Light irradiation device

Abstract

The present application provides a light irradiation device that can impart directivity to outgoing light and efficiently irradiate. The present application provides a light irradiation device that irradiates light to a movable irradiation target, and includes a substrate, a plurality of light emitting components arranged in n (n is an integer of 2 or more) x m columns (m is an integer of 2 or more) on the substrate, a cover glass that transmits light emitted from the plurality of light emitting components, a support portion that supports the cover glass having an opening portion through which light passes, and a pair of first mirrors disposed between the substrate and the cover glass and guiding light. The distance between the light emitting components in the first column closest to the upstream side and the light emitting components in the mth column closest to the downstream side is a, the interval of the pair of first mirrors is b, the height of the pair of first mirrors is h, the distance from the substrate to the support portion is d, and the width of the opening portion in the first direction is w. The following formulas (1) and (2) are satisfied: h≦(a+b) / 2√3…(1); and w≧d·2√3‑a…(2).

Description

TECHNICAL FIELD

[0001] The present application relates to a light irradiation device that irradiates light to an irradiation target being conveyed in one direction. BACKGROUND

[0002] In the past, there has been known a printing device that performs printing by using UV ink that is hardened by irradiation of ultraviolet light. Such a printing device is one that, after ejecting ink from a nozzle of a head toward a medium, irradiates ultraviolet light to an ink dot formed on the medium. By the irradiation of ultraviolet light, the ink dot is hardened and fixed to the medium, whereby even with respect to a medium that is difficult to absorb liquid, good printing can be performed.

[0003] In an ultraviolet light irradiation device for such a printing device, in recent years, in accordance with a demand for reduction of consumed power, long life, and miniaturization of the size of the device, instead of an existing discharge lamp, there has been practically provided one that utilizes an LED (Light Emitting Diode) module as a light source (for example, Patent Document 1).

[0004] [Prior Art Documents]

[0005] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent No. 5482537 SUMMARY

[0007] [Technical Problem]

[0008] The ultraviolet light irradiation device described in Patent Document 1 is one that adopts a configuration in which a light source unit having a plurality of ultraviolet light sources (ultraviolet LEDs) arranged in a direction orthogonal to a conveyance direction of an irradiation target and a pair of reflection members are provided, and the pair of reflection members are disposed between the light source unit and the irradiation target in such a manner as to sandwich the light source unit from the upstream side and the downstream side in the conveyance direction, and in which the pair of reflection members are used to guide and emit ultraviolet light emitted from the ultraviolet light sources so as to give the ultraviolet light directivity.

[0009] However, if the configuration of Patent Document 1 is adopted, since the reflection members have a certain reflectance, the light quantity (intensity) of the ultraviolet light is reduced each time the ultraviolet light is reflected by the reflection members, and in order to obtain a certain light quantity on the irradiation target (i.e., a light quantity that allows the UV ink to be surely hardened), the portion of the light quantity that is reduced must be supplemented, resulting in a necessity to increase the number of ultraviolet light LEDs. As a result, this leads to problems such as an increase in cost of the device, an increase in size of the device, an increase in consumed power, and the like. Therefore, there is currently a demand for a light irradiation device that can efficiently irradiate without increasing the number of LEDs.

[0010] The present application has been made in view of the above problems, and has an object to provide a light irradiation device that can impart directivity to outgoing light and irradiate with high efficiency.

[0011] [Technical Solution]

[0012] To achieve the above object, the light irradiation device of the present application is a light irradiation device that irradiates light to an irradiation target object that is relatively movable in a 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 components that are n in number along the second direction on the substrate and n is an integer of 2 or more, are arranged in m columns along the first direction and m is an integer of 2 or more, and are arranged so that the orientations of the optical axes are aligned in a third direction orthogonal to the first direction and the second direction; a cover glass that transmits light emitted from the plurality of light emitting components; a support portion that has an opening portion through which light transmitted through the cover glass passes and that supports the cover glass; and a pair of first mirrors that are arranged between the substrate and the cover glass so as to sandwich the light paths of the plurality of light emitting components in the first direction and that guide the light, wherein when viewed from the second direction, the distance from the light emitting components of the first column located closest to the upstream side of the first direction to the light emitting components of the mth column located closest to the downstream side of the first direction is set to a, the interval of the pair of first mirrors is set to b, the height of the pair of first mirrors in the third direction is set to h, the distance from the substrate to the support portion is set to d, and the width of the opening portion in the first direction is set to w, the following expressions (1) and (2) are satisfied.

[0013] h≦(a+b) / 2√3…(1);

[0014] w≧d·2√3-a…(2).

[0015] With this configuration, light rays (ultraviolet light) that are strong in intensity and have a divergence angle of 60° or less reach the irradiation target object P by being reflected once by the first reflecting surfaces 108a, 109a or not being reflected at all, so that the light rays are hardly affected (i.e., the amount of light is hardly reduced) by the reflection of the first reflecting surfaces 108a, 109a. Thus, the outgoing light can be imparted directivity and irradiated with high efficiency by the first reflecting surfaces 108a, 109a.

[0016] Further, a second mirror that extends toward the upstream side of the first direction from the tip portion of the first mirror located on the upstream side of the first direction so as to face the cover glass and reflects light reflected by the irradiation target object toward the irradiation target object can be provided. Also, at this time, it is preferable that the second mirror be integrally formed with the first mirror located on the upstream side of the first direction.

[0017] Further, a third reflector can be provided which extends from the tip portion of the first reflector on the downstream side of the first direction, toward the downstream side of the first direction in a manner facing the cover glass, and reflects light reflected by the irradiation target toward the irradiation target. In this case, it is preferable that the third reflector be integrally formed with the first reflector on the downstream side of the first direction.

[0018] Further, it is preferable that a housing which accommodates the substrate, the plurality of light emitting elements, and the pair of first reflectors, and the support portion and the cover glass constitute a part of the housing.

[0019] Further, it is preferable that the light be light in the ultraviolet wavelength region. In this case, it is possible to have a configuration in which the irradiation target has a sheet shape and the light in the ultraviolet wavelength region hardens the ink applied to the surface of the irradiation target.

[0020] [Effects of Invention]

[0021] As described above, according to the present application, it is possible to realize a light irradiation device which can impart directivity to the emitted light and efficiently irradiate. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a perspective view for explaining the configuration of the light irradiation device of the first embodiment of the present application.

[0023] Figure 2 is Figure 1 is a cross-sectional view taken along line A-A of (b).

[0024] Figure 3 is a schematic view for explaining the configuration of the light source unit provided in the light irradiation device of the first embodiment of the present application.

[0025] Figure 4 is a mode diagram for explaining the configuration of the light irradiation device of the first embodiment of the present application.

[0026] Figure 5 is a simulation result diagram for explaining the effect of the light irradiation device of the first embodiment of the present application.

[0027] Figure 6 is a mode diagram for explaining the configuration of the light irradiation device of the first embodiment of the present application. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the present application will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions will be denoted by the same reference numerals, and will not be repeatedly described.

[0029] (First Embodiment)

[0030] Figure 1 and Figure 2is a view showing the configuration of a light irradiation device 1 of a first embodiment of the present application, Figure 1 (a) is a perspective view, Figure 1 (b) is a front view. Furthermore, Figure 2 Figure 1 (b) is a cross-sectional view taken along line A-A thereof. As shown in Figure 1 and Figure 2 The light irradiation device 1 of the present embodiment is a light source device that hardens ultraviolet-curable ink or ultraviolet-curable resin, and is arranged above an irradiation target P (for example, a sheet-shaped recording medium or the like) that is conveyed in one direction, to emit linear ultraviolet light toward the irradiation target P. For convenience of explanation, Figure 1 In the actual printing device or the like, a plurality of recording heads that apply different color inks are arranged in the conveyance direction of the irradiation target P, and the light irradiation device 1 is arranged in a narrow space on the downstream side of each recording head. Furthermore, in the present specification, the conveyance direction of the irradiation target P is defined as the X-axis direction (first direction), the arrangement direction of the LED (Light Emitting Diode) assembly 217 described later is defined as the Y-axis direction (second direction), and the direction in which the LED assembly 217 emits ultraviolet light is defined as the Z-axis direction (third direction). Furthermore, generally, ultraviolet light means light having a wavelength of 400 nm or less, but in the present specification, ultraviolet light means light having a wavelength (for example, a wavelength of 250 to 420 nm) that can harden ultraviolet-curable ink applied to the irradiation target P.

[0031] As shown in Figure 1 and Figure 2 The light irradiation device 1 of the present embodiment includes a housing 100 that accommodates a light source unit 200, a cooling fan 300, and the like.

[0032] The housing 100 is a box-shaped casing having the Y-axis direction as the long side, and includes a cover glass 105 made of glass that can emit ultraviolet light, on the front face (the face on the positive side of the Z-axis direction). Furthermore, a pair of mirror units 108, 109 (mirror units) are arranged at intervals in the X-axis direction between the light source unit 200 and the cover glass 105, and the front face of the cover glass 105, and the edge portion of the cover glass 105 are provided with a support plate 107 (support portion) that is supported from the positive side of the Z-axis direction. Figure 2 Figure 1 (b), Figure 2 ​​The support plate 107 has a rectangular opening 107a (opening portion) in its central portion, so that ultraviolet light passing through the cover glass 105 passes through the opening 107a and irradiates the object P to be irradiated. Therefore, in this embodiment, the cover glass 105 and the support plate 107 are arranged to cover the front side of the housing 100, and the cover glass 105 and the support plate 107 constitute part of the housing 100.

[0033] Furthermore, an exhaust port 101 for exhausting air from inside the housing 100 is formed on the left side (the negative side in the X-axis direction) of the housing 100, and four air intake ports 103 for supplying air into the housing 100 are formed on the back side (the negative side in the Z-axis direction) of the housing 100, with a cooling fan 300 disposed corresponding to each air intake port 103. Figure 1 (a) Figure 2 The light irradiation device 1 is electrically connected to a power supply device (not shown in the figure), thereby supplying power from the power supply device to the internal light source unit 200, cooling fan 300, etc.

[0034] Figure 3 This is a diagram illustrating the structure of the light source unit 200 in this embodiment. Figure 3 (a) is a front view (viewed from the side along the Z-axis). Figure 3 (b) is a side view (viewed from the negative side along the X-axis). For example... Figure 3 As shown, 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 guided by a pair of reflector units 108 and 109, and shines on the object P (see reference) through the cover glass 105 and opening 107a at the front of the housing 100. Figure 2 (dashed arrow)

[0035] The LED module 210 includes a rectangular plate-shaped substrate 215 defined by the X-axis and Y-axis directions, and a plurality of LED components 217 having the same characteristics, and is fixed on the end face (the positive end face in the Z-axis direction) of the substrate 222 of the heat sink 220.

[0036] The substrate 215 of each LED module 210 is a rectangular flat cable substrate formed of a material with high thermal conductivity (e.g., aluminum nitride), such as... Figure 3 As shown in (a), its surface is mounted with 5 rows (X-axis direction) × 20 units (Y-axis direction) of LED components 217 using COB (Chip On Board). Furthermore, in this embodiment, the LED component 217 is located in the LED mounting area S (slightly centrally located in the X-axis direction of the substrate 215). Figure 3 Within the area enclosed by the dashed line in (a), they are arranged at certain intervals (e.g., 2 mm) in both the X and Y axes. Also, as...Figure 3 (b) shown, in the present specification, for the convenience of explanation, the LED assemblies 217 arranged in each column are sequentially called LED assemblies 217a, 217b, 217c, 217d, 217e along the X-axis direction.

[0037] An anode pattern (not shown in the figure) and a cathode pattern (not shown in the figure) for supplying electric power to each LED assembly 217 are formed on the substrate 215, and each LED assembly 217 is individually 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 in the figure) by a wiring cable (not shown in the figure), and a driving current supplied from the driving circuit can be supplied to each LED assembly 217 via the anode pattern and the cathode pattern. When the driving current is supplied to each LED assembly 217, each LED assembly 217 emits ultraviolet light (for example, wavelength 385 nm) in an amount corresponding to the driving current, and the LED module 210 emits linear ultraviolet light parallel to the Y-axis direction. As shown in Figure 3 (a), the configuration of the present 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. Also, each LED assembly 217 of the present embodiment is adjusted in such a manner that the driving current supplied to each LED assembly 217 can emit ultraviolet light in approximately the same light amount, and the linear ultraviolet light emitted from the four LED modules 210 has a light amount distribution that is approximately uniform in the X-axis direction and the Y-axis direction.

[0038] The heat sink 220 is arranged to be in close contact with the inside of the substrate 215 of the LED module 210, and dissipates heat generated by each LED module 210, and is also called a forced air cooling heat sink. The heat sink 220 is made of a material with good thermal conductivity such as aluminum or copper, and has a thin plate-shaped substrate 222 extending in the Y-axis direction, and a plurality of heat dissipation fins 225 formed on the opposite side of the surface that is in contact with the substrate 215. Each heat dissipation fin 225 has a thin plate shape parallel to the X-Z plane, and is arranged at a predetermined interval in the Y-axis direction. In the present embodiment, the plurality of heat dissipation fins 225 are cooled uniformly by the cooling air generated by the cooling fan 300.

[0039] Driving current flows through each LED component 217. When ultraviolet light is emitted from each LED component 217, the temperature rises due to the self-heating of the LED component 217. The heat generated in each LED component 217 is rapidly conducted through the substrate 215 and substrate 222 to the heat dissipation fins 225, and then released from each heat dissipation fin 225 into the surrounding air. Furthermore, the air heated by the heat dissipation fins 225 is rapidly exhausted through the exhaust port 101 by the cooling air generated by the cooling fan 300. Therefore, in this embodiment, by using the heat sink 220 and the cooling fan 300 to cool each LED module 210 equally, the reduction in luminous efficiency caused by the temperature rise of the LED component 217 can be suppressed.

[0040] Furthermore, as described above, in this embodiment, a pair of reflector units 108 and 109, separated in the X-axis direction, are disposed between the light source unit 200 and the cover glass 105. Figure 2 A support plate 107 (support portion) is disposed on the front of the cover glass 105, supporting the edge of the cover glass 105 from the positive Z-axis direction. Figure 1 (b) Figure 2 ).

[0041] like Figure 2 As shown, the pair of reflector units 108 and 109 are metal plate-shaped components extending in the Y-axis direction, which enclose the light paths of the ultraviolet light emitted from the LED assembly 217 in the X-axis direction. When viewed from the Y-axis direction, each reflector unit 108 and 109 extends in the Z-axis direction at a slightly perpendicular angle from the cover glass 105, and is symmetrically arranged to enclose the light paths of the ultraviolet light emitted from the LED assembly 217. Furthermore, each reflector unit 108 and 109 has first reflective surfaces 108a and 109a facing each other in order to enclose the light paths of the ultraviolet light emitted from the LED assembly 217.

[0042] The ultraviolet light emitted from the LED component 217 is generally known to diverge at a predetermined divergence angle. The larger the angle component, the weaker the intensity of the ultraviolet light. In this embodiment, since the first reflective surfaces 108a and 109a are configured in a way that encloses the light paths of each ultraviolet light emitted from the LED component 217, ultraviolet light, including those with weak intensity and large angle components, can be guided by the first reflective surfaces 108a and 109a and then emitted through the cover glass 105.

[0043] However, when such a structure is adopted (that is, a structure that guides light through the first reflective surfaces 108a and 109a), since the first reflective surfaces 108a and 109a have a certain reflectivity (e.g., 90%), the amount of ultraviolet light reflected by the first reflective surfaces 108a and 109a will decrease each time. As a result, the amount of light irradiating the object P will decrease.

[0044] Here, the present embodiment is to solve the related problems, effectively obtain the ultraviolet light emitted from the LED assembly 217, and is configured to reflect or not reflect the light rays having a small angle component (e.g., light rays having a divergence angle of ≦ 60°) of the light rays emitted from the LED assembly 217 once by the first reflecting surfaces 108a, 109a and to reflect the light rays having a large angle component (e.g., light rays having a divergence angle of > 60°) more than once by the first reflecting surfaces 108a, 109a (details will be described later).

[0045] Hereinafter, the function of the first reflecting surfaces 108a, 109a of the pair of reflecting mirror units 108, 109 will be described in detail.

[0046] Figure 4 FIGS. 13A and 13B are diagrams illustrating the configuration of the LED module 210, the reflecting mirror units 108, 109, the cover glass 105, and the support plate 107 and the relationship between the light rays emitted from each LED assembly 217. Figure 4 (a) is a diagram illustrating the relationship between the light rays of the ultraviolet light having a small divergence angle (e.g., a divergence angle of ≦ 60°), Figure 4 (b) is a diagram illustrating the relationship between the light rays of the ultraviolet light having a large divergence angle (e.g., a divergence angle of > 60°). Figure 4 In (a), L60a is a light ray having a divergence angle of 60° emitted from the LED assembly 217a, L60c is a light ray having a divergence angle of 60° emitted from the LED assembly 217c, L60e is a light ray having a divergence angle of 60° emitted from the LED assembly 217e, and L0a is a light ray having a divergence angle of 0° emitted from the LED assembly 217a. In addition, Figure 4 In (b), L65a is a light ray having a divergence angle of 65° emitted from the LED assembly 217a, and L80e is a light ray having a divergence angle of 80° emitted from the LED assembly 217e. Also, Figure 4 In (a), Figure 4 In (b), the light rays of the ultraviolet light emitted from the LED assemblies 217b, 217d are omitted for convenience of explanation, but in fact, the LED assemblies 217b, 217d also emit the same light rays as the LED assemblies 217a, 217c, 217e. In addition, Figure 4 In (a), Figure 4 In (b), the shape of each LED assembly 217 is represented in a rectangular shape for convenience of explanation, but in fact, each LED assembly 217 is very thin in the Z-axis direction, and the light emitting point of each LED assembly 217 is substantially located on the surface of the substrate 215.

[0047] As Figure 4(a) As shown in the drawing, the configuration of the present embodiment is such that, when viewed in the Y-axis direction, the width (i.e., the distance between the LED mounting region S of the first column of LED assemblies 217a located closest to the upstream side (negative side in the X-axis direction) in the X-axis direction and the fifth column of LED assemblies 217e located closest to the downstream side (positive side in the X-axis direction) in the X-axis direction) is set to a, the interval of the first reflecting surfaces 108a, 109a is set to b, the height in the Z-axis direction of the first reflecting surfaces 108a, 109a is set to h, the distance from the substrate 215 to the support plate 107 is set to d, and the interval in the X-axis direction of the support plate 107 (i.e., the width in the X-axis direction of the opening 107a) is set to w, the following equations (1) and (2) are satisfied.

[0048] h ≦ (a + b) / 2√3... (1)

[0049] w ≧ d · 2√3 - a... (2)

[0050] Specifically, among the light rays of the ultraviolet light emitted from the LED assembly 217a, the light rays L60a of a divergence angle of 60° are reflected once by the first reflecting surface 108a and transmitted through the cover glass 105 and emitted, while not being incident on the first reflecting surface 109a (i.e., avoiding the tip of the first reflecting surface 109a) and transmitted through the cover glass 105 and emitted. Figure 4 (a)).

[0051] Further, among the light rays of the ultraviolet light emitted from the LED assembly 217c, the light rays L60c of a divergence angle of 60° are reflected once by the first reflecting surfaces 108a, 109a and transmitted through the cover glass 105 and emitted.

[0052] Further, among the light rays of the ultraviolet light emitted from the LED assembly 217e, the light rays L60e of a divergence angle of 60° are reflected once by the first reflecting surface 109a and transmitted through the cover glass 105 and emitted, while not being incident on the first reflecting surface 108a (i.e., avoiding the tip of the first reflecting surface 108a) and transmitted through the cover glass 105 and emitted.

[0053] Therefore, among the light rays of the ultraviolet light emitted from each of the LED assemblies 217, the light rays of a divergence angle smaller than 60° are also similarly reflected once by the first reflecting surfaces 108a, 109a or not reflected and transmitted through the cover glass 105 and emitted. Further, the light rays (light rays L60a, L60c, L60e, L0a) of a divergence angle of 60° or less are transmitted through the cover glass 105 and reach the irradiation target object P without passing through the opening 107a (i.e., without causing a flare due to the support plate 107).

[0054] On the other hand, among the light rays of the ultraviolet light emitted from the LED assembly 217, the light rays having a divergence angle larger than 60° (i.e., the light ray L65a having a divergence angle of 65° and the light ray L80e having a divergence angle of 80°) are reflected at least once or more by the first reflecting surfaces 108a and 109a and are emitted through the cover glass 105 Figure 4 (b)). Also, the light rays having a divergence angle larger than 60° (e.g., the light ray L65a) are transmitted through the cover glass 105 and reach the irradiation target object P without being halated by the support plate 107 (i.e., without passing through the opening 107a), and the other light rays (e.g., the light ray L80e) are not transmitted through the opening 107a (i.e., are halated by the support plate 107) but reach the irradiation target object P after being randomly reflected by the support plate 107 and the like.

[0055] Here, the distance from the center axis (light emission point) of the LED assembly 217a to the first reflecting surface 109a in the X-axis direction is represented by √3h based on the relationship with the light ray L60a, and the distance from the center axis (light emission point) of the LED assembly 217e to the first reflecting surface 108a in the X-axis direction is represented by √3h based on the relationship with the light ray L60e. Thus, the interval b of the first reflecting surfaces 108a and 109a is represented by:

[0056] b ≧ √3h + √3h - a

[0057] This is converted into the above equation (1).

[0058] Also, the distance from the center axis (light emission point) of the LED assembly 217a to one side end (end portion on the positive side in the X-axis direction) of the support plate 107 in the X-axis direction is represented by √3d based on the relationship with the light ray L60a, and similarly, the distance from the center axis (light emission point) of the LED assembly 217e to the other side end (end portion on the negative side in the X-axis direction) of the support plate 107 in the X-axis direction is represented by √3d based on the relationship with the light ray L60e. Thus, the interval w of the support plate 107 in the X-axis direction is represented by:

[0059] w ≧ √3d + √3d - a

[0060] This is converted into the above equation (2).

[0061] Thus, in the present embodiment, light rays (ultraviolet light) having a high intensity and a divergence angle of 60° or less are reflected once or not at all by the first reflecting surfaces 108a, 109a to reach the irradiation target object P, and thus the influence (i.e., reduction in the amount of light) due to reflection by the first reflecting surfaces 108a, 109a can be suppressed. Also, light rays (ultraviolet light) having a divergence angle greater than 60° are reflected at least once or more by the first reflecting surfaces 108a, 109a, but the intensity of light rays (ultraviolet light) having a divergence angle greater than 60° is weak, and thus the influence on the total amount of light irradiated onto the irradiation target object P is slight (i.e., the influence of the reduction in the amount of light is small).

[0062] Figure 5 is a simulation result diagram illustrating the effect of the light irradiation device 1 of the present embodiment, and the horizontal axis is the interval in the X-axis direction of the support plate 107 (i.e., the width in the X-axis direction of the opening 107a) w (mm). Also, the vertical axis is the cumulative amount of ultraviolet light irradiated from the light irradiation device 1, and the relative value is set such that the cumulative amount of light when w is 100 (mm) is 1.

[0063] As the simulation conditions, the width (i.e., the distance between the LED assembly 217a located in the first column closest to the upstream side (negative side) in the X-axis direction and the LED assembly 217e located in the fifth column closest to the downstream side (positive side) in the X-axis direction) a of the LED mounting region S in the X-axis direction was set to 10 (mm), the interval b of the first reflecting surfaces 108a, 109a was set to 15 (mm), the height h in the Z-axis direction of the first reflecting surfaces 108a, 109a was set to 5 (mm), the distance d from the substrate 215 to the support plate 107 was set to 8 (mm), and the cumulative amount of light was calculated by converting w (mm).

[0064] As a result, it was found that the cumulative amount of light was approximately 0.9 when w was approximately 17 (mm), and the cumulative amount of light did not decrease (i.e., the ultraviolet light irradiated from the light irradiation device 1 did not reach the irradiation target object P with halation due to the support plate 107) when w was 30 (mm) or more.

[0065] Here, the above simulation conditions were substituted into the above equation (1), and the following equation (1) was satisfied.

[0066] h≦(a+b) / 2√3…(1)

[0067] 5 (mm)≦(10 (mm) + 15 (mm)) / 2√3

[0068] 5 (mm)≦7.2 (mm)

[0069] Also, the above simulation conditions were substituted into the above equation (2), and the following equation (2) was satisfied.

[0070] w≧d·2√3-a…(2)

[0071] w ≧ 8 (mm) x 2√3 - 10 (mm)

[0072] w ≧ 17.8 (mm)

[0073] That is, the conditions of the above-described equations (1), (2) are slightly the same as the above-described simulation results, and it is known that the cumulative light quantity of the ultraviolet light irradiated from the light irradiation device 1 is hardly reduced (that is, the cumulative light quantity is 0.9 or more) when the above-described equations (1), (2) are satisfied.

[0074] The above is a description of the present embodiment, but the present application is not limited to the above-described configuration, and various modifications can be made within the scope of the technical idea of the present application.

[0075] For example, in the LED module 210 of the present embodiment, the LED assembly 217 is arranged in a manner of 5 columns (X-axis direction) x 20 (Y-axis direction), but the configuration is not limited to this, and the LED assembly 217 can be arranged as long as there are n (n is an integer of 2 or more) in the Y-axis direction and m columns (m is an integer of 2 or more) in the X-axis direction.

[0076] Further, the first reflection surfaces 108a, 109a of the present embodiment extend in the Z-axis direction in a manner of standing slightly vertically from the cover glass 105 and are symmetrically arranged in a manner of sandwiching the light paths of the respective ultraviolet lights emitted from the LED assembly 217, and the first reflection surfaces 108a, 109a are not necessarily parallel in the Z-axis direction, and for example, the first reflection surfaces 108a, 109a can be arranged in a manner of spreading in a figure of eight with respect to the Z-axis direction.

[0077] Further, the present embodiment is described based on the positions of the LED assembly 217, the first reflection surfaces 108a, 109a, and the support plate 107 satisfying the equations (1), (2), but the configuration is not necessarily limited to this, and for example, the configuration can satisfy the following equations (3), (4).

[0078] h ≦ (a + b) / 2√2 … (3)

[0079] w ≧ d x 2√2 - a … (4)

[0080] (Second Embodiment)

[0081] Figure 6 is a diagram illustrating the configuration of the light irradiation device 1A of the second embodiment of the present application. As Figure 6As shown, the light irradiation device 1A of this embodiment has an L-shaped XZ cross-section in the pair of reflector units 108 and 109, and includes a second reflector 108b extending in the negative X-axis direction from the tip of the first reflector surface 108a of the reflector unit 108 facing the cover glass 105, and a third reflector 109b extending in the positive X-axis direction from the tip of the first reflector surface 109a of the reflector unit 109 facing the cover glass 105. This is different from the light irradiation device 1 of the first embodiment.

[0082] like Figure 6 As shown, the second reflector 108b and the third reflector 109b are constructed by integrating the LED assembly 217 ( Figure 6 The ultraviolet light emitted by the LED component 217c and reflected by the irradiated object P is reflected back to the irradiated object P (see reference). Figure 6 (dashed arrow).

[0083] Therefore, according to the structure of this embodiment, the ultraviolet light that was not used to cure the ultraviolet-curable ink on the irradiated object P (that is, the ultraviolet light reflected by the irradiated object P) will irradiate the irradiated object P again, thereby improving the utilization efficiency of ultraviolet light.

[0084] again, Figure 6 Figure 6 In this example, only light reflected once by the second reflector 108b and the third reflector 109b is shown, but multiple reflections can occur depending on the angular component of the ultraviolet light. Furthermore, in order to enable multiple reflections, it is preferable that the width of the second reflector 108b and the third reflector 109b in the X-axis direction is as wide as possible. In this case, it is only necessary to make the width of the cover glass 105 in the X-axis direction wider, and at the same time make the spacing of the support plate 107 in the X-axis direction (that is, the width of the opening 107a in the X-axis direction) wider.

[0085] Furthermore, it is not necessary to install both the second reflector 108b and the third reflector 109b simultaneously; either one may be installed.

[0086] Furthermore, in this embodiment, the reflector units 108 and 109 are L-shaped in the XZ section. The first reflective surface 108a and the second reflective surface 108b are integrally formed, and the first reflective surface 109a and the third reflective surface 109b are integrally formed, but the structure is not limited to this. The first reflective surface 108a and the second reflective surface 108b, and the first reflective surface 109a and the third reflective surface 109b can also be different individuals.

[0087] Furthermore, it should be considered that all points in the disclosed embodiments are illustrative and not limiting. The scope of the invention is not limited to the foregoing description, but is defined by the claims and is intended to include all modifications within the same meaning and scope as the claims.

[0088] Reference signs:

[0089] 1: light irradiation device

[0090] 1A: light irradiation device

[0091] 100: housing

[0092] 101: exhaust port

[0093] 103: air intake port

[0094] 105: cover glass

[0095] 107: support plate

[0096] 107a: opening

[0097] 108: mirror unit

[0098] 108a: first reflecting surface

[0099] 108b: second mirror

[0100] 109: mirror unit

[0101] 109a: first reflecting surface

[0102] 109b: third mirror

[0103] 200: light source unit

[0104] 210: LED module

[0105] 215: substrate

[0106] 217: LED assembly

[0107] 217a, 217b, 217c, 217d, 217e: LED assembly

[0108] 220: heat sink

[0109] 222: substrate

[0110] 225: heat releasing fin

[0111] 300: cooling fan

Claims

1. A light irradiation device for irradiating an object that is relatively movable along a first direction, comprising: The substrate is defined by the first direction and a second direction perpendicular to the first direction; Multiple light-emitting components are arranged on the substrate, with n components along the second direction and n being an integer greater than 2, and m columns along the first direction and m being an integer greater than 2, and configured such that the orientation of the optical axis is aligned in a third direction perpendicular to the first direction and the second direction; The covering glass allows the light emitted by the plurality of light-emitting components to pass through; The support portion has an opening through which light passing through the cover glass passes, and is used to support the cover glass; as well as A pair of first reflectors are arranged between the substrate and the cover glass such that the light paths of the plurality of light-emitting components are sandwiched in the first direction, thereby guiding the light. When viewed from the second direction, the distance from the light-emitting component in the first column closest to the upstream side of the first direction to the light-emitting component in the mth column closest to the downstream side of the first direction is set as a, the interval between the pair of first reflectors is set as b, the height of the pair of first reflectors in the third direction is set as h, the distance from the substrate to the support is set as d, and the width of the opening in the first direction is set as w, then the following equations (1) and (2) are satisfied.

2. The light irradiation device according to claim 1 further includes a second reflector, the second reflector extending upstream of the first reflector located upstream of the first reflector in the first direction, facing the cover glass, to reflect the light reflected by the irradiated object back to the irradiated object.

3. The light irradiation device according to claim 2, wherein, The second reflector is integrally formed with the first reflector located upstream of the first reflector in the first direction.

4. The light irradiation device according to any one of claims 1 to 3, further comprising a third reflector, the third reflector extending downstream of the first reflector located downstream of the first reflector in the first direction in a manner opposite to the cover glass, to reflect the light reflected by the irradiated object back to the irradiated object.

5. The light irradiation device according to claim 4, wherein, The third reflector is integrally formed with the first reflector located downstream of the first direction.

6. The light irradiation device according to any one of claims 1 to 3, further comprising a housing that accommodates the substrate, the plurality of light-emitting components, and the pair of first reflectors, wherein the support portion and the cover glass constitute part of the housing.

7. The light irradiation device according to any one of claims 1 to 3, wherein, The light is light in the ultraviolet wavelength region.

8. The light irradiation device according to claim 7, wherein, The object being irradiated is sheet-like in shape, and the light in the ultraviolet wavelength region can harden the ink coated on the surface of the object being irradiated.

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