JP5473673B2 - Light emitting element array and printing apparatus - Google Patents

Description

  The present invention relates to a light emitting element array and a printing apparatus.

  In recent years, printing methods using ultraviolet curable ink (UV ink) have attracted attention in industrial applications for reasons such as diversification of printing media, consideration for the environment, and increase in printing speed. In printing using UV ink, the UV ink is attached to a print medium, and the attached ink is irradiated with ultraviolet light (UV light) to cure the UV ink in a short time.

  Conventionally, fluorescent lamps such as a high-pressure mercury lamp and a low-pressure mercury lamp have been used as a light source of an ultraviolet irradiation head for curing such ultraviolet-curable ink. 2. Description of the Related Art Recently, for example, an ink jet recording apparatus described in Patent Document 1 is a printing apparatus using, as an irradiation light source, a UV-LED array in which a plurality of UV-LED elements that emit UV light are arranged on one main surface of a substrate. Proposed.

JP 2005-104108 A

  In a printing apparatus using this UV-LED array as an irradiation light source, if UV light is not irradiated to the UV ink, the UV ink remains without being cured. When attempting to connect UV-LED arrays mounted on a plurality of substrates in an attempt to expand the irradiation range of UV light, there may be a gap that is not irradiated with UV light.

  The present invention has been devised in view of such problems in the prior art. An object of the present invention is to provide a light emitting element array and a printing apparatus that can irradiate a wide range.

The light-emitting element array of the present invention contains a plurality of light-emitting elements arranged along a first direction and a second direction intersecting the first direction, and the plurality of light-emitting elements, and the light-emitting elements emit light. And a plurality of support substrates having a plurality of depressions that reflect light on the inner peripheral surface, wherein the plurality of support substrates are arranged adjacent to each other along the first direction. Chi said recess caries located at the end of the first sequence along the direction, the recess portion on the edge on the side adjacent to other of the support substrate, the inner circumferential surface outwardly in the first direction Tilted.

  The printing apparatus of the present invention includes the light emitting element array described above, a transport mechanism that transports the recording medium in the second direction, an attachment mechanism that attaches a photosensitive material that is sensitive to light emitted from the light emitting element to the recording medium, It has.

  According to the present invention, it is possible to provide a light emitting element array and a printing apparatus that can irradiate a wide range.

It is a schematic block diagram of the light irradiation head which shows an example of embodiment of the light emitting element array of this invention. It is the top view to which the principal part of the light irradiation head shown in FIG. 1 was expanded. It is sectional drawing along the III-III line shown in FIG. It is the figure which abbreviate | omitted the one part structure of the light irradiation head shown in FIG. It is the figure which expanded the principal part of the light irradiation head shown in FIG. It is a schematic block diagram of the light irradiation head which shows the other example of embodiment of the light emitting element array of this invention. FIG. 7 is an enlarged cross-sectional view of a main part of the light irradiation head shown in FIG. It is a schematic block diagram which shows an example of embodiment of the printing apparatus of this invention. It is a side view of the printing apparatus shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are illustrative, and the present invention is not limited to these embodiments.

<First Embodiment of Light-Emitting Element Array>
In this embodiment, the light irradiation head 10 shown in FIGS. 1-5 is employ | adopted as a light emitting element array. The light irradiation head 10 includes a support base 20, a plurality of support substrates 30, a plurality of light emitting elements 40, a wiring conductor 50, and a sealing material 60.

  The support base 20 has a function of supporting the plurality of support substrates 30. A plurality of support substrates 30 are arranged on the support base 20 along the first directions D1 and D2 and the second directions D3 and D4. Examples of the material for forming the support base 20 include various metal materials, ceramics, and resin materials. The support base 20 is preferably a material having a high thermal conductivity. The support base 20 of this embodiment is formed of copper.

  The support substrate 30 has a function of supporting the plurality of light emitting elements 40. A plurality of the support substrates 30 are arranged on the support base 20. The plurality of support substrates 30 are arranged along the first directions D1 and D2 and the second directions D3 and D4. The side surfaces of the plurality of support substrates 30 extend along the second directions D3 and D4. The support substrate 30 is formed with a plurality of recessed portions 30 a that are recessed from the upper surface. The recess 30a is arranged along the first direction D1, D2 and the second direction D3, D4.

  The support substrate 30 according to the present embodiment includes a first substrate 31 and a second substrate 32. The second substrate 32 is formed on the first substrate 31.

  The second substrate 32 has a through hole 32a penetrating in the thickness directions D5 and D6. The through hole 32 a has openings on the upper surface and the lower surface of the second substrate 32. The opening on the lower surface side of the through hole 32 a is closed with the first substrate 31. The recess 30a of the support substrate 30 is formed by the through hole 32a of the second substrate 32 and the first substrate 31 closing one of the openings of the through hole 32a.

Although the hollow part 30a of this embodiment is located in the end in the arrangement | sequence along 1st direction D1, D2, the internal peripheral surface inclines outside in 1st direction D1, D2. Moreover, as for the hollow part 30a, the internal peripheral surface inclines outside in the 1st direction D1, D2. This “outside in the first direction D1, D2” means that the one located on the D1 direction side from the center in the arrangement along the first direction D1, D2 is the D1 direction and located on the D2 direction side from the center. Things refer to the D2 direction. The hollow part 30a of this embodiment differs in the shape in 1st direction D1, D2. Specifically, the crossing angle θ between the extending direction of the inner peripheral surface of the recessed portion 30a and the normal direction of the bottom surface of the recessed portion 30a is different in the first directions D1 and D2. Here, recess crossing angle of the first direction D1, D2 in the direction D1 with respect to the first intersection angle theta ₁ of 30a, the crossing angle D2 direction in the first direction D1, D2 of the recess portion 30a second intersection an angle θ _2. If the inner peripheral surface is inclined in the direction D1 side in the first direction D1, D2, the first crossing angle theta ₁ is greater than the second cross angle theta _2. If D2 is inclined direction, the second crossing angle theta ₂ is larger than the first cross angle theta _1. The inclination of the inner peripheral surface of the recessed portion 30a of the present embodiment is adjusted so that light is irradiated to a predetermined range including between the adjacent support substrates 30 in the irradiated object. In this adjustment, it is important to irradiate light in a wide range in the first directions D1 and D2. The recess 30a may be configured such that light emitted from the light emitting elements 40 arranged on the plurality of support substrates 30 is reflected to the same region.

  The support substrate 30 is made of, for example, an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a ceramic such as a glass ceramic, an epoxy resin, and a resin such as a liquid crystal polymer (LCP). It is formed.

  In the manufacturing method of the support substrate 30 when the support substrate 30 is made of ceramics or the like, first, a plurality of green sheets to be the support substrate 30 are prepared by firing. Next, a metal paste that becomes the wiring conductor 50 through the electrical connection between the light emitting element 40 and the input terminal is disposed between the green sheets. As a metal paste used as this wiring conductor 50, what contains metals, such as tungsten (W), molybdenum (Mo), manganese (Mn), and copper (Cu), is mentioned, for example. Next, the support substrate 30 having the wiring conductor 50 can be formed by firing the metal paste together with firing the support substrate 30. Such a wiring conductor 50 may be formed using the known metallization method, plating method or the like.

  Moreover, in the manufacturing method of the said support substrate 30 in case the support substrate 30 is the insulator which consists of resin, the precursor of the resin used as the support substrate 30 is first prepared by hardening | curing. Next, the lead terminal that becomes the wiring conductor 50 through the electrical connection between the light emitting element 40 and the input terminal is embedded in the resin precursor that becomes the support substrate 30. When embedding in the precursor, one end of the lead terminal is led out to the mounting portion on the light emitting element 40 side, and the other end is exposed from the side surface and the lower surface of the support substrate 30, so that it is electrically connected to other elements. Can be connected. 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.

  The light emitting element 40 has a function of irradiating light. A plurality of the light emitting elements 40 are arranged on the support substrate 30. The light emitting element 40 is accommodated in the recess 30a. The light emitting element 40 is disposed at the center of the bottom surface of the recess 30a. Further, the light emitting element 40 is located on the D2 direction side in the first directions D1 and D2 from the center of the opening of the recess 30a. The greater the inclination of the inner peripheral surface toward the outside in the first direction D1, D2, the longer the distance between the center of the bottom surface of the recessed portion 30a and the center of the opening of the recessed portion 30a.

  The light emitting element 40 is configured by providing a light emitting layer 42 on a first main surface of an element substrate 41. Examples of the element substrate 41 include sapphire. Examples of the light emitting layer 42 include those made of a compound semiconductor such as GaN. In the present embodiment, a light emitting layer 42 is provided on the main surface on the side facing the upper surface of the first substrate 31 among the two main surfaces of the element substrate 41 in order to flip-chip connect the light emitting element 40. ing.

In the present embodiment, a material that emits UV light having a wavelength peak spectrum of light of 380 [nm] or less is employed. That is, in this embodiment, a UV-LED element is employed as the light emitting element 40. In the light emitting layer 42, a plurality of semiconductor layers are stacked on the first main surface of the element substrate 41 (note that the semiconductor layers are not shown individually). More specifically, for example, the light emitting layer 42 includes, from the first main surface of the element substrate 41, a first semiconductor layer of one of n-type and p-type conductivity, a first contact layer, A semiconductor layer of the second conductivity type opposite to the first semiconductor layer and a second contact layer are formed by being stacked in this order.

  In addition, element electrodes 43 and 44 mainly composed of Ag, for example, are provided on the surface of the light emitting layer 42 facing the first substrate 31. These device electrodes 43 and 44 provided on the surface of the light emitting layer 42 are connected to the wiring conductor 50 provided on the support substrate 30. The light emitting element 40 of the present embodiment is disposed in a flip chip state on one main surface of the first substrate 31. The light emitting layer 42 emits light having a light amount corresponding to the amount of current flowing between the device electrodes 43 and 44. The element substrate 41 of the present embodiment is made of sapphire and has relatively good transparency with respect to the light emitted from the light emitting layer 42. In the present embodiment, the light emitting element 40 is controlled by the amount of current, but may be controlled by the magnitude of the voltage.

  In the present embodiment, for example, the light emitting element 42 having a size of about 0.6 [mm] × 0.6 [mm] in a plan view is provided on the first main surface of the first substrate 31 with about 2. They are arranged with a relatively small mounting interval of 6 mm.

  In the light irradiation head 10, the light emitted from the light emitting element 40 toward the inner peripheral surface of the first recess 30 a of the second substrate 32 is reflected upward by the inner periphery of the first recess 30 a. , It is configured to efficiently irradiate upward in the figure. The second substrate 32 of the present embodiment is made of porous ceramic that is visually recognized as white under a white light source. This ceramic is selected so as to have a relatively good reflectivity with respect to light in the ultraviolet region, for example. Examples of the ceramic employed as the second substrate 32 include an aluminum oxide sintered body, a zirconium oxide sintered body, and an aluminum nitride sintered body. The second substrate 32 may be made of an epoxy resin and a resin such as a liquid crystal polymer (LCP). Further, in order to achieve desired reflectivity, a metallic reflective film is formed on the inner peripheral surface of the through hole 32a of the second substrate 32 according to the material of the second substrate 32, the wavelength of light emitted from the light emitting element 40, and the like. May be provided. Such a metallic reflective film can be formed by, for example, metal plating, vapor deposition, or the like.

  The wiring conductor 50 is responsible for electrical connection of the plurality of light emitting elements 40. In the wiring conductor 50 of the present embodiment, the wiring electrode 50a is provided on the bottom surface of the recess 30a. The wiring electrode 50 a is electrically connected to the element electrodes 43 and 44 of the light emitting element 40.

  As the sealing material 60, a material that transmits light emitted from the light emitting element 40 satisfactorily is selected. As this sealing material 60, a silicone resin is mentioned, for example. Further, a material closer to the refractive index of the element substrate 41 is selected as the refractive index of the sealing material 60 compared to about 1.0 which is the refractive index of air. The sealing material 60 of the present embodiment is formed of a silicone resin having a refractive index of about 1.4, and is formed of sapphire having a refractive index of 1.7 compared to air having a refractive index of about 1.0. The value is close to that of the element substrate 41.

The light irradiation head 10 accommodates a plurality of light emitting elements 40 arranged along a first direction D1, D2 and second directions D3, D4 intersecting the first direction D1, D2, and the plurality of light emitting elements 40. And a plurality of support substrates 30 having a plurality of depressions 30a that reflect light emitted from the plurality of light emitting elements 40 on the inner peripheral surface. The plurality of support substrates 30 are arranged along the first directions D1 and D2. As for the hollow part 30a located in the edge in the 1st arrangement along the 1st directions D1 and D2, the inner peripheral surface inclines outside on the 1st directions D1 and D2. Therefore, in this light irradiation head 10, the light reflected by the hollow part 30a can be irradiated to the outer side in the 1st direction D1, D2. Therefore, the light irradiation head 10 can irradiate light over a wide range even if a plurality of support substrates 30 are arranged.

<Second Embodiment of Light-Emitting Element Array>
The light irradiation head 10A of the present embodiment shown in FIGS. 6 and 7 is different from the light irradiation head 10 in that a support substrate 30A is employed. In the present embodiment, only differences from the light irradiation head 10 will be described. Moreover, about the component similar to the light irradiation head 10, the overlapping description is abbreviate | omitted using the same referential mark.

  Two support substrates 30A of this embodiment are arranged side by side in the first directions D1 and D2. The support substrate 30A has a recess 30Aa.

  The shape of the recessed portion 30Aa of the present embodiment is different between the two support substrates 30A arranged side by side in the first directions D1 and D2. Here, the recess portion of the support substrate 30A located on the D1 direction side is referred to as a first recess portion 30Ab, and the recess portion of the support substrate 30A located on the D2 direction side is referred to as a second recess portion 30Ac.

  As for this 1st hollow part 30Ab, the internal peripheral surface inclines to the D2 direction side in 1st direction D1, D2. The inclination of the inner peripheral surface increases as the first recess 30Ab is located on the D2 direction side.

  As for this 2nd hollow part 30Ac, the internal peripheral surface inclines to the D1 direction side in 1st direction D1, D2. The inclination of the inner peripheral surface is larger as the second depression 30Ac is located on the D1 direction side.

  In the light irradiation head 10A of the present embodiment, the inner peripheral surface is greatly inclined toward the D2 direction side in the first directions D1 and D2 as the first recess 30Ab moves from the D1 direction side to the D2 direction side. In the light irradiation head 10A of the present embodiment, the inner peripheral surface is greatly inclined toward the D1 direction side in the first directions D1 and D2 as the second hollow portion 30Ac goes from the D2 direction side to the D1 direction side. Therefore, in this light irradiation head 10A, the light reflected by the first depression 30Aa can be irradiated to the D2 direction side in the first directions D1 and D2. Moreover, in this light irradiation head 10A, the light reflected by 2nd hollow part 30Aa can be irradiated to the D1 direction side in 2nd direction D3, D4. Therefore, the light irradiation head 10A can irradiate light over a wide range even if the two support substrates 30A are arranged.

<Printing device>
As an embodiment of the printing apparatus of the present invention, the printing apparatus 1 shown in FIGS. 8 and 9 will be described as an example. The printing apparatus 1 includes a light irradiation head 10 as a light emitting element array, a transport mechanism 11, an inkjet head 12 as an attachment mechanism, and a control mechanism 13. Although the printing apparatus 1 of the present embodiment employs the light irradiation head 10 as the light emitting element array, the light irradiation head 10A may be employed.

  The transport mechanism 11 has a function of transporting the recording medium 90 in the second directions D3 and D4. The transport mechanism 11 is configured such that the recording medium 90 passes through the inkjet head 12 and the light irradiation head 10 in this order. The transport mechanism 11 includes a mounting table 111 and a transport roller 112. The mounting table 111 mounts the recording medium 90, and the transport roller 112 moves the recording medium 90 in the second directions D3 and D4.

  The ink jet head 12 has a function of attaching a photosensitive material to a recording medium 90 that is transported via the transport mechanism 11. The ink-jet head 12 is configured to eject droplets containing the photosensitive material toward the recording medium 90 so as to adhere to the recording medium 90. In the present embodiment, ultraviolet curable ink (UV ink) is used as the photosensitive material. Examples of the photosensitive material include, in addition to UV ink, a photosensitive resist, a photocurable resin, and the like.

  In the present embodiment, a line-type inkjet head is employed as the inkjet head 12. The inkjet head 12 is longer than the recording medium 90 in the first directions D1 and D2 intersecting the second directions D3 and D4, and causes the UV ink to adhere to the entire first main surface of the recording medium 90. It is configured. In the present embodiment, the first direction D1, D2 and the second direction D3, D4 are orthogonal. Further, the second direction is along the direction in which the first main surface of the recording medium 90 expands. In other words, the first main surface of the recording medium 90 extends in the surface direction constituted by the first directions D1, D2 and the second directions D3, D4.

  The inkjet head 12 has a plurality of ejection holes 12a, and is configured to eject UV ink from the ejection holes 12a. The inkjet head 12 is provided with a plurality of ejection holes 12a at intervals such that the UV ink attached to the first main surface of the recording medium 90 does not leave an interval in the first directions D1 and D2.

  In the present embodiment, the inkjet head 12 is taken as an example of the attachment mechanism, but the present invention is not limited to this. For example, a serial type ink jet head may be employed as the attachment mechanism. Moreover, you may employ | adopt a line type or a serial type spray head as an adhesion mechanism. Furthermore, an electrostatic head that accumulates static electricity of the recording medium 90 and adheres the photosensitive material with the static electricity may be employed as the attachment mechanism. Further, as the attachment mechanism, an immersion apparatus that immerses the recording medium 90 in a liquid photosensitive material and attaches the photosensitive material may be employed. Furthermore, you may employ | adopt a brush, a brush, and a roller as an adhesion mechanism.

  In the printing apparatus 1, the light irradiation head 10 has a function of exposing a recording medium 90 to which a photosensitive material is adhered, which is transported through a transport mechanism 11. The light irradiation head 10 is provided on the downstream side of the inkjet head 12 in the second directions D3 and D4. In the printing apparatus 1, the light emitting element 40 has a function of exposing the photosensitive material attached to the recording medium 90.

  The control mechanism 13 has a function of controlling the light emission of the light irradiation head 10. The memory of the control mechanism 13 stores information indicating the characteristics of light that makes it relatively good to cure the ink droplets ejected from the inkjet head 12. 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 1 according to the present embodiment, by including the control mechanism 13, the magnitude of the drive current input to the plurality of light emitting layers 42 can be adjusted based on the stored information of the control mechanism 13. Therefore, according to the printing apparatus 1, it is possible to irradiate the light with an appropriate amount of light according to the characteristics of the ink to be used, and it is possible to cure the ink droplets with relatively low energy light.

In the printing apparatus 1, the transport mechanism 11 transports the recording medium 90 in the second directions D3 and D4. The inkjet head 12 discharges UV ink to the recording medium 90 being conveyed, and causes the UV ink to adhere to the surface of the recording medium 90. At this time, the UV ink attached to the recording medium 90 may be attached to the entire surface, partially attached, or attached in a desired pattern. In the printing apparatus 1, UV ink emitted from the light irradiation head 10 is irradiated onto the UV ink attached to the recording medium 90 to cure the UV ink.

  The printing apparatus 1 according to the present embodiment can enjoy the effects of the light irradiation head 10. Therefore, the printing apparatus 1 can irradiate the recording medium 90 with UV light over a wide range. Therefore, the printing apparatus 1 can irradiate the photosensitive material with UV light.

  In the printing apparatus 1 according to the present embodiment, the UV light can also be irradiated to the region between the support substrates 30, so that the light irradiation head 10 can be disposed close to the recording medium 90. Therefore, this printing apparatus 1 is suitable for reducing the size.

  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.

  In this embodiment, the example which applied the light irradiation head to the printing apparatus 1 using the inkjet head 12 is shown. This light irradiation head 10 can be applied to curing various types of photo-curing resins, such as a dedicated device for curing a photo-curing resin spin-coated on the surface of the object. Further, for example, it may be used as an irradiation light source in an exposure apparatus.

  Further, the embodiment of the printing apparatus 1 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.

DESCRIPTION OF SYMBOLS 1 ... Printing apparatus 10 ... Light irradiation head 11 ... Conveyance mechanism 111 ... Mounting stand 112 ... Conveyance roller 12 ... Inkjet head 12a ... Discharge hole 13 ... Control mechanism 20 ... support base 30 ... support substrate 30a ... hollow part 31 ... first substrate 32 ... second substrate 32a ... through hole 40 ... light emitting element 41 ... element substrate 42 ... Light emitting layers 43, 44 ... Element electrode 50 ... Wiring conductor 50a ... Wiring electrode 60 ... Sealing material 90 ... Recording medium

Claims (6)

A plurality of light emitting elements arranged along a first direction and a second direction intersecting with the first direction and the plurality of light emitting elements are accommodated, and light emitted from the plurality of light emitting elements is reflected on the inner peripheral surface. A plurality of support substrates having a plurality of depressions,
The plurality of support substrates are arranged adjacently along the first direction,
The Chi sac the recess portion is located at an end of the first array along a first direction, the said recess located at the end on the side adjacent to other supporting substrate, the inner to the outer side in the first direction A light-emitting element array whose peripheral surface is inclined. In the cross section along the first direction, the hollow portion located at the end adjacent to the other support substrate is located on the outer side compared to the side located on the center side of the array. The light emitting element array according to claim 1, wherein an inclination angle of the inner peripheral surface is large.   2. The inner peripheral surfaces of the plurality of hollow portions located on one side from the center in the first array are inclined more outward in the first direction from the center toward the end. 3. The light emitting element array according to 2.   3. The light-emitting element array according to claim 1, wherein an inner peripheral surface of the plurality of hollow portions in the first array is greatly inclined outward in the first direction from the one side toward the other side.   5. The apparatus according to claim 4, further comprising: another support substrate whose inner peripheral surface is greatly inclined outward in the first direction as the plurality of depressions in the first array move from the other side toward the one side. The light emitting element array of description. The light emitting element array according to any one of claims 1 to 5,
A transport mechanism for transporting the recording medium in the second direction;
And an attachment mechanism for attaching a photosensitive material that is sensitive to light emitted from the light emitting element to the recording medium.

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