JP4277853B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus that performs printing by ejecting ink onto a recording medium.

  2. Related Art Some inkjet recording apparatuses that print a desired image on a sheet by ejecting ink from a plurality of nozzles formed on an inkjet head perform what is called borderless printing, in which an image is printed on a sheet with no margins. When borderless printing is performed on a sheet with an inkjet recording apparatus, the area printed by the ink ejected from the inkjet head is larger than the sheet, and thus the ink adheres to the conveyance belt that conveys the sheet. When ink adheres to the transport belt, the back surface of the paper is soiled by the adhered ink.

  In order to solve such a problem, by transporting paper using a net-like transport belt formed by connecting a plurality of endless wires continuous in the paper transport direction in a direction perpendicular to the transport direction, Japanese Patent Application Laid-Open No. 2004-133867 discloses an ink jet recording apparatus that reduces ink adhering to a conveyance belt.

JP 2004-299361 A

  However, in the ink jet recording apparatus described in Patent Document 1 described above, the rigidity of the transport belt is reduced because the transport belt has a mesh shape. Since the transport belt with reduced rigidity is merely stretched between the two transport rollers, the transport belt is loosened or transported while the transport belt rotates to transport the paper by the rotation of the transport roller. Deformation such as shifting in a direction perpendicular to the direction occurs in the conveyance belt. If such deformation occurs in the transport belt, stable paper transport cannot be performed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording apparatus capable of preventing deformation of a conveyor belt while suppressing ink from adhering to the conveyor belt during borderless printing.

Means for Solving the Problems and Effects of the Invention

An ink jet recording apparatus according to the present invention includes a pair of rollers whose rotation axes are parallel to each other and an endless belt that is stretched between the pair of rollers and that travels in a direction perpendicular to the rotation axis to convey a recording medium in the traveling direction. A transport belt, an ink jet head that discharges ink onto a recording medium transported by the transport belt, and a cradle that is installed at a position sandwiching the transport belt together with the ink jet head and supports the transport belt . . The conveyor belt includes a belt main body portion whose outer peripheral surface is a mounting surface on which a recording medium is placed, a plurality of through holes formed in the belt main body portion and distributed over the entire outer peripheral surface, and the belt main body. A pair of reinforcing portions formed thick on the belt main body portion along both edges of the portion, and a pair of reinforcing portions fitted on the surfaces of the pair of rollers, respectively. An annular groove is formed, and the surface of the cradle facing the ink jet head is formed in a region facing the both ends of the recording medium placed on the belt main body along the traveling direction. along are formed first grooves extending said first groove, Ru der those receiving ink droplets having passed through the through hole does not land on the recording medium is ejected from said ink jet head .

According to this, when borderless printing is performed on the recording medium transported by the transport belt, a plurality of through holes are formed in the belt main body, so that a plurality of inks ejected from the inkjet head to the outside of the recording medium. Pass through the through hole. For this reason, it becomes difficult for ink to adhere to the conveyance belt, and it is possible to suppress ink adhering to the conveyance belt from adhering to the recording medium and bleeding. If a plurality of through holes are formed in the belt main body, the rigidity of the belt main body decreases, but thick reinforcing portions are formed on both edges of the belt main body, and the reinforcing portions are annular grooves of the roller. Therefore, the conveyance belt is maintained in a state of being stretched between the pair of rollers. Therefore, even if the recording medium is transported at a high speed, the transport belt is less likely to be loosened or displaced in the direction orthogonal to the transport direction. Further, the region of the conveying belt facing the ink jet head hardly bends. Therefore, the quality of the image formed on the recording medium is improved. Further, when borderless printing is performed on the recording medium conveyed by the conveying belt, the ink ejected from the inkjet head to the outside of both end portions along the running direction of the recording medium passes through the belt main body and passes through the first groove. Accepted within. Therefore, it is possible to suppress the inside of the recording apparatus from being stained with ink.
In the present invention, the surface of the pedestal facing the inkjet head extends along a direction orthogonal to the traveling direction to a region facing both ends of the inkjet head along the direction orthogonal to the traveling direction. A second groove may be formed. As a result, when borderless printing is performed on the recording medium transported by the transport belt, the ink ejected from both ends of the inkjet head along the direction orthogonal to the traveling direction of the recording medium passes through the belt main body. And received in the second groove. Therefore, the inside of the recording apparatus can be further suppressed from being stained with ink.
Further, at this time, an ink discharge hole communicating with the first and second grooves may be formed in the cradle. As a result, the ink received by the first and second grooves flows into the ink discharge hole and is discharged. Therefore, ink does not overflow from the first and second grooves.
Further, at this time, an ink absorbing member that absorbs ink from the ink discharge hole may be disposed on a side opposite to the surface of the receiving table facing the ink jet head. As a result, the ink that has flowed into the plurality of ink discharge holes can be absorbed by the ink absorbing member. Therefore, a large volume of ink received in the first and second grooves can be held.
Further, according to another aspect, the inkjet recording apparatus of the present invention has a pair of rollers whose rotation axes are parallel to each other, and a traveling direction that is stretched between the pair of rollers and travels in a direction perpendicular to the rotation axis. An endless transport belt for transporting the recording medium, an ink jet head for discharging ink onto the recording medium transported by the transport belt, and a position sandwiching the transport belt together with the ink jet head to support the transport belt And a cradle. The conveyor belt includes a belt main body portion whose outer peripheral surface is a mounting surface on which a recording medium is placed, a plurality of through holes formed in the belt main body portion and distributed over the entire outer peripheral surface, and the belt main body. A pair of reinforcing portions formed thick on the belt main body portion along both edges of the portion, and a pair of reinforcing portions fitted on the surfaces of the pair of rollers, respectively. An annular groove is formed, and a concave portion longer than the length of the recording medium placed on the belt main body in the direction perpendicular to the traveling direction is formed on the surface of the cradle facing the ink jet head. ing. According to this, when borderless printing is performed on the recording medium transported by the transport belt, a plurality of through holes are formed in the belt main body, so that a plurality of inks ejected from the inkjet head to the outside of the recording medium. Pass through the through hole. For this reason, it becomes difficult for ink to adhere to the conveyance belt, and it is possible to suppress ink adhering to the conveyance belt from adhering to the recording medium and bleeding. If a plurality of through holes are formed in the belt main body, the rigidity of the belt main body decreases, but thick reinforcing portions are formed on both edges of the belt main body, and the reinforcing portions are annular grooves of the roller. Therefore, the conveyance belt is maintained in a state of being stretched between the pair of rollers. Therefore, even if the recording medium is transported at a high speed, the transport belt is less likely to be loosened or displaced in the direction orthogonal to the transport direction. Further, the region of the conveying belt facing the ink jet head hardly bends. Therefore, the quality of the image formed on the recording medium is improved. In addition, when borderless printing is performed on the recording medium conveyed by the conveying belt, the ink ejected from the inkjet head to the outside of both ends along the running direction of the recording medium passes through the belt main body and is received in the recess. Is done. Therefore, it is possible to suppress the inside of the recording apparatus from being stained with ink.
In the present invention, an ink absorbing member may be disposed in the recess. The ink discharged to the recess can be absorbed by the ink absorbing member. For this reason, the ink ejected into the concave portion is less likely to be scattered, and the inside of the recording apparatus can be further suppressed from being stained with ink.

  In the present invention, it is preferable that the belt main body portion has a plurality of linear portions and is configured in a mesh shape by the plurality of linear portions, and each mesh configures the through hole. . Further, in the present invention, the belt main body portion includes a plurality of first linear portions extending in the first direction within the placement surface, and the plurality of first linear portions within the placement surface. It consists of a plurality of second linear portions extending in a second direction different from the first direction so as to intersect, two adjacent ones of the plurality of first linear portions, and these two It is preferable that the through hole is constituted by two of the plurality of second linear portions intersecting with the first linear portion. This facilitates the formation of the belt main body having a plurality of through holes.

  At this time, the through hole may have a rhombus shape. Thereby, the rigidity of a belt main-body part turns into uniform rigidity. Therefore, when the recording medium is transported, the transport belt is less likely to be displaced in the direction orthogonal to the traveling direction.

  At this time, the first and second linear portions may be inclined with respect to the traveling direction of the transport belt. Thereby, the rigidity regarding the direction inclined with respect to the running direction of the belt body is improved.

  At this time, the mesh may have a hexagonal shape surrounded by the six linear portions. As a result, the rigidity of the belt body becomes even more uniform. Therefore, when the recording medium is transported, the transport belt is less likely to be displaced in the direction orthogonal to the traveling direction.

  In the present invention, it is preferable that a water repellent film is formed on the outer peripheral surface of the belt main body. As a result, ink hardly adheres to the belt main body. Therefore, it is possible to further suppress the ink adhering to the belt main body portion from adhering to the recording medium and bleeding.

  In the present invention, it is preferable to further include an ink removing member that contacts the outer peripheral surface of the belt main body. Thereby, the ink adhering to the outer peripheral surface of the belt main body is removed by the ink removing member. For this reason, it is possible to prevent the ink adhering to the belt main body from adhering to the recording medium.

  Further, in the present invention, the plurality of inkjet heads are arranged in parallel along the traveling direction, and the plurality of inkjet heads each have a nozzle group in which nozzles for ejecting ink are densely arranged. It is preferable that a pressing roller for pressing the recording medium against the conveying belt is disposed in the gap. Thereby, when an image is printed on a recording medium, it can suppress that a recording medium lifts from a conveyance belt.

  At this time, a plurality of the pressing rollers may be arranged along a direction orthogonal to the traveling direction. Thereby, it is possible to uniformly suppress the recording medium from floating from the conveyance belt.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic side view showing an overall configuration of an ink jet printer according to a first embodiment of the present invention. FIG. 2 is a partial perspective view of the interior of the inkjet printer according to the first embodiment of the present invention. As shown in FIG. 1, an inkjet printer (inkjet recording apparatus) 1 is a color inkjet printer having four inkjet heads 2. The inkjet printer 1 includes a paper feeding unit 11 on the left side in the drawing and a paper discharge unit 12 on the right side in the drawing.

  Inside the ink jet printer 1, a paper conveyance path is formed in which a paper (recording medium) P is conveyed from the paper supply unit 11 toward the paper discharge unit 12. A pair of feed rollers 5a and 5b for nipping and conveying the paper is disposed immediately downstream of the paper supply unit 11. The paper P is sent out from the paper supply unit 11 to the right in the drawing by the pair of feed rollers 5a and 5b. In an intermediate portion of the sheet conveyance path, two belt rollers 6, 7, an endless conveyance belt 8 wound so as to be stretched between both rollers 6, 7, and an area surrounded by the conveyance belt 8 A belt conveyance mechanism 13 including a platen (receiving base) 15 disposed at a position facing the inkjet head 2 is provided. The rotation shafts 6a and 7a of the belt rollers 6 and 7 are arranged in parallel to each other. The platen 15 is disposed so that its upper surface 16 is close to the inner peripheral surface 8 b of the conveying belt 8 on the upper side, and supports the conveying belt 8. A nip roller 4 is disposed at a position facing the belt roller 7. The nip roller 4 presses the paper P sent out from the paper supply unit 11 by the feed rollers 5 a and 5 b against the outer peripheral surface 8 a of the transport belt 8. The outer peripheral surface 8a of the transport belt 8 is an outer peripheral surface of a belt main body 41 described later and is a placement surface on which the paper P is placed.

  As shown in FIGS. 1 and 2, the ink jet printer 1 is provided with a pressing member 30 that presses the paper P against the outer peripheral surface 8 a. The pressing member 30 includes five shafts 31 extending in a direction orthogonal to the paper transport direction (hereinafter referred to as “transport direction”), a plurality of press rollers 32 provided rotatably on the shaft 31, and five And two connecting plates 33 that respectively support the end portions of the shaft 31. The five shafts 31 are arranged in parallel to each other on the outer side of the inkjet head 2 located between the inkjet heads 2 and on the outer side in the transport direction. The plurality of pressing rollers 32 are arranged at equal intervals in each shaft 31 with respect to the direction orthogonal to the conveying direction. Four springs 35 for urging the connecting plate 33 downward are provided at both ends of the two connecting plates 33 in the conveying direction, and the plurality of pressing rollers 32 are conveyed by the urging force of the springs 35 to the conveying belt. 8 is in contact with the outer peripheral surface 8a. With this configuration, the paper P sent out from the paper supply unit 11 is pressed against the outer peripheral surface 8 a by the pressing member 30 when passing between the outer peripheral surface 8 a of the transport belt 8 and the inkjet head 2. As a result, the sheet P does not float from the outer peripheral surface 8a while passing through the position facing the inkjet head 2. Therefore, it is possible to prevent the paper P from coming into contact with the inkjet head 2. As a result, it is possible to suppress the occurrence of paper jam between the inkjet head 2 and the outer peripheral surface 8a. Further, since the distance between the paper P and the ink ejection surface 3a of the inkjet head 2 is substantially constant, the image quality printed on the paper P is improved. Further, since the plurality of pressing rollers 32 are provided for each shaft 31, it is possible to uniformly suppress the sheet P from being lifted from the transport belt 8.

  As shown in FIG. 1, a conveyance motor 9 is disposed below the conveyance belt 8, and a drive belt 10 is stretched around a shaft 9 a of the conveyance motor 9 and a rotation shaft 6 a of the belt roller 6. As the shaft 9a of the transport motor 9 rotates in the clockwise direction in FIG. 1, the belt roller 6 is rotationally driven in the clockwise direction. Then, the conveyor belt 8 stretched between the rollers 6 and 7 travels in the conveyance direction as the belt roller 6 rotates. That is, the traveling direction of the conveyance belt 8 and the conveyance direction are the same direction. With this configuration, the conveyance belt 8 conveys the sheet P pressed against the outer peripheral surface 8 a by the nip roller 4 and the plurality of pressing rollers 32 toward the paper discharge unit 12.

  As shown in FIG. 1, two sponge rollers (ink removing members) 18 a and 18 b are disposed at a position diagonally to the left of the belt roller 6 so as to sandwich the conveyance belt 8. The two sponge rollers 18a and 18b are rotatably supported while being in contact with the outer peripheral surface 8a and the inner peripheral surface 8b of the transport belt 8. Therefore, the conveyor belt 8 itself rotates as the conveyor belt 8 travels, and sucks and removes ink adhering to the outer peripheral surface 8 a and the inner peripheral surface 8 b of the conveyor belt 8. The ink sucked by the two sponge rollers 18a and 18b is discarded in a waste ink reservoir (not shown).

  The four inkjet heads 2 are provided side by side along the transport direction corresponding to four colors of ink (magenta, yellow, cyan, and black). That is, the ink jet printer 1 is a line printer. The four ink-jet heads 2 are each formed by bonding a head body (a channel unit in which a plurality of ink channels including nozzles and pressure chambers are formed) and an actuator for applying pressure to ink in the pressure chambers at the lower end thereof. ) 3 respectively. The head main body 3 has an elongated rectangular parallelepiped shape that is long in a direction orthogonal to the transport direction. In addition, on the bottom surface of the head main body 3, a large number of nozzles having a small diameter for ejecting ink downward are arranged side by side, and this bottom surface is an ink ejection surface 3a facing the outer peripheral surface 8a. The plurality of pressing rollers 32 are arranged at positions that do not face the nozzle group formed by the plurality of nozzles formed on each ink ejection surface 3a. That is, the pressing roller 32 is not positioned between the nozzle and the conveyor belt 8. Thereby, the ink discharged from the nozzle does not adhere to the pressing roller 32.

  The head body 3 is arranged so that the ink discharge surface 3a and the outer peripheral surface 8a adjacent to the inkjet head 2 of the transport belt 8 are parallel to each other, and a small amount of gap is formed between these surfaces. A sheet conveyance path is formed in the gap portion. With this configuration, when the paper transported by the transport belt 8 sequentially passes immediately below the four head bodies 3, ink of each color is ejected from the nozzle toward the upper surface of the paper P, that is, the printing surface. Thus, a desired color image can be formed.

  Here, the configuration of the belt conveyance mechanism 13 will be described in detail with reference to FIGS. FIG. 3 is a plan view of the belt conveyance mechanism. 4A and 4B show the belt conveyance mechanism, where FIG. 4A is a cross-sectional view taken along line IVA-IVA shown in FIG. 1, and FIG. 4B is a cross-sectional view taken along line IVB-IVB shown in FIG. is there. FIG. 5 is an enlarged view of a region surrounded by a one-dot chain line depicted in FIG. 4A shows the ink jet head 2 and the paper P, and FIG. 4B shows the paper P by a two-dot chain line, so that the positional relationship of grooves formed on the platen 15 described later can be understood. It is easy. As shown in FIG. 3, the conveyance belt 8 of the belt conveyance mechanism 13 is formed on a belt main body (belt main body portion) 41 on which the paper P is placed and an end portion along the running direction of the belt main body 41. And a pair of annular reinforcing portions 45. The belt main body 41 includes a linear member (first linear portion) 42 extending in a direction intersecting the traveling direction, and a linear member (second linear shape) extending in a direction orthogonal to the linear member 42. Part) 43 is formed in a net shape in which a plurality of parts are aligned and integrated along the transport direction. That is, the belt body 41 is formed with a plurality of holes (through holes) 44 surrounded by a plurality of linear members 42 and 43. The hole 44 penetrates in the thickness direction of the belt main body 41, and the opening (mesh) shape is formed in a rhombus shape by two adjacent linear members 42 and 43, respectively. In this embodiment, the aperture ratio of the hole 44 in the belt body 41 is 85% to 95. As a result, the ink hardly adheres to the belt main body 41 and the rigidity of the belt main body 41 can be balanced. The two types of linear members 42 and 43 extend with a constant thickness, and both have the same thickness.

  Further, the linear members 42 and 43 in the present embodiment are each inclined 45 ° with respect to the transport direction. The belt rollers 6 and 7 on which the conveyor belt 8 is stretched are provided so that the conveyor belt 8 does not slack, but a certain allowable installation range is provided there. That is, the belt rollers 6 and 7 may slightly shift from the predetermined positions in the axial direction and the radial direction together with the rotation shafts 6a and 7a. When this deviation occurs, the conveyance belt 8 stretched around the belt rollers 6 and 7 is inclined with respect to the conveyance direction (that is, the direction in which the opposite ends of the belt rollers 6 and 7 are connected to each other). ) External force is applied, and the conveyor belt 8 tends to be offset or slack. In a belt body composed of two types of linear members extending in a direction parallel to and orthogonal to the traveling direction, when such an external force is applied, the linear member cannot effectively receive the external force and the conveyor belt Although the belt main body 41 of the present embodiment is slackened or offset, the linear members 42 and 43 are inclined in a direction relatively close to a direction parallel to the external force direction. Can receive each. Therefore, since the belt main body 41 is received by the linear members 42 and 43 even when the external force as described above is applied, it is difficult for the belt main body 41 to be loosened or offset.

  As shown in FIGS. 4A and 4B, the reinforcing portion 45 includes a protruding portion 45a protruding outward from the outer peripheral surface 8a and a protruding portion 45b protruding inward from the inner peripheral surface 8b. It is thicker than the linear members 42 and 43. The protruding portion 45a of the reinforcing portion 45 is smaller than the protruding amount from the inner peripheral surface 8b of the protruding portion 45b, and the protruding amount is not in contact with the ink discharge surface 3a of the inkjet head 2. Since the reinforcing portion 45 covers the both ends of the belt main body 41 to increase the rigidity of the belt main body 41 including the plurality of linear members 42 and 43, the belt main body 41 is less likely to be loosened or offset. The belt main body 41 and the reinforcing portion 45 in the present embodiment are formed by integral molding as will be described later, but in order to show each easily, a boundary line is shown in the cross-sectional portion of FIGS. 4 and 5. Each is shown with different hatching.

  As shown in FIG. 5, a water repellent film 46 is formed on the surface of the conveyor belt 8. For example, the water repellent film 46 is formed by integrally forming a band-like body in which linear members 42 and 43 made of ABS (acrylonitrile butadiene styrene) resin and the reinforcing portion 45 are integrated, and then the water-repellent film is formed on the band-like body. It is formed by spray coating a water repellent material 46. Note that the belt-like body has end faces of the reinforcing portion 45 and the belt main body 41 at one end, and the end face of the belt main body 41 has an adhesive margin at the other end from the end face of the reinforcing portion 45. The end surface of the belt main body 41 is formed at the extended position. Then, both end portions of the belt main body 41 are overlapped while aligning both end surfaces of the reinforcing portion 45 of the belt-like body, and the portions that are in contact with each other are joined with an adhesive to form the transport belt 8. In the above description, the water-repellent film 46 is formed on the belt-like body. However, the water-repellent film 46 may be formed by adhering both ends of the belt-like body and then immersing them in a water-repellent material. Since the water repellent film 46 is formed on the transport belt 8 in this way, it becomes difficult for ink to adhere to the transport belt 8. Further, even if ink adheres to the conveyor belt 8, the ink adhered easily can be wiped off by the sponge rollers 18a and 18b. In the present embodiment, the belt main body 41 and the reinforcing portion 45 are integrally formed from the same material. However, the belt main body and the reinforcing portion may be separately manufactured and bonded together with an adhesive. At this time, the rigidity of the conveyor belt can be appropriately improved by making the reinforcing portion a material stronger than the belt body.

  A pair of annular grooves 47 and 48 are formed on the outer peripheral surfaces of the belt rollers 6 and 7 at positions facing the protruding portions 45b of the pair of reinforcing portions 45, respectively. The pair of annular grooves 47 and 48 have substantially the same width as the direction perpendicular to the traveling direction of the projecting portion 45b, and when the projecting portion 45b is fitted into the annular grooves 47 and 48, the inner circumference The surface 8b has a depth that makes contact with the outer peripheral surfaces of the belt rollers 6 and 7. The pair of annular grooves 47 and 48 are formed in parallel along the rotational direction of the belt rollers 6 and 7. Since the annular grooves 47 and 48 are formed in the belt rollers 6 and 7, the conveyor belt 8 is stretched between the belt rollers 6 and 7 with the reinforcing portion 45 fitted in the annular grooves 47 and 48. It is maintained in the passed state (that is, a state in which no slack or the like occurs in the conveyor belt 8).

  As illustrated in FIGS. 4A and 4B, the platen 15 has a substantially rectangular parallelepiped shape and is disposed between the belt rollers 6 and 7. As shown in FIG. 4A, the upper surface 16 of the platen 15 has a width in the direction orthogonal to the conveying direction larger than the width of the conveying belt 8 and has a length in the conveying direction outside the four inkjet heads 2. The size is such that it protrudes further outward in the transport direction than the inkjet head 2 positioned at the position. Note that the width of the upper surface 16 in the direction orthogonal to the transport direction is smaller than the length of the inkjet head 2 in the longitudinal direction. In addition, on the upper surface 16 of the platen 15, grooves (first grooves) extending along the transport direction in regions facing both ends along the transport direction of the paper P placed on the outer peripheral surface 8 a of the transport belt 8. ) Groove 55 is formed. Eight grooves (second grooves) 56 connected to the two grooves 55 are formed on the upper surface 16. These grooves 56 extend in a direction perpendicular to the transport direction, and are formed in regions facing both end portions along the longitudinal direction of the inkjet head 2.

  A plurality of ink discharge holes 58 penetrating the platen 15 are formed at the bottoms of the grooves 55 and 56. A waste liquid foam (ink absorbing member) 60 is provided on the lower surface of the platen 15. The waste liquid form 60 absorbs ink discharged through the ink discharge holes 58 from the grooves 55 and 56 that have received ink discharged during borderless printing.

  Next, the operation of the ink jet printer when printing on paper will be described below. First, the paper P is sent from the paper supply unit 11 toward the nip roller 4 by the feed rollers 5a and 5b. At this time, the conveyance motor 9 is also driven, and the belt roller 6 rotates and the conveyance belt 8 travels in the direction in which the paper P is conveyed. Then, the sheet P is conveyed to a position facing the inkjet head 2 as the conveyance belt 8 travels while being pressed against the outer peripheral surface 8 a of the conveyance belt 8 by the nip roller 4. When normal printing (printing with margins) is performed on the paper P, ink is ejected from the nozzles facing the paper P so that the ink lands on the paper P when the paper P faces each inkjet head 2. As a result, a desired image is formed on the paper P. On the other hand, when borderless printing is performed on the paper P, ink is ejected to a region that is slightly larger than the planar size of the paper P. That is, when printing on the front edge, the rear edge, and both side edges of the paper P, when the front edge and the rear edge of the paper P overlap the groove 56 that overlaps the edge along the longitudinal direction of the inkjet head 2 that ejects ink. Furthermore, ink is ejected from the nozzle overlapping the groove 56 toward the front end of the paper P, the groove 56, the rear end, and the groove 56. Further, when both side ends of the paper P overlap the groove 55 portion that overlaps the inkjet head 2 that discharges ink, ink is discharged from the nozzle that overlaps the groove 55 portion toward both side ends of the paper P and the groove 55 portion. A desired image is formed on the front edge, the rear edge, and both side edges of the paper P. In addition, ink is ejected from the nozzles facing each inkjet head 2 in regions other than the front end, rear end, and both side ends of the paper P, and a desired image is formed. The ink is discharged toward the grooves 55 and 56 because the borderless printing is performed even if the paper P placed on the outer peripheral surface 8a of the transport belt 8 is slightly shifted from a predetermined position on the outer peripheral surface 8a. This is so that it can be performed. When such borderless printing is performed on the paper P, the ink ejected from the nozzles tends to adhere to the belt main body 41, and the belt main body 41 is constituted by a plurality of linear members 42 and 43. Since the plurality of holes 44 are formed, most of the ink traveling toward the grooves 55 and 56 without landing on the paper P does not adhere to the belt main body 41 and land on the grooves 55 and 56 through the holes 44. The ink that has landed in the grooves 55 and 56 increases when repeated borderless printing is performed. However, since a plurality of ink discharge holes 58 are formed at the bottom of the grooves 55 and 56, the ink is transferred to the grooves 55 and 56. It is discharged from the grooves 55 and 56 without accumulating and overflowing. In addition, since the ink discharged from the ink discharge hole 58 is absorbed by the waste liquid form 60, the ink discharged from the ink discharge hole 58 is not contaminated in the printer. Further, during normal and borderless printing, the paper P is pressed by the pressing member 30 so as not to float from the outer peripheral surface 8a, so that the image quality formed on the paper P is improved. Then, the sheet P on which the image is formed is conveyed to the sheet discharge unit 12 by the traveling of the conveyance belt 8 and is discharged.

  As described above, according to the inkjet printer 1 of the present embodiment, even when ink is ejected to the conveyor belt 8 during borderless printing, ink is hardly attached. For this reason, it is possible to suppress ink adhering to the conveyance belt 8 from adhering to the paper P and bleeding. In addition, if a plurality of holes 44 are formed in the belt main body 41 of the conveyor belt 8, the rigidity of the belt main body 41 is reduced, but reinforcing portions 45 are formed at both ends along the running direction of the belt main body 41, and the reinforcing portions. Since 45 is fitted in the annular grooves 47 and 48 of the belt rollers 6 and 7, even if the paper P is conveyed at a high speed, the conveying belt 8 does not become slack or be displaced in a direction perpendicular to the conveying direction. Further, the belt main body 41 is configured by forming two types of linear members 42 and 43 in a mesh shape, and a plurality of holes 44 are formed at that time, so that the belt main body 41 having a plurality of holes 44 is formed. Can be easily formed. Further, since the platen 15 is provided, the region of the conveyor belt 8 facing the inkjet head 2 is hardly bent. Therefore, the quality of the image formed on the paper P is improved. Further, since the grooves 55 and 56 are formed in the platen 15, even when ink is ejected to the outside of the paper P, that is, outside the front edge, the rear edge, and both side edges during borderless printing, the ink is received by the grooves 55 and 56. Is done. Therefore, the inside of the printer can be suppressed from being stained with ink. Further, since the waste liquid form 60 is provided, the ink received in the grooves 55 and 56 can be held in a large volume.

  Next, an inkjet printer according to a second embodiment of the present invention will be described below. FIG. 6 is a cross-sectional view of the belt conveyance mechanism of the ink jet printer according to the second embodiment of the present invention. As shown in FIGS. 6A and 6B, the ink jet printer in the present embodiment has a belt transport mechanism 113 in which the configuration of the platen 115 is different from that of the platen 15 described above, and the others are the first embodiment. It has the same composition as. Components similar to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  Unlike the platen 15 described above, the platen 115 is not formed with the plurality of grooves 55, 56 and the ink discharge holes 58, and the recesses 116 are formed at positions facing the four inkjet heads 2. The recess 116 is formed on the upper surface 117 so as to open toward the inkjet head 2. The recess 116 has a region on the upper surface 117 facing both ends along the transport direction of the paper P placed on the outer peripheral surface 8a of the transport belt 8, and a longitudinal direction of the two outermost inkjet heads 2 with respect to the transport direction. Is formed in the entire region surrounded by the outer end portion in the transport direction and the region facing the end. Specifically, both ends along the conveyance direction of the recess 116 are located outside both ends along the conveyance direction of the paper P, and both ends along the direction orthogonal to the conveyance direction of the depression 116 are conveyed by the inkjet head 2. It is located outside the outer end in the transport direction along the direction orthogonal to the direction. In the recess 116, a waste liquid foam (ink absorbing member) 118 that absorbs ink is disposed.

  According to the ink jet printer having the platen 115 as described above, when borderless printing is performed on the paper P, most of the ink ejected from the ink jet head 2 to the outside of the paper P passes through the plurality of holes 44 of the belt main body 41. Then, it is landed and received in the recess 116. Therefore, the inside of the printer can be suppressed from being stained with ink. In addition, since the formation area of the recess 116 is larger than the grooves 55 and 56 of the first embodiment, a large volume of ink can be held. Further, since the waste liquid form 118 is disposed in the recess 116, the ink ejected toward the recess 116 can be absorbed. Therefore, it is possible to suppress the ink accumulated in the recess 116 from being scattered by the ejected ink. Therefore, it is possible to further suppress the inside of the printer from being stained with ink.

  Next, an ink jet printer according to a third embodiment of the present invention will be described below. FIG. 7 is a plan view of the belt conveyance mechanism of the ink jet printer according to the third embodiment of the present invention. As shown in FIG. 7, the ink jet printer according to the present embodiment includes a belt transport mechanism 313 in which the configuration of the transport belt 308 is different from the transport belt 8 described above, and the other configurations are the same as those of the first embodiment. Have. Components similar to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 7, the transport belt 308 includes a belt main body 341 on which paper is placed and a reinforcing portion 345 similar to the reinforcing portion 45 described above. The belt main body 341 includes a plurality of linear members 351 extending in a direction orthogonal to the traveling direction, and two types of linear members 352 and 353 inclined at 60 ° in opposite directions with respect to the linear member 351. Are connected to each other to form a plurality of regular hexagons. That is, the belt body 341 is formed with a plurality of holes 344 having regular hexagonal openings surrounded by the plurality of linear members 351 to 353. Thus, the conveyance belt 308 is different from the hole 44 formed in the belt main body 41 of the first embodiment only in the shape of the hole 344 formed in the belt main body 341. The linear members 351 to 353 extend with a constant thickness, and both have the same thickness.

  According to the ink jet printer having the transport belt 308 as described above, when borderless printing is performed on the paper P, most of the ink ejected from the ink jet head 2 to the outside of the paper P is the belt as in the first embodiment. It passes through a plurality of holes 344 formed in the main body 341 and land on the grooves 55 and 56 of the platen 15, and hardly adheres to the belt main body 341. Further, since the linear member 351 is inclined by 90 ° with respect to the traveling direction and the linear members 352 and 353 are inclined by 30 ° in the opposite directions with respect to the traveling direction, respectively, the belt main body 341 in the first embodiment. Even if the external force described above and the external force in the direction orthogonal to the traveling direction are applied, the three types of linear members 351 to 353 receive the external force, respectively. For this reason, even if an external force in a direction intersecting the traveling direction is applied to the transport belt 308, it is difficult to be loosened or offset.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the belt bodies 41 and 341 of the conveyor belts 8 and 308 in each of the above-described embodiments are configured in a mesh shape by a plurality of linear members, but a plurality of through holes are provided in the belt body of the flat belt. It may be a thing. Moreover, the opening shape of the holes 44 and 344 may be a polygon excluding a circle, an ellipse, a rhombus, and a regular hexagon. Further, the linear members 55 and 56 may not be inclined with respect to the traveling direction. The printer may not be provided with the platens 15 and 115. Further, the ink discharge hole 58 may not be provided in the platen 15. In this case, it is not necessary to provide the waste liquid form 60 as well. Further, the waste liquid foam 118 may not be provided in the concave portion 116 of the platen 115. Further, the recess 116 may not be provided in the platen 115. Further, the water repellent film 46 may not be formed on the conveyor belt 8. In this case, even if the photo paper is mistakenly placed on the transport belt so that the print surface of the photo paper (that is, the glossy surface on which the ink receiving layer is formed) and the surface of the belt main body 41 are in contact with each other, Since 41 is comprised from resin, it becomes easy to peel photo paper from the surface of the belt main body 41. FIG. If the belt body is a rubber belt made of rubber, the printing surface of the photo paper and the rubber belt are in close contact with each other, and the photo paper is difficult to peel off from the rubber belt. Also, the two sponge rollers 18a and 18b may not be provided in the printer. Further, it is sufficient that one pressing roller 32 is provided for each shaft 31 of the pressing member 30. Further, only one shaft 31 may be used. Further, when the outer peripheral surface of the transport belt is sticky, the pressing member 30 is not particularly required. In addition, instead of the pressing member 30, the printer air-sucks the paper P from the inside through the holes of the transport belts 8 and 308, and holds the paper P on the outer peripheral surface of the transport belts 8 and 308. A platen with a built-in electrode may be used to supply a DC voltage to the electrode to charge the platen itself, and a charging / adsorption method in which the paper P is adsorbed to the transport belts 8 and 308 may be used.

1 is a schematic side view showing an overall configuration of an inkjet printer according to a first embodiment of the present invention. 1 is a partial perspective view of an interior of an inkjet printer according to a first embodiment of the present invention. It is a top view of a belt conveyance mechanism. The belt conveyance mechanism is shown, (a) is sectional drawing along the IVA-IVA line shown in FIG. 1, (b) is sectional drawing along the IVB-IVB line shown in FIG. It is an enlarged view of the area | region enclosed with the dashed-dotted line drawn by FIG.4 (b). It is sectional drawing of the belt conveyance mechanism of the inkjet printer by 2nd Embodiment of this invention. It is a top view of the belt conveyance mechanism of the inkjet printer by 3rd Embodiment of this invention.

1 Inkjet printer (inkjet recording device)
2 Inkjet head 6, 7 Roller 6a, 7b Rotating shaft 8,308 Conveying belt 8a Outer peripheral surface (mounting surface)
15,115 platen
18a, 18b Sponge roller (ink removing member)
32 Pressing roller 41 Belt body (belt body)
42 Linear member (first linear part)
43 linear member (second linear part)
44 holes (through holes)
45 Reinforcing part 46 Water repellent film 47, 48 Annular groove 55 Groove (first groove)
56 groove (second groove)
58 Ink discharge hole 60,118 Waste liquid foam (ink absorbing member)
116 recess 344 hole (through hole)

Claims (15)

A pair of rollers whose rotation axes are parallel to each other;
An endless conveying belt that is stretched between the pair of rollers and conveys the recording medium in the traveling direction by traveling in a direction orthogonal to the rotation axis;
An inkjet head for ejecting ink onto a recording medium conveyed by the conveyance belt ;
Installed at a position sandwiching the conveyor belt together with the inkjet head, and comprising a cradle for supporting the conveyor belt ,
The conveyor belt is
A belt main body whose outer peripheral surface is a mounting surface on which a recording medium is mounted;
A plurality of through holes formed in the belt main body and distributed over the entire outer peripheral surface;
A pair of reinforcing portions formed thick on the belt body portion along both edges of the belt body portion;
On the surface of the pair of rollers, a pair of annular grooves into which the pair of reinforcing portions are respectively fitted are formed ,
The surface of the pedestal facing the inkjet head extends to the area facing the both ends of the recording medium placed on the belt main body along the traveling direction and extends along the traveling direction. A groove is formed,
Said first groove, an ink jet recording apparatus according to claim der Rukoto those receiving ink droplets having passed through the through hole does not land on the injection has been recorded medium from said ink jet head. The surface of the pedestal facing the ink jet head extends to a region facing both ends of the ink jet head along the direction orthogonal to the traveling direction and extends along a direction orthogonal to the traveling direction. The inkjet recording apparatus according to claim 1, wherein a groove is formed. The ink jet recording apparatus according to claim 2, wherein an ink discharge hole communicating with the first and second grooves is formed in the cradle. The ink jet recording apparatus according to claim 3, wherein an ink absorbing member that absorbs ink from the ink discharge hole is disposed on a side opposite to the surface of the receiving table facing the ink jet head. A pair of rollers whose rotation axes are parallel to each other;
An endless conveying belt that is stretched between the pair of rollers and conveys the recording medium in the traveling direction by traveling in a direction orthogonal to the rotation axis;
An inkjet head for ejecting ink onto a recording medium conveyed by the conveyance belt;
Installed at a position sandwiching the conveyor belt together with the inkjet head, and comprising a cradle for supporting the conveyor belt,
The conveyor belt is
A belt main body whose outer peripheral surface is a mounting surface on which a recording medium is mounted;
A plurality of through holes formed in the belt main body and distributed over the entire outer peripheral surface;
A pair of reinforcing portions formed thick on the belt body portion along both edges of the belt body portion;
On the surface of the pair of rollers, a pair of annular grooves into which the pair of reinforcing portions are respectively fitted are formed,
An ink jet having a recess longer than a length in a direction perpendicular to the traveling direction of a recording medium placed on the belt main body is formed on a surface of the cradle facing the ink jet head. Recording device. The ink jet recording apparatus according to claim 5, wherein an ink absorbing member is disposed in the recess. The belt main body portion has a plurality of linear portions, and is configured in a mesh shape by the plurality of linear portions,
Each mesh-jet recording apparatus according to any one of claims 1-6, characterized in that constitutes the through hole. The belt main body portion extends in the first direction within the placement surface, and the first linear portions extend in the first direction, and the belt body portion intersects the plurality of first linear portions within the placement surface. A plurality of second linear portions extending in a second direction different from the one direction,
The through hole is constituted by two adjacent ones of the plurality of first linear portions and two of the plurality of second linear portions intersecting with the two first linear portions. The ink jet recording apparatus according to claim 1 , wherein the ink jet recording apparatus is provided. The ink jet recording apparatus according to claim 8 , wherein the through hole has a rhombus shape. The ink jet recording apparatus according to claim 9 , wherein the first and second linear portions are inclined with respect to a traveling direction of the transport belt. The inkjet recording apparatus according to claim 7 , wherein the mesh has a hexagonal shape surrounded by the six linear portions. Wherein the outer peripheral surface of the belt main body, the ink jet recording apparatus according to any one of claims 1 to 11, characterized in that water-repellent film is formed. The ink-jet recording apparatus according to any one of claims 1 to 12, characterized by further comprising an ink removal member in contact with the outer peripheral surface of the belt body portion. A plurality of the inkjet heads are arranged side by side along the traveling direction, and the plurality of inkjet heads each have a nozzle group in which nozzles for ejecting ink are densely arranged,
The gap between these nozzle groups, an ink jet recording apparatus according to any one of claims 1 to 13, characterized in that the pressing rollers for pressing the recording medium against the conveyance belt is arranged. The inkjet recording apparatus according to claim 14 , wherein a plurality of the pressing rollers are arranged along a direction orthogonal to the traveling direction.

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