JP2009107191A - Ultraviolet irradiation apparatus and recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultraviolet irradiation head 320 equipped with an ultraviolet light source part 322. <P>SOLUTION: The ultraviolet irradiation apparatus is equipped with a reflecting mirror 324 which has a cross section that forms a partly-opened quadratic curve, a supporting member 321 whose region opposed to the reflecting mirror 324 of a sectional shape on a surface common to the cross section has a cross section that forms a part of a polygon or a circle centering a focal point f<SB>1</SB>of the reflecting mirror 324, and light emitting elements 325 which are disposed on a surface that includes each side or the periphery of the polygon to the supporting member 321 and radiate ultraviolet rays towards the reflecting mirror 324. The light emitting element 325 may be mounted on a surface of a flexible substrate 323 arranged following a surface of the supporting member 321. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultraviolet irradiation apparatus and a recording apparatus. More specifically, in an apparatus or facility for curing an ultraviolet curable resin, such as a recording apparatus using an ultraviolet curable ink, an ultraviolet irradiation apparatus that generates ultraviolet rays to irradiate the ultraviolet curable resin, and a recording provided therewith Relating to the device.

  The ultraviolet curable resin contains a photopolymerization initiator, and radicals generated by the irradiated ultraviolet rays form a polymerizable double bond to cure. Ultraviolet curable resins are often used as base materials for paints, inks, etc., as well as optical modeling materials and adhesives. As a method for attaching the ultraviolet curable ink to the recording medium, there are coating, printing, and the like, but the use of an ink jet method capable of accurately forming an arbitrary image or pattern without a printing plate is expected.

  The ultraviolet curable ink has a preferable characteristic as a printing ink, in which the curing is very slow until it is irradiated with ultraviolet rays, and it is rapidly cured when irradiated with ultraviolet rays. In addition, since the solvent is not volatilized or released during the curing process, there is an advantage that the environmental load is small.

By the way, use of a light emitting diode has been proposed as an ultraviolet light source in an ultraviolet irradiation device. Patent Document 1 below describes a recording apparatus in which a plurality of ultraviolet light-emitting diodes are provided adjacent to an inkjet head. Patent Document 2 below describes an ultraviolet irradiation device in which a plurality of ultraviolet light emitting diodes are arranged in a matrix. Further, Patent Document 3 below describes that a light emitting diode that emits ultraviolet light is disposed in the vicinity of the ink jet recording head and irradiated with ultraviolet light immediately after landing on the recording medium.
JP 2005-104108 A JP 2006-040944 A JP 2007-136988 A

  However, when a light emitting diode is used as an ultraviolet light source, a large number of elements must be mounted in order to obtain an irradiation amount required for ultraviolet curing. In addition, since the light emitting diode emits ultraviolet rays in a certain direction with respect to the element structure, a plurality of light emitting diodes are arranged on a single plane. For this reason, the ultraviolet irradiation device using a light emitting diode occupies a large area as the output increases.

  Therefore, in order to solve the above problem, as a first embodiment of the present invention, a reflecting mirror having a quadratic cross section including an opening that is partially opened, and a position farther from the opening inside the reflecting mirror. An ultraviolet light source arranged at the focal point of the quadratic curve, and the ultraviolet light source is a polygon or circle centering on the focal point of the reflecting mirror in a region facing the reflecting mirror in a cross-sectional shape in a plane including the cross section. There is provided an ultraviolet irradiation apparatus having a support member having a cross section that forms a part, and an ultraviolet light emitting element that is disposed on a circumferential surface of a polygon or a circle with respect to the support member and emits ultraviolet light toward a reflecting mirror. As a result, a pseudo point light source or line light source that emits ultraviolet rays radially can be obtained while using a light emitting diode as the light emitting element. Therefore, the occupation area of the ultraviolet light source can be reduced, and an appropriate irradiation pattern can be formed using an optical component such as a reflecting mirror to efficiently irradiate ultraviolet rays.

  In the ultraviolet irradiation device, the ultraviolet light emitting element may be mounted on the surface of the film substrate disposed following the surface of the support member. Thereby, a some ultraviolet light emitting element can be easily mounted | worn with respect to the supporting member which has arbitrary shapes. In addition, since the wiring for the ultraviolet light emitting element can be formed at the same time, the manufacturing process of the ultraviolet irradiation device can be simplified.

  Further, in the ultraviolet irradiation device, the support member may include a heat conducting portion that propagates heat from the back surface of the ultraviolet light emitting element to the outside. Thereby, the heat generated in the ultraviolet light emitting element can be efficiently propagated to the outside, and the ultraviolet irradiation apparatus can be operated stably.

  Still further, the ultraviolet light emitting element may be disposed in a region of the peripheral surface of the support member where the optical axis of the light emitted from the ultraviolet light emitting element is reflected by the reflecting mirror and emitted to the outside of the ultraviolet irradiation device. . As a result, since the emitted light is not converged by the reflecting mirror and the ultraviolet light emitting element that irradiates the recording medium with ultraviolet light with low efficiency is omitted, the number of light emitting elements can be reduced. Moreover, the electric power input into the ultraviolet light emitting element can be used efficiently.

  Still further, in the ultraviolet irradiation apparatus, the support member may be arranged such that a polygon included in a cross-sectional shape of the support member is positioned at one of the apexes on the axis of the reflecting mirror. By these, the ultraviolet-ray irradiated from the ultraviolet light emitting element can be efficiently guide | induced to irradiation object, and the input electric power can be utilized effectively.

  As a second embodiment of the present invention, a recording head that discharges ultraviolet curable ink while reciprocating along the surface of the recording medium, and an ultraviolet curable ink that is discharged from the recording head and adheres to the recording medium. An ultraviolet irradiation unit for irradiating ultraviolet rays on the recording medium, wherein the ultraviolet irradiation unit includes a reflecting mirror having a quadratic cross section including an opening that is partially open, and an opening inside the reflecting mirror. An ultraviolet light source disposed at a focal point of a quadratic curve located on the far side from the center, and the ultraviolet light source is centered on the focal point of the reflecting mirror in a region facing the reflecting mirror in a cross-sectional shape in a plane including the cross section Provided is a recording apparatus having a support member having a cross section that forms a part of a polygon or a circle, and an ultraviolet light emitting element that is disposed on the circumferential surface of the polygon or the circle with respect to the support member and emits ultraviolet rays toward a reflecting mirror Be doneThereby, the above-described effect can be enjoyed also in the recording apparatus.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. Further, a sub-combination of these feature groups can be an invention.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a perspective view showing an appearance of an ink jet recording apparatus 100 according to an embodiment. The ink jet recording apparatus 100 performs recording by ejecting ink onto a large single sheet such as a JIS standard A0 size or a JIS standard B0 size, or roll paper having the same paper width as the single sheet. In addition to paper, a resin film or the like can be used as the recording medium.

  As shown in the figure, the ink jet recording apparatus 100 includes a casing 110 including an upper casing 112 and a lower casing 114 that are stacked on each other, and a small casing 116 that is suspended below the lower casing 114. Have The housing 110 is lifted and supported by the legs 120 from below. As a result, a space for discharging the recorded recording paper 150 is formed below the housing 110.

  The upper casing 112 is provided with an operation panel 130 that is used when the ink jet recording apparatus 100 is operated in a stand-alone manner. The operation panel 130 may be provided with a display panel, a display lamp, and the like that indicate the operation state of the ink jet recording apparatus 100. On the other hand, the lower housing 114 is provided with a cartridge holder 140 into which an ink cartridge 240 containing ink is loaded.

  In the ink jet recording apparatus 100, the recording sheet 150 on which an image is recorded is sent forward from between the upper casing 112 and the lower casing 114. The fed recording sheet 150 hangs downward due to its own weight. Therefore, a smooth guide surface 252 that smoothly guides the recording paper 150 is formed at the front end of the suction platen 250 that can be seen in the gap between the upper housing 112 and the lower housing 114.

  FIG. 2 is a perspective view showing the ink jet recording apparatus 100 as seen from the back. As shown in the figure, on the rear surface of the ink jet recording apparatus 100, a spindle 160 that is horizontally stretched and a roll 152 that is horizontally supported by being inserted through the spindle 160 are disposed at the rear of the lower housing 114. Installed. The roll 152 is formed by winding a long recording sheet 150. The recording paper 150 shown in FIG. 1 corresponds to the front end of the recording paper 150 pulled out from the roll 152 and passing through the inside of the housing 110 and then pulled out to the front.

  FIG. 3 is a perspective view schematically showing the internal mechanism 200 of the ink jet recording apparatus 100. As shown in the figure, the internal mechanism 200 includes a guide shaft 270, a recording head assembly 230, and a suction platen 250.

  The guide shaft 270 extends horizontally in the longitudinal direction of the housing 110 in the ink jet recording apparatus 100. On the other hand, the recording head assembly 230 includes a recording head 310 and an ultraviolet irradiation head 320 that covers the recording head 310 from the upper surface to the side surface. The recording head assembly 230 is inserted through the guide shaft 270 and reciprocates in the reciprocating movement direction M along the guide shaft 270. The recording head assembly 230 includes a recording head 310 that discharges ultraviolet curable ink and a pair of ultraviolet irradiation heads 320 that sandwich the recording head 310 in the reciprocating direction. See FIG. 4 for the detailed structure thereof. Will be described later.

  Behind the guide shaft 270, a timing belt 220 hung on a pair of pulleys 260 is disposed. One of the pulleys 260 is rotationally driven by a carriage motor 222. As a result, the timing belt 220 travels parallel to the guide shaft 270 between the pulleys 260.

  A portion of the timing belt 220 is coupled to the recording head assembly 230. Thereby, the movement of the recording head assembly 230 can be controlled via a drive signal supplied to the carriage motor 222.

  Further, a linear scale 214 is arranged in parallel with the reciprocating movement direction M. The linear scale 214 includes a transparent carrier and a light shielding band formed on the carrier at a constant period in the reciprocating direction M. On the other hand, the recording head assembly 230 is provided with a detection unit that detects and counts light shielding bands. Thereby, the moving amount of the recording head assembly 230 is accurately detected. The guide shaft 270, the recording head assembly 230, the timing belt 220, and the linear scale 214 are accommodated in the upper housing 112.

  Below the moving range of the recording head assembly 230, along the conveyance direction S of the recording paper 150, a conveyance unit including the conveyance drive roller 212 and the suction platen 250 are arranged in this order. The transport driving roller 212 and the suction platen 250 are accommodated in the lower housing 114.

  The conveyance driving roller 212 is rotated by a conveyance motor, and rotates while the recording paper 150 is pressed by a conveyance driven roller (not shown). As a result, the recording paper 150 is pulled out from the roll 152 and sent out onto the suction platen 250.

  The suction platen 250 supports the recording paper 150 fed from the transport unit from below. The suction platen 250 has a large number of suction holes on the surface thereof that communicate with a decompression source such as a suction fan, and sucks the supported recording paper 150. As a result, even the recording paper 150 with curl or the like is held flat on the suction platen 250 below the recording head 310.

  Further, a flushing portion 290 and a cap 280 are sequentially arranged outside the suction platen 250 in the moving direction of the recording head assembly 230. The flushing unit 290 absorbs the ejected ink when the flushing for ejecting a large amount of ink from the recording head 310 is executed. By such flushing, the thickened ink can be removed from the recording head 310.

  Further, the cap 280 hermetically seals the lower surface of the recording head 310 during a period when the ink jet recording apparatus 100 is at rest. This prevents the ink from thickening or solidifying in the recording head 310.

  The ink jet recording apparatus 100 having the above structure executes a recording operation as follows. First, the conveyance drive roller 212 feeds the recording paper 150 onto the suction platen 250, and the suction platen 250 holds the conveyed recording paper 150 flat.

  The recording head 310 ejects ink toward the surface of the recording paper 150 while moving in the reciprocating movement direction M on the recording paper 150 supported on the suction platen 250. Hereinafter, the operation of transporting the recording paper 150 in the transport direction S by the transport unit 210 and the operation of reciprocating the recording head 310 in the reciprocating movement direction M on the recording paper 150 are alternately repeated, so that an arbitrary surface of the recording paper 150 is obtained. An image is formed by attaching ink to the region.

  With respect to the ultraviolet curable ink adhering to the recording paper 150, the ultraviolet rays irradiated from the ultraviolet irradiation head 320 on the side following the recording head 310 in the moving direction of the recording head assembly 230 at that time are applied to the recording paper 150. Irradiated immediately after adhering to. Accordingly, the ultraviolet curable ink is sequentially cured, and the image is fixed on the surface of the recording paper 150.

  FIG. 4 is a partially enlarged view showing the recording head assembly 230 extracted from the ink jet recording apparatus 100. As shown in the figure, the recording head assembly 230 includes a recording head 310 and a pair of ultraviolet irradiation heads 320 disposed with the recording head 310 sandwiched in the reciprocating movement direction M. On the lower surface of the recording head 310, nozzles for discharging ultraviolet curable ink are provided.

  Each of the ultraviolet irradiation heads 320 includes an ultraviolet light source unit 322 as an ultraviolet light source, and a reflecting mirror 324 that guides light emitted from the ultraviolet light source unit 322 downward. Thereby, the ultraviolet-ray radiated | emitted from the ultraviolet light source part 322 can be utilized efficiently.

  The reflecting mirror 324 is formed by processing an aluminum plate or the like to form a quadratic cross-sectional shape. The reflective surface can be mirror-finished. Thereby, the ultraviolet rays radiated from the ultraviolet light source unit 322 are efficiently reflected and can be radiated without waste toward the recording paper 150 to which the ultraviolet curable ink is attached.

  FIG. 5 is an enlarged view showing the internal structure of the ultraviolet irradiation head 320. As shown in the figure, the ultraviolet light source unit 322 disposed inside the reflecting mirror 324 includes a support member 321, a flexible substrate 323, and a light emitting element 325. Note that as the ultraviolet light-emitting element 325, a light-emitting diode made of indium gallium nitride (InGaN), gallium nitride (GaN), aluminum gallium nitride (AlGaN), or the like can be used.

  The ultraviolet rays emitted from the ultraviolet light source unit 322 generate ultraviolet rays including a band that can cure all types of ultraviolet curable ink ejected from the recording head 310. In view of such characteristics, a plurality of types of light emitting diodes can be mixed as the light emitting element 325 disposed in the ultraviolet light source unit 322. Thereby, the ultraviolet light source part 322 which emits light uniformly in a wide band can be formed without being limited by the characteristics of the individual light emitting diodes.

  The support member 321 is cylindrical and disposed horizontally. The flexible substrate 323 is a flexible film-like member and is attached along the peripheral surface of the support member 321. Further, a large number of light emitting elements 325 are mounted on the surface of the flexible substrate 323. Since each of the light emitting elements 325 emits ultraviolet rays in the radial direction of the support member, the entire ultraviolet light source unit 322 can be regarded as a linear light source virtually formed on the central axis of the support member 321.

  One end of the support member 321 is coupled to the heat exchanger 326 via the refrigerant pipe 327. Inside the refrigerant pipe 327, the coolant circulates between the support member 321 and the heat exchanger 326. Thereby, the heat generated by the light emitting element 325 is dissipated in the heat exchanger 326, and the temperature rise of the ultraviolet light source unit 322 is suppressed.

FIG. 6 is a schematic cross-sectional view showing the optical structure of the ultraviolet irradiation head 320 shown in FIGS. 4 and 5. As shown in the figure, the center of the ultraviolet light source unit 322 that forms a virtual line light source is disposed on _one focal point f ₁ of a reflecting mirror 324 that forms an elliptic arc. Thereby, the ultraviolet rays emitted from the ultraviolet light source unit 322 are converged toward another focal point f ₂ of the reflecting mirror 324. Therefore, by arranging the recording paper 150 to be irradiated on the position plane including the focal point f ₂ , the surface of the recording paper 150 can be efficiently irradiated with the ultraviolet rays generated by the light emitting elements 325.

  As shown in the drawing, the light emitting element 325 is not mounted in the area facing the recording paper 150 on the peripheral surface of the support member 321. As a result, all the ultraviolet rays applied to the recording paper 150 are reflected by the reflecting mirror 324, and the ultraviolet curable ink on the recording paper 150 is uniformly cured.

  Further, in this embodiment, the reflecting mirror 324 having the elliptical arc-shaped cross section of the reflecting surface is used, but a reflecting mirror having a quadratic cross section other than the hyperbola may be used. Thereby, the ultraviolet rays radiated from the virtual point (line) light source can be guided to the surface of the recording paper 150 and efficiently irradiated.

  7, FIG. 8, and FIG. 9 are schematic cross-sectional views showing the structure of an ultraviolet irradiation head 320 according to another embodiment in contrast to FIG. In addition, it has the same structure as other embodiment except the part demonstrated below about each form. Therefore, the same components are assigned the same reference numerals, and duplicate descriptions are omitted.

The ultraviolet irradiation head 320 shown in FIG. 7 includes a support member 321 having a regular octagonal cross-sectional shape, which is arranged so that its center coincides with _one focal point f ₁ of the reflecting mirror 324. A flexible substrate 323 on which a plurality of light emitting elements 325 are mounted is mounted on the surface of the support member 321 along the surface of the support member 321. Thereby, a virtual point (line) light source of ultraviolet rays is formed at one focus of the reflecting mirror 324.

Further, the ultraviolet irradiation head 320 shown in FIG. 8 includes a support member 321 having a regular hexagonal cross-sectional shape, which is arranged so that the center thereof coincides with _one focus f ₁ of the reflecting mirror 324. A flexible substrate 323 on which a plurality of light emitting elements 325 are mounted is mounted on the surface of the support member 321 along the surface of the support member 321. Thereby, a virtual point (line) light source of ultraviolet rays is formed at one focus of the reflecting mirror 324.

Further, the ultraviolet irradiation head 320 shown in FIG. 9 includes a support member 321 having a regular pentagonal cross-sectional shape, which is arranged so that the center thereof coincides with _one focal point f ₁ of the reflecting mirror 324. A flexible substrate 323 on which a plurality of light emitting elements 325 are mounted is mounted on the surface of the support member 321 along the surface of the support member 321. Thereby, a virtual point (line) light source of ultraviolet rays is formed at one focus of the reflecting mirror 324.

The ultraviolet irradiation head 320 provided with the support member 321 having such a polygonal cross-sectional shape is arranged so that the other focal point f ₂ of the reflecting mirror 324 is located on the surface of the recording paper 150. Thereby, the ultraviolet rays generated by the light emitting element 325 are efficiently irradiated onto the recording paper 150.

  However, the light emitting element 325 is not mounted on a part of one or two surfaces located on the lower side in the drawing. Thereby, all the ultraviolet rays emitted from the light emitting element 325 are reflected by the reflecting mirror 324 and then irradiated to the recording paper 150. Therefore, uniform ultraviolet rays are irradiated to the whole.

  Such a regular polygonal support member 321 may be easier to manufacture than the support member 321 having a regular circular cross-sectional shape. Further, by equalizing the number of light emitting elements 325 mounted on each surface of the support member 321, it is easy to evenly distribute the light emission amount about the axis.

The polygonal support member 321 is arranged so that one of the vertexes of the polygon is positioned on the major axis C of the reflecting mirror 324. Thereby, the ultraviolet rays emitted from the light emitting element 325 enter the reflecting mirror 324 at an incident angle other than a right angle. Therefore, the stability of the operation of the light emitting element 325 is not impaired by the return light. Further, substantially because all of the emitted light is converged to the other focal point f _2, the generated ultraviolet efficiently irradiated.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. In addition, it is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

1 is a perspective view illustrating an appearance of an ink jet recording apparatus 100 as viewed from the front. 1 is a perspective view illustrating an appearance of an inkjet recording apparatus 100 as viewed from the back. 2 is a perspective view showing an internal mechanism 200 of the ink jet recording apparatus 100. FIG. FIG. 6 is a partially enlarged view of the recording head assembly 230 taken out. 3 is a perspective view showing a detailed structure of an ultraviolet irradiation head 320. FIG. 3 is a cross-sectional view schematically showing an optical structure of an ultraviolet irradiation head 320. FIG. 6 is a cross-sectional view schematically showing another structure of the ultraviolet irradiation head 320. FIG. 6 is a cross-sectional view schematically showing still another structure of the ultraviolet irradiation head 320. FIG. 6 is a cross-sectional view schematically showing still another structure of the ultraviolet irradiation head 320. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Inkjet type recording apparatus, 110, 328 Case, 112 Upper case, 114 Lower case, 116 Small case, 120 Leg, 130 Operation panel, 140 Cartridge holder, 150 Recording paper, 152 Roll, 160 Spindle, 200 Internal mechanism, 210 transport unit, 212 transport drive roller, 220 timing belt, 222 carriage motor, 230 recording head assembly, 240 ink cartridge, 250 suction platen, 252 guide surface, 260 pulley, 270 guide shaft, 280 cap, 290 flushing Part, 310 recording head, 320 ultraviolet irradiation head, 321 support member, 322 ultraviolet light source part, 323 flexible substrate, 324 reflector, 325 light emitting element, 326 heat exchanger, 327 refrigerant tube

Claims (6)

A reflecting mirror having a quadratic cross section including an opening partially open;
An ultraviolet light source disposed at the focal point of the quadratic curve located on the far side from the opening inside the reflecting mirror;
The ultraviolet light source is
A support member having a cross section forming a polygon or a part of a circle centering on a focal point of the reflecting mirror in a region facing the reflecting mirror in a cross-sectional shape in a plane including the cross section; An ultraviolet irradiating device having an ultraviolet light emitting element disposed on a circumferential surface of a polygon or the circle and emitting ultraviolet rays toward the reflecting mirror.   The ultraviolet irradiation device according to claim 1, wherein the ultraviolet light emitting element is mounted on a surface of a film substrate disposed along the surface of the support member.   The ultraviolet irradiation device according to claim 1, wherein the support member includes a heat conducting portion that propagates heat from the back surface of the ultraviolet light emitting element to the outside.   The ultraviolet light emitting element is disposed in a region of the peripheral surface of the support member where an optical axis of light emitted from the ultraviolet light emitting element is reflected by the reflecting mirror and emitted to the outside of the ultraviolet irradiation device. The ultraviolet irradiation device according to claim 1.   2. The ultraviolet irradiation device according to claim 1, wherein the support member is arranged such that one of the apexes of the polygon included in the cross-sectional shape of the support member is positioned on the axis of the reflecting mirror. A recording head that discharges ultraviolet curable ink while reciprocating along the surface of the recording medium;
A recording apparatus comprising: an ultraviolet irradiation unit that irradiates ultraviolet rays to the ultraviolet curable ink ejected by the recording head and attached to the recording medium;
The ultraviolet irradiation unit is
A reflecting mirror having a quadratic cross section including an opening partially open;
An ultraviolet light source disposed at the focal point of the quadratic curve located on the far side from the opening inside the reflecting mirror;
The ultraviolet light source is
A support member having a cross section forming a polygon or a part of a circle centering on a focal point of the reflecting mirror in a region facing the reflecting mirror in a cross-sectional shape in a plane including the cross section; A recording apparatus comprising: an ultraviolet light emitting element that is disposed on a circumferential surface of a polygon or the circle and emits ultraviolet light toward the reflecting mirror.

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