JP7589945B2 - Light irradiation device - Google Patents

Description

The technology disclosed in this specification relates to a light irradiation device.

Conventionally, an in-vehicle device 1 having a function of irradiating light has been known, for example, as described in Patent Document 1. As shown in FIG. 9, this device is configured by sequentially superimposing a structure 2 containing a substance having a photocatalytic action, an irradiation means 3 for irradiating the structure 2 with light including ultraviolet light, a heat storage material 4 for supplying stored heat to the photocatalyst of the structure 2, and an air blowing means 5 for blowing air to the structure 2. The airflow sent out from the air blowing means 5 is supplied to the irradiation means 3 and the structure 2 through the heat storage material 4.

JP 2006-21098 A

In a device that dissipates heat generated by an irradiation means using a blowing means, in a configuration in which the irradiation means 3 and the blowing means 5 are arranged in an overlapping state, as in the configuration of Patent Document 1 described above, the dimensions of the device in the overlapping direction become large. For this reason, when the device is mounted inside the vehicle cabin, for example on the ceiling of the vehicle, space is required in the direction in which it protrudes from the mounting surface, but it is not easy to secure such space in a vehicle. Also, when the device is mounted so that it protrudes from the mounting surface, it is desirable to make the protruding dimension as small as possible. In other words, there is a demand for a thinner device.

On the other hand, due to the recent increase in the need for sterilization, there is a demand for sterilization of vehicles after each use. Deep ultraviolet light (100-280 nm), which has a short wavelength among ultraviolet rays, has been known to have a sterilizing effect, and it is considered to irradiate vehicles with this deep ultraviolet light. Such deep ultraviolet light irradiation devices have a higher output than conventional visible light irradiation devices and long-wavelength ultraviolet light irradiation devices, so it is desirable to improve the cooling efficiency more than before.

The technology disclosed in this specification has been developed in consideration of the above circumstances, and aims to provide a light irradiation device that is thin and has excellent cooling efficiency.

The technology disclosed in this specification for solving the above problem is a light beam irradiation device that is attached to a mounting surface inside a vehicle, and includes an irradiation board on which an irradiation element is mounted on a mounting surface, a control board on which a drive element for driving the irradiation element is mounted, a cooling fan having an air outlet for cooling the light beam irradiation device, and a housing having an air intake port and an exhaust port and accommodating the irradiation board, the control board, and the cooling fan. When the light beam irradiation device is attached to the mounting surface, the control board is accommodated in the housing in a state where it overlaps with the cooling fan in a direction perpendicular to the mounting surface, and is located in the intake path from the air intake port to the cooling fan, and the irradiation board is accommodated in the housing in a state where it is arranged side by side with the cooling fan in a direction along the mounting surface, and is located in the exhaust path from the air intake port of the cooling fan to the exhaust port.

With this configuration, the irradiation board and the cooling fan are arranged side by side, so it is possible to make the light irradiation device thinner than in the conventional configuration in which the irradiation board and the cooling fan are arranged so as to overlap each other. In addition, by arranging the control board in the intake path from the intake port to the cooling fan, the control board can be cooled by the air drawn into the housing, and the heated air can be sent to the exhaust path. Furthermore, by arranging the irradiation board in the exhaust path from the blower port to the exhaust port, the irradiation board can be cooled by the air blown from the cooling fan, and the heated air can be exhausted from the exhaust port.

The cooling fan may be configured to take in air from a direction perpendicular to the mounting surface and send air in a direction along the mounting surface. With this configuration, the light irradiation device can be made thinner than with a configuration in which the cooling fan takes in air from a direction perpendicular to the mounting surface and sends air in a direction perpendicular to the mounting surface.

The space between both sides of the irradiation board extending along the lateral arrangement direction of the cooling fan and the irradiation board and the opposing surface of the housing arranged opposite the mounting surface of the irradiation board is blocked by a partition wall, the air outlet of the cooling fan and the irradiation board are arranged at a distance, the space between the air outlet, the irradiation board and the partition wall is blocked by a partition wall, and the space surrounded by the partition wall, the opposite surface, the partition wall and the opposing surface may constitute the exhaust path from the air outlet to the exhaust port.

With this configuration, the exhaust path from the air supply port to the exhaust port is separated from the surrounding area, and the irradiation substrate forms part of the exhaust path, so the irradiation substrate can be efficiently cooled by air with a high flow rate. In addition, the air blown from the air supply port is guided to the exhaust port (outside the housing) without spreading inside the housing, improving the cooling efficiency of the entire light irradiation device.

The facing surface may extend parallel to the opposite surface of the irradiated substrate. With this configuration, the distance from the opposite surface of the substrate to the facing surface is constant at any position, so the substrate can be cooled evenly, resulting in improved cooling efficiency.

The area around the exhaust path in the internal space of the housing may be in communication with the intake path. With this configuration, a portion of the air drawn in from the intake port can be circulated around the exhaust path, thereby cooling the exhaust path, making it easier to cool the irradiation substrate.

The drive element may be mounted on the surface of the control board that faces the cooling fan. With this configuration, the air drawn into the cooling fan is more likely to come into contact with the drive element, allowing the drive element itself to be cooled efficiently.

The drive element may be mounted on the control board at a position that overlaps with the cooling fan. With this configuration, the air whose flow rate has increased to be drawn into the cooling fan comes into contact with the drive element or the part of the control board on which the drive element is mounted, making it easier to absorb heat, thereby improving cooling efficiency.

The irradiation substrate mounts the first and second irradiation elements and includes a first portion for mounting the first irradiation element and a second portion for mounting the second irradiation element, and the first portion and the second portion may be arranged side by side in a direction intersecting the extension direction of the exhaust path and extend in directions intersecting each other.

With this configuration, the irradiation range in the height direction is wider than in a configuration in which two irradiation elements face only in one direction, so a wide range inside the vehicle cabin can be irradiated. Also, compared to a configuration in which the first and second parts are aligned along the extension direction of the exhaust duct, the airflow passing through the exhaust duct becomes linear, stabilizing the airflow and stabilizing the flow rate. In other words, the cooling efficiency is improved. Also, the first and second parts can be cooled evenly.

The irradiation substrate may be made of aluminum. Aluminum has high thermal conductivity and therefore excellent cooling efficiency.

The technology disclosed in this specification makes it possible to obtain a light irradiation device that is thin and has excellent cooling efficiency.

Cross-sectional view of a deep ultraviolet irradiation device according to an embodiment. Horizontal cross-sectional view of a deep ultraviolet irradiation device (cross-sectional view taken along II in FIG. 1) Horizontal cross-sectional view of the deep ultraviolet irradiation device (cross-sectional view taken along II-II in FIG. 1) Front view of deep ultraviolet irradiation device Cross-sectional view of the deep ultraviolet irradiation device in a direction intersecting with the exhaust path (cross-sectional view taken along line III-III in FIG. 1) Cross-sectional view of the deep ultraviolet irradiation device in a direction intersecting with the exhaust path (IV-IV cross-sectional view of Figure 1) Schematic diagram of the front-rear direction of a vehicle equipped with a deep ultraviolet irradiation device Left-right schematic diagram of a vehicle equipped with a deep ultraviolet irradiation device FIG. 1 is a cross-sectional view showing a conventional device having a light irradiation function.

An embodiment in which the light irradiation device disclosed in this specification is applied to a deep ultraviolet irradiation device 10 capable of sterilizing the interior of a vehicle will be described with reference to Figs. 1 to 8. Each drawing shows an X-axis, a Y-axis, and a Z-axis, and each axis direction is drawn so as to be a common direction in each drawing. The X-axis direction is the right direction, the Y-axis direction is the forward direction, and the Z-axis direction is the upward direction. In addition, for multiple identical components, a reference symbol may be assigned to one component and the reference symbols of the other components may be omitted.

As shown in FIG. 1, the deep ultraviolet irradiation device 10 has a housing 11 that is generally flat and box-shaped. The ceiling wall 12 of the housing 11, which is arranged at the top of FIG. 1, is composed of a front ceiling wall 13 located at the front side, a rear ceiling wall 15 located at the rear side and arranged at a position slightly higher than the front ceiling wall 13, and a connecting wall 14 that rises obliquely from the front to the rear so as to connect the front ceiling wall 13 and the rear ceiling wall 15. The inclination angle of the connecting wall 14 is set to an angle of 35 degrees from the horizontal direction. In addition, an opening 19 is provided in a portion of the bottom wall 18 of the housing 11, which is arranged at the bottom of FIG. 1, facing the LED 42 described later. Alternatively, the portion of the bottom wall 18 facing the LED 42 may be formed of a transparent or translucent material that can transmit deep ultraviolet light, such as quartz.

As shown in FIG. 1, an intake port 22 is formed through the rear wall 21 of the housing 11 so as to straddle the rear ceiling wall 15. An exhaust port 24 is formed through the front wall 23 so as to straddle the front ceiling wall 13. The intake port 22 may be formed at a position where it is not blocked by obstacles such as the side walls, ceiling wall 12, or bottom wall 18, or may be formed across multiple walls as in this embodiment. The intake port 22 in this embodiment is provided in the rear wall 21 above the mounting surface 50A of the control board 50, which will be described later. The intake port 22 and exhaust port 24 are formed in the shape of multiple vertical slits so that foreign objects, etc., do not easily enter the inside of the housing 11 (see FIGS. 2 and 4).

In the following, the space below the front ceiling wall 13 and the connecting wall 14 within the interior space of the housing 11 will be referred to as the front space R1, and the space below the rear ceiling wall 15 as the rear space R2. As shown in FIG. 1, a standing wall (an example of a partition wall) 25 rising from the bottom wall 18 is provided at part of the boundary between the front space R1 and the rear space R2, as will be described later. The front space R1 houses the irradiation unit 40. The rear space R2 houses the cooling fan 30 and the control board 50.

2 and 5, the irradiation unit 40 includes two flat plate-like first substrates (an example of an irradiation substrate and a first part) 411 and a second substrate (an example of an irradiation substrate and a second part) 412, a first LED (an example of a first irradiation element) 421 mounted on the lower surface (an example of a mounting surface) 411L of the first substrate 411, and a second LED (an example of a second irradiation element) 422 mounted on the lower surface (an example of a mounting surface) 412L of the second substrate 412. In the following, the left substrate shown in FIG. 2 and FIG. 5 will be referred to as the first substrate 411 and the right substrate as the second substrate 412, and when the two substrates are not distinguished, they will be referred to as the LED substrate 41, and when the two LEDs are not distinguished, they will be referred to as the LED 42.

The LEDs 42 in this embodiment are deep ultraviolet LEDs that irradiate deep ultraviolet light (100 to 280 nm), which has a short wavelength among ultraviolet rays. The wavelength of the deep ultraviolet light irradiated by these LEDs 42 is preferably within the range of 200 to 280 nm. Note that the first substrate 411 and the second substrate 412 may be equipped with visible light LEDs that emit visible light in addition to the deep ultraviolet LEDs 42.

The LEDs 42 in this embodiment are top-illuminating LEDs that irradiate from the end face (top face) opposite the LED board 41 when mounted on the LED board 41. The beam angle of these LEDs 42 is within a range of 120 degrees centered on an axis perpendicular to the top face (see Figures 7 and 8).

The first and second substrates 411 and 412 are made of aluminum, and as shown in FIG. 5, are arranged side by side in the left-right direction (the direction intersecting the extension direction of the exhaust passage 28 described later) in a state where they cross each other to form a flat V-shape when viewed from the front. More specifically, the first and second substrates 411 and 412 are arranged next to each other in the left-right direction, each tilted downward by about 15 degrees from the horizontal direction toward the center in the left-right direction. As a result, the top surfaces of the first LED 421 mounted on the lower surface 411L of the first substrate 411 and the second LED 422 mounted on the lower surface 412L of the second substrate 412 are each in a state where the top surface faces slightly outward (left-right direction) from below.

When the first board 411 and the second board 412 are arranged in a V-shape in the left-right direction, the left-right width dimension L1 of the first board 411 and the second board 412 is approximately half the left-right width dimension of the housing 11. In addition, the front-rear length dimension L2 of the first board 411 and the second board 412 is equal to the dimension between the front wall 23 and the standing wall 25 of the housing 11. As a result, the first board 411 and the second board 412 are accommodated in the front space R1 of the housing 11, fitting snugly between the front wall 23 and the standing wall 25 (see Figures 1 and 2).

As shown in FIG. 5, the front ceiling wall 13 described above has a recessed portion 16 with a flattened V-shaped cross section formed in the center in the left-right direction so that its lower surface 13L (part of the ceiling surface (an example of the opposing surface) 12L) faces parallel to the upper surface (an example of the opposing surface) 411U of the first board 411 and the upper surface (an example of the opposing surface) 412U of the second board 412. Both left and right sides of the recessed portion 16 in the front ceiling wall 13 are horizontal portions 17 extending horizontally. The horizontal portions 17 face parallel to the bottom wall 18 of the housing 11.

In addition, a partition rib (an example of a partition wall) 26 that protrudes downward is provided at the boundary between the recessed portion 16 and the horizontal portion 17. As shown in FIG. 1, the pair of partition ribs 26 extend linearly rearward and are connected to the lower part of the connecting wall 14. The tips (lower ends) of the pair of partition ribs 26 are arranged on the same plane over the entire front-rear direction. In other words, the protruding dimension of the part of the partition rib 26 that protrudes from the connecting wall 14 gradually increases rearward. The tips (lower ends) of the pair of partition ribs 26 are set to abut against the left end of the upper surface 411U of the first board 411 and the right end of the upper surface 412U of the second board 412 (see FIG. 5). In other words, the partition rib 26 blocks the gap between both ends of the first board 411 and the second board 412 and the ceiling surface 12L of the housing 11.

6, the above-mentioned standing wall 25 has a height dimension from the bottom wall 18 of the housing 11 that is higher than the upper surfaces 411U, 412U of the first board 411 and the second board 412, and a width in the left-right direction is equal to the left-right width dimension L1 of the first board 411 and the second board 412 when the first board 411 and the second board 412 are arranged in a V-shape in the left-right direction. With this configuration, the rear end of the partition rib 26 and both left and right ends of the standing wall 25 are arranged so as to be continuous. Note that the sides (right and left sides) of the standing wall 25 are in a state where the front space R1 and the rear space R2 are connected (see FIGS. 2 and 3).

As described above, the cooling fan 30 is accommodated in the rear space R2 of the housing 11. The cooling fan 30 is accommodated in the housing 11 in a state where it is arranged side by side with respect to the LED board 41 in a direction along the ceiling wall 12. Note that "side by side" refers to an arrangement in which the plate surface of the LED board 41 and the cooling fan 30 do not overlap when the deep ultraviolet irradiation device 10 is viewed in a plan view, and includes a case where the heights in the vertical direction are misaligned. In this embodiment, the cooling fan 30 is arranged slightly above the LED board 41.

The cooling fan 30 has a generally flat, generally cylindrical body 31. The body 31 is arranged in the rear space R2 of the housing 11 so that a pair of bottom surfaces face up and down, and is accommodated in a manner that the upper bottom surface (top surface) abuts against the rear ceiling wall 15 via a cushioning material (not shown) (see FIG. 1). The cooling fan 30 is configured to blow air drawn up from below forward, and has an air outlet 32 that protrudes forward in the shape of a flattened square tube. The air outlet 32 protrudes forward from the upper part of the body 31 so that its top surface is flush with the top surface of the body 31. In other words, the top surface of the air outlet 32 also abuts against the rear ceiling wall 15 via a cushioning material (not shown).

The width of the air outlet 32 is the same as the width L1 of the first and second substrates 411 and 412 in the left-right direction when the first and second substrates 411 and 412 are arranged in a V-shape in the left-right direction (see Figs. 5 and 6). As shown in Figs. 1, 5 and 6, the air outlet 32 is disposed at a position spaced upward (in a direction perpendicular to the ceiling surface 12L) from the upper surfaces 411U and 412U (an example of the opposite surface) of the first and second substrates 411 and 412. The tip (front end) of the air outlet 32 in the protruding direction is supported by the upper end of the standing wall 25 rising from the bottom wall 18 of the housing 11. In other words, the height of the standing wall 25 is equivalent to the dimension from the bottom wall 18 of the housing 11 to the lower end of the air outlet 32. As described above, the width of the standing wall 25 is approximately the same as the left-right width L1 of the first and second substrates 411 and 412 when the first and second substrates 411 and 412 are aligned in a V-shape in the left-right direction, that is, approximately the same as the width of the air outlet 32. As a result, the gap formed between the upper surfaces 411U, 412U of the first and second substrates 411 and 412 and the air outlet 32 is closed by the standing wall 25.

With this configuration, the exhaust path 28 from the air outlet 32 of the cooling fan 30 to the exhaust port 24 of the housing 11 is formed by a cylindrical space surrounded by the part of the vertical wall 25 that blocks the gap between the first and second boards 411 and 412 and the air outlet 32 (referred to as the blocking part 25A), the upper surfaces 411U and 412U of the first and second boards 411 and 412, the ceiling surface 12L of the housing 11, and the two partition ribs 26. The exhaust path 28 is separated from its surroundings within the housing 11, and the part other than the air outlet 32 and the exhaust port 24 is a space that is closed from the surroundings. The part of the front space R1 other than the exhaust path 28 (the periphery of the exhaust path 28) is in communication with the rear space R2.

As shown in FIG. 4, the width of the exhaust port 24 is the same as the width of the exhaust path 28, i.e., the distance between the pair of partition ribs 26. The height of the exhaust port 24 is such that a portion of the lower surfaces 411L, 412L of the first substrate 411 and the second substrate 412 can be exposed from the upper end of the front wall 23. In other words, the exhaust port 24 is configured to expose a portion of the peripheral area of the exhaust path 28 in the front space R1.

As shown in FIG. 1, the control board 50 is accommodated in the housing 11 below the cooling fan 30. In other words, the control board 50 is arranged so that its plate surface overlaps the cooling fan 30 in a direction perpendicular to the ceiling wall 12. An LED driver (an example of a driving element) 51 for driving the above-mentioned LED 42 is mounted on the mounting surface 50A of the control board 50. The control board 50 is arranged in the rear space R2 of the housing 11 with the mounting surface 50A facing the cooling fan 30. The LED driver 51 is arranged in a position overlapping the cooling fan 30 in a plan view (see FIG. 2 and FIG. 3). The control board 50 is located in the intake passage 27, which is a passage for air from the intake port 22 to the intake port (not shown) of the cooling fan 30 (the underside of the cooling fan 30).

A portion of the air drawn into the rear space R2 of the housing 11 from the intake port 22 passes through the intake path 27, specifically, from the intake port 22 over the mounting surface 50A of the control board 50, and is drawn into the cooling fan 30. The air then passes through the cooling fan 30 and is discharged forward from the air outlet 32 of the cooling fan 30, and is blown against the upper surfaces 411U, 412U of the first board 411 and the second board 412 along the connecting wall 14, the front side of which is inclined downward. At this time, the air is compressed by the connecting wall 14, and the flow rate is increased. The air then passes through the exhaust path 28 described above, and is exhausted from the exhaust port 24 to the outside of the housing 11.

Also, some of the air sucked into the rear space R2 of the housing 11 from the intake port 22 flows forward along the inner wall of the housing 11 and into the part of the front space R1 other than the exhaust path 28 (below and to the side of the exhaust path 28), and is then returned to the front space R1 by the air flow caused by the suction of the cooling fan 30. In other words, it circulates inside the housing 11. Then, some of the air is sucked into the cooling fan 30 together with the air sucked in from the intake port 22, and is released forward (to the exhaust path 28) from the blower port 32, and is exhausted to the outside of the housing 11 from the exhaust port 24.

In this way, when the air sucked in from the intake port 22 passes through the intake passage 27 and is sucked into the cooling fan 30, or circulates within the housing 11, an airflow is also generated around the LED driver 51 mounted on the control board 50, so that the LED driver 51 is efficiently cooled.

The deep ultraviolet irradiation device 10 of this embodiment is as described above, and the method of use will be described next. The deep ultraviolet irradiation device 10 can be used, for example, for the purpose of sterilizing a passenger compartment (an example of a room) of a vehicle 60 (an example of a vehicle) such as a taxi. Figures 7 and 8 are conceptual diagrams showing a state in which the deep ultraviolet irradiation device 10 is attached to a ceiling (an example of a mounting surface) 61 of a passenger compartment (rear seat) of a vehicle 60 such as a taxi. The deep ultraviolet irradiation device 10 has a ceiling wall 12 attached to the ceiling 61 of the vehicle 60 with the irradiation unit 40 arranged forward and the cooling fan 30 and the control board 50 arranged backward. That is, the LED board 41 and the cooling fan 30 are aligned in the front-rear direction, and the control board 50 and the cooling fan 30 are attached to the ceiling 61 of the vehicle 60 in a state where they overlap in a direction perpendicular to the ceiling 61.

When the deep ultraviolet irradiation device 10 is used, as described above, deep ultraviolet rays are irradiated from the top surface of the LED 42 at a directional angle of 120 degrees toward the seats and side (door trim). At this time, as shown in FIG. 8, the first LED 421 and the second LED 422 are inclined at an inclination angle of 15 degrees from the horizontal direction toward the outside in the vehicle width direction, so that sterilization can be performed by irradiating up to a high position on the side of the passenger compartment compared to when these LEDs 42 irradiate straight downward. In other words, it is possible to sterilize up to the upper end part of the door trim that is likely to be touched by the occupants. Such irradiation of deep ultraviolet rays can be performed, for example, in a hangar after operation, or during waiting time for passengers or during the return trip if a separator 62 with a deep ultraviolet cut film is provided between the front and rear seats.

Next, we will explain the effects. The deep ultraviolet irradiation device 10 of this embodiment is attached to the ceiling 61 inside the vehicle 60, and includes an LED board 41 on which an LED 42 is mounted on a mounting surface 41A, a control board 50 on which an LED driver 51 for driving the LED 42 is mounted, a cooling fan 30 having an air outlet 32 for cooling the deep ultraviolet irradiation device 10, and a housing 11 having an air intake 22 and an exhaust 24 and accommodating the LED board 41, the control board 50, and the cooling fan 30. When the deep ultraviolet irradiation device 10 is attached to the ceiling 61, the control board 50 is accommodated in the housing 11 in a state where it overlaps with the cooling fan 30 in a direction perpendicular to the ceiling 61, and is located in the intake path 27 from the air intake 22 to the cooling fan 30, and the LED board 41 is accommodated in the housing 11 in a state where it is arranged side by side with the cooling fan 30 in a direction along the ceiling 61, and is located in the exhaust path 28 from the air outlet 32 of the cooling fan 30 to the exhaust 24.

According to this configuration, since the LED board 41 and the cooling fan 30 are arranged side by side, it is possible to realize a thinner deep ultraviolet irradiation device 10 compared to the conventional configuration in which the LED board 41 and the cooling fan 30 are arranged in an overlapping arrangement. In addition, by arranging the control board 50 in the intake path 27 from the intake port 22 to the cooling fan 30, the control board 50 can be cooled by the air drawn into the housing 11, and the heated air can be sent to the exhaust path 28. Furthermore, by arranging the LED board 41 in the exhaust path 28 from the blower port 32 to the exhaust port 24, the LED board 41 can be cooled by the air blown from the cooling fan 30, and the heated air can be exhausted from the exhaust port 24. This makes it possible to drive the high current (high output) deep ultraviolet LED 42 in the same way as the conventional product.

The cooling fan 30 is configured to take in air from a direction perpendicular to the ceiling 61 and send air in a direction along the ceiling 61. With this configuration, compared to a configuration in which the cooling fan 30 takes in air from a direction perpendicular to the ceiling 61 and sends air in a direction perpendicular to the ceiling 61, the cooling fan 30 can be housed in the housing 11 in contact with one side of the housing 11 (the ceiling wall 12 in this embodiment), making it possible to further reduce the thickness of the deep ultraviolet irradiation device 10.

The partition rib 26 blocks the gap between both sides of the LED board 41 that extend along the horizontal arrangement direction (front-to-back direction) of the cooling fan 30 and the LED board 41 and the ceiling surface 12L of the housing 11 that faces the upper surface 41U of the LED board 41. The air outlet 32 of the cooling fan 30 and the LED board 41 are spaced apart, and the gap between the air outlet 32 and the LED board 41 and the partition rib 26 is blocked by the blocking portion 25A of the vertical wall 25. The space surrounded by the blocking portion 25A of the vertical wall 25, the upper surface 41U of the LED board 41, the partition rib 26, and the ceiling surface 12L constitutes the exhaust path 28 from the air outlet 32 to the exhaust port 24.

With this configuration, the exhaust path 28 from the air outlet 32 to the exhaust port 24 is separated from the surrounding area, and the LED board 41 constitutes part of the exhaust path 28, so that the LED board 41 can be efficiently cooled by the air blown from the cooling fan 30. In addition, the air blown from the air outlet 32 is not returned to the intake path 27, and the heated air is guided to the exhaust port 24 (outside the housing) without spreading inside the housing 11, so the cooling efficiency of the entire deep ultraviolet irradiation device 10 is improved.

The ceiling surface 12L of the housing 11 extends parallel to the upper surface 41U of the LED board 41. With this configuration, the distance from the upper surface 41U of the LED board 41 to the ceiling surface 12L of the housing 11 is constant at any position, so the LED board 41 can be cooled evenly, resulting in even better cooling efficiency.

The area around the exhaust path 28 in the internal space of the housing 11 is in communication with the intake path 27. With this configuration, some of the air taken in from the intake port 22 circulates around the exhaust path 28, making it possible to cool the exhaust path 28, and thus making it easier to cool the LED board 41.

The LED driver 51 is mounted on the surface of the control board 50 that faces the cooling fan 30. With this configuration, the air drawn into the cooling fan 30 is more likely to come into contact with the LED driver 51, so that the LED driver 51 itself can be cooled efficiently.

The LED driver 51 is mounted on the control board 50 at a position that overlaps with the cooling fan 30. With this configuration, the air whose flow rate has increased to be drawn into the cooling fan 30 comes into contact with the LED driver 51 or the part of the control board 50 on which the LED driver 51 is mounted, making it easier to absorb heat, thereby improving cooling efficiency.

The LED board 41 mounts a first LED 421 and a second LED 422, and includes a first board 411 that mounts the first LED 421 and a second board 412 that mounts the second LED 422. The first board 411 and the second board 412 are arranged side by side in a direction (left-right direction) that intersects with the extension direction of the exhaust passage 28, and extend in directions that intersect with each other.

With this configuration, compared to a configuration in which the two LEDs face only in one direction, the illumination range in the height direction is wider, making it possible to illuminate a wide range inside the vehicle cabin. Also, compared to a configuration in which the first board 411 and the second board 412 are aligned along the extension direction (front-to-back direction) of the exhaust passage 28, the flow of the air passing through the exhaust passage 28 becomes linear, stabilizing the airflow and stabilizing the flow speed. In other words, cooling efficiency is improved. Also, the first board 411 and the second board 412 can be cooled evenly.

The LED board 41 is made of aluminum. Aluminum has high thermal conductivity, so it has excellent cooling efficiency.

<Other embodiments>
The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings, and for example, the following embodiments are also included within the technical scope.

(1) In the above embodiment, the standing wall 25 is formed by rising from the bottom wall 18 of the housing 11, but the standing wall 25 may have any shape as long as it is capable of blocking the space between the air outlet 32 and the LED board 41. For example, it may be configured by extending from a partition rib.

(2) In the above embodiment, the air outlet 32 is disposed at a position spaced upward (in a direction perpendicular to the ceiling surface 12L) from the upper surface 41U of the LED board 41, but the air outlet and the LED board may be spaced apart in an oblique direction or in the front-to-rear direction. In that case, the exhaust path can be separated from the surrounding area by providing a wall (partition) that not only blocks the space between the air outlet and the LED board but also blocks the space between the air outlet and the partition wall.

(3) In the above embodiment, the periphery of the exhaust passage 28 in the internal space of the housing 11 is in communication with the intake passage 27, but a configuration in which the periphery of the exhaust passage is not in communication with the intake passage is also included in the technical scope disclosed in this specification.

(4) In the above embodiment, the LED driver 51 is mounted on the surface of the control board 50 that faces the cooling fan 30, but the LED driver can also be mounted on the opposite surface of the control board to the surface that faces the cooling fan. In this configuration, the airflow sucked into the cooling fan can efficiently cool the opposite surface of the control board to the mounting surface.

(5) In the above embodiment, the LED driver 51 is mounted on the control board 50 at a position that overlaps with the main body 31 of the cooling fan 30. However, the technical scope also includes a configuration in which the LED driver is mounted at a position that does not overlap with the main body of the cooling fan.

(6) In the above embodiment, the deep ultraviolet irradiation device 10 was shown as an example of a light irradiation device, but the technology disclosed in this specification can also be applied to devices that irradiate light other than deep ultraviolet light, such as visible light.

(7) In the above embodiment, the height of the front part of the housing 11 is lower than the height of the rear part, but the height of the housing may be the same overall.

(8) The ceiling surface 12L of the exhaust passage 28 does not necessarily have to be arranged parallel to the upper surface 41U of the LED substrate 41.

(9) The light irradiation device is not limited to being installed on the ceiling of the vehicle, but can also be installed on parts of the vehicle cabin other than the ceiling, such as on the side walls or floor.

(10) In the above embodiment, the irradiation unit 40 is configured by arranging two substrates, the first substrate 411 and the second substrate 412, so that they intersect with each other. However, the irradiation unit may be configured by bending a single substrate, so that the first portion carrying the first LED and the second portion carrying the second LED are formed by a single substrate. In addition, the irradiation unit may be a deep ultraviolet irradiation device that uses a single flat substrate, or has three or more LED substrates arranged so that they intersect with each other.

(11) In the above embodiment, the cooling fan 30 is configured to take in air from below and send it forward, but the cooling fan can also be configured to take in air from below and send it upward. In such a case, a space that is connected to the exhaust path formed in the front space is formed above the cooling fan. In such a case, it is preferable to provide a wall that separates the exhaust path (the part above the cooling fan) in the rear space from the rest of the exhaust path, so that the air sent from the cooling fan does not spread into the rear space.

10: Deep ultraviolet irradiation device (light irradiation device), 11: Housing, 12L: Ceiling surface (opposite surface), 22: Air intake, 24: Exhaust port, 25: standing wall, 26: partition rib (partition wall), 27: intake path, 28: exhaust path, 30: cooling fan, 31: main body, 32: air outlet, 40: irradiation part, 41: LED board (irradiation board), 41A: mounting surface, 41U: upper surface (opposite surface), 42: LED (irradiation element), 50: control board, 51: LED driver (driving element), 60: vehicle (vehicle), 61: ceiling (mounting surface), 411: first board (first part), 411L: lower surface (mounting surface), 411U: upper surface (opposite surface), 412: second board (second part), 412L: lower surface (mounting surface), 412U: upper surface (opposite surface), 421: first LED (first irradiation element), 422: second LED (second irradiation element)

Claims (9)

A light irradiation device that is attached to a mounting surface inside a vehicle,
an irradiation substrate having an irradiation element mounted on a mounting surface;
A control board on which a driving element for driving the irradiation element is mounted;
a cooling fan having an air outlet for cooling the light irradiation device;
a housing having an intake port and an exhaust port, and accommodating the irradiation board, the control board, and the cooling fan;
In a state where the light irradiation device is attached to the attachment surface,
the control board is accommodated in the housing in a state where it overlaps with the cooling fan in a direction perpendicular to the mounting surface, and is located in an air intake path from the air intake port to the cooling fan,
The irradiation substrate is accommodated within the housing in a state where it is arranged side by side in a direction along the mounting surface of the cooling fan, and is a light irradiation device located in an exhaust path from the air outlet of the cooling fan to the exhaust outlet. The light irradiation device according to claim 1, wherein the cooling fan is configured to take in air from a direction perpendicular to the mounting surface and blow air in a direction along the mounting surface. a partition wall is provided between both sides of the irradiation board extending along a lateral arrangement direction of the cooling fan and the irradiation board and an opposing surface of the housing arranged opposite to the mounting surface of the irradiation board,
the air outlet of the cooling fan and the irradiation substrate are disposed apart from each other, and a partition wall is provided between the air outlet and the irradiation substrate and between the air outlet and the partition wall, and
3. The light irradiation device according to claim 1, wherein a space surrounded by the partition wall, the opposite surface, the partition wall, and the facing surface constitutes the exhaust path from the air outlet to the exhaust outlet. The light irradiation device according to claim 3, wherein the opposing surface extends parallel to the opposite surface of the irradiation substrate. The light irradiation device according to claim 3 or 4, wherein the area around the exhaust passage in the internal space of the housing is in communication with the intake passage. The light irradiation device according to any one of claims 1 to 5, wherein the driving element is mounted on a surface of the control board that faces the cooling fan. The light irradiation device according to any one of claims 1 to 6, wherein the driving element is mounted on the control board at a position overlapping the cooling fan. the illumination substrate mounts the first and second illumination elements and includes a first portion for mounting the first illumination element and a second portion for mounting the second illumination element;
The light irradiation device according to claim 1 , wherein the first portion and the second portion are arranged side by side in a direction intersecting an extension direction of the exhaust path and extend in directions intersecting each other. The light irradiation device according to any one of claims 1 to 8, wherein the irradiation substrate is made of aluminum.

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