Patent Application
20220204302
The present invention relates to a sheet processing apparatus that processes a sheet fed from an image forming apparatus and the like and an image forming system having such a sheet processing apparatus.
There is widely known a post-processing apparatus that stacks sheets discharged from an image forming apparatus on a processing tray, binds the sheets using a binding device, and stores the resultant sheet bundle on a stack tray arranged at a downstream location. Such an apparatus may employ a stand-alone structure, in which sheets are fed along a sheet carry-in path connected to a sheet discharge port of the image forming apparatus, collated and stacked on a processing tray disposed at the discharge port of the sheet carry-in path, subjected to binding processing by a binding processing unit disposed on the processing tray, and finally stored on a stack tray disposed at a downstream location. Further, the apparatus may employ an inner finisher structure that incorporates, at a sheet discharge area of the image forming apparatus, a unit equipped with a processing tray having a binding unit and a stack tray.
Such an apparatus requires a bundle conveying mechanism for conveying a sheet bundle that has been subjected to binding processing or that has once been stacked on a processing tray to a stack tray provided on the downstream side. For example, Patent Document 1 and Patent Document 2 disclose a post-processing apparatus disposed downstream from an image forming apparatus configured to: receive image-formed sheets from the image forming apparatus; collate and stack the sheets; perform binding processing for the sheets; and store the resultant sheet bundle on a stack tray. In the post-processing apparatus in these documents, the processing tray is equipped with a sheet bundle carry-out mechanism for carrying out a sheet bundle from a binding position to the stack tray provided on the downstream side. The sheet bundle carry-out mechanism has a claw member (projecting member) which is integrally provided on a belt supported by a drive pulley so as to be engaged with the rear end edge of a sheet bundle. This claw member is configured to be movable along a tray surface from the binding end portion of the processing tray to a carry-out end portion.
Patent Document 1: Japanese Patent Application Laid-Open No. 2015-020822
Patent Document 2: Japanese Patent Application Laid-Open No. 2007-076893
Examples of the mechanism for carrying out a sheet bundle from a processing tray on which a sheet bundle is collated, stacked, and bound, to a stack tray arranged at a downstream location include a mechanism that pushes out the sheet bundle using a belt conveyer and a mechanism that carries out a sheet bundle using a roller pair. In the belt conveyer mechanism, a pair of pulleys are provided at the bottom portion of the processing tray, over which a belt (carrier member) is stretched, and a claw member (projecting member) for locking the rear end edge of a sheet bundle is integrally attached to the belt. This allows the claw member to be moved along the tray upper surface from the tray rear end to front end, providing good discharge performance. However, such a sheet bundle carry-out mechanism has the following problem. That is, the claw member reciprocates with a long stroke, i.e., performs a forward movement from the tray rear end to front end (toward an apparatus discharge port) and a return movement from the tray front end to rear end, and at the time when the claw member returns from the tray front end, it may collide with the next sheet to be conveyed to the processing tray to cause a conveyance jam.
An object of the present invention is to prevent interference between the next sheet to be conveyed and a discharge claw member after a sheet bundle is discharged by the discharge claw member and to reduce the occurrence of a conveyance jam due to curling or buckling of the front end of the next sheet.
To solve the above problem, a sheet processing apparatus according to the present invention includes: a conveying unit that conveys a sheet in a predetermined conveying direction; a processing tray on which the sheet conveyed by the conveying unit is placed; a discharge unit that discharges the sheet placed on the processing tray by pushing the rear end portion of the sheet in the sheet conveying direction; a stack tray on which the sheet discharged by the discharge unit is stacked; an aligning unit that aligns the sheet on the processing tray in a sheet width direction perpendicular to the conveying direction; a first support guide integrally provided at the upstream end portion of the discharge unit in the conveying direction and configured to support the downstream front end portion in the conveying direction of a sheet to be conveyed onto the processing tray; and a controller that controls the discharge unit and the aligning unit. The controller controls, after a sheet is discharged from the processing tray to stack tray, the first support guide to support the downstream front end portion in the conveying direction of a next sheet to convey the sheet onto the processing tray.
There can be provided a sheet processing apparatus capable of reducing the occurrence of a conveyance jam during sheet conveyance.
Hereinafter, the present invention will be described in detail based on illustrated preferred embodiments. The present invention relates to a sheet bundle binding processing mechanism that performs binding processing for a collated and stacked sheet bundle with images formed thereon in an image forming system to be described later. The image forming system illustrated in
The post-processing unit B to be described later is incorporated as a unit in a sheet discharge space (stack tray space) 15 formed in the housing of the image forming unit A. The post-processing unit B has an inner finisher structure having a post-processing mechanism that performs, on a processing tray, binding processing after collating and stacking the image-formed sheets conveyed to a sheet discharge port 16 and then stores the sheets on the stack tray provided downstream from the processing tray. Not limited to the above, the present invention may have a stand-alone structure in which the image forming unit A, the image reading unit C, and the post-processing unit B are independently arranged, and the respective units are connected by network cables to be systematized.
As illustrated in
The processing tray 24 is provided with a sheet carry-in unit 35 for carrying in a sheet, and a sheet end regulating unit 40 and an aligning unit 45 which are used for stacking carried-in sheets in a bundle form. In addition, the processing tray 24 is provided with a stapling unit 26 (first binding unit) for performing staple-binding for a sheet bundle and a non-stable binding unit 27 (second binding unit) for performing non-staple binding for a sheet bundle. Each component will be described below in detail.
The apparatus housing 20 includes an apparatus frame 20a and an external casing 20b. The apparatus frame 20a has a frame structure to support mechanisms (a path mechanism, a tray mechanism, a conveying mechanism, etc.) to be described later. In the drawings, a binding mechanism, the conveying mechanism, a tray mechanism, and a driving mechanism are arranged at a left-right pair of side frames (not illustrated) which are mutually opposed to form a monocoque structure so as to be integrated with the external casing 20b. The external casing 20b has the monocoque structure obtained by integrating, through mold processing using resin or the like, left-right side frames 20c, 20d and a stay frame (bottom frame 20e to be described later) connecting the side frames 20c and 20d. A part (at the apparatus front side) of the external casing 20b is exposed to be operable from the outside.
That is, the frames are stored in the sheet discharge space 15 of the image forming unit A to be described later with an outer circumference thereof covered with the external casing 20b. In the above state, the front side of the external casing 20b is exposed to be operable from the outside. A later-described cartridge mount opening 28 for staples, a manual feed setting part 29, and a manual operation button 30 (in the drawing, a switch having a built-in lamp) are arranged at the front side of the external casing 20b. The external casing 20b has a length Lx in the sheet discharge direction and a length Ly in a direction perpendicular to the sheet discharge direction which are set based on the maximum sheet size so as to be smaller than the sheet discharge space 15 of the later-described image forming unit A.
As illustrated in
The sheet discharge path 22 includes a linear path arranged approximately in the horizontal direction so as to traverse the apparatus housing 20 so as to prevent stress caused by a curved path from being applied to a sheet and is formed as having linearity which is allowed by apparatus layout. The carry-in roller pair 31 and discharge roller pair 32 are connected to the same driving motor M1 (hereinafter, referred to as “conveying motor”) and convey a sheet at the same circumferential speed.
Referring to
On the above processing tray 24, the sheets fed from the sheet discharge port 23 are stacked in a bundle shape, aligned to a predetermined posture, and subjected to binding processing. The resultant sheet bundle is carried out to the stack tray 25 arranged at a downstream location from the processing tray 24. To this end, the processing tray 24 has a sheet carry-in mechanism 35, a sheet aligning mechanism 45, binding processing mechanisms 26, 27, and a sheet bundle carry-out mechanism 60.
Since the processing tray 24 is disposed so as to form the step d from the sheet discharge port 23, it is required to provide the sheet carry-in unit 35 for smoothly conveying a sheet onto the processing tray 24 with a proper posture. The illustrated sheet carry-in unit 35 (friction rotor) is constituted by a paddle rotor 36, which is configured to move up and down. When a sheet rear end is discharged from the sheet discharge port 23 onto the processing tray 24, the paddle rotor 36 conveys the sheet in a direction (rightward in
An elevating arm 37 axially and swingably supported by a support shaft 37x to the apparatus frame 20a is disposed at the sheet discharge port 23. The paddle rotor 36 is axially rotatably supported to the top end part of the elevating arm 37. A pulley (not illustrated) is provided at the support shaft 37x, and the abovementioned conveying motor M1 is connected to the pulley.
In addition, the elevating arm 37 is connected with an elevating motor (hereinafter, referred to as “paddle elevating motor”) M3 through a spring clutch (torque limiter) and is configured to be elevated and lowered by rotation of the puddle elevating motor M3 between a waiting position Wp at the upper side and an operating position (sheet engaging position) Ap at the lower side. That is, the spring clutch elevates the elevating arm 37 from the operating position Ap to the waiting position Wp by rotation of the paddle elevating motor M3 in one direction and keeps the elevating arm 37 waiting at the waiting position Wp after abutting against a stopper (not illustrated). On the contrary, the spring clutch is released by rotation of the paddle elevating motor M3 in the opposite direction to cause the elevating arm 37 to be lowered under its own weight from the waiting position Wp to the operating position Ap on the lower side to be engaged with the upmost sheet on the processing tray.
In the illustrated apparatus, a pair of the paddle rotors 36 are arranged in a symmetric manner with respect to a sheet center Sx (center reference Sx) so as to be apart from each other at a predetermined distance, as illustrated in
The paddle rotor 36 is constituted by a flexible rotor formed of a rubber-made plate-shaped member, plastic-made blade member, or the like. Instead of the paddle rotor 36, the sheet carry-in unit 35 may be constituted by a friction rotating member such as a roller body or a belt body. In the above description, the illustrated apparatus includes the mechanism in which the paddle rotor 36 is lowered from the waiting position Wp at the upper side to the operating position Ap at the lower side after the sheet rear end is discharged from the sheet discharge port 23; instead of the above, it is possible to employ an elevating mechanism to be described below.
With an elevating mechanism different from the illustrated mechanism, for example, at the timing when the sheet front end is discharged from the sheet discharge port 23, a friction rotor is lowered from a waiting position to an operating position and rotated concurrently in the sheet discharge direction. Then, at the timing when the sheet rear end is discharged from the sheet discharge port 23, the friction rotor is reversely rotated in a direction opposite to the sheet discharge direction. With this operation, a sheet discharged from the sheet discharge port 23 can be conveyed to a predetermined position on the processing tray 24 at high speed without being skewed.
When a sheet is conveyed to a predetermined position on the processing tray 24 by the sheet carry-in mechanism 35 (paddle rotor) disposed at the sheet discharge port 23, a raking conveying unit 33 is required to guide the front end of the sheet (in particular, the front end of a curled or skewed sheet) to the sheet end regulating unit 40 provided at a downstream location.
In the illustrated example, a raking rotor (raking conveying unit) 33 that conveys the uppermost sheet of sheets stacked upstream of the sheet end regulating unit 40 to be described later toward the sheet end regulating member side is disposed below the sheet discharge roller pair 32. The raking rotor 33 includes a ring-shaped belt member 34 (hereinafter, referred to as “raking belt”) which is disposed above the top end part of the processing tray 24. The raking belt 34 is engaged with the uppermost sheet of the sheets stacked on the sheet placing surface and rotates in such a direction as to convey the sheet to the regulating member side.
The raking belt 34 is constituted by a high-friction belt member (roulette belt or the like) formed of a flexible material such as rubber and is supported so as to be nipped between a rotary shaft 34x connected to a drive motor (the one illustrated is the conveying motor M1) and an idle shaft 34y. The raking belt 34 is imparted with a torque in the counterclockwise direction depicted in
The raking belt 34 is configured to be elevated and lowered above the uppermost sheet of the sheets stacked on the processing tray 24 by a belt shift motor M5 (hereinafter, referred to as “roulette elevating motor”) (description of the elevating mechanism is omitted). The raking belt 34 is lowered at the timing when the sheet front end enters between the belt surface and the uppermost sheet to be engaged with the carried-in sheet. Further, when conveying a sheet bundle from the processing tray 24 to the stack tray 25 provided downstream therefrom using a sheet bundle carry-out unit 60 to be described later, the roulette elevating motor M5 is controlled such that the raking belt 34 is separated from the uppermost sheet and waits thereabove.
The processing tray 24 is provided with a sheet aligning mechanism 45 that positions a carried-in sheet to a predetermined position (processing position). The illustrated sheet aligning mechanism 45 includes the “sheet end regulating unit 40” for regulating the position of the end surface (front end surface or rear end surface) in the sheet discharge direction of a sheet fed from the sheet discharge port 23 and the “side aligning unit 45” for aligning (width-aligning) a sheet in a direction (sheet side direction) perpendicular to the sheet discharge direction. Hereinafter, the sheet end regulating unit 40 and the side aligning unit 45 will be described in this order.
The illustrated sheet end regulating unit 40 is constituted by a rear end regulating member 41 for abutment-regulating the rear end of a sheet in the sheet discharge direction. The rear end regulating member 41 has a regulating surface 41a for abutment-regulating the rear end edge of a sheet in the sheet discharge direction carried in along the sheet placing surface 24a of the processing tray 24. The rear end edge of the sheet in the sheet discharge direction conveyed by the above raking conveying unit 33 abuts against the regulating surface 41a and is stopped.
When multi-binding is performed with a stapling unit 26 to be described later, the stapling unit 26 is moved along the sheet rear end (in a direction perpendicular to the sheet discharge direction). To prevent obstruction against the movement of the stapling unit 26, the rear end regulating member 41 is configured to adopt any one of the following structures of:
(1) adopting a mechanism in which the rear end regulating member proceeds to and retracts from a movement path (motion trajectory) of the binding unit;
(2) adopting a mechanism in which the rear end regulating member is moved integrally with the binding unit; and
(3) forming the rear end regulating member, for example, as a channel-shaped folded piece disposed inside a binding space which is formed by a head and an anvil of the binding unit.
In the illustrated example, the rear end regulating member 41 is constituted by a plate-like bent member having a U-shape (channel shape) in cross section and disposed in the binding space of the stapling unit 26. With the minimum size sheet as a reference, a first member 41A is disposed at the sheet center, and second and third members 41B and 41C are disposed on both sides of the first member 41A so as to be spaced apart therefrom (see
As illustrated in
The processing tray 24 is provided with the aligning unit 45 (hereinafter, referred to as “side aligning member”) for positioning a sheet abutting against the above rear end regulating member 41 in a direction (hereinafter, referred to as “sheet width direction”) perpendicular to the sheet discharge direction.
The side aligning member 45 is configured differently based on whether sheets having different sizes are aligned on the processing tray 24 in center reference or side reference. In the apparatus illustrated in
To perform the above aligning operation, the aligning unit 45 is provided with a left-right pair of side aligning members 46 (46F, 46R) each protruding upward from the sheet placing surface 24a of the processing tray 24 and each having a regulating surface 46x engaged with the side edge of a sheet. The side aligning members 46F and 46R are disposed opposite to each other and configured to reciprocate on the processing tray 24 in a predetermined stroke. The stroke amount is set based on the difference in size between a maximum size sheet and a minimum size sheet and the amount of offset movement (offset conveyance) of the aligned sheet bundle to one side in the sheet width direction. That is, the stroke amount of each of the side aligning members 46F and 46R is set based on the movement amount for aligning sheets of different sizes and the movement amount for offsetting an aligned sheet bundle.
Thus, as illustrated in
The side aligning members 46F and 46R are each integrally formed with a rack 47 and are slidably supported by a plurality of guide rollers 49 (or rail members) on the back surface side of the processing tray 24. Aligning motors M6 and M7 are connected to the left and right racks 47 respectively through a pinion 48. The left and right aligning motors M6 and M7 are each constituted by a stepping motor. Positions of the left and right aligning members 46F and 46R are detected by position sensors (not illustrated). Based on the detected values, the side aligning members 46F and 46R can be moved respectively in either left or right direction by specified movement amounts.
In place of the illustrated rack-and-pinion mechanism, a configuration may be adopted, in which the side aligning members 46F and 46R are each fixed to a timing belt, and the timing belt is connected, through a pulley, to a motor for reciprocating the belt laterally.
According to the above configuration, a controller 75 causes the left and right side aligning members 46 to wait at predetermined waiting positions (distanced by a sheet width+a therebetween) based on sheet size information provided from the image forming unit A or the like. In this state, a sheet is carried in onto the processing tray 24, and at the timing when the end of the sheet abuts against the rear end regulating member 41, an aligning operation is started. In the aligning operation, the left and right aligning motors M6 and M7 are rotated in opposite directions (approaching directions) by the same amount. Accordingly, sheets carried in onto the processing tray 24 are positioned and stacked in a bundle form in reference to the sheet center. According to the repetition of the sheet carry-in operation and aligning operation, sheets are collated and stacked on the processing tray 24 in a bundle form. At this time, sheets of different sizes are positioned in center reference.
The sheets thus stacked on the processing tray 24 in center reference can be subjected to binding processing at a plurality of positions separated from each other by a predetermined interval (i.e., multi-binding processing) in the above posture at the rear end (or front end) of the sheets. In a case of performing the binding processing on a sheet corner, one of the left and right side aligning members 46F and 46R is moved to and stopped at a position where a sheet side end matches a specified binding position. Then, the side aligning member on the opposite side is moved in the approaching direction. A movement amount in the approaching direction is calculated in accordance with the sheet size. Accordingly, a sheet carried in onto the processing tray 24 is aligned such that a right side end matches a binding position in a case of right corner binding and a left side end matches a binding position in a case of left corner binding.
When a sheet bundle thus aligned to a predetermined position on the processing tray 24 is offset-moved for eco-binding processing to be described later, one of the following drive controls is performed:
(1) drive control that the aligning member at the rear side in the movement direction is moved in a direction perpendicular to the sheet conveying direction by a preset amount in a state where the aligning member at the front side in the movement direction is retracted to a position separated from an offset assumed position; and
(2) drive control that the left-right aligning members are moved in a direction perpendicular to the sheet conveying direction by the same amount.
The left and right side aligning members 46F and 46R and the aligning motors M6 and M7 are each provided with a position sensor (not illustrated) such as a position sensor and an encode sensor for detecting the position of the side aligning member 46. Owing to that the aligning motors M6 and M7 are constituted by stepping motors, home positions of the side aligning members 46F and 46R are detected by position sensors (not illustrated), and the motors are PWM-controlled, so that the left and right side aligning members 46F and 46R can be controlled with a relatively simple control configuration.
The following describes a first embodiment of a sheet bundle carry-out mechanism (sheet bundle carry-out unit 60) with reference to
To achieve the above operation, the sheet bundle carry-out unit 60 is disposed along the sheet placing surface 24a of the processing tray 24. The illustrated sheet bundle carry-out unit 60 includes a first conveying member 60A and a second conveying member 60B. Conveyance in a first section L1 on the processing tray 24 is performed by the first conveying member 60A and conveyance in a second section L2 is performed by the second conveying member 60B, whereby relay conveyance is performed. Since a sheet bundle is conveyed serially by the first and second conveying members 60A and 60B, the mechanisms of the first and second conveying members 60A and 60B can be made different. It is required that the member that conveys a sheet bundle from a starting point being approximately the same as the sheet rear end regulating unit 40 is formed of a less swaying member (elongated support member) and a member that causes the sheet bundle to drop at the end point of conveyance is downsized (for travelling on a loop trajectory).
The first conveying member 60A is constituted by a first carry-out member 61 formed of a folded piece having a channel shape in cross section. The first carry-out member 61 includes a stop surface 61a that stops a rear end surface of a sheet bundle and a sheet surface pressing member 62 (an elastic film member; Mylar piece) that presses an upper surface of the sheet bundle stopped by the stop surface 61a. As illustrated, the first conveying member 60A is formed of a folded piece having a channel shape in cross section. Accordingly, when being fixed to a carrier member 65a (belt) to be described later, the first conveying member 60A moves (feeds) the rear end of the sheet bundle in the conveying direction by travelling integrally with the belt with less swaying. The first conveying member 60A reciprocates with a stroke Str1 on an approximately linear trajectory without travelling on a loop trajectory curved as will be described later.
The second conveying member 60B is constituted by a second carry-out member 63 having a claw shape. The second carry-out member 63 includes a stop surface 63a that stops the rear end surface of a sheet bundle and a sheet surface pressing member 64 that presses the upper surface of the sheet bundle. The sheet surface pressing member 64 is axially swingably supported to the second carry-out member 63 and has a sheet surface pressing surface 64a. The sheet surface pressing surface 64a is biased by a biasing spring 64b so as to press the upper surface of the sheet bundle.
The sheet surface pressing surface 64a is constituted by an inclined surface inclined with respect to the traveling direction as illustrated. Accordingly, when the second conveying member 60B is moved in the direction of the arrow in
The thus configured first carry-out member 61 reciprocates with the first carrier member 65a, and the second carry-out member 63 reciprocates with a second carrier member 65b between a base end part and an exit end part of the sheet placing surface 24a. To this end, the sheet placing surface 24a is provided with drive pulleys 66a, 66b and a driven pulley 66c which are spaced apart from each other by a conveyance stroke. Reference numerals 66d and 66e are each an idling pulley.
The first carrier member 65a (toothed belt in the drawings) is installed between the drive pulley 66a and the driven pulley 66c, and the second carrier member 65b (toothed belt) is installed between the drive pulley 66b and the driven pulley 66c through the idling pulleys 66d, 66e. A drive motor M4 is connected to the drive pulleys 66a and 66b. The first drive pulley 66a is formed to have a small diameter and the second drive pulley 66b is formed to have a large diameter so that the rotational force of the drive motor M4 is transmitted to the first carrier member 65a at a low speed and to the second carrier member 65b at a high speed.
That is, the first conveying member 60A and the second conveying member 60B are connected in common to the drive motor M4 through a decelerating mechanism (belt pulleys, gear coupling, or the like) so as to travel respectively at a low speed and a high speed. In addition, a cam mechanism is incorporated in the second drive pulley 66b to delay the drive transmission. This is, as will be described later, because of the difference between the movement stroke Str1 of the first conveying member 60A and the movement stroke Str2 of the second conveying member 60B and positional adjustment of waiting positions of the respective members.
The above cam mechanism will be described with reference to
Further, the rotational force of the rotary shaft 67x of the drive motor M4 is transmitted to the drive pulley 66b of the second carrier member (second belt) 65b through a transmitting belt. The rotary shaft 67x is connected to the drive pulley 66b through transmission cams (a convex cam 67a and a concave cam 67b). According to the connection, the rotational force of the rotary shaft 67x of the drive motor M4 is transmitted to the drive pulley 66b so as to be delayed by a predetermined angle.
That is, in the state of activation of the motor rotary shaft 67x illustrated in
Similarly, when the second belt 65b is to be returned by reverse rotation of the drive motor M4, the second belt 65b starts traveling with a delay by the predetermined angle (distance) with respect to the first belt 65a and returns to a position with the delay by the predetermined distance.
Thus, the second conveying member 60B fixed to the second belt 65b starts driving with a delay by a predetermined time and returns to a position with a delay by a predetermined distance with respect to the first conveying member 60A fixed to the first belt 65a. Accordingly, the waiting position of the second conveying member 60B can be varied with respect to rotation timing of the drive motor M4. According to the above, the waiting position can be adjusted when the second conveying member 60B is caused to wait at the back face (bottom portion) side of the processing tray 24.
With the above configuration, the first conveying member 60A reciprocates on a linear trajectory with the first stroke Str1 from the rear end regulation position of the processing tray 24, and the first section Tr1 is set within the first stroke Str1. The second conveying member 60B reciprocates on a semi-loop trajectory with the second stroke Str2 from the first section Tr1 to the exit end of the processing tray 24, and the second section Tr2 is set within the second stroke Str2.
The first conveying member 60A is moved downstream from the sheet rear end regulation position (moved from the state illustrated in
When the second conveying member 60B abuts, at the relay point at a high speed, against the sheet bundle travelling at the speed V1, the sheet bundle is carried out toward the stack tray 25 while the rear end thereof is held so as to be nipped between the sheet surface pressing member 64 and the carrier member (belt) 65a (65b) with the upper surface of the sheet bundle pressed by the sheet surface pressing surface 64a.
The second conveying member 60B is moved up to the downstream side end portion of the processing tray 24 in the conveying direction to discharge a sheet bundle as described above. During this operation, sheets constituting the next sheet bundle is continuously fed from the image forming apparatus. Thus, there may be a case where the front end of the next sheet enters the processing tray 24 during or immediately after discharge of the preceding sheet bundle toward the stack tray 25, which may make the front end of the next sheet contact the second conveying member 60B, causing a conveyance jam. This inconvenience can be solved by delaying the discharge timing of the next sheet; however, in the image forming system, to prevent a reduction in productivity, the sheet post-processing apparatus preferably receives image-formed sheets from the image forming apparatus without delay so as not to stop a printing operation.
To achieve such a high level of productivity as described above, in the present embodiment, a conveying guide that cooperatively operates with a discharge claw is provided at an upstream location relative to the discharge claw in the conveying direction so as to guide the front end of the next sheet. This allows discharge of the next sheet onto the processing tray to be started in an overlapping manner with the discharge timing of the preceding sheet bundle from the processing tray to the stack tray. Thus, it is possible to receive the next sheet without delay and further to reduce the occurrence of a conveyance jam. In the following, the sheet front end guide will be described in detail.
A next sheet front end guide 68 according to a first embodiment illustrated on
Thus, when the second conveying member 60B is in the state illustrated in
A next sheet front end guide 168 according to a second embodiment illustrated in
Thus, in a state illustrated in
A next sheet front end guide 268 according to a third embodiment illustrated in
Thus, in a state where the second conveying member 260B is located at the discharge position to discharge a sheet bundle to the stack tray 25 and in a state where the second conveying member 260B is in the middle of reciprocating movement to return to the waiting position after discharge of the sheet bundle, the guide 268 functions as a conveying surface for the next sheet S delivered from the sheet discharge port 23 by the sheet discharge roller 32 to support discharge of the next sheet S.
As described above, sheets conveyed to the carry-in port 21 of the sheet discharge path 22 are collated and stacked on the processing tray 24 and positioned (aligned) by the sheet end regulating member 40 and side aligning member 46 at the previously set location and in the previously set posture. Thereafter, binding processing is performed for the sheet bundle, and the resultant sheet bundle is discharged onto the stack tray 25 provided at a downstream location. In the following, a method of the binding processing will be described.
In the illustrated example, the processing tray 24 is provided with the “first binding unit 26 for staple binding of a sheet bundle” and the “second binding unit 27 for non-staple binding of a sheet bundle”. The controller 75 to be described later performs binding for a sheet bundle using a selected one of the first and second binding units 26 and 27 and discharges the bound sheet bundle toward a downstream location. This is a first feature of the binding method. Using a staple for binding allows bookbinding to make it difficult for the bound sheets to come off the bundle; however, such convenience that the bound sheets are easily separated from the sheet bundle may be required for some uses. Further, when a used sheet bundle is to be shredded, when sheets are recycled, or the like, the metal staple needs to be removed before the shredding. Thus, it is preferable for a user to be able to select one from “staple binding” and “non-staple binding”.
Further, in addition to a series of post-processing operations including the sheet carry-in from the sheet carry-in path (sheet discharge path) 22, collation/stacking, and binding, it is possible to bind sheets (hereinafter, referred to as “manual stapling processing”) prepared outside the apparatus (outside the system). This is a second feature of the binding method.
To this end, a manual feed setting part 29 having a manual feed setting surface 29a on which the sheet bundle prepared outside is set is formed in the external casing 20b, and the abovementioned staple binding unit (stapling unit) 26 is configured to move from a sheet carry-in area Ar of the processing tray 24 to a manual feed area Fr.
Based on
Based on
As illustrated in
For the corner binding processing, there are defined binding positions as two lateral positions being a right corner binding position Cp1 where binding processing is performed at the right corner on an aligned sheet bundle stacked on the processing tray 24 and a left corner binding position Cp2 where binding processing is performed at the left corner of an aligned sheet bundle. In this case, the binding processing is performed with a staple being oblique by a predetermined angle (between about 30° to about 60°). The stapling unit 26 to be described later is mounted on the unit frame with the entire unit being oblique by the predetermined angle thereat.
The manual binding position Mp is set on the manual feed setting surface 29a formed in the external casing 20b (a part of the apparatus housing). The manual feed setting surface 29a is disposed adjacently in parallel to the sheet placing surface 24a through the side frame 20c at a height position substantially flush with the sheet placing surface 24a of the processing tray 24. In the illustrated example, both the sheet placing surface 24a of the processing tray 24 and the manual feed setting surface 29a support a sheet in a substantially horizontal posture and at substantially the same height.
That is, in
The non-staple binding position Ep (hereinafter, referred to as “eco-binding position”) is defined so that binding processing is performed at a side edge part (corner part) of sheets as illustrated in
The multi-binding positions Ma1 and Mat are defined within (inside) the sheet carry-in area Ar where sheets are carried in onto the processing tray 24 from the sheet discharge port 23. Each of the corner binding positions Cp1 and CP2 is defined outside the sheet carry-in area Ar at a reference position which is apart rightward or leftward (side alignment reference) by a predetermined distance from the sheet discharge reference Sx (center reference). As illustrated in
The multi-binding positions Ma1, Mat and manual binding position Mp are defined approximately on the same straight line. Further, the corner binding positions Cp1, Cp2 are defined at positions each having an oblique angle (e.g., 45°) to be laterally symmetric with respect to the sheet discharge reference Sx.
The manual binding position Mp is defined in the manual feed area Fr in the apparatus front side Fr and outside the sheet carry-in area Ar. The eco-binding position Ep is defined in the eco-binding area Rr at the apparatus rear side Re and outside the sheet carry-in area Ar.
Further, the manual binding position Mp is defined at a position which is offset by a predetermined amount (Of1) from the right corner binding position Cp1 of the processing tray 24. The eco-binding position Ep is defined at a position which is offset by a predetermined amount (Of2) from the left corner binding position Cp2 of the processing tray 24. Thus, the multi-binding positions Ma are defined based on the sheet carry out reference (center reference) of the processing tray 24 to which sheets are carried in, and the corner binding positions Cp1 and Cp2 are defined based on the maximum sheet size. Further, the manual binding position Mp is defined at the position which is offset by the predetermined amount (Of1) from the right corner binding position Cp1 to the apparatus front side. Similarly, the eco-binding position Ep is defined at the position which is offset by the predetermined amount (Of2) from the left corner binding position Cp2 to the apparatus rear side. According to the above, arrangement can be made in an orderly manner without causing interference of sheet movement.
The sheet movement in each binding processing will be described. In the multi-binding processing, sheets are carried in onto the processing tray 24 in center reference (or side reference) and aligned in this state, and then subjected to the binding processing. After the binding processing is performed, the sheets are discharged downstream in the above posture. In the corner binding processing, sheets are aligned at the alignment position on a designated side and subjected to the binding processing. After the binding processing is performed, the sheets are discharged downstream in the above posture. In the eco-binding processing, the sheets carried in onto the processing tray 24 are offset by the predetermined amount Oft to the apparatus rear side after being stacked into a bundle shape and are subjected to the binding processing after the offset movement. After the binding processing, the resultant sheet bundle is offset by a predetermined amount (for example, being the same as or smaller than the offset Oft) to the sheet center side and discharged downstream thereafter.
Further, in the manual binding, an operator sets sheets on the manual feed setting surface 29a distanced by the predetermined amount Of1 from the alignment reference which is positioned at the front side from the processing tray 24. This allows a plurality of the binding processing to be performed while sheet setting positions therefor are defined in the direction perpendicular to the sheet conveying direction. Therefore, sheet jamming can be suppressed while keeping high processing speed.
In the eco-binding processing, the controller 75 to be described later defines the eco-binding position Ep with sheets offset by a predetermined amount Of3 in the sheet discharge direction from the rear end reference position. This is to avoid interference between the stapling unit 26 for the left corner binding and the eco-binding unit (press binding unit 27 to be described later). Thus, if the eco-binding unit 27 is movably mounted on the apparatus housing 20 between the binding position and a retracting position retracting therefrom similarly to the stapling unit 26, the sheets need not be offset by the amount Of3 in the sheet discharge direction.
Here, the apparatus front side Fr refers to the front side of the external casing 20b set in apparatus designing where various kinds of operation are performed by an operator. Normally, a control panel, a mount cover (door) for a sheet cassette, and an open-close cover through which staples are replenished for a stapling unit are arranged at this apparatus front side. Further, the apparatus rear side Re refers to the side of the apparatus facing a wall surface of a building, for example, when the apparatus is installed (installation conditions; the back surface is designed to face a wall).
Thus, in the illustrated apparatus, the manual binding position Mp is defined on the apparatus front side Fr, and the eco-binding position Ep is defined on the apparatus rear side Re outside the sheet carry-in area Ar with reference thereto. A distance Ofx between the manual binding position Mp and the reference of the sheet carry-in area Ar (sheet carry-in reference Sx) is set larger than a distance Ofy between the sheet carry-in reference Sx and the eco-binding position Ep (i.e., Ofx>Ofy).
Thus, the manual binding position Mp is defined to be apart from the sheet carry-in reference Sx of the processing tray 24 and the eco-binding position Ep is defined to be close to the sheet carry-in reference Sx. This is because the operation of setting a sheet bundle to the manual binding position Mp from the outside is facilitated to be convenient owing to that the manual binding position Mp is distanced from the processing tray 24. Further, the eco-binding position Ep is defined to be close to the sheet carry-in reference Sx. This is because the movement amount when sheets (an aligned sheet bundle) carried in onto the processing tray 24 are offset-moved to the eco-binding position Ep can be small for speedy performance of the binding processing (i.e., improvement in productivity).
Although a detailed structure will be described later, the stapling unit 26 (first binding unit) includes a unit frame 26a (first unit frame), a staple cartridge 39, a stapling head 26b, and an anvil member 26c. The stapling unit 26 is supported by the apparatus frame 20a to reciprocate by a predetermined stroke along a sheet end surface on the processing tray 24. The following describes the supporting structure.
As illustrated in
The travel rail surface 42x and the travel cam surface 43x are formed so that the travel guide rail 42 and the slide cam 43 allow the moving unit 26 to reciprocate within a movement range SL (sheet carry-in area Ar, manual feed area Fr, and the eco-binding area Rr) (see
A drive belt 44 connected to a drive motor (travel motor) M11 is fixed to the moving unit (stapling unit) 26. The drive belt 44 is wound around a pair of pulleys axially supported by the apparatus frame 20e, and the drive motor is connected to one of the pulleys. Thus, the stapling unit 26 reciprocates by the stroke SL with forward and reverse rotation of the travel motor M11.
The travel rail surface and travel cam surface are arranged to include parallel interval sections 43a, 43b (having a span G1) where the surfaces are in parallel, a narrow swing interval sections 43c, 43d (having a span G2), and a narrower swing interval section 43e (having a span G3) (span G1>span G2>span G3). The span G1 causes the stapling unit to be in a posture parallel to the sheet rear end edge. The span G2 causes the stapling unit to be in a slant posture rightward or leftward. The span G3 causes the stapling unit to be in a posture slant at a larger angle. Thus, the slant angle of the stapling unit is varied.
Not limited to the opening groove structure, the travel guide rail 42 may adopt a variety of structures such as a guide rod, a projection rib, and others. Further, not limited to the groove cam, the slide cam 43 may adopt a variety of shapes as long as it has a cam surface to guide the moving unit 26 in a predetermined stroke direction, such as a projection stripe rib member.
The moving unit 26 is engaged with the travel guide rail 42 and the slide cam 43 as follows. As illustrated in
With the above configuration, the moving unit 26 is movably supported by the bottom frame 20e through the sliding rollers 52a, 52b and the guide roller 53. Further, the first rolling roller 50 and the second rolling roller 51 are rotated and moved along the travel rail surface 42x and the travel cam surface 43x, respectively, so as to follow the travel rail surface 42x and the travel cam surface 43x, respectively.
The travel rail surface 42x and the travel cam surface 43x are arranged so that the parallel distance sections (span G1) are arranged at the position 43a corresponding to the abovementioned multi-binding positions Ma1, Ma2 and the position 43b corresponding to the manual binding position Mp. With the span G1, the moving unit 26 is maintained in a posture perpendicular to the sheet end edge without swinging, as illustrated in
Further, the travel rail surface 42x and the travel cam surface 43x are arranged so that the swing distance sections (span G2) are arranged at the position 43e corresponding to the right corner binding position and the position 43d corresponding to the left corner binding position. The moving unit 26 is maintained in a rightward-angled posture (for example, rightward-angled by 45°) or in a leftward-angled posture (for example, leftward-angled by 45°), as illustrated in
Further, the travel rail surface 42x and the travel cam surface 43x are arranged so that the swing distance section (span G3) is arranged at the position 43c facing a position for staple loading. The span G3 is formed to be smaller than the span G2. In this state, the moving unit 26 is maintained in a rightward-angled posture (for example, rightward-angled by 60°) as illustrated in
For changing the angular posture of the moving unit 26 using the travel rail surface 42x and the travel cam surface 43x, it is preferable, from a viewpoint of compactness in layout (to reduce a movement length), to arrange a second travel cam surface or a stopper cam surface for an angle change in cooperation with the travel cam surface 43x.
The illustrated stopper cam surface will be described. As illustrated in
Thus, when the moving unit 26 is moved toward the manual binding position Mp in a state of being locked by the stopper surface 43y, the inclination of the moving unit 26 is corrected to become the original state. Further, when the moving unit 26 is returned to the opposite direction from the manual binding position Mp, the moving unit 26 is (forcedly) inclined to face the corner binding position Cp1 by the stopper surface 43z.
The stapling unit 26 has widely been known as means for performing binding processing using a staple. An example thereof will be described with reference to
On the drive cam 26d the stapling head 26b and the anvil member 26c are arranged at a binding position so as to be mutually opposed. The stapling head 26b is vertically moved between a waiting position on the upper side and a stapling position (the anvil member 26c) on the lower side with the drive cam 26d and a biasing spring (not illustrated). Further, the staple cartridge 39 is mounted on the unit frame 26a in a detachably attachable manner.
Linear blank staples are stored in the staple cartridge 39 and fed to the stapling head 26b by a staple feeding mechanism. The stapling head 26b incorporates a former member to fold a linear staple inward into a U-shape and a driver to cause the folded staple to bite into a sheet bundle. With such a configuration, the drive cam 26d is rotated by the drive motor M8 to store energy in the biasing spring. When the rotational angle reaches a predetermined angle, the stapling head 26b is vigorously lowered toward the anvil member 26c. Owing to this action, a staple is caused to bite into a sheet bundle with the driver after being folded into a U-shape. Then, the leading ends of the staple are folded by the anvil member 26c, whereby staple binding is completed.
The staple feeding mechanism is incorporated in between the staple cartridge 39 and the stapling head 26b. A sensor (empty sensor) to detect the absence of the staple is arranged in the staple feeding mechanism. Further, the unit frame 26a has a cartridge sensor (not illustrated) to detect whether or not the staple cartridge 39 has been inserted.
The illustrated staple cartridge 39 adopts a structure in which the staples connected in a belt shape are stacked in a layered manner or are stored in a roll-shape in a box-shaped cartridge.
Further, the unit frame 26a has a circuit to control the abovementioned sensors and a circuit board to control the drive motor M8, and an alarm signal is issued when the staple cartridge 39 is not mounted or the staple cartridge 39 is empty. Further, the stapling control circuit controls the drive motor M8 to perform the stapling operation with a staple signal and transmits an “operation completion signal” when the stapling head 26b is moved to an anvil position from the waiting position and returned to the waiting position.
The structure of the press binding unit 27 will be described based on
A drive motor M9 arranged at the base frame member 27a is connected to the drive cam 27e through a deceleration mechanism. Rotation of the drive motor M9 causes the drive cam 27e to be rotated, and the movable frame member 27d is swung by a cam surface (eccentric cam in the drawing) thereof.
The lower pressurizing surface 27c and the upper pressurizing surface 27b are arranged respectively at the base frame member 27a and the movable frame member 27d so as to be opposed to each other. A biasing spring (not illustrated) is arranged between the base frame member 27a and the movable frame member 27d to bias both the pressurizing surfaces in a direction to be separated.
As illustrated in an enlarged view of
The structure of the stack tray 25 will be described based on
Specifically, an elevating rail 54 is vertically fixed in the stacking direction to the apparatus frame 20a. A tray base body 25x is slidably fitted to the elevating rail 54 so as to be capable of being elevated and lowered using a slide roller 55 or the like. A rack 25r is formed in the elevating direction integrally with the tray base body 25x. A drive pinion 56 axially supported by the apparatus frame 20a is engaged with the rack 25r. Then, an elevating motor M10 is connected to the drive pinion 56 through a worm gear 57 and a worm wheel 58.
Accordingly, when the elevation motor M10 is rotated forwardly and reversely, the rack 25r connected to the drive pinion 56 is vertically moved to the upper side and lower side of the apparatus frame 20a. With the above configuration, the tray base body 25x is elevated in a cantilevered state. In addition to such a rack-pinion mechanism, the tray elevating mechanism may adopt a pulley-mounted belt mechanism or the like.
The stack tray 25 is integrally attached to the tray base body 25x. Sheets are stacked and stored on the stack surface 25a thereof. The tray aligning surface 20f to support sheet rear end edges is vertically formed in the sheet stacking direction. In the illustrated example, the tray aligning surface 20f is formed with the external casing.
Further, the stack tray 25 integrally attached to the tray base body 25x is arranged so as to be inclined in an illustrated angled direction. The angle (for example, 20° to 60°) is set so that a sheet abuts at the rear end thereof against the tray aligning surface 20f by its own weight.
The stack tray 25 has a sheet holding mechanism 53 to press the uppermost stacked sheet. The illustrated sheet holding mechanism includes an elastic pressing member 53a to press the uppermost sheet, an axially supporting member 53b to cause the elastic pressing member 53a to be rotatably axially supported by the apparatus frame 20a, a drive motor M2 to rotate the axially supporting member 53b by a predetermined angle, and a transmitting mechanism thereof. The illustrated drive motor M2 is drive-connected to the drive motor of the sheet bundle carry-out mechanism as a drive source. When a sheet bundle is carried in (carried out) to the stack tray 25, the elastic pressing member 53a is retracted outside the stack tray 25. After the rear end of the sheet bundle is stored on the uppermost sheet on the stack tray 25, the elastic pressing member 53a is rotated counterclockwise from the waiting position and engaged with the uppermost sheet to press the same.
Then, owing to an initial rotational operation of the drive motor M2 to carry out a sheet bundle on the processing tray 24 toward the stack tray 25, the elastic pressing member 53a is retracted from the sheet surface of the upmost sheet on the stack tray 25 to the retracting position.
The stack tray 25 has a level sensor to detect a sheet height of the uppermost sheet. The elevating motor M10 is rotated based on a detection signal from the level sensor, so that the stack surface 25a is lifted. A variety of mechanisms are known as the level sensor mechanism. In the illustrated example, the level sensor mechanism adopts a detection method to detect whether or not a sheet exists at the height position by emitting a detection light from the tray aligning surface 20f of the apparatus frame 20a to the tray upper side to detect a reflection light thereof.
As with the level sensor, a sensor to detect removal of sheets from the stack tray 25 is arranged at the stack tray 25. Although the structure thereof that is generally adopted will not be described in detail, it is possible to detect whether or not sheets exist on the stack surface, for example, by arranging a sensor lever which is configured to rotate integrally with the elastic pressing member 53a and detecting the sensor lever with a sensor element. When the height position of the sensor lever becomes different (varied) before and after carry-out of a sheet bundle, the controller 75 to be described later stops the sheet discharge operation or lifts the stack tray 25 to a predetermined position, for example. Such an operation is performed in an abnormal case, for example, in a case where a user carelessly removes sheets from the stack tray 25 during an operation. Further, a lower limit position is defined for the stack tray 25, so as to prevent the stack tray 25 from lowering abnormally. A limit sensor Se3 to detect the stack tray 25 is arranged at the lower limit position.
As for the embodiments of the above-mentioned next sheet front end guides 68, 168, and 268, the operation and control that is performed after sheet discharge to the stack tray 25 in particular will be described. As described above, the next sheet front end guide is provided to prevent a sheet to be subsequently fed onto the processing tray 24 after the preceding sheet is discharged from the processing tray 24 to the stack tray 25 from accidentally contacting, at its front end, the back side of the sheet bundle carry-out unit 60 (second conveying member 60B, 160B, or 260B) to cause a conveyance jam or sheet damage. The use of the guide surface of the next sheet front end guide can also reduce occurrence of a sheet jam caused due to curling of the front end of a sheet to be fed onto the processing tray 24. In the following, embodiments to positively support the front end of the next sheet will be described.
The sheet to be fed onto the processing tray 24 is delivered by the sheet discharge roller 32 without being nipped at its front end, so that the sheet front end may be curled or hang down, depending on conditions such as sheet size, sheet basis weight, and sheet hardness (rigidity). This becomes prominent particularly when a level difference between the sheet placing surface of the processing tray 24 and the discharge port (sheet discharge roller 32) is large. The following describes an operation for solving problems such as a conveyance jam. Hereinafter, with reference to the flowchart of
After completion of the discharge operation of a preceding sheet bundle by the sheet bundle carry-out unit 60 (second conveying member 60B, 160B, or 260B), it is recognized, based on information received from the image forming apparatus 1 or a detection result from the entrance sensor Se1, whether or not succeeding sheets are to be carried in (St100,
The second conveying member 60B (or 160B, 260B) is made to stay until the elapse of an estimated time taken for the front end of the next sheet, which is conveyed by the sheet discharge roller 32, contacts the next sheet front end guide 68 (or 168, 268) on the back side of the second conveying member 60B (or 160B, 260B). After the elapse of the estimated time, the sheet bundle carry-out unit 60 is returned to its home position (waiting position) by the time when the next sheet is completely discharged onto the processing tray 24.
On the other hand, when the length of the next sheet in the conveying direction is equal to less than the predetermined length, i.e., when the sheet size is less than the predetermined value (St101), the second conveying member 60B (or 160B, 260B) is retracted to the home position (waiting position) immediately after completion of the discharge (St103). When the sheet length in the conveying direction is small, the front end of the next sheet is less likely to hang down, and a buckling portion is small (if occurred), so that a conveyance jam is less likely to occur. Further, since a time period taken for sheet discharge is small (sheet discharge interval is small), it is necessary to return the second conveying member 60B (or 160B, 260B) to the waiting position earlier. Furthermore, it is preferable for the next sheet front end guide 68 (or 168, 268) not to contact the print surface of the sheet as much as possible for suppressing sheet damage. For the above reasons, the second conveying member 60B (or 160B, 260B) is retracted immediately, followed by carry-in of the next sheet (St105).
After the second conveying member 60B (or 160B, 260B) is moved to the waiting position (St106), the sheet aligning operation is performed (St107). Then, it is checked, based on information received from the image forming apparatus 1 or a detection result from the entrance sensor Se1, whether or not there are succeeding sheets, and the sheets are sequentially received if exist (St108 to St111). Subsequently, the next sheet bundle is aligned by the aligning member 45 (St112) and discharged by the sheet bundle carry-out unit 60 (St113). Then, when it is determined that there are no succeeding sheets (St100), the second conveying member 60B (or 160B, 260B) is moved to the waiting position (St114), and this routine is ended.
With the above processing flow, it is possible to achieve an optimum operation according to sheet size to thereby reduce the occurrence of a conveyance jam without lowering the productivity and to prevent deterioration in print quality.
The following describes an operation flow depending on difference in sheet basis weight with reference to the flowchart of
After completion of discharge operation of a preceding sheet bundle by the second conveying member 60B (or 160B, 260B), it is recognized, based on information received from the image forming apparatus 1 or a detection result from the entrance sensor Se1, whether or not succeeding sheets are carried in (St200). Then, it is checked, based on information received from the image forming apparatus, whether or not the basis weight of the sheet is less than a predetermined value (recognized by the controller 75) (St201). When the basis weight of the sheet is less than the predetermined value (less than 105 g/m2), it is difficult to impart stiffness to the front end of the sheet being delivered onto the processing tray 24, making it likely to cause buckling or curling, so that the second conveying member 60B (or 160B, 260B) is made to wait at the discharge position of the preceding sheet bundle to the stack tray 25, and the next sheet starts to be discharged by the sheet discharge roller 32 and carried in onto the processing tray 24 (St204) (
The second conveying member 60B (or 160B, 260B) is made to stay until the elapse of an estimation time taken for the front end of the next sheet, which is conveyed by the sheet discharge roller 32, contacts the next sheet front end guide 268 (until a pulse count for the conveying roller 32 reaches a predetermined value). After the elapse of the estimated time, the second conveying member 60B (or 160B, 260B) is returned to its home position (waiting position,
On the other hand, when the basis weight of the next sheet is equal to or more than a predetermined value (exceeding 106 g/m2) (St201), the second conveying member 60B (or 160B, 260B) starts retracting to the home position (waiting position,
After the second conveying member 60B (or 160B, 260B) is moved to the waiting position (
As described above, by changing the time period during which the sheet bundle carry-out unit 60 stays at the discharge completion position depending on various sheet conditions, it is possible to reduce the occurrence of a conveyance jam to thereby achieve stable conveying operation.
In addition to the above two embodiments, the following operations are possible. For example, when it is determined based on information related to rigidity that the sheet to be carried in has a low rigidity, the sheet bundle carry-out unit may be made to stay at the discharge position so as to support the front end of the next sheet. In addition, a stop time period during which the sheet bundle carry-out unit may be changed according to information provided for each sheet type. Moreover, a member to support the front end of the next sheet may be changed or a plurality of members may be used to support the front end of the next sheet in a combined manner depending on the printed area or printed location. Furthermore, various kinds of sheet information may be combined for complex determination.
The above description has been made on operations in the straight discharge mode in which the sheet conveyance interval is small in particular. In addition, the stop time period of the discharge claw 60 can be changed depending on the processing mode. For example, there is provided a shift mode in which the aligning member 45 is used to shift a sheet conveyed onto the processing tray 24 in a sheet width direction perpendicular to the conveying direction. In this shift mode, the aligning member 45 (at least one of the side aligning members 46F and 46R) enters the center position at which a sheet conveyed from the discharge port is located (see
The description will be given with reference to the flowchart of
The following describes a case where the succeeding sheets are also subjected to the shift discharge. When there are succeeding sheets (St300), and the next sheet is subjected to the shift discharge (St301), the aligning member 45 (at least one of the side aligning members 46F and 46R) is made to wait at the position at which the preceding sheet bundle is shifted and discharged until the next sheet is discharged (St303,
After the next sheet receiving operation in each of the above modes, the aligning member 45 is used for sheet aligning operation (St312), and after completion of the reception of the succeeding sheets, the side aligning member 45 is used to perform sheet aligning and sheet discharge onto the stack tray 25 (St313 to St318). When there are succeeding sheets, operations up to this step is repeatedly executed (St300). When there is no succeeding sheet, the aligning member 45 is returned to the home position (St319), and the sheet bundle carry-out unit 60 (second conveying member 60B, 160B, or 260B) is also moved to the home position (St320). This routine is thus completed.
As described above, in the present embodiment, when the preceding sheet is subjected to the shift job (at least one of the side aligning members 46F and 46R is at the position where it can support the next sheet), and the succeeding sheets are also subjected to the shift job, the aligning member 45 (at least one of the side aligning members 46F and 46R) is made to stay at the shifted position so as to support the front end of the next sheet at its upper portion, while the second conveying member 60B (or 160B, 260B) is moved to the waiting position. When the succeeding sheets are subjected to the straight discharge, the aligning member is moved to the waiting position, and the next sheet front end guide 68 (or 168, 268) of the second conveying member 60B (or 160B, 260B) is used to support the front end of the next sheet. Thus, it is possible to perform an operation that least affects the sheet print surface according to the operation mode of each job and to suppress dirt on the sheet, thereby providing a sheet processing apparatus having high print quality.
In the above description, either one of the second conveying member 60B (or 160B, 260B) and aligning member 45 is used; alternatively, when many images are printed on the print surface of the sheet, and it is thus necessary to distribute a load caused due to contact with the print surface, or when a sheet having extremely low rigidity, such as a thin film or a plastic sheet that is easily bent is used, the above two members may be used in combination.
Further, based on the pulse count for the sheet discharge roller 32, the conveying speed of the sheet discharge roller 32 may be reduced at or before the timing when the front end of the next sheet contacts the next sheet front end guide 68 (or 168, 268) and aligning member 45 and then increased, whereby damage on the sheet can further be reduced.
While the present invention has been described in detail in connection to the preferred embodiments thereof, it should be understood that the present invention is not limited to the above embodiment but various modification or changes may be made within the technical scope of the invention.
This application claims priority from Japanese Patent Application No. 2020-214500 and Japanese Patent Application No. 2020-214501 incorporated herein by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-214500 | Dec 2020 | JP | national |
| 2020-214501 | Dec 2020 | JP | national |
