JP2011152760A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable printer. <P>SOLUTION: The printer 10 is equipped with: a conveyer mechanism 20 for conveying a recording medium 90 in a first direction D1 and D2; an inkjet head 30 as an adhering mechanism for making UV ink as a photosensitive material adhere to the recording medium 90; and a light irradiating head 40 provided with a plurality of light emitting elements 43 for emitting light to which the UV ink is exposed. The plurality of light emitting elements 43 are divided into a plurality of light emitting groups 43a, and electric power is supplied for each light emitting group 43a. The plurality of light emitting groups 43a are arrayed along the first direction D1 and D2. Each light emitting element 43 in the light emitting group 43a are arrayed along a second direction D3 and D4 crossing the first direction D1 and D2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to 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 the UV ink is not irradiated with UV light, the UV ink may remain without being cured. Therefore, when a part of the UV-LED array stops emitting light, it is necessary to stop and replace the printing apparatus. In industrial applications, when the printing apparatus is stopped, the production efficiency is significantly reduced.

  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 printing apparatus with high reliability.

  The printing apparatus of the present invention includes a transport mechanism that transports a recording medium in a first direction, an attachment mechanism that attaches a photosensitive material to the recording medium, and a plurality of light emitting elements that emit light that sensitizes the photosensitive material. The plurality of light emitting elements are divided into a plurality of light emitting element groups, and the plurality of light emitting element groups are arranged along the first direction, Each light emitting element of the light emitting element group is arranged along a second direction intersecting the first direction.

  According to the present invention, a highly reliable printing apparatus can be provided.

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. It is a schematic block diagram of the light irradiation head with which the printing apparatus shown in FIG. 1 is provided. It is a principal part enlarged view of the light irradiation head shown in FIG. It is sectional drawing along the VV line shown in FIG. FIG. 4 is an electric circuit diagram of the light irradiation head shown in FIG. 3. It is a schematic block diagram which shows the modification of the light irradiation head shown in FIG. It is a principal part enlarged view of the light irradiation head 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.

<Printing device>
The printing apparatus 10 illustrated in FIGS. 1 and 2 includes a transport mechanism 20, an inkjet head 30 as an attachment mechanism, a light irradiation head 40, and a control mechanism 50.

  The transport mechanism 20 has a function of transporting the recording medium 90 in the first directions D1 and D2. The transport mechanism 20 is configured such that the recording medium 90 passes through the inkjet head 30 and the light irradiation head 40 in this order. The transport mechanism 20 includes a mounting table 21 and a transport roller 22. The mounting table 21 mounts the recording medium 90, and the transport roller 22 moves the recording medium 90 in the first directions D1 and D2.

  The ink jet head 30 has a function of adhering a photosensitive material to the recording medium 90 conveyed through the conveyance mechanism 20. The ink jet head 30 is configured to eject droplets containing the photosensitive material toward the recording medium 90 and 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 30. The ink jet head 30 is longer than the recording medium 90 in the second directions D3 and D4 intersecting the first directions D1 and D2, 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 30 has a plurality of ejection holes 30a, and is configured to eject UV ink from the ejection holes 30a. The inkjet head 30 is provided with a plurality of ejection holes 30a at intervals such that the UV ink adhering to the first main surface of the recording medium 90 is not spaced in the second directions D3 and D4.

  In the present embodiment, the inkjet head 30 is taken as an example of the attachment mechanism, but is not limited thereto. 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.

  The light irradiation head 40 shown in FIGS. 3 to 6 has a function of exposing a recording medium 90 to which a photosensitive material is adhered, which is transported through the transport mechanism 20. The light irradiation head 40 is provided on the downstream side of the inkjet head 30 in the first directions D1 and D2. The light irradiation head 40 includes a support base 41, a plurality of support substrates 42, a plurality of light emitting elements 43, a wiring conductor 44, and a sealing material 45.

  The support base 41 has a function of supporting the plurality of support substrates 42. A plurality of support substrates 42 are arranged on the support base 41. Examples of the material for forming the support base 41 include various metal materials, ceramics, and resin materials. The support base 41 is preferably a material having a high thermal conductivity. The support base 41 of this embodiment is made of copper.

  The support substrate 42 has a function of supporting the plurality of light emitting elements 43. A plurality of support substrates 42 are provided on the support base 41 and are arranged along the first directions D1 and D2. A plurality of recesses 42 a are provided on the upper surface of the support substrate 42. The recesses 42a are arranged in the second directions D3 and D4.

  The support substrate 42 of the present embodiment includes a first substrate 421 and a second substrate 422. The second substrate 422 is provided on the first substrate 421. The second substrate 422 has a through hole 422a. One of the openings of the through hole 422a is closed by the first substrate 421. The concave portion 42a of the support substrate 42 is formed by the through hole 422a of the second substrate and the first substrate 421 blocking one of the openings of the through hole 422a.

  The support substrate 42 is made of, for example, an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, ceramics such as glass ceramics, epoxy resin, and resin such as liquid crystal polymer (LCP). It is formed.

  In the manufacturing method of the support substrate 42 when the support substrate 42 is made of ceramics or the like, first, a plurality of green sheets to be the support substrate 42 are prepared by firing. Next, a metal paste that becomes the wiring conductor 44 through the electrical connection between the light emitting element 43 and the input terminal is disposed between the green sheets. Examples of the metal paste that becomes the wiring conductor 44 include those containing metals such as tungsten (W), molybdenum (Mo), manganese (Mn), and copper (Cu). Next, the support substrate 42 having the wiring conductors 44 can be formed by firing the metal paste together with firing the support substrate 42. Such a wiring conductor 44 may be formed using the known metallization method, plating method or the like.

  In the manufacturing method of the support substrate 42 in the case where the support substrate 42 is an insulator made of a resin, first, a resin precursor that becomes the support substrate 42 is prepared by curing. Next, the lead terminal that becomes the wiring conductor 44 through the electrical connection between the light emitting element 43 and the input terminal is embedded in the resin precursor that becomes the support substrate 42. When embedding in the precursor, one end of the lead terminal is led out to the mounting portion on the light emitting element 43 side, and the other end is exposed from the side surface and the lower surface of the support substrate 42, 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 43 has a function of exposing the photosensitive material attached to the recording medium. A plurality of the light emitting elements 43 are provided on the support substrate 42, and are provided in the recesses 42a. That is, the light emitting elements 43 are arranged in the second directions D3 and D4 that intersect the first directions D1 and D2.

  The light emitting element 43 is configured by providing a light emitting layer 432 on the first main surface of the element substrate 431. Examples of the element substrate 431 include sapphire. As this light emitting layer 432, for example, a known layer made of a compound semiconductor such as GaN can be cited. In the present embodiment, the light emitting layer 432 is provided on the main surface on the side facing the upper surface of the first substrate 421 among the two main surfaces of the element substrate 431 in order to flip-chip connect the light emitting element 43. ing.

  In the present embodiment, the light emitting layer 432 emits UV light having a wavelength peak spectrum of 380 [nm] or less. That is, in this embodiment, a UV-LED element is employed as the light emitting element 43. In the light emitting layer 432, a plurality of semiconductor layers are stacked on the first main surface of the element substrate 431 (this semiconductor layer is not shown individually). More specifically, for example, the light emitting layer 432 includes, from the first main surface of the element substrate 431, 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 433 and 434 mainly composed of Ag, for example, are provided on the surface of the light emitting layer 432 on the side facing the first substrate 421. These element electrodes 433 and 434 provided on the surface of the light emitting layer 432 are connected to a wiring conductor 44 provided on the support substrate 42. The light emitting element 43 according to the present embodiment is arranged in a flip chip state on one main surface of the first substrate 421. The light emitting layer 432 emits light having a light amount corresponding to the amount of current flowing between the device electrodes 433 and 434. The element substrate 431 of this embodiment is made of sapphire and has relatively good transparency with respect to the light emitted from the light emitting layer 432. In the present embodiment, the light emitting element 43 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 43 having a size of about 0.6 [mm] × 0.6 [mm] in a plan view of the light emitting layer 432 is formed on the first main surface of the first substrate 421 by about 2. They are arranged vertically and horizontally at a relatively small mounting interval of 6 mm.

  In the light irradiation head 40, the light emitted from the light emitting element 43 toward the inner peripheral surface of the through hole 422a of the second substrate 422 is reflected upward by the inner peripheral surface of the through hole 422a. It is configured to efficiently irradiate upward. The second substrate 422 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 422 include an aluminum oxide sintered body, a zirconium oxide sintered body, and an aluminum nitride sintered body. The second substrate 422 may be made of an epoxy resin and a resin such as a liquid crystal polymer (LCP). Further, in order to achieve the desired reflectivity, a metallic reflective film is formed on the inner peripheral surface of the through hole 422a of the second substrate 422 according to the material of the second substrate 422, the wavelength of light emitted from the light emitting element 43, 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 44 is responsible for electrical connection of the plurality of light emitting elements 43. The wiring conductor 44 of this embodiment is provided with a wiring electrode 44a on the bottom surface of the recess 42a. The wiring electrode 44 a is electrically connected to the element electrodes 433 and 434 of the light emitting element 43.

  The wiring conductor 44 of the present embodiment constitutes a light emitting element group 43a by electrically connecting a plurality of light emitting elements 43 in parallel. The light emitting elements 43 of the light emitting element group 43a are arranged in the second directions D3 and D4. That is, in this embodiment, since each light emitting element 43 that constitutes one light emitting element group 43a is electrically connected in parallel, a part of the wiring conductor 44 is electrically disconnected or short-circuited. In some cases, part of the light emitting element 43 can continue to emit light. Therefore, the printing apparatus 10 according to the present embodiment enables continuous operation while minimizing performance degradation, and can improve reliability.

  Further, a plurality of light emitting element groups 43a are configured. The plurality of light emitting element groups 43a are electrically connected in series. Furthermore, in the light irradiation head 40 of this embodiment, the light emitting element 43 provided on the one support substrate 42 is comprised as two light emitting element groups 43a. The two light emitting element groups 43a are electrically connected in series. Thus, even if the light irradiation head 40 of this embodiment connects the light emitting element group 43a which consists of the several light emitting element 43 mutually electrically connected in parallel electrically in series, it is the wiring conductor 44. Even if a part of the LED is electrically disconnected or short-circuited, the remaining light-emitting element 43 can continue to emit light, and the circuit configuration can be kept simple. Therefore, the printing apparatus 10 according to the present embodiment enables continuous operation while minimizing performance degradation, and can improve reliability.

  As the sealing material 45, a material that favorably transmits light emitted from the light emitting element 43 is selected. As this sealing material 45, a silicone resin is mentioned, for example. In addition, a material closer to the refractive index of the element substrate 431 is selected as the refractive index of the sealing material 45 than about 1.0 which is the refractive index of air. The sealing material 45 of this 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 the element substrate 431.

  The control mechanism 50 has a function of controlling the light emission of the light irradiation head 40. The memory of the control mechanism 50 stores information indicating the characteristics of light that makes it relatively good to cure the ink droplets ejected from the inkjet head 40. 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 10 of the present embodiment, by including the control mechanism 50, the magnitude of the drive current input to the plurality of light emitting layers 432 can be adjusted based on the stored information of the control mechanism 50. Therefore, according to the printing apparatus 10, it is possible to irradiate 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.

  Furthermore, the control mechanism 50 of the present embodiment is configured to increase the light emission intensity per light emitting element when the number of light emitting elements 43 to which power can be supplied decreases. In the present embodiment, the printing apparatus 10 of the present embodiment is configured as described above, thereby suppressing the amount of light necessary for curing the UV ink from being insufficient. Therefore, the printing apparatus 10 according to the present embodiment enables continuous operation while minimizing performance degradation, and can improve reliability. Such a detection of the number of light emitting elements 43 that can supply power can be performed by measuring a variation in resistance value from the supplied power, for example. Further, when the number of light emitting elements 43 to which power can be supplied decreases, it is possible to suppress the shortage of the amount of light necessary for curing the UV ink by slowing the conveyance speed 90 of the recording medium 90. it can.

  The printing apparatus 10 of the present embodiment includes a transport mechanism 20 that transports the recording medium 90 in the first directions D1 and D2, an inkjet head 30 as an attachment mechanism that attaches UV ink as a photosensitive material to the recording medium 90, and And a light irradiation head 40 provided with a plurality of light emitting elements 43 that emit light for sensitizing the UV ink. The plurality of light emitting elements 43 are divided into a plurality of light emitting element groups 43a, and power is supplied to each of the light emitting element groups 43a. The plurality of light emitting element groups 43a are arranged along the first directions D1 and D2. The light emitting elements 43 of the light emitting element group 43a are arranged along second directions D3 and D4 that intersect the first directions D1 and D2.

  In the printing apparatus 10, the transport mechanism 20 transports the recording medium 90 in the first directions D1 and D2. The inkjet head 30 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 this printing apparatus 10, UV ink emitted from the light irradiation head 40 is irradiated to the UV ink attached to the recording medium 90 to cure the UV ink.

  In the printing apparatus 10 according to the present embodiment, the first directions D1 and D2 that are the conveyance direction of the recording medium 90 and the second directions D3 and D4 that are the arrangement directions of the light emitting elements 43 of the light emitting element group 43a intersect each other. Yes. Therefore, in this printing apparatus 10, the recording medium 90 is conveyed by being irradiated with light emitted from at least one of the light emitting element groups 43a. Therefore, in this printing apparatus 10, even when any of the light emitting element groups 43a stops emitting light, the UV ink that is a photosensitive material can be exposed and cured.

  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 10 using the inkjet head 30 is shown. The light irradiation head 40 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 an object. In addition, for example, it may be used as an irradiation light source in an exposure apparatus, and the light emission from a plurality of light emitting elements is controlled independently, for example, the surface of the photosensitive material is selectively irradiated with the light. It can also be used in an image forming apparatus that forms an image corresponding to light.

  Further, the embodiment of the printing apparatus 10 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 light irradiation head 40 of the present embodiment, the support substrates 42 are provided in a line along the first directions D1 and D2 on the support base 41. However, the present invention is not limited to this configuration, and there are two or more lines. May be.

  In the light irradiation head 40 of the present embodiment, a plurality of (two) light emitting element groups 43a of the light emitting elements 43 provided on one support substrate 42 are configured. Absent. For example, as shown in FIGS. 7 and 8, all of the plurality of light emitting elements 43 provided on one supporting substrate 42 may constitute one light emitting element group, or a plurality of supporting substrates. The light emitting element 43 provided on 42 may constitute one light emitting element group.

  In the light irradiation head 40 of the present embodiment, all of the light emitting elements 43 constituting one light emitting element group 43a are electrically connected in parallel, but may be electrically connected in series, Series and parallel may be mixed. In the printing apparatus of the present invention, since the light emitting elements of the light emitting element group are arranged along the second direction intersecting the first direction, when there are light emitting elements that are electrically connected in series, Excellent effect.

DESCRIPTION OF SYMBOLS 10 ... Printing apparatus 20 ... Conveyance mechanism 21 ... Mounting stand 22 ... Conveyance roller 30 ... Inkjet head 30a ... Discharge hole 40 ... Light irradiation head 41 ... Support base 42 ... support substrate 42a ... recess 421 ... first substrate 422 ... second substrate 422a ... through hole 43 ... light emitting element 43a ... light emitting element group 431 ... element substrate 432 ... Light emitting layer 433,434 ... Element electrode 44 ... Wiring conductor 44a ... Wiring electrode 45 ... Sealing material 50 ... Control mechanism 90 ... Recording medium

Claims (4)

A transport mechanism that transports the recording medium in the first direction; an attachment mechanism that attaches a photosensitive material to the recording medium; and a light irradiation head that includes a plurality of light emitting elements that emit light that sensitizes the photosensitive material; , And
The plurality of light emitting elements are divided into a plurality of light emitting element groups, and power is supplied to each of the light emitting element groups.
The plurality of light emitting element groups are arranged along the first direction,
Each light emitting element of the said light emitting element group is a printing apparatus arranged along the 2nd direction which cross | intersects the said 1st direction.   The printing apparatus according to claim 1, wherein each light emitting element of one light emitting element group is electrically connected in parallel.   The printing apparatus according to claim 1, wherein the transport mechanism is configured to reduce a transport speed of the recording medium when the number of the light emitting element groups that supply power decreases.   The light irradiation head is configured to increase the light emission intensity of the plurality of light emitting elements when the number of the light emitting element groups supplying power decreases. Printing device.

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