WO2022209959A1

WO2022209959A1 - Light emission device

Info

Publication number: WO2022209959A1
Application number: PCT/JP2022/012302
Authority: WO
Inventors: 浩明渡邊
Original assignee: Hoya株式会社
Priority date: 2021-03-31
Filing date: 2022-03-17
Publication date: 2022-10-06
Also published as: CN117136337A; JP2022157844A

Abstract

The purpose of the present invention is to provide a light emission device which suppresses the occurrence of a pressure loss at vents and which can efficiently cool a heat dissipation unit and a light source.　A light emission device (1) which emits line-shaped light comprises: a light source unit (200) having a plurality of light sources on a substrate; a heat dissipation unit (400) having a plurality of heat dissipation fins (420) and thermally coupled to the back surface side of the substrate; a casing (100) receiving the heat dissipation unit and forming a wind tunnel in which cooling air for cooling the heat dissipation fins flows; and a cooling fan (110) for generating the cooling air, and is characterized in that at least one side surface of the casing has vents formed so as to exhaust the cooling air through the plurality of heat dissipation fins to the outside and that the relationships of A>H×(W-(t×n)) and h>H are satisfied where A is the total area of the openings of the vents, h is the height of the vents, H is the height of the plurality of heat dissipation fins, W is the width with which the plurality of heat dissipation fins are formed, t is the thickness of each heat dissipation fin, and n is the number of the plurality of heat dissipation fins.

Description

Light irradiation device

The present invention relates to a light irradiation device that includes an LED (Light Emitting Diode) as a light source and emits linear light, and more particularly to a light irradiation device that includes a heat dissipation member that dissipates heat emitted from the LED.

2. Description of the Related Art Conventionally, there has been known a printing apparatus that performs printing using UV ink that is cured by being irradiated with ultraviolet light. In such a printing apparatus, an ultraviolet irradiation device is used for the purpose of curing the material after ink is ejected from the nozzles of the head onto the medium.
In recent years, such an ultraviolet irradiation device has been constructed by assembling a large number of ultraviolet LED elements in the light source of the irradiation head. Therefore, in order to obtain stable ultraviolet rays, a heat radiation structure is provided together with a light source, especially in a device in which a large number of LED elements are assembled (for example, Patent Document 1).

Patent Document 1 describes an ultraviolet irradiation head (light irradiation device) in which a large number of ultraviolet LED elements are arranged in a row. The substrate on which the ultraviolet LED elements are arranged is thermally connected to a heat sink on which a large number of plate-like fins are formed, and is formed so that only the base end portion of the heat sink (part of the plate-like fins) is exposed. Outside air is taken in through the ventilation openings to cool the plate-like fins and further cool the ultraviolet LED elements.

JP 2015-149415 A

As in the light irradiation device described in Patent Literature 1, if the ventilation holes are formed so that only the base end portion of the heat sink is exposed, the air taken in from the outside (that is, the cooling air) flows through the many plate-like fins. It will definitely pass through the surface.
However, in the configuration described in Patent Document 1, although a vent is provided so that a part of the plate-like fins is exposed, the air that is actually taken into the device passes through the gaps between the plate-like fins. Therefore, the amount of air taken in and the wind speed are determined by the sum of the opening areas of the plate-like fins facing the vent, and there is a problem that pressure loss (intake loss) occurs at the vent.
In addition, if pressure loss (intake loss) occurs at the vent, a sufficient amount of air cannot be supplied to the radiation fins and a sufficient wind speed cannot be obtained, so the heat sink cannot be efficiently cooled, and ultraviolet rays Cooling of the LED element is also insufficient.

The present invention has been made in view of the above circumstances, and it is possible to suppress the occurrence of pressure loss (intake loss) at the vent and efficiently cool the heat sink (heat radiation part) and the LED element (light source). It is an object of the present invention to provide a light irradiation device that is

In order to achieve the above object, the light irradiation device of the present invention irradiates a line of light extending in a first direction and having a predetermined line width in a second direction perpendicular to the first direction onto an irradiation surface. a substrate defined by a first direction and a second direction; a plurality of light sources that emit light in a third direction; and a plurality of heat radiation fins standing at predetermined pitches along the first direction, and thermally coupled to the back side of the substrate. a housing that accommodates at least the heat radiating portion and forms a wind tunnel through which cooling air for cooling the heat radiating fins flows; At least one of the side surfaces facing the second direction of the housing exhausts the cooling air to the outside through between the plurality of heat radiation fins, or allows the cooling air to flow from the outside between the plurality of heat radiation fins. A vent is formed through which air is sucked, A is the total area of the opening of the vent, h is the height of the vent in the third direction, and h is the height of the plurality of heat dissipating fins in the third direction. Let H be the width, W be the width in the first direction in which the plurality of heat radiating fins are formed, t be the thickness of each heat radiating fin in the first direction, and n be the number of the plurality of heat radiating fins. It is characterized by satisfying the following conditional expressions (1) and (2).
A>H×(W−(t×n)) (1)
h>H (2)

With such a configuration, the pressure loss (intake loss) at the vent is suppressed, and a sufficient amount of air is supplied to the heat radiating fins at a sufficient wind speed. The light source can be uniformly and sufficiently cooled.

In addition, a plurality of through-holes formed in a manner of z (where z is an integer of 2 or more) along the third direction and x rows (where x is an integer of 2 or more) along the first direction. preferably configured. Further, in this case, it is desirable that the opening areas of the plurality of through-holes decrease toward the direction opposite to the third direction.
Further, it is preferable that the through-holes in odd-numbered rows among the x-rows are shifted along the third direction with respect to the through-holes in even-numbered rows, and that the plurality of through-holes are arranged in a staggered manner as a whole.
Moreover, it is desirable that at least a portion of the plurality of through holes be arranged to face the plurality of heat radiating fins.

Also, the heat sink is arranged to face at least a part of the plurality of through holes, guides the air sucked from the plurality of through holes to the plurality of heat radiating fins, or guides the air exhausted from the plurality of heat radiating fins to the plurality of through holes. It is desirable to have a baffle plate that leads to

Also, it is desirable that the pitch of the plurality of light sources in the first direction be greater than or equal to the pitch of the plurality of heat radiation fins in the first direction.

Further, the vent is formed only on one side surface of the housing, the plurality of heat radiation fins are arranged close to one side, and a space is provided between the other side surface of the housing and the plurality of heat radiation fins. is formed, and it is desirable to have a drive circuit to drive a plurality of light sources in space. Also, in this case, it is desirable that the wind tunnel is composed of a first wind tunnel and a second wind tunnel that are bisected in the second direction by the drive circuit.

In addition, it is desirable to have a filter that is arranged to block the air vent and absorbs ink mist.

In addition, it is desirable that the light includes a wavelength that acts on the ultraviolet curable resin.

As described above, according to the present invention, the occurrence of pressure loss (intake loss) at the vent is suppressed, so that a light irradiation device capable of efficiently cooling the heat radiating part and the plurality of light sources is realized. .

FIG. 1 is a diagram illustrating the configuration of a light irradiation device according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating the configuration of the light irradiation device according to the first embodiment of the present invention. 3A and 3B are schematic diagrams for explaining airflow generated in the housing of the light irradiation device according to the first embodiment of the present invention. FIG. FIG. 4 is a diagram showing a modification of the intake port of the light irradiation device according to the first embodiment of the present invention. FIG. 5 is a diagram illustrating the configuration of a light irradiation device according to a second embodiment of the present invention. FIG. 6 is a diagram illustrating the configuration of a light irradiation device according to a second embodiment of the present invention. FIG. 7 is a schematic diagram for explaining the airflow generated inside the housing of the light irradiation device according to the second embodiment of the present invention. FIG. 8 is a diagram illustrating the configuration of a light irradiation device according to a third embodiment of the present invention. FIG. 9 is a diagram illustrating the configuration of a light irradiation device according to a third embodiment of the present invention. 10A and 10B are schematic diagrams for explaining the airflow generated inside the housing of the light irradiation device according to the third embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

(First embodiment)
1 and 2 are diagrams for explaining the configuration of the light irradiation device 1 according to the first embodiment of the present invention, and FIG. 1(a) is a perspective view of the light irradiation device 1 according to the embodiment of the present invention. 1(b) is a plan view of the light irradiation device 1 of FIG. 1(a). Further, FIG. 2(a) is a cross-sectional view along the line AA in FIG. 1(b), FIG. 2(b) is a cross-sectional view along the line BB in FIG. 2(a), and FIG. ) is an enlarged view of part C in FIG. 2(b). The light irradiation device 1 of the present embodiment is a light source device that is mounted in a printing device or the like and cures ultraviolet curable ink or ultraviolet curable resin. ) to emit linear ultraviolet light. In this specification, as shown by the coordinates in FIG. 1, the direction in which the LED elements 210 are arranged (described later) is the X-axis direction (first direction), and the direction in which the LED elements 210 emit ultraviolet light is the Z-axis direction ( 3rd direction), and a direction orthogonal to the X-axis direction and the Z-axis direction are defined as the Y-axis direction (second direction).

As shown in FIG. 1 , the light irradiation device 1 of this embodiment includes a housing 100 , a light source unit 200 (light source section), a control board 300 (drive circuit), and a heat dissipation member 400 .
The housing 100 is a thin box-shaped member that houses the light source unit 200, the control board 300, and the heat dissipation member 400. The housing 100 has a glass window 105 attached to the front surface of the housing 100 through which ultraviolet light is emitted, and a housing. Two exhaust fans 110 (cooling fans) are provided on the back of the body 100 to exhaust the air in the housing 100, and the upper surface of the housing 100 has an intake port 102 ( vent) is formed.
As shown in FIG. 1B, the intake port 102 of this embodiment is configured by arranging seven circular through holes 102a to 102g along the Z-axis direction in 19 rows in the X-axis direction. It is The through-holes 102a-102g in odd-numbered rows are shifted in the Z-axis direction with respect to the through-holes 102a-102g in even-numbered rows, and the plurality of through-holes 102a-102g are arranged in a zigzag pattern as a whole.
Further, the through holes 102a to 102d up to the fourth from the positive side in the Z-axis direction have the same hole diameter (for example, a diameter of 5 mm), and the hole diameters of the through holes 102e to 102g are larger than the hole diameters of the through holes 102a to 102d. are also gradually becoming smaller (eg, 4 mm, 3 mm, and 2 mm in diameter, respectively). In other words, the intake port 102 of this embodiment is configured such that the opening area decreases from the + side toward the - side in the Z-axis direction. The through holes 102a to 102d are arranged so as to face radiation fins 420, which will be described later, and the radiation fins 420 are exposed from the through holes 102a to 102d.
Further, as shown in FIG. 2(a), inside the housing 100 of the present embodiment, there is a baffle plate 107 extending from the upper surface of the housing 100 toward the end surface of the radiation fins 420 on the Z-axis direction - side. are placed. The baffle plate 107 is a dogleg-shaped metal thin plate member that is arranged to face the through holes 102 e to 102 g and guides the air taken in through the through holes 102 e to 102 g to the heat radiating fins 420 .

The light source unit 200 includes a rectangular substrate 205 defined by the X-axis direction and the Y-axis direction, and a plurality of (for example, 100) LED elements 210 (light sources) having the same characteristics.

The plurality of LED elements 210 are aligned in the Z-axis direction, for example, 50 (X-axis direction)×2 rows (Y-axis direction) at predetermined pitches on the surface of the substrate 205 . , and electrically connected to the substrate 205 . The “pitch” at which the plurality of LED elements 210 are arranged means the distance between the centers of adjacent LED elements 210, and the pitch may differ between the X-axis direction and the Y-axis direction.
The board 205 is connected to a control board 300 (to be described later) by a cable (not shown), and each LED element 210 is supplied with a drive current from the control board 300 via the board 205 . When a drive current is supplied to each LED element 210, each LED element 210 emits ultraviolet light (for example, a wavelength of 365 nm) of a light amount corresponding to the drive current, and a line parallel to the X-axis direction is emitted from the light source unit 200. shaped ultraviolet light is emitted. The line-shaped ultraviolet light emitted from the light source unit 200 passes through the window 105 and is emitted toward the object to be irradiated.

The control board 300 has a circuit board 301 and a plurality of electronic components (not shown) arranged on one surface (Y-axis direction - side surface) of the circuit board 301. The LED elements 210 of the light source unit 200 is an electronic circuit board that controls the light emission of the light irradiation device 1 as a whole. The control board 300 receives a signal input by a user through a user interface (not shown), performs ON/OFF control and brightness control of the light source unit 200, and outputs error information to the outside through the user interface.

The heat dissipation member 400 is a member that dissipates heat emitted from the light source unit 200 . The heat dissipating member 400 of this embodiment includes a rectangular plate-shaped metal (for example, copper or aluminum) heat dissipating plate 410 and the other end surface of the heat dissipating plate 410 (the surface opposite to the surface on which the light source unit 200 is mounted). ) and a plurality of radiation fins 420 integrally formed by brazing, soldering, skiving, or the like, and erected at predetermined pitches in the X-axis direction (FIGS. 2A and 2B )). In addition, the “pitch” at which the plurality of radiating fins 420 stand means the distance between the centers of adjacent radiating fins 420 .
Radiation fins 420 are rectangular metal plates (eg, copper, aluminum, etc.) that are erected so as to protrude from radiation plate 410 in a direction opposite to the Z-axis direction, and radiate heat transferred to radiation plate 410 into the air. , metals such as iron and magnesium, and alloys containing these). The pitch in the X-axis direction of the plurality of radiating fins 420 is narrower than the pitch in the X-axis direction of the plurality of LED elements 210 . Further, although the details will be described later, in the present embodiment, air from the outside is taken into the housing 100 from the intake port 102, and the taken-in air flows on the surface of each heat radiation fin 420 as cooling air. The air heated by 420 is quickly exhausted by exhaust fan 110 .

In addition, as shown in FIG. 2A, the light source unit 200 and the heat dissipation member 400 of the present embodiment are arranged and fixed on the front side (on the + side in the Z-axis direction) in the housing 100. ing. When the light source unit 200 and the heat dissipation member 400 are fixed in the housing 100, each LED element 210 is arranged at a position facing the window 105, and the end 420a of each heat dissipation fin 420 on the + side in the Y-axis direction. abuts on the top surface of the housing 100, and a space S is formed between the negative side end 420b in the Y-axis direction and the bottom surface of the housing 100. As shown in FIG.
A wind tunnel α is formed on the rear side of each radiation fin 420 (the negative side in the Z-axis direction) through which cooling air flows after cooling the radiation fins 420 .
In addition, at least the end of the control board 300 on the positive side in the Z-axis direction is disposed in the space S, and one side of the circuit board 301 (Y-axis direction A wind tunnel β is formed through which cooling air flows for cooling a plurality of electronic components (not shown) arranged on the negative side). That is, the control board 300 divides the space inside the housing 100 into two in the Y-axis direction to form the wind tunnel α (first wind tunnel) and the wind tunnel β (second wind tunnel).

In each LED element 210 of the present embodiment, the drive current supplied to each LED element 210 is adjusted so as to emit ultraviolet light with a substantially uniform amount of light. Ultraviolet light has a substantially uniform light amount distribution in the X-axis direction.

When a drive current flows through each LED element 210 and ultraviolet light is emitted from each LED element 210, the temperature rises due to self-heating of the LED element 210. Through the plate 410 , the heat is quickly conducted (moved) to the radiating fins 420 and radiated from each radiating fin 420 into the surrounding air. The air heated by the radiation fins 420 is quickly exhausted through the exhaust fan 110 .

Here, in the configuration of the present embodiment, since the light source unit 200 and the heat dissipation member 400 extend in the X-axis direction, if the temperature of the LED element 210 of the light source unit 200 differs in the X-axis direction, the amount of light varies. Therefore, there is a problem that the heat radiating member 400 must be cooled uniformly and sufficiently. Therefore, in order to solve such a problem, in the present embodiment, a sufficient amount of air is supplied to the heat radiating fins 420 of the heat radiating member 400, and a sufficient wind speed is obtained. The height h is higher than the height H of the radiation fins 420 in the Z-axis direction, and the total area A of the openings of the intake port 102 is configured to be larger than the area B of the ventilable region of the radiation fins 420. (details will be described later). Thus, the pressure loss (intake loss) at the intake port 102 is reduced, and the heat radiating member 400 can be uniformly and sufficiently cooled.

The cooling action of the heat radiating member 400, which is a feature of the present invention, will be described below. 3A and 3B are schematic diagrams for explaining the airflow generated inside the housing 100. FIG. In addition, FIG. 3 is a diagram in which an arrow indicating the direction of the airflow is added to FIG. 2(a).

As shown in FIG. 3, the light irradiation device 1 of this embodiment includes an exhaust fan 110 on the back of the housing 100, and an air intake 102 is formed on the top of the housing 100 by a plurality of through holes 102a to 102g. It is Therefore, when the exhaust fan 110 rotates, the air inside the housing 100 is exhausted from the exhaust fan 110, so that the inside of the housing 100 becomes a negative pressure, and the air outside the housing 100 is discharged from the through holes 102a to 102g. As it is taken in, an air current indicated by solid line arrows in FIG. 3 is generated in the housing 100 . More specifically, as shown in FIG. 3, through holes 102a to 102d facing heat radiating fins 420, an airflow is generated in a direction opposite to the Y-axis direction, and through hole 102e facing air guide plate 107 is generated. 102g, an airflow is generated along the airflow guide plate 107 and flows between the heat radiation fins 420, respectively.
As described above, in the present embodiment, all the air taken in from the plurality of through holes 102a to 102g formed in the upper surface of the housing 100 flows between the heat radiation fins 420.
The height h (FIG. 1(b)) of the intake port 102 in the Z-axis direction is set so that the pressure loss (intake loss) does not occur at the intake port 102 (that is, the through holes 102a to 102g). It is higher than the height H in the Z-axis direction (FIG. 2B), and the total area A of the openings of the intake port 102 (that is, the sum of the opening areas of the plurality of through holes 102a to 102g) is the ventilation of the heat radiating fins 420. It is configured to be larger than the area B of the possible region.
Here, the area B of the ventilable region of the radiation fins 420 is the width in the X-axis direction where the radiation fins 420 are formed, and the ventilation width W (FIG. 2(b)). is the thickness of t (FIG. 2(c)) and n is the number of radiation fins 420,
B=H×(W−(t×n)).
Therefore, the relationship of the total area A of the openings of the intake port 102 in this embodiment can be expressed by the following conditional expression (1).
A>H×(W−(t×n)) (1)
Moreover, the following conditional expression (2) is obtained from the relationship between the height h of the intake port 102 in the Z-axis direction and the height H of the radiation fins 420 in the Z-axis direction.
h>H (2)
In this way, if the total area A of the openings of the intake port 102 (that is, the sum of the opening areas of the plurality of through holes 102a to 102g) is configured to be larger than the area B of the ventilable region of the radiation fins 420 ( That is, if the conditional expressions (1) and (2) are satisfied, the dynamic pressure at the intake port 102 becomes smaller than the dynamic pressure at the heat radiation fins 420 according to Bernoulli's theorem. While ensuring the flow rate of the cooling air, the wind speed of the cooling air flowing through the heat radiating fins 420 can be ensured (increased relative to the wind speed at the intake port).

Part of the air that has flowed between the radiation fins 420 (that is, the surfaces of the radiation fins 420) flows through a wind tunnel α formed above the circuit board 301 (the positive side in the Y-axis direction), and flows through the exhaust fan. 110 , the remaining air passes through the space S, flows below the circuit board 301 (Y-axis direction − side), flows through the wind tunnel β, and is exhausted from the exhaust fan 110 . Therefore, each heat radiation fin 420 is cooled substantially uniformly, and the plurality of electronic components arranged on one side (the side facing the wind tunnel β) of the circuit board 301 is also cooled.
As described above, the diameters of the through holes 102a to 102d of the present embodiment are larger than the diameters of the through holes 102e to 102g, and the opening area is configured to decrease from the + side to the - side in the Z axis direction. Therefore, a sufficient amount of cooling air to cool the radiation fins 420 flows from the through-holes 102a to 102d (that is, over the entire height of the radiation fins 420 in the Z-axis direction) in a direction opposite to the Y-axis direction. part of it flows into the space S. Therefore, the cooling air is reliably supplied to the radiation fins 420, and the cooling air is also reliably supplied to the wind tunnel β.

Although the present embodiment has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the technical idea of the present invention.

For example, the light irradiation device 1 of the present embodiment is a device that irradiates ultraviolet light, but is not limited to such a configuration, and irradiation light in other wavelength ranges (for example, visible light such as white light, The present invention can also be applied to a device that irradiates infrared light or the like.

Further, although the baffle plate 107 of the present embodiment is a V-shaped thin plate member, any form may be used as long as the air taken in through the through holes 102e to 102g can be guided to the heat radiating fins 420. I don't mind.

Further, in the present embodiment, the through holes 102a to 102d are arranged to face the radiating fins 420, and the radiating fins 420 are exposed from the through holes 102a to 102d. It is sufficient if a sufficient amount of cooling air can be supplied, and at least a part of the through holes 102 a to 102 d are arranged so as to face the heat radiating fins 420 .

Further, in the present embodiment, the inside of the housing 100 is made negative pressure by the exhaust fan 110, and the air is drawn into the housing 100 from the intake port 102. However, the configuration is not limited to this. , an intake fan may be used instead of the exhaust fan 110 . In this case, the direction of the airflow in the housing 100 is reversed, and the air is exhausted from the through holes 102a to 102g. (Intake loss) is small, and the heat radiating member 400 can be uniformly and sufficiently cooled.

Further, although the intake port 102 of the present embodiment is configured by arranging seven circular through holes 102a to 102g along the Z-axis direction in 19 rows in the X-axis direction, It is not limited to such a configuration, and is configured in a manner of z pieces (z is an integer of 2 or more) along the Z-axis direction and x rows (x is an integer of 2 or more) along the X-axis direction. Just do it.

Also, although the intake port 102 of the present embodiment is configured with a plurality of circular through holes 102a to 102g, it is not necessarily limited to such a configuration. FIG. 4 is a diagram showing a modification of the intake port 102 of this embodiment. As shown in FIG. 4(a), the air inlet 102 may be configured with a plurality of square through holes, and as shown in FIG. 4(b), the air inlet 102 may be configured with a plurality of hexagonal through holes. Alternatively, as shown in FIG. 4(c), the intake port 102 may be configured with a plurality of rhombus-shaped (including a square rotated by 45 degrees) through-holes.

(Second embodiment)
5 and 6 are diagrams for explaining the configuration of the light irradiation device 2 according to the second embodiment of the present invention. FIG. 5(a) is a perspective view of the light irradiation device 2 according to the embodiment of the present invention. 5(b) is a plan view of the light irradiation device 2 of FIG. 5(a). 6(a) is a cross-sectional view taken along line DD of FIG. 5(b), FIG. 6(b) is a cross-sectional view taken along line EE of FIG. 6(a), and FIG. ) is an enlarged view of part F in FIG. 6(b).

As shown in FIGS. 5 and 6, in the light irradiation device 2 of the present embodiment, an intake port 102A for taking in air from the outside is formed on the upper surface and the lower surface of the housing 100A. It differs from the light irradiation device 1 of the first embodiment in that it includes a baffle plate 107A.
Each intake port 102A of the present embodiment is configured by arranging nine circular through holes 102aA to 102iA along the Z-axis direction in 21 rows in the X-axis direction. The odd-numbered through holes 102aA to 102iA are shifted in the Z-axis direction with respect to the even-numbered through holes 102aA to 102iA. (eg, 5 mm in diameter), and the diameters of the through holes 102fA to 102iA are gradually smaller than the diameters of the through holes 102aA to 102eA (eg, diameters of 4 mm, 3 mm, 2 mm, and 1 mm, respectively). That is, as in the first embodiment, the intake port 102A of this embodiment is also configured such that the opening area decreases from the + side to the - side in the Z-axis direction. The through holes 102aA to 102eA are arranged to face the heat radiation fins 420A, and the heat radiation fins 420A are exposed from the through holes 102aA to 102eA.
In addition, as shown in FIG. 6A, inside the housing 100A of the present embodiment, a pair of conductors extending from the top and bottom surfaces of the housing 100A toward the end surface of the radiation fin 420A on the negative side in the Z-axis direction is provided. A wind plate 107A is arranged. Each baffle plate 107A is arranged to face the through holes 102fA to 102iA, and is configured to guide the air taken in through the through holes 102fA to 102iA to the heat radiating fins 420A.

Further, as shown in FIG. 6, the light irradiation device 2 of this embodiment includes an exhaust fan 110A inside the housing 100A.
In the light irradiation device 2, the light source unit 200A includes a rectangular substrate 205A defined by the X-axis direction and the Y-axis direction, and 50 (X-axis direction)×10 rows (Y-axis direction). and an LED element 210A arranged on a substrate 205A.
In the light irradiation device 2, the heat radiation member 400A is brazed to the rectangular heat radiation plate 410A and the other end surface of the heat radiation plate 410A (the surface opposite to the surface on which the light source unit 200A is placed). Each radiation fin 420A has an end portion 420aA on the positive side in the Y-axis direction facing the upper surface of the housing 100A, and an end portion 420bA on the negative side in the Y-axis direction facing the housing 100A. facing the bottom surface of the
A wind tunnel γ through which cooling air flows after cooling the radiation fins 420A is formed behind each radiation fin 420A (the negative side in the Z-axis direction).

FIG. 7 is a schematic diagram illustrating the relationship between the heat radiating member 400A and the airflow generated inside the housing 100A. In addition, FIG. 7 is a diagram in which an arrow indicating the direction of the airflow is added to FIG. 6(a).

As shown in FIG. 7, in the light irradiation device 2 of the present embodiment, when the exhaust fan 110A rotates, the air inside the housing 100A is exhausted from the exhaust fan 110A, so that the pressure inside the housing 100A becomes negative. , the air outside the housing 100A is taken in through the through holes 102aA to 102iA, and an air current indicated by solid line arrows in FIG. 7 is generated in the housing 100A. More specifically, as shown in FIG. 7, through holes 102aA to 102iA on the upper surface of housing 100A, an airflow is generated in a direction opposite to the Y-axis direction, and through hole 102aA faces air guide plate 107A. 102iA, an airflow is generated along the baffle plate 107A, and flows between the heat radiating fins 420A. Similarly, through holes 102aA to 102iA on the bottom surface of housing 100A generate an airflow in the Y-axis direction, and through holes 102aA to 102iA facing baffle plate 107A, airflow flows along baffle plate 107A. are generated and flow between the radiation fins 420A.
As described above, in the present embodiment, all of the air taken in from the plurality of through holes 102aA to 102iA formed in the top and bottom surfaces of the housing 100A flows between the radiating fins 420A, but each air inlet 102A (That is, the height h (FIG. 5(b)) of each intake port 102A in the Z-axis direction is set so that pressure loss (intake loss) does not occur in the through holes 102aA to 102iA. is higher than the height H (FIG. 6(b)) of the direction, and the total area A of the openings of the air inlets 102A (that is, the sum of the opening areas of the plurality of through-holes 102aA to 102iA) is enough for the heat dissipation fins 420A to ventilate. It is configured to be larger than the area B of the region. That is, as in the first embodiment, the width of the radiation fins 420A in the X-axis direction is defined as the ventilation width W (FIG. 6B), and the thickness of the radiation fins 420A in the X-axis direction is t ( 6(c)), and when the number of radiating fins 420A is n, the conditional expressions (1) and (2) are satisfied.

Then, the air that has flowed between the radiation fins 420A (that is, the surfaces of the radiation fins 420A) flows through the wind tunnel γ and is exhausted from the exhaust fan 110A.
Thus, with the configuration of the present embodiment, as in the first embodiment, the pressure loss (intake loss) at each intake port 102A (that is, the through holes 102aA to 102iA) can be reduced, and the heat dissipation member 400A can be cooled uniformly and sufficiently.

(Third embodiment)
8 and 9 are diagrams for explaining the configuration of the light irradiation device 3 according to the third embodiment of the present invention, and FIG. 8(a) is a perspective view of the light irradiation device 3 according to the embodiment of the present invention. 8(b) is a plan view of the light irradiation device 3 of FIG. 8(a). 9(a) is a cross-sectional view taken along line GG of FIG. 8(b), FIG. 9(b) is a cross-sectional view taken along line HH of FIG. 9(a), and FIG. ) is an enlarged view of part I in FIG. 9(b).

As shown in FIGS. 8 and 9, in the light irradiation device 3 of the present embodiment, the top panel 101B of the housing 100B protrudes upward (Y-axis direction + side), and the top panel 101B protrudes inside (Y-axis direction − side). ) is formed with an inner wall 108B parallel to the top panel 101B. A filter 500 is sandwiched between the top panel 101B and the inner wall 108B so as to block the intake port 102B, which is different from the light irradiation device 1 of the first embodiment.

The filter 500 is, for example, a paper filter, and has a function of absorbing ink mist around the intake port 102B. According to the configuration of this embodiment, even if the light irradiation device 3 is arranged in a space filled with ink mist, the ink mist can be absorbed by the filter 500, so that the ink mist does not enter the housing 100B. Intrusion can be prevented.

The intake port 102B of this embodiment is configured by arranging 10 circular through-holes 102aB to 102jB along the Z-axis direction in 19 rows in the X-axis direction. The odd-numbered through holes 102aB to 102jB are shifted in the Z-axis direction with respect to the even-numbered through holes 102aB to 102jB, and the sixth through-holes 102aB to 102fB from the positive side in the Z-axis direction have the same hole diameter. (eg, 5 mm in diameter), and the diameters of the through holes 102gB to 102jB are gradually smaller than the diameters of the through holes 102aB to 102fB (eg, diameters of 4 mm, 3 mm, 2 mm, and 1 mm, respectively). That is, as in the first embodiment, the intake port 102B of this embodiment is also configured such that the opening area decreases from the + side to the - side in the Z-axis direction. Through holes 102aB to 102jB are arranged to face filter 500, and filter 500 is exposed from through holes 102aB to 102jB.
Further, as shown in FIG. 9A, inside the housing 100B of the present embodiment, a baffle plate 107B extending from the inner wall 108B toward the end face of the radiation fin 420 on the Z-axis direction - side is arranged. there is The baffle plate 107B is a dogleg-shaped metal thin plate member that is arranged to face the inner wall 108B, takes in the air from the through holes 102aB to 102jB, and guides the air that has passed through the filter 500 to the heat radiating fins 420. . A through hole (not shown) is formed in the inner wall 108B so that all the air that has passed through the filter 500 is guided to the air guide plate 107B through the inner wall 108B.

FIG. 10 is a schematic diagram explaining the airflow generated inside the housing 100B. In addition, FIG. 10 is a diagram in which an arrow indicating the direction of the airflow is added to FIG. 9(a).

As shown in FIG. 10, in the light irradiation device 3 of the present embodiment, when the exhaust fan 110 rotates, the air inside the housing 100B is exhausted from the exhaust fan 110, so that the pressure inside the housing 100B becomes negative. , the air outside the housing 100B is taken in through the through holes 102aB to 102jB, and air currents indicated by solid arrows in FIG. 10 are generated in the housing 100B. More specifically, as shown in FIG. 10, air is taken in from through holes 102aB to 102jB in a direction opposite to the Y-axis direction, and the taken-in air passes through filter 500 and inner wall 108B to baffle plate 107B. , and flow between the heat radiating fins 420 .
As described above, in the present embodiment, all of the air taken in from the plurality of through holes 102aB to 102jB formed in the top panel 101B of the housing 100B flows between the radiation fins 420, but the air intake 102B ( That is, the height h (FIG. 8(b)) of the intake port 102B in the Z-axis direction should be set so that the pressure loss (intake loss) in the through holes 102aB to 102jB) and the filter 500 does not occur. It is higher than the axial height H (FIG. 9B), and the total area A of the openings of the intake port 102B (that is, the sum of the opening areas of the plurality of through holes 102aB to 102jB) is sufficient for the heat dissipation fins 420 to ventilate. It is configured to be larger than the area B of the region. That is, as in the first embodiment, the configuration satisfies the above conditional expressions (1) and (2).
As described above, the configuration of the present embodiment can also reduce the pressure loss (intake loss) at each intake port 102B (that is, the through holes 102aB to 102jB) and the filter 500, as in the first embodiment. , the heat radiating member 400 can be uniformly and sufficiently cooled.

It should be noted that the embodiments disclosed this time are illustrative in all respects and should not be considered restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning of equivalents of the scope of the claims.

1: light irradiation device 2: light irradiation device 3: light irradiation device 100: housing 100A: housing 100B: housing 101B: top panel 102: intake port 102A: intake port 102B: intake port 102a: through hole 102aA: penetration Hole 102aB : Through hole 102b : Through hole 102bA : Through hole 102bB : Through hole 102c : Through hole 102cA : Through hole 102cB : Through hole 102d : Through hole 102dA : Through hole 102dB : Through hole 102e : Through hole 102eA : Through hole 102eB : Through hole 102f : Through hole 102fA : Through hole 102fB : Through hole 102g : Through hole 102gA : Through hole 102gB : Through hole 102hA : Through hole 102hB : Through hole 102iA : Through hole 102iB : Through hole 102jB : Through hole 105 : Window Portion 107: Air guide plate 107A: Air guide plate 107B: Air guide plate 108B: Inner wall 110: Exhaust fan 110A: Exhaust fan 200: Light source unit 200A: Light source unit 205: Board 205A: Board 210: LED element 210A: LED element 300 : control board 301 : circuit board 400 : heat dissipation member 400A : heat dissipation member 410 : heat dissipation plate 410A : heat dissipation plate 420 : heat dissipation fin 420A : heat dissipation fin 420a : end 420aA : end 420b : end 420bA : end 500 : filter

Claims

A light irradiation device that irradiates an irradiation surface with linear light that extends in a first direction and has a predetermined line width in a second direction perpendicular to the first direction,
a substrate defined by the first direction and the second direction; a light source unit including a plurality of light sources that emit the light in three directions;
a heat radiating portion having a plurality of heat radiating fins erected at predetermined pitches along the first direction and thermally coupled to the rear surface side of the substrate;
a housing that houses at least the heat dissipating portion and forms a wind tunnel through which cooling air that cools the heat dissipating fins flows;
a cooling fan that generates the cooling air in the third direction or in a direction opposite to the third direction in the wind tunnel;
with
At least one of the side surfaces of the housing facing in the second direction allows the cooling air to be exhausted to the outside through between the plurality of heat radiating fins, or to be taken in from the outside through between the plurality of heat radiating fins. having a vent formed to
Let A be the total area of the openings of the vents, let h be the height of the vents in the third direction, let H be the height of the plurality of heat radiating fins in the third direction, and let the plurality of heat radiating fins The following conditional expression (1 ) and (2) are satisfied.
A>H×(W−(t×n)) (1)
h>H (2)
A plurality of through-holes in which the vent holes are formed in z (z is an integer of 2 or more) along the third direction and x rows (x is an integer of 2 or more) along the first direction. 2. The light irradiation device according to claim 1, characterized by comprising:
3. The light irradiation device according to claim 2, wherein the opening areas of the plurality of through-holes decrease in the direction opposite to the third direction.
The through-holes in odd-numbered rows among the x-rows are shifted along the third direction with respect to the through-holes in even-numbered rows, and the plurality of through-holes are arranged in a zigzag pattern as a whole. 4. The light irradiation device according to claim 2 or 3.
The light irradiation device according to any one of claims 2 to 4, characterized in that at least part of the plurality of through holes are arranged to face the plurality of heat radiation fins.
arranged to face at least a part of the plurality of through-holes, guides the air sucked from the plurality of through-holes to the plurality of heat radiating fins, or guides the air exhausted from the plurality of heat radiating fins to the plurality of heat radiating fins; 6. The light irradiation device according to any one of claims 2 to 5, further comprising a baffle plate that guides the through hole.
The light irradiation device according to any one of claims 1 to 6, wherein the pitch of the plurality of light sources in the first direction is equal to or greater than the pitch of the plurality of radiation fins in the first direction. .
The vent is formed only on one side surface of the housing,
The plurality of heat radiation fins are arranged close to the one surface,
A space is formed between the other side surface of the housing and the plurality of heat radiating fins,
Having a driving circuit for driving the plurality of light sources in the space,
The light irradiation device according to any one of claims 1 to 7, characterized in that:
The light irradiation device according to claim 8, wherein the wind tunnel is composed of a first wind tunnel and a second wind tunnel that are divided in the second direction by the drive circuit.
The light irradiation device according to any one of claims 1 to 9, further comprising a filter arranged so as to block the air vent and absorbing ink mist.
The light irradiation device according to any one of claims 1 to 10, wherein the light includes a wavelength that acts on the ultraviolet curable resin.