JP5834513B2 - Paper processing apparatus and image forming system - Google Patents

Description

  The present invention relates to a paper processing apparatus and an image forming system, and in particular, paper processing for performing predetermined processing on a sheet-like recording medium (hereinafter referred to as paper) such as paper, transfer paper, printing paper, and OHP sheet. The present invention relates to an image forming system including the apparatus and the sheet processing apparatus, and an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a digital multifunction peripheral.

  In an image forming system including a sheet processing apparatus and an image forming apparatus, an image is formed on a sheet by the image forming apparatus, and punching, alignment, and binding are performed on a sheet on which the image is formed according to a user's request. So-called post-processing such as folding can be performed. Since the post-processing is executed by the paper processing device, this type of paper processing device is called a paper post-processing device. Hereinafter, the sheet post-processing apparatus will be described.

  One such post-processing is saddle stitch binding. Saddle-stitch bookbinding is performed by performing saddle-stitching processing that binds at the center of the sheet of the binding and center-folding processing that folds into two at the center-stitched position, and performs bookbinding in the shape of a weekly magazine. is there. In the saddle stitch bookbinding, the paper post-processing process after image formation is performed in the order of a bundle aligning process, a saddle stitching process, a center folding process, and a paper discharge process. There are post-processing machines that process in the order of the folding process, bundle aligning process, binding process, and paper discharge process. However, when folding paper is transported and aligned in a bundle, the crease becomes a transport resistance and neatly aligns. This is difficult, and in order to bind the center of the folded paper once, a machine space such as a hooking method becomes large. Therefore, the former process is generally performed in which the folding process is performed after the binding process.

  When such a process is performed, only the process of stacking sheets that have undergone saddle stitching is stacked downstream after the folding process, so there is no problem even if there is a large drive mechanism on the downstream side in the folding mechanism. However, in order to perform the saddle stitching process on the upstream side before the folding process, a space for arranging the saddle stitching stapler on the transport path is necessary.

  FIG. 10 is a view showing the arrangement of the press folding plate and the saddle stitching stapler. 10A is an example in which drive mechanisms are provided on the upstream side and downstream side of the middle folding blade with reference to the vertical conveyance path, and FIG. 10B is an example in which a drive mechanism is provided on the upstream side of the middle folding blade. 10 (c) shows an example in which a drive mechanism is provided on the downstream side of the center folding blade. In saddle stitching, stapling and folding are performed at the same position and folded at the binding position. For this reason, if the saddle stitching stapler 8 is disposed at a position away from the center folding unit (the center folding blade 1, the pair of conveying rollers 2, and the press folding plates 3 and 4 on both upper and lower sides), the conveying distance from binding to folding becomes longer. (Distance L1), productivity deteriorates. In addition, when the number of sheets is large, for example, when binding a bundle of 20 sheets or more, it is necessary to transport 20 sheets or more at once. However, when the number of sheets is large, the sheet is inclined during transportation. In some cases, the consistency of the paper may be lost. Even if it is tilted in this way or the consistency is lost, it is folded in two in the subsequent process, so that it is folded obliquely or the paper is displaced and folded, leading to a decrease in folding quality. For reference numerals in the parentheses, see FIG. 1 described later.

  On the other hand, as such an apparatus, for example, an invention described in Patent Document 1 (Japanese Patent Laid-Open No. 2010-006602) is known. The present invention relates to a saddle stitch folding apparatus that creates a saddle stitch folded booklet by binding a sheet bundle at the center and folding it in two at a bound position, thereby efficiently creating a saddle stitch folded booklet with a strong fold. Is to do. In the present invention, on the downstream side of the folding portion that folds the bound sheet bundle in two, the fold of the folded paper bundle has a pressing portion that sandwiches the pressing surface from the front and back with the mutually facing pressing surfaces, The number of presses and the press operation are controlled so that the crease is surely strengthened even when the number of sheets is large.

  In an apparatus that performs saddle stitching and center folding with such a configuration, as a requirement to increase the productivity of saddle stitching processing and to prevent the folding quality of the center folding from being deteriorated, the sheet moving time between each process is set as a requirement. It is effective to shorten it. Here, shortening the sheet moving time between the steps corresponds to shortening the distance between the center folding step and the saddle stitching step (distance L2), and shortening the distance L1 as the distance L2. It can be seen that the length of the upstream conveyance path before the folding process may be shortened. That is, shortening the distances from L1 to L2 is effective for improving productivity and preventing deterioration of folding quality.

  However, in the invention described in Patent Document 1, although a crease can be surely attached, the sheet conveyance distance from the binding by the stapler to the folding becomes longer, and the saddle stitching process takes a long time. Therefore, the productivity problem has not been solved. Moreover, since the conveyance distance is long, the problem of folding quality degradation has not been solved.

  Therefore, the problem to be solved by the present invention is to improve the productivity of the middle folding process and to prevent the deterioration of folding quality.

In order to solve the above-mentioned problems, the present invention provides a pushing means for pushing the folded portion into a nip of a pair of conveying rollers while striking a folded portion of a bundle of stacked sheets conveyed along a first conveying path from the sheet surface side. A pair of pressure plates in which the upstream side of the first transport direction, which is the transport direction of the first transport path to the folding position of the sheet, is set to the fixed side and the downstream side is set to the movable side, and A second conveying unit that includes a driving unit that movably drives the pressure plate with respect to the fixed-side pressure plate and that is in the conveying direction of the second conveying path along the driving direction of the pushing unit of the conveying roller pair; pressurizing said folded portion at the downstream side in the direction, and pressure means for creasing on the folded portion, a position adjacent the pressure plates of the stationary side than said pressure plate of said fixed side said first upstream side first Setting the conveying path of vignetting, the a binding unit for binding the sheet bundle, the branches in a direction perpendicular from the first conveying path, a parallel to the second conveying direction of the sheet bundle, the A pair of guide portions for guiding the sheet bundle pushed by the pushing means between the fixed side and movable side pressure plates, and the pair of guide portions are installed at a preset interval, The surface of the fixed-side pressure plate that contacts the sheet virtually includes the guide portion on the fixed-side pressure plate side of the pair of guide portions and the conveyance center of the second conveyance path. Between the two planes extending in parallel to the transport direction of the two, located closer to the transport center than the guide portion on the fixed pressure plate side, and the second of the fixed pressure plate. Shaped with an open end on the upstream side in the transport direction Characterized in that it is.

  According to the present invention, productivity of the middle folding process can be improved, and deterioration of folding quality can be prevented.

It is a figure which shows the half-folding unit in the paper processing apparatus which concerns on embodiment of this invention. It is operation | movement explanatory drawing which shows the operation | movement of the middle folding process in a middle folding unit. It is operation | movement explanatory drawing which shows the operation | movement which a lower side press folding plate moves to a conveyance direction, and changes a pressurization point. It is operation | movement explanatory drawing which shows the pressurization operation | movement when a lower press folding plate is comprised with the curved board | plate material, and the state of a paper bundle. FIG. 10 is an operation explanatory diagram illustrating a pressing operation and a sheet bundle state when a horizontal portion is provided on the upstream side in the sheet bundle conveying direction of the lower press folding plate and a curved portion is provided on the downstream side. It is operation | movement explanatory drawing which shows the pressurization operation | movement in case an upper press folding plate is planar, and the state of a sheet bundle. It is operation | movement explanatory drawing which shows the pressurization operation | movement at the time of providing a guide part in an upper press folding plate, and the state of a sheet bundle. 1 is a block diagram illustrating a control configuration of an image forming system including a sheet post-processing apparatus and an image forming apparatus according to an embodiment of the present invention. 6 is a flowchart illustrating a processing procedure in a saddle stitch bookbinding mode executed by the sheet post-processing apparatus. It is a figure shown about arrangement | positioning of a press folding plate and a saddle stitch stapler.

  In the present invention, when folding a bundle of sheets bound at the center in the transport direction, the upper press folding plate is fixed, and the lower press folding plate is provided movably with respect to the upper press folding plate. It is characterized in that the interval and the applied pressure are variable.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a view showing a half-folding unit in a sheet post-processing apparatus according to an embodiment of the present invention. In the figure, the center folding unit includes a center folding blade 1, a transport roller pair 2, an upper press folding plate 3, a lower press folding plate 4, a press folding plate drive mechanism 5, a vertical transport path 6, and a folding transport path 7. Basically composed.

  The middle folding blade 1 and the conveying roller pair 2 are arranged on both sides in the drawing with the vertical conveying path 6 interposed therebetween. The middle folding blade 1 is movable in the horizontal direction, and the leading end 1a advances to at least the nip of the conveying roller pair 2 and retracts to a position where the vertical conveying path 6 is opened. The advance and retreat operations are performed by a motor (not shown) and its power transmission mechanism. The state of FIG. 1 is the home position, and the hole position is detected by the home position sensor 9. The home position sensor 9 is a light transmission type optical sensor, and detects that the protruding piece 10 protruding from the center folding blade 1 blocks the optical path between the light emitting element and the light receiving element. The center folding blade 1 is set to a size that can be pushed into the nip of the conveying roller pair 2 by abutting against a sheet bundle having the maximum width (a direction orthogonal to the sheet conveying direction), and is formed in, for example, a comb shape.

  The conveyance roller pair 2 has a function of applying a predetermined load to the folded portion at a nip position when the folded portion of the sheet bundle enters the nip. Although not shown, the conveyance roller pair 2 is provided with a load applying mechanism that applies a predetermined load to the nip relatively. Examples of the load applying mechanism include a mechanism that elastically applies a load by an elastic member, a mechanism that applies a load by a motor and its driving force transmission mechanism, and a mechanism that combines the two. Further, a folding conveyance path 7 is provided on the downstream side of the conveyance roller pair 2 in the conveyance direction (horizontal direction in the present embodiment), and guides the sheet bundle to a paper discharge path (not shown) on the downstream side. The folding conveyance path 7 extends on the extension of the folding plate 1 in the advance direction.

  The folding conveyance path 7 is formed between the upper and lower press folding plates 3, 4 installed on the downstream side of the conveyance roller pair 2, and is bent in the folding direction guide plate 6 a from the vertical guide plate 6 c of the vertical conveyance path 6. , 6b extending downstream. The upper press folding plate 3 is fixed, and the lower press folding plate 4 is always provided with elastic members, such as tension springs 12a and 12b, which apply elastic force in the tension direction provided upstream and downstream in the conveying direction, and the lower side. The press folding plate drive mechanism 5 installed at the lower part of the press folding plate 4 is movable in the vertical direction in the figure. The lower ends of the tension springs 12a and 12b are hooked by hooks 5a and 5b protruding from the base of the press folding plate moving mechanism 5, and the upper ends are attached to a frame (not shown) of the paper post-processing device, and a tensile force is generated between them. It is supposed to be. Thereby, the lower press folding plate 4 is always pulled upward (arrow D1 direction) with respect to the fixed side. The press folding plate drive mechanism 5 includes a motor and its power transmission mechanism, and converts the rotational drive torque of the motor into a linear moving force in the vertical direction. Thereby, the lower press folding plate 4 can be moved downward (arrow D2 direction) against the elastic force of the tension springs 12a and 12b.

  FIG. 2 is an operation explanatory view showing the operation of the half-folding process in the half-folding unit configured as described above. As shown in FIG. 5A, the sheet is conveyed vertically downward along the vertical conveyance path 6, and the lower end of the sheet abuts against a stopper (not shown) and is stacked. Then, when the sheets P as many as the number of sheets to be bound are stacked as shown in FIG. 5B, the stacked sheet bundle PB has a saddle-stapling stapler 8 (see FIG. 10) at the binding position in the center in the transport direction. It moves by the movement of the stopper to the opposite position, and is saddle stitched by the saddle stitch stapler 8 at that position.

  After the end of saddle stitching, the stopper further descends and stops at a position where the binding portion PB1 faces the front end 1a of the center folding blade 1 as shown in FIG. At that position, the center folding blade 1 advances from the horizontal direction toward the binding portion (central portion in the transport direction) PB1 of the sheet bundle PB as shown in FIG. 4D, and enters the binding portion PB1 of the sheet bundle PB. The leading edge 1a hits and pushes into the nip of the conveying roller pair 2 while deforming the sheet bundle into a linear shape.

  The pushed sheet bundle PB is conveyed in a state where the folded portion (binding portion) PB1 of the sheet bundle PB is bent by the conveying roller pair 2 as shown in FIG. The sheet bundle PB conveyed in the bent state is guided to the folding conveying path 7 as shown in FIG. 5F and is guided to the pressing positions of the upper and lower press folding plates 3 and 4. At this position, as can be seen from the figure, the folded sheet bundle PB is released from the nip of the conveying roller pair 2 and swells. In this state, the press fold plate driving mechanism 5 operates to raise the lower press fold plate 4 on the drive side as shown in FIG. 5G, apply a predetermined pressure, and attach the fold PB2. The predetermined pressure is determined by press folding plate according to the paper information such as the number of paper bundles, paper thickness (weight), paper type (special paper such as coated paper, plain paper, recycled paper, non-pulp paper, etc.) A later-described CPU that controls the drive mechanism 5 is determined. The paper information is sent from the image forming apparatus side.

  When the pressurizing process by the upper and lower press folding plates 3 and 4 is completed, the lower press folding plate 4 descends as shown in FIG. Further, it is conveyed downstream. Then, as shown in FIG. 5 (i), the paper passes through the folding conveyance path 7 and is delivered to the downstream conveyance roller pair 11, and is further conveyed downstream from the conveyance roller pair 11. In this state, the folding portion (binding portion PB1) is pressurized with a predetermined pressure to form a fold line PB2, which is a good bookbinding state in which swelling is suppressed.

  As described above, since the press folding plate driving section 5 is provided at the lower portion of the lower press folding plate 4, a space for installing a mechanism corresponding to that is necessary, but the upper press folding plate 3 is fixed. Therefore, it is not necessary to provide a drive unit, and the space for that is not necessary. As a result, as shown in FIG. 10C, the saddle stitching stapler 8 can be brought closer to the side of the folding plate 1 where the driving unit is unnecessary, and the distance from the saddle stitching position to the middle folding position is set to L1. Can be shortened from L to L2.

  By the way, when the lower press folding plate 4 is flat as shown in FIG. 2, folding pressure is dispersed. This is self-evident when the load of the pressurizing portion is converted into a load per unit area. For this reason, the pressure applied to the fold line PB2 with respect to the applied load is reduced, so that the folded height of the folded sheet bundle PB is low, and so-called springback is generated in which the folding becomes sweet.

  Therefore, in the present embodiment, the lower press folding plate 4 is curved into a convex shape so that the pressing force from the press folding plate driving unit 5 is linearly concentrated on the folding portion of the sheet bundle PB. However, if the position shifted from the binding portion PB1 which is a folding portion is pressed, the fold line PB2 is not well formed in the sheet bundle PB, and the folding height increases. Therefore, the lower press folding plate 4 is moved in the conveying direction so that the folding pressure point moves. Thereby, the part used as the crease | fold PB2 of the folding part which is a desired pressurization position can be pressurized accurately. As a result, a beautiful fold line PB2 is reliably formed.

  FIG. 3 is an operation explanatory diagram illustrating an operation in which the lower press folding plate moves in the conveyance direction (arrow D3 direction) and changes the pressurizing point. The mechanism for moving the lower press folding plate 4 in the transport direction is shown in detail in FIG. In FIG. 1, the lower press folding plate 4 includes a flat portion 4a parallel to the upper press folding plate 3, and a curved portion 4b curved with respect to the upper press folded plate 3, and the curved portion 4b is formed from the flat portion 4a. Is also positioned downstream of the sheet bundle conveyance direction. The upper press folding plate 3 is provided with a guide portion 3a having a shape opened on the upstream side in the paper transport direction on the upstream side in the paper transport direction. A pressure shaft 13 is provided on the lower surface of the lower press folding plate 4 and moves in a direction (arrow D3 or D4 direction) parallel to the paper transport direction while being in contact with the lower surface of the lower press folding plate 4. Yes. The pressing shaft 13 is moved in the direction of the arrow D3 or D4 by a motor (not shown) and a moving mechanism driven by the motor.

  The lower surface 4c, 4d of the lower folding plate 4 is configured in parallel with the flat surface portion 4a and the curved portion 4b of the upper surface, and the pressing shaft 13 moves in contact with the movement guide 14a of the support plate 14. The movement is performed by rolling or sliding. When the pressing shaft 13 moves in the direction of arrow D3 from the parallel portion 4c in FIG. 1, it comes into contact with the curved portion 4d on the lower surface of the lower press folding plate 4 and pushes the curved portion 4d upward. As a result, the lower press folding plate 4 tilts and the contact point with the sheet bundle PB changes.

  On the other hand, pins 4e and 4f are provided at both ends of the lower press folding plate 4 so as to project in a direction perpendicular to the sheet bundle conveying direction. The pins 4e and 4f are slidably mounted in guide grooves 15a and 15b that define the posture of the lower press folding plate 4. The guide grooves 15a and 15b are fixed at the positions shown in FIG. 1, and when the pressure shaft 13 moves, the movement pins 4e and 4f are moved in the guide grooves 15a and 15b in a state where the movement range is restricted. These three elements define the movement trajectory of the lower press folding plate 4. Based on this movement locus, the horizontal position of the lower press folding plate 4 and the contact position of the curved portion 4b with the sheet bundle PB change. That is, the pressure position to the sheet bundle PB is changed from the initial position as shown in FIG. As a result, the sheet bundle PB is pressurized from the front side of the folding portion (binding portion PB1), and the initial first pressurizing point 16a moves in the transport direction (in the direction of arrow D3) to move the center of the sheet bundle that becomes the fold line PB2. Pressurization can be performed as the second pressurization point 16b.

  When the first pressurizing point 16a moves in the direction of the arrow D3 and pressurizes the second pressurizing point 16b, if the moving speed of the pressurizing shaft 13 is slowed, the lower press folding plate 4 moves the sheet bundle PB. The pressurizing time is longer. As a result, more energy is applied to the portion that becomes the fold line PB2 of the folded portion (binding portion PB1) of the sheet bundle PB, and the folding height can be reduced.

  FIG. 4 is an operation explanatory view showing an operation when the lower press folding plate is formed of a curved plate material. When the lower press folding plate 4 has an upwardly convex shape with the same curvature as shown in FIG. 4A, when pressurizing the sheet bundle PB, as shown in FIG. In the curved portion 4g, the sheet bundle PB may slide down along the curved inclined surface of the curved portion 4g, and the sheet bundle PB may escape from the pressure point of the sheet bundle PB. Therefore, in the present embodiment, as shown in FIGS. 1 and 5 described above, the upstream side of the lower press folding plate 4 is formed in a plane parallel to the upper press folding plate 3.

  Thus, when the flat portion 4a is provided on the upstream side of the lower press folding plate 4 and the curved portion 4b is provided on the downstream side, the paper bundle PB is fed along the curved inclined surface 4g as shown in FIG. 4B. The PB slides down and the sheet bundle PB does not escape from the pressing point.

  FIG. 6 is an operation explanatory view showing a pressurizing operation when the upper (fixed side) press-folding plate is flat (flat). As shown in FIG. 6A, when the upper press folding plate 3 is formed in a flat shape as shown in FIG. 6 and is arranged at a continuous position with respect to the downstream end of the folding direction guide plate 6a in the sheet conveying direction. In addition, the space between the upper press folding plate 3 on the fixed side and the portion where the folded portion of the sheet bundle PB is positioned is widened. Since folding is performed by pressing the sheet bundle PB against the upper press folding plate 3 on the fixed side, the folding position is shifted to the upper side from the transport center 7a as shown in FIGS. This deviation leads to a deviation of the fold line PB2 of the sheet bundle PB.

  In order to prevent this, the interval between the folding direction guides 6a and 6b, and hence the conveyance interval of the folding conveyance path 7 may be narrowed. However, when the sheet bundle PB is narrowed, the thickness is defined by the thickness of the sheet bundle PB, or the width of the sheet bundle is narrowed. When the sheet bundle PB is thick, a large number of sheets cannot be folded.

  Therefore, in the present embodiment, as shown in FIG. 1, a guide portion 3 a having a shape in which the upstream side in the sheet conveyance direction is opened upstream of the upper press folding plate 3 in the sheet conveyance direction. FIG. 7 is an operation explanatory view showing the pressurizing operation when the guide portion 3a is provided. When the guide portion 3a is provided in this way, the folded portion side of the sheet bundle PB can be guided by the guide portion 3a as shown in FIG. It becomes possible to position.

  FIG. 7A shows a state before the sheet bundle PB enters the same position as FIG. 6A and the pressing operation by the lower press folding plate 4 is performed. FIG. 7 shows the upper press in FIG. It can be seen that the lower surface 3u of the folding plate 3 is lowered to the position of 3u ′. This position is set to a position where the binding portion (folding portion) PB1 coincides with the transport center 7a in the pressurized state of FIG. 7B, and pressure is applied to the deflection of the sheet bundle PB at this position. . In FIG. 8C, final pressurization is performed, and a fold line PB2 is attached to the folded portion (binding portion PB1) of the sheet bundle. When the guide portion 3a is provided in this way, the upper press folding plate 3 can be arranged so that the fold line PB2 of the sheet bundle PB is positioned at the transport center 7a during the folding process, and therefore the binding portion PB1 at the center of the sheet bundle PB. It is possible to prevent the sheet bundle PB from being folded at a position shifted from the position.

  The folding direction guide plates 6a and 6b are formed in parallel with the flat portion of the upper press folding plate 3, and the contact surface of the upper press folding plate 3 with the sheet bundle PB is the sheet bundle conveying direction of the folding direction guide plates 6a and 6b. If it is located in virtual planes 3u, 3p parallel to (in the direction of arrow D1), the contact surface with the sheet bundle PB corresponding to the lower surface of the upper press folding plate 3 is added to the sheet bundle PB at a position closer to the sheet conveyance center 7a. I can press. At that time, the guide portion 3a is necessary for guiding the sheet bundle PB.

  FIG. 8 is a block diagram illustrating a control configuration of an image forming system including a sheet post-processing apparatus and an image forming apparatus in the present embodiment. In the figure, the control configuration in this embodiment includes an image forming apparatus PR and a sheet post-processing apparatus FR. The paper post-processing FR and the image forming apparatus PR are connected by a communication interface PR2, and notification of paper information, post-processing mode, abnormality information, and the like is performed bidirectionally, and control information from the image forming apparatus PR is also processed by paper post-processing The device FR is notified.

  The paper post-processing device FR is a control in which the CPU_FR2, CPU_FR2 that controls the entire paper post-processing device FR and each unit, and an I / O unit FR3 that controls input and output between each sensor, solenoid, motor, and other drivers are mounted. A circuit FR1 is provided. The CPU_FR2 develops a program code stored in a ROM (not shown) in a RAM (not shown), executes control according to the program defined by the program code while using the RAM as a work area and a data buffer, Operate each part through etc. A memory such as an EEPROM is also provided to hold data.

  The middle folding unit FU includes first and second motors FU1 and FU2, and a sensor FU3. The first motor FU1 is a motor for moving the lower press folding plate 4 in the vertical direction, and the second motor FU2 is a motor for moving the pressure shaft 13 of the lower press folding plate 4 in the horizontal direction. It is. The sensor FU3 is a sensor for detecting the position of the sheet bundle PB, and a plurality of sensors FU3 are provided although not shown in FIG.

  The control of the sheet post-processing apparatus FR in FIG. 8 is executed based on an instruction or information from the CPU of the image forming apparatus PR. The user's operation instruction is issued from the operation panel PR1 of the image forming apparatus PR, and the image forming apparatus PR and the operation panel PR1 are connected to each other via a communication interface PR2. As a result, the operation signal from the operation panel PR1 is transmitted from the image forming apparatus PR to the sheet post-processing apparatus FR, and the processing state and function of the sheet post-processing apparatus FR are notified to the user via the operation panel PR1. .

  When the control system of the image forming apparatus PR is configured in this way, the CPU_FR2 detects sheet information sent from the image forming apparatus PR side, sheet conveyance information, and detection output of the sensor FU3 provided in the sheet post-processing apparatus FR. Based on the above, the first motor FU1 and the second motor FU2 of the middle folding unit FU are controlled to perform the folding process of the sheet bundle. The sheet information includes the sheet size, the sheet thickness, the number of sheets in a bundle of sheets to be sorted (the number of sheets to be bound), and the like. The sheet post-processing device FR also includes an amplifier FU3a that amplifies the detection output from the motor drivers FU1a and FU2a and the sensor FU3 for driving the first and second motors 11 and 20 and outputs the amplified output to the CPU_FR2 side. As prepared.

  FIG. 9 is a flowchart showing a processing procedure in the saddle stitch binding mode executed by the sheet post-processing apparatus. In the saddle stitch binding mode, which is one of the processing modes executed by the paper post-processing apparatus FR, the paper bundle PB in which a plurality of papers P are aligned is bound at the center in the transport direction (saddle). Binding) is a mode of folding from the binding portion PB1 and folding it in half. This mode is entered and executed by the CPU_FR2 of the sheet post-processing apparatus FR when the user inputs an operation from the operation panel PR1 of the image forming apparatus PR.

  In the present embodiment, when this saddle stitch binding mode is executed, it is possible to set whether or not to lower the folding height. This setting is also input by the user from the operation panel PR1. In this processing procedure, first, the user selects the saddle stitch binding mode from the operation panel PR1 (step S1). Next, it is selected whether or not to lower the folding height (step S2). If the mode for lowering the folding height is not selected (step S2: NO), the normal saddle stitching middle folding is executed as it is. In the normal saddle stitching, the binding portion PB1 of the sheet bundle PB is pushed into the nip of the conveyance roller pair 2 by the middle folding blade 1 and a predetermined load is applied to the nip of the conveyance roller pair 2 to bend the sheet bundle PB. This means that the operation shown in FIG. 2 is performed in which the sheet is conveyed by the conveying roller pair 2 in a bent state, the lower press folding plate 4 is raised and pressurized, and discharged after releasing the pressure. Alternatively, when the pressing shaft 13 is moved as shown in FIG. 3, the pressing process by the lower press folding plate 4 is executed at a first speed so that productivity does not decrease.

  On the other hand, when the mode for lowering the folding height is selected in step S2 (step S2: YES), a process for increasing the pressing time by the lower press folding plate 4 and lowering the folding height is selected. (Step S3). In this process, the pressing time by the lower press folding plate 4 is lengthened during the middle folding process, so the moving speed of the pressing shaft 13 is slowed down, the folding part is sufficiently pressurized, and the folding height is kept low. The pressurizing process is executed at the second speed that can be performed (step S4).

  In this way, normal half-folding processing or half-folding processing that lowers the folding height can be selected according to user selection, so the former is used when productivity is important, and the quality of folding height after bookbinding is important If the latter is selected, saddle stitch binding according to the user's request becomes possible.

  The first and second speeds are stored in advance as a database (speed determination table) in the memory as data for setting these speeds. The CPU_FR2 refers to the speed determination table based on the sheet information regarding the sheet bundle SB to be bound, determines the moving speed of the pressure shaft 13, and drives the second motor FU2.

  The speed determination table changes various conditions such as the thickness of the paper to be bound (weighing), the paper size, the number of sheets to be bound, the paper type (plain paper, fine paper, special paper (coated paper, glossy paper, etc.), etc. The moving speed data of the pressure shaft 13 in which the PB2 is surely formed and the bulge of the folded portion is minimized is obtained in a laboratory, and this data is accumulated and tabulated. The decision table is stored in a memory such as an EEPROM, and is shipped from the factory while holding this table, and the CPU_FR 2b refers to the table based on the paper information notified from the CPU of the image forming apparatus PR and pressurizes it. The speed of the axis 13 is determined.

As described above, according to the present embodiment, the following effects can be obtained.
1) The upper press folding plate 3 is fixed, the lower press folding plate 4 is set so as to be movable in the vertical direction, and the sheet bundle PB is pressed by the lower press folding plate 4 toward the upper press folding plate 3 side. A drive mechanism for the press folding plate 4 is not required, and the conveyance distance in the vertical conveyance path can be shortened accordingly. As a result, it is possible to prevent an improvement in sheet processing productivity and a decrease in folding quality. In addition, it is possible to reduce the size and cost of the machine configuration of the apparatus.

2) The stapler can be placed on the shortened upstream transport path as the transport distance is shortened, shortening the transport distance from the binding processing position to the center folding position, and improving the productivity of the saddle stitching bookbinding process. Can be raised.

3) Since the shape of the lower press folding plate 4 is curved and the lower press folding plate 4 moves parallel to the conveyance direction of the sheet bundle PB, the sheet is linearly formed at the contact portion of the curved surface instead of the surface. The fold line PB2 portion of the folded portion (binding portion PB1) of the bundle PB can be pressurized. As a result, it is possible to prevent springback of the folded sheet bundle PB.

4) The shape of the lower press folding plate 4 has a flat portion 4a on the upstream side and a curved portion 4b on the downstream side, and the sheet bundle PB is folded by the conveying roller pair 2 so that the upper and lower press folding plates 3, 4, after the leading end of the folded portion (the leading end of the binding portion PB1) of the sheet bundle PB passes over the flat portion 4a and reaches the curved portion 4b, the conveyance of the sheet bundle PB is stopped, and the lower press folding plate 4 is raised to pressurize the sheet bundle PB at the plane portion 4a and the plane portion of the upper press folding plate 3, and then the lower press folding plate 4 is moved in the conveying direction of the sheet bundle PB to move the sheet bundle at the bending portion 4b. Since the folds PB2 are linearly pressed and crushed to form the folds PB2, the folds PB2 side of the sheet bundle PB is prevented from escaping from the curved portions 4b of the lower press folding plate 4 when the sheet bundle PB is pressurized. Can do. As a result, the central portion of the sheet conveyed while being bent by the conveying roller pair 2 can be surely pressurized and the crease PB2 can be attached.

5) Although it is necessary to apply more pressure to the sheet bundle as the number of sheets and the sheet thickness increase, the sheet bundle of the lower press folding plate 4 is conveyed based on the sheet information such as the number of sheets of the sheet bundle PB and the sheet thickness. Since the moving speed in the direction parallel to the direction (arrow D1 direction) is changed, when the number of sheets and the paper thickness are increased, the moving speed can be slowed to make the folding height lower.

6) When the user selects a mode for slowing the movement speed of the lower press folding plate in the sheet bundle conveyance direction (mode for lowering the folding height), the movement speed is slowed down. Whether to give priority to productivity or folding quality can be selected.

7) Folding direction guide plates 6a and 6b for guiding the sheet bundle PB positioned in the vertical conveyance path 6 between the upper and lower press folding plates 3 and 4 are provided in parallel with the flat portion of the upper press folding plate 3 and the upper press Since the surface of the folding plate 3 in contact with the sheet bundle PB is disposed between two parallel planes virtually extending the pair of folding direction guide plates 6a and 6b, the folding position of the sheet bundle PB is the transport center of the sheet bundle PB. The fold line PB2 can be attached at a position closer to 7a. As a result, it is possible to prevent the fold line PB2 from being formed at a position shifted from the center of the sheet bundle PB.

  Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention, and all the technical matters included in the technical idea described in the claims are all included. The subject of the present invention. The above-described embodiments show preferred examples, but those skilled in the art can realize various alternatives, modifications, variations, and improvements from the contents disclosed in the present specification. These are included in the technical scope described in the appended claims.

1 Folding blade 1
2 Conveying roller pair 3 Upper press folding plate 3u, 3p Two planes extending virtually parallel to the sheet bundle conveying direction 4 Lower press folding plate 4a Plane portion 4b Bending portion 5 Press folding plate drive mechanism 6 Vertical conveyance path 6a, 6b Folding direction guide plate 8 Saddle stitching stapler 12a, 12b Tension spring 13 Pressure shaft FR Paper post-processing device FR2 CPU
PB Paper bundle PB1 Binding section (folding section)
PB2 crease PR image forming device

JP 2010-006602 A

Claims (8)

A pushing means for striking the folded portion of the bundle of paper bundles conveyed along the first conveyance path from the paper surface side and pushing the folded portion into the nip of the pair of conveyance rollers;
A pair of pressure plates in which the upstream side in the first conveyance direction, which is the conveyance direction of the first conveyance path to the folding position of the sheet, is set to the fixed side and the downstream side is set to the movable side, and the pressure plate on the movable side Drive means for movably driving the pressure plate on the fixed side in a second transport direction that is a transport direction of the second transport path along the drive direction of the pushing means of the transport roller pair. Pressurizing means for pressurizing the fold portion on the downstream side and applying a crease to the fold portion;
A position close to the pressure plates of the stationary side, wherein the first set in the transport path of the than pressure plate of the fixed-side first transport direction upstream side vignetting, stapling the sheet bundle Binding means;
The sheet bundle is branched from the first conveyance path in a direction perpendicular to the second conveyance direction of the sheet bundle, and the sheet bundle pushed by the pushing means is added to the fixed side and the movable side. A pair of guide portions for guiding between the pressure plates;
With
The pair of guide portions are installed at a predetermined interval, and the surface of the fixed pressure plate that contacts the paper is the guide portion on the fixed pressure plate side of the pair of guide portions and the surface of the pair of guide portions. Between the two planes extending virtually parallel to the second conveyance direction with the conveyance center of the second conveyance path, the conveyance center side from the guide portion on the fixed pressure plate side The sheet processing apparatus is characterized in that the end of the pressure plate on the fixed side on the upstream side in the second transport direction is formed in an open shape. The sheet processing apparatus according to claim 1,
The sheet processing apparatus according to claim 1, wherein the pushing means includes a first plate-like member that has an end face abutted at a position bound by the binding means and pushes the stuck binding portion into the nip. The sheet processing apparatus according to claim 1 or 2,
The movable pressure plate is composed of a second plate-like member having a curved portion curved in a convex shape with respect to the fixed pressure plate.
A sheet processing apparatus comprising: means for moving the movable pressure plate in parallel with the second transport direction. The sheet processing apparatus according to claim 3,
A pressure shaft that moves in parallel with the second transport direction in contact with the portion of the second plate-shaped member that contacts the back side of the fixed-side pressure plate;
A pressure member that constantly pressurizes the movable pressure plate in the direction of the fixed pressure plate;
A sheet processing apparatus comprising: The sheet processing apparatus according to claim 3 or 4,
The pressure plate of the stationary side in a plane, the movable side of the pressure plate is a flat portion in the second conveying direction upstream side of having the curved portion on the downstream side,
At the time of pressurization by the pressurizing means, after the leading end of the folded portion of the sheet bundle reaches the curved portion beyond the flat portion, the conveyance of the sheet bundle is stopped and the movable pressure plate is moved to the fixed side. To the pressure plate, pressurize the sheet bundle with the respective flat portions of the movable side and the fixed side, and then move the pressure plate on the movable side in the second transport direction to move the movable plate. sheet processing apparatus characterized by comprising a control means for pressurized the folded portion at the curved portion of the side of the pressure plate. The sheet processing apparatus according to claim 5,
The sheet processing apparatus, wherein the control unit changes a moving speed of the movable pressure plate based on sheet information including any of the number of sheet bundles, sheet thickness, and sheet quality. The sheet processing apparatus according to claim 5,
The paper processing apparatus, wherein the control means slows the moving speed of the movable pressure plate when a user selects a mode for slowing the moving speed of the movable pressure plate.   An image forming system comprising the sheet processing apparatus according to claim 1.