JP2006188323A - Ink jet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet printer capable of preventing a print paper, in particular, its front end or rear end from uplifting from a print stand by firmly pressing the print paper against the print stand while suppressing the cost of the ink jet printer. <P>SOLUTION: The ink jet printer comprises a conveying roller 75 to feed a print paper P toward a print stand 66 obliquely from an upper part, and a delivery roller 81C to deliver the print paper P from the print stand 66 obliquely to an upper part, and conveys the print paper P by the conveying roller 75 and the delivery roller 81C while pressing the print paper against the print stand 66 with the print surface of the print paper P directed to a print head 67 side at a print unit 4. The ink jet printer further comprises a switch-back unit U4 to adjust the curl amount when viewed in the width direction of the print paper P with respect to the print paper P before being pressed against the print stand 66, and the conveying roller 75 in the middle of a conveying passage. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention belongs to a technical field related to an ink jet printer in which a print paper set in a paper set unit is pulled out from the paper set unit and conveyed to the print unit, and printing is performed on the print surface of the print paper. .

  In general, an inkjet printer used in a photographic print system or the like includes a print unit having a printer head and a print table. In this print unit, printing is performed by ejecting ink from the print head to print paper. In order to discharge ink to an accurate position of the print paper, the print surface of the print paper is usually faced upward, and the print head is opposed to the upper side. At the same time, in order to keep the distance between the print head and the print paper constant, a configuration is adopted in which the print paper does not float from the print table. The configuration that prevents the print paper from lifting up from the print table includes a method of sucking the print paper against the print table by suction, a method of sucking it by electrostatic attraction, and a method of transporting the print paper by pressing it against the print table. There is a method to do. In order to enable printing in the entire width direction of the print paper, so-called borderless printing, these ink jet printers are not provided with a member that presses the edge of the print paper from above at a position where the print head faces. .

As an example of the image recording apparatus that performs printing with the print head and the print paper having a predetermined distance as described above, the first conveying roller provided on the upstream side and the upper side of the print table, and the downstream side of the print table And a second transport roller provided on the upper side, and the first transport roller inclines the print paper with respect to the print table, while the second transport roller inclines the print paper from the print table and carries it out. There is a thing (refer patent document 1). In this image recording apparatus, while the print paper is curved by the first transport roller and the second transport roller, the curved portion of the print paper is pressed against the print table so that the print paper does not float from the print table.
JP-A-62-65558

  By the way, the image recording apparatus disclosed in Japanese Patent Application Laid-Open No. 2004-151561 curves the print paper by pressing the print paper with both the upstream and downstream conveying rollers of the print table and presses the print paper against the print table. However, the print paper is not always given a force to press against the print table by both the first and second transport rollers. When the front end portion or the rear end portion of the print paper is positioned on the print table, a force to press the print table is applied only by one of the upstream and downstream transfer rollers of the print table. Alternatively, the rear end is a free end. For this reason, the print paper cannot be firmly pressed against the print table. In particular, when the print paper conveyed to the print table is curled in a convex shape toward the side facing the print table as viewed in the paper width direction, the end of the print paper is lifted from the print table. If printing is performed on the end portion of the print paper in this state, there is a possibility that ink cannot be ejected to an accurate position. Furthermore, there is a possibility that the front end or the rear end of the print paper is conveyed on the print table while being lifted from the print table, and the front end or the rear end of the print paper may interfere with the print head.

  Further, as described above, as means for preventing the print paper from lifting from the print stand, there are a method of sucking by suction and a method of sucking by electrostatic attraction, but these are expensive.

  The present invention has been made in view of the above points, and an object of the present invention is to suppress the cost of an ink jet printer and press the print paper firmly against the print table, in particular the front end or the rear end thereof. Is to prevent it from floating from the print table.

  In order to achieve the above object, according to the present invention, the curl amount of the print paper can be adjusted to a desired curl amount so that the end portion of the print paper conveyed to the print unit does not float from the print table.

  Specifically, in the first invention, a paper set unit in which print paper is set, a print unit that performs printing on a print surface of the print paper, and a print paper set in the paper set unit are provided as described above. An inkjet printer including a conveyance path for conveyance to a printing unit is an object.

  The print section includes a print head that performs printing by discharging ink to a print surface of a print paper, a print stand that is provided on the opposite side of the print paper and supports the print paper, A paper feed unit that is located upstream of the print table and feeds the print paper obliquely from above toward the print table, and a discharge unit that is located downstream of the print table and discharges the print paper obliquely upward from the print table. The paper feed unit and the discharge unit are configured to feed the print paper to the print table so that the print surface faces the print head and to press the print paper against the print table. And

  Further, a curl amount adjusting means for adjusting a curl amount of the printed paper viewed in the paper width direction is further provided in the middle of the transport path and upstream of the paper feeding unit.

  In the case of the above configuration, the print paper is fed obliquely from the upper side toward the print table by the paper feed unit located on the upstream side of the print table, and from the print table by the discharge unit located on the downstream side of the print table. By being discharged obliquely upward, the sheet is conveyed while being given a pressing force against the print table. For this reason, the print paper is reliably pressed against the print table and prevented from being lifted off the print table.

  However, in the configuration in which the print paper is pressed against the print table by the upstream paper supply unit and the downstream discharge unit, the front end or the rear end of the print paper is positioned on the print table, that is, the print When the paper is applied with a pressing force by only one of the paper feed unit and the discharge unit, and the front end or rear end of the print paper is a free end, the front end or rear end of the print paper May rise from the print stand. For example, when the print paper conveyed to the print table is curled in a convex shape on the side opposite to the print surface when viewed in the paper width direction, that is, on the print table side, the print paper is fed by the paper feed unit or the discharge unit. Even when is pressed against the print table, the end of the print paper is curled away from the print table, so that the end cannot be pressed against the print table, and the end is lifted off the print table. As a result, the landing position of the ink from the print head varies and print quality deteriorates.

  Therefore, in the present invention, a curl amount adjusting means for adjusting a curl amount of the print paper viewed in the paper width direction is provided on the upstream side of the paper feed unit in the middle of the conveyance path, and the paper is fed to the print table. Adjust the curl amount viewed in the width direction of the previous print paper. Then, the curl amount of the print paper is adjusted so that the front end portion or the rear end portion of the print paper conveyed while being pressed against the print stand does not rise from the print stand.

  According to a second invention, in the first invention, the curl amount adjusting means is such that the print paper fed to the print table is curled in a convex shape on the print surface side in the paper width direction. In addition, the curl amount of the print paper is adjusted so as to obtain a flat shape.

  As described above, in the configuration in which the print paper is conveyed while being pressed against the print table, when the print paper fed to the print table is curled in a convex shape on the print table side when viewed in the paper width direction, As described above, the front end or the rear end of the print paper is lifted from the print table. Therefore, the curl amount adjusting means causes the print paper fed to the print table to be curled in a convex shape on the print head side, that is, the print surface side as viewed in the paper width direction, or flat. Adjust the curl amount of the printed paper so that it has a shape. That is, by adjusting the curl amount of the print paper so as not to be curled into a convex shape at least on the print table side, it is possible to prevent the front end portion or the rear end portion of the print paper from floating from the print table.

  In other words, when feeding flat print paper to the print table, the print paper is pressed against the print table and then touches the print table to ensure flatness on the print table. It will be transported.

  In addition, when printing paper curled in a convex shape on the printing surface side as viewed in the paper width direction is fed to the printing table, the printing paper is fed when force is applied in the direction of pressing against the printing table. It becomes a flat shape on the top. Even if the print paper tries to return to the original curled state due to the curl of the print paper itself, the intermediate portion of the print paper is in a state of being substantially in contact with the print table. That is, the intermediate portion curled in a convex shape on the print surface side when viewed in the paper width direction of the print paper may be lifted like the front end portion or the rear end portion of the print paper curled in the convex shape on the print table side described above. Absent. As described above, in the configuration in which the print paper is conveyed while being pressed against the print table, the curl amount of the print paper fed to the print table is curled in a convex shape toward the print surface when viewed in the paper width direction. Alternatively, by adjusting to a flat shape, it is possible to prevent the front end portion or the rear end portion of the print paper from floating from the print table, and to ensure the overall flatness of the print paper in the print portion. .

  According to a third invention, in the first or second invention, the curl amount adjusting means includes a holding member that holds one end portion of the print paper, and a paper width direction of the print paper held by the holding member. And the pair of rollers that grips the print paper in the state of being held by the holding member and the pair of rollers that grips the print paper in a state of being held by the holding member. A moving mechanism that is wound around one roller of the pair and moves to the other roller side in the opposing direction of the roller pair so that tension is applied to the print paper. Along with the movement, the portion of the print paper gripped by the roller pair is moved from the vicinity of the one end portion to the other end portion side, and the print paper is moved. The curl amount of the print paper is adjusted, and the curl amount adjusting means further changes the curl adjustment amount of the print paper by changing the squeezing operation of the print paper. To do.

  In the case of the above configuration, when the roller pair of the curl amount adjusting means moves to the other roller side, the print paper is wound around the one roller and the print paper is placed between the holding member and the roller pair. A tension is applied, and as the roller pair moves, a portion of the print paper gripped by the roller pair moves from the vicinity of one end to the other end. As a result, the printed paper is squeezed by the roller pair while being bent to the side wound around the one roller. At this time, the curled print paper is wound around the roller so as to be bent on the side opposite to the curl, and the curling amount can be adjusted so as to reduce the curl amount. In this way, not only the print paper is bent, but also tension is applied while gripping by the roller pair.

  The curl amount adjusting means is configured to change the curl adjustment amount by changing the ironing operation of the print paper. As a result, the front edge or the rear edge of the print paper on the print table does not float from the print table, specifically, the print paper is curled in a convex shape on the print surface side in the paper width direction. In addition, the curl amount can be adjusted so as to obtain a flat shape.

  The change of the ironing operation is specifically a change of the moving speed of the roller pair. That is, as the moving speed of the roller pair is slower, the print paper is slowly squeezed and the curl adjustment amount is increased. As the moving speed of the roller pair is faster, the print paper is quickly squeezed and the curl adjustment amount is reduced.

  Further, during the adjustment of the curl amount, at least one roller of the roller pair may be rotated around the central axis, and the rotation speed may be changed as a change of the ironing operation. That is, when the roller is rotated in the direction in which the print paper is sent out (the direction in which the roller is driven to rotate by the movement of the roller pair), the rotation speed and the moving speed of the roller pair are applied to the print paper so that tension is applied. However, the lower the rotation speed of the roller, the stronger the tension applied to the print paper and the larger the curl adjustment amount. The higher the rotation speed of the roller, the higher the tension applied to the print paper. Becomes weaker and the curl adjustment amount becomes smaller. On the other hand, when rotating the roller in the opposite direction, the higher the rotation speed of the roller, the stronger the tension applied to the print paper and the greater the curl adjustment amount, and the slower the rotation speed of the roller, The tension applied to the print paper is weakened and the curl adjustment amount is reduced.

  According to a fourth aspect of the present invention, in the first or second aspect, the curl amount adjusting means includes a paper receiving member having a pressing surface, a printed paper, and the printed paper with respect to the pressing surface of the paper receiving member. The paper receiving member having a feeding means for feeding to the paper receiving member so as to enter at a predetermined angle and to bend after the entering and to follow the pressing surface; and to print the paper fed by the feeding means to the paper receiving member The curling amount of the printed paper is adjusted by bending it along the pressing surface, and the curling amount adjusting means is further configured so that the feeding means can perform a plurality of feeding operations. In addition, the number of times of feeding by the feeding means and the approach angle of the printed paper fed by the feeding means with respect to the pressing surface of the paper receiving member are reduced. By changing one Kutomo shall change the curl adjustment amount of the print paper.

  In the case of the above configuration, the printed paper sent to the paper receiving member by the sending means is bent while being pressed against the pressing surface of the paper receiving member. Thereby, the curl amount of the print paper can be adjusted. At this time, the curled print paper is pressed against the pressing surface and bent to the side opposite to the curl, thereby adjusting the curl amount.

  The curl amount adjusting means is configured such that the sending means can perform a plurality of sending operations, and the number of sending times of the sending means and the sending means with respect to the pressing surface of the paper receiving member. The curl adjustment amount of the print paper is changed by changing at least one of the approach angles of the sent print paper. As a result, the front edge or the rear edge of the print paper on the print table does not float from the print table, specifically, the print paper is curled in a convex shape on the print surface side in the paper width direction. In addition, the curl amount can be adjusted so as to obtain a flat shape.

  As for the change in the number of times of sending by the sending means, the larger the number of times of sending, the larger the curl adjustment amount of the print paper, and the smaller the number of times of sending, the smaller the curl adjustment amount of the print paper.

  In addition, regarding the change in the approach angle of the print paper fed from the feeding means to the pressing surface of the paper receiving member, the greater the approach angle, the larger the bend of the print paper and the greater the curl adjustment amount, and the approach angle becomes larger. The smaller it is, the smaller the bending of the printed paper and the smaller the curl adjustment amount. Specifically, the inclination angle of the pressing surface of the paper receiving member is changed with respect to the sending direction of the sending means, or the sending of the sending means is performed with respect to the inclination angle of the pressing surface of the paper receiving member. The approach angle can be changed by changing the direction.

  According to a fifth aspect of the present invention, in the first or second aspect of the invention, the paper set portion is set with a long print paper wound in a roll shape with the print surface facing outward, and the curl amount The adjusting means has a cross curl applying portion that bends the printed paper to be conveyed in a direction orthogonal to the conveying direction, and the printing paper is bent in a direction orthogonal to the conveying direction. It is configured to adjust the curl amount of the paper, and the curl amount adjusting means further changes the curl adjustment amount of the print paper by changing the bending amount of the cross curl applying portion.

  In the case of the above configuration, the print paper is curled so as to protrude toward the print surface due to the winding curl of the roll in the paper set portion when viewed in the paper width direction. The printed paper is bent in a direction perpendicular to the transport direction by the cross curl applying unit, whereby the curl amount seen in the paper width direction is reduced. That is, by curling the printed paper curled in a convex shape when viewed in the paper width direction by the roll curl, the curl due to the roll curl and the bending due to the cross curl imparting portion are mutually connected. The curling and bending are regulated to reduce the amount of curling of the printed paper viewed in the paper width direction.

  Then, the curl adjustment amount of the print paper is changed by changing the bending amount of the cross curl applying portion. As a result, the front edge or the rear edge of the print paper on the print table does not float from the print table, specifically, the print paper is curled in a convex shape on the print surface side in the paper width direction. In addition, the curl amount can be adjusted so as to obtain a flat shape. Specifically, the curl adjustment amount increases as the amount of bending of the cross curl imparting portion increases.

  According to the first aspect of the invention, in the ink jet printer that conveys the print paper while being pressed against the print table, the curl amount adjusting means that adjusts the curl amount of the print paper is provided on the upstream side of the paper feeding unit, and the print paper By adjusting the curl amount viewed in the width direction, when the paper is fed while the front edge of the print paper is pressed against the print table by the paper feed unit, or the rear edge of the print paper is pressed against the print table by the discharge unit. However, when the paper is discharged, the curl amount of the print paper viewed in the paper width direction can be adjusted so that the front end or the rear end of the print paper does not float from the print table. As a result, the flatness of the print paper can be ensured without providing a suction device or the like in the print unit, and the print quality can be improved while suppressing the cost of the ink jet printer.

  According to the second aspect of the invention, the print paper is curled by the curl amount adjusting means so that the print paper is curled convexly toward the print surface as viewed in the paper width direction, or flat. By adjusting the curl amount, the print paper is prevented from being conveyed to the print table in a state of being curled in a convex shape at least on the print table side, and the end of the print paper is prevented from floating from the print table. be able to.

  According to the third aspect of the invention, the curl amount of the print paper can be adjusted by squeezing the print paper while the print paper is wound around the roller by the roller pair, and the flatness of the print paper on the printing table is ensured. be able to.

  According to the fourth invention, the curl amount of the print paper can be adjusted by pressing and bending the print paper against the pressing surface of the paper receiving surface, and the flatness of the print paper on the print table is ensured. Can do.

  According to the fifth aspect, the curl amount of the print paper can be adjusted by bending the print paper in the direction perpendicular to the transport direction by the cross curl imparting portion, and the flatness of the print paper on the print table is ensured. can do.

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

Embodiment 1 of the Invention
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 a 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 portion 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 from the third conveyance path to the outside of the housing 1. The front-rear direction of the paper transport direction in the print unit 4 is the front-rear direction of the housing, the front-rear direction of the housing is the left-right direction of FIG. 1, and the front side of the housing as the front side of the paper transport direction is the right side of FIG. The rear side of the housing as the rear side in the paper transport direction is the left side of FIG. The left-right direction of the housing is a direction perpendicular to the paper surface of FIG.

  A long print paper P wound in a roll shape is set in the magazine storage section 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. 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 on the upper side, and is pressed against a later-described feed roller 35 positioned on the upper side by the pressing plate 10. Yes. The magazine storage unit 2 and the cassette storage unit 3 constitute a paper set unit in which the print paper P is set. 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, and when the print paper P is all pulled out from the magazine housing 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 gripping member that receives and grips the print paper P transported from the upstream transport path. In the present embodiment, the gripping member is configured as a roller pair 41 that is configured to be rotatable forward and backward about the central axis, and is opposed to each other in the vertical direction, and sandwiches the print paper P therebetween. One (the roller in contact with the back surface of the print paper P in this embodiment) is the driving roller 41a, and the other (the roller in contact with 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 driven may be reversed up and down.

  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 is fixed to a vertical frame 6 (see FIG. 1, omitted in FIGS. 2 and 3) and extends in a vertical direction and a horizontal direction of the casing, and the rail frame. A running rail 46 attached to one end of the housing 45 in the left-right direction so as to extend in the vertical direction, and two pulleys 47 provided in the vicinity of both upper and lower ends of the running rail 46 are wound around the running rail 46. And an electric motor 49 attached and fixed to the rail mount 45 and directly connected 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 transport path, and at a position spaced apart from the receiving position by a predetermined distance and transports the print paper P 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 transport 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 delivery 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 traveling direction of the print paper P when the print paper P is received at the delivery 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 case 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 front end portion 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 is provided at 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 is provided at an intermediate portion in the vertical direction of the fixed base 65, and supports the print paper P during printing. A print table 66 and a print head 67 facing the print paper P located on the print table 66 and discharging ink onto the print surface of the print paper P are provided. The print table 66 and the print head 67 constitute the print unit 4. In addition, the transport direction of the print paper P is simply referred to as a paper transport direction. In the print paper P, the same direction as the paper transport direction (Y direction shown in FIG. 4) in the print unit 4 is the paper longitudinal direction. The direction orthogonal to the direction (X direction shown in FIG. 4) is the paper width direction.

  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. .

  The transport roller 75 is provided 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). It has a role of receiving the print paper P sent out by the roller pair 41 located at the sending position and feeding it to the printing unit 4. Like the feed roller 25 in the cutter unit U2, the transport roller 75 includes one drive roller 75a and two driven rollers 75b that sandwich the print paper P, and the two driven rollers 75b are one compression coil spring. 76 is pressed against the driving roller 75a. The drive roller 75a is rotated by an electric motor 77 via a transmission belt 78. The conveying roller 75 is such that the nipping portion for nipping the print paper P is located above the upper surface of the print table 66, and the tangent L (see FIG. 9) of the driven roller 75b on the downstream side of the drive 75a and the two driven rollers 75b. Is provided so as to extend upwardly with respect to the upper surface of the print table 66. Thus, the transport roller 75 feeds the print paper P toward the print table 66 from obliquely above. The conveyance roller 75 including the driving roller 75 a and the two driven rollers 75 b constitutes a paper feeding unit located on the upstream side of the print head 67.

  A guide roller 79 is provided on the upstream end of the print table 66 on the downstream side of the transport roller 75 so that a gap is formed above the upstream end. The guide roller 79 plays a role of reliably pressing the print paper P, which is fed obliquely from the transport roller 75 toward the print table 66, against the upper surface of the print table 66.

  The print paper P sandwiched between the transport rollers 75 is fed from the oblique upper side to the print table 66 while being wound around the drive roller 75a. It is bent to the opposite side of the portion wound around 75 a and is conveyed in a state where the back surface of the print paper P is substantially in contact with the upper surface of the print table 66.

  On the other hand, at the downstream end of the print unit U5, in order to discharge the printed paper P to the outside of the casing 1, a pressure-bonding type discharge roller 81A composed of driving and driven rollers 81a and 81b, and the discharge roller 81A And a pressure-bonding type discharge roller 81C composed of driving and driven rollers 81c and 81d are provided at an interval in the paper conveying direction. In the discharge roller 81A, the nipping portion for nipping the print paper P is located at the same height as the upper surface of the print table 66, and the tangent line M (see FIG. 11) of the driving and driven rollers 81a and 81b is The print paper P is disposed so as to extend along the upper surface, and the print paper P on the print table 66 is discharged in a direction along the upper surface of the print table 66. In the discharge roller 81C, the nipping portion for nipping the print paper P is positioned above the upper surface of the print table 66, and the tangent N (see FIG. 11) of the driving and driven rollers 81c and 81d is on the upper surface of the print table 66. In contrast, the print paper P is disposed so as to extend obliquely upward, and the print paper P discharged from the print table 66 by the discharge roller 81A is discharged obliquely upward from the print table 66. Thus, the print paper P is discharged obliquely upward from the print table 66 by the discharge roller 81C while being pressed against the upper surface of the print table 66 by the discharge roller 81A. The discharge roller 81 </ b> C constitutes a discharge unit located on the downstream side of the print head 67. The drive rollers 81a and 81c of the discharge rollers 81A and 81C are simultaneously driven by the electric motor 82 via the transmission belt 83. A guide member 84 is provided between the upstream discharge roller 81A and the downstream discharge roller 81C to lift the print paper P and guide it from the upstream discharge roller 81A to the downstream discharge roller 81C. Yes.

  As described above, since the print paper P is lifted to a position higher than the upper surface of the print table 66 on the upstream side and the downstream side of the print table 66, the portion of the print paper P on the print table 66 is the print table 66. It comes to be pressed against the top surface. Thereby, the flatness of the print paper P on the print table 66 is 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.

  In the present embodiment, the transport rollers 75 of the switchback unit U4 and the print unit U5 adjust the curl amount of the print paper P after the print paper P transported from the magazine housing unit 2 is cut by the cutter 26. The curl amount adjusting device is configured. Here, the curl amount refers to the degree to which the print paper P is curled in a convex shape when viewed in the paper width direction. The larger the curl amount, the more the curl is curled in the convex shape on the print surface side, and the curl amount is zero. In this case, it is assumed that the printed paper is in a flat state without curling, and is curled in a convex shape on the surface opposite to the printed surface when the curl amount decreases and becomes a negative value. The curl amount adjusting means reduces the curl amount when the curl amount is large with respect to the print paper P set in the magazine accommodating portion 2, and the print paper P is viewed in the paper width direction. Adjustment is made so that a predetermined curl amount curled convexly on the print surface side is obtained. The predetermined curl amount is not only that the end of the print paper P is not lifted from the print table 66 when the print paper P is conveyed while being pressed against the print table 66 in the print unit U5, but also the center of the print paper P from the end. The amount of curl is such that the overall flatness of the printed paper P can be secured without causing the intermediate portion to rise. Note that the predetermined curl amount is a negative value for the curl amount of the print paper P even if an error occurs in the adjustment amount of the curl amount adjusting device, that is, the print surface when the print paper P is viewed in the paper width direction. It is set to a value that does not curl into a convex shape on the opposite surface side.

  Specifically, the transport roller 75 of the print unit U5 has a role as a holding member that holds one end portion of the print paper P sent out by the roller pair 41 of the switchback unit U4 at the sending position. Reference numerals 41 respectively extend along the width direction of the print paper P held by the transport roller 75 and face each other while holding the vicinity of the one end of the print paper P therebetween. That is, when the transport roller 75 receives the print paper P sent out from the switchback unit U4 and clamps the front end portion (rear end portion at the time of receiving), the transport roller 75 temporarily stops its operation and holds the front end portion. It is supposed to be. At this time, the roller pair 41 of the switchback unit U4 holds the vicinity of the front end portion of the print paper P held by the transport roller 75.

  Then, as shown in FIG. 7, in a state where the print paper P is held by the transport roller 75, the roller pair 41 holding the print paper P is opposed to the roller pair 41 by the moving mechanism of the switchback unit U4. It moves to the drive roller 41a side in the direction. As a result, the print paper P is wound around the driven roller 41b on the upper side of the roller pair 41 in a state bent to the side opposite to the curl, and a portion between the transport roller 75 and the roller pair 41 of the print paper P A tension is applied to. In other words, the print paper P is curled by the curl caused by the roll so that the central portion in the length direction protrudes toward the print surface with respect to both ends. By wrapping, bend to the opposite side of the curl. For this purpose, the roller pair 41 is moved to the drive roller 41a side (that is, the lower side), which is the roller opposite to the print surface, so that the print paper P is wound around the driven roller 41b. As the roller pair 41 moves, the portion of the print paper P gripped by the roller pair 41 moves from the vicinity of the front end portion to the rear end portion side. As a result, the print paper P is squeezed by the roller pair 41 so that the side protruding from the curl (print surface side) is inside, and the curl amount is reduced.

  The conveyance roller 75 is configured to hold the print paper P in a state where conveyance is stopped while the curl amount of the print paper P is being adjusted.

  Then, the curl adjustment amount is changed by changing the ironing operation of the roller pair 41, and the curl amount of the print paper P is adjusted. Specifically, according to the configuration of the curl amount adjusting device, the curl adjustment amount of the print paper P can be changed by changing the moving speed of the roller pair 41 downward by the moving mechanism. That is, the slower the moving speed of the roller pair 41, the slower the print paper P is and the larger the curl adjustment amount.

  Alternatively, by changing the winding length of the print paper P around the roller (here, the driven roller 41b) around which the print paper P is wound when the roller pair 41 is moved by the moving mechanism, The curl adjustment amount of the print paper P may be changed. That is, the curl adjustment amount increases as the winding length around the driven roller 41b increases. In order to change the winding length around the driven roller 41b in this way, for example, a roller that presses the portion of the print paper P closer to the rear end than the roller pair 41 to the driven roller 41b or the drive roller 41a. The winding length can be changed by changing the pressing amount.

  Alternatively, the curl adjustment amount of the print paper P may be changed by changing the diameter of the roller (driven roller 41b) around which the print paper P is wound in the roller pair 41. That is, the curl adjustment amount increases as the diameter of the driven roller 41b or the drive roller 41a decreases. In order to change the diameter of the roller in this way, for example, a plurality of portions having different diameters in the length direction of the roller are provided in a plurality of stages, and the roller is moved in the length direction corresponding to the portion contacting the print paper P. The roller diameter can be changed by moving it.

  Alternatively, the driving roller 41a of the roller pair 41 is driven while the roller pair 41 is moving (that is, while the curling amount of the print paper P is being adjusted), and the rotation speed of the driving roller 41a at this time is changed, thereby printing. The curl adjustment amount of the paper P may be changed. That is, when the drive roller 41a is rotated in the reverse direction (rotated in the same direction as when the print paper P is sent out at the sending position), the rotation speed and the moving speed of the roller pair 41 are applied to the print paper P with tension. However, as the rotational speed of the drive roller 41a is slower, the tension applied to the print paper P becomes stronger and the curl adjustment amount becomes larger. On the other hand, when the drive roller 41a is rotated forward (rotates in the same direction as when the print paper P is received and pulled into the space 12 at the first receiving position), the faster the drive roller 41a rotates, the higher the print paper P The tension applied to the lens increases and the amount of curl adjustment increases. If the roller around which the print paper P is wound in the roller pair 41 is driven, the curl adjustment amount of the print paper P can be changed more reliably by changing the rotation speed of the roller.

  As will be described in detail later, the curl amount adjusting device changes the moving speed of the roller pair 41, changes the rotational speed of the driving roller 41a, changes the winding length of the print paper P, and the driven roller 41b or drive. One of the changes in the diameter of the roller 41a is adopted, and the curl adjustment amount is changed according to the curl amount of the print paper P. The curl adjustment amount may be changed according to the curl amount of the print paper P by combining any two or any three of these four methods or by combining all four methods. .

  When the rear end portion of the print paper P is disengaged from the roller pair 41, the roller pair 41 continues to move downward and returns to the first receiving position or the second receiving position in order to receive the next print paper P. When adjusting the curl amount, if the length of the print paper P is longer than the distance between the first receiving position or the second receiving position and the sending position, the roller pair 41 is moved to the first receiving position. The curl amount is adjusted to the rear end of the print paper P by moving further downward than the position or the second receiving position, and then returned to the first receiving position or the second receiving position. Even when the print paper P is long as described above, the amount of curl up to the rear end of the print paper P can be obtained without using the space for hanging the print paper P downward as described above, without enlarging the casing 1 up and down. Adjustments can be made.

  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.

  First, the curl amount of the print paper P used for printing is detected. Specifically, if the print paper P used for printing is stored in the magazine storage unit 2, stored in the cassette storage unit 3, or stored in the magazine storage unit 2, it is stored. Detect the winding diameter at the time. By detecting these, the curl amount of the print paper P before adjustment can be detected. Here, it is detected from the data input from the receiving block 100 which storage unit the print paper P is stored in. Further, the winding diameter of the print paper P in the magazine storage unit 2 is the total accumulated length of the print paper P drawn from the magazine storage unit 2 accumulated by the first paper detection sensor 20 provided in the first supply unit U1. It can be calculated from the roll diameter in the initial state of the print paper P stored in the magazine storage unit 2.

  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. At this time, the print paper P is curled in a convex shape on the print surface side with the print surface facing upward due to the roll curl of the magazine accommodating portion 2.

  The driving roller 41a of the roller pair 41 starts to drive when the front end 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 front end 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 by this detection, the conveyance roller 75 of the print unit U5 starts to operate. When the print paper P is sent by a predetermined amount (the amount until the leading end of the print paper P is nipped by the transport roller 75), the operation of the transport roller 75 is temporarily stopped. As a result, the leading end portion of the print paper P is held and held between the transport rollers 75. Thereafter, in this holding state, as described above, the roller pair 41 holding the print paper P is moved downward to adjust the curl amount of the print paper P (see FIG. 7). At this time, according to the detected curl amount of the print paper P, the moving speed of the roller pair 41 is changed, the rotational speed of the driving roller 41a is changed, the winding length of the print paper P is changed, or the driven roller 41b is changed. By changing the diameter, the curl adjustment amount for the print paper P is changed so that the curl amount of the print paper P becomes the predetermined curl amount.

  If the curl amount of the print paper P is equal to the predetermined curl amount or smaller than the predetermined curl amount, the curling amount is not adjusted and the conveying roller 75 continues to operate. Then, the print paper P is conveyed to the print table 66.

  Eventually, the rear end portion of the print paper P is detached from the roller pair 41, but the roller pair 41 continues to move downward and returns to the first receiving position.

  After the roller pair 41 returns to the first receiving position, or before returning to the first receiving position and after the rear end portion of the print paper P has passed the position where it deviates from the roller pair 41, the transport roller 75 is actuated again. Then, the print paper P held at the time of curl amount adjustment is conveyed to the print stand 66. The print head 67 is moved in the main scanning direction while being intermittently conveyed by the conveyance amount by the conveyance roller 75, and printing on the print table 66 is performed from the ink discharge nozzle 67 b of each head unit 67 a of the print head 67. Printing is performed by ejecting ink to the paper P.

  The printed print paper P is discharged to the outside of the housing 1 with the print surface facing upward by the discharge rollers 81A and 81C and received by 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, when the roller pair 41 receives the print paper P and grips the rear end portion of the print paper P, the forward rotation of the drive roller 41a is stopped, and then the roller pair 41 moves upward to the sending position. Stop. 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 transport roller 75, the leading end of the print paper P is detected by the second paper detection sensor 58, and the transport roller 75 of the print unit U5 starts operating by this detection. In the case of the print paper P set in the cassette accommodating portion 3, it is not necessary to adjust the curl amount. Therefore, the transport roller 75 continues to operate without stopping, and the print paper fed from the switchback unit U4. P is received and conveyed to the printing stand 66 as it is. The roller pair 41 of the switchback unit U4 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.

  Next, in the same manner as the print paper P drawn out from the magazine housing unit 2, printing is performed by moving the print head 67 in the main scanning direction while intermittently transporting the print paper P by the transport amount by the transport roller 75. . 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.

  Here, the conveyance in the print unit U5 of the print paper P whose curl amount is adjusted to a predetermined curl amount will be described in detail.

  First, the case where the print paper P is fed to the print table 66 will be described. As shown in FIG. 9, the print paper P sandwiched by the conveyance roller 75 at the upstream end of the print unit U5 is in the direction of the tangent L between the driven roller 75b and the drive roller 75a on the downstream side with respect to the print table 66. A sheet is fed (firstly, it is assumed that the guide roller 79 is not provided). A tangent L between the downstream driven roller 75b and the driving roller 75a intersects the upper surface of the print table 66 so as to form a predetermined inclination angle. At this time, the print paper P is curled in a convex shape on the print surface side when viewed from the paper width direction with the print surface facing upward, that is, toward the print head 67 side. In this state, it is in contact with the upper surface of the print table 66 in a state where it hangs down to the drive roller 75a side ((a) figure).

  When the print paper P is further fed by the transport roller 75, the print paper P fed obliquely from above toward the print table 66 is pressed against the print table 66 orthogonal to the print table 66 and along the print table 66. Force acting in the paper transport direction Y. As a result, the print paper P is conveyed in the paper conveyance direction Y while being pressed against the print table 66 (FIG. 5B).

  Since the front end of the printed paper P that is conveyed in this manner is in contact with the printing table 66, the force that is pressed against the printing table 66 acts on the middle portion of the printed paper P, so that the printed paper P itself has a convex shape. It is forcibly molded into a flat shape. That is, even if the intermediate portion curled into the convex shape of the print paper P is pressed against the print table 66, the front end portion of the print paper P is not lifted but is pressed against the print table 66. As a result, even immediately after the print paper P is fed to the print table 66, the print paper P is held only by the transport roller 75, and the front end of the print paper P is a free end. It is possible to prevent the front end of the print paper P from being lifted from the print table 66 and to press the print paper P against the print table 66 to ensure the overall flatness of the print paper P (FIG. (C)).

  In FIGS. 4A and 4B, the contact start position of the print paper P and the print table 66 depends on the incident angle of the print paper P to the print table 66 and the elasticity (paper quality) and curl shape of the print paper P. Is decided. Therefore, as shown in FIG. 5C, when the guide roller 79 is provided immediately downstream of the conveying roller 75, the print paper P is further applied with a force for pressing the print stand 66 at the position of the guide roller 79. Therefore, by providing the guide roller 79, the print paper P comes into contact with the print table 66 from the upstream side in the paper transport direction Y, and flatness can be secured in a wider range.

  Here, contrary to the present embodiment, the print paper P fed to the print unit U5 has a convex shape on the side opposite to the print surface when viewed in the paper width direction with the print surface facing upward. In the case where the curling is performed, the print paper P fed by the transport roller 75 is warped upward from the tangential L direction toward the driven roller 75b as shown in FIG. It abuts on the upper surface (FIG. (A)).

  When the print paper P is further fed by the conveying roller 75, a force for pressing the print paper is applied to the print paper P. However, since the front end of the print paper P is not in contact with the print base 66, the pressing force is applied to the print paper. It does not act effectively on the middle part of P. Further, at the portion where the print paper P and the print table 66 abut, the print paper P is guided in the direction along the curl shape of the print paper P by the incident angle, and the front end of the print paper P is lifted from the print table. There is also a possibility ((b) figure).

  When the print paper P is conveyed as it is, its intermediate portion is pressed against the print table 66, but its front end is above the curl amount determined by the curl shape, elasticity (paper quality), own weight, etc. of the print paper P itself. And rises up from the print stand 66. Here, when the guide roller 79 is provided, the print paper P is given a pressing force on the upstream side of the print table 66, that is, the front end portion thereof is lifted from the upstream side of the print table 66 ( (C) Figure.

  Next, when the print paper P is discharged from the print table 66, as shown in FIG. 11, the discharge roller 81A serves as the guide roller 79, and the discharge roller 81C serves as the transport roller 75. Fulfill. The tangent line M of the drive and driven rollers 81a and 81b constituting the discharge roller 81A extends in the paper transport direction Y along the upper surface of the print table 66, and the tangent line N of the drive and driven rollers 81c and 81d constituting the discharge roller 81C is printed. It intersects with the upper surface of the base 66 so as to form a predetermined discharge angle. That is, by discharging the print paper P obliquely upward from the print table 66 by the discharge roller 81C, the force in the paper transport direction Y along the print table 66 and the print table P are applied to the rear end portion of the print paper P. The force which presses to 66 acts. As a result, similarly to the above-described front end portion of the print paper P, even when the rear end of the print paper P is a free end, the rear end of the print paper P is prevented from being lifted from the print table 66. The print paper P can be pressed against the print table 66 to ensure the overall flatness of the print paper P. By providing the discharge roller 81A on the upstream side of the discharge roller 81C, the print paper P comes into contact with the print table 66 to the downstream side in the paper transport direction Y, and the flatness is secured in a wider range. can do.

  On the other hand, the print paper P carried out from the print unit U5 has a convex shape on the side opposite to the print surface when viewed in the paper width direction with the print surface facing upward, contrary to the present embodiment. 12, the rear end portion of the print paper P is conveyed while being lifted from the print table 66 as shown in FIG. 12.

  By the way, when the front end or the rear end of the print paper P is not positioned on the print table 66, that is, when the print paper P is nipped and transported by the transport roller 75 and the discharge rollers 81A and 81C, the print paper P is Even when curled, the conveying roller 75 and the discharge rollers 81 </ b> A and 81 </ b> C give a pressing force to the print table 66, so that flatness can be ensured without being attracted to the print table 66.

  As described above, the curl amount of the print paper P is adjusted to the predetermined curl amount by the switchback unit U4 as the curl amount adjusting device and the transport roller 75 of the print unit U5, so that the print paper P is transported. When pressed against the print table 66 by the roller 75 and / or the discharge rollers 81A and 81C, the flatness of the end portion of the print paper P and the intermediate portion other than the end portion is more reliably ensured. The predetermined curl amount is determined by the paper quality of the print paper P, the inclination angle between the print paper P to be fed / discharged and the print table 66, and the like. 9 and 11, the print paper P is exaggerated to clarify the curled state. Preferably, the print paper P located on the print table 66 has its front end or rear end. The entire surface is in contact with the printing stand 66 from the intermediate portion to the intermediate portion.

  On the other hand, a flat shape (or a print paper P set in the cassette storage unit 3 or a print paper P set in the magazine storage unit 2 and having a large roll diameter at the beginning of use) (or When the print paper P having a substantially flat shape is fed to the print table 66, the print paper P contacts the print table 66 and ensures flatness even after being pressed against the print table 66. In this state, it is transported on the print table 66.

  Accordingly, in the first embodiment, the curl amount of the print paper P set in the magazine storage unit 2 is adjusted to the predetermined curl amount, and the print paper P set in the cassette storage unit 3 is adjusted. The curl amount adjusting device adjusts the curl amount of the print paper P before being fed to the print table 66 to a desired value so that the curl amount is fed to the print table 66 without adjusting the curl amount. The front or rear end of the print paper P is fed from the print table 66 as well as the intermediate portion of the print paper P that is fed to the table 66 and conveyed while being pressed against the print table by the conveyance rollers 75 and the discharge rollers 81A and 81C. Preventing floating and ensuring the overall flatness of the print paper P on the print table 66 It can be. As a result, the distance between the print paper P and the print head 67 in the print unit 4 can be stabilized, the deterioration of ink landing accuracy can be prevented, and the print paper P can be lifted at the end. It is possible to prevent the end of the print paper P and the print head 67 from interfering with each other when conveyed on the print table 66. Specifically, by adjusting the curl amount of the print paper P set in the magazine housing unit 2 to the predetermined curl amount, not only the end portion of the print paper P but also an intermediate portion other than the end portion is placed on the print stand 66. The printed paper P can be prevented from curling in a convex shape on the side opposite to the printed surface when viewed in the paper width direction. As a result, the end of the printed paper P and It is possible to more reliably prevent intermediate portions other than the end portions from floating from the print table 66.

  In the first embodiment, the roll diameter of the print paper P in the magazine housing unit 2 changes as printing is performed, and the curl amount due to curl of the print paper P also changes. Further, there is a case where printing is performed on the print paper P having a different curl amount as in the case where a plurality of magazine storage units 2 are provided. Even in such a case, by adjusting the curl amount of the print paper P by the curl amount adjusting device, the flatness of the print paper P on the print table 66 can be kept constant. As a result, the print paper P Regardless of the paper quality or the like, the print quality can be maintained uniformly at a high level.

  Further, the print paper P is conveyed while being pressed against the print table 66 by the conveyance roller 75 and the discharge rollers 81A and 81C, and the curl amount of the print paper P before being pressed against the print table 66 is adjusted, whereby the print paper P is adjusted. Since the lift from the print table 66 can be prevented, the cost can be reduced as compared with an ink jet printer that prevents the print paper P from being lifted from the print table 66 by means such as suction or electrostatic attraction. Furthermore, in addition to the need for a device for directly pressing the front end or the rear end of the print paper against the print table, it is necessary to provide a device for directly pressing the side edge of the print paper at the position of the print head. Therefore, printing without four edges can be easily performed.

  In addition, about the said Embodiment 1, it is good also as the following structures. That is, in the first embodiment, the guide roller 79 is provided at the upstream end of the print unit U5. However, the guide roller 79 may be omitted. Even in such a case, the print paper P is given a force to be pressed against the print table 66 by the transport roller 75, and can be prevented from being lifted from the print table 66.

  Further, the discharge roller 81A may be omitted at the downstream end of the print unit U5. That is, even when only the discharge roller 81 </ b> C is provided, the print paper P can be discharged obliquely upward while applying a force pressing the print paper P against the print table 66.

  In the first embodiment, the predetermined curl amount of the print paper P after the adjustment by the curl amount adjusting device is such that when the print paper P is conveyed while being pressed against the print table 66, an end portion thereof is from the print table 66. The curl amount is set such that not only does not float, but also the intermediate portion from the center of the print paper P does not float, and the overall flatness of the print paper P can be secured, but this is not limited thereto. It is not a thing. That is, according to the configuration in which the print paper P is conveyed while being pressed against the print table 66, the print paper P is transported to the print table 66 as long as the print paper P is not curled convexly toward the print table 66. It is possible to prevent the end portion from floating from the print table 66. Therefore, the predetermined curl amount is set to an arbitrary value as long as the print paper P is in a flat shape or is curled convexly toward the print surface when viewed in the paper width direction. As a result, it is possible to prevent the end of the print paper P from floating on the print table 66. However, in order to ensure the overall flatness of the print paper P on the print table 66, the predetermined curl amount is not limited to the fact that the end of the print paper P does not float from the print table 66. It is preferable to set the curl amount so that the intermediate portion from the center of the paper P does not rise.

  In the first embodiment, the switchback unit U4 as the paper transport device and switchback device is also used as the curl amount adjustment device. However, the present invention is not limited to this. That is, a unit that serves only as a curl amount adjusting device may be provided. However, since the switchback unit U4 can also be used as a curl amount adjusting device, the number of parts can be reduced and the cost can be reduced. Therefore, the switchback unit U4 can also be used as a curl amount adjusting device as in this embodiment. It is preferable.

  Furthermore, in the first embodiment, both the magazine housing part 2 and the cassette housing part 3 are provided. However, only the magazine housing part 2 may be provided, and a plurality of magazine housing parts 2 or cassette housing parts 3 may be provided. You may make it provide.

  Furthermore, in the first embodiment, the ink jet printer of the present invention is applied to the one used in the photographic printing system. The present invention can be applied to any ink-jet printer as long as it is transported from the printing section to the printing section 4.

  Subsequently, another embodiment of the present invention will be described. In the following, the same components as those in the first embodiment are denoted by the same reference numerals, and further description thereof is omitted.

<< Embodiment 2 of the Invention >>
The second embodiment is different from the first embodiment in the configuration of a curl amount adjusting device that adjusts the curl amount of the print paper P.

  As shown in FIG. 13, the switchback unit U4 is provided with a paper receiving guide 63 having a curl adjustment surface 63a instead of the second support member 57 of the first embodiment. The paper receiving guide 63 is supported at the rear portion of the housing of the roller pair 41 so as to be rotatable about a rotation axis extending in the paper width direction of the print paper P gripped by the roller pair 41 and extending in parallel with the roller pair 41. It is pivotally supported on the plate 52. The paper receiving guide 63 is rotated about the rotation axis, the curl adjustment surface 63a is inclined upward and toward the front of the housing, and the curl adjustment surface 63a is inclined so as to intersect the print paper drawing-in direction. (A solid line in the figure) and a horizontal posture (two-dot chain line in the figure) in which the curl adjustment surface 63a is in a horizontal state and the paper receiving guide 63 is positioned below the print paper drawing direction are configured to be switchable. ing. Further, in the inclined posture, the curl adjustment surface 63a is configured to be able to change the inclination angle of the curl adjustment surface 63a with respect to the print paper drawing direction by rotating around the rotation axis.

  When the paper receiving guide 63 is in the inclined posture, the print paper P drawn by the roller pair 41 is pressed against the curl adjusting surface 63a of the inclined paper receiving guide 63, and the curl adjusting surface 63a from the print paper drawing direction. Is bent obliquely upward. At this time, since the print paper P is conveyed with the print surface facing upward, the print paper P is bent with the print surface inside, and the curl amount is adjusted to be reduced.

  Then, by changing the inclination angle of the paper receiving guide 63, the approach angle of the print paper P to the curl adjustment surface 63a is changed to change the curl adjustment amount. Also, the roller pair 41 not only presses the print paper P against the paper receiving guide 63 once, but also pulls in the print paper P (sending operation for the paper receiving guide 63) and a sending operation ( The printing paper P can be pressed against the paper receiving guide 63 a plurality of times by repeating the operation of returning the paper receiving guide 63 a plurality of times. The curl adjustment amount can also be changed by changing the number of times of pressing. The approach angle of the print paper P to the curl adjustment surface 63a can be changed by changing the print paper pull-in direction of the roller pair 41. Specifically, the driven paper 41b is rotated around the central axis of the drive roller 41a to change the tangential direction of the rollers 41a and 41b, thereby changing the print paper drawing direction of the roller pair 41.

  On the other hand, when the paper receiving guide 63 is in a horizontal posture, the printed paper P drawn by the roller pair 41 is drawn to the rear of the housing while hanging down on the upper or upper surface of the paper receiving guide 63, and the curl amount is Not adjusted.

  The paper receiving guide 63 constitutes a paper receiving member, the curl adjusting surface 63a constitutes a pressing surface of the paper receiving member, and the switchback unit U4 as a paper conveying device and switchback device also serves as a curl amount adjusting device.

  The curl amount adjustment by the switchback unit U4 is performed when the roller pair 41 receives the print paper P from the upstream conveyance path.

  That is, for the print paper P set in the magazine accommodating portion 2, the roller pair 41 is positioned at the first receiving position, and the paper receiving guide 63 is inclined. At this time, the curl adjustment amount is determined from the predetermined curl amount and the detected curl amount of the print paper P, and the inclination angle and the number of pressings of the paper receiving guide 63 are determined according to the curl adjustment amount.

  If the curl amount of the print paper P is equal to the predetermined curl amount or smaller than the predetermined curl amount, the paper receiving guide 63 is set in a horizontal posture to adjust the curl amount. Absent.

  For the print paper P set in the cassette housing 3, the roller pair 41 is positioned at the second receiving position, and the paper receiving guide 63 is in a horizontal posture. That is, the curl amount adjustment of the print paper P is not performed.

  The curl adjustment amount may be changed by changing only one of the inclination angle of the paper receiving guide 63 and the number of pressings.

  Therefore, according to the second embodiment, the curl amount of the print paper P viewed in the paper width direction is changed to the predetermined curl amount by the switchback unit U4 having the paper receiving guide 63 and the roller pair 41 as the feeding means. Therefore, in the configuration in which the print paper P is conveyed while applying a pressing force to the print table 66, the front portion or the rear end of the print paper P is of course the intermediate portion of the print paper P. It is possible to prevent the printing unit 66 from being lifted from the print table 66 and to secure the overall flatness of the print paper P on the print table 66. As a result, the distance between the print paper P and the print head 67 in the print unit 4 can be stabilized, the deterioration of ink landing accuracy can be prevented, and the print paper P can be lifted at the end. It is possible to prevent the end of the print paper P and the print head 67 from interfering with each other when conveyed on the print table 66.

  That is, the roll diameter of the print paper P in the magazine storage unit 2 changes as printing is performed, or the print paper P having different paper quality and curl amount, such as the magazine storage unit 2 and the cassette storage unit 3, etc. Even when printing is performed, by adjusting the curl amount of the print paper P by the switchback unit U4, the flatness of the print paper P on the print table 66 can be kept substantially constant, and as a result, Regardless of the paper quality of the print paper P, the print quality can be maintained uniformly at a high level.

  In the second embodiment, the paper receiving guide 63 is used as the paper receiving member. However, the present invention is not limited to this. For example, as shown in FIG. 14, a paper receiving roller 64 may be used as the paper receiving member. The paper receiving roller 64 is a support plate at the rear portion of the housing of the roller pair 41 that is rotatable about a rotation axis that extends in the paper width direction of the print paper P gripped by the roller pair 41 and extends in parallel with the roller pair 41. 52 is pivotally supported. Further, the circumferential surface 64a of the roller-to-paper receiving roller 64 constitutes a pressing surface of the paper receiving member. The paper receiving roller 64 is configured to be movable in a direction (vertical direction in the drawing) orthogonal to the print paper drawing direction by a known moving mechanism (not shown) such as a cam mechanism. A curl amount adjustment posture (solid line in the figure) positioned on a straight line extending in the print paper drawing direction (one-dot chain line in the figure) of the roller pair 41 when viewed at least partially in the paper width direction, and its circumferential surface 64a Can be switched to an unadjusted posture (two-dot chain line in the figure) located below the straight line. When the paper receiving roller 64 is in the curl amount adjusting posture, the print paper P drawn by the roller pair 41 is pressed against the circumferential surface 64a and bent obliquely upward along the circumferential surface 64a from the print paper drawing direction. It is done. At this time, since the print paper P is conveyed with the print surface facing upward, the print paper P is bent with the print surface inside, and the curl amount is adjusted to be reduced.

  Then, by changing the position of the paper receiving roller 64 in the direction orthogonal to the print paper drawing-in direction, the approach angle of the print paper P drawn by the roller pair 41 with respect to the circumferential surface 64a of the paper receiving roller 64 is changed. Change the curl adjustment amount. That is, the curl adjustment amount increases as the amount of protrusion of the circumferential surface 64a of the paper receiving roller 64 to the side (upward in the drawing) that protrudes due to curling of the print paper P with respect to the print paper pull-in direction increases. Further, the roller pair 41 not only presses the print paper P once against the paper receiving roller 64 but also pulls in the print paper P (sending operation for the paper receiving roller 64) and a sending operation ( The printing paper P can be pressed against the paper receiving roller 64 a plurality of times by repeating the operation of returning to the paper receiving roller 64 a plurality of times. The curl adjustment amount can also be changed by changing the number of times of pressing. The angle of entry of the print paper P into the circumferential surface 64a can be changed by changing the print paper pull-in direction of the roller pair 41. Specifically, the driven paper 41b is rotated around the central axis of the drive roller 41a to change the tangential direction of the rollers 41a and 41b, thereby changing the print paper drawing direction of the roller pair 41.

  On the other hand, when the paper receiving roller 64 is in the non-adjustment posture, the print paper P drawn by the roller pair 41 is drawn to the rear of the casing while hanging down on the paper receiving roller 64 or on the circumferential surface 64a. The curl amount is not adjusted.

  The paper receiving roller 64 constitutes a paper receiving member, the circumferential surface 64a constitutes a pressing surface of the paper receiving member, and the switchback unit U4 as a paper conveying device and switchback device also serves as a curl amount adjusting device.

  In the second embodiment, the curl amount adjusting device is configured by the switchback unit U4 having the paper receiving guide 63 and the roller pair 41 as the feeding means. However, the present invention is not limited to this. In other words, the curl amount adjusting device can be configured by providing a paper receiving member having a pressing surface for pressing the print paper P and a sending means for sending the print paper P to the paper receiving member. Specifically, a curl amount adjusting device can be configured by the transport roller 75 (feeding means) and the print table 66 (paper receiving member) in the print unit U5. That is, the curling amount of the print paper P can be adjusted by inclining and pressing the print paper P against the print table 66 by the transport roller 75. At this time, the curl adjustment amount can be changed by changing the number of times the print paper P is pressed against the print table 66. Further, a guide roller 79 located on the downstream side of the conveying roller 75 is configured to be movable in a direction orthogonal to or parallel to the print table 66, and by changing the position of the guide roller 79, the print paper is changed. The curl adjustment amount can be changed by changing the angle at which P enters the print table 66.

  Furthermore, a curl amount adjusting device can be provided in the magazine housing portion 2. For example, the curl amount adjusting device is disposed immediately after the print paper P is pulled out from the roll-shaped state in the magazine housing portion 2. The curl amount adjusting device can be configured by, for example, a conveyance roller and a pressing guide.

  As described above, the curl amount adjusting device can be disposed at any position in the conveyance path from the paper set unit (the magazine housing unit 2 and the cassette housing unit 3) to the printing unit 4.

<< Embodiment 3 of the Invention >>
The third embodiment is different from the first embodiment in the configuration of a curl amount adjusting device that adjusts the curl amount of the print paper P.

  In the third embodiment, as shown in FIG. 15, a curl amount adjusting unit U6 as a curl amount adjusting device is disposed downstream of the cutter unit U2.

  The curl amount adjusting unit U6 is configured as a roller pair 61 that is configured to be rotatable forward and backward around the central axis and that is opposed to each other in the vertical direction and allows the print paper P to pass therebetween. As shown in FIG. 16, the first roller portion 61a located on the upper side of the roller pair 61 is adjacent to a large-diameter portion 61a1 as a plurality of rollers arranged at predetermined intervals in the rotation axis direction. And a plurality of small diameter portions 61a2 provided between the diameter portions 61a1. Similarly, the second roller portion 61b located on the lower side of the roller pair 61 also has a large-diameter portion 61b1 as a plurality of rollers arranged at predetermined intervals in the rotation axis direction, and an adjacent large-diameter portion. A plurality of small diameter portions 61b2 provided between 61b1 and the large diameter portion 61b1 of the second roller portion 61b is opposed to the small diameter portion 61a2 of the first roller portion 61a, and the small diameter of the second roller portion 61b. The portion 61b2 is opposed to the large diameter portion 61a1 of the first roller portion 61a. In addition, the first roller portion 61a and the second roller portion 61b include a large diameter portion 61a1 of the first roller portion 61a, a large diameter portion and small diameter portions 61b1 and 61b2 of the second roller portion 61b, and a second roller portion 61b. The large-diameter portion 61b1 and the large-diameter portion of the first roller portion 61a and the small-diameter portions 61a1, 61a2 are not in contact with each other, and the outer peripheral edge portion of the large-diameter portion 61a1 of the first roller portion 61a and the second roller portion 61b. It arrange | positions so that it may overlap with the outer peripheral edge part of the large diameter part 61b1 up and down seeing in a rotating shaft direction. In this way, the plurality of large diameter portions 61b1 of the second roller portion 61b enter between the plurality of large diameter portions 61a1 of the first roller portion 61a, that is, the large diameter portions 61a1 of the first roller portion 61a. The large diameter portion 61b1 of the second roller portion 61b is arranged in a so-called staggered manner in the rotation axis direction. As shown in FIG. 17, a wave-shaped gap is formed between the first roller portion 61 a and the second roller portion 61 b configured as described above as viewed from the paper transport direction. The second roller portion 61b is configured to be movable by a known moving mechanism (not shown) such as a cam mechanism in the direction facing the first roller portion 61a. The first roller portion 61a and the second roller The gap formed between the portion 61b is configured to be adjustable to a desired width.

  In the third embodiment, the curling amount is adjusted by pulling out the print paper P from the magazine housing portion 2 by operating 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. It passes through the gap between the roller pair 61 of the unit U6 and is conveyed to the roller pair 41 located at the first receiving position. Here, the printed paper P is bent into a wave shape when viewed from the longitudinal direction of the paper by passing through the gap between the first roller 61a and the second roller 61b having the large diameter portions 61a1 and 61b1 and the small diameter portions 61a2 and 61b2, respectively. As a result, the curl amount of the printed paper P curled by the roll curl is adjusted. At this time, the curl adjustment amount can be changed by changing the width of the gap in the facing direction of the first roller 61a and the first roller 61b. That is, when the width of the gap between the first roller 61a and the second roller 61b is reduced, the curvature of the printed paper P to be bent increases and the curl adjustment amount also increases. On the other hand, when the width of the gap between the first roller 61a and the second roller 61b is increased, the curvature of the printed paper P to be bent is reduced and the curl adjustment amount is also reduced. When the width of the gap between the first roller 61a and the second roller 61b is further increased, the print paper P is not bent and the curl amount is not adjusted.

  Therefore, according to the third embodiment, the curl amount viewed in the paper width direction of the print paper P can be adjusted to the predetermined curl amount by the roller pair 61 and conveyed to the print table 66. In the configuration in which the paper P is conveyed while applying a force to press the print table 66, not only the middle portion of the print paper P but also the front end portion or the rear end portion thereof is prevented from being lifted from the print table 66. The overall flatness of the print paper P can be ensured. As a result, the distance between the print paper P and the print head 67 in the print unit 4 can be stabilized, the deterioration of ink landing accuracy can be prevented, and the print paper P can be lifted at the end. It is possible to prevent the end of the print paper P and the print head 67 from interfering with each other when conveyed on the print table 66.

  That is, the roll diameter of the print paper P in the magazine storage unit 2 changes as printing is performed, or the print paper P having different paper quality, curl amount, or the like such as the magazine storage unit 2 or the cassette storage unit 3 is used. Even when printing is performed, by adjusting the curl amount of the print paper P by the roller pair 61, the flatness of the print paper P on the print table 66 can be kept constant. Regardless of the paper quality or the like of the paper P, the print quality can be maintained uniformly at a high level.

  In the third embodiment, the roller pair 61 is disposed between the cutter unit U2 and the roller pair 41 of the switchback unit U4. However, the present invention is not limited to this. In other words, it can be placed at any location as long as it is in the middle of the conveyance path from the magazine housing unit 2 to the printing unit 4. For example, the roller pair 61 may be employed instead of the roller pair 41 of the switchback unit 4. In such a case, at least one of the rollers constituting the roller pair 61 serves as a driving roller, and the print paper P can be drawn and sent out by the roller pair 61.

  Further, the number of the large diameter portions 61a1 and 61b1 of the first roller 61a and the second roller 61b can be configured by an arbitrary number. That is, if the large diameter portions 61a1 and 61b1 are arranged so that the print paper P can be bent in a direction orthogonal to the conveyance direction, the number can be set to an arbitrary number.

  Further, the first roller portion 61a and the second roller portion 61b are configured to be rotatable, but the shaft portions of the first roller portion 61a and the second roller portion 61b are fixed, The large-diameter portion 61a1 and the large-diameter portion 61b1 may be configured to be rotatable with respect to the shaft portion.

<< Other Embodiments >>
In the first to third embodiments, in consideration of an error in the curl adjustment amount of the curl amount adjusting device, even if an error occurs in the curl adjustment amount of the curl amount adjusting device, the curl of the print paper P is curled. The amount is set to a negative value, that is, a value that the printed paper P does not curl in a convex shape on the side opposite to the printed surface when viewed in the paper width direction, but is not limited thereto. When the error of the curl adjustment amount by the curl amount adjustment device is small, the curl amount may be adjusted so that the print paper P has a flat shape. As a result, the print paper P can be transported on the print table 66 in a state in which the flatness is reliably ensured.

  In the first and second embodiments, the curl amount adjusting device is adjusted so as to reduce the curl amount of the print paper P whose curl amount is too large. However, the present invention is not limited to this, and the curl amount is small. The configuration may be such that the curl amount of the print paper P is increased to adjust to the predetermined curl amount. That is, unlike the transport paths of the first and second embodiments, the print paper P set in the magazine housing unit 2 and the cassette housing unit 3 is the side opposite to the print surface when viewed in the paper width direction during transport. If the curl is curled into a convex shape, or if the print paper P set in the magazine holder 2 is wound in a roll shape with the print surface inside, the curl amount adjusting device will look in the paper width direction. Then, the curling amount of the printed paper P is adjusted so as to curl into a convex shape on the printing surface side or to have a flat shape.

  Specifically, in the first embodiment, the roller pair 41 that holds the print paper P is moved to the driven roller 41 b side in the opposing direction of the roller pair 41 while the end portion of the print paper P is held by the transport roller 75. Move. As a result, the print paper P is wound around the lower driving roller 41a of the roller pair 41 while being bent with the print surface facing outward, and the portion of the print paper P between the transport roller 75 and the roller pair 41. Is tensioned. In this way, the print paper P is rubbed in a state where the print surface is bent outward by the curl by the roller pair 41, and the curl amount increases.

  In the second embodiment, the paper receiving guide 63 is inclined with its curl adjustment surface 63a facing upward and rearward of the housing, that is, the surface opposite to the curl adjustment surface 63a is downward and forward of the housing. The surface is inclined so that the surface opposite to the curl adjustment surface 63a intersects with the print paper drawing direction. Then, the amount of curl is increased by pressing the print paper P drawn in the print paper pull-in direction by the roll pair 41 against the surface opposite to the curl adjustment surface 63a and bending the print surface outward.

  As described above, the curl amount adjusting device reduces the curl amount when the print paper P can be conveyed to the print table 66 in a convex shape on the side opposite to the print surface when viewed in the paper width direction. In addition to decreasing, the curl amount may be increased and the print paper P may be adjusted so as to be curled convexly on the print surface side when viewed in the paper width direction or to have a flat shape. .

  INDUSTRIAL APPLICABILITY The present invention is useful for an ink jet printer in which print paper set in a paper set portion is pulled out from the paper set portion and conveyed to the print portion, and is particularly useful for an ink jet printer used in a photographic print system.

It is the schematic seen from the housing | casing side which shows the structure of the inkjet printer which concerns on Embodiment 1 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. 2 is a view corresponding to FIG. 1 showing a state in which the curl amount of the print paper is adjusted to be reduced. It is a block diagram which shows the structure of a control system. FIG. 7 is a diagram illustrating a state when print paper curled in a convex shape on the print surface side as viewed in the paper width direction is fed at the upstream end portion of the print table, and FIG. The figure which shows the state when contacting with a printing stand, (b) is the figure which shows the state in which the printed paper was further conveyed from the state of (a), (c) was provided with the guide roller in the downstream of the conveyance roller. It is a figure which shows the state at the time. FIG. 7 is a diagram showing a state when print paper curled in a concave shape is fed to the print surface side when viewed in the paper width direction at the upstream end portion of the print table, where (a) shows the front end portion of the print paper The figure which shows the state when contacting with a printing stand, (b) is the figure which shows the state in which the printed paper was further conveyed from the state of (a), (c) was provided with the guide roller in the downstream of the conveyance roller. It is a figure which shows the state at the time. FIG. 7 is a diagram illustrating a state when print paper curled in a convex shape on the print surface side as viewed in the paper width direction at the downstream end of the print table is discharged. FIG. 7 is a diagram illustrating a state when print paper curled in a convex shape on the print surface side as viewed in the paper width direction at the downstream end of the print table is discharged. It is the schematic seen from the housing | casing side which shows the structure of the curl amount adjustment apparatus of the inkjet printer which concerns on Embodiment 2 of this invention. It is the schematic seen from the housing | casing side which shows another structure of the curl amount adjustment apparatus of the inkjet printer which concerns on Embodiment 2 of this invention. It is the schematic seen from the housing | casing side which shows the structure of the inkjet printer which concerns on Embodiment 3 of this invention. It is a perspective view which shows the curl amount adjusting apparatus which concerns on Embodiment 3 of this invention. It is the figure which looked at the curl amount adjusting device concerning Embodiment 3 of the present invention from the case front.

Explanation of symbols

P Print paper U4 Switchback unit (curl amount adjusting means)
2 Magazine storage (paper set)
3 Cassette housing (paper set)
4 Print section 41 Roller pair (roller pair of curl amount adjusting means, feeding means)
45 rail mount (movement mechanism)
46 Traveling rail (movement mechanism)
47 Pulley (movement mechanism)
48 Drive belt (moving mechanism)
49 Electric motor (movement mechanism)
61 Roller pair (Cross curling section)
63 Paper receiving guide (paper receiving member)
63a Curling reduction surface (pressing surface)
63b Curl increasing surface (pressing surface)
64 Paper receiving roller (paper receiving member)
64a Circumference surface (pressing surface)
66 Print stand 67 Print head 75 Conveying roller (paper feeding unit, holding member)
81C discharge roller (discharge section)

Claims (5)

A paper set section on which the print paper is set, a print section for printing on the print surface of the print paper, and a transport path for transporting the print paper set in the paper set section to the print section. An inkjet printer comprising:
The print section includes a print head that performs printing by discharging ink to a print surface of a print paper, a print stand that is provided on the opposite side of the print paper and supports the print paper, A paper feed unit that is located upstream of the print table and feeds the print paper obliquely from above toward the print table, and a discharge unit that is located downstream of the print table and discharges the print paper obliquely upward from the print table. The paper feed unit and the discharge unit are configured to feed the print paper to the print table so that the print surface faces the print head, and to press the print paper against the print table.
An ink jet printer further comprising curl amount adjusting means for adjusting a curl amount of the print paper viewed in the paper width direction in the middle of the transport path and upstream of the paper feeding unit. The inkjet printer according to claim 1, wherein
The curl amount adjusting means prints so that the print paper fed to the print table is curled in a convex shape on the print surface side when viewed in the paper width direction or in a flat shape. An ink-jet printer characterized by adjusting a paper curl amount. The inkjet printer according to claim 1 or 2,
The curl amount adjusting means is
A holding member for holding one end portion of the print paper, and extending along the paper width direction of the print paper held by the holding member, and facing each other and gripping the vicinity of the one end portion of the print paper therebetween The roller pair and the roller pair that holds the print paper in a state of being held by the holding member are arranged so that the print paper is wound around one roller of the roller pair and tension is applied to the print paper. A moving mechanism that moves to the other roller side in the opposing direction of the pair,
Along with the movement of the roller pair by the moving mechanism, the portion of the print paper gripped by the roller pair is moved from the vicinity of the one end portion to the other end side to squeeze the print paper, thereby curling the print paper. Configured to adjust the amount,
The ink-jet printer, wherein the curl amount adjusting means further changes a curl adjustment amount of the print paper by changing a squeezing operation of the print paper. The inkjet printer according to claim 1 or 2,
The curl amount adjusting means is
A paper receiving member having a pressing surface and a printed paper such that the printed paper enters at a predetermined angle with respect to the pressing surface of the paper receiving member and bends and follows the pressing surface after the entering. Delivery means for delivering to the receiving member,
It is configured to adjust the curl amount of the printed paper by bending the printed paper fed by the feeding means along the pressing surface of the paper receiving member,
The curl amount adjusting means is further configured such that the sending means can perform a plurality of sending operations, and the number of sending times of the sending means and the sending means for the pressing surface of the paper receiving member. An ink jet printer, wherein the curl adjustment amount of the print paper is changed by changing at least one of the approach angles of the print paper sent out by the printer. The inkjet printer according to claim 1 or 2,
In the paper set part, a long print paper is set in a state of being wound in a roll shape with the print surface facing outside,
The curl amount adjusting means has a cross curl applying section that bends the conveyed print paper in a direction perpendicular to the conveyance direction, and the curl amount adjusting means bends the print paper in a direction orthogonal to the conveyance direction. It is configured to adjust the curl amount of the print paper,
The above-described curl amount adjusting means further changes the curl adjustment amount of the print paper by changing the bending amount of the cross curl applying portion.

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