JP2016026929A - Light radiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light radiation device which is small and light-weight and yet achieves small variations of radiation intensity between LEDs.SOLUTION: A light radiation device radiates linear light on a radiation surface and includes: a substrate arranged substantially parallel to a first direction and a second direction; light emitting elements which are disposed on a surface of the substrate so as to be arranged along the first direction at a first interval and emit light in a third direction perpendicular to the surface of the substrate; and a cooling device which is provided so as to closely contact with a rear surface of the substrate and radiates heat generated by the light emitting elements into air. The cooling device includes: heat pipes which are disposed on the rear surface of the substrate so as to be arranged along the first direction at a second interval; and plate-like heat radiation fins through which the heat pipes penetrate through. Each heat pipe includes: a bottom part extending in the second direction and thermally coupled to the substrate; and an arm part which protrudes from the bottom part in a predetermined direction and is thermally coupled to the heat radiation fins. The heat pipe transfers heat from the substrate to the heat radiation fins.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a light irradiation device that includes an LED (Light Emitting Diode) as a light source and emits line-shaped light, and more particularly to a light irradiation device that includes a cooling device that dissipates heat generated from the LED.

  2. Description of the Related Art Conventionally, printing apparatuses that perform printing using UV ink that is cured by irradiation with ultraviolet light are known. In such a printing apparatus, after ejecting ink from the nozzles of the head onto the medium, the dots formed on the medium are irradiated with ultraviolet light. Since the dots are cured and fixed on the medium by irradiation with ultraviolet light, good printing can be performed even on a medium that hardly absorbs liquid. Such a printing apparatus is described in Patent Document 1, for example.

  Patent Document 1 discloses a transport unit that transports a print medium, six heads that are arranged in the transport direction and discharge color inks of cyan, magenta, yellow, black, orange, and green, and downstream in the transport direction between the heads. 6 temporary curing irradiation units that are disposed on the side and temporarily cure (pinning) the dot ink ejected from each head onto the printing medium, and the main curing irradiation unit that permanently cures the dot ink and fixes it to the printing medium. And a printing device comprising: The printing apparatus described in Patent Document 1 suppresses bleeding between color inks and spread of dots by curing the dot ink in two stages of temporary curing and main curing.

  The pre-curing irradiation unit described in Patent Document 1 is a so-called ultraviolet light irradiation device that is disposed above a print medium and irradiates the print medium with ultraviolet light, and emits linear ultraviolet light in the width direction of the print medium. Irradiate. In the temporary curing irradiation unit, LEDs are used as a light source in order to reduce the weight and size of the printing apparatus itself, and a plurality of LEDs are arranged along the width direction of the print medium.

  However, when an LED is used as the light source, most of the input electric power becomes heat, so that there is a problem that the light emission efficiency and life are reduced by the heat generated by the LED itself, and heat treatment becomes a problem. For this reason, in the light irradiation apparatus using LED as a light source, the structure which forcibly radiates the heat which generate | occur | produces with LED is taken.

  For example, a light irradiation device (light source device) described in Patent Document 2 includes a plurality of LEDs, a substrate on which the plurality of LEDs are mounted, and a heat radiation fin disposed in contact with the back surface of the substrate. The heat from the heat is dissipated into the air through the radiation fins.

  Patent Document 3 discloses a light irradiation device (light source unit) including a base (header) and a plurality of LEDs arranged in a straight line on the base. A plurality of flow paths for flowing cooling water are formed in the base along the LED arrangement direction, and each LED is cooled by flowing cooling water through the flow paths. Moreover, if the cooling water is allowed to flow only in the LED alignment direction (that is, in one direction), a temperature difference is generated between the upstream side and the downstream side of the cooling water, and a temperature difference is generated between the LEDs. Since variations occur, in the light irradiation device described in Patent Document 3, cooling water is allowed to flow in the LED alignment direction and the direction opposite to the LED alignment direction to reduce the temperature difference between the LEDs. .

JP 2013-252720 A JP 2012-186015 A JP 2009-064987 A

  According to the light irradiation devices disclosed in Patent Document 2 and Patent Document 3, since the LED is efficiently cooled with air or cooling water, it is possible to prevent degradation and damage of the LED, and to achieve high brightness. Light emission is possible.

  However, since the light irradiation device of Patent Document 2 has a configuration in which the LED is air-cooled by the radiation fins, the cooling capacity is determined by the thermal conductivity and size of the radiation fins. There is a problem in that the heat radiation fins must be formed of a high-rate material or the size of the heat radiation fins must be increased, and the light irradiation device itself is increased in size.

  Moreover, since the light irradiation apparatus of patent document 3 is a structure which water-cools LED by a base, compared with the structure of air cooling like the light irradiation apparatus of patent document 2, although cooling capability itself is improved, it is installed. There is a problem that it takes time and cost. In addition, for example, when the cooling water supply means adopts a configuration in which the cooling water is circulated (that is, a configuration in which the cooling water flowing through the flow path is discarded as it is), there is a problem that the consumption amount of the cooling water is large. In addition, when the configuration in which the cooling water is circulated is used, there is a problem that a device for cooling the cooling water itself is required and the device itself becomes large.

  This invention is made | formed in view of such a situation, The place made into the objective is providing the light irradiation apparatus with few irradiation intensity variations between LED, although it is small and lightweight.

  In order to achieve the above object, the light irradiation apparatus of the present invention irradiates a line-shaped light extending in the first direction and having a predetermined line width in the second direction orthogonal to the first direction on the irradiation surface. A light irradiation device that is arranged in parallel with the first direction and the second direction, and arranged on the surface of the substrate at a first interval along the first direction and orthogonal to the surface of the substrate. A plurality of light emitting elements that emit light in three directions, and a cooling device that is provided in close contact with the back surface of the substrate and that radiates heat generated by the plurality of light emitting elements into the air. A plurality of heat pipes arranged side by side along the first direction on the back surface of the plate, and a plurality of plate-like heat radiation fins through which the plurality of heat pipes penetrate, Each includes a bottom extending in the second direction and thermally coupled to the substrate, and the bottom Projecting in a predetermined direction and an arm portion which is respectively thermally coupled to the plurality of heat radiating fins, characterized in that transport heat from the substrate into a plurality of heat radiation fins.

  According to such a configuration, the heat generated in each light emitting element quickly moves to the radiation fin via the substrate and the heat pipe, and is efficiently radiated from the radiation fin to the air. For this reason, the temperature of each light emitting element does not rise excessively, and the problem that the light emission efficiency decreases remarkably does not occur. Moreover, each heat pipe is arrange | positioned so that the bottom part may extend in a 2nd direction, and is arrange | positioned at equal intervals along a 1st direction. For this reason, there is little variation in the cooling capacity in the second direction and the first direction, the substrate can be uniformly (uniformly) cooled, and the plurality of light emitting elements arranged on the substrate are also uniformly cooled. . Accordingly, there is no temperature difference between the light emitting elements, and there is no variation in irradiation intensity due to temperature characteristics. Moreover, since it is the structure which arranges a several plate-shaped heat radiation fin along a 3rd direction, a heat radiation fin has sufficient surface area. Moreover, since the cooling device is constituted by the heat pipe and the heat radiating fins, it is smaller and lighter than a conventional cooling device using cooling water.

  Each of the plurality of heat pipes can be configured to have a U-shape or an L-shape when viewed from the first direction.

  In addition, each of the plurality of radiating fins is preferably disposed substantially parallel to the substrate.

The plurality of heat pipes includes a first heat pipe located at a first position in the second direction and a second heat pipe located at a second position in the second direction. It is desirable that the second heat pipes are alternately arranged along the first direction. In this case, it is desirable that the first heat pipe and the second heat pipe are arranged so as to be in close contact with each other in the first direction.

  Moreover, it is desirable to provide the fan which produces an airflow in a 1st direction or a 2nd direction with respect to a radiation fin. In this case, each of the plurality of heat pipes has an L-shape when viewed from the first direction, and the light irradiation device is disposed in a space surrounded by the L-shape. The fan is disposed on the opposite side of the drive circuit and the plurality of heat pipes in the third direction, and generates an air flow in the second direction so as to cool the drive circuit and the heat radiating fins. Is desirable.

  Each of the plurality of heat pipes has an L-shape when viewed from the first direction, and the fan is disposed in a space surrounded by the L-shape so as to cool the radiation fins. It is desirable to generate airflow in the second direction.

  Each of the plurality of heat pipes can be configured to have a U-shape when viewed from the first direction. The tip of the arm is bent so as to be substantially parallel to the bottom, and each of the plurality of radiating fins is disposed at the tip of the arm so as to be substantially perpendicular to the substrate. desirable.

  The plurality of heat pipes include a first heat pipe and a second heat pipe having different lengths in the third direction, and the first heat pipe and the second heat pipe are alternately arranged along the first direction. It is desirable that they are arranged. In this case, it is desirable that the first heat pipe and the second heat pipe are arranged so as to be in close contact with each other in the first direction.

  Moreover, it is desirable to provide the fan which produces an airflow in a 1st direction or a 3rd direction with respect to a radiation fin. In this case, it is desirable that the fan be disposed in a space surrounded by a U-shape and generate an airflow in the third direction so as to cool the heat radiating fins.

  In addition, the fan is preferably disposed on the opposite side of the plurality of heat pipes in the third direction, and generates airflow in the third direction so as to cool the radiation fins.

  Moreover, it is desirable that each of the plurality of heat pipes is flat in the second direction.

  Further, it is desirable that the angle formed by the arm portion and the bottom portion is approximately 90 °.

  In addition, the light irradiation device may include a plurality of cooling devices connected along the first direction.

  Further, it is desirable that the light emitting element emit light having a wavelength that acts on the ultraviolet curable resin.

  The light emitting element is preferably an LED (Light Emitting Diode).

  As described above, according to the present invention, it is possible to realize a light irradiation device that is small and light and has little variation in irradiation intensity between LEDs.

It is a front view of the light irradiation apparatus which concerns on the 1st Embodiment of this invention. It is a top view of the light irradiation apparatus which concerns on the 1st Embodiment of this invention. It is a rear view of the light irradiation apparatus which concerns on the 1st Embodiment of this invention. It is a right view of the light irradiation apparatus which concerns on the 1st Embodiment of this invention. It is a rear view of the modification of the light irradiation apparatus which concerns on the 1st Embodiment of this invention. It is a right view of the light irradiation apparatus which concerns on the 2nd Embodiment of this invention. It is a right view of the light irradiation apparatus which concerns on the 3rd Embodiment of this invention. It is a rear view of the light irradiation apparatus which concerns on the 4th Embodiment of this invention. It is a right view of the light irradiation apparatus which concerns on the 4th Embodiment of this invention. It is a rear view of the light irradiation apparatus which concerns on the 5th Embodiment of this invention. It is a right view of the light irradiation apparatus which concerns on the 5th Embodiment of this invention. It is a right view of the light irradiation apparatus which concerns on the 6th Embodiment of this invention. It is a right view of the light irradiation apparatus which concerns on the 7th Embodiment of this invention. It is a top view of the light irradiation apparatus which concerns on the 8th Embodiment of this invention. It is a right view of the light irradiation apparatus which concerns on the 8th Embodiment of this invention. It is a right view of the light irradiation apparatus which concerns on the 9th Embodiment of this invention. It is a right view of the light irradiation apparatus which concerns on the 10th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent part in a figure, and the description is not repeated.

(First embodiment)
FIG. 1 is a front view of a light irradiation apparatus 1 according to the first embodiment of the present invention. 2 is a top view of the light irradiation apparatus 1 in FIG. 1, FIG. 3 is a rear view of the light irradiation apparatus 1 in FIG. 1, and FIG. 4 is a right side view of the light irradiation apparatus 1 in FIG. FIG. The light irradiation apparatus 1 of this embodiment is an apparatus mounted on a printing apparatus that performs printing using UV ink that is cured by irradiation with ultraviolet light. The light irradiation apparatus 1 is disposed to face a print medium (not shown) and Line-shaped ultraviolet light is irradiated in the width direction (that is, the direction orthogonal to the direction in which the print medium is conveyed). In this specification, for convenience of explanation, the longitudinal (line length) direction of the line-shaped ultraviolet light emitted from the light irradiation device 1 is the X-axis direction and the short direction (that is, the vertical direction in FIG. 1). ) Is defined as the Y-axis direction, and the direction orthogonal to the X-axis and the Y-axis (that is, the ultraviolet light emission direction) is defined as the Z-axis direction.

  As shown in FIGS. 1 to 4, the light irradiation apparatus 1 according to the present embodiment includes a rectangular substrate 101 parallel to the X-axis direction and the Y-axis direction, and a plurality of LEDs (Light Emitting) arranged on the substrate 101. Diode) element 103 (light emitting element) and cooling device 200 are provided.

  The substrate 101 is a rectangular wiring substrate formed of a material having high thermal conductivity (for example, copper, aluminum, aluminum nitride), and the surface thereof has a predetermined interval in the X-axis direction and the Y-axis direction. 40 (X-axis direction) × 5 (Y-axis direction) LED elements 103 are mounted. An anode pattern (not shown) and a cathode pattern (not shown) for supplying power to each LED element 103 are formed on the substrate 101, and each LED element 103 has an anode pattern and a cathode pattern. Each is soldered and electrically connected. The anode pattern and the cathode pattern are electrically connected to an LED drive circuit (not shown), and each LED element 103 is supplied with drive current from the LED drive circuit via the anode pattern and the cathode pattern. It has become.

  The LED element 103 is a semiconductor element that includes an LED chip (not shown) having a substantially square light emitting surface and emits ultraviolet light having a wavelength of 385 nm upon receiving a drive current from the LED drive circuit. When a driving current is supplied to each LED element 103, ultraviolet light having a light amount corresponding to the driving current is emitted from each LED element 103, and a linear ultraviolet light substantially parallel to the X-axis direction is emitted from the light irradiation device 1. Is emitted. In addition, the drive current supplied to each LED element 103 is adjusted so that each LED element 103 of this embodiment radiates | emits the ultraviolet light of a substantially uniform light quantity, The line radiate | emitted from the light irradiation apparatus 1 is adjusted. The ultraviolet light has a substantially uniform light amount distribution in the X-axis direction and the Y-axis direction.

  The cooling device 200 is a device that is disposed so as to be in close contact with the back surface of the substrate 101 (the surface opposite to the surface on which the LED elements 103 are mounted), and dissipates the heat generated in each LED element 103. It consists of a pipe 201 and a plurality of radiating fins 203. When a drive current flows through each LED element 103 and ultraviolet light is emitted from each LED element 103, the temperature rises due to the self-heating of the LED element 103, and the light emission efficiency significantly decreases. In the embodiment, the cooling device 200 is provided so as to be in close contact with the back surface of the substrate 101, and heat generated in the LED element 103 is conducted to the cooling device 200 through the substrate 101 to forcibly radiate heat.

  The heat pipe 201 is a hollow metal (eg, a metal such as copper, aluminum, iron, magnesium, or an alloy containing these) in which a hydraulic fluid (eg, water, alcohol, ammonia, etc.) is sealed under reduced pressure. This is a sealed tube. As shown in FIG. 4, each heat pipe 201 of the present embodiment has a substantially U-shape when viewed from the X-axis direction, and a bottom 201 a that is in close contact with the back surface of the substrate 101, and a bottom It is comprised from a pair of arm part 201b which protrudes in the Z-axis direction negative side (namely, direction opposite to the emission direction of ultraviolet light) from 201a. In the present embodiment, 20 heat pipes 201 are arranged in a line at predetermined intervals along the X-axis direction (FIGS. 2 and 3), and the bottom 201a of each heat pipe 201 is It is fixed in close contact with the back surface of the substrate 101 by a fixing tool or an adhesive (not shown), and is thermally coupled to the substrate 101 (FIG. 4).

  The heat radiation fin 203 is a member made of a rectangular plate-like metal (for example, a metal such as copper, aluminum, iron, magnesium, or an alloy containing these metals). As shown in FIG. 3, each through-hole 203a into which the pair of arm portions 201b of each heat pipe 201 is inserted is formed in each radiating fin 203 of the present embodiment. In the present embodiment, Fifteen radiating fins 203 are sequentially inserted into the pair of arm portions 201b of each heat pipe 201, and are arranged side by side at a predetermined interval along the Z-axis direction (that is, in parallel with the substrate 101) ( 2 and 4). Each radiating fin 203 is mechanically and thermally coupled to each arm portion 201b by welding or bonding in each through hole 203a.

  When a drive current flows through each LED element 103 and ultraviolet light is emitted from each LED element 103, the temperature rises due to self-heating of the LED element 103, but the heat generated in each LED element 103 passes through the substrate 101. Then, it quickly conducts (moves) to the bottom 201a of each heat pipe 201. When the heat moves to the bottom 201a of each heat pipe 201, the working fluid in each heat pipe 201 absorbs the heat and evaporates, and the vapor of the working fluid moves through the cavities in the pair of arm portions 201b. Therefore, the heat of the bottom part 201a moves to the pair of arm parts 201b. And the heat which moved to a pair of arm part 201b moves to the several radiation fin 203 further couple | bonded with a pair of arm part 201b, and is radiated | emitted from the radiation fin 203 in the air. When heat is radiated from each of the heat dissipating fins 203, the temperature of the pair of arm portions 201b also decreases, so that the vapor of the working fluid in the pair of arm portions 201b is cooled and returned to the liquid and moves to the bottom portion 201a. The hydraulic fluid that has moved to the bottom 201a is used to absorb heat that is newly conducted through the substrate 101.

  As described above, in the present embodiment, the operating fluid in each heat pipe 201 circulates between the bottom portion 201a and the pair of arm portions 201b, so that the heat generated in each LED element 103 is quickly radiated. So that heat is efficiently radiated from the radiating fins 203 into the air. For this reason, the temperature of the LED element 103 does not rise excessively, and the problem that the light emission efficiency significantly decreases does not occur.

  In addition, since the cooling capacity of the cooling device 200 is determined by the heat transport amount of the heat pipe 201 and the heat dissipation amount of the radiation fins 203, from the viewpoint of the cooling capacity, the number of the heat pipes 201 and the radiation fins 203 is larger. Is preferred. In addition, if a temperature difference occurs between the LED elements 103 arranged two-dimensionally on the substrate 101, variation in irradiation intensity due to temperature characteristics occurs. Therefore, from the viewpoint of irradiation intensity, the substrate 101 is arranged in the Y-axis direction. And cooling uniformly along the X-axis direction.

  Therefore, in the cooling device 200 of the present embodiment, the substrate 101 is arranged by arranging the bottom 201a of each heat pipe 201 so as to face the short direction of the substrate 101 (that is, extending along the Y-axis direction). Are uniformly cooled along the Y-axis direction, and a large number of heat pipes 201 are arranged along the longitudinal direction (that is, the X-axis direction). Further, by arranging the heat pipes 201 at equal intervals in the X-axis direction, the substrate 101 is uniformly cooled along the X-axis direction.

  As described above, according to the configuration of the present embodiment, there is little variation in the cooling capacity in the Y-axis direction and the X-axis direction, and the substrate 101 can be uniformly (uniformly) cooled and disposed on the substrate 101. The 200 LED elements 103 thus formed are also cooled uniformly. Therefore, there is no temperature difference between the LED elements 103, and there is no variation in irradiation intensity due to temperature characteristics.

  The above is the description of the present embodiment, but the present invention is not limited to the above configuration, and various modifications can be made within the scope of the technical idea of the present invention.

  For example, the cooling device 200 according to the present embodiment includes 15 heat pipes 201 arranged in a line at a predetermined interval along the X-axis direction, and 15 sheets joined to the pair of arm portions 201b of each heat pipe 201. However, the number of heat pipes 201 and heat radiating fins 203 is not limited to this. The number of radiating fins 203 is determined by the relationship between the amount of heat generated by the LED elements 103 and the temperature of the air around the radiating fins 203, and the heat generated by the LED elements 103 can be radiated according to the so-called fin area. It is selected appropriately. The number of heat pipes 201 is determined by the relationship between the heat generation amount of the LED elements 103, the heat transport amount of each heat pipe 201, and the like, and is appropriately selected so that the heat generated by the LED elements 103 can be sufficiently transported. Is done. However, when the number of the heat pipes 201 is increased, the interval between the arm portions 201b of the adjacent heat pipes 201 becomes narrow, the air flow in the Y-axis direction is hindered, and the cooling capacity is deteriorated. Therefore, when increasing the number of heat pipes 201, as shown in FIG. 5, a flat heat pipe 201 'thin in the X-axis direction (that is, flat in the Y-axis direction) is used. It is preferable to configure so that the interval does not become too narrow. In this case, the flatness of the heat pipe 201 '(that is, the short radius (radius in the X-axis direction) with respect to the long radius (radius in the Y-axis direction) is preferably 0.5 or less. It is more preferable that the bottom 201a of the heat pipe 201 ′ is configured not to be flat so that the contact area between the bottom 201a and the substrate 101 does not become small.

  Further, in the cooling device 200 of the present embodiment, the bottom 201a of each heat pipe 201 has been described as being fixed in a state of being in close contact with the back surface of the substrate 101 by a fixing tool or an adhesive (not shown). It is not limited to a simple configuration. For example, the cooling device 200 may include a metal base to which the bottom 201 a of each heat pipe 201 is bonded, and the base 200 may be fixed in a state of being in close contact with the back surface of the substrate 101. In addition, for example, the cooling device 200 includes five heat pipes 201, a base on which the bottom portions 201a of the five heat pipes 201 are joined, and a plurality of (for example, five heat pipes 201). 15) and by connecting four cooling devices 200 along the X-axis direction, a cooling device of the same size as the cooling device 200 of the present embodiment may be configured. it can. In this case, in order to uniformly cool the substrate 101 along the X-axis direction, the interval between the heat pipes 201 (that is, the 20 heat pipes 201 arranged in the X-axis direction) in the four cooling devices 200 connected. It is desirable that the intervals be equal to each other.

  Moreover, although the cooling apparatus 200 of this embodiment was demonstrated as what is naturally air-cooled, the fan and duct which supply cooling air to the cooling apparatus 200 are further provided, and the cooling apparatus 200 can also be forced-air-cooled.

  Moreover, although the LED element 103 of this embodiment was demonstrated as what radiate | emits an ultraviolet light with a wavelength of 385 nm, you may radiate | emit the ultraviolet light of another wavelength, and radiate | emit visible light and infrared light. The application of the light irradiation device 1 is not limited to a printing device that performs printing using UV ink.

  Further, in the heat pipe 201 of the present embodiment, the arm portion 201b has been described as protruding from the bottom portion 201a to the Z axis direction negative side, but the angle formed by the arm portion 201b and the bottom portion 201a is not necessarily 90 °. There is no need.

(Second Embodiment)
FIG. 6 is a right side view of the light irradiation apparatus 1A according to the second embodiment of the present invention. As shown in FIG. 6, in the light irradiation apparatus 1 </ b> A of this embodiment, each heat pipe 201 </ b> A has a substantially L-shaped shape, and a bottom 201 </ b> Aa that is in close contact with the back surface of the substrate 101, and bottoms 201 </ b> Aa to Z Each arm 201Ab of each heat pipe 201A is inserted into 20 through-holes 203Aa formed in each heat dissipating fin 203A and each heat dissipating. It differs from the heat pipe 201 of the light irradiation apparatus 1 of the first embodiment in that it is mechanically and thermally coupled to the fin 203A.

  Thus, in this embodiment, since each heat pipe 201A and each heat radiation fin 203A are coupled by a single arm portion 201Ab, the amount of heat transport from each heat pipe 201A to each heat radiation fin 203A is Although it becomes 1/2 compared with the structure of 1st Embodiment, if the heat dissipation of 203 A of radiation fins is sufficiently larger than the emitted-heat amount of LED element 103, each LED element will be carried out similarly to 1st Embodiment. The heat generated in 103 can be efficiently radiated into the air.

  In the heat pipe 201A of the present embodiment as well, as in the heat pipe 201 of the first embodiment, the arm portion 201Ab protrudes from the bottom portion 201Aa on the negative side in the Z-axis direction (that is, perpendicular to the bottom portion 201Aa). However, the present invention is not necessarily limited to such a configuration. For example, the arm part 201Ab may be provided to be inclined at a predetermined angle (for example, at 60 degrees) with respect to the bottom part 201Aa. In this case, each of the heat radiating fins 203A coupled to the arm portion 201Ab of each heat pipe 201A is also inclined with respect to the substrate 101. can get.

(Third embodiment)
FIG. 7 is a right side view of a light irradiation apparatus 1B according to the third embodiment of the present invention. As shown in FIG. 7, in the light irradiation apparatus 1 </ b> B of the present embodiment, each heat pipe 201 </ b> B has a substantially U-shaped shape, and the bottom 201 </ b> Ba is in close contact with the back surface of the substrate 101. The arm portion 201Bb protrudes to the negative side in the Z-axis direction and is further bent to the negative side in the Y-axis direction, and the tip portion of the arm portion 201Bb of each heat pipe 201B is formed in each radiating fin 203B. The heat pipe 201 of the first embodiment is different from the heat pipe 201 of the first embodiment in that it is inserted through the 20 through holes 203Ba and mechanically and thermally coupled to the heat radiating fins 203B.

  Also in this embodiment, since each heat pipe 201B and each heat radiation fin 203B are coupled by one arm portion 201Bb, similarly to the heat pipe 201A of the second embodiment, each heat pipe 201B to each heat radiation fin. The amount of heat transported to 203B is ½ that of the configuration of the first embodiment. However, if the heat dissipation amount of the heat dissipation fin 203B is sufficiently larger than the heat generation amount of the LED element 103, the first and As in the second embodiment, the heat generated in each LED element 103 can be efficiently radiated into the air.

(Fourth embodiment)
FIG. 8 is a rear view of the light irradiation apparatus 1C according to the fourth embodiment of the present invention, and FIG. 9 is a right side view of the light irradiation apparatus 1C. As shown in FIGS. 8 and 9, in the light irradiation apparatus 1 </ b> C of the present embodiment, two types of heat pipes 201 </ b> C <b> 1 and 201 </ b> C <b> 2 having different positions in the Y-axis direction are arranged in close contact with each other along the X-axis direction. It differs from the heat pipe 201 of the light irradiation apparatus 1 of 1st Embodiment by the point. In FIG. 8, for convenience of explanation, a part of the substrate 101 and the heat radiation fin 203 extending in the X-axis direction is omitted.

  Thus, when the two types of heat pipes 201C1 and 201C2 are arranged alternately, a space in the Y-axis direction is formed between the arm portion 201C1b of the adjacent heat pipe 201C1 and the arm portion 201C2b of the heat pipe 201C2. For this reason, even if many heat pipes 201C1 and 201C2 are arranged so as to be in close contact with each other in the X-axis direction, the air flow in the Y-axis direction is hardly obstructed. That is, according to such a configuration, more heat pipes 201C1 and 201C2 can be arranged in the X-axis direction than in the first embodiment, and the cooling capacity can be further improved. Become. In addition, it is set as the structure further provided with either the fan (not shown) which produces | generates an airflow in a X-axis direction with respect to the radiation fin 203, or the fan (not shown) which produces an airflow in a Y-axis direction, and further improves cooling capability. You can also. In the present embodiment, when viewed from the first direction, a region where the bottom 201C1a of the heat pipe 201C1 and the bottom 201C2a of the heat pipe 201C2 overlap and a region where they do not overlap are formed, but the bottom 201C1a of the heat pipe 201C1 is formed. In a region where the heat pipe 201C2 and the bottom 201C2a of the heat pipe 201C do not overlap, temperature unevenness occurs, so that the LED is located in a region where the bottom 201C1a of the heat pipe 201C1 and the bottom 201C2a of the heat pipe 201C2 overlap (that is, in the center of the substrate 101). It is preferable to dispose the element 103.

(Fifth embodiment)
FIG. 10 is a rear view of the light irradiation apparatus 1D according to the fifth embodiment of the present invention, and FIG. 11 is a right side view of the light irradiation apparatus 1D. As shown in FIGS. 10 and 11, the light irradiation apparatus 1D of the present embodiment has two types of heat pipes 201D1 and 201D2 having different positions in the Y-axis direction (that is, the lengths of the bottom portions 201D1a and 201D2a are different). It is different from the heat pipe 201A of the light irradiation apparatus 1A of the second embodiment in that it is alternately arranged along the X-axis direction. In FIG. 10, for convenience of explanation, a part of the substrate 101 and the heat radiation fins 203 extending in the X-axis direction is omitted.

  As described above, when the two types of heat pipes 201D1 and 201D2 are alternately arranged, a space is formed in the Y-axis direction between the arm portion 201D1b of the adjacent heat pipe 201D1 and the arm portion 201D2b of the heat pipe 201D2. For this reason, even if many heat pipes 201D1 and 201D2 are arranged so as to be in close contact with each other in the X-axis direction, the air flow in the Y-axis direction is hardly obstructed. That is, according to such a configuration, more heat pipes 201D1 and 201D2 can be arranged in the X-axis direction than in the second embodiment, and the cooling capacity can be further improved. Become. In addition, it is set as the structure further provided with either the fan (not shown) which produces | generates an airflow in a X-axis direction with respect to the radiation fin 203, or the fan (not shown) which produces an airflow in a Y-axis direction, and further improves cooling capability. You can also. In the present embodiment, when viewed from the first direction, a region where the bottom 201D1a of the heat pipe 201D1 and the bottom 201D2a of the heat pipe 201D2 overlap and a region where they do not overlap are formed, but the bottom 201D1a of the heat pipe 201D1 is formed. In the region where the heat pipe 201D2 and the bottom 201D2a of the heat pipe 201D do not overlap, temperature unevenness can occur, and therefore, in the region where the bottom 201D1a of the heat pipe 201D1 and the bottom 201D2a of the heat pipe 201D2 overlap (that is, the Y axis direction positive side of the substrate 101) It is more preferable to arrange the LED element 103 (on the right side of FIG. 11).

(Sixth embodiment)
FIG. 12 is a right side view of a light irradiation apparatus 1E according to the sixth embodiment of the present invention. As shown in FIG. 12, the light irradiation apparatus 1E of this embodiment reduces the width | variety of the Y-axis direction of the radiation fin 203 of the light irradiation apparatus 1D which concerns on 5th Embodiment, and, thereby, LED element in the empty space The LED driving circuit 401 for driving the 103 is arranged. The light irradiation device 1E also includes a case 501 that covers the heat pipes 201D1 and 201D2 and the heat radiation fins 203, and ends in the Z-axis direction of the case 501 (Z-axis direction with respect to the heat pipes 201D1 and 201D2 and the LED drive circuit 401). On the negative side, a fan 301 is provided.

  The fan 301 is a fan that takes in external air from an opening 501 a formed on the upper surface of the case 501 and exhausts the air in the case 501. When the fan 301 rotates, air currents in the Y-axis direction and the Z-axis direction are generated in the case 501 as indicated by the dotted arrows in FIG. 12, and the heat radiation fins 203 are cooled, and the LED driving circuit 401 is also cooled. . As described above, in the present embodiment, the LED drive circuit 401 is disposed in a space surrounded by the arm portions 201D1b and 201D2b and the bottom portions 201D1a and 201D2a (not shown) of the substantially L-shaped heat pipes 201D1 and 201D2. The heat radiation fin 203 and the LED drive circuit 401 are efficiently cooled while suppressing the dimension of the case 501 in the Y-axis direction. The light irradiation device 1E of the present embodiment is fixed at a predetermined position in the printing apparatus (not shown) by fixing and supporting the bottom surface 501b of the case 501 that does not affect the airflow.

(Seventh embodiment)
FIG. 13 is a right side view of the light irradiation apparatus 1F according to the seventh embodiment of the present invention. As illustrated in FIG. 13, the light irradiation device 1 </ b> F according to the present embodiment includes a fan 301 </ b> F instead of the LED drive circuit 401 of the light irradiation device 1 </ b> E according to the sixth embodiment.

  The fan 301F is a fan that takes in external air from an opening 501a formed on the upper surface of the case 501 and exhausts air in the case 501 from an opening 501c formed on the bottom surface 501b of the case 501. When the fan 301F rotates, an air flow in the Y-axis direction is generated in the case 501 as indicated by the dotted arrow in FIG. As described above, in the present embodiment, the fan 301F is disposed in the space surrounded by the arm portions 201D1b and 201D2b and the bottom portions 201D1a and 201D2a (not shown) of the substantially L-shaped heat pipes 201D1 and 201D2. The heat radiation fin 203 is efficiently cooled while suppressing the dimension of the Y axis direction of 501.

(Eighth embodiment)
FIG. 14 is a top view of the light irradiation apparatus 1G according to the eighth embodiment of the present invention, and FIG. 15 is a right side view of the light irradiation apparatus 1G. As shown in FIGS. 14 and 15, the light irradiation apparatus 1 </ b> G according to the present embodiment has two types of heat pipes 201 </ b> G <b> 1 and 201 </ b> G <b> 2 having different lengths in the Z-axis direction arranged in close contact with each other along the X-axis direction. This is different from the heat pipe 201B of the light irradiation apparatus 1B of the third embodiment. In FIG. 14, for convenience of explanation, a part of the substrate 101 and the radiation fins 203 </ b> B extending in the X-axis direction is omitted.

  As described above, when the two types of heat pipes 201G1 and 201G2 are arranged alternately, the distal end portion of the arm portion 201G1b of the adjacent heat pipe 201G1 (the portion to which the radiation fin 203B is attached) and the distal end portion of the arm portion 201G2b of the heat pipe 201G2 A space in the Z-axis direction is formed between the radiating fin 203B and the portion to which the radiating fin 203B is attached. For this reason, even if it arrange | positions so that many heat pipes 201G1 and 201G2 may be closely_contact | adhered to a X-axis direction, it will hardly inhibit the air flow of a Z-axis direction. That is, according to such a configuration, more heat pipes 201G1 and 201G2 can be arranged in the X-axis direction than in the third embodiment, and the cooling capacity can be further improved. Become. In addition, it is set as the structure further equipped with either the fan (not shown) which produces an airflow in a X-axis direction with respect to the radiation fin 203B, or the fan (not shown) which produces an airflow in a Z-axis direction, and further improves cooling capacity You can also.

(Ninth embodiment)
FIG. 16 is a right side view of the light irradiation apparatus 1H according to the ninth embodiment of the present invention. As shown in FIG. 16, the light irradiation apparatus 1H of the present embodiment includes arm portions 201G1b and 201G2b and bottom portions 201G1a and 201G2a (not shown) of the heat pipes 201G1 and 201G2 of the light irradiation apparatus 1G according to the eighth embodiment. A fan 301G is added in the space surrounded by.

  The fan 301G takes in external air, generates an airflow in the Z-axis direction, and cools the heat radiating fins 203B. As described above, in this embodiment, the fan 301G is disposed in a space surrounded by the arm portions 201G1b and 201G2b of the substantially U-shaped heat pipes 201G1 and 201G2 and the bottom portions 201G1a and 201G2a (not shown). Thus, the heat radiation fin 203B is efficiently cooled while suppressing the dimension of the light irradiation device 1H in the Y-axis direction.

(Tenth embodiment)
FIG. 17 is a right side view of the light irradiation apparatus 1J according to the tenth embodiment of the present invention. As shown in FIG. 17, the light irradiation apparatus 1J of this embodiment is obtained by adding a fan 301J to the outside of the heat pipes 201G1, 201G2 and the radiation fins 203B in the Z-axis direction of the light irradiation apparatus 1G according to the eighth embodiment. It is.

  The fan 301J takes in external air, generates an airflow in the Z-axis direction, and cools the heat radiation fin 203B. As described above, in this embodiment, by disposing the fan 301J outside the radiating fin 203B in the Z-axis direction, the radiating fin 203B is efficiently cooled while suppressing the dimension of the light irradiation device 1J in the Y-axis direction. Yes.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1J Light irradiation device 101 Substrate 103 LED element 200 Cooling device 201, 201 ′, 201A, 201B, 201C1, 201C2, 201D1, 201D2, 201G1, 201G2 Heat pipes 201a, 201Aa, 201Ba, 201D1a, 201D2a, 201G1a, 201G2a Bottom 201b, 201Ab, 201Bb, 201C1b, 201C2b, 201D1b, 201D2b, 201G1b, 201G2b Arm portions 203, 203A, 203B, 203A Through holes 203a, 203A Hole 301, 301F, 301G, 301J Fan 401 LED drive circuit 501 Case 501a, 501c Opening 501b Bottom

Claims (20)

A light irradiation apparatus that irradiates a line-shaped light having a predetermined line width in a second direction that extends in a first direction and is orthogonal to the first direction on an irradiation surface,
A substrate substantially parallel to the first direction and the second direction;
A plurality of light emitting elements arranged on the surface of the substrate at a first interval along the first direction and emitting the light in a third direction orthogonal to the surface of the substrate;
A cooling device that is provided in close contact with the back surface of the substrate and radiates heat generated in the plurality of light emitting elements into the air;
With
The cooling device is
A plurality of heat pipes arranged on the back surface of the substrate in a second interval along the first direction;
A plurality of plate-like heat radiating fins through which the plurality of heat pipes penetrate;
With
Each of the plurality of heat pipes includes a bottom portion extending in the second direction and thermally coupled to the substrate, and an arm projecting from the bottom portion in a predetermined direction and thermally coupled to each of the plurality of radiation fins. And a heat radiating device for transporting heat from the substrate to the plurality of radiating fins.   2. The light irradiation apparatus according to claim 1, wherein each of the plurality of heat pipes has a U-shape or an L-shape when viewed from the first direction.   The light irradiation apparatus according to claim 2, wherein each of the plurality of radiating fins is disposed substantially parallel to the substrate. The plurality of heat pipes includes a first heat pipe located at a first position in the second direction and a second heat pipe located at a second position in the second direction,
The light irradiation apparatus according to claim 2, wherein the first heat pipe and the second heat pipe are alternately arranged along the first direction.   The light irradiation apparatus according to claim 4, wherein the first heat pipe and the second heat pipe are arranged so as to be in close contact with each other in the first direction.   The light irradiation apparatus according to any one of claims 2 to 5, further comprising a fan that generates an air flow in the first direction or the second direction with respect to the heat radiation fin. Each of the plurality of heat pipes has an L-shape when viewed from the first direction,
The light irradiation device includes a drive circuit that is disposed in a space surrounded by the L-shape and drives the plurality of light emitting elements.
The fan is disposed on the opposite side in the third direction of the drive circuit and the plurality of heat pipes, and generates an air flow in the second direction so as to cool the drive circuit and the heat radiating fins. The light irradiation apparatus according to claim 6. Each of the plurality of heat pipes has an L-shape when viewed from the first direction,
The light irradiation apparatus according to claim 6, wherein the fan is disposed in a space surrounded by the L-shape and generates an air flow in the second direction so as to cool the radiation fin.   2. The light irradiation apparatus according to claim 1, wherein each of the plurality of heat pipes has a U-shape when viewed from the first direction.   The distal end portion of the arm portion is bent so as to be substantially parallel to the bottom portion, and each of the plurality of radiating fins is disposed at the distal end portion of the arm portion so as to be substantially perpendicular to the substrate. The light irradiation apparatus according to claim 9. The plurality of heat pipes includes a first heat pipe and a second heat pipe having different lengths in the third direction,
The light irradiation apparatus according to claim 9 or 10, wherein the first heat pipe and the second heat pipe are alternately arranged along the first direction.   The light irradiation apparatus according to claim 11, wherein the first heat pipe and the second heat pipe are disposed so as to be in close contact with each other in the first direction.   The light irradiation apparatus according to any one of claims 9 to 12, further comprising a fan that generates an air flow in the first direction or the third direction with respect to the heat radiation fin.   The light irradiation device according to claim 13, wherein the fan is disposed in a space surrounded by the U-shape, and generates an air flow in the third direction so as to cool the radiation fin. .   The light irradiation according to claim 13, wherein the fan is disposed on the opposite side of the plurality of heat pipes in the third direction, and generates an air flow in the third direction so as to cool the radiation fins. apparatus.   Each of these heat pipes is flat in the said 2nd direction, The light irradiation apparatus as described in any one of Claims 1-15 characterized by the above-mentioned.   The light irradiation apparatus according to any one of claims 1 to 16, wherein an angle formed by the arm portion and the bottom portion is approximately 90 °.   The said light irradiation apparatus is provided with the said several cooling device connected along the said 1st direction, The light irradiation apparatus as described in any one of Claims 1-17 characterized by the above-mentioned.   The light emitting device according to any one of claims 1 to 18, wherein the light emitting element emits light having a wavelength acting on an ultraviolet curable resin.   The light emitting device according to any one of claims 1 to 19, wherein the light emitting element is an LED (Light Emitting Diode).

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