JP6642158B2 - Post-processing device, image forming system, and control program - Google Patents

Description

  The present invention relates to a post-processing device, an image forming system, and a control program.

  An image forming system comprising: an image forming apparatus; and a post-processing apparatus that performs a punching process, a stapling process, a reversing process, a saddle stitching process, a flat stitching process, and the like on a sheet on which an image is formed by the image forming device. Is generally known.

  When a paper jam (also referred to as “paper jam”) occurs in such an image forming system, it is desired to reduce the burden on the user who responds to the paper jam. Normally, when the image forming system detects the occurrence of a paper jam in the paper transport path on which the paper is transported, the image forming system temporarily suspends the printing process being performed and restores the normal paper transport before the paper jam occurs. Jam processing is started. At this time, since the paper conveyance in the paper conveyance path is also temporarily stopped, the paper being conveyed may remain on the paper conveyance path. Hereinafter, the paper remaining on the paper transport path is referred to as “remaining paper”.

  Normally, in the jam processing, the image forming system first supplies a user with a remaining sheet that may be an obstacle to later sheet conveyance, such as a sheet that has caused a sheet jam (hereinafter, referred to as “jam-caused paper”). Urged to be removed from It is often difficult to mechanically remove such a residual sheet that may be an obstacle to sheet conveyance, and therefore it is necessary for the user to remove it. In this connection, recent image forming systems have been provided with a function of displaying information such as a position of a paper caused by jam or a removing method on a touch panel display or the like in order to reduce a burden on a user. There is something.

  Further, some image forming systems have a function of automatically discharging remaining paper on the paper transport path without relying on the user in order to reduce the burden on the user. After the user removes the remaining sheet that may be an obstacle to the sheet conveyance, a sheet that does not interfere with the sheet conveyance may remain on the sheet conveyance path. The image forming system mechanically and automatically conveys the sheet when the sheet that does not hinder the sheet conveyance remains on the sheet conveyance path and discharges the sheet outside the image forming system (hereinafter, referred to as a residual sheet). Paper "auto purge"). In connection with this, for example, Japanese Patent Application Laid-Open No. H11-163,009 discloses a technique for controlling conveyance while sequentially grasping sheets remaining on the sheet conveyance path after a jam processing by a sensor arranged on the sheet conveyance path. Further, for example, Patent Document 2 below discloses a technique for determining whether re-use of automatically purged paper is appropriate when a paper conveyance failure occurs.

  However, when the user opens the door on the front of the post-processing device and pulls out the pedestal containing the paper transport path, the user mistakenly removes the residual paper that interferes with the automatic purging, such as paper caused by jam. The remaining paper that can be automatically purged may be moved. For example, when the user removes the paper caused by jams, the remaining paper that can be automatically purged is noticeable and may be pulled out by mistake, or the position of the automatically purged residual paper may be shifted when the release work lever is operated. May be lost. As a result, when the automatic purging is started, a phenomenon may occur in which the state of the remaining sheet recognized by the post-processing apparatus is different from the state of the actual remaining sheet on the sheet conveyance path. In this case, the post-processing device will face an unexpected situation, such as missing residual paper or the position of the residual paper has changed, and will not be able to properly complete the ongoing print job. There is a risk.

JP-A-62-85261 JP 2009-184795 A

  The present invention has been made in view of the above problems. Therefore, an object of the present invention is to provide a post-processing apparatus, an image forming system, and a control program that can properly complete a print job that is being executed even if residual paper that can be automatically purged is moved before the automatic purge is started. To provide.

  The above object of the present invention is achieved by the following.

  (1) a paper introduction unit for introducing paper, a paper discharge unit for discharging the paper introduced by the paper introduction unit to the outside, a post-processing unit for performing a predetermined process on the paper, and the paper A paper transport path that connects the introduction section and the paper discharge section, and transports the paper along the paper transport path; and a paper detection section that detects the paper passing through the paper transport path. A control unit that controls the paper transport unit and the paper detection unit, wherein the control unit temporarily stops the paper transport when an abnormal situation occurs during the transport of the paper in the paper transport path. When the abnormal situation is resolved and the sheet conveyance is resumed after the interruption, and the plurality of sheets remaining on the sheet conveyance path are discharged to the outside, the sheets are conveyed one by one along the sheet conveyance path. About the plurality of sheets to be Based on the detection result of each of the papers detected by the paper detection unit, a time interval for each of the plurality of continuously conveyed papers is measured, and based on the measured time intervals, the paper A post-processing device that specifies a sheet that has been moved before restarting the sheet conveyance among a plurality of sheets remaining on the conveyance path.

  (2) The post-processing device according to (1), wherein the control unit compares the time interval of the plurality of sheets with a specified value, and specifies a moved sheet based on a comparison result.

  (3) The post-processing device according to (2), wherein the specified value is adjusted within a predetermined range.

  (4) The post-processing device according to (3), wherein the specified value is adjusted according to a type, size, or basis weight of the paper.

  (5) The post-processing device according to (3), wherein the specified value is adjusted according to a type of a drive motor provided in the paper transport unit.

  (6) a paper introduction unit for introducing paper, a paper discharge unit for discharging the paper introduced by the paper introduction unit to the outside, a post-processing unit for performing predetermined processing on the paper, and the paper A paper transport path for connecting the introduction section and the paper discharge section; a paper transport section for transporting the paper along the paper transport path; and detecting the paper passing through a first position on the paper transport path. A first sheet detecting unit that detects the sheet passing through a second position on the sheet conveying path downstream of the first position in the sheet conveying direction, and a second sheet detecting unit that detects the sheet. A control unit that controls a transport unit and the first and second paper detection units, wherein the control unit is configured to, when an abnormal situation occurs during the transport of the paper in the paper transport path, perform the paper transfer. Abnormalities after temporarily stopping transport When the paper conveyance is resumed after the state is resolved and the paper remaining on the paper conveyance path is discharged to the outside, the paper conveyance is interrupted after the paper is detected by the first paper detection unit. And a second time from when the paper conveyance is restarted until the paper is detected by the second paper detection unit is measured, and the first and second times are measured. Based on the distance between the first position and the second position, and the paper transport speed of the paper, of the paper remaining on the paper transport path, the paper moved before restarting the paper transport Identify the post-processing device.

  (7) The control unit is configured to perform, based on the first time, the distance, and the paper transport speed of the paper, from when the paper transport is restarted until each of the papers reaches the second position. Calculating the expected arrival time, and comparing the estimated arrival time with the second time, among the sheets remaining on the sheet conveyance path, before restarting the sheet conveyance. The post-processing device according to (6), wherein the moved paper is specified.

  (8) The post-processing device according to (7), wherein the expected arrival time is adjusted within a predetermined range.

  (9) The post-processing device according to (8), wherein the estimated arrival time is adjusted according to the type, size, or basis weight of the paper.

  (10) The post-processing device according to (8), wherein the estimated arrival time is adjusted according to a type of a drive motor provided in the paper transport unit.

  (11) The post-processing device according to any one of (1) to (10), wherein the control unit notifies a user of information on the specified moved sheet.

  (12) The control unit according to any one of (1) to (11), wherein the control unit specifies a sheet that has been moved to another position on the sheet conveyance path before restarting the sheet conveyance. Processing equipment.

  (13) The post-processing device according to any one of (1) to (12), wherein the control unit specifies a sheet that has been moved to the outside of the sheet conveyance path before restarting the sheet conveyance. .

  (14) The image forming apparatus according to any one of (1) to (13), wherein the image forming apparatus forms an image on a sheet, and post-processing is performed on the sheet on which the image is formed. An image forming system, comprising: a post-processing device.

  (15) A control program for an image processing system including an image forming apparatus and a post-processing apparatus, wherein when an abnormal situation occurs during conveyance of a sheet in a sheet conveyance path of the post-processing apparatus, the sheet conveyance is temporarily stopped. Temporarily stopping the sheet conveyance, resuming the sheet conveyance so as to discharge the plurality of sheets remaining on the sheet conveyance path to the outside of the post-processing device after the abnormal situation is resolved, and the sheet conveyance A step of detecting the plurality of sheets conveyed one by one along a path and measuring a time interval between two sheets conveyed continuously; and A step of specifying, among a plurality of sheets remaining on the conveyance path, a sheet that has been moved before restarting the sheet conveyance, a computer-executable process.

  (16) A control program for an image processing system including an image forming apparatus and a post-processing apparatus, wherein when an abnormal situation occurs during the conveyance of a sheet in a sheet conveyance path of the post-processing apparatus, the sheet conveyance is temporarily stopped. Temporarily stopping the sheet, restarting the sheet conveyance so as to discharge the sheet remaining on the sheet conveyance path to the outside of the post-processing device after the abnormal situation is resolved, and executing the sheet conveyance A first time from the passage of the first position of the path to the interruption of the sheet conveyance, and a first time from the restart of the sheet conveyance to the arrival of the sheet at the second position of the sheet conveyance path. 2, the time for measuring the time, the first and second times, the distance between the first position and the second position, and the paper transport speed of the paper based on the paper transport speed. Of the paper remaining on the road, To execute a procedure to locate the moved sheet before resuming paper conveyed to a computer, the control program.

  (17) A procedure for reprinting a page of a print job corresponding to the moved paper on new paper before restarting the paper transport, and performing a recovery process using the reprinted new paper. The control program according to the above (15) or (16), further comprising:

  According to the present invention, since the remaining paper moved before the automatic purge is started is specified, the state of the remaining paper grasped by the post-processing device and the state of the remaining paper on the actual paper conveyance path are different. Can be prevented or suppressed. Therefore, the post-processing device can appropriately complete the print job being executed.

FIG. 1 is a perspective view illustrating a configuration of an image forming system according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the image forming system shown in FIG. 1 taken along the line II-II. FIG. 2 is a schematic block diagram illustrating a hardware configuration of the image forming system shown in FIG. 1. 5 is a flowchart illustrating a control method according to the first embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a control method when a sheet remains in a second post-processing device in the first embodiment of the present invention. FIG. 5 is a conceptual diagram illustrating a method of specifying a moved sheet based on a time interval between two sheets that are continuously conveyed in the first embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a recovery operation setting screen according to the first embodiment of the present invention. FIG. 9 is a schematic diagram illustrating a control method when a sheet remains in a third post-processing device in the first embodiment of the present invention. 9 is a flowchart illustrating a control method according to the second embodiment of the present invention. FIG. 9 is a conceptual diagram illustrating a method of specifying a moved sheet based on a time from when automatic purging is started to when a remaining sheet reaches a sheet sensor disposed downstream of a first sheet conveyance path. .

  Hereinafter, an embodiment of a post-processing device, an image forming system, and a control program of the present invention will be described with reference to the attached drawings. In the drawings, the same members are denoted by the same reference numerals. In addition, the dimensional ratios in the drawings are exaggerated for convenience of description, and may be different from the actual ratios.

(First embodiment)
<Image forming system 100>
FIG. 1 is a perspective view illustrating the configuration of the image forming system according to the first embodiment. As shown in FIG. 1, the image forming system 100 according to the present embodiment includes a sheet feeding device 110, an image forming device 120, a first post-processing device 130, a second post-processing device 140, and a third post-processing device 150. Having. Note that the configuration of the image forming system 100 shown in FIG. 1 is an example, and the type and number of apparatuses included in the image forming system 100 are not limited to the example shown in FIG.

<Paper feeding device 110>
The sheet feeding device 110 supplies a sheet to the image forming apparatus 120 according to an instruction from the image forming apparatus 120. The paper feeding device 110 has a plurality of paper feeding trays and can store a large amount of a plurality of types of paper having different sizes and thicknesses.

<Image forming apparatus 120>
FIG. 2 is a schematic sectional view taken along line II-II of the image forming system 100 shown in FIG. 1, and FIG. 3 is a schematic block diagram illustrating a hardware configuration of the image forming system 100 shown in FIG. The illustration of the sheet feeding device 110 is omitted in FIGS. 2 and 3.

  The image forming apparatus 120 is disposed between the sheet feeding device 110 and the first post-processing device 130, and includes an image reading unit 121, an image forming unit 122, a sheet feeding unit 123, a sheet conveying unit 124, an operation display unit 125, It has a communication unit 126 and a control unit 127. These components are interconnected by an internal bus B1.

  The image reading unit 121 includes an optical system including a mirror, a lens, and the like, and a reading sensor. The image reading unit 121 reads a document placed on a reading surface or a document conveyed by an ADF (Auto Document Feeder) and outputs an image signal.

  The image forming unit 122 converts the print job or the image signal received from the client terminal through the network using a known image forming process such as an electrophotographic process including the steps of charging, exposing, developing, transferring, and fixing. An image is formed on a sheet based on the image.

  The paper supply unit 123 supplies paper as a recording material used for printing. The paper supply unit 123 has a plurality of paper trays, and each paper tray stores plain paper of, for example, A4, A3, or B5 size for each size.

  The paper transport unit 124 transports paper in the image forming apparatus 120. The paper transport unit 124 has a paper transport path, and the paper supplied from the paper feed unit 123 or the paper feed device 110 is transported to the image forming unit 122 through the paper transport path. In the image forming unit 122, the sheet on which the image is formed is output to the outside of the image forming apparatus 120 through the sheet discharging unit, and is supplied to the first post-processing apparatus 130.

  The operation display unit 125 has, for example, a display and a keyboard or a touch panel, and functions as an input unit and an output unit. The keyboard has a plurality of keys such as a selection key for designating a sheet size, a numeric keypad for setting the number of copies, a start key for instructing start of operation, and a stop key for instructing stop of operation. The input unit is used by the user to perform various instructions (input) such as character input, various settings, and a start instruction. The output unit is used for presenting the device configuration, the progress status of the print job, the occurrence status of the paper jam, the occurrence status of the error, the currently changeable setting, and the like to the user. In the present embodiment, the output unit is used to display a recovery operation setting screen described later, and the input unit is used to input a user's instruction from the recovery operation setting screen.

  The communication unit 126 is connected to a client terminal such as a personal computer via a network, and transmits and receives data such as a print job. The network includes various networks such as a local information network (LAN: Local Area Network), a wide area information network (WAN: Wide Area Network) in which LANs are connected by a dedicated line, the Internet, and a combination thereof. The LAN standard is, for example, Ethernet (registered trademark), token ring, or FDDI (Fiber-Distributed Data Interface). The communication protocol is, for example, TCP / IP (Transmission Control Protocol / Internet Protocol).

  Further, the communication unit 126 is communicably connected to the first post-processing device 130 via an inter-device communication line C1.

  The control unit 127 controls the image reading unit 121, the image forming unit 122, the sheet feeding unit 123, the sheet conveying unit 124, the operation display unit 125, and the communication unit 126. The control unit 127 includes an auxiliary storage device (not shown), a memory, and a CPU (Central Processing Unit). These components are communicably connected to each other via a bus. The control unit 127 plays a role as a print controller.

  The auxiliary storage device includes a large-capacity storage device such as a hard disk drive and a flash memory. The memory includes a RAM (Random Access Memory) and a ROM (Read Only Memory). The RAM stores calculation results, jam occurrence information, and the like accompanying execution of the CPU. The jam occurrence information is information regarding a paper jam that has occurred in the image forming system 100.

  The CPU of the control unit 127 executes a control program for the image forming apparatus. The control program for the image forming apparatus is stored in the auxiliary storage device, and is loaded into the RAM of the memory of the control unit 127 when executed by the CPU of the control unit 127. The CPU of the control unit 127 controls the image reading unit 121, the image forming unit 122, the sheet feeding unit 123, the sheet conveying unit 124, the operation display unit 125, and the communication unit 126 according to a control program for the image forming apparatus.

<First post-processing device 130>
The first post-processing device 130 includes a sheet introducing unit 131, a sheet discharging unit 132, a sheet conveying unit 133, a sheet reversing unit 134, a PI (Page Inserter) inserting unit 135, a sheet detecting unit 136, a communication unit 137, and a control unit 138. Having. These components are interconnected by an internal bus B2. The first post-processing device 130 of the present embodiment is disposed between the image forming device 120 and the second post-processing device 140, and functions as a reverse transport device.

  The paper introduction unit 131 introduces the paper supplied from the image forming apparatus 120 and supplies the paper to the paper transport unit 133. The paper discharge unit 132 discharges the paper transported by the paper transport unit 133 to the outside of the first post-processing device 130.

  The paper transport section 133 includes a first paper transport path 133a, a second paper transport path 133b, a third paper transport path 133c, and a fourth paper transport path 133d. The paper transport unit 133 transports the paper along the first paper transport path 133a, the second paper transport path 133b, the third paper transport path 133c, or the fourth paper transport path 133d.

  Each of the paper transport paths 133a, 133b, 133c, and 133d includes a guide member (not shown) for guiding the transported paper. The paper transport section 133 includes a plurality of transport rollers (not shown) and a drive motor, and the transport rollers are arranged in pairs along the guide member. Further, the drive motor is attached to each of the transport rollers, and drives the transport rollers in accordance with an instruction from the control unit 138.

  The first paper transport path 133a is a paper transport path that connects between the paper introduction unit 131 and the paper discharge unit 132. The second paper transport path 133b is a paper transport path that branches off from the first paper transport path 133a and connects the first paper transport path 133a and the paper reversing unit 134. The paper introduced from the paper introduction unit 131 is transported to a first gate (not shown) located at a branch point between the first paper transport 133a and the second paper transport path 133b. One of the first paper transport path 133a and the second paper transport path 133b is selected by the first gate, and the paper is transported along the selected paper transport path.

  The third paper transport path 133c is a paper transport path that connects between the paper reversing unit 134 and the first paper transport path 133a. The sheet conveyed from the sheet reversing unit 134 passes through the third sheet conveying path 133c and joins the first sheet conveying path 133a.

  The fourth paper transport path 133d is a paper transport path that connects between the PI insertion unit 135 and the first paper transport path 133a. The paper transported from the PI insertion unit 135 passes through the fourth paper transport path 133d and joins the first paper transport path 133a.

  The sheet reversing section 134 includes a sheet conveying path extending downward from a connection between the sheet reversing section 134 and the second sheet conveying path 133b. The sheet reversing unit 134 conveys the sheet conveyed from the second sheet conveyance path 133b downward to a predetermined position along the sheet conveyance path, and then reverses the traveling direction of the sheet to perform the third sheet conveyance. The sheet is turned over by being conveyed toward the path 133c. The sheet whose front and back are reversed is transported from the second paper transport path 133c to the paper discharge unit 132 through the first paper transport path 133a, and is discharged outside the first post-processing device 130. The sheet reversing unit 134 functions as a post-processing unit.

  The PI insertion unit 135 supplies the insertion sheets placed on the tray one by one to the fourth sheet conveyance path 133d.

  The paper detection unit 136 includes a plurality of paper sensors installed at predetermined locations on the paper transport path including the first to fourth paper transport paths 133a, 133b, 133c, and 133d. Each sheet sensor notifies the control unit 138 by an electric signal whether or not a sheet exists on the sheet conveyance path at the installed position. The sheet detection unit 136 is used to detect a sheet jam in a sheet conveyance path including the first sheet conveyance path 133a, the second sheet conveyance path 133b, the third sheet conveyance path 133c, and the fourth sheet conveyance path 133d. Can also be used.

  The paper sensor may be, for example, an optical sensor. For example, a transmission-type optical sensor includes a light-emitting unit and a light-receiving unit that are arranged to face each other, and the light emitted from the light-emitting unit is blocked by conveyed paper, and the amount of light reaching the light-receiving unit is reduced. Based on the detected paper. The paper sensor outputs an electric signal having a strength corresponding to the amount of light reaching the light receiving unit from the light emitting unit.

  The communication unit 137 transmits and receives data to and from another device of the image forming system 100 such as the image forming device 120. The communication unit 137 is communicably connected to the image forming apparatus 120 and the second post-processing apparatus 140 via the apparatus communication lines C1 and C2.

  The control unit 138 controls the sheet introduction unit 131, the sheet ejection unit 132, the sheet conveyance unit 133, the sheet reversing unit 134, the PI insertion unit 135, the sheet detection unit 136, and the communication unit 137. The control unit 138 includes an auxiliary storage device (not shown), a memory, an RTC (Real-Time Clock), and a CPU. These components are communicably connected to each other via a bus.

  The CPU of the control unit 138 executes a control program for the first post-processing device. The control program for the first post-processing device is stored in the auxiliary storage device, and is loaded into the RAM of the memory of the control unit 138 when executed by the CPU of the control unit 138. In accordance with the control program for the first post-processing device, the CPU of the control unit 138 controls the sheet introduction unit 131, the sheet discharge unit 132, the sheet conveyance unit 133, the sheet reversing unit 134, the PI insertion unit 135, the sheet detection unit 136, The communication unit 137 is controlled.

  The RTC has a timing function, and measures the transport time of the paper transported through the first paper transport path 133a based on the detection result of the paper detection unit 136.

<Second post-processing device 140>
The second post-processing device 140 includes a paper introduction unit 141, a paper discharge unit 142, a paper transport unit 143, a saddle stapling staple unit 144, a booklet discharge unit 145, a sub-tray discharge unit 146, a paper detection unit 147, a communication unit 148, and a control unit. A portion 149. These components are interconnected by an internal bus B3. In the present embodiment, the second post-processing device 140 is disposed between the first post-processing device 130 and the third post-processing device 150, and functions as a saddle stitching apparatus.

  The paper introduction unit 141 introduces the paper supplied from the first post-processing device 130 into the paper transport unit 143. Further, the paper discharge unit 142 discharges the paper transported by the paper transport unit 143 to the outside of the second post-processing device 140.

  The paper transport section 143 includes a first paper transport path 143a, a second paper transport path 143b, and a third paper transport path 143c, and the first paper transport path 143a, the second paper transport path 143b, or the third paper transport path 143b. The paper is transported along the paper transport path 143c.

  Each of the paper transport paths 143a, 143b, and 143c includes a guide member (not shown) for guiding the transported paper. The paper transport unit 143 includes a plurality of transport rollers (not shown) and a drive motor, and the transport rollers are arranged in pairs along the guide member. Further, the drive motor is attached to each of the transport rollers, and drives the transport rollers in accordance with an instruction from the control unit 149.

  The first paper transport path 143a is a paper transport path that connects between the paper introduction unit 141 and the paper discharge unit 142. The second paper transport path 143b is a paper transport path that connects between the paper introduction unit 141 and the saddle stapling staple unit 144 and between the saddle stitch staple unit 144 and the booklet discharge unit 145 (see FIG. 1). is there. The paper introduced from the paper introduction unit 141 is transported to a second gate (not shown) located at a branch point between the first paper transport path 143a and the second paper transport path 143b. One of the first paper transport path 143a and the second paper transport path 143b is selected by the second gate, and the paper is transported along the selected paper transport path.

  The third paper transport path 143c is a paper transport path that connects between the sub-tray discharge unit 146 and the first paper transport path 143a. A third gate (not shown) is provided at a connection portion between the first paper transport path 143a and the third paper transport path 143c, and the third gate transports the third paper from the first paper transport path 143a at the third gate. The road 143c is branched. The paper conveyed from the paper introduction section 141 along the first paper conveyance path 143a is directly conveyed along the first paper conveyance path 143a by switching the third gate, or 3 is transported along the third paper transport path 143c.

  The saddle stitching staple unit 144 staples a central portion of a sheet bundle in which a plurality of sheets are stacked, conveys the sheet between a pair of rollers starting from the central portion, and folds the booklet. create. The created booklet is discharged from the booklet discharge unit 145 to the outside. The saddle stapling section 144 functions as a post-processing section.

  The sub-tray discharge unit 146 discharges the paper transported along the third paper transport path 143c to the sub-tray. When a plurality of sheets are discharged, the sheets are stacked on the sub tray in order from the bottom.

  The paper detection unit 147 includes a plurality of paper sensors installed at predetermined positions in a paper transport path including a first paper transport path 143a, a second paper transport path 143b, and a third paper transport path 143c. Each sheet sensor notifies the control unit 149 by an electric signal whether or not a sheet exists on the sheet conveyance path at the installed position.

  Note that the sheet detection unit 147 can also be used for detecting a sheet jam in a sheet conveyance path including the first sheet conveyance path 143a, the second sheet conveyance path 143b, and the third sheet conveyance path 143c. The configuration of the paper sensor has the same configuration as that of the paper sensor of the paper detection unit 136, and a description thereof will be omitted.

  The communication unit 148 transmits and receives data to and from another device of the image forming system 100 such as the image forming device 120. The communication unit 148 is communicably connected to the second post-processing device 140 and the third post-processing device 150 via the inter-device communication lines C2 and C3.

  The control unit 149 controls the paper introduction unit 141, the paper discharge unit 142, the paper transport unit 143, the saddle stitch staple unit 144, the booklet discharge unit 145, the sub tray discharge unit 146, the paper detection unit 147, and the communication unit 148. The control unit 149 includes an auxiliary storage device (not shown), a memory, an RTC, and a CPU (not shown). These components are communicably connected to each other via a bus.

  The CPU of the control unit 149 executes a control program for the second post-processing device. The control program for the second post-processing device is stored in the auxiliary storage device, and is loaded into the RAM of the memory of the control unit 149 when executed by the CPU of the control unit 149. In accordance with the control program for the second post-processing apparatus, the CPU of the control unit 149 controls the sheet introduction unit 141, the sheet discharge unit 142, the sheet transport unit 143, the saddle stapling unit 144, the booklet discharge unit 145, and the sub-tray discharge unit 146. , The paper detection unit 147 and the communication unit 148 are controlled.

<Third post-processing device 150>
The third post-processing device 150 is disposed downstream of the second post-processing device 140, and includes a paper introduction unit 151, a paper discharge unit 152, a paper transport unit 153, a flat stapling staple unit 154, a booklet discharge unit 155, and a sub-tray discharge. Unit 156, a paper detection unit 157, a communication unit 158, and a control unit 159. These components are interconnected by an internal bus B4. In the present embodiment, the third post-processing device 150 functions as a flat stitch bookbinding device.

  The paper introduction unit 151 introduces the paper supplied from the second post-processing device 140 into the paper transport unit 153. Further, the paper discharge unit 152 discharges the paper transported by the paper transport unit 153 to the outside of the third post-processing device 150.

  The paper transport section 153 includes a first paper transport path 153a, a second paper transport path 153b, a third paper transport path 153c, and a fourth paper transport path 153d. The paper transport unit 153 transports the paper along the first paper transport path 153a, the second paper transport path 153b, the third paper transport path 153c, or the fourth paper transport path 153d.

  Each of the paper transport paths 153a, 153b, 153c, and 153d includes a guide member (not shown) for guiding the transported paper. The paper transport unit 153 includes a plurality of transport rollers (not shown) and a drive motor, and the transport rollers are arranged in pairs along the guide member. In addition, the drive motor is attached to each of the transport rollers, and drives the transport rollers in accordance with an instruction from the control unit 159.

  The first paper transport path 153a is a paper transport path that connects between the paper introduction unit 151 and the paper discharge unit 152. The second paper transport path 153b is a paper transport path that connects between the paper introduction unit 151 and the flat stapling staple unit 154. The third paper transport path 153c is a paper transport path that connects between the flat stapling staple unit 154 and the booklet discharge unit 155. The paper introduced from the paper introduction unit 151 is transported to a fourth gate (not shown) located at a branch point between the first paper transport path 153a and the second paper transport path 153b. The fourth gate selects one of the first paper transport path 153a and the second paper transport path 153b, and the paper is transported along the selected paper transport path.

  The fourth paper transport path 153d is a paper transport path connecting between the sub-tray discharge unit 156 and the first paper transport path 153a. A fifth gate (not shown) is provided at a connection portion between the first paper transport path 153a and the fourth paper transport path 153d, and the fifth gate transports the fourth paper from the first paper transport path 153a at the fifth gate. The road 153d is branched. The paper conveyed from the paper introduction unit 151 along the first paper conveyance path 153a is conveyed as it is along the first paper conveyance path 153a by switching the fifth gate, or The sheet is transported along the five sheet transport path 153d.

  The flat stapling section 154 performs stapling at a position at a predetermined distance from the end of the sheet bundle, and forms a booklet by side binding the sheet bundle. The created booklet is discharged from the booklet discharge unit 155 to the outside. The flat stapling staple unit 154 functions as a post-processing unit.

  The sub-tray discharge unit 156 discharges the paper transported along the third paper transport path 153c to the sub-tray. When a plurality of sheets are discharged, the sheets are stacked on the sub tray in order from the bottom.

  The sheet detection unit 157 includes a plurality of sheet detection units provided at predetermined positions of a sheet conveyance path including a first sheet conveyance path 153a, a second sheet conveyance path 153b, a third sheet conveyance path 153c, and a fourth sheet conveyance path 153d. Paper sensor. Each sheet sensor notifies the control unit 159 by an electric signal whether or not a sheet exists on the sheet conveyance path at the installed position.

  The sheet detection unit 157 detects a sheet jam in a sheet conveyance path including the first sheet conveyance path 153a, the second sheet conveyance path 153b, the third sheet conveyance path 153c, and the fourth sheet conveyance path 153d. Can also be used. The configuration of the paper sensor has the same configuration as that of the paper sensor of the paper detection unit 136, and a description thereof will be omitted.

  The communication unit 158 transmits and receives data to and from another device of the image forming system 100 such as the image forming device 120. The communication unit 158 is communicably connected to the second post-processing device 140 via an inter-device communication line C3.

  The control unit 159 controls the paper introduction unit 151, the paper discharge unit 152, the paper transport unit 153, the side binding stapling unit 154, the booklet discharge unit 155, the sub-tray discharge unit 156, the paper detection unit 157, and the communication unit 158. The control unit 159 includes an auxiliary storage device (not shown), a memory, an RTC, and a CPU. These components are communicably connected to each other via a bus.

  The CPU of the control unit 159 executes a control program for the third post-processing device. The control program for the third post-processing device is stored in the auxiliary storage device, and is loaded into the RAM of the memory of the control unit 159 when executed by the CPU of the control unit 159. In accordance with the control program for the third post-processing device, the CPU of the control unit 159 controls the sheet introduction unit 151, the sheet discharge unit 152, the sheet transport unit 153, the flat stapling unit 154, the booklet discharge unit 155, and the sub-tray discharge unit 156. , And a paper detection unit 157 and a communication unit 158.

<Control method>
Next, a control method in the case where a sheet remains in the second post-processing device 140 or the third post-processing device 150 will be described in detail with reference to FIGS.

(1) Control Method When Sheets Remain in Second Post-Processing Apparatus 140 FIG. 4 is a flowchart illustrating a control method according to the first embodiment. The processing of the flowchart shown in FIG. 4 includes a control unit 127, a control unit 138, a control unit 149, and a control unit that respectively execute the control program for the image forming apparatus and the control program for the first to third post-processing apparatuses. This is realized by the cooperation of the CPUs of the units 159.

  FIG. 5 is a schematic diagram illustrating a control method when a sheet remains in the second post-processing device 140 in the first embodiment. FIG. 5A is a schematic diagram illustrating a state of the sheets P1 to P4 remaining in the second post-processing device 140 immediately after the user removes the paper caused by jam. FIG. 5B is a schematic view illustrating a state in which the sheets P1 to P4 are automatically purged, the sheets P1, P3, and P4 are discharged to the sub-tray discharge unit 146, and the sheet P2 is discharged to the sub-tray discharge unit 156. . FIG. 5C is a schematic view exemplifying a state in which the sheets P1, P3, and P4 of the sub-tray ejection unit 146 are set in the PI insertion unit 135 by the user. FIG. 5D is a schematic diagram illustrating a state of a sheet in the second post-processing device 140 after the recovery process has been performed.

  FIG. 6 is a conceptual diagram illustrating a method of specifying a moved sheet based on a time interval (period) of a plurality of continuously conveyed sheets in the first embodiment. FIG. 6A is a conceptual diagram illustrating a case where the sheet P2 is shifted on the first sheet transport path 143a, and FIG. 6B is a view illustrating the sheet P1 shifted on the first sheet transport path 143a. It is a conceptual diagram which illustrates the case where it has. FIG. 6C is a conceptual diagram exemplifying a case where the sheet P2 that is not the paper caused by the jam is removed from the first sheet conveying path 143a contrary to the intention.

  FIG. 7 is a schematic diagram illustrating a recovery operation setting screen according to the first embodiment.

  The control unit 127 receives a print job from a client terminal via a network and controls each component of the image forming apparatus 120 so as to print an image on a sheet. The sheet on which the image is printed on both sides or one side is output to the outside of the image forming apparatus 120 through the sheet discharging unit, and is supplied to the first post-processing apparatus 130.

  For example, it is assumed that a print job includes four pages of image data, and the image of the four pages is sequentially printed on sheets P1 to P4 supplied from sheet feeding unit 123 in image forming apparatus 120, respectively. The sheets P <b> 1 to P <b> 4 are conveyed to the second post-processing device 140 after the first post-processing device 130 performs a reversing process as necessary.

  As shown in FIG. 4, first, it is determined whether or not a paper jam has occurred on the paper transport path of the image forming system 100 as an “abnormal situation” (step S101). The control unit 149 determines whether a paper jam has occurred on any of the paper transport paths in the image forming system 100 based on the jam occurrence information. The jam occurrence information is provided by the control unit 127. If no paper jam has occurred on any of the paper transport paths of the image forming system 100 (step S101: NO), the process ends (end).

  On the other hand, when a paper jam occurs on the paper transport path of the image forming system 100 (step S101: YES), the paper transport of the post-processing device is interrupted (step S102). The control unit 149 controls the sheet conveyance unit 143 to interrupt the sheet conveyance on the first sheet conveyance path 143a, the second sheet conveyance path 143b, and the third sheet conveyance path 143c. As a result, for example, the sheet conveyed along the first sheet conveyance path 143a may remain on the first sheet conveyance path 143a.

  Next, it is determined whether the jam-caused paper on the paper transport path has been removed (step S103). The control unit 127 displays, for example, the position of the paper caused by jam on the paper transport path together with the illustration of the image forming system 100 on the touch panel of the operation display unit 125, and prompts the user to remove the paper caused by jam. If the jam-causing paper on the paper transport path has not been removed (step S103: NO), the user is repeatedly prompted to remove the jam-causing paper. The user removes the paper caused by the jam according to the display content of the touch panel.

  However, when the user removes the jammed paper on the paper transport path, the user may erroneously move the remaining paper other than the jammed paper. For example, in FIG. 5A, four sheets P1 to P4 remain on the first sheet transport path 143a, and among these, the position of the sheet P2 is shifted when the user removes the paper due to jam. Is shown.

  When the jam-causing paper on the paper transport path is removed and the "abnormal situation" is resolved (step S103: YES), automatic purging is started (step S104). The control unit 149 controls the sheet conveyance unit 143 to restart the sheet conveyance on the first sheet conveyance path 143a in order to start the automatic purge. The sheets P1 to P4 are transported along the first paper transport path 143a to the paper discharge unit 142.

  Next, the interval between the remaining conveyed sheets is measured (step S105). The sheet detection unit 147 detects the presence or absence of the sheets P1 to P4 conveyed along the first sheet conveyance path 143a, for example, at intervals of several ms.

  More specifically, the sheet sensor S installed downstream of the first sheet conveyance path 143a, that is, at a position near the sheet discharge unit 142 of the first sheet conveyance path 143a, detects the sheet P1 to P4 to be conveyed. The front and rear ends are detected, and a detection signal is transmitted to the control unit 149. Preferably, the sheet sensor S detects that the sheet conveyed from the sheet introduction section 141 along the first sheet conveyance path 143a is at a branch point between the third sheet conveyance path 143c and the first sheet conveyance path 143a. It is arranged at a position just before it.

  The control unit 149 determines the leading edge and the trailing edge of each of the transported sheets P1 to P4 based on a change in the detection signal from the sheet sensor S, and determines the interval (period) at which the leading edge of the sheet appears. Is measured by the RTC to obtain the time interval of the sheets P1 to P4, that is, the sheet interval.

  Next, it is determined whether the sheet intervals are equal or not (step S106). The control unit 149 compares the measured time interval between the sheets P1 to P4 with the specified value, and specifies the moved sheet based on the comparison result.

  For example, in FIG. 6A, the time interval between the sheets P1 and P2 is t1, the time interval between the sheets P2 and P3 is t2, and the time interval between the sheets P3 and P4 is t3. It is shown. In FIG. 6 and subsequent drawings, in order to facilitate understanding, the time interval (s) obtained by dividing the distance interval (mm) between the respective sheets at the time of interruption by the steady-state transport speed (mm / s) of the sheets. ).

  The control unit 149 compares the time intervals t1, t2, and t3 measured for the sheets P1 to P4 with the specified value t0, and obtains a comparison result of t1> t0, t2 <t0, and t3 = t0. The control unit 149 determines that the sheet P2 has been moved to the upstream side in the sheet conveyance direction on the first sheet conveyance path 143a based on the comparison result.

  FIG. 6B illustrates a case where the time interval between the sheets P1 and P2 is t4, the time interval between the sheets P2 and P3 is t5, and the time interval between the sheets P3 and P4 is t6. It is shown.

  The control unit 149 compares the time intervals t4, t5, and t6 measured for the sheets P1 to P4 with the specified value t0, and obtains a comparison result of t4 <t0, t5 = t0, and t6 = t0. The control unit 149 determines that the sheet P1 has been moved to the upstream side in the sheet conveyance direction on the first sheet conveyance path 143a based on the comparison result.

  FIG. 6C shows a case where the sheet P2 has moved to the outside of the first sheet conveyance path 143a, that is, has been removed from the first sheet conveyance path 143a. The time interval between the sheets P1 and P3 is t7, and the time interval between the sheets P3 and P4 is t8.

  The control unit 149 compares the time intervals t7 and t8 measured for the sheets P1 to P4 with the specified value t0, and obtains a comparison result of t7 = 2 × t0 and t8 = t0. The controller 149 determines that the user has removed the sheet P2 from the first sheet transport path 143a based on the comparison result.

  Note that the specified value t0 may change depending on the characteristics of the sheet, for example, the slipperiness of the sheet. In the present embodiment, a predetermined range of possible values of the specified value t0 (hereinafter, referred to as “buffer time of the specified value t0”) can be set according to the type, size, or basis weight of the paper. Therefore, for example, when comparing the measured time interval t1 with the specified value t0, if the time interval t1 is within the buffer time of the specified value t0, it is determined that they match.

  Further, the buffer time of the specified value t0 can be determined according to the type of the drive motor provided in the paper transport unit 143, that is, in consideration of the inertia of the drive system. A DC motor and a stepping motor can coexist in the paper transport path of the paper transport unit 143. Since the DC motor cannot be stopped immediately as in the case of the stepping motor, the buffer time of the specified value t0 can be set wider for the paper stopped by the DC motor.

  The buffer time is set, for example, to the extent that the boundary between successively conveyed sheets can be determined, preferably, the trailing edge of the preceding sheet and the leading edge of the succeeding sheet in a normal case where the remaining sheet is not moved. Can be set to about half of the time interval between.

  As described above, by adjusting the specified value t0 using the buffer time, when the sheet interval changes due to the characteristics of the sheet or the type of the driving motor, the measured time interval and the specified value t0 are compared. Since the comparison results do not match, it can be prevented that the sheet is determined to have been moved.

  Instead of comparing the measured time interval with the specified value t0, a configuration may be adopted in which the measured time interval is compared with the average value of the time intervals measured for a plurality of sheets.

  As described above, in the present embodiment, based on the sheet interval of the sheets P1 to P4 conveyed along the first sheet conveying path 143a, of the sheets P1 to P4 before the automatic purge is started. If there is a sheet that has been moved to, specify which sheet it is. Therefore, in the present embodiment, it is determined whether or not there is a sheet that has been erroneously moved when the user moves the paper due to jam, and if there is a sheet that has been moved, which sheet is specified. .

  When the paper intervals are equal (step S106: YES), the control unit 149 determines that the papers P1 to P4 have not been moved when removing the paper due to jam, and executes a recovery process (step S107). . The recovery process according to the present embodiment is a process for redoing the process of a print job interrupted by a paper jam.

  The user sets the sheets P1 to P4 discharged to the sub-tray discharge unit 146 by the automatic purge in the PI insertion unit 135 of the first post-processing device 130, and executes the recovery process through the operation display unit 125 to the image forming system 100. To instruct. The first post-processing device 130, the second post-processing device 140, and the third post-processing device 150 operate before the sheet conveyance for the sheets P <b> 1 to P <b> 4 discharged by the automatic purge is interrupted by the sheet jam. Perform the scheduled post-processing. Then, the control unit 149 ends the process (end).

  On the other hand, when the paper intervals are not equal intervals (step S106: NO), a notification of paper that is not equal intervals is given (step S108). If the paper interval is not equal, the control unit 149 determines that the remaining paper has been moved when removing the paper due to jam.

  For example, as shown in FIG. 5A, the position of the sheet P2 is shifted in the first sheet transport path 143a, and the shift of the sheet interval between the sheet P1 and the sheet P2 is outside the allowable range, that is, outside the buffer time. If, the control unit 159 determines that the sheet P2 has been moved.

  In this case, as shown in FIG. 5B, the control unit 149 discharges the sheets P1, P3, and P4 to the sub-tray discharge unit 146. On the other hand, the control unit 149 and the control unit 159 discharge the sheet P2 to the sub-tray discharge unit 156 of the third post-processing device 150 as invalid paper (scrap paper). That is, only the sheet P2 whose position has been shifted is discharged to the sub-tray discharge unit 156 separately from the other sheets.

  Then, as shown in FIG. 7, the control unit 149 controls the operation display unit 125 to display “The sheet of the following page number has been moved at the time of the automatic purging. Please do. "Is displayed. In the example shown in FIG. 5A, since the sheet P2 corresponding to the second page of the print job has been moved, “2” is displayed as a page number below the message.

  Next, a recovery operation is specified (step S109). As shown in FIG. 5C, the user sets the sheets P1, P3, and P4 discharged to the sub-tray discharge unit 146 in the PI insertion unit 135 of the first post-processing device 130.

  The user selects one of “all page recovery” 202, “recover only movement detection page No.” 203 and “edit movement detection page No.” 204 on the recovery operation setting screen 200, and executes execution of the recovery processing to form an image. Instruct system 100.

  “All page recovery” is a mode in which reprinting is performed from the image forming apparatus 120 with all pages of the print job being executed as reprint targets. Therefore, when this mode is executed, the image forming apparatus 120 reprints the first to fourth pages. Further, the control unit 149 controls the sheet conveyance unit 143 so that the sheets P1 to P4 remaining in the first sheet conveyance path 143a due to the sheet jam are discharged to the sub tray discharge unit 156 as invalid paper.

  “Recover only the movement detection page No.” is a mode in which only the page of the print job corresponding to the paper whose movement has been detected is to be reprinted, and the image forming apparatus 120 reprints the page.

  “Edit movement detection page number” is a mode for specifying a page on a screen on which a movement page number can be edited. Detailed description of this mode is omitted.

  In the example illustrated in FIG. 5, when “recover only the movement detection page No.” is selected, only the second page of the print job corresponding to the sheet P2 whose movement has been detected is set as the reprint target. The control unit 127 newly prints the second page of the print job on the sheet P <b> 2 ′ supplied from the paper supply unit 123, and supplies the second page to the first post-processing device 130. Further, the control unit 138 sequentially introduces the sheets P1, P3, and P4 of the PI insertion unit 135 into the third sheet conveyance path 131c. Further, the paper P2 whose movement has been detected is discharged to the sub-tray discharge unit 156 as invalid paper.

  The PI insertion unit 135 inserts the sheets P1, P3, and P4 in accordance with the timing at which the control unit 127 supplies the sheet P2 ′ to the first post-processing device 130, and thereby the sheet P1 is sent to the second post-processing device 140. , P2 ′, P3, and P4 in this order. As a result, as shown in FIG. 5D, the reprinted sheet P2 'is discharged to the sheet discharge unit 152 after the sheet P1 of the first page is discharged. The control unit 149 performs a recovery process (step S107), and ends the process (END).

(2) Case Where Sheets Remain in Third Post-Processing Apparatus 150 FIG. 8 illustrates a control method in the case where sheets remain in the third post-processing apparatus 150 in the first embodiment. It is a schematic diagram. FIG. 8A is a schematic diagram illustrating a state of the sheets P1 to P4 remaining in the third post-processing device 150 immediately after the user removes the paper caused by jam. FIG. 8B is a schematic view illustrating a state in which the sheets P1 to P4 are automatically purged and discharged to the sub-tray discharge unit 156. FIG. 8C is a schematic diagram illustrating a state in which the user has set all the sheets P1 to P4 of the sub-tray ejection unit 156 in the PI insertion unit 135. FIG. 8D is a schematic view illustrating the state of the sheet in the third post-processing device 150 after the recovery process has been performed.

  The control unit 127 receives a print job from a client terminal via a network and controls each component of the image forming apparatus 120 so as to print an image on a sheet. The sheet on which the image is printed on both sides or one side is output to the outside of the image forming apparatus 120 through the sheet discharging unit, and is supplied to the first post-processing apparatus 130.

  For example, the print job includes four pages of image data, and four pages of images are sequentially printed on sheets P1 to P4 supplied from the sheet feeding unit 123, respectively. The sheets P <b> 1 to P <b> 4 are subjected to a reversing process as necessary in the first post-processing device 130, pass through the second post-processing device 140, and are supplied to the third post-processing device 150. The control unit 159 interrupts the sheet conveyance of the first sheet conveyance path 153a when a sheet jam occurs.

  As shown in FIG. 8A, immediately after the user removes the paper caused by the jam, the papers P1 to P4 remain in the first paper transport path 153a of the third post-processing device 150, and the paper P2 among these remains. Assume that the position is shifted when the user removes the paper caused by jam.

  Next, an automatic purge is started, and the sheet interval of the conveyed sheets P1 to P4 is measured. If the sheet interval is not equal, for example, if the shift of the sheet interval between the sheet P1 and the sheet P2 is outside the allowable range, that is, outside the buffer time, the control unit 159 determines that the sheet P2 has been moved.

  As shown in FIG. 8B, the control unit 159 sets the second page of the print job corresponding to the sheet P2 as a reprint target, and displays on the “recovery operation setting screen” that the sheet P2 has been moved. Then, the sheets P1 to P4 are discharged to the sub tray discharge unit 156.

  Next, as shown in FIG. 8C, the user sets all of the sheets P1 to P4 discharged to the sub-tray discharge unit 156 in the PI insertion unit 135 of the first post-processing device 130. Then, on the “Recovery operation setting screen”, the user selects one of “All page recovery”, “Recover only movement detection page No.” and “Edit movement detection page No.”, and executes execution of the recovery processing. Instruct system 100.

  Next, as shown in FIG. 8D, when the recovery process is executed, the reprinted sheet P2 'is ejected to the sheet ejection unit 152 after the sheet P1 of the first page is ejected. The sheet P2 is discharged to the sub tray discharge unit 156 as invalid paper.

  As described above, in the present embodiment, when automatically purging a plurality of sheets remaining in the first sheet conveyance paths 143a and 153a, the time interval between two sheets conveyed continuously is measured. Is done. Then, based on the time interval, of the plurality of sheets, the sheet that is moved after the sheet conveyance is interrupted and before the automatic purge is started is specified.

  The second and third post-processing devices 140 and 150 and the image forming system 100 of the present embodiment have the following effects.

  Since the residual paper moved before the automatic purge is started is specified, the state of the residual paper grasped by the second and third post-processing devices 140 and 150 and the actual paper transport paths 143a and 153a It is possible to prevent or suppress a difference from the state of the upper remaining paper. Therefore, the second and third post-processing devices 140 and 150 can appropriately complete the print job being executed.

  In addition, since the moved paper is specified, the page of the print job corresponding to the moved paper can be reprinted on a new paper, and the reprinted paper can be used to perform the recovery process.

  Further, when reprinting is performed only on a page for which movement has been detected, the moved paper is specified and the page that needs reprinting is notified to the user, so that the recovery process can be appropriately performed.

  Also, since the user is notified of the page that needs to be reprinted, the amount of invalid paper can be reduced when performing the recovery process.

(Second embodiment)
In the first embodiment, based on the sheet interval of the sheets P1 to P4 conveyed along the first sheet conveyance path, when the user moves the paper caused by the jam, the user specifies the paper that has been erroneously moved. Was explained. In the second embodiment, based on the time from the start of the automatic purge to the time when the sheets P1 to P4 reach the sheet sensors arranged downstream of the first sheet conveyance path, the user can determine whether the jam-caused sheet has occurred. A description will be given of how to specify a sheet that has been erroneously moved when moving. In the following, detailed description of the same configuration as in the first embodiment will be omitted to avoid duplication of description.

<Control method>
Hereinafter, a control method according to the second embodiment will be described in detail with reference to FIGS. 9 and 10. FIG. 9 is a flowchart illustrating a control method according to the second embodiment. The processing of the flowchart shown in FIG. 9 includes the control program for the image forming apparatus and the control program for the first to third post-processing apparatuses, which are executed by the control unit 127, the control unit 138, the control unit 149, and the control unit 159. It is realized by execution of each CPU.

  FIG. 10 illustrates an example of a method of specifying a moved sheet based on a time from when automatic purging is started to when a remaining sheet reaches a sheet sensor disposed downstream of the first sheet conveyance path. FIG. FIG. 10A is a conceptual diagram illustrating a case where the paper P2 is shifted on the first paper transport path 143a, and FIG. 10B is a view in which the paper P2 is removed from the first paper transport path 143a. It is a conceptual diagram which illustrates a case.

  The control unit 127 receives a print job from a client terminal via a network and controls each component of the image forming apparatus 120 so as to print an image on a sheet. The sheet on which the image is printed on both sides or one side is output to the outside of the image forming apparatus 120 through the sheet discharging unit, and is supplied to the first post-processing apparatus 130. For example, it is assumed that a print job includes image data of five pages, and images of five pages are sequentially printed on sheets P1 to P5 supplied from a sheet feeding unit. The sheets P <b> 1 to P <b> 5 are conveyed to the second post-processing device 140 after the first post-processing device 130 performs a reversing process as necessary.

  As shown in FIG. 9, first, time measurement is started immediately after the sheet has passed the upstream sheet sensor (step S201). The sheet detection unit 147 detects the presence or absence of the sheets P1 to P5 conveyed along the first sheet conveyance path 143a, for example, at intervals of several ms.

  More specifically, the sheet sensor S1 installed at an upstream side of the first sheet conveyance path 143a, that is, at a first position near the sheet introduction section 141 of the first sheet conveyance path 143a, detects the sheet P1 to be conveyed. To P5, and transmits a detection signal to the control unit 149. The paper sensor S1 can be arranged, for example, on the first paper transport path 143a near the paper introduction unit 141.

  The control unit 149 immediately determines the leading edge and the trailing edge of each of the transported sheets P1 to P5 based on the change in the detection signal from the sheet sensor S1, and determines whether the leading edge of the sheet is the sheet sensor. Immediately after passing through S1, timing of RTC is started.

  Next, it is determined whether or not a paper jam has occurred on the paper transport path of the image forming system 100 as an “abnormal situation” (step S202). The control unit 149 determines whether a paper jam has occurred on any of the paper transport paths in the image forming system 100 based on the jam occurrence information. If no paper jam has occurred on any of the paper transport paths of the image forming system 100 (step S202: NO), the process ends (end).

  On the other hand, if a paper jam has occurred on the paper transport path of the image forming system 100 (step S202: YES), a first time until the paper jam occurs is measured (step S203). The control unit 149 causes the RAM of the memory to store the time from passing the upstream sheet sensor S1 to the occurrence of the sheet jam as the first time for each of the sheets P1 to P5. The control unit 149 ends the time measurement by the RTC for each of the sheets P1 to P5, and resets the count value of the sheets P1 to P5.

  Next, the sheet conveyance of the post-processing device is interrupted (step S204). The control unit 149 controls the sheet conveyance unit 143 to interrupt the sheet conveyance on the first sheet conveyance path 143a, the second sheet conveyance path 143b, and the third sheet conveyance path 143c. As a result, for example, the sheets P1 to P5 conveyed along the first sheet conveyance path 143a may remain on the first sheet conveyance path 143a.

  Next, it is determined whether the jam-causing paper on the paper transport path has been removed and the "abnormal situation" has been eliminated (step S205). The control unit 127 displays, for example, the position of the paper caused by jam on the paper transport path together with the illustration of the image forming system 100 on the touch panel of the operation display unit 125, and urges the user to remove the paper caused by jam. If the jam-causing paper on the paper transport path has not been removed (step S205: NO), the user is repeatedly prompted to remove the jam-causing paper. The user removes the paper caused by the jam according to the display content of the touch panel.

  However, when the user removes the jam-causing paper on the paper conveyance path, the user may erroneously move the remaining paper other than the jam-causing paper.

  For example, FIG. 10A shows a case where five sheets P1 to P5 remain on the first sheet conveyance path 143a. The sheet P1 is a sheet caused by jam. Further, it is shown that the position of the sheet P3 has been shifted when the user removes the sheet P1.

  If the jam-caused paper on the paper transport path has been removed (step S205: YES), automatic purging is started (step S206). The control unit 149 controls the paper transport unit 143 to restart the paper transport on the first paper transport path 143a in order to start automatic purging when the paper P1 that is the paper caused by the jam is removed. The sheets P2 to P5 are conveyed to the sheet discharge section 142 along the first sheet conveyance path 143a. Further, the control unit 149 starts time counting by RTC for each of the sheets P2 to P5.

  Next, the second time to the downstream paper sensor is measured (step S207). The sheet detection unit 147 detects the presence or absence of the sheets P2 to P5 conveyed along the first sheet conveyance path 143a.

  More specifically, the sheet sensor S2 installed downstream of the first sheet conveyance path 143a from the first position, that is, at a second position near the sheet discharge section 142 of the first sheet conveyance path 143a is provided. , The leading edge and the trailing edge of each of the conveyed sheets P2 to P5, and transmits a detection signal to the control unit 149. The paper sensor S2 can be arranged on the first paper transport path 143a near a branch point where the first paper transport path 143a branches from the third paper transport path 143c, for example.

  The control unit 149 immediately determines the leading edge and the trailing edge of each of the conveyed sheets P2 to P5 based on the change of the detection signal from the sheet sensor S2, and sets the sheet after the automatic purge is started. A second time until P2 to P5 reach the paper sensor S2 is measured.

  Next, it is determined whether the sheet has been moved before the start of the automatic purge (step S208). The control unit 149 determines whether the sheets P2 to P5 have been moved before the start of the automatic purge, based on the time from when the automatic purge is started to when the sheets P2 to P5 reach the sheet sensor S2.

  For example, as shown in FIG. 10A, it is assumed that immediately after the paper jam occurs, the papers P1 to P5 remain at positions of 3000 ms, 2500 ms, 2000 ms, 1200 ms and 600 ms from the upstream paper sensor S1, respectively. I do.

  Since the sheet P1 is a sheet caused by a jam, the sheet P1 has already been removed by the user before the automatic purge is started. Assuming that it takes 4000 ms for the papers P2 to P5 to be transported the distance between the paper sensors S1 and S2, the time for the papers P2 to P5 to reach the paper sensor S2 from the start of the automatic purge is 1500 ms, 2000 ms, 2800 ms and Expected to be 3400 ms. The control unit 149 compares the second time with the expected time to reach the paper sensor S2 (hereinafter, referred to as “expected arrival time”) for the papers P2 to P5 to determine whether the paper has been moved. Judge. For example, the estimated arrival time of the sheet P3 is 2000 ms, but if the position of the sheet P3 is shifted to the upstream side in the sheet conveyance direction, the second time of the sheet P3 becomes longer than 2000 ms. It is determined that the position of P3 has been moved.

  Note that the estimated arrival time may change depending on the characteristics of the sheet, for example, the slipperiness of the sheet. In the present embodiment, a predetermined range of values that the expected arrival time can take (referred to as “buffer time of the expected arrival time”) can be set according to the type, size, or basis weight of the paper. Therefore, for example, when comparing the second time with the expected arrival time, if the second time is within the buffer time of the expected arrival time, it is determined that they match.

  In addition, the buffer time of the expected arrival time can be set according to the type of the drive motor provided in the sheet transport unit 143, that is, in consideration of the inertia of the drive system. A DC motor and a stepping motor can coexist in the paper transport path of the paper transport unit 143. Since the DC motor cannot be stopped immediately like the stepping motor, the buffer time of the estimated arrival time can be set wider for the paper stopped by the DC motor.

  The buffer time is set, for example, to the extent that the boundary between successively conveyed sheets can be determined, preferably, the trailing edge of the preceding sheet and the leading edge of the succeeding sheet in a normal case where the remaining sheet is not moved. Can be set to about half of the time interval between.

  As described above, by adjusting the estimated arrival time using the buffer time, when the second time changes due to the characteristics of the paper or the type of the drive motor, the second time and the estimated arrival time are changed. Can be prevented from being determined to have been moved because the comparison results do not match.

  Further, as shown in FIG. 10B, when the sheet P3 is removed from the sheet transport path 143a, after the sheet P2 reaches the sheet sensor S2, the sheet does not reach until the sheet P4 arrives. Therefore, control unit 149 determines that sheet P3 has been removed, for example, by being removed from sheet transport path 143a.

  If the sheet has not been moved before the start of the automatic purge (step S208: NO), the control unit 149 executes a recovery process (step S209). The user sets the sheets P2 to P5 discharged to the sub-tray discharge unit 146 by the automatic purge in the PI insertion unit 135 of the first post-processing device 130, and executes the recovery process through the operation display unit 125 to the image forming system 100. To instruct. The first post-processing device 130, the second post-processing device 140, and the third post-processing device 150 are scheduled for the sheets P2 to P5 discharged by the automatic purge before being interrupted by the sheet jam. Post-processing is performed.

  On the other hand, if the sheet has been moved before the start of the automatic purging (step S208: YES), the notified sheet is notified (step S210). The control unit 149 determines that the residual paper has been removed by the user or moved, for example, when the position of the residual paper has been shifted, when removing the paper caused by the jam. In the example shown in FIG. 10A, since the sheet P3 corresponding to the third page of the print job has been moved, “3” is displayed as the moved page No. on the recovery operation setting screen.

  Next, a recovery operation is specified (step S211). The user sets the sheets P2, P4, and P5 discharged to the sub-tray discharge unit 146 in the PI insertion unit 135 of the first post-processing device 130.

  Then, on the recovery operation setting screen, the user selects one of “all page recovery”, “recover only movement detection page No.” and “edit movement detection page No.”, and executes the recovery processing by the image forming system 100. To instruct. The recovery operation setting screen is as described with reference to FIG.

  The control unit 127 newly prints the first page of the print job on the sheet P1 ′ supplied from the sheet feeding unit 123 and the third page of the print job on the sheet P3 ′ and supplies the first page to the first post-processing device 130. I do. Further, the control unit 138 sequentially introduces the sheets P2, P4, and P5 of the PI insertion unit 135 into the third sheet conveyance path 131c.

  The PI insertion unit 135 inserts the sheets P2, P4, and P5 in accordance with the timing at which the control unit 127 supplies the sheets P1 ′ and P3 ′ to the first post-processing device 130, and thereby the second post-processing device 140 Are supplied in the order of sheets P1 ', P2, P3', P4, P5.

  As described above, in the present embodiment, based on the time from when the automatic purge is started to when the sheets P2 to P5 reach the sheet sensor S2 disposed downstream of the first sheet conveyance path 153a, Identify the paper that was moved before the automatic purge started. Therefore, in the present embodiment, it is determined whether or not there is a sheet that has been erroneously moved when the user moves the paper due to jam, and if there is a sheet that has been moved, which sheet is specified. .

  The second post-processing device 140 and the image forming system 100 of the present embodiment have the following effects in addition to the effects of the first embodiment.

  Since the second time is individually measured for each of the remaining papers and compared with the estimated arrival time, even if a plurality of the remaining papers are moved before the automatic purge starts, the relative positional relationship between the remaining papers. Irrespective of this, the moved residual sheet can be specified reliably.

  As described above, in the embodiment, the post-processing device, the image forming system, and the control program of the present invention have been described. However, it goes without saying that those skilled in the art can appropriately add, modify, and omit the present invention within the scope of the technical idea.

  For example, in the above-described first embodiment, the case where the sheet remains in the saddle stitching apparatus and the side stitching apparatus has been described as an example. Can also be applied to the case where remains.

  Further, in the above-described second embodiment, the case where the sheet remains in the saddle stitching apparatus has been described as an example. However, the present invention is applied to a reverse transport apparatus, a flat stitching apparatus, and another post-processing apparatus. Can also be applied to the case where remains.

  Further, in the first and second embodiments described above, the case where the sheet conveyance is interrupted due to the occurrence of the paper jam as the “abnormal situation” has been exemplified. However, the present invention can be applied to a case where the sheet conveyance is interrupted due to another “abnormal situation” such as a power failure or an emergency stop.

Further, the program for operating the image processing system 100 may be provided by a computer-readable recording medium such as a USB memory, a flexible disk, or a CD-ROM, or may be provided online via a network such as the Internet. Good. In this case, the program recorded on the computer-readable recording medium is usually
The data is transferred and stored in a memory or a storage. This program may be provided as, for example, independent application software, or may be incorporated in software of each device as one function of the image processing system 100.

P1 to P5 paper,
S, S1, S2 paper sensor,
100 image forming system,
110 paper feeder,
120 image forming apparatus,
130 first post-processing device,
131 paper introduction section,
132 paper discharge section,
133 paper transport unit,
134 paper reversing unit,
135 PI insertion section,
136 paper detection unit,
137 communication unit,
138 control unit,
140 second post-processing device;
141 paper introduction section,
142 paper discharge unit,
143 paper transport unit,
144 Saddle Stapler
145 booklet discharge section,
146 sub-tray discharge unit,
147 paper detection unit,
148 communication section,
149 control unit,
150 third post-processing device;
151 paper introduction section,
152 paper discharge unit,
153 paper transport unit,
154 flat stapling part,
155 booklet discharge section,
156 sub tray ejection section,
157 paper detection unit,
158 communication unit,
159 Control unit.

Claims (17)

A paper introduction unit for introducing paper,
A paper discharge unit that discharges the paper introduced by the paper introduction unit to the outside,
A post-processing unit that performs a predetermined process on the paper,
A paper transport unit that includes a paper transport path that connects the paper introduction unit and the paper discharge unit, and transports the paper along the paper transport path;
A paper detection unit that detects the paper passing through the paper transport path;
A control unit that controls the paper transport unit and the paper detection unit,
The control unit includes:
When an abnormal situation occurs during the paper transport of the paper transport path, the paper transport is temporarily interrupted, and after the abnormal situation is resolved, the paper transport is resumed and the paper transport path remains on the paper transport path. When discharging multiple sheets of paper to the outside,
The plurality of sheets conveyed continuously based on a detection result of each of the plurality of sheets conveyed one by one along the sheet conveyance path based on a detection result of each sheet detected by the sheet detection unit. Measure the time interval for each,
A post-processing device that specifies, based on the measured time interval, a sheet that has been moved before restarting the sheet conveyance among a plurality of sheets remaining on the sheet conveyance path. The control unit includes:
The post-processing device according to claim 1, wherein the time interval of the plurality of sheets is compared with a specified value, and the moved sheet is specified based on a comparison result.   The post-processing device according to claim 2, wherein the specified value is adjusted within a predetermined range.   The post-processing device according to claim 3, wherein the specified value is adjusted according to a type, a size, or a basis weight of the paper.   The post-processing device according to claim 3, wherein the predetermined value is adjusted according to a type of a drive motor provided in the paper transport unit. A paper introduction unit for introducing paper,
A paper discharge unit that discharges the paper introduced by the paper introduction unit to the outside,
A post-processing unit that performs a predetermined process on the paper,
A paper transport unit that includes a paper transport path that connects the paper introduction unit and the paper discharge unit, and transports the paper along the paper transport path;
A first paper detection unit that detects the paper passing through a first position on the paper transport path;
A second sheet detection unit that detects the sheet passing through a second position on the sheet conveyance path downstream of the first position in the sheet conveyance direction with respect to the first position;
A control unit that controls the paper transport unit and the first and second paper detection units,
The control unit includes:
When an abnormal situation occurs during the paper transport of the paper transport path, the paper transport is temporarily interrupted, and after the abnormal situation is resolved, the paper transport is resumed and the paper transport path remains on the paper transport path. When discharging the discharged paper to the outside,
A first time from when the paper is detected by the first paper detection unit to when the paper conveyance is interrupted, and when the paper conveyance is restarted, the paper is detected by the second paper detection unit And the second time until
Based on the first and second times, the distance between the first position and the second position, and the paper transport speed of the paper, the paper remaining on the paper transport path is the paper A post-processing device that identifies the paper that has been moved before resuming transport. The control unit includes:
Estimated arrival time that is expected to be required for each of the sheets to reach the second position after the sheet conveyance is restarted, based on the first time, the distance, and the sheet conveyance speed of the sheet. Is calculated,
7. The method according to claim 6, wherein, based on a result of the comparison between the expected arrival time and the second time, a sheet moved before restarting the sheet conveyance is specified among the sheets remaining on the sheet conveyance path. Post-processing device as described.   The post-processing device according to claim 7, wherein the expected arrival time is adjusted within a predetermined range.   The post-processing device according to claim 8, wherein the expected arrival time is adjusted according to a type, a size, or a basis weight of the paper.   The post-processing device according to claim 8, wherein the estimated arrival time is adjusted according to a type of a drive motor provided in the paper transport unit. The control unit includes:
The post-processing device according to claim 1, wherein a user is notified of information on the specified moved sheet. The control unit includes:
The post-processing device according to claim 1, wherein a sheet moved to another position on the sheet conveyance path is specified before restarting the sheet conveyance. The control unit includes:
The post-processing apparatus according to any one of claims 1 to 12, wherein the sheet moved outside the sheet conveyance path is specified before the sheet conveyance is restarted. An image forming apparatus for forming an image on paper,
An image forming system comprising: the post-processing device according to claim 1, wherein the post-processing device is configured to be capable of performing post-processing on the sheet on which an image is formed. A control program for an image processing system including an image forming apparatus and a post-processing apparatus,
A procedure for temporarily suspending the paper transport when an abnormal situation occurs during the paper transport of the paper transport path of the post-processing device;
After the abnormal situation is resolved, a procedure of restarting the sheet conveyance so as to discharge the plurality of sheets remaining on the sheet conveyance path to the outside of the post-processing device,
Detecting the plurality of sheets conveyed one by one along the sheet conveyance path and measuring a time interval between two sheets conveyed continuously;
A program for causing a computer to execute, based on the measured time interval, a step of identifying a sheet that has been moved before resuming the sheet conveyance among a plurality of sheets remaining on the sheet conveyance path. . A control program for an image processing system including an image forming apparatus and a post-processing apparatus,
A procedure for temporarily suspending the paper transport when an abnormal situation occurs during the paper transport of the paper transport path of the post-processing device;
After the abnormal situation is resolved, a procedure of restarting the sheet conveyance so as to discharge the sheet remaining on the sheet conveyance path to the outside of the post-processing device,
A first time from when the sheet passes through the first position of the sheet conveyance path to when the sheet conveyance is interrupted, and when the sheet conveyance is resumed, the sheet moves to a second position in the sheet conveyance path. Measuring a second time to reach,
The first and second times, the distance between the first position and the second position, and the sheet conveyance speed of the sheets remaining on the sheet conveyance path based on the sheet conveyance speed of the sheet. A control program that causes the computer to execute a procedure to identify the paper that has been moved before resuming operation. A step of reprinting a page of a print job corresponding to the moved sheet on a new sheet before restarting the sheet conveyance;
17. The control program according to claim 15, further comprising: performing a recovery process using the reprinted new sheet.