JP2019196256A - Sheet loading device and image formation system - Google Patents

Abstract

To provide a sheet loading device and an image formation system capable of suppressing deterioration of productivity, correcting inclination of a sheet and loading the sheet.SOLUTION: A sheet loading device comprises a sheet loading part 38, a sheet detection part 34, a pair of correction rollers 51A, 51B, a sheet holding part 52 and a control part. The sheet holding part 52 holds a sheet S in a state where the sheet S is conveyed by a pair of the correction rollers 51A, 51B. The control part controls the pair of the correction rollers 51A, 51B and the sheet holding part 52 based on detection information detected by the sheet detection part 34. The control part controls a conveyance speed of the sheet S in the pair of the correction rollers 51A, 51B based on the detection information detected by the sheet detection part 34, and controls a moving speed in a conveyance direction in the sheet holding part 52 based on the conveyance speed of the pair of the correction rollers 51A, 51B after correcting inclination of the sheet S.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sheet stacking apparatus and an image forming system for stacking sheets.

  2. Description of the Related Art Conventionally, an image forming system including an image forming apparatus that forms an image on a sheet and a sheet stacking apparatus on which a sheet on which an image is formed by the image forming apparatus is stacked has been proposed.

  Note that in order to increase the processing accuracy of the post-processing device that performs post-processing such as stapling, punching, and binding, and to easily carry out the paper by the user, the paper stacking device stacks the paper with the same inclination. It is required to be loaded on the department.

  As a technique for correcting the inclination of the paper, for example, there is a technique described in Patent Document 1. Patent Document 1 describes a technique for correcting the inclination of a sheet during the conveyance of the sheet. In recent years, after correcting the inclination of the paper, the paper is held by the paper holding unit and stacked on the stacking unit.

JP 2017-208628 A

  However, when the sheet is held by the sheet holding unit after correcting the inclination of the sheet, since the conveyance of the sheet is temporarily stopped, the productivity is lowered.

  In view of the above-described conventional problems, the present invention provides a paper stacking apparatus and an image forming system capable of suppressing a decrease in productivity and correcting and stacking paper. With the goal.

In order to solve the above problems and achieve the object of the present invention, a paper stacking apparatus of the present invention includes a paper stacking unit on which paper is stacked, a paper detection unit, a pair of correction rollers, a paper holding unit, and a control. And a section.
The paper detection unit is disposed upstream of the paper stacking unit in the paper conveyance direction, and detects the conveyed paper. The pair of correction rollers are arranged on the upstream side in the transport direction from the paper stacking unit, transport the paper, and correct the inclination of the paper. The paper holding unit approaches the paper whose inclination is corrected by the pair of correction rollers from the upstream side in the conveyance direction, holds the paper in a state where the paper is conveyed by the pair of correction rollers, and loads the paper on the paper stacking unit. To do. The control unit controls the pair of correction rollers and the sheet holding unit based on the detection information detected by the sheet detection unit.
The control unit controls the conveyance speed of the paper in the pair of correction rollers based on the detection information detected by the paper detection unit, and the conveyance direction in the paper holding unit based on the conveyance speed of the pair of correction rollers after correction of the inclination of the paper Control the moving speed to.

  The image forming system of the present invention includes an image forming apparatus that forms an image on a sheet, and a sheet stacking apparatus that conveys the sheet from the image forming apparatus. As the paper stacking device, the above paper stacking device is applied.

  According to the paper stacking apparatus and the image forming system configured as described above, it is possible to suppress a decrease in productivity, and to stack paper by correcting the inclination of the paper.

1 is a schematic configuration diagram of an image forming system according to an exemplary embodiment of the present invention. 1 is a schematic configuration diagram showing a paper stacking apparatus according to an embodiment of the present invention. It is a perspective view which shows the paper stacking mechanism of the paper stacking apparatus concerning the embodiment of this invention. It is a top view which shows the paper stacking mechanism of the paper stacking apparatus concerning the embodiment of this invention. It is a top view which shows the correction | amendment roller of the paper stacking apparatus concerning the embodiment of this invention. 1 is a block diagram illustrating a configuration of a control system of an image forming system according to an exemplary embodiment of the present invention. It is explanatory drawing which shows the state in which the paper was conveyed to the paper detection part of the paper stacking apparatus concerning the embodiment of this invention. It is a time chart which shows the operation example of the paper stacking apparatus concerning the embodiment of this invention. 6 is a flowchart illustrating an operation example of the paper stacking apparatus according to the exemplary embodiment of the present invention. It is explanatory drawing which shows the stacking operation | movement to the paper stacking part in the paper stacking apparatus concerning the embodiment of this invention. It is explanatory drawing which shows the stacking operation | movement to the paper stacking part in the paper stacking apparatus concerning the embodiment of this invention.

  Hereinafter, embodiments for carrying out the paper stacking apparatus and the image forming system of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the common member in each figure. The present invention is not limited to the following form.

1. Embodiment 1-1. Configuration of Image Forming System First, the overall configuration of an image forming system according to an embodiment of the present invention (hereinafter referred to as “this example”) will be described. FIG. 1 is a schematic configuration diagram of an image forming system 1 of the present example.

  As shown in FIG. 1, the image forming system 1 includes an image forming apparatus 10, a paper feeding apparatus 20, and a paper stacking apparatus 30. In the image forming system 1, the paper feeding device 20, the image forming device 10, and the paper stacking device 30 are arranged in this order from the upstream side of the paper conveyance path, and are connected in series. The image forming system 1 is capable of transporting paper between the apparatuses and communicating with each other. Note that the image forming system 1 of the present example is not limited to the configuration shown in FIG. 1, and the sheet forming device 10 and the paper stacking device 30 or on the downstream side of the paper stacking device 30 are not limited to the configuration shown in FIG. A sheet processing apparatus that performs processing such as stapling, punching, and binding may be arranged.

  The paper feeding device 20 includes a plurality (three in this example) of paper feeding trays 21 and can store a large amount of paper. The paper feeding device 20 feeds the paper stored in the paper feeding tray 21 to the image forming apparatus 10.

  The image forming apparatus 10 forms an image on the fed paper. The image forming apparatus 10 includes a plurality of paper feed trays 10a, a conveyance path 10b, an image forming unit 17, a fixing unit 10c, a reverse conveyance path 10d, and an operation display unit 14. The operation display unit 14 is installed on the upper part of the image forming apparatus 10. The operation display unit 14 is configured by overlapping a display panel and a touch panel (operation unit), and can be operated by an operator and displayed upward.

  The plurality of paper feed trays 10 a are installed in the lower part of the image forming apparatus 10. A sheet fed from either the plurality of sheet feeding trays 10a or the sheet feeding device 20 is conveyed to the conveying path 10b. An image forming unit 17 is provided in the middle of the conveyance path 10b.

  The image forming unit 17 includes, for example, an image forming unit of a plurality of colors (cyan, magenta, yellow, black, etc.), and can form a color toner image on a sheet. On the downstream side of the image forming unit 17 in the paper conveyance direction (simply referred to as “downstream side”), a fixing unit 10 c to which the paper on which the toner image is formed is arranged.

  The fixing unit 10c fixes the toner image transferred to the front side of the sheet on the sheet by applying pressure and heating to the sheet to be conveyed. The sheet on which the fixing process has been performed by the fixing unit 10c is conveyed to the sheet stacking device 30 by the conveyance path 10b or is conveyed to the reverse conveyance path 10d.

  Connected to the conveyance path 10b is a reversal conveyance path 10d that branches on the downstream side of the fixing unit 10c and joins the conveyance path 10b on the upstream side of the image forming unit 17. A reversing unit for reversing the paper is provided in the reversing conveyance path 10d. The paper whose front and back or front and back are reversed by the reversing unit is conveyed to the conveying path 10b on the upstream side of the image forming unit 17 or the conveying path 10b on the downstream side of the fixing unit 10c through the reversing conveying path 10d. Then, the sheet discharged from the conveyance path 10 b of the image forming apparatus 10 is conveyed to the sheet stacking apparatus 30.

1-2. Configuration Example of Paper Stacking Device 30 Next, the configuration of the paper stacking device 30 will be described with reference to FIGS.
FIG. 2 is a schematic configuration diagram showing the paper stacking device 30.
Hereinafter, a direction in which the sheet is conveyed from the image forming apparatus 10 is defined as a conveyance direction X, and a direction perpendicular to the conveyance direction X and also perpendicular to the vertical direction is defined as a width direction Y. A direction perpendicular to the transport direction X and the width direction Y is defined as a vertical direction Z.

  As shown in FIGS. 1 and 2, the paper stacking device 30 includes a paper detection unit 34, a plurality of transport rollers 35, a paper stacking mechanism 37, a paper stacking unit 38, and a transport path 39. Yes. The conveyance path 39 conveys the sheet conveyed from the image forming apparatus 10 to the sheet stacking mechanism 37 and the sheet stacking unit 38. A plurality of transport rollers 35 and a paper detection unit 34 are arranged in the transport path 39.

  The paper detection unit 34 includes a first inclination detection sensor 34a and a second inclination detection sensor 34b (see FIG. 6). The first inclination detection sensor 34a and the second inclination detection sensor 34b are arranged on the upstream side in the transport direction X with respect to correction rollers 51A and 51B of a sheet stacking mechanism 37 described later. Further, the first inclination detection sensor 34a and the second inclination detection sensor 34b are arranged with an interval in the width direction Y (see FIG. 7). Then, the first inclination detection sensor 34a and the second inclination detection sensor 34b detect the leading end of the transported paper S in the transport direction X.

  In addition, the paper detection unit 34 is disposed between the transport roller 35 disposed on the most downstream side in the transport direction X among the plurality of transport rollers 35 and a pair of correction rollers 51A and 51B provided in a paper stacking mechanism 37 described later. The

  In this example, the sheet detection unit 34 is disposed upstream of the correction rollers 51A and 51B in the transport direction X. However, the present invention is not limited to this, and the sheet detection unit 34 is disposed on the correction roller 51A. , 51B may be arranged on the downstream side in the transport direction X. Further, the paper detection unit 34 is not limited to the example of detecting the leading end of the transported paper S in the transport direction X, and may detect the rear end of the transport direction X of the paper S.

[Paper loading section]
The paper stacking unit 38 includes a stacking tray 38a and a lifting mechanism (not shown) that moves the stacking tray 38a up and down in the vertical direction Z. The sheets S conveyed by the sheet stacking mechanism 37 are stacked on the stacking tray 38a. A paper stacking mechanism 37 is disposed on the upstream side in the transport direction X of the paper stacking unit 38.

[Paper loading mechanism]
FIG. 3 is a perspective view showing the paper stacking mechanism 37, and FIG. 4 is a plan view showing the paper stacking mechanism 37.
As shown in FIGS. 3 and 4, the paper stacking mechanism 37 includes a stacking conveyance unit 41, a housing 42, and a width direction moving mechanism 43. The housing | casing 42 is formed in the hollow substantially rectangular parallelepiped shape. A stacking and conveying unit 41 is accommodated in the housing 42 via a width direction moving mechanism 43. The housing 42 has an abutting surface 42 a with which the end on the downstream side in the transport direction X of the sheets S stacked on the sheet stacking unit 38, that is, the rear end abuts. The contact surface 42 a faces the paper stacking unit 38. Further, the contact surface 42a is formed with openings facing correction rollers 51A and 51B and paper holding portions 52 and 52 provided in a stacking and conveying unit 41 described later.

  The width direction moving mechanism 43 supports the stack conveyance unit 41 so as to be movable in the width direction Y on the casing 42. The width direction moving mechanism 43 includes a guide shaft 43a and a movement driving unit 43b. Both ends of the guide shaft 43a in the width direction Y are fixed to the housing 42. The guide shaft 43a penetrates the stacking and conveying unit 41 along the width direction Y, and supports the stacking and conveying unit 41 so as to be movable in the width direction Y. Then, when the movement driving unit 43b is driven, the stack conveyance unit 41 moves in the width direction Y along the guide shaft 43a.

[Loading unit]
The stack conveyance unit 41 includes a pair of correction rollers 51A and 51B, two sheet holding units 52 and 52, and two roller driving units 53A and 53B (see FIG. 5). The pair of correction rollers 51 </ b> A and 51 </ b> B are arranged at corners of the upper end portion in the vertical direction Z and the downstream end portion in the transport direction X in the stacking transport unit 41. The pair of correction rollers 51 </ b> A and 51 </ b> B is disposed immediately before the upstream side in the transport direction X in the paper stacking unit 38. Further, no other roller is arranged downstream of the pair of correction rollers 51A and 51B in the conveyance direction X, and the pair of correction rollers 51A and 51B is arranged on the most downstream side on the conveyance path 39. It is a conveyance roller.

  As described above, the first inclination detection sensor 34a and the second inclination detection sensor 34b that constitute the paper detection unit 34 are disposed upstream of the pair of correction rollers 51A and 51B in the transport direction X (see FIG. 2). As described above, the sheet detection unit 34 is disposed between the conveyance roller 35 disposed on the most downstream side in the conveyance direction X of the plurality of conveyance rollers 35 and the pair of correction rollers 51A and 51B. That is, no other transport roller 35 is disposed between the pair of correction rollers 51A and 51B and the first tilt detection sensor 34a and the second tilt detection sensor 34b. Each of the pair of correction rollers 51A and 51B has a driven roller 51c facing each other in the vertical direction Z.

FIG. 5 is a plan view showing the correction rollers 51A and 51B.
The first correction roller 51A and the second correction roller 51B are arranged with an interval in the width direction Y. The first correction roller 51A is connected to the drive shaft of the first roller drive unit 53A via the first drive belt 54A. The first correction roller 51A is rotationally driven by the first roller driving unit 53A. The second correction roller 51B is connected to the drive shaft of the second roller drive unit 53B via the second drive belt 54B. The second correction roller 51B is rotationally driven by the second roller driving unit 53B.

  Further, the first roller driving unit 53A and the second roller driving unit 53B are connected to a CPU 31 (see FIG. 6) showing an example of a control unit described later, and are individually controlled. For this reason, the rotational speeds of the first correction roller 51A and the second correction roller 51B, that is, the so-called transport speed of the sheet S are configured to be individually controllable. Then, the CPU 31 corrects the inclination of the conveyed paper S by controlling the conveyance speed of the first correction roller 51A and the second correction roller 51B.

[Paper holder]
As shown in FIGS. 3 and 4, the two sheet holding portions 52 and 52 are disposed outside the pair of correction rollers 51 </ b> A and 51 </ b> B in the width direction Y. Further, the two paper holding units 52 and 52 have the same configuration. The sheet holding unit 52 includes a gripper member 61 and a gripper moving mechanism 62.

  The gripper member 61 has a lower gripper 81 and an upper gripper 82. The upper gripper 82 is rotatably supported by the lower gripper 81 via a rotation shaft 85. The downstream end of the upper gripper 82 in the transport direction X approaches and separates from the lower gripper 81. The end of the upper gripper 82 approaches the lower gripper 81 to hold the conveyed paper S. The lower gripper 81 is movably supported by the gripper moving mechanism 62.

  The gripper moving mechanism 62 includes a gripper driving unit 71 (see FIG. 6) and a driving roller, a plurality of rollers, and a driving belt 74 formed in an endless shape. The driving belt 74 is wound around a driving roller and a plurality of rollers. When the gripper driving unit 71 is driven, the driving belt 74 rotates along the driving roller and the plurality of rollers.

  Further, the gripper member 61 connected to the drive belt 74 moves in the transport direction X and the vertical direction Z along with the rotation operation of the drive belt 74. When the gripper member 61 moves in the up-down direction Z, the gripper member 61 can move from the lower side in the up-down direction Z of the transport path 39 through which the paper S passes to the transport path 39.

  Further, sheet holding units 52 and 52 for holding the sheet S and correction rollers 51A and 51B for correcting the inclination of the sheet S are provided in one member of the stacking conveyance unit 41. Further, as described above, the stack conveyance unit 41 is supported by the width direction moving mechanism 43 so as to be movable in the width direction Y. Accordingly, the sheet holding units 52 and 52 and the correction rollers 51A and 51B can be moved in the width direction Y at the same time.

  In this example, the example in which the two sheet holding units 52 and 52 are arranged outside the correction rollers 51A and 51B in the width direction Y has been described. However, the present invention is not limited to this. The two paper holding units 52 and 52 may be arranged between the first correction roller 51A and the second correction roller 51B in the width direction Y.

1-3. Configuration Example of Control System Next, a configuration example of the control system of the image forming system 1 will be described with reference to FIG.
FIG. 6 is a block diagram illustrating a configuration of a control system of each apparatus included in the image forming system 1.

  As shown in FIG. 6, in the image forming system 1, each device is connected to a client terminal 50 via a network N. For example, a personal computer is applied to the client terminal 50. The client terminal 50 generates image data for image formation by a document creation or image formation application based on a user input operation. The client terminal 50 has a function of generating an image forming job including image forming setting information (also referred to as “job ticket”) and image data, and outputting the image forming job to the image forming apparatus 10.

  The image forming apparatus 10 receives the image forming job output from the client terminal 50 via the network N, forms an image on a sheet based on the image forming setting of the image forming job and the image forming data, and outputs the image (hereinafter referred to as “image forming job”). And “image forming process”). The image forming apparatus 10 may be a multi-function peripheral (MFP) having a plurality of types of functions (image forming function, copying function, scanning function, etc.).

  The image forming apparatus 10 includes a CPU 11, a memory 12, an auxiliary storage device 13, an operation display unit 14, an input data processing unit 15, a RIP processing unit 16, an image forming unit 17, and a communication I / F 18 that constitute a control unit. Each unit is connected to be communicable with each other via a system bus.

  A CPU 11 (Central Processing Unit) is a central processing unit that controls the operation of each unit of the image forming apparatus 10 and performs arithmetic processing. The CPU 11 reads out a program code of software that realizes each function according to the present embodiment from the auxiliary storage device 13 and executes it. Note that the image forming apparatus 10 may include a processing apparatus such as an MPU instead of the CPU 11.

  The memory 12 is a main storage device, and variables, parameters, and the like generated during the arithmetic processing are temporarily written in the memory 12. For example, a RAM (Random Access Memory) or the like is applied to the memory 12.

  The auxiliary storage device 13 is a storage device that plays an auxiliary role of the memory 12. The auxiliary storage device 13 normally has a mechanism capable of storing data for a long time. In addition to the OS and various parameters, the auxiliary storage device 13 stores a program for causing the image forming apparatus 10 to function.

  The operation display unit 14 is configured by laminating a touch panel as an operation unit on a flat panel display as a display unit. The operation display unit 14 generates an operation signal corresponding to the content of the operation input from the user, and supplies the generated operation signal to the CPU 11. The operation display unit 14 displays the processing result of the CPU 11.

  The submitted data processing unit 15 analyzes the image forming job input to the image forming apparatus 10 and processes the submitted image forming data. Each image forming data processed by the submitted data processing unit 15 is supplied to the RIP processing unit 16.

  The RIP processing unit 16 reflects the image formation setting in the image formation data, converts it into a language (PDL: Page Description Language) that can be identified by the image forming apparatus 10 (RIP processing), and outputs it. Languages that can be identified by the image forming apparatus 10 include PCL and PostScript.

  The image forming unit 17 forms an image on a sheet based on the RIP processed image formation data output from the RIP processing unit 16. The image forming unit 17 is configured as a printer engine.

  The communication I / F 18 uses, for example, a network interface card (NIC) or the like, and is configured to be able to transmit and receive various data between devices via the network N.

  A controller including the submitted data processing unit 15 and the RIP processing unit 16 may be connected to the network N. Then, the image forming data processed by the submitted data processing unit 15 and the RIP processing unit are input to the image forming apparatus 10 and the paper stacking apparatus 30, respectively.

  The paper stacking device 30 receives the image forming data from the image forming device 10 and determines the size, basis weight, etc. of the paper to be transported, and the presence / absence of post-processing such as stapling, punching, and binding.

  The paper stacking device 30 includes a CPU 31, a memory 32, an auxiliary storage device 33, a paper detection unit 34, a communication I / F 36, a paper stacking mechanism 37, and the like. Each unit is connected to be communicable with each other via a system bus.

  The CPU 31, which shows an example of a control unit, is a central processing unit that controls the operation of each unit of the paper stacking device 30 and performs arithmetic processing. The CPU 31 reads out the program code of software that realizes each function according to the present embodiment from the auxiliary storage device 33 and executes it. Note that the paper stacking device 30 may include a processing device such as an MPU instead of the CPU 31.

  The memory 32 is a main storage device, and variables, parameters, and the like generated during the arithmetic processing are temporarily written in the memory 32. For example, a RAM (Random Access Memory) or the like is applied to the memory 32.

  The auxiliary storage device 33 is a storage device that plays an auxiliary role of the memory 32. The auxiliary storage device 33 normally has a mechanism capable of storing data for a long time. In addition to the OS and various parameters, the auxiliary storage device 33 stores a program for causing the paper stacking device 30 to function.

  The paper detection unit 34 includes a first inclination detection sensor 34a and a second inclination detection sensor 34b. The first inclination detection sensor 34 a and the second inclination detection sensor 34 b detect the leading edge of the paper S that has been conveyed to the conveyance path 39. Then, the first inclination detection sensor 34a and the second inclination detection sensor 34b output the detected detection information to the CPU 31. The CPU 31 detects the inclination of the conveyed paper S from the timing when the first inclination detection sensor 34 a and the second inclination detection sensor 34 b detect the leading edge of the paper S.

  The sheet stacking mechanism 37 includes a first roller driving unit 53A that rotates the first correction roller 51A, a second roller driving unit 53B that rotates the second correction roller 51B, and a sheet holding unit 52. . The first roller drive unit 53A rotates and drives the first correction roller 51A based on the drive signal from the CPU 31, and the second roller drive unit 53B drives and rotates the second correction roller 51B based on the drive signal from the CPU 31. Let

  The paper holding unit 52 drives the gripper drive 71 of the gripper moving mechanism 62 based on the drive signal from the CPU 31. Accordingly, the gripper member 61 of the paper holding unit 52 performs the holding operation of the paper S, the paper stacking operation, and the like.

  The communication I / F 36 uses, for example, a network interface card (NIC) or the like, and is configured to be able to transmit and receive various types of data between devices via the network N.

2. Example of Operation of Paper Stacking Device Next, an example of the inclination correction operation and stacking operation of the paper S by the paper stacking device 30 having the above-described configuration will be described with reference to FIGS.
FIG. 7 is an explanatory diagram illustrating a state in which the sheet S is conveyed to the first inclination detection sensor 34 a and the second inclination detection sensor 34 b which are the sheet detection unit 34. FIG. 8 is a time chart showing the operation of the paper stacking device 30, and FIG. 9 is a flowchart showing the operation of the paper stacking device 30. 10 and 11 are explanatory diagrams showing a stacking operation on the sheet stacking unit 38. FIG.

  First, as shown in FIG. 9, the feeding of the sheet S to the conveyance path 39 of the sheet stacking device 30 is started. Then, as shown in FIG. 7, it is determined whether or not the first inclination detection sensor 34a has detected the leading edge of the paper S (step S11). In the process of step S11, when the CPU 31 determines that the first inclination detection sensor 34a has detected the leading edge of the sheet S (YES determination in step S11), the CPU 31 detects that the second inclination detection sensor 34b has detected the leading edge of the sheet S. It is determined whether or not it has been detected (step S12).

  In the process of step S11, if the CPU 31 determines that the first inclination detection sensor 34a has not detected the leading edge of the sheet S (NO determination in step S11), the CPU 31 determines that the second inclination detection sensor 34b is the sheet. It is determined whether or not the tip of S has been detected (step S13). In the process of step S13, when the CPU 31 determines that the second inclination detection sensor 34b has detected the leading edge of the sheet S (YES determination in step S13), the CPU 31 detects that the first inclination detection sensor 34a has detected the leading edge of the sheet S. It is determined whether or not it has been detected (step S14).

  In the process of step S13, if the CPU 31 determines that the second inclination detection sensor 34b has not detected the leading edge of the paper S (NO determination in step S13), the CPU 31 returns to the process of step S11.

In the process of step S12, when the CPU 31 determines that the second inclination detection sensor 34b has detected the leading edge of the sheet S (YES determination in step S12), the first inclination detection sensor 34a side in the width direction Y of the sheet S is transported. It can be seen that it is inclined downstream in the direction X. Then, the CPU 31 calculates a time difference t ₁ (see FIG. 8), which is a difference value between the time when the first inclination detection sensor 34a detects the paper S and the time when the second inclination detection sensor 34b detects the paper S (see FIG. 8). Step S15). The CPU 31 calculates the amount of inclination of the paper S from the calculated time difference t ₁ .

  In the process of step S14, when the CPU 31 determines that the first inclination detection sensor 34a has detected the leading edge of the sheet S (YES determination in step S14), the second inclination detection sensor 34b in the width direction Y of the sheet S. It can be seen that the side is inclined downstream in the transport direction X. Then, the CPU 31 calculates a time difference which is a difference value of time from when the second inclination detection sensor 34b detects the paper S to when the first inclination detection sensor 34a detects the paper S (step S20).

Further, as shown in FIG. 8, the rotation speed of the first correction roller 51A and the second correction roller 51B, that is, the conveyance speed of the paper S is determined by either the first inclination detection sensor 34a or the second inclination detection sensor 34b. It is set to a speed V ₂ until it detects a S.

  When the sheet S is detected by the first inclination detection sensor 34a in the process of step S11, the CPU 31 controls the first roller driving unit 53A and the second roller driving unit 53B, and depends on the size of the sheet S and the sheet passing interval. The sheet S is passed through only the pre-correction adjustment area 101 (see FIG. 8) (step S16). Further, when the sheet S is detected by the second inclination detection sensor 34b in step S13, the CPU 31 controls the first roller driving unit 53A and the second roller driving unit 53B to pass the sheet S by the pre-correction adjustment area 101. (Step S21).

When the paper S is passed through the pre-correction adjustment area 101 by the process of step S16, the CPU 31 controls the first roller driving unit 53A to reduce the rotation speed of the first correction roller 51A, that is, the conveyance speed of the paper S. Start (step S17). Thus, as shown in FIG. 8, the conveying speed of the sheet S by the first correction roller 51A is through the reduction region 102, decelerates from the speed _{V 2} to velocity _{V 1.}

Incidentally, when the conveying speed of the sheet S by the first correction roller 51A is decelerated to the velocity _{V 1,} CPU 31 maintains the transport speed of the first correction roller 51A to the state of the speed _{V 1.} Then, as shown in FIG. 8, to drive the first correction roller 51A by a time difference _{t 1} calculated in step S15 at a velocity _{V 1.} Region driven by the speed _{V 1} is, the uncorrected low speed range 104 of the first correction roller 51A.

The processing is passed only sheet S before correction adjusting region 101 by a step S16, further by a time difference _{t 1} calculated in step S15, thereby passed the sheet S (step S18). In the process of step S18, as shown in FIG. 8, the second correction roller 51B is a high speed region 103 in which the conveying speed is fast velocity V ₂ state than the speed V _1. In the high speed region 103 by the second correction roller 51B, the first correction roller 51A is the deceleration region 102. The inclination of the sheet S is corrected by the speed difference between the conveyance speeds of the first correction roller 51A and the second correction roller 51B.

Then, the time difference _{t 1} elapses in the processing of step S18, i.e., when the high speed region 103 of the second correction roller 51B has passed, CPU 31 controls the second roller driving unit 53B, the rotation speed of the second correction roller 51B That is, deceleration of the conveyance speed of the paper S is started (step S19). Thus, as shown in FIG. 8, the conveying speed of the sheet S by the second correction roller 51B is through the reduction region 102, decelerates from the speed _{V 2} to velocity _{V 1.}

Further, when the sheet S is passed through the pre-correction adjustment area 101 by the process of step S21, the CPU 31 controls the second roller driving unit 53B to control the rotation speed of the second correction roller 51B, that is, the conveyance speed of the sheet S. Deceleration is started (step S22). Accordingly, the conveying speed of the sheet S by the second correction roller 51B is decelerated from the speed _{V 2} to velocity _{V 1.}

The processing is passed only sheet S before correction adjusting region 101 by a step S21, further by a time difference _{t 1} calculated in step S20, thereby passed the sheet S (step S23). In the process of step S23, the conveyance speed of the sheet S by the first correction roller 51A is maintained the state of the fast speed V ₂ than the speed V _1. Thereby, the inclination of the paper S is corrected.

When the time difference _{t 1} in the processing of step S23 has elapsed, CPU 31 controls the first roller driving section 53A, the rotational speed of the first correction roller 51A, i.e. to start deceleration of the conveying speed of the sheet S (step S24). Accordingly, the conveying speed of the sheet S by the first correction roller 51A is decelerated from the speed _{V 2} to velocity _{V 1.}

In the processing of step S19 or step S24 and the first correction roller 51A when the conveying speed of the second correction roller 51B is decelerated to the velocity _{V 1,} CPU 31 causes the fed sheet S only preliminary correction region 106. Note that the maximum amount of inclination correction of the paper S is from the pre-correction adjustment area 101 to the preliminary correction area 106.

When the process of step S19 or step S24 is completed, CPU 31 is a conveying speed of the first correction roller 51A and the second correction roller 51B is controlled by the state of the speed _{V 1,} to fed the paper S by the correction after adjusting region 105 (Step S25).

Then, CPU 31, when a predetermined time _{t 4} either from the detection of the sheet S in the first tilt detection sensor 34a and the second tilt detection sensor 34b has elapsed, controls the gripper driving portion 71, the gripper member 61 Is started, that is, acceleration is started (step S27). Then, as shown in FIG. 8, the moving speed of the conveying direction X in the gripper member 61 is accelerated to the speed V _2. As a result, the gripper member 61 approaches the sheet S conveyed by the first correction roller 51A and the second correction roller 51B from the rear in the conveying direction X, that is, from the upstream side.

Further, when the post-correction low speed region 107 shown in FIG. 8 has elapsed, the CPU 31 controls the first roller driving unit 53A and the second roller driving unit 53B, and sets the conveyance speeds of the first correction roller 51A and the second correction roller 51B. V ₁ is accelerated to V ₂ (step S28).

  Next, as shown in FIG. 10B, the gripper member 61 catches up with the sheet S conveyed by the first correction roller 51A and the second correction roller 51B. The gripper member 61 rotates the upper gripper 82 and holds the edge of the paper S by the upper gripper 82 and the lower gripper 81 (step S29).

  Next, as shown in FIGS. 11A and 11B, the CPU 31 controls the gripper moving mechanism 62 to move the gripper member 61 downward in the vertical direction Z to convey the paper S to the paper stacking unit 38. The sheets S are stacked on the stacking tray 38a.

Here, as shown in FIG. 8, the first correction roller 51A and the second correction roller 51B, when the corrected adjusting region 105 passes, paper corrected low speed region 107 in the speed _{V 1} is conveyed at the speed _{V 1} S Transport. Then, the first correction roller 51A and the second correction roller 51B, when the low-speed region 107 has elapsed after the correction, through the acceleration region 108, is accelerated from the speed _{V 1} to velocity _{V 2.}

The gripper member 61 is accelerated from the stop state (0) to the speed V < _b > ₂ through the gripper-side acceleration region 110. When accelerated to the speed V ₂ , the gripper member 61 moves along the transport direction X at the speed V ₂ . The areas moving at this speed V ₂ are the gripper side high speed areas 111 and 120.

  Here, the integrated value of the corrected low speed region 107 and the integrated value of the acceleration region 108, that is, the value obtained by adding the distances of the first correction roller 51A and the second correction roller 51B for transporting the paper S is shown in FIG. This is the same as the sum of the integral values (movement distance in the transport direction X) of the gripper side acceleration region 110 and the first gripper side high speed region 111 of the member 61. Further, the moving speed of the gripper member 61 is obtained by adding the integral value of the gripper side acceleration area 110 and the first gripper side high speed area 111 (movement distance in the transport direction X) to the integral value of the second gripper side high speed area 120. Set from the value added.

  Here, as shown in FIG. 10A, the standby position of the gripper member 61 is located behind the sheet S to be conveyed. Therefore, in order for the gripper member 61 to catch up with the conveyed paper S, it is necessary to consider the standby position of the gripper member 61 and the distance to the paper S when the gripper member 61 starts moving. The integral value of the second gripper side high speed region 120 is a value set in consideration of the distance between the gripper member 61 and the paper S, and is a value indicating the amount of movement that the gripper member 61 catches up with the paper S. is there.

  That is, the CPU 31 sets the moving speed of the gripper member 61 in the transport direction X based on the transport speed of the first correction roller 51A and the second correction roller 51B after the correction operation is completed.

  Accordingly, the paper S can be held by the gripper member 61 without stopping the conveyance of the paper S by the first correction roller 51A and the second correction roller 51B. As a result, since the transport operation of the paper S does not stop, it is possible to suppress a decrease in productivity.

Further, the moving speed in the transport direction X when the gripper member 61 holds the paper S is set to the same speed V ₂ as the transport speed V ₂ of transporting the paper S on the first correction roller 51A and the second correction roller 51B. Has been. Accordingly, it is possible to prevent the paper S from being wrinkled due to the speed difference when the gripper member 61 holds the paper S.

Further, the sheet stacking apparatus 30 of the present embodiment, as shown in the process of step 28, and the conveying speed of the sheet S is again accelerated to the speed V ₂ of the first correction roller 51A and the second correction roller 51B after the correction . Thereby, the conveyance speed of the paper S can be increased, and productivity can be improved. Note that the conveyance speed of the paper S on the first correction roller 51A and the second correction roller 51B after correction is not limited to the example of accelerating to the speed V2, and the first correction roller 51A and the second correction roller after correction are not limited. The conveyance speed of the paper S in 51B may not be accelerated.

In the above-described example, the example in which the pre-correction adjustment area 101 and the post-correction adjustment area 105 are provided in step S16, step S21, and step S25 has been described. However, the present invention is not limited to this, and the pre-correction adjustment area is provided. 101, the post-correction adjustment area 105 may not be provided. Then, an example has been described in which either moves the gripper member 61 after a predetermined time t ₄ has passed from the detection of the sheet S in the first tilt detection sensor 34a and the second tilt detection sensor 34b, to It is not limited. The timing for starting the movement of the gripper member 61, the inclination of the paper first inclination detection sensor 34a and the second tilt detection sensor 34b detects, i.e. may be varied according to the time difference t ₁ of the detection.

  For example, the movement of the gripper member 61 is started after the correction of the inclination of the sheet S by the first correction roller 51A and the second correction roller 51B is completed without providing the post-correction adjustment area 105 and the preliminary correction area 106. In the example shown in FIG. 8, the movement of the gripper member 61 may be started after the deceleration region 102 of the second correction roller 51B is completed.

  The embodiment of the paper stacking apparatus and the image forming system has been described above including the effects thereof. However, the paper stacking apparatus and the image forming system of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention described in the claims. is there.

  In the embodiment described above, a color image is formed using four sets of image forming units. However, as an image forming apparatus according to the present invention, a single color image is formed using one image forming unit. It is good also as a structure. Further, the image forming apparatus is not limited to a copying machine, but may be a printer, a facsimile, or a multifunction machine having a plurality of functions.

  In the above-described embodiment, the example in which the control of the paper stacking mechanism 37 is performed by the CPU 31 of the paper stacking device 30 has been described. However, the present invention is not limited to this, and for example, by the CPU 11 of the image forming apparatus 10. The paper stacking mechanism 37 may be controlled.

  In this specification, words such as “parallel” and “orthogonal” are used, but these do not mean only strict “parallel” and “orthogonal”, but include “parallel” and “orthogonal”. Further, it may be in a state of “substantially parallel” or “substantially orthogonal” within a range where the function can be exhibited.

  DESCRIPTION OF SYMBOLS 1 ... Image forming system, 10 ... Image forming apparatus, 11 ... CPU (control part), 30 ... Paper stacking apparatus, 31 ... CPU (control part), 34 ... Paper detection part, 34a ... 1st inclination detection sensor, 34b ... Second tilt detection sensor 35 ... conveying roller 37 ... paper stacking mechanism 38 ... paper stacking unit 38a ... stacking tray 39 ... conveying path 41 ... stacking conveying unit 42 ... casing 42a ... contact surface 51A ... first correction roller, 51B ... second correction roller, 52 ... paper holding section, 53A ... first roller driving section, 53B ... second roller driving section, 61 ... gripper member, 62 ... gripper moving mechanism, 6, 74 ... Drive belt, 75 ... Guide rail, 77 ... Connecting member, 81 ... Lower gripper, 82 ... Upper gripper

Claims (7)

A paper stacking unit on which paper is loaded;
A paper detection unit that is disposed upstream of the paper stacking unit in the paper conveyance direction and detects the conveyed paper;
A pair of correction rollers disposed upstream of the paper stacking unit in the transport direction, transports the paper, and corrects the inclination of the paper;
The sheet stacking unit holds the sheet in a state in which the sheet is inclined from the upstream side in the conveyance direction with respect to the sheet whose inclination is corrected by the pair of correction rollers and is conveyed by the pair of correction rollers. A paper holding unit to be loaded on
A control unit that controls the pair of correction rollers and the sheet holding unit based on detection information detected by the sheet detection unit;
The control unit controls the conveyance speed of the paper in the pair of correction rollers based on the detection information detected by the paper detection unit, and based on the conveyance speed of the pair of correction rollers after correcting the inclination of the paper. A paper stacking device that controls a moving speed of the paper holding unit in the transport direction. The paper stacking apparatus according to claim 1, wherein the control unit starts movement of the paper holding unit in the transport direction based on a timing at which the paper detection unit detects the paper. The paper detection unit includes a first inclination detection sensor and a second inclination detection sensor that are spaced apart from each other in a width direction orthogonal to the conveyance direction of the paper.
The control unit calculates a difference between a time when the first inclination detection sensor detects the paper and a time when the second inclination detection sensor detects the paper, and the pair of correction rollers based on the calculated time difference. The paper stacking apparatus according to claim 1, wherein the paper stacking device is controlled. The control unit calculates a distance from the standby position of the sheet holding unit to the sheet when the sheet holding unit starts moving, based on an integral value of the conveyance speeds of the pair of correction rollers after correcting the sheet inclination. The paper stacking apparatus according to claim 1, wherein the moving speed of the paper holding unit is set from the added value. The said control part controls the moving speed of the said paper holding part, and the conveyance speed of a pair of said correction | amendment roller to the same speed, when the said paper holding part hold | maintains the said paper. The paper stacking device described in 1. The control unit decelerates the pair of correction rollers based on detection information detected by the sheet detection unit, and accelerates the pair of correction rollers after correcting the inclination of the sheet. The paper stacking device described in 1. An image forming apparatus for forming an image on paper;
A paper stacking device for transporting the paper from the image forming apparatus,
The image forming system to which the paper stacking device according to claim 1 is applied as the paper stacking device.

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