JP7131091B2 - Sheet post-processing device - Google Patents

Description

The present invention relates to a sheet post-processing apparatus for stapling a bundle of sheets.

In recent years, sheet post-processing apparatuses have become widespread. A sheet post-processing device is a device that, after printing an image on each of a plurality of sheets by a printer, bundles the sheets and binds them with staples. After images are printed on each sheet, each sheet is stacked on a post-processing tray (hereinafter referred to as a "post-processing tray") and stapled by a sheet post-processing device (Patent Documents 1 to 3). reference).

Specifically, the post-processing tray is normally arranged at an angle such that the side closer to the stapler is lower than the side farther from the stapler. When the sheet is conveyed to the post-processing tray, it descends along the inclined surface of the post-processing tray and stops by hitting a stopper provided at the lower end of the post-processing tray. A pair of aligning plates provided on both sides of the post-processing tray approach the sheet and touch both side edges of the sheet to adjust the posture of the sheet. Then move away from the seat. By performing such an operation for each sheet, the sheet bundle accommodated in the post-processing tray is aligned.

Then, in a state where the sheet bundle is aligned, the sheet bundle is stapled by the stapler as follows.

The stapler has a staple driving portion and a staple receiving portion which are vertically spaced apart from each other. When all the sheets to be bound as one bundle are stacked on the post-processing tray and aligned, the staple driving portion and the staple receiving portion sandwich the sheet bundle from above and below and relatively approach each other. While the sheet bundle is pressed against the sheet bundle, the staple driving section drives staples into the sheet bundle. Then, the tip of the staple penetrates the sheet bundle and is bent at the staple receiver. This completes the stapling.

When stapling is completed, the staple driving portion and the staple receiving portion are vertically separated from the sheet bundle and returned to their original positions.

The stapler may return to the home position away from the post-processing tray along the sheet conveying direction when not performing stapling.

JP 2007-153552 A JP 2013-136429 A Japanese Unexamined Patent Application Publication No. 2013-32208

In addition, downsizing of the sheet post-processing apparatus has been conventionally promoted. As one of the methods of miniaturization, it has been proposed to use the space in which the stapler moves to clear sheet jams.

However, when miniaturization is attempted in this way, when a jam occurs inside the sheet post-processing apparatus, the stapler must be moved to clear the jam. At this time, the stapler may hit the sheet bundle and disturb the sheet bundle.

It is not preferable to perform stapling while the sheet bundle is disordered. The user then has to resubmit the job again. Alternatively, you have to take out the sheet stack and bind it yourself.

SUMMARY OF THE INVENTION In view of such problems, it is an object of the present invention to make it possible to eliminate jams more easily than before while keeping the size of a sheet post-processing apparatus small and without disturbing the sheet stack.

A sheet post-processing apparatus according to one aspect of the present invention includes stacking means for stacking a bundle of a plurality of sheets, a stapler having two insertion members, and four sides of the bundle stacked on the stacking means. A first section through which a main guide groove and a sub-guide groove parallel to the binding margin side, which is one specific side of one of the a moving section in which the stapler is movable , including a second section continuing to the main guide groove beyond an extension line of a boundary side, which is a side perpendicular to the binding margin side among the four sides; A communication groove that connects the guide groove and the sub-guide groove, and a state in which both of the two insertion members are inserted into the main guide groove at a position where the stapler is parallel-stitched when the bundle is to be parallel-stitched. When moving and obliquely binding the bundle, one of the two insertion members is inserted into the main guide groove and the other is inserted into the sub guide groove to the position where the stapler is obliquely bound. and moving means for moving.

Preferably, the moving means moves the stapler to the second section when a jam occurs. More preferably, the length of the second section is equal to or longer than the length of the stapler in the moving direction.

According to the present invention, jams can be eliminated more easily than in the past without disturbing the sheet bundle while keeping the size of the sheet post-processing apparatus small.

1 is a diagram illustrating an example of the appearance of an image forming apparatus; FIG. 4 is a diagram schematically showing the internal configuration of the sheet post-processing unit; FIG. 1 is a perspective view of a stapler; FIG. 4 is a front view of the stapler; FIG. It is a figure which shows a mode that the drive mechanism was seen from the Z direction. It is a perspective view of a moving plate. It is a front view of a moving plate. It is a perspective view of a guide part. It is a figure which shows a mode that the guide part was seen from the Z direction. FIG. 10 is a diagram showing an example of transition of a guide section and a stapler; FIG. 5 is a diagram showing an example of the positional relationship between the moving plate and the stapler; It is a figure which shows the example of operation|movement, such as a stapler, on a front side. It is a figure which shows the example of operation|movement, such as a stapler, on a back side. It is a figure which shows the modification of a guide part.

FIG. 1 is a diagram showing an example of the appearance of an image forming apparatus 1. As shown in FIG. FIG. 2 is a diagram schematically showing the internal configuration of the sheet post-processing unit 2. As shown in FIG.

The image forming apparatus 1 shown in FIG. 1 is a device generally called "MFP (Multi Function Peripherals)" or "multi-function peripheral", and has functions such as copying, PC printing, facsimile, scanning, and a document server. It is a device.

The image forming apparatus 1 includes a main controller 10, a print unit 11, a scan unit 12, a document feeder 13, a touch panel display 14, a relay transport unit 15, a sheet post-processing unit 2, and the like. The print unit 11 and the scan unit 12 are constructed integrally.

The main controller 10 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an auxiliary storage device, and the like. It controls the relay transport unit 15 and the sheet post-processing unit 2 .

The document feeder 13 is an ADF (Auto Document Feeder) and includes a paper feed tray, a transport mechanism, a paper discharge tray, and the like. The transport mechanism transports the sheets set on the paper feed tray one by one to the scan unit 12 and discharges them to the paper discharge tray.

The scanning unit 12 is composed of a document reading section, platen glass, slit glass, and the like. The document reading unit reads an image from a sheet set on the platen glass. Also, when the sheet conveyed by the document feeder 13 passes through the slit glass, an image is read from the sheet.

The print unit 11 prints the image read by the scan unit 12 on a sheet. Also, an image is printed on a sheet based on image data transmitted from another apparatus or image data stored in a storage. A page printer, an inkjet printer, or the like is used as the print unit 11 .

The touch panel display 14 is a device for displaying a screen and allowing a user to input data or commands to the image forming apparatus 1 . Hereinafter, the side of the image forming apparatus 1 on which the touch panel display 14 is provided is referred to as "front", and the side opposite to the front is referred to as "back".

The relay conveying unit 15 conveys the sheet on which the image is printed by the printing unit 11 to the sheet post-processing unit 2 .

The sheet post-processing unit 2 is a device generally called a “finisher” or the like, and performs post-processing on one or more sheets conveyed from the relay conveying unit 15 . Examples of post-processing include a process of binding sheets with staples, a process of punching holes in sheets, and a process of folding sheets. A case where the sheet post-processing unit 2 performs at least stapling processing among these post-processing will be described below as an example.

As shown in FIG. 1 or 2, the sheet post-processing unit 2 includes a housing 20, eight sets of conveying roller pairs 201 to 209, a paper discharge tray 211, a stapling tray 212, a paper discharge tray 213, and a jam processing guide 24. , stapler 3, drive mechanism 7, and the like.

The sheets conveyed by the relay conveying unit 15 are conveyed to the discharge tray 211 by conveying roller pairs 201, 202, 203, and 204 if they do not need to be stapled. If the sheet needs to be stapled, it is conveyed to the staple tray 212 by conveying roller pairs 201 , 202 and 205 .

When the sheet is placed on the staple tray 212, it hits a stopper 212a of the staple tray 212 and stops. Then, the sheet is aligned with other sheets previously placed on the staple tray 212 by the alignment plates on both sides of the staple tray 212 . The sheets are set on the stapler 3 in this way.

Then, the sheet is stapled together with other sheets as one sheet bundle. After being bound, the sheet is conveyed to the discharge tray 213 by the conveying roller pair 209 .

However, if the sheet is to be stapled separately from the other sheets previously conveyed to staple tray 212 , it is switched back by conveying roller pairs 205 , 206 , 207 and 208 and retracted to retraction path 22 . Then, after the other sheets are stapled and conveyed to the discharge tray 213 , they are conveyed to the stapling tray 212 by conveying roller pairs 205 , 206 , 207 and 208 .

The housing 20 accommodates the conveying roller pairs 201 to 209, the staple tray 212, the jam processing guide 24, the stapler 3, the drive mechanism 7, and the like. A door 29 is provided on the front wall of the housing 20 so that it can be opened and closed. The door 29 is normally closed, but is opened when a jam occurs in the sheet post-processing unit 2 and the sheet is removed.

FIG. 3 is a perspective view of the stapler 3. FIG. FIG. 4 is a front view of the stapler 3. FIG. FIG. 5 is a diagram showing the drive mechanism 7 as seen from the Z direction. 6 is a perspective view of the moving plate 72. FIG. FIG. 7 is a front view of the moving plate 72. FIG.

The stapler 3 is a device for binding the sheet bundle 4 placed on the staple tray 212 with staples, and as shown in FIGS. 33, a base 34, and the like.

Hereinafter, the direction in which the sheets are conveyed from the stapling tray 212 toward the stapler 3 will be referred to as "sheet conveying direction". A direction perpendicular to the sheet conveying direction and parallel to the horizontal plane is referred to as a “sheet width direction”. A direction from top to bottom perpendicular to a plane parallel to the sheet conveying direction and the sheet width direction is referred to as a "Z direction".

A staple driving portion 301 and a staple receiving portion 302 are vertically spaced apart from each other near the position adjacent to the staple binding tray 212 on the upper portion of the main body 30 .

The staple driving section 301 drives staples, and the staple receiving section 302 bends the driven staples. Stapling is performed with the leading edge of the sheet bundle 4 on the tray 35 interposed between the staple driving portion 301 and the staple receiving portion 302 . Specifically, the staple driving portion 301 descends toward the needle receiving portion 302 , and the leading end portion of the sheet bundle 4 is sandwiched between the needle driving portion 301 and the needle receiving portion 302 . Then, the staple driving section 301 drives staples while the bottom portion of the staple driving section 301 is in pressure contact with the sheet bundle 4 .

The stapler 3 can also drive staples parallel to the sheet width direction, and can also drive staples obliquely to the sheet width direction. Hereinafter, the former is described as "parallel binding" and the latter is described as "diagonal binding".

A base 34 is provided at the bottom of the main body 30 . The base 34 is a plate-like foundation, and has bent pieces 341 and 342 bent downward at respective ends on the downstream side (the stapler 3 side) and the upstream side (the staple binding tray 212 side) in the sheet conveying direction. are provided, and rollers 343 and 344 are respectively supported by the bending pieces 341 and 342 so as to rotate around axes parallel to the upper surface of the base 34 . This axis is parallel to the sheet conveying direction when the stapler 3 is in a posture for parallel binding.

An engaging member 31 , an engaging member 32 , and a switching projection 33 extend downward from the base 34 . The engaging member 31 and the engaging member 32 have substantially the same length, but the switching projection 33 is shorter than the engaging member 31 and the engaging member 32 .

The drive mechanism 7 includes a base 71, a moving plate 72, a guide portion 73, a guide bar 74, a guide belt 75, a pulley pair 76, a pulley 77, a drive belt 78, a drive pulley 79, and a drive motor 70, as shown in FIG. etc.

The base 71 is a plate-like member elongated along the sheet width direction, and is supported by the main body of the sheet post-processing unit 2. It holds pair 76 , pulley 77 , drive belt 78 , drive pulley 79 and drive motor 70 .

The guide portion 73 is provided elongated along the sheet width direction at substantially the center of the base 71 in the sheet conveying direction, and guides the stapler 3 along the sheet width direction. The configuration of the guide portion 73 will be described later.

The guide bar 74 is a shaft-shaped member elongated in the sheet width direction and having a circular cross section, and is provided downstream of the guide portion 73 in the sheet conveying direction. A support portion 713 and a support portion 714 are provided at both ends of the base 71 in the sheet width direction, and both ends of the guide bar 74 are fixed.

The pulley pair 76 is composed of two pulleys 761, 762, etc., and is provided on the base 71 downstream of the guide bar 74 in the sheet conveying direction and at the end on the back side of the image forming apparatus 1. .

The pulley 77 is provided on the base 71 downstream of the guide bar 74 in the sheet conveying direction and at the front end of the image forming apparatus 1 .

The guide belt 75 is wound around pulleys 762 and 77 of the pulley pair 76 .

The drive pulley 79 is provided on the base 71 at the rear end of the image forming apparatus 1 and attached to the rotation shaft of the drive motor 70 .

Drive belt 78 is entrained around pulley 761 and drive pulley 79 of pulley pair 76 .

When the driving motor 70 is driven to rotate the rotating shaft, the driving force is transmitted to the guide belt 75 via the driving pulley 79, the driving belt 78, and the pulley pair 76, and the guide belt 75 rotates.

The moving plate 72 is arranged between the stapler 3 and the base 71 and has a through hole 720 in the center as shown in FIG. 6 or 7 .

The through hole 720 is a U-shaped hole, and includes a hole portion 721 that is long in the sheet width direction, and a hole portion 722 and a hole portion 723 that are long in the sheet conveying direction at both ends of the sheet width direction. The engaging members 31 and 32 pass through the hole portions 722 and 723 respectively to reach the guide portion 73 . The vertical position of the stapler 3 with respect to the moving plate 72 is determined by the rollers 343 and 344 (see FIG. 4) coming into contact with the upper surface of the moving plate 72 .

The width of the hole portion 722 and the width of the hole portion 723 are slightly longer than the diameter of the engaging member 31 and the diameter of the engaging member 32, respectively, and are determined so that there is almost no rattling in the seat width direction. .

The switching projection 33 penetrates through the hole 721 , and the tip of the switching projection 33 protrudes slightly from the lower surface of the moving plate 72 .

As will be described later, the stapler 3 moves so as to rotate with respect to the moving plate 72 when performing oblique binding. At this time, the rollers 343 and 344 roll on the upper surface of the moving plate 72, so that the stapler 3 rotates smoothly.

A bending piece 725 and a bending piece 726 that bend downward are provided at both ends of the moving plate 72 in the sheet conveying direction. A roller 727 and a roller 728 are respectively supported by the bending piece 725 and the bending piece 726 so as to rotate around an axis parallel to the sheet conveying direction.

Furthermore, a connecting portion 729 that connects with a portion of the guide belt 75 is provided on the lower surface of the moving plate 72 . A cylindrical member 724 elongated in the seat width direction is provided in the vicinity of the connecting portion 729 . A guide bar 74 passes through the cylindrical member 724 .

The roller 727 is in contact with the guide surface 711 on the upper surface of the base 71 , and the roller 728 is in contact with the guide surface 712 on the upper surface of the base 71 . When the moving plate 72 moves along the guide bar 74, the rollers 727 and 728 roll on the guide surfaces 711 and 712, respectively. As a result, the moving plate 72 slides while maintaining a constant distance from the base 71 .

Since the moving plate 72 is connected to the guide belt 75 by the connecting portion 729, it moves along the seat width direction when the guide belt 75 rotates. Further, since the stapler 3 is fitted on the moving plate 72 , the stapler 3 moves along the sheet width direction together with the moving plate 72 when the guide belt 75 rotates.

Specifically, when the drive pulley 79 rotates clockwise when viewed from the Z direction, the stapler 3 moves toward the front of the image forming apparatus 1 , and when it rotates counterclockwise, it moves toward the back of the image forming apparatus 1 . Move to

8 is a perspective view of the guide portion 73. FIG. FIG. 9 is a diagram showing how the guide portion 73 is viewed from the Z direction. 10A and 10B are diagrams showing an example of transition of the guide portion 73 and the stapler 3. FIG. FIG. 11 is a diagram showing an example of the positional relationship between the moving plate 72 and the stapler 3. As shown in FIG. FIG. 12 is a diagram showing an example of operations of the stapler 3 and the like on the front side. FIG. 13 is a diagram showing an example of the operation of the stapler 3 on the back side.

As shown in FIG. 8 or 9, the guide portion 73 is formed by providing a guide hole 732 penetrating in the thickness direction in a plate-like guide portion main body 731 elongated in the sheet width direction.

The guide hole 732 is composed of a main guide groove 80 , a first sub-guide groove 81 , a second sub-guide groove 82 , a first communication groove 83 and a second communication groove 84 .

The main guide groove 80 extends linearly along the seat width direction. The coordinates of the front end 801 of the main guide groove 80 in the sheet width direction substantially match the coordinates of the front end 61 of the sheet passing range 60 in the sheet width direction. The "sheet passing range 60" is the range in the sheet width direction occupied by the sheets with the longest width that can be stapled by the stapler 3 when the sheets are set on the stapler 3. FIG.

The length of the main guide groove 80 is longer than the sum of the length of the sheet passing range 60 and the length of the stapler 3 in the sheet width direction. That is, the main guide groove 80 has a section corresponding to the sheet passing range 60 and a section corresponding to the extended range 64 outside the sheet passing range 60 and longer than the length of the stapler 3 in the sheet width direction.

The first sub-guide groove 81 and the second sub-guide groove 82 are provided upstream of the main guide groove 80 in the sheet conveying direction along the sheet width direction. Also, the respective positions are the front side and the back side of the image forming apparatus 1 .

The position of the front end 811 of the first sub-guide groove 81 in the seat width direction is closer to the front than the position of the end 801 in the seat width direction.

The first communication groove 83 connects the end portion 801 and the end portion 811 or its vicinity. It is desirable that the angle between the main guide groove 80 and the first communication groove 83 is about 45 degrees. The length of the first communication groove 83 is equal to or shorter than the distance between the engaging members 31 and 32 . The angle of oblique binding is determined by adjusting the length of the first communication groove 83 or the angle between the main guide groove 80 and the first communication groove 83 .

The second communication groove 84 connects the branch position 803 of the main guide groove 80 and the rear end 821 of the second sub-guide groove 82 or its vicinity. The coordinates of the branch position 803 in the sheet width direction are substantially the same as the coordinates of the end portion 62 on the back side of the sheet passing range 60 in the sheet width direction. The position of the end portion 821 in the sheet width direction is on the rear side of the position of the branch position 803 in the sheet width direction. It is desirable that the angle between the main guide groove 80 and the second communication groove 84 is about 45 degrees. The length of the second communication groove 84 is equal to or shorter than the distance between the engaging members 31 and 32 . The angle of oblique binding is determined by adjusting the length of the second communication groove 84 or the angle between the main guide groove 80 and the second communication groove 84 .

The widths of the main guide groove 80, the first sub-guide groove 81, the second sub-guide groove 82, the first communication groove 83, and the second communication groove 84 are the diameters of the engaging members 31 and 32. is slightly longer than the main guide groove 80, the first sub-guide groove 81, the second sub-guide groove 82, the first communication groove 83, or the second is smoothly guided along the communication groove 84.

A switching member 851 , a movable guide 852 , a switching member 853 , and a movable guide 854 are provided on the upper surface of the guide portion main body 731 . The switching member 851, movable guide 852, switching member 853, and movable guide 854 are switches for determining the path along which the stapler 3 moves, and operate as follows.

When the stapler 3 performs oblique binding at the upstream and back side corners of the four corners of the sheet bundle 4, the switching member 851 contacts the switching projection 33 as shown in FIG. 10(A). The movable guide 852 switches to a position that opens the boundary between the second communication groove 84 and the second sub-guide groove 82 .

When the stapler 3 moves from the front side to the back side of the main guide groove 80, the switching projection 33 and the switching member 851 come into contact with each other as shown in FIG. 10B, and the switching projection 33 pushes the switching member 851. rotate while Then, the engaging member 32 enters the second communication groove 84 and reaches the end portion 821 as shown in FIG. 10(C). The switching member 851 is pushed backward by the switching projection 33, and returns to its original position when the switching projection 33 passes through.

Furthermore, the movable guide 852 switches to a position that closes the boundary between the second communication groove 84 and the second sub-guide groove 82 . Then, as shown in FIG. 10(D), the stapler 3 moves in the front direction to a position for oblique binding.

When the stapler 3 returns from the position shown in FIG. 10(D) to the position shown in FIG. 10(B), when the stapler 3 moves to the position shown in FIG. The position is switched to open the boundary between 84 and the second sub guide groove 82 . Then, the engaging member 32 enters the second communication groove 84 and the main guide groove 80 and returns to the position shown in FIG. 10(B).

In addition, when the engaging member 31 is in the main guide groove 80 and the engaging member 32 is in the second sub-guide groove 82, the engaging member 31, the engaging member 32, and the switching projection 33 are in the through hole. 720 in the position shown in FIG. Further, when the engaging member 31 is in the first sub-guide groove 81 and the engaging member 32 is in the main guide groove 80, the engaging member 31, the engaging member 32 and the switching projection 33 are in the through hole. 720 in the position shown in FIG. 11(B).

Further, the heights h1, h2, and h3 of the bottom surface of the switching projection 33, the top surface of the switching member 851, and the top surface of the movable guide 852 from the top surface of the guide portion 73 are h3<h1<h2. be. Therefore, the switching projection 33 can contact the movable guide 852 but not the switching member 851 . Since both the engaging member 31 and the engaging member 32 pass through the main guide groove 80 , they can come into contact with the switching member 851 .

Alternatively, when the stapler 3 performs oblique binding at the upstream and front corners of the four corners of the sheet bundle 4, as shown in FIG. , and the movable guide 852 switches to a position that opens the boundary between the first communication groove 83 and the first sub-guide groove 81 .

When the stapler 3 moves from the rear side to the front side of the main guide groove 80, the switching projection 33 and the switching member 853 come into contact with each other as shown in FIG. rotate while Then, the engaging member 31 enters the first communication groove 83 and reaches the end portion 811 as shown in FIG. 12(C). The switching member 853 is pushed forward by the switching projection 33 and returns to its original position after the switching projection 33 has passed.

Furthermore, the movable guide 854 switches to a position that closes the boundary between the first communication groove 83 and the first sub-guide groove 81 . Then, as shown in FIG. 12(D), the stapler 3 moves backward to a position for oblique binding.

When the stapler 3 returns from the position shown in FIG. 12(D) to the position shown in FIG. 12(B), when the stapler 3 moves to the position shown in FIG. The position is switched to open the boundary between 83 and first sub guide groove 81 . Then, the engaging member 31 enters the first communication groove 83 and the main guide groove 80 and returns to the position shown in FIG. 12(B).

Alternatively, if a sheet jam occurs in the evacuation path 22 (see FIG. 2), the image forming apparatus 1 has to make the user remove the sheet. Therefore, each part operates as follows.

As shown in FIG. 13A, the switching member 851 switches to a position where it cannot contact the switching protrusion 33 .

When the stapler 3 moves in the main guide groove 80 from the front side to the back side, the switching projection 33 does not come into contact with the switching member 851. Therefore, the engaging member 32 is not guided to the second communication groove 84, and the state shown in FIG. As shown in (B), it advances straight along the main guide groove 80 toward the back. Then, as shown in FIG. 13C, it reaches the end 802 of the main guide groove 80 on the back side. That is, it moves to the section corresponding to the extension range 64 in the main guide groove 80 .

If a sheet jam occurs in the evacuation path 22 when the stapler 3 is at the position shown in FIG. 10D, the stapler 3 returns to the position shown in FIG. The procedure moves to end 802 .

The user removes the jammed sheet by opening the door 29 (see FIG. 1) and operating the jam clearing guide 24 . Since the stapler 3 is retracted to the section corresponding to the extension range 64, the sheet bundle 4 on the staple tray 212 is less likely to be disturbed than before when removing the jammed sheets. The user then closes the door 29 .

According to the present embodiment, it is possible to eliminate a jam more easily than in the conventional art without disturbing the sheet bundle 4 while maintaining the miniaturization of the sheet post-processing unit 2 .

FIG. 14 is a diagram showing a modification of the guide portion 73. As shown in FIG. In this embodiment, the guide hole 732, the switching members 851 and 853, and the movable guides 852 and 854 as shown in FIG. 8 are provided in the guide portion 73. Switching members 855, 856 and movable guides 857 may be provided.

The guide hole 733 is composed of a main guide groove 86 , a first sub-guide groove 87 , a second sub-guide groove 88 , a first communication groove 891 and a second communication groove 892 .

The main guide groove 86 extends linearly along the seat width direction. The coordinates of the front end 861 of the main guide groove 86 in the sheet width direction substantially match the coordinates of the end 61 of the sheet passing range 60 in the sheet width direction.

Like the main guide groove 80, the main guide groove 86 has a section corresponding to the sheet passing range 60 and a section corresponding to the extension range 64 outside the sheet passing range 60 and longer than the length of the stapler 3 in the sheet width direction. , has

First sub-guide groove 87, first communication groove 891, switching member 856, and movable guide 857 are connected to first sub-guide groove 81, first communication groove 83, switching member 853, and movable guide 854, respectively. (see FIGS. 9 and 12). However, the first communication groove 891 connects the main guide groove 86 and the first sub-guide groove 87 .

When obliquely binding the front corner, the switching member 856 and the movable guide 857 operate in the same manner as the switching member 853 and the movable guide 854 (see FIG. 12). Also, the stapler 3 moves as described with reference to FIG.

The second sub guide groove 88 is provided along the sheet width direction upstream of the main guide groove 86 in the sheet conveying direction. The front end portion 881 of the second sub guide groove 88 is located on the back side of the branch position 863 of the main guide groove 86 .

The second sub-guide groove 88 has a section corresponding to a range in which oblique binding is possible, and a section corresponding to an extension range 64 outside the sheet passing range 60 and longer than the length of the stapler 3 in the sheet width direction. .

A second communication groove 892 connects the branch position 863 and the end portion 881 . By the way, when oblique binding is performed at the corner on the back side, the stapler 3 assumes a posture in which the engaging member 32 is moved upstream, as shown in FIGS. 10(C) and 10(D). The same applies to this modified example. Therefore, the position of the second communication groove 892 is determined according to the range in which oblique binding can be performed at the corners on the back side. By connecting the first sub-guide groove 87 and the second sub-guide groove 88, oblique binding may be performed at any position in the sheet width direction. The first sub-guide groove 81 and the second sub-guide groove 82 are also the same.

The widths of the main guide groove 86, the second sub-guide groove 88, and the second communication groove 892 are the same as the widths of the main guide groove 80, the second sub-guide groove 82, and the second communication groove 84. .

When oblique binding is performed at the corners on the back side, the switching member 855 is switched to a position where it can come into contact with the switching projection 33 . When the stapler 3 moves from the front side to the back side, the switching projection 33 and the switching member 855 come into contact with each other, and the switching projection 33 pushes the switching member 855 to rotate. Furthermore, the engaging member 32 enters the second communication groove 892 and further enters the second sub-guide groove 88 . Then, the stapler 3 moves to a position for oblique binding and performs oblique binding.

Alternatively, when oblique binding is performed, the switching member 855 switches to a position where it cannot contact the switching projection 33 .

When the stapler 3 moves from the front side to the back side of the main guide groove 86 , the switching projection 33 does not contact the switching member 855 . Go straight through the groove 80 toward the back.

When a sheet jam occurs in the evacuation path 22, the stapler 3 moves backward from its current position. Switching member 855 may not operate. As a result, when the stapler 3 is positioned for oblique binding at the corners on the back side, the stapler 3 moves to the end on the back side as shown in FIG. 14(B). Alternatively, if it is in the position for parallel binding, it moves to the end on the back side as shown in FIG. 14(C).

In addition, the configuration of the image forming apparatus 1 and the sheet post-processing unit 2 as a whole or each part, the contents of the processing, the order of the processing, etc. can be appropriately changed in accordance with the gist of the present invention.

2 Sheet post-processing unit (sheet post-processing device)
20 housing 212 staple binding tray (loading means)
29 door 3 stapler 31 engagement member (insertion member)
32 engagement member (insertion member)
4 sheet bundle (bundle)
60 Paper passing range 64 Extension range 7 Drive mechanism (moving means)
80 Main guide groove 82 Second sub-guide groove (sub-guide groove)
84 Second communication groove (connection groove)
88 Second sub guide groove (sub guide groove)
892 second communication groove (connection groove)

Claims (5)

a stacking means for stacking a bundle of a plurality of sheets;
a stapler having two insert members ;
A main guide groove and a sub-guide groove parallel to a specific binding margin side, which is one of the four sides of the bundle loaded on the stacking means, pass through the stapler along the binding margin side . is the first section where staples can be driven in, and the second section that continues to the main guide groove beyond the extension of the boundary side, which is the side of the four sides that is perpendicular to the binding margin side. a moving section in which the stapler including
a communication groove that connects the main guide groove and the sub-guide groove;
When the bundle is to be parallel-stitched, the stapler is moved to a parallel-stitching position with both of the two insertion members inserted into the main guide grooves, and when the bundle is to be diagonally-stitched, the stapler one of the two insertion members is inserted into the main guide groove and the other is inserted into the sub-guide groove to a position for oblique binding ;
A sheet post-processing device comprising: the moving means moves the stapler to the second section when a jam occurs;
The sheet post-processing apparatus according to claim 1. the length of the second section is equal to or greater than the length of the stapler in the moving direction;
The sheet post-processing apparatus according to claim 1 or 2. A housing housing the loading means, the stapler, and the moving means, and having a door provided on one specific surface perpendicular to the binding margin side;
has
The second section is provided on the opposite surface side of the housing that faces the specific surface,
The sheet post-processing apparatus according to any one of claims 1 to 3. The distance between the sub guide groove and the binding margin side is shorter than the distance between the main guide groove and the binding margin side,
The sheet post-processing apparatus according to any one of claims 1 to 4 .

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