TW202210171A - light irradiation device - Google Patents

Abstract

A light irradiation device for irradiating, with light, an irradiation object that is capable of moving relative thereto, the light irradiation device comprising: a substrate; a plurality of light-emitting elements which are arranged on the substrate in an array of n-units (n is an integer of 2 or more) by m-rows (m is an integer of 2 or more); a cover glass which allows light from the respective light-emitting elements to pass therethrough; a support part which has an opening for light to pass therethrough and which supports the cover glass; and a pair of first reflective mirrors which are disposed between the substrate and the cover glass and which is for guiding light, wherein the formulae (1) and (2) are satisfied, where a represents the distance from a light-emitting element in the first row positioned on the most upstream side to a light-emitting element in the m-th row positioned on the most downstream side, b represents the interval between the pair of first reflective mirrors, h represents the height of the pair of first reflective mirrors, d represents the distance from the substrate to the support part, and w represents the width of the opening in a first direction. (1): h ≤ (a+b)/2√3, (2): w ≥ d. 2√3-a.

Description

light irradiation device

The present invention relates to a light irradiation device for irradiating light to an irradiation object conveyed in one direction.

Conventionally, there is known a printing apparatus that performs printing by using UV ink hardened by irradiation of ultraviolet light. In such a printing apparatus, after the ink is ejected from the nozzle of the head to the medium, the ink dots formed on the medium are irradiated with ultraviolet light. By irradiating with ultraviolet light, the ink dots are hardened and fixed to the medium, whereby better printing can be performed even on a medium that is difficult to absorb liquid.

In the ultraviolet light irradiation device used in such a printing device, in recent years, according to the demand for reduction in power consumption, long life, and miniaturization of the device size, instead of the conventional discharge lamp, an LED (Light Emitting Diode) element is used as a light source user (for example, Patent Document 1). [Prior Art Literature]

[Patent Document 1] Specification of Japanese Patent No. 5482537

The ultraviolet light irradiation device described in Patent Document 1 is provided with a light source unit and a pair of reflecting members, and uses a pair of reflecting members to guide and emit ultraviolet light emitted by the ultraviolet light source to make the ultraviolet light directional. The light source unit has a plurality of ultraviolet light sources (ultraviolet LEDs) arranged in a direction orthogonal to the conveying direction of the irradiation object; a pair of reflecting members is arranged between the light source unit and the irradiation object, and is It arrange|positions so that a light source unit may be sandwiched from the upstream side and the downstream side of a conveyance direction.

However, according to the configuration as in Patent Document 1, since the reflecting member has a predetermined reflectance, the light quantity (intensity) of the ultraviolet light decreases every time the ultraviolet light is reflected by the reflecting member, so that the predetermined light quantity is obtained on the irradiation object. (that is, the amount of light that actually hardens the UV ink), the portion where the amount of light is reduced has to be supplemented, so that the number of UV LEDs must be increased. Furthermore, as a result, problems such as an increase in cost of the device, an increase in size, and an increase in power consumption are caused. Therefore, there is currently a need for a light irradiation device that can emit light efficiently without increasing the number of LEDs.

In view of the above-mentioned problems, the present invention aims to provide a light irradiation device capable of imparting directivity to outgoing light and irradiating efficiently. [technical means]

In order to achieve the above-mentioned object, the light irradiation device of the present invention irradiates light to the irradiation object that is relatively movable along the first direction, and includes: a substrate defined by the first direction and a second direction orthogonal to the first direction A plurality of light-emitting elements are arranged along the second direction on the substrate, and n is an integer of 2 or more, and m rows are arranged along the first direction, and m is an integer of 2 or more, and are arranged so that the orientation of the optical axis Aligned in the third direction perpendicular to the first direction and the second direction; the cover glass allows the light emitted by the plurality of light-emitting elements to pass therethrough; the support part has an opening for passing the light passing through the cover glass, and is used for supporting the cover glass; and a pair of first reflectors, arranged between the substrate and the cover glass in such a way that the light paths of the plurality of light-emitting elements are sandwiched in the first direction, to guide light; from the second When viewed from one direction, the distance from the light-emitting element located in the 1st column closest to the upstream side in the first direction to the light-emitting element located in the m-th column closest to the downstream side in the first direction is set as a, and a pair of the first reflector When the interval is set as b, the height in the third direction of the pair of first mirrors is set as h, the distance from the substrate to the support portion is set as d, and the width of the opening in the first direction is set as w, the following formula ( 1) and (2); h≦(a+b)/2√3 ･･･(1); w≧d･2√3-a ･･･(2).

With such a configuration, the light rays (ultraviolet light) having a strong intensity and a divergence angle of 60° or less can reach the irradiation object P after being reflected once or not reflected by the first reflecting surfaces 108a and 109a. There is hardly any influence (that is, a decrease in the amount of light) due to the reflection of the first reflection surfaces 108a and 109a. Therefore, the directivity of the outgoing light can be imparted by the first reflection surfaces 108a and 109a, and the emitted light can be irradiated efficiently.

In addition, a second reflector may be provided that extends from the tip portion of the first reflector located on the upstream side in the first direction to the upstream side in the first direction so as to face the cover glass, and transmits the radiation to the upstream side in the first direction. The light reflected by the object is reflected toward the irradiated object. Furthermore, in this case, preferably, the second reflector is integrally formed with the first reflector located on the upstream side in the first direction.

In addition, a third reflector may be provided, and the third reflector may extend from the tip portion of the first reflector located on the downstream side in the first direction toward the downstream side in the first direction so as to face the cover glass, so as to irradiate the object. The light reflected by the object is reflected toward the irradiated object. Furthermore, at this time, preferably, the third reflector is integrally formed with the first reflector located on the downstream side in the first direction.

In addition, it is preferable to have a case that accommodates the substrate, a plurality of light-emitting elements, and a pair of first reflectors, and the support portion and the cover glass constitute a part of the case.

Further, the light is preferably light in the ultraviolet wavelength region. In this case, the object to be irradiated may have a sheet-like shape, and the light in the ultraviolet wavelength region may harden the ink applied on the surface of the object to be irradiated. [Inventive effect]

As described above, according to the present invention, it is possible to realize a light irradiation device capable of imparting directivity to outgoing light and irradiating efficiently.

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 equivalent part in a figure, and description is not repeated.

(first embodiment) 1 and 2 are diagrams showing the structure of a light irradiation device 1 according to a first embodiment of the present invention, in which FIG. 1( a ) is a perspective view and FIG. 1( b ) is a front view. In addition, FIG. 2 is a cross-sectional view taken along the line A-A of FIG. 1(b). As shown in FIG. 1 and FIG. 2 , the light irradiation device 1 of this embodiment is assembled to a printing device or the like, and a light source device for curing UV-curable ink or UV-curable resin is arranged on the irradiation object conveyed in one direction. Above P (for example, a sheet-shaped recording medium, etc.), a linear ultraviolet light is emitted with respect to the irradiation target P. 1(a) only shows the light irradiation device 1, but in an actual printing device or the like, a plurality of recording heads for applying different color inks are arranged in the conveying direction of the irradiation object P, and in the actual printing device, etc. The light irradiation device 1 is arranged in a narrow space on the downstream side of each recording head. In addition, in this specification, the conveying direction of the irradiation object P is defined as the X-axis direction (first direction), and the arrangement direction of the LED (Light Emitting Diode) elements 217 described later is defined as the Y-axis direction (second direction), The direction in which the LED element 217 emits ultraviolet light is defined as the Z-axis direction (third direction). In addition, in general, ultraviolet light refers to light with a wavelength of 400 nm or less, but in this specification, ultraviolet light refers to a wavelength (for example, a wavelength of 250 to 420 nm) that can cure the ultraviolet curable ink coated on the object P to be irradiated. of light.

As shown in FIGS. 1 and 2 , the light irradiation device 1 of the present embodiment includes a case 100 for accommodating a light source unit 200 , a cooling fan 300 , the light source unit 200 and the cooling fan 300 , and the like.

The casing 100 is a box-shaped case with a long side in the Y-axis direction, and includes a cover glass 105 made of glass that can emit ultraviolet light on the front surface (the surface on the positive side in the Z-axis direction). In addition, between the light source unit 200 and the cover glass 105, a pair of mirror units 108 and 109 ( FIG. 2 ) are arranged at intervals in the X-axis direction, and the front surface of the cover glass 105 and the edge of the cover glass 105 are arranged from the Z-axis. The support plate 107 (support part) supported by the normal direction side (FIG. 1(b), FIG. 2). The support plate 107 has a rectangular opening 107a (opening portion) in the center portion, so that the ultraviolet light transmitted through the cover glass 105 is irradiated on the irradiation target P through the opening 107a. Therefore, in this embodiment, the cover glass 105 and the support plate 107 are arranged to cover the front surface of the casing 100 , and the cover glass 105 and the support plate 107 constitute a part of the casing 100 .

In addition, an exhaust port 101 for exhausting the air in the case 100 is formed on the left side surface of the case 100 (the surface on the negative side in the X-axis direction), and the rear surface of the case 100 (the surface on the negative side in the Z-axis direction) is formed There are four air intake ports 103 for supplying air into the casing 100 , and a cooling fan 300 is arranged corresponding to each air intake port 103 ( FIG. 1( a ), FIG. 2 ). The light irradiation device 1 is electrically connected to a power supply device not shown in the figure, so that the electric power obtained by the power supply device is supplied to the light source unit 200 , the cooling fan 300 , and the like inside.

FIG. 3 is a diagram illustrating the structure of the light source unit 200 of the present embodiment. FIG. 3(a) is a front view (viewed from the positive side in the Z-axis direction), and FIG. 3(b) is a side view (viewed from the negative side of the X-axis direction). side view). As shown in FIG. 3 , the light source unit 200 includes four LED modules 210 arranged in the Y-axis direction, and a heat sink 220 . The ultraviolet light emitted from the LED modules 210 is radiated by the pair of reflecting mirror units 108 and 109 . The guided light passes through the cover glass 105 and the opening 107a on the front surface of the casing 100 and is irradiated on the irradiation target P (see the dotted arrow in FIG. 2 ).

The LED module 210 includes a rectangular plate-shaped substrate 215 defined by the X-axis direction and the Y-axis direction, and a plurality of LED elements 217 having the same characteristics, and is fixed to the end surface of the substrate 222 of the heat sink 220 (positive in the Z-axis direction). side end).

The substrate 215 of each LED module 210 is a rectangular wiring substrate formed of a material with high thermal conductivity (eg, aluminum nitride). As shown in FIG. 3(a), the surface of which is COB (Chip On Board) Five rows (X-axis direction)×20 (Y-axis direction) LED elements 217 are mounted. In addition, in this embodiment, the LED element 217 is attached to the LED mounting area S (the area enclosed by the dotted line in FIG. 3( a )) of the substrate 215 at the center of the X-axis direction, so that the LED element 217 is in the X-axis direction. The direction and the Y-axis direction are separated from each other by a predetermined distance (for example, 2 mm). Moreover, as shown in FIG.3(b), in this specification, for convenience of description, the LED element 217 arrange|positioned in each row is called LED element 217a, 217b, 217c, 217d, 217e in this order along the X-axis direction.

An anode pattern (not shown) and a cathode pattern (not shown) for supplying power to each LED element 217 are formed on the substrate 215, and each LED element 217 is soldered to the anode pattern and the cathode pattern and electrically connected. In addition, the substrate 215 is electrically connected to a driving circuit (not shown) through a flat cable (not shown), and the driving current supplied by the driving circuit can be supplied to each LED element 217 through the anode pattern and the cathode pattern. When the driving current is supplied to each LED element 217, each LED element 217 emits ultraviolet light (eg, wavelength 385 nm) corresponding to the light quantity of the driving current, and the LED module 210 emits linear ultraviolet light parallel to the Y-axis direction. As shown in FIG. 3( a ), the structure of this embodiment is that four LED modules 210 are arranged in the Y-axis direction, and the linear ultraviolet light from each LED module 210 is continuous in the Y-axis direction. In addition, each LED element 217 in this embodiment adjusts the driving current supplied to each LED element 217 in such a way that it can emit ultraviolet light of approximately the same amount of light, and the linear ultraviolet light emitted from the four LED modules 210, It has a slightly uniform light intensity distribution in the X-axis direction and the Y-axis direction.

The heat sink 220 is configured to be closely connected to the inside of the substrate 215 of the LED modules 210 to dissipate the heat generated by each LED module 210, which is also called an air-cooled heat sink. The heat sink 220 is made of a material with good thermal conductivity such as aluminum or copper, and includes: a thin plate-shaped substrate 222 extending in the Y-axis direction, and a plurality of heat dissipation surfaces formed on the surface facing the substrate 215 on the opposite side Fins 225. The shape of each heat radiation fin 225 is a thin plate shape parallel to the X-Z plane, and is provided at predetermined intervals in the Y-axis direction. In addition, in this embodiment, the plurality of radiating fins 225 are cooled equally by the cooling air generated by the cooling fan 300 .

The driving current flows in each LED element 217, and when the ultraviolet light is emitted from each LED element 217, the temperature rises due to the self-heating of the LED element 217, and the heat generated in the heat insulating substrate 215 and the substrate 222 of each LED element 217 is rapidly conducted to the heat dissipation The fins 225 further radiate heat from the heat radiating fins 225 to the surrounding air. In addition, the air heated by the heat radiating fins 225 is rapidly exhausted through the exhaust port 101 by the cooling air generated by the cooling fan 300 . In this way, in this embodiment, each LED module 210 is cooled equally by the heat sink 220 and the cooling fan 300 , so that the reduction of the luminous efficiency caused by the temperature rise of the LED element 217 can be suppressed.

Furthermore, as described above, in this embodiment, between the light source unit 200 and the cover glass 105, a pair of mirror units 108 and 109 ( FIG. 2 ) separated in the X-axis direction are arranged, and the front surface of the cover glass 105 is arranged with a pair of mirror units 108 and 109 ( FIG. 2 ). The support plate 107 (support part) which supports the edge part of the cover glass 105 from the Z-axis positive direction side (FIG. 1(b), FIG. 2).

As shown in FIG. 2 , a pair of mirror units 108 and 109 is a metal plate-shaped member extending in the Y-axis direction so as to sandwich the light paths of the respective ultraviolet lights emitted from the LED element 217 from the X-axis direction. . The mirror units 108 and 109 extend in the Z-axis direction so as to stand slightly perpendicular to the cover glass 105 when viewed from the Y-axis direction, and are symmetrically arranged so that the respective ultraviolet rays emitted from the LED elements 217 are arranged symmetrically. Path folder. Further, each of the mirror units 108 and 109 includes first reflection surfaces 108 a and 109 a facing each other so as to sandwich the optical path of each ultraviolet light emitted from the LED element 217 .

Generally speaking, the ultraviolet light emitted from the LED element 217 is known to diverge at a predetermined divergence angle. The larger the angle component, the weaker the ultraviolet light intensity. The first reflecting surfaces 108a and 109a are arranged in such a way that the light path of the ultraviolet light is enclosed, so that ultraviolet light with weak intensity and large angular component can be guided by the first reflecting surfaces 108a and 109a, and then pass through the cover glass 105 and shoot out. However, when such a configuration is adopted (that is, a configuration in which light is guided by the first reflecting surfaces 108a and 109a), since the first reflecting surfaces 108a and 109a have a predetermined reflectance (eg, 90%), the ultraviolet light is The amount of light reflected by the first reflecting surfaces 108a and 109a decreases, and as a result, the amount of light irradiated on the object P to be irradiated decreases. Here, in order to solve the related problems and effectively obtain the ultraviolet light emitted from the LED element 217 in this embodiment, the first reflecting surfaces 108a and 109a use the first reflecting surfaces 108a and 109a to convert the ultraviolet light emitted from the LED element 217 to light with a smaller angle component. (For example, the light with a divergence angle ≦ 60°) is reflected once or not reflected and emitted, and the first reflecting surface 108a, 109a is used for the light with a large angular component (for example, the divergence angle> 60° The light is reflected more than once. The structure of reflection and output (details will be described later).

Hereinafter, the function of the first reflecting surfaces 108a and 109a of the pair of mirror units 108 and 109 will be described in detail. FIG. 4 is a schematic diagram illustrating the arrangement of the LED module 210 , the mirror units 108 and 109 , the cover glass 105 , and the support plate 107 , and the relationship between these and the light rays emitted from each LED element 217 . Fig. 4(a) is a graph showing the relationship between ultraviolet rays with a small divergence angle (for example, divergence angle ≤ 60°), and Fig. 4(b) is a graph showing a relationship with ultraviolet light with a large divergence angle (for example, divergence angle>60°) °) Diagram of the relationship between the rays of UV light. In Fig. 4(a), L60a is the light with a divergence angle of 60° emitted from the LED element 217a, L60c is the light with a divergence angle of 60° emitted from the LED element 217c, and L60e is the light with a divergence angle of 60° emitted from the LED element 217e The light, L0a, is the light with a divergence angle of 0° emitted from the LED element 217a. In addition, in FIG. 4( b ), L65a is a light beam with a divergence angle of 65° emitted from the LED element 217a, and L80e is a light beam with a divergence angle of 80° emitted from the LED element 217e. 4( a ) and FIG. 4( b ), the ultraviolet rays emitted from the LED elements 217b and 217d are omitted for the convenience of description, but in fact, the LED elements 217b and 217d also have and the LED elements 217a and 217c , 217e the same light out. 4(a) and 4(b), for convenience of description, the shape of each LED element 217 is shown as a rectangle, but in reality each LED element 217 is very thin in the Z-axis direction, and each LED element 217 has a The light-emitting point is substantially located on the surface of the substrate 215 .

As shown in FIG. 4( a ), the present embodiment is configured such that, when viewed from the Y-axis direction, the width of the LED mounting region S in the X-axis direction (that is, the width of the LED mounting region S in the X-axis direction, that is, the position closest to the upstream side in the X-axis direction (the X-axis direction) The distance from the LED element 217a in the first column on the negative side) to the LED element 217e in the fifth column located closest to the downstream side in the X-axis direction (positive side in the X-axis direction) is set as a, and the distance between the first reflecting surfaces 108a and 109a is a. The interval is set as b, the height of the first reflection surfaces 108a and 109a in the Z-axis direction is set as h, the distance from the substrate 215 to the support plate 107 is set as d, and the distance in the X-axis direction of the support plate 107 (that is, the distance between the openings 107a is set as d). When the width in the X-axis direction is set to w, the following equations (1) and (2) are satisfied. h≦(a+b)/2√3 ･･･(1) w≧d･2√3-a ･･･(2)

Specifically, among the ultraviolet light rays emitted from the LED element 217a, the light rays L60a with a divergence angle of 60° are reflected once by the first reflecting surface 108a, pass through the cover glass 105 and exit, and at the same time, do not enter the first reflection surface 108a. The reflective surface 109a (ie, avoiding the tip of the first reflective surface 109a) passes through the cover glass 105 and exits (FIG. 4(a)). In addition, among the ultraviolet light rays emitted from the LED element 217c, the light rays L60c with a divergence angle of 60° are reflected once by the first reflecting surfaces 108a and 109a, pass through the cover glass 105 and exit. In addition, among the ultraviolet light rays emitted from the LED element 217e, the light rays L60e with a divergence angle of 60° are reflected once by the first reflecting surface 109a, pass through the cover glass 105 and exit, and at the same time, do not enter the first reflecting surface 108a (ie, avoid the tip of the first reflecting surface 108a) and cover the glass 105 and emit. Therefore, among the ultraviolet light rays emitted by each LED element 217, the light rays with a divergence angle smaller than 60° are also reflected once by the first reflecting surfaces 108a and 109a or not reflected, and then pass through the cover glass 105 and exit. In addition, light rays with a divergence angle of 60° or less (light rays L60a, L60c, L60e, L0a) pass through the cover glass 105, pass through the opening 107a (that is, do not cause halo by the support plate 107) and reach the irradiation object P superior.

On the other hand, among the light rays of the ultraviolet light emitted by the LED element 217, the light rays with a divergence angle larger than 60° (ie, the light rays L65a with a divergence angle of 65°, and the light rays L80e with a divergence angle of 80°) will be reflected by the first reflecting surface. 108a and 109a are reflected at least once or more, and are transmitted through the cover glass 105 and emitted ( FIG. 4( b )). In addition, a part of the light rays with a divergence angle larger than 60° (for example, the light rays L65a) pass through the opening 107a after passing through the cover glass 105 (that is, no halo is generated by the support plate 107) and reach the irradiation object P , other light (eg, light L80e ) will not pass through the opening 107a (ie, halo will be generated by the support plate 107 ), but will be randomly reflected by components such as the support plate 107 and then reach the irradiation object P.

Here, the positional relationship between the LED element 217, the first reflecting surfaces 108a, 109a, and the support plate 107 is discussed, and the distance from the central axis (light emitting point) of the LED element 217a to the X-axis direction of the first reflecting surface 109a is based on The relationship with the light L60a can be expressed as √3h, and the distance from the central axis (light-emitting point) of the LED element 217e to the X-axis direction of the first reflective surface 108a can be expressed as √3h based on the relationship with the light L60e, so that the first The interval b between the reflecting surfaces 108a and 109a can be expressed as: b≧√3h+√3h-a The above formula (1) is obtained by converting this. In addition, the distance in the X-axis direction from the central axis (light emitting point) of the LED element 217a to one side end of the support plate 107 (the end on the positive side in the X-axis direction) can be expressed as √3d based on the relationship with the light ray L60a, Similarly, the distance in the X-axis direction from the central axis (light-emitting point) of the LED element 217e to the other end of the support plate 107 (the end on the negative side in the X-axis direction) can be expressed as √ based on the relationship with the light ray L60e 3d, the interval w between the X-axis direction of the support plate 107 can be expressed as: w≧√3d+√3d-a The above formula (2) is obtained by converting this.

In this way, in the present embodiment, since the light (ultraviolet light) with strong intensity and a divergence angle of 60° or less is reflected once or not reflected by the first reflecting surfaces 108a and 109a and reaches the irradiation object P, it can be The influence (that is, the reduction of the amount of light) due to the reflection of the first reflection surfaces 108a and 109a is suppressed. In addition, the light rays (ultraviolet light) with a divergence angle larger than 60° are reflected at least once by the first reflecting surfaces 108a and 109a, but the intensity of the light rays (ultraviolet light) with a divergence angle larger than 60° is weak, so The influence on the total amount of light irradiated onto the irradiation object P is relatively small (that is, the influence of the decrease in the amount of light is relatively small).

5 is a simulation result diagram illustrating the effect of the light irradiation device 1 of this embodiment. The horizontal axis is the interval (ie, the width of the opening 107a in the X-axis direction) w (mm) of the support plate 107 in the X-axis direction. In addition, the vertical axis represents the cumulative light quantity of the ultraviolet light irradiated from the light irradiation device 1, and is a relative value which takes the cumulative light quantity when w is 100 (mm) as 1. In terms of the simulation conditions, the width of the LED mounting region S in the X-axis direction (that is, the LED element 217a located in the first row closest to the upstream side in the X-axis direction (the negative side in the X-axis direction) to the position closest to the X-axis direction The distance (a) of the LED elements 217e in the fifth column on the downstream side (positive side in the X-axis direction) is set to 10 (mm), the distance b between the first reflecting surfaces 108a and 109a is set to 15 (mm), and the first reflecting surface The height h in the Z-axis direction of 108a and 109a is set to 5 (mm), the distance d from the substrate 215 to the support plate 107 is set to 8 (mm), and the accumulated light amount is obtained by converting to w (mm). As a result, it can be seen that when w is about 17 (mm), the cumulative light intensity is about 0.9, and when w is 30 (mm) or more, the cumulative light intensity does not decrease (that is, the ultraviolet light irradiated from the light irradiation device 1 does not suffer from support. The plate 107 reaches the irradiation object P with a halo.

Here, when the above-mentioned simulation conditions are substituted into the above-mentioned formula (1), the formula (1) is satisfied as follows. h≦(a+b)/2√3 ･･･(1) 5(mm)≦(10(mm)+15(mm))/2√3 5(mm)≦7.2(mm)

In addition, the simulation conditions are substituted into the above-mentioned formula (2), as follows. w≧d･2√3-a ･･･(2) w≧8(mm)×2√3-10(mm) w≧17.8(mm)

That is, the conditions of the above equations (1) and (2) are almost the same as the above simulation results, and it can be seen that when the above equations (1) and (2) are satisfied, the cumulative light intensity of the ultraviolet light irradiated from the light irradiation device 1 hardly decreases. (That is, the cumulative light amount is 0.9 or more).

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

For example, in the LED module 210 of this embodiment, the LED elements 217 are arranged in a state of 5 rows (X-axis direction)×20 (Y-axis direction), but it is not limited to such a configuration. The LED elements 217 It is sufficient that there are n (n is an integer of 2 or more) along the Y-axis direction, and m columns (m is an integer of 2 or more) are arranged along the X-axis direction.

In addition, the first reflecting surfaces 108a and 109a of this embodiment extend from the cover glass 105 to the Z-axis direction in a manner of standing slightly vertically, and are symmetrical in a manner of sandwiching the light paths of the ultraviolet light emitted from the LED element 217 In the arrangement, the first reflecting surfaces 108a and 109a do not necessarily have to be parallel in the Z-axis direction. For example, the first reflecting surfaces 108a and 109a may be spread out in a figure-eight shape with respect to the Z-axis direction.

In addition, the present embodiment is described based on the positional relationship between the LED element 217 , the first reflecting surfaces 108 a , 109 a , and the support plate 107 satisfying equations (1) and (2), but the structure is not necessarily limited. In order to satisfy the following formulas (3) and (4), the structure is obtained. h≦(a+b)/2√2 ･･･(3) w≧d･2√2-a ･･･(4)

(Second Embodiment) FIG. 6 is a diagram illustrating the configuration of a light irradiation apparatus 1A according to a second embodiment of the present invention. As shown in FIG. 6 , the light irradiation device 1A of the present embodiment has an L-shape in the X-Z cross section of the pair of mirror units 108 and 109 , and has a tip portion extending from the first reflection surface 108 a of the mirror unit 108 The second mirror 108b extending to the negative side in the X-axis direction so as to face the cover glass 105, and the tip portion of the first reflection surface 109a of the mirror unit 109 extending to the positive side of the X-axis direction facing the cover glass 105 The viewpoint of the third reflecting mirror 109b is different from that of the light irradiation device 1 of the first embodiment.

As shown in FIG. 6 , the second reflector 108b and the third reflector 109b are configured to direct the ultraviolet light emitted from the LED element 217 (the LED element 217c in FIG. 6 ) and reflected by the irradiation object P toward the irradiation object P is reflected again (see the dashed arrow in Figure 6). Thus, according to the configuration of the present embodiment, the ultraviolet light not used for curing the ultraviolet curable ink on the irradiation object P (that is, the ultraviolet light reflected by the irradiation object P) is irradiated to the irradiation object again. P, which can further improve the utilization efficiency of ultraviolet light.

6, only the second reflecting mirror 108b and the third reflecting mirror 109b reflect light only once, but it can be reflected multiple times depending on the angle component of the ultraviolet light. In addition, in order to be able to perform multiple reflections, the width of the second mirror 108b and the third mirror 109b in the X-axis direction is preferably as wide as possible. In this case, it is only necessary to make the cover glass 105 wider in the X-axis direction. The interval in the X-axis direction of the support plate 107 (that is, the width of the opening 107a in the X-axis direction) may be wider.

In addition, the second reflecting mirror 108b and the third reflecting mirror 109b need not be provided at the same time, and only one of them may be provided.

In addition, the mirror units 108 and 109 of this embodiment are L-shaped in the X-Z cross section, the first reflecting surface 108a and the second reflecting mirror 108b are integrally formed, the first reflecting surface 109a and the third reflecting mirror 109b are integrally formed, and the is not limited to such a constitution. The first reflecting surface 108a, the second reflecting mirror 108b, the first reflecting surface 109a and the third reflecting mirror 109b may also be different entities.

In addition, it should be understood that all points of the embodiments disclosed this time are examples and not limitations. The scope of the present invention is shown not by the above description but by the scope of claims, and is intended to include the meaning equivalent to the scope of claims and all modifications within the scope.

1: Light irradiation device 1A: Light irradiation device 100: Shell 101: exhaust port 103: Inhalation port 105: Cover glass 107: Support plate 107a: Opening 108: Mirror unit 108a: first reflecting surface 108b: Second reflector 109: Mirror unit 109a: first reflecting surface 109b: Third reflector 200: Light source unit 210: LED module 215: Substrate 217: LED Components 217a, 217b, 217c, 217d, 217e: LED elements 220: heat sink 222: Substrate 225: Exothermic Fins 300: cooling fan P: Object to be irradiated L0a, L60a, L60c, L60e, L65e, L80e: Light

1 is an external perspective view illustrating the configuration of a light irradiation device according to a first embodiment of the present invention. [Fig. 2] is a cross-sectional view taken along the line A-A in Fig. 1(b). 3 is a schematic diagram illustrating a configuration of a light source unit included in the light irradiation device according to the first embodiment of the present invention. 4 is a schematic diagram illustrating the configuration of the light irradiation device according to the first embodiment of the present invention. FIG. 5 is a simulation result diagram illustrating the effect of the light irradiation device according to the first embodiment of the present invention. 6 is a schematic diagram illustrating the configuration of the light irradiation device according to the first embodiment of the present invention.

1: Light irradiation device

105: Cover glass

107: Support plate

107a: Opening

108: Mirror unit

108a: first reflecting surface

109: Mirror unit

109a: first reflecting surface

215: Substrate

217a, 217b, 217c, 217d, 217e: LED elements

P: Object to be irradiated

L0a, L60a, L60c, L60e, L65e, L80e: Light

Claims (8)

A light irradiating device for irradiating light to an irradiating object relatively movable along a first direction, comprising: a substrate, defined by the first direction and a second direction orthogonal to the first direction; A plurality of light-emitting elements are arranged on the substrate along the second direction with n pieces, and n is an integer of 2 or more, and are arranged in m rows along the first direction, and m is an integer of 2 or more, and are arranged so that the optical axis is The orientation is aligned in a third direction orthogonal to the first direction and the second direction; cover glass, which can transmit the light emitted by the plurality of light-emitting elements; a support portion having an opening portion through which the light passing through the cover glass passes, and used to support the cover glass; and A pair of first reflecting mirrors are arranged between the substrate and the cover glass in such a manner that the light paths of the plurality of light-emitting elements are sandwiched in the first direction, and guide the light; When viewed from the second direction, set the distance from the light-emitting element located in the first row closest to the upstream side of the first direction to the light-emitting element located in the m-th row closest to the downstream side of the first direction as a, the one The interval of the pair of first mirrors is set as b, the height of the third direction of the pair of first mirrors is set as h, the distance from the substrate to the support portion is set as d, and the first mirror of the opening is set as d. When the width in one direction is set to w, the following equations (1) and (2) are satisfied; h≦(a+b)/2√3 ･･･(1); w≧d･2√3-a ･･･(2). The light irradiation device according to claim 1, further comprising a second reflecting mirror, the second reflecting mirror is formed from the tip of the first reflecting mirror located on the upstream side in the first direction to face the cover glass. In a manner, the light is extended toward the upstream side of the first direction, and the light reflected by the irradiation object is reflected toward the irradiation object. The light irradiation device according to claim 2, wherein the second reflecting mirror is integrally formed with the first reflecting mirror located on the upstream side of the first direction. The light irradiating device according to any one of claims 1 to 3, further comprising a third reflecting mirror, the third reflecting mirror being connected to the front end of the first reflecting mirror on the downstream side in the first direction to The cover glass is extended toward the downstream side in the first direction so that the cover glass is opposite, and the light reflected by the irradiation object is reflected toward the irradiation object. The light irradiation device according to claim 4, wherein the third reflecting mirror is integrally formed with the first reflecting mirror located on the downstream side of the first direction. The light irradiation device according to any one of Claims 1 to 5, further comprising a casing, the casing accommodating the substrate, the plurality of light-emitting elements, and the pair of first reflecting mirrors, and the supporting portion and The cover glass forms part of the housing. The light irradiation device according to any one of claims 1 to 6, wherein the light is light in an ultraviolet wavelength region. The light irradiation device according to claim 7, wherein the object to be irradiated has a sheet-like shape, and the light in the ultraviolet wavelength region can harden the ink applied on the surface of the object to be irradiated.

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