JP2012062156A - Paper discharge device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper discharge device that prevents paper jams in an image forming apparatus when a preceding paper discharged at high conveyance speed collides with a following paper.SOLUTION: The paper discharge device 16 discharges printing paper 7 from the image forming apparatus 1 to an discharge table 16 includes a collision avoidance means 461 that is provided near a discharge port of the image forming apparatus 1 which discharges the printing paper and that pushes down a rear end portion of the printing paper 7 during discharge. Moreover, the collision avoidance means 461 includes a plurality of rotation bodies 49 with a plurality of fin-shaped members 51 in contact with both edges of the rear end portion of the paper 7 to push down the printing paper 7.

Description

  The present invention relates to a paper discharge device that suppresses jamming of a paper sheet in a paper discharge unit when discharging a paper sheet to be printed at a high conveyance speed, and an image of a printing machine, a copier, or the like using the paper discharge device. The present invention relates to a forming apparatus.

  In general, an image forming apparatus such as a stencil printing apparatus, a printer, a copier, and a facsimile includes an image forming unit that forms an image on a sheet, and a sheet discharge table on which a sheet discharged from the image forming apparatus main body is stacked. In such an image forming apparatus, there is known an image forming apparatus having means for transporting a sheet of paper from an image forming unit to a sheet discharge table. In the paper discharge table, it is necessary to improve the alignment of the sheets to be loaded. For this purpose, the paper sheets conveyed / discharged by the conveying means are collided by the end fence attached to the paper discharge table, or It is generally known that a method of absorbing the impact at that time and naturally descending from a fixed position is effective.

However, when the sheet delivery speed is low, the conventional conveying means has a problem even if the discharged sheets are lowered after being received by the end fence and the sheets are aligned and stacked. Does not occur. On the other hand, when the sheet discharge speed is increased, the conventional conveying means causes a problem of counterclaim.
FIG. 12 is a conceptual diagram illustrating a state of paper discharge of an image forming apparatus including a paper discharge device.
When the sheet discharge speed increases, for example, at a speed of 150 cpm or more, the sheet collides with the end fence of the sheet discharge table, and then descends and is stacked on the sheet discharge table. It takes a certain amount of time to complete. For this reason, the sheet to be discharged next may collide with the rear end portion of the preceding sheet, and the sheets may not be stacked in order or orderly on the sheet discharge table. Alternatively, the next sheet to be discharged may not be discharged and may jam in the discharge device.

Further, the next sheet of the sheet that collided with the end fence is discharged with a sufficient time difference that does not collide with the preceding sheet.
Corresponding to this, Patent Document 1 is disclosed as means for lowering discharged sheets more efficiently and at high speed.
In Patent Document 1, the sheet pile is formed by stacking sequentially while increasing the descending speed of the sheets by blowing an air current on the upper surface of the sheets sequentially discharged from the printing apparatus. An airflow blowing structure of a paper discharge device, wherein the airflow is blown substantially vertically toward a substantially central portion in a width direction of a sheet and over the entire length in a paper feeding direction, and the substantially central portion is a boundary. Thus, there is disclosed an airflow blowing structure of a paper discharge device which is configured to blow obliquely toward the left and right surfaces of a sheet toward the outside and away from each other. Thus, the air shower is sprayed on the sheet to promote the lowering of the sheet.
Further, Patent Document 2 is disclosed as means for lowering the discharged sheet more efficiently and at a high speed, although it does not avoid collision with the sheet discharged later.
In Cited Document 2, a first conveying unit that conveys a sheet, a stacking unit that stacks the sheets sent out from the first conveying unit, and the sheet on the downstream side in the sheet conveying direction of the first conveying unit. A second conveying unit that conveys; and a switching member that selectively switches a conveying direction of the sheet sent out from the first conveying unit between the stacking unit and the second conveying unit, and the switching member includes: There is disclosed a sheet conveyance switching device that is movable from an upper position where the sheet conveyance direction is switched to the stacking means to a lower position where the sheets discharged to the stacking means are pressed and dropped. Thus, the sheet conveyance direction can be switched.

  However, in the technique disclosed in Patent Document 1, since the sheet discharged by the air shower is forcibly lowered, a rear-end jam is avoided, but a fan or other device is installed on the upper part of the sheet discharge table. There is a problem in operability such as moving the apparatus when taking out the stacked sheets from the paper discharge table. Further, in the technique disclosed in Patent Document 2, the front side of the conveyed sheet is pressed and forcibly dropped onto the sheet discharge tray so that the discharged sheet does not bridge, and a jam of the subsequent sheet occurs. Can be prevented. In this case, when the speed of conveyance of a sheet to be discharged later is high, there is a problem that it is not possible to avoid a collision with a sheet that has been discharged previously.

  Accordingly, the present invention has been made in view of the above-described problems, and the problem is that an image is formed by a collision between a preceding sheet and a subsequent sheet that are discharged at a high conveyance speed. It is an object of the present invention to provide a paper discharge device that avoids the occurrence of a jam in the device.

The features of the present invention, which is a means for solving the above problems, are listed below.
A paper discharge device according to the present invention is a paper discharge device that discharges a sheet from an image forming apparatus to a paper discharge tray, and the paper discharge apparatus is located near a discharge port of the image forming apparatus from which the sheet is discharged. It is provided and has a collision avoidance means which pushes down the rear end side of the sheet when discharging.
Further, in the paper discharge device of the present invention, the collision avoiding means further includes a plurality of rotating bodies having a plurality of blade-like members that abut against both side edges on the rear end side of the sheet and push down downward. It is a posture setting means.
Further, in the paper discharge device of the present invention, the flying posture setting means is configured such that when the blade-shaped member comes into contact with the side edge of the sheet, the main surface of the blade-shaped member and the side edge of the sheet are separated. The drive timing of the rotating body is controlled so that the main surface is substantially perpendicular to the main surface.
Further, in the paper discharge device of the present invention, the collision avoidance means further inserts a pressing member between the sheet discharged first and collided with the end fence, and the sheet discharged next. It is a rear end pressing means for pressing down the rear end side of the sheet discharged first by the pressing member.

  An image forming apparatus according to the present invention is an image forming apparatus that forms an image on a sheet of paper, and includes the paper discharge device described above.

The present invention, which is a means for solving the above problems, has the following specific effects.
The paper discharge apparatus or image forming apparatus of the present invention is an image forming apparatus and can discharge paper without a rear-end jam in high-speed printing of 150 cpm or more.

1 is a diagram illustrating an overall configuration of a stencil printing apparatus as an image forming apparatus having a paper discharge device to which the present invention is applied. It is a figure which shows one form of the operation panel in the stencil printing apparatus of the image forming apparatus of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structure of one Embodiment in the paper discharge apparatus of this invention, (a) is the side view which looked at the structure of the flight attitude | position setting apparatus in the paper discharge apparatus of this invention from the conveyance direction of a sheet, FIG. 5B is a side view, a perspective view, and a plan view showing the configuration of the flying posture setting device as viewed from the front of the image forming apparatus. It is a figure explaining operation | movement of the flight attitude | position setting apparatus in the paper discharge apparatus of this invention. It is a figure explaining operation | movement of the blade-shaped member of the flight attitude | position setting apparatus in the paper discharge apparatus of this invention. It is a figure which shows the blade-shaped member of the flight attitude | position setting apparatus in the paper discharge apparatus of this invention. FIG. 5A is a diagram illustrating a conveyance state of a printing paper in a stencil printing apparatus using the paper discharge device of the present invention, and FIG. 5B is a diagram illustrating a conveyance state of the printing paper in the stencil printing apparatus using the paper discharge device of the present invention. FIG. FIG. 7 is a diagram illustrating a configuration of another embodiment of the paper discharge device of the present invention, and is a front view, a side view, a perspective view, and a plan view illustrating a configuration of a rear end side pressing device viewed from the front of the image forming apparatus. It is a figure explaining operation | movement of the rear end side pressing-down apparatus in the paper discharge apparatus of this invention. FIG. 7 is a diagram illustrating a configuration of another embodiment of the paper discharge device of the present invention, and is a front view, a side view, a perspective view, and a plan view illustrating a configuration of a rear end side pressing device viewed from the front of the image forming apparatus. It is a figure explaining operation | movement of the rear end side pressing-down apparatus in the paper discharge apparatus of this invention. FIG. 4 is a conceptual diagram illustrating a state of paper discharge of an image forming apparatus including a paper discharge device.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

FIG. 1 is a diagram showing an overall configuration of a stencil printing apparatus as an image forming apparatus having a paper discharge device to which the present invention is applied.
The stencil printing apparatus 1 has the structure of the thermosensitive digital plate-making integrated stencil printing apparatus 1. The stencil printing machine 1 is a plate cylinder 3 that wraps a master-made master 2 around an outer peripheral surface, and a plate-making machine that is disposed on the upper right side of the plate cylinder 3 and makes the master 2. An apparatus 4, a plate removing apparatus 5 that is disposed on the upper left side of the plate cylinder 3, peels and removes the used master 2 from the plate cylinder 3, and is disposed below the plate making apparatus 4 and loaded on the paper feed tray 6. A sheet feeding device 8 that feeds printing paper 7 as a sheet and a registration roller 9 that conveys the printing paper 7 fed from the paper feeding device 8 side to the plate cylinder 3 at a predetermined timing are provided. .
Then, the printing paper (hereinafter referred to as “printing paper”) 7, which is a sheet fed and disposed below the plate cylinder 3, is pressed against the master 2 on the plate cylinder 3 that has been made. Are arranged on the left side of the stencil printing apparatus 1, the printing pressure apparatus 10 that performs printing, the document cylinder 12, the plate making apparatus 4, the plate ejection apparatus 5, the document reading apparatus 12 that is positioned above the plate printing apparatus 5, and the image reader 11. The air knife 13 and the paper discharge claw 14 for peeling the printed printing paper 7 printed by the printing pressure device 10 from the plate cylinder 3 are conveyed to the outside of the image forming apparatus 1 main body. And a paper discharge device 15.
Furthermore, a paper discharge table 16 is provided on which the printing paper 7 conveyed by the paper discharge device 15 and discharged from the main body of the stencil printing apparatus 1 is stacked.
FIG. 2 is a view showing an embodiment of the operation panel in the stencil printing apparatus of the image forming apparatus of the present invention.
Further, it mainly comprises a face plate 17 as a separating member for isolating the inside and outside of the stencil printing apparatus 1 and an operation panel 18 for operating the stencil printing apparatus 1 to perform printing.

As shown in FIG. 1, the plate cylinder 3 has a porous cylindrical shape and is rotatably supported around a drum shaft 19. The plate cylinder 3 is rotated by a main motor (not shown).
An openable / closable clamper 20 that clamps the front end portion of the master 2 is provided on one bus bar of the outer peripheral portion of the plate cylinder 3.
Inside the plate cylinder 3, ink supply means 21 for supplying ink from the inner peripheral surface of the plate cylinder 3 toward the outer peripheral surface is disposed.
The master 2 is made of a thermoplastic resin film made of polyester or the like and bonded with Japanese paper or the like as a porous support, but is not limited to this, and only a very thin substantially thermoplastic resin film is used. It is also possible to use.
First, when an operator sets a document 11 to be printed on a document tray (not shown) of the document reading device 12 and presses a start key 22 on an operation panel 18 for starting plate making, a plate discharging process is performed in the plate cylinder 5. Executed.
The plate cylinder 3 rotates in the counterclockwise direction opposite to the arrow a direction indicating the clockwise direction in the figure, and the used master 2 wound around the outer peripheral surface of the plate cylinder 3 is removed from the outer peripheral surface of the plate cylinder 3. The plate discharging process is completed by being discharged into the plate discharging box 23 of the plate discharging device 5 while being gradually peeled off and conveyed.

In parallel with the plate removal process, the document reading unit 12 operates to read the document. In the detailed configuration and operation relating to the document reading, an image read from the document is finally photoelectrically converted by an image sensor including a photoelectric conversion element such as a CCD (charge coupled device). The electrical signal photoelectrically converted by the image sensor is converted to a digital image signal by being transmitted to an analog / digital (A / D) conversion board (not shown).
In parallel with the document reading operation, a plate making / plate feeding process is performed in the plate making apparatus 4 based on the digital image signal. Due to the rotation of the platen roller 25 pressed against the thermal head 24, the master 2 is pulled out from the master roll 26 and conveyed downstream of the master conveyance path.
A large number of minute heating elements arranged in a line in the main scanning direction of the thermal head 24 are formed on the A / D conversion board and the subsequent plate-making control board (not shown) with respect to the master 2 thus transported. The thermoplastic resin film of the master 2 that is selectively heated in accordance with the digital image signal sent after being subjected to various processes and is in contact with the generated heating element is melt-pierced.
In this way, image information is written as a drilling pattern by position-selective melt drilling of the master 2 according to the image information. The front end of the master 2 that has been subjected to image making and has been made is sent toward the outer peripheral side of the plate cylinder 3 by the rotation of the feed roller pair 27, and the plate cylinder 3 in the plate feeding position state shown in the figure is sent. Move toward the expanded clamper 20.

At this time, the used master 2 has already been removed from the plate cylinder 3 by the plate discharging process. When the tip of the master 2 that has been subjected to plate making is clamped by the clamper 20 at a fixed timing, the plate cylinder 3 is gradually wound around the outer peripheral surface while rotating in the direction of arrow a in the figure. The rear end portion of the master 2 that has been subjected to plate making is cut into a predetermined length by the operation of the cutting means 28 disposed in the plate making apparatus 4 after the plate making is completed, so that the master 2 is completely formed on the outer peripheral surface of the plate cylinder 3. Once wound, the so-called plate feeding process is completed.
When the master 2 that has been subjected to plate making is wound around the outer peripheral surface of the plate cylinder 3 in this way, the plate making / plate feeding process is completed and the printing process is started. The uppermost printing paper 7 loaded on the paper feed tray 6 is raised and the paper feed tray 6 is raised by a well-known means (not shown) until it contacts the contact roller 29. The printing paper 7, which is the uppermost sheet in contact with the calling roller 29, is conveyed by the rotation operation of the calling roller 29 and is separated into one sheet by the separation roller pair 30, toward the registration roller 9. Be fed.

At this time, the leading edge of the conveyed printing paper 7 comes into contact with the portion immediately before the nip portion of the registration roller 9 and stops in a bent state.
When the printing operation starts, the plate cylinder 3 starts to rotate at the printing rotation speed. On the inner peripheral side of the plate cylinder 3, ink is supplied from an ink supply distributor (not shown) to an ink reservoir 33 formed between an ink roller 31 and a doctor roller 32 as ink supply means. As the roller 31 and the doctor roller 32 rotate, they are kneaded and stretched, and are uniformly attached to the outer peripheral surface of the ink roller 31. The remaining amount of ink is detected by the ink detection means, and is supplied from the ink supply distributor when the ink is low.
Thus, ink is supplied to the inner peripheral side of the plate cylinder 3 by the ink roller 31 that is in contact with the inner peripheral surface while rotating in the same direction as the rotation direction of the plate cylinder 3 and in synchronization with the rotation speed of the plate cylinder 3. Is done.

The printing pressure device 10 is mainly configured by an ink roller 31, a press roller 34, a press roller bracket (not shown), a press roller tension including a spring (not shown), and a press roller cam (not shown).
The press roller 34 has a function as a pressing unit that presses the printing paper 7 fed by the registration roller 9 at a predetermined timing against the plate cylinder 3 to form a printed image on the printing paper 7. The press roller 34 is rotatably supported at one oscillating end of the press roller bracket, and is provided so as to be able to contact with and separate from the outer peripheral surface of the plate cylinder 3 by a known mechanism including a press roller tension and a press roller cam. Yes.
The printing paper 7 is placed between the printing cylinder 3 and the press roller 34 at a predetermined timing synchronized with the rotation of the printing cylinder 3 by the registration roller 9, that is, in a printing unit 35 as an image forming unit that forms an image on the printing paper 7. When the sheet is fed, the press roller 34 that has been separated from the side of the outer peripheral surface of the plate cylinder 3 is swung in synchronism with this, so that the plate making is wound around the outer peripheral surface of the plate cylinder 3. The master 2 is pressed.
As a result, the master 2 that has been subjected to the plate making comes into close contact with the outer peripheral surface of the plate cylinder 3 due to the adhesive force due to the viscosity of the ink that has oozed out from the porous portion of the plate cylinder 3, and at the same time, from the perforation pattern portion of the master 2 that has already been made. Ink oozes out, and the oozed ink is transferred to the surface of the printing paper 7 to form a desired print image.

The printing paper 7 on which the printing image is formed has a leading end that forms part of the paper discharge device 15, a driving roller 36, a driven roller 37, a belt 38 that is stretched over these rollers, and air that sucks the printing paper 7. 7 is separated from the plate cylinder 3 by the air knife 13 and the paper discharge claw 14 when it reaches the vicinity of the conveying means 40 having a fan 39 for closely contacting the belt 7 with the belt 38.
The printed printing paper 7 that has been separated and peeled off is conveyed in close contact with the belt 38 by a fan 39 provided below the belt 38, and is conveyed toward the paper discharge tray 16 by the paper discharge device 15. The paper is discharged while flying toward the paper discharge table 16. In this way, the so-called “printing process” or “trial printing” is completed.
Next, when the number of prints is set with the numeric keypad 41 on the operation panel 18 and the start key 22 is pressed again, the paper feed, printing, and paper discharge processes are repeated for the set number of prints in the same process as the trial printing. This is the end of the entire stencil printing process.

  The paper discharge table 16 includes a bottom plate 42 on which the printing paper 7 is stacked, a pair of side fences 43 that regulate the edge of the printing paper 7 that is slidably attached to the bottom plate 42 in the width direction of the printing paper 7, And an end plate 44 that regulates the front end of the printing paper 7. Each of the side fences 43 is displaced according to the width of the printing paper 7 by a driving means (not shown), and the falling printing paper 7 and the printing paper 7 or the bottom plate 42 already loaded are dropped. There is a hole 45 for satisfactorily stacking the printing paper 7 that is discharged by discharging the air therebetween. A plurality of, specifically three, holes 45 are provided in each side fence 43 in the discharge direction of the printing paper 7 indicated by the arrow b.

The paper discharge device 15 according to the present invention discharges the printing paper 7 from the main body of the stencil printing apparatus 1 to the paper discharge table 16, and includes a body 40 that makes the paper shape U-shaped, a fan 39, and the paper discharge table 16. Collision avoiding means 46 for pushing down the rear end side of the printing paper 7 discharged to the bottom.
As shown in FIG. 12, when the printing paper 7 is discharged at a higher speed, the printing paper 7 collides with the fence 44 of the paper discharge tray 16 and then descends to the paper discharge tray 16. A certain amount of time is required for loading. For this reason, the next printing paper 72 to be discharged next may collide with the rear end portion of the preceding preceding printing paper 71, and the printing paper 7 may not be stacked in order or orderly on the paper discharge tray 16, or Then, the next print sheet 72 to be discharged next is not discharged and jammed in the discharge device 15.
For this reason, in the paper discharge device 15 of the present invention, the rear end side of the preceding front print paper 71 is pushed down by the collision avoiding means 46 that pushes the rear end side of the print paper 7 downward, and is conveyed at high speed. Collision of the next printing paper 72 is avoided.

FIG. 3 is a diagram showing a configuration of an embodiment of the paper discharge device of the present invention. FIG. 3A is a side view of the configuration of the flying posture setting device in the paper discharge device of the present invention from the sheet transport direction. FIG. 4B is a side view, a perspective view, and a plan view showing the configuration of the flying posture setting device viewed from the front of the image forming apparatus.
In the embodiment of the collision avoidance device 46 in the paper discharge device of the present invention, both sides of the rear end portion of the preceding front print paper 71 are pushed down, and the flying posture at the time of discharge of the print paper 7 which is a sheet is set as the paper discharge device 15. The flying posture setting device 461 is configured so that the rear end of the printing paper 7 is lowered as compared with the posture that is transported and mounted on the paper.
As shown in (a), the flying posture setting device 461 includes a sensor unit 47 that senses the printing paper 7, a stepping motor unit 49 that operates a rotating body 48 including a blade-like member (convex shape) 52, and a rotating body 48. And the installation is attached to the face plate 17 or the paper discharge tray 16.
Furthermore, it can be seen from the side view, perspective view, and plan view shown in (b) that the rotating body 48 of the stepping motor unit 49 includes a blade-like member (convex shape) 52.

FIG. 4 is a diagram for explaining the operation of the flight posture setting device in the paper discharge device of the present invention.
Regarding the operation of the paper discharge device 15 of the present invention, the rear end portion of the print paper 7 discharged by the conveying means 40 is sensed by the sensor unit 47, and then 30-50 mm from the rear end portion of the print paper 7 by a signal. From the extent, the stepping motor 49 is operated, the rotating body 48 supported by the casing 50 is rotated, and immediately after being discharged by the conveying means 40, both side edges are formed on the rear end side of the printing paper 7 and the blade-like member 51. Are brought into contact with each other, and the rear terminal of the preceding preceding printing sheet 71 is gradually pushed down to a height below the leading edge of the next printing sheet 72 to be conveyed next.
As a result, it is possible to prevent a jam that occurs when the leading edge of the next printing paper 72 to be discharged next collides with the trailing edge of the preceding preceding printing paper 71.

FIG. 5 is a diagram for explaining the operation of the blade-like member of the flight posture setting device in the paper discharge device of the present invention.
The angle at which the blade-like member 51 of the rotating body 48 presses both side edges on the rear end side of the printing paper 7 is preferably in the range of 90 ± 10 °. Actually, when the blade-like member 51 comes into contact with the side edge portion of the printing paper 7, the rotating body 48 so that the main surface of the blade-like member 51 and the main surface of the side edge portion of the printing paper 7 are substantially perpendicular. The drive timing is controlled. This is because the rotation center of the rotating body 48 is set higher than the height of the printing paper 7 being conveyed, so that the main surface of the blade-like member 51 and the main surface of the side edge of the printing paper 7 are substantially perpendicular. Even if it becomes, it will not collide. On the other hand, if the pressing angle exceeds 90 + 10 °, it is necessary to increase the rotation speed of the rotating body 48 and the printing paper 7 may be damaged. Further, when the pressing angle is less than 90-10 °, the blade-like member 51 and the printing paper 7 may collide.
In this way, the leading edge of the next printing paper 72 to be discharged next is prevented from colliding with the trailing edge of the preceding preceding printing paper 71, and the stepping motor 49 is stopped immediately after the jam is avoided. Preparations are made to push down both sides of the rear end of the printing paper 72. This is repeated during printing.
The control can change the timing according to the printing speed, here, the conveyance speed of the printing paper 7.
Further, here, the paper discharge device 15 provided in the image forming apparatus 1 arranges the linear or thin belt belt 38 arranged along the body 40 while sucking the printing paper 7 by the fan 39. Yes. By transporting the printing paper 7 by the linear or thin belt 38, the printing paper 7 can be transported at a predetermined transportation speed even if the printing paper 7 is made U-shaped by the flying posture setting device 46. it can.

FIG. 6 is a view showing a blade-like member of the flying posture setting device in the paper discharge device of the present invention.
In addition, the blade-like member 51 at the portion that is disposed on the rotating body 48 and presses both side edges of the printing paper 7 is preferably made of a material such as POM that has a low friction coefficient with the printing paper 7 and has a high rubber-based friction coefficient. Is not desirable. Further, as shown in FIG. 6, by setting a convex shape or a corrugated shape on a hemisphere having a height of 1 mm or less with respect to the blade-like member 51, the both end surfaces of the printing paper 7 are more reliably pushed down. be able to.
FIG. 7A is a diagram illustrating a conveyance state of the printing paper in the stencil printing apparatus using the paper discharge device of the present invention, and FIG. 7B is a diagram illustrating the printing paper in the stencil printing device using the paper discharge device of the present invention. It is a figure which shows a conveyance state.
As shown to (a), in the paper discharge apparatus 15 of this invention, the attitude | position in the flight state of the printing paper 7 has the rear end of the printing paper 7 compared with the state conveyed and mounted in the paper discharge apparatus 15. The posture is set so that the part is lowered. Accordingly, the printing paper 7 printed by the stencil printing apparatus 1 is tilted with respect to the bottom plate 42 by the flying posture setting device 461 in the paper discharge device 15 of the present invention being pushed down on both side edges on the rear end side. It is dropped and loaded.
On the other hand, as shown in (b), in the conventional paper discharge device, the paper is dropped and stacked on the bottom plate 42 while being discharged by the stencil printing device.

FIG. 8 is a diagram showing a configuration of another embodiment of the paper discharge device of the present invention, and is a front view, a side view, a perspective view, and a plan view showing the configuration of the rear end side pressing device viewed from the front of the image forming apparatus. is there.
FIG. 9 is a diagram for explaining the operation of the rear end side pressing device in the paper discharge device of the present invention.
As shown in FIGS. 1 and 8, the rear end side pressing device 462 includes a belt or a rotation guide member 52 provided with a plurality or a single convex portion, a stepping motor 49 for operating the belt or the rotation guide member 52, and a sensor for detecting the printing paper 7. The configuration is a unit 47. This convex portion can be used with the same structure and material as the previous blade-like member 51.
Further, the rear end side pressing device 462 is installed on the paper discharge tray 16 side from the flying posture setting device 461 in the stencil printing apparatus 1 shown in FIG.
As shown in FIG. 9, the rear end portion of the printing paper 7 discharged by the conveying means 40 is detected by the sensor unit 47, and then the stepping motor 49 is operated by a signal. The rotation of the stepping motor 49 causes the convex leading end portion of the rotation guide member 52 to move from the position (1) to the rear end portion of the preceding previous printing paper 71 that collided with the end plate 44 and the next printing paper 72 to be discharged next. Move to the insertion position (2). At the same time that the trailing edge of the preceding front printing paper 71 passes at the insertion position (2), the trailing edge of the preceding preceding printing paper 71 is rotated to the position (1) and comes into contact with the preceding printing paper 71. Press down.
After that, the front end of the convex portion of the next rotation guide member 52 is inserted into the rear end of the next next printing paper 72 while further rotating and pushing down the rear end of the preceding previous printing paper 71. As a result, it is possible to avoid rear-end jam more reliably.
Like the blade-like member 5, the plurality of rotation guide members 52 are rotated counterclockwise in FIG. 9 while the rear end portion of the preceding preceding printing sheet 71 and the next printing sheet 72 to be discharged next. It may be moved to the insertion position (2).
Further, the flying posture setting device 461 can prevent the rear end portion of the previous print sheet 71 discharged first and the front end portion of the next print sheet 72 discharged next, but the front print sheet 71 can be changed depending on the printing speed. There is a case where the printing surface and the back surface of the next printing paper 72 are rubbed. Since the stencil printing apparatus 1 takes time for the ink to dry, there is a possibility that ink smear may occur due to rubbing between the printing papers 7, but the trailing edge side pressing device 462 prevents ink smear due to this rubbing. can do.

FIG. 10 is a diagram showing a configuration of another embodiment of the paper discharge device of the present invention, and is a front view, a side view, a perspective view, and a plan view showing the configuration of the rear end side pressing device viewed from the front side of the image forming apparatus. is there.
FIG. 11 is a diagram for explaining the operation of the rear end side pressing device in the paper discharge device of the present invention.
The rear end side pressing device 462 includes a sensor unit 47 that senses the printing paper 7, a stepping motor 49 that operates the sheet-like sheet-like guide member 53, and a housing 50 that supports the sheet-like guide member 53. Yes.
Further, the rear end side pressing device 462 is installed on the paper discharge tray 16 side from the flying posture setting device 461 in the stencil printing apparatus 1 shown in FIG.
As for the operation, as shown in FIG. 11, the rear end portion of the printing paper 7 discharged by the conveying means 40 is detected by the sensor unit 47, and then the stepping motor 49 is operated by the signal and supported by the casing 50. The sheet-like guide member 53 thus moved is moved to the insertion position (2) between the rear end portion of the printing paper 7 colliding with the end plate 44 and the next printing paper 72 to be discharged next, and then the stepping motor 49 is restarted. Then, the sheet-like guide member 53 is moved to the position (1), and the rear end portion of the preceding preprint sheet 71 is pushed down. This is repeated during printing. The control can change the timing according to the printing speed. Thereby, there exists an effect similar to the rear end side pushing device 462 of FIG.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus / Stencil printing apparatus 2 Master 3 Plate cylinder 4 Plate making apparatus 5 Plate discharging apparatus 6 Paper feed tray 7 Sheet paper / printing paper 71 Pre-printing paper 72 Secondary printing paper 8 Paper feeding device 9 Registration roller 10 Printing pressure device 11 Document 12 Document reading device 13 Air knife 14 Discharge claw 15 Discharge device 16 Discharge stand 17 Face plate 18 Operation panel 19 Drum shaft 20 Clamper 21 Ink supply means 22 Start key 23 Discharge box 24 Thermal head 25 Platen roller 26 Master roll 27 Sending out Roller pair 28 Cutting means 29 Calling roller 30 Separating roller pair 31 Ink roller 32 Doctor roller 33 Ink reservoir 34 Press roller 35 Printing unit 36 Drive roller 37 Followed roller 38 Belt 39 Fan 40 Body 41 Tenkey 42 Bottom plate 43 Side fence 44 End plate 45 Hole 46 Collision avoidance device 461 Flying posture setting device 462 Rear end side pressing device 47 Sensor unit 48 Rotating body 49 Stepping motor 50 Housing 51 Blade-like member 52 Rotating guide member 53 Sheet-like guide member

JP 2004-217359 A JP2007-039150

Claims (5)

A paper discharge device that discharges a sheet from an image forming apparatus to a paper discharge tray,
The paper discharge device is provided in the vicinity of the discharge port of the image forming apparatus from which the sheet is discharged,
A paper discharge device comprising collision avoiding means for pushing down the rear end side of the sheet when discharging. The paper discharge device according to claim 1.
The collision avoiding means is a flying posture setting means including a plurality of rotating bodies having a plurality of blade-like members that are pressed against the both side edges on the rear end side of the sheet and pushed downward. apparatus. The paper discharge device according to claim 2.
The flying posture setting means includes
When the blade-shaped member comes into contact with the side edge of the sheet, the drive timing of the rotating body is controlled so that the main surface of the blade-shaped member and the main surface of the side edge of the sheet are substantially perpendicular to each other. A paper discharge device. In the paper discharge device according to any one of claims 1 to 3,
The collision avoiding means inserts a pressing member between the sheet discharged first and colliding with the end fence and the sheet discharged next, and the sheet discharged first by the pressing member. A paper discharge device, characterized in that the paper discharge device is a rear end pressing means for pressing the rear end side downward. In an image forming apparatus that forms an image on a sheet of paper,
The image forming apparatus includes the paper discharge device according to claim 1.

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