JP2014177329A - Image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a spiral form guide member compact when not used.SOLUTION: A paper discharge tray 7 has spiral form guide members 71, 71, guiding an end of a form 10 in a direction orthogonal to its discharge direction, arranged, and the spiral form guide members 71 have extendable coil members 72, and are fitted to a top plate 73 fixed to a shaft part 75 and a bottom plate part 74 fitted rotatably to the shaft part 75 respectively to be held by the shaft part 75 in an extendable state, the spiral form guide members 71 being made compact when not used by contracting the coil members 72.

Description

  The present invention relates to an image forming apparatus.

  As an image forming apparatus such as a printer, a facsimile machine, a copying apparatus, a plotter, and a complex machine of these, for example, an ink jet recording apparatus is known as an image forming apparatus of a liquid discharge recording method using a recording head for discharging ink droplets. .

  In particular, in a liquid discharge type image forming apparatus, curling due to drying of the liquid is likely to occur, and if curling occurs on the paper discharge tray after paper discharge, it interferes with the subsequent paper and the paper discharge stacking property is degraded. To do.

  In view of this, there is conventionally known a device in which a spiral body that guides both ends of a sheet to be discharged is arranged in the paper discharge unit (Patent Document 1).

Japanese Patent Laid-Open No. 10-087144

  However, in the case of using the above-described conventional spiral body, there is a problem that it is exposed to the paper discharge unit in a used state even when it is not used.

  The present invention has been made in view of the above problems, and an object of the present invention is to make the spiral paper guide member small when not in use.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A paper discharge unit for discharging the paper on which the image is formed;
The paper discharge unit is provided with a spiral paper guide member for guiding an end in a direction orthogonal to the paper discharge direction,
The spiral paper guide member has a coil member that can expand and contract.

  According to the present invention, the spiral paper guide member can be made small when not in use.

FIG. 2 is a side explanatory view of a mechanism unit of the image forming apparatus according to the first embodiment of the present invention. It is a back surface explanatory drawing used for description of the mechanism part. FIG. 6 is a perspective explanatory view for explaining curling of a sheet in a sheet discharge tray (sheet discharge unit). FIG. 3 is a perspective explanatory view of a paper discharge unit for explaining the first embodiment of the present invention. It is a side explanatory view similarly. It is a perspective explanatory view of a spiral paper guide member. FIG. 6 is a perspective explanatory view of a paper discharge unit when a spiral paper guide member is used for explaining the operation of the embodiment. FIG. 6 is a perspective explanatory view of the paper discharge unit when the spiral paper guide member is not used. It is a side explanatory view similarly. FIG. 10 is a perspective explanatory view of a paper discharge unit in a spiral paper guide member storage state for explanation of a second embodiment of the present invention. It is a side explanatory view similarly. It is a side view of the spiral paper guide member used for description of the third embodiment of the present invention. It is a bottom view of a spiral paper guide member similarly. FIG. 10 is a perspective explanatory view of a paper discharge unit for explaining a fourth embodiment of the present invention. It is explanatory drawing which looked at the paper discharge tray used for description of the coil shape of coil member, arrangement | positioning, etc. toward the paper discharge outlet.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an image forming apparatus according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory side view of a mechanism portion of the image forming apparatus, and FIG. 2 is an explanatory rear view for explaining the mechanism portion.

  This image forming apparatus is a serial type image forming apparatus. The apparatus main body includes an image forming unit 2 as an image forming unit, a transport mechanism unit 5 as a transport unit, and the like. (Including a paper cassette and used in the meaning of a paper feed unit).

  Then, the paper 10 fed from the paper feed tray 4 is taken in, and the paper 10 is intermittently transported in the vertical direction (direction along the vertical direction) by the transport mechanism unit 5, while being horizontally moved by the image forming unit 2. A droplet is ejected to record a required image. Thereafter, the sheet 10 on which the image is formed is further conveyed upward through the sheet discharge conveyance unit 6, and the sheet 10 is discharged to a sheet discharge tray 7 which is a sheet discharge unit provided on the upper side of the apparatus main body.

  When performing double-sided printing, after the printing on one side (front surface) is completed, the paper 10 is taken into the reversing unit 8 from the paper discharge conveyance unit 6 and conveyed by the conveyance mechanism unit 5 in the reverse direction (downward). Inverted, the other side (back side) is sent to the transport mechanism unit 5 again as a printable side. Then, in the same manner as described above, after the other side (back side) printing is completed, the sheet 10 is discharged to the discharge tray 7.

  Here, the image forming unit 2 holds the carriage 23 on which the recording head 24 is mounted by a main guide member 21 and a sub guide member 22 which are horizontally mounted between the left and right side plates 101L and 101R, and moves the carriage (not shown). The main scanning motor of the mechanism moves and scans in the main scanning direction via a timing belt spanned between the driving pulley and the driven pulley.

  The carriage 23 has recording heads 24a and 24b composed of liquid ejection heads for ejecting ink droplets of yellow (Y), magenta (M), cyan (C), and black (K). Recording head 24 "). The recording head 24 is mounted with a nozzle row composed of a plurality of nozzles arranged in the sub-scanning direction orthogonal to the main scanning direction and the droplet discharge direction oriented in the horizontal direction. That is, a horizontal driving method is employed in which a nozzle surface on which nozzles for discharging droplets are formed is arranged in the vertical direction and includes a recording head 24 that discharges droplets in the horizontal direction.

  The recording head 24 has two nozzle rows in which nozzles that eject a plurality of droplets are arranged in a row. Then, one nozzle row of the recording head 24a discharges yellow (Y) droplets, and the other nozzle row discharges magenta (Y) droplets. One nozzle row of the recording head 24b discharges black (K) droplets, and the other nozzle row discharges cyan (C) droplets.

  The carriage 23 is mounted with a head tank 29 for supplying ink of each color corresponding to each nozzle row of the recording head 24. Ink is supplied to the head tank 29 from ink cartridges (main tanks) of respective colors that are detachably attached to the apparatus main body.

  The sheets 10 in the sheet feeding tray 4 are separated one by one by a sheet feeding roller (half-moon roller) 43 and a separation pad 44 and fed into the apparatus main body. Then, the sheet is fed along the conveyance guide member 45 between the conveyance belt 51 of the conveyance mechanism unit 5 and the presser roller 48 and is sucked and conveyed by the conveyance belt 51.

  The transport mechanism 5 includes an endless transport belt 51 that is stretched between a transport roller 52 that is a driving roller and a driven roller 53. A charging roller 54 for charging the conveying belt 51 and a platen member 55 that maintains the flatness of the conveying belt 51 at a portion facing the image forming unit 2 are provided. The conveyance belt 51 rotates in the belt conveyance direction (sub-scanning direction, paper conveyance direction) when the conveyance roller 52 is rotationally driven by a sub-scanning motor (not shown) via a timing belt and a timing pulley.

  The paper discharge transport unit 6 includes a paper discharge guide member 61, a paper discharge transport roller 62 and a spur 63, a paper discharge transport roller 66 and a spur 67, and a paper discharge roller 64 and a spur 65. Then, the sheet 10 on which the image is formed is discharged face down on the sheet discharge tray 7 from between the sheet discharge roller 64 and the spur 65.

  The reversing unit 8 reverses the paper 10 partially discharged to the paper discharge tray 7 by the switchback method and feeds the paper 10 between the conveyance belt 51 and the presser roller 48. A claw 81, a reverse guide member 82, a reverse roller 83 and a spur 84 as a reverse roller, a conveyance auxiliary roller 85 facing the driven roller 53, a reverse conveyance portion 51b of the conveyance belt 51, and a reverse conveyance of the conveyance belt 51 A detour guide member 86 for guiding the sheet 10 separated from the portion 51 b between the conveyance belt 51 and the pressing roller 48 by detouring the charging roller 54 is provided.

  In this image forming apparatus configured as described above, the paper 10 is separated and fed from the paper feed tray 4 one by one, and the paper 10 is electrostatically attracted to the charged transport belt 51, and the transport belt 51 is moved by the circular movement. The paper 10 is conveyed in the vertical direction. Therefore, by driving the recording head 24 according to the image signal while moving the carriage 23, ink droplets are ejected onto the stopped paper 10 to record one line, and after the paper 10 is conveyed by a predetermined amount, The next line is recorded, and the sheet 10 for which recording has been completed is discharged to the discharge tray 7.

  In the case of performing duplex printing, the first surface printing performs the operation as described above, and when the rear end of the paper 10 passes through the reversing part branch (switching claw 81), the paper discharge roller 64 is driven in reverse. The paper 10 is switched back. Then, it is guided to the reverse guide member 82 side, conveyed between the reverse roller 83 and the spur 84, and the paper 10 is fed between the reverse conveyance portion of the conveyance belt 51 and the conveyance auxiliary roller 85.

  As a result, the paper 10 is attracted to the transport belt 51 and transported by the circular movement of the transport belt 51. Then, it is separated from the conveyance belt 51 on the conveyance roller 52 side, guided by a detour guide member 86 (via a detour path), and sent again between the normal conveyance portion of the conveyance belt 51 and the pressing roller 48. Adsorbed to the conveyor belt 51. Thereafter, the second side printing is performed by suction conveyance to the image forming area by the recording head 24, and then the sheet is discharged onto the discharge tray 7.

  Next, the curling of the paper in the paper discharge tray (paper discharge unit) will be described with reference to FIG. FIG. 3 is a perspective view for explaining the same.

  As shown in FIG. 3A, when the paper 10A on which the image discharged to the paper discharge tray 7 is formed curls and the end of the paper 10A becomes higher than the discharge port 100 to the paper discharge tray 7, FIG. As shown in (b), the succeeding paper 10B is pushed out by interfering with the paper 10A, and the paper discharge stackability is extremely lowered.

  Note that curl in the case of ink jet recording occurs when ink penetrates the print surface (the lower surface on the paper discharge tray) and the fibers extend.

  Next, a first embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a perspective explanatory view of a paper discharge unit for explaining the embodiment, FIG. 5 is a side explanatory view, and FIG. 6 is a perspective explanatory view of a spiral paper guide member.

  In the present embodiment, spiral paper guide members 71 and 71 that guide end portions of the paper discharge tray 7 in the direction orthogonal to the paper discharge direction are disposed.

  The spiral paper guide member 71 has a coil member 72 that can be expanded and contracted. Then, both end portions of the coil member 72 are attached to the top plate 73 fixed to the shaft portion 75 and the bottom plate portion 74 fitted to the shaft portion 75 so as to be rotatable, and are held by the shaft portion 75 in an extendable state. Yes.

  Here, the shaft portion 75 of the spiral paper guide member 71 passes through the paper discharge tray 7, is rotatable with respect to the paper discharge tray 7, and is held up and down. The shaft member 75 is rotationally driven by the rotary lift mechanism 501 and moved up and down, whereby the coil member 72 rotates and expands and contracts.

  The rotary elevating mechanism 501 is driven by a control unit 500 that controls the entire image forming apparatus. The rotary elevating mechanism 501 includes a drive source such as a drive motor, a cam, a link mechanism, and the like.

  Next, the operation of this embodiment will be described with reference to FIGS. 7 is an explanatory perspective view of the paper discharge unit when the spiral paper guide member is used, FIG. 8 is an explanatory perspective view of the paper discharge unit when the spiral paper guide member is not used, and FIG. It is explanatory drawing.

  First, when the spiral paper guide members 71 and 71 are used, as shown in FIGS. 4 and 5, the spiral paper guide members 71 and 71 are lifted and extended.

  In this state, when the paper 10 on which the image is formed is discharged from the discharge port 100 to the paper discharge tray 7, both ends of the paper 10 are guided and held by the spiral paper guide members 71 and 71 as shown in FIG. Therefore, curling of the paper 10 can be suppressed. At this time, the paper 10 is gradually lowered toward the front side of the paper discharge tray 7 by rotating the spiral paper guide members 71 and 71 in a predetermined direction.

  Thereby, it is possible to prevent the discharge stacking property from being deteriorated.

  On the other hand, when the spiral paper guide member 71 is not used, as shown in FIGS. 8 and 9, the spiral paper guide member 71 is lowered to a contracted state so that the spiral protrudes from the paper discharge tray 7. The size of the sheet guide member 71 can be reduced.

  When the spiral paper guide member 71 is not used, it is predicted that the occurrence of curling is small. For example, the control unit 500 discriminates print information, for example, a printing rate (ink amount per sheet), and when the printing rate is smaller than a predetermined threshold value, the controller 500 drives the rotary lift mechanism 501 to form a spiral shape. The sheet guide member 71 is contracted.

  In this case, if the paper 10 is present when the spiral paper guide member 71 is contracted, the paper 10 is bent. Therefore, a paper detection unit that detects whether or not the paper 10 is on the paper discharge tray 7 is provided. It is preferable.

  Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a perspective explanatory view of the paper discharge unit in a state where the spiral paper guide member is accommodated for explanation of the embodiment, and FIG. 11 is a side explanatory view of the same.

  In the present embodiment, a recess 77 having a depth about the thickness when the spiral paper guide member 71 is contracted is formed in the paper discharge tray 7.

  With this configuration, when the spiral paper guide member 71 is not used, the spiral paper guide member 71 can be stored in the recessed portion 77 in a contracted state, from the surface of the spiral paper guide member 71. Can be stored without protruding.

  Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 12 is a side view of a spiral paper guide member for explaining the embodiment, and FIG. 13 is a bottom view of the spiral paper guide member.

  In the present embodiment, the spiral paper guide member 71 has a spiral shape with a gradually decreasing diameter.

  Thereby, the thickness when the spiral paper guide member 71 is contracted can be further reduced.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 14 is a perspective explanatory view of a paper discharge unit for explaining the embodiment.

  In the present embodiment, a plurality of spiral paper guide members 71 are arranged along the discharge direction (here, three, but two or four or more) may be arranged.

  In this way, the curl can be pressed more reliably.

  Note that the paper 10 can be moved upward by rotating the spiral paper guide member 71 described above in reverse.

  Therefore, for example, when performing face-up paper discharge, the paper can be moved upward in order and aligned in page order. In this case, it is preferable to provide a guide member so that the paper does not fall. For example, this can be dealt with by extending the shaft 75 of the spiral paper guide member 71 upward.

  It is also possible to extract only pages that have been interrupt printed by moving them upward.

  Further, the height position of the spiral paper guide member 71 can be adjusted between when the paper 10 is sent down and when the paper 10 is sent up. Thereby, the drying time of the paper can be secured.

  Further, if the coil pitch of the spiral paper guide member 71 can be changed, the interval between the discharged paper sheets can be kept optimal, and color transfer can be prevented.

  Next, the coil shape and arrangement of the coil member will be described with reference to FIG. FIG. 15 is an explanatory view of the discharge tray as viewed toward the discharge outlet.

  On the paper discharge tray 7, spiral paper guide members 71 and 71 including two coil members 72 are arranged in a direction orthogonal to the paper discharge direction.

  The turning direction of the coil member 72 may be clockwise (right screw) or counterclockwise (left screw).

  The direction of rotation of the coil member 72 is to turn counterclockwise for a right-hand screw and clockwise for a left-hand screw to move the paper downward. On the other hand, when the sheet is to be moved up, the rotation is reversed (in this case, as described above, the print surface can be arranged in the page order even on the top).

  In particular, with respect to the turning direction and the rotation direction, it is preferable that the right side toward the paper discharge port 100 is clockwise with a left screw, and the left side toward the paper discharge port 100 is counterclockwise with a right screw.

  Thus, by setting the turning direction and the rotation direction as described above, the sheet 10 comes into contact with the discharge port 100 and is aligned.

  On the other hand, when the sheet is not set as described above, when the discharged sheet is moved downward by the rotation of the coil member 72, the sheet is pushed out in the discharge direction by the rotation of the coil member 72. The discharged sheets are not aligned or pushed out of the discharge tray 7.

  The number of turns of the coil member 72 is one or more. In particular, in the case of stably pressing the paper, if it is 1.5 or more, the groove formed by the winding portions can be secured for 0.5 turns, so that the paper pressing performance can be secured.

  The coil member 72 is preferably disposed adjacent to the discharge port 100. Thus, the discharged paper 10 can be reliably passed between the winding portions of the coil member 72 and the end of the paper 10 to be curled can be pressed.

  The distance between the axes of the two coil members 72 arranged in the width direction of the paper discharge port 100 is set to be larger than the sum of the sheet width and the shaft diameter. Thereby, the paper 10 can be stacked between the shafts.

  However, when there is no bearing on the paper discharge tray 7, for example, when a bearing is provided on the upper side and suspended, it is not necessary to consider the inter-axis distance.

The distance between the two coil members 72 needs to be smaller than the value obtained by 2 × {(half the width of the paper) ² − (height of the paper discharge port) ² } ^(1/2) .

  This is to prevent the curled paper from coming out of the coil member 72.

  The height of the coil member 72 is set to be at least near the height of the paper discharge port 100.

  Since sheets can be stacked only between the lower end of the coil member 72 and the sheet discharge tray 7, the distance between the lower end of the coil member 72 and the sheet discharge tray 7 is increased when a large amount of sheets are to be stacked.

  The coil pitch of the coil member 72 is preferably larger than the height of the paper discharge port 100.

  This is because the sheet 10 discharged from the discharge port 100 surely passes between the winding portions of the coil member 72.

  In the present application, “paper” is not limited to paper, but includes OHP, cloth, glass, a substrate, and the like, and can be attached to ink droplets and other liquids. This includes recording media, recording media, recording paper, recording paper, and the like. In addition, image formation, recording, printing, printing, and printing are all synonymous.

  The “image forming apparatus” means an apparatus that forms an image by discharging a liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics or the like. In addition, “image formation” not only applies an image having a meaning such as a character or a figure to a medium but also applies an image having no meaning such as a pattern to the medium (simply applying a droplet to the medium). It also means to land on.

  The “ink” is not limited to an ink unless otherwise specified, but includes any liquid that can form an image, such as a recording liquid, a fixing processing liquid, or a liquid. Used generically, for example, includes DNA samples, resists, pattern materials, resins, and the like.

  In addition, the “image” is not limited to a planar image, and includes an image given to a three-dimensionally formed image and an image formed by three-dimensionally modeling a solid itself.

  In the above embodiment, the liquid ejection type image forming apparatus is described. However, the present invention can be applied to an electrophotographic type image forming apparatus.

2 Image forming section 4 Paper feeding section 5 Transport mechanism section 6 Paper discharge transport section 7 Paper discharge tray 8 Reversing section 10 Paper (recording medium)
23 Carriage 24 Recording head 51 Conveying belt 71 Spiral paper guide member 72 Coil member

Claims (4)

A paper discharge unit for discharging the paper on which the image is formed;
The paper discharge unit is provided with a spiral paper guide member for guiding an end in a direction orthogonal to the paper discharge direction,
The image forming apparatus, wherein the spiral paper guide member includes a coil member that can be expanded and contracted.   The image forming apparatus according to claim 1, wherein the spiral paper guide member is held in a contracted state when not in use.   The image forming apparatus according to claim 2, wherein the paper discharge unit is formed with a concave portion for storing the spiral paper guide member in a contracted state.   4. The image forming apparatus according to claim 1, wherein the coil member has a spiral shape with a gradually decreasing diameter.

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