JP2007008690A - Sheet handling device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet handling device capable of making a stapling position and a folding position set to a central position of a sheet even if the type of sheet or surroundings (temperature/humidity) are changed. <P>SOLUTION: Length of a sheet to be conveyed by the sheet handling device in the conveying direction is detected, and a sheet stopper position is controlled so that folding position and stapling position are set in a central part of the sheet on the basis of the information about the detected sheet length. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention particularly relates to a sheet processing apparatus that performs processing on a sheet and an image forming apparatus including the sheet processing apparatus.

  In recent years, in image forming apparatuses such as copying machines, printing machines, and laser beam printers, for example, after sequentially taking sheets of images formed by the image forming apparatus main body, the sheets are conveyed to a sheet folding unit and folded in two or the like. There is a sheet processing apparatus that performs the process and then discharges and stacks the sheet on the sheet stacking unit (see Patent Document 1).

  FIG. 15 shows a schematic configuration of a conventional sheet processing apparatus provided in the image forming apparatus as described above. Since the sheet processing apparatus 1000 performs a folding process, a conveyance roller 203, a sheet stopper 205, and a stapler 206 are illustrated. A projecting plate (sheet folding means) 209, a pair of folding rollers 208, a paper discharge roller 210, a stacking tray (sheet bundle stacking means) 211, and the like.

  In the sheet processing apparatus 1000 as shown in FIG. 15, a sheet conveyed from the image forming apparatus main body (not shown) into the sheet processing apparatus is first conveyed by the conveyance roller 203 until the leading end reaches the sheet stopper 205 of the sheet folding portion. Thus, alignment in the sheet conveyance direction is performed. Thereafter, the side end portions are aligned by a sheet aligning unit (not shown), thereby aligning in the direction orthogonal to the sheet conveying direction.

  Here, the standby position of the sheet stopper 205 against which the sheet is abutted is generally determined by sheet size information obtained from the image forming apparatus main body.

  By repeating such an operation for each of a plurality of sheets, the plurality of sheets are brought into contact with the sheet stopper 205 and aligned, and the stapler 206 performs a binding process near the center. After that, when the pushing plate 209 is protruded to the center portion of the bound sheet bundle, the sheet bundle enters the nip of the pair of folding rollers 208 with the center portion at the head, and is folded in two. The folded sheet bundle is discharged and stacked by a discharge roller 210 on a stacking tray 211 provided at the lower portion of the sheet processing apparatus main body 1001 with the folded portion at the top.

  By the way, when the sheet bundle folded in this way is discharged to the stacking tray 211, the sheet bundle bulges upward at the open end opposite to the folded portion, and thus a plurality of sheet bundles are stacked on the stacking tray 211. In this case, the end of the sheet bundle on the sheet discharge roller 210 side swells upward.

When the end of the sheet bundle on the sheet discharge roller 210 side swells upward in this way, there is a possibility that the subsequent sheet bundle will not be properly discharged onto the stacking tray 211. As described above, a pressing member 212 for pressing the end of the sheet bundle on the sheet discharge roller 210 side is provided above the stacking tray 211 so as to be rotatable around a fulcrum 216.
JP 2001-26359 A

  However, the actual dimensions such as the length and width of the sheet used for recording in the image forming apparatus have an error in the cutting process with respect to the sheet dimension determined by the standard. It is generally known that the size of the conveyed sheet varies depending on the type and size of the sheet and the environmental conditions of the apparatus (for example, temperature, humidity, etc.), and the binding position and folding position of the sheet are determined. In order to adjust to the predetermined processing position, it is necessary to operate the sheet processing apparatus in advance and adjust the position of the sheet stopper 205.

  This operation must be performed even when the size or type of the sheet to be processed is changed, which is troublesome for the user. If this operation is neglected, a sheet misalignment occurs during image formation, and as a result, a low-quality product is generated in sheet processing.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to provide a predetermined sheet even when the size and type of the sheet to be used or the usage environment of the sheet processing apparatus changes. It is an object of the present invention to provide a sheet processing apparatus capable of performing a binding process and a folding process with high accuracy at the processing position.

  In order to achieve the above object, the main configuration of the present invention includes a sheet stacking unit that stacks sheets, a sheet transport unit that transports sheets to the sheet stacking unit, and a sheet transport unit that transports the sheet to the sheet stacking unit. Sheet abutting means that abuts the end of the sheet in the sheet conveyance direction, sheet processing means that performs processing to the processing position of the sheets stacked on the sheet stacking means, and the sheet abutting means is moved to perform the processing A control unit that controls a position, and a detection unit that detects expansion / contraction amount information in a sheet conveyance direction of a sheet conveyed by the sheet conveyance unit, and the control unit includes the detection unit The abutting means is moved based on the expansion / contraction amount information in the sheet conveying direction detected by the above.

  According to the present invention, it is possible to obtain a product in which a binding process and a folding process are accurately performed at a predetermined processing position of a sheet without being affected by the size and type of the sheet or the use environment of the apparatus. it can.

  Conventionally, since the bookbinding operation was performed after the adjustment work was first performed, the sheet processing time and cost were extra, but the adjustment work became unnecessary by applying the present invention, The time and cost for sheet processing can be reduced.

  Even when the environment changes during use, the sheet stopper position is controlled in response to the environmental change, so that the binding process and the folding process are performed with high accuracy at the center position of the sheet bundle. You can get deliverables.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  1 to 13 are views for explaining a sheet processing apparatus according to the present invention. The same parts as those in the conventional example are denoted by the same reference numerals and the description thereof is omitted.

(Embodiment 1)
<Overall configuration>
FIG. 1 is a cross-sectional view showing a main part configuration of an image forming apparatus according to the present embodiment.

  As shown in FIG. 1, the image forming apparatus according to the present embodiment includes an image forming apparatus main body 10, a folding apparatus 400, and a finisher 500. The image forming apparatus main body 10 includes an image reader 200 that reads a document image, and A printer 300 is provided.

  The image reader 200 is equipped with the document feeder 100. The document feeder 100 feeds documents set upward on the document tray one by one in order from the first page to the left in FIG. 1, and passes over the platen glass 102 through the curved path in FIG. It flows from the left, passes through the reading position, is conveyed to the right in FIG. 1, and is then discharged toward the external paper discharge tray 112. When the document passes through the sink reading position on the platen glass 102 from the left to the right, the document image is read by the scanner unit 104 held at a position corresponding to the sink reading position.

  This reading method is generally an original reading method called original flow reading. Specifically, when the original passes through the reading position, the read image surface of the original is irradiated with light from the lamp 103 of the scanner unit 104, and the reflected light from the read image surface of the original is mirrors 105, 106, 107. Through the lens 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, the document is transported so as to pass through the flow reading position from the left to the right in FIG. 1, so that the direction perpendicular to the document transport direction is the main scanning direction and the document transport direction is the sub-scanning direction. A document reading scan is performed. That is, when the original passes the reading position, the original image is read by conveying the original in the sub-scanning direction while reading the original 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. The image data output from the image sensor 109 is input to the exposure control unit 110 of the printer 300 as a video signal after being subjected to predetermined processing in an image signal control unit 202 described later.

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

  Since the original is a book-like thick original (book original), the operator may directly place the book original on the platen glass 102 and read it without using the original feeder 100. When reading a document without using the document feeder 100, the user first lifts the document feeder 100 and places the document on the platen glass 102, and then the document feeder 100 scans the document on the platen glass 102. The document is read by setting it to be pressed and scanning the scanner unit 104 from left to right. That is, the original fixed reading is performed even when the original is read without using the original feeding device 100.

  The exposure control unit 110 of the printer 300 modulates and outputs the laser beam based on the input video signal. The laser beam 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.

  The electrostatic latent image on the photosensitive drum 111 is visualized as a developer image by the developer supplied from the developing device 113. In addition, a recording sheet (hereinafter referred to as a sheet) is fed from each of the cassettes 114 and 115, the manual sheet feeding unit 125, or the double-sided conveyance path 124 at a timing synchronized with the start of laser beam irradiation. It is conveyed between the photosensitive drum 111 and the transfer unit 116. The developer image formed on the photosensitive drum 111 is transferred onto the fed sheet in the transfer unit 116.

  The sheet on which the developer image has been transferred is conveyed to the fixing unit 117, and the developer image is fixed on the sheet by heat-pressing the sheet in the fixing unit 117. The sheet that has passed through the fixing unit 117 is discharged from the printer 300 to the outside (folding device 400) through the flapper 121 and the discharge roller 118.

  Here, when the sheet is discharged with its image forming surface facing down (face down), the sheet that has passed through the fixing unit 117 is once guided into the reversing path 122 by the switching operation of the flapper 121, and the trailing edge of the sheet is After passing through the flapper 121, the sheet is switched back and discharged from the printer 300 by the discharge roller 118. Hereinafter, this form of paper discharge is referred to as face-down paper discharge. Face-down paper discharge forms images sequentially from the first page, such as when an image read from a document conveyed to a reading position by the document feeder 100 is formed, or when an image output from a computer is formed. The sheet order after face-down 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 forming an image on both sides of the sheet is set, the sheet is guided to the reverse path 122 by the switching operation of the flapper 121 and then conveyed to the double-sided conveyance path 124 and then to the double-sided conveyance path 124. Control is performed to feed the sheet again between the photosensitive drum 111 and the transfer unit 116 at the timing described above.

  The sheet discharged from the printer 300 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 an A3 size sheet or a B4 size sheet is specified and the folding process is specified, the folding apparatus 400 performs the folding process. In other cases, the sheet discharged from the printer 300 passes through the folding apparatus 400. It is sent to the finisher 500. The finisher 500 is provided with an inserter 900 for feeding a cover sheet for binding a sheet on which an image is formed, or a special sheet such as a slip sheet inserted into a sheet bundle as a partition. The finisher 500 performs bookbinding processing, binding processing, punching, and other processing.

<System block diagram>
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 illustrating a configuration of a controller that controls the entire image forming apparatus.

  As shown in FIG. 2, the controller includes a CPU circuit unit 150. The CPU circuit unit 150 includes a CPU (not shown), a ROM 151, and a RAM 152. Each block 101 is controlled by a control program stored in the ROM 151. , 153, 201, 202, 209, 301, 401, 501 are collectively controlled. The RAM 152 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. In addition, the digital image signal input from the computer 210 via the external I / F 209 is subjected to various processes, and the digital image signal is converted into a video signal and output 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 153 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. This control content will be described later.

<Folding part>
Next, the configuration of the folding device 400 and the finisher 500 will be described with reference to FIG. FIG. 3 is a diagram showing the configuration of the folding device 400 and the finisher 500.

  As shown in FIG. 3, the folding device 400 has a folding conveyance horizontal path 402 for introducing the sheet discharged from the printer 300 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 directly sent from the printer 300 to the finisher 500 via the folding conveyance horizontal path 402.

<Finisher>
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 bundled sheet bundle, and takes in Each sheet post-processing such as punching, perforating, sorting, non-sorting, and bookbinding is performed in the vicinity of the trailing edge of the sheet.

  As shown in FIG. 3, the finisher 500 includes an entrance roller pair 502 for guiding the sheet discharged from the printer 300 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. Further, 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 with a finisher path 552 for conveying a sheet from the inlet roller pair 502 to the conveying roller pair 503. However, the conveying roller pair 503 reverses and the sheet is conveyed from the conveying roller pair 503 side to the inlet sensor 531. When transported to the side, a one-way mechanism is transported only to the second bookbinding path 554 side.

  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 sheet.

  The buffer roller 505 is a roller capable of laminating a predetermined number of fed sheets around the outer periphery of the buffer roller 505 and winding the sheet around the outer periphery of the buffer roller 505 by pressing rollers 512, 513, and 514 as necessary. The wound sheet 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 guiding the sheet wound around the buffer roller 505 to the non-sort path 521 or the sorting path 522, and the switching flapper 511 is a sheet wound around the buffer roller 505 to the sort path 522 or the buffer roller 505. This is a flapper for guiding the sheet wound around the buffer path 523 as it is wound.

  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 conveyance 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 bundle 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 movable up and down.

<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 end 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 in a direction orthogonal to the sheet conveying direction, and the staplers 818 cooperate with an anvil 819 facing the stapler 818 as a sheet processing position. The center of the sheet bundle is configured to be bound.

  A folding roller pair 826 is provided at a downstream position of the stapler 818. A protruding member 825 is provided at a position facing the pair of folding rollers 816. By projecting the projecting 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 passed through the origami paper discharge roller 827. It is discharged 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 the sheet bundle bound by the stapler 818 is folded, the positioning member 823 is lowered by a predetermined distance so that the staple position of the sheet bundle becomes the center position of the folding roller pair 826 after the staple processing is completed.

<Outline of operation in bookbinding mode>
Next, image formation in the bookbinding mode will be described with reference to FIG. FIG. 4 is a diagram for explaining image formation in the bookbinding mode.

  When the bookbinding mode is designated, the original set on the original feeder 100 is read in order from the first page, the read original images are sequentially stored in the hard disk 206, and the number of read originals is counted simultaneously.

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: Document number n: integer greater than or equal to 1; sheet number k: any one of 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 read originals is eight. As shown in FIG. 4A, eight pages of original image data (R1 to R8) are stored in the hard disk 206. Stored in the order of reading.

  The image forming order and image forming position are determined for each image data (R1 to R8). As a result, as shown in FIG. 4B, after the mirror image processing is performed, the R4 image on the left half and the R5 image on the right half are formed on the first surface (front surface) of the sheet P1 of the first page. The sheet P <b> 1 is formed and guided to the duplex conveyance path 124. 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 reversal discharge and discharged, and then sent to the bookbinding path 553 of the finisher 500. As shown in FIG. 4C, the reverse sheet discharge causes the sheet P1 to have the second surface on which the R6 image and the R3 image are formed facing upward and the direction of the arrow in FIG. It is conveyed to.

  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. 4C, the sheet P2 is conveyed in the direction of the arrow in the figure with the second surface on which the R8 image and the R1 image are formed facing upward and the R8 image at the head, as shown in FIG. 4C. Is done.

  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. 4D, the sheet P1 is stored on the protruding member 825 side, and the sheet P2 is stored on the folding roller pair 826 side. Further, the first surfaces of the sheets P1 and P2 are stored facing the protruding member 825 side.

  The positioning of the sheets P1 and P2 in the storage guide 820 is performed by a positioning member 823.

<Inserter section>
The inserter 900 is provided in the upper part of the finisher 500 and sequentially separates from a sheet stack of special sheets such as a cover sheet and a slip sheet stacked on the tray 901 and conveys them to the finisher path 552 or the bookbinding path 553. On the tray 901 of the inserter 900, special sheets are stacked in a normal view as viewed from the operator. That is, the special sheets are stacked on the tray 901 with the surface thereof facing up.

  The special sheets on the tray 901 are conveyed by a conveyance roller paper feed roller 902 to a separation unit including a conveyance roller 903 and a separation belt 904, and are sequentially separated and conveyed one by one from the uppermost sheet.

  A drawing roller pair 905 is disposed on the downstream side of the separation unit, and the special sheet separated by the drawing roller pair 905 is stably guided to the conveyance path 908. A paper feed sensor 907 is provided on the downstream side of the drawing roller pair 905, and conveyance for guiding a special sheet on the conveyance path 908 to the inlet roller pair 502 between the paper feed sensor 907 and the entrance roller pair 502. A roller 906 is provided.

<Overview of inserter operation in bookbinding mode>
Next, sheet conveyance from the inserter 900 and the printer 300 in the bookbinding mode to the storage guide 820 in the finisher will be described with reference to FIGS. 5 to 11 are diagrams for explaining the flow of sheets from the inserter and the printer to the storage guide in the finisher in the bookbinding mode, and FIG. 12 is an example of bookbinding processing by folding processing and binding processing in the finisher. FIG.

  When bookbinding is performed by inserting the sheet C1 as a cover sheet into a sheet after image formation, the sheet C1 is set on the tray 901 of the inserter 900 as shown in FIG. At this time, as shown in FIG. 5A, 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 as viewed from the operator, and the setting state of the sheet C1 is the same as the original setting state in the original feeder 100. Therefore, operability when setting the sheet C1 can be improved.

  When the sheet C1 is set on the tray 901, as shown in FIG. 6, feeding of the uppermost sheet 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 sheet after image formation from the printer 300 (shown in FIG. 7). The feeding of the sheet P) is started.

  Next, as shown in FIG. 7, the sheet P fed from the printer 300 is guided into the finisher 500, and the sheet 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.

  When the sheet C1 is further guided to the non-sort path 521 side and conveyed until the trailing edge passes through the inlet sensor 531, the sheet C1 is temporarily stopped as shown in FIG. At this time, the sheet P from the printer 300 is guided into the finisher 500. Then, with the sheet C1 being stopped, the sheet 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. To the first bookbinding path 553. At this time, the sheet C2 following the sheet C1 is separated and conveyed to the front of the conveying 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, as shown in FIG. 9, the sheet C1 is reversely fed and guided into the storage guide 820 via the branch A and the second bookbinding path 554. At this time, as shown in FIG. 10, the sheet C <b> 1 is transported with the image R side as the head, and is stacked and stored on a bundle of sheets P that are already stored in the storage guide 820. When the sheet C1 is stored in the storage guide 820, feeding of the sheet C2 following the sheet C1 is started. Here, for example, when the sheet C2 is an inappropriate sheet having a size different from the predetermined size, as shown in FIG. 11, the sheet C2 is discharged to the sample tray 701 without being temporarily stopped in the state shown in FIG. The

  After the sheet C1 is stacked and stored on the bundle of sheets P in the storage guide 820, the protrusion member 825 acts on the bundle of sheets C1 and P and protrudes toward the folding roller pair 826. Next, the sheet is folded by the pair of folding rollers 826 at the central portion (image boundary portion of the image surface) of the sheet bundle as the sheet processing position and discharged to the saddle discharge tray 832. In this folded state, as shown in FIG. 12B, the image F of the sheet C1 is arranged as a cover page and the image R is arranged as the last page, and the images of the sheets P are arranged in page order, and The sheets C1 and P are superposed with their images oriented in the same direction.

  In this way, by the sheet C1 feeding control from the inserter 900 and the sheet P conveyance control from the printer 300, after the bookbinding process, the image R of the sheet C1 is arranged on the cover page and the image R is arranged on the last page. The images on the sheet P are overlaid in page order and with the image orientations matched. Therefore, the image-formed sheet and the special sheet can be bound together without impairing the print quality of the special sheet from the inserter 900 and the sheet conveyance durability of the printer 300. Further, in the sort mode, the special sheet inserted by the finisher 500 is temporarily held in the finisher path 552, the image-formed sheet is guided and stored in the storage guide 820, and then the special sheet is standby in the finisher path 552. Since the image is guided and stored in the storage guide 820, the productivity of the bookbinding operation for binding the image-formed sheet and the special sheet together can be improved.

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

  Next, the expansion / contraction mechanism of the recording sheet will be described below.

  In general, a sheet on which an image is formed by the image forming apparatus main body 10 expands and contracts as compared with a sheet size defined by a standard. There are several causes for the expansion and contraction of the sheet after image formation, and one of them is a change in the sheet length due to evaporation of moisture contained in the sheet due to heat applied from the fixing device 117. Thereafter, the sheet heated by heat absorbs moisture in the air during the cooling process, so that the sheet length changes again. As described above, the amount of expansion and contraction varies depending on the environmental conditions (humidity, temperature, etc.).

It also changes depending on the size and type of the sheet. For example, in the case of A4 size paper (297 mm × 210 mm, 64 g / m ² ), it is generally known that the maximum expansion and contraction is about ± 1 mm. In the case of A3 size paper, the expansion amount is proportional to the length. Is about double. Furthermore, for example, the expansion / contraction rate varies depending on the type of sheet (material, surface treatment, etc.) such as plain paper, coated paper, OHT paper, and recycled paper, and even when image formation is performed under the same conditions under the same environment Later expansion and contraction amount will be different.

  Although the amount of expansion / contraction is small compared to the sheet after image formation, even when the sheet before image formation stored in each of the cassettes 114 and 115 and the manual sheet feeding unit 125, errors during cutting processing, environmental conditions, In addition, there is already a difference in the amount of expansion and contraction due to the difference in sheet size and type. After the image forming process is performed on the sheet, it can be easily predicted that the difference in the amount of expansion and contraction further increases.

  The amount of expansion / contraction has a great influence on the quality of the product after the bookbinding process. In particular, when the folding process is performed by ignoring the amount of expansion and contraction and fixing the distance from the sheet edge to the folding position with the standard sheet size according to the sheet size, the first half of the page is folded and bound by the bookbinding fold. And the latter half of the page will be stepped, resulting in a poor-looking product.

  Accordingly, it is necessary to accurately grasp the amount of expansion and contraction of the sheet caused by changes in environmental conditions and the size and type of the sheet, and correct the processing position of the folding process.

  This series of flows will be described with reference to the block diagram of FIG.

  A sheet is discharged from the image forming apparatus, and the sheet stopper is adjusted according to the length of the sheet. When the sheet stopper adjustment is performed only once, the sheet stopper is kept waiting at the stopper position until the last sheet of one job is sent. After the last sheet of the job is sent, stapling / pushing / folding operations are performed, and the bookbinding operation is completed. This operation is repeated when the bookbinding operation is performed for a plurality of jobs.

  Next, when the sheet stopper is finely adjusted every time, the sheet length is detected every time the sheet is discharged until the last sheet of the job is sent, and the sheet stopper is finely adjusted. Thereafter, stapling / pushing / folding operations are performed, and the bookbinding operation is completed. When performing a bookbinding operation for a plurality of jobs, this operation is repeated.

  The operation described in the block diagram of FIG. 13 will be described with reference to the cross-sectional view of FIG.

  Information on the size of the sheet discharged from the image forming apparatus main body 10 is input in advance from the operation unit 153 by the user to the CPU of the finisher 500 as a control unit, and is positioned at a position corresponding to the input sheet size. The sheet stopper 823 is put on standby. The sheet discharged from the image forming apparatus main body 10 is guided to the conveyance path 553 by the switching flapper 551 after passing through the conveyance path 402. Thereafter, the sheet is conveyed to the storage guide 820, and a predetermined number of sheets are stacked on the storage guide 820.

  When the first sheet is transported on the transport path 553, the ON time of the sensor 817 serving as a detection unit disposed on the transport path 553 is detected, and the detection result is an unillustrated integration unit serving as a calculation unit. By integrating with the conveyance speed at, the conveyance direction length of the conveyed sheet can be calculated. The length actually calculated by the detection means comprising the sensor 817 and an unillustrated integration unit is compared with the sheet length corresponding to the sheet size registered in advance, and the difference is set as the amount of expansion and contraction in the sheet conveyance direction. By adjusting by moving up and down 823, the binding process and the folding process can be accurately performed at the sheet center position as the sheet processing position.

  In the present embodiment, a method for detecting the sheet length when the first sheet is conveyed to the storage guide 820 has been described as a method for detecting the sheet length. It is not always the first one. For example, there is no problem even if the conveyance direction length is detected for all the sheets and the average value is used as the sheet length of the sheet bundle. By doing in this way, the more exact expansion-contraction amount of a sheet conveyance direction is obtained. However, when the number of sheets constituting the sheet bundle is large, a sufficiently accurate expansion / contraction amount in the sheet conveyance direction can be obtained even if the sheet length from the first sheet to the predetermined number is averaged.

(Embodiment 2)
In the present embodiment, as shown in FIG. 14, when forming an image, a mark 751 indicating the center of the sheet as a sheet processing position is formed outside the effective image area of the sheet 750. Thereafter, the sheet leading edge and the mark 751 are read by an image reading device (not shown) arranged in the conveyance path of the finisher 500 as a detecting unit, and the distance from the leading edge of the sheet after image formation to the center is detected. The position of the sheet stopper 823 is set based on the expansion / contraction amount information.

  In order to form an image of the mark 751 indicating the center of the sheet 750 during image formation, a sheet detection sensor similar to the sensor 817 described in the first embodiment is added to each of the cassettes 114 and 115 and the manual sheet feeding unit 125. It is necessary to provide at the junction of the conveyance path. Based on the detection result of the sheet detection sensor, the mark 751 can be accurately formed in the center of the sheet 750. Since the sheet detection sensor is provided on the image forming apparatus main body 10 side, the sensor 817 of the finisher 500 is not necessary for detecting the sheet length, but is necessary for simply detecting the sheet.

  The sheet on which the mark 751 is formed in the center of the sheet is then shrunk to pass through the fixing device 117 and fix the developer image on the sheet. There is almost no deviation. Similarly, the change in sheet length in the cooling process after fixing is considered to be uniform over the entire sheet.

  As in the first embodiment, as the expansion / contraction amount information in the sheet conveyance direction from the leading end of the sheet to the center portion, only the first sheet is read, the length is detected, and the expansion / contraction amount information is used as a basis. Although the position of the sheet stopper 823 may be determined, there is no problem even if the position of the sheet stopper 823 is determined based on the expansion / contraction amount information in all the sheet conveyance directions constituting the sheet bundle to be bound.

  Note that, after the mark 751 is read first by an image reading device (not shown), the center of the sheet as the sheet processing position may be recognized by reading the trailing edge of the sheet.

  In the present embodiment, the configuration in which the sheet processing position and the image forming position of the mark 751 are matched is described by taking the case where the sheet processing position is the sheet center as an example, but the sheet processing position is an arbitrary position other than the sheet center. There may be. For example, in addition to the mark 751 indicating the center of the sheet, an end mark indicating an accurate finished size after bookbinding is formed as an image, and the sheet bundle subjected to the binding process and the folding process as described above is used as, for example, a trimmer. By cutting the sheet end portion on which the end mark image is formed by a cutting device such as the above, it can be provided as high-quality bookbinding. Further, the sheet processing position and the image forming position of the mark 751 do not need to be matched. For example, the length of the entire sheet is calculated by recognizing the position of the mark 751, and an arbitrary sheet processing position is calculated from the amount of expansion / contraction. You may control to.

(Embodiment 3)
As described in the first embodiment, the length of the sheet after image formation changes. Although the amount of expansion and contraction varies depending on the environmental conditions and the size and type of the sheet, it is generally known that the amount of expansion and contraction is substantially constant under the same conditions.

  For this reason, in this embodiment, an experiment is performed to obtain the amount of expansion / contraction of the sheet by changing the environmental conditions and the size and type of the sheet in various ways, and the expansion / contraction amount of the sheet obtained from the experiment is stored in advance as data storage means. A sheet processing apparatus and an image forming apparatus that are stored in a memory and respond to changes in environmental conditions, sheet size, and type will be described.

  The expansion / contraction amount of the sheet stored in the storage guide 820 is predicted based on information from an environmental sensor (temperature / humidity sensor) provided in at least one of the finisher 500 and the image forming apparatus main body 10 and information on the size and type of the sheet. it can. By disposing the sheet stopper 823 at a position corresponding to the amount of expansion / contraction, it is possible to create a high-quality sheet bundle in which stapling and folding processing are accurately performed at the center of the sheet.

  As a method for determining the sheet size, in the same manner as in the first embodiment, in addition to a method in which the user inputs in advance from the operation unit 153 of the image forming apparatus main body 10 (not shown), the cassettes 114 and 115 and the manual sheet feeding unit 125 A method of sending sheet size information set by providing a size detection sensor to the finisher control unit 501 of the sheet processing apparatus via the CPU circuit unit 150 of the image forming apparatus main body 10 shown in FIG. And a method of determining the size by calculating the length of the first sheet conveyed from the manual sheet feeding unit 125 from the detection result of the sensor 817 described in the first embodiment.

  As a method for determining the sheet type, in addition to a method in which the user inputs in advance from the operation unit 153, a detection unit that detects the gloss of the sheet surface or the like is disposed in the image forming apparatus to determine the sheet type. There is a way to do it.

  In any of the methods, the data stored in the memory in advance and the data are sent to the finisher control unit 501 of the sheet processing apparatus directly or via the CPU circuit unit 150 of the image forming apparatus body 10 to the finisher control unit 501 of the sheet processing apparatus. The amount of expansion and contraction is predicted by comparing the information from the obtained environmental sensor (temperature / humidity sensor) and the determination result determined based on the information on the size and type of the sheet.

  Depending on the environmental conditions and the determination result of the sheet size and type, the expansion / contraction amount data stored in the memory is called, and the staple position from the sheet edge and the folding position are optimally controlled. In addition, it is possible to create a high-quality bookbinding in which the folding position is accurately applied to a predetermined sheet processing position.

  In the first to third embodiments, the binding position and folding position of the sheet bundle have been described as the center position of the length in the sheet conveying direction. However, the present invention is not limited to this. For example, the folding position for three-fold or four-fold The position of the sheet stopper 823 corresponding to the above may be determined. At this time, the binding position and the folding position need not be matched.

Sectional drawing explaining the image forming apparatus of this invention 1 is a block diagram showing the configuration of a controller that controls the entire image forming apparatus of the present invention The figure which shows the structure of the folding apparatus and finisher of this invention The figure for demonstrating the image formation at the time of bookbinding mode of this invention The figure for demonstrating the flow of the sheet | seat from the inserter at the time of bookbinding mode of this invention, and a printer to a storage guide The figure for demonstrating the flow of the sheet | seat from the inserter at the time of bookbinding mode of this invention, and a printer to a storage guide The figure for demonstrating the flow of the sheet | seat from the inserter at the time of bookbinding mode of this invention, and a printer to a storage guide The figure for demonstrating the flow of the sheet | seat from the inserter at the time of bookbinding mode of this invention, and a printer to a storage guide The figure for demonstrating the flow of the sheet | seat from the inserter at the time of bookbinding mode of this invention, and a printer to a storage guide The figure for demonstrating the flow of the sheet | seat from the inserter at the time of bookbinding mode of this invention, and a printer to a storage guide The figure for demonstrating the flow of the sheet | seat from the inserter at the time of bookbinding mode of this invention, and a printer to a storage guide The figure which shows the example which performs a bookbinding process by the folding process in the finisher of this invention, and a binding process FIG. 3 is a block diagram for explaining a series of flows for optimally controlling the stapling position and the folding position from the sheet edge according to the present invention The figure explaining Embodiment 2 of this invention Sectional drawing explaining a conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 114 Cassette 115 Cassette 117 Fixing device 200 Image reader 300 Printer 400 Folding device 402 Conveyance path 500 Finisher 551 Switching flapper 553 Conveyance path 817 Sensor 820 Storage guide 823 Sheet stopper 900 Inserter

Claims (18)

Sheet stacking means for stacking sheets, sheet transporting means for transporting sheets to the sheet stacking means, and sheet abutting for striking the end of the sheet transported by the sheet transporting means to the sheet stacking means in the sheet transporting direction A sheet processing apparatus comprising: means; a sheet processing unit that performs processing to a processing position of a sheet stacked on the sheet stacking unit; and a control unit that controls the processing position by moving the sheet abutting unit. ,
Detecting means for detecting expansion / contraction amount information in the sheet conveying direction of the sheet conveyed by the sheet conveying means;
The sheet processing apparatus, wherein the control unit moves the abutting unit based on expansion / contraction amount information in the sheet conveyance direction detected by the detection unit.   The sheet processing apparatus according to claim 1, wherein the detection unit includes a detection unit configured to detect a length of a sheet conveyed by the sheet conveyance unit.   The said control part determines the expansion-contraction amount of the said sheet conveyance direction based on the average value of the sheet conveyance direction length of the several sheet | seat detected by the said detection means, The Claim 1 or 2 characterized by the above-mentioned. The sheet processing apparatus according to the description.   The sheet processing apparatus according to claim 1, wherein the detection unit includes an image reading unit that reads information on a sheet conveyed by the sheet conveyance unit.   The sheet processing apparatus according to claim 4, wherein the information on the sheet is a mark indicating the processing position.   The sheet processing apparatus according to claim 1, wherein the detection unit includes an environment detection unit that detects an environment, and predicts expansion / contraction amount information in a sheet conveyance direction from a detection result of the environment detection unit.   The sheet processing apparatus according to claim 6, wherein the environment detection unit is a temperature detection unit and a humidity detection unit arranged in the sheet processing apparatus.   The sheet processing apparatus according to claim 6, wherein the environment detection unit is a temperature detection unit and a humidity detection unit arranged in a connected image forming apparatus.   The sheet processing apparatus according to any one of claims 1 to 8, wherein the sheet processing apparatus is at least one of a binding unit that binds sheets and a folding unit that performs a folding process on a sheet. .   The sheet processing apparatus according to claim 1, wherein the processing position is a center position in a sheet conveyance direction of the sheet.   11. The sheet processing apparatus according to claim 1, further comprising an alignment unit configured to align an end portion orthogonal to a sheet conveyance direction on the sheet stacking unit. In an image forming apparatus comprising an image forming means for forming an image on a sheet, and a sheet processing apparatus for processing a sheet image formed by the image forming means,
12. The image forming apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus according to claim 1. An image forming apparatus comprising: an image forming unit that forms an image on a sheet; a sheet processing device that processes a sheet image formed by the image forming unit; and a control unit that controls the sheet processing device.
The sheet processing apparatus includes: a sheet stacking unit that stacks sheets; a sheet transport unit that transports a sheet to the sheet stacking unit; and an end of the sheet transported to the sheet stacking unit by the sheet transport unit in the sheet transport direction Sheet abutting means for abutting, sheet processing means for processing the processing position of the sheets stacked on the sheet stacking means, and information on the amount of expansion / contraction in the sheet conveying direction of the sheet conveyed by the sheet conveying means Having detection means;
The image forming apparatus, wherein the control unit moves the abutting unit based on expansion / contraction amount information in the sheet conveying direction detected by the detection unit.   The image forming apparatus according to claim 13, wherein the detection unit includes a detection unit configured to detect a length of the sheet conveyed by the sheet conveyance unit.   The image forming apparatus according to claim 13, wherein the detection unit includes an image reading unit that reads information on a sheet conveyed by the sheet conveyance unit.   The image forming apparatus according to claim 13, wherein the detection unit includes an environment detection unit that detects an environment, and predicts expansion / contraction amount information in a sheet conveyance direction from a detection result of the environment detection unit.   The image forming apparatus according to claim 16, wherein the environment detecting unit is a temperature detecting unit and a humidity detecting unit arranged in the image forming apparatus.   The image forming apparatus according to claim 16, wherein the environment detection unit is a temperature detection unit and a humidity detection unit arranged in a connected sheet processing apparatus.

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