JP2020070122A - Sheet discharge device - Google Patents

Abstract

To provide a sheet discharge device capable of positively discharging a sheet by a simple structure.SOLUTION: A sheet discharge device comprises a sheet discharge unit 20 that discharges a sheet P on which an image is formed, a loading table 60 that loads the sheet P discharged from the sheet discharge unit 20 below the sheet discharge unit 20, a pair of right and left side fences 40 (41) that are provided on the loading table 60 and adjusted in right-left spacing in accordance with a width of the sheet P to be discharged, a pair of rotors 30 (31) that are provided in positions above or upstream of the side fences 40 (41), have conical slant surfaces 30b (31b) whose outer peripheral surfaces increase in diameter downwardly, and are rotatably driven faster in circumferential speed at the outer peripheral surfaces than a discharge speed of the sheet P, and an end fence 50 that is provided on the loading table 60 with which the sheet P after contacted the pair of rotors 30 (31) collides.SELECTED DRAWING: Figure 1

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper discharge device that discharges paper on which an image is formed.

  When the paper ejecting device is provided with an end fence that aligns the positions of the leading ends in the paper ejecting direction and side fences that align the positions of both ends in the direction orthogonal to the paper ejecting direction for the purpose of aligning the ejected paper There is. The end fence is provided perpendicularly to a stacking table on which sheets are stacked, and the leading end of discharged sheets is brought into contact with the vertical surface (vertical surface) to drop the sheets onto the stacking table. The side fences guide the sheets stacked on the stacking table so that both sides (both ends of the sheets) do not spread.

  Recently, for example, the discharging speed of printed paper in a printing apparatus has been increased. For fast paper, the number of sheets discharged per minute is about 190 sheets, for example. If this is expressed in frequency, it will be about 3.2 Hz. That is, about 3 sheets are ejected per second.

  The ejected paper is affected by gravity and air resistance. After being discharged, the thin paper having a small basis weight is bent downward at the central portion of the paper due to gravity. The amount of bending increases as the sheet becomes thinner. Further, when the amount of bending is large, the front projection area of the paper is large, and the thinner the paper is, the more the air resistance is increased. Also, the faster the discharge speed, the greater the air resistance.

  As a result, the discharged thin paper may not reach the end fence, and may drop onto the stacking table with the front end in the discharging direction warped. Further, the ejected sheets may collide with each other in the air and overlap each other. In such a case, the sheets cannot be aligned.

  Therefore, efforts are being made to make it possible to properly align sheets even with thin sheets. For example, Patent Document 1 discloses a technique for giving a curvature to a sheet viewed in a cross section orthogonal to the discharge direction. The curve has a U-shape or a W-shape when viewed from the paper discharge direction (front-back direction). By giving this curvature to the paper, the apparent rigidity in the paper discharge direction can be increased.

  By increasing the apparent rigidity of the sheet, the amount of downward bending is reduced, and the air resistance can be reduced. As a result, even thin paper can surely reach the end fence, and paper can be reliably aligned.

JP, 6-239901, A

  However, in the technique disclosed in Patent Document 1, it is necessary to change the shape of the curve given to the paper according to the type of the paper, and the structure of the drive means for bending the paper is complicated. In addition, it is necessary to control the operation of the driving means for bending. For example, when the paper size is A4 size, a U-shaped curve is provided, and when the paper size is A3 size, a W-shaped curve that further increases rigidity is provided. As described above, there is a problem in that the structure and control of the driving unit that bends the sheet becomes complicated.

  The present invention has been made in view of the above, and an object of the present invention is to provide a paper discharge device that can reliably discharge paper with a simple structure.

  In order to achieve the above object, a paper discharge device according to the present invention has a paper discharge unit for discharging a paper on which an image is formed and a paper discharged from the paper discharge unit below the paper discharge unit. A stacking platform, a pair of left and right side fences provided on the stacking platform and having a left-right spacing adjusted according to the width of discharged paper, and an outer periphery provided at a position above or upstream of the side fences. Provided on the stacking base and a pair of rotating bodies, each of which has a conical inclined surface whose diameter expands downward, and whose peripheral speed of the outer peripheral surface is rotationally driven faster than the discharging speed of the sheet. And an end fence against which the sheet of paper collides after coming into contact with the pair of rotating bodies.

  According to the present invention, it is possible to reliably eject a sheet with a simple structure.

It is a schematic diagram which shows the structural example of the paper discharge apparatus which concerns on embodiment of this invention. It is a figure which shows typically the shape of one side when the discharged | emitted sheet | seat falls. FIG. 2 is a schematic perspective view of the rotating body, side fences, end fences, and stacking base shown in FIG. It is a schematic diagram which shows the front of the rotary body shown in FIG. It is a schematic diagram which shows the relationship between a rotating body and paper. 6 is a flowchart showing an example of a processing procedure of the paper discharge device shown in FIG. 1. It is a schematic diagram which shows the structural example of the paper discharge apparatus which concerns on the modification of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. Throughout the drawings, the same or equivalent parts or constituents will be denoted by the same or equivalent reference numerals, and the description thereof will be omitted or simplified.

(Paper discharge device)
FIG. 1 is a schematic diagram showing a configuration example of a paper discharge device according to an embodiment of the present invention. The paper discharge device 100 shown in FIG. 1 is, for example, a device that stacks printed paper discharged from a printing device to form a stack.

  The paper discharge device 100 may be integrated with the printing device. The integrated device is not limited to the printing device. For example, it may be integrated with a copying apparatus. That is, the paper discharge device 100 is a device that is used in combination with the image forming device that discharges the paper on which the image is formed, and forms a part of the image forming device.

  The paper discharge device 100 shown in FIG. 1 is shown as an example integrated with the housing 10 of the image forming apparatus. The paper discharge device 100 includes a paper discharge unit 20, a rotating body 30 (31), a side fence 40 (41), an end fence 50, and a loading platform 60. FIG. 1 shows an example in which the rotating body 30 (31) is provided on the side fence 40 (41). The rotating body 30 (31) may be provided separately from the side fence 40 (41). An example in which the rotating body 30 (31) is provided separately from the side fence 40 (41) will be described later. (31) and the like are reference numerals shown in FIG.

  The paper discharge unit 20 discharges the paper P on which an image is formed. In FIG. 1, the discharge direction of the paper P is defined as the right direction (right). Further, the front side of FIG. 1 is defined as the front (F) side, and the back side is defined as the rear (R) side.

  The paper discharge unit 20 is provided inside the housing 10 of the image forming apparatus and includes a discharge roller 21 and a discharge port 22. The discharge roller 21 rotates at a predetermined rotation speed, and discharges the nipped paper P to the outside from a discharge port 22 which is an opening provided in the housing 10. The rotation speed of the discharge roller 21 is set based on the printing conditions input to the operation unit (not shown) of the image forming apparatus. From here, it will be described with reference to FIG.

  The pair of rotating bodies 30 and 31 are arranged to face each other in the horizontal direction orthogonal to the discharge direction of the paper P. The rotary body 30 has a shape obtained by cutting a cone in two planes perpendicular to the central axis, and a rotary shaft 30a is provided along the central line. The outer peripheral surface is an inclined surface 30b having a positive taper ratio. The rotating body 31 has the same configuration. In FIG. 3, the rotating body 30 is driven to rotate clockwise, and the rotating body 30 is driven to rotate so that the peripheral speed of the inclined surface 30b becomes faster than the discharging speed of the paper P. Rotational speeds of the rotating bodies 30 and 31 can be controlled by transmitting rotational movement of a motor (not shown) to the rotating shafts 30a and 30b.

  The peripheral speed of the inclined surface 30b differs depending on the position of the inclined surface 30b in the height direction. Therefore, the peripheral speed of the upper end portion of the inclined surface 30b having the smallest outer diameter is higher than the discharging speed of the paper P. The rotating body 31 is rotationally driven in the opposite direction (counterclockwise) to the rotating body 30. Here, the positive taper ratio means a shape in which the outer diameter of the upper end of the rotating body is smaller than the outer diameter of the lower end. The details will be described later.

  The paper P ejected from the paper ejection unit 20 contacts the rotating body 30, and then is accelerated to a speed faster than the ejection speed, and is ejected toward the end fence 50. Although FIG. 1 illustrates an example in which the sheet P contacts the rotating body 30 while being nipped by the discharge roller 21, the present invention is not limited to this example.

  For example, the rotating body 30 may be arranged at a position further away from the housing 10. In that case, the paper P is ejected from the ejection port 22 and flies, and comes into contact with the rotating body 50. In any case, the rotating body 30 is arranged at a predetermined distance from the paper discharge unit 20.

  When the position of the rotating body 30 is fixed, the position on the inclined surface 30b where the rotating body 30 and the paper P contact each other changes depending on the basis weight of the paper P. In the case of thin paper having a small basis weight, the paper P contacts below the inclined surface 30b. Further, in the case of thick paper having a large basis weight of the paper P, the paper P comes in contact above the inclined surface 30b. The reason will be described with reference to FIG.

  FIG. 2 is a diagram schematically showing the shape of the short side when the discharged paper P is dropped. FIG. 2 is a diagram showing an example in which short-side paper feeding is performed. Short-side paper feeding means that the paper P is fed to the image forming apparatus from the short side and discharged from the short side.

  FIG. 2A is a diagram in which the short side of the thin paper is viewed from the right side (end fence 50 side). FIG. 2B is a diagram in which the short side of the thick paper is viewed from the right side.

As shown in FIGS. 2 (a) and 2 (b), the paper P falling in the air has a shape in which both ends of the short side are lifted up due to air resistance, and the central portion of the short side is dented. The deflection amount t _{uR of} thin paper that is dented in the central portion is larger than the deflection amount t _{aR of} thick paper.

  This phenomenon also occurs when the sheet P contacts the rotating body 30 while being nipped by the discharge roller 21 as shown in FIG. Therefore, both ends in the horizontal direction orthogonal to the discharging direction of the thin paper (paper P) having a large amount of bending come into contact with each other below the inclined surface 30b of the rotating body 30. Further, the same portion of the cardboard with a small amount of bending comes into contact above the inclined surface 30b.

  The inclined surface 30b of the rotator 30 and both ends of the sheet P in the short side direction continue to contact each other in the long side direction of the sheet P.

  The peripheral speed below the inclined surfaces 30b and 31b of the rotating bodies 30 and 31 is fast because the outer diameter of the inclined surfaces 30b and 31b is large. Further, the peripheral speed above the inclined surfaces 30b and 31b is slower than that below. Therefore, the thin paper contacting the lower side of the inclined surfaces 30b and 31b is accelerated to a speed faster than the thick paper contacting the upper side and is blown toward the end fence 50.

  The end fence 50 is collided with the paper P that is blown by the rotating bodies 30 and 31. The thinner the paper P is toward the end fence 50, the more the paper P is bent, so that the apparent rigidity of the paper P is increased. Further, the sheet having the increased rigidity is accelerated faster as the amount of bending increases, so that the sheet reliably reaches the end fence 50.

  The loading platform 60 is provided integrally with the housing 10 of the image forming apparatus, and the side fences 40 and 41 and the end fence 50 are slidably movable and fixed on the loading platform 60 as described above. There is. The paper P that is accelerated and flies by the rotating body 30 collides the end portion 50 in the discharge direction with the end fence 50. The paper P that has collided with the end fence 50 descends along the vertical surface (contact surface) of the end fence 50, and is stacked on the loading platform 60 to form a stack.

  As described above, in the paper discharge device 100 according to the present embodiment, the paper discharge unit 20 that discharges the paper P on which the image is formed and the paper P discharged from the paper discharge unit 20 below the paper discharge unit 20 are provided. A loading platform 60 to be loaded, a pair of left and right side fences 40, 41 provided on the loading platform 60 and having a left-right spacing adjusted according to the width of the discharged paper P, and above the side fences 40, 41. Side or upstream side, the outer peripheral surface has conical inclined surfaces 30b and 31b whose diameter expands downward, and the peripheral speed of the outer peripheral surface is rotationally driven faster than the discharge speed of the paper P. The pair of rotating bodies 30 and 31 and the end fence 50 provided on the stacking table 60 and on which the sheet P collides after contacting the pair of rotating bodies 30 and 31. With this, with a simple configuration including only the pair of rotating bodies 30 and 31, it is possible to carry out stiffness according to the thickness of the sheet P and reliably convey the sheet P. The amount of flexure of the paper P viewed from the front side (F) is 0 (straight line).

  Further, the thick paper having a large basis weight is blown toward the end fence 50 with a small amount of bending and a small acceleration. Further, thin paper having a small basis weight is blown toward the end fence 50 with a large amount of bending and a large acceleration. In this way, the thinner the paper is, the more it is subjected to the air resistance, the greater the apparent rigidity is given and the acceleration is accelerated, so that the discharging speed of the paper P can be increased.

  FIG. 3 is a diagram schematically showing a perspective view of the rotating bodies 30 and 31, the side fences 40 and 41, the end fence 50, and the stacking platform 60 as seen from the sheet discharge section 20 side (left side). As shown in FIG. 3, the paper discharge device 100 includes side fences 40 and 41. The side fences 40 and 41 are arranged on the upper surface of the stacking table 60 so as to face each other with an interval corresponding to the width of the paper P.

  The distance between the side fences 40 and 41 is adjusted manually or automatically according to the width of the paper P. In the case of automatic adjustment, the side fences 40, 41 are moved to the front (F)-by the rotation of a motor (not shown) corresponding to the paper size of the paper P input to the operation unit (not shown). Move in the rear (R) direction.

  An end fence 50 is arranged behind the sheet P in the discharging direction. The end fence 50 can move from right to left. The position of the end fence 50 is manually or automatically adjusted like the side fences 40 and 41.

  The rotating bodies 30 and 31 are provided on the upper portions of the side fences 40 and 41 on the side of the paper discharge unit 20. The rotating shafts 30a and 31a of the rotating bodies 30 and 31 of this example are arranged in the vertical direction. The rotary shafts 30a and 31a may be inclined with respect to the vertical direction.

  Then, the innermost portions of the inclined surfaces 30b and 31b of the rotating bodies 30 and 31 are arranged substantially on the same plane as the inner surfaces of the side fences 40 and 41. In addition, the innermost part of the lowermost part of the inclined surfaces 30b and 31b is arranged inside the inner surface of the side fence.

  By configuring the rotating bodies 30 and 31 in this way, the sheet P discharged from the sheet discharge unit 20 is accelerated toward the end fence 50 by adding a bending amount according to the thickness of the sheet P and accelerating the sheet P. Can be flown.

  As described above, the paper discharge device 100 according to the present embodiment includes the side fences 40 and 41 arranged on the upper surface of the stacking table 60 so as to face each other with an interval corresponding to the width of the paper P, and the rotating bodies 30 and 31. Is provided in the upper part of the side fences 40, 41 on the side of the paper discharge unit 20, and the uppermost inside of the inclined surfaces 30b, 31b is arranged substantially on the same plane as the inner surface of the side fences 40, 41. The innermost portions of the lowermost portions of 30b and 31b are arranged inside the inner surfaces of the side fences 40 and 41. As a result, the inclined surfaces 30b and 31b of the rotating bodies 30 and 31 can reliably catch both ends in the horizontal direction orthogonal to the discharge direction of the paper P discharged from the paper discharge unit 20, and the end fence 50. You can fly to.

  In addition, the rotating bodies 30 and 31 may be configured such that the positions in the two directions of the horizontal direction and the height direction can be adjusted. It is possible to easily realize a structure in which each of the rotating shafts 30a and 31a can be moved in two directions of a horizontal direction and a height direction within a range of, for example, about 10 mm.

(Rotating body)
FIG. 4 is a schematic view showing the front surface of the rotating body 30. The same applies to the rotating body 31. As shown in FIG. 4, the rotating body 30 has a rotating shaft 30a in the height direction. Further, it has an inclined surface 30b having a predetermined taper ratio. The taper ratio can be expressed by the following equation.

  Here, D is a large diameter, d is a small diameter, and L is a height (length).

  The rotating body 30 has an inclined surface 30b having a predetermined positive taper ratio in the height direction. As a result, the sheet P discharged from the sheet discharge unit 20 can be provided with a bending amount that is dented downward as viewed from the end fence 50 side according to the thickness of the sheet P. A positive taper ratio represents a case where the large diameter D is larger than the small diameter d (D> d).

  FIG. 5 is a diagram schematically showing how different amounts of flexure are applied depending on the thickness of the paper P, and is a view of the paper P and the rotating bodies 30 and 31 as viewed from the discharge direction (right). 5A shows the case where the paper P is thin paper, and FIG. 5B shows the case where the paper P is thick paper.

  As shown in FIG. 5A, when the paper P is a thin paper, the central portion of the paper P is largely bent downward when viewed from the right. Therefore, in the case of thin paper, both ends in the horizontal direction orthogonal to the discharge direction of the paper P come into contact with the large outer diameter portions below the inclined surfaces 30b and 31b. Therefore, the paper P is given a large apparent rigidity, and the flight speed thereof is greatly accelerated.

  As shown in FIG. 5B, the paper P in the case of thick paper has a small dent amount in the central portion when the paper P is viewed from (right). Therefore, in the case of thick paper, both ends in the horizontal direction orthogonal to the discharge direction of the paper P come into contact with the portions having a small outer diameter above the inclined surfaces 30b and 31b. Therefore, a cardboard having high rigidity is given a small amount of deflection and its flight speed is accelerated to a small extent.

  FIG. 6 is a flowchart showing an example of a processing procedure of a paper discharge control unit (not shown) that controls the operation of the paper discharge device 100. The paper discharge control unit is realized by a computer including, for example, a ROM, a RAM, a CPU, and the processing procedure to be executed is described by a program stored in the ROM.

  The paper discharge control unit starts operation when, for example, a print start button of an operation unit (not shown) of the image forming apparatus is pressed. In FIG. 6, the notation of the processing step is omitted.

  The paper discharge control unit that has started the operation first acquires the paper discharge speed information (step S1). The paper discharge speed information can be obtained from the printing conditions set on the operation unit.

  The paper discharge control unit that has obtained the paper discharge speed sets the rotation speed (rpm) of the discharge roller 21 (step S2). The discharge speed of the paper P that is nipped by the discharge roller 21 and discharged to the outside changes according to the rotation speed of the discharge roller 21.

  Next, the paper discharge control unit sets the peripheral speed (rotation speed) of the rotating bodies 30 and 31 (step S3). The peripheral speed is set such that the peripheral speed of the uppermost portion of the inclined surfaces 30b and 31b having the smallest outer diameter is higher than the discharging speed of the paper P. As a result, the flying speed of the paper P that comes into contact with the rotating bodies 30 and 31 is not reduced, and thus it is possible to prevent the paper P ejected first from colliding with another paper P ejected later. ..

  The inclined surfaces 30b and 31b of the rotating bodies 30 and 31 may be formed of a material having a larger friction coefficient than metal or a surface state that increases friction. As a material having a friction coefficient larger than that of metal, for example, a rubber material can be considered. Alternatively, it may be configured such that minute irregularities in the shape of a paper file are provided.

  As a result, the frictional force between the paper P and the inclined surfaces 30b and 31b can be increased, and the paper P can be made to fly toward the end fence 50 at a speed faster than the discharge speed thereof.

  As described above, the paper discharge device 100 includes the paper discharge unit 20 that discharges the paper P on which an image is formed, and the stacking platform on which the paper P discharged from the paper discharge unit 20 is stacked below the paper discharge unit 20. 60, a pair of left and right side fences 40 and 41 provided on the stacking table 60 and having a left and right spacing adjusted according to the width of the discharged paper P, and an upper side or an upstream side of the side fences 40 and 41. A pair of rotations that are provided at positions and have conical inclined surfaces 30b and 31b whose outer peripheral surface expands downward and whose peripheral speed is rotationally faster than the discharge speed of the paper P. The bodies 30 and 31 and the end fence 50 that is provided on the loading platform 60 and on which the sheet P collides after contacting the pair of rotating bodies 30 and 31 are provided. As a result, even thin paper, which is susceptible to air resistance, is given an apparent rigidity and accelerated. As a result, the discharge speed of the paper P can be increased. Further, the paper P can be surely arranged.

  According to the paper discharge device 100 according to the present embodiment, the paper P can be bent and stiffened with a simple configuration including only the pair of rotating bodies 30 and 31. Further, it is not necessary to change the control according to the paper size. That is, the amount of bending of the sheet P is automatically determined, and it is not necessary to control the amount.

  Although the above embodiment has been described with reference to the example in which the rotating bodies 30 and 31 are provided on the side fences 40 and 41, the present invention is not limited to this example. The rotating bodies 30 and 31 may be arranged at other positions.

  The discharge path of the paper P is defined as the paper P colliding with the end fence 50 and forming a stack on the stacking base 60. In such a case, the rotating bodies 30 and 31 may be arranged at any position of the discharge path.

  FIG. 7 is a diagram schematically showing a configuration of a paper discharge device according to a modified example of the present invention. The paper discharge device 110 shown in FIG. 7 includes rotary bodies 30 and 31 arranged between the side fences 40 and 41 and the paper discharge unit 20. The rotating body 30 is locked to the support column 70. The same applies to the rotating body 31. As described above, the rotating bodies 30 and 31 do not need to be integrated with the side fences 40 and 41. It may be arranged somewhere in the paper P discharge path.

  Further, the paper discharge unit 20 may be configured by a suction belt. The suction belt moves the paper P while sucking it with air and discharges it to the outside. Further, the loading platform 60 may be moved up and down. Further, the paper P may be a film.

  As described above, needless to say, the present invention includes various embodiments and the like not described here. Therefore, the technical scope of the present invention is defined only by the matters specifying the invention according to the scope of claims appropriate from the above description.

[Appendix]
This application discloses the following inventions.

(Appendix 1)
A paper ejection unit for ejecting paper with an image formed,
A stacking table on which the sheets discharged from the sheet discharging section are stacked below the sheet discharging section;
A pair of left and right side fences which are provided on the stacking table and whose left and right intervals are adjusted according to the width of the discharged paper;
The outer peripheral surface is provided at a position on the upper side or the upstream side of the side fence, and the outer peripheral surface has a conical inclined surface whose diameter expands downward, and the peripheral speed of the outer peripheral surface rotates faster than the discharging speed of the paper. A pair of driven rotating bodies,
An end fence that is provided on the stacking table and on which the sheet of paper collides after coming into contact with the pair of rotating bodies.

(Appendix 2)
The rotating body is
2. The paper discharge device according to appendix 1, wherein the position is adjustable in two directions, a horizontal direction and a height direction.

(Appendix 3)
The inclined surface is
3. The paper discharge device according to appendix 1 or 2, which is formed of a material having a friction coefficient larger than that of metal or a surface state that increases friction.

10 Housing 20 Paper Ejection Part 21 Ejection Roller 22 Ejection Ports 30 and 31 Rotators 30a and 31a Rotating Shafts 30b and 31b Sloping Surfaces 40 and 41 Side Fence 50 End Fence 60 Loading Platform 70 Support Pillars 100 and 110 Paper Ejection Device

Claims (3)

A paper ejection unit for ejecting paper with an image formed,
A stacking table on which the sheets discharged from the sheet discharging section are stacked below the sheet discharging section;
A pair of left and right side fences which are provided on the stacking table and whose left and right intervals are adjusted according to the width of the discharged paper;
The outer peripheral surface is provided at a position on the upper side or the upstream side of the side fence, and the outer peripheral surface has a conical inclined surface whose diameter expands downward, and the peripheral speed of the outer peripheral surface rotates faster than the discharging speed of the paper. A pair of driven rotating bodies,
An end fence which is provided on the stacking table and which collides with the sheet after contacting the pair of rotating bodies. The rotating body is
The paper discharge device according to claim 1, wherein positions in two directions of a horizontal direction and a height direction are adjustable. The inclined surface is
The sheet discharge device according to claim 1 or 2, wherein the sheet discharge device is formed of a material having a friction coefficient larger than that of metal or a surface state that increases friction.

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