JP2012135714A - Light irradiation device, and printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light irradiation device and a printing device with less thermal influence by ultraviolet irradiation.SOLUTION: The light irradiation device for irradiating light to an object with light transmitting property to which ultraviolet curable ink or ultraviolet curable resin is attached has a pair of light irradiating devices arranged so as to face each other in a surface to be attached of the ultraviolet curable ink or the ultraviolet curable resin of the object and a surface not to be attached located in a position opposite side to the surface to be attached respectively, the pair of light irradiating devices has a plurality of light emitting elements arranged in longitudinal and lateral lines in the base body and the main surface of the objective side of the base body, the number of the light emitting elements in the light irradiating device of the side of the surface not to be attached is less than the number of the light emitting elements in the light irradiation device of the side of the surface to be attached, thereby the thermal influence from the light emitting devices can be relatively reduced because light brightness of the light emitting elements can be relatively lowered.

Description

  The present invention relates to a light irradiation apparatus 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. High pressure mercury lamps are used as lamp light sources for UV irradiation devices used for curing UV curable resins used for bonding small parts in the field of electronic components, etc., and UV curable inks used in the field of printing. And metal halide lamps are used.

  In recent years, reduction of global environmental load is desired on a global scale, so there is an active movement to adopt UV light emitting elements as lamp light sources that can suppress the generation of ozone and heat with relatively long life, energy saving. It has become to.

  However, even when an ultraviolet light emitting element capable of relatively suppressing the generation of heat is used as a lamp light source, if the ultraviolet ray is irradiated onto a heat sensitive plastic film or the like, the plastic film contracts due to the heat generated from the lamp light source. Such problems occur. Therefore, for example, as described in Patent Document 1, an apparatus for cooling an object while performing ultraviolet irradiation has been proposed.

  However, since such a device is a complicated and large-sized device that requires the provision of a cooler, it is possible to reduce the size of the light by using an ultraviolet light emitting element and sufficiently curing the ultraviolet ray while having a relatively small heat influence. An irradiation device was desired.

JP-A-11-170683

  This invention is made | formed in view of the said problem, and it aims at providing the light irradiation apparatus and printing apparatus with little heat influence by ultraviolet irradiation.

  A light irradiation apparatus according to the present invention is a light irradiation apparatus for irradiating light to a light-transmitting target object coated with ultraviolet curable ink or ultraviolet curable resin, A pair of light irradiation devices disposed so as to oppose the adherend surface of the ultraviolet curable ink or the ultraviolet curable resin and the non-adhesion surface located on the opposite side of the adherend surface, Each of the pair of light irradiating devices has a base and a plurality of light emitting elements arranged vertically and horizontally on the main surface of the base on the object side, and the light emission in the light irradiating device on the non-attached surface side The number of elements is smaller than the number of the light emitting elements in the light irradiation device on the deposition surface side.

  Further, the wavelength of the light emitted from the light emitting device in the light irradiation device on the non-attached surface side is longer than the wavelength of the light emitted from the light emitting device in the light irradiation device on the attachment surface side. Features.

  Furthermore, the distance from the light emitting element to the object in the light irradiation device on the non-adhering surface side is shorter than the distance from the light emitting element to the object in the light irradiation device on the adhesion surface side. It is characterized by that.

  In addition, a reflection plate that reflects light incident on the main surface toward the main surface is disposed on the main surface side of the base in the light irradiation device on the non-adhering surface side. And

  Furthermore, the present invention provides a conveying means for conveying a light-transmitting recording medium, a printing means for printing an ultraviolet curable ink or an ultraviolet curable resin on the recording medium, and the printed recording medium. And a printing apparatus characterized by having a light irradiation device for irradiating light.

  According to the light irradiation apparatus of the present invention, there is provided a light irradiation apparatus for irradiating light onto a light-transmitting object on which an ultraviolet curable ink or an ultraviolet curable resin is applied, and the object A pair of light irradiating devices disposed so as to oppose the surface to which the ultraviolet curable ink or the ultraviolet curable resin is applied and the non-adhered surface located on the opposite side of the applied surface, Each of the pair of light irradiation devices includes a base and a plurality of light emitting elements arranged vertically and horizontally on a main surface of the base on the object side, and the light irradiation device on the non-attached surface side of the light irradiation device Since the number of light emitting elements is smaller than the number of the light emitting elements in the light irradiation device on the adherend surface side, the light illuminance of the light emitting elements can be made relatively low. As a result, a miniaturized light irradiating apparatus is realized in which UV curing is sufficiently performed and the thermal influence from the light emitting element is relatively small.

FIG. 1 is a schematic view of a light irradiation apparatus according to an embodiment of the present invention. FIG. 2 is a plan view of the light irradiation device shown in FIG. FIG. 3 is a cross-sectional view taken along line 2I-2I in the light irradiation device shown in FIG. FIG. 4A shows the arrangement of the light emitting elements of the light irradiation device 2a according to the embodiment of the present invention, and FIG. 4B shows the arrangement of the light emitting elements of the light irradiation device 2b according to the embodiment of the present invention. It is a figure explaining. FIG. 5 is a top view of a printing apparatus using the light irradiation module shown in FIG. 6 is a side view of the printing apparatus shown in FIG.

  Hereinafter, a light irradiation apparatus and a printing apparatus of the present invention will be described with reference to the drawings.

(Embodiment of light irradiation device)
A light irradiation apparatus 1 shown in FIG. 1 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 light transmissive object 4 (recording medium) with the ultraviolet curable ink. It functions as an ultraviolet irradiation device that cures the ultraviolet curable ink 3 by irradiating ultraviolet rays after being applied.

The light irradiation apparatus 1 includes a pair of light irradiation devices 2, and the surface of the object 4 to which the ultraviolet curable ink 3 is applied and the object so as to sandwich the object 4 to which the ultraviolet curable ink 3 is applied. It arrange | positions so that it may each oppose to the non-adhesion surface located in the opposite side to the adhesion surface of the ultraviolet curable ink 3 of the thing 4. In addition, the number of light emitting elements 20 included in the light irradiation device 2 on the non-attachment surface side is smaller than the number of light emitting elements 20 included in the irradiation device 2 on the attachment surface side. By arranging in this way, it becomes possible to relatively reduce the illuminance of ultraviolet rays irradiated from each light irradiation device 2, while sufficiently curing the ultraviolet curable ink 3 applied to the object 4, The thermal influence on the object 4 can be made relatively small. The reason why the thermal influence on the object 4 can be made relatively small will be described in detail after the description of the next light irradiation device 2.

  Here, the light irradiation device 2 which comprises the light irradiation apparatus 1 is demonstrated using FIG. 2, FIG.

  The light irradiation device 2 functions as an ultraviolet irradiation light source of the light irradiation apparatus 1.

  The light irradiation device 2 is disposed in the base 10 having a plurality of openings 12 on one main surface 11a, a plurality of connection pads 13 provided in the openings 12, and in the openings 12 of the base 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 openings 12 and covering the light emitting elements 20, and an adhesive on the other main surface 11 b of the substrate 10 50, and a heat radiating member 60.

  The base 10 includes a stacked body 40 in which a first insulating layer 41 and a second insulating layer 42 are stacked, and an electric wiring 60 that connects the light emitting elements 20 to each other, and is viewed from the main surface 11a side in plan view. The light emitting element 20 is supported in the opening 12 provided on the upper surface.

  The first insulating layer 41 includes, for example, an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, ceramics such as glass ceramics, and resins such as epoxy resins and liquid crystal polymers (LCP). , Etc.

  Next, the electrical wiring 60 is formed in a predetermined pattern using a conductive material such as tungsten (W), molybdenum (Mo), manganese (Mn), copper (Cu), and the like. Alternatively, it functions as a power supply wiring for supplying a current from the light emitting element 20.

  Next, in the second insulating layer 42 laminated on the first insulating layer 41, the opening 12 that penetrates the second insulating layer 42 is formed.

  The opening 12 has an inner peripheral surface 14 inclined so that each opening has a larger opening area on the one main surface 11a side of the substrate 10 than the surface on which the light emitting element 20 is mounted. For example, it has a substantially circular shape. The opening shape is not limited to a circle, and may be a substantially rectangular shape.

  Such an opening 12 has a function of reflecting light emitted from the light emitting element 20 upward on the inner peripheral surface 14 to improve 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, an oxide It is preferable to form a zirconium sintered body and an 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 entire main surface 11 a of the base body 10. For example, the light emitting elements 20 can be arranged at a higher density by arranging in a staggered pattern, and the illuminance per unit area can be increased. Here, arranging in a staggered lattice is synonymous with arranging at lattice points of an oblique lattice.

  If sufficient illuminance per unit area can be ensured, it may be arranged in a regular lattice shape or the like, and there is no need to limit the arrangement shape.

  The base 10 provided with the laminate 40 composed of the first insulating layer 41 and the second insulating layer 42 as described above, when the first insulating layer 41 and the second insulating layer 42 are made of ceramics or the like, It is manufactured through the following steps.

  First, a plurality of ceramic green sheets manufactured by a conventionally known method is prepared. A hole corresponding to the opening is formed in the ceramic green sheet corresponding to the opening 12 by a method such as punching. Next, a metal paste to be the internal wiring 60 is printed (not shown) on the green sheet, and then the green sheet is laminated so that the printed metal paste is positioned between the green sheets. Examples of the metal paste that becomes the internal wiring 60 include a paste containing a metal such as tungsten (W), molybdenum (Mo), manganese (Mn), and copper (Cu). Next, the substrate 10 having the internal wiring 60 and the opening 12 can be formed by firing the laminate and firing the green sheet and the metal paste together.

  Moreover, when the 1st insulating layer 41 and the 2nd insulating layer 42 consist of resin, the manufacturing method of the base | substrate 10 can consider the following methods, for example.

  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 internal wiring 60 are disposed between the precursor sheets and the lead terminals are embedded in the precursor sheets. Examples of the material for forming the lead terminal include metal materials such as Cu, Ag, Al, iron (Fe) -nickel (Ni) -cobalt (Co) alloy, and Fe-Ni alloy. 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.

  On the other hand, in the opening 12 of the base body 10, a connection pad 13 electrically connected to the light emitting element 20 and a bonding material 15 such as solder, gold (Au) wire, aluminum (Al) wire, etc. are connected to the connection pad 13. And the sealing material 30 for sealing the light emitting element 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, or aluminum (Al) wire.

  The light-emitting element 20 includes, for example, a light-emitting diode in which a p-type semiconductor layer and an n-type semiconductor layer made of a semiconductor material such as GaAs or GaN are stacked on an element substrate 21 such as a sapphire substrate, or a semiconductor layer made of an organic material. It is comprised by the organic EL element etc. which consist of.

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 through a bonding material 15 such as solder, gold (Au) wire, aluminum (Al) wire, or the like. Element electrodes 23 and 24 made of a metal material such as Ag are provided, and are wire-bonded to the base 10. 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, and emits the light to the outside through the element substrate 21. As is well known, 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 conventionally known flip connection technique using solder or the like as the bonding material 15.

  In the present embodiment, an LED that emits UV light having a wavelength peak spectrum of light emitted from the light emitting element 20 of, for example, 250 to 395 [nm] or less is employed. That is, in this embodiment, a UV-LED element is employed 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 formed of an insulating material such as a light-transmitting resin material, and prevents the entry of moisture from the outside by sealing the light emitting element 20 well, or from the outside. The impact is absorbed and the light emitting element 20 is protected.

  The sealing material 30 is 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), such as silicone. By being formed of 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.

  Moreover, the light irradiation device 2 can enhance the heat radiation effect by adhering to the heat radiating member 60 via an adhesive 50 such as a silicone resin or an epoxy resin. As a material for forming the heat radiating member 60, a material having high thermal conductivity is preferable. Examples thereof include various metal materials, ceramics, and resin materials.

  Although the light irradiation device 2 has the above-described configuration, the light irradiation device 2a is disposed so as to face the surface to which the ultraviolet curable ink 3 is attached, and is disposed so as to face the non-attachment surface. The number of light emitting elements 20 is different from the light irradiation device 2b. The number of light emitting elements 20 in the light irradiation device 2b is smaller than the number of light emitting elements 20 in the light irradiation device 2a.

  Specifically, for example, as illustrated in FIGS. 4A and 4B, the light emitting element 20 has a direction in which the object 4 moves relative to the light irradiation device 2 a and the light irradiation device 2 b. A plurality of light emitting element rows 25 are formed, and the number of light emitting element rows 25 of the light irradiation device 2b is smaller than that of the light irradiation device 2a. In the present embodiment, the number of light emitting elements 20 of the light irradiation device 2b is one half of the number of light emitting elements 20 of the light irradiation device 2a.

  The number of light emitting elements 20 included in the light irradiation devices 2a and 2b, the ratio of the number of light emitting elements 20 included in the light irradiation device 2a and the number of light emitting elements 20 included in the light irradiation device 2b, and the like are the types of ultraviolet curable ink. And the thickness to which the ink is applied, the type of the light-transmitting object 4, the thickness of the object 4, and the like may be appropriately adjusted.

  With such a configuration, the illuminance of ultraviolet rays emitted from the light irradiation devices 2a and 2b can be made relatively low, and the ultraviolet curable ink 3 attached to the object 4 can be sufficiently cured. The influence of heat on the object 4 can be made relatively small.

  Here, a mechanism for obtaining such an effect will be described in detail.

  In order to cure the ultraviolet curable ink 3, a predetermined integrated light quantity of ultraviolet rays is required. The integrated light quantity of ultraviolet rays is obtained by the product of the illuminance of ultraviolet rays and the time during which the ultraviolet rays are applied. That is, if the illuminance of ultraviolet rays is increased, curing of the ultraviolet curable ink 3 is completed in a short time. However, even when the light emitting element 20 that generates a relatively small amount of heat when the illuminance of ultraviolet rays is increased is used as the light source, the heat generated from the light emitting element 20 when the plastic film or the like that is easily affected by heat is the object 4. This causes a problem that the object 4 contracts.

  Therefore, when the light-transmitting plastic film or the like is the object 4, the surface of the object 4 on which the ultraviolet curable ink 3 is applied and the non-position located on the opposite side of the surface of the object 4 as in this embodiment. The light irradiation devices 2a and 2b are respectively arranged so as to face the adherend surface.

  By irradiating ultraviolet rays from above and below with the object 4 sandwiched in this manner, the illuminance of the ultraviolet rays of the light emitting elements 20 in the respective light irradiation devices 2a and 2b can be made relatively small. Heat to be generated can be relatively reduced.

  Further, it is generally known that curing of ultraviolet curable ink or ultraviolet curable resin by ultraviolet irradiation is damaged by oxygen in the air (oxygen inhibition). In other words, since all the irradiated ultraviolet rays do not contribute to the curing reaction of the ultraviolet curable ink or the ultraviolet curable resin, it is necessary to irradiate ultraviolet rays having a relatively high illuminance considering oxygen inhibition.

  However, according to the light irradiation device 1 of the present embodiment, since the ultraviolet light is irradiated from the non-adhered surface side of the ultraviolet curable ink 3 of the object 4, the illuminance of the ultraviolet light is further lowered. It becomes possible to do. This is because the non-adhered surface side of the ultraviolet curable ink 3 is covered with a light-transmitting object and is not easily affected by oxygen inhibition. This is because the ultraviolet curable ink 3 is sufficiently cured and can secure adhesion to the object 4. Therefore, the number of the light emitting elements 20 in the light irradiation device 2b disposed on the non-attached surface side of the ultraviolet curable ink 3 of the object 4 can be reduced.

  Furthermore, the second insulating layer 42 of the light irradiation devices 2a and 2b according to the present embodiment includes an aluminum oxide, a zirconium oxide sintered body, and an aluminum nitride sintered body that have relatively good reflectivity with respect to light in the ultraviolet region. Therefore, the ultraviolet rays irradiated from the light irradiation devices 2a and 2b and transmitted through the light-transmitting object 4 are the second insulation of the light irradiation devices 2b and 2a facing each other. Reflected by layer 42. In particular, since the number of the light emitting elements 20 in the light irradiation device 2b disposed on the non-attached surface side of the ultraviolet curable ink 3 of the object 4 is reduced, the one main surface 11a of the insulating layer 42 of the light irradiation device 2b. Can be made relatively wide, and more ultraviolet rays irradiated from the light irradiation device 2a and transmitted through the light-transmitting object 4 can be reflected. Therefore, the illuminance of the light emitting element 20 in the light irradiation device 2b can be further reduced.

  As described above, in the present embodiment, the number of the light emitting elements 20 of the light irradiation device 2b is one half of the number of the light emitting elements 20 of the light irradiation device 2a. However, as described above, the second insulating layer 42 is used. However, since it has the function to reflect the ultraviolet-ray which permeate | transmitted the transparent object 4, the number of the light emitting elements 20 of the light irradiation device 2b is a ratio of 50 to 90% of the number of the light emitting elements 20 of the light irradiation device 2a. It is preferable that

(Embodiment of printing apparatus)
As an embodiment of the printing apparatus of the present invention, the printing apparatus 200 shown in FIGS. 5 and 6 will be described as an example. The printing apparatus 200 includes a transport mechanism 210 for transporting a light-transmissive recording medium 250, an inkjet head 220 as a printing mechanism for printing on the transported recording medium 250, and a recording medium 250 after printing. And the control mechanism 230 for controlling the light emission of the light irradiation device 1. Here, the light transmissive recording medium 250 corresponds to the above-described light transmissive object 4.

  The transport mechanism 210 is for transporting the recording medium 250 so as to pass through the inkjet head 220 and the light irradiation device 1 in this order. The transport mechanism 210 and the mounting table 211 are opposed to each other and are rotatably supported. And a roller 212. The recording medium 250 supported by the mounting table 211 is sent between the pair of transport rollers 212, and the transport roller 212 is rotated to send the recording medium 250 in the transport direction.

  Here, the light irradiation devices 2a and 2b of the light irradiation apparatus 1 are disposed so as to face the surface to which the ultraviolet curable ink 3 of the recording medium 250 is attached and the non-attached surface opposite to the surface to be attached.

  The inkjet head 220 has a function of attaching a photosensitive material to the recording medium 250 conveyed via the conveyance mechanism 210. The ink-jet head 220 is configured to eject droplets containing the photosensitive material toward the recording medium 250 and adhere to the recording medium 250. In the present embodiment, ultraviolet curable ink is employed as the photosensitive material. Examples of the photosensitive material include a photosensitive resist and a photocurable resin in addition to the ultraviolet curable ink.

  In the present embodiment, a line-type inkjet head is adopted as the inkjet head 220. The inkjet head 220 has a plurality of ejection holes 220a arranged in a line, and is configured to eject ultraviolet curable ink from the ejection holes 220a. The inkjet head 220 ejects ink from the ejection holes 220a to the recording medium 250 transported in a direction orthogonal to the arrangement of the ejection holes 220a, and deposits the ink on the recording medium, thereby causing the recording medium to adhere to the recording medium. Printing is performed.

  In the present embodiment, a line-type inkjet head has been described as an example of the printing mechanism, but the present invention is not limited to this. For example, a serial-type inkjet head may be employed, A serial type spray head may be employed. Further, as the printing mechanism, an electrostatic head that accumulates static electricity of the recording medium 250 and attaches the photosensitive material with the static electricity may be employed, or the recording medium 250 is immersed in a liquid photosensitive material and the photosensitive medium is used. An immersion apparatus for attaching a conductive material may be employed. Further, a brush, a brush, and a roller may be employed as the 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 conveyance mechanism 210. The light irradiation device 1 is provided on the downstream side in the transport direction with respect to the inkjet head 220. In the printing apparatus 200, the light emitting element 20 has a function of exposing a photosensitive material attached to the recording medium 250.

The control mechanism 230 has a function of controlling the light emission of the light irradiation device 1. The memory of the control mechanism 230 stores information indicating light characteristics that make it relatively good to cure the ink droplets ejected from the inkjet head 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 the present embodiment, 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, it is possible to irradiate light with an appropriate amount of light according to the characteristics of the ink used, and it is possible to cure the ink droplets with relatively low energy light.

  In the printing apparatus 200, the transport mechanism 210 transports the recording medium 250 in the transport direction. The inkjet head 220 discharges 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.

  The printing apparatus 200 according to the present embodiment can enjoy the effects of the light irradiation apparatus 1. In the printing apparatus 200 of the present embodiment, the light irradiation apparatus 1 includes a pair of light irradiation devices 2, and the object 4 is attached so as to sandwich the object 4 to which the ultraviolet curable ink 3 is applied. It arrange | positions so that the surface and the non-adhesion surface located in the other side of the adhesion surface of the target object 4 may each be opposed. By arranging in this way, it becomes possible to relatively reduce the illuminance of ultraviolet rays irradiated from each light irradiation device 2, while sufficiently curing the ultraviolet curable ink 3 applied to the object 4, The thermal influence on the object 4 can be made relatively small.

  While specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  For example, in the above-described embodiment, the light irradiation device 2 is configured by the single base body 10, but a plurality of base bodies 10 may be arranged in the heat dissipation member 80 vertically and horizontally.

  Further, the wavelength of light emitted from the light emitting element 20 in the light irradiation device 2a disposed on the surface of the object 4 on which the ultraviolet curable ink 3 is applied is the non-attached surface located on the opposite side of the attached surface. It may be shorter than the wavelength of the light emitted by the light emitting element 20 in the light irradiation device 2b arranged on the side. One of the mechanisms of oxygen inhibition in the ultraviolet curing reaction described above is considered to be that the curing reaction of the ultraviolet curable ink and the ultraviolet curable resin is inhibited by oxygen combined with the ultraviolet curable ink and the ultraviolet curable resin. However, it is known that short-wavelength ultraviolet rays have an effect of separating the ultraviolet curable ink and ultraviolet curable resin from the oxygen associated therewith. Therefore, when the wavelength of the light irradiated by the light emitting element 20 in the light irradiation device 2a disposed on the surface to which the ultraviolet curable ink 3 is attached is short, the influence of oxygen inhibition can be relatively reduced.

  Furthermore, the distance from the light irradiation device 2b arranged on the non-adhesion surface side opposite to the adhesion surface side of the ultraviolet curable ink 3 to the object 4 is the light irradiation device arranged on the adhesion surface side. The distance from 2a to the object 4 may be shorter. By setting it as such a structure, the ultraviolet-ray irradiated from the light irradiation device 2a and permeate | transmitted the light-transmitting target object 4 can be reflected more efficiently, and the illumination intensity of the light emitting element 20 in the light irradiation device 2b is made. It can be further lowered.

  Further, a reflecting plate may be disposed on the one main surface 11a side of the substrate 10 in the light irradiation device 2b disposed on the non-attached surface side opposite to the attached surface side of the ultraviolet curable ink 3. By setting it as such a structure, the ultraviolet-ray which injected toward the one main surface 11a can be reflected more efficiently. As a material for the reflector, metals such as gold (Au), silver (Ag), and copper (Cu) are preferable. A metal plate such as gold (Au), silver (Ag), or copper (Cu) may be deposited on a resin plate by plating or the like.

Furthermore, the embodiment of the printing apparatus 200 is not limited to the above embodiment. 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 present embodiment, an example in which the light irradiation device 1 is applied to the printing device 200 using the inkjet head 220 is shown. The light irradiation device 1 cures, for example, a photo-curing resin spin-coated on the surface of the object. It can also be applied to the curing of various types of photo-curing resins such as dedicated devices. Moreover, you may use the light irradiation apparatus 1 for the irradiation light source etc. in an exposure apparatus, for example.

DESCRIPTION OF SYMBOLS 1 Light irradiation apparatus 2 Light irradiation device 3 Ultraviolet curable ink 4 Object 10 Base | substrate 11a One main surface 11b The other main surface 12 Opening part 13 Connection pad 14 Inner peripheral surface 15 Bonding material 20 Light emitting element 21 Element substrate 22 Semiconductor layer 23, 24 Element electrode 25 Light emitting element row 30 Sealing material 40 Laminate body 41 First insulating layer 42 Second insulating layer 50 Adhesive 60 Heat radiation member 200 Printing device 210 Conveying mechanism 211 Mounting table 212 Conveying roller 220 Inkjet head 220a Ejection Hole 230 control mechanism 250 recording medium

Claims (5)

A light irradiating device for irradiating light to a light-transmitting object coated with an ultraviolet curable ink or an ultraviolet curable resin,
A pair of light irradiation devices disposed so as to face the surface of the object to be coated with ultraviolet curable ink or ultraviolet curable resin and the non-coated surface located on the opposite side of the coated surface; And
Each of the pair of light irradiation devices includes a base and a plurality of light emitting elements arranged vertically and horizontally on a main surface of the base on the object side,
The number of the said light emitting elements in the said light irradiation device of the said non-adhering surface side is fewer than the number of the said light emitting elements in the said light irradiation device of the said adhesion surface side, The light irradiation apparatus characterized by the above-mentioned.   The wavelength of the light emitted from the light emitting device in the light irradiation device on the non-attached surface side is longer than the wavelength of the light emitted from the light emitting device in the light irradiation device on the adherend surface side. The light irradiation apparatus according to claim 1.   The distance from the light emitting element to the object in the light irradiation device on the non-adhering surface side is shorter than the distance from the light emitting element to the object in the light irradiation device on the adhesion surface side. The light irradiation apparatus according to claim 1, wherein the light irradiation apparatus is a light irradiation apparatus. In the light irradiation device on the non-adhering surface side, a reflecting plate that reflects light incident on the main surface toward the main surface is disposed on the main surface side of the base. Claim 1
4. The light irradiation apparatus according to any one of items 1 to 3. A conveying means for conveying a recording medium having optical transparency;
Printing means for printing ultraviolet curable ink or ultraviolet curable resin on the recording medium;
A printing apparatus comprising: the light irradiation apparatus according to claim 1, which irradiates light onto the printed recording medium.

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