JP2015151247A - Sheet folding apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to properly fold a paper sheet with the paper sheet placed in position when folding the paper sheet by guiding a loop portion of the paper sheet to between nip parts of paired folding rollers.SOLUTION: When a loop portion of a paper sheet S is guided to between nip parts of paired folding rollers 14a, 14b to fold the sheet, upstream transfer means 11a, 11b and downstream transfer means 12a, 12b are controlled by a control unit 20 to transfer the sheet beyond the folding rollers to a predetermined position and to control the amount of loop formed between the folding rollers. When a predetermined amount of loop is formed, the upstream transfer means and downstream transfer means are stopped. With this state kept, a pressing member 15 is moved to between the folding rollers, and the pressing member is used to press the loop portion of the sheet formed between the folding rollers, toward the nip parts of the folding rollers.

Description

  The present invention relates to a sheet folding apparatus that folds a sheet at a predetermined position and an image forming apparatus including such a sheet folding apparatus. In particular, a paper loop is formed in the vicinity of a pair of folding rollers that are rotationally driven, and the paper loop portion is pushed toward the nip portion of the folding roller by a pressing member, and the paper loop portion is rotationally driven. In a paper folding device that folds paper by guiding it to the nip part of the roller, even when various types of paper with different basis weights, etc., or when environmental conditions change, the paper is properly placed in the specified position. It has a feature in that it can be folded.

  Conventionally, a sheet is folded at a predetermined position by a sheet folding device. For example, when a booklet or the like is formed, an image is formed on a large size sheet by an image forming apparatus such as a copying machine, and then the sheet The large sheet is folded at a predetermined position by a folding device.

  Here, as such a sheet folding device, for example, in Patent Document 1, the sheet is directed toward the folding roller by an upstream conveyance roller provided upstream of the pair of folding rollers in the sheet conveyance direction. In a state where the paper is transported and passed over the folding roller to a predetermined position, the paper is stopped by the brake means provided downstream of the folding roller in the paper transport direction. A paper is proposed in which the paper is conveyed toward the folding roller by a roller, a paper loop is formed in the vicinity of the folding roller, and the formed paper loop is guided to the nip portion of the folding roller to fold the paper. Has been.

  However, when a paper loop is formed between the folding rollers in this way, the state of the paper loop to be formed is not constant. For example, depending on the type of paper, basis weight, environmental conditions, etc. The shape of the loop formed is different, and in this state, when the paper is folded by guiding the loop portion of the paper to the nip part of the pair of folding rollers that are rotationally driven, the folding position of the paper becomes unstable, especially There is a problem that the folding position is different between a thick sheet having a large basis weight and high rigidity and a thin sheet having a small basis weight and low rigidity.

  In Patent Document 2, the upstream conveyance roller provided upstream of the pair of folding rollers in the conveyance direction of the sheet conveys the sheet beyond the folding roller and waits for the leading edge of the sheet at a predetermined position. After stopping the conveyance of the paper by making contact with the stopper member, the upstream-side conveyance roller is opened, and in this state, the sheet is retracted to a position facing the folding roller via the paper. There has been proposed a structure in which a pressing member that has been moved is moved toward a folding roller, and the paper at a position facing the folding roller is pushed into a nip portion of the folding roller to fold the paper.

  However, if the upstream conveying roller is opened with the leading edge of the paper in contact with the stopper member as described above, the paper will bend due to the weight of the paper, and the like. The state varies depending on the type, basis weight, environmental conditions, etc. of the paper.In this state, if the paper is folded by pushing the paper into the nip portion of the folding roller as described above, The folding position is not constant, and in particular, there is a problem that the folding position is different between a thick sheet having a large basis weight and high rigidity and a thin sheet having a small basis weight and low rigidity.

  Also, in Patent Document 2, as described above, the front end of the sheet is brought into contact with the stopper member to stop the conveyance of the sheet, and then the pressing member is moved toward the folding roller, and Also shown is that the sheet is guided to the nip portion of the folding roller by the pushing member while rotating the upstream conveying roller and feeding the sheet.

  However, in this case, if the speed at which the pressing member is moved toward the folding roller and the speed at which the upstream conveying roller is rotated to feed the paper are not set appropriately, the paper guided by the pressing member to the nip portion of the folding roller. This causes a problem that the sheet cannot be folded at an appropriate position.

JP 2000-44115 A JP 2004-99187 A

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems in a sheet folding apparatus that folds a sheet at a predetermined position.

  In the present invention, a paper loop is formed in the vicinity of the pair of folding rollers that are rotationally driven, and the loop portion of the paper thus formed is directed toward the nip portion of the folding roller by the pressing member. In the paper folding device that pushes and folds the paper by guiding the loop part of the paper to the nip part of the rotationally driven folding roller, when various types of paper with different basis weights are used, the environmental conditions change Even in this case, it is an object to enable the paper to be appropriately folded at a predetermined position.

  In the paper folding device according to the present invention, in order to solve the above-described problems, a pair of folding rollers that are driven to rotate and a paper that is provided upstream of the folding roller in the paper conveyance direction are provided. An upstream conveying unit that conveys the sheet toward the folding roller, a downstream conveying unit that conveys the sheet conveyed beyond the folding roller by the upstream conveying unit further downstream in the sheet conveying direction, and at least the upstream side A control device that controls the driving of the side conveying means and the downstream conveying means, and a pressing member that pushes the loop portion of the paper formed in the vicinity of the folding roller between the folding rollers, and the loop portion of the paper In the paper folding apparatus configured to fold at the nip portion of the rotationally driven folding roller, the control device controls the upstream conveying means and the downstream conveying means. The paper is transported to the predetermined position beyond the folding roller, and the loop amount of the paper formed in the vicinity of the folding roller is controlled. The side conveying means and the downstream conveying means are stopped, and in this state, the pressing member is moved toward the folding rollers, and the loop portion of the paper formed in the vicinity of the folding rollers is moved by the pressing members. It was pushed toward the nip part of the folding roller.

  When the loop portion of the paper is pushed toward the nip portion of the folding roller by the pressing member in a state where a predetermined amount of loop is formed in the vicinity of the folding roller in this way, the folding roller in a state where the paper loop portion is stable. It will be appropriately guided to the nip portion.

  In addition, with the paper loop portion formed near the folding roller as described above being pushed toward the nip portion of the folding roller by the pressing member, the upstream conveying means conveys the paper by the control device. And the downstream conveyance means is driven in the direction opposite to the paper conveyance direction to grow the paper loop portion, the paper loop portion is properly introduced into the nip portion of the folding roller. The sheet is folded at an appropriate position at the nip portion of the folding roller.

  Here, in the sheet folding apparatus according to the present invention, when the upstream side conveying unit and the downstream side conveying unit are controlled by the control unit as described above, the sheet is conveyed to a predetermined position beyond the folding roller. A paper detection device that detects the position of the paper conveyed by the upstream conveyance device and the downstream conveyance device, and based on the position of the paper detected by the paper detection device, the control device controls the upstream conveyance. By controlling the means and the downstream conveying means, the sheet can be conveyed to a predetermined position beyond the folding roller.

  In the paper folding apparatus according to the present invention, the upstream side conveying means and the downstream side conveying means are controlled by the control device as described above to convey the paper to the predetermined position beyond the folding roller, and to fold the paper. In controlling the loop amount of the paper formed in the vicinity of the roller, the downstream conveying means is stopped by the control device while the paper is conveyed to a predetermined position, while the upstream conveying means It is possible to control the loop amount of the paper formed in the vicinity of the folding roller by carrying the paper by a predetermined time.

  In the paper folding device according to the present invention, when the loop amount of the paper formed in the vicinity of the folding roller is controlled by the control device as described above, the loop amount of the paper to be formed is set according to the type of the paper. For example, in the case of a thick sheet having a large basis weight and a high rigidity, the loop amount of the sheet can be increased as compared with a thin sheet having a small basis weight and a low rigidity.

  In the paper folding device according to the present invention, when the surface of the pressing member that faces at least one of the folding rollers is formed on a curved surface corresponding to the outer peripheral surface of the folding roller, the paper is moved along the curved surface of the pressing member. The loop portion is properly guided between the pair of folding rollers.

  In the sheet folding device according to the present invention, a folding roller provided on the downstream side in the sheet conveying direction can be used as the downstream conveying unit.

  Further, the image forming apparatus according to the present invention is provided with the paper folding device as described above, and the image-formed paper is folded at an appropriate position by the paper folding device.

  In the sheet folding device of the present invention, the upstream conveying unit and the downstream conveying unit are controlled by the control device as described above to convey the sheet to the predetermined position beyond the folding roller, and the folding roller The amount of paper loop formed in the vicinity is controlled, and in a state where a predetermined amount of loop is formed, the control device stops the upstream conveying means and the downstream conveying means. The member is moved toward the folding roller, and the paper loop formed near the folding roller is pushed toward the nip of the folding roller by this pushing member, so the paper loop is stable. Thus, the sheet is appropriately guided to the nip portion of the folding roller, and various types of sheets can be appropriately folded at predetermined positions.

FIG. 3 is a schematic explanatory diagram illustrating an example in which a sheet post-processing apparatus including a sheet folding apparatus is attached to the image forming apparatus in the embodiment of the present invention. 1 is a schematic side view of a sheet folding device according to an embodiment of the present invention. FIG. 5A shows a process of folding a sheet using the sheet folding apparatus according to the embodiment, and FIG. 5A shows an upstream feed roller, a downstream feed roller, and a push member retracted to the upper side of the sheet conveyance path; FIG. 4B is a schematic side view showing a state in which the paper is conveyed by rotating the paper in the paper conveyance direction. FIG. Schematic side view showing a state in which a suitable loop is formed on the paper between the rollers. (C) is a state where a predetermined amount of loop is formed between the folding rollers, and the rotation of the upstream feed roller is stopped. (D) is a state in which rotation of the upstream feed roller and the downstream feed roller is stopped, the push member is rotated downward, and the tip of the push member is Fold the paper loop FIG. 4E is a schematic side view showing a state where the roller is guided to a position near the nip portion of the roller, and FIG. 5E is a state where the paper loop portion is guided to a position near the nip portion of the folding roller by a pressing member, and the upstream feed roller is moved to the paper Rotating in the transport direction of the paper and rotating the downstream feed roller in the direction opposite to the transport direction of the paper to grow the paper loop and showing the state in which the loop portion of the paper is guided to the nip portion of the folding roller Side view (F) is a schematic side view showing a state in which the paper loop portion is fed downward through the nip portion of the folding roller to fold the paper. In the paper folding apparatus according to the above embodiment, a step of further Z-folding the paper folded as shown in FIG. 3 is shown, and (A) shows a loop portion of the paper as shown in FIG. Is a schematic side view showing a state in which the sheet is fed downward through the nip portion of the folding roller to a predetermined position, and (B) stops the rotation of the upstream feeding roller and the downstream feeding roller from the state (A). In addition, a schematic side view showing a state in which the push member is rotated upward and retracted to the upper side of the sheet conveyance path. FIG. Rotating in the transport direction, folded up as described above and overlaid on the paper that exists between the downstream feed roller and folding roller, showing the state of feeding the paper toward the downstream feed roller while folding the paper General side , (D) is a schematic side view showing a state in which the folded sheet portion is guided to the downstream feed roller as shown in (C), and (E) is from the state of (D). Rotate the folding roller in the direction opposite to the direction of folding the paper, rotate the downstream feed roller in the paper transport direction, and fold the folded paper part between the downstream feed rollers of the paper. FIG. 6 is a schematic side view showing a state where paper is fed to the downstream side in the paper conveyance direction through the downstream side feed rollers. In the paper folding apparatus according to the above-described embodiment, a modification example using a pressing member in which the surface of the pressing member facing each folding roller is formed into a curved surface corresponding to the outer peripheral surface of each folding roller is shown. It is the schematic side view which showed the state which led the loop part of the paper to the nip part of the folding roller with the member. In the paper folding apparatus according to the above-described embodiment, a modification example in which a folding roller located downstream in the paper conveyance direction is used as one of the downstream conveyance means is shown. FIG. FIG. 5 is a schematic side view showing a state in which a sheet is conveyed downstream in the sheet conveyance direction by a folding roller and a downstream feed roller positioned downstream in the sheet conveyance direction in a state where the sheet is retracted to the upper side of the conveyance path; FIG. 7B is a schematic side view showing a state in which the paper is folded by guiding the loop portion of the paper to the nip portion of the folding roller in a state where the pushing member is rotated downward.

  Next, a sheet folding apparatus and an image forming apparatus according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. The sheet folding apparatus and the image forming apparatus according to the present invention are not limited to those shown in the following embodiments, and can be implemented with appropriate modifications within a range that does not change the gist thereof.

  In this embodiment, as shown in FIG. 1, a sheet post-processing device 3 is connected to an image forming apparatus 1 such as a copying machine via a horizontal conveyance unit 2. The sheet on which the image is formed is sent to the sheet post-processing apparatus 3 through the horizontal conveyance unit 2, and the sheet thus sent to the sheet post-processing apparatus 3 is provided in the sheet post-processing apparatus 3. The sheet is folded at a predetermined position by the sheet folding device.

  Here, in the sheet folding device 10 according to the embodiment of the present invention, as shown in FIG. 11b is provided, and downstream feed rollers 12a and 12b are provided as a pair of downstream transport means at a downstream position in the transport direction of the paper S, and the paper S is required by the upstream feed rollers 11a and 11b. It is made to convey to the said downstream side feed rollers 12a and 12b through between the guide members 13a and 13b provided through the space | interval.

  Further, between the upstream feed rollers 11a, 11b and the downstream feed rollers 12a, 12b, at a position below the transport path of the paper S transported between the guide members 13a, 13b, While the paired folding rollers 14a and 14b are provided, a push member 15 that is rotated around a fulcrum 15a is provided at a position above the conveyance path of the paper S that is conveyed between the guide members 13a and 13b. ing.

  Then, from the state in which the pressing member 15 is retracted on the upper side of the conveyance path of the sheet S, the pressing member 15 is rotated downward around the fulcrum 15a, and the introduction hole (provided in the upper guide member 13a) The leading end of the pressing member 15 is moved to a predetermined position in the vicinity of the nip portion of the paired folding rollers 14a and 14b on the lower side of the sheet S conveyance path.

  Here, in the pressing member 15, the tip end portion is formed at an acute angle, and the pressing member 15 is rotated downward to move to a predetermined position near the nip portion of the paired folding rollers 14a and 14b. In this case, the surface of the pressing member 15 facing the folding roller 14a on the upstream side in the transport direction of the paper S is formed into a curved surface corresponding to the outer peripheral surface of the folding roller 14a on the upstream side in the transport direction of the paper S. Yes.

  Further, the paper detection device 16 is provided at a position downstream of the downstream feed rollers 12a and 12b in the transport direction of the paper S, and is transported between the guide members 13a and 13b by the downstream feed rollers 12a and 12b. The paper S to be detected is detected by the paper detection device 16 through a detection hole (not shown) provided in the upper guide member 13a.

  Further, in the paper folding device 10, the result detected by the paper detection device 16 is output to the control device 20, and the upstream feed rollers 11a and 11b and the downstream feed are controlled by the control device 20. The rotations of the rollers 12a and 12b and the folding rollers 14a and 14b are controlled, and the rotation of the pressing member 15 is controlled.

  Here, in the paper folding device 10 in this embodiment, when the paper S is folded at an appropriate position, as shown in FIG. 3A, the control member 20 rotates the pressing member 15 upward. With the pushing member 15 retracted to the upper side of the transport path of the paper S, the upstream feed rollers 11a and 11b and the downstream feed rollers 12a and 12b are rotated in the transport direction of the paper S, and the paper S A sheet fed from the upstream feed rollers 11a and 11b to the downstream feed rollers 12a and 12b through the guide members 12a and 12b and guided to the downstream side in the transport direction of the paper S from the downstream feed rollers 12a and 12b. S is detected by the paper detection device 16 described above.

  When the paper S is detected by the paper detection device 16 as described above, the result is output to the control device 20, and the control device 20 causes the upstream feed rollers 11a and 11b and the downstream feed rollers to be output. As shown in FIG. 3B, the rotation of the downstream feed rollers 12a and 12b is stopped when the sheet S is fed to a predetermined position, as shown in FIG. The upstream feed rollers 11a and 11b are continuously rotated to feed the paper S toward the folding rollers 14a and 14b, and a loop is formed on the paper S in the vicinity of the folding rollers 14a and 14b. .

  In addition, as a result of rotating only the upstream feed rollers 11a and 11b for a predetermined time in a state where the rotation of the downstream feed rollers 12a and 12b is stopped in this way, a predetermined amount of loop is formed in the vicinity of the folding rollers 14a and 14b. When formed, as shown in FIG. 3C, the rotation of the upstream feed rollers 11a and 11b is stopped. Here, as described above, the control device 20 stops the rotation of the downstream feed rollers 12a and 12b and changes the time for rotating only the upstream feed rollers 11a and 11b, thereby changing the folding rollers 14a and 14b. The amount of loop formed in the vicinity can be changed. For example, when the paper S is a thick paper having a large basis weight and a high rigidity, it is upstream compared to a thin paper having a small basis weight and a low rigidity. By increasing the time for rotating only the side feed rollers 11a and 11b, the loop amount of the paper S formed in the vicinity of the folding rollers 14a and 14b can be increased.

  Then, in the state where a predetermined amount of loop is formed in the vicinity of the folding rollers 14a and 14b in this way, as shown in FIG. 3D, the control device 20 rotates the push member 15 downward. Then, the pushing member 15 pushes the loop portion of the sheet S toward the folding rollers 14a and 14b, and the pushing portion 15 makes the sharp end of the pushing member 15 push the loop portion of the sheet S to the nip of the folding rollers 14a and 14b. To the position near the part. In this way, even if the loop of the paper S is formed at a position away from the nip portion of the folding rollers 14a and 14b, the loop portion of the paper S is pushed by the tip of the pressing member 15 at an acute angle. Thus, the loop portion of the paper S is appropriately guided to a position near the nip portion of the folding rollers 14a and 14b.

  Next, as shown in FIG. 3E, the upstream feed rollers 11a and 11b are rotated in the transport direction of the paper S by the control device 20, and the paper S is directed toward the folding rollers 14a and 14b. On the other hand, the downstream-side feed rollers 12a and 12b are rotated in the direction opposite to the transport direction of the paper S, and the paper S sent to a predetermined position is sent back to the folding rollers 14a and 14b. In the direction in which the folding rollers 14a and 14b are folded by guiding the loop portion of the paper S to the nip portion, in the example shown in the figure, The loop portion is rotated in the direction of feeding downward through the nip portions of the folding rollers 14a and 14b.

  Then, as described above, the upstream feed rollers 11a and 11b are rotated in the transport direction of the paper S, the downstream feed rollers 12a and 12b are rotated in the direction opposite to the transport direction of the paper S, and the folding rollers 14a and 14b are rotated in the paper S. The loop portion of the sheet S is guided to the nip portion and rotated in the folding direction, and the loop portion of the sheet S is sent downward through the nip portions of the folding rollers 14a and 14b as shown in FIG. To. In this way, even if the type of the paper S is a thick paper having a large basis weight and a high rigidity, or a thin paper having a low basis weight and a low rigidity, the loop portion of the paper S has the folding rollers 14a and 14b. Accordingly, the sheet S is appropriately guided to the nip portion of the sheet S, and the sheet S can be folded at an appropriate position.

  Further, a case will be described in which the sheet S is folded at an appropriate position and then the sheet S is folded at another position and the sheet S is Z-folded.

  Here, when the sheet S is Z-folded, as shown in FIG. 3F, the loop portion of the sheet S is replaced with the nip portion of the folding rollers 14a and 14b as shown in FIG. Through a predetermined length.

  Then, when the loop portion of the sheet S is fed downward by a predetermined length through the nip portions of the folding rollers 14a and 14b in this way, as shown in FIG. The upstream side feed rollers 11a and 11b, the downstream side feed rollers 12a and 12b, and the folding rollers 14a and 14b are stopped from rotating, and the push member 15 is rotated upward so that the push member 15 is transported along the sheet S. Evacuate to the upper side.

  Next, in a state where the rotation of the downstream feed rollers 12a and 12b and the folding rollers 14a and 14b is stopped, the control device 20 causes the upstream feed rollers 11a and 11b as shown in FIG. Only the sheet S is rotated in the transport direction of the sheet S, and the sheet S is fed toward the downstream feed rollers 12a and 12b. In this way, the fed paper S is folded while being folded as described above so as to be overlapped on the paper S existing between the downstream feed rollers 12a, 12b and the folding rollers 14a, 14. It is fed toward the side feed rollers 12a and 12b.

  Then, the paper S is fed toward the downstream feed rollers 12a and 12b while being folded so as to overlap the paper S existing between the downstream feed rollers 12a and 12b and the folding rollers 14a and 14, As shown in FIG. 4D, the folded portion of the sheet S is guided between the downstream feed rollers 12a and 12b.

  When the folded portion of the sheet S is guided between the downstream feed rollers 12a and 12b in this way, the control device 20 causes the upstream feed roller as shown in FIG. 4 (E). With the rotation of the folding rollers 14a and 14b in the direction opposite to the folding of the paper S in the state in which the rotation of the paper S is continued in the state in which the rotation of the paper S is continued, the downward movement through the nip portion of the folding rollers 14a and 14b The sheet S fed to the sheet is fed in a direction to return upward through the nip portions of the folding rollers 14a and 14b, and the downstream feed rollers 12a and 12b are rotated in the conveying direction of the sheet S. In this way, the folded portion of the sheet S is folded at the nip portion of the downstream side feed rollers 12a and 12b, while the sheet S passes between the downstream side feed rollers 12a and 12b, and the downstream side in the transport direction of the sheet S. Will be sent to.

  As a result, the paper S is formed with folds by the folding rollers 14a and 14b and folds by the downstream feed rollers 12a and 12b, and the paper S is Z-folded.

  In this embodiment, as the pressing member 15, only the surface of the pressing member 15 facing the folding roller 14a on the upstream side in the transport direction of the paper S is the outer peripheral surface of the folding roller 14a on the upstream side in the transport direction of the paper S. A correspondingly curved surface is used, but as shown in FIG. 5, the pressing member 15 is rotated downward so that a predetermined value near the nip portion of the paired folding rollers 14a and 14b is obtained. When moved to the position, the surface of the pressing member 15 facing the folding rollers 14a and 14b can be formed into a curved surface corresponding to the outer peripheral surface of the folding rollers 14a and 14b.

  Then, using the pressing member 15, the upstream feed rollers 11a and 11b are rotated in the transport direction of the paper S as described above, while the downstream feed rollers 12a and 12b are rotated in the direction opposite to the transport direction of the paper S. When the loop portion of the sheet S is guided to the nip portion of the folding rollers 14a and 14b, along the surface of the pressing member 15 formed on the curved surface corresponding to the outer peripheral surface of each of the folding rollers 14a and 14b, The loop portion of the sheet S is appropriately guided to the nip portion of the folding rollers 14a and 14b.

  Further, in this embodiment, as the downstream conveying means, the downstream feeding rollers 12a and 12b are provided on the downstream side in the conveying direction of the sheet S from the folding rollers 14a and 14b, separately from the folding rollers 14a and 14b. However, as shown in FIGS. 6A and 6B, the folding roller 14b located on the downstream side in the transport direction of the paper S is used as one of the downstream transport means so as to face the folding roller 14b. It is also possible to provide only one downstream feed roller 12a.

  When the folding roller 14b positioned on the downstream side in the transport direction of the sheet S is used as one of the downstream transport units, the sheet S is fed by the folding roller 14b and the downstream feed roller 12a. When transporting the sheet S downstream in the transport direction, as shown in FIG. 6A, the folding rollers 14a and 14b are rotated in a direction opposite to the direction in which the loop portion of the sheet S is folded to the nip portion. The folding roller 14b and the downstream feed roller 12a are rotated in the transport direction of the paper S, and the paper S is transported downstream in the transport direction of the paper S by the folding roller 14b and the downstream feed roller 12a. Like that. On the other hand, when the paper S is folded by guiding the loop portion of the paper S to the nip portions of the folding rollers 14a and 14b, the downstream-side feed roller 12a is rotated in the direction opposite to the conveyance direction of the paper S, and The folding rollers 14a and 14b are rotated in the folding direction by guiding the loop portion of the paper S to the nip portion, and the loop portion of the paper S is guided to the nip portion of the folding rollers 14a and 14b, and the nip of the folding rollers 14a and 14b. The sheet S is folded through the portion and folded.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Horizontal conveyance unit 3 Paper post-processing apparatus 10 Paper folding apparatus 11a, 11b Upstream feed roller (upstream conveyance means)
12a, 12b downstream feed roller (downstream transport means)
13a, 13b Guide member 14a Folding roller on the upstream side in the paper transport direction, 14b Folding roller on the downstream side in the paper transport direction (downstream transport means)
15 Pushing member, 15a fulcrum 16 Paper detection device 20 Control device S Paper

Claims (8)

  A pair of folding rollers that are rotationally driven, an upstream conveying unit that is provided upstream of the folding roller in the sheet conveying direction and conveys the sheet toward the folding roller, and the upstream conveying unit. A downstream conveying unit that further conveys the sheet conveyed beyond the folding roller to the downstream side in the sheet conveying direction; a control device that controls at least the driving of the upstream conveying unit and the downstream conveying unit; and the folding unit. A paper folding apparatus comprising: a pressing member that pushes a loop portion of the paper formed in the vicinity of the roller toward the folding roller, wherein the paper loop portion is folded at a nip portion of a folding roller that is rotationally driven. The control device controls the upstream conveying means and the downstream conveying means to convey the paper to the predetermined position beyond the folding roller, The loop amount of the paper formed in the vicinity of the roller is controlled, and with the predetermined amount of loop formed, the upstream conveying unit and the downstream conveying unit are stopped by the control device, and in this state, A paper folding apparatus characterized in that the pressing member is moved toward the folding roller, and a loop portion of the paper formed in the vicinity of the folding roller is pushed toward the nip portion of the folding roller by the pressing member. .   The paper folding device according to claim 1, wherein the pressing member is moved toward the folding roller, and the loop portion of the paper formed in the vicinity of the folding roller is moved to the nip portion of the folding roller by the pressing member. In the pressed state, the control device drives the upstream transport means in the paper transport direction, and drives the downstream transport means in a direction opposite to the paper transport direction. A paper folding device for folding a paper by guiding a loop portion of the paper between nip portions of folding rollers.   The sheet folding device according to claim 1 or 2, further comprising a sheet detection device that detects a position of the sheet conveyed by the upstream conveyance unit and the downstream conveyance unit, and is detected by the sheet detection device. A sheet folding device characterized in that the control unit controls the upstream-side conveyance unit and the downstream-side conveyance unit based on the position of the sheet, and conveys the sheet to a predetermined position beyond the folding roller. .   The paper folding device according to any one of claims 1 to 3, wherein the control device controls the upstream conveying means and the downstream conveying means so that the paper is predetermined beyond the folding roller. In order to control the loop of the paper formed in the vicinity of the folding roller while transporting to the position, while the paper is transported to a predetermined position, the control device stops the downstream transport means, The sheet folding apparatus is characterized in that the sheet is conveyed by the upstream conveying means for a predetermined time to control the loop amount of the sheet formed in the vicinity of the folding roller.   5. The sheet folding device according to claim 1, wherein the control device controls the loop of the sheet formed in the vicinity of the folding roller according to the type of the sheet. A paper folding device characterized in that the amount of paper loop to be changed is changed.   6. The sheet folding device according to claim 1, wherein a surface of the pressing member facing the at least one folding roller is a curved surface corresponding to an outer peripheral surface of the folding roller. A sheet folding apparatus characterized by the above.   7. The image forming apparatus according to claim 1, wherein a folding roller provided on a downstream side in a sheet conveyance direction is used as the downstream conveyance unit. 8. .   An image forming apparatus comprising the sheet folding device according to claim 1.

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