JP2007045580A - Sheet feeder and sheet inserting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that paper feeding retry control is not performed when a time for completing the feeding operation of paper is restricted. <P>SOLUTION: A paper feeding retry control means determines paper feeding retry to be performed or not and the frequency of retry to be performed by comparing a first carrying time as a reference time from starting paper feeding with a feeding means to reaching a predetermined position, a second carrying time as a maximum allowable time from starting paper feeding with the paper feeding means to reaching the predetermined position, a re-feeding interval time up to starting retry paper feeding with the retry control means, a retry possible time as a difference time between the second carrying time and the first carrying time, and an addition time for the retry possible time to the first carrying time and the re-feeding interval time, with one another. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, when a sheet stacked on a sheet stacking mechanism such as a cassette or a tray is fed, a sheet feeding that performs a plurality of sheet feeding retry operations to relieve a jam that occurs due to a pickup error or the like. The present invention relates to an apparatus and an apparatus including a sheet feeding mechanism.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrophotographic copying machine or a laser beam printer, in a sheet feeding operation from a sheet stacking mechanism such as a sheet feeding cassette or a sheet feeding deck for stacking sheets for recording a formed image, There is known an apparatus that detects a paper feed jam when a predetermined distance from a start position to a sheet detection position provided downstream of the conveyance path is not detected within a predetermined detection time.

  In the prior art, as a relief means when a paper jam occurs, a paper feed retry control that performs a predetermined number of paper feed retries is provided, and the occurrence of paper jam can be reduced by a paper feed retry operation. Has been done.

With regard to this paper feed retry retry control, there is a setting means that can arbitrarily set the number of retries, a sheet paper feed mechanism that performs paper feed retries for the set number of times (see, for example, Patent Document 1), and the type of sheet. A number of preset retry times, such as a sheet feeding mechanism (see, for example, Patent Document 2) that has setting means for setting the number of sheet feeding retries for each sheet type and performs sheet feeding retries set for each sheet type to be fed Only paper feed retries have been proposed.
Japanese Patent Laid-Open No. 11-3349358 JP 2003-306251 A

  However, the conventional paper feed retry control is performed only when there is no problem even if the paper feeding operation is delayed due to the paper feeding retry. In the prior art, there is a time constraint on the completion of the paper feeding operation. In some cases, paper feed retry was not performed.

  To describe a specific example, in a sheet post-processing device such as a finisher that stacks paper sent from the image forming apparatus and performs stapling processing in alignment, a cover sheet between the paper sent from the image forming apparatus, A sheet post-processing apparatus having an insert function for inserting a back cover and a slip sheet is known. In the paper feed mechanism for feeding the paper to be inserted, the paper is conveyed from the image forming apparatus after the paper to be inserted. Therefore, if the paper feed for the paper to be inserted is not completed within a specified time, the succeeding sheet There will be time constraints such as overlapping.

  Then, in order to save the paper jam of the insert paper, if the paper feed retry is performed a set number of times, the sheet interval between the paper to be inserted and the paper sent from the image forming apparatus is estimated in advance for the paper feed retry time. However, there was a problem that productivity would drop because it was necessary to make extra.

  As described above, according to the conventional technique, when there is a time restriction for completion of the sheet feeding operation, such as a sheet feeding mechanism such as an inserter of a sheet post-processing apparatus mounted downstream of the image forming apparatus, the sheet feeding retry is performed. Control was not implemented.

  However, in recent years, for the print on demand market, a large-scale image forming system (see FIG. 21) has been proposed in which a plurality of post-processing apparatuses are cascade-connected to an image forming apparatus to perform various functions such as a bookbinding function. However, in such a large-scale system, a large amount of sheets are conveyed in the system. Therefore, when an abnormal stop due to a jam occurs, a large number of invalid sheets are returned to the operator to restore the jam. Must be removed. In addition, it is important to minimize the occurrence of a system failure due to jamming, such as having to deliver the output product as a product to the client by the delivery date.

  The present invention has been made in consideration of such points, and even when there is a time constraint on completion of the sheet feeding operation, such as a sheet feeding operation of a sheet post-processing apparatus having an insert function, the sheet feeding is performed. A device that uses a paper jam by determining whether or not to perform a paper feed retry operation based on the time allowed to complete the operation, changing the number of retries based on the time allowed, and performing paper feed retry control according to the situation. The purpose is to remedy as much as possible.

  In order to achieve the above object, according to the first aspect of the present invention, a sheet is fed from a sheet stacking unit for stacking sheets by a sheet feeding unit, and the fed sheet is detected by a sheet detecting unit on a conveyance path, and the feeding is performed. In the paper feed retry control means for performing paper feed retry when the time from the start of paper feeding to the time when the sheet is detected by the sheet detecting means exceeds a predetermined jam detection time, A first transport time, which is a reference time from the start of paper feeding by the paper feeding means to reaching a predetermined position, and a second allowable time from the start of paper feeding by the paper feeding means to reaching a predetermined position. A retry time which is a difference between the transport time, the refeed interval time until the retry feed is started by the retry control means, and the second transport time and the first transport time. A paper feed retry control means for determining whether or not to perform the paper feed retry and the number of times of retrying are performed by comparing the performance time, the retry possible time, and the addition time of the first transport time and the refeed interval time; A sheet feeding apparatus is provided.

  According to a second aspect of the present invention, there is provided a sheet insert apparatus for inserting a sheet into an image-formed recording sheet that is mounted downstream of the image forming apparatus, the sheet stacking means for stacking the insert sheet mounted on the sheet insert apparatus. The sheet feeding means feeds the sheet to be fed by the sheet detecting means on the conveying path, and the time from the start of feeding by the sheet feeding means until the sheet is detected by the sheet detecting means, In a paper feed retry control means for performing paper feed retry when a predetermined jam detection time is exceeded, the first transport is a reference time from the start of paper feed by the paper feed means until reaching a predetermined position. Time, a second transport time which is a maximum allowable time from the start of paper feeding by the paper feeding means until reaching a predetermined position, and the retry control Thus, the refeeding interval time until the retry feeding is started, the retryable time which is the difference time between the second transporting time and the first transporting time, the retryable time, and the first transporting time And a sheet feeding retry control means for determining whether or not to perform the sheet feeding retry and the number of times of retrying are performed by comparing the addition time of the sheet re-feeding interval time.

  As described above, even when there is a time limit for completing the paper feed operation, whether or not to perform the paper feed retry operation is determined based on the allowable time until the paper feed operation is completed, and the retry paper feed is performed. Even in this case, by changing the number of retries depending on the allowable time, it is possible to relieve the stoppage of the apparatus due to the paper feed jam by performing the paper feed retry as much as possible according to the situation.

  Next, sheet feeding retry control according to the present invention will be described by taking an image forming system including a sheet post-processing apparatus having an inserter function as an example.

<Overall configuration of image forming apparatus>
FIG. 1 is a configuration diagram showing a longitudinal sectional structure of a main part of the image forming apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the image forming apparatus includes an image forming apparatus main body 10, a folding device 400, and a finisher 500. The image forming apparatus main body 10 includes an image reader 200 that reads an image from a document and a printer 300 that forms the read image on a sheet.

  More specifically, the document feeder 100 is mounted on the image reader 200 of the image forming apparatus main body 10. The document feeder 100 feeds documents set upward on the document tray one by one from the first page in order to the left in FIG. 1, and flows from the left on the platen glass 102 through a curved path to a reading position. Then, the paper is conveyed to the right, and then discharged toward the external paper discharge tray 112. When the original passes through the plate reading position on the platen glass 102 from the left to the right, the original image is read by the scanner unit 104 held at a position corresponding to the flow reading position. This reading method is generally referred to as document scanning. Specifically, when the original passes through the reading position, the original reading surface is irradiated with the light from the lamp 103 of the scanner unit 104, and the reflected light from the original passes through the mirrors 105, 106, and 107 to the lens. To 108. The light that has passed through the lens 108 forms an image on the imaging surface of the image sensor 109.

  In this way, by transporting the document so that it passes from the left side to the right of the sink reading position, the document reading scan in which the direction orthogonal to the document transport direction is the main scanning direction and the transport direction is the sub-scanning direction. Is done. That is, when the document passes the flow reading position, the document image is read in the sub-scanning direction while reading the document image by the image sensor 109 line by line in the main scanning direction. The optically read image is converted into image data by the image sensor 109 and output. Image data output from the image sensor 109 is subjected to predetermined processing in an image signal control unit 202 described later, and then input to the exposure control unit 110 of the printer 300 as a video signal.

  Note that it is also possible to read a document by conveying the document onto the platen glass 102 by the document feeder 100 and stopping it at a predetermined position, and scanning the scanner unit 104 from left to right in this state. This reading method is a so-called fixed original reading method.

  When reading a document without using the document feeder 100, the user first lifts the document feeder 100 to place the document on the platen glass 102, and then scans the scanner unit 104 from left to right. The original is read by. That is, when reading a document without using the document feeder 100, a fixed document reading is performed.

  The exposure control unit 110 of the printer 300 modulates and outputs laser light based on the video signal input from the image reader 200. The laser light is irradiated onto the photosensitive drum 111 while being scanned by the polygon mirror 110a. An electrostatic latent image corresponding to the scanned laser beam is formed on the photosensitive drum 111. Here, as will be described later, the exposure control unit 110 outputs a laser beam so that a correct image (an image that is not a mirror image) is formed during document fixed reading. The electrostatic latent image on the photosensitive drum 111 is visualized as a developer image by the developer supplied from the developing device 113.

  On the other hand, sheets fed by the pickup rollers 127 and 128 from the upper cassette 114 or the lower cassette 115 provided in the printer 300 are conveyed to the registration rollers 126 by the sheet feeding rollers 129 and 130. When the leading edge of the sheet reaches the registration roller 126, the registration roller 126 is driven at an arbitrary timing, and the sheet is conveyed between the photosensitive drum 111 and the transfer unit 116 at a timing synchronized with the start of laser beam irradiation. To do. The developer image formed on the photosensitive drum 111 is transferred by the transfer unit 116 onto the fed paper. The sheet onto which the developer image has been transferred is conveyed to the fixing unit 117, and the fixing unit 117 fixes the developer image on the sheet by heating and pressurizing the sheet. The sheet that has passed through the fixing unit 117 is discharged from the printer 300 toward the outside of the image forming apparatus main body (folding apparatus 400) via the flapper 121 and the discharge roller 118.

  Here, when the sheet is discharged with its image forming surface facing downward (face-down), the sheet that has passed through the fixing unit 117 is once guided into the reverse path 122 by the switching operation of the flapper 121, and the trailing edge of the sheet. After passing through the flapper 121, the paper is switched back and discharged from the printer 300 by the discharge roller 118. Hereinafter, this form of paper discharge is referred to as reverse paper discharge. This reverse paper discharge is performed when forming an image in order from the first page, such as when forming an image read using the document feeder 100 or when forming an image output from a computer. The paper order after the paper discharge is the correct page order.

  Further, when a hard sheet such as an OHP sheet is fed from the manual sheet feeding unit 125 and an image is formed on this sheet, the image forming surface is faced up without leading the sheet to the reverse path 122 (face-up). ) By the discharge roller 118. Further, when double-sided recording for image formation is set on both sides of the paper, the paper is guided to the reverse path 122 by the switching operation of the flapper 121 and then transported to the double-sided transport path 124 and then guided to the double-sided transport path 124. Control is performed so that the fed paper is fed again between the photosensitive drum 111 and the transfer unit 116 at the timing described above.

  The paper discharged from the printer 300 of the image forming apparatus main body 10 is sent to the folding device 400. The folding device 400 performs a process of folding a sheet into a Z shape. For example, when the folding process is designated for A3 size or B4 size paper, the folding device 400 performs the folding processing. In other cases, the paper discharged from the printer 300 passes through the folding device 400. It is sent to the finisher 500. The finisher 500 is provided with an inserter 900 for feeding a special sheet such as a cover sheet or a slip sheet to be inserted into a sheet on which an image is formed. The finisher 500 performs bookbinding processing, binding processing, and punching processing.

<System Block Diagram of Image Forming Apparatus>
Next, the configuration of a controller that controls the entire image forming apparatus will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration of a controller that controls the entire image forming apparatus shown in FIG. As shown in FIG. 2, the controller includes a CPU circuit unit 150, a document feeder control unit 101, an image reader control unit 201, an image signal control unit 202, a printer control unit 301, a folding device control unit 401, and a finisher control unit 501. An external interface (I / F) 209 is provided. In the figure, 153 is an operation unit of the image forming apparatus, and 210 is a computer capable of communicating with the image forming apparatus.

  The configuration of each unit will be described in detail. The CPU circuit unit 150 includes a CPU 151, a ROM 152, and a RAM 153, and controls a document feeder control unit 101, an operation unit 154, and an image reader by a control program stored in the ROM 152. Unit 201, image signal control unit 202, external I / F 209, printer control unit 301, folding device control unit 401, and finisher control unit 501. The RAM 153 temporarily stores control data and is used as a work area for arithmetic processing associated with control. The document feeder control unit 101 controls driving of the document feeder 100 based on an instruction from the CPU circuit unit 150. The image reader control unit 201 performs drive control on the above-described scanner unit 104, the image sensor 109, and the like, and transfers an analog image signal output from the image sensor 109 to the image signal control unit 202.

  The image signal control unit 202 converts each analog image signal from the image sensor 109 into a digital signal, performs each process, converts the digital signal into a video signal, and outputs the video signal to the printer control unit 301. The image signal control unit 202 performs various processes on the digital image signal input from the computer 210 via the external I / F 209, converts the digital image signal into a video signal, and outputs the video signal to the printer control unit 301. The processing operation by the image signal control unit 202 is controlled by the CPU circuit unit 150. The printer control unit 301 drives the above-described exposure control unit 110 based on the input video signal. The operation unit 154 includes a plurality of keys for setting various functions related to image formation, a display unit for displaying information indicating a setting state, and the like, and outputs a key signal corresponding to the operation of each key to the CPU circuit unit 150. At the same time, the corresponding information is displayed on the display unit based on the signal from the CPU circuit unit 150.

  The folding device control unit 401 is mounted on the folding device 400 and performs drive control of the entire folding device by exchanging information with the CPU circuit unit 150. The finisher control unit 501 is mounted on the finisher 500 and performs drive control of the entire finisher by exchanging information with the CPU circuit unit 150.

<Folding part>
Next, configurations of the folding device 400 and the finisher 500 provided in the image forming apparatus will be described with reference to FIG. FIG. 3 is a configuration diagram showing configurations of the folding device 400 and the finisher 500 shown in FIG. As shown in FIG. 3, the folding device 400 has a folding conveyance horizontal path 402 for introducing paper discharged from the printer 300 of the image forming apparatus main body 10 and guiding it to the finisher 500 side. On the folding conveyance horizontal path 402, a conveyance roller pair 403 and a conveyance roller pair 404 are provided. Further, a folding path selection flapper 410 is provided at the exit portion (finisher 500 side) of the folding conveyance horizontal path 402. The folding path selection flapper 410 performs a switching operation for guiding the sheet on the folding conveyance horizontal path 402 to the folding path 420 or the finisher side 500.

  Here, when the folding process is performed, the folding path selection flapper 410 is turned on, and the sheet is guided to the folding path 420. The sheet guided to the folding path 420 is conveyed to the folding roller 421 and folded into a Z shape. On the other hand, when the folding process is not performed, the folding path selection flapper 410 is turned off, and the sheet is sent directly from the printer 300 to the finisher 500 via the folding conveyance horizontal path 402.

<Finisher main part>
The finisher 500 sequentially takes in the sheets ejected via the folding device 400, aligns a plurality of fetched sheets and bundles them into one bundle, staples the staple end of the bundle of bundled sheets, and takes in Each sheet post-processing such as punch processing for punching near the rear end of the paper, sorting processing for sorting the paper, non-sorting processing for not sorting the paper, and bookbinding processing for binding the paper is performed.

  As shown in FIG. 3, the finisher 500 includes a pair of entrance rollers 502 for guiding the sheet discharged from the printer 300 of the image forming apparatus main body 10 through the folding device 400 to the inside. A switching flapper 551 for guiding the sheet to the finisher path 552 or the first bookbinding path 553 is provided downstream of the inlet roller pair 502. The sheet guided to the finisher path 552 is sent toward the buffer roller 505 via the conveyance roller pair 503. The conveyance roller pair 503 and the buffer roller 505 are configured to be capable of forward and reverse rotation.

  An entrance sensor 531 is provided between the entrance roller pair 502 and the transport roller pair 503. In addition, the second bookbinding path 554 branches off from the finisher path 552 in the vicinity of the upstream of the entrance sensor 531 in the sheet conveyance direction. Hereinafter, this branch point is referred to as branch A. This branch A forms a branch from the entrance roller pair 502 to the transport path for transporting the paper to the transport roller pair 503, but the transport roller pair 503 reverses to feed the paper from the transport roller pair 503 side to the entrance sensor 531 side. When transporting to the side, a branch having a one-way mechanism transported only to the second bookbinding path 554 side is formed.

  A punch unit 550 is provided between the conveying roller pair 503 and the buffer roller 505, and the punch unit 550 operates as necessary to punch near the rear end of the conveyed paper. The buffer roller 505 is a roller capable of laminating a predetermined number of sheets sent to the outer periphery of the buffer roller 505 and winding the paper around the outer periphery of the roller by pressing rollers 512, 513, and 514 as necessary. The paper wound around the buffer roller 505 is conveyed in the rotation direction of the buffer roller 505.

  A switching flapper 510 is disposed between the pressing rollers 513 and 514, and a switching flapper 511 is disposed downstream of the pressing rollers 514. The switching flapper 510 is a flapper for separating the paper wound around the buffer roller 505 from the buffer roller 505 and guiding it to the non-sort path 521 or the sort path 522. The switching flapper 511 is a flapper for separating the paper wound around the buffer roller 505 from the buffer roller 505 and guiding it to the sort path 522 or the paper wound around the buffer roller 505 to the buffer path 523 in a wound state. .

  The sheet guided to the non-sort path 521 by the switching flapper 510 is discharged onto the sample tray 701 via the discharge roller pair 509. In the middle of the non-sort path 521, a paper discharge sensor 533 for jam detection and the like is provided. The sheets guided to the sort path 522 by the switching flapper 510 are stacked on an intermediate tray (hereinafter, referred to as a processing tray) 630 via transport rollers 506 and 507. The sheets stacked in a bundle on the processing tray 630 are subjected to alignment processing, stapling processing, and the like as necessary, and then discharged onto the stack tray 700 by the discharge rollers 680a and 680b. A stapler 601 is used for the stapling process for binding sheets stacked in a bundle on the processing tray 630. The operation of the stapler 601 will be described later. The stack tray 700 is configured to be capable of self-propelling in the vertical direction.

<Bookbinding Department>
The sheets from the first bookbinding path 553 and the second bookbinding path 554 are stored in the storage guide 820 by the conveyance roller pair 813 and further conveyed until the leading edge of the sheet comes into contact with the movable sheet positioning member 823. A bookbinding entrance sensor 817 is disposed on the upstream side of the conveying roller pair 813. Further, two pairs of staplers 818 are provided in the middle of the storage guide 820, and the staplers 818 are configured to bind the center of the sheet bundle in cooperation with the anvil 819 facing the staplers 818.

  A folding roller pair 826 is provided at a downstream position of the stapler 818. A protruding member 825 is provided at a position opposite to the folding roller pair 816. By projecting the protruding member 825 toward the sheet bundle stored in the storage guide 820, the sheet bundle is pushed out between the folding roller pair 826, folded by the folding roller pair 826, and then the origami paper discharge roller 827. To the saddle discharge tray 832. A bookbinding paper discharge sensor 830 is disposed on the downstream side of the origami paper discharge roller 827. Further, when folding the bundle of sheets bound by the stapler 818, the positioning member 823 is lowered by a predetermined distance so that the staple position of the bundle of sheets becomes the center position of the folding roller pair 826 after the staple processing is completed.

<Inserter section>
The inserter 900 is provided in the upper part of the finisher 500, and sequentially separates a cover sheet stacked on the tray 901 (sheet stacking means) and a sheet bundle forming a slip sheet, and conveys them to the finisher path 552 or the bookbinding path 553. Here, on the tray 901 of the inserter 900, the special paper is stacked in a normal view as viewed from the user. That is, the special sheets are stacked on the tray 901 with the surface thereof facing up. The special paper on the tray 901 is conveyed to a separation unit including a conveyance roller 903 and a separation belt 904 by a conveyance roller / feed roller 902 (sheet feeding unit), and sequentially separated one by one from the uppermost sheet. Be transported.

  A drawing roller pair 905 is disposed on the downstream side of the separation unit, and the special paper separated by the drawing roller pair 905 is stably guided to the conveyance path 908. A paper feed sensor 907 (sheet detection means) is provided on the downstream side of the drawing roller pair 905. Further, a conveyance roller 906 for guiding the special sheet on the conveyance path 908 to the inlet roller pair 502 is provided between the paper feed sensor 907 and the inlet roller pair 502. In the conveyance path of the conveyance path 908, a double feed detection sensor 950 for detecting whether or not two or more special sheets separated and conveyed from the tray 901 are overlapped is provided.

The inserter 900 separates and conveys the sheets stacked on the tray 901 by the sheet feeding roller 902 and detects a predetermined distance to the sheet feeding sensor 907 within a predetermined detection time. Furthermore, a paper feed retry control means for retrying the paper feed operation is provided as a relief means when a paper jam occurs. (Details will be described later)
<Finisher block diagram>
Next, the configuration of the finisher control unit 501 that drives and controls the finisher 500 will be described with reference to FIG. FIG. 4 is a block diagram showing a detailed configuration of the finisher control unit 501 shown in FIG. As shown in FIG. 4, the finisher control unit 501 includes a CPU circuit unit 510 including a CPU 511, a ROM 512, a RAM 513, and the like. The CPU circuit unit 510 communicates with the CPU circuit unit 150 provided on the image forming apparatus main body side via the communication IC 514 to exchange data, and various programs stored in the ROM 512 based on instructions from the CPU circuit unit 150. To control the drive of the finisher 500.

  When this drive control is performed, detection signals from various sensors are taken into the CPU circuit unit 150. As these various sensors, there are an inlet sensor 531, a bookbinding entrance sensor 817, a bookbinding paper discharge sensor 830, a paper feed sensor 907, a paper set sensor 910, and a double feed detection sensor 950. The paper set sensor 910 is a sensor for detecting whether or not special paper is set on the tray 901 of the inserter 900.

  A driver 520 is connected to the CPU circuit unit 510. The driver 520 drives a motor and a solenoid based on a signal from the CPU circuit unit 510. Further, the CPU circuit unit 150 drives the clutch. Here, as the motor, the inlet roller pair 502, the conveying roller pair 503, the inlet motor M1 that is a driving source of the conveying roller pair 906, the buffer motor M2 that is the driving source of the buffer roller 505, the conveying roller pair 506, and the discharging roller pair. 507, a discharge motor M3 that is a drive source of the discharge roller pair 509, a bundle discharge motor M4 that is a drive source of each of the discharge rollers 680a and 680b, a transport motor M10 that is a drive source of the transport roller pair 813, and a sheet positioning member 823 Positioning motor M11 as a driving source, protruding member 825, folding roller pair 826, folding motor M12 as a driving source for origami paper discharge roller pair 827, paper feed roller 902 of inserter 900, conveying roller 903, shunt belt 904, pulling out There is a paper feed motor M20 which is a drive source of the roller pair 905.

  The inlet motor M1, the buffer motor M2, and the paper discharge motor M3 are composed of stepping motors. By controlling the excitation pulse rate, the roller pair driven by each motor is rotated at a constant speed or rotated at its own speed. You can make it. Further, the inlet motor M1 and the buffer motor M2 can be driven by the driver 520 in forward and reverse rotational directions. The conveyance motor M10 and the positioning motor M11 are composed of stepping motors, and the folding motor M12 is composed of a DC motor. The transport motor M10 is configured to be capable of transporting paper in synchronization with the inlet motor M1. The paper feed motor M20 is composed of a stepping motor, and is configured to be capable of transporting paper in synchronism with the inlet motor M1.

  Solenoids include a solenoid SL1 for switching the switching flapper 510, a solenoid SL2 for switching the switching flapper 511, a solenoid SL10 for switching the switching flapper 551, and a paper feed shutter (not shown in FIG. 3) of the inserter 900. There is a solenoid SL20 that drives, and a solenoid SL21 that drives the paper feed roller 902 of the inserter 900 up and down. As the clutch, there are a clutch CL1 for projecting the drive of the folding motor M12 to the protruding member 825, and a clutch CL10 for transmitting the drive of the paper feed motor M20 to the paper feed roller 902.

<Operation unit>
Next, an example of selecting the post-processing mode using the operation unit 154 of the image forming apparatus will be described with reference to FIG. FIG. 5 is a diagram showing an example of a screen related to post-processing mode selection of the operation unit 154 in the image forming apparatus shown in FIG. This image forming apparatus has various processing modes such as a non-sort mode, a sort mode, a staple sort mode (binding mode), and a bookbinding mode as post-processing modes, and is inserted into a cover sheet, final sheet, or halfway as a slip sheet mode. It is configured so that paper can be inserted. Such setting of the processing mode is performed by an input operation from the operation unit 154.

  For example, when setting the post-processing mode, the menu selection screen shown in FIG. 5A is displayed on the operation unit 154, and the processing mode is set using this menu selection screen. Further, for example, when setting the slip sheet mode, an insertion setting screen shown in FIG. 5B is displayed on the operation unit 154, and the insertion setting screen is used to insert special paper from the inserter 900 or manually. It is possible to set the number of sheets to be inserted from the sheet feeding unit 125 and use the screen shown in FIG. 5C. If the special paper is fed only to the cover, only “1” is selected, and when there are a plurality of sheets to be inserted, the desired number can be selected and set.

<Finisher operation overview>
Next, sheet conveyance from the inserter 900 and the printer 300 in the sort mode to the processing tray 630 in the finisher 500 will be described with reference to FIGS. 6 to 11 are diagrams for explaining the flow of sheets from the inserter 900 and the printer 300 to the processing tray 630 in the finisher 500 in the sort mode in the image forming apparatus shown in FIG. 6 and the subsequent drawings, the paper is indicated by a thick solid line, and a semicircle of “C” or “P” is added to the end of the solid line.

  When the paper C is inserted into the paper after image formation as a cover, the paper is set on the tray 901 of the inserter 900 as shown in FIG. At this time, as shown in FIG. 6A, the sheet C is set so that the image surface faces upward and the binding position is left when viewed from the user, and is fed in the direction of the arrow in the figure. The setting state of the paper C is the same as the setting state of the original in the original feeder 100, and the operability when setting the paper C can be improved.

  When the paper C is set on the tray 901, as shown in FIG. 7, the feeding of the uppermost paper C1 is started, and the switching flapper 551 is switched to the finisher path 552 side. The sheet C1 is guided from the conveyance path 908 through the entrance roller pair 502 into the finisher path 552, and when the leading end of the sheet C1 is detected by the entrance sensor 531, the image C1 after the image formation from the printer 300 of the main body 10 of the image forming apparatus 10 Feeding of the paper (paper P1 shown in FIG. 8) is started.

  Next, as shown in FIG. 8, the paper P <b> 1 fed from the printer 300 of the image forming apparatus main body 10 is guided into the finisher 500, and the paper C <b> 1 is guided to the sort path 522 via the buffer roller 505. At this time, the switching flappers 510 and 511 are all switched to the sort path 522 side. The sheet C1 guided to the sort path 522 is stored on the processing tray 630 as shown in FIG.

  At this time, the sheet P 1 from the printer 300 of the image forming apparatus main body 10 is guided into the finisher path 522. As shown in FIG. 10, the sheet P1 is guided to the sort path 522 via the buffer roller 505 and conveyed toward the processing tray 630 in the same manner as the sheet C1. Further, the sheet P2 following the sheet P1 is guided into the finisher path 552. Then, as shown in FIG. 11, the paper P1 is stacked and stored on the paper C1 already stored in the processing tray 630, and the subsequent paper P2 is stacked and stored on the paper P1.

  Here, mirror images are formed on the sheets P1 and P2 from the printer 300 of the image forming apparatus main body 10, and the sheets P1 and P2 are discharged by reverse discharge. Similarly to the sheet C1, the sheets P1 and P2 are stored in the processing tray 630 with the image surface facing downward and the binding position facing the stapler 601 side. Although not shown in FIG. 11, when there is a special sheet for the next sheet bundle, the special sheet is fed to the transport path 908 while the sheets P1 and P2 constituting the current sheet bundle are being fed. Configured to wait. With this configuration, productivity during sort mode processing can be improved.

<Outline of bookbinding operation>
Next, image formation in the bookbinding mode will be described with reference to FIG. FIG. 12 is a view for explaining image formation in the bookbinding mode in the image forming apparatus shown in FIG. When the bookbinding mode is designated, the original set on the original feeder 100 is read in order from the first page, and the read original images are sequentially stored in a hard disk (not shown) in the image forming apparatus main body 10. At the same time, the number of documents read is counted.

  When the reading of the original is completed, the read original image is classified by the following equation (1), and the image forming order and the image forming position are determined.

M = n × 4-k (1)
M: Number of original documents n: integer greater than or equal to 1; any number of sheets k: 0, 1, 2, 3 Detailed description of the image formation order and image formation position control is omitted. The image formation in the bookbinding mode will be described by taking an example in which the number of originals to be read is eight. As shown in FIG. 12 (a), eight pages of original image data (from R1) are stored in a hard disk (not shown). R8) is stored in the order of reading. The image forming order and the image forming position are determined for each original image data (R1 to R8). As a result, as shown in FIG. 12B, after the above-described mirror image processing is performed, the first surface (front surface) of the first page of paper P1 has an R4 image on the left half and an R5 image on the right half. An image is formed, and the sheet P1 is guided to the duplex conveyance path 124.

  Next, the sheet P1 is fed again to the transfer unit 116, and an R6 image is formed on the left half of the second surface (back surface), and an R3 image is formed on the right half. Then, the sheet P1 on which images are formed on both sides in this way is reversed by the reversed sheet discharge and then discharged to the bookbinding path 553 of the finisher 500. As shown in FIG. 12C, with this reverse paper discharge, the sheet P1 has the second surface on which the R6 image and the R3 image are formed facing upward and the R6 image at the head in the direction of the arrow in the figure. Be transported.

  Next, an R2 image is formed on the left half and an R7 image is formed on the right half of the first surface (front surface) of the sheet P2 of the second page, and the sheet P2 is guided to the duplex conveyance path 124. The sheet P2 is fed again to the transfer unit 116, and an R8 image is formed on the left half of the second surface (back surface), and an R1 image is formed on the right half. Then, the sheet P2 is reversed and discharged, and then sent to the first bookbinding path 553 of the finisher 500. As shown in FIG. 12C, the reverse sheet discharge causes the sheet P2 to face upward with the second surface on which the R8 image and the R1 image are formed facing upward, and in the direction of the arrow in the drawing. Be transported.

  The sheets P1 and P2 are guided and stored in the storage guide 820 via the bookbinding path 553 of the finisher 500. In the storage guide 820, as shown in FIG. 12D, the paper P1 protrudes and is stored on the member 825 side, and the paper P2 is stored on the folding roller pair 826 side. In addition, the first surface of each of the sheets P1 and P2 is stored while facing the protruding member 825 side. Positioning of the sheets P1 and P2 in the storage guide 820 is performed by a positioning member 823.

<Outline of bookbinding and inserter operations>
Sheet conveyance from the inserter 900 and the printer 300 to the storage guide 820 in the finisher 500 in the bookbinding mode will be described with reference to FIGS. 13 to 19 are diagrams for explaining the flow of paper from the inserter 900 and the printer 300 to the storage guide 820 in the finisher 500 in the bookbinding mode in the image forming apparatus shown in FIG. 1, and FIG. 6 is a diagram illustrating an example of bookbinding by folding processing and binding processing in the finisher 500 illustrated in FIG.

  When the sheet C1 is inserted into a sheet after image formation as a cover and bookbinding is performed, the sheet C1 is set on the tray 901 of the inserter 900 as shown in FIG. At this time, as shown in FIG. 13A, the sheet C1 is set on the tray 901 with the image surface on which the image R and the image F are formed facing upward, and is fed with the image F at the top. That is, the sheet C1 is set in a normal view when viewed from the user, and the setting state of the sheet C1 is the same as the setting state of the document in the document feeder 100. Therefore, the operability when setting the paper C1 can be improved.

  When the sheet C1 is set on the tray 901, as shown in FIG. 14, the feeding of the uppermost sheet C1 is started, and the switching flapper 551 is switched to the finisher path 552 side (see FIG. 3). The sheet C1 is guided from the transport path 908 through the inlet roller pair 502 into the finisher path 552, the leading end of the sheet C1 is detected by the inlet sensor 531, and the image from the printer 300 of the image forming apparatus main body 10 is detected after the sheet C1. The formed paper (paper P shown in FIG. 15) is conveyed.

  Next, as shown in FIG. 15, the paper P fed from the printer 300 of the image forming apparatus main body 10 is guided into the finisher 500, and the paper C1 is guided to the non-sort path 521 side via the buffer roller 505. . At this time, the switching flapper 510 is switched to the non-sort path 521 side. Further, when the paper C1 is guided to the non-sort path 521 side and conveyed until the trailing edge passes through the inlet sensor 531, the paper C1 is temporarily stopped as shown in FIG. At this time, the paper P from the printer 300 of the image forming apparatus main body 10 is guided into the finisher 500.

  Then, with the paper C1 being stopped, the paper P is guided to the first bookbinding path 553 by the switching flapper 551 and stored in the storage guide 820 as shown in FIG. The paper P is similarly guided to the first bookbinding path 553. At this time, the sheet C2 following the sheet C1 is separated and transported to the front of the transport roller pair 906, and waits until a predetermined number of sheets are stored in the storage guide 820.

  When a predetermined number of sheets P are stored in the storage guide 820, the sheet C1 is reversed and fed into the storage guide 820 via the branch A and the second bookbinding path 554 as shown in FIG. (See FIG. 3). At this time, as shown in FIG. 18, the sheet C1 is transported with the image R side as the head, and is stacked and stored on the bundle of sheets P already stored in the storage guide 820. When the paper C1 is stored in the storage guide 820, feeding of the paper C2 following the paper C1 is started. Here, for example, when the paper C2 is an inappropriate paper having a size different from the predetermined size, as shown in FIG. 19, the paper C2 is discharged to the sample tray 701 without being temporarily stopped in the state shown in FIG. Is done.

  After the sheet C1 is stacked and stored in the bundle of sheets P in the storage guide 820, a protruding member 825 protrudes from the bundle of sheets C1 and P as shown in FIG. Is pushed out toward the folding roller pair 826. The bundle is folded by the folding roller pair 826 at the center of the bundle (image boundary portion of the image surface) and discharged to the saddle discharge tray 832. In the folded state in this way, as shown in FIG. 20B, the image F (FRONT) of the sheet C1 is arranged on the cover page and the image R (REAR) is arranged on the last page, and the image of each sheet P is displayed. Are arranged in page order, and the orientations of the images on the sheets C1 and P are matched.

  In this way, the image F of the sheet C1 is arranged on the cover page in the bookbinding state by the sheet feeding control of the sheet C1 from the inserter 900 and the conveyance control of the sheet P from the printer 300 of the image forming apparatus body 10. Since R is arranged on the last page, the images of each paper P are arranged in page order, and the orientations of the images are matched, the print quality of the special paper from the inserter 900 and the paper conveyance durability of the printer 300 are impaired. In addition, it is possible to bind a sheet and a special sheet together. In this sort mode, the finisher 500 temporarily puts the special paper into the finisher path 552 and then guides and stores the paper in the storage guide 820. After storing the paper, the finisher 500 waits in the finisher path 552. Since the special paper being used is guided and stored in the storage guide 820, productivity when binding the paper and the special paper together can be improved.

  If necessary, the stapler 818 can bind the bundle at the center in a state where the sheet C1 is superimposed on the bundle of sheets P and stored in the storage guide 820.

<Description of paper feed retry control>
Next, the paper feed retry control of the inserter 900 of the present invention in the image forming apparatus according to the first embodiment will be described with reference to FIG.

  In the paper feeding retry control, a sheet feeding operation is started by a paper feeding roller 902 (sheet feeding means) for a sheet on the tray 901 (sheet stacking means) in FIG. 22, and is detected by a paper feeding sensor 907 (sheet detecting means). If the sheet feed sensor 907 cannot detect a sheet even after the sheet jam detection time Tj obtained by adding a jam detection time (hereinafter referred to as a jam margin) to the time until the sheet is fed, the sheet feeding operation is temporarily stopped. In this control, after the re-feeding interval time T_interval until the paper feeding operation is started again, the paper feeding operation is performed again to relieve the jam stop due to the paper feeding jam.

  In the present invention, it is determined whether or not the paper feed retry can be performed depending on the time of the retry possible time T_retry for determining whether or not the paper feed retry control can be performed. To do.

  For example, if the output speed (number of sheets / minute) of the image forming apparatus is 60 sheets / minute for the A4 size, the reference sheet interval T_base from the leading edge of the sheet to the leading edge of the next sheet is 1000 msec. When inserting paper from the inserter 900, the inter-sheet time between the sheet B to be inserted and the sheet A from the preceding image forming apparatus, and the inter-sheet time between the inserted sheet B and the subsequent sheet C are respectively the reference inter-sheet times. By controlling the feeding operation start timing from the inserter so as to be T_base, productivity as an image forming system is not reduced.

  Next, the relationship between the preceding sheet A, the insert sheet B, and the subsequent sheet C will be described.

<Relationship between preceding sheet A and insert sheet B>
A sheet on the tray 901 (sheet stacking unit) is fed by a sheet feeding roller 902 (sheet feeding unit), and the maximum time T1 detected by the conveyance path sensor 531 is a sheet feeding jam detection time Tj. Assuming that the maximum time to reach the transport path sensor 531 after detecting 907 is T2, the first transport time T_FIRST, which is the reference time from the start of the paper feeding operation to the arrival at the predetermined position (here, the transport path sensor 531), is T_FIRST. = T1 + T2.

  If T_FISRT> T_base, in order to set the sheet interval between the insert sheet B and the preceding sheet A to the reference sheet interval time T_base, the sheet A detects the conveyance path sensor 531 and detects the interval between the reference sheets from T_FIRST. It is only necessary to start the paper feeding operation before the time Tα obtained by subtracting from the time T_base.

  If T_FISRT <T_base, in order to make the interval between the insert sheet B and the preceding sheet A equal to the reference sheet interval time T_base, from the reference sheet interval time T_base after the sheet A detects the conveyance path sensor 531. The paper feeding operation may be started when the time Tα from which T_FIRST has been subtracted has elapsed.

  Further, since the first transport time T_FISRT includes the jam margin, when the paper feed separation is performed in the shortest time, the first transport time T_FISRT may reach the transport path sensor 531 earlier than the first transport time T_FISRT. Therefore, in the present invention, control is performed so as to become the reference inter-paper time T_base by stopping once at a pre-merging standby position (not shown) provided before the merging of the paths and adjusting the inter-paper time.

  As described above, by controlling the sheet feeding timing so that the sheet feeding operation of the insert sheet B is performed at the timing when the preceding sheet A reaches the predetermined position, the preceding sheet A and the insert sheet B have the reference inter-sheet time T_base. It is controlled to become.

<Relationship between Insert Sheet B and Subsequent Sheet C>
The succeeding sheet C output from the image forming apparatus has an image so as to have an interval between the preceding sheets A that is an extra sheet interval T_base of the insert sheet B, that is, an interval between T_base × 2. The forming device adjusts the output interval to allow time for inserting the insert sheet B. However, in practice, when an adjustment operation or the like is performed due to the convenience of the image forming apparatus, there may be a paper gap longer than the reference paper gap time T_base.

  The sheet feeding operation of the insert sheet B may be delayed by the time Tβ obtained by subtracting the actual sheet interval time T_real and the reference sheet interval time T_base. Therefore, the second transport time T_SECOND, which is the maximum allowable time from the start of the paper feeding operation to the predetermined position (here, the transport path sensor 531) is T_SECOND = T_FIRST + Tβ.

  The actual sheet interval time T_real needs to be known before the sheet feeding operation of the insert sheet B is started. In this embodiment, the CPU circuit unit 150 of the image forming apparatus sets the reference sheet interval time T_base. Then, the paper interval time obtained by adding the time extended by the adjustment operation or the like is calculated and notified to the CPU circuit unit 510 of the finisher via the communication IC 514 of the finisher control unit 501 before the feeding operation of the insert sheet B is started. Like to do.

  The retry possible time is a difference time between the second transport time and the first transport time calculated from the calculation formula of T_retry = T_SECOND−T_FIRST. Here, the difference between the actual sheet time T_real and the reference sheet time T_base. Equal to time.

  The paper feed retry control means according to the present invention includes a retry possible time T_retry at the start of the feed operation of the insert sheet B, a refeed interval time T_interval until the refeed operation is started when a paper feed retry occurs. Whether or not the paper feed retry can be performed is determined by comparing the addition time T_total with the one transport time T_FIRST, and if possible, the number of possible paper feed retries is determined.

To explain the above explanation with specific numerical examples,
<Specific example 1>
Reference paper interval T_base: 1000 msec (output speed of 60 sheets / min)
Actual paper interval T_real: 3000 msec (between sheets B and C in FIG. 27)
First transfer time T_FIRST: 700 msec
Second transfer time T_SECOND: 2700msec
Refeed interval time T_interval: 500 msec
If it was
Retryable time T_retry = T_SECOND−T_FIRST = 2000 msec,
Since T_total = T_FIRST + T_interval = 1200 msec and T_retry> T_total, the retry feeding can be performed, and the number of retries calculated from T_retry ÷ T_total is one.

<Specific example 2>
Reference paper interval T_base: 1000 msec (output speed of 60 sheets / min)
Actual paper interval T_real: 5000 msec (between sheets B and C in FIG. 27)
First transfer time T_FIRST: 700 msec
Second transfer time T_SECOND: 4700msec
Refeed interval time T_interval: 500 msec
If it was
Retryable time T_retry = T_SECOND−T_FIRST = 4000 msec,
Since T_total = T_FIRST + T_interval = 1200 msec and T_retry> T_total, the retry feeding is possible, and the number of retries calculated from T_retry ÷ T_total is three.

<Specific example 3>
Reference paper interval T_base: 1000 msec (output speed of 60 sheets / min)
Real paper interval time T_real: 1500 msec (between sheets B and C in FIG. 27)
First transfer time T_FIRST: 700 msec
Second transfer time T_SECOND: 1200msec
Refeed interval time T_interval: 500 msec
If it was
Retryable time T_retry = T_SECOND−T_FIRST = 500 msec,
Since T_total = T_FIRST + T_interval = 1200 msec and T_retry <T_total, the retry sheet cannot be fed, and the number of retries is 0.

<Explanation of operation by flowchart>
Next, the paper feed retry control according to the present invention will be described with reference to the flowchart of FIG.

  In step S101, when the preceding sheet reaches a predetermined position and a paper feed operation start request is issued to the inserter 900, paper feed retry determination is started.

  In step S102, since the paper supply margin time is calculated from the time obtained by subtracting the reference inter-paper time T_base from the real paper time T_real notified in advance from the image forming apparatus, the second transport time T_SECOND and the first transport time are calculated. A retry possible time T_retry is calculated from T_FISRT.

  In step S103, the retry possible time T_retry is compared with the addition time T_total of the first transport time T_FIRST and the refeed interval time T_interval. Judge that retry is possible. If the retry possible time T_retry is less than the addition time T_total, it is determined that the retry is impossible and the process proceeds to step S106.

  In step S105, the number of retries is determined from the calculation formula T_retry ÷ T_total (= T_FIRST + T_interval).

  In step S107, since it is determined that retry is not possible, the number of retries is determined to be zero. In step S108, since the number of retries has been determined, the paper feeding operation is started.

  In step S109, it is detected whether a paper feed jam has occurred. If it has occurred, the process proceeds to step S110.

  In step S110, it is determined whether a paper feed retry is possible. If the number of retries is 0, the process proceeds to step S111 and a paper jam occurs. If the number of retries is not 0, the process proceeds to step S108 again to perform a paper feeding operation. Thereafter, the paper feed retry is performed for the number of retries calculated until normal paper feeding is performed.

[Other embodiments]
The sheet feeding retry control means in the present invention has been described by taking the sheet feeding mechanism of the insert function provided in the sheet post-processing apparatus as an example, but the present invention is not limited thereto, and the sheet feeding mechanism in the image forming apparatus You may apply to.

1 is a configuration diagram showing an internal structure of an image forming apparatus according to a first embodiment of the present invention. 1 is a block diagram illustrating a configuration of a controller of an image forming apparatus according to a first embodiment. It is a block diagram which shows the internal structure of the finisher which concerns on 1st Embodiment. It is a block diagram which shows the structure of the finisher control part of the finisher which concerns on 1st Embodiment. 4A and 4B are diagrams illustrating an example of a screen of an operation unit of the image forming apparatus according to the first embodiment, where FIG. 5A is a menu selection screen, FIG. 5B is a setting screen, and FIG. 2A and 2B are diagrams for explaining the operation of the finisher according to the first embodiment, in which FIG. 3A is a binding side of a sheet and a conveyance direction, and FIG. 2B is a configuration diagram of the finisher. It is a block diagram for demonstrating operation | movement of the finisher which concerns on 1st Embodiment. It is a block diagram for demonstrating operation | movement of the finisher which concerns on 1st Embodiment. It is a block diagram for demonstrating operation | movement of the finisher which concerns on 1st Embodiment. It is a block diagram for demonstrating operation | movement of the finisher which concerns on 1st Embodiment. It is a block diagram for demonstrating operation | movement of the finisher which concerns on 1st Embodiment. 4A and 4B are diagrams for explaining the operation in the bookbinding mode of the finisher according to the first embodiment, where FIG. 5A is original image data, FIG. 5B is image data formed on each surface of each page of paper, and FIG. (c) is the paper transport direction, and (d) is the paper storage state. 4A and 4B are diagrams for explaining an operation in a bookbinding mode using the inserter of the finisher according to the first embodiment, where FIG. 5A is a sheet conveyance direction, and FIG. 5B is a configuration diagram of the finisher. It is a block diagram for demonstrating the operation | movement at the time of bookbinding mode using the inserter of the finisher which concerns on 1st Embodiment. It is a block diagram for demonstrating the operation | movement at the time of bookbinding mode using the inserter of the finisher which concerns on 1st Embodiment. It is a block diagram for demonstrating the operation | movement at the time of bookbinding mode using the inserter of the finisher which concerns on 1st Embodiment. It is a block diagram for demonstrating the operation | movement at the time of bookbinding mode using the inserter of the finisher which concerns on 1st Embodiment. It is a block diagram for demonstrating the operation | movement at the time of bookbinding mode using the inserter of the finisher which concerns on 1st Embodiment. It is a block diagram for demonstrating the operation | movement at the time of bookbinding mode using the inserter of the finisher which concerns on 1st Embodiment. It is a block diagram for demonstrating the operation | movement at the time of bookbinding mode using the inserter of the finisher which concerns on 1st Embodiment. 1 is a diagram illustrating a large-scale image forming system in which a large number of sheet processing apparatuses are cascade-connected downstream of an image forming apparatus. It is a figure which shows the relationship between the sheet | seat to insert and the preceding sheet | seat output from an image forming apparatus with respect to an insert sheet | seat. 6 is a flowchart illustrating sheet feeding retry control according to the first embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus main body 114, 115 Cassette 127, 128 Pickup roller 300 Printer 500 Finisher 501 Finisher control part 630 Processing tray 700 Stack tray 701 Sample tray 900 Inserter 903 Conveyance roller 904 Separation belt 950 Double feed detection sensor

Claims (2)

The sheet is fed from the sheet stacking means for stacking the sheets by the sheet feeding means, the sheet to be fed is detected by the sheet detecting means on the conveyance path, and the sheet is detected by the sheet detecting means from the start of feeding of the sheet feeding means. In the paper feed retry control means for performing paper feed retry when the time until detection exceeds a predetermined jam detection time,
A first transport time, which is a reference time from the start of paper feeding by the paper feeding means to reaching a predetermined position, and a maximum allowable time from the start of paper feeding by the paper feeding means to reaching a predetermined position. A second transport time, and a refeed interval time until the retry feed is started by the retry control means;
By comparing the retry possible time that is the difference time between the second transport time and the first transport time, the retry possible time, and the addition time of the first transport time and the refeed interval time, the paper feed retry time is calculated. A sheet feeding apparatus comprising sheet feeding retry control means for determining whether or not to perform the above and the number of retry executions. In a sheet insert device that is mounted downstream of an image forming apparatus and inserts a sheet into an image-formed recording sheet,
A sheet feeding unit that feeds an insert sheet mounted on the sheet insert device feeds by a sheet feeding unit, detects the fed sheet by a sheet detection unit on a conveyance path, and starts feeding the sheet feeding unit. In the paper feed retry control means for performing the paper feed retry when the time from when the sheet is detected by the sheet detection means exceeds a predetermined jam detection time,
A first transport time, which is a reference time from the start of paper feeding by the paper feeding means to reaching a predetermined position, and a maximum allowable time from the start of paper feeding by the paper feeding means to reaching a predetermined position. A second transport time, and a refeed interval time until the retry feed is started by the retry control means;
By comparing the retry possible time that is the difference time between the second transport time and the first transport time, the retry possible time, and the addition time of the first transport time and the refeed interval time, the paper feed retry time is calculated. A sheet insert device comprising sheet feeding retry control means for determining whether or not to implement the number of retries and the number of retries performed.

Images