JP2011184130A - Sheet processing device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet processing device capable of sufficiently preventing a flap from rising during a sheet folding processing, and also provide an image forming device having the sheet folding device. <P>SOLUTION: This sheet processing device includes a folding means for folding a sheet, a sheet conveying passage having guide members 104a-104d for guiding the sheet to the folding means, a stopper 144 for determining the folding position of the sheet, and a sheet pressing part installed so as to face the folding means. The sheet pressing part includes a sheet pressing member 161, a fixing part 171 to which the sheet pressing part 161 is fixed, and a drive means for driving the sheet pressing member 161 and the fixing part 171 so as to press the sheet pressing member and the fixing part against the folding means and the guide members 104a-104d which face the sheet pressing means and the fixing part. The sheet pressing member 161 is made of an elastic body having a surface frictional force which enables the sheet pressing member to elastically deform along the shapes of the folding means and the guide members 104a-104d and which enables the sheet to slide thereon in the deformed state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sheet processing apparatus that performs sheet folding and the like and an image forming apparatus including the sheet processing apparatus.

  Sheet folding processing performed by a sheet processing apparatus that performs folding processing on a sheet such as paper includes three-fold folding and kannon folding. When the sheet folding device performs three-fold folding or kannon folding, the flaps formed by the folds are recessed inside the sheet. Therefore, the flaps are also folded inward in the folding process performed after the folding process is performed upstream. There is a problem in that it may rise up and turn over and cause the ear to be crushed by the folding process. In addition, since the approach of the flap into the folding means is delayed, there is a problem that bending is accumulated in the vicinity of the fold processed upstream, which may cause double folding.

  In order to solve the above problem, a technique is disclosed in which a protrusion is provided on a guide plate in the vicinity of a folding roller, or a spherical member is disposed to prevent the sheet from being lifted during folding processing (for example, Patent Documents). 1). In addition, as another technique for solving the above problem, a technique is disclosed in which a movable guide member is moved to the vicinity of the folding roller to guide the sheet and prevent the flap from being lifted during the folding process (for example, Patent Document 2).

  However, in the technique described in Patent Document 1, the lift prevention mechanism is a fixed type, and since the range pressed against the sheet is only a point, a line, or a very small area close thereto, the lift of the sheet is completely prevented. There was a problem that it was virtually difficult to prevent.

  Further, in the technique described in Patent Document 2, since the guide member is a rigid body, a conveyance gap for conveying the sheet is necessarily required. For this reason, there is a case in which the flap is lifted by the conveyance gap, and there is a problem that it is practically difficult to completely prevent the flap from being lifted.

  The present invention has been made in view of such circumstances, and provides a sheet processing apparatus capable of sufficiently preventing the flaps from being lifted during the sheet folding process, and an image forming apparatus including the sheet folding apparatus. With the goal.

  The sheet processing apparatus of the present invention includes a folding unit that folds a sheet, a sheet conveyance path having a guide member that guides the sheet to the folding unit, a stopper unit that determines a folding position of the sheet, and a folding unit. A sheet pressing means provided, and the sheet pressing means forms a sheet pressing member, a fixing means for fixing the sheet pressing member, a sheet pressing member and the fixing means, and an opposing folding means and a sheet conveying path. Drive means for driving the sheet against the guide member, and the sheet pressing member is capable of elastic deformation along the shape of the folding member and the guide member of the sheet conveying path, and the sheet is in a deformed state. It is characterized by comprising an elastic body having a surface frictional force that enables sliding.

  An image forming apparatus according to the present invention includes the sheet processing apparatus.

  According to the present invention, the sheet pressing member is brought into direct contact with and pressed on the sheet, and the flap of the sheet subjected to the folding process is brought into close contact with the sheet, thereby sufficiently preventing the flap from being lifted during the sheet folding process. It becomes possible.

It is a figure which shows the example of schematic structure of the sheet folding apparatus which concerns on this embodiment. 1 is a diagram illustrating a schematic configuration example of an image forming apparatus according to an embodiment. It is a figure for demonstrating Z folding operation | movement. It is a figure for demonstrating an inside 3 folding operation | movement. It is a figure for demonstrating a Kannon four-folding operation | movement. It is a figure which shows the example of schematic structure of the sheet pressing part of the sheet processing apparatus which concerns on this embodiment. It is a figure which shows the example when the sheet pressing part of the sheet processing apparatus which concerns on this embodiment has pressed the sheet | seat. It is a figure which shows the example of schematic structure of the sheet pressing part of the sheet processing apparatus which concerns on this embodiment. It is a figure for demonstrating generation | occurrence | production of double folding. It is a figure which shows the example of schematic structure of the sheet pressing part of the sheet processing apparatus which concerns on this embodiment.

  Hereinafter, examples of embodiments of the present invention will be described in detail with reference to the drawings. In the present exemplary embodiment, as an example of the sheet processing apparatus, an image forming apparatus capable of various types of folding processing such as two-fold, inner three-fold, outer three-fold, Z-fold, four-fold, and kannon-fold is exemplified. explain. However, the types of folding processing that can be processed by the sheet processing apparatus according to the present embodiment are not limited to the above.

  FIG. 1 shows a schematic configuration example of a sheet processing apparatus according to the present embodiment. With the configuration shown in FIG. 1, for example, each folding operation such as two-folding, Z-folding, outer three-folding, inner three-folding, simple four-folding, and four-tone folding is possible. FIG. 2 shows a schematic configuration example of an image forming apparatus having the above-described sheet processing apparatus. As illustrated in FIG. 2, a sheet feeding device 2, a sheet feeding device 3, a post-treatment device 4, and a sheet processing device 100 are connected to the image forming apparatus 1 according to the present embodiment. Note that the image forming apparatus does not necessarily have a post-processing apparatus, and the number of paper feeding apparatuses to be connected is not particularly limited.

  The sheet on which the image is formed by the image forming apparatus 1 is conveyed from the upstream image forming apparatus, and is conveyed from the sheet receiving port of FIG. In order to convey the sheet to the downstream side post-processing device 4 without folding, the sheet is directly discharged from the sheet carry-out port by switching the first switching claw 121. On the other hand, when folding is performed, the first switching claw 121 is switched to guide the sheet to each conveyance path inside the sheet processing apparatus and perform each folding operation. After the folding is completed, folding is performed by the folding mechanism 151.

  Next, a folding operation example will be described in detail.

<Z-fold>
FIG. 3 is a diagram for explaining the Z-folding operation. Hereinafter, the Z-folding operation of the sheet processing apparatus 100 according to the present embodiment will be described with reference to FIGS.

  First, as shown in FIG. 3A, the sheet is guided to the first conveyance path 101 by switching the first switching claw 121. A guide member (not shown) is provided at the nip portion between the first folding roller 111 and the second folding roller 112, and the sheet guided by the operation of the guide member is the first folding roller 111 and the second folding roller 112. Pass through the nip. Next, the leading edge of the sheet hits the second stopper 142 that can move to the folding position arranged in the third conveyance path 103, and the sheet temporarily stops. Here, the nip portion indicates a region where the sheet is folded by sandwiching and pressing the sheet.

  Subsequently, as shown in FIG. 3B, the conveyance of the sheet is resumed, and the bent portion of the sheet enters the nip portion between the second folding roller 112 and the third folding roller 113 to perform the first folding. After that, the sheet is conveyed to the fourth conveyance path 104 by switching the second switching claw 122. Then, as shown in FIG. 3C, the leading edge of the sheet hits the third stopper 143 that can move to the folding position arranged in the fourth conveyance path 104, and the sheet temporarily stops. After that, as shown in FIG. 3D, the bent portion of the sheet enters the nip portion between the fourth folding roller 114 and the fifth folding roller 115, and the second folding is performed to complete the Z folding.

  After the folding is completed, the Z-folded sheet is folded by the folding mechanism 151, passes through the sixth transport path 106, is guided to the seventh transport path 107 by the third switching claw 123, and is stacked on the sheet storage unit 131. Is done. When the sheet is conveyed to the post-processing apparatus, the sheet is conveyed to the post-processing apparatus by switching the third switching claw 123.

<Fold in half>
First, the sheet is guided to the first conveyance path 101 by switching the first switching claw 121. The leading edge of the sheet hits the first stopper 141 that can move to the folding position arranged in the second conveyance path 102, and the sheet temporarily stops. Thereafter, the bent portion of the sheet is made to enter the nip portion between the first folding roller 111 and the second folding roller 112, and the first folding is performed to complete the second folding.

  A guide member (not shown) is provided downstream of the nip portion between the first folding roller 111 and the second folding roller 112, and the folded sheet guided by the operation of the guide member enters the third conveyance path 103. Without passing through the nip portion between the second folding roller 112 and the third folding roller 113. Then, the folded sheet is guided to the fifth conveyance path 105 by the second switching claw 122.

  The folded sheet is folded by the folding mechanism 151, passes through the sixth conveyance path 106, is guided to the seventh conveyance path 107 by the third switching claw 123, and is stacked in the sheet storage unit 131. When the sheet is conveyed to the post-processing apparatus, the sheet is conveyed to the post-processing apparatus by switching the third switching claw 123.

<Outer 3 fold, Inner 3 fold, Simple 4 fold>
FIG. 4 is a diagram for explaining the inner three-fold operation. Hereinafter, a three-fold operation of the sheet processing apparatus 100 according to the present embodiment will be described with reference to FIGS.

  First, the sheet is guided to the first conveyance path 101 by switching the first switching claw 121. Then, as shown in FIG. 4A, the leading edge of the sheet hits the first stopper 141 that can move to the folding position arranged in the second conveyance path 102, and the sheet temporarily stops. Thereafter, the bent portion of the sheet enters the nip portion between the first folding roller 111 and the second folding roller 112 to perform the first folding, and then the sheet is conveyed to the third conveyance path 103.

  Next, as shown in FIG. 4B, the leading edge of the sheet hits the second stopper 142 that can move to the folding position arranged in the third conveyance path 103, and the sheet temporarily stops. Then, as shown in FIG. 4C, the bent portion of the sheet enters the nip portion between the second folding roller 112 and the third folding roller 113 to perform the second folding, and the folding is completed.

  After completion of folding, the folded sheet is guided to the fifth conveyance path 105 by the second switching claw 122. The folded sheet passes through the sixth conveyance path 106 while being folded by the folding mechanism 151, is guided to the seventh conveyance path 107 by the third switching claw 123, and is stacked on the sheet storage unit 131. Is done. When the sheet is conveyed to the post-processing apparatus, the sheet is conveyed to the post-processing apparatus by switching the third switching claw 123.

<Four folds of Kannon>
FIG. 5 is a diagram for explaining a four-fold folding operation. Hereinafter, a four-fold folding operation of the sheet processing apparatus 100 according to the present embodiment will be described with reference to (a) to (d) of FIG.

  First, the sheet is guided to the first conveyance path 101 by switching the first switching claw 121. Then, as shown in FIG. 5A, the leading edge of the sheet hits the first stopper 141 that can move to the folding position arranged in the second conveyance path 102, and the sheet temporarily stops. Thereafter, the bent portion of the sheet enters the nip portion between the first folding roller 111 and the second folding roller 112 to perform the first folding, and then the sheet is conveyed to the third conveyance path 103.

  Next, as shown in FIG. 5B, the leading edge of the sheet hits the second stopper 142 that can move to the folding position arranged in the third conveyance path 103, and the sheet temporarily stops. Then, the conveyance of the sheet is resumed, the bent portion of the sheet enters the nip portion of the second folding roller 112 and the third folding roller 113, and the second folding is performed. 4 is conveyed to the conveyance path 104.

  As shown in FIG. 5C, the sheet conveyed to the fourth conveyance path 104 hits the third stopper 143 that can move to the folding position arranged in the fourth conveyance path 104, and temporarily Stop. Then, as shown in FIG. 5D, the bent portion of the sheet is made to enter the nip portion between the fourth folding roller 114 and the fifth folding roller 115 to perform the third folding, and the fourfold folding is completed.

  In addition, after the sheet abuts against the third stopper 143 that can move to the folding position arranged in the fourth conveyance path 104 and the sheet temporarily stops, the bent portion of the sheet is moved to the fourth folding roller 114 and the fifth folding roller 115. When entering the nip portion, the four-fold guide member (not shown) operates, and the end portion of the sheet to be wound can surely enter the nip portion of the fourth folding roller 114 and the fifth folding roller 115.

  After the folding is completed, the quadrifolded folding sheet passes through the sixth conveyance path 106 while being folded by the folding mechanism 151 and is guided to the seventh conveyance path 107 by the third switching claw 123, and the sheet storage unit 131. Stacked. When the sheet is conveyed to the post-processing apparatus, the sheet is conveyed to the post-processing apparatus by switching the third switching claw 123.

(Embodiment 1)
FIG. 6 schematically illustrates a schematic configuration example of the sheet folding mechanism of the sheet processing apparatus according to the present embodiment. FIG. 7 schematically illustrates an example in which the sheet processing apparatus according to the present embodiment directly contacts and presses a sheet pressing portion configured to include an elastic body. As shown in FIGS. 6 and 7, the sheet apparatus according to the present embodiment includes a sheet conveyance path, a sheet folding unit, a stopper, and a sheet pressing unit.

  The sheet conveyance path includes a guide member 104a for conveying a sheet bundle, a guide member 104b, a guide member 104c, and a guide member 104d. The sheet folding unit includes a folding roller pair including a folding roller 116 that can be rotated by a roller driving unit (not shown) and a folding roller 117 that can be rotated in conjunction with the folding roller 116 as folding means for the sheet bundle. is doing. The stopper 144 determines the folding position of the conveyed sheet bundle and guides it to the folding means. The stopper 144 can be moved up and down along the transport path by a stopper driving unit (not shown).

  The sheet pressing unit includes a sheet pressing member 161, a fixing unit 171 and a sheet pressing member driving unit. The sheet pressing member 161 is provided at a position facing the folding roller pair. The material of the sheet pressing member 161 is preferably an elastic body that has a surface frictional force that enables elastic deformation along the pair of folding rollers and the sheet conveying path and that allows the sheet to slide without being damaged. For example, resin or the like can be applied as the sheet pressing member, but the present invention is not limited to this. The fixing portion 171 fixes the sheet pressing member 161. The sheet pressing member drive unit includes a rack 181a integrated with the fixing unit 171 and a gear pulley 181b in which a gear and a timing pulley are integrated in order to move the sheet pressing member 161 and the fixing unit 171 in the direction of the folding roller pair. And a timing belt 181c and a motor 181d.

  Next, the operation of the sheet processing apparatus according to the present embodiment will be described.

  First, the sheet 191 that has been folded upstream is conveyed by a sheet conveying unit (not shown) from the upstream side of the conveying path (not shown in FIG. 6) along the sheet conveying direction 201 and reaches the stopper 144. At this time, the folding roller pair is not rotating, and the sheet is stopped on the conveyance path without being conveyed.

  When a sensor installed on the conveyance path detects that the sheet has stopped on the conveyance path, the motor 181d of the sheet pressing unit rotates. The driving force of the motor 181d is transmitted via the timing belt 181c, the gear pulley 181b, and the rack 181a, and as shown in FIG. 7, the fixing portion 171 integrated with the rack 181a and the sheet pressing member fixed to the fixing portion 171. 161 is moved in the sheet pressing member moving direction 202.

  The sheet pressing member 161 winds the sheet 191 while moving, and elastically deforms along the shapes of the guide member 104 a, the guide member 104 b, the folding roller 116, and the folding roller 117, and simultaneously presses the sheet 191. Thereby, in the sheet 191, the flap generated by the fold is in close contact with the sheet 191. Then, the folding roller pair rotates in the folding roller rotation direction 203 and conveys the sheet 191 to a downstream conveyance path (not shown). As described above, since the flap is in close contact with the sheet 191, the sheet 191 is conveyed to the downstream conveying path while being folded without causing a folding failure due to the floating of the flap. At this time, the sheet pressing member 161 has sufficient slidability between the sheet 191 and is not caught by the pair of folding rollers. When the sheet 191 is conveyed, the motor 181d rotates again, and the sheet pressing member 161 and the fixing portion 171 move backward to a predetermined position.

  The length of the sheet pressing member 161 in the conveyance direction is not particularly limited, but preferably has a size larger than the sheet bundle to be pressed. Thereby, the whole sheet bundle is pressed, and it is possible to suppress the occurrence of unnecessary bending that may occur in the sheet bundle due to the escape caused by being pressed.

  According to the present embodiment, the elastic body, which is a sheet pressing member, is brought into direct contact with and pressed against the sheet so that the folded flap of the sheet is brought into close contact with the sheet, and the folding of the ear that occurs due to the floating of the flap, It is possible to prevent double folding, wrinkles and the like and achieve high folding quality.

  In addition, by setting the length of the sheet pressing member in the conveyance direction to be larger than the sheet bundle to be pressed, unnecessary bending remains in the sheet only by pressing the flap of the sheet. It is possible to solve the problem of the possibility of causing double folding, and to prevent double folding or wrinkles due to unnecessary bending.

(Embodiment 2)
FIG. 8 schematically shows a schematic configuration example of the folding mechanism of the sheet processing apparatus according to the present embodiment. The difference between the sheet processing apparatus according to the present embodiment and the sheet processing apparatus according to the first embodiment is the shape of the sheet pressing member. In addition, about the structure similar to the said Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 9, when pressing the flap of the sheet 191, the sheet flap length 195, which is the distance from the flap tip to the fold, and the distance from the point on the sheet where the flap tip is in close contact to the crease When the contact portion length 194 is different, unnecessary bending may accumulate in the vicinity of the sheet fold line 193 through the folding process by the folding unit, and the unnecessary bending may be crushed by the folding unit, resulting in double folding. Therefore, in order to avoid this, it is preferable that the sheet flap length 195 and the sheet contact portion length 194 have substantially the same value.

  A configuration example of the sheet folding processing mechanism of the sheet processing apparatus according to the present embodiment will be described below.

  As shown in FIG. 8, the sheet processing apparatus according to this embodiment includes a sheet conveyance path, a sheet folding unit, a stopper, and a sheet pressing unit. The sheet conveyance path includes a guide member 104a, a guide member 104b, and a guide member 104c for conveying the sheet bundle. The sheet folding unit includes a folding roller pair including a folding roller 116 that can be rotated by a roller driving unit (not shown) and a folding roller 117 that can be rotated in conjunction with the folding roller 116 as folding means for the sheet bundle. is doing. The stopper 144 determines the folding position of the conveyed sheet bundle and guides it to the folding means. The stopper 144 can be moved up and down along the transport path by a stopper driving unit (not shown).

  The sheet pressing portion is provided at a position facing the pair of folding rollers, and includes a sheet pressing member 162, a fixing portion 172, a sheet pressing member driving portion, and the like. The material of the sheet pressing member 162 is preferably an elastic body that has a surface frictional force that enables elastic deformation along the pair of folding rollers and the sheet conveyance path and that allows the sheet to slide without being damaged. Moreover, in this embodiment, as shown in FIG. 8, the shape of the sheet pressing member 162 is a shape that is recessed toward a substantially central portion. In other words, the region where the sheet end 192 contacts is the thickest, and the thickness gradually decreases toward the center. However, the shape of the sheet pressing member is not limited to this, and when the sheet pressing portion is driven to press the sheet, the pressing starts from the sheet end surface, and the pressing gradually proceeds toward the sheet central portion. Any shape can be used.

  The fixing portion 172 fixes the sheet pressing member 162. Note that the mechanism for moving the sheet pressing member 162 and the fixing portion 172 in the direction of the pair of folding rollers can be the same as that in the first embodiment, and a description thereof will be omitted here.

  Next, the operation of the sheet processing apparatus according to the present embodiment will be described.

  First, the sheet 191 that has been folded upstream is conveyed by a sheet conveying unit (not shown) from the upstream side of the conveying path (not shown in FIG. 8) along the sheet conveying direction and reaches the stopper 144. At this time, the folding roller pair is not rotating, and the sheet is stopped on the conveyance path without being conveyed.

  And when it detects with the sensor installed on the conveyance path that the sheet | seat stopped on the conveyance path, the sheet pressing member fixed to the fixing | fixed part 172 and the fixing | fixed part 172 by the sheet pressing member drive part similarly to the said Embodiment 1. 162 is moved in the sheet pressing member moving direction 202.

  The sheet pressing member 162 rolls in the sheet 191 while moving, and elastically deforms along the shapes of the guide member 104a, the guide member 104b, the folding roller 116, and the folding roller 117, and simultaneously presses the sheet 191. Thereby, in the sheet 191, the flap generated by the fold is in close contact with the sheet 191. At this time, since the end of the sheet pressing member 162 is thick, when the sheet pressing member 162 comes into contact with the sheet 191, it first comes into contact with the sheet end 192, and approaches the opposing folding roller pair and the conveyance path. Gradually contact the center of the sheet 191. Even when the sheet pressing member 162 comes into contact with the opposing pair of folding rollers and the conveyance path and starts elastic deformation, the sheet pressing member 162 is gradually pressed from the sheet end 192 toward the center of the sheet. As a result, unnecessary deflection does not accumulate at the fold and the deflection escapes from the flap tip of the sheet 191, so that the sheet flap length 195 and the sheet contact portion length 194 shown in FIG. it can.

  According to the present embodiment, when pressing the sheet, if the front end of the flap is pressed first, the problem that unnecessary bending may occur and remain may be solved, and the sheet is sequentially moved from the end fold toward the center. By pressing, in addition to preventing the flap of the sheet from lifting, it becomes possible to acclimatize and remove the remaining unnecessary deflection.

(Embodiment 3)
In the first and second embodiments, the configuration example has been described in which the sheet pressing portion prevents the flap of the sheet from being lifted. However, the characteristics, size, and folding mode of the sheet to be pressed may vary widely, and in this case, it may be difficult to deal with these with only one type of sheet pressing member. In addition, when a sheet pressing unit, which is a mechanism for actually pressing a sheet, is mounted on a sheet processing apparatus, there is a possibility that function loss or function variation may occur due to structural differences in the structure.

  Therefore, in the present embodiment, a sheet processing apparatus that can cope with various sheet characteristics and folding modes and that can adjust the entry angle, the pressing amount, and the like of the pressing member will be described with reference to the diagram shown in FIG. To do. 10A is a side view showing an example of the sheet folding portion according to the present embodiment, and FIG. 10B is a top view showing an example of the sheet folding portion according to the embodiment. is there.

  The sheet pressing portion according to the present embodiment includes a sheet pressing member 161, and a fixing portion having a fixing member 173a and a fixing member 174a for fixing the sheet pressing member 161. In the present embodiment, as shown in FIG. 10A, the sheet pressing member 161 will be described as an example in which the sheet pressing member 161 is integrated with the fixing member 173a. However, the present invention is not limited to this. The fixing member 174a is fixed to the sheet folding apparatus side.

  The fixing member 173a and the fixing member 174a are fixed by fastening means such as a screw 211 at four locations of a hole 173b and a hole 173c provided in the fixing member 173a and a hole 174b and a hole 174c provided in the fixing member 174a. ing. Each hole is provided in one place on each of the front side and the back side (not shown) in the transport direction. That is, two holes are provided in the entire sheet pressing portion. Further, the rack 181 integrated with the fixing member 174a is connected to a driving means starting from a stepping motor (not shown). In addition, the number and position of a hole are not limited to this, What is necessary is just to be able to fix the fixing member 173a and the fixing member 174a. Further, the fastening means for fixing the fixing member is not limited to the screw, and can be appropriately changed. That is, the holes are not limited to screw holes and can be changed as appropriate.

  Since the fixing member 173a can be freely removed, a plurality of sheet pressing members having different shapes and materials can be applied to the sheet pressing portion, and the replacement thereof is easy. That is, it is possible to select an optimal sheet pressing member corresponding to the sheet. In addition, with the above configuration, it becomes easy to replace an aging sheet pressing member.

  The hole 174c of the fixing member 174a for fixing the fixing member 173a is a substantially arc-shaped long hole centered on the hole 174b. Therefore, when fixing the fixing member 173a to the fixing member 174a, the fixing member 173a can freely rotate within the range of the arc length of the hole 174c with the hole 173b as the center of rotation. That is, the fixing with the screw 211 can be freely determined within the range of the arc length of the hole 174c. As a result, the sheet pressing member 161 fixed to the fixing member 173a also rotates in the sheet pressing member rotation direction 204, so that the angle can be freely set within the range of the arc length of the hole 174c. Further, the feed amount of the sheet pressing member 161 can be freely set by changing the pulse amount by a stepping motor (not shown).

  In FIG. 10, an example in which the sheet pressing member 161 is applied to the sheet pressing portion has been described. However, the shape of the sheet pressing member is not particularly limited, and is, for example, the sheet pressing member 162 of the second embodiment. Also good. That is, it is possible to select an optimal sheet pressing member corresponding to the sheet. Moreover, although FIG. 10 gave and demonstrated the example provided with two fixing members, it is not limited to this.

  According to this embodiment, the shape and material of the presser member can be freely exchanged, so that it is possible to prevent flap lifting corresponding to a wider range of sheet characteristics and folding modes, and the angle of the presser member Therefore, it becomes possible to freely adjust the amount of push-in, to prevent functional loss and variation due to machine differences, and to realize more stable prevention of flap lifting.

  Although the present invention has been specifically described based on the preferred embodiments, the present invention is not limited to the above-described sheet processing apparatus and image forming apparatus, and various modifications can be made without departing from the scope of the invention. Needless to say.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Paper feeding apparatus 3 Paper feeding apparatus 4 Sheet post-processing apparatus 100 Sheet processing apparatus 101 1st conveyance path 102 2nd conveyance path 103 3rd conveyance path 104 4th conveyance path 104a Guide member 104b Guide member 104c Guide member 104d Guide member 105 5th conveyance path 106 6th conveyance path 107 7th conveyance path 108 8th conveyance path 109 9th conveyance path 111 1st folding roller 112 2nd folding roller 113 3rd folding roller 114 4th folding roller 115 1st Folding roller 116 Folding roller 117 Folding roller 121 First switching claw 122 Second switching claw 123 Third switching claw 124 Fourth switching claw 131 Sheet storage portion 141 First stopper 142 Second stopper 143 Third stopper 144 Stopper 151 Additional folding Mechanism 161 Sheet pressing member 162 C Gripper member 171 Fixing part 172 Fixing part 173a Fixing member 173b Hole 173c Hole 174a Fixing member 174b Hole 174c Hole 181a Rack 181b Gear pulley 181c Timing belt 181d Motor 191 Sheet 192 Long sheet end 193 Seat end 193 201 Sheet conveying direction 202 Sheet pressing member moving direction 203 Folding roller rotating direction 204 Sheet pressing member rotating direction 211 Screw

JP 2004-352421 A JP 2004-189453 A

Claims (8)

Folding means for imparting folding to the sheet;
A sheet conveying path having a guide member for guiding the sheet to the folding means;
Stopper means for determining the folding position of the sheet;
Sheet pressing means provided opposite to the folding means,
The sheet pressing means includes a sheet pressing member, a fixing means for fixing the sheet pressing member, the sheet pressing member and the fixing means with respect to the opposing folding means and a guide member that forms the sheet conveyance path. Driving means for driving to press,
The sheet pressing member can be elastically deformed along the shape of the folding means and the guide member of the sheet conveying path, and the elastic member has a surface frictional force that allows the sheet to slide in the deformed state. A sheet processing apparatus.   The sheet processing apparatus according to claim 1, wherein a length of the sheet pressing member in a sheet conveying direction is equal to or longer than a length of a sheet conveyed in the sheet conveying path.   The shape of the sheet pressing member is such that when the sheet pressing means is driven to press the sheet, the pressing starts from the sheet end surface, and the pressing gradually proceeds toward the center of the sheet. The sheet processing apparatus according to claim 1 or 2.   4. The sheet processing apparatus according to claim 1, wherein a shape of the sheet pressing member is a shape in which a substantially central portion of a surface pressing the sheet is recessed. 5.   The sheet processing apparatus according to claim 1, wherein the sheet pressing member is detachable.   The fixing means is capable of adjusting an amount of movement of the sheet pressing member in the folding means direction and an angle of the sheet pressing member with an axis parallel to the width direction of the sheet bundle as a rotation axis. Item 6. The sheet processing apparatus according to any one of Items 1 to 5. The fixing means includes a fixing member, and fastening means that are inserted into a plurality of holes provided in the fixing member and fix the fixing member and the sheet pressing member.
At least one of the holes is a substantially arc-shaped slot,
The sheet processing apparatus according to claim 1, wherein the fixing position by the fastening means can be adjusted within a range of the length of the substantially arc shape.   An image forming apparatus comprising the sheet processing apparatus according to claim 1.

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