JP2006168948A - Ink-jet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently secure flatness of printing paper at a printing part without a suction device or with a small suction device in an ink-jet printer using the printing paper having curling due to setting. <P>SOLUTION: This ink-jet printer is provided with a carrying roller 75 to feed the printing paper P before printing to a printing base 66 in such a way that the printing paper P advances to a support surface of the printing base 66 at the printing part 4 at a prescribed angle, and that it is fed along the support surface to be bent toward the opposite side to the curling due to setting after advancing. The carrying roller 75 is composed to repeat feeding action and returning action to the printing paper P in such a way that at least a printing range of the printing paper P is bent toward the opposite side to the curling for a plurality of times by a plurality of the feeding action. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention pulls out a long print paper set in a roll form around a paper set unit from the paper set unit and conveys it to the print unit, and the print unit prints on the print surface of the print paper. The present invention belongs to a technical field related to an inkjet printer.

  In general, an ink jet printer used in a photographic print system or the like includes a paper set unit in which print paper is set, and conveyance for pulling out the print paper set in the paper set unit from the paper set unit and conveying it to the print unit. And road. In this printing unit, printing is performed by ejecting ink from the print head to the print paper, and the print paper printed by the printing unit is discharged to the outside.

  In the ink jet printer as described above, long paper wound in a roll shape is used, and the print paper is set in the paper set portion in a state wound in a roll shape. For this reason, the printed paper conveyed to the printing unit is curled by the curl of the roll. The print surface of the printed paper wound in a roll is usually radially outward, and the cut print paper is curled so that the center in the length direction protrudes toward the print surface with respect to both ends. ing.

  However, when the print paper is curled as described above, the flatness of the print paper in the print section is lowered, which becomes a factor that adversely affects the print quality. For this reason, conventionally, the flatness of the print paper is ensured by sucking the print paper to the print table by the suction device in the printing unit (see, for example, Patent Document 1).

On the other hand, it is also known to correct the curl by bending the print paper to the opposite side of the curl in the middle of the conveyance path to the print unit (for example, see Patent Document 2). If the curl is corrected on the upstream side of the print unit, the flatness can be secured with a simple and small suction device, or the possibility that the planarity can be secured even if the suction device is eliminated is increased.
Japanese Patent Laid-Open No. 2003-260827 Japanese Patent Laid-Open No. 10-86411

  However, in the above conventional curl correction method, when the printed paper passes through the roller, it is bent only for a moment, so there is a possibility that the curl correction cannot be sufficiently performed. For this reason, there is a possibility that sufficient flatness cannot be ensured during printing, and a large suction device having a large suction force is required, resulting in an increase in cost.

  The present invention has been made in view of such a point, and an object of the present invention is to make it possible to surely correct the curl of the print paper in the ink jet printer using the print paper curled by the curl as described above. Thus, the flatness of the print paper in the print unit can be sufficiently ensured without a suction device or with a small suction device.

  In order to achieve the above object, according to the present invention, the curl correcting means enters the print paper before printing at a predetermined angle with respect to the support surface of the print table in the print section. A feeding means for feeding to the printing table so as to bend to the opposite side of the roll and to be along the supporting surface later is provided, and the feeding means is used so that at least the area to be printed of the printed paper is fed a plurality of times. The printing paper feeding and returning operations are repeated so that the printing paper can be bent to the opposite side of the roll a plurality of times.

  Specifically, according to the first aspect of the present invention, a paper set portion in which a long print paper is set in a state of being wound in a roll shape with the print surface facing outward, and printing is performed on the print surface of the print paper. An inkjet printer including a printing unit that performs printing and a conveyance path for conveying the print paper set in the paper setting unit to the printing unit is an object.

  The print unit includes a print table provided on a side opposite to the print surface of the print paper in the print unit and having a support surface for supporting the print paper, and a print paper supported on the support surface of the print table. A print head that performs printing by discharging ink onto the print surface, and the print paper before being printed by the print unit is placed at a predetermined angle with respect to the support surface of the print table. It has a feeding means for feeding to the printing table so that it enters and bends to the opposite side of the roll after the entry and follows the support surface, and is opposite to the roll of the printed paper fed by the feeding means. A curl correcting means for correcting curling due to curling of the roll in the printed paper by side bending. The printing means is configured to be able to return the sent print paper to the side opposite to that at the time of sending, and at least the area to be printed of the print paper is moved to the roll a plurality of times by a plurality of sending operations. It is assumed that the print paper is repeatedly sent and returned so that it is bent to the opposite side.

  With the above configuration, the print paper sent to the printing table by the feeding means is pressed against the support surface of the printing table by the feeding and bent to the side opposite to the roll (that is, the printing surface is inside). As a result, the curl correction of the printed paper is performed. Moreover, in addition to bending the print paper against the support surface of the print table, at least the printed area of the print paper is bent to the side opposite to the roll a plurality of times, so that the printed area of the print paper can be reliably and The curl can be sufficiently corrected. Therefore, the flatness of the printed paper in the printing unit can be sufficiently ensured without the suction device or with a small suction device.

  According to a second aspect of the present invention, in the first aspect of the present invention, the feeding means is a roller for controlling the transport amount of the print paper when printing on the print paper in the printing unit.

  That is, the roller for controlling the transport amount of the print paper at the time of printing has a relatively large transport force in order to transport the print paper with high accuracy. For this reason, the print paper is placed on the support surface of the print table. It becomes possible to press with a large force. Therefore, the feeding means can be easily configured using existing rollers, and curl correction can be sufficiently performed.

  According to a third aspect of the invention, in the first or second aspect of the invention, there is provided cutting means provided on the upstream side of the sending means, and cutting the print paper into a predetermined length, wherein the sending means is the cutting means. It is assumed that the print paper of a predetermined length cut by the above is received and sent out to the print table.

  When curling the printed paper having a predetermined length thus cut, it is difficult to completely wrap the front and rear ends of the printed paper around the roller by the conventional method of winding the paper around the roller. Therefore, curl correction is insufficient in a considerably wide range on the front end side and the rear end side. However, in the present invention, on the front end portion side of the print paper, by providing a guide roller or the like, the front end portion of the print paper can be bent immediately after coming into contact with the support surface of the print table. The impossible range can be kept to a slight range. Further, on the rear end side of the print paper, the feeding means is arranged as close as possible to the upstream side of the print table, so that the range where the curl cannot be corrected can be kept to a slight range. Therefore, the curl can be sufficiently corrected for the printed area. Therefore, the effect of the invention of claim 1 or 2 can be exhibited more effectively.

  As described above, according to the ink jet printer of the present invention, the print paper is pressed against the support surface of the print table and bent to the opposite side of the roll, and at least the printed area of the print paper is opposite to the roll a plurality of times. As a result, the printed paper can be surely and sufficiently curled, and the flatness of the printed paper in the print section can be sufficiently secured without a suction device or with a small suction device.

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

  FIG. 1 shows an inkjet printer according to an embodiment of the present invention. This ink jet printer is used in a photographic printing system, and is connected via a communication cable to a receiving block 100 (see FIG. 8) that acquires image data and order information and performs necessary correction processing and the like. The image data transmitted from the receiving block 100 via the communication cable is printed on the print paper P based on the order information.

  The ink jet printer includes a housing 1, a magazine housing portion 2 disposed in the lower portion of the housing 1, a cassette housing portion 3 disposed in a substantially central portion in the vertical direction in the housing 1, and a housing. A print unit 4 that is disposed in an upper part of the body 1 and prints image data on the print paper P; a first transport path for transporting the print paper P from the magazine housing unit 2 to the print unit 4; A second transport path for transporting the print paper P from the cassette housing unit 3 to the print unit 4 and a second transport path for discharging the print paper P printed by the print unit 4 from the print unit 4 to the outside of the housing 1. 3 and a discharge tray 5 provided outside the housing 1 and receiving the print paper P discharged to the outside of the housing 1 through the third conveyance path. The front-rear direction of the case is the left-right direction in FIG. 1, the front side of the case is the right side of FIG. 1, and the rear side of the case is the left side of FIG. The left-right direction of the housing is a direction perpendicular to the paper surface of FIG.

  A print paper P, which is a long paper wound in a roll shape, is set in the magazine storage portion 2 while being stored and held in the paper magazine 8. The print paper P is wound so that the print surface to be printed is on the outside. Thus, the magazine housing unit 2 constitutes a paper set unit in which long print paper is set in a state of being rolled. On the other hand, a plurality of print papers P, which are cut sheets, are set in the cassette storage unit 3 while being stored and held in a rectangular box-shaped paper feed cassette 9. The print paper P in the paper feed cassette 9 is stacked in the thickness direction (vertical direction) with the print surface facing upward, and is pressed against a later-described feed roller 35 positioned above by the pressing plate 10. Yes. Then, the print paper P set in the magazine housing unit 2 or the cassette housing unit 3 is conveyed to the printing unit 4 as described later, printed by the printing unit 4, and discharged to the discharge tray 5. ing. In the magazine housing 2, it is also possible to set two print papers P having a small width in parallel in the left-right direction of the housing, and when two are set in parallel in this way, The set two print papers P are simultaneously pulled out from the magazine housing unit 2 and conveyed in two rows. The print unit 4 prints the two print papers P and discharges them simultaneously to the discharge tray.

  In the casing 1, a first supply unit U1, a cutter unit U2, a second supply unit U3, a switchback unit U4, and a print unit U5 are provided to constitute the first to third transport paths. The first transport path is composed of a first supply unit U1, a cutter unit U2, a switchback unit U4, and a print unit U5 in order from the magazine accommodating portion 2. Further, the second transport path is configured by a second supply unit U3, a switchback unit U4, and a print unit U5 in order from the cassette housing portion 3. Further, the third transport path is constituted by a print unit U5.

  The first supply unit U1 is provided in the magazine housing portion 2 (paper magazine 8). The first supply unit U1 includes three support rollers 15 that support the roll-shaped print paper P, a guide member 16 that guides the print paper P to the cutter unit U2, and a print member that is provided in the middle of the guide member 16. A pressure supply roller 17 composed of driving and driven rollers 17a and 17b for transporting the paper P to the cutter unit U2, and a guide roller 18 provided on the upstream side of the guide member 16 and around which the print paper P is wound. It has. Of the three support rollers 15, a roller disposed on the front side of the casing is rotationally driven by an electric motor (not shown) to apply a rotational force to the print paper P around the center of the roll. Further, the drive roller 17a of the supply roller 17 is fed by an electric motor 30 disposed in the cutter unit U2 via a transmission belt 31 and a gear train 19 and a later-described feed roller 25 disposed in the cutter unit U2. The drive roller 25a is rotationally driven. A first paper detection sensor 20 is provided at the downstream end of the first supply unit U1. When the print paper P is all pulled out from the magazine accommodating portion 2 by the first paper detection sensor 20, the first paper detection sensor 20 is provided. The rear end of the print paper P is detected. When the rear end of the print paper P is detected, the fact is notified to the operator via a display or the like.

  The cutter unit U2 is disposed on the rear side of the housing of the first supply unit U1 in a state of being fixed to the vertical frame 6 extending in the vertical direction, and is a crimp-type delivery unit that sends out the print paper P to the switchback unit U4. A cutting roller 25, a cutter 26 that is disposed downstream of the feeding roller 25 and that cuts the print paper P and includes a fixed blade 26 a and a movable blade 26 b, a drive mechanism that drives the movable blade 26 b, and the like And a guide member 28 that extends in the horizontal direction and feeds the print paper P from the roller 25 to a cutting position by the cutter 26. The cutter 26 cuts the print paper P drawn from the magazine housing unit 2 to a predetermined length based on the order information from the receiving block 100. The feed roller 25 includes one drive roller 25 a and two driven rollers 25 b that sandwich the print paper P, and these driven rollers 25 b are pressed against the drive roller 25 a by one compression coil spring 29. As described above, the drive roller 25a is rotationally driven by the electric motor 30 through the transmission belt 31 together with the drive roller 17a of the supply roller 17 in the first supply unit U1. The print paper P is moved rearward in the horizontal direction by the feed roller 25 and the guide member 28 and sent to the switchback unit U4, and is received by the roller pair 41 of the switchback unit U4 as will be described later. After being gripped, it is cut by the cutter 26. The roller pair 41 may receive the print paper P after cutting instead of receiving the print paper P before cutting. However, in this case, since the conveyance path in the cutter unit U2 becomes long, it is preferable to receive it before cutting.

  The second supply unit U3 includes a feed roller 35 that comes into contact with the print surface of the print paper P positioned at the top of a plurality of print papers P (cut sheet paper) set in the cassette housing unit 3, and the feed roller 35. And an electric motor 36 that drives the cutting roller 35 through a gear train 37. By driving the feeding roller 35, only one print paper P located at the top moves horizontally in the rearward direction of the housing. Then, it is sent out to the switchback unit U4.

  The switchback unit U4 constitutes a paper transport device and switchback device provided in the middle of the first transport path and the second transport path. The switchback unit U4 receives the print paper P conveyed from the upstream conveyance path (that is, the first supply unit U1 and the cutter unit U2 or the second supply unit U3) located on the upstream side of the switchback unit U4. Upon receipt, the print paper P is sent out to the downstream conveyance path (that is, the print unit U5) located downstream of the switchback unit U4 in the direction opposite to the print paper moving direction at the time of receipt. That is, in the upstream conveyance path, the print paper P is conveyed toward the rear side of the housing with the print surface facing upward, and in the downstream conveyance path provided at a position above the upstream conveyance path, The paper P is transported toward the front side of the casing opposite to the upstream transport path with the print surface facing upward. However, in the switchback unit U4, the traveling direction of the print paper P faces the print surface upward. In this state, the print paper P is reversed without being bent so that the print paper P can be smoothly transferred from the upstream transport path to the downstream transport path without bending the print paper P.

  Specifically, the switchback unit U4 includes a roller pair 41 that receives and grips the print paper P that has been transported from the upstream transport path. In this embodiment, the roller pair 41 is configured to be rotatable forward and backward around the central axis, and is opposed to each other in the vertical direction so as to sandwich the print paper P therebetween. One of them (the roller that contacts the back surface of the print paper P (the surface opposite to the print surface)) is the driving roller 41a, and the other (the roller that contacts the print surface of the print paper P) is the driven roller 41b. The drive roller 41a is rotationally driven around the central axis by an electric motor 42 and a transmission belt 43 (see FIGS. 2 and 3) as a drive mechanism. By forward rotation and reverse rotation, the printing paper P is received and retracted from the upstream conveying path, and the printing paper P is sent to the downstream conveying path. Note that both rollers of the roller pair 41 may be driven, and the functions of driving and following may be reversed.

  The roller pair 41 is linearly moved in the vertical direction by the moving mechanism at the housing rear side position of the cutter unit U2, the second supply unit U3, and the print unit U5. As shown in FIGS. 2 and 3, the moving mechanism includes a rail mount 45 that is fixed to the vertical frame 6 and extends in the vertical and horizontal directions, and a vertical position at one end of the rail horizontal direction in the horizontal direction of the casing. A traveling rail 46 attached to extend, and a drive belt 48 that is wound around two pulleys 47 provided near the upper and lower ends of the traveling rail 46 and extends along the traveling rail 46, and a rail mount 45. And an electric motor 49 directly attached to the lower pulley 47. The drive belt 48 is driven forward and reverse by the electric motor 49. A bracket 50 is attached and fixed to the drive belt 48, and a slide member 51 that fits and slides on the travel rail 46 is fixed to the bracket 50, and the drive belt 48 is driven forward and backward by the electric motor 49. As a result, the bracket 50 reciprocates in the vertical direction. The vertical position of the bracket 50 can be determined by measuring the amount of movement (for example, the amount of rotation of the motor) from a reference position (for example, the lowermost end) where a sensor or the like for detecting the bracket 50 is provided. .

  A support plate 52 is fixed to the bracket 50, and one end portions of the driving roller 41 a and the driven roller 41 b in the roller pair 41 are rotatably supported by the support plate 52. Along with the movement, the roller pair 41 moves linearly in the vertical direction. Although not shown, the other end portions of the driving roller 41a and the driven roller 41b are supported by a support portion formed at the other end portion in the left-right direction of the housing of the rail mount 45 so as to be slidable in the vertical direction. .

  The above-described electric motor 42 for driving the drive roller 41a is fixed to the support plate 52. Pulleys 54 are fixed to the rotating shaft of the electric motor 42 and one end of the driving roller 41a. The transmission belt 43 is wound around both pulleys 54, and the driving roller is passed through the transmission belt 43. 41a is driven.

  By the moving mechanism, the roller pair 41 is provided at a receiving position for receiving the print paper P from the upstream side conveyance path, and at a position spaced apart by a predetermined distance from the reception position, and the print paper P is conveyed on the downstream side. It moves linearly between the delivery position and the delivery position. That is, a position substantially the same as the downstream end of the cutter unit U2 (a position near the lower end of the traveling rail 46) is a receiving position for receiving the print paper P from the cutter unit U2 (hereinafter referred to as a first receiving position). A receiving position (hereinafter referred to as a second receiving position) for receiving the print paper P from the second supplying unit U3 is a height position that is substantially the same as the downstream end of the second supplying unit U3 (a substantially central position in the vertical direction of the traveling rail 46). Has been. On the other hand, a height position (position near the upper end of the traveling rail 46) that is substantially the same as the upstream end of the print unit U5 is a sending position for sending the print paper P to the print unit U5. Thus, the downstream end of the upstream conveyance path and the upstream end of the downstream conveyance path are separated by a predetermined distance (a value determined by the arrangement of the units U1 to U5 and set to the smallest possible value). In response to this, the roller pair 41 moves.

  The switchback unit U4 receives the print paper P from the upstream conveyance path (cutter unit U2) by the roller pair 41 at the first receiving position, and after the print paper P is cut by the cutter 26, Alternatively, after receiving and gripping the print paper P from the upstream conveyance path (second supply unit U3) by the roller pair 41 at the second receiving position, the roller pair 41 that grips the print paper P by the moving mechanism is The print paper P is moved to the sending position while being separated from the upstream conveyance path, and the print paper P is moved to the downstream conveyance path in the direction opposite to the moving direction of the print paper P when receiving the print paper P at the sending position. It is configured to send out. The moving direction of the print paper P sent out to the downstream side conveyance path is in the horizontal direction opposite to the moving direction at the time of reception (frontward of the casing).

  As shown in FIG. 2, the support plate 52 has first and second support portions for supporting the print paper P positioned below the print paper P held by the roller pair 41 at the front and rear portions of the casing of the roller pair 41. The second support members 56 and 57 are fixed (not shown in FIG. 3). The first support member 56 has a role of guiding the print paper P from the cutter unit U2 to the roller pair 41 in a horizontal state. The first support member 56 is provided with a second paper detection sensor 58 for detecting the print paper P.

  On the other hand, a bent portion bent downward is formed at the rear portion of the housing of the second support member 57, and a pressing roller 59 is in contact with the bent portion. The presser roller 59 is rotatably attached to the tip of the arm 60 that is rotatably supported by the support plate 52, and abuts against the bent portion of the second support member 57 by the weight of the presser roller 59. ing. The bent portion of the second support member 57 and the pressing roller 59 prevent the printed paper P gripped by the roller pair 41 from dropping down and coming into contact with the rear inner wall surface of the housing 1. That is, on the rear side of the switchback unit U4 in the casing 1 (the portion corresponding to the moving range of the roller pair 41 on the opposite side of the upstream conveyance path and the downstream conveyance path with respect to the roller pair 41). Is provided with a space 12 for the print paper P that is gripped by the roller pair 41. By hanging the print paper P downward as described above, the front and rear direction of the space space 12 in the front and rear of the housing is provided. The length along the (upstream direction of the upstream conveyance path) can be made as small as possible. On the other hand, by hanging the print paper P downward, the space 12 for the print paper P gripped by the roller pair 41 is below the portion corresponding to the moving range (below the first receiving position). Although it is necessary to extend, in the present embodiment, with respect to the first transport path, the upstream transport path located on the upstream side of the switchback unit U4 and the first receiving position are set to the print paper P set in the magazine housing portion 2. Therefore, the space 12 can be easily extended downward without increasing the height of the housing 1.

  Although not shown, restriction members for restricting the movement of the print paper P in the width direction are provided at both ends of the first and second support members 56 and 57 in the paper width direction. Both regulating members are configured to be able to change the interval in accordance with the paper width (the width of the paper can be determined by detecting the identification code portion provided in the paper magazine 8). When the print paper P is conveyed in two rows as described above, another regulating member enters the conveyance path at the center between the two regulating members, and is conveyed in two rows by these three regulating members. The movement of each printed paper P in the width direction is restricted.

  The print unit U5 includes a fixed base 65 fixed to a horizontal frame 7 extending in the horizontal direction at the upper end position of the vertical frame 6, and a side opposite to the print surface of the print paper P (lower side) in the vertical middle portion of the fixed base 65. And a print table 66 having a support surface for supporting the print paper P at the time of printing, and a print surface of the print paper P supported by the support surface of the print table 66 so as to be printed. And a print head 67 that performs printing by discharging ink onto the surface. The support surface of the print table 66 is constituted by the upper surface of the print table 66 and is formed in a flat shape. The print table 66 and the print head 67 constitute the print unit 4.

  The print table 66 is not configured to suck and hold the print paper P from the lower side of the print table 66 with a fan or the like, and does not have a suction hole or the like as shown in FIG. . At both ends of the print table 66 in the paper width direction (X direction shown in FIG. 4), a plurality of grooves 66a (6 in each embodiment) extending in the paper transport direction (Y direction) are provided in the paper width direction. It is formed to line up at a predetermined interval. Each of the grooves 66a is provided corresponding to both positions in the width direction of the print paper P having various sizes. In each groove 66a, the ink ejected from the print head 67 is arranged in the width direction of the print paper P. An ink absorbing material 68 for absorbing the ink is fitted when it comes off from both ends (especially, it easily comes off when performing borderless printing). A concave portion 66b is formed in the central portion of the print table 66 in the paper width direction, corresponding to each position of three head units 67a described later, and 2 pieces of print paper P are placed in each concave portion 66b. An ink absorbing material 69 that absorbs ink preliminarily ejected (trial strike before printing) from each head unit 67a of the print head 67 when being printed in a row is fitted.

  In the present embodiment, as shown in FIG. 4, the print head 67 has a plurality of ink discharge nozzles 67b on the bottom surface (the surface facing the print table 66) in the sub-scanning direction (paper transport direction (Y direction)). Three head units 67a are provided so as to form a row, and these three head units 67a are arranged at intervals in the sub-scanning direction. Note that only one nozzle row of each head unit 67a is shown in FIG. 4, but actually, a plurality of nozzle rows are arranged in the paper width direction corresponding to each of a plurality of colors of ink. Further, the number of head units 67a is not necessarily three, but may be one or two, or may be four or more.

  The upper surface of the print head 67 is fixedly attached to a drive belt 70 for reciprocating the print head 67 in the main scanning direction (direction perpendicular to the paper surface of FIG. 1 (X direction shown in FIG. 4)). The drive belt 70 extends in the main scanning direction, and is wound around two pulleys 71 (only one is shown in FIG. 1) disposed at both ends thereof and rotatably supported on the upper portion of the fixed base 65. It is hung. The one pulley 71 is rotationally driven by an electric motor (not shown). A guide rail 72 extending in the main scanning direction along the drive belt 70 is attached and fixed to the upper portion of the fixed base 65, and the print head 67 is guided by the guide rail 72 while being driven by the drive belt 70. It reciprocates in the scanning direction. The print paper P on the print table 66 is intermittently (stepwise) conveyed in the sub-scanning direction by a constant unit conveyance amount by a conveyance roller 75 provided on the upstream side of the print table 66, and this intermittent conveyance is performed. At each stop of the print paper P at the time, the print head 67 is scanned one time in the main scanning direction (one-way operation or one-time operation), and the ink of each head unit 67a at each position in the main scanning direction during this scanning. Ink is ejected from the ejection nozzle 67b. That is, after one scan of the print head 67, the print paper P is transported by the unit transport amount, and then the print head 67 is scanned once again, and this operation is repeated to print a desired image. . Thus, the conveyance roller 75 is a roller for controlling the conveyance amount of the print paper P when printing on the print paper P in the printing unit 4.

  The transport roller 75 is located at the upstream end of the print unit U5 (that is, the upstream end of the downstream transport path and in the vicinity of the roller pair 41 (see FIG. 5) positioned at the delivery position and upstream of the print table 66. Print paper P provided by the roller pair 41 located at the delivery position (cutting by the cutter 26 provided on the upstream side of the conveying roller 75) and having a predetermined length. It also has a role of receiving the paper P) and sending it out to the printing stand 66 of the printing unit 4. The transport roller 75 is composed of a plurality of rollers arranged above and below. That is, similar to the feeding roller 25 in the cutter unit U2, the driving roller 75a (lower roller) and the two driven rollers 75b (upper roller) sandwich the print paper P up and down. The driven roller 75b is pressed against the drive roller 75a by one compression coil spring 76. The drive roller 75a is rotated by an electric motor 77 via a transmission belt 78.

  As shown in detail in FIG. 7, the height position of the sandwiched portion of the print paper P sandwiched by the transport roller 75 is set higher than the support surface (upper surface) of the print table 66, and the transport roller 75. The print paper P before being printed by the print unit 4 enters the print paper P at a predetermined angle with respect to the support surface of the print table 66, and after the entry, the side opposite to the roll in the magazine housing unit 2 (I.e., the print surface is on the inside) and is sent to the print table 66 so as to follow the support surface. As a result, the print paper P enters the support surface of the print table 66 obliquely from above and is pressed against the upstream end of the support surface of the print table 66 and bent to the opposite side of the roll. After being printed, the print paper P is transported in a state where the back surface of the print paper P is substantially in contact with the support surface of the print table 66. In this way, the print paper P is pressed against the support surface of the print table 66 and bent to the opposite side of the roll, so that curl due to roll curl in the print paper P is corrected. As a result, the transport roller 75 constitutes a sending means for sending the print paper P to the printing table 66 as a curl correcting means.

  A guide roller 79 is supported on the print table 66 so that there is a gap above the upstream end of the support surface of the print table 66, and the guide roller 79 is sent out by a conveying roller 75. The print paper P is guided to bend along the support surface immediately after the front end of the print paper P abuts the support surface of the print table 66 (after the front end of the print paper P has passed, the print paper P 66 and is hardly contacted with the guide roller 79), and when the transport roller 75 returns the sent print paper to the side opposite to the sending time as will be described later, the print paper P is on the upper side. It is made not to go to.

  In the present embodiment, the transport roller 75 is configured to be able to return the sent print paper P to the side opposite to the time of sending. That is, the driving roller 75a of the conveying roller 75 is driven to rotate in the forward and reverse directions by the electric motor 77, and during normal rotation (when rotating in the clockwise direction in FIG. 7), the print paper P is While being sent out to the print table 66, at the time of reverse rotation (when rotating in the counterclockwise direction in FIG. 7), the sent out print paper P is returned to the side opposite to that at the time of sending. The transport roller 75 feeds the print paper P so that at least the printed area of the print paper P is bent to the opposite side of the roll a plurality of times (for example, five times) by a plurality of feed operations. And the returning operation are repeated, so that the curl correction is surely performed. However, in the case of the print paper P that has been transported from the cassette housing unit 3, since it is not normally curled, the transport roller 75 does not perform the return operation. The print paper P from the cassette housing portion 3 is bent so that the print surface is only once inside, but it is bent only once and is not bent for a long time. There is almost no curling due to bending.

  On the other hand, on the downstream side of the printing table 66, two pairs of pressure bonding composed of driving and driven rollers 81a and 81b are provided to form a third transport path for discharging the printed paper P to the outside of the housing 1. The mold discharge rollers 81 are provided at intervals in the paper transport direction. The drive roller 81 a of each discharge roller 81 is driven simultaneously by the electric motor 82 via the transmission belt 83. The height of the downstream discharge roller 81 is higher than that of the upstream discharge roller 81, and the print paper P is lifted between the downstream discharge roller 81 and the upstream discharge roller 81 and the downstream side. A guide member 84 that leads to the discharge roller 81 is provided.

  As described above, the print paper P is lifted to a position higher than the support surface of the print table 66 on the upstream side and the downstream side of the print table 66, and this also causes a portion of the print paper P on the print table 66. Is pressed against the support surface of the print table 66. Thereby, the flatness of the print paper P on the print table 66 is reliably ensured.

  The discharge tray 5 is provided on the front side of the discharge roller 81 outside the casing 1 and protrudes forward of the casing 1, and an auxiliary tray 5a is stored at the front end thereof. . When the length of the printed paper P to be discharged is longer than the length of the discharge tray 5, the auxiliary tray 5a can receive the long printed paper P by pulling it forward of the housing 1. ing.

  As shown in FIG. 8, the inkjet printer has a microprocessor 101 (hereinafter referred to as a CPU), a conveyance control unit 102 connected to the CPU 101 via a data bus, a head control unit 103, and a print control. Unit 104, semiconductor memory RAM / ROM 105, communication interface 106, and first paper detection sensor 20 and second paper detection sensor 58 described above.

  The conveyance control unit 102 controls the operation of each of the units U1 to U5. The head control unit 103 controls the operation of the print head 67. The communication interface 106 is for transmitting and receiving information to and from the reception block 100. The print control unit 104 controls the print paper P to print image data based on the image data received from the receiving block 100 via the communication interface 106.

  Under the control of the conveyance control unit 102, the units U1 to U5 operate as follows.

  When printing is performed on the print paper P set in the magazine housing unit 2, the roller pair 41 of the switchback unit U4 is positioned at the first receiving position (see FIG. 1). Then, by operating the support roller 15 and supply roller 17 of the first supply unit U1 and the feed roller 25 of the cutter unit U2, the print paper P is pulled out of the magazine housing portion 2 and is positioned at the first receiving position. Transport to pair 41.

  The driving roller 41a of the roller pair 41 starts to drive when the tip of the print paper P is detected by the second paper detection sensor 58, and rotates (forward) in the counterclockwise direction in FIGS. The print paper P conveyed from the unit U2 in the horizontal direction to the rear of the housing is received and gripped. That is, the print paper P is sandwiched between the driving roller 41a and the driven roller 41b. The drive roller 41a continues to drive and draws the print paper P into the space space 12 on the rear side of the casing. Then, after the leading edge of the print paper P is detected by the second paper detection sensor 58, after the amount determined based on the order information is conveyed, the movable blade 26b of the cutter 26 is operated to cut the print paper P. The After this cutting, the driving roller 41a continues to drive, and stops when the rear end portion of the cut print paper P is gripped by the roller pair 41. At this stage, the print paper P gripped by the roller pair 41 is not on the upstream conveyance path, but is separated from the upstream conveyance path. The operations of the support roller 15 and the supply roller 17 of the first supply unit U1 and the feed roller 25 of the cutter unit U2 are stopped after the print paper P is cut.

  Subsequently, the drive belt 48 of the switchback unit U4 operates, and the roller pair 41 moves upward and stops at the delivery position (see FIG. 5). As a result, the print paper P is conveyed from the receiving position to the sending position in a state where it is separated from the upstream conveying path (cutter unit U2).

  Thereafter, the drive roller 41a of the roller pair 41 rotates (reverses) in the clockwise direction in FIG. 5, and the cut print paper P is sent to the transport roller 75 of the print unit U5 in the horizontal direction toward the front of the casing.

  When the print paper P is sent out, the front end of the print paper P (rear end at the time of receipt) is detected by the second paper detection sensor 58, and the conveyance roller 75 of the print unit U5 starts to operate by this detection (drive roller 75). Starts normal rotation). Eventually, the transport roller 75 receives the print paper P sent out from the roller pair 41 and sends it out to the print table 66. As described above, the print paper P sent out by the transport roller 75 is pressed against the upstream end portion of the support surface of the print table 66 and bent to the opposite side of the roll. After being bent, the print paper P is printed. The back surface of P is conveyed in a state in which it substantially contacts the support surface of the print table 66 (see FIG. 7). The roller pair 41 moves downward from the sending position and returns to the first receiving position after the rear end of the print paper P is detected by the second paper detection sensor 58.

  When the rear end portion of the print paper P is sandwiched by the transport roller 75 (the position between the second paper detection sensor 58 and the transport roller 75 after the front end of the print paper P is detected by the second paper detection sensor 58). The forward rotation of the driving roller 75 of the conveyance roller 75 is stopped when the conveyance roller 75 is conveyed by an amount determined based on the relationship, the length of the print paper P, and the like. It is returned until it is nipped by the conveying roller 75. Thereafter, the print paper P is sent again to the print table 66 by the forward rotation of the drive roller 75, and the sending and returning operations are repeated, so that at least the area to be printed of the print paper P is obtained by a plurality of sending operations. Bend to the opposite side of the roll multiple times. In this way, curl correction is performed on the print paper P.

  When the last returning operation is completed, the conveyance roller 75 conveys the print paper P downstream while controlling the conveyance amount in order to perform printing on the print paper P this time. That is, the print paper P is transported intermittently at a constant unit transport amount after the print area is transported to a position where the printed region faces the ink discharge nozzle 67b of the head unit 67a. At each stop of the print paper P during the intermittent conveyance, the print head 67 is moved in the main scanning direction, and the ink discharge nozzles 67b of the head units 67a of the print head 67 are applied to the print paper P on the print table 66. Printing is performed by ejecting ink.

  The printed print paper P is discharged to the outside of the housing 1 with the print surface facing upward by the discharge roller 81 and received by the discharge tray 5.

  In this way, the printed paper P drawn out from the magazine accommodating unit 2 is sequentially cut by the cutter 26, and the cut printed paper P is sequentially conveyed to the printing unit 4 and printed by the printing unit 4 in order. It is discharged to the outside of the body 1 and stacked on the discharge tray 5.

  On the other hand, when printing is performed on the print paper P set in the cassette housing portion 3, the roller pair 41 of the switchback unit U4 is positioned at the second receiving position (see FIG. 6). Then, by the operation of the feed roller 35 of the second supply unit U3, the print paper P is pulled out from the cassette housing portion 2 and conveyed to the roller pair 41 located at the second receiving position.

  Subsequently, like the print paper P pulled out from the magazine accommodating portion 2, the roller pair 41 grips the rear end portion of the print paper P, and then moves upward and stops at the sending position. As a result, the print paper P is conveyed from the receiving position to the sending position in a state where the print paper P is cut off from the upstream conveying path (second supply unit U3). Thereafter, the driving roller 41a of the roller pair 41 reverses and sends the print paper P to the transport roller 75 of the print unit U5 in the direction opposite to the moving direction when receiving the print paper P.

  When the print paper P is delivered to the conveyance roller 75, the leading edge of the print paper P is detected by the second paper detection sensor 58, and the conveyance roller 75 of the print unit U5 starts to operate by this detection. Eventually, the transport roller 75 receives the print paper P sent out from the roller pair 41 and sends it out to the print table 66. At this time, since it is not necessary to perform curl correction, the print paper P is transported downstream while controlling the transport amount without repeating the feeding and returning operations. That is, as with the print paper P pulled out from the magazine accommodating unit 2, the print head 67 is moved in the main scanning direction while the print paper P is intermittently conveyed by the conveyance roller 75 by the unit conveyance amount. . The printed print paper P is discharged by the discharge roller 81 to the outside of the housing 1 with the print surface facing upward, and is received by the discharge tray 5. The roller pair 41 moves downward and returns to the second receiving position after the rear end of the print paper P is detected by the second paper detection sensor 58.

  Therefore, in the above embodiment, the print paper P is pressed against the support surface of the print table 66 and bent to the side opposite to the roll, so that the curl correction is performed on the portion from the vicinity of the front end portion to the vicinity of the rear end portion of the print paper P. It can be carried out. Here, the front end portion and the rear end portion of the print paper P cannot be curled, but the front end portion of the print paper P is in contact with the support surface of the print table 66 and bent immediately by the guide roller 79, so that the curl cannot be corrected. Can be kept in a slight range. In addition, by arranging the transport roller 75 as close as possible to the upstream side of the print table 66, the range where the curl correction of the rear end portion cannot be corrected can be kept to a slight range. As a result, the curl can be sufficiently corrected for the printed area. In addition, since at least the printed area of the print paper P is bent to the opposite side of the roll a plurality of times, the printed area of the print paper P can be reliably curled. Therefore, the flatness of the print paper P in the print unit 4 can be sufficiently secured without a suction device or with a small suction device.

  In the above embodiment, the cutter 26 that cuts the print paper P to a predetermined length is provided on the upstream side of the transport roller 75, and the transport roller 75 cuts the print paper P having a predetermined length cut by the cutter 26. The cutter 26 is provided on the downstream side of the printing unit 4 so as to cut the print paper P to a predetermined length after printing. The print paper P may be received and sent to the print table 66. In this case, before the next printed area is printed on the print paper P, the sending and returning operations are repeated so that the printed area is bent to the opposite side of the roll a plurality of times. Good.

  Moreover, in the said embodiment, although both the magazine accommodating part 2 and the cassette accommodating part 3 were provided, you may make it provide only the magazine accommodating part 2. FIG.

  Furthermore, in the said embodiment, although the inkjet printer of this invention was applied to what is used for a photographic printing system, from the paper set part set in the state where the elongate print paper P was wound in roll shape, The present invention can be applied to any ink-jet printer as long as the print paper P is pulled out and conveyed to the printing unit 4.

  INDUSTRIAL APPLICABILITY The present invention is useful for an ink jet printer in which a print paper set in a roll-shaped state is drawn out from the paper set unit and is conveyed to the print unit, and particularly used for a photographic printing system. It is useful for an inkjet printer.

It is the schematic seen from the housing | casing side which shows the structure of the inkjet printer which concerns on embodiment of this invention. It is the figure seen from the housing | casing side which shows the structure of a switchback unit. It is the figure seen from the housing | casing which shows the principal part of a switchback unit. It is a top view which shows a printing stand. FIG. 2 is a view corresponding to FIG. 1 illustrating a state when a roller pair of the switchback unit is located at a delivery position. FIG. 3 is a view corresponding to FIG. 1 showing a state when a roller pair of the switchback unit is located at a second receiving position. FIG. 6 is an enlarged view of the vicinity of a conveyance roller showing a state in which curling of printed paper is corrected. It is a block diagram which shows the structure of a control system.

Explanation of symbols

P Print paper 2 Magazine housing (paper set)
4 Print section 26 Cutter (cutting means)
66 Print base 67 Print head 75 Conveying roller (feeding means for curl correction means)

Claims (3)

A paper set unit in which a long print paper is set in a roll shape with the print surface facing outward, a print unit for printing on the print surface of the print paper, and a set in the paper set unit An inkjet printer comprising a transport path for transporting the printed paper to the print unit,
The print unit includes a print table provided on a side opposite to a print surface of the print paper in the print unit and having a support surface for supporting the print paper, and a print surface of the print paper supported by the support surface of the print table And a print head that prints by discharging ink,
The print paper before being printed by the print unit is made to enter the print paper at a predetermined angle with respect to the support surface of the print table, and bend to the opposite side of the roll and follow the support surface after the entry. And curling correction for correcting curling due to curl of the roll in the printed paper by bending the printed paper fed by the feeding means opposite to the roll. With means,
The sending means is configured to be able to return the sent print paper to the side opposite to the time of sending, and at least the area to be printed of the print paper is a plurality of times by a plurality of sending operations. An ink jet printer configured to repeat feeding and returning operations of the print paper so as to be bent to the opposite side of the roll. The inkjet printer according to claim 1.
The ink jet printer, wherein the feeding means is a roller for controlling a transport amount of the print paper when printing on the print paper in the printing unit. The inkjet printer according to claim 1 or 2,
Provided upstream of the sending means, and provided with cutting means for cutting the print paper into a predetermined length,
The inkjet printer is configured to receive the print paper having a predetermined length cut by the cutting means and send the print paper to a printing table.

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