JP2006175733A - Inkjet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet printer which can prevent the generation of blanking in each printing paper. <P>SOLUTION: When a deviation of a leading end position of each printing paper P transferred in parallel from a first transfer path to a printing part is detected, a size at the time of printing of each image data corresponding to each printing paper P is made larger than a predetermined size on the basis of the deviation amount. When a leading end of the printing paper P transferred first to a printing stand 66 of the two printing papers P reaches a predetermined printing start position, printing is started simultaneously to each printing paper P. Each image data is printed to each printing paper P by the size larger than the predetermined size. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet printer.

Conventionally, an ink jet printer as shown in Patent Document 1 is known. This inkjet printer simultaneously prints each image data corresponding to each print paper on a transport path for transporting two print papers in parallel and each print paper transported in parallel from the transport path. And a print section. In this print section, when the leading edge of each print paper reaches a predetermined print start position, printing is started simultaneously for each print paper, and ink is ejected from the print head to each print paper while transporting each print paper. Print.
Japanese Patent Laid-Open No. 9-30664

  By the way, in the inkjet printer, from the viewpoint of maintaining print quality, it is preferable that the front end positions of the respective print papers are aligned. However, as shown in FIG. In some cases, the leading end positions of the paper may be shifted from each other.

  However, the ink jet printer is not provided with means for aligning the front end positions of the print papers in such a situation. Therefore, in the above inkjet printer, if the front end position of each print paper is shifted, if printing is performed simultaneously on each print paper as it is, there is a possibility that the print paper conveyed late will be whitened. is there.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a technique for preventing the occurrence of whitening in each print paper in an inkjet printer.

  According to a first aspect of the present invention, printing is simultaneously started for a transport path for transporting a plurality of print papers in parallel, and for each print paper transported in parallel from the transport path. An ink jet printer having a print unit that prints each image data corresponding to each print paper in a predetermined size, the leading end of each print paper being transported in parallel from the transport path to the print unit Detecting means for detecting a positional deviation, wherein the printing unit detects a deviation of the printed paper conveyed late with respect to the printed paper conveyed late when the deviation is detected by the detecting means; The corresponding image data is configured to be printed at a size larger than the predetermined size based on the shift amount. It is an butterfly.

  As a result, when a deviation in the tip position of each print paper conveyed in parallel from the conveyance path to the print unit is detected, the print unit simultaneously starts printing on each print paper and is conveyed with a delay. Since the image data corresponding to the print paper that has been transported with a delay is printed with a size larger than a predetermined size based on the amount of deviation, the deviation of the front end position of each print paper is prevented. It is possible to prevent whiteout from occurring on the printed paper that has been conveyed with no correction.

  According to a second invention, in the first invention, when the shift is detected by the detection means, the print unit receives, for each print paper, each image data corresponding to each print paper, The printing apparatus is configured to print at a size larger than the predetermined size based on the shift amount.

  As a result, when a deviation of the leading end position of each print paper conveyed in parallel from the conveyance path to the print unit is detected, each image data corresponding to each print paper is detected by the print unit for each print paper. Are uniformly printed based on the above-described deviation amount, so that the image data corresponding to the print paper that has been conveyed with a delay by the print control means for controlling the size of each image data at the time of printing. Compared with the case where only the size at the time of printing is larger than the predetermined size, the control of the print control means is simplified.

  According to the present invention, it is possible to prevent the print paper that has been transported with a delay and, moreover, the occurrence of white spots on each print paper without correcting the deviation of the front end position of each print paper. Therefore, the print quality can be maintained.

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

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

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

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

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

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

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

  By the moving mechanism, the roller pair 41 is provided at a receiving position for receiving the print paper P from the upstream 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 conveyance path (second supply unit U3) by the roller pair 41 at the second receiving position, the roller pair 41 that grips the print paper P by the moving mechanism is The print paper P is moved to the sending position while being separated from the upstream conveyance path, and the print paper P is moved to the downstream conveyance path in the direction opposite to the moving direction of the print paper P when receiving the print paper P at the sending position. It is configured to send out. The moving direction of the print paper P sent out to the downstream side conveyance path is in the horizontal direction opposite to the moving direction at the time of reception (frontward of the casing).

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

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

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

  The print unit U5 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 ejecting ink to the print paper P for printing are provided. The print table 66 and the print head 67 constitute the print unit 4. The print unit 4 prints on the print paper P when the leading edge of the print paper P conveyed to the print unit 4 from the first conveyance path or the second conveyance path reaches a predetermined print start position. It starts (see FIG. 9).

  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. .

  Further, in the case where printing is performed on two print papers P set in the magazine accommodating unit 2, each of the second paper detection sensors 58 conveyed in parallel to the print unit 4 from the first conveyance path. When the deviation of the front end position of the print paper P is not detected (that is, when the front end position of each print paper P is aligned), each print paper P is detected when the front end of each print paper P reaches the print start position. The printing is started at the same time, and the image data is simultaneously printed on each print paper P in a predetermined size (see FIG. 9).

  On the other hand, in the case where printing is performed on two print papers P set in the magazine accommodating unit 2, each of the second paper detection sensors 58 is conveyed in parallel to the print unit 4 from the first conveyance path. When the deviation of the front end position of the print paper P is detected, when the front end of the print paper P first transported to the print unit 4 among the two print papers P reaches the print start position, the print paper P is moved to each print paper P. On the other hand, printing is started at the same time, and each image data is simultaneously printed on each print paper P in an enlarged size described later based on the shift amount (see FIG. 9).

  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). The print paper P delivered by the roller pair 41 positioned at the delivery position is received and conveyed 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 height position of the sandwiched portion of the print paper P sandwiched by the transport roller 75 is higher than the upper surface of the print table 66, and the print paper P is wound around the drive roller 75a while being printed. The portion of the print base 66 that is wound around the drive roller 75a by the guide roller 79 that is supported from the upper end of the print table 66 so as to have a gap above the upstream end. In other words, the print paper P 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, on the downstream side of the printing table 66, two pairs of pressure bonding composed of driving and driven rollers 81a and 81b are provided to form a third transport path for discharging the printed paper P to the outside of the housing 1. The mold discharge rollers 81 are provided at intervals in the paper transport direction. The drive roller 81 a of each discharge roller 81 is driven simultaneously by the electric motor 82 via the transmission belt 83. The height of the downstream discharge roller 81 is higher than that of the upstream discharge roller 81, and the print paper P is lifted between the downstream discharge roller 81 and the upstream discharge roller 81 and the downstream side. A guide member 84 that leads to the discharge roller 81 is provided.

  As described above, 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. In particular, the print paper P conveyed from the magazine housing unit 2 is curled so that the central portion in the length direction protrudes toward the print surface side with respect to both ends by the rolls of the roll. Even if the print paper P is curled, the flatness can be secured without being attracted to the print table 66. In the present embodiment, as will be described later, the print paper P conveyed from the magazine accommodating portion 2 is corrected for the curl before being supplied to the print table 66, so that the flatness is further improved. Can do.

  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 are configured to wind the roll on the print paper P after the print paper P transported from the magazine housing unit 2 is cut by the cutter 26. It constitutes a curl correction device that corrects curl caused by wrinkles. In the case of the print paper P conveyed from the cassette housing unit 3, since the curl is not normally curled, the curl correction device does not operate.

  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 moved in the opposite direction of the roller pair 41 by the moving mechanism of the switchback unit U4. Move to the other roller (drive roller 41a) side. 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 such that the side protruding from the curl (print surface side) is inside, and the curl is corrected. The conveyance roller 75 is configured to hold the print paper P in a state where the conveyance is stopped during the curl correction of the print paper P.

  Even if the rear end portion of the print paper P is detached from the roller pair 41, the roller pair 41 continues to move downward and returns to the first receiving position in order to receive the next print paper P. That is, the curl of the print paper P is corrected when the roller pair 41 moves from the sending position to the first receiving position. If the length of the print paper P is longer than the distance between the first receiving position and the sending position, the roller pair 41 is moved further downward than the first receiving position to omit the print paper P. The curl is corrected throughout and then returned to the first receiving position. Even when the print paper P is long as described above, the use of the space for hanging the print paper P downward as described above makes it possible to correct the curl over the entire print paper P without enlarging the casing 1 up and down. Can be done.

  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. Section (print control means) 104, semiconductor memory RAM / ROM 105, communication interface 106, and the above-described first paper detection sensor 20 and second paper detection sensor 58.

  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. The print control unit 104 performs printing on two print papers P set in the magazine housing unit 2, and is transported in parallel from the first transport path to the print unit 4 by the second paper detection sensor 58. When the deviation of the leading end position of each printed paper P is not detected (that is, when the leading end position of each printed paper P is aligned), the image data corresponding to each printed paper P is printed at the time of printing. Let the size be a predetermined size. The predetermined size is changed according to the size of the print paper P, and specifically, is set to be slightly larger than the size of the print paper P (see FIG. 9). In other words, the predetermined size is set so that each print paper P is positioned within each image data area during printing. On the other hand, the print control unit 104 performs printing on two print papers P set in the magazine storage unit 2, and is parallel to the print unit 4 from the first conveyance path by the second paper detection sensor 58. When the deviation of the leading end position of each print paper P conveyed in step S1 is detected, the size of each image data corresponding to each print paper P at the time of printing is larger than the predetermined size based on the deviation amount. Let it be a size (hereinafter referred to as an enlarged size) (see FIG. 9). As described above, when the deviation of the front end position of each print paper P is detected, the size at the time of printing of each image data is set to the enlarged size. The position of the paper P (that is, the print paper P other than the print paper P first conveyed to the print unit 4; the right side print paper P in FIG. 9) and the position of the image data of a predetermined size corresponding to the position. This is because they will shift. The enlarged size is based on the amount of deviation, and the position of the upstream end (rear end) in the sub-scanning direction of each image data during printing is later than the upstream end (rear end) position of the print paper P that has been conveyed. It is set so as to be positioned upstream in the sub-scanning direction. In other words, the enlarged size is set so that each print paper P is positioned in the area of each image data during printing.

  The units U1 to U5 operate as follows under the control of the conveyance control unit 102 and the like.

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

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

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

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

  When the print paper P is sent out, the front end of the print paper P (rear end at the time of receipt) is detected by the second paper detection sensor 58, and 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 correct the curl of the print paper P (see FIG. 7). At this time, the driving roller 41a of the roller pair 41 may continue to reverse or may be stopped. However, when the drive roller 41a is continuously rotated in the reverse direction, it is necessary to set the rotational speed and the moving speed of the roller pair 41 so that tension is applied to the print paper P. 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 conveying roller 75 is actuated again. Then, the print paper P held at the time of curl correction is conveyed to the print table 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 roller 81 and received by the discharge tray 5.

  Further, when printing is performed on the two print papers P set in the magazine housing portion 2, the roller pair 41 of the switchback unit U4 is positioned at the first receiving position (see FIG. 1). Then, each print paper P is pulled out from the magazine housing portion 2 and conveyed to the roller pair 41 located at the first receiving position.

  The driving roller 41a of the roller pair 41 starts to rotate when the leading ends of the two print papers P are detected by the second paper detection sensor 58, and is conveyed forward from the cutter unit U2 in the horizontal direction. Each received print paper P is received and gripped. The drive roller 41a continues to drive and draws each print paper P into the space space 12 on the rear side of the casing. Then, after the leading edge of each 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 26 b of the cutter 26 is operated and each print paper P is moved. Disconnected at the same time. Even after this cutting, the driving roller 41a continues to drive, and stops when the rear end of each cut print paper P is gripped by the roller pair 41.

  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 two print papers P are conveyed from the receiving position to the sending position in a state where they are separated from the upstream conveying path (cutter unit U2).

  Thereafter, the driving roller 41a of the roller pair 41 is reversed, and the two print papers P after being cut are sent out to the transport roller 75 of the print unit U5 in the horizontal direction toward the front of the casing.

  At the time of sending out the two print papers P, the leading edge of each print paper P is detected by the second paper detection sensor 58, and by this detection, the transport roller 75 of the print unit U5 starts to operate. Is sent out by a predetermined amount, the operation of the conveying roller 75 is temporarily stopped. As a result, the leading end portion of each print paper P is held and held by the transport roller 75. Further, based on the above detection, a deviation of the leading end position of each print paper P is detected. Thereafter, in this holding state, as described above, the roller pair 41 that holds each print paper P is moved downward to correct the curl of each print paper P (see FIG. 7). Eventually, the rear end portion of each 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.

  When the deviation of the leading end positions of the two print papers P is not detected, the rear end of each print paper P is detected after the roller pair 41 returns to the first receiving position or before returning to the first receiving position. After passing the position deviating from the roller pair 41, the conveyance roller 75 is actuated again, and each print paper P held at the time of curl correction is conveyed to the print table 66. Also, the size at the time of printing each image data is set to a predetermined size. Then, when the leading edge of each print paper P reaches the print start position, printing is simultaneously started on each print paper P, and the print head 67 is moved while being intermittently transported by a transport amount by the transport roller 75. Each image data is simultaneously printed at a predetermined size by moving in the main scanning direction and discharging ink to each print paper P on the print table 66 from the ink discharge nozzle 67b of each head unit 67a of the print head 67. To do.

  On the other hand, when a deviation of the leading end positions of the two print papers P is detected, after the roller pair 41 returns to the first receiving position or before returning to the first receiving position and the rear end portion of each print paper P After passing the position where the roller is deviated from the roller pair 41, the conveyance roller 75 is actuated again to convey each print paper P held at the time of curl correction to the print table 66. In addition, the size of each image data at the time of printing is set to an enlarged size based on the shift amount. Then, when the leading edge of the print paper P (the left-side print paper P in FIG. 9) that has been first transported to the print table 66 reaches the print start position, printing is simultaneously started for each print paper P and transported. The print head 67 is moved in the main scanning direction while being intermittently conveyed by the unit amount by the roller 75, and each print paper P on the print table 66 from the ink discharge nozzle 67 b of each head unit 67 a of the print head 67. In contrast, by ejecting ink, each image data is simultaneously printed in an enlarged size.

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

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

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

  When the print paper P is delivered to the conveyance roller 75, the leading edge of the print paper P is detected by the second paper detection sensor 58, and the conveyance roller 75 of the print unit U5 starts to operate by this detection. In the case of the print paper P set in the cassette housing unit 3, it is not necessary to correct the curl. Therefore, the transport roller 75 continues to operate without stopping, and the print paper P sent out from the switchback unit U4 is removed. Receiving and transporting 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.

-Effect-
As described above, according to the present embodiment, when a deviation of the leading end position of each print paper P conveyed in parallel from the first conveyance path to the print unit 4 is detected, the print unit 4 causes each print paper P to be printed. On the other hand, printing is started at the same time, and each image data corresponding to each print paper P is printed on each print paper P in a size larger than a predetermined size based on the shift amount. Without correcting the deviation of the leading end position of P, it is possible to prevent the print paper P that has been conveyed with a delay, and hence the occurrence of white spots on each print paper P. Therefore, the print quality can be maintained.

  Further, when a deviation of the tip position of each print paper P conveyed in parallel from the first conveyance path to the printing unit 4 is detected, each print conveyed in parallel from the first conveyance path by the printing unit 4 is detected. Since each image data corresponding to each print paper P is uniformly printed on the paper P in a size larger than a predetermined size based on the deviation amount, it has been conveyed by the print control unit 104 with a delay. Compared with the case where only the size at the time of printing of the image data corresponding to the print paper P is larger than the predetermined size, the control of the print control unit 104 is simplified.

  In the present embodiment, when the deviation of the leading end position of each print paper P is detected, each image data corresponding to each print paper P is printed in an enlarged size. However, the print paper P that has been transported first is printed. The corresponding image data may be printed at a predetermined size, and the image data corresponding to the print paper P that has been conveyed with a delay may be printed at an enlarged size. In this case as well, it is possible to prevent the printing paper P that has been conveyed with a delay and, consequently, the occurrence of whitening on each printing paper P without correcting the deviation of the leading edge position of each printing paper P.

  In the present embodiment, when the print paper P is sent to the transport roller 75, the second paper detection sensor 58 detects the deviation of the front end position of each print paper P. If it is in the middle of conveying to 4, it may be detected by any detection means, and may be detected at any time. However, this detection is preferably performed immediately before each print paper P is sent to the print unit 4 from the viewpoint of maintaining print quality.

  Further, in the present embodiment, two print papers P can be set in parallel in the magazine housing portion 2, but three or more may be set in parallel. When three or more are set in parallel as described above, the set print papers P are simultaneously pulled out from the magazine housing unit 2 and conveyed in parallel as in the case where two are set in parallel. In step 4, printing is performed on each print paper P at the same time. Also in this case, when the deviation of the leading end position of each print paper P is detected, each image data corresponding to each print paper P is printed in an enlarged size.

  In the present embodiment, the sizes of the two print papers P are not mentioned, but they may be the same size or different sizes.

  In the present embodiment, the difference between the two image data corresponding to the two print papers P is not mentioned, but they may be the same or different.

  The present invention is not limited to the embodiments, and can be implemented in various other forms without departing from the spirit or main features thereof.

  As described above, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  As described above, the present invention is useful for an ink jet printer in which print paper is conveyed to a printing unit, 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 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 curling of the printed paper is corrected. It is a block diagram which shows the structure of a control system. FIG. 3 is a schematic diagram illustrating a positional relationship between print paper and image data. It is the schematic which shows the positional relationship of the conventional print paper and image data.

Explanation of symbols

P Print paper U1 First supply unit (conveyance path)
U2 Cutter unit (conveyance path)
U4 switchback unit (conveyance path)
U5 Print unit (conveyance path)
2 Magazine storage section 3 Cassette storage section 4 Printing section 41 Roller pair 42 Electric motor 43 Transmission belt 45 Rail mount 46 Travel rail 47 Pulley 48 Drive belt 49 Electric motor 58 Second paper detection sensor (detection means)
104 Print controller

Claims (2)

Printing is simultaneously started on a transport path for transporting a plurality of print papers in parallel, and on each print paper transported in parallel from the transport path. An ink jet printer comprising a print unit that prints each image data corresponding to a predetermined size,
A detection means for detecting a deviation of the tip position of each print paper conveyed in parallel from the conveyance path to the print unit;
When the deviation is detected by the detection means, the print unit is configured to, based on the deviation amount, print data corresponding to the print paper conveyed late with respect to the print paper conveyed late. An ink jet printer configured to print at a size larger than the predetermined size. The inkjet printer according to claim 1.
When the shift is detected by the detection unit, the print unit is configured so that each image data corresponding to each print paper is larger than the predetermined size on the basis of the shift amount. An ink jet printer characterized by being configured to print with.

Images