Light irradiation device, light source unit

Abstract

To provide a light radiation device which enables improvement of cooling efficiency of an LED element without increasing the size of the entire device, and to provide a light source unit.SOLUTION: A light radiation device includes: a heat sink 33 including a heat pipe 34; an LED substrate 32 which is disposed so as to contact with the heat sink 33; and a housing which houses the heat sink 33 and the LED substrate 32. The LED substrate 32 has a light emission area 31a in which multiple LED elements 31 are arranged in line. A part of the heat pipe 34 is located at the inner side of the light emission area 31a and another part of the heat pipe 34 is located at the outer side of the light emission area 31a when viewed in a direction orthogonal to a major surface 32a of the LED substrate 32.SELECTED DRAWING: Figure 5A

Description

Technical Field

[0001] The present invention relates to an optical irradiation device and a light source unit, and particularly to an optical irradiation device and a light source unit using an LED element as a light source.

Background Art

[0002] A printing device (hereinafter, appropriately referred to as a "UV printing device") that performs printing using a photocurable ink that is cured by irradiation with ultraviolet light is known. Conventionally, a discharge lamp has been used as a light source for a UV printing device. However, in recent years, LED elements have begun to be used instead of discharge lamps because they have advantages such as low energy consumption and long life. However, since the output of an LED element alone is low, it is necessary to arrange a plurality of LED elements as a light source in order to irradiate ultraviolet light with an amount of light that enables ink curing in a short time.

[0003] When a plurality of LED elements are arranged as a light source in this way, a problem of heat generation on the light source side occurs. Since the luminous efficiency and lifespan of an LED element decrease when the operating temperature increases, it is necessary to ensure high heat dissipation performance from the viewpoints of improving efficiency and lifespan characteristics. For example, Patent Document 1 below discloses a technique related to a cooling mechanism provided in a light source for a UV printing device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Currently, there is a market demand for high-quality, high-speed printing technology. To meet this demand, it is necessary to further improve the light output from the light source. However, the more the light output is increased, the more heat is generated in the light source. As mentioned above, when the light source is composed of multiple LED elements, it is necessary to avoid temperature rise as much as possible from the standpoint of luminous efficiency and lifespan, so it is necessary to achieve even higher heat dissipation.

[0006] According to the configuration disclosed in Patent Document 1, the exhaust air, after heat exchange through the heat sink, is discharged to the outside of the light irradiation device. As described above, from the viewpoint of further improving the light output, it is preferable to increase the airflow rate of the cooling air supplied to the heat sink in order to improve the cooling efficiency.

[0007] However, increasing the airflow of cooling air supplied to the heatsink requires the installation of large air intakes and air ducts, which would lead to an overall increase in the size of the light irradiation device. In particular, for light irradiation devices applied to UV printing equipment, the overall size of the device is determined to some extent by the printing press and the printed materials, so measures that increase the overall size of the device are undesirable.

[0008] In view of the above problems, the present invention aims to provide a light irradiation device and a light source unit in which the cooling efficiency of LED elements is improved without increasing the overall size of the device. [Means for solving the problem]

[0009] The light irradiation device of the present invention is A heatsink with a heat pipe, An LED substrate is positioned so as to be in contact with the heat sink, The system comprises the heat sink and the housing that houses the LED substrate, The LED substrate has a light-emitting region in which multiple LED elements are arranged, The LED substrate is characterized in that, when viewed from a direction perpendicular to the main surface, a portion of the heat pipe is located inside the light-emitting region, and another portion of the heat pipe is located outside the light-emitting region.

[0010] In this specification, "light-emitting region" refers to the region enclosed by an envelope connecting the outer perimeters of multiple LED elements placed on a single LED substrate.

[0011] A heat pipe is a component in which a fibrous or mesh-like material called a wick and a liquid that absorbs heat and evaporates (hereinafter referred to as "working fluid") are sealed inside a metal tube. Heat transport by a heat pipe is carried out by the evaporation of the working fluid due to absorbed heat, the condensation of the working fluid due to heat dissipation, and the high-speed movement of the evaporated and condensed working fluid inside the tube.

[0012] The heat pipe absorbs the heat generated in the light-emitting region of the LED substrate, that is, the heat generated when multiple LED elements light up, and sequentially transfers it to regions away from the light-emitting region.

[0013] Therefore, with the above configuration, the heat generated in the light-emitting region can be dissipated more quickly and sequentially, improving the heat dissipation efficiency in the light-emitting region of the heat sink. In other words, the mounted LED elements are cooled more effectively compared to conventional light irradiation devices.

[0014] The above-mentioned light irradiation device is The heat sink is provided with a plurality of fins that form spaced portions for allowing cooling air to pass through, An air intake port for drawing the cooling air from the outside of the housing into the inside of the housing, The housing is equipped with an air inlet region into which the cooling air taken in from the air intake port flows, A portion of the heat pipe located outside the light-emitting region may be configured to be located closer to the air inflow region than to the light-emitting region.

[0015] Furthermore, the above-mentioned light irradiation device is At least one end of the heat pipe may be configured to be located outside the light-emitting region and closer to the air inflow region than the light-emitting region.

[0016] The cooling air drawn in from the outside of the enclosure passes near the heat pipes, which transport heat from the light-emitting area, before reaching the area around the light-emitting area. The cooling air, whose temperature has risen due to absorbing heat, is then pushed out by the continuously incoming cooling air, so it does not accumulate near the fins but is discharged to the outside of the heatsink through the gaps between the fins.

[0017] Therefore, with the above configuration, the heat generated in the light-emitting region is sequentially transported by the heat pipe to regions away from the light-emitting region. The transported heat is then sequentially dissipated by cooling air that flows in from the outside of the housing at a relatively low temperature. In other words, the light irradiation device of the present invention can dissipate the heat generated by the LED element more efficiently than conventional light irradiation devices, and achieves higher cooling efficiency.

[0018] The above-mentioned light irradiation device is At least a portion of the heat pipe is arranged along the first direction, The separated portion may be formed so that the cooling air flows in the first direction.

[0019] With the above configuration, the heat generated in the light-emitting region is transferred directly to the air inlet region where cooling air that has not absorbed heat from the light-emitting region flows in, at least in part of the heat pipe. In other words, the cooling air flows from the heat transfer destination towards the heat absorption region. As a result, the cooling air can absorb heat more effectively at the point from which the heat is transferred, thus improving the heat dissipation efficiency of the heat sink.

[0020] The above-mentioned light irradiation device is The housing may be formed with a first air inlet and a first air guiding passage for introducing the cooling air to one edge portion side of the fins, and a second air inlet and a second air guiding passage for introducing the cooling air to the other edge portion side of the fins.

[0021] With the above configuration, in the first direction, when a light emitting region is formed on the central portion side of the fins and an end portion to which the heat absorbed by the heat pipe is transported is arranged on the other edge portion side, the cooling air introduced from each of the first air guiding passage and the second air guiding passage can absorb the heat released from the heat pipe, and in addition, can be configured to absorb heat from the light emitting region and exhaust the heat.

[0022] Furthermore, when heat is transported from the central portion in the first direction of the heat sink toward both end portions by one or a plurality of heat pipes, the heat transported to both end portions can be exhausted by the cooling air introduced from each air guiding passage. Therefore, a light irradiation device with higher exhaust heat efficiency can be realized.

[0023] The above light irradiation device The heat sink may be configured such that the protruding length of the fins is shorter on the edge portion side than on the central portion side.

[0024] The cooling air introduced between the fins of the heat sink preferably flows as close as possible to the LED substrate, which is the heat source, and further near the base body of the heat sink where the heat pipe is provided, in order to absorb more heat. For this reason, the region connecting the air guiding passage and the heat sink is designed to be as close as possible to the base body of the heat sink.

[0025] And in order to increase the total amount of the cooling air supplied to the heat sink to improve the cooling efficiency, it is necessary to increase the flow path cross-sectional area of the air guiding passage as much as possible. However, simply enlarging the flow path will cause the entire light irradiation device to become larger by the amount of the expanded air guiding passage. For this reason, in order to expand the air guiding passage, it is preferable to reduce some components in the light irradiation device to secure a region.

[0026] Therefore, by adopting the above configuration, the region connecting the air guide and the heat sink can be narrowed to be limited to the vicinity of the base body. The region where the protruding length of the fins is shortened can then be used to expand the air guide. In addition, the heat sink may be configured such that the protruding length of the fins is relatively shorter in the region located outside the light-emitting area.

[0027] The above-mentioned light irradiation device is The system may also include a discharge passage for discharging the cooling air that has passed through the separated section, a fan positioned within the discharge passage that guides the cooling air from the intake port to the discharge passage, and a wind-shielding member provided between the inner wall surface of the discharge passage and the fan.

[0028] If the fan is located near the heatsink, the cooling air that has absorbed heat and become hot may flow back through the exhaust channel. This could cause the cooling air to mix with the cooling air that has not absorbed heat and entered from the air intake channel, and be introduced into the air inlet area. As a result, the temperature of the cooling air introduced from the air intake channel will rise, and the amount of cooling air flowing from the air intake channel to the heatsink will decrease, potentially reducing cooling efficiency.

[0029] Therefore, by using the above configuration, the cooling air that has passed through the fan is prevented from flowing back upstream through the gaps around the fan.

[0030] The above-mentioned light irradiation device is When viewed in the direction in which the fins protrude, a portion of the heat pipe may be positioned to overlap with the center of the light-emitting region.

[0031] In this specification, the "center of the light-emitting region" corresponds to the centroid point of the shape of the light-emitting region when viewed from a direction perpendicular to the main surface of the LED substrate.

[0032] With the above configuration, the heat pipe absorbs heat from the center of the light-emitting region, which is difficult to dissipate, and sequentially transports the heat to the outside of the light-emitting region. As a result, the amount of heat dissipated from the LED substrate per unit time by the heat pipe increases, further improving the cooling efficiency of the LED element.

[0033] The above-mentioned light irradiation device is The LED substrate and at least a portion of the heat pipe may be configured to be in contact with each other.

[0034] Furthermore, in the above-mentioned light irradiation device, The heat pipe may have a flattened shape in at least the portion that is in contact with the LED substrate.

[0035] By adopting the above configuration, the thermal conductivity between the LED substrate and the peat pipe is improved, thereby further enhancing the cooling efficiency of the LED elements.

[0036] The above-mentioned light irradiation device is The LED substrate, on which the light-emitting region is formed across both ends of two opposing sides on the main surface, and the heat pipe and the heat sink may be arranged in a plurality of light source units, and the plurality of light source units may be arranged to emit line-shaped light.

[0037] In this specification, "a light-emitting region is formed across both ends" means that, with respect to the second direction, the LED elements are arranged such that the widest part of the light-emitting region is 80% or more of the width of the LED substrate.

[0038] With the above configuration, the light irradiation device can be replaced for each light source unit, making maintenance and repair easier. Furthermore, by configuring the light irradiation device with the above configuration to allow adjustment of the number of light source units installed and to select the light source unit that supplies power, the length of the emitted light can be appropriately adjusted according to the size of the printed material, etc.

[0039] The light source unit of the present invention is A light source unit comprising the LED substrate, the heat sink, and the heat pipe, which are mounted in a plurality in the light irradiation device arranged in the second direction, The light-emitting region is characterized in that it is formed across both ends in the second direction on the first main surface of the LED substrate. [Effects of the Invention]

[0040] According to the present invention, a light irradiation device and light source unit can be realized that improve the cooling efficiency of LED elements without increasing the overall size of the device. [Brief explanation of the drawing]

[0041] [Figure 1] This is a schematic top perspective view of one embodiment of a light irradiation device. [Figure 2] This is an overhead perspective view of the light irradiation device shown in Figure 1, with a portion of the casing removed. [Figure 3] This is an overhead perspective view of the light irradiation device shown in Figure 1, with a portion of the casing removed. [Figure 4] This is a diagram of the light irradiation device shown in Figure 2, viewed from the +Y side. [Figure 5A] This is an overhead perspective view of the light source unit alone. [Figure 5B] This diagram shows the light source unit shown in Figure 5A with the LED board removed. [Figure 5C] This is an overhead perspective view of the light source unit alone. [Figure 6A] This is a diagram showing the light irradiation device as viewed from the -Z side. [Figure 6B] This is a diagram of the light irradiation device shown in Figure 6A with some components removed. [Figure 7] This is a diagram showing a light source unit with the LED substrate removed, viewed from the -Z side, in one embodiment of the deactivation device. [Figure 8] This is a diagram showing a light source unit with the LED substrate removed, viewed from the -Z side, in one embodiment of the deactivation device. [Figure 9] This is a drawing of another embodiment of the light irradiation device, viewed from the +Y side with a portion of the housing removed. [Figure 10] Figure 9 shows the light irradiation device as viewed from the -Z side. [Modes for carrying out the invention]

[0042] [First Embodiment] The light irradiation device of the present invention will be described below with reference to the drawings. Note that the following drawings are schematic illustrations, and the dimensional ratios and numbers shown in the drawings do not necessarily correspond to the actual dimensional ratios and numbers.

[0043] (Light irradiation device 1) Figure 1 is a schematic top perspective view of the first embodiment of the light irradiation device 1. Figures 2 and 3 are drawings of the light irradiation device 1 from Figure 1 with a portion of the housing 10 removed, and are top perspective views from different angles. As shown in Figure 1, the light irradiation device 1 in the first embodiment comprises a housing 10, and the housing 10 is provided with a light emission window 11, an air intake port 12, and an exhaust port 13, as shown in Figures 1 to 3.

[0044] Furthermore, as shown in Figures 2 and 3, the light irradiation device 1 houses multiple light source units 20, a fan 14, and a power supply unit 21 inside the housing 10. In the first embodiment of the light irradiation device 1, two air intakes are provided: a first air intake 12a on the +X side of the housing 10 and a second air intake 12b on the -X side. However, the second air intake 12b is located on the -X side of the housing 10 and is hidden by other components, so it is not shown in Figures 1 to 3.

[0045] In the following explanation, as shown in Figure 1, the light-emitting surface 11a of the light-emitting window 11 is assumed to be arranged parallel to the XY plane, and the direction perpendicular to the light-emitting surface 11a of the light-emitting window 11, i.e., the optical axis of the principal ray of the emitted light, is described as the Z direction. Then, as shown in Figure 2, the direction in which the light source units 20 are arranged is described as the Y direction. Note that the X direction corresponds to the "first direction" and the Y direction corresponds to the "second direction".

[0046] Furthermore, when expressing direction, if positive and negative directions need to be distinguished, they are written with a positive or negative sign, such as "+Z direction" or "-Z direction." When expressing direction without distinguishing between positive and negative directions, it is simply written as "Z direction."

[0047] Figure 4 is a view of the light irradiation device 1 of Figure 2 from the +Y side. As shown in Figure 4, the housing 10 has a first air guide passage 15a that guides the cooling air W1 taken in from the first air intake port 12a to the first air inflow region A1, which is the +X side edge of the fins 33b of the heat sink 33 (described later), and a second air guide passage 15b that guides the cooling air W1 taken in from the second air intake port 12b to the second air inflow region A2, which is the -X side edge of the fins 33b. In Figure 4, the fins are shown as a surface shape and are arranged in the Y direction, but the fins 33b of the heat sink 33 may be configured as needles or rods, or other scattered configurations. Even if a heat sink with such a configuration is used, the light source unit 20 is designed so that the cooling air flows between the fins in the X direction.

[0048] In the first embodiment, the intake ports (12a, 12b) are configured to draw in air from outside the housing 10 into the housing 10 as cooling air W1.

[0049] In the first embodiment, two first intake ports 12a are provided in parallel in the Y direction, as shown in Figure 1. However, the number of first intake ports 12a may be one or three or more. This configuration can also be similarly adopted for the second intake port 12b, which is hidden and not shown in Figure 1.

[0050] As shown in Figure 4, each of the air guide passages (15a, 15b) in the first embodiment is a flow path for directing the cooling air W1 taken in from the intake ports (12a, 12b) in the -Z direction to the respective air inlet regions (A1, A2).

[0051] As shown in Figure 4, the discharge passage 16 is a flow path for guiding the cooling air W2, which has absorbed heat from the light source unit 20, to the exhaust port 13 by passing it in the +Z direction.

[0052] Furthermore, in the first embodiment, a power supply unit 21 is provided within the discharge passage 16 to supply power to the light source unit 20 and the fan 14 (see Figure 4), and the heat generated by the power supply unit 21 is dissipated by the cooling air W2. The power supply unit 21 may also be located on the outside of the housing 10.

[0053] As shown in Figure 4, the fan 14 is positioned within the exhaust passage 16 of the housing 10. When it starts blowing air, it takes in cooling air W1 from each intake port (12a, 12b), and directs the cooling air W1 through the guide passages (15a, 15b), between the fins 33b of the heat sink 33 (described later), and through the exhaust passage 16, where it discharges the heat-absorbing cooling air W2 from the exhaust port 13.

[0054] As shown in Figure 4, a windbreak member 17 is provided between the fan 14 and the inner wall surface 16a of the discharge passage 16 to prevent the cooling air W2 from flowing back from around the fan 14 to the -Z side. The windbreak member 17 is, for example, a member made of ethylene propylene diene rubber, molded to fill the gap between the fan 14 and the inner wall surface 16a of the discharge passage 16. The shape of the windbreak member 17 is adjusted as appropriate according to the shape of the gap between the fan 14 and the inner wall surface 16a of the discharge passage 16.

[0055] Furthermore, if the fan 14 is positioned closer to the exhaust port 13 and it is not a problem for some of the cooling air W2 to flow back around the fan 14, then the windbreak member 17 may not be provided. In addition, if sufficient heat dissipation is possible by natural convection caused by temperature differences inside the enclosure, or if a water-cooled cooling mechanism is provided, then the intake ports (12a, 12b) and the fan 14 may not be provided.

[0056] The light emission window 11 is a window provided to emit light emitted from the light source unit 20 in the -Z direction. The light emission window 11 may be a simple opening, but it is preferable that it be covered with a material that transmits light emitted from the light source unit 20 to prevent dust and other debris from adhering to the light source unit 20. If the opening is covered with such a material, the material of the material constituting the light emission window 11 may be, for example, quartz glass or borosilicate glass.

[0057] (Light source unit 20) Figure 5A is an overhead perspective view of the light source unit 20 alone, and Figure 5B is a drawing showing the light source unit 20 with the LED substrate 32 removed from Figure 5A. Figure 5C is an overhead perspective view of the light source unit 20 alone, different from Figure 5A. As shown in Figures 5A and 5B, the light source unit 20 comprises a plurality of LED elements 31, an LED substrate 32, a heat sink 33 including a base body 33a, a plurality of fins 33b, and a heat pipe 34. The specific configuration of the light source unit 20 will be described in the section on the light source unit 20 below.

[0058] As shown in Figure 5A, the LED substrate 32 has multiple LED elements 31 arranged in the X and Y directions, forming a light-emitting region 31a. As shown in Figures 5A and 5C, the light-emitting region 31a is the area enclosed by the outer envelope of the multiple LED elements 31 arranged on the first main surface 32a of the LED substrate 32.

[0059] In the first embodiment, the size of the LED substrate 32 is (X,Y)=(70mm,25mm), and multiple LED elements 31 are arranged in an array in the X and Y directions on the first main surface 32a of the LED substrate 32 such that the size of the light-emitting area 31a is rectangular with dimensions of (X,Y)=(33mm,24mm).

[0060] In the first embodiment, the LED element 31 emits light whose main emission wavelength, which is the wavelength showing peak intensity in the intensity spectrum of the emitted light, is 400 nm. However, the main emission wavelength of the light emitted by the mounted LED element 31 can be arbitrarily selected.

[0061] Furthermore, in the case of a light source for ink curing used in a UV printing apparatus, the LED element 31 is preferably an element that emits light whose main emission wavelength is within the range of 250 nm to 500 nm, and more preferably an element that emits light whose main emission wavelength is within the range of 260 nm to 450 nm.

[0062] Furthermore, in the first embodiment, the LED elements 31 are arranged in a grid pattern at equal intervals in the X and Y directions on the first main surface 32a of the LED substrate 32, as shown in Figure 5A. However, the arrangement of the LED elements 31 does not have to be entirely at equal intervals. As shown in Figure 5C, an arrangement configuration in which the arrangement of LED elements 31 is partially shifted in a predetermined direction (in Figure 5C, the rows aligned in the X direction are partially shifted in the Y direction) may also be adopted.

[0063] As shown in Figure 5A, the heat sink 33 comprises a base body 33a provided to contact the LED substrate 32, and a plurality of planar fins 33b arranged so as to extend in the X direction and have spaced portions in the Y direction. The plurality of fins 33b are configured such that, in the X direction, the length protruding from the air inlet area (A1, A2) side is shorter than the length protruding from the central side, i.e., the length in the Z direction is shorter, in order to widen the area that constitutes the air guide path (15a, 15b) within the housing 10 as much as possible.

[0064] In the first embodiment, the heat sink 33 has a base body 33a and fins 33b made of aluminum alloy, but the base body 33a and fins 33b can be made of copper, magnesium alloy, or the like. Furthermore, if the heat sink 33 is configured to allow cooling air to flow in a predetermined direction near it via a fan or air duct, it does not need to have fins 33b.

[0065] As shown in Figure 5B, the heat pipe 34 has a straight tube shape and is embedded in the base body 33a of the heat sink 33, with its tube axis 34a aligned along the X direction. The heat pipe 34 has a flat surface on the -Z side that is parallel to the XY plane, so that it makes contact over a wide area with the main surface of the LED substrate 32 opposite to the first main surface 32a.

[0066] In the first embodiment, the heat pipe 34 is made of copper and has a length of 70 mm in the extension direction. It is known that the longer the distance over which heat is transported, the higher the cooling efficiency of the heat pipe 34. Also, if the heat pipe 34 is too long, it becomes difficult to secure the area for placement. For this reason, the length of the heat pipe 34 mounted on the light irradiation device 1 in the extension direction is preferably 50 mm or more and 100 mm or less, and more preferably 70 mm or more and 80 mm or less.

[0067] The heat pipe 34 may be configured to have a flattened shape overall so as to make surface contact with the LED substrate 32, or it may be configured so that only the portion in contact with the LED substrate 32 has a flattened shape. Alternatively, the heat pipe 34 may be configured so that only the portion in contact with the LED substrate 32 has a flat surface on the -Z side.

[0068] Furthermore, the heat pipe 34 may be configured to have a straight tube shape and be entirely embedded inside the base body 33a of the heat sink 33 so as not to come into direct contact with the LED substrate 32. Moreover, the heat pipe 34 may be a straight tube shape, and its length in the extension direction may be longer than the width of the heat sink 33 in the X direction.

[0069] Figure 6A is a view of the light irradiation device 1 from the -Z side, and Figure 6B is a view of the light irradiation device 1 from Figure 6A with some components removed. As shown in Figure 6B, the heat pipe 34 is positioned so as to overlap with the light-emitting region 31a when viewed in the Z direction, with its central portion overlapping with the center 31c of the light-emitting region 31a. In other words, the heat pipe 34 is configured to absorb heat in the region that overlaps with the light-emitting region 31a (the central portion in the first embodiment) when viewed in the Z direction, and to transport the absorbed heat to both ends.

[0070] With the above configuration, the heat generated in the light-emitting region 31a is sequentially transported by the heat pipe 34 to a location close to the air inflow regions (A1, A2) away from the light-emitting region 31a. The heat transported to the locations close to the air inflow regions (A1, A2) is then sequentially absorbed and dissipated by the cooling air W1 flowing in from each air guide (15a, 15b), which is at a relatively low temperature and has not yet absorbed heat within the housing 10. In other words, the light irradiation device 1 can dissipate the heat generated by the LED element 31 more efficiently than the configuration of a conventional light irradiation device, thus achieving higher cooling efficiency.

[0071] As shown in Figure 6A, the light source unit 20 in the first embodiment has LED elements 31 arranged across both ends in the Y direction on the LED substrate 32. Therefore, the first embodiment of the light irradiation device 1 is configured to emit a line of light extending in the Y direction from the light emission window 11 from a plurality of light source units 20 arranged in the Y direction. The length of the line of light emitted from the light emission window 11 can be adjusted by the number of light source units 20 installed.

[0072] Furthermore, as shown in Figure 6A, the first embodiment of the light irradiation device 1 is configured such that LED elements 31 are arranged across both ends of the housing 10 in the Y direction. Therefore, by connecting multiple light irradiation devices 1, the length of the emitted light in the Y direction can be arbitrarily adjusted according to the size of the printed material, etc.

[0073] In the above description, the light irradiation device 1 was described as being able to emit a line of light by arranging multiple light source units 20 in a row. However, it is also conceivable that a device that emits an even longer line of light can be constructed by connecting multiple light irradiation devices 1 in the Y direction.

[0074] For example, in cases where the light irradiation device 1 is used only for small objects, the light irradiation device 1 may be configured to have only one light source unit 20 in which a light-emitting region 31a of a desired size is formed. Also, as shown in Figure 5A, the light-emitting region 31a does not have to be formed across both ends of the LED substrate 32 in the Y direction.

[0075] In the first embodiment, the housing 10 is configured to be disassembled into multiple components, as shown in Figures 2 and 3, but it may also be a box-shaped component with a single integrated structure.

[0076] In the first embodiment, the fan 14 is located in the exhaust passage 16, but it may also be located in the intake port 12 or the introduction passages (15a, 15b).

[0077] In the first embodiment, the heat sink 33 is configured such that the base body 33a is in direct contact with the LED substrate 32. However, the heat sink 33 and the LED substrate 32 may be arranged to be in thermal contact via a heat pipe 34, rather than in direct contact.

[0078] [Second Embodiment] The configuration of the second embodiment of the light irradiation device 1 of the present invention will be described, focusing on the differences from the first embodiment.

[0079] Figure 7 is a view of the light source unit 20 from the -Z side in the second embodiment of the light irradiation device 1, with the LED substrate 32 removed. In the second embodiment, as shown in Figure 7, the heat pipes 34 are U-shaped and arranged in multiple locations in the first direction. Although the LED elements 31 are not shown in Figure 7, for illustrative purposes, the light-emitting region 31a in the first embodiment is virtually shown by a dashed line.

[0080] The cooling efficiency of the heat pipe 34 increases as the distance from which heat is transported from its position in the light-emitting region 31a increases. In other words, the cooling efficiency of a single heat pipe 34 increases as its length in the extension direction increases.

[0081] In the second embodiment, the heat pipe 34 provided in the light source unit 20 can be a heat pipe 34 with a longer length in the extension direction than the heat pipe 34 provided in the first embodiment, thereby improving cooling performance.

[0082] In the second embodiment, the light source unit 20 has a configuration in which two U-shaped heat pipes 34 are arranged, but it may also be configured in which one S-shaped heat pipe 34 is arranged so as to pass through the +Z side of each light-emitting region 31a.

[0083] [Third Embodiment] The configuration of the third embodiment of the light irradiation device 1 of the present invention will be described, focusing on the differences from the first and second embodiments.

[0084] Figure 8 is a view of the light source unit 20 from the -Z side, with the LED substrate 32 removed, in the third embodiment of the light irradiation device 1. As shown in Figure 8, the light source unit 20 in the third embodiment has multiple straight-tube-shaped heat pipes 34 arranged in the X direction.

[0085] In the third embodiment, the light irradiation device 1 has shorter individual heat pipes 34 than those in the light source unit 20 of the first embodiment. However, since heat is dissipated from a single light-emitting region 31a by multiple heat pipes 34, the cooling performance is further improved.

[0086] [Alternative Embodiment] The following describes other embodiments.

[0087] <1> Figure 9 is a drawing of another embodiment of the light irradiation device 1, viewed from the +Y side with a part of the housing 10 removed, and Figure 10 is a drawing of the light irradiation device 1 of Figure 9 viewed from the -Z side. Note that, for explanatory purposes, Figure 10 is shown with some components removed, similar to Figure 6B.

[0088] As shown in Figure 9, in another embodiment of the light irradiation device 1, unlike the first embodiment, the air intake port 12 and the air guide 15 are formed only on the +X side of the housing 10. Also, as shown in Figure 10, in the light source unit 20 of the other embodiment, the light-emitting region 31a is formed not in the center of the first main surface 32a of the LED substrate 32, but at a position shifted to the -X side.

[0089] In another embodiment, the light source unit 20 is configured such that, when viewed in the Z direction, one end of the heat pipe 34 is positioned inside the light-emitting region 31a. That is, in this configuration, the heat pipe 34 absorbs heat at the end positioned on the light-emitting region 31a side and transports it to a position close to the first air inlet region A1. Then, as shown in Figure 9, the heat is absorbed by the cooling air W1 introduced into the first air inlet region A1 by the air guide 15.

[0090] With the above configuration, the intake port 12 and the air guide 15 can each be made up of only one unit, thus reducing the overall size of the light irradiation device 1.

[0091] <2> The configuration of the light irradiation device 1 described above is merely an example, and the present invention is not limited to the configurations shown in the figures. [Explanation of Symbols]

[0092] 1 : Light irradiation device 10: Cabinet 11: Light-emitting window 11a: Light exit surface 12: Air intake 12a: First air intake 12b: Second air intake 13: Exhaust vent 14: Fan 15: Air guide path 15a: First air guide path 15b: Second air guide path 16: Exhaust channel 16a: Inner wall surface 17 : Wind shielding member 20: Light source unit 21: Power supply unit 31: LED element 31a: Emitting region 31c: center 32: LED board 32a: First principal surface 33: Heatsink 33a: Base body 33b: Finn 34: Heat pipe 34a: Tube shaft A1: First wind inflow area A2: Secondary wind inflow area W1,W2: Cooling air

Claims

1. A heatsink with a heat pipe, An LED substrate is positioned so as to be in contact with the heat sink, The heat sink and the housing that houses the LED board, The heat sink is provided with a plurality of fins that form spaced portions for allowing cooling air to pass through, The enclosure is equipped with an air intake port for drawing the cooling air from the outside of the enclosure into the inside of the enclosure, The LED substrate has a light-emitting region in which a plurality of LED elements are arranged, When viewed from a direction perpendicular to the main surface of the LED substrate, a portion of the heat pipe is located inside the light-emitting region, and another portion of the heat pipe is located outside the light-emitting region. The air intake is formed on the side surface of the housing perpendicular to the main surface of the LED substrate, The light irradiation device is characterized in that the housing has an air guide path that guides the cooling air taken into the housing from the intake port toward the plurality of fins in a direction perpendicular to the main surface of the LED substrate, and an exhaust path that guides the cooling air that has passed through the separated portion toward away from the plurality of fins in a direction perpendicular to the main surface of the LED substrate.

2. The housing is equipped with an air inflow region into which the cooling air taken in from the air intake port flows, The light irradiation device according to claim 1, characterized in that a part of the heat pipe located outside the light-emitting region is located closer to the air inflow region than the light-emitting region.

3. The light irradiation device according to claim 2, characterized in that at least one end of the heat pipe is located outside the light-emitting region and closer to the air inflow region than the light-emitting region.

4. At least a portion of the heat pipe is arranged along the first direction, The light irradiation device according to claim 2 or 3, characterized in that the separated portion is formed so that the cooling air flows toward the first direction.

5. The light irradiation device according to claim 2 or 3, characterized in that the housing has a first intake port and a first air guide for introducing the cooling air on one end edge of the fin, and a second intake port and a second air guide for introducing the cooling air on the other end edge of the fin.

6. The light irradiation device according to claim 2 or 3, characterized in that the heat sink has a shorter protruding length of the fins on the edge side than on the central side.

7. The light irradiation device according to claim 2 or 3, further comprising: an exhaust passage for discharging the cooling air that has passed through the separated portion; a fan positioned in the exhaust passage for guiding the cooling air from the intake port to the exhaust passage; and a wind-shielding member provided between the inner wall surface of the exhaust passage and the fan.

8. The light irradiation device according to any one of claims 1 to 3, characterized in that when viewed in a direction perpendicular to the LED substrate, a part of the heat pipe is arranged to overlap with the center of the light-emitting region.

9. The light irradiation device according to any one of claims 1 to 3, characterized in that the LED substrate and at least a portion of the heat pipe are in contact.

10. The light irradiation device according to claim 9, characterized in that the heat pipe has a flattened shape in at least the portion that is in contact with the LED substrate.

11. The light irradiation device according to any one of claims 1 to 3, comprising an LED substrate on which the light-emitting region is formed over both ends of two opposing sides on the main surface, a heat pipe, and a plurality of light source units including the heat sink, wherein the plurality of light source units are arranged to emit line-shaped light.

12. A light source unit mounted on the light irradiation device according to claim 11.

Images