JP2012126475A - Paper post-processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of paper folding accuracy by preventing the paper feeding amounts from varying depending on the slip generated between a pair of conveying rollers and the paper and the folding length from varying depending on the deviation of timing of a deflection auxiliary member to contact with the paper.SOLUTION: The quality of paper folding accuracy is maintained by integrally providing a paper end detection sensor 6 on an end stopper 7 to keep the distance between the paper end detection sensor 6 and the end stopper 7 short so that the motion timing of a deflection auxiliary member 8 to the end position of the paper 4 becomes hard to deviate even if a slip is generated between a conveying route 5 and the paper 4.

Description

  The present invention relates to a sheet post-processing apparatus that folds a sheet discharged from an image forming apparatus such as a copying machine or a printing machine.

  Conventionally, for the purpose of suppressing the generation of wrinkles around the crease in the folding process of the sheet post-processing apparatus, a curved portion is formed on the sheet, and the sheet is subjected to the folding process by winding the curved portion around a pair of rollers. In the processing apparatus, a structure of a pressing member that performs an operation of pressing the curved portion of the paper when it is wound around the nip of the roller pair and a folding assist device provided with a flexible film on the pressing member (for example, disclosed) Patent Document 1).

Japanese Patent No. 4341504

  However, in the conventional techniques as described above, when the paper folding process is performed by moving the member that presses the curved portion of the paper, the paper type (for example, size and paper thickness) and the paper conveyance speed are used. However, since the difference in the sheet feed amount is not taken into consideration, there is a problem that the folding accuracy quality of the sheet is lowered.

  The present invention has been made in view of the above, and is due to the fact that the sheet feed amount changes due to the slip generated between the pair of conveying rollers and the sheet, and the timing at which the folding assist device contacts the sheet shifts. An object of the present invention is to improve the folding accuracy quality of paper by preventing the folding length from varying.

  In order to solve the above-described problems and achieve the object, the present invention provides a conveyance unit that conveys a sheet to be folded on a curved conveyance path, and is disposed downstream of the conveyance unit and is conveyed by the conveyance unit. A pair of folding rollers that folds the paper to be conveyed at the nip portion, a paper front end stopping unit that is provided in the transport path and stops the paper by contacting a front end portion of the paper transported by the transport unit, and the paper front end stop And a paper leading edge detecting means for detecting the leading edge of the paper conveyed by the conveying means, and stopped by the paper leading edge stopping means, and contacting and separating the curved paper on the conveying path. A sheet introducing means configured to contact the vicinity of the fold of the sheet having the curved shape and to guide the sheet to the nip portion of the pair of folding rollers, to control the conveying speed of the conveying means and to introduce the sheet A paper introduction control means for controlling the contact and separation operation to the paper stage, characterized in that it comprises a.

  In the present invention, the paper leading edge detecting means is provided integrally with the paper leading edge stopping means, and the distance from the paper leading edge detecting means to the paper leading edge stop is kept short and constant, so that even if slip occurs between the conveyance path and the paper, The operation timing of the sheet introducing means for guiding the sheet curved with respect to the leading edge position to the nip of the folding roller is less likely to be shifted, and an effect is achieved that high folding accuracy quality can be maintained.

FIG. 1 is an explanatory diagram showing the system configuration of the sheet post-processing apparatus according to this embodiment. FIG. 2 is an explanatory diagram showing a layout configuration when the bending assisting member of the sheet folding portion in FIG. 1 is retracted. FIG. 3 is an explanatory diagram showing a layout configuration at the time of contact of the bending assisting member of the sheet folding portion in FIG. FIG. 4 is a graph showing a paper feed delay amount data example (1) according to this embodiment. FIG. 5 is a flowchart showing the sheet folding operation according to this embodiment. FIG. 6 is a chart showing an example of the paper feed delay amount (time) stored in advance. FIG. 7 is a graph showing a paper feed delay amount data example (2) according to this embodiment. FIG. 8 is an explanatory diagram showing the configuration of a sheet post-processing apparatus having a plurality of sheet folding sections according to this embodiment. FIG. 9A is an explanatory diagram illustrating folding operations (A) to (C) in the sheet post-processing apparatus of FIG. 8. FIG. 9B is an explanatory diagram illustrating folding operations (D) to (F) in the sheet post-processing apparatus of FIG.

  Hereinafter, an embodiment of a sheet post-processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is an explanatory diagram showing the system configuration of the sheet post-processing apparatus according to this embodiment. In FIG. 1, reference numeral 10 denotes a sheet folding portion. As will be described later, the conveyance roller pairs 1 and 3, the folding roller pairs 1 and 2, the conveyance path 5, the sheet end detection sensor 6, the leading end stopper 7, and a deflection assisting member. 8, etc. Reference numeral 20 is a control section, reference numeral 21 is a stopper driving section, reference numeral 22 is a driver, reference numeral 23 is a roller driving section, reference numeral 24 is a driver, reference numeral 25 is a deflection assisting member driving section, reference numeral 26 is a delay amount data storage section, Reference numeral 50 denotes a sheet post-processing apparatus, reference numeral 60 denotes an image forming apparatus, reference numeral 61 denotes a system controller, and reference numeral 62 denotes an operation panel.

  In FIG. 1, a sheet post-processing apparatus 50 having a sheet folding function and an image forming apparatus 60 such as a copying machine or a printer are a sheet discharge side of the image forming apparatus 60 and a sheet carry-in port of the sheet post-processing apparatus 50 is a sheet. 4 is mechanically connected with a transfer mechanism capable of delivering four, and is also electrically connected so that control signals and the like can be exchanged with each other. Further, the sheet folding unit 10 receives the processing target sheet 4 discharged from the image forming apparatus 60 and performs a predetermined sheet folding process according to the sheet folding mode input by the user on the operation panel 62 of the image forming apparatus 60. .

  Although not shown, the control unit 20 is composed of a microcomputer system including a CPU, ROM, RAM, and the like, receives a control signal from the system controller 61 of the image forming apparatus 60, and the CPU stores it in the ROM. Each part of the device is controlled in accordance with the control program that is provided. The stopper drive unit 21 uses a stepping motor as a drive source and operates the tip stopper 7 to determine the position according to the paper size and folding position. The driver 22 drives the stopper drive unit 21 in accordance with a control signal from the control unit 20. The roller driving unit 23 drives the folding roller pairs 1 and 2 and the conveying roller pairs 1 and 3 using a DC brushless motor or a stepping motor as a driving source. The driver 24 drives the roller driving unit 23 according to a control signal from the control unit 20. The deflection assisting member driving unit 25 uses a solenoid or a stepping motor as a drive source, and operates the deflection assisting member 8 in accordance with a control signal from the control unit 20. The delay amount data storage unit 26 uses a writable / readable non-volatile memory, and stores sheet delay amount data (see, for example, FIGS. 4 and 7) described later.

  The system controller 61 is composed of a microcomputer system including a CPU, a ROM, a RAM (all not shown), and controls each part necessary for image formation such as image formation by an electrophotographic process and paper feeding and conveyance. In addition, control signals are communicated with external devices and peripheral devices (here, paper post-processing device 50 and the like). The operation panel 62 also includes keys and buttons (including soft keys) for receiving various inputs by the user, and a liquid crystal panel for displaying the device status, input settings, mode setting status, and the like.

  Next, the configuration and operation of the sheet folding unit 10 will be described. 2 and 3 are explanatory diagrams showing the layout configuration of the sheet folding unit 10 in FIG. The basic operation for folding the sheet will be described below. The sheet 4 is conveyed by the folding roller pairs 1 and 2 including the driving side and the driven side and the conveying roller pairs 1 and 3 adjacent to the driving side. In the transport path 5, a paper end detection sensor 6 that detects that the front end of the paper has passed is provided in a front end stopper (folding positioning means) 7. As the sheet end detection sensor 6, for example, a reflection type optical sensor in which an LED light emitting element and a light receiving element are combined together is used. After the sheet passes through the sheet end detection sensor 6, the sheet comes into contact with a leading end stopper (folding positioning means) 7 that blocks the conveyance path 5. Even after this contact, the conveyance roller pairs 1 and 3 rotate in the direction of the arrow in FIG. 2 to feed the paper 4, so that the paper 4 starts to bend in the vicinity of the nip between the folding roller pairs 1 and 2.

  Subsequently, the control unit 20 controls the conveyance roller pairs 1 and 3 and the folding roller pairs 1 and 2 via the driver 24 so as to push the paper 4 at a predetermined timing with a detection signal from the paper edge detection sensor 6 as a trigger. The paper 4 is pushed into the nip side of the pair of folding rollers 1 and 2. Immediately after this, the control unit 20 controls the deflection assisting member driving unit 25 to move the deflection assisting member 8 to the nip side of the pair of folding rollers 1 and 2 (state of FIG. 3). After the sheet 4 is pushed into the nip between the pair of folding rollers 1 and 2, the control unit 20 controls the deflection assisting member driving unit 25 to operate the deflection assisting member 8 so as to return to the original position (the state in FIG. 2). Let

  In this embodiment, the tip stopper 7 has a shaft 7a near the center of the arc with respect to the arc-shaped transport path 5, and is movable around the shaft 7a. The control unit 20 calculates the contact timing of the front end stopper 7 from the transport distance between the paper end detection sensor 6 and the front end stopper 7 and the linear speed (paper transport speed).

  FIG. 4 shows a paper feed delay amount (time) caused by slipping of the conveyance roller pairs 1 and 3 in the paper folding operation described with reference to FIG. Specifically, when the linear speed is 650 mm / sec and the paper size is A4, the paper 4 is further conveyed by the conveying roller pairs 1 and 3 after the leading edge of the paper 4 comes into contact with the leading edge stopper 7 and the bending occurs. In this process, the feed amount of the paper 4 is delayed by 90 msec from the theoretical value. Further, it can be seen from the measured data that this delay tends to increase as the linear velocity decreases and the paper size increases. The paper size information is sent to the control unit 20 via the system controller 61 of the image forming apparatus 60.

[Operation control example 1]
FIG. 5 is a flowchart showing the sheet folding operation according to this embodiment. FIG. 6 is a chart showing an example of the paper feed delay amount (time) stored in advance. Here, as shown in FIG. 2, the sheet end detection sensor 6 is attached to the leading end stopper 7 in a posture in which the detecting unit 6a faces the conveyance path 5, and the sheet contact of the leading end stopper 7 from the detecting unit 6a. The distance L to the contact surface is always kept constant.

  In the flowchart shown in FIG. 5, the processing relating to the first folding portion will be described by taking the case where the folding mode is Z-folding and A3 as an example. A detailed description of Z-folding will be described with reference to FIGS. This operation is executed by the control unit 20. When the operation is started, first, paper information (paper size: A3) is acquired from the image forming apparatus 60 (step S101). Subsequently, folding mode information (Z-folding) is acquired from the image forming apparatus 60 (step S102). Here, the linear velocity is set to 650 mm / sec based on the folding mode information (Z folding). The first folding position from the paper information (paper size: A3) and the folding mode information (Z-fold) is 1/4 of A3 vertical. Therefore, the tip stopper 7 is operated so that the distance from the tip stopper 7 to the nip between the pair of folding rollers 1 and 2 becomes 1/4 of A3 length (step S103).

  Thereafter, a paper acceptance permission signal is transmitted to the image forming apparatus 60 (step S104). The operation timing of the bending assisting member 8 is calculated (step S106), triggered by the reception of the signal for detecting the leading edge of the paper 4 by the paper edge detection sensor 6 (step S105).

Specifically, the time from the detection of the leading edge of the paper 4 to the start of movement is T1 [msec], the transport path distance from the detection of the leading edge to the start of movement is Lh [mm], the linear velocity is Vs [mm / sec], and the delay amount (In this example, A3, 650 mm / sec, and t1> t ≧ t2 is 100 msec), where Ts [msec] can be obtained by the following calculation formula. The conveyance path distance Lh and the linear velocity Vs are set in advance as the processing speed of the apparatus at the time of design.
T1 = (Lh ÷ Vs) × 10 ³ + Ts

  Subsequently, the bending auxiliary member 8 is operated (auxiliary operation) after a lapse of T1 from the tip detection (step S107). Next, it is determined whether or not a specified time has elapsed (step S108). Here, after determining that the specified time has elapsed (determination: Yes). An operation (retraction operation) is performed to return the bending assisting member 8 to the original position (the position in FIG. 2) (step S109). In step S108, if the specified time has not elapsed (determination: No), the process waits until the specified time has passed.

  FIG. 7 is a graph showing that a difference (time) in paper feeding varies depending on the paper thickness. The sheets A, B, and C have different thicknesses, and the thicknesses have a relationship of A> B> C. Specifically, when the linear velocity is 650 mm / sec and the paper size is A4, the difference is small depending on the thickness. However, in the case of A3, the difference between B and C is small, but the difference from A is 10 msec. When the linear velocity is 250 mms, the difference between B and C depending on the thickness and paper size is small. Information on the paper size and paper thickness is sent to the control unit 20 via the system controller 61 of the image forming apparatus 60.

[Operation control example 2]
Next, an operation control example 2 will be described. The sheet 4 fed into the conveyance path 5 by the conveyance roller pairs 1 and 3 advances along the conveyance path 5, and the bending assisting member 8 is near the nip between the folding roller pairs 1 and 2 in accordance with the timing of contact with the leading end stopper 7. Then, the paper 4 is pushed, and the paper 4 is bent. The sheet 4 is normally fed at the same conveyance speed as that of the image forming apparatus 60 to which the sheet folding apparatus is mounted. However, the sheet 4 is moved in the direction opposite to the conveyance direction by the reaction when the leading edge of the sheet 4 comes into contact with the leading end stopper 7. The paper 4 is pushed back and folded in a state where the front end of the paper 4 is separated from the front end stopper 7, and the folding position may be shifted.

  Therefore, in order to eliminate the above-described problem, here, the conveyance roller pair 1 and 3 starts to decelerate from the time when the leading edge of the sheet 4 passes the sheet end detection sensor 6, and the sheet is rotated at a speed slower than the conveyance speed before deceleration. 4 is brought into contact with the tip stopper 7. Accordingly, the paper 4 can be prevented from being rebounded, and the leading end of the paper 4 can be reliably brought into contact with the leading end stopper 7 when the bending assisting member 8 is operated.

(Second Embodiment)
FIG. 8 is an explanatory diagram illustrating a configuration of a sheet post-processing apparatus having a plurality of sheet folding units. The sheet post-processing apparatus 50a shown in FIG. 8 has a configuration in which a plurality of the sheet folding sections 10 described above in the first embodiment are provided, that is, the sheet folding sections 10a, 10b, and 10c. Is basically the same as FIG.

  In FIG. 8, reference numeral 101 denotes a horizontal conveyance path, reference numeral 102 denotes a first stopper conveyance path, reference numeral 103 denotes a first relay conveyance path, reference numeral 104 denotes a second stopper conveyance path, reference numeral 105 denotes a second relay conveyance path, and reference numeral 106 denotes A third stopper conveying path 107 is a stacker discharge conveying path.

  Reference numeral 111 denotes an entrance conveyance roller, reference numeral 112 denotes a paper discharge conveyance roller, reference numeral 113 denotes a stacker discharge conveyance roller, reference numeral 201 denotes a first folding roller, reference numeral 202 denotes a second folding roller, reference numeral 203 denotes a third folding roller, Reference numeral 204 is the fourth folding roller, reference numeral 205 is the fifth folding roller, reference numeral 206 is the sixth folding roller, reference numeral 301 is the first stopper, reference numeral 302 is the second stopper, reference numeral 303 is the third stopper, and reference numeral 400 is the inlet switching. Reference numeral 401 denotes a first bending assisting member, reference numeral 402 denotes a second bending assisting member, reference numeral 403 denotes a third bending assisting member, reference numeral 500 denotes a stacker portion, reference numerals 501a and 501 denote elevating trays, and reference numeral 502 denotes a movable plate. .

  The operation of the sheet folding apparatus 50a configured as shown in FIG. 8 will be described with reference to FIGS. 9-1 and 9-2, taking Z folding as an example. In this example, since there are three sheet folding portions, bending assist members 401, 402, and 403 are provided in each folding portion. In each of the Z-folding, bi-folding, outer tri-folding, and inner tri-folding operations, the control unit 20 controls based on the paper feed delay amount (time) data stored in advance based on the paper information and linear velocity information. Further, the movable timing is corrected and controlled based on the length measurement result. Hereinafter, each folding operation will be described.

<Z-fold>
The Z-folding operation will be described below. The paper received from the image forming apparatus 60 is guided to the first stopper conveyance path 102 by the entrance switching claw 400. The leading edge of the sheet is abutted against the first stopper 301 in the first stopper conveyance path 102 and bent, and the first folding is performed at the first nip formed by the first folding roller 201 and the second folding roller (202) ( (Fig. 9 (A), (B))

  When the first folding is formed, the first bending assisting member 401 is operated to uniformly bend the sheet toward the folding roller. After completion of the first folding, the sheet is conveyed from the first relay conveyance path 103 to the second stopper conveyance path 104, and is bent by abutting the front end of the paper against the second stopper 302 in the second stopper conveyance path (104). Second folding is performed at the second nip formed by the roller 203 and the fourth folding roller 204 (FIGS. 9C and 9D), and the Z-folding is completed in the second relay conveyance path 105.

  When the second folding is formed, the second bending assisting member 402 is operated as in the first time. After the folding is completed, the paper passes through the third stopper transport path 106 and is transported to the downstream machine by the paper discharge transport roller 112 (FIGS. 9E and 9F). In the Z-folding mode, the third stopper 303 is not used, and therefore is in a position retracted from the third stopper conveyance path 106.

<Folded>
Hereinafter, the folding operation will be described. The sheet received from the image forming apparatus 60 is formed by the first folding roller 201 and the second folding roller 202 without entering the first stopper conveyance path 102 by the entrance switching claw 400 and the first bending assisting member 401. The first nip passes through the first relay conveyance path 103 and is guided to the second stopper conveyance path 104.

  The front end of the sheet is abutted against the second stopper 302 in the second stopper conveyance path 104 and bent, and the second fold is formed at the second nip formed by the third folding roller 203 and the fourth folding roller 204, and the second Folding is completed on the relay conveyance path 105. When the first folding is formed, the second bending assisting member 402 is operated to uniformly bend the sheet toward the folding roller. After the folding is completed, the paper passes through the third stopper transport path 106 and is transported to the downstream machine by the paper discharge transport roller 112. In the two-fold mode, the third stopper 303 is not used, and therefore is in a position retracted from the third stopper conveyance path 106.

<Outer trifold, inner trifold>
The operation of the outer trifold and the inner trifold will be described below. The sheet received from the image forming apparatus 60 is formed by the first folding roller 201 and the second folding roller 202 without entering the first stopper conveyance path 102 by the entrance switching claw 400 and the first bending assisting member 401. The first nip passes through the first relay conveyance path 103 and is guided to the second stopper conveyance 104.

  The front end of the sheet is abutted against the second stopper 302 in the second stopper conveyance path 104 and bent, and the second nip formed by the third folding roller 203 and the fourth folding roller 204 is folded for the first time, and the second relay. The first folding is completed on the conveyance path 105. After completion of the first folding, the sheet is conveyed to the third stopper conveying path 106, and is bent by abutting the leading edge of the sheet against the third stopper 303 in the third stopper conveying path 106, by the fifth folding roller 205 and the sixth folding roller 206. The second fold is performed at the formed third nip, and the inner trifold and the outer trifold are completed in the stacker conveyance path 107. After the folding is completed, the paper is stored in the stacker unit 500 by the stacker paper discharge conveyance roller 113.

  Therefore, according to the above-described embodiment, the paper end detection sensor 6 is provided integrally with the front end stopper 7, and the distance from the paper end detection sensor 6 to the front end stopper 7 is kept short and constant, whereby the conveyance path 5 and the paper 4 Even if slip occurs, the operation timing of the bending assisting member 8 is less likely to shift with respect to the leading end position of the paper 4, and high folding accuracy quality can be maintained.

  When the leading edge of the paper 4 is detected by the paper edge detection sensor 6, the paper delay amount in the transport path 5 is calculated from the paper information and the paper transport speed, and the paper 4 of the deflection assisting member 8 is calculated according to the paper delay amount. When the sheet 4 is brought into contact with the leading end stopper 7, the sheet 4 rebounds in the direction opposite to the conveying direction and is held in the nip of the pair of folding rollers 1 and 2 as it is. Can be prevented from being folded at a shorter position.

  Further, as described with reference to FIGS. 8 and 9, in the configuration having a plurality of paper folding portions, the bending assisting member 8 is controlled for each paper folding portion 10a, 10b, 10c and for each folding mode. Therefore, even if the folding mode is different, the degradation of folding accuracy quality can be minimized.

  As described above, the sheet post-processing apparatus according to the present invention is useful for a sheet folding apparatus that finishes a sheet discharged from a copying machine, a printer, or the like into a predetermined fold. It is suitable for an apparatus that performs folding / separating operation at a predetermined timing to ensure folding finish quality.

DESCRIPTION OF SYMBOLS 1, 2 Folding roller pair 1,3 Conveying roller pair 5 Conveyance path 6 Paper edge detection sensor 7 End stopper 8 Deflection auxiliary member 10a, 10b, 10c Paper folding part 20 Control part 21 Stopper drive part 23 Roller driving part 25 Deflection auxiliary member Drive unit 26 Delay amount data storage unit 50, 50a Paper post-processing device 60 Image forming device 61 System controller 62 Operation panel

Claims (5)

Conveying means for conveying a sheet to be folded to a curved conveying path;
A pair of folding rollers which are arranged on the downstream side of the conveying means and fold the paper conveyed by the conveying means at a nip portion;
A paper front end stopping means provided in the transport path, for stopping the paper by contacting a front end portion of the paper transported by the transport means;
A paper leading edge detecting means which is provided integrally with the paper leading edge stopping means and detects the leading edge of the paper conveyed by the conveying means;
The folding roller pair is configured to be stopped by the sheet leading edge stopping means and to be able to come into contact with and separate from a curved sheet on the conveyance path, and to come into contact with the vicinity of the fold of the curved sheet. Paper introducing means for guiding the paper to the nip portion of
Paper introduction control means for controlling the conveyance speed of the conveyance means and controlling the contact and separation of the paper introduction means to the paper;
A sheet post-processing apparatus comprising: The paper information is paper size and paper thickness,
When the leading edge of the paper is detected by the paper leading edge detecting means, the paper introduction control means calculates a paper delay amount in the transport path from the paper information and the paper transport speed, and the paper introduction control means calculates the paper delay according to the paper delay amount. The sheet post-processing apparatus according to claim 1, wherein the introducing unit performs a contact operation on the sheet. The paper information is paper size and paper thickness,
For each of the paper information and the paper conveyance speed, a paper delay amount storage means for actually measuring and storing the paper delay amount of the conveyance path,
When the leading edge of the paper is detected by the paper leading edge detection means, the paper introduction control means stores the paper delay amount in the transport path from the paper information and the paper transport speed in the paper delay amount storage means. 2. The paper post-processing apparatus according to claim 1, wherein the paper post-processing device reads out from a predetermined value and makes contact with the paper by the paper introducing means according to the paper delay amount.   The paper introduction control means decelerates the conveying speed of the conveying means from the time when the leading edge of the paper is detected by the paper leading edge detecting means, and makes the paper contact the paper leading edge stopping means. Item 4. A sheet post-processing apparatus according to item 1, 2 or 3.   5. A plurality of sets of sheet folding means including the conveying means, the pair of folding rollers, the sheet leading edge stopping means, the sheet leading edge detecting means, and the sheet introducing means. The sheet post-processing apparatus according to any one of the above.

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