Sheet processing apparatus and image forming system

Abstract

To provide a sheet processing device that can control the behavior of a saddle-stitched bundle of sheets and perform more accurate alternate stacking.SOLUTION: The present invention relates to a sheet processing device, the sheet processing device comprises a post-processing device 102 including: binding processing means, such as a post-processing unit 103 that performs saddle-stitching on sheets; a loading container 1 for loading paper 2 such as saddle-stitched paper bundles; a pair of left and right conveyance paths, such as conveyance paths 4a and 4b for discharging the loaded paper 2 to the bottom 1c of the loading container; discharge means, such as a conveyance roller 5 for discharging the loaded paper 2 to the lower side of the loading container; and a lifting member, such as an arm 3, for lifting the loaded paper 2 in the loading container, wherein the loading paper 2 in the loading container is lifted by the lifting member, and the loading paper 2 is conveyed in one of a pair of left and right conveyance paths to discharge it to the underside of the lifted loading paper 2, and by repeatedly moving the lifting member back out of the loading container and lowering the loaded paper 2, the left and right directions of the loaded paper 2 are changed and the loaded paper 2 is loaded from the bottom of the loading container.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a sheet processing apparatus and an image forming system. [Background technology]

[0002] For the purpose of simply stacking a large amount of saddle-stitched paper bundles at low cost, a configuration (saddle-stitching folding bookbinding discharge device) is known in which the paper bundles are transported alternately along two transport paths and stacked with the fold positions of the paper bundles staggered (see Patent Document 1). In addition, a technology (paper processing device) is known in which sliding members are placed on both sides of the paper output tray and moved up and down to sequentially discharge recording paper to the lower layers, with the aim of ensuring that the first page of paper is always at the top even when the paper sheets discharged from the image forming device are stacked (see Patent Document 2).

[0003] The invention described in Patent Document 1 is certainly similar to the present invention in that the direction of the paper stacks is changed and they are alternately stacked from two paper discharge ports on the left and right. However, the invention described in Patent Document 1 has a problem in that it is difficult to control the behavior of the paper stack during free fall, making the stack unstable.

[0004] The invention described in Patent Document 2 is certainly similar to the present invention in that the paper is discharged from below. However, the invention described in Patent Document 2 has a problem in that when saddle-stitched paper bundles are loaded, the fold positions bulge, making it impossible to load a large amount. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION A main object of the present invention is to provide a sheet processing apparatus that controls the behavior of a saddle-stitched stack of sheets and allows for more accurate staggered stacking. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a sheet processing apparatus including a saddle stitching processing unit that saddle stitches image-formed sheets, a stacking container that holds the saddle-stitched sheet bundle, a pair of left and right conveying paths that discharge the saddle-stitched sheet bundle to a bottom surface of the stacking container, a discharge unit that discharges the saddle-stitched sheet bundle onto the bottom surface of the stacking container or onto the saddle-stitched sheet bundle stacked on the bottom surface, and a lifting member that lifts up the saddle-stitched sheet bundle stacked on the stacking container, This sheet processing device uses a lifting member to lift the saddle-stitched sheet bundle in the stacking container, transports the saddle-stitched sheet bundle along one of the pair of left and right transport paths, and discharges the saddle-stitched sheet bundle below the saddle-stitched sheet bundle lifted by the lifting member.By repeating this operation of retracting the lifting member to the outside of the stacking container and lowering the saddle-stitched sheet bundle, the sheet processing device changes the left and right orientation of the saddle-stitched sheet bundle and loads the saddle-stitched sheet bundle from below the stacking container. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a sheet processing apparatus that controls the behavior of a saddle-stitched sheet bundle and can stack sheets alternately more accurately. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an image forming system configured by connecting an image forming apparatus and a post-processing apparatus capable of binding processing and the like. [Figure 2] 1 is a configuration diagram of a post-processing device for explaining an example of saddle-stitching processing of a plurality of sheets of paper; [Figure 3] 10A and 10B are diagrams illustrating the configuration of a stacking unit for stacking items alternately from below. [Figure 4] FIG. 2 is a perspective view schematically showing the 3D shape and positional relationship of the loading unit. [Figure 5] 10(a) to 10(f) are explanatory diagrams illustrating arm operations (1) to (4) when a saddle-stitched stack of sheets is discharged from the opening at the bottom right of the stacking container. [Figure 6] 10 is a flowchart showing the operation sequence when stacking N copies in a staggered manner. [Figure 7] 10(a) to 10(c) are diagrams showing the state in which sheets are stacked in a stacking container in various discharge patterns. [Figure 8] 7A is a diagram illustrating the state of the stack of papers stacked in the stack container corresponding to the first half of the embodiment shown in FIG. 6, and FIG. 7B is a flowchart corresponding to the first half of the embodiment. [Figure 9] 7A is a diagram for explaining the state of the stack of papers stacked in the stack container corresponding to the second half of the embodiment of FIG. 6, and FIG. 7B is a flowchart corresponding to the second half of the embodiment. [Figure 10] FIG. 10(a) is a plan view of a first modified example of the shape and driving operation of the arm, and FIG. 10(b) is a front view of FIG. [Figure 11] FIG. 10(a) is a plan view of a second modified example of the arm shape and driving operation, and FIG. 10(b) is a front view of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Throughout the embodiments and examples, components (members and components) having the same function, shape, etc. will be designated by the same reference numerals once explained, and their explanation will be omitted unless there is a risk of confusion.

[0010] An image forming system according to one embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of an image forming system configured by connecting an image forming apparatus and a post-processing apparatus capable of performing multiple types of binding processing, etc. As shown in FIG. 1, the image forming system 100 is configured by connecting an image forming device 101 that forms an image on a sheet of paper or the like, and a post-processing device 102 that receives the paper or the like on which the image has been formed by the image forming device 101, performs various processes such as punching, edge binding, and saddle stitching, and then discharges the paper or the like onto one of multiple stacking sections that serve as a sheet stacking device.

[0011] The sheet processing device according to the present invention is a technology in which a stack of sheets, which has been saddle-stitched and folded in half in a post-processing unit 103 of a post-processing device 102, is transported to a stacking unit 104 configured as a sheet stacking device at the bottom of the machine, and is stacked from below with the fold positions staggered left and right.

[0012] The post-processing device will be described with reference to Fig. 2, taking an example of saddle-stitching multiple sheets of paper. Fig. 2 is a structural diagram of the post-processing unit, which will be described with reference to an example of saddle-stitching multiple sheets of paper, and will explain the outline of the operations of "paper transport," "staple," and "folding in half." The configuration and operation related to the "sheet transport" shown in Fig. 2 are as follows: A sheet of paper on which an image has been formed in the image forming apparatus 101 in Fig. 1 is transported into the post-processing device 102 through a transport path 201 and a group of multiple transport rollers 202, and is discharged to a vertically movable paper discharge tray 206 installed outside the post-processing device 102. When about half of the sheet of paper P on which the image has been formed is discharged outside the post-processing device 102 as shown in Fig. 2, a striking roller 203 and an opening / closing guide plate 204 move down as shown by the dotted lines, pressing the sheet against a staple tray 207, and then the paper discharge roller 205 begins to rotate in the reverse direction, switching the sheet back toward the stapler 212, where it strikes a reference fence 213 and aligns in the paper transport direction 215.

[0013] The configuration and operation related to the "stapling" shown in Fig. 2 are as follows: The above paper transport is repeated, and when the transport of the number of sheets to be bound is completed, the stack of sheets is aligned perpendicular to the paper transport direction 215 by the alignment jogger 211, and the stapler 212 performs the binding process at the center of the stack of sheets.

[0014] The configuration and operation related to the "folding in half" shown in Figure 2 are as follows: Reference fence 213 moves in paper transport direction 215 via moving belt 214, sending the stack of sheets to folding means consisting of folding blade 210, folding rollers 208, and opening 209. When the binding position of the stack of sheets reaches the folding position, folding blade 210 pushes the stack of sheets into folding rollers 208, and the stack is folded in half. The stack of sheets is then transported, with the fold position at the leading edge, to stacking unit 104, the configuration of which is shown in detail in Figure 3.

[0015] At this time, the sheet stack transported to the stacking unit 104 with the fold position at the leading edge has its transport path switched by the branch claw 8 disposed at the most upstream of the stacking unit 104 shown in Fig. 3. That is, when the branch claw 8 changes its angle using a drive source (for example, a combination of a solenoid and a spring) not shown, the saddle-stitched sheet stack is switched so as to be transported to either the right-side transport path 4a or the left-side transport path 4b.

[0016] The configuration of the stacking unit 104 for staggered stacking from below will be described with reference to Figures 3 and 4. Figure 3 is a diagram illustrating the configuration of the stacking unit for staggered stacking from below. Figure 4 is a perspective view that schematically shows the 3D shape and positional relationship of the stacking unit 104. Since the components shown in Figures 3 and 4 are arranged symmetrically as will be described later, the configuration of the right side of the stacking unit 104 will be mainly described to avoid redundant explanation. The loading unit 104 comprises a loading container 1, a pair of left and right approximately L-shaped arms 3, a drive source 6B that moves each arm 3 independently in the vertical direction Z, and a pair of left and right conveying paths 4a, 4b that discharge the saddle-stitched stack of paper onto the bottom surface of the loading container 1. The loading unit 104 also includes conveying rollers 5 arranged downstream of each of the conveying paths 4a, 4b, a driving source 6A that independently drives each of the conveying rollers 5, and slide rails 7 arranged on a pair of front and rear wall surfaces of each arm 3 as shown in Figure 3.

[0017] The loading container 1 is a roughly box-shaped container surrounded by walls, and has an opening 1a at the front that is open as shown in Fig. 4 for removing the saddle-stitched paper stacks loaded in the loading container 1. In addition, a paper discharge port 11 is formed at the bottom of the left and right side walls of the loading container 1 to receive the saddle-stitched paper stacks 2 discharged by the transport rollers 5, and as shown in Fig. 4, a groove 1b is formed so as not to interfere with the arm 3 when it moves up and down. The saddle-stitched paper stacks in the loading container 1 will hereinafter also be referred to as the loaded paper stacks 2. Each arm 3 is roughly L-shaped along the corners of the bottom of the stacking container 1, and a protrusion 9 is formed to protrude roughly vertically at the right-angled portion. Each arm 3 is integrally formed with a protrusion 3a formed so as to be able to protrude inside the stacking container 1 in order to contact the stack of papers 2 and lift the stack of papers 2 from below, and a drive transmission part 3b to which the driving force of the drive source 6B is transmitted outside the stacking container 1 in order to move each arm 3 in the up-down direction Z.

[0018] 3 and 4, the lifting mechanism for moving the arm 3 in the vertical direction Z uses a rack and pinion mechanism as an example. That is, the lifting mechanism for the arm 3 is mainly composed of a pinion 6Ba fixed to the output shaft of the drive source 6B, a rack 6Bb that is constantly meshed with the pinion 6Ba to move the arm 3 in the vertical Z direction, and a guide member (not shown) that guides the rack 6Bb in the vertical Z direction. The drive source 6B is, for example, an electric motor such as a DC motor, and is fixed to the frame of the loading unit 104. The rack 6Bb is connected to the vicinity of the upper end of the drive transmission section 3b of the arm 3. In addition, a home position detection sensor (not shown) that detects the home position or lower limit position of the arm 3, and an upper limit position detection sensor (not shown) that detects the upper limit position of the arm 3 are arranged around the loading container 1. Furthermore, taking into consideration the change in posture of the arm 3 shown in Figure 5(c) described later, the connecting portion between the upper end of the drive transmission portion 3b of the arm 3 and the lower end of the rack 6Bb may be connected via a spherical bearing or a cylindrical bearing.

[0019] The drive of each arm 3 is controlled by an independent drive source 6B, and based on signals from an arm passage sensor and a paper detection sensor (not shown), a control unit equipped with a CPU (not shown) as a control means is configured to drive each arm 3 and transport a stack of paper at a preset timing.

[0020] The pair of left and right transport rollers 5 are discharge members that transport the saddle-stitched stack of paper sheets (loaded paper 2) to the bottom of the stacking container 1. The drive of each transport roller 5 is controlled by an independent drive source 6A, and the control unit is configured to drive each transport roller 5 and transport the stack of paper sheets at a preset timing based on signals from an arm passage sensor and a paper detection sensor (not shown). The drive mechanism of each conveying roller 5 is composed of a drive pulley (not shown) fixed to the output shaft of a drive source 6A (for example, an electric motor), a driven pulley (not shown) attached to the shaft of the conveying roller 5 that serves as the drive roller, and an endless belt 22 wound around the drive pulley and the driven pulley. The drive source 6A is composed of an electric motor such as a stepping motor, and is fixed to the frame of the loading unit 104.

[0021] In the drawing, slide rails 7 are arranged on the front and rear sides of each arm 3. The slide rails 7 are generally D-shaped, and protrusions 9 formed at the corners of each arm 3 move along grooves 7c formed in the slide rails 7. The grooves 7c of the slide rails 7 have a path 7a for lifting the arm 3 straight up in the vertical direction, and a path 7b for lowering the arm 3 while retracting the protrusions 3a of the arm 3 to the outside of the loading container 1 and opening it.

[0022] A fullness detection sensor 12 is installed on the top surface of the stacking container 1, and when the height of the stacked papers 2 stacked in the stacking container 1 reaches the height of the fullness detection sensor 12, it detects that the stacking upper limit has been reached.

[0023] The driving operation of the arm 3 when the saddle-stitched stack of sheets is discharged from the lower right opening will be described with reference to Figure 5. Figures 5(a) to 5(f) are explanatory diagrams that explain the operations (1) to (4) of the arm when the saddle-stitched stack of sheets is discharged from the lower right opening 1a of the stacking container 1. The driving operation of the arm when the saddle-stitched stack of sheets is discharged from the lower left opening is also the same as that described below. 5(a), before the paper is discharged, the protruding portion 3a of the arm 3 is stopped at the bottom surface 1c of the stacking container 1. This stopping position is set as the home position of the arm 3.

[0024] Operation(1) When saddle stitching processing is started upstream of the post-processing device 102 shown in Fig. 2, as shown in Fig. 5(b), the right arm 3 moves to the upper end along the path 7a of the slide rail 7 via the engagement between the protrusion 9 of the right arm 3 and the path 7a of the slide rail 7, lifts the right side of the stack of sheets 2, and stops. Then, the branch claw 8 shown in Fig. 3 switches to carry the saddle-stitched stack of sheets into the right-hand transport path 4a, and discharges the stack of sheets from the discharge outlet 11 on the lower right side of the stack container 1 shown in Figs. 3 and 5(f). At this time, the left arm 3 is stopped at its home position to block the left discharge outlet 11, and the discharged stack of sheets hits the inside part of the left arm 3 and is aligned in the transport direction.

[0025] Operation (2) Two switching claws 10a and 10b installed on slide rail 7 are always biased in one direction by springs or the like so as to block path 7a. As shown in Figure 5(e), when arm 3 passes, protrusions 9 on the L-shaped corners of arm 3 push up switching claw 10b to block path 7b. After arm 3 rises, path 7a is again blocked by the biasing force (torque) applied to switching claw 10b, and as arm 3 descends as shown in Figure 5(c), it is guided from path 7a to path 7b via protrusions 9.

[0026] Operation(3) Once the paper ejection is complete, arm 3 is lowered. The upper end of the L-shaped drive transmission part 3b of arm 3 moves only vertically due to drive source 6B shown in Figure 3, but the corners of the L-shape move along the curve of path 7b, so as the arm 3 lowers, it opens outward with the upper end of drive transmission part 3b of the L-shaped arm 3 as a fulcrum. As shown in Figure 5(c), when arm 3 is fully opened, it retreats completely to the outside of stack container 1 and drops the paper stack 2 that it had been holding onto the ejected and stacked paper stack.

[0027] Operation(4) When the arm 3 reaches the lower end of the slide rail 7, the path of the arm is switched from path 7b to path 7a in the same manner as in the operation (2) above, and the arm 3 is raised to the home position.

[0028] By repeating the above steps (1) to (4), the stack of sheets can be stacked in order from the bottom up. Furthermore, since the stack is aligned in the transport direction each time step (1) is performed, the stack of sheets can be stacked in order.

[0029] The operation sequence when stacking N copies in a staggered manner will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the operation sequence when stacking N copies in a staggered manner. Here, N can be set by the user, and the loading states when N is set to 1 and 3 respectively are shown in Figures 7(b) and 7(c). On the left and right sides of Figure 6 are shown perspective views representing each operation, with some components omitted, and the ranges corresponding to the above operations (1) to (4) are shown in parentheses.

[0030] First, in step S1, the post-processing device 102 receives a processing signal for saddle stitching and staggered stacking every N copies selected by the user, and the saddle stitching process for the first copy is started. At this time, the number of copies n discharged and the number of left / right switching times m, which are counted during the subsequent repeat steps, are initialized to n=0 and m=0. Next, steps S2 to S5, which correspond to the above operations (1) to (3), are executed.

[0031] In operation (4), when the arm 3 reaches the lower end in step S6, the number of sheets discharged n is incremented (n = n + 1). Next, in step S7, it is determined whether the number of sheets discharged n (0 ≤ n ≤ N) has reached N. If n < N, the process returns to step S2 to raise the arm again and repeat steps S2 to S7. If n = N, since the crease positions of the stacked paper 2 are aligned in N sheets, the process branches to step S8 to stop the arm 3 at the home position and increment the number of left / right switches m (m = m + 1). Further, in step S9, it is determined whether the total number of sheets discharged N × m has reached the number of printed sheets. If not, the number of sheets discharged n is reset to n = 0, the process branches to step S10 to switch the transport paths 4a, 4b and the arm 3 left / right, and repeat the operations of operations (1) to (4) again. If the total number of printed sheets has been reached, printing is completed. Note that "HP" shown in step S8 of FIG. 6 indicates the above-mentioned "home position". The operation of FIG. 6 has steps S1 to step S10, and the details are as described above.

[0032] Referring to FIG. 7, the state of being loaded in the loading container with various paper discharge patterns will be described. FIGS. 7(a) to 7(c) are diagrams showing the state of being loaded in the loading container with various paper discharge patterns. If loading continues from one side, as shown in FIG. 7(a), the bulge on the crease position side becomes bulky and the loading amount cannot be increased. Therefore, by switching the transport paths 4a, 4b and the arm 3 left / right after the operation of (4) above and executing the operations of (1) to (4) above, it is possible to load with the directions of the crease positions alternating as shown in FIG. 7(b), and load a larger amount while keeping the loading surface horizontal. Also, since the timing of left / right switching can be set as described in FIG. 6, for example, it is possible to load with the direction changed every three sheets as shown in FIG. 7(c), and it is also possible to automatically sort into an arbitrary number of sheets so that the user can easily distribute the printed materials.

[0033] An embodiment of Fig. 6 will be described with reference to Fig. 8 and Fig. 9. Fig. 8(a) is a diagram illustrating the state of the stack of paper loaded in the stack container corresponding to the first half of the embodiment of Fig. 6, and Fig. 8(b) is a flowchart corresponding to the first half of the embodiment. Fig. 9(a) is a diagram illustrating the state of the stack of paper loaded in the stack container corresponding to the second half of the embodiment of Fig. 6, and Fig. 9(b) is a flowchart corresponding to the second half of the embodiment. In the embodiment shown in FIGS. 8 and 9, for example, a case where 12 copies of printed matter are discharged as the stack of paper 2 are stacked in staggered fashion in groups of three (N=3) will be described.

[0034] As shown in Fig. 8(a), the number of discharged copies n of the stack of paper 2 stacked on the bottom surface 1c of the stacking container 1 is 3. Also, as shown in Fig. 8(b), the operational flow for obtaining the number of copies n=3 of the stack of paper 2 in Fig. 8(a) is to loop the operations from step S2 to step S7 three times, and in step S6, n=n+1 is set.

[0035] As shown in Figure 9(b), after three loops of the operations from step S2 to step S7 in Figure 8(b), left-right switching (left-right switching number m) is performed in step S10 to switch the conveying paths 4a, 4b and the arm 3 left and right, and four loops of left-right switching of steps S2 to S7 and step S10 in Figure 8(b) are performed. Then, when m = 4, N × m = 3 × 4 in step S9, so paper ejection and printing are completed.

[0036] With reference to Figure 10, a first modified example of the arm shape and drive operation different from those of the embodiment shown in Figures 3 and 4 will be described. Figure 10(a) is a plan view of the first modified example of the arm shape and drive operation, and Figure 10(b) is a front view of Figure 10(a). In the first variant, as shown in Figure 10(a), the claw portion of the arm 3A rotates horizontally around the axis portion 3Aa, which is also the joint, and retreats to the outside of the loading container 1, lowering the saddle-stitched stack of paper 2 that was being held up.

[0037] With reference to Figure 11, a second modified example, which is different from the shape and drive operation of the arm of the embodiment shown in Figures 3 and 4 and the first modified example shown in Figure 10, will be described. Figure 11(a) is a plan view showing the second modified example of the shape and drive operation of the arm, and Figure 11(b) is a front view of Figure 11(a). In the second modified example, as shown in FIG. 11(a), the claw portion of the arm 3B breaks, causing the arm 3B to retreat to the outside of the stacking container 1, and the saddle-stitched stack of paper sheets 2 that was being held up is lowered.

[0038] The above embodiment and the like can be said to have substantially described the following aspects and effects. That is, the first aspect is a post-processing device having a binding processing means such as a post-processing unit 103 that saddle-stitches image-formed sheets, a stacking container such as a stacking container 1 that stacks the saddle-stitched sheet bundle, a pair of left and right conveying paths such as conveying paths 4a and 4b that discharge the saddle-stitched sheet bundle such as a saddle-stitched paper bundle 2 to a bottom surface such as a bottom surface 1c of the stacking container, a discharge means such as a conveying roller 5 that discharges the saddle-stitched sheet bundle to the bottom of the stacking container, and a lifting member such as an arm 3 that lifts the saddle-stitched sheet bundle stacked in the stacking container. 102, which uses the lifting member to lift the saddle-stitched sheet bundle in the stacking container, transports the saddle-stitched sheet bundle along one of the pair of left and right transport paths, discharges the saddle-stitched sheet bundle below the saddle-stitched sheet bundle lifted by the lifting member, and repeats the operation of retracting the lifting member to the outside of the stacking container and lowering the saddle-stitched sheet bundle, thereby changing the left and right orientation of the saddle-stitched sheet bundle and loading the saddle-stitched sheet bundle from below the stacking container.

[0039] With this configuration, according to the first aspect, it is possible to provide a sheet processing apparatus that can control the behavior of the saddle-stitched sheet bundle and stack the sheets alternately more accurately.

[0040] The second aspect is characterized in that, in the first aspect, the lifting members are arranged one on each side of the stacking container, have abutting members such as arms 3 against which the saddle-stitched sheet bundle is abutted, and lift one side of the saddle-stitched sheet bundle, discharge the saddle-stitched sheet bundle from a conveying path such as conveying path 4a or conveying path 4b on the lifted side, and abut against the lifting member on the opposite side to align it. With this configuration, according to the second aspect, the sheets are aligned in the conveying direction every time they are discharged, thereby improving sheet stack alignment.

[0041] The third aspect is the first or second aspect, wherein the lifting member is composed of a drive source such as drive source 6B that moves the lifting member up and down, a guide member such as slide rail 7 that has two paths such as ascending and descending path 7a and path 7b, a support member such as protrusion 9 that engages with the guide member to move the lifting member along the guide member, and a branching member such as branching claw 8 that guides the movement of the guide member to the other path, and is characterized in that the saddle-stitched sheet bundle is lifted on the ascending path, switched to the descending path by the branching member, and the saddle-stitched sheet bundle is lowered by being separated from the saddle-stitched sheet bundle on the descending path, and then moved below the stacked saddle-stitched sheet bundle. With this configuration, according to the third aspect, two actions of lifting straight up and lowering after retracting can be performed using only the drive source for vertical movement, thereby reducing costs.

[0042] The fourth aspect is characterized in that, in any one of the aspects described in the first to third aspects, the pair of left and right conveying paths is switched each time one copy of the saddle-stitched sheet bundle is discharged into the stacking container. With this configuration, according to the fourth aspect, by alternating the positions of the bulging folds on the left and right, a large amount of items can be loaded while keeping the loading surface horizontal.

[0043] The fifth aspect is characterized in that, in any one of the aspects described in the first to third aspects, the conveying path is switched to one of the pair of left and right conveying paths each time multiple copies of the saddle-stitched sheet bundle are discharged into the stacking container. With this configuration, according to the fifth aspect, the printed materials can be automatically sorted into any number of copies so that the user can easily distribute the printed materials.

[0044] The sixth aspect is an image forming system characterized by connecting an image forming device that forms an image on a sheet and a sheet processing device described in any one of the first to fifth aspects that is capable of at least saddle-stitching the sheet on which the image has been formed by the image forming device. With this configuration, according to the sixth aspect, the effects of the sheet processing apparatus according to any one of the first to fifth aspects can be achieved.

[0045] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and unless otherwise specifically limited in the above description, various modifications and variations are possible within the spirit and scope of the present invention as defined in the claims. For example, the technical matters described in the above embodiments, examples, or variations may be appropriately combined.

[0046] The effects appropriately described in the embodiments of the present invention are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention. [Explanation of symbols]

[0047] 1 Loading container 2. Paper stack (example of a saddle-stitched sheet stack) 3 Arm (an example of a lifting member, an example of a butting member) 3a Protrusion 3b Drive transmission section 4a Conveying path (one example of a pair of conveying paths on the left and right) 4b Conveying path (one example of a pair of conveying paths on the left and right) 5. Conveying roller (an example of a discharging means, a discharging member) 6A drive source 6B Drive source 8 Branch claw (an example of a branching member) 9. Protrusion (an example of a support member) 10a, 10b Switching claw 11 Paper output slot 12 Full detection sensor 100 Image forming system 101 Image forming device 102 post-processing device (an example of a sheet processing device) 103 Post-processing unit (an example of binding processing means) 104 Loading unit (sheet loading device) 215 Paper transport direction (sheet transport direction) X Left / right / horizontal direction Y Front / back / depth direction Z Up / down / vertical direction [Prior art documents] [Patent documents]

[0048] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-192162 [Patent Document 2] Japanese Patent Application Publication No. 10-203702

Claims

1. a binding processing means for saddle-stitching the image-formed sheets; a loading container for loading the saddle-stitched sheet bundle; a pair of left and right conveyance paths for discharging the saddle-stitched sheet bundle to the bottom surface of the stacking container; a discharge means for discharging the saddle-stitched sheet bundle onto the bottom surface or onto the saddle-stitched sheet bundles stacked on the bottom surface; a lifting member for lifting the saddle-stitched sheet bundle loaded in the loading container; A sheet processing apparatus comprising: The sheet processing device uses the lifting member to lift the saddle-stitched sheet bundle in the loading container, transports the saddle-stitched sheet bundle along one of the pair of left and right transport paths, and discharges the saddle-stitched sheet bundle below the saddle-stitched sheet bundle lifted by the lifting member.By repeating this operation of retracting the lifting member to the outside of the loading container and lowering the saddle-stitched sheet bundle, the sheet processing device changes the left and right orientation of the saddle-stitched sheet bundle and loads the saddle-stitched sheet bundle from below the loading container.

2. 2. The sheet processing apparatus according to claim 1, wherein the lifting members are arranged on the left and right sides of the stacking container, each having an abutment member against which the saddle-stitched sheet bundle is abutted, and the lifting members lift one side of the saddle-stitched sheet bundle, discharge the saddle-stitched sheet bundle from the conveying path on the lifted side, and align it by abutting it against the lifting member on the opposite side.

3. The lifting member is a drive source that moves the lifting member up and down; a guide member having two paths, ascending and descending; a support member that engages with the guide member to move the lifting member along the guide member; a branching member that guides the movement of the guide member to another path, 3. The sheet processing apparatus according to claim 1, wherein the saddle-stitched sheet bundle is lifted up on an upward path, switched to a downward path by the branching member, and the saddle-stitched sheet bundle is lowered on the downward path by separating it from the saddle-stitched sheet bundle, and then moved below the stacked saddle-stitched sheet bundle.

4. 4. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus switches to one of the pair of left and right conveying paths every time one set of the saddle-stitched sheet bundle is discharged to the stacking container.

5. 4. The sheet processing apparatus according to claim 1, wherein the conveying path is switched to one of the pair of left and right conveying paths every time a plurality of copies of the saddle-stitched sheet bundle are discharged to the stacking container.

6. An image forming system characterized by connecting an image forming device that forms an image on a sheet and a sheet processing device described in any one of claims 1 to 5 that is capable of at least saddle-stitching the sheet on which the image has been formed by the image forming device.

Images