SHEET CONVEYING APPARATUS AND IMAGE FORMING SYSTEM HAVING THE SAME

TECHNICAL FIELD

The present invention relates to a sheet conveying apparatus for conveying sheets fed from an image forming apparatus and the like, and to an image forming system having the same.

BACKGROUND ART

Generally, as a post-processing apparatus is widely known an apparatus for collecting sheets discharged from an image forming apparatus on a processing tray, performing binding processing with a binding apparatus and storing in a stack tray on the downstream side. The configuration adopts a structure (standalone structure) where a sheet carry-in path is coupled to a sheet discharge outlet of the image forming apparatus, the processing tray is disposed in a sheet discharge outlet of the path to collate and collect sheets with image formed, a binding processing unit disposed in the tray performs binding processing, and then, the sheets are stored in the stack tray disposed on the downstream side. Further, another structure (inner finisher structure) is also adopted where a unit equipped with the processing tray provided with a binding section and the stack tray are built into a sheet discharge area of the image forming apparatus.

Such an apparatus needs a bunch conveying mechanism for conveying a sheet bunch subjected to the binding processing, or processing for once collecting and the like in the processing tray to the stack tray on the downstream side. For example, in Patent Documents 1 and 2 are disclosed post-processing apparatuses for collating and collecting sheets with images formed in the image forming apparatus in the post-processing apparatus on the downstream side to perform the binding processing, and then, storing in the stack tray. Then, in the same documents, the processing tray is equipped with a sheet bunch carrying-out mechanism for carrying out the sheet bunch from a binding position to the stack tray on the downstream side. In the mechanism, a belt supported by a drive pulley is integrally provided with a hook member (protruding member; the same hereinafter) for engaging in a rear end edge of the sheet bunch, and the hook member is shifted from a binding end portion to a carrying-out end portion of the processing tray along a tray face.

PRIOR ART DOCUMENT
Patent Document

[Patent Document 1] Japanese Unexamined Patent Publication No. 2015-020822

[Patent Document 2] Japanese Unexamined Patent Publication No. 2007-076893

DISCLOSURE OF INVENTION
Problems to be Solved by the Invention

In the mechanism for carrying out a sheet bunch from the processing tray for collating, collecting and performing the binding processing on the sheet bunch to the stack tray on the downstream side, each of a mechanism for pushing out the sheet bunch with a belt conveyor and another mechanism for carrying out the sheet bunch with a roller pair is known. In the belt conveyor mechanism, a pair of pulleys is disposed in a bottom portion of the processing tray to loop a belt (carrier member), and a hook member (protruding member) for locking a rear end edge of the sheet bunch is integrally provided in the belt. By this means, the hook member shifts in position from the tray rear end portion to the tray front end portion along the tray upper face, and therefore, discharge performance is excellent in bunch-shaped sheets. However, in such a sheet bunch carrying-out mechanism, the hook member performs forward route operation at a long stroke from the tray rear end portion to the tray front end portion (toward a discharge outlet outside the apparatus), and in performing backward route operation from the tray front end portion, there is a possibility that the hook member collides with the next sheet conveyed to the processing tray, and that a conveyance jam occurs. In order to avoid such a collision, since the next sheet front end is conveyed to the processing tray, after waiting for the hook member to perform the backward route operation with a certain amount, the problem occurs that the processing time is taken in surplus.

Means for Solving the Problem

In order to solve the above-mentioned problem, a sheet conveying apparatus of the present invention is provided with a sheet conveying section for conveying a sheet in a predetermined conveyance direction, a placement portion to place sheets conveyed by the sheet conveying section, a contact portion for coming into contact with an upstream side end portion in the conveyance direction of placed sheets placed in the placement portion, a sheet discharge section for shifting the contact portion to the downstream side in the conveyance direction and thereby discharging the placed sheets from the placement portion, and a sheet conveyance guide portion for supporting a front end of a next sheet conveyed to the placement portion by the sheet conveying section on the upstream side of the contact portion in the conveyance direction, where the sheet conveyance guide portion is provided with an inclined face for supporting the front end of the next sheet discharged to the placement portion.

Advantageous Effect of the Invention

Productivity for enabling the next sheet to be conveyed is high, irrespective of a position of the hook member.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory view of an entire configuration of an image forming system according to the present invention;

FIG. 2 is a perspective explanatory view illustrating the entire configuration of a post-processing apparatus in the image forming system of FIG. 1;

FIG. 3 is a side cross-sectional view (apparatus front side) of the apparatus of FIG. 2;

FIGS. 4A and 4B contain explanatory views of a sheet carry-in mechanism in the apparatus of FIG. 2, where FIG. 4A illustrates a state in which a paddle rotating body is in a waiting position, and FIG. 4B illustrates a state in which the body is in an engagement position;

FIG. 5 is an explanatory view illustrating an arrangement relationship between each area and an alignment position in the apparatus of FIG. 2;

FIG. 6 is a configuration explanatory view of a side aligning section in the apparatus of FIG. 2;

FIG. 7 is an explanatory view of a shift mechanism of a stapler unit;

FIG. 8 is an explanatory view illustrating binding positions of the stapler unit;

FIG. 9 is an explanatory view of multi-binding and left corner binding of the stapler unit;

FIGS. 10A and 10B illustrate states of the stapler in the binding positions, where FIG. 10A illustrates a state in a right corner binding position, FIG. 10B illustrates a state in a stapler load position, and FIG. 10C illustrates a state in a manual binding position;

FIG. 11 is an explanatory view of a sheet bunch carrying-out mechanism in Embodiment 1, and illustrates a waiting state;

FIG. 12 is another explanatory view of the sheet bunch carrying-out mechanism in Embodiment 1, and illustrates a relay conveyance state;

FIG. 13 is still another explanatory view of the sheet bunch carrying-out mechanism in Embodiment 1, and illustrates a structure of a second conveying member;

FIG. 14 is still another explanatory view of the sheet bunch carrying-out mechanism in Embodiment 1, and illustrates a state in which sheets are discharged to a stack tray;

FIG. 15 is still another explanatory view of the sheet bunch carrying-out mechanism in Embodiment 1, and illustrates a state in which the next sheet is conveyed to a processing tray;

FIG. 16 illustrates an entire view of a sheet bunch carrying-out mechanism in Embodiment 2;

FIG. 17 is an explanatory view of the sheet bunch carrying-out mechanism in Embodiment 2, and illustrates a waiting state;

FIG. 18 is another explanatory view of the sheet bunch carrying-out mechanism in Embodiment 2, and illustrates a relay conveyance state;

FIG. 19 is still another explanatory view of the sheet bunch carrying-out mechanism in Embodiment 2, and illustrates a state during conveyance by a second conveying member;

FIG. 20 is still another explanatory view of the sheet bunch carrying-out mechanism in Embodiment 2, and illustrates a state immediately before the second conveying member arrives at a discharge position and a state in which the second conveying member starts to return from the discharge position to the waiting position;

FIG. 21 is still another explanatory view of the sheet bunch carrying-out mechanism in Embodiment 2, and illustrates a state in which the second conveying member is in the discharge position;

FIG. 22 is an explanatory view of a sheet bunch carrying-out mechanism in Embodiment 3, and illustrates a state in which a second conveying member is in a discharge position;

FIGS. 23A to 23C contain explanatory views of a drive configuration of the sheet bunch carrying-out mechanism, where FIG. 23A illustrates a principal part enlarged view, FIG. 23B illustrates a startup state of a motor, and FIG. 23C is a state view after rotating a predetermined angle;

FIGS. 24A to 24G illustrate binding processing methods for a bunch of sheets; FIG. 25A is a configuration explanatory view of the stapler unit; FIG. 25B is a configuration explanatory view of a press bind unit; and

FIG. 26 is a configuration explanatory view of the stack tray in the apparatus of FIG. 2.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described below in detail according to preferred Embodiments shown in the drawings. The present invention relates to a sheet bunch binding processing mechanism for performing binding processing on a bunch of sheets which are collated and collected after forming images thereon in an image forming system and the like described later. An image forming system shown in FIG. 1 is comprised of an image forming unit A, image reading unit C, and post-processing unit B. Then, an original document image is read by the image reading unit C, and based on the image data, an image is formed on a sheet by the image forming unit A. Then, the image-formed sheet is collated, collected, subjected to the binding processing by the post-processing unit B (sheet bunch binding processing apparatus; the same hereinafter), and is stored in a stack tray 25 on the downstream side.

The post-processing unit B described later is incorporated, as a unit, into sheet discharge space (stack tray space) 15 formed in a housing of the image forming unit A, and shows an inner finisher structure provided with a post-processing mechanism for collating image-formed sheets sent to a sheet discharge outlet 16 to collect, performing the binding processing, and then, storing in the stack tray disposed on the downstream side. The present invention is not limited thereto, and also enables a system to be made where each of the image forming unit A, image reading unit C and post-processing unit B is configured by independent standalone structure, and respective apparatuses are connected by network cables.

[Sheet Bunch Binding Processing Apparatus (Post-Processing Unit)]

FIG. 2 illustrates a perspective configuration of the post-processing unit B, and FIG. 3 illustrates a sectional configuration of the unit B. As shown in the figures, the post-processing unit B is comprised of an apparatus housing 20, a sheet carry-in path 22 disposed in the housing, a processing tray 24 disposed on the downstream side of a sheet discharge outlet 23 of the path, and the stack tray 25 disposed on the downstream side of the tray 24.

In the processing tray 24 are disposed a sheet carry-in section 35 for carrying a sheet in, a sheet regulating section 40 for collecting carried-in sheets in the shape of a bunch, and an aligning section 45. Together with the sections, in the processing tray 24 are disposed a staple binding section 26 (first binding section) for performing staple binding on a bunch of sheets, and a needleless binding section 27 (second binding section) for performing needleless binding on a bunch of sheets. Each configuration will be described below in detail.

[Apparatus Housing]

The apparatus housing 20 is comprised of an apparatus frame 20a and exterior casing 20b, and the apparatus frame is configured by frame structure for supporting each mechanism section (path mechanism, tray mechanism, conveyance mechanism, etc.) described later. The apparatus shown in the figure is configured by monocoque structure where a binding mechanism, conveyance mechanism, tray mechanism and drive mechanism are disposed in a pair of mutually opposed right and left side frames (not shown) and are integrated by the exterior casing 20b. The exterior casing 20b is configured by monocoque structure where right and left side frames 20c, 20d and a stay frame (bottom frame 20e described later) for connecting between opposite side frames are integrated by mold processing with resin and the like, and a part thereof (apparatus front side) is exposed to enable operation to be performed from outside the apparatus.

In other words, the outer regions of frames are covered with the exterior casing 20b, and are incorporated into the sheet discharge space 15 of the image forming unit A described later. In this state, an exterior case on the apparatus front side is exposed in the state for enabling operation to be performed from the outside. On the front side of the exterior casing 20b are equipped a cartridge insertion opening 28 for staples, a manual set section 29, and a manual operation button 30 (shown in the figure is a switch with an integrated display lamp), described later. In the aforementioned exterior casing 20b, a length dimension Lx in a sheet discharge direction, and a length dimension Ly in a sheet discharge orthogonal direction are set with reference to a maximum-sized sheet, and are set at dimensions smaller than the sheet discharge space 15 of the image forming unit A described later.

[Sheet Carry-In Path (Sheet Discharge Path)]

In the apparatus housing 20 described above, as shown in FIG. 3, the sheet carry-in path 22 (hereinafter, referred to as a “sheet discharge path”) having a carry-in entrance 21 and sheet discharge outlet 23 is disposed, and the path shown in the figure is configured to receive a sheet in the horizontal direction to convey substantially in the horizontal direction, and carry out from the sheet discharge outlet 23. The sheet discharge path 22 is formed of an appropriate paper guide (plate) 22a, and includes an integrated feeder mechanism for conveying the sheet. The feeder mechanism is comprised of conveyance roller pairs at predetermined intervals corresponding to a path length. In the mechanism shown in the figure, a carry-in roller pair 31 is disposed in the vicinity of the carry-in entrance 21, and a sheet discharge roller pair 32 is disposed in the vicinity of the sheet discharge outlet 23. Further, in the sheet discharge path 22 is disposed a sheet sensor Se1 for detecting a front end and/or rear end of the sheet.

The above-mentioned sheet discharge path 22 is formed of a linear path substantially in the horizontal direction to extend across the apparatus housing 20. This is because of preventing stress from being imposed on the sheet by a curved path, and the path is formed with a linear characteristic allowed by apparatus layout. The above-mentioned carry-in roller pair 31 and sheet discharge roller pair 32 are coupled to the same drive motor M1 (hereinafter, referred to as a conveyance motor), and convey the sheet at the same circumferential velocity.

[Processing Tray]

The description will be given according to FIG. 3. In the sheet discharge outlet 23 of the sheet discharge path 22, the processing tray 24 is disposed on the downstream side of the outlet with a height difference d formed. In order to stack sheets fed from the sheet discharge outlet 23 upward to collect in the shape of a bunch, the processing tray 24 is provided with a paper mount face 24a for supporting at least a part of the sheet. The apparatus shown in the figure adopts a structure (bridge support structure) where the stack tray 25 described later supports the sheet front end side, and the processing tray 24 supports the sheet rear end side. By this means, tray dimensions are made smaller.

The above-mentioned processing tray 24 is configured to collect sheets fed from the sheet discharge outlet 23 in the shape of a bunch, align in a predetermined posture, then perform the binding processing, and carry out the processed bunch of sheets to the stack tray 25 on the downstream side. Therefore, into the processing tray 24 are incorporated the “sheet carry-in mechanism 35”, “sheet aligning mechanism 45”, “binding processing mechanisms 26, 27” and “sheet bunch carrying-out mechanism 60”.

[Sheet Carry-In Mechanism (Sheet Carry-In Section)]

The processing tray 24 is disposed in the above-mentioned sheet discharge outlet 23 with the height difference d formed. On the processing tray 24 is required the sheet carry-in section 35 for smoothly conveying the sheet in a correct posture. The sheet carry-in section 35 (friction rotating body) shown in the figure is comprised paddle rotating bodies 36 that move up and down, and in a stage in which the sheet rear end is carried out onto the tray from the sheet discharge outlet 23, the paddle rotating bodies 36 transfer the sheet in a sheet discharge opposite direction (rightward in FIG. 3), and strike the sheet end regulating section 40 described later to align (position).

Therefore, the sheet discharge outlet 23 is provided with an up-and-down arm 37 axially supported by the apparatus frame 20a swingably by a spindle 37x, and the paddle rotating body 36 is axially supported rotatably in a front end portion of the up-and-down arm. The aforementioned spindle 37x is equipped with a pulley not shown, and the pulley is coupled to the conveyance motor M1 described previously.

Concurrently therewith, an up-and-down motor M3 (hereinafter, referred to as a paddle up-and-down motor) is coupled to the up-and-down arm 37 via a spring clutch (torque limiter), and it is configured that the up-and-down arm 37 is moved up and down between an upper waiting position Wp and a lower operation position (sheet engagement position) Ap by rotation of the motor. In other words, the spring clutch raises the up-and-down arm 37 from the operation position Ap to the waiting position Wp by one-direction rotation of the paddle up-and-down motor M3, and after striking a locking stopper not shown, the arm waits in the waiting position. Further, by opposite-direction rotation of the paddle up-and-down motor M3, the spring clutch relaxes, and the up-and-down arm 37 moves downward under its own weight from the waiting position Wp to the lower operation position Ap and engages in the uppermost sheet on the processing tray.

In the apparatus shown in the figure, as shown in FIG. 5, a pair of paddle rotating bodies 36 are disposed left-right symmetrically at a predetermined distance with a sheet center as reference (center reference (Sx)). In addition thereto, total three paddle rotating bodies may be disposed in the sheet center and opposite sides, or one paddle rotating body may be disposed in the sheet center.

Further, the above-mentioned paddle rotating body 36 is comprised of a flexible rotating body such as a plate member made of rubber material and plastic wing member. In addition to the paddle rotating body, as the sheet carry-in section 35, the section 35 is capable of being comprised of a friction rotating member such as a roller body and belt body. Furthermore, the apparatus shown in the figure shows the mechanism for moving the paddle rotating body 36 downward from the upper waiting position Wp to the lower operation position Ap after the sheet rear end is carried out from the sheet discharge outlet 23, and is also capable of adopting the next up-and-down mechanism.

In the up-and-down mechanism different from the mechanism shown in the figure, for example, in a stage in which the sheet front end is carried out from the sheet discharge outlet 23, the friction rotating body is moved down from the waiting position to the operation position, is concurrently rotated in the sheet discharge direction, and at timing at which the sheet rear end is carried out from the sheet discharge outlet 23, is rotated backward in the sheet discharge opposite direction. By this means, it is possible to shift the sheet, which is carried out from the sheet discharge outlet 23, to a predetermined position of the processing tray 24 at a high velocity without skew.

[Take-In Rotating Body (Take-In Conveying Section)]

In the case of conveying the sheet to the predetermined position of the processing tray 24 by the sheet carry-in mechanism 35 (paddle rotating body) disposed in the above-mentioned sheet discharge outlet 23, a take-in conveying section 33 is required which guides the sheet front end to the regulating stopper 40 on the downstream side, due to effects of the curled sheet, skewed sheet and the like.

In the apparatus shown in the figure is disposed the take-in rotating body (take-in conveying section) 33 for applying a conveyance force to the regulating member side to the uppermost sheet of sheets stacked on the upstream side of the sheet end regulating stopper 40 described later, below the sheet discharge roller pair 32. As the body shown in the figure, a ring-shaped belt member 34 (hereinafter, referred to as a “take-in belt”) is disposed above the front end portion of the processing tray 24, and the take-in belt 34 engages in the uppermost sheet on the paper mount face, while rotating in a direction for conveying the sheet to the regulating member side.

Therefore, the take-in belt 34 is comprised of a belt material (knurling belt, etc.) with high frictional force made of soft materials such as rubber materials, and is nipped and supported between a rotation shaft 34x coupled to a drive motor (which is common to the conveyance motor M1 in the apparatus shown in the figure) and an idle shaft 34y. Then, a rotation force in a counterclockwise direction in FIG. 3 is applied from the rotation shaft 34x. Concurrently therewith, the take-in belt 34 presses the sheet front end, which is carried in along the uppermost sheet stacked on the processing tray, to strike the regulating stopper 40 on the downstream side.

The above-mentioned take-in belt 34 is configured to move up and down above the uppermost sheet on the tray by a belt shift motor M5 (hereinafter, referred to as a knurl up-and-down motor) (its up-and-down mechanism is omitted). Then, at timing at which the sheet front end enters between the belt surface and the uppermost sheet, the take-in belt 34 moves down to engage in the carried-in sheet. Further, in shifting the sheet from the processing tray 24 to the stack tray 25 on the downstream side by the sheet bunch carrying-out section 60 described later, the knurl up-and-down motor M5 is controlled so that the take-in belt 34 separates from the uppermost sheet to wait above.

[Sheet Aligning Mechanism]

In the processing tray 24 is disposed the sheet aligning mechanism 45 for positioning the carried-in sheet in a predetermined position (processing position). The sheet aligning mechanism 45 shown in the figure is comprised of the “sheet end regulating section 40” for position-regulating an end face (front end face or rear end face) in the sheet discharge direction of the sheet fed from the sheet discharge outlet 23, and the “side aligning section 45” for width-aligning in the sheet discharge orthogonal direction (sheet side direction). The sections will be described below in this order.

[Sheet End Regulating Section]

The sheet end regulating section 40 shown in the figure is comprised of rear end regulating members 41 for striking the rear end edge in the sheet discharge direction to regulate. The rear end regulating member 41 is provided with a regulating face 41a for striking and regulating the rear end edge in the sheet discharge direction of the sheet that is carried in along the paper mount face 24a on the processing tray, and strikes the rear end edge of the sheet fed by the take-in conveying section 33 to halt.

The stapler unit shifts along (in the sheet discharge orthogonal direction) the sheet rear end, when the stapler section 26 described later performs multi-binding. Therefore, in order not to interfere with the unit shift, the rear end regulating member 41 (1) adopts a mechanism for causing the rear end regulating member to enter and retract from a shift path (motion locus) of the binding unit, (2) adopts a mechanism for shifting in position integrally with the binding unit, or (3) is comprised of, for example, a bent piece in the shape of a channel inside binding space formed of a head and an anvil of the binding unit.

In the member shown in the figure, the rear end regulating member 41 is comprised of a plate-shaped bent member of C-shaped (channel-shaped) cross section disposed inside the binding space of the staple binding section 26. Then, with reference to the minimum-sized sheet, a first member 41A is disposed in the center, and second and third members 41B, 41C are disposed to the left and right of the member 41A spaced apart from the member 41A (see FIG. 5). By this means, the staple binding unit 26 is capable of shifting in the sheet width direction.

As shown in FIGS. 5 and 7, a plurality of rear end regulating members 41 each comprised of the channel-shaped bent piece is fixed to the processing tray 24 (the front end portion of the member is fixed to a tray rear wall with a screw.) In each of the aforementioned rear end regulating members 41, the regulating face 41a is formed, and to the bent front end portion is coupled an inclined face 41b for guiding the sheet end to the regulating face.

[Side Aligning Section]

In the processing tray 24 is provided the aligning section 45 (hereinafter, referred to as the “side aligning member”) for positioning the sheet struck by the above-mentioned rear end regulating member 41 in the sheet discharge orthogonal direction (sheet width direction).

Corresponding to whether to align sheets of different sizes on the processing tray in center reference or one-side reference, the configuration of the side aligning member 45 is varied. In the apparatus shown in FIG. 5, different-sized sheets are discharged from the sheet discharge outlet 23 in center reference, and the sheets are aligned on the processing tray in center reference. Then, corresponding to the binding processing, in multi-binding, a bunch of sheets aligned in the shape of a bunch in center reference is subjected to the binding processing in the aligned posture in binding positions Ma1, Ma2 by the stapler unit 26. In right/left corner binding, a bunch of sheets is offset in the right/left direction by a predetermined amount, and is subjected to the binding processing in the binding position Cp1/Cp2 by the stapler unit 26.

Therefore, in the aligning section 45, a pair of right and left side aligning members 46 (46F, 46R) are disposed to be mutually opposed. The member 46 protrudes upward from the paper mount face 24a of the processing tray, and includes a regulating face 46x for engaging in the side edge of the sheet. Then, the pair of right and left side aligning members 46 are disposed in the processing tray 24 to be able to perform reciprocating motion at a predetermined stroke. The stroke is set using a size difference between the maximum-sized sheet and the minimum-sized sheet and an offset amount for position-shifting (offset-conveying) the aligned sheet bunch to the left or right direction. In other words, a shift stroke of each of the right and left side aligning members 46F, 46R is set by a shift amount to align different-sized sheets and the offset amount of the aligned sheet bunch.

Therefore, as shown in FIG. 6, the side aligning members 46 are comprised of the right-side aligning member 46F (apparatus front side) and left-side aligning member 46R (apparatus rear side), and both of the side aligning members 46 are supported by a tray member so that the regulating faces 46x for engaging in the sheet side ends shift mutually in approaching directions or in separating directions. The processing tray 24 is provided with slit grooves 24x penetrating the frontside and the backside, and the side aligning member 46 having the regulating face 46x for engaging in the sheet side edge is slidably fitted into the tray upper face from the slit.

Each of the side aligning members 46F, 46R is supported by a plurality of guide rollers 49 (which may be a rail member) slidably on the tray rear side, and a rack 47 is integrally formed. Right and left racks 47 are coupled to alignment motors M6, M7 via pinions 48, respectively. The right and left alignment motors M6, M7 are comprised of stepping motors, and are configured so that position sensors not shown detect positions of the right and left side aligning members 46F, 46R, and that using the detected values as reference, each regulating member is capable of shifting in position in both the right and left directions by a designated shift amount.

In addition, as well as the rack-pinion mechanism shown in the figure, it is also possible to adopt a configuration where each of the side aligning members 46F, 46R is fixed to a timing belt, and the belt is coupled to a motor for causing the belt to perform right-left reciprocating motion with a pulley.

In such a configuration, a control section 75 described later causes the right and left side aligning members 46 to wait in predetermined waiting positions (width size of a sheet +α position), based on sheet size information provided from the image forming unit A and the like. In this state, the sheet is carried onto the processing tray, and at timing at which the sheet end is stuck by the sheet end regulating member 41, alignment operation is started. The alignment operation is to rotate the right and left alignment motors M6, M7 in the opposite directions (approaching directions) by the same amount. Then, the sheet carried in the processing tray 24 is positioned with reference to the sheet center, and is stacked in the shape of a bunch. By repeating the carry-in operation and alignment operation for the sheet, the sheet is collated and collected in the shape of a bunch on the processing tray. At this point, different-sized sheets are positioned in center reference.

Sheets thus collected on the processing tray in center reference are capable of being subjected to the binding processing (multi-binding processing) in this posture in a plurality of portions at a predetermined interval in the sheet rear end edge (or front end edge). Further, in the case of performing the binding processing in a sheet corner, one of the right and left side aligning members 46F, 46R is shifted to a designated binding position that is a position with which the sheet side end coincides and is halted. Then, the side aligning member on the opposite side is position-shifted in the approaching direction. The shift amount in the approaching direction is calculated corresponding to the sheet size. By this means, in right corner binding, the sheets carried onto the processing tray 24 are aligned so that the right-side edge coincides with the binding position. In the left corner binding position, the sheets are aligned so that the left-side edge coincides with the binding position.

In the case of offset-shifting to perform “eco-binding processing” described later on a bunch of sheets aligned in the predetermined position on the processing tray as described above, one of the following types of drive control is adopted:

(1) In a state in which the aligning member on the front side in a shift direction is retracted to a position spaced apart from an offset scheduled position, the aligning member on the rear side in the shift direction is shifted in a conveyance orthogonal direction by a beforehand set amount; and
(2) the right and left aligning members are shifted in the conveyance orthogonal direction by the same amount.

In addition, position sensors (not shown) such as position sensors and encode sensors are disposed in the right and left side aligning members 46F, 46R and alignment motors M6, M7 thereof to detect positions of the side aligning members 46. Further, the alignment motors M6, M7 are comprised of stepping motors, home positions of the side aligning members 46 are detected by position sensors (not shown), the motors are subjected to PWM control, and it is thereby possible to control the right and left side aligning members 46F, 46R with relatively simple control configuration.

[Sheet Bunch Carrying-Out Mechanism]

Embodiment 1 of the sheet bunch carrying-out mechanism (sheet bunch carrying-out section 60) will be described according to FIGS. 11 to 13. In the above-mentioned processing tray 24 is disposed the sheet bunch carrying-out mechanism for carrying out the bunch of sheets subjected to the binding processing by one of the first and second binding sections 26, 27 to the stack tray 25 on the downstream side. In the processing tray 24 described according to FIG. 5, the first sheet rear end regulating member 41A is disposed in a sheet center Sx, and to the right and left of the member 41A, the second and third sheet rear end regulating members 41B, 41C are disposed, while being spaced apart. Then, it is configured that the bunch of sheets locked by the regulating members 41 is carried out to the stack tray 25 on the downstream side, after performing the binding processing on the sheets by the binding section 26 (27).

Therefore, the sheet bunch carrying-out section 60 is disposed along the paper mount face 24a in the processing tray 24. The sheet bunch carrying-out section 60 shown in the figure is comprised of a first conveying member 60A and second conveying member 60B, the first conveying member 60A performs relay conveyance in a first zone Tr1 on the processing tray, and the second conveyance member 60B performs relay conveyance in a second zone Tr2. Thus, by relay-conveying the sheet by the first and second conveying members 60A, 60B, it is possible to make a mechanism of each conveying member a different structure. Then, it is necessary that a member for conveying the bunch of sheets from almost the same starting point as that of the sheet rear end regulating section 40 is comprised of a member (long support member) with little sway, and that a member for dropping the bunch of sheets into the stack tray 25 at a conveyance endpoint is small in size (because of traveling in a rotation locus).

The first conveying member 60A is comprised of a first carrying-out member 61 formed of a bent piece of C-shaped cross section, and this member is provided with a locking face 61a for locking a rear end face of the bunch of sheets, and a paper surface press member 62 (elastic film member; Mylar piece) for pressing the top face of the sheets locked on the face 61a. Since the first conveying member 60A is comprised of the channel-shaped bent piece as shown in the figure, when the member 60A is fixed to a carrier member 65a (belt) described later, the member 60A sways little, travels integrally with the belt, and shifts (feeds out) the rear end of the bunch of sheets in the conveyance direction. Then, the first conveying member 60A does not travel in a curved rotation locus as described later, and reciprocates at a stroke Str1 in an almost linear locus.

The second conveying member 60B is comprised of a hook-shaped second carrying-out member 63, and is provided with a locking face 63a for locking the rear end face of the bunch of sheets, and a paper surface press member 64 for pressing the top face of the bunch of sheets. The paper surface press member 64 is axially supported by the second carrying-out member 63 swingably, and is provided with a paper surface press face 64a, and the paper surface press face is biased by a biasing spring 64b so as to press the top face of the bunch of sheets.

Further, the paper surface press face 64a is comprised of an inclined face inclined in a travel direction as shown in the figure, and in shifting in the arrow direction shown in FIG. 12, engages in the rear end of the sheet at a nip angle of y. At this point, the paper surface press face 64a deforms upward (counterclockwise direction shown in the figure) in the arrow direction against the biasing spring 64b. Then, as shown in FIG. 13, by action of the biasing spring 64b, the paper surface press face 64a presses the top face of the bunch of sheets to the paper mount face side.

The first carrying-out member 61 configured as described above reciprocates from a base end portion to an exit end portion of the paper mount face 24a by the first carrier member 65a, and the second carrying-out member 63 reciprocates from the base end portion to the exit end portion by a second carrier member 65b. Therefore, in the paper mount face 24a, drive pulleys 66a, 66b and driven pulley 66c are disposed in positions spaced a conveyance stroke. Notations of 66d, 66e shown in the figure are idle pulleys.

Then, the first carrier member 65a (shown in the figure is a belt with teeth) is looped between the drive pulley 66a and the driven pulley 66c, and the second carrier member 65b (belt with teeth) is looped between the drive pulley 66b and the driven pulley 66c via the idle pulleys 66d, 66e. The drive pulleys 66a, 66b are coupled to a drive motor M4, and in order to transfer rotation of the motor to the first carrier member 65a at a low velocity, while transferring to the second carrier member 65b at a high velocity, the first drive pulley 66a is formed to be a small diameter, while the second drive pulley 66b is formed to be a large diameter.

In other words, to the common drive motor M4, the first conveying member 60A is coupled to travel at the low velocity, and the second conveying member 60B is coupled to travel at the high velocity, via a deceleration mechanism (belt-pulley, gear coupling, etc.) Concurrently therewith, the second drive pulley 66b includes an integral cam mechanism with the following structure to delay drive transfer. This is because the shift stroke Strl of the first conveying member 60A is different from a shift stroke Str2 of the second conveying member 60B as described later, and a waiting position of each member is adjusted in position.

The above-mentioned cam mechanism will be described with reference to FIGS. 23A to 23C. As described above, rotation of a rotation shaft 67x of the motor M4 is transferred to the drive pulley 66a of the first carrier member (first belt) 65a via a transfer belt. Accordingly, forward-backward rotation of the drive motor M4 is directly transferred to the first belt 65a, and the first belt 65a is moved in a sheet bunch carrying-out direction by forward rotation thereof, and is moved in a return direction by backward rotation thereof.

Further, rotation of the rotation shaft 67x of the drive motor M4 is coupled to the drive pulley 66b of the second carrier member (second belt) 65b via a transfer belt. Rotation of the rotation shaft 67x is coupled to the drive pulley 66b via transfer cams (protruding cam 67a and concave dent cam 67b), and the coupling is to delay rotation of the rotation shaft 67x of the drive motor by a predetermined angle so as to transfer rotation to the drive pulley 66b.

FIG. 23B illustrates a startup state of the motor rotation shaft 67x, and FIG. 23C illustrates a state after rotating a predetermined angle. As shown in the figure, the protruding cam 67a is integrally formed in the motor rotation shaft 67x, and the concave dent cam 67b for engaging in the protruding cam 67a is formed in the drive pulley 66b. Then, the protruding cam 67a and concave dent cam 67b do not engage within a range of the predetermined angle, and to engage after rotating the predetermined angle, an idle angle (η) is formed.

In other words, in FIG. 23B illustrating the startup time of the motor rotation shaft 67x, since the idle angle η is formed with respect to the concave dent cam 67b, the protruding cam 67a rotating in the counterclockwise direction becomes the state of FIG. 23C after rotating the angle to transfer drive to the concave dent cam 67b, and the drive pulley 66b starts to rotate.

This is the same as the time the drive motor M4 is rotated backward to cause the second belt 65b to perform return motion, and the second belt 65b starts to travel after a delay of the predetermined angle (distance) with respect to the first belt 65a, and returns to a position delayed by the predetermined distance.

Accordingly, with respect to the first conveying member 60A fixed to the first belt 65a, the second conveying member 60B fixed to the second belt 65b starts to drive after a delay of a predetermined time, and returns to the position delayed by the predetermined time. Accordingly, it is possible to vary the waiting position of the second conveying member 60B with respect to rotation timing of the drive motor M4. By this means, when the second conveying member 60B waits on the rear side (bottom) of the processing tray 24, it is possible to adjust the position.

According to the configuration described above, the first conveying member 60A performs reciprocating motion in a liner locus at the first stroke Str1 from the rear end regulating position of the processing tray 24, and the first zone Tr1 is set inside the stroke. The second conveying member 60B performs reciprocating motion in a semi-loop-shaped locus at the second stroke Str2 from the first zone Tr1 to the exit end of the processing tray 24, and the second zone Tr2 is set inside the stroke.

Then, the first conveying member 60A shifts from the sheet rear end regulating position to the downstream side (FIG. 11 to FIG. 12) at a velocity V1 by one-direction rotation of the drive motor M4, and presses the rear end of the sheet bunch by the locking face 61a thereof to shift. After a delay of the predetermined time from the first conveying member 60A, the second conveying member 60B protrudes onto the paper mount face from the waiting position (FIG. 11) on the rear side of the processing tray, follows the first conveying member 60A, travels and shifts in the same direction at a velocity V2. At this point, since velocities are set to be V1>V2, the sheet bunch on the processing tray is relayed from the first conveying member 60A to the second conveying member 60B.

FIG. 12 illustrates a relay conveyance state, and the second conveying member 60B traveling at the velocity V2 catches up with the sheet bunch traveling at the velocity V1. In other words, after passing through the first zone Tr1, the first conveying member 60A is caught up with the second conveying member 60B, and the second conveying member 60B engages in the sheet rear end face to convey to the downstream side in the second zone Tr2.

Then, when the second conveying member 60B strikes the sheet bunch, which travels at the velocity V1, at the high velocity at a relay point, in the paper surface press member 64, the paper surface press face 64a presses the top face of the sheet bunch, holds the sheet bunch rear end with the carrier member (belt) 65a (65b) so as to nip, and carries out to the stack tray 25.

[Next-Sheet Front End Guide]

As described up to herein, the second conveying member 60B shifts to the end portion on the downstream side of the processing tray 24 in the conveyance direction to discharge the sheet, and also during the shift, a sheet for forming the next sheet bunch is continued to be fed from the image forming apparatus. Then, there is the case where the front end of the next sheet is forced to be fed to the processing tray 24 for a period during which the prior sheet bunch is discharged to the stack tray 25 or immediately after completing discharge, and there is a possibility that the second conveying member 60B contacts the front end of the next sheet to cause a conveyance jam. These issues are capable of being resolved by delaying discharge of the next sheet, but in the image forming system, in order to prevent productivity from decreasing, it is desirable that the sheet post-processing apparatus receives the image-formed sheet from the image forming apparatus without delay so as not to halt printing operation.

In order to meet high productivity as described above, in this Embodiment, a conveyance guide in cooperation with a discharge hook is provided on the upstream side of the discharge hook in the conveyance direction, and thereby guides the front end portion of the next sheet. Then, overlapping with timing at which the sheet is discharged to the stack tray from the processing tray, discharge of the next sheet onto the processing tray is started, and it is thereby made possible to receive the sheet promptly and reduce the occurrence of the conveyance jam. The next-sheet front end guide will be described below in detail.

[Embodiment 1]

A next-sheet front end guide 68 in Embodiment 1 shown in FIGS. 14 and 15 is comprised of a lever shape provided with a rotation shaft positioned on the upstream side of the discharge hook 60B in the conveyance direction, and is provided rotatably by its own weight. As shown in FIGS. 14 and 15, in the conveyance guide 68, the other end of the side on which the rotation shaft is provided is in a state in contact with the conveyance belt 65b, and the guide is in a state of having a predetermined inclined angle so that the front end of the next fed sheet S climbs over. Further, the front end of the conveyance guide 68 is in a state of getting below the sheet mount face 24a of the processing tray, and therefore, when the next sheet is discharged, prevents the sheet from being caught in the rear of the discharge hook.

By this means, also when the second conveying member 60B is in the state of FIG. 15 where the member 60B is in the discharge position for discharging the sheet bunch to the stack tray 25, and is in reciprocating operation (position in FIG. 14) for returning to the waiting position after discharging the sheet bunch, in feeding the next sheet out of the sheet discharge outlet 23 by the sheet discharge roller 32, the guide 68 functions as a conveyance face so as not to interfere with discharge of the next sheet S.

[Embodiment 2]

A next-sheet front end guide 168 in Embodiment 2 shown in FIGS. 16 to 21 is comprised of a rotatable lever shape provided with a rotation shaft B on the upstream side of a discharge hook 160B in the conveyance direction, as shown in a perspective view of FIG. 16. The next-sheet front end guide 168 attached to the discharge hook 160B is provided to be pressed against the belt 65b by a helical torsion coil spring (SP in FIG. 21) provided in the rotation shaft B. As shown in FIG. 17 illustrating a waiting position of the guide 168 and FIG. 18 illustrating a state during a shift of the guide 168, also in a state in which the belt passes through the position where the belt is wound around the pulley and rotates, the guide 168 follows the belt, and is in a state of being always in contact with the belt 65b. Further, on the rotation shaft side of the guide 168 is provided a stopper portion 168S that comes into contact with the discharge hook 160B so as not to rotate a predetermined angle or more. Since the guide 168 is not raised higher than the position in which the guide contacts the stopper portion 168S and halts, as shown in FIGS. 19 and 20 illustrating states under conveyance, in positions where the belt 65b is linear, the downstream end of the guide 168 in the conveyance direction is further pressed against the belt 65b. Since the belt 65b is comprised of a flexible material such as rubber, in the position in which the belt 65b is linear, the belt 65b is pressed in by the guide 168, and distortion is formed in the belt 65b. Since the belt 65b is substantially the same plane as the sheet mount face 24a of the processing tray 24 or is in a position slightly lower the face 24a, when the belt is pressed by the guide 168, the upstream end of the guide 168 in the conveyance direction enters below the face 24a provided in the processing tray 24, and reduces the occurrence of the conveyance jam caused by the front end of the next sheet being caught in the upstream side of the discharge hook in the discharge direction. FIG. 21 illustrates a position in which the sheet is discharged by the discharge hook 160B in Embodiment 2. Also in this position, a roller 168C in the front end of the guide 168 contacts the belt 65b, and distorts the belt 65b.

By this means, also when the second conveying member 160B is in the state of FIG. 21 where the member 160B is in the discharge position for discharging the sheet bunch to the stack tray 25, and is in reciprocating operation (position in FIG. 20) for returning to the waiting position after discharging the sheet bunch, in feeding the next sheet out of the sheet discharge outlet 23 by the sheet discharge roller 32, the guide 168 functions as a conveyance face so as not to interfere with discharge of the next sheet S.

[Embodiment 3]

A next-sheet front end guide 268 in Embodiment 3 shown in FIG. 22 is provided on the upstream side of a discharge hook 260B in the conveyance direction, and is attached to the same conveyance belt 65b as the discharge hook 260B. The conveyance guide 268 performs reciprocating motion in the sheet conveyance direction in conjunction with the discharge hook 260B. Then, when the discharge hook 260B rotates in the discharge position so as to discharge the sheet bunch, the next-sheet front end guide 268 stays in a position (linear portion) of not rotating as shown in FIG. 22, is thereby not changed in angle, and is in a state in which the member (guide face) for guiding the sheet is left. By this means, also when the discharge hook 260B rotates, a gap which the sheet enters is not formed on the upstream side of the discharge hook in the conveyance direction, and further, there are few cases where the sheet front end strikes and is halted.

By this means, also when the second conveying member 260B is in the state of FIG. 22 where the member 260B is in the discharge position for discharging the sheet bunch to the stack tray 25, and is in reciprocating operation for returning to the waiting position after discharging the sheet bunch, in feeding the next sheet out of the sheet discharge outlet 23 by the sheet discharge roller 32, the guide 268 functions as a conveyance face so as not to interfere with discharge of the next sheet S.

[Binding Processing Method (Binding Position)]

As described above, the sheet fed to the carry-in entrance 21 of the sheet discharge path 22 is collated and collected on the processing tray, and is positioned (aligned) in beforehand set position and posture by the sheet end regulating member 40 and side aligning member 46. Then, this bunch of sheets is subjected to the binding processing, and is carried out to the stack tray 25 on the downstream side. The binding processing method in this case will be described.

In the apparatus shown in the figure, as the binding processing method, the processing tray 24 is provided with the “first binding section 26 for performing staple binding on the sheet bunch” and “second binding section 27 for performing needleless binding on the sheet bunch”. Then, it is a first feature that the control section 75 described later performs the binding processing on the sheet bunch by the selected first or second binding section 26 (27), and then, carries out to the downstream side. This is because it is possible to perform bookbinding where sheets are easily not removed when a bunch of the sheets is subjected to the binding processing with a staple, but corresponding to a use of a user, conveyance is sometimes required where a bound bunch of sheets is separated with ease. Further, since metal needles become a problem when the used sheet bunch is cut with a shredder, is recycled as recycled paper or the like, it is intended to enable the binding sections “with needles” and “without needles” to be selected and used.

Further, in the apparatus shown in the figure, as well as a series of post-processing operation for performing the binding processing after carrying sheets in from the sheet carry-in path (discharge path) 22 to collate and collect, it is a second feature that sheets created outside the apparatus (outside the system) are subjected to the binding processing (hereinafter, referred to as “manual staple processing”).

Therefore, the manual set section 29 to set a sheet bunch from the outside is disposed in the exterior casing 20b, a mutual set face 29a to set a sheet bunch is formed in the casing, and the staple binding section (stapler unit 26) described previously is configured to shift in position from a sheet carry-in area Ar of the processing tray 24 to a manual area Fr.

Each binding processing method will be described based on FIGS. 8 to 10C. In the apparatus shown in the figure are set “multi-binding positions Ma1, Ma2” for performing the binding processing in a plurality of portions of sheets with staples, “corner binding positions Cp1, Cp2” for performing the binding processing in a sheet corner, “manual binding position Mp” for performing the binding processing on manually set sheets, and “needleless binding position Ep” for performing needleless binding in a sheet corner. A position relationship among binding positions will be described.

The binding processing method will be described based on FIG. 8. In the apparatus shown in the figure are set the “multi-binding positions Ma1, Ma2” for performing the binding processing in a plurality of portions of sheets with staples, the “corner binding positions Cp1, Cp2” for performing the binding processing in a sheet corner, the “manual binding position Mp” for performing the binding processing on manually set sheets, and the “needleless binding position Ep” for performing needleless binding in a sheet corner. The position relationship among the binding positions will be described.

[Multi-Binding]

As shown in FIG. 5, the multi-binding processing is to perform the binding processing on the end edge (shown in the figure is the rear end edge) of a bunch of sheets (hereinafter, referred to as an “aligned sheet bunch”) positioned on the processing tray 24 by the sheet end regulating member 41 and side aligning member 46. In FIG. 9, the binding positions Ma1, Ma2 are set to perform the binding processing in two spaced portions. The stapler unit 26 described later shifts from a home position to the binding position Ma1, and next to the binding position Ma2 in this order to perform the binding processing in respective positions. In addition, the multi-binding position Ma is not limited to two portions, and there are cases of performing the binding processing in three or more portions. FIG. 24A illustrates a state subjected to multi-binding.

[Corner Binding]

In the corner binding processing, binding positions are set at two right and left portions in the right corner binding position Cp1 for performing the binding processing on the right corner of the aligned sheet bunch collected on the processing tray 24, and left corner binding position Cp2 for performing the binding processing on the left corner of the aligned sheet bunch. In this case, the binding processing is performed with a staple being inclined a predetermined angle (about 30 degrees to 60 degrees). (The stapler unit 26 described later is mounted on the apparatus frame so that the entire unit is inclined the predetermined angle in this position.) FIGS. 24B and 24C illustrate states subjected to corner binding.

Apparatus specifications shown in the figure illustrate the case of selecting one of the left and the right of a bunch of sheets to perform the binding processing, and the case of inclining a staple the predetermined angle to perform the binding processing. The present invention is not limited thereto, and is capable of also adopting a configuration for applying corner binding to only one of the right and the left, and a configuration for binding parallel with the sheet end edge without inclining the staple.

[Manual Binding]

The manual binding position Mp is disposed in the manual set face 29a formed in the exterior casing 20b (a part of the apparatus housing) described later. The manual set face 29a is disposed (parallel disposed) in a height position for forming almost the same plane as the paper mount face 24a of the processing tray, and in the position adjacent to the paper mount face 24a via the side frame 20c. In the apparatus shown in the figure, both the paper mount face 24a of the processing tray and the manual set face 29a support the sheet substantially in the horizontal posture, and are disposed in approximately same height positions. FIG. 24D illustrates a state subjected to manual binding.

In other words, in FIG. 5, via the side frame 20c, the manual set face 29a is disposed to the right of the frame, and the paper mount face 24a is disposed to the left thereof. Then, the manual binding position Mp is arranged in the same line as the multi-binding position Ma described previously disposed in the paper mount face. This is because of performing the binding processing in both of the positions with the common stapler unit 26. Accordingly, the sheet carry-in area Ar is disposed in the processing tray 24, the manual area Fr is disposed on the apparatus front side thereof, and an eco-binding area Rr described later is disposed on the apparatus rear side.

[Needleless Binding Position]

The needleless binding position Ep (hereinafter, referred to as an “eco-binding position”) is disposed to perform the binding processing on a side edge portion (corner portion) of sheets as shown in FIG. 5. The eco-binding position Ep shown in the figure is disposed in a position for performing the binding processing on one portion in the side edge portion of the sheet bunch in the sheet discharge direction, and is to perform the binding processing in an angle position inclined a predetermined angle with respect to the sheet. Then, the eco-binding position Ep is disposed in the eco-binding area Rr at a distance from the sheet carry-in area Ar of the processing tray 24 toward the apparatus rear side.

[Mutual Relationship Between Binding Positions]

The multi-binding positions Ma1, Ma2 are disposed within (inside) the carrying-out area Ar of the sheet carried in the processing tray 24 from the sheet discharge outlet 23. Further, each of the corner-binding positions Cp1, Cp2 is disposed in a reference position (side alignment reference) spaced a predetermined distance apart from the sheet discharge reference Sx (center reference) of the sheet to the right or the left outside the sheet carry-in area Ar. As shown in FIG. 6, on the outer side of the side edge of the maximum-sized sheet (to perform the binding processing), the right corner binding position Cp1 is disposed in a position leaning to the right side by a predetermined amount (δ1) from the sheet side edge, and the left corner binding position Cp2 is disposed in a position leaning to the left side by a predetermined amount (δ2) from the sheet side edge. Both of leaning amounts are set at the same distance (δ1=δ2).

The multi-binding positions Ma1, Ma2 and manual binding position Mp are disposed substantially in a straight line. Further, the corner binding positions Cp1, Cp2 are set for inclined angles (e.g., 45-degree angle position) to be right-left symmetry via the sheet discharge reference Sx.

The manual binding position Mp is disposed in the manual area Fr on the apparatus front side Fr outside the sheet carry-in area Ar, and the eco-binding position Ep is disposed in the eco-binding area Rr on the apparatus rear side Re outside the sheet carry-in area Ar.

Further, the manual binding position Mp is disposed in a position offset by a predetermined amount (Of1) from the right corner binding position of the processing tray, and the eco-binding position Ep is disposed in a position offset by a predetermined amount (Of2) from the left corner binding position of the processing tray 24. Thus, the multi-binding position Mp is set based on carrying-out reference (center reference) of the processing tray to carry the sheet in, the corner binding position Cp is set based on the maximum-sized sheet, further the manual binding position Mp is set in the position offset by the predetermined amount Of1 from the right/left corner position to the apparatus front side, similarly the eco-binding position Ep is set in the position offset by the predetermined amount Oft to the apparatus rear side, and it is thereby possible to arrange neatly without sheet shifts mutually interfering.

A sheet shift in each binding processing will be described. In the multi-binding processing, sheets are carried in the processing tray in center reference (which may be one-side reference), and are aligned in this state to be subjected to the binding processing. After the binding processing, the sheets are carried out to the downstream side in this posture. In the corner binding processing, sheets are aligned in a designated side alignment position, and are subjected to the binding processing. After the binding processing, the sheets are carried out to the downstream side in this posture. Further, in the eco-binding processing, sheets carried on the processing tray are collected in the shape of a bunch, are then offset by the predetermined amount Oft to the apparatus rear side, and after the offset shift, are subjected to the binding processing. After the binding processing, the sheets are offset by a predetermined amount (e.g., a shift amount the same or smaller as/than the offset Of2) to the sheet center side, and then, are carried out to the downstream side.

Further, in the manual binding, an operator sets sheets on the manual set face spaced the predetermined offset amount Of1 apart from the alignment reference positioned on the front side from the processing tray 24. By this means, in a plurality of types of binding processing, set positions of sheets are allocated in the conveyance orthogonal direction to execute the binding processing, and it is thereby possible to perform the processing at prompt processing speed with few sheet jams.

In addition, in the eco-binding processing, the control section 75 described later offsets sheets by a predetermined amount Of3 from the rear end reference position in the sheet discharge direction to set the binding position Ep. This is because of avoiding interference between the stapler unit 26 for left corner binding of sheets and an eco-binding unit (press bind unit 27 described later). Accordingly, similarly to the stapler binding unit 26, when the eco-binding unit 27 is mounted on the apparatus frame 20 to be able to shift between the binding position and a retract position retracted therefrom, it is not necessary to offset Of3 in the sheet discharge direction.

In addition, herein, the apparatus front side Fr refers to the front side of the exterior casing 20b configured at the time of apparatus design for an operator to execute various types of operation. Generally, on the apparatus front side is disposed a control panel, installation cover (door) of sheet cassettes, or an open/close cover to supplement staples of the stapler unit. Further, the apparatus rear side Re refers to the side facing a wall face of the structure in installing the apparatus, for example, (installation condition where the wall is on the back in design).

Thus, in the apparatus shown in the figure, with reference to the sheet carry-in area Ar, the manual binding position Mp is disposed on the apparatus front side Fr outside the area, and the eco-binding position Ep is disposed on the apparatus rear side Re. At this point, a distance Ofx between the reference (sheet carry-in reference Sx) of the sheet carry-in area Ar and the manual binding position Mp is set to be longer than a distance Ofy between the carry-in reference Sx ad the eco-binding position Ep (in a farther position; Ofx>Ofy).

Thus, the manual binding position Mp is configured in the position spaced apart from the sheet carry-in reference (Sx) of the processing tray 24, and the eco-binding position Ep is configured in the near position close to the carry-in reference. This is because the position Mp is spaced apart from the processing tray 24, and therefore, there is convenience such that operation is easy in setting a bunch of sheets in the manual binding position Mp from the outside. Concurrently therewith, the reason why the eco-binding position Ep is configured in the position near (close to) the carry-in reference Sx is that a shift amount is decreased in offset-shifting sheets (aligned sheet bound) carried onto the processing tray to the binding position to perform speedy binding processing (improve productivity).

[Shift Mechanism of the Stapler Unit]

Although the structure of the stapler unit 26 (first binding processing section) will be described later, a unit frame 26a (referred to as a first unit frame) is equipped with a staple cartridge 39, staple head 26b and anvil member 26c. The unit 26 is supported by the apparatus frame 20a to perform reciprocating motion at a predetermined stroke along the sheet end face of the processing tray 24. The support structure thereof will be described below.

FIG. 7 illustrates a front configuration where the stapler unit 26 is installed in the apparatus frame 20, and FIG. 8 illustrates its plane configuration. Further, FIGS. 9 and 10A to 10C illustrate partial explanatory views of a guide rail mechanism for guiding the stapler unit.

As shown in FIG. 7, the chassis frame 20e (hereinafter, referred to as the “bottom frame”) is disposed in the right and left side frames 20c, 20d constituting the apparatus frame 20a. The stapler unit 26 is mounted on the bottom frame 20e to be able to shift at a predetermined stroke. On the bottom frame 20e are disposed a travel guide rail 42 (hereinafter, simply referred to as a “guide rail”) and a slide cam 43. A travel rail face 42x is formed in the guide rail, a travel cam face 43x is formed in the slide cam 43, and the travel rail face 42x and travel cam face 43x mutually cooperate to support the stapler unit 26 (hereinafter, in this article, referred to as a “shift unit”) to enable the unit to perform reciprocating motion at the predetermined stroke, and concurrently, control its angle posture.

The rail face 42x and cam face 43x are respectively formed in the above-mentioned travel guide rail 42 and slide cam 43 to cause reciprocating motion in a shift range (the sheet carry-in area, manual area and eco-binding area) SL of the shift unit (see FIG. 8). The above-mentioned travel guide rail 42 is comprised of a rail member having the stroke SL along the rear end regulating member 41 of the processing tray 24, and the rail shown in the figure is comprised of an opening groove formed in the bottom frame 20e. The travel rail face 42x is formed in its opening edge, and the travel rail face is disposed in the same straight line as the rear end regulating member 41 of the processing tray in a relationship of being mutually parallel. Further, the slide cam 43 is disposed spaced a distance apart from the travel rail face, and the cam shown in the figure is comprised of a groove cam formed in the bottom frame 20e. The travel cam face 43x is formed in the groove cam.

To the shift unit 26 (stapler unit) is fixed a travel belt 44 coupled to a drive motor (travel motor) M11. The travel belt 44 is wound around a pair of pulleys axially supported by the apparatus frame 20e, and one of the pulleys is coupled to the drive motor. Accordingly, by forward/backward rotation of the travel motor M11, the stapler unit 26 performs reciprocating motion at the stroke SL.

In the above-mentioned travel rail face and travel cam face, distances are formed and set for parallel distance portions (span G1) 43a, 43b mutually parallel, narrow oscillation distance portions (span G2) 43c, 43d, and an oscillation distance portion (span G3) 43e with a narrower distance. Then, the distances are configured in the relationship of span G1>span G2>span G3. The oscillation angle is changed so that the unit is in a posture parallel with the sheet rear end edge in the span G1, is in a posture inclined to the right or left in the span G2, and is in a further inclined angle posture in the span G3.

In addition, the travel guide rail 42 is not limited to the opening groove structure, and is capable of adopting various structures such as a guide rod, protrusion-shaped rib and the like. Further, the slide cam 43 is not limited to the groove cam, and is capable of adopting various shapes such as a protrusion-shaped rib portion, as long as the cam is provided with the cam face for guiding the shift unit 26 in the predetermined stoke direction.

The above-mentioned shift unit 26 is engaged in the above-mentioned travel guide rai142 and slide cam 43 as described below. As shown in FIG. 7, the shift unit 26 is provided with a first rolling roller 50 (rail fit member) for engaging in the travel rail face 42x, and a second rolling roller 51 (cam follower member) for engaging in the travel cam face 43x. Concurrently therewith, the shift unit 26 is provided with slide rollers 52 (the roller shown in the figure is formed in two portions as ball-shaped slide rollers 52a, 52b) for engaging in a support face of the bottom frame 20e. Further, a guide roller 53 for engaging in the bottom of the bottom frame is formed in the shift unit, and prevents the shift unit 26 from floating from the bottom frame.

By the configuration as described above, the shift unit 26 is supported by the bottom frame 20e to be able to shift with the slide rollers 52a, 52b and guide roller 53. Concurrently therewith, the first rolling roller 50 and second rolling roller 52 shift and travel along the rail face 42x and cam face 43x, while rotating along the travel rail face 42x and travel cam face 43x, respectively.

Then, in the distance between the rail face 42x and the cam face 43x, the parallel distance portion (span G1) is formed in the position 43a shown in the figure opposed to the multi-binding positions Ma1 and Ma2, and the position 43b shown in the figure opposed to the manual binding position Mp. In the span G1, as shown in FIGS. 9 and 10C, the shift unit 26 does not oscillate, and is held in the posture orthogonal to the sheet end edge. Accordingly, in the multi-binding position and manual binding position, the sheet bunch is subjected to the binding processing with the staple parallel to the sheet end edge.

Further, in the distance between the rail face 42x and the cam face 43x, the oscillation distance (span G2) is formed in the position 43e shown in the figure opposed to the right corner binding position and the position 43d shown in the figure opposed to the left corner binding position. Then, as shown in FIGS. 9 and 10A, the shift unit is held in the posture inclined in the right inclined angle posture (e.g., right 45-degree inclination) and in the left inclined angle posture (e.g., left 45-degree inclination).

Furthermore, in the distance between the rail face 42x and the cam face 43x, the oscillation distance (span G3) is formed in the position 43c shown in the figure opposed to a staple load position. The span G3 is formed to be a shorter distance than the span G2, and in this state, as shown in FIG. 10B, the shift unit 26 is held in the right inclined angle posture (e.g., 60-degree inclination). In addition, the reason why the shift unit 26 is changed in angle in the staple load position is that the unit posture is made to coincide with the angle direction to install the staple cartridge 39 in the unit, and the angle is set corresponding to the relationship with the open/close cover disposed in the exterior casing.

In changing the angle posture of the shift unit by the travel rail face 42x and travel cam face 43x as described above, in order to shorten the shift length, it is preferable to change the angle in cooperation with the travel cam face by providing a second travel cam face, or stopper cam face, from the viewpoint of compact characteristics of layout.

The stopper cam face shown in the figure will be described. As shown in FIG. 8, in the side frame 20e are disposed stopper faces 43y, 43z in positions shown in the figure to engage in a part (the part shown in the figure is the rolling roller 52a) of the shift unit so as to change the unit posture in the right corner binding position Cp1 and manual binding position Mp on the apparatus front side. By this means, it is necessary to change, in the manual binding position Mp, inclination of the unit inclined in the staple load position, but it makes the shift stroke redundant to change the angle by only the cam face and rail face described previously.

Then, when the shift unit is moved to the manual binding side in a state in which the unit is locked by the stopper face 43y, the unit is restored to the original state from the inclined state. Further, in causing the unit to perform return operation in the opposite direction from the manual binding position, the stopper face 43z (forcibly) inclines the unit to move toward the corner binding position.

[Stapler Unit]

The stapler unit 26 is already known widely as an apparatus for performing binding processing with staples. One example thereof will be described according to FIG. 25A. The stapler unit 26 is configured as a unit independently of the sheet bunch binding processing apparatus B (post-processing apparatus). On the frame are mounted the box-shaped unit frame 26a, a drive cam 26d axially supported by the frame swingably, and a drive motor M8 for rotating the drive cam 26d.

Then, in the drive cam 26d, the staple head 26b and anvil member 26c are disposed to be opposed in the binding position, and the staple head moves up and down from an upper waiting position to a lower staple position (anvil member) by a biasing spring (not shown) with the drive cam. Then, the staple cartridge 39 is installed in the unit frame to be attachable/detachable.

The staple cartridge 39 stores linear blank staples, and supplies a staple to the head 26b by a staple feed mechanism. Into the head portion 26b are incorporated a former member for bending the linear staple in the shape of a C, and a driver for press-inserting the bent staple in the sheet bunch. By such a configuration, the drive cam 26d is rotated by the drive motor M8 to store energy in the biasing spring. Then, when a rotation angle reaches a predetermined angle, the head portion 26b moves down to the anvil member 26c side vigorously. By this operation, the staple is bend in the shape of a C, and then, is inserted in the sheet bunch by the driver. Then, its front ends are bent by the anvil member 26c, and the bunch is subjected to staple binding.

Further, the staple feed mechanism is incorporated into between the staple cartridge 39 and the staple head 26b, and a sensor (empty sensor) for detecting the absence of the staple is disposed in the staple feed portion. Furthermore, in the unit frame 26a is disposed a cartridge sensor (not shown) for detecting whether or not the staple cartridge 39 is inserted.

The staple cartridge 39 shown in the figure adopts a structure for stacking staples coupled in the shape of a band in the shape of layers in the box-shaped cartridge to store, and another structure for storing in the shape of a roll.

Further, the unit frame 26a is provided with a circuit for controlling each of above-mentioned sensors, and a circuit board for controlling the drive motor M8, and is configured to issue an alarm signal in the case where the staple cartridge 39 is not stored and in the case of empty of staples. Furthermore, the staple control circuit is configured to control the drive motor to execute staple operation with a staple signal, and transmit an “operation end signal” when the staple head shifts from the waiting position to the anvil position, and returns again to the waiting position.

[Press Binder Unit]

According to FIG. 25B, a configuration of the press binder unit 27 will be described. As a press binder mechanism, there are known fold binding mechanism (see Japanese Unexamined Patent Publication No. 2011-256008) for forming a notch opening in a binding portion of several sheets to fold one side, and thereby binding, and press bind mechanism for forming concavo-convex faces in press faces 27b, 27c capable of mutually coming into press-contact and separating, and press-deforming a sheet bunch to bind.

FIG. 25B illustrates the press binder unit, a movable frame member 27d is axially supported by a base frame member 27a swingably, and by a spindle 27x, both of the frames swing to be able to come into press-contact and separate. A follower roller 27f is disposed in the movable frame member 27d, and a drive cam 27e disposed in the base frame 27a is engaged in the follower roller.

To the above-mentioned drive cam 27e is couped a drive motor M9 disposed in the base frame member 27a via a deceleration mechanism, the drive cam 27e rotates by rotation of the motor, and it is configured that the cam face (the cam shown in the figure is an eccentric cam) swings the movable frame member 27d.

Then, a lower press face 27c and an upper press face 27b are respectively disposed in the base frame member 27a and the movable frame member 27d in mutually opposed positions. A biasing spring not shown is disposed between the base frame member 27a and the movable frame member 27d, and biases both of the press faces in a separating direction.

As shown in an enlarged view in FIG. 25B, in the above-mentioned upper press face 27b and lower press face 27c, protrusion bars are formed in one, and concave dent grooves adapted to the bars are formed in the other one. The protrusion bars and concave dent grooves are formed in the shape of ribs with a predetermined length. Accordingly, a sheet bunch pressed by the upper press face 27b and lower press face 27c is deformed in the shape of a corrugated sheet and is brought into intimate contact. A position sensor not shown is disposed in the above-mentioned base frame member 27a (unit frame), and is configured to detect whether the upper and lower press faces 27b, 27c are in press positions or in separation positions.

[Stack Tray]

A configuration of the stack tray will be described according to FIG. 26. The stack tray 25 is disposed on the downstream side of the processing tray 24, and stacks the sheet bunch collected on the processing tray to store. A tray up-and-down mechanism is provided to sequentially descend corresponding to a stacked amount of the stack tray 25. A stack face (uppermost sheet height) of the tray is controlled to be a height position to be substantially the same plane as the paper mount face of the processing tray. Further, in stacked sheets, the rear end edge in the sheet discharge direction is inclined an angle formed by striking a tray aligning face 53 (standing face) under its own weight.

A specific configuration thereof will be described. An up-and-down rail 54 is fixed to the apparatus frame 20a vertically in the stacking direction, and a tray base 25x is fitted into the up-and-down rail to be able to move up and down and slide by a slide roller 50 and the like. Concurrently therewith, a rack 25r is integrally formed in the tray base 25x in the up-and-down direction, and meshes with a drive pinion 56 axially supported by the apparatus frame. Then, the drive pinion 56 is coupled to an up-and-down motor M10 via a worm gear 57 and worm wheel 58.

Accordingly, by rotating the up-and-down motor M10 forward and backward, the rack 25r coupled to the drive pinion 56 moves up and down to an upper portion and a lower portion of the apparatus frame. In this configuration, the tray base 25x performs up-and-down operation in a cantilever state. As the tray up-and-down mechanism, as well as the rack-pinion mechanism, it is possible to adopt a pulley suspension belt mechanism and the like.

The stack tray 25 is integrally attached to the tray base 25x, and is configured to stack and store sheets on the stack face 25a. Further, in the apparatus frame is formed a tray aligning face 20f for supporting the rear end edge of the sheet vertically in the stacking direction of the sheet, and in the apparatus shown in the figure, the exterior casing forms the tray aligning face.

Further, the stack tray 25 integrally attached to the tray base 25x is formed to be inclined in the angle direction shown in the figure, and the angle is set (e.g., 20 degrees to 60 degrees) so that the sheet rear end strikes the tray aligning face 20f under its own weight.

[Sheet Press Mechanism]

The above-mentioned stack tray 25 is provided with a paper press mechanism 53 for pressing the uppermost sheet of collected sheets. The paper press mechanism shown in the figure is comprised of an elastic press member 53a for pressing the uppermost sheet, a shaft member 53b for axially supporting the elastic press member on the apparatus frame 20a rotatably, a drive motor M2 for rotating the shaft member in a predetermined angle direction, and a transfer mechanism thereof. The drive motor M2 shown in the figure is drive-coupled to the drive motor of the sheet bunch carrying-out mechanism as a drive source, and the elastic press member 53a retracts outside the tray in carrying in (carrying out) a sheet bunch in the stack tray 25, and after storing the rear end of the sheet bunch on the uppermost sheet on the stack tray, rotates from a waiting position in a counterclockwise direction shown in the figure to engage on the uppermost sheet to press.

Further, the above-mentioned elastic press member 53a retracts from the paper surface of the uppermost sheet on the stack tray to a retract position, by initial rotating operation of the drive motor M2 for carrying the sheet bunch on the processing tray out to the stack tray.

[Level Sensor]

A level sensor for detecting a paper surface height of the uppermost sheet is disposed in the above-mentioned stack tray 25, the hoist motor described previously is rotated with a detection signal of the level sensor, and the tray paper mount face 25a is thereby moved up to ascend. Various types of the level sensor mechanism are known, and the sensor shown in the figure adopts a detection method where detection light is applied to above the tray from the tray aligning face 20f of the apparatus frame, and the reflected light is detected to detect whether or not a sheet exists in the height position.

[Stacked-Sheet Amount Sensor]

In the above-mentioned stack tray 25 is disposed a sensor for detecting removal of sheets from the tray as the level sensor. Although the structure is not described in detail, for example, by providing a sensor lever rotating integrally with the paper press elastic press mechanism 53a described previously, and detecting the sensor lever with a sensor element, it is possible to detect whether or not the sheet exists on the stack face. Then, when a height position of the sensor lever is different (changed) between before and after carrying-out of the sheet bunch, for example, the control section 75 described later halts sheet discharge operation, or moves the tray up to a predetermined position. In addition, such operation is abnormal operation and is inconvenience occurring when a user removes sheets from the stack tray carelessly during operation of the apparatus, and the like. Further, the stack tray 25 is set for a lower limit position so that the tray does not descend abnormally, and a limit sensor Se3 for detecting the tray is disposed in the lower limit position.

As described above, the present invention is described in association with preferred Embodiments, but the invention is not limited to the above-mentioned Embodiments, and it is obvious that the invention is capable of being carried into practice with various changes or modifications added within the technical scope of the invention.

In addition, this application claims priority from Japanese Patent Application No. 2020-134343, entire content of which is expressly incorporated by reference herein.

SHEET CONVEYING APPARATUS AND IMAGE FORMING SYSTEM HAVING THE SAME

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