JP2015012119A - Light irradiation device, light irradiation module and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light irradiation device capable of enhancing the optical intensity per unit area, even if a plurality of light-emitting elements are mounted on one substrate.SOLUTION: A light irradiation device 1 for irradiating a relatively moving object with light includes a substrate 10, a plurality of light-emitting element groups 20A having a plurality of light-emitting elements 20 arranged vertically and horizontally on the upper surface of the substrate 10, and a plurality of lenses 17 provided to cover the light-emitting element groups 20A, respectively, and passing the light emitted from the light-emitting element groups 20A to the outside. Since the optical axis of light emitted, respectively, via the plurality of lenses 17 is determined by controlling the irradiance of the plurality of light-emitting elements 20, respectively, ultraviolet irradiation intensity (irradiance) of the light irradiation device per unit area can be enhanced.

Description

  The present invention relates to a light irradiation device, a light irradiation module, and a printing apparatus used for curing an ultraviolet curable resin or a paint.

  2. Description of the Related Art Conventionally, ultraviolet irradiation apparatuses are widely used for the purpose of fluorescence reaction observation in medical and bio fields, sterilization applications, adhesion of electronic components, curing of ultraviolet curable resins and inks, and the like. In particular, the UV light source lamp light source used for curing UV curable resin used for bonding small parts in the field of electronic components and UV curable ink used for printing, etc. Mercury lamps and metal halide lamps are used.

  In recent years, there has been a strong desire to reduce the global environmental load on a global scale, and there has been an active movement to adopt an ultraviolet light emitting element as a lamp light source capable of suppressing the generation of ozone with a relatively long life, energy saving. .

  However, since the irradiance of the ultraviolet light emitting element is relatively low, for example, as described in Patent Document 1, a device in which a plurality of light emitting elements are mounted on one substrate is generally used. The UV irradiation energy (integrated light amount) necessary for ink curing is secured.

  However, in such a device, in the case of a certain ultraviolet curable ink, although the accumulated ultraviolet irradiation energy to be irradiated can be secured, the ultraviolet irradiation intensity (irradiance) per unit area is not high, so that the curing is insufficient. There was a problem that occurred.

JP 2003-124528 A

  The present invention has been made in view of the above problems, and even if it is a device in which a plurality of light emitting elements are mounted on one substrate, the ultraviolet irradiation intensity (irradiance) per unit area can be increased. An object is to provide a light irradiation device, a light irradiation module, and a printing apparatus.

  A light irradiation device according to the present invention is a light irradiation device for irradiating light to a relatively moving object, and includes a base and a plurality of light emitting elements arranged vertically and horizontally on the upper surface of the base. And a plurality of lenses provided so as to cover each of the light emitting element groups for emitting light emitted from the light emitting element group to the outside, and each of the plurality of light emitting elements. By controlling the irradiance, the optical axis of the light emitted through each of the plurality of lenses is determined.

  Moreover, the light irradiation device of the present invention is characterized in that, in the above configuration, the irradiance is controlled by an amount of electric power applied to each of the plurality of light emitting elements.

Furthermore, the light irradiation device of the present invention is characterized in that, in the above configuration, the irradiance is controlled by a value of irradiance with respect to an applied power per unit of the plurality of light emitting elements.

  Moreover, the light irradiation device of the present invention is characterized in that, in the above configuration, the irradiance is controlled by a value of a light emitting area of each of the plurality of light emitting elements.

  The light irradiation module of the present invention is characterized in that a plurality of any of the above light irradiation devices are placed on a heat radiating member.

  The printing apparatus of the present invention includes a printing unit that performs printing on a recording medium, and the light irradiation module that irradiates light onto the printed recording medium.

  According to the light irradiation device of the present invention, there is provided a light irradiation device for irradiating light to a relatively moving object, and a substrate and a plurality of light emitting elements arranged in a row and column on the upper surface of the substrate. A plurality of light emitting element groups, and a plurality of lenses provided so as to cover each of the light emitting element groups for emitting light emitted from the light emitting element group to the outside, and the plurality of light emitting elements By controlling the respective irradiance, the optical axis of the light emitted through each of the plurality of lenses is determined. Therefore, the optical axis of the light emitted from a plurality of light emitting element groups can be directed in the direction in which the ultraviolet illuminance per unit area is desired to be increased, so that the ultraviolet irradiation intensity (irradiance) per unit area of the light irradiation device can be Can be high.

It is a top view which shows an example of the form of the light irradiation device of this invention. It is a principal part top view of the light irradiation device shown in FIG. It is sectional drawing along the 1I-1I line | wire of the light irradiation device shown in FIG. It is a figure explaining how to obtain the centroid. It is a figure for demonstrating the difference in the light intensity per unit area. It is principal part sectional drawing which shows the light irradiation module using the light irradiation device shown in FIG. It is a top view of the printing apparatus using the light irradiation device shown in FIG. It is a side view of the printing apparatus shown in FIG. It is a figure explaining the 1st modification of the light irradiation module shown in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a light irradiation device, a light irradiation module, and a printing apparatus according to the present invention will be described with reference to the drawings. The following examples illustrate the embodiments of the present invention, and the present invention is not limited to the examples of these embodiments.

(Light irradiation device)
An example of the embodiment of the light irradiation device of the present invention will be described. FIG. 1 is a plan view of the light irradiation device 1 of this example, FIG. 2 is a plan view of the main part of the light irradiation device 1 shown in FIG. 1, and FIG. 3 is a line 1I-1I of the light irradiation device shown in FIG. FIG. The light irradiation device 1 of this example is incorporated in a printing apparatus such as an offset printing apparatus or an inkjet printing apparatus that uses an ultraviolet curable ink, and covers the relatively moving object (recording medium) with the ultraviolet curable ink. By irradiating ultraviolet rays after being applied, it functions as an ultraviolet ray generating light source for curing the ultraviolet curable ink.

The light irradiation device 1 is disposed in a base body 10 having a plurality of openings 12 on one main surface 11 a, a plurality of connection pads 13 provided in the openings 12, and the openings 12 of the base body 10. A plurality of light emitting elements 20 electrically connected to the connection pads 13, a plurality of sealing materials 30 filled in the respective opening portions 12 to cover the light emitting elements 20, and a plurality of lenses corresponding to the respective opening portions 12 17.

  The base 10 includes a laminated body 40 in which a first insulating layer 41 and a second insulating layer 42 are laminated, and an electrical wiring 50 that connects the light emitting elements 20 to each other. It has a shape (for example, a rectangular shape), and a plurality of light emitting elements 20 are supported in the opening 12 provided on the one main surface 11a.

  A plurality of light emitting elements 20 (four in this example) are arranged in each opening 12 to constitute a light emitting element group 20A. For convenience of explanation, as shown in FIG. 2, the four light emitting elements 20 belonging to the light emitting element group 20A of this example are viewed upstream of the light emitting element group 20A from the one main surface 11a side in the moving direction of the object. The two light emitting elements positioned at 20 are 20a and 20b, and the two light emitting elements positioned on the downstream side are 20c and 20d. The four light emitting elements 20a, 20b, 20c, and 20d that belong to the light emitting element group 20A of this example are light emitting elements 20a, 20b, and 20c clockwise when the light emitting element group 20A is viewed in plan view from the one main surface 11a side. , 20d in this order. In the following description, the matters common to the light emitting elements 20a, 20b, 20c, and 20d may be simply referred to as the light emitting element 20 as a general term for the light emitting elements 20a, 20b, 20c, and 20d.

  The first insulating layer 41 is formed of, for example, an aluminum oxide sintered body, an aluminum nitride sintered body, a ceramic such as a mullite sintered body, and a glass ceramic, and a resin such as an epoxy resin and a liquid crystal polymer (LCP). Is done.

  The electric wiring 50 is formed in a predetermined pattern by a conductive material such as tungsten (W), molybdenum (Mo), manganese (Mn), and copper (Cu), and the electric current to the light emitting element 20 or the light emitting element It functions as a power supply wiring for supplying current from 20.

  In the second insulating layer 42 laminated on the first insulating layer 41, the opening 12 penetrating the second insulating layer 42 is formed.

  The shape of each opening 12 is such that the inner peripheral surface 14 is inclined so that the hole diameter is larger on the one main surface 11a side of the substrate 10 than the mounting surface of the light emitting element 20, It has a circular shape. The opening shape is not limited to a circular shape, and may be a rectangular shape.

  Such an opening 12 has a function as a reflector that reflects light emitted from the light emitting element 20 upward on the inner peripheral surface 14 and improves the light extraction efficiency.

  In order to improve the light extraction efficiency, the material of the second insulating layer 42 is a porous ceramic material having a relatively good reflectivity with respect to light in the ultraviolet region, such as an aluminum oxide sintered body, zirconium oxide. It is preferable to form the sintered body and the aluminum nitride sintered body. Further, from the viewpoint of improving the light extraction efficiency, a metal reflection film may be provided on the inner peripheral surface 14 of the opening 12.

  Such openings 12 are arranged vertically and horizontally over the upper surface of the substrate 10, that is, the entire one main surface 11 a. In this example, they are arranged in a rectangular lattice shape.

If you want to increase the light intensity per unit area, for example, arrange in a staggered pattern,
That is, the light emitting elements 20, that is, the light emitting element group 20A may be arranged at a higher density in a zigzag array of a plurality of rows. Here, to arrange in a zigzag pattern is synonymous with the arrangement so as to be positioned at the lattice points of the diagonal lattice. Further, since the light emitting element group 20A composed of a plurality of light emitting elements 20 is arranged in the opening 12, arranging the opening 12 is synonymous with arranging the light emitting element group 20A.

  In this example, the light emitting element group 20 </ b> A is disposed in the opening 12, but the opening 12 is not necessarily required, and the plurality of light emitting elements 20 may be disposed on the first insulating layer 41. The thickness of the second insulating layer 42 may be thin for the purpose of protecting the electrical wiring 50 on the first insulating layer.

  The base body 10 including the laminate 40 composed of the first insulating layer 41 and the second insulating layer 42 as described above is as follows if the first insulating layer 41 and the second insulating layer 42 are made of ceramics or the like. It is manufactured through processes such as

  First, a plurality of ceramic green sheets manufactured by a normal method are prepared. A hole corresponding to the opening 12 is formed in the ceramic green sheet corresponding to the opening 12 by a method such as punching. Next, after printing (not shown) a metal paste to be the electric wiring 50 on the green sheet, the green sheets are laminated so that the printed metal paste is positioned between the green sheets. Examples of the metal paste used for the electric wiring 50 include a paste containing a metal such as tungsten (W), molybdenum (Mo), manganese (Mn), and copper (Cu). Next, the base body 10 having the electrical wiring 50 and the opening 12 can be formed by firing the laminate and firing the green sheet and the metal paste together.

  Further, if the first insulating layer 41 and the second insulating layer 42 are made of resin, for example, the following method can be considered as a method of manufacturing the base 10.

  First, a precursor sheet of a thermosetting resin is prepared. Next, a plurality of precursor sheets are laminated so that lead terminals made of a metal material to be the electrical wiring 50 are arranged between the precursor sheets and the lead terminals are embedded in the precursor sheets. Examples of the material for forming the lead terminal include copper (Cu), silver (Ag), aluminum (Al), iron (Fe) -nickel (Ni) -cobalt (Co) alloy, and iron (Fe) -nickel (Ni). Examples include metal materials such as alloys. And after forming the hole corresponding to the opening part 12 in a precursor sheet | seat by methods, such as a laser processing and an etching, the base | substrate 10 is completed by thermosetting this. In addition, when forming the opening part 12 by laser processing, you may process after thermosetting a precursor sheet | seat.

  On the other hand, a plurality of connection pads 13 electrically connected to the plurality of light emitting elements 20 and solder, gold (Au) wires, aluminum (Al) wires, etc. are connected to the connection pads 13 in the openings 12 of the substrate 10. A plurality of light emitting elements 20 connected by the bonding material 15 and a sealing material 30 for sealing the plurality of light emitting elements 20 are provided.

  The connection pad 13 is formed of a metal layer made of a metal material such as tungsten (W), molybdenum (Mo), manganese (Mn), and copper (Cu). If necessary, a nickel (Ni) layer, a palladium (Pd) layer, a gold (Au) layer, or the like may be further laminated on the metal layer. The connection pad 13 is connected to the light emitting element 20 by a bonding material 15 such as solder, gold (Au) wire, and aluminum (Al) wire.

The light emitting element 20 is, for example, gallium arsenide (GaAs) or gallium nitride (GaN).
A light emitting diode in which a p-type semiconductor layer and an n-type semiconductor layer made of a semiconductor material such as the above are stacked on an element substrate 21 such as a sapphire substrate, an organic EL element in which the semiconductor layer is made of an organic material, and the like.

  The light-emitting element 20 is connected to a semiconductor layer 22 having a light-emitting layer and a connection pad 13 disposed on the substrate 10 via a bonding material 15 such as solder, gold (Au) wire, and aluminum (Al) wire. And device electrodes 23 and 24 made of a metal material such as silver (Ag), and are connected to the base 10 by wire bonding. The light emitting element 20 emits light having a predetermined wavelength with a predetermined luminance according to the current flowing between the element electrodes 23 and 24. The element substrate 21 can be omitted. Further, the connection between the device electrodes 23 and 24 of the light emitting device 20 and the connection pad 13 may be performed by a normal flip chip connection technique using solder or the like for the bonding material 15.

  In this example, an LED that emits UV light having a wavelength peak of light of 280 to 440 nm, for example, is employed. That is, in this example, a UV-LED element is adopted as the light emitting element 20. The light emitting element 20 is formed by a conventionally known thin film forming technique.

  And this light emitting element 20 is sealed with the sealing material 30 mentioned above.

  The sealing material 30 is made of an insulating material such as a light-transmitting resin material. By sealing the light-emitting element 20 well, entry of moisture from the outside can be prevented, or from the outside. The light emitting element 20 is protected by absorbing an impact.

  Further, a material having a refractive index between the refractive index of the element substrate 21 constituting the light emitting element 20 (in the case of sapphire: 1.7) and the refractive index of air (about 1.0) is used as the sealing material 30, for example By using a silicone resin (refractive index: about 1.4) or the like, the light extraction efficiency of the light emitting element 20 can be improved.

  The sealing material 30 is formed by mounting the light emitting element 20 on the substrate 10, filling a precursor such as a silicone resin into the opening 12, and curing it.

  And the lens 17 is arrange | positioned so that 20 A of light emitting element groups may be covered on the above-mentioned sealing material 30 via the lens adhesive agent 60. FIG. In the light irradiation device 1 of this example, a plano-convex lens is used as the optical lens 17. That is, in the optical lens 17 of the present embodiment, one main surface is convex and the other main surface is flat, and the cross-sectional area decreases from the other main surface toward the one main surface.

  The optical lens 17 is formed of, for example, silicone and is for emitting light emitted from the light emitting element group 20A to the outside, and has a function of condensing light emitted from the light emitting element group 20A. In addition to the silicone described above, examples of the material of the optical lens include thermosetting resins such as urethane and epoxy, plastics such as thermoplastic resins such as polycarbonate and acrylic, sapphire, and inorganic glass.

  In this example, since the lenses 17 are arranged in a rectangular lattice shape, the plurality of lenses 17 have the same arrangement interval in the moving direction of the object, and the arrangement interval in the direction perpendicular to the moving direction of the object. Are the same. If comprised in this way, it will become possible to arrange | position the several lens 17 with high density and compactly, and it contributes to size reduction of the light irradiation device 1. FIG.

  The centers of the plurality of lenses 17 in a plan view substantially coincide with the centers (centroids) of the corresponding light emitting element group 20A in a plan view.

  Here, the center of the light emitting element group 20A is the centroid in plan view of the plurality of light emitting elements 20 included in the light emitting element group 20A. Here, the centroid is obtained by dividing the first moment of section at an arbitrary point by the total sectional area.

  The method for obtaining the centroid will be specifically described with reference to FIG.

  FIG. 4 schematically shows the four light emitting elements 20a, 20b, 20c, and 20d of the light emitting element group 20A of this example. The upper left corner of the upper left light emitting element 20a in FIG. 4 is the origin O, and as shown in FIG. 4, a straight line extending in one direction from the origin O is the x axis, and a straight line passing through the origin O and orthogonal to the x axis is the y axis. . The cross-sectional areas of the upper left, upper right, lower right, and lower left light emitting elements 20a, 20b, 20c, and 20d in FIG. 4 are S1, S2, S3, and S4, and the centers of the light emitting elements 20a, 20b, 20c, and 20d (FIG. 4). In this case, assuming that the distances from the x axis to the points where the diagonal lines of the light emitting elements 20 intersect each other are y1, y2, y2 and y1, the moment about the x axis of the origin O is y1 × S1 + y2 × S2 + y2 × S3 + y1. × S4. This moment is the cross-sectional primary moment, and when this is divided by the total area S1 + S2 + S3 + S4, the y coordinate yG of the centroid is obtained. That is, yG = (y1 * S1 + y2 * S2 + y2 * S3 + y1 * S4) / (S1 + S2 + S3 + S4).

  Similarly, if the distances from the y axis to the centers of the light emitting elements 20a, 20b, 20c, and 20d are x1, x2, x3, and x4, respectively, the moment about the y axis of the origin O is x1 × S1 + x2 × S2 + x2 × S3 + x1 ×. S4. Dividing this by the total area S1 + S2 + S3 + S4 gives the x-coordinate xG of the centroid. That is, xG = (x1 * S1 + x2 * S2 + x2 * S3 + x1 * S4) / (S1 + S2 + S3 + S4).

  The center of the lens 17 is the center of the lens bottom surface.

  By arranging the light emitting element group 20A and the lens 17 in this way, the optical axis of the light emitted through the lens 17 of the light emitting element group 20A is the light emitted by each of the light emitting elements 20a, 20b, 20c, and 20d. When the irradiances are equal, the normal direction of the upper surface (one main surface 11a) of the substrate 10 is obtained.

  In the light irradiation device 1 of this example, since the connection pads 13 are provided corresponding to the plurality of light emitting elements 20, power is independently applied to the plurality of light emitting elements 20 by an external power source. It is possible to do. Therefore, by controlling the amount of power applied to each of the plurality of light emitting elements 20, it is possible to control the irradiance of the light emitted by each of the plurality of light emitting elements 20, that is, to vary the irradiance. It has become.

  The light emitting element group 20A of this example includes a plurality of first light emitting element groups 20Aa located on the upstream side in the moving direction of the object and a plurality of second light emitting element groups 20Ab located on the downstream side. The lens 17 has a plurality of first lenses 17a corresponding to each of the first light emitting element groups 20Aa and a second lens 17b corresponding to each of the second light emitting element groups 20Ab.

  In the first light emitting element group 20Aa, the amount of power applied to the light emitting elements 20a and 20b located on the upstream side in the moving direction of the object is larger than the amount of power applied to the light emitting elements 20c and 20d located on the downstream side. It is getting bigger. That is, the irradiance of light emitted from the light emitting elements 20a and 20b is higher than the irradiance of light emitted from the light emitting elements 20c and 20d. In this case, the optical axis of the light emitted through the first lens 17a of the first light emitting element group 20Aa is downstream in the moving direction of the object with respect to the normal of the upper surface (one main surface 11a) of the base body 10. Will be inclined toward.

  On the other hand, in the second light emitting element group 20Ab, the amount of power applied to the light emitting elements 20c and 20d located on the downstream side in the moving direction of the object is the amount of power applied to the light emitting elements 20a and 20b located on the upstream side. Is bigger than. That is, the irradiance of light emitted from the light emitting elements 20c and 20d is higher than the irradiance of light emitted from the light emitting elements 20a and 20b. In this case, the optical axis of the light emitted through the second lens 17b of the second light emitting element group 20Ab is upstream in the moving direction of the object with respect to the normal of the upper surface (one main surface 11a) of the base 10. Will be inclined toward. As a result, the light intensity per unit area on the object of the light emitted from the light irradiation device 1 can be increased.

  FIG. 5 schematically shows the light intensity per unit area of the light irradiation device 1 in the moving direction of the object. In the first light emitting element group 20Aa, the solid line indicates that the irradiance of light emitted from the light emitting elements 20a and 20b is higher than the irradiance of light emitted from the light emitting elements 20c and 20d in the first light emitting element group 20Aa. In the group 20Ab, the irradiance of light emitted from the light emitting elements 20c and 20d is the light intensity per unit area when the irradiance of light emitted from the light emitting elements 20a and 20b is higher, and the broken line indicates the first light emission. The light intensity per unit area when the irradiance of the light emitted from each of the light emitting elements 20 is approximately equal for both the element group 20Aa and the second light emitting element group 20Ab.

  Note that the total sum of irradiances of the light emitting elements 20a, 20b, 20c, and 20d belonging to the first light emitting element group 20Aa and the second light emitting element group 20Ab is equal in both the solid line and the broken line. That is, the sum total of the electric energy applied to the light emitting elements 20a, 20b, 20c, and 20d is equal. Therefore, although the total amount of power applied to the light irradiation device 1 is equal to the total amount of power applied to the conventional light irradiation device, the ultraviolet irradiation intensity (irradiance) per unit area of the light irradiation device ) Can be increased.

  As a matter of course, the total amount of power applied to the light irradiation device 1 does not necessarily need to be equal to the total amount of power applied to the conventional light irradiation device, and is appropriately adjusted so as to obtain desired characteristics. do it.

  The area of the region surrounded by the horizontal axis and each of the solid line and the broken line is the integrated light energy, and the integrated light energy is equal, but the maximum value of the light intensity per unit area is different. That is, in the light irradiation device 1 of this example, the light intensity per unit area can be increased.

Here, the light intensity per unit area is the intensity of light per unit area on the object, and normal measurement in which a light receiving unit of an ultraviolet illuminance meter is installed on the object may be performed. The light intensity per unit area is also called irradiance, and W / cm ² or the like is used as a unit.

  In this example, the optical axis of light emitted through the first lens 17a of the first light emitting element group 20Aa and the optical axis of light emitted through the second lens 17b of the second optical element group 20Ab are respectively The inclination with respect to the normal of the upper surface (one main surface 11a) of the base 10 is the same. This is because the amount of power applied to the light emitting elements 20a, 20b of each first light emitting element group 20Aa and the value of the amount of power applied to the light emitting elements 20c, 20d, and the light emitting elements of each second light emitting element group 20Ab. This is because the amount of power applied to 20a and 20b and the amount of power applied to the light emitting elements 20c and 20d are the same.

However, the inclination of the optical axis of the light emitted through the second lens 17a of the first light emitting element group 20Aa is set upstream of the normal line of the upper surface (one main surface 11a) of the substrate 10 in the moving direction of the object. The inclination of the optical axis of the light emitted through the second lens 17b of the second light emitting element group 20Ab is gradually decreased from the side toward the downstream side, and the normal line of the upper surface (one main surface 11a) of the substrate 10 is set. On the other hand, the light intensity per unit area can be further increased by gradually decreasing from the downstream side in the moving direction of the object toward the upstream side. In this case, the ratio of the amount of power applied to the light emitting elements 20a and 20b of the first light emitting element group 20Aa and the amount of power applied to the light emitting elements 20c and 20d is changed from the upstream side to the downstream side of the object. Can be gradually reduced. Similarly, in the second light emitting element group 20Ab, the ratio of the amount of power applied to the light emitting elements 20c and 20d of the second light emitting element group 20Ab and the amount of power applied to the light emitting elements 20a and 20b is set downstream of the object. What is necessary is just to make it gradually small toward the upstream from the side.

(Light irradiation module)
The light irradiation module 2 of this example is provided with the heat radiating member 110 and the light irradiating device 1 disposed on the heat radiating member 110, as shown in FIG. Is disposed on the main surface of the heat radiating member 110 via an adhesive 120 such as silicone resin or epoxy resin.

  The heat radiating member 110 functions as a support for the light irradiation device 1 and as a heat radiator that radiates heat generated by the light irradiation device 1 to the outside. As a material for forming the heat radiating member 110, a material having a high thermal conductivity is preferable. Examples thereof include various metal materials, ceramics, and resin materials. The heat radiating member 110 in this example is made of copper.

  According to the light irradiation module 2 of this example, the above-described effects of the light irradiation device 1 can be achieved.

(Printer)
As an example of the embodiment of the printing apparatus of the present invention, the printing apparatus 200 shown in FIGS. 7 and 8 will be described as an example. The printing apparatus 200 includes a conveying unit 210 for conveying the recording medium 250, a printing unit 220 as a printing mechanism for printing on the conveyed recording medium 250, and an ultraviolet ray for the recording medium 250 after printing. The light irradiation device 1 that irradiates light and the control mechanism 230 that controls the light emission of the light irradiation device 1 are provided. The recording medium 250 corresponds to the above-described object.

  The transport unit 210 is for transporting the recording medium 250 so as to pass through the printing unit 220 and the light irradiation device 1 in this order. The transport unit 210 and the mounting table 211 are arranged so as to face each other and are rotatably supported. And a roller 212. The transport unit 210 is for sending the recording medium 250 supported by the mounting table 211 between the pair of transport rollers 212 and rotating the transport roller 212 to feed the recording medium 250 in the transport direction. .

  The printing unit 220 has a function of attaching a photosensitive material to the recording medium 250 conveyed via the conveying unit 210. The printing unit 220 is configured to eject droplets containing the photosensitive material toward the recording medium 250 and attach the droplets to the recording medium 250. In this example, ultraviolet curable ink is used as the photosensitive material. Examples of the photosensitive material include, in addition to the ultraviolet curable ink, a photosensitive resist or a photocurable resin.

In this example, a line-type printing unit is employed as the printing unit 220. The printing unit 220 has a plurality of ejection holes 220a arranged in a line in the main scanning direction, and is configured to eject ultraviolet curable ink from the ejection holes 220a. The printing unit 220 ejects ink from the ejection holes 220a and deposits the ink on the recording medium with respect to the recording medium 250 conveyed in a direction (sub-scanning direction) orthogonal to the arrangement of the ejection holes 220a. Thus, printing is performed on the recording medium.

  In this example, the line-type printing unit is exemplified as the printing mechanism. However, the printing mechanism is not limited to this. For example, a serial-type printing unit may be employed, or a line-type or serial-type printing unit may be used. You may employ | adopt a spray head (for example, inkjet head). Further, as the printing mechanism, an electrostatic head that accumulates static electricity on the recording medium 250 and attaches the photosensitive material with the static electricity may be employed. Alternatively, the recording medium 250 may be immersed in a liquid photosensitive material and the photosensitive medium may be used. An immersion apparatus for attaching a conductive material may be employed. Further, a brush, a brush, a roller, or the like may be employed as a printing mechanism.

  In the printing apparatus 200, the light irradiation device 1 has a function of exposing the photosensitive material attached to the recording medium 250 conveyed through the conveying unit 210. The light irradiation device 1 is provided on the downstream side in the transport direction with respect to the printing unit 220. In the printing apparatus 200, the light emitting element 20 has a function of exposing the photosensitive material attached to the recording medium 250.

  The control mechanism 230 has a function of controlling light emission of the light irradiation device 1. The memory of the control mechanism 230 stores information indicating the characteristics of light that makes it relatively good to cure the ink droplets ejected from the printing unit 220. Specific examples of the stored information include wavelength distribution characteristics suitable for curing ejected ink droplets, and numerical values representing emission intensity (emission intensity in each wavelength range). In the printing apparatus 200 of this example, by including the control mechanism 230, the magnitude of the drive current input to the plurality of light emitting elements 20 can be adjusted based on the stored information of the control mechanism 230. Therefore, according to the printing apparatus 200 of this example, it is possible to irradiate light with an appropriate ultraviolet irradiation energy according to the characteristics of the ink to be used, and to cure the ink droplet with a relatively low energy light. it can.

  In the printing apparatus 200, the transport unit 210 transports the recording medium 250 in the transport direction. The printing unit 220 discharges the ultraviolet curable ink to the recording medium 250 being conveyed, and causes the ultraviolet curable ink to adhere to the surface of the recording medium 250. At this time, the ultraviolet curable ink to be attached to the recording medium 250 may be attached to the entire surface, partially attached, or attached in a desired pattern. In the printing apparatus 200, the ultraviolet curable ink attached to the recording medium 250 is irradiated with ultraviolet rays emitted from the light irradiation device 1 to cure the ultraviolet curable ink.

  According to the printing apparatus 200 of this example, the above-described effects of the light irradiation device 1 can be achieved.

  As mentioned above, although the example of specific embodiment of this invention was shown, this invention is not limited to this, A various change is possible within the range which does not deviate from the summary of this invention.

  For example, the irradiance of each of the plurality of light emitting elements 20 is controlled by the amount of power applied to the plurality of light emitting elements 20, but the value of the irradiance with respect to the applied power per unit of the plurality of light emitting elements 20 is determined. May be performed.

When controlling the irradiance of each of the plurality of light emitting elements 20 according to the value of the irradiance with respect to the applied power per unit of the plurality of light emitting elements 20, the amount of power applied to each of the plurality of light emitting elements 20 is determined. Since the connection pads 13 of the light irradiation device 1 can be shared between the light emitting elements 20a, 20b, 20c, and 20d, the layout of the electric wiring 50 should be simplified. Since the manufacturing of the light irradiation device 1 becomes easy, the productivity is improved and the manufacturing yield is improved, which contributes to the reduction of the manufacturing cost. As a matter of course, the amount of power applied to each of the plurality of light emitting elements 20 can be varied.

  Further, the irradiance of each of the plurality of light emitting elements 20 may be controlled by the value of the light emitting area of each of the plurality of light emitting elements 20.

  In the case where the irradiance of each of the plurality of light emitting elements 20 is controlled by the value of the light emitting area of each of the plurality of light emitting elements 20, it is possible to equalize the amount of power applied to each of the plurality of light emitting elements 20. Therefore, the connection pad 13 of the light irradiation device 1 can be shared between the light emitting elements 20a, 20b, 20c, and 20d. For example, the layout of the electric wiring 50 can be simplified, and light irradiation can be performed. Since the device 1 can be easily manufactured, the productivity can be improved and the manufacturing yield can be improved. As a matter of course, the amount of power applied to each of the plurality of light emitting elements 20 can be varied.

  Further, the inclination of the optical axis is not limited to this example, and may be adjusted as appropriate.

  For example, in the case of ultraviolet curable ink, oxygen inhibition is known in which the photopolymerization reaction is inhibited by oxygen in the air. If the time from when the ultraviolet curable ink is applied to the object to when the ultraviolet ray is irradiated becomes longer, the curability of the ultraviolet curable ink becomes worse due to the influence of oxygen inhibition. Therefore, the UV curable ink is attached to the object by tilting the optical axis of the light emitted from each of the plurality of light emitting element groups 20A to the upstream side in the moving direction of the object of the light irradiation device 1. It is possible to irradiate ultraviolet light with high irradiance in a short time.

  Further, it is known that the irradiance of ultraviolet light decreases at both ends of the light irradiation device 1 in a direction orthogonal to the moving direction of the object. Therefore, in general, the width of the light irradiation device 1 for irradiating light is wider than the width of the object. However, at both ends of the light irradiation device 1 in the direction orthogonal to the moving direction of the object, the optical axis of the light emitted from the light emitting element group 20A is away from the light irradiation device 1 in the direction orthogonal to the moving direction of the object. If directed, it is possible to increase the irradiance of ultraviolet light at both ends of the light irradiation device 1, so that the width in the direction orthogonal to the moving direction of the object of the light irradiation device 1 can be reduced. Contributes to the miniaturization of device 1.

  Moreover, the example of embodiment of the light irradiation module 2 is not limited to the above example. For example, as in the first modification shown in FIG. 9, a plurality of light irradiation devices 1 constituting the light irradiation module 2 are arranged in the width direction perpendicular to the moving direction of the target and in the moving direction of the target. May be. In the case of the first modification, four light irradiation devices 1 are arranged in the width direction and two in the movement direction. In this case, the light irradiation device 1 includes a light irradiation device 1A located on the upstream side in the moving direction of the object and a light irradiation device 1B located on the downstream side. The light irradiation device 1A is composed of only the first light emitting element group 20Aa, and the light irradiation device 1B is composed of only the second light emitting element group 20Ab. By comprising in this way, the above-mentioned effect similar to the light irradiation device 1 can be show | played as the light irradiation module 2. FIG.

  Further, the example of the embodiment of the printing apparatus 200 is not limited to the above example. For example, a so-called offset printing type printer that rotates a shaft-supported roller and conveys a recording medium along the roller surface may exhibit the same effect.

In the example of the above-described embodiment, an example in which the light irradiation device 1 is applied to the printing apparatus 200 using the inkjet head 220 is shown. This light irradiation device 1 is, for example, photocuring by spin coating on the surface of the object. The present invention can also be applied to curing various types of photo-curing resins such as a dedicated device for curing the resin. Moreover, you may use the light irradiation device 1 for the irradiation light source etc. in an exposure apparatus, for example.

  Needless to say, the light irradiation module 2 may be applied instead of applying the light irradiation device 1 to the printing apparatus 200.

DESCRIPTION OF SYMBOLS 1 Light irradiation device 2 Light irradiation module 10 Board | substrate 11a One main surface 12 Opening part 13 Connection pad 14 Inner peripheral surface 15 Bonding material 17 Lens 20 (20a, 20b, 20c, 20d) Light emitting element 20A Light emitting element group 20Aa 1st light emitting element Group 20 Ab Second light emitting element group 21 Element substrate 22 Semiconductor layers 23 and 24 Element electrode 30 Sealing material 40 Laminate 41 First insulating layer 42 Second insulating layer 50 Electrical wiring 60 Lens adhesive 110 Heat radiation member 120 Adhesive 200 Printing device 210 Conveying means 211 Loading table 212 Conveying roller 220 Printing means 220a Discharge hole 230 Control mechanism 250 Recording medium

Claims (6)

A light irradiation device for irradiating a relatively moving object with light,
A base, a plurality of light emitting elements having a plurality of light emitting elements arranged vertically and horizontally on the upper surface of the base, and light emitted from the light emitting elements provided to cover each of the light emitting elements; And a plurality of lenses for emitting light to
A light irradiation device, wherein an optical axis of light emitted through each of the plurality of lenses is determined by controlling irradiance of each of the plurality of light emitting elements.   The light irradiation device according to claim 1, wherein the irradiance is controlled by an amount of electric power applied to each of the plurality of light emitting elements.   The light irradiation device according to claim 1, wherein the irradiance is controlled by a value of irradiance with respect to an applied power per unit of each of the plurality of light emitting elements.   The light irradiation device according to claim 1, wherein the irradiance is controlled by a value of a light emitting area of each of the plurality of light emitting elements.   A light irradiation module, wherein a plurality of the light irradiation devices according to any one of claims 1 to 4 are placed on a heat radiating member. Printing means for printing on a recording medium;
A printing apparatus comprising: the light irradiation module according to claim 5, which irradiates light onto the printed recording medium.

Images