JP2007084302A - Sheet processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet processing device capable of making a skew correction and performing an accurate punching process. <P>SOLUTION: A first transport roller is installed upstream in the sheet transporting path while a second transport roller is arranged in the downstream, and a punch unit is provided between the first and second transport rollers, in which the second transport roller is rotated reversely for feeding a sheet reversely upon sensing that the trailing edge of the sheet being transported has passed the first transport path, and a stopper is allowed to emerge in the position where the sheet trailing edge is fed reversely for the prescribed distance to cause the sheet fed reversely to run against the stopper. Thereby the skew is corrected. A boring process is applied by the punch unit to this sheet with the skew corrected, and the sheet is transported by rotating the two transport rollers in the regular direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet processing apparatus that performs skew correction and punch processing on sheets discharged from an image forming apparatus such as an MFP (Multi Function Peripherals), which is a digital multifunction peripheral, a copying machine, or a printer.

  In image forming apparatuses such as MFPs, copiers, and printers, post-processing is performed on the paper discharge unit of the main body of the image forming apparatus in order to sort sheets after image formation or to perform post-processing such as stapling and punching. Devices are provided adjacent to each other.

  In such a post-processing apparatus, the paper discharged from the image forming apparatus may be skewed (hereinafter referred to as skew) with respect to the conveyance direction. As a result, there will be a hindrance when filing. For this reason, the skew correction means is provided to correct the skew of the paper and perform the punching process.

  For example, Patent Document 1 discloses an example in which a punch unit is provided for an image-formed paper that is conveyed, and the skew is corrected by abutting the paper against a nipper of an inlet roller provided on the upstream side of the punch unit. Are listed. However, in the example of Patent Document 1, since there is a distance between the correction of the paper skew and the arrival at the punch unit, there is a possibility that the skew may occur while the paper is transported within this distance. is there.

Further, Patent Document 2 discloses an example in which a registration member (registration roller) is disposed on the downstream side of the punching unit, and the leading edge of the sheet is brought into contact with the registration member by the conveying force of the sheet discharge roller of the image forming apparatus main body to correct the skew. Are listed. However, in the example of Patent Document 2, since the conveyance force of the discharge roller of the image forming apparatus main body is used, accuracy is required in setting the positions of the image forming apparatus main body and the post-processing apparatus, and the mechanical configuration of the post-processing apparatus. There is a problem of being restricted.
JP 2002-274699 A JP 2002-193493 A

  In the conventional image forming apparatus described above, skew correction is performed on the paper ejected from the image forming apparatus to perform punch processing. However, after the skew is corrected, the paper reaches the punch unit. Skew may occur. Further, when the skew feeding is performed using the conveying force of the sheet discharge roller of the image forming apparatus main body, there is a problem that the mechanical configuration of the post-processing apparatus is limited, and further improvement is required.

 The present invention has been made in view of the above circumstances, and an object thereof is to provide a paper processing apparatus capable of performing skew correction and accurate punch processing.

The invention of the present application is a paper processing apparatus that performs a punching process on a paper that has been carried in and carries it out, and includes a first transport roller disposed upstream of the paper transport path and a first transport roller disposed downstream. A sheet conveying unit that has two conveying rollers and conveys the sheet from the upstream side to the downstream side by normal rotation of the first and second conveying rollers; and is provided between the first and second conveying rollers, A punch unit for perforating the paper;
When the trailing end of the sheet in the middle of conveyance passes the first conveying roller, the second conveying roller is rotated in the reverse direction to reversely feed the sheet, and the sheet trailing end is stopped at a position where it is reversely fed by a predetermined distance. And a skew correction unit that corrects skew by abutting the reversely fed paper against the stopper, and punching the skew-corrected paper by the punch unit, The first and second transport rollers are rotated forward to transport the paper.

 The invention of the present application is a paper processing apparatus for carrying out a punching process for a paper that has been carried in and carrying it out, and a first transport roller disposed on the upstream side of the paper transport path and a downstream side. A sheet conveying section having a second conveying roller and conveying the sheet from the upstream side to the downstream side by normal rotation of the first and second conveying rollers; provided between the first and second conveying rollers A punch unit having a perforating blade for perforating the paper; and the second transport roller is reversely rotated when a terminal portion of the paper in the middle of transport passes the first transport roller. When the paper is fed back, a stopper is made to appear at a position shifted to the upstream side of the conveying path by a predetermined distance from the punching position of the punch unit at the time of reverse feeding, and the paper fed back is abutted against the stopper and skewed. To correct A punch correction unit; and determining a punching position of the paper according to a distance between the punching blade of the punch unit and the stopper, and subjecting the skew-corrected paper to a punching process in the vicinity of the end of the paper. It is characterized by being applied.

 According to the present invention, when the paper is transported from the upstream to the downstream, the skew is corrected by temporarily feeding the paper back and hitting the stopper, and the punching process is performed while the skew is corrected. It is possible to provide a paper processing apparatus capable of performing punch processing at a regular position.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram schematically showing the overall configuration of an image forming apparatus provided with a paper processing apparatus of the present invention, and FIG. 2 is a block diagram for explaining the configuration of the main part of the paper processing apparatus of the present invention.

  FIG. 1 shows an example of an MFP (Multi Function Peripherals) as an image forming apparatus. In FIG. 1, an image forming apparatus 10 includes a scanner unit 11, an automatic document feeder (ADF) 12, and an operation unit 13 in the upper part, a printer unit 14 in the central part, and a paper feeding part 15 in the lower part. is doing. In the image forming apparatus 10, a finisher 20 that performs post-processing such as punching and stapling is disposed adjacently.

  The printer unit 14 is, for example, a tandem color laser printer. In general, the laser beam from the laser 141 is reflected by a polygon mirror, and the surface of the photoconductor 142 is scanned and exposed to create an electrostatic latent image. Then, a toner image is formed and transferred onto a sheet of paper, and a charging device 143, a developing device 144, a transfer device 145, and the like are disposed around the photosensitive drum 142. The developing device 144 is supplied with toner from a toner cartridge. When performing color printing processing, for example, toner cartridges of four colors of cyan, magenta, yellow, and black are arranged in a line, and a photosensitive drum and an optical unit are provided for each color.

  The paper supply unit 15 is provided with a plurality of paper supply cassettes for storing various sizes of paper. From these paper supply cassettes, the paper P is sent to the transport belt 16 to form an image. ing. The paper P on which the image is formed is discharged through the paper discharge unit 17 and conveyed to the finisher 20.

  The finisher 20 performs post-processing such as stapling and punching and discharges the paper to either one of the paper discharge trays 21 and 22. The paper discharge trays 21 and 22 are lifted and lowered by the paper discharge tray driving unit, and the paper is discharged to one of the trays.

 The finisher 20 is provided with a sheet processing apparatus 30 which is a characteristic part of the present invention. The sheet processing apparatus 30 includes a punch unit 40 that performs a punching process on the sheet P conveyed from the image forming apparatus 10 and a skew correction unit 50 that corrects a skew of the sheet before the punching process.

 FIG. 2 shows a specific configuration of the sheet processing apparatus 30. In FIG. 2, reference numeral 40 denotes a punch unit, which includes a punching blade 41, an eccentric cam 42 for driving the punching blade 41 in the vertical direction in the figure, a punch motor 43 for rotationally driving the eccentric cam 42, and a punch die 44. It is configured. The punch die 44 is composed of an upper die 441 and a lower die 442, and the paper P is conveyed between the dies 441 and 442. The direction of the punch die 44 (perpendicular to the conveyance direction of the paper P). The punching process is performed by reciprocating the perforating blade 41 in the direction in which the punching is performed.

 On the other hand, first and second transport rollers 51 and 52 are arranged on the paper carry-in side and the carry-out side of the punch unit 40, and these transport rollers 51 and 52 are rotationally driven by transport motors 53 and 54. The first transport roller 51 is composed of upper and lower roller pairs 511 and 512, and is rotated by a transport motor 53 to transport the paper P so as to be sandwiched between the roller pairs.

 Similarly, the second transport roller 52 is composed of upper and lower roller pairs 521 and 522, and is rotated by a transport motor 54 to transport the paper P so as to be sandwiched between the roller pairs. The second transport roller 52 can also be rotated in reverse by the transport motor 54 and is driven to rotate in a forward rotation state in which the paper P is transported to the discharge trays 21 and 22 or in a reverse rotation state in which the paper P is transported in the reverse direction. .

 Further, the second conveying roller 52 can change the joining state of the roller pair 521 and 522 by the load controller 55, and has a registration roller function in which the roller pair 521 and 522 are in strong contact and a slip roller function in which the roller pair 521 and 522 are in light contact. In the forward rotation state, it becomes a registration roller, and in the reverse rotation state, it becomes a slip roller.

 Further, a sensor 56 is disposed between the carry-in side of the punch unit 40 and the first transport roller 51 so as to detect the transport state of the paper P. In the embodiment of the present invention, the paper P is conveyed in the direction of the arrow X in an inverted state (a state where the surface is the lower side of the figure). Various examples of the inside-out mechanism can be considered.

 FIG. 3 is a block diagram showing a control system of the image forming apparatus 10 and the sheet processing apparatus 30 of the present invention. In FIG. 3, reference numeral 61 denotes a control unit, which is composed of a microprocessor including a CPU. Reference numeral 62 denotes a motor drive circuit for driving the punch motor 43, and reference numerals 63 and 64 denote motor drive circuits for driving the transport motors 53 and 54. The control unit 61 controls the load controller 55 and receives the detection result from the sensor 56.

 A control unit 65 controls the image forming apparatus 10 and includes a microprocessor including a CPU. The control unit 61 and the control unit 65 transmit information to each other, and the image forming operation and the finisher 20 are controlled. The operation is coordinated. Various instructions from the user are input to the control unit 65 via the operation unit 13, and the operations of the printer 14, the paper feeding unit 15, and the like are controlled according to the instructions, and the paper P on which the image is formed is sent to the finisher 20. Transport.

 Next, the operation of the sheet processing apparatus 30 according to the present invention will be described with reference to FIGS. First, FIG. 4A shows a state in which the paper P is being conveyed through the image forming apparatus 10. In this case, the first and second transport rollers 51 and 52 are both rotated forward by the transport motors 53 and 54, and the paper P is transported in the direction of the arrow X from upstream to downstream. Further, the punching blade 41 of the punch unit 40 is in an upward position away from the punch die 44.

 When the sheet P is conveyed further downstream, and the sensor 56 detects that the end of the sheet P has passed away from the first conveying roller 51 as shown in FIG. 4B, the motors 53 and 54 are stopped. The first and second transport rollers 51 and 52 are stopped. Then, while the first transport roller 51 is stopped, the pair of rollers of the second transport roller 52 are lightly contacted by the load controller 55 and rotated reversely by the motor 54.

 As a result, the paper P is transported (reversely fed) in the reverse direction by the second transport roller 54, and the end portion abuts against the first transport roller 51 as shown in FIG. 4C. That is, the first transport roller 51 serves as a stopper that appears at a position where the paper end portion is reversely fed by a predetermined distance. On the other hand, the second transport roller 52 functions as a slip roller at this time, and rotates in a reverse direction while being in light contact with the paper P. Therefore, when the paper P is skewed, the first transport roller 52 is slightly deflected. The skew is corrected to press against the 51 side. At this time, the sensor 56 detects that the paper P has returned and returned.

 When the return of the paper P is detected by the sensor 56, the second conveying roller 52 rotates in the reverse direction for a predetermined time and stops, and the eccentric cam 42 of the punch unit 40 is moved to the punch motor 43 as shown in FIG. , And the drilling blade 41 descends. As a result, the paper P is punched. Moreover, since the skew is corrected when punching, the punching is performed at an accurate position.

 After the punching process, the second conveyance roller 52 is controlled by the load controller 55 so as to function as a registration roller, and the conveyance rollers 51 and 52 are rotated forward by the motors 53 and 54, and the sheet P is shown in FIG. As indicated by E), the sheet is conveyed in the direction of arrow X and waits for the next sheet to be loaded. Thereafter, the operations of FIGS. 4A to 4E are repeated, and the sheets P are sequentially punched one by one and discharged to the discharge trays 21 and 22.

 The sensor 56 detects when the paper P is carried in, when the paper passes through the first transport roller, when the paper is back, and when it passes again, and notifies the control unit 61 of the detected result. Controls the motor drive circuits 62, 63, 64 and the load controller 55 in response to the detection result of the sensor 56.

 FIG. 5 is a plan view for explaining skew correction and punching processing, and shows a state in which the paper P once passes through the first transport roller 51 and is backed by the second transport roller 52 (not shown in FIG. 5). ing. When the paper P is skewed as indicated by a solid line, when the paper P is returned in the reverse direction by the second conveyance roller 52, the paper P hits the first conveyance roller 51 and is pushed back. Skew is corrected. Then, since the punching process is performed by the punch unit 40, the paper P is carried out after being punched H at a regular position.

 Note that the punching position by the punching process is set to a predetermined distance L1 (for example, 12 mm) from the conveyance direction end portion p0 of the paper P, for example, and therefore the distance L2 between the first conveyance roller 51 and the punching blade 41 is set as a dimension. It is important to set L2≈L1 in consideration of L1.

 As described above, in the paper processing apparatus 30 of the present invention, the paper P is transported from the upstream to the downstream, and when the paper P passes through the first transport roller 51, the paper P is back in the reverse direction and abuts against the first transport roller 51. Since the skew is corrected and skew correction is performed on the upstream side in the sheet conveyance direction, punching can be performed while the skew is corrected, and punching can always be performed at a regular position.

  FIG. 6 is a block diagram showing another embodiment of the sheet processing apparatus 30 of the present invention. In FIG. 6, a shutter 57 is disposed between the sensor 56 and the first transport roller 51, and the shutter 57 is driven in the vertical direction by a motor 58. For example, when the shutter 57 is disposed below the transport path of the paper P, the shutter 57 can be projected in the transport path direction by the motor 58. That is, the shutter 57 serves as a stopper that appears at a position where the paper end portion is reversely fed a predetermined distance when the paper is reversely fed.

  That is, in the example of FIG. 2, when the paper P is transported in the reverse direction, the paper P is abutted against the first transport roller 51. However, in the example of FIG. 6, the shutter 57 is projected to the transport path and transported in the reverse direction. The sheet P is abutted against the shutter 57 and the skew is corrected. The timing at which the shutter 57 protrudes toward the transport path is when the sensor 56 detects that the end portion p0 of the paper P has passed (immediately after FIG. 4B), and the timing at which the shutter 57 is retracted is the end of the punching process. It is a time point (immediately before FIG. 4E).

  In order to control the forward / backward movement of the shutter 57 with respect to the conveyance path, a motor drive circuit 66 for driving the motor 58 is provided as shown within the dotted line in FIG. 3, and this motor drive circuit 66 is controlled by the control unit 61 and detected by the sensor 56. In response to the result, the movement of the shutter 57 is controlled.

 If the shutter 57 is used in this way, the paper P can be reliably abutted when the paper P is back, so that the skew can be corrected more accurately.

  As described above, according to the image forming apparatus and the paper processing apparatus of the present invention, skew correction and accurate punching can be performed.

    The present invention is not limited to the above description, and various modifications can be made without departing from the scope of the claims.

1 is a configuration diagram schematically showing the overall structure of an image forming apparatus provided with a paper processing apparatus of the present invention. The block diagram explaining the structure of one Embodiment of the paper processing apparatus of this invention. FIG. 3 is a block diagram illustrating a control system of the sheet processing apparatus according to the embodiment. FIG. 6 is an operation explanatory diagram illustrating an operation of the sheet processing apparatus according to the embodiment. FIG. 6 is a plan view for explaining the skew correction operation of the sheet processing apparatus according to the embodiment. The block diagram explaining the structure of other embodiment of the paper processing apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus 11 ... Scanner part 12 ... Automatic document feeder 13 ... Operation part 14 ... Printer part 15 ... Paper feed part 16 ... Conveyor belt 17 ... Paper discharge part 20 ... Finishers 21, 22 ... Paper discharge tray 30 ... Paper Processing device 40 ... Punch unit 41 ... Punching blade 42 ... Eccentric cam 43 ... Punch motor 44 ... Punch die 50 ... Skew correction unit 51 ... First transport roller 52 ... Second transport roller 53, 54 ... Transport motor 55 ... Load controller 56 ... Sensor 57 ... Shutter 58 ... Motor 61, 65 ... Control unit 62, 63, 64, 66 ... Motor drive circuit

Claims (10)

A paper processing apparatus for carrying out a punching process on a paper that has been carried in and carrying it out,
A first conveying roller disposed on the upstream side of the sheet conveying path, and a second conveying roller disposed on the downstream side, and the sheet is moved from the upstream side by forward rotation of the first and second conveying rollers. A paper transport section for transporting downstream;
A punch unit provided between the first and second transport rollers, for punching the paper;
When the trailing end of the sheet in the middle of conveyance passes the first conveying roller, the second conveying roller is rotated in the reverse direction to reversely feed the sheet, and the sheet trailing end is stopped at a position where it is reversely fed by a predetermined distance. And a skew correction unit that corrects skew by abutting the reversely fed paper against the stopper,
A paper processing apparatus, wherein after punching the skew-corrected paper by the punch unit, the paper is transported by rotating the first and second transport rollers forward.  The stopper is also used as the first conveying roller, and the first conveying roller has a pair of rollers, and conveys the sheet with the pair of rollers sandwiched between the pair of rollers. 2. The sheet processing apparatus according to claim 1, wherein the rotation of the sheet is stopped, the sheet fed backward is abutted against the stopped first transport roller, and the skew is corrected.  The stopper is configured by a shutter that can protrude with respect to the reverse feeding path, and protrudes into the conveyance path when the paper is reversely fed, so that the reversely fed paper abuts against the shutter to correct the skew. The sheet processing apparatus according to claim 1.  4. The sheet processing apparatus according to claim 3, wherein the shutter can be moved back and forth with respect to the reverse path by a driving motor.  The skew correction unit includes a sensor that detects that a terminal portion of a sheet in the middle of conveyance has passed the first conveyance roller and that the sheet has been reversely fed, and uses a detection result of the sensor. The sheet processing apparatus according to claim 1, wherein the rotation state of the first and second transport rollers is controlled.  The second transport roller has a pair of rollers, and transports the sheet with the paper sandwiched between the pair of rollers. When the second transport roller rotates in the reverse direction, the pair of rollers is in a lightly joined state. The sheet processing apparatus according to claim 1. A paper processing apparatus for carrying out a punching process on a paper that has been carried in and carrying it out,
A first conveying roller disposed on the upstream side of the sheet conveying path, and a second conveying roller disposed on the downstream side, and the sheet is moved from the upstream side by forward rotation of the first and second conveying rollers. A paper transport section for transporting downstream;
A punch unit provided between the first and second transport rollers and having a punching blade for punching the paper;
When the end portion of the paper in the middle of conveyance passes through the first conveyance path, the second conveyance roller is reversely rotated to reversely feed the paper, and at the time of reverse feeding, a predetermined distance from the punching position of the punch unit A skew correction unit that causes a stopper to appear only at a position shifted to the upstream side of the conveyance path, abuts the reversely fed paper against the stopper, and corrects skew.
The punching position of the paper is determined by the distance between the punching blade of the punch unit and the stopper, and the punching process is performed in the vicinity of the end of the paper on the skew-corrected paper. Paper processing device.  2. The sheet processing apparatus according to claim 1, wherein when the interval from the sheet end portion to the punching position is L1, the interval L2 between the punching position by the punch unit and the stopper is set to L2≈L1. . A paper processing apparatus for carrying out a punching process on a paper that has been carried in and carrying it out,
A first conveying roller disposed on the upstream side of the sheet conveying path, and a second conveying roller disposed on the downstream side, and the sheet is moved from the upstream side by forward rotation of the first and second conveying rollers. A paper transport section for transporting downstream;
A punch unit provided between the first and second transport rollers, for punching the paper;
When the trailing edge of the sheet in the middle of conveyance passes through the first conveyance path, the second conveyance roller is reversely rotated to reversely feed the paper, and the paper trailing edge is stopped at a position where it is reversely fed by a predetermined distance. And a skew correction unit for correcting the skew by abutting the reversely fed paper against the stopper,
A skew correction unit comprising: a control unit that detects a position of the sheet on the transport path and controls a rotation state of the first and second transport rollers, appearance of the stopper, and punch processing of the punch unit. A paper processing apparatus which carries out a punching process on the paper that has been used and carries it out.   The sheet processing apparatus according to claim 9, wherein a sensor is disposed adjacent to a downstream side of the first conveying roller to detect a position of the sheet on the conveying path.

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