WO2014171317A1

WO2014171317A1 - Photoirradiation device

Info

Publication number: WO2014171317A1
Application number: PCT/JP2014/059461
Authority: WO
Inventors: Tsutomu Kishine (岸根努)
Original assignee: ＨｏｙａＣａｎｄｅｏＯｐｔｒｏｎｉｃｓ株式会社
Priority date: 2013-04-15
Filing date: 2014-03-31
Publication date: 2014-10-23
Also published as: CN105229368A; JP6360475B2; JPWO2014171317A1; KR20150132880A; KR101930041B1; TW201502424A; TWI620889B; CN105229368B

Abstract

A photoirradiation device for irradiating a prescribed irradiation position on an irradiation surface with line-shaped light extending in a first direction and having a prescribed line width in a second direction perpendicular to the first direction is equipped with an optical unit for irradiating the irradiation surface with line-shaped light parallel to the first direction, and having: N number (N is an integer of 2 or higher) of light-source modules arranged in the first direction on a substrate with a first interval interposed therebetween, and positioned in a manner such that the optical axes thereof are oriented in a prescribed direction; and N number of optical elements for guiding the light from each of the light-source modules to a prescribed optical path, and positioned along the optical path of each of the light-source modules. Therein: each of the light-source modules has a light-emitting part extending in a first direction; and each of the optical elements magnifies the light emitted from the light-emitting parts at a prescribed magnification factor in the first direction, and satisfies conditional expression (1), given that the first interval is a, the length of the light-emitting parts in the first direction is b, and the prescribed magnification factor is α. α×b≥a ... (1)

Description

Light irradiation device

The present invention relates to a light irradiation device that emits line-shaped irradiation light, and more particularly to a light irradiation device including a plurality of light source modules arranged in a line on a substrate.

Conventionally, as an ink for offset sheet-fed printing, an ultraviolet curable ink that is cured by irradiation with ultraviolet light has been used. Further, an ultraviolet curable resin is used as a sealant for FPD (Flat Panel Display) such as a liquid crystal panel and an organic EL (Electro Luminescence) panel. For curing such UV-curable inks and UV-curable resins, generally, an ultraviolet light irradiation device that irradiates ultraviolet light is used. However, particularly in offset sheet-fed printing and FPD applications, a wide irradiation region is irradiated. Therefore, a line light irradiation device that irradiates line-shaped irradiation light is used. Such a line light irradiation apparatus is described in Patent Document 1, for example.

The line light irradiation device described in Patent Document 1 includes a long substrate, a plurality of LEDs (Light Emitting Diode) arranged at equal intervals along the longitudinal direction of the substrate, and light from the plurality of LEDs. This is a so-called LED unit that includes a rod lens that collects light in the short direction of the substrate, and emits line light along the longitudinal direction of the substrate.

In addition, in order to cure UV curable ink and UV curable resin stably and reliably, high irradiation intensity of UV light is required. Therefore, it is high by using a plurality of LED units as described in Patent Document 1. A light irradiation apparatus that can irradiate ultraviolet light having an irradiation intensity is also in practical use (for example, Patent Document 2).

The light irradiation apparatus described in Patent Document 2 arranges a plurality of LED units radially (in an arc shape) with respect to an irradiation object, and superimposes line light emitted from each LED unit at a predetermined position on the irradiation object. By combining them, the irradiation object is irradiated with ultraviolet light having a high linear irradiation intensity.

JP 2012-186015 A JP 2010-287547 A

According to the light irradiation apparatus described in Patent Document 2, since it is possible to irradiate ultraviolet light having an irradiation intensity proportional to the number of LED units, if it is desired to obtain ultraviolet light having a high irradiation intensity, the number of LED units is simply set. You can increase it. However, there is a problem that the number of LED units that can be arranged radially is limited due to the physical size of the LED units. In order to solve such a problem, it is conceivable to dispose each LED unit away from the object to be irradiated. However, with such an arrangement, there arises a problem that the entire light irradiation device is enlarged.

Further, when a plurality of LED units are arranged in a radial manner as in the light irradiation device described in Patent Document 2, the incident angles of the line light emitted from the LED units to the irradiation object are different. When the incident angle increases (that is, when the incident light is obliquely incident on the irradiation object), the line width (thickness) of the line light on the irradiation object increases, and the irradiation intensity distribution in the line width direction also becomes gentle. Therefore, there is a problem that a desired irradiation intensity cannot be obtained. Such a problem becomes more prominent as the number of radially arranged LED units increases. Therefore, there is a demand for reducing the number of LED units to be used from this viewpoint.

The present invention has been made in view of such circumstances, and its object is to increase the number of LED units (optical units) without increasing the number (that is, without increasing the size of the device). It is an object of the present invention to provide a light irradiation device capable of emitting intense line-shaped light.

In order to achieve the above object, a light irradiation apparatus of the present invention is a line that extends in a first direction at a predetermined irradiation position on an irradiation surface and has a predetermined line width in a second direction orthogonal to the first direction. Light irradiation device for irradiating a shaped light, and N pieces (N) arranged on a substrate at a first interval along the first direction and arranged with the direction of the optical axis aligned in a predetermined direction. Is an integer of 2 or more) and N optical elements that are arranged on the optical path of each light source module and guide light from each light source module to a predetermined optical path. The light source module includes a light emitting unit extending along the first direction, and each optical element emits light emitted from the light emitting unit in the first direction. Is enlarged at a predetermined magnification, the first interval is a, and the length of the light emitting unit in the first direction is , The predetermined magnification when the alpha, and satisfies the following condition (1).
α × b ≧ a (1)

According to such a configuration, since the light emitted from each light source module is expanded in the first direction, a portion where the light emitted from the plurality of light source modules overlaps with each other at the irradiation position on the irradiation surface. For this reason, linear light having a high peak intensity is emitted from the optical unit.

Also, the light emitting unit can be configured to have at least one light emitting element that emits light.

Further, the light emitting unit can be configured to have M (M is an integer of 2 or more) light emitting elements arranged at a second interval along the first direction. In this case, the light emitting element is preferably an LED (Light Emitting Diode) having a substantially square light emitting surface.

Further, the first interval a, the length b of the light emitting portion in the first direction, and the predetermined magnification α can be configured to satisfy the following conditional expressions (2) and (3).
0.30 ≦ b / a ≦ 0.42 (2)
3.3 ≦ α (3)

Each optical element is emitted from the light emitting element in a third direction orthogonal to the direction of the optical axis and the first direction so that the light emitted from the light emitting element falls within a predetermined line width at the irradiation position. It can be configured to collect light.

Each optical element includes a first lens on which light from each light source module is incident and a second lens on which light transmitted through the first lens is incident. The first lens is a flat surface, a convex surface, or a concave surface. The second lens includes an incident surface formed with a cylindrical surface having a positive power in the third direction, a first direction and a third direction. It is desirable that the aspherical lens has an exit surface on which a toroidal surface having positive power in the direction is formed.

Each optical element includes a first lens on which light from each light source module is incident and a second lens on which light transmitted through the first lens is incident. The first lens is a flat surface, a convex surface, or a concave surface. The second lens has an incident surface formed as a plane, and a toroidal surface having positive power in the first direction and the third direction. An aspherical lens having a formed exit surface is desirable.

Each optical element includes a first lens on which light from each light source module is incident and a second lens on which light transmitted through the first lens is incident. The first lens is a flat surface, a convex surface, or a concave surface. The second lens is a spherical biconvex lens having an incident surface formed by a convex surface and an output surface formed by a convex surface. Is desirable.

Also, the second lens can be configured to have a rectangular outer shape when viewed from the optical axis direction. In this case, it is desirable that the second lens of each optical element is coupled along the first direction.

The light irradiation device includes a plurality of optical units, and the plurality of optical units are relative to the first optical unit in the first direction by a distance that is ½ of the first interval with respect to the first optical unit. The first optical unit and the second optical unit are symmetrical with respect to the perpendicular line at the irradiation position when viewed from the first direction. It can be set as the structure arrange | positioned alternately along the periphery centering on an irradiation position so that it may become line symmetrical as an axis | shaft. According to such a configuration, the light from the first optical unit and the second optical unit having different irradiation intensity distributions overlap at the irradiation position, so that the line-shaped light having a uniform and higher irradiation intensity as a whole can be obtained. can get.

As described above, according to the present invention, the light emitted from the plurality of light source modules arranged along the first direction overlaps in the first direction on the irradiation surface. Shaped light is emitted. For this reason, the light irradiation apparatus which can radiate | emit the linear light of high irradiation intensity is provided, without increasing the number of optical units (that is, without enlarging an apparatus).

It is an external view of the light irradiation apparatus which concerns on embodiment of this invention. It is an enlarged view explaining the structure and arrangement | positioning of the LED unit mounted in the light irradiation apparatus which concerns on embodiment of this invention. It is an enlarged view explaining the structure of the LED unit shown to Fig.2 (a). FIG. 4 is a cross-sectional view taken along line A-A ′ of FIG. 3. FIG. 4 is a cross-sectional view taken along the line B-B ′ of FIG. 3. It is the A section (dotted line frame) enlarged view of FIG. It is a figure explaining the structure of the LED element of the LED unit mounted in the light irradiation apparatus which concerns on embodiment of this invention. It is a figure which shows the irradiation intensity distribution of the Y-axis direction of the ultraviolet light radiate | emitted from the light irradiation apparatus of this embodiment. It is a figure which shows the irradiation intensity distribution of the X-axis direction of the ultraviolet light radiate | emitted from the light irradiation apparatus of this embodiment. It is a figure which shows the relationship between the length of the light emission surface of the LED die mounted in the light irradiation apparatus which concerns on embodiment of this invention, and the efficiency of the emitted ultraviolet light. It is a figure which shows the relationship between the length of the light emission surface of the LED die mounted in the light irradiation apparatus which concerns on embodiment of this invention, and the length of an effective irradiation area. It is a figure which shows the relationship between the length of the light emission surface of the LED die mounted in the light irradiation apparatus which concerns on embodiment of this invention, and the peak intensity of the emitted ultraviolet light. It is a figure which shows the relationship between the length of the light emission surface of the LED die mounted in the light irradiation apparatus which concerns on embodiment of this invention, and the uniformity of the irradiation intensity distribution of the emitted ultraviolet light.

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.

FIG. 1 is an external view of a light irradiation apparatus 1 according to an embodiment of the present invention. The light irradiation device 1 of this embodiment is mounted on a light source device that cures an ultraviolet curable ink used as an ink for offset sheet-fed printing or an ultraviolet curable resin used as a sealant in FPD (Flat Panel Display) or the like. As will be described later, the apparatus is disposed above the irradiation object, and emits linear ultraviolet light to the irradiation object (FIG. 2B). In this specification, the longitudinal (line length) direction of the linear ultraviolet light emitted from the light irradiation device 1 is the X-axis direction (first direction), and the short (line width) direction is the Y-axis direction (second direction). Direction), a direction orthogonal to the X axis and the Y axis (that is, a vertical direction) is defined as a Z axis direction. Fig.1 (a) is a front view of the light irradiation apparatus 1 when it sees from the Y-axis direction. FIG. 1B is a bottom view of the light irradiation apparatus 1 when viewed from the Z-axis direction (when viewed from the lower side to the upper side of FIG. 1A). FIG.1 (c) is a side view of the light irradiation apparatus 1 when it sees from the X-axis direction (when it sees from the right side of FIG. 1A to the left side).

As shown in FIG. 1, the light irradiation device 1 includes a case 10, a base block 20, and five LED units 100a to 100e. The case 10 is a case for housing the base block 20 and the LED units 100a to 100e. The LED units 100a to 100e are units that emit line-shaped ultraviolet light parallel to the X axis. In the present specification, the LED units 100a to 100e are collectively referred to as an “optical unit 100”.

The base block 20 is a support member for fixing the optical unit 100, and is formed of a metal such as stainless steel. As shown in FIGS. 1B and 1C, the base block 20 is a substantially rectangular plate-like member extending in the X-axis direction, and the lower surface is a partial cylindrical surface recessed along the Y-axis direction. Yes. LED units 100a to 100e extending in the X-axis direction are arranged side by side along the Y-axis direction (that is, along the partial cylindrical surface) on the lower surface (that is, the partial cylindrical surface) of the base block 20, and screwed It is fixed by soldering.

The lower surface of the case 10 (the lower surface of the light irradiation apparatus 1) has an opening 10a, and ultraviolet light from each of the LED units 100a to 100e is emitted toward the irradiation object through the opening 10a. It is configured.

FIG. 2 is an enlarged view for explaining the configuration and arrangement of the optical unit 100 mounted on the light irradiation apparatus 1 according to this embodiment. 2A is an enlarged view of FIG. 1B. For convenience of explanation, the base block 20 is omitted, and the optical unit 100 shown in FIG. 1B is rotated by 90 °. The partial cylindrical surface of the base block 20 is shown in a flat plane (that is, extended to the left and right). FIG. 2B is an enlarged cross-sectional view of FIG. 1C, and shows the arrangement of the LED units 100a to 100e when viewed from the X-axis direction.

In the light irradiation device 1 of the present embodiment, a position 100 mm away from the lower end of the case 10 (in the Z-axis direction) (that is, a position having a working distance of 100 mm (shown as “WD100” in FIG. 2B)). The XY plane in FIG. 5 is used as a reference irradiation surface R, and the irradiation object is configured to be conveyed from right to left along the Y-axis direction on the irradiation surface R by a conveying device (not shown). Then, as the irradiation object is sequentially conveyed from right to left on the irradiation surface R, the ultraviolet light emitted from the LED units 100a to 100e sequentially moves (scans) on the irradiation object, and the irradiation object The UV curable ink and UV curable resin are sequentially cured (fixed). In FIG. 2B, “F1” indicates a condensing position on the irradiation surface R where the ultraviolet light emitted from the LED units 100a to 100e is collected. In FIG. 2B, for the convenience of explanation, the perpendicular line of the irradiation surface R passing through the condensing position F1 is shown as the center line O of the optical path of the ultraviolet light emitted from the light irradiation device 1.

As shown in FIG. 2A, when the light irradiation device 1 according to the present embodiment is viewed from the Z-axis direction, the LED units 100a to 100e are arranged in order from the right side to the left side (that is, along the Y-axis). Is arranged. The

LED units

100a, 100c, and 100e are arranged offset from the

LED units

100b and 100d by a distance of P / 2 in the X-axis direction (that is, 1/2 of the arrangement interval P of the LED modules 110). (Details will be described later).

As shown in FIG. 2B, the LED units 100a to 100e of the present embodiment are arranged on a circular arc having a radius of 125 mm with the condensing position F1 as the center when viewed from the X-axis direction. They are arranged at an angular interval of 5 °. In the present embodiment, the LED unit 100c is arranged vertically above the condensing position F1 so that the optical axis of the LED unit 100c substantially coincides with the center line O, and the LED units 100a to 100e are arranged from the X-axis direction. When viewed, they are arranged in line symmetry with the center line O as the axis of symmetry. The ultraviolet light from each of the LED units 100a to 100e is emitted toward the condensing position F1 on the reference irradiation surface R, and the range of the line width LW centering on the condensing position F1 on the reference irradiation surface R. It is configured to irradiate. In the present embodiment, the line width LW of the ultraviolet light is set to about ± 20 mm with respect to the condensing position F1, and the line length LL (length in the X-axis direction) is set to about 100 mm. . In the present embodiment, the ultraviolet light from the five LED units 100a to 100e is superposed at the condensing position F1 in this way, so that the irradiation object is irradiated with the ultraviolet light with high irradiation intensity.

FIG. 3 is a diagram illustrating the configuration of the LED units 100a to 100e, and is an enlarged view of FIG. 2 (a). 4, FIG. 5 and FIG. 6 are diagrams for explaining the internal configuration of the LED units 100a to 100e shown in FIG. 3. FIG. 4 is a cross-sectional view taken along the line AA 'in FIG. FIG. 6 is a cross-sectional view taken along the line BB ′ of FIG. 3, and FIG. 6 is an enlarged view of a portion A (dotted line frame) of FIG. 4, 5, and 6, a part of the configuration is omitted for easy understanding of the drawings. 4, 5, and 6, the optical axis of the ultraviolet light emitted from the LED modules 110 of the LED units 100a to 100e is indicated by a one-dot chain line, and the optical path OP of the ultraviolet light is indicated by a solid line.

Note that the LED units 100a to 100e of the present embodiment differ only in the positions where they are arranged, and the internal configuration is the same. Therefore, the LED unit 100c will be described below as a representative.

As shown in FIGS. 2A and 3, the LED unit 100c includes a rectangular substrate 101 extending in the X-axis direction and ten LED modules 110. The ten LED modules 110 are densely arranged on the substrate 101 along the center line CL (FIG. 3) of the substrate 101 extending in the X-axis direction, and are electrically connected to the substrate 101. The substrate 101 of the LED unit 100c is connected to an LED drive circuit (not shown), and a drive current from the LED drive circuit is supplied to each LED module 110 via the substrate 101. When a driving current is supplied to each LED module 110, each LED module 110 emits ultraviolet light with a light amount corresponding to the driving current, and a linear ultraviolet light parallel to the X axis is emitted from the LED unit 100c. The As will be described later, each LED module 110 of the present embodiment includes an LED element 111 having four LED (Light Emitting Diode) dies 111a (FIG. 3), and substantially equal irradiation from each LED die 111a. The drive current supplied to each LED module 110 (that is, each LED die 111a) is adjusted so that ultraviolet light having an intensity distribution is emitted. The linear ultraviolet light emitted from the LED unit 100c has a predetermined irradiation intensity distribution in the X-axis direction on the irradiation surface R (details will be described later). As shown in FIGS. 2A and 3, the arrangement interval P of the LED modules 110 of this embodiment is equal to the size of a package 111p of the LED element 111 described later, and is about 14 mm in this embodiment. Is set.

As shown in FIGS. 3 to 6, the LED unit 100a includes an LED element 111 (light source module), a lens 113, and a lens 115 (optical element).

7A and 7B are diagrams for explaining the configuration of the LED element 111, FIG. 7A is a plan view, and FIG. 7B is a cross-sectional view taken along the line C-C ′ of FIG. As shown in FIG. 7, the LED element 111 of the present embodiment includes a bowl-shaped package 111p, and includes four LED dies 111a (light emitting elements) therein. The opening of the package 111p is sealed with a cover glass 111c. The LED die 111a is a semiconductor element that has a substantially square light emitting surface and emits ultraviolet light having a wavelength of 365 nm upon receiving a drive current from the LED drive circuit. In the present embodiment, each LED die 111a has a light emitting surface of 0.85 × 0.85 mm, and is 1.2 mm along the center line of the package 111p (that is, a center line parallel to a pair of opposing sides). They are arranged at intervals. Each LED element 111 is attached to the substrate 101 so that the LED dies 111a are arranged along the X-axis direction.

As shown in FIGS. 3 to 6, on the optical axis of each LED element 111, a lens 113 and a lens 115 held by a lens holder (not shown) are arranged. The lens 113 is formed by, for example, injection molding of a silicone resin, for example, a spherical plano-convex lens having a flat LED element 111 side, and condenses the ultraviolet light that is incident while diffusing from each LED die 111a, and the subsequent lens 115. To guide the light. The lens 115 is an aspherical lens formed by injection molding of, for example, silicone resin, and has an incident surface on which a cylindrical surface having power in the Y-axis direction is formed, and powers that are different in the Y-axis direction and the X-axis direction. And an exit surface on which a toroidal surface is formed. The ultraviolet light incident from the lens 113 is condensed in the Y-axis direction and enlarged at a predetermined magnification (for example, about 10 times) in the X-axis direction. For this reason, as shown in FIG. 4, when viewed from the X-axis direction, the ultraviolet light emitted from each LED element 111 (that is, each LED die 111a) passes through the lens 113 and the lens 115, and is in a condensing position F1. Condensed to Further, as shown in FIG. 5, when viewed from the Y-axis direction, the ultraviolet light emitted from each LED element 111 passes through the lens 113 and the lens 115, spreads in the X-axis direction, and is emitted from the other LED elements 111. The ultraviolet light and the irradiation surface R are configured to overlap each other. In the present embodiment, the lens 113 is a lens having a maximum diameter of φ13.5 mm in a direction orthogonal to the optical axis. The lens 115 is a lens having a rectangular cross section in a direction perpendicular to the optical axis. In this embodiment, the lens 115 of each LED unit 100a is connected in the X-axis direction, and is configured as one member. Yes. With such a configuration, ultraviolet light incident from each LED die 111a is efficiently guided onto the irradiation surface R (that is, without vignetting by the lens 113 and the lens 115).

As described above, in the present embodiment, the ultraviolet light emitted from each LED element 111 is configured to overlap each other in the X-axis direction on the irradiation surface R, so that ultraviolet light with high irradiation intensity (peak intensity) is generated. The LED units 100a to 100e are configured to emit light. That is, each LED unit 100a to 100e itself emits ultraviolet light having a peak intensity higher than that of a conventional LED unit (for example, one described in Patent Document 2). Further, the light irradiation device 1 of the present embodiment uses the five LED units 100a to 100e having such a configuration, and superimposes the ultraviolet light from the LED units 100a to 100e at the light condensing position F1, thereby further increasing the irradiation. Irradiate the object to be irradiated with intense ultraviolet light.

FIG. 8 is a diagram showing the irradiation intensity distribution in the Y-axis direction of the ultraviolet light emitted from the light irradiation apparatus 1 of the present embodiment, and the center position in the longitudinal direction of the light irradiation apparatus 1 (that is, the line length of the ultraviolet light). The irradiation intensity distribution in the Y-axis direction at LL (1/2 position of the length in the X-axis direction) is shown. FIG. 8A shows the irradiation intensity distribution of the ultraviolet light emitted from the LED units 100a to 100e, and FIG. 8B shows the total irradiation of the ultraviolet light emitted from the five LED units 100a to 100e. The intensity distribution is shown. As can be seen by comparing FIGS. 8A and 8B, the ultraviolet light from the five LED units 100a to 100e is overlapped at the condensing position F1, so that the condensing position F1 (in FIG. 8, “ In the case of “0 mm”, ultraviolet light that is five times the peak intensity of the ultraviolet light emitted from each LED unit 100a to 100e (peak intensity of about 8000 mW / cm ² ) is obtained.

FIG. 9 is a diagram showing an irradiation intensity distribution in the X-axis direction of the ultraviolet light emitted from the light irradiation apparatus 1 of the present embodiment, and the center position in the short direction of the light irradiation apparatus 1 (that is, the condensing position F1). ) Shows the irradiation intensity distribution in the X-axis direction. FIG. 9A shows the irradiation intensity distribution of the ultraviolet light emitted from each of the

LED units

100a, 100c, and 100e, and FIG. 9B shows the ultraviolet light emitted from each of the

LED units

100b and 100d. An irradiation intensity distribution is shown, and FIG. 9C shows a total irradiation intensity distribution of ultraviolet light emitted from the five LED units 100a to 100e. 9 (a) and 9 (b), for convenience of explanation, the irradiation intensity distribution of the ultraviolet light emitted from each LED element 111 of each LED unit 100a to 100e is shown by a solid line, and the LED unit The irradiation intensity distribution of the ultraviolet light emitted from the whole (that is, the total of ultraviolet light emitted from each LED element 111) is indicated by a dotted line.

As described above, the ultraviolet light emitted from each LED element 111 of the present embodiment is spread in the X-axis direction by the lens 113 and the lens 115 and is irradiated onto the irradiation surface R. Here, since the ultraviolet light emitted from each LED element 111 is nothing but the ultraviolet light emitted from the four LED dies 111a arranged at equal intervals along the X-axis direction, it is emitted from each LED element 111. The irradiation intensity distribution of the ultraviolet light in the X-axis direction is a discrete irradiation intensity distribution having four peaks. Then, the ultraviolet light having such a discrete irradiation intensity distribution is spread by the lens 113 and the lens 115 in the X-axis direction at a predetermined magnification and irradiated onto the irradiation surface R (FIG. 9A and FIG. 9). (A solid line part of Drawing 9 (b)). As a result, the ultraviolet light from the plurality of LED elements 111 overlaps in the X-axis direction on the irradiation surface R, and the longitudinal position of the light irradiation device 1 (that is, the line length LL of the ultraviolet light (the length in the X-axis direction). The irradiation intensity is increased within a predetermined range (in this embodiment, a range of about ± 35 mm) centered at a position that is a half of (b)) (dotted line portions in FIGS. 9A and 9B). ). Thus, in the present embodiment, ultraviolet light having a high peak intensity is obtained by superimposing ultraviolet light from the plurality of LED elements 111 arranged in the X-axis direction in the X-axis direction. In the present specification, a portion where the ultraviolet light overlaps and the peak intensity is high is referred to as an “effective irradiation area”, and in this embodiment, an irradiation object is arranged in this portion.

As shown in FIGS. 9 (a) and 9 (b), the irradiation intensity distribution of the ultraviolet light emitted from each LED unit 100a to 100e is comb-toothed in some places although the peak intensity is increased in the effective irradiation area. It becomes a thing fluctuate | varied in shape (that is, a non-uniform thing). This is because the density of the LED dies 111 a arranged in the X-axis direction is not constant, and there is a portion where the LED dies 111 a are not arranged between the LED elements 111. Therefore, in the present embodiment, the

LED units

100a, 100c, and 100 are compared with the

LED units

100b and 100d so that the irradiation intensity distribution of the ultraviolet light emitted from the entire light irradiation device 1 is substantially uniform. They are arranged offset in the axial direction by a distance of P / 2 (that is, 1/2 of the arrangement interval P of the LED modules 110). When the LED units 100a to 100e are arranged in this way, the portions where the irradiation intensity of the ultraviolet light emitted from the LED units 100a to 100e is lowered cancel each other on the irradiation surface R. For this reason, the ultraviolet light irradiation intensity distribution of the entire light irradiation apparatus 1 (that is, the total irradiation intensity distribution of ultraviolet light emitted from the five LED units 100a to 100e) is substantially uniform in the X-axis direction. In addition, the peak intensity is five times (about 8000 mW / cm ² ) the peak intensity of the ultraviolet light emitted from each of the LED units 100a to 100e.

As described above, in each of the LED units 100a to 100e of the present embodiment, a plurality (10) of LED elements 111 including a plurality (four) of LED dies 111a are arranged in the X-axis direction, and emitted from each LED element 111. The ultraviolet light having a high peak intensity is emitted by expanding the ultraviolet light in the X-axis direction. That is, high peak intensity ultraviolet light is emitted from the LED units 100a to 100e themselves. Further, by arranging the LED units 100a to 100e so that the ultraviolet light from the five LED units 100a to 100e is condensed at the condensing position F1 on the irradiation surface R, the peak intensity is further increased and uniform. Ultraviolet light having an irradiation intensity distribution is emitted. Therefore, according to the light irradiation apparatus 1 having such a configuration, it is possible to stably cure (fix) the ultraviolet curable ink or the ultraviolet curable resin on the irradiation object.

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

For example, although the light irradiation apparatus 1 of the present embodiment has been described as including five LED units 100a to 100e, as described above, ultraviolet light having a high peak intensity is emitted from each of the LED units 100a to 100e. Since it is comprised, what is necessary is just to adjust the number of LED units to be used according to the desired peak intensity, and the light irradiation apparatus 1 should just be provided with one or more LED units.

Further, the LED units 100a to 100e of the present embodiment have been described as including the ten LED modules 110. However, the ultraviolet light emitted from the LED modules 110 is configured to overlap even slightly on the irradiation surface R. If this is done, the peak intensity of the ultraviolet light can be increased, so that each of the LED units 100a to 100e may include at least two LED modules 110 in the X-axis direction.

In addition, the LED element 111 of the present embodiment has been described as including four LED dies 111a having a light emitting surface of 0.85 × 0.85 mm and arranged at intervals of 1.2 mm in the X-axis direction. The size, the number of LED dies 111a, and the distance between the LED dies 111a are not necessarily limited to such a configuration. In other words, when the ultraviolet light emitted from the LED element 111 is expanded in the X-axis direction, the ultraviolet light is configured to overlap with ultraviolet light from other LED elements 111 (for example, adjacent LED elements 111) as much as possible. Since the peak intensity of light can be increased, the LED element 111 may be any element that can emit ultraviolet light extending in the X-axis direction. For example, the LED element 111 may be replaced with one having a plurality of LED dies 111a. It is possible to apply one provided with one light emitting surface (that is, one LED die 111a). In this case, the size (length) of the light emitting surface is the length of the light emitting part constituted by the plurality of LED dies 111a of the present embodiment (that is, the X axis of the region where the plurality of LED dies 111a are arranged). The length of the lens 113 and the lens 115 to be used, the length of the effective irradiation area, the peak intensity of the desired ultraviolet light, the uniformity of the desired irradiation intensity distribution of the ultraviolet light, etc. Set as appropriate. However, in order for the ultraviolet light emitted from one LED element 111 to expand in the X-axis direction and overlap the ultraviolet light from the other LED elements 111, the distance between the LED elements 111 is a, and the X-axis direction of the light emitting surface Where b is the length of the lens and α is the magnification of the lens 113 and the lens 115 in the X-axis direction, the following conditional expression (1) is satisfied.
α × b ≧ a (1)

FIGS. 10 to 13 are graphs showing the results of simulation performed by the inventor in order to obtain the length of the light emitting surface (light emitting portion) of the LED die 111a. FIG. 10 shows the result of simulating the relationship between the length of the light emitting surface (light emission length) of the LED die 111a and the efficiency of the emitted ultraviolet light. Here, the efficiency of the emitted ultraviolet light refers to the efficiency of the ultraviolet light emitted from the LED die 111a. In this specification, (the amount of ultraviolet light on the irradiation surface R) / (the LED die 111a). The amount of ultraviolet light emitted from the light source). FIG. 11 shows the result of simulating the relationship between the length of the light emitting surface of the LED die 111a and the length of the effective irradiation area. FIG. 12 shows the result of simulating the relationship between the length of the light emitting surface of the LED die 111a and the peak intensity of the emitted ultraviolet light. FIG. 13 shows the result of simulating the relationship between the length of the light emitting surface of the LED die 111a and the uniformity of the irradiation intensity distribution of the emitted ultraviolet light. The uniformity of the irradiation intensity distribution of the emitted ultraviolet light refers to the variation in irradiation intensity within the effective irradiation area. In this specification, ((maximum intensity within the effective irradiation area)-(within the effective irradiation area) Minimum intensity)) / ((maximum intensity in effective irradiation area) + (minimum intensity in effective irradiation area)). In the simulations shown in FIGS. 10 to 13, the same lens 113 and lens 115 as those of the present embodiment are arranged on the optical path of the LED element 111, and the arrangement interval P of each LED module 110 (that is, the LED element 111) is set. Also, the simulation was performed assuming that the thickness is 14 mm, which is the same as that of the present embodiment.

As shown in FIG. 10, as the length of the light emitting surface (light emitting length) of the LED die 111a increases, the efficiency of the emitted ultraviolet light gradually decreases. This is because vignetting is generated by the lens 113 and the lens 115 due to an increase in the length of the light emitting surface of the LED die 111a (that is, a part of the ultraviolet light emitted from the light emitting surface is generated in the lens 113 and the lens 115). Because it will not be captured). Therefore, when the efficiency ≧ 75% is set as the target value, when the lens 113 and the lens 115 of the present embodiment are used, the length of the light emitting surface of the LED die 111a is preferably 5.8 mm or less.

As shown in FIG. 11, as the length of the light emitting surface (light emitting length) of the LED die 111a increases, the length of the effective irradiation area (effective irradiation area length) gradually decreases. This is because as the emission length increases, the peak intensity increases because the overlap of ultraviolet light increases at the center of the effective irradiation area length, but the irradiation intensity on both ends of the effective irradiation area length decreases relatively. It is. Therefore, when the effective irradiation area length ≧ 70 mm is a target value, the length of the light emitting surface of the LED die 111a is preferably 5.8 mm or less.

As shown in FIG. 12, the peak intensity of the emitted ultraviolet light gradually increases as the length of the light emitting surface (light emission length) of the LED die 111a increases. This is because the length of the ultraviolet light irradiated from each LED die 111a on the irradiation surface R is increased, and the length of the ultraviolet light superimposed in the X-axis direction is thereby increased. Therefore, when the peak value of ultraviolet light ≧ 600 mW is set as a target value, the length of the light emitting surface of the LED die 111a is preferably set to 4.2 mm or more.

As shown in FIG. 13, the uniformity of the emitted ultraviolet light changes according to the length (light emission length) of the light emitting surface of the LED die 111a. Therefore, when the uniformity of the irradiation intensity distribution of ultraviolet light ≦ 7% is set as a target value, the length of the light emitting surface of the LED die 111a is preferably set to 4.2 mm or more.

From the above simulation results, considering the efficiency of the ultraviolet light, the length of the effective irradiation area, the peak intensity of the ultraviolet light, and the uniformity of the irradiation intensity distribution of the ultraviolet light, the length (b) of the light emitting surface of the LED die 111a is It can be said that the thickness is preferably set in the range of 4.2 mm to 5.8 mm. Considering that the distance (a) between the LED elements 111 of this embodiment is 14 mm, the following conditional expression (2) is obtained from the conditional expression (1).
0.30 ≦ b / a ≦ 0.42 (2)
That is, it is understood that the length (b) of the light emitting surface of the LED die 111a is preferably set in the range of 0.30 to 0.42 with respect to the interval (a) of the LED elements 111.

Further, from the conditional expressions (1) and (2), the following conditional expressions (3) and (4) are obtained.
3.3 ≦ α (3)
2.3 ≦ α (4)
That is, when the distance (a) between the LED elements 111 and the length (b) of the light emitting surface of the LED die 111a satisfy the conditional expression (2), the ultraviolet light irradiated from each LED die 111a overlaps on the irradiation surface R. For this purpose, it can be seen that it is preferable to set the magnification (α) in the X-axis direction by the lens 113 and the lens 115 to 3.3 or more (that is, satisfy the conditional expression (3)).

In the present embodiment, the lens 115 of each LED unit 100a has been described as being connected in the X-axis direction. However, the lens 115 may be disposed independently of each LED unit 100a.

In the present embodiment, the lens 113 is a spherical plano-convex lens. However, the present invention is not limited to such a configuration. For example, a biconvex lens or an uneven lens can be applied.

In this embodiment, the lens 115 is an aspherical lens in which a cylindrical surface and a toroidal surface are formed. However, the present invention is not limited to such a configuration. For example, a flat surface and a toroidal surface are formed. It is also possible to apply aspherical lenses and spherical biconvex lenses.

In the present embodiment, the lens 113 and the lens 115 are formed of silicone resin. However, the lens 113 and the lens 115 are not limited to silicone resin, and other optical transparent resins and glass can be applied. It is.

It should be noted that the embodiments disclosed this time are examples in all respects and are 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.

Claims

A light irradiation apparatus that irradiates a line-shaped light that extends in a first direction and has a predetermined line width in a second direction orthogonal to the first direction at a predetermined irradiation position on an irradiation surface,
N light source modules (N is an integer of 2 or more) light source modules arranged on the substrate at a first interval along the first direction and arranged with the direction of the optical axis aligned in a predetermined direction; Linear light that is arranged on the optical path of each light source module and has N optical elements that guide light from each of the light source modules to a predetermined optical path, and is parallel to the first direction with respect to the irradiation surface An optical unit that emits light,
Each of the light source modules has a light emitting portion extending along the first direction,
Each of the optical elements expands the light emitted from the light emitting unit in the first direction at a predetermined magnification,
The light irradiation satisfying the following conditional expression (1), where a is the first interval, b is the length of the light emitting portion in the first direction, and α is the predetermined magnification: apparatus.
α × b ≧ a (1)
The light emitting device according to claim 1, wherein the light emitting unit includes at least one light emitting element that emits light.
3. The light according to claim 2, wherein the light emitting unit includes M (M is an integer of 2 or more) the light emitting elements arranged at a second interval along the first direction. Irradiation device.
The light emitting device according to claim 3, wherein the light emitting element is an LED (Light Emitting Diode) having a substantially square light emitting surface.
The first interval a, the length b of the light emitting unit in the first direction, and the predetermined magnification α satisfy the following conditional expressions (2) and (3): The light irradiation apparatus as described in any one of Claims 4.
0.30 ≦ b / a ≦ 0.42 (2)
3.3 ≦ α (3)
Each of the optical elements has the third direction orthogonal to the direction of the optical axis and the first direction so that the light emitted from the light emitting element falls within the predetermined line width at the irradiation position. The light irradiation apparatus according to claim 1, wherein the light emitted from the light emitting element is collected.
Each optical element includes a first lens on which light from each light source module is incident, and a second lens on which light transmitted through the first lens is incident,
The first lens has an incident surface formed of a flat surface, a convex surface or a concave surface, and an output surface formed of a convex surface.
The second lens includes an incident surface on which a cylindrical surface having positive power in the third direction is formed, and an exit surface on which toroidal surfaces having positive power in the first direction and the third direction are formed. The light irradiation device according to claim 6, wherein the light irradiation device is an aspherical lens.
Each optical element includes a first lens on which light from each light source module is incident, and a second lens on which light transmitted through the first lens is incident,
The first lens has an incident surface formed of a flat surface, a convex surface or a concave surface, and an output surface formed of a convex surface.
The second lens is an aspherical lens having an entrance surface formed in a plane and an exit surface on which a toroidal surface having positive power in the first direction and the third direction is formed. The light irradiation apparatus according to claim 6.
Each optical element includes a first lens on which light from each light source module is incident, and a second lens on which light transmitted through the first lens is incident,
The first lens has an incident surface formed of a flat surface, a convex surface or a concave surface, and an output surface formed of a convex surface.
The light irradiation apparatus according to claim 6, wherein the second lens is a spherical biconvex lens having an incident surface formed of a convex surface and an output surface formed of a convex surface.
The light irradiation apparatus according to any one of claims 7 to 9, wherein the second lens has a rectangular outer shape when viewed from the optical axis direction.
The light irradiation apparatus according to claim 10, wherein the second lens of each optical element is connected along the first direction.
The light irradiation device includes a plurality of the optical units,
The plurality of optical units include a first optical unit and a second optical unit that is relatively shifted from the first optical unit by a distance of ½ of the first interval in the first direction. Consisting of
When viewed from the first direction, the first optical unit and the second optical unit are configured such that the optical path of the light emitted from each optical unit is axisymmetric with respect to a perpendicular line at the irradiation position. The light irradiation device according to claim 1, wherein the light irradiation device is alternately arranged along a circumference centered on the irradiation position.