JP2010023374A - Image recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image recording device improved in recording accuracy on a recording medium. <P>SOLUTION: When the leading end of a through-hole 19 of a conveying belt 8 in the direction of conveyance faces a nozzle, an inkjet printer discharges ink to an ink receptacle 32 from an inkjet head as a flashing operation. This inkjet printer has ribs 24c apart from ink flying paths of ink emitted from the inkjet head. The ink is passed between the two adjacent ribs 24c, and is received in the ink receptacle 32. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image recording apparatus for recording an image.

  Patent Document 1 describes an ink jet recording apparatus that adsorbs a sheet material, which is a recording medium, to a carrying surface of a conveyance belt by sucking air from a back surface side of the conveyance belt through a suction hole formed in the conveyance belt. Has been. In this ink jet recording apparatus, an ink receiving member is disposed in an inner region formed by the transport belt and facing the ink jet head across the transport belt. When the ink is ejected from the ink jet head, the ejected ink passes through the suction hole and is received by the ink receiving member.

JP 2007-168277 A (FIG. 2)

  However, in the ink jet recording apparatus described in Patent Document 1, an ink receiving member is disposed at a position facing the ink jet head across the transport belt, and a member that supports the back surface of the carrying surface of the transport belt facing the ink jet head. Is not provided. For this reason, when air is sucked from the back surface side of the transport belt through the suction hole, the region of the transport belt facing the inkjet head is recessed inward. As described above, when the conveyance belt is recessed inward, the recording medium placed in the recessed area is also recessed, and the recording accuracy on the recording medium is lowered.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image recording apparatus with improved recording accuracy on a recording medium.

  The image recording apparatus of the present invention has a suction surface in which a plurality of holes are formed, a transport belt that transports a recording medium in a transport direction, and the suction surface that faces the suction surface and discharges droplets to the suction surface. A recording head, suction means for sucking air from the surface opposite to the suction surface of the conveyor belt through the hole, and suctioning the recording medium to the suction surface, and the recording head of the opposite surface A support member having a support surface that supports a surface facing the recording head, and the recording head with the conveying belt and the support member interposed therebetween, and the recording is performed by a flushing operation through at least one of the plurality of holes. A receiving portion for receiving the droplets discharged from the head. The support surface of the support member is disposed at a position that avoids a flight path of droplets ejected from the recording head.

  According to the image recording apparatus of the present invention, at the time of recording on a recording medium, the surface opposite to the suction surface of the conveying belt that faces the recording head is supported by the support surface of the support member. It is suppressed and the recording accuracy to the recording medium can be improved. Further, during the flushing operation, the support surface of the support member is arranged at a position that avoids the flying direction of the liquid droplets, so that the liquid droplets ejected from the recording head can be reliably collected by the receiving unit.

  The recording head includes a plurality of nozzle rows arranged along a direction perpendicular to the transport direction and parallel to the suction surface, the nozzle array including a plurality of nozzles for discharging droplets. Preferably, the support surface of the support member extends along the orthogonal direction between two adjacent nozzle rows in the transport direction. According to this, the support surface of the support member can be easily arranged at a position that avoids the droplet flight path.

  Further, a plurality of holes are formed around the support member, and further provided with a support plate that supports the opposite surface, and an opening is formed in the support plate in a region facing the recording head. It is preferable that the support surface of the support member is disposed in the opening.

  In addition, it is preferable that a filter for capturing droplets discharged from the recording head is disposed in the receiving portion. According to this, it is possible to reliably capture the droplets ejected from the recording head and to prevent the droplets from rebounding.

  The filter is preferably close to the support member. According to this, it is possible to more reliably capture the droplets ejected from the recording head.

  Furthermore, it is preferable that the receiving portion has a discharge port for discharging the received droplet. According to this, the droplet received in the receiving portion is discharged from the discharge port, and the droplet does not accumulate in the receiving portion, and it is not necessary to discard the droplet received in the receiving portion.

  In addition, it is preferable that the suction means sucks air from the periphery of the receiving portion during the flushing operation. According to this, it is possible to suck a droplet or mist that has not been received by the receiving portion.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. This embodiment is an example in which the present invention is applied to an ink jet printer that records characters, images, and the like by ejecting ink onto paper.

  FIG. 1 is a schematic configuration diagram of an ink jet printer according to an embodiment of the present invention. FIG. 2 is a plan view of the ink jet head of FIG. 1 as viewed from below. FIG. 3 is a plan view of the conveyor belt of FIG. 1 as viewed from above. FIG. 4 is a plan view of the platen as viewed from above. FIG. 5 is a perspective view of a longitudinal section along the conveying direction in the vicinity of the conveying belt.

  As shown in FIG. 1, an ink jet printer 1 that is an image recording apparatus is a color ink jet printer having four ink jet heads 2 and a belt conveying device 3. The ink jet printer 1 has a control unit 60 (see FIG. 6) for controlling the ink jet printer 1.

  The four inkjet heads 2 are arranged side by side along the conveyance direction (arrow direction in FIG. 1) of the paper P that is a recording medium, corresponding to the four color inks (magenta, yellow, cyan, and black). Yes. That is, the inkjet printer 1 is a line printer.

  The four inkjet heads 2 have a suction surface 8a of a conveyance belt 8 described later (a surface that is parallel to the bottom surface of the inkjet head 2 on the outer circumferential surface of the conveyance belt 8 and moves in the conveyance direction of the paper P). It has a rectangular parallelepiped shape that is long in the width direction (perpendicular to the plane of FIG. 1) perpendicular to the transport direction. The bottom surface of the inkjet head 2 faces a suction surface 8a of a conveyance belt 8 described later.

  Further, as shown in FIG. 2, a plurality of minute diameter nozzles 2 a that eject ink onto the suction surface 8 a are formed on the bottom surface of the inkjet head 2. The plurality of nozzles 2a constitute four trapezoidal regions 2b arranged in the width direction. In the four trapezoidal regions 2b, the plurality of nozzles 2a constitute a nozzle row arranged along the width direction, and a plurality (six in this embodiment) of nozzle rows are arranged along the transport direction. Has been.

  Returning to FIG. 1, the belt conveyance device 3 includes a paper feeding unit 11 on the left side in FIG. 1 and a paper discharge unit 12 on the right side in FIG. 1. The paper P is transported in the transport direction toward. A pair of feed rollers 9a and 9b that convey the sheet while sandwiching the sheet are disposed immediately downstream of the sheet feeding unit 11. The paper P is fed from left to right in FIG. 1 by the pair of feed rollers 9a and 9b.

  The belt conveying device 3 is wound around a pair of belt rollers 13 and 14 having rotation axes parallel to each other and the pair of belt rollers 13 and 14, and the pair of belt rollers 13 and 14 is rotated. And an endless transport belt 8 that transports the paper P placed on the suction surface 8a.

  As shown in FIG. 3, a plurality of elongated through holes 19 are formed in the transport belt 8 in the transport direction through which ink ejected from the plurality of nozzles 2a passes during a flushing operation described later. The plurality of through holes 19 constitute a row arranged along the width direction, and a plurality of the rows are arranged along the transport direction. When the transport belt 8 travels, the two through holes 19 adjacent to each other in the width direction are close to each other so that the plurality of nozzles 2a always overlaps one of the plurality of through holes 19 along the vertical direction.

  In addition, a plurality of through holes 18 that are evenly distributed over the entire surface are formed in the conveyance belt 8 in a region other than a region where the plurality of through holes 19 are formed. That is, the transport belt 8 is formed with a plurality of holes including a plurality of through holes 18 and a plurality of through holes 19. Of the outer peripheral surface of the conveyor belt 8, the outer peripheral surface in the region where the plurality of through holes 18 are formed, excluding the region where the plurality of through holes 19 are formed, is the suction surface 8a. The paper P is placed on the suction surface 8a and is transported in the transport direction.

  The belt roller 13 is a driving roller that receives a driving force from a conveyance motor 74 (see FIG. 6) and rotates clockwise. The belt roller 14 is driven to rotate by the rotational force applied from the conveying belt 8 as the belt roller 13 rotates. The transport belt 8 travels in the transport direction as the pair of belt rollers 13 and 14 rotate.

  An encoder 15 (see FIG. 6) is provided on the rotating shaft of the belt roller 13. The encoder 15 detects the rotational position of the belt roller 13. Based on the rotational position of the belt roller 13 detected by the encoder 15, a through-hole position acquisition unit 64 described later acquires the position of the through-hole 19 formed in the transport belt 8 in the transport direction.

  The paper P sent out from the paper supply unit 11 by the feed rollers 9 a and 9 b is pressed against the suction surface 8 a of the transport belt 8 by the pressing roller 16 facing the belt roller 14. The sheet P pressed against the suction surface 8a by the pressing roller 16 is conveyed downstream in the conveying direction (to the right in FIG. 1) as the conveying belt 8 is driven by the clockwise rotation driving of the belt roller 13. Then, the sheet is peeled from the suction surface 8 a by the peeling mechanism 17 immediately downstream of the transport belt 8 and sent to the paper discharge unit 12.

  The four inkjet heads 2 eject ink of each color from the nozzles 2a toward the upper surface of the paper P when the paper P transported on the suction surface 8a passes immediately below the desired surface of the paper P. The recording operation for recording the color image is performed. Further, the four inkjet heads 2 perform a flushing operation for ejecting ink from the nozzles 2 a to the ink tray 32 described later through the through hole 19. During the flushing operation, the conveyor belt 8 is running, so that the ink lands on the conveyor belt 8 when the ejection timing of the ink from the nozzles 2a is deviated. Therefore, by forming the through hole 19 long in the transport direction, it is possible to prevent ink ejected from the nozzles 2a from landing on the transport belt 8 during the flushing operation.

  Returning to FIG. 1, in the inner region surrounded by the conveyor belt 8, a platen 22 (support plate), a suction box in order from the top along the vertical direction (direction in which the inkjet head 2 and the conveyor belt 8 face each other). 30 and a rotary fan 5 (suction means) are arranged.

  The platen 22 has a width similar to the width of the conveyor belt 8, extends between the pair of belt rollers 13 and 14, and contacts the surface opposite to the suction surface 8 a of the conveyor belt 8. Thus, the conveyor belt 8 is supported. As shown in FIG. 4, the platen 22 is formed with a plurality of through-holes 23 elongated in the transport direction and four parallelogram-shaped openings 24 elongated in the width direction, penetrating in the thickness direction.

  The four openings 24 are formed in the central region of the platen 22 along the conveyance direction so as to face the four inkjet heads 2 with the conveyance belt 8 interposed therebetween. The opening 24 is divided into four trapezoidal regions 24b arranged in the width direction by three ribs 24a. The plurality of trapezoidal regions 24b arranged in the width direction and arranged in four rows in the conveyance direction are opposed to the plurality of trapezoidal regions 2b formed on the lower surfaces of the four inkjet heads 2 with the conveyance belt 8 interposed therebetween. Yes.

  In addition, a plurality of ribs 24c (support members) extending in the width direction are formed in the trapezoidal region 24b (five in the present embodiment) in the transport direction. The rib 24c extends along the width direction between two nozzle rows adjacent to each other in the transport direction. That is, the plurality of ribs 24 c are arranged at positions that avoid the flight path of the ink ejected from the nozzles 2 a of the inkjet head 2. And the some rib 24c is supporting the surface which opposes the inkjet head 2 among the surfaces opposite to the adsorption surface 8a of the conveyance belt 8 by using the front-end | tip part as a support surface.

  As shown in FIGS. 1 and 5, the suction box 30 has a width similar to the width of the transport belt 8 and extends over a longer length than the four inkjet heads 2 arranged in the transport direction. is doing. The suction box 30 is open at the top and bottom, its upper end is in contact with the lower surface of the platen 22, and its lower end is connected to the rotary fan 5.

  In the suction box 30, four ink trays 32 (receiving portions) are arranged at positions that overlap the four openings 24 of the platen 22 along the vertical direction. That is, the four inkjet heads 2, the four openings 24 of the platen 22, and the four ink trays 32 overlap in the vertical direction.

  The ink tray 32 receives ink ejected from the nozzles 2 a of the inkjet head 2, and has an opening opened upward in the same size as the bottom surface of the inkjet head 2. A discharge port 33 for discharging the received ink is formed on the bottom surface of the ink tray 32, and the discharge port 33 is connected to a waste liquid tank (not shown). That is, the ink received in the ink tray 32 is discharged from the discharge port 33, so that no ink is collected in the ink tray 32, and there is no need to discard the ink received in the ink tray 32.

  A filter 34 that captures ink ejected from the inkjet head 2 is disposed in the ink tray 32. By providing the filter 34 in the ink tray 32, the ink ejected from the inkjet head 2 can be reliably captured, and the ink can be prevented from bouncing back. Further, the filter 34 is close to the rib 24c formed in the opening 24 in the vertical direction. Therefore, ink can be captured more reliably.

  The rotary fan 5 has a substantially rectangular parallelepiped shape and is connected to an opening below the suction box 30. The rotary fan 5 sucks the air in the suction box 30 by rotating the rotary blades provided inside. Then, the inside of the suction box 30 is depressurized, and passes through the plurality of through holes 18 and 19 of the conveyor belt 8 formed in the region facing the suction box 30 and the through holes 23 and the openings 24 of the platen 22. Air flows into the suction box 30. The air that has flowed in is sucked from the periphery of the ink tray 32. With this air flow, the paper P placed on the suction surface 8a is sucked to the suction surface 8a. Further, ink that has not been received by the ink tray 32 during the flushing operation or mist floating in the atmosphere can be sucked.

  Next, the control system of the inkjet printer 1 will be described with reference to FIG. FIG. 6 is a schematic block diagram showing a control configuration of the ink jet printer according to the embodiment of the present invention. The control unit 60 included in the inkjet printer 1 includes a CPU (Central Processing Unit) that is an arithmetic processing device, a ROM (Read Only Memory) that stores a control program executed by the CPU and data used in the control program. A RAM (Random Access Memory) for temporarily storing data during program execution.

  As shown in FIG. 6, the control unit 60 includes a head control unit 61, a conveyance control unit 62, a belt roller control unit 63, a through-hole position acquisition unit 64, and a suction control unit 65.

  When the control unit 60 receives a print signal from the PC 80 (personal computer), the head control unit 61 controls the head drive circuit 71 to eject ink from the corresponding ink jet head 2 so that an image or the like is generated on the paper P. The recording operation is performed.

  Further, the head controller 61 acquires that the vicinity of the front end in the transport direction of the through hole 19 of the transport belt 8 traveling by the through hole position acquiring unit 64 has reached a position facing each nozzle 2 a of the inkjet head 2. Then, the head driving circuit 71 is controlled to discharge the ink from the corresponding nozzles 2a of the inkjet head 2 to the ink tray 32 to perform the flushing operation.

  When the control unit 60 receives a print signal from the PC 80, the transport control unit 62 drives the feed motor 72 to rotate both the feed rollers 9 a and 9 b, thereby causing the paper P to be attracted to the transport belt 8. The motor driver 73 is controlled so as to be supplied onto 8a.

  The belt roller control unit 63 drives the conveyance motor 74 to rotate the belt roller 13 when the paper P is supplied onto the suction surface 8a of the conveyance belt 8 as a recording operation under the control of the conveyance control unit 62. Then, the motor driver 75 is controlled so that the transport belt 8 is caused to travel and the paper P on the suction surface 8a is transported in the transport direction.

  The through-hole position acquisition unit 64 acquires the position of the through-hole 19 formed in the transport belt 8 in the transport direction from the rotational position of the belt roller 13 detected by the encoder 15.

  The suction control unit 65 controls the motor driver 79 to drive the rotary motor 78 and rotate the rotary blades of the rotary fan 5.

  In the ink jet printer 1, during the recording operation, when the paper P conveyed on the suction surface 8 a passes just below the ejection area 2 b of the ink jet head 2, ink of each color is ejected from the nozzle 2 a toward the upper surface of the paper P. By ejecting, a desired color image is recorded on the paper P. At this time, since the surface opposite to the suction surface 8a of the transport belt 8 that faces the inkjet head 2 is supported by the support surface of the rib 24c, the suction surface 8a of the transport belt 8 is suppressed from being recessed, and the sheet P Recording accuracy can be improved.

  Further, during the flushing operation, the inkjet printer 1 discharges ink from the opposed nozzle 2a when the conveyance direction tip of the through hole 19 of the conveyance belt 8 faces the nozzle 2a of the inkjet head 2. Then, the ejected ink flies between the two adjacent ribs 24 c and is received by the ink tray 32. As described above, the rib 24c extending along the width direction between two nozzle rows adjacent to each other in the transport direction can be easily disposed at a position avoiding the ink flight path, and the transport belt 8 Of the surface opposite to the suction surface 8a, the surface facing the inkjet head 2 can be supported.

  Next, modified examples in which various modifications are added to the above-described embodiment will be described. In the above-described embodiment, the conveyance belt 8 is provided with the through hole 18 for sucking the paper P and the through hole 19 through which the ink ejected from the inkjet head 2 passes during the flushing operation. A plurality of through holes 18 may be formed on the entire surface of the transport belt 8 without providing the holes 19. That is, the hole for sucking the paper P and the hole through which the ink ejected from the inkjet head 2 during the flushing operation may be shared. At this time, each nozzle 2 a has a time to face any one of the plurality of through holes 18 while the transport belt 8 travels once.

  In the above-described embodiment, the plurality of ribs 24c extend along the width direction between two adjacent nozzle rows in the transport direction. The ink ejected from the nozzle 2a located at the position may fly inward in the transport direction. In that case, the two ribs 24c positioned on the outer side in the transport direction may be disposed slightly on the inner side in the transport direction. That is, the rib 24c may be a position that avoids the ink flight path, and may overlap the nozzle 2a along the vertical direction.

  Further, the ink flight path may have an end point below the support surface of the rib 24c. That is, the ink ejected from the inkjet head 2 during the flushing operation may adhere to a portion below the support surface of the rib 24c, or may not adhere to the support surface of the rib 24c. Ink that has deviated from the flight path due to disturbance or the like may adhere to the support surface of the rib 24c.

  The present invention is not limited to the ink jet printer as in the above-described embodiment, and can be applied to various apparatuses as long as the apparatus is an image recording apparatus.

1 is a schematic configuration diagram of an inkjet printer according to an embodiment of the present invention. It is the top view which looked at the inkjet head of FIG. 1 from the lower surface. It is the top view which looked at the conveyance belt of Drawing 1 from the upper surface. It is the top view which looked at the platen from the upper surface. It is a perspective view of the longitudinal section along the conveyance direction of the conveyance belt vicinity. It is a schematic block diagram which shows the control structure of the inkjet printer which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Inkjet head 2a Nozzle 3 Belt conveying apparatus 5 Rotating fan 8 Conveying belt 18, 19 Through hole 22 Platen 24a, 24c Rib 32 Ink tray

Claims (7)

A conveyance belt having a suction surface formed with a plurality of holes and conveying a recording medium in a conveyance direction;
A recording head facing the suction surface and discharging droplets to the suction surface;
Suction means for sucking air from the surface opposite to the suction surface of the transport belt through the hole to suck the recording medium on the suction surface;
A support member having a support surface for supporting a surface facing the recording head among the opposite surfaces;
A receiving portion that faces the recording head across the conveying belt and the support member and receives droplets discharged from the recording head by a flushing operation through at least one of the plurality of holes; Has
The image recording apparatus according to claim 1, wherein the support surface of the support member is disposed at a position that avoids a flight path of droplets ejected from the recording head. The recording head includes a plurality of nozzle arrays arranged along a direction perpendicular to the transport direction and parallel to the suction surface, the nozzle array including a plurality of nozzles that discharge droplets. And
The image recording apparatus according to claim 1, wherein the support surface of the support member extends along the orthogonal direction between two nozzle rows adjacent to each other in the transport direction. A plurality of holes are formed around the support member, and further includes a support plate that supports the opposite surface,
The support plate has an opening formed in a region facing the recording head,
The image recording apparatus according to claim 2, wherein the support surface of the support member is disposed in the opening.   The image recording apparatus according to claim 1, wherein a filter that captures droplets ejected from the recording head is disposed in the receiving portion.   The image recording apparatus according to claim 4, wherein the filter is close to the support member.   The image recording apparatus according to claim 1, wherein the receiving unit has a discharge port for discharging the received liquid droplets. The image recording apparatus according to claim 1, wherein the suction unit sucks air from around the receiving portion during the flushing operation.

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