JP5228710B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an ink supply apparatus in an image forming apparatus including a recording head that ejects droplets.

  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. . This liquid discharge recording type image forming apparatus means that ink droplets are transported from a recording head (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Yes, it is also ejected onto a recording medium or a recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). And a serial type image forming apparatus that forms an image by ejecting liquid droplets while the recording head moves in the main scanning direction, and a line type head that forms images by ejecting liquid droplets without moving the recording head There are line type image forming apparatuses using

  In the present application, the “image forming apparatus” of the liquid discharge method is an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. In addition, “image formation” means not only that an image having a meaning such as a character or a figure is imparted to the medium but also an image having no meaning such as a pattern is imparted to the medium (simply liquid. It also means that a droplet hits the medium). “Ink” is not limited to ink, but is used as a general term for all liquids capable of image formation, such as recording liquid, fixing processing liquid, and liquid. DNA samples, resists, pattern materials and the like are also included.

  In such an image forming apparatus (hereinafter, also simply referred to as “inkjet recording apparatus”), the recording head is caused by the evaporation of the solvent from the nozzle because of recording by discharging ink from the nozzle onto the paper. Maintaining the nozzle state of the head well due to the problem of poor printing due to ink viscosity increase, ink solidification, dust adhesion, and air bubbles. A maintenance and recovery mechanism is provided.

  As such a maintenance and recovery mechanism, a suction means is connected, a suction cap for performing suction from the nozzle in a state where the head nozzle surface is capped, and a moisturizing state is maintained by preventing the head nozzle from drying. It is known to provide a moisture retention cap, and to use both a suction cap and a moisture retention cap.

  By the way, in a line type image forming apparatus including a line type head in which nozzle rows corresponding to the full width of the conveyed paper are arranged, the line type recording head has, for example, a nozzle row in which nozzles for discharging droplets are arranged. A head array (also referred to as a multi-array head, a multi-head unit, etc.) in which a plurality of short heads are arranged in a staggered manner along a nozzle arrangement direction is used.

  As a maintenance / recovery mechanism for sucking and moisturizing such a multi-array head, as described in Patent Document 1, conventionally, there are at least two or more abutting against the ink ejection surface of the recording head and the entire multi-head unit. A cap member having a number smaller than the number of recording heads, first moving means for moving the cap member in parallel with the ink ejection surface, and a contact position for abutting the cap member against the ink ejection surface to perform ink suction. Ink is sucked through a second moving means for individually moving between a non-contact position away from the ink discharge surface and a recording head with which the cap member contacts via an ink discharge path communicating with the cap member. What has a suction means is known.

JP 2006-096017 A

  As described above, when using a multi-array head in which a plurality of heads are arranged side by side, if a cap member is arranged for each head, the suction mechanism becomes complicated, and the maintenance and recovery device becomes complicated and large. .

  In this case, even if a configuration in which the number of suction cap members is smaller than the number of heads as described in Patent Document 1, it is necessary to perform moisture retention for preventing the nozzles from drying on all the heads. Yes, it is not sufficient for the simplification and miniaturization of the configuration of the maintenance and recovery device.

  The present invention has been made in view of the above problems, and an object of the present invention is to simplify and reduce the size of a maintenance / recovery mechanism when a multi-array head is used.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A recording head unit in which a plurality of heads in which a plurality of heads for ejecting liquid droplets are arranged in a staggered manner are arranged in a plurality of rows in a paper passing direction orthogonal to the head arrangement direction
Suction means is connected, said suction cap member to suction by capping the head part of the head row of the recording head unit, possess some of the heads column fraction only of the recording head unit, relative to the head A suction cap unit that sucks the heads for all colors by relatively moving ,
A plurality of head modules in which the heads of the recording head unit are arranged in a line on a module base member are attached to the heads for all colors in a state where the heads are arranged in a staggered manner between the head modules. An array base member;
A box-shaped moisturizing cap member that is in contact with the array base member of the recording head unit and covers the heads for all the colors of the recording head unit, and that is not connected to the suction means and is open at the top; , equipped with a,
When the moisturizing cap is not in use, it stands by below the suction cap unit so as to overlap the suction cap unit in the vertical direction, and when in use, the moisturizing cap can be moved to the moisturizing position while avoiding the suction cap unit. It was set as the structure provided in .

According to the image forming apparatus according to the present invention, the configuration of the maintenance recovery mechanism is simplified, downsizing.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of an image forming apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 is a schematic configuration diagram for explaining the overall configuration of the image forming apparatus, and FIG. 2 is a schematic plan explanatory diagram of the apparatus.

  This image forming apparatus is a line type image forming apparatus, and includes an apparatus main body 1, a paper feed tray 2 on which paper P is stacked and fed, a paper discharge tray 3 on which printed paper P is discharged and stacked, and paper P An image forming unit 5 that includes a head module 51 according to the present invention that discharges and prints droplets on a sheet P that is transported by the transport unit 4, After completion or at a required timing, the cleaning device 6 is a maintenance / recovery mechanism for maintaining and recovering each recording head of the image forming unit 5, the conveyance guide portion 7 that opens and closes the cleaning device 6, and the head module 51 of the image forming unit 5. An ink tank unit 8 that supplies ink to the ink tank and a main tank unit 9 that supplies ink to the ink tank unit 8 are provided.

  The apparatus main body 1 includes front and rear side plates and stays (not shown), and the sheets P stacked on the sheet feed tray 2 are fed one by one to the transport unit 4 by the separation roller 21 and the sheet feed roller 22. Is done.

  The transport unit 4 includes a transport driving roller 41A, a transport driven roller 41B, and an endless transport belt 43 wound around these rollers 41A and 41B. A plurality of holes (not shown) are formed on the surface of the transport belt 43, and a suction fan 44 that sucks the paper P is disposed below the transport belt 43. Further, conveyance guide rollers 42A and 42B are respectively held on guides (not shown) on the conveyance driving roller 41A and conveyance driven roller 41B and are in contact with the belt 43 by their own weight.

  The conveyance belt 43 rotates around when the conveyance driving roller 41A is rotated by a motor (not shown), and the paper P is sucked onto the conveyance belt 43 by the suction fan 44 and is conveyed by the rotation movement of the conveyance belt 43. The transport driven roller 41 </ b> B and the transport guide rollers 42 </ b> A and 42 </ b> B rotate following the transport belt 43.

  An image forming unit 5 composed of a plurality of head modules 51 for discharging droplets to be printed on the paper P is disposed above the transport unit 4 so as to be movable in the arrow A direction (and the reverse direction). The image forming unit 5 is moved to above the head cleaning device 6 during the maintenance / recovery operation (during cleaning), and is returned to the position shown in FIG.

  As shown in FIG. 3, the image forming unit 5 includes head modules 51A, 51B, 51C, and 51D that constitute a head row in which a plurality of heads 101 are arranged in a row on a module base 53 (the head module 51 Are arranged along the paper transport direction (direction orthogonal to the nozzle arrangement direction) so as to be arranged in a staggered manner between the head modules 51A and 51B and between 51C and 51D. A recording head unit (multi-array head) 50 is provided. The head module 51 is integrally provided with a distribution member 54 that distributes ink to each head 101.

  Here, as shown in FIG. 4, one head 101 has two nozzle rows 102 </ b> A and 102 </ b> B in which a plurality of nozzles 102 that eject droplets are arranged on the nozzle surface 103. Then, one of the two nozzle arrays of the head modules 51A and 51B discharges yellow (Y) droplets, and the other ejects magenta (M) droplets, and the two nozzle arrays of the head modules 51C and 51D. On the one hand, cyan (C) droplets are ejected, and on the other hand, black (K) droplets are ejected.

  That is, in the recording head unit 50 of the image forming unit 5, two head modules 51 that discharge droplets of the same color are arranged side by side in the paper transport direction, and the two head modules 51 correspond to one row corresponding to the paper width. The nozzle array is configured.

  The configuration of the recording head unit 50 is not limited to the above example. As shown in FIG. 5, the head module 51 is configured by arranging a plurality of heads 101 on a single module base member 53, The four head modules 51 may be arranged on the common array base member 52 along the paper conveyance direction (direction orthogonal to the nozzle arrangement direction). As shown in FIG. 6, the heads 101 for all colors are arranged in a staggered pattern on the array base member 52 and arranged along the paper transport direction (direction perpendicular to the nozzle arrangement direction). You can also.

  On the upstream side of the image forming unit 5, an ink tank 81 of the ink tank unit 8 (only one ink tank is denoted by a sign for convenience of illustration) is arranged, and each head module 51 is connected via a supply tube 82. The negative pressure on each head 101 of the head module 51 is formed by the water head difference between the ink tank 81 and the head module 51. The ink tank unit 8 is arranged so as to be movable in the direction of arrow A together with the image forming unit 5. Note that the supply tube 82 from the ink tank 81 to the head module 51 is shown as being connected from above the head module 51 for easy understanding, but in reality, the longitudinal direction of the head module 51 (perpendicular to the paper transport direction). Connected to the end in the direction of

  Further, the main tank unit 9 is disposed on the upstream side of the ink tank 81, and ink is supplied from the main tank 91 through the supply tube 92 to the ink tank 81.

  On the downstream side of the transport unit 4, a transport guide portion 7 that discharges the paper P to the paper discharge tray 3 is provided. The paper P guided and conveyed by the conveyance guide plate 71 of the conveyance guide unit 7 is discharged to the discharge tray 3. The paper discharge tray 3 includes a pair of side fences 31 that regulate the width direction of the paper P and an end fence 32 that regulates the front end of the paper P.

  The maintenance / recovery mechanism (head cleaning device) 6 includes six moisturizing cap members 61 for capping the entire recording head unit 50 of the image forming unit 5 and six heads 101 for the six head modules 51 in two rows. A suction cap (member) 63 arranged in a staggered manner, and a suction cap unit 62 having a suction pump 64 as a suction means connected to each suction cap 63. The suction cap unit 62 includes a wiper member for wiping the nozzle surface of the head 101, but is not shown.

  In this image forming apparatus, after the printing is completed, when the nozzle surface of each head 101 of the head module 51 that discharges droplets is capped with the cap 63 of the suction cap unit 62, the ink is sucked from the nozzle 102, or When the ink adhering to the nozzle surface of each head 101 of the head module 51 is cleaned with a wiping member, as shown in FIG. 1, after the printing is stopped, the entire transport unit 4 uses the transport driven roller 41B as a fulcrum and the arrow B The space for moving the image forming unit 5 is secured by rotating in the direction and making the space between the image forming unit 5 larger than that at the time of image formation. At this time, the conveyance guide plate 71 of the conveyance guide portion 7 disposed on the upper portion of the head cleaning device 6 is also rotated upward in the direction of arrow C at the fulcrum 72, and the upper portion of the head cleaning device 6 is opened.

  After the transport unit 4 and the transport guide portion 7 are released (released), the image forming unit 5 moves in the paper passing direction (arrow A direction) and is stopped above the head cleaning device 6 for suction. The cap 63 of the cap unit 62 is lifted and the two head modules 51 are sucked from the head 101 and cleaned by a wiper member (not shown), and then the image forming unit 5 is moved to move the heads 101 of the remaining two head modules 51. Similarly, suction and wiping are performed.

  When the printing operation is finished and the image forming unit 5 is in a standby state, the image forming unit 5 moves above the head cleaning device 6 and the moisturizing cap member 61 rises to contact the array base member 52 of the recording head unit 50. Then, the entire head 101 of the recording head unit 50 is capped together.

  As described above, the maintenance and recovery mechanism includes the moisture retention cap member that covers the entire recording head unit and the suction cap unit that has the suction cap member that caps each head of a part of the recording head unit. This simplifies the configuration and can be downsized.

Next, a second embodiment of the present invention will be described with reference to FIGS. 7 is an explanatory plan view of the maintenance / recovery mechanism (head cleaning device) used for explanation of the embodiment when sucking, FIG. 8 is an explanatory front view of FIG. 7, and FIG. 9 is an explanatory plan view of the same when moisturizing. FIG. 10 is also a front explanatory view of FIG. 9, and FIG. 11 is a front explanatory view of FIG. 7 at another suction position.
Here, the recording head unit 50 having the configuration described with reference to FIG. 6 is used. As in the first embodiment described above, the head cleaning device 6 caps the moisturizing cap member 61 for capping the entire recording head unit 50 and the heads 101 of a part of the head rows (here, two rows). And a suction cap unit 62 having a cap 63 and a suction pump 64.

  The moisturizing cap member 61 is in contact with the array base member 52 of the recording head unit 50 to cover all the heads 101 of the recording head unit 50. That is, the nip position of the moisturizing cap 61 is not the nozzle surface of the head 101 but the array base member (head mounting base member) 52 to which the head 101 is mounted. The moisturizing cap member 61 is formed of a member in which at least the nip portion 61 a that contacts the array base member 52 has elasticity. In addition, the moisturizing cap member 61 is moved up and down by a cam 65, for example.

  In the suction cap unit 62, the suction cap 62 is held by the cap holder 66 via the spring 67, and the cap holder 66 is moved up and down with respect to the unit base member 68 by the cam 69. The suction cap 63 abuts on the nozzle surface 103 of each head 101 to perform capping. In this example, since the recording head unit 50 is configured to eject droplets of one color with two nozzle rows, the suction cap unit 62 performs suction with the six heads 101 for one color. is there.

  Also in this embodiment, when performing the suction operation, as shown in FIGS. 7 and 8, the image forming unit 5 is moved so that the two head rows of the recording head unit 50 face the suction cap unit 62. Then, the cam 69 of the suction cap unit 62 is rotationally driven to raise the suction cap 62 and cap each head 101. Thereafter, the suction pump 64 is driven to suck ink from the nozzles 102 of the head 101. Then, as shown in FIG. 9, the image forming unit 50 is moved and the same suction operation is repeated for the remaining head rows.

  Further, when performing the moisturizing operation, as shown in FIGS. 10 and 11, the image forming unit 5 is moved so that the recording head unit 50 is positioned opposite the moisturizing cap member 61 and the cam 65 is rotated. The moisturizing cap member 61 is raised, and the nip portion 61 a of the moisturizing cap member 61 is brought into contact with the array base member 52 so as to cover all the heads 101 of the recording head unit 50.

  Also in this embodiment, the configuration is simplified as compared with the case where all the heads of the recording head unit are individually provided with a moisture retention cap member.

Next, a third embodiment of the present invention will be described with reference to FIG. In addition, FIG. 12 is a front explanatory view at the time of suction of the maintenance / recovery mechanism for explaining the embodiment.
In this embodiment, two suction cap units 62A and 62B are provided so that the suction operation can be performed by capping the heads 101 belonging to four head rows with the suction caps 63. In this example, since the recording head unit 50 is configured to eject droplets for one color with two nozzle rows, the suction cap units 62A and 62B perform suction with 12 heads for two colors. 101.

  Even if comprised in this way, a structure becomes simple compared with the case where the cap member for moisture retention is provided individually about all the heads of a recording head unit.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 13 is a front explanatory view of the maintenance / recovery mechanism used for description of the embodiment during standby, and FIG. 14 is a front explanatory view of moisture retention.
The moisturizing cap member 61 includes an elevating mechanism (such as a cam 65), and includes a recording head at a standby position located below the suction cap unit 62 and the transport belt 43, and downstream of the suction cap unit 62 in the paper transport direction. The unit 50 is arranged so as to be movable in the horizontal direction (arrow D direction) and in the vertical direction (arrow E direction) between the moisturizing position (cap position) for capping the unit 50.

  That is, since the configuration of the moisturizing cap member 61 is simple because it has only the function of moisturizing, the arrangement and movement of the moisturizing cap member 61 is facilitated. Therefore, when the moisturizing cap member 61 is not used (when not in use), it is possible to wait at the lower portion of the transport unit 4 and to reduce the size of the maintenance / recovery device.

Next, a fifth embodiment of the present invention will be described with reference to FIGS. 15 and 16. 15 is an explanatory front view of the maintenance / recovery mechanism used for the description of the embodiment when moisturizing, and FIG. 16 is an explanatory front view of the same when sucking.
A recess 61b is formed inside the moisturizing cap member 61, and the suction cap unit 62 is stored in the recess 61b. When moisturizing, the cap 63 of the suction cap unit 62 is lowered as shown in FIG. 15, and when sucking, the cap 63 of the suction cap unit 62 is lowered as shown in FIG. The suction operation is performed while capping the head 101 of the recording head unit 50.

  Thus, by storing the suction cap unit 62 in the moisturizing cap member 61, the maintenance and recovery device can be further reduced in size.

1 is a schematic side view illustrating an overall configuration of an example of an image forming apparatus according to a first embodiment of the present invention. Similarly it is principal part plane explanatory drawing. It is explanatory drawing of a head module. It is explanatory drawing of a head. It is explanatory drawing which shows the other example of a head module. It is explanatory drawing which shows the other example of a recording head unit. It is plane explanatory drawing at the time of attraction | suction of the maintenance recovery mechanism with which it uses for description of 2nd Embodiment of this invention. It is a front explanatory drawing of FIG. It is a plane explanatory view at the time of moisture retention similarly. FIG. 10 is also a front explanatory view of FIG. 9. It is front explanatory drawing of FIG. 7 in another suction position similarly. It is front explanatory drawing at the time of attraction | suction of the maintenance recovery mechanism with which it uses for description of 3rd Embodiment of this invention. It is front explanatory drawing at the time of the standby of the maintenance recovery mechanism with which it uses for description of 4th Embodiment of this invention. It is front explanatory drawing similarly at the time of moisture retention. It is front explanatory drawing at the time of moisture retention of the maintenance recovery mechanism used for description of 5th Embodiment of this invention. It is front explanatory drawing similarly at the time of suction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Apparatus main body 4 ... Conveyance unit (conveyance part)
5. Image forming unit 6. Head cleaning device (maintenance and recovery mechanism)
DESCRIPTION OF SYMBOLS 7 ... Conveyance guide part 8 ... Ink tank unit 9 ... Main tank unit 50 ... Recording head unit 51 ... Head module 61 ... Moisturizing cap member 62 ... Suction cap unit 63 ... Suction cap 64 ... Suction pump 101 ... Head

Claims (1)

A recording head unit in which a plurality of heads in which a plurality of heads for ejecting liquid droplets are arranged in a staggered manner are arranged in a plurality of rows in a paper passing direction orthogonal to the head arrangement direction
Suction means is connected, said suction cap member to suction by capping the head part of the head row of the recording head unit, possess some of the heads column fraction only of the recording head unit, relative to the head A suction cap unit that sucks the heads for all colors by relatively moving ,
A plurality of head modules in which the heads of the recording head unit are arranged in a line on a module base member are attached to the heads for all colors in a state where the heads are arranged in a staggered manner between the head modules. An array base member;
A box-shaped moisturizing cap member that is in contact with the array base member of the recording head unit and covers the heads for all the colors of the recording head unit, and that is not connected to the suction means and is open at the top; , equipped with a,
When the moisturizing cap is not in use, it stands by below the suction cap unit so as to overlap the suction cap unit in the vertical direction. An image forming apparatus provided in the apparatus.

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