JP2011051774A - Double-sided printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid a collision in a storage part of paper successively carried in the storage part, in a double-sided printer. <P>SOLUTION: This double-sided printer has a first printing part for printing on one surface of the paper, a second printing part for printing on the other surface of the paper and the storage part 5 for carrying out the paper to the second printing part after carrying in and storing the paper printed by the first printing part. The storage part 5 has a carrying-in surface 5d for moving the paper on its part in carrying-in and a carrying-out surface 5e arranged at a predetermined interval to this carrying-in surface and moving the paper on its part in carrying-out. The storage part 5 carries in the paper P2 up to the lowest position on the carrying-in surface 5d. A lower end part P2L of the carried-in paper P2 is successively held, and is moved to the carrying-out surface 5e side in a state of having mutually a predetermined clearance in the respective lower end parts P2L. An upper end part of the carried-in paper is separated from the carrying-in surface 5d, and is regulated so as not to return again to the carrying-in surface 5d. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a duplex printing apparatus that performs printing on one side and the other side of a sheet. More specifically, the present invention relates to a double-sided printing apparatus that stores a sheet printed on one side for a predetermined time and prints it on the other side.

  In recent years, from the viewpoint of environmental problems and the like, it has been desired to reduce the amount of paper used for printing, and double-sided printing that performs printing on one side and the other side of paper is popular. As an example of this double-sided printing apparatus, a cylindrical first drum and a second drum each having a base paper wound around an outer peripheral surface are disposed adjacent to each other, and printing is performed on one surface of the paper with the first drum. 2. Description of the Related Art A double-sided stencil printing apparatus that conveys paper and prints on the other side of the paper with a second drum is known.

  In the case of such a double-sided printing apparatus, there is a possibility that the paper is soiled by carrying for other-side printing or performing other-side printing before the ink printed on one side is sufficiently dried.

  In Patent Document 1, the first sheet is printed on the first drum and printed on one side of the sheet. The sheet on which the one side is printed is secondarily fed to the storage unit and stored for a predetermined time, and then conveyed to the first drum. A double-sided printing apparatus that performs tertiary paper feeding to two drums has been proposed.

JP-A-2005-29375

  As such a storage unit, the paper that is secondarily fed is moved on the carry-in surface in the storage unit and carried in, and after the carry-in, the paper is peeled off from the carry-in surface and moved to a carry-out surface with a predetermined interval. A storage unit may be considered in which the paper is dried and moved on the carry-out surface in accordance with the timing of the third paper feed in which the second drum is in a predetermined position.

  However, in such a storage unit, there is an air flow in the storage unit generated by a transport mechanism used for carrying in the storage unit and carrying out of the storage unit, a moving mechanism for moving the sheet from the carry-in surface to the carry-out surface, and the like. There is a possibility that the sheet peeled off from the carry-in surface will return to the carry-in surface again due to the effect of being stiffened due to the curling that is curved with the one side inward on the printed paper.

  As described above, when the sheet peeled off from the carry-in surface returns to the carry-in surface again, there is a possibility that the paper once peeled and the paper that moves next on the carry-in surface collides with each other. This collision may occur particularly as the printing speed increases.

  In view of the above circumstances, an object of the present invention is to provide a double-sided printing apparatus capable of avoiding a collision in a storage unit of sheets sequentially loaded into a storage unit.

  In order to solve the above problems, a duplex printing apparatus according to the present invention includes a first printing unit that prints on one side of a sheet, a second printing unit that prints on the other side of the sheet, and a sheet printed by the first printing unit. Is a double-sided printing apparatus including a storage unit that transports the paper to the second printing unit, and stores the transporting surface on which the sheet moves when the storage unit is transported. A carry-out surface on which paper is moved when unloaded, a first conveying means for carrying the paper on the carry-in surface to the lowest position in the storage unit, and a storage unit for storing the paper on the carry-out surface Second conveying means for carrying out the paper, and holding and moving means for sequentially holding the lower end portions of the respective papers carried to the lowermost position and moving the respective papers to the carry-out surface side with the lower end portions having a predetermined gap. And the upper end of the paper carried to the lowest position is peeled off from the carry-in surface, And an end portion is provided with a release means for regulating such does not return to the carry face again.

  Here, the “lowermost position” means the lowest position at which the loaded paper can move. The “lower end portion” means a portion in the vicinity of the lower end of the sheet, and specifically, a portion from the lower end to the position of about 20% of the total length of the sheet in the upper end direction. The “upper end portion” means a portion in the vicinity of the upper end of the paper, specifically, a portion from the upper end to the lower end direction to a position of about 30% of the total length of the paper.

  In addition, the above "not return to the loading surface" is not limited to the case where the entire peeled upper end portion does not return to the loading surface again, and a part of the peeled upper end portion is loaded again. It means to include the case of not returning to the surface.

  Further, in the double-sided printing apparatus of the present invention, the peeling means peels the upper end portion of the sheet at the lowest position from the carry-in surface, moves the upper end portion to the carry-out surface side, and moves each upper end portion on the carry-out surface. You may hold | maintain in the state which overlapped.

  Here, “move to the carry-out surface side” means that when the upper end portion returns to the carry-in surface, the upper end portion moves not only to the carry-out surface side by pressing or the like, but also to the carry-out surface side. In this case, it means that it is moved so as not to return to the carry-in surface.

  The above “state of being overlapped on the carry-out surface” means not only a state in which each upper end portion is overlapped so as to be in close contact on the carry-out surface, but also a state of being overlapped with a slight gap.

  Further, in the double-sided printing apparatus of the present invention, the peeling means enters between the peeling claw that protrudes on the carry-in surface and peels the upper end portion of the paper from the carry-in surface and the peeled upper end portion, and the upper end portion. It may be provided with a movable guide which is moved to the carry-out surface side and is held near the carry-out surface.

  Further, in the double-sided printing apparatus of the present invention, the storage unit has the carry-in surface inclined and the carry-out surface is provided obliquely below the carry-in surface, and the holding and moving means tilts each sheet and moves the inside of the storage unit to the carry-out surface side. It may be a thing.

  In the duplex printing apparatus of the present invention, the holding and moving means may hold each sheet in the storage unit in a state of being curled so as to bend with one surface of each sheet being inward.

  In the duplex printing apparatus of the present invention, the carry-in surface is above the carry-out surface, and the distance between the upper end of the carry-in surface and the upper end of the carry-out surface is greater than the distance between the lower end of the carry-in surface and the lower end of the carry-out surface. It may be short.

  According to the double-sided printing apparatus of the present invention, the first printing unit that prints on one side of the paper, the second printing unit that prints on the other side of the paper, and the paper printed by the first printing unit are carried in and stored. And a storage unit that is carried out to the second printing unit, and the storage unit is arranged with a carry-in surface on which the paper moves at the time of carry-in and a predetermined interval from the carry-in surface. A carry-out surface that moves above, a first transport unit that carries the paper on the carry-in surface to the lowest position in the storage unit, a second transport unit that carries out the paper on the carry-out surface from the storage unit, and sequentially lowermost A holding and moving means for sequentially holding the lower end portions of the respective sheets carried to the position and moving the respective sheets to the carry-out surface side with the lower end portions having a predetermined gap, and the upper end of the sheets carried to the lowest position The part is peeled off from the carry-in surface, and the upper end is regulated so that it does not return to the carry-in surface again. The lower end portion of the paper carried to the lowest position is held and forcibly moved from the carry-in surface to the carry-out surface side, while the upper end portion of the paper is moved from the carry-in surface. Since it is regulated so that it does not return to the carry-in surface again after being peeled off, the airflow generated in the storage unit or the paper that has been carried to the lowest position due to the sheeting by the single-sided printing is again on the carry-in surface. Even when trying to return to the sheet, it is possible to reliably separate the sheet from the carry-in surface, and to avoid collision with the next carried-in sheet.

Configuration diagram of a duplex printing apparatus according to an embodiment Reservoir configuration diagram Partial perspective view of reservoir Configuration diagram of peeling means The figure which shows series operation | movement of a peeling means (the 1) The figure which shows series operation | movement of a peeling means (the 2) The figure which shows a series of operation | movement of a peeling means (the 3) The figure which shows series operation | movement of a peeling means (the 4)

  Hereinafter, embodiments of the duplex printing apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram of a duplex printing apparatus 1 that is an embodiment of the duplex printing apparatus of the present invention.

  The double-sided printing apparatus 1 is a double-sided stencil printing apparatus, which feeds an unprinted paper P1 and prints it on one side, stores the paper P2 after the single-sided printing for a predetermined time, and re-feeds the paper P2 to the other side. And the paper P3 after the other side printing is discharged.

  The duplex printing apparatus 1 includes a paper feeding unit 2 that feeds unprinted paper P1, a first printing unit 3 that prints on one side of the paper P1 fed from the paper feeding unit 2, and the first printing unit. 3, the reversing unit 4 that reverses the paper P2 printed on one side, the storage unit 5 that stores the reversed paper P2 for a predetermined time, and the refeed that refeeds the paper P2 stored in the storage unit 5 The paper unit 6, the second printing unit 7 that prints on the other side of the paper P <b> 2 re-feeded from the re-feeding unit 6, and the paper P <b> 3 printed on the other side by the second printing unit 7 are discharged. And a paper discharge unit 8 that performs the above operation.

  The paper feeding unit 2 feeds unprinted paper P1 to the first printing unit 3.

  The configuration of the paper feeding unit 2 will be described. The paper feed unit 2 is provided on the side surface of the apparatus main body 11, and includes a paper feed base 21 on which the paper P 1 is stacked, a paper feed roller 22 that takes out the paper P 1 from the paper feed base 21 one by one, and a paper handling roller 23. , And a timing roller pair 24 for feeding the paper P1 to the first printing unit 3.

  The operation of the paper feed unit 2 will be described. The paper feed unit 2 takes out the paper P1 stacked on the paper feed tray 21 by the paper feed roller 22 and the paper rolling roller 23, and sends it to the first printing unit 3 at a predetermined timing by the timing roller pair 24.

  The first printing unit 3 prints on one side of the paper P1.

  The configuration of the first printing unit 3 will be described. The first printing unit 3 includes a first plate cylinder 31. The first plate cylinder 31 has an ink-permeable peripheral wall 31a, and is driven to rotate in the direction of arrow A in the figure by a driving means (not shown).

  Inside the first plate cylinder 31, there are an ink supply roller 32 in contact with the inner peripheral surface of the peripheral wall 31a, a doctor roller 33 for supplying a predetermined amount of ink to the ink supply roller 32, and an ink bottle 34 filled with ink. Is provided.

  A base paper M is wound around the outer peripheral surface of the first plate cylinder 31 by a clamp (not shown). A press roller 35 is provided below the first plate cylinder 31, and the press roller 35 moves in the direction B in the drawing so as to be close to and away from the first plate cylinder 31. Print by pinching with pressure. On the lower right side of the first plate cylinder 31, a separation claw 36 that separates the paper P <b> 2 on which one side is printed by the first printing unit 3 from the base paper M is provided.

  The operation of the first printing unit 3 will be described. When the base paper M is supplied, the first printing unit 3 is wound around the outer peripheral surface of the first plate cylinder 31 with the rotation of the first plate cylinder 31 and is held by a clamp (not shown). . Thereafter, the first plate cylinder 31 is driven to rotate at a predetermined peripheral speed, and the press roller 35 is moved to a position where the paper P1 can be pressed with a preset pressing force.

  When the paper P1 is fed from the paper supply unit 2 at a predetermined timing, the paper P1 is nipped and conveyed by the first plate cylinder 31 and the press roller 35, and the paper P1 is pressed onto the base paper M for printing. The paper P2 on which one side is printed is separated from the base paper M by the separation claw 36.

  The reversing unit 4 is for reversing the paper P2 so that one printed surface is on the lower side.

  The configuration of the inverting unit 4 will be described. The reversing unit 4 includes four pulleys 41 arranged along an arcuate locus, a conveyor belt 42 that is stretched over the outer periphery of the four pulleys 41 and moves as the pulleys 41 rotate, An adsorption fan 43 is provided.

  The operation of the inverting unit 4 will be described. The reversing unit 4 sucks the paper P2 printed by the first printing unit 3 with the suction fan 43, and stores the paper P2 on the transport belt 42 along an arcuate path along with the rotation of the pulley 41. Transport to. As the sheet P2 moves along an arcuate path, one side of the printed sheet is positioned downward.

  FIG. 2 is a configuration diagram of the storage unit 5. The storage unit 5 carries the paper P2 printed on one side into the storage unit 5, stores the paper P2 for a predetermined time in order to dry it, and carries it out of the storage unit 5 for refeeding.

  The configuration of the storage unit 5 will be described. As shown in FIG. 2, the storage unit 5 includes a support plate 5a that supports the paper P2 from an obliquely lower side, a side plate 5b that stands substantially perpendicular to the support plate 5a on both sides of the support plate 5a, and the support plate. And a cover plate 5c positioned obliquely upward with respect to 5a.

  In addition, the storage unit 5 includes a carry-in surface 5d on which the paper P2 moves on the inner surface of the cover plate 5c and a carry-out surface 5e on which the paper P2 moves on the inner surface of the support plate 5a. Have. The inner surface of the side plate 5b serves as a guide surface that guides the movement of the paper P2 from the carry-in surface 5d to the carry-out surface 5e. Further, the support plate 5a and the cover plate 5c are arranged so that the distance between the upper end of the carry-in surface 5d and the upper end of the carry-out surface 5e is shorter than the distance between the lower end of the carry-in surface 5d and the lower end of the carry-out surface 5d. That is, as shown in FIG. 1 and FIG. 2, the storage part 5 has a fan-shaped outer shape.

  In addition, the storage unit 5 moves the paper P2 on the carry-in surface 5d to carry the paper P2 to the lowermost position and the printed surface of the paper P2 carried to the lowermost position to the inside. Curling application means 52 for applying a curl that is curved, holding movement means 53 for holding the lower end portion P2L of the paper P2 carried to the lowermost position and moving it toward the carry-out surface 5e, and carried to the lowermost position Separating means 55 for separating the upper end portion P2U of the paper P2 so as to prevent the upper end portion P2U from returning onto the carry-in surface 5d again, and second conveying means for carrying out the paper P2 on the carry-out surface 5e from the storage unit 5. 56.

  Here, the lower end portion P2L of the paper P2 is in the vicinity of the lower end of the paper P2, and specifically means a portion from the lower end to the upper end direction to a position of about 20% of the total length of the paper P2. On the other hand, the upper end portion P2U of the paper P2 is in the vicinity of the upper end of the paper P2, specifically, a portion from the upper end to the lower end direction to a position that is about 30% of the total length of the paper P2.

  The first transport means 51 carries the paper P2 from the reversing unit 4 by moving it on the carry-in surface 5d to the lowest position in the storage unit 5.

  The structure of the 1st conveyance means 51 is demonstrated. As shown in FIG. 2, the first transport unit 51 includes a housing 511 that is fixed to the cover plate 5 c and is substantially hermetically sealed, a pair of pulleys 512 that are arranged at a predetermined interval in the housing 511, and a pair of pulleys 512. And an annular belt 513 that moves as the pulley 512 is rotated by a driving means (not shown).

  The cover plate 5c is formed with a slot so that the annular belt 513 is exposed, and the pair of pulleys 512 is disposed in the housing 511 so that the surface of the exposed annular belt 513 is substantially flat with the carry-in surface 5d. ing. Here, FIG. 3 shows a partial perspective view of the reservoir 5, but the annular belt 513 is formed with a plurality of through holes 513 a as shown in FIG. 3. Note that FIG. 3 does not show the housing 511 for easy understanding.

  Refer to FIG. 2 again. The first conveying means 51 is disposed outside the housing 511 and the forced peeling claw 514 that can project from the loading surface 5d by rotating around the rotation shaft 514a. The first conveying means 51 discharges the air inside the housing 511 and negatively moves inside the housing 511. The intake fan 515 that is brought into a pressure state, the intake shutter 516 that is provided between the housing 511 and the intake fan 515 and controls the intake air by the intake fan 515, and the outside air is supplied into the housing 511 that is in a negative pressure state. An air supply shutter 517 for returning to atmospheric pressure is provided.

  The operation of the first transport means 51 will be described. The intake fan 515 is rotated in advance, the intake shutter 516 is opened at a predetermined timing, the supply shutter 517 is closed, and the air in the housing 511 is discharged to make a negative pressure state. Outside air flows into the housing 511 in the negative pressure state from the through-hole 513a of the annular belt 513 exposed to the carry-in surface 5d, and a suction force is generated in the through-hole 513a.

  The paper P2 carried into the storage unit 5 from the reversing unit 4 is sucked toward the annular belt 513 from the through hole 513a. The driving means (not shown) drives the pulley 512, so that the paper P2 on which one side is printed moves on the exposed annular belt 513 and the substantially flat carry-in surface 5d.

  When the paper P2 is carried to the lowest position in the storage unit 5, the intake shutter 516 is closed and the air supply shutter 517 is opened, the inside of the housing 511 is returned to atmospheric pressure, and then the forced peeling claw 514 is rotated around the rotation shaft 514a. The paper P2 on the carry-in surface 5d is peeled off by being rotated to the upper surface and projecting onto the carry-in surface 5d. In the present embodiment, the description will be made assuming that the intake fan 515 is always driven.

  Refer to FIG. 3 again. The curl imparting means 52 imparts a curl that is curved with one surface printed on each paper P2 in the storage unit 5 facing inward.

  The configuration of the curling unit 52 will be described. As shown in FIG. 3, the curling unit 52 includes a fulcrum shaft 521 that is fixed at both ends by mounting plates (not shown) standing on the carry-in surface 5 d on both sides of the first transport unit 51, and the fulcrum shaft 521. A support plate 522 attached to be rotatable in the direction of arrow C around the center, and a guide plate 523 extending in a blade shape obliquely downward from the support plate 522 are provided.

  The operation of the curling means 52 will be described. The curling means 52 includes a support plate 522 and a guide plate that are centered on the fulcrum shaft 521 so that the guide plate 523 faces obliquely downward with respect to the carry-in surface 5d before the paper P2 is carried into the storage unit 5. 523 is rotated.

  As a result, the left and right portions of the paper P2 moved and moved on the carry-in surface 5d move from the carry-in surface 5d onto the guide plate 523, and the left and right portions of the paper P2 move on the carry-in surface 5d. When the sheet P2 moves obliquely below the central portion and the sheet P2 is carried to the lowest position, the sheet P2 is given a curl that is curved with the printed one side inward.

  Since the curl is applied, the paper P2 has a property of being set back to the carry-in surface 5d side even after the paper P2 is seated and peeled off by the first transport means 51.

  Refer to FIG. 2 again. The holding and moving means 53 sequentially holds the lower end portion P2L of the paper P2 carried to the lowest position, and each paper P2 is moved from the carry-in surface 5d side to the carry-out surface 5e side with the lower end portion P2L having a predetermined gap therebetween. It is to be moved. In the present embodiment, description will be made assuming that the carry-in surface 5d side is the moving upstream side and the carry-out surface 5e side is the moving downstream side.

  On the other hand, the upper end portion P2U of the paper P2 moves by free-falling to the carry-out surface 5e side after peeling. As described above, the support plate 5a and the cover plate 5c are arranged so that the distance between the upper end of the carry-in surface 5d and the upper end of the carry-out surface 5e is shorter than the distance between the lower end of the carry-in surface 5d and the lower end of the carry-out surface 5d. By doing this, it is avoided that the movement of the upper end portion P2U toward the unloading surface 5e is slower than the lower end portion P2L that is forcibly moved to the unloading surface 5e side.

  The configuration of the holding and moving means 53 will be described. As shown in FIG. 2, the holding and moving means 53 is stretched over a pair of pulleys 531, one of which is arranged near the carry-in surface 5 d and the other is arranged near the carry-out surface 5 e, and the outer periphery of the pair of pulleys 531. And an annular belt 532 that moves in accordance with the rotation of the pulley 531 by a driving means (not shown).

  In addition, a plurality of plates 533 are erected on the entire outer peripheral surface of the annular belt 532 substantially vertically with a predetermined interval therebetween. Each plate 533 has an elastically deformable claw piece 534 that extends toward the adjacent plate 533.

  The operation of the holding and moving means 53 will be described. The operation of the holding and moving means 53 is an intermittent operation that operates at a predetermined timing each time the paper P2 is carried to the lowest position. When the paper P2 moves on the carry-in surface 5d, the lower end portion P2L of the paper P2 is inserted one by one into the recess 535 between the plates 533, and the paper P2 comes into contact with the annular belt 532.

  Here, the lowest position in the present embodiment is the lowest position in the storage unit 5 to which the loaded paper P2 can move. Specifically, the lower end P2P of the paper P2 is inserted into the recess 535. As a result, the sheet P2 comes into contact with the annular belt 532.

  Here, in the vicinity of the carry-in surface 5d, the upstream plate 533 faces the circumferential direction of the pulley 531, and the downstream plate 533 faces substantially perpendicular to the annular belt 532, so the dimension of the recess 535 is the thickness of the paper P2. The lower end portion P2L of the paper P2 can be inserted into the concave portion 535 between the plates 533.

  After the paper P2 is carried in, driving means (not shown) rotates the pulley 531 at a predetermined timing, so that the upstream plate 533 in which the paper P2 is inserted into the recess 535 near the carry-in surface 5d is also carried out. By moving to the 5e side, it is substantially perpendicular to the annular belt 532. As a result, the size of the concave portion 535 becomes narrower than the thickness of the paper P2, and the downstream claw piece 534 comes into contact with the lower end portion P2L and is elastically deformed, so that the lower end portion P2L is connected to the upstream plate 533 and the downstream side. It is held by the claw piece 534.

  When the pulley 531 further rotates and the downstream plate 533 moves to the vicinity of the carry-out surface 5e, the downstream plate 533 faces the circumferential direction of the pulley 531, and the size of the concave portion 535 is again wider than the thickness of the paper P2. Thus, the holding of the lower end portion P2L of the paper P2 is released.

  The printed surface of the paper P2 is dried by the moving time of the paper P2 from the carry-in surface 5d to the carry-out surface 5e, which is the intermittent operation.

  FIG. 4 is a configuration diagram of the peeling means 55. The peeling means 55 is configured to peel the upper end portion P2U of the paper P2 carried to the lowest position from the carry-in surface 5d and to prevent the upper end portion P2U from returning to the carry-in surface 5d again.

  The configuration of the peeling unit 55 will be described. The peeling means 55 includes a drive shaft 551 disposed above the unloading surface 5e side of the reservoir 5, a cam 552 that is substantially semicircular and is fixed to the drive shaft 551 at the center of the semicircle, and a cam 552. A movable guide 553 that is rotatably connected to the cam 552 in the vicinity of the circumference thereof, and a first guide shaft 554 that is inserted into a slot 553a formed in the movable guide 553 and guides the trajectory of the movable guide 553. Yes. The first guide shaft 554 is connected to one rotation shaft of a pickup roller pair 61 of the refeed unit 6 described later.

  Further, the peeling means 55 is fixed to the rotary shaft 555 disposed on the carry-in surface 5d side of the reservoir 5, the peeling claw 556 fixedly supported on the rotary shaft 555, and a spring (not shown). , A lever 557 biased in the direction of arrow A in the figure, one of which is rotatably connected to the lever 557 and the other of which is in contact with the outer peripheral surface 552a of the cam 552, and a slot 558a formed in the link 558. And a second guide shaft 559 that guides the track of the link 558.

  The operation of the peeling means 55 will be described. The peeling means 55 rotates the drive shaft 551 in the direction of arrow B in the figure by the drive means (not shown) substantially simultaneously when the paper P2 is carried to the lowest position. The cam 552 rotates with the rotation of the drive shaft 551, and the movable guide 553 rotatably connected to the cam 552 is guided and moved by the first guide shaft 554 inserted into the slot 553a.

  As the cam 552 rotates, the outer peripheral surface 552a of the cam 552 contacts the link 558, whereby the link 558 is guided to the second guide shaft 559 and moves in the direction of arrow C in the figure. As the link 558 moves, the lever 557 rotates around the rotation axis 555 against the biasing direction. By the rotation of the rotation shaft 555, the peeling claw 556 rotates around the rotation shaft 555 in the direction of arrow D in the figure. That is, the peeling means 55 operates the movable guide 553 and the peeling claw 556 in synchronization with the rotation of the drive shaft 551.

  A series of operations of the peeling means 55 will be described with reference to FIGS. 5A to 5D.

  As shown in FIG. 5A, the peeling means 55 is retracted from the carry-in surface 5d so that the peel claw 556 is substantially parallel to the carry-in surface 5d, and the movable guide 553 overlaps the upper end portions P2U on the carry-out surface 5e. In a state where the upper end portion P2U of the stacked paper P2 is held, it waits for the paper P2 to be carried to the lowest position. The sheet P2 on the carry-out surface 5e is carried out at the timing when the peeling means 55 is on standby and the second plate cylinder 71 of the second printing unit 7 is at a predetermined position. That is, the standby movable guide 553 guides the conveyance of the paper P2 to the pickup roller pair 61.

  The peeling means 55 rotates the drive shaft 551 in the direction of arrow A in the figure by the drive means (not shown) substantially simultaneously with the paper P2 being carried to the lowest position. Due to the rotation of the drive shaft 551, the movable guide 553 starts to move in a substantially unloading direction indicated by an arrow B in the figure.

  As shown in FIG. 5B, rotation of the drive shaft 551 in the direction of arrow A in the drawing causes the outer peripheral surface 552a of the cam 552 to contact the link 558 and the peeling claw 556 rotates in the direction of arrow B in the drawing via the lever 557. Projecting on the carry-in surface 5d. When the peeling claw 556 protrudes on the carry-in surface 5d, the upper end portion P2U of the paper P2 is peeled from the carry-in surface 5d.

  As shown in FIG. 5C, when the drive shaft 551 further rotates, the peeling claw 556 further protrudes on the carry-in surface 5d, and the movable guide 553 moves in the substantially carry-out direction and then moves upward and in the substantially carry-in direction. Further, when the equal circular portion of the outer peripheral surface 552a abuts on the lever 557, the separation claw 556 protruding on the carry-in surface 5d is stopped in a protruding state.

  After the movable guide 553 has moved in the substantially unloading direction, the movable guide 553 is moved upward in the vicinity of the loading surface 5d and in the substantially loading direction, so that the movable guide 553 is peeled off by the peeling claw 556 and moved downward. Is entered between the carry-in surface 5d and the upper end P2U of the paper P2. This restricts the upper end portion P2U of the paper P2 from returning again to the carry-in surface 5d due to the thickness of the paper P2, curling due to curling, and the airflow in the storage unit 5. By restricting the upper end portion P2U of the paper P2 from returning to the carry-in surface 5d again, the collision between the next paper P2 to be carried in and the upper end portion P2U of the paper P2 returning to the carry-out surface 5e can be avoided.

  As shown in FIG. 5D, when the drive shaft 551 further rotates, the outer peripheral surface 552a of the cam 552 is separated from the link 558, and the link 558 urged by a spring (not shown) returns to the original position in the direction of arrow A in the figure. Accordingly, the peeling claw 556 starts moving again toward the loading surface 5d side in the direction of arrow B in the figure, and the movable guide 553 moved upward to the vicinity of the loading surface 5d is indicated by the arrow C in the figure. It moves downward on the unloading surface 5e side shown. At this time, the movable guide 553 forcibly moves the upper end portion P2U of the paper P2 toward the carry-out surface 5e.

  Here, as described above, when the sheet P2 tries to return to the carry-in surface 5d again due to the thickness of the sheet P2, curling, or the airflow in the storage unit 5, the peeling unit 55 is configured to remove the sheet P2. The upper end P2U may be pressed and moved. However, when the paper P2 does not return to the carry-in surface 5d and moves to the carry-in surface 5d by its own weight, there is no need to press the paper P2. Any sheet that moves while restricting the return of the sheet P2 to the carry-in surface 5d may be used.

  As shown in FIG. 5A again, the peeling means 55 is retracted from the loading surface 5d so that the peeling claw 556 is substantially flat with respect to the loading surface 5d, and the movable guide 553 overlaps the upper end portions P2U on the loading surface 5e. Thus, the upper end portion P2U of the stacked paper P2 is held. The peeling means 55 has a specific operation cycle of about 0.6 seconds, of which about 0.5 seconds is in a standby state, and performs a series of operations in the remaining about 0.1 seconds.

  Refer to FIG. 2 again. The second transporting unit 56 carries out the paper P2 on the carry-out surface 5e from the storage unit 5 to the re-feeding unit 6.

  The second transporting unit 56 is different from the first transporting unit 51 in that the housing 561 is fixed to the support plate 5a and the sheet P2 does not need to be forcibly separated from the carry-out surface 5e. However, other configurations are substantially the same as those of the first transport unit 51, and detailed description thereof is omitted.

  The second conveying means 56 moves the paper P2 on the carry-out surface 5e on the carry-out surface 5e at the timing when a second plate cylinder 71 of the second printing unit 7 described later is at a predetermined position, and carries it out from the storage unit 5. . The operation of carrying out the paper P2 is substantially the same as that of the first transport unit 51, and the detailed description thereof is omitted.

  A description will be given with reference to FIG. 1 again. The refeed unit 6 refeeds the stored paper P2 to the second printing unit 7.

  The configuration of the refeed unit 6 will be described. The refeed unit 6 includes a pickup roller pair 61 that picks up the paper P2 carried out from the storage unit 5, and a timing roller pair 62 that feeds the picked up paper P2 to the second printing unit 7 at a predetermined timing. .

  The operation of the refeed unit 6 will be described. The pickup roller pair 61 sequentially picks up the paper P2 carried out from the second conveying means 56, and the timing roller pair 62 sends the picked up paper P2 to the second printing unit 7 at a predetermined timing.

  The second printing unit prints on the other surface of the stored paper P2. The configuration and operation of the second printing unit 7 are the same as those of the first printing unit 3, and detailed description thereof is omitted.

  The paper discharge unit 8 discharges the paper P3 on which the other side is printed.

  The configuration of the paper discharge unit 8 will be described. The paper discharge unit 8 includes a paper discharge conveyance unit 81 that conveys the paper P3 printed on the other side by the second printing unit 7, and a paper discharge table 82 that is provided on the side of the apparatus main body 11 and stacks the paper P3. Consists of The paper discharge conveying means 81 includes a driving roller 81a, a driven roller 81b, a conveying belt 81c, and a suction fan 81d.

  The operation of the paper discharge unit 8 will be described. When the paper P3 printed on the other side by the second printing unit 7 is supplied onto the transport belt 81c, the paper discharge unit 8 sucks and transports the paper P3 by the suction fan 81d and stacks it on the paper discharge table 82.

  The overall operation of the duplex printing apparatus 1 will be described. The paper feeding unit 2 feeds the unprinted paper P1 to the first printing unit 3, and the first printing unit 3 prints on one side of the paper P1. The reversing unit 4 inverts the paper P2 and conveys it to the storage unit 5 so that one side of the printed paper P2 faces downward.

  In the storage unit 5, the first transport unit 51 sucks and transports the sheet P <b> 2 to the lowermost position with one side of the sheet P <b> 2 facing down. At this time, the curl imparting means 52 imparts a curl that is curved with the printed one side inward to the paper P2.

  The lower end portion P2L of the paper P2 carried to the lowest position is held by the holding and moving means 53 and held and moved toward the carry-out surface 5e. The upper end portion P2U of the paper P2 is removed from the carry-in surface 5d by the peeling means 55. While being peeled off, it is regulated not to return to the carry-in surface 5d again.

  The second transport means 56 carries out the paper P2 on the carry-out surface 5e from the storage unit 5 to the refeed unit 6, and the refeed unit 6 refeeds the paper P2 to the second printing unit 7 at a predetermined timing. To do. The second printing unit 7 prints on the other side of the paper P2, and the paper discharge unit 8 discharges the paper P3 on which the other side is printed. Specifically, the duplex printing apparatus 1 can print one side and the other side of the paper P1 in a cycle of about 100 sheets per minute.

  In the present embodiment, the double-sided printing apparatus 1 has been described as a double-sided stencil printing apparatus. However, the present invention is not limited to this, and an inkjet printer or the like that can print on one side and the other side of an unprinted paper P1. It doesn't matter.

  As described above, according to the double-sided printing apparatus 1 according to the embodiment of the present invention, the holding and moving unit 53 holds the lower end portion P2L of the paper P2 and moves from the carry-in surface 5d toward the carry-out surface 5e, and peels off. The means 55 peels off the upper end portion P2U of the paper P2 from the carry-in surface 5d, and restricts the upper end portion P2U from returning to the carry-in surface 5d again, so that the paper P2 carried into the lowermost position in the storage portion 5 is removed. Once the paper P2 has been peeled off, the paper P2 can be reliably peeled off from the carry-in surface 5d even if it is about to return to the carry-in surface 5d due to the thickness of the paper, curling, or the airflow in the storage unit 5. This makes it possible to avoid a collision between sheets P2 that are sequentially carried in.

  In addition, the duplex printing apparatus 1 is configured such that the waiting peeling unit 55 holds the upper end portion P2U of the paper P2 stacked with the upper end portions P2 overlapping each other on the carry-out surface 5e. When the sheet P2 is carried out, it is not necessary to provide a dedicated guide to the sheet refeeding unit 6, and the peeling unit 55 can guide the sheet P2 to the sheet refeeding unit 6.

  Further, the duplex printing apparatus 1 enters between the peeling claw 556 for peeling the upper end portion P2U of the paper P2 from the carry-out surface 5d and the upper end portion P2U of the paper P2 and the carry-in surface 5d, and the upper end portion P2U is placed on the carry-out surface 5e side. The sheet P2 can be reliably peeled off from the carry-in surface 5d by a simple mechanism with the movable guide 553 that is moved to and held in the vicinity of the carry-out surface 5e.

  Further, in the double-sided printing device 1, the storage unit 5 inclines the carry-in surface 5d and includes the carry-out surface 5e obliquely below the carry-in surface 5d, so that each sheet P2 is inclined to bring the inside of the storage unit 5 into the carry-out surface 5e. Even if the upper end P2U of the paper P2 falls to the carry-out surface 5e side by its own weight during the movement, the paper P2 can be reliably peeled from the carry-in surface 5d.

  The duplex printing apparatus 1 has a structure in which the holding and moving means 53 holds each sheet P2 in the storage unit 5 in a state of being curled so that the printed surface of each sheet P2 is curved inward. Even when the paper P2 is curled back to the carry-in surface 5d side by curling, the paper P2 can be reliably peeled from the carry-in surface 5d.

  Further, in the double-sided printing apparatus 1, the storage unit 5 is above the carry-out surface 5e, and the distance between the upper end of the carry-in surface 5d and the upper end of the carry-out surface is such that the lower end of the carry-in surface 5d and the lower end of the carry-out surface 5d are By disposing the support plate 5a and the cover plate 5c so as to be shorter than this distance, it is possible to avoid that the moving time of the upper end portion P2U is later than the moving time of the lower end portion P2L, and in the device housing 11 Space can be saved.

P1, P2, P3 Paper P2L Lower end part P2U Upper end part 1 Double-sided printing device 3 First printing part 5 Storage part 5d Carry-in surface 5e Carry-out surface 7 Second printing part 51 First conveying means 52 Curl applying means 53 Holding and moving means 55 Peeling Means 56 Second conveying means 553 Movable guide 556 Peeling claw

Claims (6)

A first printing unit that prints on one side of the paper, a second printing unit that prints on the other side of the paper, and a paper printed by the first printing unit is loaded and stored, and then to the second printing unit A double-sided printing device comprising a storage unit for carrying out,
The reservoir is
A carry-in surface on which the paper moves upon loading;
A carry-out surface that is arranged at a predetermined interval from the carry-in surface, and on which the paper moves when the carry-out is performed;
First conveying means for carrying the paper on the carry-in surface to the lowest position in the storage unit;
Second conveying means for carrying out the paper on the carry-out surface from the storage unit;
Holding and moving means for sequentially holding the lower end portions of the respective sheets sequentially carried to the lowermost position and moving the respective sheets to the unloading surface side in a state where the lower end portions have a predetermined gap with each other;
Double-sided printing comprising: peeling means for peeling off an upper end portion of the paper carried to the lowermost position from the carry-in surface and restricting the upper end portion from returning to the carry-in surface again. apparatus.   The peeling means peels the upper end portion of the sheet at the lowermost position from the carry-in surface, moves the upper end portion to the carry-out surface side, and overlaps the upper end portions on the carry-out surface. 2. The double-sided printing apparatus according to claim 1, wherein The peeling means is
A peeling claw that protrudes on the carry-in surface and peels the upper end of the paper from the carry-in surface;
2. A movable guide that is interposed between the carry-in surface and the peeled upper end, moves the upper end toward the carry-out surface, and holds the movable guide near the carry-out surface. Or the double-sided printing apparatus of 2. The storage section inclines the carry-in surface and includes the carry-out surface obliquely below the carry-in surface;
The double-sided printing apparatus according to any one of claims 1 to 3, wherein the holding and moving unit is configured to incline each sheet and move the inside of the storage unit toward the carry-out surface side.   The said holding | maintenance movement means hold | maintains each said sheet | seat in the said storage part in the state curled so that the said one surface of each said sheet | seat might become inward. On both sides printing device.   The carry-in surface is above the carry-out surface, and the distance between the upper end of the carry-in surface and the upper end of the carry-out surface is shorter than the distance between the lower end of the carry-in surface and the lower end of the carry-out surface. The double-sided printing apparatus according to any one of claims 1 to 5.

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