lateral direction are defined. Also, in the ultraviolet light irradiation device 1 and the housing 2, one side in the height direction is the upper side (arrow Z1 side), and the side opposite to the upper side in the height direction is the lower side (arrow Z2 side).

[0018] Figure 2 is a perspective view of the ultraviolet light irradiation device 1 of Figure 1, cut in a section perpendicular or approximately perpendicular to the depth direction. Figure 3 is a perspective view of the ultraviolet light irradiation device 1 of Figure 1, cut in a section perpendicular or approximately perpendicular to the lateral direction. Figure 4 is a cross-sectional view of the ultraviolet light irradiation device 1 of Figure 1, cut in a section perpendicular or approximately perpendicular to the depth direction. As shown in Figures 1 to 4, the housing 2 comprises a top wall plate 3, a bottom wall plate 5, and a peripheral wall plate 6. An internal cavity 7 is formed inside the housing 2. The top wall plate 3 covers the internal cavity 7 from above in the height direction, and the bottom wall plate 5 covers the internal cavity 7 from below in the height direction. The bottom wall plate 5 faces the top wall plate 3 with the internal cavity 7 in between. The peripheral wall plate 6 extends along the height direction between the top wall plate 3 and the bottom wall plate 5. The peripheral wall plate 6 covers the internal cavity 7 from the outer periphery of the housing 2, and covers the internal cavity 7 over its entire circumference.

[0019] In the example shown in Figures 1 to 4, the top wall plate 3 and the bottom wall plate 5 are each detachably attached to the perimeter wall plate 6. The top wall plate 3 is attached to the perimeter wall plate 6 from the upper side in the height direction. A packing 8 is provided at the connection point between the top wall plate 3 and the perimeter wall plate 6. At the connection point between the top wall plate 3 and the perimeter wall plate 6, the packing 8 maintains a watertight (liquid-tight) seal between the top wall plate 3 and the perimeter wall plate 6. Therefore, the inflow of water, etc., into the internal cavity 7 through the connection point between the top wall plate 3 and the perimeter wall plate 6 is suppressed by the packing 8. The bottom wall plate 5 is attached to the perimeter wall plate 6 from the lower side in the height direction. A packing 9 is provided at the connection point between the bottom wall plate 5 and the perimeter wall plate 6. At the connection point between the bottom wall plate 5 and the perimeter wall plate 6, the packing 9 maintains a watertight (liquid-tight) seal between the bottom wall plate 5 and the perimeter wall plate 6. Therefore, the inflow of water and other liquids into the internal cavity 7 through the connection portion of the bottom wall plate 5 to the peripheral wall plate 6 is suppressed by the packing 9.

[0020] In the example shown in Figures 1 to 4, the peripheral wall plate 6 comprises a pair of short side wall plate sections 11 and 12, and a pair of long side wall plate sections 15 and 16. Each of the short side wall plate sections 11 and 12 extends between the long side wall plate sections 15 and 16 along the depth direction of the housing 2. The short side wall plate section 11 covers the internal cavity 7 from one side in the lateral direction, and the short side wall plate section 12 covers the internal cavity 7 from the opposite side of the short side wall plate section 11 in the lateral direction. The short side wall plate section 12 faces the short side wall plate section 11 with the internal cavity 7 in between. Each of the long side wall plate sections 15 and 16 extends between the short side wall plate sections 11 and 12 along the lateral direction of the housing 2. The long side wall panel 15 covers the internal cavity 7 from one side in the depth direction, and the long side wall panel 16 covers the internal cavity 7 from the opposite side in the depth direction from the long side wall panel 15. The long side wall panel 16 faces the long side wall panel 15 with the internal cavity 7 in between.

[0021] The housing 2 has an air intake port 17 and an exhaust port 18. The internal cavity 7 of the housing 2 opens to the outside of the housing 2 at the air intake port 17 and the exhaust port 18, respectively. In the example shown in Figures 1 to 4, the air intake port 17 is formed in the short side wall portion 11 of the peripheral wall plate 6, and the exhaust port 18 is formed in the short side wall portion 11 of the peripheral wall plate 6. Therefore, the internal cavity 7 opens towards one side of the housing 2 in the lateral direction at the air intake port 17, and opens towards the opposite side from the side where the air intake port 17 opens in the lateral direction at the exhaust port 18.

[0022] Furthermore, the housing 2 is equipped with an illumination window 13. The illumination window 13 is made of, for example, glass, and light such as ultraviolet light can pass through the illumination window 13. In the example shown in Figures 1 to 4, the illumination window 13 is attached to the bottom wall plate 5 with a window frame 21 in between. The light that is emitted to the outside of the housing 2 through the illumination window 13 is emitted from the illumination window 13 toward the lower side in the height direction of the housing 2. A packing 22 is also provided at the connection portion of the illumination window 13 to the bottom wall plate 5. At the connection portion of the illumination window 13 to the bottom wall plate 5, the inflow of water or the like into the internal cavity 7 is suppressed by the packing 22.

[0023] A partition plate 23 is placed in the internal cavity 7 of the housing 2. The partition plate 23 is attached, for example, to the inner surface of the peripheral wall plate 6, and is positioned so that the thickness direction of the partition plate 23 is aligned with the height direction of the housing 2. The internal cavity 7 of the housing 2 is divided into a first space 25 and a second space 26 by the partition plate 23. The intake port 17 and exhaust port 18 are located in the second space 26, and the illumination window 13 is located in the first space 25. In the example shown in Figures 1 to 4, the first space 25 is formed below the partition plate 23 in the height direction of the housing 2, and is formed between the partition plate 23 and the bottom wall plate 5. The second space 26 is formed above the partition plate 23 in the height direction of the housing 2, and is formed between the partition plate 23 and the top wall plate 3.

[0024] An ultraviolet light source 27 is placed in the first space 25 of the internal cavity 7. In the example shown in Figures 1 to 4, the ultraviolet light source 27 is installed on the side of the partition plate 23 facing the side where the first space 25 is located. The ultraviolet light source 27 is operated by power supply and emits ultraviolet light. At this time, ultraviolet light with a peak wavelength of either 200 nm or more and 400 nm or less is emitted from the ultraviolet light source 27. The ultraviolet light source 27 emits ultraviolet light toward the irradiation window 13, and the ultraviolet light from the ultraviolet light source 27 is irradiated to the outside of the housing 2 through the irradiation window 13. At this time, the ultraviolet light is irradiated from the irradiation window 13 toward the lower side in the height direction of the housing 2.

[0025] Furthermore, the ultraviolet light source 27 is equipped with one or more ultraviolet lamps 28, and in the example shown in Figures 1 to 4, multiple ultraviolet lamps 28 are provided. Each ultraviolet lamp 28 has a defined longitudinal direction, and each ultraviolet lamp 28 extends along the longitudinal direction. In the example shown in Figures 1 to 4, each ultraviolet lamp 28 is positioned so that its longitudinal direction is aligned with the lateral direction of the housing 2. Also in the example shown in Figures 1 to 4, the multiple ultraviolet lamps 28 are arranged in the depth direction of the housing 2. Each ultraviolet lamp 28 can be an LED lamp, mercury lamp, metal halide lamp, fluorescent ultraviolet lamp, or excimer lamp. In the example shown in Figures 1 to 4, four ultraviolet lamps 28 are provided in the ultraviolet light source 27, but the number of ultraviolet lamps 28 provided in the ultraviolet light source 27 is not limited.

[0026] A fan 31 is placed in the second space 26 of the internal cavity 7. In one example shown in Figures 1 to 4, two fans 31A and 31B are placed in the second space 26, with one fan 31 attached to the inner surface of each of the short side wall plates 11 and 12. Fan 31A faces the intake port 17 in the second space 26 and is positioned adjacent to the inside of the intake port 17. Fan 31B faces the exhaust port 18 in the second space 26 and is positioned adjacent to the inside of the exhaust port 18. In one example, only one of the two fans 31A and 31B shown in Figures 1 to 4 is placed in the second space 26. In this case, only one of the fans 31A, which faces the intake port 17, and the fan 31B, which faces the exhaust port 18, is provided. It is also possible that only one of the fans, either fan 31A or fan 31B, is placed inside the housing 2. Furthermore, at least one of the fans 31 may be placed in the first space 25, or at the boundary between the first space 25 and the second space 26.

[0027] The fan 31 operates when power is supplied. When the fan 31 operates, an airflow is formed in the second space 26 from the intake port 17 to the exhaust port 18. At this time, air flows into the second space 26 from outside the housing 2 through the intake port 17. Then, the air that has flowed from the intake port 17 to the exhaust port 18 in the second space 26 flows out to the outside of the housing 2 through the exhaust port 18. For this reason, if the fan 31 is provided with two fans, it is desirable to configure it so that one operates as an intake fan and the other operates as an exhaust fan.

[0028] In the example shown in Figures 1 to 4, the power supply unit 30 is positioned in the second space 26. The power supply unit 30 is installed on the side of the partition plate 23 facing the side where the second space 26 is located. Also in the example shown in Figures 1 to 4, the power supply unit 30 is positioned between the two fans 31A and 31B in the lateral direction of the housing 2. The power supply unit 30 includes a lamp power supply 32, a fan power supply 33, and a control board 35. The lamp power supply 32 converts power supplied from an external source into power corresponding to the ultraviolet light source 27. The lamp power supply 32 then supplies the converted power to the ultraviolet light source 27, causing the ultraviolet light source 27 to emit ultraviolet light. The lamp power supply 32 converts external power, such as power from a commercial power supply, into DC power with a voltage corresponding to the ultraviolet light source 27 (ultraviolet light lamp 28) by AC / DC conversion and voltage transformation, etc.

[0029] In the example shown in Figures 1 to 4, the fan power supply 33 is positioned alongside the lamp power supply 32 on one side of the housing 2 in the depth direction. The fan power supply 33 converts power supplied from an external source into power corresponding to the fan 31. The fan power supply 33 then operates the fan 31 by supplying the converted power to the fan 31. The fan power supply 33 converts external power, such as power from a commercial power supply, into DC power of a voltage corresponding to the fan 31 by AC / DC conversion and voltage transformation, etc. In the example shown in Figures 1 to 4, the control board 35 is positioned between the partition plate 23 and the lamp power supply 32. A control circuit is formed on the control board 35, and control The circuit controls the operation of the ultraviolet light source 27, the operation of the fan 31, and other related functions.

[0030] Furthermore, as mentioned above, in the example shown in Figures 1 to 4, the top wall plate 3 and the bottom wall plate 5 are each removable from the peripheral wall plate 6. In the ultraviolet light irradiation device 1, the bottom wall plate 5 is removed from the peripheral wall plate 6 to clean the inside of the housing 2, and to perform maintenance and replacement of the irradiation window 13 and ultraviolet light source 27. Then, the top wall plate 3 is removed from the peripheral wall plate 6 to clean the inside of the housing 2, and to perform maintenance on the fan 31 and power supply unit 30.

[0031] Furthermore, in the example ultraviolet light irradiation device 1 shown in Figures 1 to 4, a connector section 36 and a switching operation section 37 are arranged on the outer surface of the long side wall plate section 15 of the housing 2. External wiring is connected to the connector section 36, for example, wiring that supplies external power to the ultraviolet light irradiation device 1 is connected to it. The switching operation section 37 allows the user of the ultraviolet light irradiation device 1 to input an operation to switch the ultraviolet light irradiation device 1 on and off. In both the connector section 36 and the switching operation section 37, the inflow of water or the like into the internal cavity 7 is suppressed by a packing (not shown), etc. The switching operation section 37 may be configured to switch the output of ultraviolet light. In this case, for example, the output of ultraviolet light can be switched by changing the number of ultraviolet light sources 27 that are lit.

[0032] Furthermore, in the example shown in Figures 1 to 4, louver units 40 are arranged at both the intake port 17 and the exhaust port 18. The louver unit 40 at the intake port 17 is attached to the short side wall portion 11 of the peripheral wall plate 6, and the louver unit 40 at the exhaust port 18 is attached to the short side wall portion 12 of the peripheral wall plate 6. Figure 5 is a schematic cross-sectional view showing the configuration of the louver unit 40 at the intake port 17 and its vicinity in the ultraviolet light irradiation device 1 of the example shown in Figures 1 to 4. In Figure 5, a cross-section perpendicular or approximately perpendicular to the depth direction of the housing 2 is shown. The following description will focus on the louver unit 40 at the intake port 17. However, the louver unit 40 at the exhaust port 18 has a similar configuration to the louver unit 40 at the intake port 17 and is attached to the peripheral wall plate 6 in the same manner.

[0033] As shown in Figure 5, the louver unit 40 is attached to the peripheral wall plate 6 via a ring member 43. A packing 45 is also provided at the connection portion of the louver unit 40 to the peripheral wall plate 6. Therefore, the inflow of water and other substances into the internal cavity 7 through the connection portion of the louver unit 40 to the peripheral wall plate 6 is suppressed by the packing 45. The louver unit 40 comprises an outer louver 41 and an inner louver 42, and the inner louver 42 is attached to the outer louver 41 adjacent to the outer louver 41 from the inside. Therefore, the inner louver 42 is stacked on top of the outer louver 41 from the side where the internal cavity 7 (second space 26) is located.

[0034] Multiple external flow channels 46 are formed in the external louvers 41, and multiple internal flow channels 47 are formed in the internal louvers 42. Each external flow channel 46 opens to the outside of the housing 2 at one end, and the opening is directed downward in the height direction of the housing 2. In each external flow channel 46, the end opposite to the opening to the outside communicates with a corresponding internal flow channel 47. Each internal flow channel 47 opens to the second space 26 of the internal cavity 7 at one end, and the opening is directed downward in the height direction of the housing 2. In each internal flow channel 47, the end opposite to the opening to the second space 26 communicates with a corresponding external flow channel 46. As described above, the formation of external flow channels 46 and internal flow channels 47 suppresses the inflow of water and other substances into the internal cavity 7 through the external flow channels 46 and internal flow channels 47.

[0035] In the example ultraviolet light irradiation device 1 shown in Figures 1 to 5, a configuration is formed to suppress the inflow of water and other substances into the internal cavity 7 as described above. Therefore, the ultraviolet light irradiation device 1 has a waterproof performance of IPX5 or higher in the IPX rating defined by the IP (International Protection) standard. Here, IPX5 waterproof performance corresponds to a level of waterproof performance in which the device can operate properly even when water is sprayed onto the device from a distance of about 3m at a flow rate of about 12.5L / min from any direction for about 3 minutes.

[0036] Furthermore, as shown in Figures 1 to 4, the ultraviolet light irradiation device 1 of this embodiment has ventilation holes 51, 52, and 53 that penetrate the partition plate 23 in the thickness direction. In the internal cavity 7, the first space 25 and the second space 26 are connected at each of the ventilation holes 51, 52, and 53. Therefore, each of the ventilation holes 51, 52, and 53 connects the first space 25 and the second space 26. The ventilation hole (first ventilation hole) 51 is positioned closer to the intake port 17 than the ventilation holes 52 and 53. In one example shown in Figures 1 to 4, the ventilation hole 51 is positioned closer to the intake port 17 than the power supply unit 30, and the ventilation hole 51 is positioned between the fan 31A and the power supply unit 30.

[0037] Furthermore, the ventilation holes 52 and 53 are positioned closer to the exhaust port 18 than the ventilation hole 51. In one example shown in Figures 1 to 4, the ventilation holes 52 and 53 are positioned closer to the exhaust port 18 than the power supply unit 30, and are located between the fan 31B and the power supply unit 30. Also in one example shown in Figures 1 to 4, the ventilation hole (second ventilation hole) 52 is positioned on the opposite side from the exhaust port 18 relative to the ventilation hole (third ventilation hole) 53. Therefore, the ventilation hole 52 is located between the ventilation hole 53 and the power supply unit 30. In one example shown in Figures 1 to 4, the dimensions of each of the ventilation holes 51 to 53 along the depth direction of the housing 2 are larger than the dimensions along the width direction of the housing 2. When projected from the height direction of the housing 2, each of the ventilation holes 51 to 53 is rectangular or approximately rectangular in shape, with a larger dimension along the depth direction of the housing 2. Thus, the partition plate 23 is provided with at least one ventilation hole on the intake port 17 side and one ventilation hole on the exhaust port 18 side.

[0038] Furthermore, each of the ultraviolet light lamps 28 of the ultraviolet light source 27 has a longitudinal end E1 and an end E2 on the opposite side of the longitudinal end E1. Each of the ultraviolet light lamps 28 also has a central part C as the longitudinal center and a portion near the central position. A pair of lamp connectors 55 and 56 are installed on the side of the partition plate 23 facing the side where the first space 25 is located. In each of the ultraviolet light lamps 28, the end (first end) E1 is connected to the lamp connector 55, and the end (second end) E2 is connected to the lamp connector 56. In each of the ultraviolet light lamps 28, when emitting ultraviolet light, the temperature of the respective ends E1 and E2 is lower than the temperature of the other parts, including the central part C. Furthermore, in each of the ultraviolet light lamps 28, when emitting ultraviolet light, at least one (or both) of the ends E1 and E2 becomes the coldest part, which is the lowest temperature in the light-emitting portion of each ultraviolet light lamp 28 or its vicinity.

[0039] In each of the ultraviolet lamps 28, the end (first end) E1 is adjacent to the ventilation hole (first ventilation hole) 51 from the side where the second space 26 is located. In the projection from the height direction of the housing 2, each end E1 of the ultraviolet lamps 28 coincides with the ventilation hole 51. In addition, in each of the ultraviolet lamps 28, the end (second end) E2 is adjacent to the ventilation hole (second ventilation hole) 52 from the side where the second space 26 is located. In the projection from the height direction of the housing 2, each end E2 of the ultraviolet lamps 28 coincides with the ventilation hole 52.

[0040] Furthermore, the ventilation holes (third ventilation holes) 53 are positioned offset from each end E2 of the ultraviolet lamp 28 toward the side where the lateral exhaust port 18 of the housing 2 is located. The ventilation holes 53 are also positioned offset from the lamp connector 56 toward the side where the exhaust port 18 is located. Therefore, in a projection of the housing 2 from the height direction, the ends E2 of the ultraviolet lamp 28 and the lamp connector 56 do not overlap with the ventilation holes 53. In a projection of the housing 2 from the height direction, the ventilation holes 53 are located between each of the ultraviolet lamps 28 and the exhaust port 18, and between the lamp connector 56 and the exhaust port 18.

[0041] In addition, in the example shown in Figures 1 to 4, a louver plate 57 is attached to the side of the partition plate 23 facing the side where the second space 26 is located. The louver plate 57 protrudes from the partition plate 23 into the second space 26 and protrudes from the partition plate 23 toward the upper side in the height direction of the housing 2. In the second space 26, the louver plate 57 is positioned near the ventilation holes 51 and opposite the air intake 17. In the example shown in Figures 1 to 4, the louver plate 57 is positioned opposite the fan 31A.

[0042] The louver plate 57 has a base position J1 and a protruding end J2 of the portion that protrudes from the partition plate 23. In the example shown in Figures 1 to 4, the base position J1 of the protruding portion of the louver plate 57 is adjacent to the ventilation hole (first ventilation hole) 51 from the side opposite to the side where the air intake 17 is located. Therefore, the base position J1 of the protruding portion of the louver plate 57 is located between the ventilation hole 51 and the power supply unit 30. In addition, the louver plate 57 has a plate width direction that intersects (orthogonal or nearly orthogonal to) the protruding direction from the base position J1 to the protruding end J2, and a plate thickness direction that intersects (orthogonal or nearly orthogonal to) both the protruding direction and the plate width direction. In the example shown in Figures 1 to 4, the protruding portion of the louver plate 57 is positioned such that the plate width direction is aligned with the depth direction of the housing 2.

[0043] Furthermore, in a preferred example including the example shown in Figures 1 to 4, the protruding portion of the louver plate 57 is inclined with respect to the partition plate 23 and with respect to the opening surface of the ventilation hole 51 leading to the second space 26. In this case, the louver plate 57 is inclined with respect to the opening surface of the ventilation hole in a posture (inclination) that is closer to the intake port 17 the closer it is to the protruding end J2. Also, if the acute angle that the louver plate 57 makes with respect to the opening surface of the ventilation hole 51 is defined as the inclination angle θ, it is preferable that the inclination angle θ is about 45°. In this embodiment, the protruding end J2 of the louver plate 57 is provided so as to be below the central axis of the opposing fan 31A in the height direction (on the side where the bottom wall plate 5 is located).

[0044] In this embodiment, since a ventilation hole 51 is provided, when the fan 31 operates, a portion of the air that flows into the second space 26 through the intake port 17 flows into the first space 25 through the ventilation hole (first ventilation hole) 51. Therefore, when the fan 31 operates, it causes air to flow from the intake port 17 into the first space 25 through the second space 26 and the ventilation hole 51.

[0045] Furthermore, in the example shown in Figures 1 to 4, a louver plate 57 is positioned in the second space 26 near the ventilation hole 51, facing the intake port 17. As a result, some of the air flowing into the second space from the intake port 17 collides with the louver plate 57. The air that collides with the louver plate 57 then flows into the first space 25 through the ventilation hole 51. In addition, by positioning the louver plate 57 as described above, it becomes possible to introduce air to the power supply unit 30 side of the second space 26 as well.

[0046] Furthermore, in this embodiment, since ventilation holes 52 and 53 are provided, when the fan 31 operates, the air that flows into the first space 25 through the ventilation hole 51 flows in the first space 25 from the ventilation hole 51 toward the ventilation holes 52 and 53. The air that has flowed in the first space 25 toward the ventilation holes 52 and 53 then flows into the second space 26 through the ventilation holes 52 and 53 and flows out to the outside of the housing 2 through the exhaust port 18.

[0047] In one example shown in Figures 1 to 4, a plurality of wiring holes 58 and a plurality of wiring holes 59 are formed in the partition plate 23. Each of the wiring holes 58 and 59 penetrates the partition plate 23 in the thickness direction. Each of the wiring holes 58 is adjacent to the ventilation hole 51 from the side where the air intake 17 is located. Each of the wiring holes 59 is adjacent to the ventilation hole (second ventilation hole) 52 from the side where the exhaust port 18 is located, and is located between the ventilation holes 52 and 53. The wiring between the lamp power supply 32 and the ultraviolet light source 27, and the wiring between the control board 35 and the ultraviolet light source 27 are extended through either of the wiring holes 58 or 59. In one example, the wiring connected to the lamp connector 55 is extended through either of the wiring holes 58, and the wiring connected to the lamp connector 56 is extended through either of the wiring holes 59.

[0048] As described above, in this embodiment, the internal cavity 7 of the housing 2 is partitioned by the partition plate 23 into a first space 25 where the irradiation window 13 is located and a second space 26 where the air intake port 17 and exhaust port 18 are located. The ultraviolet light source 27 is placed in the first space 25. With this configuration, the first space 25 where the ultraviolet light source 27 is located is partitioned from the second space 26 where the air intake port 17 and exhaust port 18 are located, making it difficult for water to adhere to the ultraviolet light source 27, and thus ensuring a high level of waterproof performance for the ultraviolet light irradiation device 1.

[0049] Furthermore, in this embodiment, ventilation holes 51, 52, and 53 are formed to connect the first space 25 and the second space 26, and a fan 31 is formed in the second space 26. With this configuration, when the fan 31 operates, air flows from the intake port 17 through the second space 26 and the ventilation holes 51 into the first space 25. As a result, even though the first space 25 and the second space 26 are separated, the ultraviolet light source 27 placed in the first space 25 can be cooled by the air flowing in through the ventilation holes 51. This makes it possible to realize a configuration in the ultraviolet light irradiation device 1 in which the ultraviolet light source 27 can be cooled.

[0050] Furthermore, in this embodiment, the second space 26, where the intake port 17 and exhaust port 18 are located, is separated from the first space 25, where the ultraviolet light source 27 is located, by a partition plate 23. This effectively prevents ultraviolet light from the ultraviolet light source 27 from leaking to the outside of the housing 2 through either the intake port 17 or the exhaust port 18. Also, the second space 26, where the fan 31 is located, is separated from the first space 25, where the ultraviolet light source 27 is located. This appropriately reduces the influence of ultraviolet light from the ultraviolet light source 27 on the fan 31. In addition, in the example shown in Figures 1 to 4, the power supply unit 30 is located in the second space 26, which is separated from the first space 25, where the ultraviolet light source 27 is located. This appropriately reduces the influence of ultraviolet light from the ultraviolet light source 27 on the power supply unit 30.

[0051] Furthermore, in the example shown in Figures 1 to 4, louver units 40 are provided at each of the intake port 17 and exhaust port 18, so that the ultraviolet light irradiation device 1 has a waterproof performance of IPX5 or higher in the IPX rating. Therefore, a high level of waterproof performance is ensured in the ultraviolet light irradiation device 1.

[0052] Furthermore, in this embodiment, in the first space 25, each longitudinal end E1 of the ultraviolet lamp 28 is adjacent to a ventilation hole (first ventilation hole) 51. As a result, each end E1 of the ultraviolet lamp 28 is properly cooled by the air flowing into the first space 25 through the ventilation hole 51. In each of the ultraviolet lamps 28, as described above, when emitting ultraviolet light, for example, the coldest part is generated at the end E1, so the temperature of the end E1 is lower than the temperature of other parts such as the central part C. Because the end E1, which is cooler than other parts when emitting ultraviolet light, is properly cooled, each of the ultraviolet lamps 28 performs its light emission operation properly, and ultraviolet light is properly emitted from the ultraviolet lamps 28.

[0053] Furthermore, in the example shown in Figures 1 to 4, in the first space 25, the end E2 of each ultraviolet lamp 28 opposite to the end E1 is adjacent to the ventilation hole (second ventilation hole) 52. As a result, each end E2 of the ultraviolet lamp 28 is properly cooled by the air that flows through the first space 25 and then into the second space 26. In each ultraviolet lamp 28, as described above, when emitting ultraviolet light, for example, the coldest part is generated at the end E2, so the temperature of the end E2 is lower than the temperature of other parts such as the central part C. When emitting ultraviolet light, both ends E1 and E2, which are lower in temperature than other parts, are properly cooled, so each ultraviolet lamp 28 performs light emission operation more appropriately, and ultraviolet light is emitted from the ultraviolet lamp 28 more appropriately.

[0054] Furthermore, in the example shown in Figures 1 to 4, the ventilation hole (third ventilation hole) 53 is positioned on the side of the exhaust port 18 relative to the ventilation hole 52, and the ventilation hole 53 is offset relative to each end E2 of the ultraviolet lamp 28 and the lamp connector 56 toward the side of the exhaust port 18 located laterally on the housing 2. With this configuration, air flowing through the first space 25 toward the ventilation holes 52 and 53 can easily flow into the second space 26 through the ventilation hole 53. As a result, air flowing from the second space 26 into the first space 25 through the ventilation hole 51 can easily flow toward the ventilation holes 52 and 53 in the first space 25.

[0055] Furthermore, in the example shown in Figures 1 to 4, a louver plate 57 is positioned in the second space 26 near the ventilation holes 51, facing the air intake 17. When air flows from the air intake 17 into the second space 26, it collides with the louver plate 57, causing the impacted air to flow into the first space 25 through the ventilation holes 51. As a result, air flows into the first space 25 through the ventilation holes 51 more reliably. This allows the ultraviolet light source 27 located in the first space 25 to be cooled more effectively, and the respective ends E1, E2, etc. of the ultraviolet light lamp 28 to be cooled more effectively.

[0056] Furthermore, in the example shown in Figures 1 to 4, the louver plate 57 is positioned in the second space 26 at an angle to the opening surface of the ventilation hole 51 to the second space 26. This allows air to flow more reliably into the first space 25 through the ventilation hole 51. Consequently, the ultraviolet light source 27 positioned in the first space 25 is cooled more effectively, and the respective ends E1, E2, etc. of the ultraviolet light lamp 28 are cooled more effectively. Note that by setting the aforementioned inclination angle θ of the louver plate 57 to approximately 45°, air can flow even more reliably into the first space 25 through the ventilation hole 51.

[0057] Here, the following verifications were performed as part of the verifications related to the embodiments. In the verifications, the temperature was measured in each of the ultraviolet light irradiation devices 1 of structures α1 and α2 with the ultraviolet light source 27 and the fan 31 operating. For the ultraviolet light irradiation device 1 of structure α1, an ultraviolet light irradiation device 1 similar to the example in Figures 1 to 4 was used. Therefore, in structure α1, a louver plate 57 is provided, and the louver plate 57 is positioned in the second space 26 at an angle to the opening surface of the ventilation hole 51 to the second space 26. The aforementioned inclination angle θ of the louver plate 57 was set to approximately 45°. On the other hand, structure α2 is configured without the louver plate 57 as in structure α1. However, in structure α2 as well, ventilation holes 51, 52, and 53 are formed in the partition plate 23.

[0058] In the verification, temperatures were measured for each of the following: the lamp power supply 32, the fan power supply 33, the ends of the ultraviolet light lamp 28, and the central part C of the ultraviolet light lamp 28, for both structure α1 and structure α2. In this case, the temperature of the ends of the ultraviolet light lamp 28 was measured as the average of the measurement results at ends E1 and E2. Figure 6 is a schematic diagram showing the temperature measurement results in verification related to the embodiment, etc. In Figure 6, a graph is shown in which the horizontal axis represents the measurement location and the vertical axis represents temperature.

[0059] As shown in Figure 6, in structure α1, the temperatures of the ends and the center of the ultraviolet lamp 28 when the ultraviolet light source 27 is operating are lower compared to structure α2. In particular, in structure α1, the temperature of the ends of the ultraviolet lamp 28, where the coldest part occurs, is kept low, at a temperature similar to that of the lamp power supply 32 and the fan power supply 33. From the above verification, it has been demonstrated that by providing the louver plate 57, the ultraviolet light source 27 placed in the first space 25 is cooled more appropriately, and the respective ends E1, E2, etc. of the ultraviolet lamp 28 are cooled more appropriately.

[0060] Next, a freshness preservation device equipped with the ultraviolet light irradiation device 1 described above will be explained. In addition to the ultraviolet light irradiation device 1 described above, the freshness preservation device is equipped with a conveying unit. In the conveying unit of the freshness preservation device, the conveying direction in which the conveyed object is conveyed is defined. Figure 7 is a cross-sectional view of an example of the freshness preservation device 60 according to the embodiment, taken in a cross section perpendicular or substantially perpendicular to the conveying direction in the conveying unit 61. Figure 8 is a cross-sectional view of the freshness preservation device 60 of the example in Figure 7, taken in a cross section along the conveying direction in the conveying unit 61.

[0061] In the freshness preservation device 60 and conveying unit 61 shown in Figures 7 and 8, the aforementioned conveying direction (indicated by arrow P1) is defined as the downstream side, and the direction opposite to the conveying direction (indicated by arrow P2) is defined as the upstream side. In the conveying unit 61, food and the like are conveyed as the conveyed object 62 and are conveyed from the upstream side to the downstream side. In addition, the freshness preservation device 60 and conveying unit 61 have a width direction (indicated by arrow W) that intersects (orthogonal or nearly orthogonal to) the conveying direction, and a height direction (indicated by arrows H1 and H2) that intersects (orthogonal or nearly orthogonal to) both the conveying direction and the width direction. In the freshness preservation device 60 and conveying unit 61, one side in the height direction is the upper side (arrow H1 side), and the opposite side in the height direction is the lower side (arrow H2 side). Figure 8 shows a cross-section of the conveying unit 61 that is orthogonal or nearly orthogonal to the width direction.

[0062] The conveying unit 61 uses one of several rollers and a conveyor belt to convey the object to be conveyed 62 in the conveying direction. The conveying unit 61 also has a conveying surface 63, which faces upward in the height direction. In the conveying unit 61, the object to be conveyed 62 is conveyed with the object to be conveyed 62 positioned on the conveying surface 63. In the example shown in Figures 7 and 8, the conveying direction of the object to be conveyed 62 positioned on the conveying surface 63 is along a virtual horizontal plane, and the object to be conveyed 62 is conveyed along the horizontal plane. The width direction of the conveying unit 61 also follows the horizontal plane. The upper side of the conveying unit 61 in the height direction coincides with or approximately coincides with the vertically upward side (arrow V1 side), and the lower side of the conveying unit 61 in the height direction coincides with or approximately coincides with the vertically downward side (arrow V2 side).

[0063] In the example shown in Figures 7 and 8, the ultraviolet light irradiation device 1 is installed on the transport section 61 via a mounting base 65. However, the configuration of installing the ultraviolet light irradiation device 1 on the transport section 61 in the freshness preservation device 60 is not particularly limited. In the freshness preservation device 60, the ultraviolet light irradiation device 1 is positioned above the transport section 61 in the height direction. The ultraviolet light irradiation device 1 is positioned so that the irradiation window 13 faces the transport surface 63 of the transport section 61, creating a gap between the irradiation window 13 and the transport surface 63. The transport object 62, placed on the transport surface 63, is transported downstream through the gap between the irradiation window 13 and the transport surface 63.

[0064] In the freshness preservation device 60, ultraviolet light from the ultraviolet light source 27 is irradiated from above in the height direction of the transport unit 61, through the irradiation window 13, toward the transport surface 63. As a result, the ultraviolet light from the ultraviolet light source 27 is irradiated onto the transport object 62 that is being transported through the gap between the irradiation window 13 and the transport surface 63 in the transport unit 61. In the transport object 62, such as food, mold and bacteria are removed or reduced by the irradiation with ultraviolet light, and freshness is maintained.

[0065] In the example shown in Figures 7 and 8, the lateral direction of the housing 2 aligns with the width direction of the transport unit 61, and the depth direction of the housing 2 aligns with the transport direction in the transport unit 61. Therefore, the longitudinal direction of each ultraviolet lamp 28 aligns with the width direction of the transport unit 61, and the direction in which the multiple ultraviolet lamps 28 are arranged aligns with the transport direction.

[0066] In the freshness preservation device 60, the ultraviolet light irradiation device 1 is installed near the conveying section 61 that conveys food and other items as transport targets 62. Therefore, from the standpoint of maintaining a hygienic environment, the ultraviolet light irradiation device 1 is cleaned by washing with detergent and water. In this embodiment, as described above, the ultraviolet light irradiation device 1 has high waterproof performance, and the ultraviolet light irradiation device 1 has waterproof performance of IPX5 or higher in the IPX rating, for example. Therefore, the ultraviolet light irradiation device 1 has waterproof performance that can withstand washing.

[0067] Figure 9 is a cross-sectional view showing an example of a freshness preservation device 60 according to a modified example, taken along the transport direction in the transport section 61. In the modified example of Figure 9, the transport direction of the transport object 62 in the transport section 61 (arrow P1 side) is along a virtual horizontal plane, and the transport object 62 is transported along the horizontal plane. The upper side in the height direction of the transport section 61 (arrow H1 side) coincides with or approximately coincides with the upper vertical side (arrow V1 side), and the ultraviolet light irradiation device 1 is positioned above the transport section 61 in the height direction. In this modified example as well, the ultraviolet light irradiation device 1 is positioned with the irradiation window 13 facing the transport surface 63 of the transport section 61, and the transport object 62 placed on the transport surface 63 is transported downstream through the gap between the irradiation window 13 and the transport surface 63. The ultraviolet light from the ultraviolet light source 27 is irradiated from the upper side in the height direction of the transport section 61 through the irradiation window 13 onto the transport object 62 placed on the transport surface 63. In Figure 9, a cross-section perpendicular or nearly perpendicular to the width direction of the transport section 61 is shown.

[0068] However, in this modified example, unlike the examples in Figures 7 and 8, the lateral direction of the housing 2 aligns with the transport direction in the transport unit 61, and the depth direction of the housing 2 aligns with the width direction of the transport unit 61. Therefore, in this modified example, the longitudinal direction of each ultraviolet light lamp 28 aligns with the transport direction in the transport unit 61, and the direction in which the multiple ultraviolet light lamps 28 are arranged aligns with the width direction of the transport unit 61.

[0069] In the embodiments described above, the transport direction of the transport object 62 is along the horizontal plane, but this is not the only possible configuration. In one modified example, the transport direction in the transport section 61 may be inclined with respect to the horizontal plane. In this case, the height direction of the transport section 61 is inclined with respect to the vertical direction. The ultraviolet light from the ultraviolet light source 27 is irradiated onto the transport object 62 placed on the transport surface 63 from above in the height direction of the transport section 61, through the irradiation window 13.

[0070] Figure 10 is a schematic diagram showing an example of a freshness preservation device 60 according to a modification different from the modification shown in Figure 9. In the modification shown in Figure 10, the conveying section 61 is composed of, for example, a conveyor lift, and in the conveying section 61, the object to be conveyed 62, such as food, is conveyed along the vertical direction. In the example shown in Figure 10, the conveying direction in the conveying section 61 (arrow P1 side) coincides with or approximately coincides with the vertically upward side (arrow V1 side). In this modification, the conveying section 61 is equipped with a plurality of support plates 66. Each of the plurality of support plates 66 supports a corresponding one of the conveyed object 62 from the vertically downward side.

[0071] In this modified example, the freshness preservation device 60 and the conveying unit 61 are defined as having a width direction (a direction perpendicular or approximately perpendicular to the plane of the paper in Figure 10) that intersects (orthogonal or approximately perpendicular to) the conveying direction, and a depth direction (indicated by arrows D1 and D2) that intersects (orthogonal or approximately perpendicular to) both the conveying direction and the width direction. In this modified example, the width direction and depth direction of the conveying unit 61 are aligned with a virtual horizontal plane. The ultraviolet light irradiation device 1 is positioned at a distance from the conveying unit 61 on one side in the depth direction.

[0072] In this modified example, the ultraviolet light irradiation device 1 is positioned such that its height direction (indicated by arrows Z1 and Z2) aligns with the depth direction of the transport unit 61, and the irradiation window 13 of the ultraviolet light irradiation device 1 faces the transport unit 61 from one side in the depth direction of the transport unit 61. The transport object 62 being transported in the transport unit 61 is then irradiated with ultraviolet light from the ultraviolet light source 27 through the irradiation window 13 from one side in the depth direction (arrow D1 side). In other words, the ultraviolet light from the ultraviolet light source 27 irradiates the transport object 62 from a direction aligned with the horizontal plane.

[0073] Furthermore, even when the transport direction in the transport section 61 coincides with or nearly coincides with the vertically downward direction, by positioning the ultraviolet light irradiation device 1 in the same position as in the example in Figure 10, ultraviolet light from the ultraviolet light source 27 is irradiated onto the transported object 62 in the same manner as in the example in Figure 10. In addition, in a configuration in which the transported object 62 is transported along the vertical direction, by positioning the ultraviolet light irradiation device 1 at an appropriate position, ultraviolet light from the ultraviolet light source 27 can be irradiated onto the transported object 62 through the irradiation window 13 from either the vertically upward or vertically downward side.

[0074] Therefore, by using the ultraviolet light irradiation device 1 of the embodiment described above, the ultraviolet light irradiation device 1 can be positioned at an appropriate location in accordance with the configuration of the transport unit 61, including the transport direction in the transport unit 61. Furthermore, the direction in which the ultraviolet light from the ultraviolet light source 27 is irradiated onto the transport object 62 can be adjusted as appropriate in accordance with the configuration of the transport unit 61.

[0075] Figure 11 is a schematic diagram showing an example of a freshness preservation device 60 that is a modified version of Figure 9 and a modified version of Figure 10, and is different from the modified version of Figure 10. In the modified version of Figure 11, the freshness preservation device 60 includes a power supply unit 70 in addition to the ultraviolet light irradiation device 1 and the transport unit 61. The power supply unit 70 is electrically connected to the ultraviolet light irradiation device 1 via a cable 71. In this modified version, ultraviolet light from the ultraviolet light source 27 is irradiated onto the transported object 62, which is being transported, in the same manner as in the examples of Figures 7 and 8.

[0076] In this modified example, the power supply unit 30 is not mounted on the ultraviolet light irradiation device 1, and the power supply unit 30, which includes the lamp power supply 32, fan power supply 33, and control board 35, is mounted on the power supply device 70. However, even in this modified example, the internal cavity 7 of the housing 2 of the ultraviolet light irradiation device 1 is partitioned into a first space 25 where the irradiation window 13 is located, and a second space 26 where the intake port 17 and exhaust port 18 are located. Also in this modified example, the ultraviolet light source 27 is placed in the first space 25, and the fan 31 is placed in the second space 26. Ventilation holes 51, 52, 53, etc. are formed in the partition plate 23 to connect the first space 25 and the second space 26. For this reason, even in this modified example, where the power supply device 70 is provided separately from the ultraviolet light irradiation device 1, the same functions and effects as in the above-described embodiments are achieved. In other words, even in this modified example, the ultraviolet light irradiation device 1 can ensure high waterproof performance and allow the ultraviolet light source 27 to be cooled.

[0077] Furthermore, in this modified configuration, even with a large number of ultraviolet lamps 28 constituting the ultraviolet light source 27, the lamp power supply 32 is mounted on a separate power supply unit 70 from the ultraviolet light irradiation device 1. Therefore, even if the number of ultraviolet lamps 28 constituting the ultraviolet light source 27 increases, the weight of the ultraviolet light irradiation device 1 is reduced. In addition, since the power supply unit 30 is not provided in the ultraviolet light irradiation device 1, the amount of heat generated in the ultraviolet light irradiation device 1 can be reduced.

[0078] According to at least one of these embodiments, the partition plate divides the internal cavity of the housing into a first space where the irradiation window is located and a second space where the air intake and exhaust ports are located. The ultraviolet light source placed in the first space can irradiate ultraviolet light to the outside of the housing through the irradiation window. The fan placed in the second space operates to draw air from the air intake through the second space and the ventilation holes in the partition plate into the first space. This makes it possible to provide an ultraviolet light irradiation device that can ensure high waterproof performance and cool the ultraviolet light source, as well as a freshness preservation device equipped with the ultraviolet light irradiation device.

[0079] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0080] 1... Ultraviolet light irradiation device, 2... Housing, 7... Internal cavity, 13... Irradiation window, 17... Intake port, 18... Exhaust port, 23... Partition plate, 25... First space, 26... Second space, 27... Ultraviolet light source, 28... Ultraviolet light lamp, 30... Power supply unit, 31 (31A, 31B)... Fan, 40... Louver unit, 51... Ventilation hole (First ventilation hole), 52... Ventilation hole (Second ventilation hole), 57... Louver plate, 60... Freshness maintenance device, 61... Conveying section, 62... Conveying object, E1... End (First end), E2... End (Second end), C... Central part.

Claims

1. A housing having an illumination window through which light can pass, and in which the internal cavity opens to the outside at both the intake and exhaust ports; A partition plate that divides the internal cavity of the housing into a first space where the irradiation window is located and a second space where the intake port and exhaust port are located, and has ventilation holes that connect the first space and the second space; An ultraviolet light source is provided, which is positioned in the first space and capable of irradiating ultraviolet light to the outside of the housing through the irradiation window; A fan positioned in the second space and operating to draw air from the intake port through the second space and the vent into the first space; A device for irradiating ultraviolet light, equipped with the following features.

2. The ultraviolet light source comprises an ultraviolet light lamp extending along the longitudinal direction, The ultraviolet light lamp is positioned in the first space such that its longitudinal end is adjacent to the ventilation hole. The ultraviolet light irradiation device according to claim 1.

3. The ultraviolet light irradiation device according to claim 1, further comprising a louver plate positioned in the vicinity of the ventilation hole in the second space and facing the intake port, which causes the air flowing into the second space from the intake port to collide with the louver plate and flow the collided air into the first space through the ventilation hole.

4. The ultraviolet light irradiation device according to claim 3, wherein the louver plate is arranged in the second space in a position inclined with respect to the opening surface of the ventilation hole to the second space.

5. The ultraviolet light irradiation device according to claim 1, further comprising a power supply unit which is arranged in the second space and converts external power to supply to the ultraviolet light source and the fan.

6. The ultraviolet light irradiation device according to claim 1, having waterproof performance of IPX5 or higher in the IPX rating system.

7. A UV light irradiation device according to any one of claims 1 to 6; A transport unit that transports an object to be transported, and in which ultraviolet light from the ultraviolet light source of the ultraviolet light irradiation device is irradiated onto the object being transported through the irradiation window; A freshness preservation device equipped with the following features.

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