JP2013032197A - Sheet processing device, image forming system and sheet alignment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately load a sheet or a bundle of sheets even if a sheet has a significantly curled-up end, and to make the curled-up end pressed down without a need for an independent drive source for pressing the sheet.SOLUTION: A sheet processing device for applying a predetermined process to a conveyed sheet includes: a sheet discharge tray 203 on which a sheet or a sheet bundle is discharged and stacked; a staple tray 219 on which a conveyed sheet is temporarily stacked; a sheet discharge roller 206 for discharging the conveyed sheet to the sheet discharge tray 203, or discharging the sheet bundle stacked on the staple tray 219 to the sheet discharge tray 203; and a sheet pressing member 209 attached to a drive axis 223 of the sheet discharge roller 206 for pressing the trailing end of the sheet or sheet bundle in a conveyance direction according to a relative distance to an end of a movable tray 208b of the sheet discharge tray 203, or rotating around the drive axis 223 without making contact with the movable tray 208b.

Description

  The present invention relates to a sheet processing apparatus, an image forming apparatus, and a sheet aligning method, and in particular, a sheet process for performing a predetermined process on a sheet-like recording medium that has been carried in (referred to as “sheet” in the present specification). The present invention relates to an apparatus, an image forming system including the sheet processing apparatus and an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a digital multifunction peripheral, and a sheet alignment method executed by the sheet processing apparatus.

  For a plurality of sheets ejected from the image forming apparatus, the sheet aligning means aligns the sheet conveying direction and the sheet width direction (direction perpendicular to the sheet conveying direction), and performs predetermined post-processing such as binding processing and ejects the sheets. There is a sheet processing apparatus, a so-called sheet post-processing apparatus. In such a paper post-processing apparatus, when a plurality of sheets on which images are formed by the image forming apparatus are discharged and stacked on a paper discharge tray, the paper discharged from the paper post-processing apparatus is discharged and stacked first. In some cases, the quality of the loaded paper is reduced. To prevent this, a paper pressing lever is provided, and when the paper is discharged from the discharge port, the trailing edge of the paper loaded first is pressed with the paper pressing lever to prevent misalignment of the stacked paper. The disclosed invention is described in, for example, Japanese Patent Application Laid-Open No. 2011-020775.

  In the invention described in Patent Document 1, it is necessary to provide an independent drive source such as a motor or a solenoid in order to drive a sheet pressing lever that presses the trailing edge of the sheet discharged to the sheet discharge tray. Further, in the configuration described in Patent Document 1, the retracting position of the sheet pressing lever has to be the same as or lower than the sheet discharge roller so as not to interfere with the sheet conveyance. For this reason, when the trailing edge of the paper is greatly lifted due to the curling of the paper and reaches the vicinity of the paper discharge roller, it cannot be pressed by the paper pressing lever.

  Accordingly, the problem to be solved by the present invention is that an independent drive source is not required to hold the paper, and even when the lift of the rear end of the paper is large, the lift of the rear end can be suppressed and the paper or the sheet bundle can be accurately stacked. There is in doing so.

  In order to solve the above-described problem, the first means is a paper processing apparatus that performs a preset process on the paper that has been carried in and discharges the paper, and the first means for stacking the discharged paper or paper bundle. Stacking means, second stacking means for temporarily stacking the loaded paper, and discharging the loaded paper to the first stacking means or stacking on the second stacking means. A discharge unit for discharging the bundle of sheets to the first stacking unit, and a relative distance between the rotation driving shaft of the discharge unit and the upstream end of the first stacking unit in the sheet transport direction. Accordingly, a sheet pressing unit that presses a rear end portion in the transport direction of the sheet or the sheet bundle or rotates about a drive shaft is provided.

  The second means is characterized by an image forming system including the sheet processing apparatus according to the first means.

  The third means includes a first stacking means for stacking the discharged paper or a bundle of sheets, and a second stacking means for temporarily stacking the loaded paper, and the loaded paper Is a paper processing method for performing a preset process on the paper and discharging the discharged paper. The paper that has been carried in is discharged to the first stacking means by the discharging means or stacked on the second stacking means. A step of discharging the sheet bundle to the first stacking unit by the discharging unit, and a rear end portion of the first stacking unit in the sheet transport direction being brought close to and away from the sheet discharge unit, and the first stacking unit Pressing the rear end of the sheet or sheet bundle in the conveying direction by a sheet pressing means attached to the rotational drive shaft of the discharging means with the relative distance from the upstream end of the sheet conveying direction being close The paper presser is separated by a relative distance. Stage characterized in that it and a step of retracting to a position that is not in contact with the conveying direction trailing end portion of the sheet or sheet bundle.

  According to the present invention, an independent drive source is not required for pressing the paper, and even when the trailing edge of the sheet is lifted up, the lifting of the trailing edge can be suppressed and the sheets or the sheet bundle can be accurately stacked.

1 is a diagram illustrating an outline of a system configuration of an image forming system according to an embodiment of the present invention. 1 is a diagram illustrating a schematic configuration of a sheet post-processing apparatus according to an embodiment of the present invention. It is a figure which shows the paper pressing mechanism in the paper post-processing apparatus which concerns on embodiment of this invention. 1 is a block diagram illustrating a control configuration of an image forming system according to an embodiment of the present invention. FIG. 9 is an operation explanatory diagram showing an operation in a shift mode, and shows a state when a sheet is conveyed to a sheet post-processing device. FIG. 9 is an operation explanatory diagram showing an operation in a shift mode, and shows a state when a sheet is transferred from a shift conveyance roller to a sheet discharge roller. FIG. 9 is an operation explanatory diagram showing an operation in a shift mode, and shows a state when a sheet is discharged from a discharge roller to a discharge tray. FIG. 9 is an operation explanatory diagram showing an operation in a shift mode, and shows a state when the movable tray portion is lowered and the sheet pressing member starts to rotate. FIG. 9 is an operation explanatory diagram showing an operation in a shift mode, and shows a state when the movable tray portion has finished moving to the paper press avoiding position and the paper discharge motor is driven a predetermined number of steps. FIG. 9 is an operation explanatory diagram illustrating an operation in a shift mode, and shows a state when the sheet pressing member moves to a position where it does not contact the movable tray section and the movable tray section rises to the sheet pressing position. FIG. 9 is an operation explanatory diagram showing an operation in a shift mode, and shows a state when the sheet pressing member rotates until it abuts on the movable tray. FIG. 9 is an operation explanatory diagram showing an operation in a shift mode, and shows a state when sheets are stacked on the sheet discharge tray and the leading edge of the next sheet reaches the sheet discharge tray. FIG. 9 is an operation explanatory diagram illustrating an operation in a stipple mode, and shows a state when a sheet is conveyed to a sheet post-processing apparatus. FIG. 9 is an operation explanatory diagram showing an operation in a staple mode, and shows a state when a trailing roller is lowered at a timing when a rear end of a sheet passes a shift conveyance roller. FIG. 9 is an operation explanatory diagram showing an operation in a stipple mode, and shows a state when a sheet is switched back by a hitting roller. FIG. 9 is an operation explanatory diagram showing an operation in a stipple mode, and shows a state when alignment in the paper width direction by a jogger fence. FIG. 9 is an operation explanatory diagram illustrating an operation in a stipple mode, and shows a state when the paper discharge opening / closing guide plate is lowered after the binding process. FIG. 9 is an operation explanatory diagram illustrating an operation in a staple mode, and illustrates a state when a closed sheet bundle is discharged to a discharge tray. FIG. 9 is an operation explanatory diagram illustrating an operation in a stipple mode, and illustrates a state at the time of starting a sheet pressing operation. FIG. 9 is an operation explanatory view showing an operation in a stipple mode, and shows a state when the free end side of the movable tray portion is lowered and moved to a paper press avoiding position. FIG. 9 is an operation explanatory diagram showing an operation in a stipple mode, and shows a state when the sheet pressing member moves to a sheet pressing avoidance position where it does not contact the movable tray portion. FIG. 9 is an operation explanatory diagram showing an operation in a stipple mode, and shows a state when the movable tray portion is raised and moved to a sheet pressing position. FIG. 9 is an operation explanatory view showing an operation in the staple mode, and shows a state when the sheet rear end in contact with the lifted state is contacted from above and rotated until it contacts the movable tray portion to hold the sheet bundle. 6 is a timing chart illustrating operation timings during paper discharge, paper pressing, and stacking operations in a shift mode. 6 is a timing chart illustrating operation timings during paper discharge, paper pressing, and stacking operations in the staple mode. It is a figure which shows the other example of a paper pressing mechanism.

  The present invention provides a sheet pressing member via a so-called torque limiter on the drive shaft of the discharging means for discharging the sheet to the sheet discharge tray, and when the sheet discharge tray is at the sheet pressing position, the rotation of the sheet pressing member is controlled. And the rear end of the stacked paper is pressed against the paper discharge tray.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, equivalent parts are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate.

  FIG. 1 is a diagram showing an outline of the system configuration of an image forming system according to an embodiment of the present invention. In the figure, the image forming system according to the present embodiment is an image forming apparatus 100 and a sheet processing apparatus (in the present embodiment, since the post-processing of an image-formed sheet is performed, it is hereinafter referred to as a “sheet post-processing apparatus”). 200 and an image reading apparatus 300.

  The image forming apparatus 100 is an indirect transfer type tandem color image forming apparatus. In the figure, an image forming unit 110 having a four-color image forming station 111 disposed substantially in the center thereof is adjacent to the lower side of the image forming unit 110. The optical writing unit (not shown) provided in this manner, the paper feeding unit 120 provided below the image forming unit 110, and the paper picked up by the paper feeding unit 120 are conveyed to the secondary transfer unit 140 and the fixing unit 150. A paper feed conveyance path (vertical conveyance path) 130, a paper discharge path 160 for conveying the paper on which the image is fixed to the paper post-processing apparatus 200 side, a paper on which an image is formed on one side is reversed, and an image is formed on the other side For this purpose, a double-sided conveyance path 170 is provided.

  The image forming unit 110 includes a photosensitive drum for each color of YMCK of the image forming station 111, and a charging unit, a developing unit, a primary transfer unit, a cleaning unit, and a charge eliminating unit arranged along the outer periphery of the photosensitive drum. And an intermediate transfer belt 112 for intermediate transfer of an image formed on the photosensitive drum by a primary transfer unit, and an optical writing unit for writing an image for each color on the photosensitive drum. The optical writing unit is disposed below the image forming station 111, and the intermediate transfer belt 112 is disposed above the image forming station 111.

  The intermediate transfer belt 112 is rotatably supported by a plurality of support rollers, and one of the support rollers 114 is opposed to the secondary transfer roller 115 via the intermediate transfer belt 112 in the secondary transfer unit 140, and the intermediate transfer belt 112. The upper image can be secondarily transferred to the paper.

  The image forming process of the indirect transfer tandem color image forming apparatus is well known and is not directly related to the gist of the present invention, and thus detailed description thereof is omitted.

  The paper feeding unit 120 includes a paper feeding tray 121, a pickup roller 122, and a paper feeding / conveying roller 123, and feeds the paper picked up from the paper feeding tray 121 upward along the vertical conveying path 130. The fed sheet is transferred with an image by the secondary transfer unit 140 and sent to the fixing unit 150. The fixing unit 150 includes a roller pair 151 including a fixing roller and a pressure roller. Heat and pressure are applied in a process in which the sheet passes through the nip between the roller pair 151, and the toner is fixed to the sheet.

  A paper discharge conveyance path 160 and a double-sided conveyance path 170 are provided downstream of the fixing unit 150, both of which are branched in two directions by a branching claw 161 and conveyed to the sheet post-processing apparatus 200 side, and a double-sided conveyance path. The transport path is selected when transported to 170. A branch conveyance roller 162 is provided in the immediate vicinity of the branch claw 161 on the upstream side in the sheet conveyance direction, and applies a conveyance force to the sheet.

  The sheet post-processing apparatus 200 is disposed inside the image forming apparatus 100 or mounted on a paper discharge tray (housing tray) of the image forming apparatus 100 and is applied to an image-formed sheet conveyed from the image forming apparatus 100. And is stacked on the discharge tray 203 located on the most downstream side, which will be described in detail later. When the image reading apparatus 300 is provided as shown in FIG. 1, the sheet post-processing apparatus 200 is between the image forming apparatus 100 and the image reading apparatus 300, and is the housing of the image forming apparatus 100. A paper discharge tray formed on the upper surface, that is, a so-called housing tray, is mounted on a portion that was originally a space portion. Thereby, space can be used effectively and space saving can be promoted.

  The image reading device 300 is a known device that optically scans an original set on a contact glass and reads an image on the original surface. Since the configuration and function of the image reading apparatus 300 itself are known and are not directly related to the gist of the present invention, detailed description thereof is omitted.

  The image forming apparatus 100 configured generally as described above generates image data used for writing based on original data read from the image reading apparatus 300 or print data transferred from an external PC or the like, and the image data Based on the data, optical writing is performed from the optical writing unit to each photosensitive drum, and the image formed for each color at each image forming station 111 is sequentially transferred to the intermediate transfer belt 112 and is transferred onto the intermediate transfer belt 112. A color image in which images of four colors are superimposed is formed. On the other hand, paper is fed from the paper feed tray 121 according to the image formation. The sheet is temporarily stopped at a registration roller position (not shown) immediately before the intermediate transfer unit 140, sent in time with the leading edge of the image on the intermediate transfer belt 112, secondarily transferred by the intermediate transfer unit 140, and sent to the fixing unit 150. It is sent.

  In the case of single-sided printing or after double-sided printing of double-sided printing, the paper on which the image is fixed by the fixing unit 150 is transported to the discharge path 160 side by the switching operation of the branching claw 161, and in the case of double-sided printing. It is conveyed to the double-sided conveyance path 170 side. The sheet transported to the duplex transport path 170 is reversed, sent to the last intermediate transfer unit 140, an image is formed on the other surface, and then returned to the paper discharge path 160 side. The paper transported to the paper discharge path 160 side is transported to the paper post-processing device 200 and is subjected to predetermined paper processing by the paper post-processing device 200 or discharged to the paper discharge tray 203 without any processing.

  A paper discharge tray 203 disposed downstream of the paper discharge roller 206 includes a fixed tray portion 208a on the downstream side in the transport direction and a movable tray portion 208b on the upstream side. The movable tray portion 208b includes a paper discharge tray motor 221a and a cam link. It moves up and down by the mechanism 221b. The movable tray portion 208b is pivotally supported by the fixed tray portion 208a via a support shaft 221c with the upstream end as a fulcrum, and the operating end of the cam / link mechanism 221b is connected to the movable tray 208b. . As a result, the paper discharge tray motor 221a rotates, and the movable tray 208b swings about the support shaft 221c in response to this rotation.

FIG. 2 is a diagram showing a schematic configuration of the sheet post-processing apparatus 200 according to the present embodiment.
The sheet post-processing apparatus 200 includes an inlet roller pair 201, a discharge conveyance path 202, a shift discharge roller pair 204, a staple tray 219, a tapping roller 211, a rear end reference fence 220, a jogger fence 212, an upstream side in the sheet conveyance direction. A paper discharge opening / closing guide plate 205 provided with a paper discharge roller 206 and a paper discharge driven roller 205a as discharge means, and a paper discharge tray 203 are mainly constituted.

  That is, the paper receiving unit of the paper post-processing apparatus 200 has a pair of inlet rollers 201 that receives paper from the paper discharge transport path 160 of the image forming apparatus 100 and a paper discharge transport path that transports the received paper to the shift paper discharge roller pair 204 side. 202 and a shift discharge roller pair 204 having a function of shifting and discharging the paper to the discharge tray 203 are provided, and the inlet motor 216 rotates the inlet roller pair 201 and the shift discharge roller pair 204 to discharge the paper. The paper is conveyed along the paper conveyance path 202.

  In addition, an entrance sensor 207 serving as a paper position detection unit is disposed in the paper discharge conveyance path 202, detects the leading edge and the trailing edge of the sheet, and detects the leading edge and the trailing edge of the sheet detected by the CPU 401, which will be described later. The timing when each paper processing is performed is based on the number of driving steps of an inlet motor 216 which is a stepping motor and a paper discharge motor 217 which will be described later.

  An inlet roller pair 201 and a shift paper discharge roller pair 204 provided along the paper discharge conveyance path 202 function as a conveyance unit.

  FIG. 3 is a diagram illustrating a sheet pressing mechanism in the sheet post-processing apparatus according to the present embodiment.

  The sheet pressing mechanism M1 includes a torque limiter 230 provided on the (rotation) drive shaft 223 of the paper discharge roller 206, and a sheet pressing member 209 provided on the drive shaft 223 via the torque limiter 230. .

  In this embodiment, two sheet pressing members 209 are arranged in parallel to the drive shaft 223. As shown in FIG. 3A, a sponge material 224 is attached to the front end (contact portion) of the sheet pressing member 209 that contacts the sheet P or the sheet bundle P ′. When a rotational force in the direction of arrow R21 is applied to the drive shaft, the rotation of the sheet pressing member 209 is performed when the movable tray portion 208b of the paper discharge tray 203 is in a position where it contacts the tip of the sheet pressing member 209, that is, in the sheet pressing position. Is regulated by the discharge tray movable portion 208b. If there is paper on the paper discharge tray 203 at this time, the rear end of the paper stacked on the paper discharge tray 203 is pressed against the movable tray portion 208b as shown in FIG.

  As described above, the discharge tray motor 221a rotates in the movable tray portion 208b, and the movable tray portion 208b swings around the support shaft 221c in response to this rotation. Therefore, when the rear end of the sheet is pressed against the movable tray portion 208b by the sheet pressing member 209, the free end of the movable tray portion 208b can be lowered like Q21. When the movable tray portion 208b moves to a position where it does not come into contact with the front end of the paper pressing member 209, that is, to a paper pressing avoidance position, the paper pressing member 209 moves the drive shaft of the paper discharge roller 206 as shown in FIG. According to the movement of 223 (in the direction of arrow R21), it can rotate in the direction of arrow R21a.

  FIG. 4 is a block diagram showing a control configuration of the image forming system according to the present embodiment.

  In the figure, control of the image forming apparatus 100 is executed by an image forming apparatus control unit 410 having a built-in CPU 411, ROM 412, RAM 413, nonvolatile RAM 414, serial I / F 415, timer 416, and the like.

  The program code for control is stored in the ROM 412, and the CPU 411 expands the program code in the RAM 413, stores data necessary for control in the RAM 413, and uses the RAM as a work area, and defines the program code defined by the program code. To control each part.

  The image forming apparatus control unit 410 includes a motor used in the image forming unit 110 such as a photosensitive member, various DC loads 450 such as various motors and clutches in the sheet feeding unit 120, the sheet feeding conveyance path 130, and the double-side conveyance path 170, Various AC loads 470 and various sensors 460 such as a temperature sensor for detecting the temperature of the fixing roller are connected. Further, the image reading apparatus 300 and the operation display unit 440 are connected, and each unit is controlled via the image forming apparatus control unit 407.

  Control of the sheet post-processing apparatus 200 is executed by a sheet processing apparatus control unit 400 including a CPU 401, a ROM 402, a RAM 403, a serial I / F 404, a timer 405, and the like. The program code for control is stored in the ROM 402, and the CPU 401 expands the program code in the RAM 403, stores data necessary for control in the RAM 403, and uses the RAM as a work area, and the control defined by the program code. And various DC loads 420 are controlled. Examples of the various DC loads 420 include an inlet motor 216, a paper discharge motor 217, a shift motor 420a, a paper discharge opening / closing guide plate drive motor 420b, a paper discharge tray motor 221a, and the like.

  The image forming apparatus 100 and the paper post-processing apparatus 200 send and receive commands necessary for paper transport control via the serial I / Fs 415 and 404, and the CPU 401 of the paper post-processing apparatus 200 receives the commands and papers obtained from the various sensors 430. Based on the position information, drive control of the discharge opening / closing guide plate 204, drive control of the staple discharge roller 203, shift drive control of a shift mechanism (not shown), control of the height position of the discharge tray 206, and control of the discharge tray movable unit 207 Rotation control, rotation control of paper trailing edge press 208, alignment control of jogger fence 212, alignment control by tapping roller 211, swing control of swing member 228 by solenoid 229, elevation control of discharge roller 206 by link, Various controls including sheet abutting control by the tapping roller 211 and binding control of the stapler 215 are executed. The

  In this embodiment, the paper post-processing device 200 is provided in a space between the image reading device 300 and the main body having the image forming unit of the image forming device 100. However, the mounting space of the paper post-processing device 200 is as follows. The present invention is not limited to this embodiment. For example, in the case of a form that is discharged from the side surface of the main body of the image forming apparatus 100, it is installed on the side surface of the main body. In any case, the installation position is set according to the main body shape, main body structure, and paper discharge position of the image forming apparatus 100. However, the configuration, operation, and control of the sheet post-processing apparatus 200 are the same regardless of the position at which the sheet post-processing apparatus 200 is mounted on the paper discharge tray (housing tray) of the image forming apparatus 100.

  The operation of the sheet post-processing apparatus 200 after receiving the sheet discharged from the image forming apparatus 100 is different between a shift mode in which the sheet is shifted and discharged and a stipple mode in which a plurality of sheets are bound and discharged. Therefore, description will be made by adding each part configuration for each mode.

  FIG. 5 to FIG. 12 are operation explanatory views showing respective operations of paper conveyance, paper discharge, paper pressing, and stacking operations in the shift mode of the paper post-processing apparatus according to the present embodiment.

  The shift mode is a mode in which the paper discharge position is shifted in a direction perpendicular to the paper transport direction by a predetermined number of sheets P discharged from the image forming apparatus 100, and the paper P is sorted by this shift.

  The shift conveyance roller pair 204 is provided at the most downstream end of the paper discharge conveyance path 202 and is driven to reciprocate in a direction perpendicular to the paper conveyance direction by a shift motor (not shown). That is, when sorting the paper P in the shift mode, the shift transport roller pair 204 moves in a direction perpendicular to the paper transport direction every predetermined number of sheets, and the paper P transport direction is shifted by the amount moved in the vertical direction. Paper is discharged to the paper discharge tray 203. Thus, when the paper P is stacked on the paper discharge tray 203, the paper discharge positions are alternately shifted every predetermined number of sheets, and the paper P is sorted.

  Further, a paper discharge opening / closing guide plate 205 and a paper discharge roller 206 as paper discharge means are disposed downstream of the shift conveyance roller pair 204. The paper discharge roller 206 is driven by a paper discharge motor 217 as a drive source of the discharge means, and the paper discharge opening / closing guide plate 205 can be moved up and down by a paper discharge opening / closing guide plate drive motor (not shown). The paper is nipped and conveyed by a driven roller attached to the paper opening / closing guide plate 205, and the paper P is discharged onto the paper discharge tray 203 and stacked on the paper discharge tray 203.

  That is, as shown in FIG. 5, the paper P conveyed from the image forming apparatus 100 to the paper discharge conveyance path 202 is preset in a direction orthogonal to the paper conveyance direction while being conveyed by the shift conveyance roller pair 204. The amount is moved and delivered to the paper discharge roller 206 and the paper discharge driven roller 205a. At this time, the front end portion of the sheet pressing member 209 is in contact with the raised movable tray portion 208b.

  The paper P transferred from the shift conveying roller pair 204 to the paper discharge roller 206 and the paper discharge driven roller 205a is discharged to the paper discharge tray 203 side by both rollers 206 and 205a as shown in FIG. In this way, it is discharged onto the paper discharge tray 203.

  The paper pressing operation is executed when the trailing edge of the discharged paper P passes the paper pressing start position. The sheet pressing start position is conveyed by a distance D1 mm that the trailing edge of the sheet passes the position of the sheet discharge roller 206 when the sheet discharge motor 217 is driven a predetermined number of steps ST1 after the entrance sensor 207 serving as the sheet position detection unit is turned off. (See FIG. 24).

  Next, as shown in FIG. 8, the movable tray portion 208b is lowered (rotated) (in the direction of arrow D21), and the sheet pressing member 209 is rotated in the counterclockwise direction (in the direction of arrow R11). In the figure, the trailing edge of the paper P is curled and positioned at substantially the same height as the paper discharge roller 206.

  Next, as shown in FIG. 9, after the movable tray portion 208b is lowered to the lowermost end and the movable tray portion 208b completes the movement to the paper pressing avoidance position, the paper discharge motor 217 is driven a predetermined number of steps ST2. wait. When the sheet pressing member 209 further rotates counterclockwise and moves to a position where it does not contact the movable tray section 208b, the movable tray section 208b is raised (in the direction of arrow 22) and moved to the sheet pressing position as shown in FIG. Let

  In parallel with this operation, the sheet pressing member 209 makes one rotation according to the rotation of the drive shaft 223, contacts the rear end of the sheet in a lifted state as shown in FIG. 10, and further moves the movable tray portion as shown in FIG. It rotates until it abuts against 208b. Since the sheet pressing member 209 is attached to the drive shaft 223 via the torque limiter 230, the sheet pressing member 209 stops in contact with the movable tray 208b without hindering the rotation of the sheet discharge roller 206.

  In this way, the rear end of the paper is pressed against the movable tray portion 208b by the paper pressing member 209 and stacked on the paper discharge tray 203 as shown in FIG. When the stacking of the sheets P is completed and there is no subsequent sheet, the operation of the sheet discharge motor 217 is stopped. FIG. 12 shows a state when the next sheet is conveyed on the sheet stacked on the sheet discharge tray 203.

  FIG. 13 to FIG. 23 are operation explanatory views showing respective operations of paper conveyance, paper discharge, paper pressing, and stacking operations in the staple mode of the paper post-processing apparatus according to the present embodiment.

  In the staple mode, the sheets P discharged from the image forming apparatus 100 are temporarily stacked on the staple tray 219 and bound by the stapler 215 every predetermined number of sheets, and the bound sheet bundle P ′ is discharged to the discharge tray 203. It is a mode to do.

  A stepping (not shown) is provided between a pair of shift conveying rollers 204 provided at the most downstream end of the paper discharge conveyance path 202 and a paper discharge opening / closing guide plate 205 provided immediately before paper discharge to the paper discharge tray 203. A hitting roller 211 that is driven in the vertical direction by a motor (striking roller driving motor: FIG. 25-420c) is disposed. The hitting roller 211 is composed of a lever portion and a roller portion that move up and down, and the roller portion is rotationally driven by a paper discharge motor 217 in the direction opposite to the paper transport direction.

  In the stipple mode, the sheet P conveyed from the image forming apparatus 100 to the sheet discharge conveyance path 202 as shown in FIG. 13 has passed through the shift conveyance roller pair 204 at the rear end of the sheet P as shown in FIG. The tapping roller 211 is lowered at the timing (in the direction of arrow D31), and the paper P is pressed against the staple tray 219 at the roller portion as shown in FIG. Switch back until it hits 220.

  Further, a return roller 214 driven by an entrance motor 216 is disposed above the rear end reference fence 220, assisting the switchback of the sheet and aligning the sheet conveyance direction. This alignment is performed based on the rear end reference fence 220 by abutting against the rear end reference fence 220.

  When the paper switchback is completed, as shown in FIG. 16, the tapping roller 211 is raised (arrow D32 direction D), and in the paper width direction perpendicular to the paper transport direction by the jogger fence 212 arranged on the staple tray 219. Align. The jogger fence 212 is composed of two parts, a fixed side and a movable side, and the movable side part moves in a direction perpendicular to the paper conveyance direction (not shown in FIG. 25). The sheet is moved so as to be sandwiched between the fixed part and the sheet P is brought into contact with the side edge of the sheet P to align and align the sheet at the reference position. At that time, the end surface on one side of the rear end of the sheet is inserted up to the binding position of the staple needle of the stapler 215, and after the transport operation, the switchback operation, and the alignment operation of the designated number of sheets are completed, the stapler (not illustrated) is performed. The motor (FIG. 25—reference numeral 420e) is bound.

  After the binding process, the paper discharge opening / closing guide plate 205 is lowered as indicated by the chain line in FIG. 2 (FIG. 17: direction of arrow D11), and the paper bundle P ′ is sandwiched between the paper discharge roller 206 and the paper discharge driven roller 205a. By driving the paper motor 217, the sheet bundle P ′ is discharged to the discharge tray 203 as shown in FIG. The paper presence / absence sensor 213 is a sensor that detects the presence / absence of paper temporarily stacked on the staple tray 219, and is used to detect remaining paper in the apparatus when the power is turned on or when a jam occurs.

  The sheet pressing operation after FIG. 19 is executed when the rear end of the discharged sheet bundle P ′ passes the sheet pressing start position. When the trailing edge has passed the paper pressing start position, the paper discharge sensor 210 as the paper position detecting means is turned off and the number of drive steps of the paper discharge motor 217 is driven by a preset number of steps ST3. Further, it is assumed that the sheet bundle P ′ has been conveyed by a distance D2 mm that passes the position of the sheet discharge roller 206.

  When the sheet bundle P ′ passes through the position regarded as the position of the sheet discharge roller 206, the sheet discharge tray motor 221a rotates for a predetermined time Ta according to a command from the control unit, and the movable tray as shown in FIG. The free end side of the portion 208b is lowered (in the direction of arrow D21) and moved to the paper pressing avoidance position. When the movable tray portion 208 b is at the paper pressing avoidance position, the paper pressing member 209 can rotate according to the movement of the drive shaft 223 of the paper discharge roller 206.

  After completion of the movement of the movable tray portion 208b to the paper pressing avoidance position, it waits for the paper discharge motor 217 to be driven for a preset number of steps ST4. Then, when the sheet pressing member 209 moves to the sheet pressing avoidance position where it does not contact the movable tray section 208b as shown in FIG. 21, the movable tray section 208b is raised and moved to the sheet pressing position as shown in FIG.

  The sheet pressing member 209 makes one rotation according to the movement of the drive shaft 223, contacts the rear end of the sheet in the lifted state from above, and further rotates until it contacts the movable tray portion 208b as shown in FIG. Since the sheet pressing member 209 is attached to the drive shaft 223 via the torque limiter 230, the sheet pressing member 209 stops in contact with the movable tray 208b without hindering the rotation of the sheet discharge roller 206. In this way, the rear end of the sheet bundle P ′ is pressed against the movable tray unit 208 b by the sheet pressing member 209 and stacked on the sheet discharge tray 203. When the stacking of the sheet bundle P ′ is completed and there is no subsequent sheet, the operation of the sheet discharge motor 217 is stopped.

  By repeating the above operation, the sheets sorted on the sheet discharge tray 203 and the bundle of sheets subjected to the binding process are stacked.

  In the present embodiment, the sheet pressing start position is a position where the sheet trailing edge passes the sheet discharge roller 206 position (position where the sheet discharge sensor 210 detects the sheet bundle P ′ trailing edge: see FIG. 25). As a result, when a thin sheet such as thin paper is discharged, the sheet P moves over the sheet pressing member 209 stopped on the movable tray portion 208b of the discharge tray 203 as shown in FIG. Therefore, the sheet P can be prevented from being bent and folded, and the sheet P can be discharged onto the sheet discharge tray 203 without causing a stacking defect.

  FIG. 24 is a timing chart showing the operation timing at the time of paper discharge, paper pressing and stacking operations in the shift mode.

  This timing chart shows the timing of commands from the CPU 411 of the image forming apparatus 100 to the CPU 401 of the paper post-processing apparatus 200, the inlet sensor 207, the inlet motor 216, the paper discharge motor 217, the shift motor 420a, and the paper discharge opening / closing guide plate drive motor 420b. The relationship of the drive timing of the paper discharge tray motor 420c is shown.

  In this timing chart, when a paper discharge signal ON is input from the image forming apparatus 100 to the paper post-processing apparatus 200 (T1), the entrance motor 216 is turned on (T2) and driven at the main body paper discharge speed (linear speed). The paper P from the image forming apparatus 100 is received and conveyed. The inlet sensor 207 detects the leading edge of the paper P (T3), and when a preset timing has elapsed, the paper discharge motor 217 starts rotating in the transport direction at the same speed as the main body paper discharge speed (T4). . When the paper discharge signal from the image forming apparatus 100 is turned off (T5), that is, when the paper P passes through the image forming apparatus 100, the entrance motor 216 and the paper discharge motor 217 are accelerated, and the shift motor 420a is driven ( T6) The shift roller 204 is moved by a preset distance in a direction orthogonal to the paper transport direction (here, from the labor side to the back side of the apparatus), and the paper P is shifted.

  After the shift operation is started, when the trailing edge of the sheet is removed from the inlet sensor 207 (T7), the discharge opening / closing guide plate 205 is lowered (T8), and the discharge roller 206 and the discharge driven roller accelerated by the discharge motor 217 are closed. The sheet P is discharged to the discharge tray 203 side by 205a.

  Next, a paper pressing operation is executed. The paper pressing operation is executed when the trailing edge of the discharged paper P passes the paper pressing start position (T9). The sheet pressing start position is regarded as having been conveyed by a distance D1 mm that the trailing edge of the sheet passes the position of the sheet discharge roller 206 when the sheet discharge motor 217 is driven a predetermined number of steps ST1 after the entrance sensor 207 is turned off. The tray motor 221a is driven in the downward direction (T10) to lower the movable tray portion 208b and move it to the paper pressing avoidance position. When the paper discharge motor 217 is driven by a predetermined number of steps ST2 at the paper discharge linear speed (T11), the paper discharge tray motor 221a is driven in the upward direction to raise the movable tray portion 208b and press the paper P. While the paper discharge motor 217 is driven by the predetermined number of steps ST2, the paper discharge guide plate drive motor 420b is driven in the upward direction (T12), and the paper discharge driven roller 205a is separated from the paper P. Further, during this pressing operation, the next sheet P is carried from the image forming apparatus 100, the shift operation in the reverse direction is performed by the shift ON signal (T13), and the same operation is repeated for the number of sheets conveyed.

  FIG. 25 is a timing chart showing the operation timing at the time of paper discharge, paper pressing and stacking operations in the stipple mode.

  This timing chart shows the timing of commands from the CPU 411 of the image forming apparatus 100 to the CPU 401 of the paper post-processing apparatus 200, the inlet sensor 207, the inlet motor 216, the paper discharge motor 217, the shift motor 420a, and the paper discharge opening / closing guide plate drive motor 420b. The relationship between the driving timings of the tapping roller driving motor 420c, the jogger driving motor 420d, the paper discharge tray motor 221a, the paper discharge sensor 210, and the stapler motor 420e is shown.

  In this timing chart, when a paper discharge signal ON is input from the image forming apparatus 100 to the paper post-processing apparatus 200 (T21), the entrance motor 216 is turned on (T22) and driven at the main body paper discharge speed (linear speed). The paper P from the image forming apparatus 100 is received and conveyed. The entrance sensor 207 detects the leading edge of the paper P (T23), and when a preset timing has elapsed, the paper discharge motor 217 starts rotating at the same speed as the main body paper discharge speed (T24). When the paper discharge signal from the image forming apparatus 100 is turned off (T25) and the paper P passes through the image forming apparatus 100, the entrance motor 216 and the paper discharge motor 217 are accelerated and the shift motor 420a is driven (T26). Then, the shift roller 204 is moved by a preset distance in a direction orthogonal to the paper conveyance direction (here, from the labor side to the back side of the apparatus), and the paper P is shifted. In the stipple mode, a plurality of sheets P are aligned at the same position to form the sheet bundle P 'and stipple, so that the shift direction is the same direction.

  After the start of the shift operation, the tapping roller driving motor 420c is driven (T27), the paper P is moved to the rear end fence 220 side to align the conveyance direction, and the jogger driving motor 420d is driven (T28) in the width direction. The matching is also performed. The jogger fence 212 reciprocates between a standby (home) position and an alignment position (outside the home), presses the sheet against the fixed-side jogger fence, and aligns the width direction of the sheet.

  When the paper discharge motor 217 performs the first shift operation, the roller portion of the hitting roller 211 is driven to rotate in the direction opposite to the paper transport direction (T29), the hitting roller driving motor 420c is driven, and the roller portion becomes the paper. When contacting P, the paper is moved in the return direction. These operations are repeated here for two sheets, and two sheets form one set of aligned sheet bundle P '.

  When two aligned sheet bundles P 'are created, the stipple operation is started. When the staple start signal is output (T30) and the staple operation is started, the jogger drive motor 420d is driven (T31), the width direction of the sheet bundle P ′ is aligned, and then the sheet discharge motor 217 is stopped. (T32) A stippling state is enabled. After this state is reached, the stipple motor 420e is driven (T33), and actual stipple hitting, that is, stipple processing is performed.

  After the stapling process is performed, the paper discharge opening / closing guide drive motor 420b is driven (T34), and the tapping roller 211 is lowered. When the lowering is completed, the paper discharge motor 217 is driven at the line discharge speed of the sheet bundle P ′ (T35), and the sheet bundle P ′ is moved to the sheet discharge tray 203 side.

  Next, the sheet bundle P ′ pressing process is executed. As described above, when the paper discharge sensor 210 is turned off (T36) and the number of drive steps of the paper discharge motor 217 is driven by a preset number of steps ST3 (T37) as described above, the paper discharge tray motor 221a is pressed. Is rotated for a predetermined time Ta (T38), and the free end side of the movable tray portion 208b is moved to the paper pressing avoidance position.

  After the movement of the movable tray portion 208b to the paper pressing avoidance position is completed, when the paper discharge motor 217 is driven for a preset number of steps ST4 (T39), the movable tray portion 208b is raised and moved to the paper pressing position. The paper discharge motor 217 stops when driving for the number of steps ST3 is completed (T40), and then the paper discharge opening / closing guide plate drive motor 420b is driven to raise the paper discharge driven roller 205a (T41).

FIG. 26 is a diagram illustrating another example of the sheet pressing mechanism.
The sheet pressing mechanism M2 shown in FIG. 3 uses a driving force from the drive shaft 223 of the paper discharge roller 206 as a torque limiter 230 and a gear train 240 as a speed change unit, compared to the sheet pressing mechanism M1 shown in FIG. Via the sheet pressing member 209.

  The gear train 240 is a reduction mechanism 250 including a first gear 241, a second gear 242, a third gear 244, a fourth gear 245, and a rotating shaft 243. A second gear 242 and a third gear 244 are attached to the rotation shaft 243, and the rotation shaft 243 and the third gear 244 rotate according to the rotation of the second gear 242. The second gear 242 is a two-stage gear composed of a large gear and a small gear, and the small gear 242 a of the second gear 242 has the same diameter and the same number of teeth as the third gear 244.

  The fourth gears 245a and 245b receive driving force from the small gear 242a and the third gear 244 of the second gear 242, respectively, and rotationally drive the sheet pressing members 209a and 209b.

  A first gear 241 is attached to the outer ring of the torque limiter 230, and is driven to rotate in the direction of arrow R71 at a speed of V1 according to the movement of the drive shaft 223 of the paper discharge roller 206. The first gear 241 transmits driving force to the second gear 242, and the second gear 242 is rotationally driven in the direction of the arrow R72 opposite to the paper discharge roller 206 at a speed of V2. The second gear 242 transmits the driving force to the third gear 244 via the rotation shaft 243, and the small gear 242a and the third gear 244 of the second gear 242 transmit the driving force to the fourth gear 245. The gear 245 transmits a driving force to the sheet pressing member 209. Finally, the sheet pressing members 209a and 209b are rotationally driven in the same arrow R73 direction as the sheet discharge roller 206 at a speed of V3 lower than V1.

  When such a speed reduction mechanism 250 is provided, the rotational speed of the paper pressing member 209 is lower than the rotational speed of the paper discharge roller 206, so that the impact when the paper pressing member 209 contacts the paper can be reduced. Does not damage the paper.

  As described above, according to the present embodiment, the following effects can be obtained.

1) The contact portion 224 of the pressing member 209 that rotates in synchronization with the paper discharge roller 206 comes down from a position higher than the position where the paper discharge roller 206 is disposed, and presses the paper P or the paper bundle P ′. Therefore, it is possible to reliably suppress the trailing edge of the paper from being lifted up due to paper curl or the like without providing an independent drive source.

2) At that time, a predetermined driving step is counted by using the trailing edge detection signal of the paper P by the inlet sensor 207 or the trailing edge detection signal of the paper bundle P ′ by the paper discharge sensor 210 as a trigger, and it is movable based on the count value. Since the tray portion 208b is lowered (separated from the paper discharge roller 206), the trailing edge of the paper can be reliably prevented from rising due to paper curl or the like without using an independent control signal, and is discharged onto the paper discharge tray. Paper can be loaded accurately.

3) After the rear end of the sheet P or the sheet bundle P ′ passes the discharge roller 206, the movable tray portion 208b on the rear end side of the sheet discharge tray 203 is set at the sheet pressing avoidance position. The sheet pressing member stopped above serves as a guide, so that it is possible to prevent a sheet having a low stiffness such as a thin sheet from being folded and causing a stack failure.

4) Since the contact portion 224 at the leading end of the sheet pressing member 209 and abutting against the rear end of the sheet P or the sheet bundle P ′ is made of an elastic material, the sheet pressing member 209 is formed of the sheet P or the sheet bundle P ′. When it contacts the rear end with a certain load, it can be elastically deformed. Thereby, the trailing edge of the sheet can be pressed without damaging the sheet P or the sheet bundle P ′.

5) Since the (rotation) drive shaft 223 of the paper discharge roller 206 is provided with the speed reduction mechanism 250 that rotates the paper pressing means at a rotational speed lower than the rotational speed of the drive shaft 223, Even if the rotation speed is high, the rotation speed of the sheet pressing member 209 can be appropriately reduced. As a result, it is possible to hold the trailing edge of the paper without damaging the paper.

6) In the image forming system according to the present embodiment, a sheet on which an image is formed by the image forming apparatus 100 is placed on the sheet discharge tray 203 of the sheet processing apparatus 20 without using an independent drive source and control signal. The sheets can be stacked on the sheet discharge tray 203 with accuracy or as a sheet bundle.

  In this embodiment, the sheet processing apparatus in the claims to be described later is denoted by reference numeral 200, the sheet is denoted by reference numeral P, the sheet bundle is denoted by reference numeral P ', the first stacking unit is denoted by the discharge tray 203, The stacking means is the staple tray 219, the discharge means is the discharge roller 206, the rotational drive shaft is the drive shaft 223, the paper pressing means is the paper pressing member 209, the driving force limiting transmission means is the torque limiter 230, 1 is the movable tray 208b, the sheet pressing position is the position shown in FIG. 3B, the sheet pressing avoidance position is the position shown in FIG. 3C, and the contact portion is 224. Further, the speed reduction means corresponds to the speed reduction mechanism 250, respectively.

  Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention, and all the technical matters included in the technical idea described in the claims are all included. The subject of the present invention. Although the above-described embodiment is a preferred example, those skilled in the art can realize various alternatives, modifications, variations, and improvements from the content disclosed in this specification. These are included in the technical scope described in the appended claims.

100 Image forming apparatus 200 Paper post-processing apparatus (paper processing apparatus)
203 Paper discharge tray 206 Paper discharge roller 208b Movable tray section 209 Paper pressing member 219 Staple tray 223 Drive shaft 224 Contact section 230 Torque limiter 250 Deceleration mechanism P Paper P 'Paper bundle

JP 2011-020775 A

Claims (8)

A paper processing device that performs a preset process on a paper that has been carried in and discharges the paper,
First stacking means for stacking discharged sheets or sheet bundles;
A second stacking means for temporarily stacking the loaded paper;
Discharging means for discharging the loaded paper to the first stacking means, or discharging a bundle of sheets stacked on the second stacking means to the first stacking means;
It is attached to the rotational drive shaft of the discharge means and presses the rear end in the transport direction of the paper or paper bundle according to the relative distance from the upstream end of the first stacking means in the paper transport direction, or A sheet pressing means that rotates around the drive shaft without contacting the upstream end of the first stacking means in the sheet conveying direction;
A sheet processing apparatus comprising: The sheet processing apparatus according to claim 1,
The paper processing apparatus, wherein the paper pressing means is attached to the rotary drive shaft via a drive force limited transmission means for transmitting a limited rotational drive force. The sheet processing apparatus according to claim 1 or 2,
Driving means for causing the rear end portion side of the first stacking means to approach and separate from the drive shaft;
A sheet for controlling the driving means to press the relative distance between the upstream end of the first stacking means in the sheet conveying direction and the sheet pressing means to the rear end of the sheet or sheet bundle. A pressing unit, and a control unit that rotates around the rotation drive shaft and sets the sheet pressing avoidance position to avoid sheet pressing;
A sheet processing apparatus comprising: The sheet processing apparatus according to claim 3,
The control means sets the rear end side of the first stacking means at the paper pressing avoidance position after the rear end of the paper or the sheet bundle passes through the discharge means. . The sheet processing apparatus according to any one of claims 1 to 4,
The sheet processing apparatus, wherein the sheet pressing unit includes a contact portion made of an elastic material at a portion that contacts the rear end of the sheet or sheet bundle. The sheet processing apparatus according to any one of claims 1 to 5,
A sheet processing apparatus, wherein the rotation driving shaft is provided with a speed reduction unit that rotates the sheet pressing unit at a rotation speed lower than the rotation speed of the rotation driving shaft. An image forming system comprising the sheet processing apparatus according to claim 1. First stacking means for stacking discharged sheets or sheet bundles;
A second stacking means for temporarily stacking the loaded paper;
With
A paper processing method for carrying out a preset process on paper that has been carried in and discharging the paper,
Discharging the carried paper to the first stacking means by the discharging means, or discharging the sheet bundle loaded on the second stacking means to the first stacking means by the discharging means;
The paper stacking direction rear end of the first stacking unit is moved close to and away from the paper discharge unit, and the relative distance from the upstream end of the first stacking unit in the sheet transporting direction is made closer. The sheet pressing means attached to the rotational drive shaft of the discharging means presses the rear end of the sheet or sheet bundle in the transport direction, or separates the relative distance, so that the sheet pressing means moves the sheet or sheet bundle. A step of retracting to a rotatable position without contacting the rear end of the conveyance direction;
A paper processing method.