Ultraviolet light irradiation device and ultraviolet light irradiation system

Abstract

To provide an ultraviolet light irradiation device that allows for appropriate adjustment of the amount of ultraviolet light irradiated onto a transported object without changing the emission state of ultraviolet light from an ultraviolet light source. [Solution] The ultraviolet light irradiation device of the embodiment comprises a housing, an ultraviolet light source, and a light-shielding unit. The housing has an internal cavity opening on the side where the transport unit is located. The ultraviolet light source is placed in the internal cavity of the housing and is capable of irradiating ultraviolet light toward the transport unit. The light-shielding unit, in response to the operation of the light-shielding operation unit, shields the ultraviolet light from the ultraviolet light source to the transport unit between the ultraviolet light source and the transport unit, and also changes the range over which the ultraviolet light is shielded in response to the operation of the light-shielding operation unit.

Description

Technical Field

[0005] , , ,

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

Background Art

[0002] In food factories and fruit sorting plants, etc., an ultraviolet light irradiation system is used in which an ultraviolet light irradiation device is installed in a transport unit to irradiate food being transported as a transport target in the transport unit with ultraviolet light from an ultraviolet light source of the ultraviolet light irradiation device. By irradiating the food to be transported with ultraviolet light, the number of bacteria present on the surface and surface layer of the food is reduced and the freshness of the food is maintained.

[0003] In such an ultraviolet light irradiation system, for example, it is required to appropriately adjust the amount of ultraviolet light irradiated to the transport target in response to the transport state of the transport target in the transport unit, such as suppressing excessive irradiation of the transport target with ultraviolet light. In addition, in the ultraviolet light source of the ultraviolet light irradiation device, once the emission of ultraviolet light is stopped, it takes a long time until the ultraviolet light is stably emitted, or the configuration becomes complicated by making it possible to adjust the emission amount of ultraviolet light from the ultraviolet light source, etc. For this reason, it is required to be able to appropriately adjust the amount of ultraviolet light irradiated to the transport target without changing the emission state of the ultraviolet light from the ultraviolet light source.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] According to the embodiment, the ultraviolet light irradiation device comprises a housing, an ultraviolet light source, and a light-shielding unit, wherein the housing has an internal cavity opening on the side where the transport unit is located. The ultraviolet light source is positioned in the internal cavity of the housing and is capable of irradiating ultraviolet light toward the transport unit. The light-shielding unit comprises a light-shielding operation unit, which, in response to the operation of the light-shielding operation unit, shields the ultraviolet light from the ultraviolet light source to the transport unit between the ultraviolet light source and the transport unit, and also changes the range over which the ultraviolet light is shielded in response to the operation of the light-shielding operation unit. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an ultraviolet light irradiation device and an ultraviolet light irradiation system that can appropriately adjust the amount of ultraviolet light irradiated onto a transported object without changing the emission state of ultraviolet light from an ultraviolet light source. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing an example of an ultraviolet light irradiation system according to the first embodiment. [Figure 2] Figure 2 is a schematic block diagram showing an example of the control system of the ultraviolet light irradiation system according to the first embodiment. [Figure 3] Figure 3 is a schematic diagram of the ultraviolet light irradiation device shown in Figure 1, with the shutter sheet of the light-shielding unit not extended, viewed from the side where the transport unit is located (the lower side in the height direction). [Figure 4] Figure 4 is a schematic diagram of the ultraviolet light irradiation device shown in Figure 1, with the shutter sheet of the light-shielding unit fully extended, viewed from the side where the transport unit is located (the lower side in the height direction). [Figure 5] Figure 5 is a schematic perspective view showing the state in which the shutter sheet of the light-shielding unit is extended in the ultraviolet light irradiation device shown in Figure 1. [Figure 6]Figure 6 is a flowchart illustrating an example of the process related to controlling the operation of the light-shielding unit, which is performed by the control unit in the ultraviolet light irradiation system according to the first embodiment. [Figure 7] Figure 7 is a schematic diagram showing the configuration of an ultraviolet light irradiation device and its vicinity according to a modified example. [Figure 8] Figure 8 is a schematic diagram showing an ultraviolet light irradiation system relating to a different modification from the modification shown in Figure 7. [Modes for carrying out the invention]

[0009] The ultraviolet light irradiation device (3) of the embodiment comprises a housing (12), an ultraviolet light source (13), and a light-shielding unit (25). The housing (12) has an internal cavity (15) opening on the side where the transport unit (2) is located. The ultraviolet light source (13) is positioned in the internal cavity (15) of the housing (12) and is capable of irradiating ultraviolet light toward the transport unit (2). The light-shielding unit (25) comprises a light-shielding operation unit (26). In response to the operation of the light-shielding operation unit (26), it shields the ultraviolet light from the ultraviolet light source (13) to the transport unit (2) between the ultraviolet light source (13) and the transport unit (2), and also changes the range over which the ultraviolet light is shielded in response to the operation of the light-shielding operation unit (26). With this configuration, the amount of ultraviolet light irradiated onto the transport object (5) can be appropriately adjusted without changing the emission state of ultraviolet light from the ultraviolet light source (13) by adjusting the range of ultraviolet light shielding by the light shielding unit (25).

[0010] In the ultraviolet light irradiation device (3) of the embodiment, the light shielding unit (25) further comprises a shutter sheet (27) wound in a roll shape. In the light shielding unit (25), the shutter sheet (27) is pulled out in response to the operation of the light shielding operation unit (26), thereby shielding the ultraviolet light from the ultraviolet light source (13) from the shutter sheet (27). Additionally, the amount of the shutter sheet (27) pulled out changes in response to the operation of the light shielding operation unit (26), thereby changing the range over which the shutter sheet (27) shields the ultraviolet light. With this configuration, the light shielding unit (25) appropriately realizes a configuration in which the amount of ultraviolet light irradiated onto the transport object (5) is adjusted without changing the emission state of ultraviolet light from the ultraviolet light source (13).

[0011] In the ultraviolet light irradiation device (3) of this embodiment, the light shielding unit (25) is equipped with a plurality of shutter sheets (27A, 27B) that can be pulled out independently of each other, as shutter sheets (27). With this configuration, the amount of ultraviolet light irradiated onto the transported object (5) can be appropriately adjusted according to the type of transported object (5) being transported.

[0012] The ultraviolet light irradiation system (1) of the embodiment comprises a transport unit (2), a light source module (11), and a light shielding unit (25), the transport unit (2) transports the object to be transported (5). The light source module (11) comprises a housing (12) with an internal cavity (15) opening toward the side where the transport unit (2) is located, and an ultraviolet light source (13) positioned in the internal cavity (15) of the housing (12), and the ultraviolet light source (13) is capable of irradiating ultraviolet light toward the transport unit (2). The light shielding unit (25) comprises a light shielding operation unit (26), and in response to the operation of the light shielding operation unit (26), it shields the ultraviolet light from the ultraviolet light source (13) to the transport unit (2) between the ultraviolet light source (13) and the transport unit (2), and changes the range over which the ultraviolet light is shielded in response to the operation of the light shielding operation unit (26). With this configuration, the amount of ultraviolet light irradiated onto the transport object (5) can be appropriately adjusted without changing the emission state of ultraviolet light from the ultraviolet light source (13) by adjusting the range of ultraviolet light shielding by the light shielding unit (25).

[0013] The embodiments will be described below with reference to the drawings.

[0014] First, as an example of an embodiment, a first embodiment will be described. Figure 1 is a schematic diagram showing an example of an ultraviolet light irradiation system 1 according to the first embodiment. As shown in Figure 1, the ultraviolet light irradiation system 1 comprises a transport unit 2 and an ultraviolet light irradiation device 3. Food and the like are transported as transport targets 5 in the transport unit 2.

[0015] In the ultraviolet light irradiation system 1 and transport unit 2, the transport direction (indicated by arrow X1) in which the transport object 5 is transported is defined. In the ultraviolet light irradiation system 1 and transport unit 2, the transport direction is also referred to as the "downstream side," and the direction opposite to the transport direction (indicated by arrow X2) is also referred to as the "upstream side." Furthermore, in the ultraviolet light irradiation system 1 and transport unit 2, the width direction (indicated as orthogonal or nearly orthogonal to the plane of the paper in Figure 1) that intersects (orthogonal or nearly orthogonal to) the transport direction, and the height direction (indicated by arrows Z1 and Z2) that intersects (orthogonal or nearly orthogonal to) both the transport direction and the width direction are defined. In the ultraviolet light irradiation system 1 and transport unit 2, one side of the height direction (arrow Z1 side) is also referred to as the "upper side," and the opposite side of the height direction (arrow Z2 side) is also referred to as the "lower side." Figure 1 shows a cross-section that is orthogonal or nearly orthogonal to the width direction.

[0016] Examples of food items to be transported (5) include fruits and vegetables. In one example, the food items to be transported (5) are transported in a container. In this case, the container on which the food items are placed opens to the upper side in the height direction of the transport unit 2. The ultraviolet light irradiation system 1 functions as a freshness preservation device that uses ultraviolet light to suppress the deterioration of the freshness of the food items to be transported (5).

[0017] In the conveying unit 2, a conveying surface 6 is formed, and the conveying surface 6 faces upward in the height direction. When the conveying unit 2 includes a conveyor, the conveying surface 6 is the surface of the conveyor. When the conveying unit 2 includes rollers, the conveying surface 6 corresponds to a virtual surface connecting the uppermost sides of the respective rollers. In the conveying unit 2, the object to be conveyed 5 such as food is conveyed from the upstream side to the downstream side while being disposed on the conveying surface 6. In one example, the conveying surface 6 extends along a virtual horizontal plane, and the conveying direction of the object to be conveyed 5 in the conveying unit 2 is parallel or substantially parallel to the horizontal plane. In this case, the height direction in the ultraviolet light irradiation system 1 and the conveying unit 2 coincides or substantially coincides with the vertical direction. In another example, the conveying surface 6 is inclined with respect to the horizontal plane, and the conveying direction in the conveying unit 2 is inclined with respect to the horizontal plane.

[0018] The ultraviolet light irradiation device 3 includes a light source module 11. The light source module 11 is disposed above the conveying unit 2 in the height direction and on the side where the conveying surface 6 faces with respect to the conveying unit 2. The light source module 11 includes a housing 12 and an ultraviolet light source 13. An internal cavity 15 is formed inside the housing 12, and the ultraviolet light source 13 is disposed in the internal cavity 15. The housing 12 is formed of a metal or resin that does not transmit light such as ultraviolet light. Further, it is preferable that the inner surface of the housing 12 is coated with a paint (for example, black paint or the like) such that the reflectivity of ultraviolet light is low.

[0019] The housing 12 includes a top wall 16 and a peripheral wall 17. The top wall 16 covers the internal cavity 15 from above in the height direction. The peripheral wall 17 covers the internal cavity 15 from each of the upstream side, the downstream side, and both sides in the width direction of the conveying unit 2, and covers the internal cavity 15 from the outer peripheral side over the entire circumference in the circumferential direction. The internal cavity 15 of the housing 12 opens downward in the height direction and toward the side where the conveying unit 2 is located. The peripheral wall 17 extends downward in the height direction from the top wall 16 to the opening and forms the opening edge of the opening downward in the height direction.

[0020] In the ultraviolet light irradiation system 1, the housing 12 is attached to the transport unit 2 from above in the height direction, thereby installing the light source module 11 and the ultraviolet light irradiation device 3 in the transport unit 2. With the ultraviolet light irradiation device 3 installed in the transport unit 2, the top wall 16 of the housing 12 faces the transport surface 6 of the transport unit 2, with the internal cavity 15 in between.

[0021] In addition, in the example shown in Figure 1, an entrance 21 and an exit 22 are formed in the housing 12 of the light source module 11. The entrance 21 and the exit 22 are formed in the peripheral wall 17 of the housing 12. When the light source module 11 (ultraviolet light irradiation device 3) is installed in the transport unit 2, the internal cavity 15 opens upstream at the entrance 21 and downstream at the exit 22. The transport object 5 being transported in the transport unit 2 is brought into the internal cavity 15 from outside the housing 12 through the entrance 21 and is brought out from the internal cavity 15 to the outside of the housing 12 through the exit 22.

[0022] The ultraviolet light source 13 is positioned in the internal cavity 15, for example, by being mounted on the inner surface of the housing 12. The ultraviolet light source 13 is activated 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 13. The ultraviolet light source 13 irradiates ultraviolet light from the internal cavity 15 of the housing 12 toward the transport surface 6 of the transport unit 2. As a result, ultraviolet light from the ultraviolet light source 13 is irradiated toward the transport object 5 being transported in the internal cavity 15. In addition, when the food to be transported 5 is placed in a container, ultraviolet light is irradiated toward the transport object 5 through the opening of the container.

[0023] Furthermore, the ultraviolet light source 13 comprises one or more ultraviolet lamps 23, and in the example shown in Figure 1, multiple ultraviolet lamps 23 are provided. Each ultraviolet lamp 23 has a defined longitudinal direction, and each ultraviolet lamp 23 extends along its longitudinal direction. In the example shown in Figure 1, each ultraviolet lamp 23 is arranged such that its longitudinal direction aligns with the width direction of the transport section 2. Also in the example shown in Figure 1, the multiple ultraviolet lamps 23 are arranged along the transport direction in the transport section 2. Each ultraviolet lamp 23 can be a mercury lamp, a metal halide lamp, a fluorescent ultraviolet lamp, or an excimer lamp, among others.

[0024] In the example shown in Figure 1, four ultraviolet lamps 23 are provided on the ultraviolet light source 13, but the number of ultraviolet lamps 23 provided on the ultraviolet light source 13 is not limited. In one example, each ultraviolet lamp 23 is arranged so that its longitudinal direction aligns with the transport direction in the transport unit 2. In a configuration with multiple ultraviolet lamps 23, the multiple ultraviolet lamps 23 are arranged along the width direction of the transport unit 2.

[0025] The ultraviolet light irradiation device 3 includes a light-shielding unit 25. In the example shown in Figure 1, the light-shielding unit 25 is positioned in the internal cavity 15, for example, by being attached to the inner surface of the housing 12. Specifically, the light-shielding unit 25 is positioned so as not to leave a gap between it and the housing 12, and when the light-shielding unit 25 is operating (i.e., in a light-shielding state), the amount of ultraviolet light reaching the transport object 5 is limited (or reduced to zero). Also in the example shown in Figure 1, the light-shielding unit 25 is integrally assembled with the housing 12 and the light source module 11, which includes the ultraviolet light source 13. The light-shielding unit 25 is positioned in the height direction between the ultraviolet light source 13 and the transport surface 6 of the transport unit 2. Furthermore, the transport object 5, which is brought into the internal cavity 15 from the entrance 21, is transported towards the exit 22 by passing between the light-shielding unit 25 and the transport surface 6.

[0026] In the example shown in Figure 1, the light-shielding unit 25 comprises a light-shielding operating unit 26 and a shutter sheet 27. The shutter sheet 27 is wound into a roll. The shutter sheet 27 is made of a metal or resin that does not transmit light such as ultraviolet light, and is made of, for example, polytetrafluoroethylene (PTFE) and aluminum glass cloth. The light-shielding operating unit 26 operates when power is supplied. When the light-shielding operating unit 26 operates, the wound shutter sheet 27 is pulled out, or the pulled-out shutter sheet 27 is wound into a roll.

[0027] Figure 2 is a schematic block diagram showing an example of the control system of the ultraviolet light irradiation system 1 according to the first embodiment. In the example in Figure 2, the ultraviolet light irradiation system 1 includes a power supply unit 30, a transport operation unit 31, and a transport control unit 32, in addition to the ultraviolet light irradiation device 3 and the transport unit 2. The power supply unit 30 also includes a power supply circuit 33 and a control unit 35. In the example in Figure 2, the power supply unit 30 is provided separately from the ultraviolet light irradiation device 3 and is electrically connected to the ultraviolet light irradiation device 3 via a cable or the like.

[0028] The transport operation unit 31 is formed from, for example, buttons, switches, a touch panel, and a remote control. The transport operation unit 31 receives input from the user of the ultraviolet light irradiation system 1, etc., regarding operations related to transport in the transport unit 2. The transport control unit 32 controls the transport operation in the transport unit 2 based on the operations input from the transport operation unit 31. The transport control unit 32 consists of a processor or integrated circuit and a storage medium such as memory. The processor or integrated circuit constituting the transport control unit 32 includes any of the following: CPU (Central Processing Unit), ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), and DSP (Digital Signal Processor). The transport control unit 32 switches between a state where transport operation is being performed and a state where transport operation is stopped by controlling the transport operation in the transport unit 2. That is, the transport control unit 32 switches the transport operation on and off. The transport control unit 32 may also be configured to allow switching of the transport speed.

[0029] The power supply circuit 33 converts power supplied from an external source into power corresponding to the ultraviolet light source 13 and power corresponding to the light-shielding operation unit 26. The power supply circuit 33 supplies the converted power to the ultraviolet light source 13, causing ultraviolet light to be emitted from each of the ultraviolet light lamps 23 of the ultraviolet light source 13. The power supply circuit 33 also supplies the converted power to the light-shielding operation unit 26, operating the light-shielding operation unit 26. For example, the power supply circuit 33 converts power from an external source, such as power from a commercial power source, into DC power with a voltage corresponding to the ultraviolet light source 13 (ultraviolet light lamp 23) and DC power with a voltage corresponding to the light-shielding operation unit 26 by AC / DC conversion and voltage transformation.

[0030] The control unit 35 controls the power supply to the ultraviolet light source 13 and the light-shielding operation unit 26 by controlling the operation of the power supply circuit 33. This controls the emission of ultraviolet light from the ultraviolet light source 13 and the operation of the light-shielding operation unit 26. In one example, the control unit 35, like the transport control unit 32, is composed of a processor or integrated circuit and a storage medium such as memory. The processor or integrated circuit that constitutes the control unit 35 includes any of the following: CPU, ASIC, FPGA, and DSP. The control unit 35 may have only one integrated circuit or may have multiple integrated circuits.

[0031] The control unit 35 switches between a state where ultraviolet light is emitted and a state where ultraviolet light emission is stopped by controlling the emission of ultraviolet light from the ultraviolet light source 13. In other words, the control unit 35 switches the emission of ultraviolet light on and off. The control unit 35 can also communicate with the transport control unit 32 wirelessly or via wired connection. The control unit 35 receives information from the transport control unit 32 regarding the transport status of the transport object 5 in the transport unit 2. At this time, the control unit 35 receives from the transport control unit 32 either a signal indicating that transport operation is being performed in the transport unit 2, or a signal indicating that transport operation has stopped in the transport unit 2. Based on the transport status of the transport object 5 in the transport unit 2, the control unit 35 controls the operation of the light shielding unit 26.

[0032] In one example, at least one of the power supply circuit 33 and the control unit 35 is mounted on the ultraviolet light irradiation device 3. In this case, at least one of the power supply circuit 33 and the control unit 35 is located in the internal cavity 15 of the housing 12. In another example, the control of ultraviolet light emission from the ultraviolet light source 13 and the control of the operation of the light-shielding operation unit 26 are performed collaboratively by the processors or integrated circuits of multiple computers. In yet another example, at least part of the control of ultraviolet light emission from the ultraviolet light source 13 and the control of the operation of the light-shielding operation unit 26 is performed by a server in a cloud environment. The server in the cloud environment is composed of virtual processors such as virtual CPUs and cloud memory.

[0033] Figure 3 is a schematic diagram of the ultraviolet light irradiation device 3 of the example shown in Figure 1, with the shutter sheet 27 of the light shielding unit 25 not extended, viewed from the side where the transport unit 2 is located (the lower side in the height direction). Figure 4 is a schematic diagram of the ultraviolet light irradiation device 3 of the example shown in Figure 1, with the shutter sheet 27 of the light shielding unit 25 fully extended, viewed from the side where the transport unit 2 is located (the lower side in the height direction). Figure 5 is a schematic perspective view of the ultraviolet light irradiation device 3 of the example shown in Figure 1, with the shutter sheet 27 of the light shielding unit 25 extended.

[0034] In the example shown in Figures 3 to 5, the light-shielding mechanism 26 comprises a pair of electric cylinders 36. Each electric cylinder 36 is equipped with a gripping arm 37. The shutter sheet 27 has a defined length and has an edge E1 that forms one end in the length direction. The shutter sheet 27 is wound so that its length is along the circumferential direction of the roll-shaped portion and the edge E1 is at the outer circumferential end of the roll-shaped portion. A support bar 38 is fixed to the edge E1 or its vicinity on the shutter sheet 27. Each gripping arm 37 of the electric cylinder 36 grips the support bar 38.

[0035] Power supplied from the power supply circuit 33 causes each gripping arm 37 of the electric cylinder 36 to move. In the example shown in Figures 3 to 5, the direction of movement of the gripping arm 37 (indicated by arrows Y1 and Y2) is along the longitudinal direction of each ultraviolet light lamp 23. When the gripping arm 37 moves to one side in the direction of movement (towards arrow Y1), the rolled shutter sheet 27 is pulled out. At this time, the shutter sheet 27 is pulled out with its edge E1 as the leading edge (arrow A1 in Figure 5) by the pulling force of the moving gripping arm 37. The shutter sheet 27 can be pulled out to the fully extended state shown in Figure 4. When the shutter sheet 27 is pulled out, the gripping arm 37 moves to the opposite side of the movement of the shutter sheet 27 (towards arrow Y2), causing the shutter sheet 27 to be wound into a roll. The shutter sheet 27 can be wound up to the unextended state shown in Figure 3.

[0036] Due to the configuration described above, in the light-shielding unit 25, the shutter sheet 27 is pulled out in response to the operation of the light-shielding operation unit 26, which includes the electric cylinder 36. When ultraviolet light is emitted from the ultraviolet light source 13, the shutter sheet 27 is pulled out, thereby shielding the ultraviolet light from the ultraviolet light source 13 to the transport unit 2 between the ultraviolet light source 13 and the transport unit 2. In addition, in the example light-shielding unit 25 shown in Figures 3 to 5, the amount the shutter sheet 27 is pulled out changes in response to the operation of the light-shielding operation unit 26. When ultraviolet light is emitted from the ultraviolet light source 13, the amount the shutter sheet 27 is pulled out changes, which alters the range over which the shutter sheet 27 shields the ultraviolet light between the ultraviolet light source 13 and the transport unit 2.

[0037] In the state shown in Figure 3, when the shutter sheet 27 is not extended, the shutter sheet 27 does not block ultraviolet light from the ultraviolet light source 13. The greater the amount the shutter sheet 27 is extended, the wider the area over which the shutter sheet 27 blocks ultraviolet light. Furthermore, in the state shown in Figure 4, when the shutter sheet 27 is fully extended, the entire ultraviolet light source 13 overlaps with the extended portion of the shutter sheet 27 in the projection from the side where the transport unit 2 is located. Therefore, in the state where the shutter sheet 27 is fully extended, in the projection from the height direction of the transport unit 2, all of the ultraviolet light lamps 23 constituting the ultraviolet light source 13 are included in the projection range of the extended portion of the shutter sheet 27.

[0038] In the example shown in Figures 3 to 5, the direction of movement of the gripping arm 37 is aligned with the longitudinal direction of each ultraviolet lamp 23, so the direction in which the shutter sheet 27 is pulled out is aligned with the longitudinal direction of each ultraviolet lamp 23. In this case, in a configuration in which each ultraviolet lamp 23 is arranged with its longitudinal direction aligned with the width direction of the transport unit 2, the direction in which the shutter sheet 27 is pulled out is aligned with the width direction of the transport unit 2. Also, in a configuration in which each ultraviolet lamp 23 is arranged with its longitudinal direction aligned with the transport direction in the transport unit 2, the direction in which the shutter sheet 27 is pulled out is aligned with the transport direction in the transport unit 2.

[0039] In one example, the direction in which the shutter sheet 27 is pulled out intersects (orthogonal or nearly orthogonal) the longitudinal direction of each ultraviolet lamp 23 and aligns with the direction in which the multiple ultraviolet lamps 23 are arranged. In this case, if the multiple ultraviolet lamps 23 are arranged along the transport direction in the transport unit 2, the direction in which the shutter sheet 27 is pulled out aligns with the transport direction in the transport unit 2. Also, if the multiple ultraviolet lamps 23 are arranged along the width direction of the transport unit 2, the direction in which the shutter sheet 27 is pulled out aligns with the width direction of the transport unit 2.

[0040] Figure 6 is a schematic flowchart showing an example of a process related to the control of the operation of the light-shielding unit 26 performed by the control unit 35 in the ultraviolet light irradiation system 1 according to the first embodiment. The process in the example in Figure 6 is repeated at predetermined time intervals while ultraviolet light is being irradiated from the ultraviolet light source 13 toward the transport unit 2. When the process in the example in Figure 6 is started, the control unit 35 receives information regarding the transport status of the transport object 5 in the transport unit 2 from the transport control unit 32, and determines whether or not the transport operation in the transport unit 2 has been stopped based on the information regarding the transport status of the transport object 5 (S101). At this time, the control unit 35 may also determine whether or not the transport operation in the transport unit 2 has been stopped based on the value indicated by the transport speed sensor provided in the ultraviolet light irradiation system 1, or it may be configured to determine whether or not the transport operation in the transport unit 2 is about to be stopped based on the history of the values ​​indicated by the sensor.

[0041] If the transport operation is stopped (S101-Yes), the control unit 35 controls the operation of the light-shielding operation unit 26 to pull out the wound shutter sheet 27 or maintain the state in which the shutter sheet 27 is pulled out (S102). As a result, the ultraviolet light from the ultraviolet light source 13 is blocked by the shutter sheet 27 between the ultraviolet light source 13 and the transport unit 2, or the state in which the ultraviolet light from the ultraviolet light source 13 is blocked by the shutter sheet 27 is maintained.

[0042] On the other hand, if the transport operation is not stopped, that is, if the transport unit 2 is transporting the transport object 5 (S101-No), the control unit 35 controls the operation of the light-shielding operation unit 26 to wind up the pulled-out shutter sheet 27 or maintain the state in which the shutter sheet 27 is wound up (S103). As a result, the ultraviolet light from the ultraviolet light source 13 is not blocked between the ultraviolet light source 13 and the transport unit 2, or the state in which the ultraviolet light from the ultraviolet light source 13 is not blocked is maintained.

[0043] As described above, in this embodiment, the ultraviolet light source 13, which is located in the internal cavity 15 of the housing 12, is capable of irradiating ultraviolet light toward the transport unit 2. The light-shielding unit 25, in response to the operation of the light-shielding operation unit 26, shields the ultraviolet light from the ultraviolet light source 13 to the transport unit 2 between the ultraviolet light source 13 and the transport unit 2, and also changes the range over which the ultraviolet light is shielded in response to the operation of the light-shielding operation unit 26. With this configuration, by adjusting the range over which the ultraviolet light is shielded by the light-shielding unit 25, the amount of ultraviolet light irradiated toward the transport unit 2 and the transport object 5 can be appropriately adjusted. By appropriately adjusting the amount of ultraviolet light irradiated toward the transport object 5, excessive irradiation of the transport object 5 with ultraviolet light is suppressed.

[0044] Furthermore, by adjusting the range over which ultraviolet light is blocked by the light-shielding unit 25, the amount of ultraviolet light irradiated onto the transport target 5 is adjusted without changing the emission state of ultraviolet light from the ultraviolet light source 13. In other words, the amount of ultraviolet light irradiated onto the transport target 5 is adjusted without stopping the emission of ultraviolet light from the ultraviolet light source 13 or changing the amount of ultraviolet light emitted from the ultraviolet light source 13.

[0045] Furthermore, in this embodiment, the shutter sheet 27 is pulled out in response to the operation of the light-shielding unit 26, thereby shielding the ultraviolet light from the ultraviolet light source 13 from the shutter sheet 27. Additionally, the amount the shutter sheet 27 is pulled out changes in response to the operation of the light-shielding unit 26, thereby changing the range over which the shutter sheet 27 shields the ultraviolet light. With this configuration, the light-shielding unit 25 appropriately adjusts the amount of ultraviolet light irradiated onto the transport target 5 without changing the emission state of ultraviolet light from the ultraviolet light source 13.

[0046] Furthermore, in this embodiment, the control unit 35 either pulls out the wound shutter sheet 27 or maintains the shutter sheet 27 in the pulled-out state based on the fact that the transport operation in the transport unit 2 has stopped. By controlling the operation of the light-shielding operation unit 26 in this way, the amount of ultraviolet light irradiated onto the transport object 5 is appropriately adjusted in accordance with the transport state of the transport object 5 in the transport unit 2. For example, when the transport object 5 is not being transported in the transport unit 2, the ultraviolet light from the ultraviolet light source 13 to the transport unit 2 and the transport object 5 is appropriately shielded by the light-shielding unit 25. Therefore, excessive irradiation of the transport object 5 with ultraviolet light is further appropriately suppressed.

[0047] Figure 7 is a schematic diagram showing the configuration of an ultraviolet light irradiation device 3 and its vicinity according to a modified example. In Figure 7, a cross-section perpendicular or approximately perpendicular to the width direction of the transport unit 2 is shown. In the modified example of Figure 7, the light-shielding unit 25 is provided with a plurality of light-shielding operating units 26A, 26B and a plurality of shutter sheets 27A, 27B. In this modified example, the control unit 35 controls the operation of each of the light-shielding operating units 26A and 26B. The shutter sheet 27A is pulled out in the same manner as the shutter sheet 27 in the above-described embodiment, in response to the operation of the light-shielding operating unit 26A, and the amount of pulling it out changes. Similarly, the shutter sheet 27B is pulled out in the same manner as the shutter sheet 27 in the above-described embodiment, in response to the operation of the light-shielding operating unit 26B, and the amount of pulling it out changes.

[0048] Due to this configuration, in this modified example, each of the shutter sheets 27A and 27B blocks ultraviolet light from the ultraviolet light source 13 to the transport unit 2 in the same manner as the shutter sheet 27, and also changes the range over which the ultraviolet light is blocked. In this modified example, the shutter sheets 27A and 27B are positioned offset from each other in the height direction of the transport unit 2. In the example shown in Figure 7, the shutter sheet 27A is positioned above the shutter sheet 27B in the height direction and is positioned closer to the ultraviolet light source 13 than the shutter sheet 27B.

[0049] In one example, multiple shutter sheets 27A and 27B have different light transmittance and wavelength selectivity relative to each other. If the light transmittance differs among the multiple shutter sheets 27A and 27B, shutter sheets with higher transmittance are positioned closer to the ultraviolet light source 13. Also, if the light transmittance differs among the multiple shutter sheets 27A and 27B, shutter sheets with lower light transmittance in the infrared wavelength range are positioned further away from the ultraviolet light source 13. As a result, when ultraviolet light is emitted from the ultraviolet light source 13, shutter sheets with higher temperatures are positioned further away from the ultraviolet light source 13.

[0050] Furthermore, with multiple shutter sheets 27A and 27B, the directions in which they are pulled out may be the same or different with respect to each other. If the directions in which the two shutter sheets 27A and 27B are pulled out are different, in one example the direction in which shutter sheet 27B is pulled out is opposite to the direction in which shutter sheet 27A is pulled out. In another example the direction in which shutter sheet 27B is pulled out intersects (orthogonal or nearly orthogonal) the direction in which shutter sheet 27A is pulled out.

[0051] This modified version also produces the same functions and effects as the embodiments described above. Furthermore, in this modified version, by making the light transmittance different among the multiple shutter sheets 27A and 27B, the amount of ultraviolet light irradiated onto the transported object 5 can be appropriately adjusted according to the type of transported object 5 being transported. In another modified version, both of the multiple shutter sheets 27A and 27B are made of a material that blocks ultraviolet light, and the range and area of ​​ultraviolet light irradiation can be adjusted by setting the direction in which each shutter sheet is pulled out to be perpendicular to each other.

[0052] In one example of this modified configuration, the light transmittance of shutter sheet 27A is higher than that of shutter sheet 27B. When the transport operation of the transport unit 2 is stopped, the shutter sheet 27B is pulled out, preventing or minimizing the irradiation of ultraviolet light from the ultraviolet light source 13 to the transport unit 2 and the transported object 5. When food of type α1 is being transported as the transported object 5, ultraviolet light from the ultraviolet light source 13 is irradiated onto the transported object 5 without pulling out either shutter sheet 27A or 27B. When food of type α2 is being transported as the transported object 5, shutter sheet 27A is pulled out, and the ultraviolet light transmitted through shutter sheet 27A is irradiated onto the transported object 5. As a result, food of type α2 is irradiated with ultraviolet light with a smaller amount of irradiation compared to food of type α1, and the amount of ultraviolet light irradiated onto the transported object 5 is adjusted according to the type of transported object 5.

[0053] In the example shown in Figure 7, two shutter sheets 27A and 27B are provided on the light-shielding unit 25. However, in one modified example, three or more shutter sheets 27 are provided on the light-shielding unit 25. In this case as well, the three or more shutter sheets 27 are arranged offset from each other in the height direction of the transport unit 2. In one example of this modified example, at least one of the light transmittance and wavelength selectivity of the three or more shutter sheets 27 differs from one another.

[0054] Figure 8 is a schematic diagram showing an ultraviolet light irradiation system 1 according to a modification different from the modification shown in Figure 7. In Figure 8, a cross-section perpendicular or nearly perpendicular to the width direction of the transport unit 2 is shown. In the modification shown in Figure 8, the ultraviolet light irradiation device 3 is composed of a light source module 11 equipped with a housing 12 and an ultraviolet light source 13, and the light shielding unit 25 is provided in an assembly 40 separate from the ultraviolet light irradiation device 3. In this modification, the assembly 40 is positioned between the light source module 11 (ultraviolet light irradiation device 3) and the transport unit 2 in the height direction, and between the light source module 11 and the transport surface 6.

[0055] The assembly 40 includes a light-shielding frame 41, and an internal space 42 is formed inside the light-shielding frame 41. The light-shielding frame 41 is made of a metal or resin that does not transmit light such as ultraviolet light. It is also preferable that the inner surface of the light-shielding frame 41 is coated with black paint or the like.

[0056] In this modified example, the housing 12 is attached to the light-shielding frame 41 from the upper side in the height direction, and the housing 12 is removablely attached to the light-shielding frame 41. The internal cavity 15 of the housing 12 is adjacent to the internal space 42 of the light-shielding frame 41 from the upper side in the height direction, and the internal cavity 15 communicates with the internal space 42 through an opening on the side where the transport unit 2 is located. The transport surface 6 of the transport unit 2 is adjacent to the internal space 42 from the lower side in the height direction. The light-shielding frame 41 covers the internal space 42 from both sides in the width direction of the transport unit 2. In the example in Figure 8, the light-shielding frame 41 protrudes from the housing 12 to the upstream and downstream sides. At the protruding portions of the light-shielding frame 41 from the housing 12 to the upstream and downstream sides, the light-shielding frame 41 covers the internal space 42 from the upper side in the height direction.

[0057] In this modified example, an entrance 21 and an exit 22 are formed in the light-shielding frame 41. When the light source module 11 (ultraviolet light irradiation device 3) and assembly 40 are installed in the transport unit 2, the internal space 42 opens upstream at the entrance 21 and downstream at the exit 22. The transport object 5 being transported in the transport unit 2 is brought into the internal space 42 from outside the light-shielding frame 41 and housing 12 through the entrance 21, and is transported out of the internal space 42 to the outside of the light-shielding frame 41 and housing 12 through the exit 22. In this modified example, ultraviolet light from the ultraviolet light source 13 is irradiated onto the transport object 5 being transported in the internal space 42 of the light-shielding frame 41. At this time, the ultraviolet light from the ultraviolet light source 13, which is located in the internal cavity 15, passes through the opening of the internal cavity 15 toward the side where the transport unit 2 is located, and is irradiated onto the transport object 5 being transported in the internal space 42.

[0058] In the example shown in Figure 8, the light-shielding unit 25 is positioned in the internal space 42, for example, by being attached to the inner surface of the light-shielding frame 41. In this modified example as well, when the shutter sheet 27 is pulled out in the light-shielding unit 25, ultraviolet light from the ultraviolet light source 13 to the transport unit 2 is blocked between the ultraviolet light source 13 and the transport unit 2. And, as with the embodiments described above, as the amount the shutter sheet 27 is pulled out changes, the range over which the shutter sheet 27 blocks ultraviolet light between the ultraviolet light source 13 and the transport unit 2 changes.

[0059] In another modified configuration, a light-shielding frame 41 is provided, similar to the example in Figure 8, and a light-shielding unit 25 is placed in the internal cavity 15 of the housing 12. In this case, the ultraviolet light irradiation device 3 is composed of a light source module 11 comprising an ultraviolet light source 13 and a housing 12, and a light-shielding unit 25. The light-shielding unit 25 is placed in the internal cavity 15, for example, by being attached to the inner surface of the housing 12. In this modified configuration as well, in the light-shielding unit 25, the shutter sheet 27 is pulled out, thereby shielding the ultraviolet light from the ultraviolet light source 13 to the transport unit 2 between the ultraviolet light source 13 and the transport unit 2. And, similar to the embodiments described above, the range over which the shutter sheet 27 shields the ultraviolet light between the ultraviolet light source 13 and the transport unit 2 changes as the amount the shutter sheet 27 is pulled out changes.

[0060] Furthermore, in the above-described embodiment, the ultraviolet light from the ultraviolet light source 13 to the transport unit 2 is blocked by pulling out the roll-shaped shutter sheet 27 between the ultraviolet light source 13 and the transport unit 2. However, the configuration for blocking ultraviolet light to the transport unit 2 is not limited to this. That is, in the embodiment, it is sufficient that the ultraviolet light from the ultraviolet light source 13 to the transport unit 2 is blocked between the ultraviolet light source 13 and the transport unit 2 in accordance with the operation of the light-blocking operation unit 26 of the light-blocking unit 25. And it is sufficient that the range over which ultraviolet light is blocked changes in accordance with the operation of the light-blocking operation unit 26.

[0061] According to at least one of these embodiments, the light-shielding unit, in response to the operation of the light-shielding unit, shields ultraviolet light from the ultraviolet light source to the transport unit between the ultraviolet light source and the transport unit, and also changes the range over which ultraviolet light is shielded in response to the operation of the light-shielding unit. This makes it possible to provide an ultraviolet light irradiation device and an ultraviolet light irradiation system that can appropriately adjust the amount of ultraviolet light irradiated onto the transport object without changing the emission state of ultraviolet light from the ultraviolet light source.

[0062] 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]

[0063] 1…Ultraviolet light irradiation system, 2…Transportation unit, 3…Ultraviolet light irradiation device, 5…Transport object, 11…Light source module, 12…Housing, 13…Ultraviolet light source, 15…Internal cavity, 25…Light shielding unit, 26(26A,26B)…Light shielding operation unit, 27(27A,27B)…Shutter sheet, 35… Control unit.

Claims

1. A housing with an internal cavity opening on the side where the transport section is located; An ultraviolet light source is provided, which is positioned in the internal cavity of the housing and capable of irradiating ultraviolet light toward the transport section; A light-shielding unit comprising a light-shielding mechanism, which, in response to the operation of the light-shielding mechanism, shields the ultraviolet light from the ultraviolet light source to the transport unit between the ultraviolet light source and the transport unit, and changes the range over which the ultraviolet light is shielded in response to the operation of the light-shielding mechanism; A device for irradiating ultraviolet light, equipped with the following features.

2. The light-shielding unit further comprises a shutter sheet wound in a roll shape, In the light-shielding unit, the shutter sheet is pulled out in response to the operation of the light-shielding mechanism, thereby shielding the ultraviolet light from the ultraviolet light source from the shutter sheet. Furthermore, the amount the shutter sheet is pulled out changes in response to the operation of the light-shielding mechanism, thereby changing the range over which the shutter sheet shields the ultraviolet light. The ultraviolet light irradiation device according to claim 1.

3. The ultraviolet light irradiation device according to claim 2, wherein the light-shielding unit comprises a plurality of shutter sheets that can be pulled out independently of each other as the shutter sheets.

4. A transport unit that transports the object to be transported; A housing having an internal cavity opening toward the side where the transport unit is located, and a light source module comprising an ultraviolet light source positioned in the internal cavity of the housing, and the ultraviolet light source capable of irradiating ultraviolet light toward the transport unit; A light-shielding unit comprising a light-shielding mechanism, which, in response to the operation of the light-shielding mechanism, shields the ultraviolet light from the ultraviolet light source to the transport unit between the ultraviolet light source and the transport unit, and changes the range over which the ultraviolet light is shielded in response to the operation of the light-shielding mechanism; A UV light irradiation system equipped with the following features.

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