TWI537524B - Light irradiation device - Google Patents

Description

Light irradiation device

The present invention relates to a light irradiation device that illuminates linear irradiation light.

In the past, a printing machine that performs printing by transferring an ink that has been cured by irradiation of ultraviolet light to a printing object such as paper is known. Such a printing machine is provided with an ultraviolet light irradiation device in order to cure the ink on the printing object. Then, in such an ultraviolet light irradiation device, a structure in which an LED (Light Emitting Diode) is used as a light source instead of a conventional discharge lamp has been proposed in accordance with the demand for low power consumption and long life (for example, Patent Document 1).

The ultraviolet light irradiation device (LED unit) described in Patent Document 1 includes a plurality of bases that emit a linear light beam by arranging a plurality of LED modules (LED chips) at a predetermined interval in the longitudinal direction (first direction). Block. Each of the base blocks is inclined at a predetermined angle so that the linear light emitted from each of the base blocks is concentrated at a predetermined position on the printing object, and is interposed in the short-side direction (second direction). Configured at intervals.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2011-146646

According to the ultraviolet light irradiation device described in Patent Document 1, the irradiation intensity of the ultraviolet light can be increased at a predetermined position on the printing object, and the irradiation intensity distribution can be made uniform. However, in a printing machine (for example, a lithographic printing machine) equipped with an ultraviolet light irradiation device, there is a case where the printing target to be irradiated with ultraviolet light is a paper that is easily deformed, and many papers are wrinkled during transportation. situation. When the printing object is deformed, the linear light does not converge at a predetermined position on the printing object. Therefore, the desired irradiation intensity and the irradiation intensity distribution cannot be obtained on the printing object, and the dry state of the ink may not occur. Uniform problem.

The present invention has been made in view of such circumstances, and an object thereof is to provide a light irradiation device capable of irradiating a linear light having a predetermined irradiation intensity and an irradiation intensity distribution within a predetermined working distance.

In order to achieve the above object, the light irradiation device of the present invention has a linear line having a predetermined line width in a second direction orthogonal to the first direction, with respect to a predetermined irradiation position on the reference irradiation surface. Light illuminating device characterized by: having: a plurality of optical units, Each of the plurality of light sources disposed on the substrate at a predetermined interval along the first direction and aligned in the direction orthogonal to the substrate surface, and the light path disposed on each of the light sources The light rays from the respective light sources are a plurality of optical elements shaped to be slightly parallel light, and the plurality of optical units are a plurality of first optical units and a plurality of optical rays that emit linear rays parallel to the first direction from the reference irradiation surface. In the first optical unit, when the light is emitted from the first direction, the emitted light passes through a predetermined condensing position vertically above the irradiation position, and is arranged so that the reference irradiation surface converges within the line width. Each of the second optical units is disposed such that the emitted light converges within the line width on the reference irradiation surface when viewed from the first direction, and within a predetermined range including the condensed position from the irradiation position to the vertical direction. The sum of the energy of the light emitted from each of the first optical units and the energy of the light emitted from each of the second optical units is slightly constant.

According to this configuration, the ultraviolet light from the first optical unit is densely distributed around the condensing position, and the ultraviolet light from the second optical unit is in contact with the light from the first optical unit at a position away from the illuminating surface side of the condensing position. The way the ultraviolet light crosses is dense. Therefore, in a predetermined range (within a predetermined working distance) including the condensing position from the irradiation position to the vertical direction, a linear ray of a predetermined irradiation intensity can be obtained. Further, in a predetermined working distance, the sum of the energy of the light emitted from each of the first optical units and the energy of the light emitted from each of the second optical units is slightly constant, so that the irradiation intensity distribution of the light emitted from the light irradiation device is It is within a certain working distance and becomes slightly certain.

Also, the complex optical unit is viewed from the first direction When the vertical line of the irradiation position can be used as the axis of symmetry, it is arranged in line symmetry.

Further, the plurality of first optical units and the plurality of second optical units are preferably arranged alternately along the second direction when viewed from the first direction.

Further, each of the first optical units is arranged in line symmetry with the perpendicular line of the irradiation position as the symmetry axis when viewed from the first direction, and the second optical unit is the first optical unit when viewed from the first direction. The outer side of the unit, with the vertical line as the axis of symmetry, is preferably arranged as a pair of wires.

Further, each of the first optical units is disposed on an arc centered on the condensing position when viewed from the first direction, and each of the second optical units is disposed when viewed from the first direction. It is preferable that the irradiation position is centered on the arc.

Further, the number of the plurality of first optical units is equal to or larger than the number of the plurality of second optical units. In this case, the number of the first optical units is 4N (N is a natural number), and the number of the second optical units is 2N.

Further, 2N of the first optical units of the 4N first optical units are disposed in the other 2N first optical units by a distance of 1/2 of the predetermined interval in the first direction; and 2N second optical units are disposed. The N second optical units are preferably arranged such that the other N second optical units are shifted by a distance of 1/2 of the predetermined interval in the first direction. According to this configuration, the irradiation intensity distribution in the first direction of the light emitted from the light irradiation device is slightly uniform.

Further, the plurality of light sources are arranged on the substrate in two rows and arranged in a direction orthogonal to the first direction, and when viewed from the first direction, It is preferable that the optical axis emitted from one of the light sources and the light emitted from the other of the light sources intersect at the condensing position or the irradiation position so that the optical axis of each optical element deviates from the optical axis of each light source. In this case, it is preferable that the light source of one of the rows is disposed in the other direction only by a distance of 1/2 of the predetermined interval in the first direction. According to this configuration, the irradiation intensity distribution in the first direction of the light emitted from each of the first optical unit and each of the plurality of second optical units is slightly uniform.

Further, the plurality of light sources are surface-emitting LEDs having a light-emitting surface having a substantially square shape, and it is preferable that the diagonal line of one of the light-emitting surfaces is arranged parallel to the first direction.

As described above, according to the light irradiation device of the present invention, linear light having a predetermined irradiation intensity and irradiation intensity distribution can be irradiated within a predetermined working distance.

1,2,3,4,5‧‧‧Lighting device

10‧‧‧shell

10a‧‧‧ openings

20,20M‧‧‧Base Block

20Ma, 20Mb, 20Mc, 20Md, 20Me, 20Mf‧‧‧ Mounting inclined surface

100,100A‧‧‧1st LED unit

101‧‧‧Substrate

110,210‧‧‧LED modules

111‧‧‧LED components

113,115,215‧‧‧ lens

200,200A‧‧‧2nd LED unit

CL1, CL2‧‧‧ center line

VL1, VL2‧‧‧ vertical line

LL‧‧‧Line length

LW‧‧‧ line width

P‧‧‧ interval

F1, F2‧‧‧ spotlight position

R‧‧‧ illuminated surface

WD‧‧‧Working distance

O‧‧‧ center line

Fig. 1 is an external view of a light irradiation device according to a first embodiment of the present invention.

FIG. 2 is an enlarged view showing the structure and arrangement of the first LED unit and the second LED unit mounted in the light irradiation device according to the first embodiment of the present invention.

[Fig. 3] A first LED unit and a second LED unit shown in Fig. 2(a) will be described An enlarged view of the construction of 200.

Fig. 4 is a view for explaining an internal structure of a first LED unit and a second LED unit shown in Fig. 3 .

FIG. 5 is a light path diagram of ultraviolet light emitted from the first LED unit and the second LED unit mounted in the light irradiation device according to the first embodiment of the present invention.

[Fig. 6] Fig. 6 is a view showing an irradiation intensity distribution of ultraviolet light emitted from a first LED unit and a second LED unit mounted in the light irradiation device according to the first embodiment of the present invention.

[Fig. 7] Fig. 7 is a view showing an irradiation intensity distribution at a position of WD80 of ultraviolet light emitted from the light irradiation device according to the first embodiment of the present invention.

[Fig. 8] Fig. 8 is a view showing an irradiation intensity distribution at a position of WD90 of ultraviolet light emitted from the light irradiation device according to the first embodiment of the present invention.

[Fig. 9] Fig. 9 is a view showing an irradiation intensity distribution at a position of WD100 of ultraviolet light emitted from the light irradiation device according to the first embodiment of the present invention.

Fig. 10 is a view for explaining a light irradiation device according to a second embodiment of the present invention.

Fig. 11 is a view for explaining a light irradiation device according to a third embodiment of the present invention.

FIG. 12 is a view showing a structure of a first LED unit and a second LED unit included in the light irradiation device according to the fourth embodiment of the present invention.

FIG. 13 is a view illustrating a mounting structure of a first LED unit and a second LED unit included in the light irradiation device according to the fifth embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Incidentally, the same or corresponding portions in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

(First embodiment)

Fig. 1 is an external view of a light irradiation device 1 according to a first embodiment of the present invention. The light-emitting device 1 of the present embodiment is mounted on a printing machine (not shown) that performs printing by transferring an ink that has been cured by ultraviolet light to a printing target such as paper, and is disposed in the printing as will be described later. Above the object, linear ultraviolet light is emitted to the printing object (Fig. 2(b)). In the present specification, the long side (line length) direction of the linear ultraviolet light emitted from the light irradiation device 1 is defined as the X-axis direction (first direction), and the short side (line width) direction is defined as the Y-axis direction. (The second direction) will be described by defining the direction orthogonal to the X-axis and the Y-axis (that is, the vertical direction) as the Z-axis direction. Fig. 1(a) is a front view of the light irradiation device 1 as seen from the Y-axis direction. Fig. 1(b) is a bottom view of the light irradiation device 1 as seen from the Z-axis direction (when the upper side is viewed from the lower side of Fig. 1(a)). Fig. 1 (c) is a side view of the light irradiation device 1 when viewed from the X-axis direction (when the left side is viewed from the right side of Fig. 1 (a)).

As shown in FIG. 1, the light irradiation device 1 includes a casing 10, a base block 20, four first LED units 100 (first optical unit), and two second LED units 200 (second optical units). The casing 10 houses the casing (frame) of the base block 20, the first LED unit 100, and the second LED unit 200. Moreover, both the first LED unit 100 and the second LED unit 200 are A unit that emits linear ultraviolet light parallel to the X-axis (described in detail later).

The base block 20 is a fixing member for fixing the first LED unit 100 and the second LED unit 200, and is formed of a metal such as stainless steel. As shown in FIGS. 1(b) and 1(c), the base block 20 is a substantially rectangular plate-like member extending in the X-axis direction, and the lower surface is a recessed cylindrical surface along the Y-axis direction. On the lower surface of the base block 20 (that is, a partial cylindrical surface), the first LED unit 100 and the second LED unit 200 extending in the X-axis direction are arranged side by side along the Y-axis direction (that is, along a partial cylindrical surface). The configuration is fixed by screwing or welding.

The lower surface of the casing 10 (the lower surface of the light irradiation device 1) has an opening 10a through which the ultraviolet light from the first LED unit 100 and the second LED unit 200 is emitted toward the printing target.

FIG. 2 is an enlarged view showing the structure and arrangement of the first LED unit 100 and the second LED unit 200 mounted on the light irradiation device 1 according to the first embodiment of the present invention. 2(a) is an enlarged view of FIG. 1(b), for convenience of explanation, the base block 20 is omitted, and the first LED unit 100 and the second LED unit 200 shown in FIG. 1(b) are rotated by 90°, and A portion of the cylindrical surface of the abutment block 20 is unfolded (extended) for disclosure. 2(b) is an enlarged cross-sectional view of FIG. 1(c), showing the arrangement of the first LED unit 100 and the second LED unit 200 when viewed in the X-axis direction.

FIG. 3 is an enlarged view showing the structure of the first LED unit 100 and the second LED unit 200 shown in FIG. 2(a). 4 shows the internal structure of the first LED unit 100 and the second LED unit 200 shown in FIG. Figure 3 is a cross-sectional view taken along line A-A' of Figure 3. In addition, in the first LED unit 100 and the second LED unit 200 of the present embodiment, only the structure of the lens 115 (215) to be described later is different, and the other structures are common. Therefore, in FIG. 3 and FIG. 4, the same structure is provided. Symbols, the first LED unit 100 and the second LED unit 200 are disclosed using the same drawings.

2(a), as shown in FIG. 3, each of the first LED units 100 includes a rectangular substrate 101 extending in the X-axis direction and 20 LED modules 110. Further, similarly to the first LED unit 100, the second LED unit 200 includes a rectangular substrate 101 extending in the X-axis direction and 20 LED modules 210. In the LED module 110 of the first LED unit 100, the center line CL1 of the substrate 101 extending in the X-axis direction is densely arranged on the substrate 101 in two rows (Y-axis direction) × 10 (X-axis direction). The two-dimensional square lattice is electrically connected to the substrate 101. Further, the LED module 210 of the second LED unit 200 is arranged in a two-dimensional square lattice shape of two rows (Y-axis direction) × 10 (X-axis direction) in the center line CL2 of the substrate 101 extending in the X-axis direction. The substrate 101 is densely disposed on the substrate 101 and electrically connected to the substrate 101. The substrate 101 of the first LED unit 100 and the second LED unit 200 is connected to an LED drive circuit of a printer (not shown), and a drive current from the LED drive circuit is supplied to the LED modules 110 and 210 through the substrate 101. When the driving current is supplied to each of the LED modules 110 and 210, ultraviolet light corresponding to the amount of light of the driving current is emitted from each of the LED modules 110 and 210, and the lines parallel to the X-axis are emitted from the first LED unit 100 and the second LED unit 200, respectively. Shaped ultraviolet light. Furthermore, each of the LED modules 110 and 210 of the present embodiment emits slightly the same light. The amount of ultraviolet light is used to adjust the driving power supplied to each of the LED modules 110 and 210, and the linear ultraviolet light emitted from the first LED unit 100 and the second LED unit 200 has a slightly uniform illumination in the X-axis direction. Intensity distribution (detailed later). Further, as shown in FIGS. 2(a) and 3, the interval P between the LED modules 110 and 210 of the present embodiment is set to be about 12 mm.

As shown in FIGS. 3 and 4, each of the LED modules 110 of the first LED unit 100 includes an LED (Light Emitting Diode) element 111 (light source), a lens 113, and a lens 115 (optical element). Further, each of the LED modules 210 of the second LED unit 200 is the same as the LED module 110, and includes an LED element 111, a lens 113, and a lens 215. That is, the LED module 210 of the present embodiment is different from the LED module 110 in that it has a lens 215 different from the lens 115.

The LED element 111 includes a light-emitting surface having a substantially square shape, receives supply of a driving power source from the LED driving circuit, and emits ultraviolet light having a hardening wavelength (for example, 385 nm) of the ink. The LED element 111 is mounted on the substrate 101 such that the two diagonal lines of the light-emitting surface are inclined by 45° so as to face the X-axis direction and the Y-axis direction, respectively. Therefore, the LED elements 111 of the adjacent LED modules 110 (or 210) are arranged in such a manner that the respective sides of the light-emitting surface are oriented in the X-axis direction or the Y-axis direction (that is, not inclined at 45°). Adjacent to each other, the ultraviolet light from the adjacent LED modules 110 (or 210) is also emitted in a state close to each other.

On the optical axis of each of the LED elements 111 of the LED module 110, a lens 113 held by a lens holding portion (not shown) and a lens 113 are disposed. Mirror 115 (Fig. 4). The lens 113 is formed by injection molding of, for example, a decane resin, and the side of the LED element 111 is a plano-convex lens that condenses ultraviolet light incident on one side while diffusing from the LED element 111, and guides the light to the lens at the rear stage. 115. The lens 115 is formed by injection molding of, for example, a decane resin, and the lenticular lens having both the incident surface and the exit surface is convex, and the ultraviolet light incident from the lens 113 is formed into a substantially parallel light. Therefore, the lens 115 (i.e., each of the LED modules 110) emits slightly parallel ultraviolet light having a predetermined beam diameter. Further, the lens 113 and the lens 115 of the present embodiment are designed such that the beam diameter of the emitted ultraviolet light in the X-axis direction is about 18 mm (half width), and the beam diameter in the Y-axis direction is about 12 mm (half width).

As described above, the LED module 110 of the present embodiment is placed on the substrate 101 and is densely arranged in two rows (Y-axis direction) × 10 (X-axis directions) in a two-dimensional square lattice shape, and is adjacent to each of the LED modules. The ultraviolet light of the group 110 is emitted in a state close to it. Therefore, from the respective first LED units 100, linear ultraviolet light extending in the X-axis direction is emitted in parallel in two rows in the Y-axis direction.

Further, as shown in FIG. 4, in the present embodiment, the optical axis of the lens 113 coincides with the lens 115, and the optical axis of the lens 113 and the lens 115 with respect to the optical axis of the LED element 111 (through the central axis of the center of the light-emitting surface) ), offset in the Y-axis direction to configure. That is, the optical axis of the lens 113 and the lens 115 of each LED module 110 is biased toward the center of the substrate 101 (center line CL1), and is only biased by a predetermined distance. Therefore, the optical path of the ultraviolet light emitted from the LED element 111 is bent to the inner side (the center line CL1 side) by the lens 113 and the lens 115. As described later, the first embodiment The 1 LED unit 100 is disposed such that the perpendicular line VL1 (virtual line) passing through the center line CL1 of the substrate 101 passes through the condensing position F1 (FIG. 2(b) and FIG. 4), and the two LED units 100 are emitted from the first LED unit 100. The linear ultraviolet light is formed so as to gradually cross the vertical line VL1 as it leaves the first LED unit 100 and intersect at the condensing position F1.

Similarly to the LED module 110, the optical axis of each of the LED elements 111 of the LED module 210 is provided with a lens 113 and a lens 215 (FIG. 4) held by a lens holding portion (not shown). The lens 215 is a lenticular lens having an incident surface and a convex surface, and is common to the lens 115 of the LED module 110 at a point where the ultraviolet light incident from the lens 113 is formed into a substantially parallel light, but the curvature of the convex surface The thickness of the lens is different from that of the lens 115. In other words, in the present embodiment, the beam diameter in the Y-axis direction of the ultraviolet light emitted from the lens 215 is larger than the beam diameter in the Y-axis direction of the ultraviolet light emitted from the lens 115, and the ultraviolet light emitted from the lens 215 is emitted. The light beam has a beam diameter of about 18 mm (half width) in the X-axis direction and a beam diameter of about 14 mm (half width) in the Y-axis direction. In another embodiment, the beam diameter in the Y-axis direction of the ultraviolet light emitted from the lens 215 may be smaller than the beam diameter in the Y-axis direction of the ultraviolet light emitted from the lens 115.

As described above, the LED module 210 of the present embodiment is formed on the substrate 101 and is densely arranged in two rows (Y-axis direction) × 10 (X-axis directions) in a two-dimensional square lattice shape, and is adjacent to each of the LED modules. The ultraviolet light of the group 210 is emitted in an approaching state. Therefore, from each of the second LED units 200, the linear ultraviolet light extending in the X-axis direction is two columns in the Y-axis direction. Shot side by side.

Further, as shown in FIG. 4, in the present embodiment, the lens 113 and the optical axis of the lens 215 coincide with each other, and the optical axis of the lens 113 and the lens 215 are offset in the Y-axis direction with respect to the optical axis of the LED element 111. Configuration. That is, the optical axis of the lens 113 and the lens 215 of each LED module 210 is biased toward the center of the substrate 101 (center line CL2), and is only biased by a predetermined distance. Therefore, the optical path of the ultraviolet light emitted from the LED element 111 is bent to the inner side (the center line CL2 side) by the lens 113 and the lens 215. As will be described later, the second LED unit 200 of the present embodiment is arranged such that the perpendicular line VL2 (virtual line) of the substrate 101 passing through the center line CL2 of the substrate 101 passes through the condensing position F2 (FIG. 2(b) and FIG. 4). The linear ultraviolet light emitted from the second LED unit 200 is configured to gradually cross the vertical line VL2 as it leaves the second LED unit 200 and intersect (condense) at the condensing position F2.

Next, the arrangement of the first LED unit 100 and the second LED unit 200 described above will be described. As shown in FIG. 2(b), in the light irradiation device 1 of the present embodiment, the four first LED units 100 and the two second LED units 200 are along the lower surface of the base block 20 when viewed from the X-axis direction. (that is, a part of the cylindrical surface) is arranged in an arc shape. Then, the ultraviolet light from each of the first LED unit 100 and each of the second LED units 200 is emitted toward the reference irradiation position on the reference irradiation surface R, and is configured to illuminate the range of the line width LW at the reference irradiation position. Further, in the present embodiment, the line width LW of the ultraviolet light is set to ±20 mm with respect to the reference irradiation position, and the line length LL (length in the X-axis direction) is set to be about 100mm.

Further, in the light irradiation device 1 of the present embodiment, the XY plane is disposed at a position away from the lower end of the casing 10 (Z-axis direction) by 100 mm (indicated as "WD100" in FIG. 2(b)). In the reference irradiation surface R, the object to be printed is configured to be conveyed from the right to the left in the Y-axis direction on the reference irradiation surface R by a conveyance device of a printing machine (not shown). Therefore, the printing object is sequentially transferred from the left to the irradiation surface R, and the ultraviolet light emitted from the first LED unit 100 and the second LED unit 200 is sequentially moved (scanned) onto the printing object to cause the printing object to be printed. The ink on the surface is hardened (fixed) in sequence. In the present specification, the distance below the lower end of the casing 10 (in the Z-axis direction) is referred to as the working distance (WD) of the light irradiation device 1, and hereinafter, for example, a position having a working distance of 100 mm is referred to as "WD100".

Further, when the four first LED units 100 of the present embodiment are viewed from the Z-axis direction, the two first LED units 100 (the second and fourth first LED units 100 from the right side) are opposed to each other as shown in Fig. 2(a). The other two first LED units 100 (the first and third first LED units 100 from the right side) are only biased by P/2 in the X-axis direction (that is, 1/2 of the interval P of the LED module 110). The distance is configured. As described above, the LED modules 110 of the first LED units 100 are densely arranged side by side in the X-axis direction. However, the ultraviolet light emitted from each of the LED modules 110 is slightly parallel light, so that the adjacent LED module 110 is adjacent. The emitted ultraviolet light does not overlap in the X-axis direction, but becomes a comb-like intensity distribution. Therefore, in the present embodiment, the second and fourth first LED units 100 from the right side are used, with respect to the right side. The first and third first LED units 100 are disposed only by a distance of P/2, and cancel the portion where the intensity distribution is low, and when the ultraviolet light from each of the first LED units 100 is irradiated onto the printing object, A slightly uniform intensity distribution in the X-axis direction.

In the same manner, when the two second LED units 200 of the present embodiment are viewed from the Z-axis direction, the first LED unit 100 on the right side is biased by P/2 in the X-axis direction with respect to the second LED unit 200 on the left side (ie, The distance between the LED modules 110 and the interval P of 1/2 is configured. Therefore, when the ultraviolet light from each of the second LED units 200 is irradiated onto the printing target, the portions where the intensity distribution becomes low cancel each other and have a slightly uniform intensity distribution in the X-axis direction.

As described above, the linear ultraviolet light emitted from the plurality of first LED units 100 and the second LED unit 200 is condensed on the printing target (that is, the reference irradiation position on the reference irradiation surface R). The ink on the printing object can be fixed. Here, it is preferable that the plurality of linear ultraviolet rays are condensed on the printing target in a narrow range from the viewpoint of the irradiation intensity of the ultraviolet light required for fixing the ink. However, many of the printing objects to be irradiated with ultraviolet light are paper sheets, and there are many cases in which wrinkles are generated (that is, positional changes in the Z-axis direction). When the position of the printing object changes in the Z-axis direction (that is, when the printing object does not pass through the reference irradiation surface R), each linear ultraviolet light is incident on the printing object at a position different from the predetermined working distance. In the above, there is a problem that ultraviolet light of a predetermined irradiation intensity cannot be irradiated onto the printing object. Then, the intensity of the ultraviolet light is not as strong as the illumination required to fix the ink. If the degree is low, the dry state of the ink may cause unevenness. Therefore, in the present embodiment, the linear ultraviolet light emitted from the first LED unit 100 is condensed at the condensing position F1 vertically above the reference irradiation position, and the linear shape emitted from the second LED unit 200 is emitted. The ultraviolet light is condensed at the condensing position F2 at the irradiation position of the reference, thereby being separated from the lower end of the casing 10 to the lower side (Z-axis direction) by 80 mm (that is, the working distance of 80 mm, FIG. 2 In (b), it is disclosed as "WD80") and WD100, and it is possible to obtain a desired ultraviolet light irradiation intensity and irradiation intensity distribution. Further, in the present embodiment, the condensing position F1 is set to a position that is 15 mm apart from the reference irradiation surface. Further, in FIG. 2(b), for convenience of explanation, the perpendicular line of the irradiation surface R passing through the reference irradiation position (that is, a straight line passing through the condensing position F1 and the condensing position F2) is revealed as the grading light. The center line O of the light path of the ultraviolet light emitted from the illumination device 1.

Fig. 5 is a light path diagram of ultraviolet light emitted from the first LED unit 100 and the second LED unit 200 of the present embodiment. 5(a) is a light path diagram showing ultraviolet light emitted from the first LED unit 100, and FIG. 5(b) is a light path diagram showing ultraviolet light emitted from the second LED unit 200.

As shown in Fig. 2 (b) and Fig. 5 (a), the four first LED units 100 of the present embodiment are arranged such that the vertical line VL1 of each of the first LED units 100 passes through the condensing position F1 when viewed from the X-axis direction. The center line O on the arc of the circumference with respect to the circumference having a radius of 115 mm centered on the condensing position F1, the position of ±6.5° and the position of ±19.5°. That is, the four first LED units 100 are centered by the center line O when viewed from the X-axis direction. For the axis of symmetry, it is configured to be line symmetrical. Further, as described above, the linear ultraviolet light emitted from the first LED unit 100 is configured to cross (converge) at the condensing position F1 when viewed from the X-axis direction. Therefore, a total of eight (eight rows) of linear ultraviolet light emitted from the four first LED units 100 are crossed at the condensing position F1 to the reference irradiation surface R (WD100), and are irradiated onto the printing object. The line width is within the range of LW.

Further, as shown in FIGS. 2(b) and 5(b), the two second LED units 200 of the present embodiment pass through the condensing position F2 when the perpendicular line VL2 of each of the second LED units 200 is viewed from the X-axis direction. In this manner, they are respectively disposed at positions of ±30° with respect to the center line O on a predetermined arc (for example, an arc of a circumference having a radius of 125 mm) centering on the condensing position F2. In other words, the two second LED units 200 are arranged in line symmetry with the center line O as an axis of symmetry when the four first LED units 100 are held when viewed from the X-axis direction. Further, as described above, the linear ultraviolet light emitted from the second LED unit 200 is configured to be collected at the condensing position F2. Therefore, a total of four (four columns) of linear ultraviolet light emitted from the two second LED units 200 are collected at the condensing position F2, and the line width LW is irradiated on the reference irradiation surface R (WD100). Within the scope.

6 is an irradiation intensity distribution (beam profile) of ultraviolet light emitted from each of the LED modules 110 and 210, and reveals a center position on the XY plane in the longitudinal direction of the light irradiation device 1 (that is, a line length of ultraviolet light). Irradiation intensity distribution in the Y-axis direction of LL (1/2 position in the X-axis direction). The "α" of FIG. 6 discloses the sum of the irradiation intensity of the ultraviolet light emitted from each of the LED modules 110 (that is, the first LED unit 100), and the "β" is disclosed from each of the LED modules 210 (that is, the second LED). Unit 200) the sum of the illumination intensities of the emitted ultraviolet light. 6(a) discloses the irradiation intensity distribution at the position of WD80, and FIG. 6(b) discloses the irradiation intensity distribution at WD90 (a position separated from the lower end of the casing 10 to the lower side (Z-axis direction) by 90 mm), Figure 6(c) reveals the illumination intensity distribution at the location of WD100. In addition, the horizontal axis of FIGS. 6(a), (b), and (c) is the distance when the center line O is "0 mm", and the vertical axis of each figure is the irradiation intensity of ultraviolet light per unit area ( mW/cm ² ).

As shown in FIG. 5 and FIG. 6( a ), in the position of WD 80, ultraviolet light from each LED module 110 toward the condensing position F1 is concentrated around the center line O, so α becomes near the center line O. (0 mm position) has a large peak distribution. Further, the ultraviolet light from each of the LED modules 210 facing the condensing position F2 passes through the position away from the center line O, so that there are two lower peaks at β at about ±12 mm.

As shown in FIG. 5 and FIG. 6(b), in the position of the WD 90, the ultraviolet light from each of the LED modules 110 condensed in the condensing position F1 gradually expands as it leaves the condensing position F1, but Close to the condensing position F1 (WD85), there is no large expansion, and α becomes a distribution having a large peak near the center line O. Further, the ultraviolet light from each of the LED modules 210 toward the condensing position F2 is closer to the center line O than the state of the WD 80, so β becomes a stable peak shape distribution.

As shown in FIG. 5 and FIG. 6(c), in the position of WD100, the ultraviolet light from each LED module 110 concentrated in the condensing position F1 More diffuse, so α becomes a broader distribution than in Figs. 6(a) and (b). Further, since the ultraviolet light from each of the LED modules 210 is configured to condense at the condensing position F2 (that is, WD100), β has a distribution having a peak near the center line O (0 mm position). Further, in the present embodiment, β is constituted by the light beams irradiated by the two LED units 200, and the total irradiation light intensity is 1/2 as compared with α which is composed of the irradiation light from the four LED units 100.

As described above, in the present embodiment, the ultraviolet light from the LED module 110 (the first LED unit 100) is concentrated on the periphery of the center line O at the position of the WD 80, but with the distance from the lower end of the casing 10 (working When the distance is longer, the ultraviolet light from the LED module 210 (the second LED unit 200) gathers around the center line O, and if the working distance becomes longer than the condensing position F1, the LED module 110 (the first LED unit 100) The ultraviolet light will be formed from the center line O. Then, with such a configuration, in the range of WD80 to WD100, the irradiation intensity required for fixing the ink can be obtained, and a slightly constant light energy can be obtained. That is, in each of FIGS. 6(a), (b), and (c), the sum of the integral value of the intensity distribution of α in the line width LW (±20 mm) and the integral value of the intensity distribution of β (also That is, the light energy is slightly equal, and the maximum value of the light energy is sufficiently higher than the intensity required to fix the ink.

Figs. 7, 8, and 9 are views showing the irradiation intensity distribution of the ultraviolet light emitted from the light irradiation device 1 of the present embodiment. Fig. 7 is a view showing the irradiation intensity distribution of ultraviolet light at the position of WD80, Fig. 8 showing the irradiation intensity distribution of ultraviolet light at the position of WD90, and Fig. 9 showing the irradiation intensity distribution of ultraviolet light at the position of WD100. Further, Fig. 7(a), Fig. 8(a), and Fig. 9(a) show the irradiation intensity distribution in the X-axis direction at the position of the center line O on the XY plane, and the horizontal axis represents the long side of the light irradiation device 1. The center of the direction (that is, the distance 1/2 of the ultraviolet light line length LL (the length in the X-axis direction) is set to "0 mm", and the vertical axis is the irradiation intensity of ultraviolet light per unit area (mW) /cm ² ). 7(b), 8(b), and 9(b) are the center positions in the longitudinal direction of the light irradiation device 1 on the XY plane (that is, the line length LL of the ultraviolet light (X-axis direction) The irradiation intensity distribution in the Y-axis direction of the 1/2 position of the length), the horizontal axis is the distance when the center line O is "0 mm", and the vertical axis is the irradiation intensity of ultraviolet light per unit area (mW) /cm ² ). In addition, "α" of FIGS. 7, 8, and 9 discloses the sum of the irradiation intensity of the ultraviolet light emitted from the four first LED units 100, and "β" discloses the irradiation of the ultraviolet light emitted from the two second LED units 200. The sum of the intensities, "α + β", reveals the result of adding α to the α (that is, the irradiation intensity of the ultraviolet light emitted from the light irradiation device 1).

As described above, in the position of the WD 80, in the Y-axis direction, the ultraviolet light emitted from the second LED unit 200 passes through the position away from the center line O (see Fig. 6(a), Fig. 7(a), (b). ))), the intensity of β near the centerline O will be lower. However, α + β (that is, the irradiation intensity of the entire ultraviolet light emitted from the light irradiation device 1) covers the entire range (± about 50 mm) of the line length LL, and maintains a strength of about 3500 mW/cm ² , which is a sufficient ratio. In order to set the ink to a desired intensity (for example, 3000 mW/cm ² ), the strength is large. In addition, in order to set the required irradiation intensity of the ink, it differs depending on the type of ink, the printing speed, and the printing conditions such as paper, and is appropriately set in accordance with the printing conditions.

Further, as described above, in the position of the WD 90, in the Y-axis direction, the state in which the ultraviolet light emitted from the second LED unit 200 is WD80 is closer to the center line O (Fig. 6(b)), as shown in Fig. 8 (a). As shown in (b), the intensity of β in the vicinity of the center line O is larger than that in the case of WD80. Further, since the state of the ultraviolet light emitted from the first LED unit 100 is larger than that of the center line O (FIG. 6(b)), the intensity of α is smaller than that of the WD 80. However, α + β (that is, the irradiation intensity of the entire ultraviolet light emitted from the light irradiation device 1) covers the entire range (± about 50 mm) of the line length LL, and maintains an irradiation intensity of about 3500 mW/cm ² on average. It is sufficiently stronger than the intensity of the irradiation required to fix the ink.

Further, as described above, in the position of the WD 100, in the Y-axis direction, the state in which the ultraviolet light emitted from the second LED unit 200 is WD90 is closer to the center line O (Fig. 6(c)), as shown in Fig. 9 (a). As shown in (b), the intensity of β in the vicinity of the center line O is larger than that in the case of WD90. Further, since the ultraviolet light emitted from the first LED unit 100 has a larger expansion ratio with respect to the center line O than the center line O (Fig. 6(c)), the intensity of α is more horizontal (line width LW direction) than the condition of WD90. The spikes become smaller. However, α + β (that is, the irradiation intensity of the entire ultraviolet light emitted from the light irradiation device 1) covers the entire range (± about 50 mm) of the line length LL, and maintains an irradiation intensity of about 3500 mW/cm ² on average. It is sufficiently stronger than the intensity of the irradiation required to fix the ink.

In this way, the irradiation intensity of the ultraviolet light emitted from the light irradiation device 1 of the present embodiment is configured to maintain an average peak intensity of about 3,500 mW/cm ² in the range of WD80 to WD100. Further, the energy of the ultraviolet light emitted from the light irradiation device 1 is the sum of the energy of the ultraviolet light from each of the first optical units and the energy of the ultraviolet light from each of the second optical units, and is slightly smaller in the range of WD80 to WD100. Therefore, the irradiation intensity distribution of the ultraviolet light emitted from the light irradiation device 1 is in the range of WD80 to WD100, which is slightly constant. Therefore, even if the printing object (for example, paper) to be irradiated with ultraviolet light is wrinkled in the range of WD80 to WD100, the ultraviolet light of the irradiation intensity required for fixing the ink can be uniformly irradiated to the printing object. Therefore, the dry state of the ink can be stabilized (that is, the dry state does not cause unevenness).

The above is the description of the embodiment, but the present invention is not limited to the above-described configuration, and various modifications can be made without departing from the spirit and scope of the invention.

(Second embodiment)

FIG. 10 is a view for explaining the light irradiation device 2 according to the second embodiment of the present invention. Fig. 10 (a) is a light path diagram of ultraviolet light emitted from the light irradiation device 2. FIG. 10(b) shows the respective irradiation intensity distributions of the WDs 80, 90, and 100 of the ultraviolet light emitted from the light irradiation device 2, and discloses the X-axis direction of the position of the center line O on each of the XY planes of the WDs 80, 90, and 100. Irradiation intensity distribution. Further, Fig. 10(c) shows the respective irradiation intensity distributions of the WDs 80, 90, and 100 of the ultraviolet light emitted from the light irradiation device 2, and reveals the longitudinal direction of the light irradiation device 2 on each of the XY planes of the WDs 80, 90, and 100. Center position (that is, 1/2 bit of the line length LL (length in the X-axis direction) of the ultraviolet light The irradiation intensity distribution in the Y-axis direction.

As shown in Fig. 10 (a), the light irradiation device 2 of the first embodiment is replaced with the first LED unit 100 in the first embodiment, and the light irradiation device 1 of the first embodiment. different.

As shown in Fig. 10 (b) and (c), even in the irradiation intensity distribution of the ultraviolet light emitted from the light irradiation device 2 of the present embodiment, the average value of about 340 to 4,000 mW can be maintained in the range of WD80 to WD100. Peak intensity of /cm ² . Further, in FIG. 10(c), since the respective irradiation intensity distributions of WDs 80, 90, and 100 are almost overlapped, it can be said that in the range of WD80 to WD100, the light energy in the line width LW (±20 mm) is slightly constant. Therefore, in the structure of the present embodiment, as in the first embodiment, even if the printing target (for example, paper) to be irradiated with ultraviolet light is wrinkled in the range of WD80 to WD100, the ink can be fixed. The ultraviolet light of the required irradiation intensity is uniformly irradiated to the printing object.

(Third embodiment)

Fig. 11 is a view for explaining the light irradiation device 3 according to the third embodiment of the present invention. Fig. 11 (a) is a light path diagram of ultraviolet light emitted from the light irradiation device 3. Fig. 11(b) shows the respective irradiation intensity distributions of the WDs 80, 90, and 100 of the ultraviolet light emitted from the light irradiation device 3, and discloses the X-axis direction of the position of the center line O on each of the XY planes of the WDs 80, 90, and 100. Irradiation intensity distribution. Further, Fig. 11(c) shows the respective irradiation intensity distributions of WD80, 90, and 100 of the ultraviolet light emitted from the light irradiation device 3, revealing WD80, 90, Irradiation intensity distribution in the Y-axis direction at the center position of the longitudinal direction of the light irradiation device 3 (that is, the line length LL (length in the X-axis direction) of the ultraviolet light) on the XY plane of 100 .

As shown in Fig. 11 (a), the light irradiation device 3 of the present embodiment includes three first LED units 100 and three second LED units 200. When viewed in the X-axis direction, the first LED unit 100 and the second LED unit 200 are The Y-axis direction is alternately arranged, which is different from the light irradiation device 1 of the first embodiment.

As shown in Fig. 11 (b) and (c), even in the irradiation intensity distribution of the ultraviolet light emitted from the light irradiation device 3 of the present embodiment, an average of about 3,500 to 4,500 mW can be maintained in the range of WD80 to WD100. Peak intensity of /cm ² . Further, in FIG. 11(c), since the respective irradiation intensity distributions of WDs 80, 90, and 100 are almost overlapped, it can be said that in the range of WD80 to WD100, the light energy in the line width LW (±20 mm) is slightly constant. Therefore, in the structure of the present embodiment, as in the first embodiment, even if the printing target (for example, paper) to be irradiated with ultraviolet light is wrinkled in the range of WD80 to WD100, the ink can be fixed. The ultraviolet light of the required irradiation intensity is uniformly irradiated to the printing object.

(Fourth embodiment)

FIG. 12 is a view showing a structure of the first LED unit 100A and the second LED unit 200A included in the light irradiation device 4 according to the fourth embodiment of the present invention. In the first LED unit 100A and the second LED unit 200A of the present embodiment, the LED modules 110 and 210 are densely arranged in a zigzag shape. (That is, the LED modules 110 and 210 of one column × 10 squares are offset from each other by the 1/2 distance of the interval P with respect to the LED modules 110 and 210 of the other column of 10 columns) The difference is different from the light irradiation device 1 of the first embodiment.

When the LED modules 110 and 210 are arranged as described above, the linear ultraviolet light emitted from each of the first LED unit 100A and each of the second LED units 200A is biased only in the X-axis direction by the LED modules 110 and 210. 1/2 distance of P. Therefore, in the same manner as in the first embodiment, each of the linear ultraviolet light cancels the portion where the intensity distribution is low, and the printing target has a slightly uniform intensity distribution in the X-axis direction. According to the structure of the present embodiment, since the first LED unit 100 and the second LED unit 200 are not biased in the X-axis direction as in the light irradiation device 1 of the first embodiment, the first LED unit 100A and the second LED unit are disposed. The 200A can be simplified for the installation position adjustment of the base block 20.

(Fifth Embodiment)

FIG. 13 is a view showing a mounting structure of the first LED unit 100 and the second LED unit 200 included in the light irradiation device 5 according to the fifth embodiment of the present invention. The light irradiation device 5 of the present embodiment is provided with a base block 20M for fixing the mounting inclined faces 20Ma to 2Mf of the first LED unit 100 and the second LED unit 200, instead of the first cylindrical surface having the first cylindrical surface. The base block 20 of the embodiment is different from the light irradiation device 1 of the first embodiment.

Thus, the base block 20M is formed to fix the first When the tilting faces 20Ma to 20Mf of the LED unit 100 and the second LED unit 200 are mounted, the first LED unit 100 and each of the second LED units 200 can be accurately mounted on the base block 20M, and the first LED unit 100 and the first LED unit 100 are not required. The adjustment of the mounting angle of each of the second LED units 200.

In the above-described embodiments, the wrinkles of the paper to be printed are set to the range of WD80 to WD100 by the irradiation surface R on which the position of the WD 100 is used as the reference, and can be in the range of WD80 to WD100. The medium is irradiated with uniform ultraviolet light (hereinafter, the range in which such uniform ultraviolet light can be irradiated is referred to as "irradiation range"), but it is not limited to such a structure.

Table 1 discloses the distance between the light irradiation device 1 and the irradiation surface R (that is, the working distance), the irradiation range, and the range of the condensing position F1 (the distance range from the light irradiation device 1 to the condensing position F1). The table of relationships. As shown in Table 1, when the distance between the light irradiation device 1 and the irradiation surface R is 125 mm and the irradiation range is 30 mm, the position of the condensing position F1 is set to be within a range from the light irradiation device 1 to 98 mm to 107 mm. When the irradiation range is 15 mm, it is set in the range of 111 mm to 116 mm, whereby the predetermined line length LL can be covered to uniformly illuminate the irradiation range. Further, when the distance between the light irradiation device 1 and the irradiation surface R is 75 mm and the irradiation range is 25 mm, the position of the condensing position F1 is set to be within a range from the light irradiation device 1 to 53 mm to 60 mm, and the irradiation range is In the case of 10 mm, it is set in the range of 66 mm to 69 mm, whereby the predetermined line length LL can be covered to uniformly illuminate the irradiation range.

Furthermore, the embodiments disclosed herein are all illustrative and are not intended to limit the invention. The scope of the present invention is not limited by the foregoing description, and all modifications within the scope and scope of the invention are intended to be

10‧‧‧shell

100‧‧‧1st LED unit

101‧‧‧Substrate

110,210‧‧‧LED modules

111‧‧‧LED components

113,115,215‧‧‧ lens

200‧‧‧2nd LED unit

CL1, CL2‧‧‧ center line

VL1, VL2‧‧‧ vertical line

LL‧‧‧Line length

LW‧‧‧ line width

F1, F2‧‧‧ spotlight position

Claims (11)

A light irradiation device is a light irradiation device that irradiates a predetermined amount of light having a predetermined line width in a second direction orthogonal to the first direction on a predetermined irradiation position on a reference irradiation surface Further, the present invention includes a plurality of optical units each having a substrate and arranged on the substrate at a predetermined interval along the first direction, and aligning the orientation of the optical axis with a direction orthogonal to the substrate surface a light source and a plurality of optical elements disposed on the light path of each of the light sources to form light rays from the respective light sources so as to be slightly parallel light; and the plurality of optical units are output parallel to the irradiation surface of the reference light The plurality of first optical units and the plurality of second optical units are formed by the linear light rays in the first direction; and each of the first optical units is perpendicular to the irradiation position when the light is emitted from the first direction. The predetermined condensing position on the upper side is arranged so that the irradiation surface of the reference converges within the line width; and each of the second optical units is from the first side In the observation, the emitted light is collected at the irradiation position, and is disposed so as to converge in the line width on the irradiation surface of the reference; and in a predetermined range including the condensing position from the irradiation position to the vertical direction, The sum of the energy of the light emitted from each of the first optical units and the energy of the light emitted from each of the second optical units is slightly constant, and the peak of the irradiation intensity distribution is slightly constant. A light irradiation device as recited in claim 1, wherein In the above-described first optical unit, the perpendicular optical unit is arranged in line symmetry with the perpendicular line of the irradiation position as an axis of symmetry. The light irradiation device according to the first or second aspect of the invention, wherein the plurality of first optical units and the plurality of second optical units are along the second direction when viewed from the first direction. And interactive configuration. The light-irradiating device according to the first or second aspect of the invention, wherein the first optical unit is arranged in a line with the perpendicular line of the irradiation position as an axis of symmetry when viewed from the first direction. The second optical unit is arranged in line symmetry with the perpendicular line as an axis of symmetry on the outer side of the first optical unit when viewed from the first direction. The light irradiation device according to the first or second aspect of the invention, wherein the first optical unit is disposed in an arc centered on the condensing position when viewed from the first direction Each of the second optical units is disposed on an arc centered on the irradiation position when viewed from the first direction. The light irradiation device according to the first or second aspect of the invention, wherein the number of the plurality of first optical units and the plurality of second optical sheets The number of yuan is equal, or more. The light irradiation device according to the sixth aspect of the invention, wherein the first optical unit is 4N (N is a natural number), and the second optical unit is 2N. The light irradiation device according to claim 7, wherein the 2N first optical units of the 4N first optical units are offset from the other 2N first optical units only in the first direction. The 1/2 distance of the predetermined interval is arranged; and the N second optical units of the 2N second optical units are offset from the other N second optical units by only 1/2 of the predetermined interval in the first direction. Distance to configure. The light irradiation device according to the first or second aspect of the invention, wherein the plurality of light sources are arranged on the substrate in two rows and arranged in a direction orthogonal to the first direction, and When viewed in the first direction, the optical axis emitted from one of the light sources and the light emitted from the other of the light sources intersect at the condensing position or the irradiation position, thereby making the optical axes of the optical elements The optical axis of the light source is offset. The light-emitting device according to claim 9, wherein the light source of the one of the other ones is arranged such that the light source of the other one of the distances deviates from the first interval by a distance of 1/2 of the predetermined interval. Set. The light-emitting device according to the first or second aspect of the invention, wherein the plurality of light sources are surface-emitting LEDs having a light-emitting surface having a substantially square shape, and a diagonal line of one of the light-emitting surfaces and the first The 1 direction is arranged in parallel.