JP2013023337A - Sheet processor and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processor which reduces stains and an image forming apparatus provided with the same.SOLUTION: The sheet processor, which includes a paper sheet conveying means for conveying paper sheets, a stack tray on which paper sheets conveyed by the paper sheet conveying means are stacked on the stack surface as a bundle of paper sheets, an alignment member which abuts the rear end of the paper sheets stacked on the stack tray in the paper sheet conveying direction and aligns them, and a paper sheet moving means for contacting its contact surface to the paper sheets and moving the paper sheets toward the alignment member, has a plurality of the paper sheet moving mean to switch the paper sheet moving means to be used at a predetermined timing.

Description

  The present invention relates to a sheet processing apparatus that performs predetermined processing on a sheet after image formation, and an image forming apparatus that can be connected to the sheet processing apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus that includes a sheet processing apparatus that performs a binding process or the like on a sheet on which an image is formed by an image forming unit is known (eg, Patent Document 1). In this sheet processing apparatus, a plurality of sheets are stacked on a sheet stacking surface of a staple tray to form a sheet bundle, and a stapler as a binding processing unit drives a staple into a predetermined position of the sheet bundle to perform a binding process. is there. Before performing such a binding process, by rotating the return roller, which is a sheet moving means, in contact with the sheet and rotating it, the trailing end of the sheet in the sheet conveyance direction (hereinafter referred to as the sheet rear) The sheet is aligned by abutting the edge.

  When the paper is moved toward the alignment member by the return roller, the paper is moved such that the return roller rubs the paper surface. Therefore, when the paper surface is rubbed with the return roller, the toner or ink of the image on the paper surface is scraped off and adheres to the contact surface of the return roller. For this reason, if toner or ink adheres to the contact surface of the return roller and the stain becomes severe, the toner or ink attached to the contact surface of the return roller moves onto the paper, resulting in paper stain. Problems arise.

  The present invention has been made in view of the above problems, and an object thereof is to provide a sheet processing apparatus capable of reducing sheet contamination and an image forming apparatus including the sheet processing apparatus.

  In order to achieve the above object, the invention of claim 1 includes a sheet conveying unit that conveys a sheet, a stacking tray that stacks a plurality of sheets conveyed by the sheet conveying unit on a stacking surface, and stacks them as a bundle of sheets. , An alignment member that aligns the sheet by abutting the rear end of the sheet loaded in the stacking tray in the sheet conveying direction, and a sheet that moves the sheet toward the alignment member by bringing its contact surface into contact with the sheet A paper processing apparatus comprising a moving means, comprising a plurality of the paper moving means, wherein the paper moving means used at a predetermined timing is switched.

  In the present invention, since the sheet moving means to be used is switched at a predetermined timing, the contact surface is not soiled or soiled from the sheet moving means in which the contact surface contacting the sheet surface is severely contaminated. It is possible to switch to another sheet moving means to move the sheet toward the alignment member. Therefore, paper contamination can be reduced as compared with the case where only one paper moving means is continuously used to move the paper toward the alignment member.

  As described above, according to the present invention, there is an excellent effect that paper contamination can be reduced.

1 is a schematic configuration diagram of a sheet post-processing apparatus according to an embodiment. FIG. 6 is an operation explanatory diagram of a staple tray. FIG. 6 is an explanatory diagram regarding alignment in the conveyance direction on a staple tray. FIG. FIG. 10 is a flowchart of control for changing a return roller to be operated according to an image density at a contact portion between the return roller and a sheet. Explanatory drawing about the change of the contact surface with the paper of a return roller.

Hereinafter, an embodiment of a paper processing apparatus to which the present invention is applied will be described.
FIG. 1 illustrates a post-processing device 200 that is a paper processing device according to the present embodiment, and an image forming unit 300 such as a copier or a printer that supplies the post-processing device 200 with paper P that is a sheet material after image formation. 1 is a schematic configuration diagram of an image forming apparatus 600 comprising:

  The image forming unit 300 of the present embodiment is an electrophotographic image forming apparatus including an image processing circuit, a photoconductor, an optical writing device, a developing device, a transfer device, and a fixing device, although not particularly illustrated.

  The image processing circuit converts image data read by a scanner unit when the image forming unit 300 is a copying machine or image data input from an external device such as a personal computer into printable image data, and the converted image data Is output to the optical writing device.

  The optical writing device performs optical writing on the photoconductor based on the image signal output from the image processing circuit to form an electrostatic latent image on the surface of the photoconductor.

  The developing device develops the electrostatic latent image formed on the surface of the photoreceptor by optical writing with toner.

  The transfer device transfers the toner image on the surface of the photoreceptor visualized by the developing device onto the paper P.

  The fixing device fixes the toner image transferred onto the paper P onto the paper P.

  The paper P on which the toner image is fixed by the image forming unit 300 is sent to the post-processing device 200, and the post-processing device 200 performs desired post-processing. As described above, the image forming unit 300 of the present embodiment is of an electrophotographic system, but all known image forming apparatuses such as an ink jet system and a thermal transfer system can be combined with the post-processing apparatus 200 as the image forming unit 300. it can.

  As shown in FIG. 1, the post-processing device 200 is attached to the side portion of the image forming unit 300, and the paper P discharged from the image forming unit 300 is guided to the post-processing device 200.

  The entrance portion A of the post-processing apparatus 200 is a portion where the paper P discharged from the image forming unit 300 is first carried. A discharge conveyance path that guides the paper P to the shift tray 202 is formed on the side of the entrance A (left side in FIG. 1). In addition, a binding processing conveyance path that guides the sheet P to the staple tray 21 that performs alignment, staple binding, and the like is formed below the inlet portion A of the post-processing device 200.

  The entrance A is a transport path located upstream in the transport direction with respect to the discharge transport path and the binding processing transport path, and is common to all sheets P transferred from the image forming unit 300 to the post-processing device 200. Configure the transport path. An entrance sensor 301 that detects the passage of the paper P received from the image forming unit 300 is disposed at the entrance A, and the entrance roller pair 1 is disposed downstream thereof. Further, a branching claw 8 is disposed on the downstream side of the inlet roller pair 1 in the inlet portion A.

  The branching claw 8 is connected to a solenoid (not shown). By changing the posture of the branching claw 8 by the solenoid, the conveyance path of the paper P passing through the position where the branching claw 8 is arranged is changed to the discharge conveyance path or the binding. It is possible to switch to the processing conveyance path.

  The discharge conveyance path includes a plurality of upper conveyance roller pairs 2, a paper discharge sensor 38, a discharge roller pair 3, a moving roller 7 that brings the sheets stacked on the paper discharge tray 12 to one side, an upper surface of the paper discharge tray 12, or a discharge roller. A paper surface that detects the height of the top surface of the stacked paper on the paper discharge tray 12 by detecting the position of the paper surface lever 13 that moves up and down in contact with the top surface of the paper stacked on the paper tray 12. Sensors 32 and 33 are arranged. Further, the paper discharge tray 12 is appropriately moved up and down (up and down direction in FIG. 1) and left and right (in the direction orthogonal to the paper surface of FIG. 1, that is, orthogonal to the paper discharge direction to the paper discharge tray 12 by a vertical motor and shift motor (not shown). Direction).

  On the other hand, on the binding processing transport path, a plurality of lower transport roller pairs 4, a paper discharge sensor 37, a paper feed roller 6a as a discharge roller, and a brush disposed coaxially with the paper feed roller 6a from the upstream side in the transport direction. A roller 6b and the like are disposed. The lower conveyance roller pair 4 is driven by a conveyance motor (not shown). As shown in FIG. 1, the binding processing conveyance path on the downstream side of the lower conveyance roller pair 4 on the downstream side is a curve, and a paper discharge sensor 37 is arranged at the entrance of this curve. The presence or absence of passage of the paper P at the position is detected. The paper feed roller 6a and the brush roller 6b, which are paper transport means for transporting the paper, transport and transfer the paper P that has passed through the binding processing transport path to the staple tray 21, and are disposed at the exit of the curve. Yes.

Next, the binding processing tray unit will be described.
FIG. 2 is a perspective view showing a schematic configuration of each member constituting the binding processing tray portion and its attached mechanism. FIG. 3 is an enlarged side view of the vicinity of the return roller 5.

  The staple tray 21 serving as a stacking tray is configured to stack a plurality of sheets of paper P conveyed by the paper feed roller 6a and the brush roller 6b on a paper stacking surface 21a serving as a stacking surface as a sheet bundle.

  The return roller 5a and the return roller 5b (which are also simply referred to as the return roller 5 when they are not distinguished from each other), which are paper moving means, have their contact surfaces in contact with the paper P and direct the paper P toward the rear end reference fence 19 described later. To move. Thus, the sheet P can be aligned in the vertical direction (conveyance direction) by causing the sheet trailing edge to abut the trailing edge reference fence 19.

  The paper P guided to the staple tray 21 by the paper feed roller 6a and the brush roller 6b is sequentially stacked on the staple tray 21 disposed in an inclined manner in the apparatus as shown in FIG. At this time, every time the paper P reaches the staple tray 21, alignment in the vertical direction (conveyance direction) is performed by the return roller 5a or the return roller 5b, and the jogger fence 9 (front side jogger fence 9a, back side jogger fence 9b). As a result, alignment in the horizontal direction (paper width direction which is a direction orthogonal to the transport direction) is performed.

  Further, the paper feed roller 6a and the brush roller 6b are rotated counterclockwise in FIG. 3 by obtaining a rotational driving force from the brush roller belt 47 as shown in FIG.

  As shown in FIG. 3, a rear end reference fence 19 having a reference surface (abutment surface) 19B for abutting and vertically aligning the rear end of the paper is provided at the lower end of the staple tray 21. That is, the rear end reference fence 19 extends from the lower end of the staple tray 21 to a reference surface 19B extending substantially perpendicular to the paper stacking surface 21a of the staple tray 21, and from the upper end of the reference surface 19B to the paper stacking surface 21a. It has a bending guide portion 19A that is bent in parallel and bent in a direction away from the upper portion. The rear end of the sheet conveyed downward by the bending guide portion 19 </ b> A is guided into the rear end reference fence 19.

  The return roller 5b is given a pendulum motion around the fulcrum 55 as shown by arrows m1 and m2 in FIG. Further, the return roller 5b itself rotates counterclockwise as indicated by an arrow n in FIG. As a result, the conveying force in the direction of the trailing edge reference fence generated when the return roller 5 rotates counterclockwise and contacts the upper surface of the sheet is intermittently applied to the sheet P fed to the staple tray 21. The paper P is abutted against the rear end reference fence 19. Further, the return roller 5a also operates by the same mechanism as the return roller 5b, and abuts the paper P against the rear end reference fence 19.

  As shown in FIG. 2, the jogger fence 9 is provided as a pair (9a, 9b) in the paper width direction, and is driven by a jogger motor 26 capable of forward and reverse rotation via a timing belt 49 to reciprocate in the paper width direction.

Here, the reciprocation of the jogger fence 9 in the paper width direction will be described.
When the length of the sheet P to be aligned in the sheet width direction is the sheet width W, in the standby state until the sheet P is transported, the sheet width direction of the near side jogger fence 9a and the back side jogger fence 9b Is a little wider than the paper width W. When the paper P is fed into the staple tray 21 and reaches between the two jogger fences 9, the front jogger fence 9a is in the k1 direction in FIG. 2, and the back jogger fence 9b is in the l1 direction in FIG. Moving.

  When the distance in the paper width direction between the two jogger fences 9 becomes the paper width W, the jogger motor 26 is reversed and the front jogger is rotated until the distance in the paper width direction between the two jogger fences 9 becomes the distance in the standby state. The fence 9a is moved in the k2 direction in FIG. 2, and the back jogger fence 9b is moved in the l2 direction in FIG.

  By such control, after the two jogger fences 9 move inward at the same time, the jogger fence 9 that moves outward simultaneously is reciprocated. Each time the paper P is sent to the staple tray 21, the reciprocation described above is performed once or a plurality of times, thereby aligning a bundle of sheets P (hereinafter also referred to as a paper bundle) stacked on the staple tray 21 in the paper width direction. I do.

  As shown in FIG. 4, the stapling apparatus 11 is driven via a stapler timing belt 50 by a staple moving motor 27 capable of forward and reverse rotation, and is used to bind a predetermined position at the end on the rear end side in the conveyance direction of the sheet bundle. It moves in the paper width direction indicated by the middle arrow L. A staple home position sensor 22 that detects the home position of the stapling apparatus 11 is provided at one end of the moving range, and the binding position in the paper width direction is controlled by the amount of movement of the stapling apparatus 11 from the home position. Is done.

  Although the sheet width direction of the stapling apparatus 11 is not shown, strictly speaking, the pulley of the discharge belt 10 is disposed below the center portion of the staple tray 21. Therefore, in order to avoid this, the stapling apparatus 11 is moved in the paper width direction by being lowered at the center.

  Further, on the rear end reference fence 19, fixed pieces 19 a and 19 b that are arranged at a distance from the center of the lower end of the staple tray 21 and fixed in position, and are arranged at both ends of the lower end of the staple tray 21, respectively. Has movable pieces 19c, 19d that move together when the moves.

  Further, immediately after the trailing edge of the paper is detected by the paper discharge sensor 37 in the transport path upstream of the stapling apparatus 11, the timing when the on-command is issued to the return solenoid 30 to operate the return roller 5b. Thus, the paper discharge sensor 37 is arranged at a position where the return roller 5b can hit the trailing edge of the paper.

  FIG. 5 is a perspective explanatory view for explaining the discharging operation of the discharge belt 10. Further, β in FIG. 5 is an enlarged perspective view in the vicinity of the discharge belt home position sensor 39.

  The discharge belt 10 is positioned at the alignment center in the paper width direction, and the discharge belt 52 is stretched between three pulleys 62 as shown in FIG. By driving the discharge motor 57, the pulley 62 that supports the upper end of the discharge belt 10 is rotationally driven, the drive is transmitted to the discharge belt 10, and the discharge belt 10 moves endlessly.

  The discharge belt 10 is provided with a discharge claw 10a protruding on the outer periphery thereof, and the discharge motor 57 is driven to rotate the discharge belt 10 counterclockwise in FIG. The discharge claw 10a comes into contact with the rear end (lower end) of the sheet bundle subjected to the binding process. Thereafter, the discharge belt 10 further moves endlessly, whereby the sheet bundle is lifted by the discharge claw 10 a, discharged from the staple tray 21, and discharged to the discharge tray 12.

  When the paper P is transported toward the trailing edge reference fence 19 by the return roller 5a or the return roller 5b, the paper P is transported so that the return roller 5a or the return roller 5b rubs the surface of the paper. For this reason, when a large number of sheets P are stacked in the jogger fence 9 (between the front jogger fence 9a and the back jogger fence 9b), when the sheet surface is rubbed by the return roller 5a or the return roller 5b, The toner and ink of the image adhere to the contact surfaces of the return roller 5a and the return roller 5b with the paper. Then, the toner or ink attached to the contact surface of the return roller 5a or the return roller 5b moves onto the paper P, and thus the paper is soiled. In particular, if the toner or ink attached to the contact surface of the return roller 5a or the return roller 5b moves to a place where there is no image on the paper P or a place where the image density is low, the paper stains become conspicuous.

[Configuration example 1]
In this configuration example, after a predetermined number of operations are carried out using the return roller 5b to the rear end reference fence 19, the operation is switched from the return roller 5b to the return roller 5a. As a result, if the return roller 5a becomes dirty due to use over time, the return roller 5b is used as the new return roller 5 to convey the paper P to the rear end reference fence 19, so that the paper P is transferred to the rear end reference fence only by the return roller 5b. Paper contamination can be reduced over a longer period than when the paper is continuously conveyed to the fence 19.

  The return roller 5a and the return roller 5b are arranged side by side on the center line in the paper width direction. Accordingly, when the paper P is conveyed toward the trailing edge reference fence 19 by the return roller 5a or the return roller 5b, it is difficult to generate a force for rotating the paper P on the paper stacking surface 21a of the staple tray 21. The alignment accuracy of the paper P becomes good.

  Further, when a plurality of return rollers, that is, the return roller 5a and the return roller 5b are arranged side by side on the same straight line in the sheet conveying direction as in this configuration example, as shown in FIG. 3, the return roller 5a and the return roller The position where the paper P is struck differs between 5b and 5b. Therefore, the timing at which the paper P comes to the hit position of the paper P by the return roller 5a and the return roller 5b is different, the distance from the position where the paper P is hit by the return roller 5a to the trailing edge reference fence 19, and the paper by the return roller 5b. The distance from the position of hitting P to the rear end reference fence 19 is different.

  Therefore, if the timing for operating the return roller 5a and the timing for operating the return roller 5b are the same, even if one of the return rollers 5 can abut the trailing edge of the sheet against the trailing edge reference fence 19, The return roller 5 may not be able to abut the trailing edge of the sheet against the trailing edge reference fence 19.

  Therefore, by changing the timing of operation between the return roller 5a and the return roller 5b, the return roller 5a and the return roller 5b are brought into contact with the paper P at an appropriate timing, and the paper P is directed toward the rear end reference fence 19. The rear end of the sheet can be abutted against the rear end reference fence 19 regardless of the return roller 5 that is conveyed and used. Therefore, it is possible to optimally align the trailing edge of the sheet at the trailing edge reference fence 19.

[Configuration example 2]
The darker the toner or ink of the image on the paper P at the contact portion between the return roller 5 and the paper P, the easier the toner or ink or the like moves to the return roller 5.

  Therefore, in this configuration example, in order to estimate how much toner or ink is attached to the return roller 5, the return roller 5 is set to the number n of sheets that is the number of sheets P that have passed through the staple tray 21. A value n × G obtained by multiplying a coefficient G set in advance according to the image density at the contact portion between the toner and the paper P is used as a criterion for determining the degree of toner or ink adhesion to the return roller 5. Note that the image density at the contact portion between the return roller 5 and the paper P can be obtained from image data used when an image is formed on the paper P by the image forming apparatus.

  As a result, when the return roller 5b used before is switched to the return roller 5a after the return roller 5b used previously becomes dirty, the toner and ink of the return roller 5b are only used by the number of sheets P as in the configuration example 1. Rather than estimating the degree of adhesion, the degree of adhesion of toner and ink on the return roller 5b can be estimated with higher accuracy by considering the density of the image at the contact portion between the return roller 5b and the paper P. Therefore, it is possible to switch the return roller 5 used for the return roller 5a from the return roller 5b at a more appropriate timing, and it is possible to suppress paper stains that may occur when the return roller 5b is used.

[Configuration example 3]
The higher the image density at the contact portion between the return roller 5 and the paper P, the greater the amount of toner and ink adhering to the return roller 5. Therefore, when a plurality of return rollers 5 are provided, the return roller 5 is provided. By selecting and using the return roller 5 where the image density on the paper P is low at the contact portion between the paper P and the paper P, the return roller 5 becomes difficult to get dirty, and each of the plurality of return rollers 5 is in a state where there is little dirt. Can be used for a long time.

  Therefore, in the present configuration example, the image density at the contact portion of the return roller 5a is compared with the image density at the contact portion of the return roller 5b, and the image density at the contact portion of the return roller 5a is compared with the return roller. When the image density is less than or equal to the image density at the contact portion 5b, the return roller 5a is used. On the other hand, when the image density at the contact portion of the return roller 5b is lower than the image density at the contact portion of the return roller 5b, the return roller 5b is used. FIG. 6 shows a flowchart of operation control of the return roller 5 at this time.

  First, the density of the image on the paper P at the contact portion between the return roller 5a and the paper P is obtained from the image data used when the image is formed on the paper P by the image forming apparatus (S1). Next, the density of the image on the paper P at the contact portion between the return roller 5b and the paper P is obtained from the image data used when the image forming apparatus forms an image on the paper P (S2). Then, the image density at the contact portion of the return roller 5a is compared with the image density at the contact portion of the return roller 5b, and the image density at the contact portion of the return roller 5a is compared with the image density at the contact portion of the return roller 5b. If the image density is less than or equal to the image density (YES in S3), the return roller 5a is operated, the paper P is conveyed toward the rear end reference fence 19, and the rear end of the paper is abutted against the rear end reference fence 19. The rear end of the sheet is aligned at the rear end reference fence 19 (S4). On the other hand, when the image density at the contact portion of the return roller 5b is lower than the image density at the contact portion of the return roller 5b (NO in S3), the return roller 5a is operated and the rear end reference fence 19 is moved. The paper P is conveyed toward the rear, and the rear edge of the paper is abutted against the rear edge reference fence 19 to align the rear edge of the paper at the rear edge reference fence 19 (S5).

[Configuration example 4]
As shown in FIG. 7, the shape of the return roller 5 used in this configuration example is an arc shape having a convex surface at the cut surface obtained by cutting the return roller 5 in the axial direction, in other words, the center in the axial direction of the return roller 5. The crown shape is such that the part has a larger diameter than both ends.

  Since the return roller 5 has a crown shape, the contact surface of the return roller 5 that contacts the paper P can be changed by tilting the return roller 5 with respect to the paper P. Accordingly, as the number of sheets passing increases, in other words, as the number of sheets P sent to the rear end reference fence 19 by the return roller 5 increases, the posture of the return roller 5 shown in FIG. By gradually tilting the return roller 5 to the posture of the return roller 5 shown in FIG. 5B and changing the posture, the surface of the return roller 5 on which no toner or ink adheres is brought into contact with the paper P. The sheet P can be conveyed toward the rear end reference fence 19. Therefore, it is possible to suppress paper contamination more than when the same surface of the return roller 5 is always brought into contact with the paper P.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A paper transporting means such as a paper feed roller 6a and a brush roller 6b for transporting paper; a stacking tray such as a staple tray 21 for stacking a plurality of paper transported by the paper transporting means on a stacking surface and stacking them as a paper bundle; An alignment member such as a trailing edge reference fence 19 that aligns the paper by abutting the rear end of the paper loaded in the stacking tray in the paper conveyance direction, and the contact surface of the paper contact the paper so that the paper faces the alignment member. The sheet processing apparatus having the sheet moving means such as the return roller 5 to be moved has a plurality of sheet moving means and switches the sheet moving means to be used at a predetermined timing. According to this, as described in the above embodiment, from the sheet moving means in which the contact surface that is in contact with the sheet surface is heavily soiled, the other contact sheet is not soiled or soiled. By switching to the moving means, the paper can be moved toward the alignment member. Therefore, paper contamination can be reduced as compared with a case where only one paper moving unit is continuously used to move the paper toward the alignment member.
(Aspect B)
In (Aspect A), the predetermined timing is determined from the density of the image of the portion of the sheet that contacts the sheet moving means and the number of sheets passed. According to this, as described in the above embodiment, the amount of toner or ink adhering to the contact surface of the sheet moving unit can be accurately grasped, and the sheet moving unit is switched at a more appropriate timing. Is possible.
(Aspect C)
In (Aspect A), based on the image density at the contact portion between each sheet moving unit and the sheet, the sheet moving unit used to move the sheet from the plurality of sheet moving units is determined. According to this, as described in the above embodiment, the sheet moving means is hardly contaminated, and each of the plurality of sheet moving means can be used for a long time with little contamination.
(Aspect D)
In (Aspect A), (Aspect B), or (Aspect C), the contact surface of the paper moving means with the paper is variable. According to this, as described in the above embodiment, paper contamination can be reduced as compared with the case where the same surface of the paper moving means is always brought into contact with the paper.
(Aspect E)
In (Aspect D), the sheet moving means is a crown-shaped roller member having a larger diameter at the central portion in the axial direction than the diameter at both ends in the axial direction, and makes contact with the sheet by changing the inclination of the roller member with respect to the sheet. Change the contact surface. According to this, as described in the above embodiment, by tilting the sheet moving unit with respect to the sheet, the contact surface of the sheet moving unit with the sheet can be changed, and sheet contamination can be reduced.
(Aspect F)
In (Aspect A), (Aspect B), (Aspect C), (Aspect D) or (Aspect E), the respective sheet moving means are arranged so that the contact positions with the sheets differ among the plurality of sheet moving means. The timing for operating each sheet moving means is different. According to this, as described in the above embodiment, it is possible to convey the sheet toward the alignment member at an optimal timing in accordance with the contact position of each sheet moving unit with the sheet, and perform excellent sheet alignment. it can.
(Aspect G)
In (Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E) or (Aspect F), a plurality of paper moving means are arranged side by side on the center line in the paper width direction. According to this, as described in the above embodiment, when the sheet is moved toward the alignment member by the sheet moving unit, a force that rotates the sheet on the stacking surface of the stacking tray is hardly generated. The paper alignment accuracy is improved.
(Aspect H)
In an image forming apparatus including an image forming unit that forms an image on a sheet and a sheet processing unit that performs a predetermined process on the sheet formed by the image forming unit, the sheet processing unit is configured as (Aspect A ), (Aspect B), (Aspect C), (Aspect D), (Aspect E), (Aspect F) or (Aspect G) paper processing apparatus was used. Thereby, as described in the above embodiment, the contamination of the paper can be reduced.

DESCRIPTION OF SYMBOLS 1 Entrance roller pair 2 Upper conveyance roller pair 3 Ejection roller pair 4 Lower conveyance roller pair 5 Return roller 5a Return roller 5b Return roller 6a Paper feed roller 6b Brush roller 7 Shift roller 8 Branch claw 9 Jogger fence 9a Front side jogger fence 9b Back Side jogger fence 10 Discharge belt 10a Discharge claw 11 Staple device 12 Paper discharge tray 13 Paper lever 19 Rear reference fence 19A Guide portion 19B Reference surface 19a Fixed piece 19b Fixed piece 19c Movable piece 19d Movable piece 21 Staple tray 21a Paper stacking surface 22 Staple home position sensor 26 Jogger motor 27 Staple moving motor 30 Solenoid 32 Paper surface sensor 33 Paper surface sensor 37 Paper discharge sensor 38 Paper discharge sensor 39 Release belt home position sensor 47 Brush Raberuto 49 timing belt 50 stapler timing belt 52 discharge belt 55 fulcrum 57 release motor 62 pulley 200 post-processing apparatus 202 shift tray 300 image forming section 301 entrance sensor 600 an image forming apparatus

JP 2008-74569 A

Claims (8)

Paper transport means for transporting paper,
A stacking tray on which a plurality of sheets conveyed by the sheet conveying unit are stacked on a stacking surface and stacked as a sheet bundle;
An alignment member that aligns paper by abutting the rear end in the paper transport direction of the paper loaded on the stacking tray;
In a paper processing apparatus comprising paper moving means for moving the paper toward the alignment member by bringing its contact surface into contact with the paper,
A sheet processing apparatus comprising a plurality of the sheet moving means and switching the sheet moving means used at a predetermined timing. The sheet processing apparatus according to claim 1, wherein
The paper processing apparatus according to claim 1, wherein the predetermined timing is determined from a density of an image of a portion of the paper that comes into contact with the paper moving means and a number of papers to be passed. The sheet processing apparatus according to claim 1, wherein
A paper processing apparatus that determines a paper moving means to be used for moving paper from the plurality of paper moving means based on an image density at a contact portion between each paper moving means and the paper. In the paper processing apparatus of Claim 1, 2, or 3,
A sheet processing apparatus, wherein a contact surface of the sheet moving means with the sheet is variable. The sheet processing apparatus according to claim 4.
The sheet moving means is a crown-shaped roller member having a diameter in the central portion in the axial direction that is larger than the diameter at both ends in the axial direction. By changing the inclination of the roller member with respect to the sheet, the contact surface that contacts the sheet is changed. A paper processing apparatus characterized by changing. The sheet processing apparatus according to claim 1, 2, 3, 4 or 5.
A sheet processing apparatus, wherein each of the plurality of sheet moving means is provided with each sheet moving means so that a contact position with the sheet is different, and the timing of operation of each sheet moving means is different. In the paper processing apparatus according to claim 1, 2, 3, 4, 5 or 6,
A sheet processing apparatus comprising a plurality of the sheet moving means arranged side by side on a center line in the sheet width direction. Image forming means for forming an image on paper;
In an image forming apparatus comprising a paper processing unit that performs a predetermined process on a paper image formed by an image forming unit,
An image forming apparatus using the paper processing apparatus according to claim 1 as the paper processing means.

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