JP2015042460A - Stencil printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid collision between paper rear end of first paper and a paper tip end of second paper at the time of paper discharge, relating to an image formation device which employs a double speed printing mode.SOLUTION: A stencil printing device includes an upper side paper sucking transportation device 7 and a lower side paper sucking transportation device 9 arranged to sandwich a transportation path in vertical direction, and a switching member 10 for switching to make a tip end of paper 8 advance either to the upper side paper sucking transportation device 7 or to the lower side paper sucking transportation device 9 arranged on the upper side and the lower side. Control means 21 is provided which, during operation in the double speed printing mode, controls operation of the switching means so that first paper 4a and second paper 4b are made to advance to the upper side paper sucking transportation device of the transportation path.

Description

  The present invention relates to a stencil printing apparatus having a double speed printing mode.

  In order to speed up the stencil printing apparatus, there is a so-called “double speed printing mode”. In the stencil printing machine, one sheet is fed per one rotation of the plate cylinder and printed on it. For example, if the rotation speed of the plate cylinder is 120 rpm, the printing speed is 120 sheets / minute. On the other hand, in the “double speed printing mode”, images on two sides are made side by side on a stencil sheet of one plate, and two sheets are fed per one rotation of the plate cylinder. Thereby, if the rotational speed of the plate cylinder is 120 rpm, the printing speed is as high as 240 sheets / minute.

  Japanese Patent Application Laid-Open No. 2004-260688 has an image forming apparatus having a two-stage upper and lower discharge tray, and has two suction conveyance units at the top and bottom, and a switching claw for switching which adsorption conveyance unit is to be conveyed upstream. Is disclosed. When this is applied to an image forming apparatus having a double speed printing mode, if the first sheet is discharged from the lower discharge port and the second sheet is discharged from the upper discharge port, the two sheets collide. Can be avoided.

  However, in the double speed printing mode, as described above, two images are made side by side on one stencil sheet, and two sheets are continuously fed with respect to one rotation of the drum and printed on the two sheets. The distance between the trailing edge of the first sheet and the leading edge of the second sheet becomes extremely narrow. As a result, there arises a problem that when the sheet is discharged, the leading edge of the second sheet collides with the trailing edge of the first sheet at the sheet discharge platform, resulting in a sheet discharge jam.

  Moreover, since the thing of patent document 1 has two or more paper discharge stands, in addition to incurring cost, the installation space must be taken widely. In addition, when it is desired to sequentially discharge the sheets from the same discharge port, a phenomenon may occur in which the rear end of the first sheet collides with the front end of the second sheet. The problem of rear-end jam in continuous discharge of paper from the same paper discharge port still remains.

  The present invention has been made in view of the above points. The present invention is an image forming apparatus that employs a double-speed printing mode, in which the trailing edge of the first sheet and the leading edge of the second sheet are discharged. An object of the present invention is to provide a stencil printing apparatus capable of avoiding a collision.

  A stencil printing apparatus according to the present invention includes a stencil plate making unit that performs plate making on a stencil sheet according to document image information, a paper feed unit that separates and feeds stacked sheets one by one from the upper side, A printing unit that presses the formed paper against a rotationally driven cylindrical plate cylinder to form a printed image on the paper, and a paper discharge conveyance unit that peels and conveys the image-formed paper from the plate cylinder And two sheets of paper are continuously fed for one rotation of the plate cylinder on which a two-sided stencil stencil sheet in which two images are stenciled on one stencil stencil sheet is mounted. In the stencil printing apparatus capable of performing an operation in a double speed printing mode for printing on a sheet, the paper discharge transport unit includes an upper paper suction transport device and a lower paper suction transport device arranged with a transport path sandwiched in the vertical direction. , The front end of the paper is arranged on the upper side and the lower side Switching means for switching to either the side paper suction transport device or the lower paper suction transport device, and when operating in the double speed printing mode, the first paper and the second paper A stencil printing apparatus, comprising: a control unit configured to control the operation of the switching unit so as to direct the progress of the sheet toward the upper sheet adsorbing and conveying apparatus in the conveying path.

  According to the present invention, not only the lower part of the suction conveyance path but also the upper part, the paper suction conveyance apparatus is installed, the suction conveyance path is sandwiched between the two paper adsorption conveyance apparatuses, and the first sheet is conveyed to the lower part, When transporting the second sheet, a difference in height is generated between the sheets by being attracted to the upper part. As a result, the second sheet is discharged in a state of being lifted from the first sheet at the time of discharging, and collision can be avoided. A height difference can be generated between the first sheet and the second sheet at the time of paper discharge, and the rear-end collision of the second sheet can be avoided.

It is sectional drawing which shows the structure of the stencil printing apparatus which concerns on embodiment of the stencil printing apparatus which concerns on this invention. It is a disassembled perspective view which shows the structure of the upper sheet | seat adsorption | suction conveyance apparatus of the same stencil printing apparatus. It is sectional drawing which shows the adsorption conveyance path of the same stencil printing apparatus. It is sectional drawing which shows the adsorption conveyance path of the stencil printing apparatus which concerns on Embodiment 2 of the stencil printing apparatus which concerns on this invention. It is sectional drawing which shows the adsorption conveyance path of the stencil printing apparatus which concerns on Embodiment 3 of the stencil printing apparatus which concerns on this invention. It is sectional drawing which shows the adsorption conveyance path of the stencil printing apparatus which concerns on Embodiment 5 of the stencil printing apparatus which concerns on this invention. It is a perspective view which shows the U-shaped formation auxiliary member of the stencil printing apparatus which concerns on Embodiment 5 of the stencil printing apparatus which concerns on this invention.

  A stencil printing apparatus according to an embodiment for carrying out the present invention will be described. A stencil printing apparatus according to an embodiment of the present invention has the following characteristics when a sheet is sucked and conveyed in a double speed printing mode using a two-sided stencil sheet. That is, a sheet suction conveyance device is provided above and below the suction conveyance unit, the first sheet is conveyed by the lower sheet adsorption conveyance device, the subsequent second sheet is conveyed by the upper sheet adsorption conveyance device, and is discharged. Sometimes the second sheet is discharged in a state where it floats above the first sheet. Thereby, the collision of both can be prevented.

<Embodiment 1>

  Hereinafter, a stencil printing apparatus according to Embodiment 1 of the stencil printing apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of a stencil printing apparatus according to Embodiment 1 of the stencil printing apparatus according to the present invention. The basic structure of a stencil printing apparatus is well known.

  This stencil printing apparatus includes an image reading unit 1, a stencil plate making unit 2, a printing unit 3, a plate discharging unit 4, a paper feeding unit 5, a paper discharge conveying unit 6, and the like. The image reading unit 1 includes a certification device and an image reading sensor, and reads image information of a document. The stencil plate making unit 2 performs perforating plate making on the stencil sheet according to the document image information. The printing unit 3 includes a cylindrical plate cylinder 3a around which a stencil original made by stencil is wound, and forms a print image with ink that oozes from a perforation part of the stencil original. The paper feed unit 5 separates and feeds the stacked paper 8 one by one from the upper side. The paper discharge conveyance unit 6 is provided with a tray on which the paper 8 on which an image has been formed is discharged and on which the paper 8 that has been printed and discharged is placed. On the conveyance path of the paper 8 from the printing unit 3 to the paper discharge conveyance unit 6, there is provided an upper paper suction conveyance device 7 that adsorbs the printed paper 8 and conveys it toward the paper discharge conveyance unit 6. ing.

  In the stencil printing apparatus according to the first embodiment, a lower sheet suction conveyance device 9 having the same mechanism is newly provided at the upper part of the upper side of the upper sheet suction conveyance device 7 and is sandwiched in the vertical direction. The upper sheet adsorbing and conveying apparatus 7 and the lower sheet adsorbing and conveying apparatus 9 sandwich the conveying path, and the sheet 8b, which is the succeeding sheet of the sheet 8a, is discharged to the discharge conveying section 6 while being adsorbed on the upper part of the conveying path. Hereinafter, in the double speed printing mode, when the drum is rotated once, the first sheet to be fed continuously is referred to as the sheet 8a, the second sheet 8b, and the case where the order is not distinguished is referred to as the sheet 8.

  Further, a switching member 10 is arranged as a switching means for directing the progress of the paper 8b toward the lower paper suction conveyance device 9. The switching member 10 is a plate-like member that moves up and down and has a lateral width corresponding to the width of the conveyance path. Note that the switching member 10 may be a claw member arranged in a shape orthogonal to the paper transport direction. In this stencil printing machine, two sheets of paper are continuously fed with respect to one rotation of the plate cylinder 3a on which a two-sided stencil stencil sheet on which two images are stenciled on one stencil sheet is mounted. Can operate in double-speed printing mode to print on these two sheets

  FIG. 2 is an exploded perspective view showing the configuration of the upper sheet adsorbing and conveying apparatus of the stencil printing apparatus. Here, the basic structure of the upper sheet adsorbing and conveying apparatus 7 is well known. The upper sheet suction conveyance device 7 includes a sheet conveyance belt 11, a guide plate 12, a jump table 13, a duct 14, a bracket 15, and a fan 16. The paper transport belt 11 is rotationally driven along the transport direction of the paper 8 at a speed corresponding to the printing speed, and three paper transport belts 11 are arranged. The guide plate 12 is a member that guides the paper 8, and has a large number of openings for applying an adsorption force to the paper 8 being conveyed. The jump tables 13 are disposed on both sides of the upper side of the guide plate 12 and in the direction orthogonal to the conveyance direction of the paper 8. The duct 14 is disposed below the guide plate 12 and the paper transport belt 11.

  When the fan 16 is driven, an adsorbing force (negative pressure) acts on the paper 8 conveyed from the printing unit 3 onto the upper paper adsorbing and conveying device 7, and the paper 8 is adsorbed on the paper conveying belt 11. Then, it is conveyed to the paper discharge conveyance unit 6. The lower sheet suction conveyance device 9 is disposed with the suction conveyance path interposed therebetween, and has the same configuration as the upper sheet suction conveyance device 7. However, the lower sheet suction conveyance device 9 does not include the jump table 13.

  Next, the operation will be described. FIG. 3 is a cross-sectional view showing the suction conveyance path of the stencil printing apparatus. In this stencil printing apparatus, during the operation in the double speed printing mode, the switching member 10 discriminates the paper 8a and the paper 8b based on the rotation angle from the home position of the plate cylinder 3a of the printing unit 3 and is driven up and down. . The switching member 10 is raised at a timing before the leading edge of the paper 8a reaches the switching member 10, and then the rear end of the paper 8a passes through the switching member 10 and before the leading edge of the paper 8b reaches the switching member 10. The switching member 10 is lowered at the timing. At the same time, the lower sheet suction conveyance device 9 is driven. The control of the switching member 10 is performed by the control means 21. The control means 21 includes a motor or the like that drives the switching member 10 and drives the switching member 10 under certain conditions.

  The sheet 8 a passing under the switching member 10 is conveyed by the sheet conveying belt 11 a while being attracted to the lower portion of the conveying path by the upper sheet adsorbing and conveying device 7 that is always driven, and the subsequent sheet 8 b is picked up by the switching member 10. It progresses to the upper part of the conveyance path. Further, the sheet is conveyed by the sheet conveying belt 11b while being attracted to the upper portion of the conveying path by the lower sheet adsorbing and conveying device 9. At this time, the upper sheet adsorbing and conveying apparatus 7 remains driven, but the sheet 8b advances to the upper part of the conveying path by the switching member 10 and is adsorbed by the lower sheet adsorbing and conveying apparatus 9. It will not be attracted.

  At the timing when the paper 8b passes through the lower paper suction conveyance device 9, the lower paper suction conveyance device 9 stops. In this way, the paper 8a is discharged by the upper paper suction conveyance device 7 and the subsequent paper 8b is discharged by the lower paper suction conveyance device 9, so that there is a difference in height between the paper 8a and the paper 8b, and the collision between the two occurs. Can be avoided.

<Embodiment 2>
Next, a stencil printing apparatus according to Embodiment 2 of the stencil printing apparatus according to the present invention will be described. FIG. 4 is a cross-sectional view showing the suction conveyance path of the stencil printing apparatus according to Embodiment 2 of the stencil printing apparatus according to the present invention. In the stencil printing apparatus according to the second embodiment, as a switching means for directing the progress of the paper 8b to the lower paper suction conveyance device 9, a line is formed on the conveyance path perpendicular to the paper conveyance direction as shown in FIG. A plurality of air knives 18 are used. When the paper 8 b is conveyed from the printing unit 3, air is jetted from the air knife 18 to lift the paper 8 b and advance it toward the lower paper suction conveyance device 9.

  The air knife 18 is controlled based on the rotation angle of the plate cylinder 3a as in the first embodiment. The air knife 18 discriminates between the paper 8a and the paper 8b based on the rotation angle from the home position of the plate cylinder 3a of the printing unit 3 and performs a discharge operation. When the leading edge of the paper 8a reaches the air knife 18, the air knife 18 is stopped, and then the timing before the trailing edge of the paper 8a passes through the air knife 18 and the leading edge of the paper 8b reaches the air knife 18. Then, the air knife 18 is discharged. At the same time, the lower sheet suction conveyance device 9 is driven.

  The paper 8a passing through the air knife 18 is transported by the paper transport belt 11a while being attracted to the lower part of the transport path by the upper paper suction transport device 7 that is always driven. The subsequent paper 8b travels to the upper part of the transport path in a form blown up by the air knife 18, and is transported by the paper transport belt 11b while being sucked to the upper part of the transport path by the lower paper suction transporting device 9. At this time, the upper sheet adsorbing and conveying apparatus 7 remains driven, but the sheet 8b advances to the upper part of the conveying path by the air knife 18 and is adsorbed by the lower sheet adsorbing and conveying apparatus 9. It will not be attracted.

  At the timing when the paper 8b passes through the lower paper suction conveyance device 9, the lower paper suction conveyance device 9 stops. In this way, the paper 8a is discharged by the upper paper suction conveyance device 7 and the subsequent paper 8b is discharged by the lower paper suction conveyance device 9, so that a height difference is generated between the paper 8a and the paper 8b, and the two collisions occur. Can be avoided.

<Embodiment 3>
Next, a stencil printing apparatus according to Embodiment 2 of the stencil printing apparatus according to the present invention will be described. FIG. 5 is a cross-sectional view showing the suction conveyance path of the stencil printing apparatus according to Embodiment 3 of the stencil printing apparatus according to the present invention. In the stencil printing apparatus according to the fifth embodiment, a fan 16c provided on the upstream side of the fan 16a of the upper sheet suction conveyance device 7 is used as a switching unit. When the paper 8 b is conveyed from the printing unit 3, air is discharged from the fan 16 c to lift the paper 8 b and advance it toward the lower paper suction conveyance device 9.

  The fan 16c is controlled based on the rotation angle of the plate cylinder 3a as in the first and second embodiments. The fan 16c discriminates between the paper 8a and the paper 8b based on the rotation angle from the home position of the plate cylinder 3a of the printing unit 3, and performs the discharge operation and the suction operation. When the leading edge of the paper 8a reaches the fan 16c, the fan 16c performs a suction operation, and then the fan 16c is moved at a timing before the trailing edge of the paper 8a passes through the fan 16c and the leading edge of the paper 8b reaches the fan 16c. Discharge operation is performed. At the same time, the lower sheet suction conveyance device 9 is driven.

  The paper 8a sucked and transported by the fan 16c is transferred to the fan 16a that is always sucked and transported by the paper transport belt 11a while being sucked to the lower part of the transport path. The succeeding paper 8b advances to the upper part of the transport path in a form blown up by the fan 16c, and is transported by the paper transport belt 11b while being attracted to the upper part of the transport path by the lower paper suction transporting device 9. At this time, the fan 16a remains sucked, but the paper 8b advances to the upper part of the transport path by the fan 16c and is sucked by the lower paper suction / conveyance device 9, so that it is not attracted to the upper paper suction / conveyance device 7.

  At the timing when the paper 8b passes through the lower paper suction conveyance device 9, the lower paper suction conveyance device 9 stops. In this way, the paper 8a is discharged by the upper paper suction conveyance device 7 and the subsequent paper 8b is discharged by the lower paper suction conveyance device 9, so that a height difference is generated between the paper 8a and the paper 8b, and the two collisions occur. Can be avoided.

<Embodiment 4>
The control of the switching means can be performed based on the reflection type paper detection sensor 19 provided upstream from the suction conveyance path without being based on the rotation angle of the plate cylinder 3a. Switching means (switching member 10, air knife 18, fan 16 c) and lower sheet suction / conveyance device 9 are changed from ON to OFF by the reflection type sheet detection sensor 19 passing through the rear end of the sheet 8 a or the rear end of the sheet 8 b. Control to change the state only when When the leading edge of the paper 8a or the leading edge of the paper 8b changes from OFF to ON, the switching unit and the lower paper suction / conveyance device 9 are controlled to maintain the current state.

  Hereinafter, an embodiment using the reflection type paper detection sensor 19 in the switching member 10 will be described. In FIG. 3, when the paper 8a is conveyed from the printing unit 3, the reflection type paper detection sensor 19 is changed from the OFF state to the ON state by the arrival of the leading end of the paper 8a. Here, when switching from the OFF state to the ON state, the switching member 10 and the lower sheet suction conveyance device 9 are controlled to maintain the current switching state, so the switching member 10 maintains the raised state (initial position). To do. In addition, the lower sheet adsorbing and conveying apparatus 9 also maintains the stopped state, and the sheet 8a passes under the switching member 10 and is adsorbed to the lower part of the conveying path by the upper sheet adsorbing and conveying apparatus 7 that is always driven. Is conveyed by the sheet conveying belt 11a.

  When the rear end of the paper 8a passes and the reflective paper detection sensor 19 changes from the ON state to the OFF state, the state of the switching member 10 and the lower paper suction conveyance device 9 is controlled to change. Then, the switching member 10 is lowered, and the lower sheet suction / conveyance device 9 is driven. Immediately after, the leading edge of the paper 8b conveyed from the printing unit 3 reaches the reflection type paper detection sensor 19, but the switching member 10 and the lower paper suction / conveyance device 9 are present at the change from the OFF state to the ON state. The state is maintained. Then, the paper 8b travels to the upper part of the transport path while being scooped up by the switching member 10, and is transported by the paper transport belt 11b while being attracted to the upper part of the transport path by the lower paper suction / conveyance device 9. At this time, the upper sheet suction / conveyance device 7 remains driven, but the paper 8b advances to the upper part of the transport path by the switching member 10 and is attracted to the lower paper suction / conveyance device 9, so that it is attracted to the upper sheet suction / conveyance device 7. There is nothing.

  When the rear end of the paper 8b passes and the reflective paper detection sensor 19 is turned from ON to OFF, the switching member 10 is raised, the lower paper suction conveyance device 9 is stopped, and the first paper at the next rotation is the upper paper The process proceeds to the sheet suction conveyance device 7. In this way, the paper 8a is discharged by the upper paper suction conveyance device 7 and the subsequent paper 8b is discharged by the lower paper suction conveyance device 9, so that a height difference is generated between the paper 8a and the paper 8b, and the two collisions occur. Can be avoided.

  The state is changed when the reflection type paper detection sensor 19 is turned from ON to OFF because the switching member 10 is operated when the leading edge of the paper 8b reaches the reflection type paper detection sensor 19. This is because switching may not be in time. If switching is in time, there is no problem with control that changes the state from OFF to ON.

  A similar sensor detection method is used when the air knife 18 or the fan 16c is used. 4 and 5, the reflection type paper detection sensor 19 changes from the OFF state to the ON state by the arrival of the leading edge of the paper 8a. In this case, the air knife 18 remains stopped, and the fan 16c maintains the suction operation. The lower sheet suction conveyance device 9 also maintains the stopped state. As a result, the sheet 8 a is conveyed by the upper sheet suction conveyance device 7.

  When the rear end of the paper 8a passes through the reflection type paper detection sensor 19 and changes from the ON state to the OFF state, the air knife 18 changes to the discharge operation, and the fan 16c also changes to the discharge operation. Drive. As a result, the succeeding paper 8 b is blown up to the upper part of the transport path and is transported by the lower paper suction transport device 9. Note that the state of the air knife 18, the fan 16c, and the lower sheet suction conveyance device 9 does not change when the reflective sheet detection sensor 19 changes from the OFF state to the ON state due to the arrival of the leading end of the sheet 8b.

<Embodiment 5>
Next, a stencil printing apparatus according to Embodiment 5 of the stencil printing apparatus according to the present invention will be described. 6 is a cross-sectional view showing a suction conveyance path of a stencil printing apparatus according to Embodiment 5 of the stencil printing apparatus according to the present invention, and FIG. 7 is a U-shape of the stencil printing apparatus according to Embodiment 5 of the stencil printing apparatus according to the present invention. It is a perspective view which shows a formation auxiliary member. The paper 8a discharged by the upper paper suction conveyance device 7 is seated in a U shape by a jump base 13 which is a known mechanism, and is discharged without causing the paper to shake. A mechanism such as a jump table 13 cannot be installed in the lower sheet suction conveyance device 9 due to its structure. For this reason, the guide plate 12b around the paper transport belt 11b and both ends of the side surface of the duct 14b stored in the guide plate 12b are refracted at an elevation angle. Thereby, both ends of the paper 8b sucked by the lower paper suction / conveying device 9 can be seated in a U-shape, and the same effect as the jump table 13 can be obtained.

  However, there is a possibility that the left and right ends of the sheet in the traveling direction cannot be adsorbed and the U-shape is not formed. For this reason, U-shaped auxiliary members 20 (see FIGS. 6 and 7) for guiding both side portions of the discharged paper are installed on the side surface of the lower paper suction conveyance device 9, that is, on both side surfaces of the guide plate 12. . The U-shaped auxiliary member 20 is a member that includes a bottom surface portion 20a and an elevation surface portion 20b.

  As shown in FIG. 7, the U-shaped auxiliary member 20 is formed by reducing the size of the bottom surface portion 20a on the printing unit 3 side in the paper width direction, and the dimension between the U-shaped auxiliary members 20 and 20 on both sides (digging). To make it easier to accept paper. Then, as it approaches the sheet delivery / conveying unit 6 side, the dimension (drilling) between the U-shaped auxiliary members 20 and 20 on both sides is narrowed. With this configuration, the left and right ends of the paper 8b in the advancing direction are pressed against the guide plate 12b, thereby making the paper 8b more surely U-shaped.

<Embodiment 6>
Next, a stencil printing apparatus according to Embodiment 6 of the stencil printing apparatus according to the present invention will be described. In the stencil printing apparatus according to the sixth embodiment, the speed of the paper transport belt 11a is made slightly slower than the speed of the paper transport belt 11b. As a result, the trailing edge of the paper 8a and the leading edge of the paper 8b overlap from the point of conveyance (reference numeral 17 in FIG. 3). Thereby, both collision avoidance rates at the time of discharge can be further increased.

  Conversely, by making the speed of the paper transport belt 11b slightly slower than the speed of the paper transport belt 11a, the distance from the rear end of the paper 8a to the front end of the paper 8b is increased, and collision between the two is less likely to occur during ejection. Become. When the speed of the paper transport belt 11b is decreased, the transport speed of the paper 8b is decreased. However, since there is a sufficient interval to the first sheet at the time of the next printing, there is no problem even if the first sheet at the time of the next printing is conveyed at a normal timing, and the conveyance of the sheet 8b is delayed. There is no impact on overall productivity.

<Embodiment 7>
Next, a stencil printing apparatus according to Embodiment 7 of the stencil printing apparatus according to the present invention will be described. In each of the above-described embodiments, the present invention avoids the collision between the two sheets at the time of discharge by newly providing the lower sheet suction conveyance device 9 and dividing the conveyance path of the two sheets in the upper and lower directions in the double speed printing mode. In the stencil printing apparatus according to the seventh embodiment, in addition to the operations of the respective embodiments, when the normal single-sided printing mode that is not the double speed printing mode is executed, the fan 16b of the lower sheet suction conveyance device 9 is rotated in the reverse direction. Thus, air is always discharged from the fan 16b toward the paper. As a result, it is possible to apply wind to the printing surface of the paper conveyed by the upper paper suction conveyance device 7 and to promote drying of the ink.

  Further, even in the double speed printing mode, the fan 16b is operated in the same manner when there is no possibility that the paper 8a and the paper 8b collide, that is, when the paper 8b does not need to be transported by the lower paper suction transport device 9. Can do. This is a case where a sufficient interval between the image on the first side and the image on the second side can be secured, such as when printing a small-size image. The fan 16b of the lower paper suction conveyance device 9 can be rotated in the reverse direction to always perform the discharge operation, and air can be applied to the printing surface of the paper conveyed by the upper paper suction conveyance device 7 to promote the drying of the ink.

1: image reading unit 2: stencil plate making unit 3: printing unit 3a: plate cylinder 4: plate discharging unit 5: paper feeding unit 6: paper discharging unit 7: upper paper suction conveyance device 8: paper 8a: paper 8b: paper 9: Lower sheet suction conveying device 10: switching member 11: sheet conveying belt 11a: sheet conveying belt 11b: sheet conveying belt 12: guide plate 12b: guide plate 13: jump base 14: duct 14b: duct 15: bracket 16: fan 16a : Fan 16b: Fan 16c: Fan 17: Reference numeral 18 in FIG. 3: Air knife 19: Reflective paper detection sensor 20: U-shaped auxiliary member 21: Control means

JP 2006-015572 A

Claims (10)

A stencil plate making unit that performs piercing and stencil printing on a stencil sheet according to document image information, a paper feed unit that separates and feeds stacked sheets one by one from the upper side, and the fed paper is rotated. A printing unit that presses against a cylindrical plate cylinder to form a printed image on the paper; and a paper discharge conveyance unit that peels and conveys the image-formed paper from the plate cylinder. In double-speed printing mode, two sheets of paper are continuously fed for one rotation of the plate cylinder on which a two-side plate-making stencil sheet with two images arranged side by side is mounted and printed on the two sheets. In a stencil printing apparatus capable of performing operations,
The paper discharge transport unit includes an upper paper suction transport device and a lower paper suction transport device arranged with the transport path sandwiched in the vertical direction,
A switching unit that switches between the upper sheet suction conveyance device and the lower paper suction conveyance device in which the leading end of the paper is disposed on the upper side and the lower side;
Have
Control means for controlling the operation of the switching means so as to direct the progress of the first sheet and the second sheet to the upper sheet suction conveyance device in the conveyance path during the operation in the double speed printing mode; ,
A stencil printing apparatus comprising:   The stencil printing apparatus according to claim 1, further comprising a switching member that moves up and down as the switching unit.   The stencil printing apparatus according to claim 1, further comprising: an air knife that discharges air toward the upper sheet suction conveyance device as the switching unit.   2. The stencil according to claim 1, wherein as the switching unit, a fan is disposed on the upstream side of the lower sheet suction conveyance device, and the advancing direction of the sheet is switched by switching suction and discharge of the fan. Printing device.   5. The upper sheet adsorbing and conveying apparatus includes a guide plate that guides the sheet, and the guide plate includes a shape that seats the conveyed sheet in a U shape. The stencil printing apparatus according to any one of the above.   6. A U-shaped formation assisting member for assisting an operation of guiding both sides of the sheet to be discharged and sitting on the U-shape of the sheet on both side surfaces of the guide plate. 2. A stencil printing apparatus according to 1.   The upper sheet adsorbing and conveying apparatus includes a sheet conveying belt, and the upper sheet adsorbing and conveying apparatus includes a speed of the sheet conveying belt included in the lower sheet adsorbing and conveying apparatus. The stencil printing apparatus according to any one of claims 1 to 6, wherein the stencil printing apparatus is made slower than the speed of the stencil printing machine. The upper paper suction transport device and the lower paper suction transport device include a paper transport belt,
The speed of the paper transport belt provided in the upper paper suction transport device is made slower than the speed of the paper transport belt provided in the lower paper suction transport device. The stencil printing apparatus according to one item. A paper detection sensor is installed on the upstream side of the upper paper suction conveyance device and the lower paper suction conveyance device,
The control means maintains the switching state of the switching means when the paper detection sensor changes from the ON state to the OFF state, and changes the switching state of the switching means when the paper detection sensor changes from the OFF state to the ON state. The stencil printing apparatus according to claim 1, wherein the stencil printing apparatus is changed.   The upper sheet adsorbing / conveying device includes a fan, and when performing normal single-sided printing, the upper sheet adsorbing / conveying device discharges the fan and blows air to the ink of the sheet conveyed by the lower sheet adsorbing / conveying device. The stencil printing apparatus according to any one of claims 1 to 9, wherein: