Light irradiation device

Abstract

To provide a light irradiation device that is thin and excellent in cooling efficiency.SOLUTION: A light irradiation device 10 mounted on a ceiling of a vehicle comprises: an irradiation section 40 having a substrate 41 and at least one irradiation element 42 mounted on a lower side of the substrate 41; a cooling fan 30 for cooling the irradiation section 40; and a housing 11 having a suction port 22 and an exhaust port 24 and housing the irradiation section 40 and the cooling fan 30, in which the irradiation section 40 and the cooling fan 30 are housed in the housing 11 in a state where the cooling fan 30 is laterally arranged on a sideward of the substrate 41, and an upper surface of the substrate 41 constitutes a part of an exhaust path 28 from the cooling fan 30 to the exhaust port 24.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a light irradiation device. [Background technology]

[0002] 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. 8, this device has a configuration in which a structure 2 containing a substance having a photocatalytic action, an irradiation means 3 for irradiating the structure 2 with light containing 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 are superimposed in this order. 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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-21098 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a device for dissipating heat generated in an irradiation means by 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 the above-mentioned Patent Document 1, the dimensions of the device in the overlapping direction become large. For this reason, when the device is mounted in a vehicle cabin, such as on the ceiling of a vehicle, a space is required in a direction protruding from the mounting surface in order to place the device, but it is not easy to secure such a space in a vehicle. In addition, when the device is mounted so as to protrude from the mounting surface, it is desired to make the protruding dimension as small as possible. In other words, there is a demand for a thinner device.

[0005] Meanwhile, recently, the need for sterilization has been increasing in various places. Conventionally, deep ultraviolet rays (100 to 280 nm), which have a short wavelength among ultraviolet rays, have been known to have a sterilization effect, and it is considered to irradiate this deep ultraviolet rays, for example, on vehicles after use. Since such deep ultraviolet ray irradiation devices are made to have a higher output than conventional visible light irradiation devices and long-wavelength ultraviolet ray irradiation devices, it is desired to improve the cooling efficiency more than before.

[0006] The technique disclosed in this specification has been made in consideration of the above circumstances, and has an object to provide a light irradiation device that is thin and has excellent cooling efficiency. [Means for solving the problem]

[0007] The technology disclosed in this specification for solving the above problem is a light irradiation device to be attached to a mounting surface inside a vehicle, the light irradiation device comprising: a substrate having a first surface arranged opposite to the mounting surface and a second surface opposite to the first surface; an irradiation unit having at least one irradiation element mounted on the second surface of the substrate; a cooling fan for cooling the irradiation unit; and a housing having an intake port and an exhaust port and accommodating the irradiation unit and the cooling fan, the irradiation unit and the cooling fan are accommodated in the housing with the cooling fan aligned side by side in a direction along the mounting surface relative to the substrate when the light irradiation device is attached to the mounting surface, and the first surface of the substrate forms a part of an exhaust path from the cooling fan to the exhaust port.

[0008] According to this configuration, since the irradiation unit and the cooling fan are arranged side by side, it is possible to realize a thinner light irradiation device compared to a conventional configuration in which the irradiation unit and the cooling fan are arranged so as to overlap each other. Also, since the first surface of the substrate of the irradiation unit constitutes a part of the exhaust path, it is possible to efficiently cool the substrate.

[0009] The irradiation section may include a first and a second irradiation element, and the substrate may include a first portion carrying the first irradiation element and a second portion carrying the second irradiation element, and the first portion and the second portion may extend in directions that intersect with each other.

[0010] Since the first and second parts extend in intersecting directions, the first and second irradiation elements are arranged to face in different directions. With this configuration, the irradiation range in the height direction is wider than in a configuration in which the two irradiation elements face only in one direction, so that a wide range in the vehicle cabin can be irradiated.

[0011] The first portion and the second portion may be aligned in a direction intersecting an extension direction of the exhaust path.

[0012] According to this configuration, the airflow passing through the exhaust passage becomes linear, and the airflow and flow speed are stabilized, compared with a configuration in which the first and second portions are aligned along the extension direction of the exhaust passage. That is, the cooling efficiency is improved. Also, the first and second portions can be cooled evenly.

[0013] The lamp may be attachable to a ceiling of a vehicle, and the first portion and the second portion may be aligned in a vehicle width direction.

[0014] According to this configuration, deep ultraviolet rays can be irradiated up to the upper end of the door trim, which is likely to be touched by the occupants, to sterilize it.

[0015] An opposing surface of the exhaust path that is disposed opposite the first surface of the substrate may extend parallel to the first surface of the substrate.

[0016] According to this configuration, the distance from the first surface of the substrate to the opposing surface of the exhaust path is constant at any position, which further improves the cooling efficiency and enables the substrate to be cooled evenly. Effect of the Invention

[0017] According to the technology disclosed in this specification, it is possible to obtain a light irradiation device that is thin and has excellent cooling efficiency. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view of a deep ultraviolet irradiation device according to an embodiment in a direction along an exhaust path. [Diagram 2] Horizontal cross-sectional view of the deep ultraviolet irradiation device (cross-sectional view II in Figure 1) [Diagram 3] Front view of deep ultraviolet irradiation device [Figure 4] Cross-sectional view of the deep ultraviolet irradiation device in the direction intersecting with the exhaust path (cross-sectional view of II-II in Figure 1) [Diagram 5] Schematic diagram of the front-rear direction of a vehicle equipped with a deep ultraviolet irradiation device [Figure 6] Left-right schematic diagram of a vehicle equipped with a deep ultraviolet irradiation device [Figure 7] 1 is a cross-sectional view of a deep ultraviolet irradiation device according to another embodiment of the present invention, taken in a direction intersecting with an exhaust path; [Figure 8] FIG. 1 is a cross-sectional view showing a conventional device having a light irradiation function. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 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 6. 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 members, a reference symbol may be attached to one member and the reference symbols of the other members may be omitted.

[0020] 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 disposed 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 disposed 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, the bottom wall 18 of the housing 11, which is disposed at the bottom of FIG. 1, has an opening 19 in a portion facing the LED 42 described later. Alternatively, the bottom wall 18 may be formed of a transparent or translucent material that can transmit deep ultraviolet rays, such as quartz.

[0021] As shown in Figures 1 and 2, an intake port 22 is formed through the rear wall 21 of the housing 11, and an exhaust port 24 is formed through the front wall 23. The intake port 22 may be formed across the bottom wall 18 and the side wall. The intake port 22 and the exhaust port 24 are formed in the shape of multiple vertical slits so that foreign matter and the like do not easily get into the inside of the housing 11 (see Figure 3). Note that the slits are omitted in Figures 1 and 2 for convenience.

[0022] 1 and 2, housing 11 is provided with a partition wall 25 that divides the space inside housing 11 into a front portion and a rear portion. Partition wall 25 is located at the boundary between rear ceiling wall 15 and connecting wall 14. Hereinafter, within the internal space of housing 11, the space in front of partition wall 25 is referred to as a front space R1, and the space behind partition wall 25 is referred to as a rear space R2.

[0023] The cooling fan 30 and a control circuit board (not shown) are accommodated in the rear space R2 of the housing 11. The irradiation unit 40 is accommodated in the front space R1 of the housing 11.

[0024] The cooling fan 30 is generally flat and cylindrical, and is housed in the rear space R2 with a pair of bottom surfaces facing up and down. The cooling fan 30 is configured to suck air up from below in the rear space R2 and blow it forward. The air intake 22 of the housing 11 described above is formed to be located below the lower end of the cooling fan 30 when the cooling fan 30 is installed at a predetermined position in the rear space R2 of the housing 11.

[0025] On the other hand, the irradiation unit 40 accommodated in the front space R1 of the housing 11 includes two flat plate-like first substrates 411 (an example of a first portion) and a second substrate 412 (an example of a second portion), a first LED 421 (an example of an irradiation element) mounted on a lower surface (an example of a second surface) 411L of the first substrate 411, and a second LED 422 (an example of an irradiation element) mounted on a lower surface (an example of a second surface) 412L of the second substrate 412, as shown in Fig. 2 and Fig. 4. Hereinafter, the left substrate shown in Fig. 2 and Fig. 4 will be referred to as the first substrate 411, and the right substrate will be referred to as the second substrate 412, and when the two substrates are not distinguished, they will be referred to as the substrate 41, and when the two LEDs are not distinguished, they will be referred to as the LED 42.

[0026] The LEDs 42 of the present embodiment described above are deep ultraviolet LEDs that irradiate deep ultraviolet rays (100 to 280 nm) that have a short wavelength among ultraviolet rays. The wavelength of the deep ultraviolet rays irradiated by these LEDs 42 is preferably within a range of 200 to 280 nm. In addition, 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.

[0027] The LEDs 42 in this embodiment are top-illuminated LEDs that, when mounted on the substrate 41, emit light from the end face (top face) opposite the substrate 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 FIG. 5).

[0028] The first substrate 411 and the second substrate 412 are made of aluminum, and are arranged side by side in the left-right direction (the direction intersecting the extension direction of the exhaust path 28 described later) in a state where they cross each other to form a flat V-shape when viewed from the front, as shown in Fig. 4. More specifically, the first substrate 411 and the second substrate 412 are arranged next to each other in a state where they are inclined 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 they face slightly outward (left-right direction) from below.

[0029] The width dimension L1 in the left-right direction 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 is about half the width dimension in the left-right direction of the housing 11. The first board 411 and the second board 412 are set to have a length dimension in the front-rear direction such that they fit snugly into the front space R1 formed in the housing 11 (see FIGS. 1 and 2). The width dimension of the exhaust port 24 described above is set to be equal to or slightly larger than the width dimension L1 in the left-right direction of the first board 411 and the second board 412.

[0030] 4, the front ceiling wall 13 described above has a recessed portion 16 whose central portion in the left-right direction is recessed into a flat V-shape in cross section so that its lower surface 13L (part of the ceiling surface (an example of the opposing surface) 12L) faces in parallel with an upper surface (an example of the first surface) 411U of the first substrate 411 and an upper surface (an example of the first surface) 412U of the second substrate 412. Both left and right sides of the recessed portion 16 in the front ceiling wall 13 are horizontal portions 17 extending horizontally.

[0031] In addition, a rib 26 protruding downward is provided at the boundary between the recessed portion 16 and the horizontal portion 17. As shown in FIG. 1, the pair of ribs 26 extends linearly rearward and continues to the lower portion of the connecting wall 14. The tips (lower ends) of the pair of ribs 26 are arranged on the same plane over the entire front-rear direction. In other words, the protruding dimension of the portion of the rib 26 protruding from the connecting wall 14 gradually increases rearward. The tips (lower ends) of the pair of ribs 26 are set to abut against the left end of the upper surface 411U of the first substrate 411 and the right end of the upper surface 412U of the second substrate 412 (see FIG. 4). The rear ends of the pair of ribs 26 are integrally connected to the front surface of the partition wall 25.

[0032] The height dimension of the exhaust port 24 described above is a dimension that enables the upper surface 411U of the first substrate 411 and the upper surface 412U of the second substrate 412 to be exposed forward from the upper end of the front wall 23, i.e., a dimension that is equal to or slightly larger than the protruding dimension of the rib 26 from the front ceiling wall 13.

[0033] The above-mentioned partition wall 25 is provided with an air vent 27 penetrating in the front-rear direction so as to include an area surrounded by the first board 411, the second board 412, the pair of ribs 26, and a line connecting the pair of horizontal portions 17 (see FIGS. 1 and 4). The air vent 27 allows the front space R1 and the rear space R2 of the housing 11 to communicate with each other. The size of the air vent 27 is set so as to be included inside the outlet 31 of the cooling fan 30.

[0034] The air sucked from the intake port 22 into the lower part of the rear space R2 of the housing 11 (below the cooling fan 30) passes through the cooling fan 30 and is discharged forward from the outlet 31 of the cooling fan 30, and flows into the front space R1 of the housing 11 through the ventilation hole 27. Then, as shown in FIG. 4, it passes through the region S surrounded by the upper surfaces 411U of the first substrate 411 and the upper surfaces 412U of the second substrate 412, the opposing inner surfaces 26I of the pair of ribs 26, and the lower surface (ceiling surface 12L) of the ceiling wall 12 (connecting wall 14 and front ceiling wall 13), and is exhausted to the outside of the housing 11 from the exhaust port 24. That is, the outlet 31 of the cooling fan 30, the ventilation hole 27, the region S, and the exhaust port 24 are the exhaust path 28 of the air flow.

[0035] Also, as described above, the width dimension of the exhaust port 24 is made equal to or slightly larger than the width dimension L1 in the left-right direction of the first substrate 411 and the second substrate 412, and the height dimension is made equal to or slightly larger than the protruding dimension of the rib 26 from the front ceiling wall 13 from the upper end of the front wall 23 (a dimension that can expose the upper surfaces 411U and 412U of the first substrate 411 and the second substrate 412). That is, the exhaust port 24 is configured to include the cross-section of the lower part of the front ceiling wall 13 (referred to as the front region S1) in the exhaust path 28, and the air flow passing through the exhaust path 28 hits the front wall 23 without hitting it, and is quickly discharged from the exhaust port 24 at a high flow rate without stagnation. Also, by this, the upper surfaces 411U and 412U of the substrates 411 and 412 constituting the exhaust path 28 can be efficiently cooled.

[0036] Note that the cross-sectional area of the front region S1 in the exhaust path 28 is preferably in the range of 0.1 to 1.5 times the area of the ventilation hole 27. If it is less than 0.1 times, the air resistance of the air flow compressed by the lower surface of the connecting wall 14 from the ventilation hole 27 toward the front region S1 becomes too large, and there is a risk of a part of the air flow flowing backward. On the other hand, if it is more than 1.5 times, the air flow is not sufficiently compressed in the front region S1, and it becomes difficult to obtain the effect of increasing the flow rate of the air flow.

[0037] 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 (one example of a room) of a vehicle 50 (one example of a vehicle) such as a taxi. FIG. 5 and FIG. 6 are conceptual diagrams showing a state in which the deep ultraviolet irradiation device 10 is attached to a ceiling (one example of a mounting surface) 51 of a passenger compartment (rear seat) of a vehicle 50 such as a taxi. The deep ultraviolet irradiation device 10 is attached to the ceiling 51 of the vehicle 50 in an orientation in which the cooling fan 30 is arranged at the rear and the irradiation unit 40 is arranged at the front. That is, the first board 411 and the second board 412 are attached to the ceiling 51 of the vehicle 50 in a state in which they are arranged in the vehicle width direction. The attachment of the deep ultraviolet irradiation device 10 to the ceiling 51 of the vehicle 50 may be designed to be installed in advance (fixed type) when the vehicle is manufactured, or may be attached later (detachable type).

[0038] 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 directivity angle of 120 degrees to the seats and side (door trim). At this time, as shown in FIG. 6, 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, sterilization can be performed up to the upper end part of the door trim that is likely to be touched by the occupant. Such irradiation of deep ultraviolet rays can be performed, for example, in a hangar after operation, or during waiting time or out-of-service time during operation if a separator 52 with a deep ultraviolet cut film is provided between the front seat and the rear seat.

[0039] Next, the effects of the deep ultraviolet ray irradiation device 10 of this embodiment are described. The deep ultraviolet ray irradiation device 10 is attached to the ceiling 51 of the vehicle 50, and includes an irradiation unit 40 having a first substrate 411 and a second substrate 412 arranged opposite to the ceiling 51, a first LED 421 mounted on a lower surface 411L of the first substrate 411 and a second LED 422 mounted on a lower surface 412L of the second substrate 412, a cooling fan 30 for cooling the irradiation unit 40, and a cooling fan 30 for cooling the irradiation unit 40 having an intake port 22 and an exhaust port 24. The deep ultraviolet irradiation device 10 includes a housing 11 that accommodates the cooling fan 30, and when the deep ultraviolet irradiation device 10 is attached to the ceiling 51, the irradiation unit 40 and the cooling fan 30 are accommodated within the housing 11 with the cooling fan 30 lined up side by side on the side of the irradiation unit 40 (in the direction along the ceiling 51), and the upper surface 411U of the first substrate 411 and the upper surface 412U of the second substrate 412 form part of the exhaust path 28 from the outlet 31 of the cooling fan 30 to the exhaust port 24.

[0040] According to this configuration, since the irradiation unit 40 and the cooling fan 30 are arranged side by side, it is possible to realize a thinner deep ultraviolet irradiation device 10 compared to a conventional configuration in which the irradiation unit and the cooling fan are arranged so as to overlap each other. In addition, since the upper surface 41U of the substrate 41 of the irradiation unit 40 constitutes a part of the exhaust path 28, it is possible to efficiently cool the substrate 41.

[0041] The first substrate 411 and the second substrate 412 extend in directions intersecting each other. With this configuration, the first LED 421 and the second LED 422 are arranged so that their top surfaces, which are their irradiating surfaces, face different directions. With this configuration, the irradiation range in the height direction is wider than in a configuration in which the two LEDs 42 face only in one direction, so that a wide range in the vehicle cabin can be irradiated.

[0042] Further, the first substrate 411 and the second substrate 412 are arranged side by side in a direction (vehicle width direction) intersecting the extending direction (vehicle longitudinal direction) of the exhaust passage 28. According to such a configuration, compared with a configuration in which the first substrate 411 and the second substrate 412 are arranged along the extending direction of the exhaust passage 28, the flow of the air current passing through the exhaust passage 28 becomes linear, the air current is stabilized, and the flow velocity is also stabilized. That is, the cooling efficiency is improved. Further, the first substrate 411 and the second substrate 412 can be cooled evenly.

[0043] In a state where they are attached to the ceiling 51 of the vehicle 50, the first substrate 411 and the second substrate 412 are arranged side by side in the vehicle width direction. According to such a configuration, deep ultraviolet rays can be irradiated up to the upper end of the door trim where there is a high possibility of being touched by a passenger to perform disinfection.

[0044] The ceiling surface 12L (lower surface of the ceiling wall 12) of the exhaust passage 28 arranged to face the upper surface 41U of the substrate 41 extends in parallel with the upper surface 41U of the substrate 41. According to such a configuration, since the distance from the upper surface 41U of the substrate 41 to the ceiling surface 12L of the exhaust passage 28 is constant at any position, the flow of the air current is stabilized and the cooling efficiency becomes even better. Further, the first substrate 411 and the second substrate 412 can be cooled more evenly.

[0045] <Other Embodiments> The technology disclosed in this specification is not limited to the embodiments described by the above description and drawings. For example, the following embodiments are also included in the technical scope.

[0046] (1) In the above embodiment, a configuration in which two first substrates 411 and 412 are arranged so as to intersect each other is shown. However, one substrate may be bent to form a first portion on which the first LED is mounted and a second portion on which the second LED is mounted with one substrate.

[0047] (2) In the above embodiment, the first substrate 411 (first portion) and the second substrate 412 (second portion) are arranged with their left-right central portions tilted downward, but the first substrate (first portion) and the second substrate (second portion) may be arranged with their left-right central portions tilted upward. In this case, the illumination range of the first LED and the second LED in the height direction can be expanded.

[0048] (3) In the above embodiment, the irradiation unit 40 is configured to have two substrates 41 arranged to intersect with each other. However, the irradiation unit may use a single flat substrate, or may be a deep ultraviolet irradiation device 101 in which three or more substrates 41 are arranged to intersect with each other, as shown in FIG. 7.

[0049] (4) In the above embodiment, the first substrate 411 and the second substrate 412 are arranged in a direction (left-right direction) intersecting the extension direction of the exhaust path 28, but a configuration in which the first substrate 411 and the second substrate 412 are arranged along the extension direction of the exhaust path (front-back direction) is also included in the technical scope of the present disclosure.

[0050] (5) In the above embodiment, the directivity angle of the deep ultraviolet LED 42 is 120 degrees, but the directivity angle of the LED is not limited to the above embodiment and can be set arbitrarily. Also, a device that can change the directivity angle can be used.

[0051] (6) In the above embodiment, the height of the front portion of the housing is made lower than the height of the rear portion. However, the height of the housing may be the same overall.

[0052] (7) The ceiling surface 12L of the exhaust path 28 does not necessarily have to be arranged parallel to the upper surface 41U of the substrate 41.

[0053] (8) In the above embodiment, the deep ultraviolet irradiation device 10 is configured to be attached to the ceiling 51 of the vehicle 50 with the cooling fan 30 arranged at the rear and the irradiation unit 40 arranged at the front, but the orientation of the deep ultraviolet irradiation device 10 is not limited to the above embodiment.

[0054] (9) The deep ultraviolet ray irradiation device 10 can be installed not only on the ceiling of the vehicle but also on parts of the vehicle cabin other than the ceiling, such as on the side walls or floor. [Explanation of symbols]

[0055] 10, 101: deep ultraviolet irradiation device (light irradiation device), 11: housing, 12: ceiling wall, 12L: ceiling surface (opposing surface), 22: intake port, 24: exhaust port, 25: partition wall, 26: rib, 27: vent, 28: exhaust path, 30: cooling fan, 31: outlet, 40: irradiation unit, 41: board, 42: LED (irradiation element), 50: vehicle (vehicle), 51: ceiling (mounting surface inside the room), 411: first board (first part), 411L: bottom surface (second surface), 411U: top surface (first surface), 412: second board (second part), 412L: bottom surface (second surface), 412U: top surface (first surface), 421: first LED (irradiation element), 422: second LED (irradiation element)

Claims

1. A light irradiation device that is attached to a mounting surface inside a vehicle, a substrate having a first surface disposed opposite the mounting surface and a second surface opposite the first surface; an illumination unit having at least one illumination element mounted on the second surface of the substrate; A cooling fan for cooling the irradiation unit; a housing having an intake port and an exhaust port and accommodating the irradiation unit and the cooling fan; the irradiation unit and the cooling fan are accommodated in the housing in a state in which the cooling fan is arranged side by side in a direction along the mounting surface with respect to the board when the light irradiation device is attached to the mounting surface, a pair of ribs are provided on a surface of the housing facing the first surface of the board, the pair of ribs protruding toward the board and extending from the cooling fan to the exhaust port, and tips of the pair of ribs are in contact with ends of the board, A light beam irradiation device, wherein an area surrounded by the first surface of the substrate, the opposing inner surfaces of the pair of ribs, and the opposing surface constitutes an exhaust path.

2. A light irradiation device to be attached to a mounting surface inside a vehicle, comprising: a substrate having a first surface disposed opposite the mounting surface and a second surface opposite the first surface; an illumination unit having at least one illumination element mounted on the second surface of the substrate; A cooling fan for cooling the irradiation unit; a housing having an intake port and an exhaust port and accommodating the irradiation unit and the cooling fan; the irradiation unit and the cooling fan are accommodated in the housing in a state in which the cooling fan is arranged side by side in a direction along the mounting surface with respect to the board when the light irradiation device is attached to the mounting surface, the first surface of the substrate constitutes a part of an exhaust path from the cooling fan to the exhaust port, A light beam irradiation device, wherein an opposing surface of the exhaust path arranged opposite the first surface of the substrate extends parallel to the first surface of the substrate.

3. The irradiation unit includes the first and second irradiation elements, the substrate comprises a first portion carrying the first radiation element and a second portion carrying the second radiation element; 3. The light irradiation device according to claim 1, wherein the first portion and the second portion extend in directions intersecting each other.

4. The light irradiation device according to claim 3 , wherein the first portion and the second portion are arranged side by side in a direction intersecting an extension direction of the exhaust path.

5. 5. The light irradiation device according to claim 3, wherein the light irradiation device is attachable to a ceiling of a vehicle, and the first portion and the second portion are aligned in a vehicle width direction.

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