JP4859193B2 - Sheet post-processing control method and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including a sheet post-processing device that performs post-processing such as stapling operation on a sheet bundle discharged after image formation.

  Conventionally, the body of an image forming apparatus such as a copier, a printer, a facsimile machine, or a multifunction machine having these functions is connected to or incorporated in a sheet post-processing apparatus that binds a sheet on which an image is formed. There may be.

  In such a sheet post-processing apparatus, the sheets sequentially discharged from the main body of the image forming apparatus are once stacked on the sheet stacking unit to form a bundle, and then discharged to the discharge sheet stacking unit by the discharging unit. ing. In this case, each time the sheet bundle is discharged, the discharged sheet stacking unit descends by the thickness of the sheet bundle, and the next discharged sheet bundle is stacked on the previously discharged sheet bundle. It can be done.

  The post-processing tray is provided with a stapler for binding the sheet bundle, and the post-processing may be performed on the sheet bundle as needed.

  Patent Document 1 proposes a technique for stopping a stapling operation when there is a sheet that does not reach the binding portion in a sheet bundle of irregular sizes.

There is also known a post-processing apparatus that stacks a stack of sheets shifted for each job in a horizontal direction so that the sheet bundle can be easily divided even when the stack of sheets of a plurality of jobs are stacked and discharged.
Japanese Patent Laid-Open No. 2003-238021

  As described above, when the sheets stacked on the sheet feeding unit of the image forming apparatus are different from the designated sheet size, the size difference is found after feeding, so the image forming apparatus sends the information to the sheet post-processing apparatus. The printing process was interrupted after the sheet was discharged. In such a case, it is necessary for the user to specify a correct sheet size or to replace the sheets stacked on the sheet feeding unit with a sheet having the specified sheet size. At the same time, it is necessary to remove the wrong size sheet discharged to the sheet post-processing apparatus from the sheet post-processing apparatus.

  In particular, when stapling is performed as post-processing, if the processing is continued while a wrong size sheet is left in the sheet post-processing apparatus, the sheet will be bound together. Could not be resumed.

  In the present invention, even if the designated sheet size and the fed sheet size do not match, the image forming operation is continued without removing the sheet discharged to the sheet post-processing apparatus, and the sheet post-processing is performed. It is an object of the present invention to provide a sheet post-processing control method that can be executed and an image forming apparatus that employs this method.

Sheet post-processing control method according to the present invention, a sheet in an image forming apparatus having the sheet post-processing apparatus having a post-processing means for performing post-processing in the post-processing position of the sheet in pairs and plants constant that is discharged onto the finishing tray In the post-processing control method, when the sheet post-processing by the sheet post-processing apparatus is performed,
When the specified sheet size matches the sheet size of the sheet fed from the sheet feed stage of the image forming apparatus, the size does not match the discharge position on the post-processing tray for the post-processing target sheet. all together to shift the emissions position on said post-processing tray on the sheet at a position deviated from the post-processing position of the post means, to continue the image forming operation of the succeeding sheet that matches the size, the post-processing object After the sheet is discharged onto the post-processing tray , the post- processing is performed by the post- processing means .

The shifting direction may be a direction orthogonal to the sheet conveyance direction or the sheet conveyance direction. Or both directions may be sufficient. By shifting the discharge position, the non-matching sheets can be removed from the post-processing target such as a binding operation for binding the sheet bundle. In addition, by removing from the post-processing target, even if a non-matching sheet is ejected on top of another sheet, it is not necessary to remove the sheet, and printing of the succeeding size-matching sheet is continued, and all the post-processing targets After the first sheet is discharged, post-processing can be executed while leaving the sheet whose size does not match.

An image forming apparatus according to the present invention includes a post-processing unit that is connected to the image forming apparatus and includes a post-processing unit that performs post-processing at a predetermined post-processing position on a sheet discharged from the image forming apparatus onto a post-processing tray. In the processing apparatus, with respect to the sheet discharge position on the post-processing tray for the post-processing target when the non-matching sheet is discharged from the image forming apparatus with a control unit that controls the post-processing of the discharged sheet, and a seat position changing means to shift the emissions position on said post-processing tray to the size mismatch sheet at a position deviated from the post-processing position of the post-processing means, the control means, by said seat position changing means with shifting the sheets of the size mismatch, continuing the discharge of the succeeding sheet that matches the size, after all sheets to be post-processing object is the After discharged sense tray, characterized in that to perform more pre-SL after treatment with the post-processing means.

  When there are a plurality of sheet feeding stages that can be selectively used as the sheet feeding stage, the control unit switches to another sheet feeding stage that feeds the same sheet as the designated size, and forms an image. You may make it resume. As a result, the printing process can be continued without interruption.

  A setting unit may be provided for the user to initially set whether or not to switch to the other paper feed stage. Thus, when a size mismatch is detected, the user can select whether or not to automatically continue the printing process by switching the paper feed stage to be used.

  When the display means for displaying information is provided, the control means supplies the user when the sheet size comparison means detects that the fed sheet size does not match the designated sheet size. The display means may prompt the user to instruct whether or not to change the paper tray.

  When it is designated not to switch the paper feed stage, the control unit may rescale the image to the sheet size of the current paper feed stage and resume image formation. As a result, the printing process can be resumed without changing the paper feed stage or replacing the sheet.

  The post-processing is post-processing for performing a sheet bundle binding operation, and the control unit detects that the fed sheet size does not match the designated sheet size by the sheet size comparing unit. If the staple position is not the sheet corner but one side of the sheet is designated, the staple position may be changed to the sheet corner when the image forming operation is resumed. Such processing is effective when the sheet discharge position is not shifted from the target position for post-processing simply by shifting the sheet discharge position.

  According to the present invention, even when a sheet having a size different from the designated sheet size is fed and conveyed, the sheet post-processing apparatus is configured to stack the different size sheets on a discharge position that is not a target for post-processing. The sheet post-processing can be executed by continuing the image forming operation without removing the discharged sheet.

  In addition, when there is another sheet feeding unit that accommodates a sheet having the same size as the designated sheet size, the printing operation can be interrupted by switching to the sheet feeding unit. As a result, productivity can be increased.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. Here, a copier will be described as an example of an image forming apparatus. However, the image forming apparatus includes a copying machine, a facsimile, a printer, and a complex machine of these. Therefore, the present invention is not limited to a copying machine. In addition, the sheet post-processing apparatus is shown as being incorporated in the main body of the copying machine, but may be externally attached to the main body.

  FIG. 1 is a schematic front sectional view of a copying machine as an example of an image forming apparatus including a sheet post-processing apparatus according to the present embodiment. As an example of the sheet post-processing apparatus in the present embodiment, a finisher including a stapler that binds a sheet bundle is given as an example. Instead of the stapler, a punching device or the like that punches holes in the sheet may be used.

<Copier>
In FIG. 1, reference numeral 1 denotes an electrophotographic recording unit, 2 a document table for reading a document, and 3 an automatic document feeding unit for conveying the document to a reading position. The document table 2 is also provided with an operation unit (including a display panel) (not shown). Reference numeral 4 denotes a duplex unit that reverses and conveys a sheet, and 400 denotes a sheet post-processing apparatus as a finisher having functions such as a shift tray and a staple. 10, 11, 12, and 13 are paper feeding cassettes for feeding recording paper, 14 is a conveyance path for conveying sheets fed from the paper feeding cassettes 10 to 13, and 15 is a manual paper feeding unit.

  Further, in FIG. 1, reference numeral 17 denotes a laser emitting unit that receives an image signal and generates a laser beam corresponding to the image signal, 18 is a photosensitive drum for forming a latent image based on the generated laser beam, and 19 is a photosensitive drum. A transfer roller for transferring a toner image obtained by developing the latent image formed from the drum 18 to the sheet, 20 a ceramic heater for fixing the image transferred to the sheet by the transfer roller 19, and 21 a ceramic heater and a sheet Reference numeral 22 denotes a pressure roller that conveys the sheet by pressing the sheet against the ceramic heater via the fixing film. The ceramic heater 20, the fixing film 21, and the pressure roller 22 constitute a fixing unit 23.

  When the electrophotographic recording unit 1 receives a print instruction from the operation unit or an external device (for example, an information processing apparatus such as a PC), the electrophotographic recording unit 1 has a paper feed unit or a paper feed cassette that matches the sheet size specified from the operation unit or the PC. Sheet conveyance starts from the paper feed stage. After the toner image obtained by developing the latent image is transferred to a sheet, the toner image is fixed by a fixing unit.

  The sheet on which the toner image has been fixed passes through the first paper discharge path 25 and is discharged from the main body of the copying machine. Thereafter, post-processing such as sorting and binding is performed on the sheet in accordance with an operation mode designated in advance by a sheet post-processing apparatus 400 as shown in FIG.

  Next, the order of forming sequentially read images on both sides of one sheet will be described.

  The sheet on which the toner image is fixed on one side by the fixing unit 23 is guided to the double-side reversing path 28 by a direction switching member (not shown). After the trailing edge of the sheet passes through the direction switching member, the direction is switched and the rotation direction of the roller is reversed. Then, the sheet is reversed in the conveyance direction and sent to the photosensitive drum 18 via the duplex unit 4. It is done. When the next document is prepared on the platen glass 31, the image of the document is read in the same manner as the above process. However, since the sheet is supplied from the duplex unit 4, a document image is formed on the back surface of the same sheet. Can do.

  Also, a method for confirming the sheet size by the copying machine will be described.

  When the electrophotographic recording unit 1 receives a print instruction from the operation unit or the PC, the electrophotographic recording unit 1 starts conveying the sheet from a paper feed stage having a paper feed unit or a sheet cassette suitable for the sheet size designated from the operation unit or the PC. For the fed paper, a sensor (not shown) installed upstream of the photosensitive drum 18 is turned on at the front end of the paper and turned off at the rear end of the paper. The length of the paper is determined based on the time taken to turn on / off the sensor and the conveyance speed of the paper, and it is determined whether or not the specified sheet size is compared with the specified paper length.

<Sheet post-processing device>
FIG. 2 is a schematic front sectional view of the sheet post-processing apparatus 400. FIG. 3A shows a control hardware configuration of the sheet post-processing apparatus 400.

  The sheet post-processing apparatus 400 performs a sheet bundle binding operation in addition to a sorting operation for sorting sheets. The binding operation in the present embodiment is realized by a staple function by, for example, a stapler unit 420, which is a kind of post-processing means.

  Specifically, the sheet post-processing apparatus 400 receives, for example, a post-processing tray 410 that is a sheet stacking unit that accommodates sheets sequentially discharged from the apparatus main body of the copier, and sheets discharged from the apparatus main body of the copier, An offset roller 407 that performs alignment processing on the post-processing tray 410, a discharge sheet stacking unit that finally stacks a sheet bundle formed on the post-processing tray 410, for example, a stack tray 421, sensors 230, 403, and 415, A motor 135, a stapler unit 420 that binds the sheet bundle, and the like are provided, and a bundle of sheets corresponding to the number of documents is formed on the post-processing tray 410 and discharged to the stack tray 421 for each sheet bundle. is there. In addition, the sheet post-processing apparatus 400 includes a conveying roller 405 (FIG. 4), an offset roller arm 406 (FIG. 4), an offset roller 407 (FIG. 4), and a trailing end stopper 411 (FIG. 6) each having functions described later. , Gripper claw 412 (FIG. 4), clamp mechanism 413 (FIG. 4), and side end stopper 416.

  3A, a CPU 111 is a control unit that controls the sheet post-processing apparatus 400, and includes a ROM 110, a RAM 120, and a serial I / O 130. The ROM 110 stores a control program for controlling the operation of this apparatus. The CPU 111 controls each unit while reading a control program from the ROM 110. The CPU 111 has a RAM 120. The RAM 120 stores work data 121 shown in FIG. The CPU 111 controls each unit based on the work data 121. The work data 121 includes an “offset movement amount” that is a shift amount of the sheet, a “sheet size” designated for the job, and the like.

  Various sensors are connected to the input port of the CPU 111. The various sensors include an inlet sensor 403 that detects a sheet sent from the apparatus main body to the sheet receiving unit 401 shown in FIG. 2, and an offset home that detects whether or not the offset roller 407 shown in FIG. The position sensor 150, a bundle discharge home position sensor 160 that detects whether or not the clamp mechanism 413 shown in FIG. 7 is at the home position 413a, and a sheet that detects whether or not a sheet bundle is discharged to the stack tray 421 shown in FIG. A bundle discharge sensor 230 and a sheet discharge sensor 415 for detecting whether or not sheets are discharged and stacked on the post-processing tray 410 shown in FIG. 6 are included.

  Based on the detection signals of these sensors, the CPU 111 performs control of the conveyance motor 431, the offset motor 432, the sheet bundle discharge motor 430, and the stack tray lifting / lowering motor 135 connected to the output port according to the control program stored in the ROM 110. Various motors such as these, a solenoid such as a pickup solenoid 433 and a clamp solenoid 434, a stapler unit 420, and the like are controlled.

  As the motor, a conveyance motor 431 that can rotate the offset roller 407 shown in FIG. 5 in either the direction of conveying the sheet downstream or the direction of conveying the sheet upstream, shown in FIG. An offset motor 432 that moves the offset roller 407 in a direction intersecting the sheet conveying direction between the offset home position 416m and a position where the sheet is moved to the side edge alignment position 416a, and a clamp mechanism 413 shown in FIG. There are a sheet bundle discharge motor 430 that moves between a bundle discharge home position and a sheet bundle discharge position, a stack tray lifting motor 135 that lifts and lowers the stack tray 421 shown in FIG. The solenoid includes a pickup solenoid 433 that moves up and down the offset roller 407 shown in FIG. 5, a clamp solenoid 434 that opens and closes the gripper pawl 412 shown in FIG. The offset home position 416m of the offset roller 407 is also a sheet stacking position (FIG. 5).

  The CPU 111 includes a serial interface unit 130. The CPU 111 exchanges control data and control signals (information such as mode) with the control unit of the apparatus main body through the serial interface unit 130 to control each unit.

  The control unit in the apparatus main body and the CPU 111 may be integrated into either one.

  FIG. 4 is a side view showing a schematic configuration of a drive mechanism of the offset roller 407 and the conveyance roller 405 of the sheet post-processing apparatus 400 in the present embodiment. FIG. 5 shows a plan view thereof. FIG. 6 is an enlarged side view showing the offset roller portion.

  In FIG. 5, the conveyance motor 431, the belt 435, the square shaft 418, the pulleys 442 and 443, the belt 437, the offset roller arm 406, the offset roller 407, and the like select the sheet on the downstream side and the upstream side in the sheet conveyance direction. The transfer direction moving device 446 is configured to be moved automatically.

  Further, the offset motor 432, the pinion 439, the rack 441, the rack support member 444, the square shaft 418, the offset roller arm 406, and the like are configured such that the offset roller 407 has an offset home position and a side edge of the sheet is aligned with a side edge alignment position 416a. For example, a cross-direction moving device 445 that is a cross-direction moving unit that moves in the direction crossing the sheet conveying direction is configured. The sheet whose side edge has been moved to the side edge alignment position 416a is naturally moved to a predetermined position, for example, the binding position 416t.

  The transport direction moving device 446 and the cross direction moving device 445 constitute a moving device 447. The transport direction moving device 446 performs an operation of moving the sheet along the sheet transport direction. The cross direction moving device 445 moves from the sheet stacking position (416m) on which the sheets sequentially discharged to the post-processing tray 410 are stacked to move to the side end alignment position 416a through the binding position 416t, and the side end alignment position. The operation of moving from 416a to the sheet stacking position (416m) side is performed. At the side edge alignment position 416a, for example, a side edge stopper 416 that is a side edge alignment unit that receives the side edge of the sheet and aligns the side edge of the sheet is disposed.

  As can be seen from FIGS. 4 to 6, the offset roller 407 is supported by an offset roller arm 406 that can be moved up and down in the directions of arrows U and D so that the sheet can be received on the post-processing tray 410. The offset roller arm 406 is rotatably supported on a square shaft 418 having a square cross section by a round hole 406a. The offset roller arm 406 is disposed outside the pair of offset rollers 407 in FIG. 6 for easy understanding of the configuration, but actually, as shown in FIG. It is disposed between a pair of offset rollers 407. The offset roller arm 406 is moved up and down by a pickup solenoid 433 via a down lever. The offset roller 407 is rotated in any one of directions E and F by a conveyance motor 431 via a belt 435, a square shaft 418, a pulley 442, a belt 437, and a pulley 443. The conveyance motor 431 rotates the conveyance roller 405 and the offset roller 407 in the sheet conveyance direction or in the opposite direction to the sheet conveyance direction by an amount corresponding to the rotation amount. The pulley 442 is provided on the square shaft 418 by a square hole (not shown) so that the pulley 442 rotates integrally with the square shaft 418 and can move in the thrust direction on the square shaft 418 by the engagement of the square hole and the square shaft 418. It has become.

  Between the pair of offset roller arms 406, a U-shaped rack support member 444 having a rack 441 is supported by a square shaft 418. The rack support member 444 is rotatably provided on the square shaft 418 through a round hole (not shown). For this reason, the rack support member 444 does not rotate following the angular axis 418 even when the angular axis 418 rotates, and can move in the thrust direction on the angular axis 418. The rack 441 meshes with a pinion 439 provided on a fixed offset motor 432. The pickup solenoid 433 is movable along the angular axis 418. Accordingly, the belt 437, the pulley 443, the offset roller arm 406, and the offset roller 407 can be rotated up and down in the directions of arrows U and D in FIG. 4 around the angular axis 418 and guided to the angular axis 418. As the rack support member 444 moves, the stapler unit 420 can be moved closer to and away from the stapler unit 420.

  The offset roller 407 (see FIG. 6) is loaded by the post-processing tray 410, is detected by the sheet discharge sensor 415, and is lowered by its own weight when the pickup solenoid 433 is turned off. The sheet is conveyed in the downstream side so that the entire sheet is stacked on the post-processing tray 410 under pressure contact. The offset roller 407, after conveying the sheet to the post-processing tray 410, stops and rotates in the reverse direction, abuts the upstream end of the sheet against, for example, the rear end stopper 411, which is upstream end alignment means, and the upstream Edge alignment is performed. Further, in FIG. 5, when the offset motor 432 rotates, the offset roller 407 can be moved by the pinion 439 and the rack 441 toward the sheet side edge alignment position 416a that is the binding position of the stapler unit 420. . The offset roller 407 moves toward the side edge alignment position 416a of the sheet by using the contact friction of the offset roller 407 with respect to the sheet to move the sheet following the offset roller 407 and thereby adjust the side edge alignment position 416a of the sheet. It is for moving to.

  The configuration of the clamp mechanism 413 will be described with reference to FIGS. 4, 6, and 7. The clamp mechanism 413 is a holding unit installed in the vicinity of the rear end stopper 411. When the sheet bundle discharge motor 430 (FIG. 4), which is a discharge unit, rotates, the pinion 451 and the rack 452 cause the stack tray 421 (FIG. 7) can be moved closer and away. The gripper claw 412 of the clamp mechanism 413 is opened and closed in the direction of the arrow shown in FIG. 4 by the operation of the clamp solenoid 434 (FIG. 4).

  In the above configuration, the control unit of the main body of the copying machine to which the sheet post-processing apparatus 400 shown in FIG. 1 is attached knows the size of the sheet discharged from the sheet discharge unit 208. For this reason, the CPU 111 of the sheet post-processing apparatus 400 including the microcomputer system performs serial communication with the control unit of the apparatus main body, and performs a binding process on the size of the sheet carried on the post-processing tray 410 and the sheet. It is possible to grasp whether or not.

  Therefore, the CPU 111 of the sheet post-processing apparatus 400 grasps the size of the sheet every time the sheet is discharged from the copying machine main body, and moves the offset roller 407 in the width direction to the offset motor 432 to move the sheet size. In addition, the amount of movement is controlled according to the binding operation. As a result, the offset roller 407 moves by an amount corresponding to the size of the sheets stacked on the post-processing tray 410, so that the side edges of the sheets can be reliably aligned with the alignment position 416a. ing.

  For example, a clamp mechanism 413 serving as a holding unit and a discharge unit holds the sheet bundle PB aligned by the alignment operation of the offset roller 407 on the post-processing tray 410 from the home position 413a to the stack tray 421. The sheet is moved toward the bundling position 413b and discharged from the post-processing tray 410 to the stack tray 421. The clamp mechanism 413 is moved when the sheet bundle discharge motor 430 rotates the pinion 451 to move the rack 452. The home position 413 a of the clamp mechanism 413 is detected by a bundle discharge home position sensor 160. Further, whether or not a sheet bundle is discharged to the stack tray 421 is detected by a sheet bundle discharge sensor 230 provided on the stack tray 421.

  In the sheet post-processing apparatus 400 according to the present embodiment, since the sheet bundle PB stacked on the stack tray 421 constitutes a part of the post-processing tray 410, the sheet bundle PB is discharged from the post-processing tray 410. The stack tray 421 is lowered by the stack tray lifting / lowering motor 135 until the uppermost surface of the sheet bundle PB stacked on the stack tray 421 substantially coincides with the post-processing tray 410.

  Next, operations of the copying machine and the sheet post-processing apparatus according to the present embodiment will be described with reference to FIGS. The processing of the flowchart of FIG. 9 is realized by the CPU 111 of the copier control unit and the sheet post-processing apparatus reading and executing programs stored in the respective ROMs.

  When printing is started, data such as the above-described work data (FIG. 3B) is first transmitted from the copying machine to the sheet post-processing apparatus (S11). Thereafter, the copying machine executes printing (S12). When the stapling operation is performed after printing a plurality of sheets, it is checked whether the sheet size specified by the user or the sheet size specified in the sheet cassette matches the actual sheet size (S13). . If the sheet sizes match, the copying machine does not transmit any data indicating a failure to the sheet post-processing apparatus (that is, notifies normal discharge) (S19), and the sheet post-processing apparatus puts it on the post-processing tray. The apparatus waits until the sheet P is discharged (S20), and shifts the sheet P toward the stapler unit 420 (in the direction of the right arrow in FIG. 8) in order to perform a stapling operation. When the shifted number of sheets reaches the designated number (S22), a staple operation is performed by the stapler unit 420, and the bound sheet bundle is discharged onto the stack tray (S23). Until the job is completed (S24), the process returns to step S12 and the above processing is repeated.

  If the sheet size designated by the user or the sheet size designated in the sheet cassette and the sheet size of the sheet P ′ actually fed and conveyed are different (S13), the copying machine sends the sheet post-processing device. Notifying that the sheet size is different (S14) and waiting until the sheet is discharged to the post-processing tray (S15), and the discharged sheet is in the direction opposite to the stapler unit side (left in FIG. 8). The sheet post-processing apparatus is instructed to stack in the direction of the arrow (S17).

  A sheet size mismatch is caused when a sheet of a size different from the size specified in the cassette is stored in the paper cassette, or when the size of the sheet in the paper cassette changes from the middle. This may occur if the size of the sheet is different from the specified size.

  The sheet post-processing apparatus shifts sheets of different sizes in the direction in accordance with the instruction. When the copying machine confirms that a sheet of a different size has been discharged to the sheet post-processing apparatus, the copier designates a cassette having a sheet of the same size as the sheet designated by the user as the paper feed stage, and feeds from the cassette. The paper is resumed (S18). Returning to step S12, the above process is repeated, and when the number of shifted sheets reaches the designated number (S22), a stapling operation is performed (S23).

  By such an operation, the sheets having different sizes are shifted to the opposite side to the stapler unit 420 even if they overlap with other sheets, so that they are out of the binding position of the stapler unit 420 and are therefore bound. There is no. Therefore, the user can obtain a desired output by extracting sheets having different sizes from the sheet bundle after the stapling operation after the printing of all pages is completed.

  Next, another operation example of the copying machine and the sheet post-processing apparatus according to the present embodiment will be described with reference to FIGS. In this operation example, as shown in FIG. 10, prior to the stapling operation, the discharged sheet P is transported downstream by the offset roller 407 by an amount sufficient to deviate from the binding position of the stapler unit 420 (down arrow in the figure). Then, the sheet is pulled back to the root position of the post-processing tray 410, and the sheet is further shifted in the direction of the right arrow in the drawing to be moved to the range of the binding position. The sheets of different sizes stop moving in the state where they are conveyed downstream and stay at this position. By such an operation, the sheets P ′ having different sizes are not bound because they are out of the binding position of the stapler unit 420 even if they overlap with other sheets P.

  FIG. 11 shows a processing flow for realizing another operation example. Steps S31 to S44 of this processing flow are similar to steps S1 to S14 in the processing flow of FIG. 9, and redundant description will be omitted, and only different points will be described. The process of FIG. 11 differs from the process of FIG. 9 in the processes of steps S36 and S41. That is, in step S36, when the paper is discharged to the discharge tray, the paper is transported downstream (in the direction of the downward arrow in the figure) by an amount sufficient to deviate from the binding position of the stapler unit 420, and remains at this position. In step S41, the discharged sheet is pulled in as described above, shifted, and moved to the binding position range. The processing of the other steps is the same as the processing of the corresponding steps in FIG. The order of pulling in and shifting may be reversed. This pull-in operation is suitable for aligning the sheet edge before the stapling operation. However, if the sheets having the same size are not transported downstream as described above, drawing is not necessary. In this case, only the unmatched sheets are transported downstream.

  In addition to the configuration described above, the following modifications can be considered.

  For example, in a copying machine, it is possible to set whether or not to perform paper feed resumption processing for each paper feed stage at the operation unit, so that paper or colored paper printed on the back side of the paper feed stage or an OHP sheet can be set. Even if it is present, it is possible to prevent the paper refeed process from being executed from that paper feed stage.

  In the copier, when a sheet different from the specified sheet size is fed, a message with a different sheet size is displayed on the operation unit, and whether or not the user switches the paper feed stage to continue printing. Can be designated, so that re-feeding that the user does not want can be stopped.

  In the copier, when paper different from the specified sheet size is fed and the user specifies that the paper feed stage should be switched and printing should not continue, the copier will place a sheet of a different size in the opposite direction to the stapler unit side. After the shift, printing may be resumed when it is confirmed that the paper in the paper feed tray designated for printing by the user has been replaced.

  In the copying machine, when paper different from the specified sheet size is fed and the user specifies that the paper feed stage is not changed and printing is continued, the sheet is shifted in the direction opposite to the stapler unit side. Thereafter, the image may be scaled to fit sheets of different sizes, and the user may be inquired at the operation unit whether or not to perform printing according to the size of the designated paper feed stage. Thereby, even if the sheet size is different, the user can resume printing with the sheet size.

  In the copying machine, when one side of the paper is specified as the stapling position in the stapler unit, the user is notified that the sheet size is different, and when the paper feed stage is changed and printing is continued, the stapling position is set to the paper. The user is informed that printing can be resumed by changing to the corner, and printing is continued when an instruction to change the staple position to the corner is received from the user. If one side of the paper is specified as the stapling position, the sheet may not be removed from the stapling position only by shifting the sheet in a predetermined direction. The change of the stapling position corresponds to such a case. is there.

1 is a schematic front sectional view of a copying machine as an example of an image forming apparatus including a sheet post-processing apparatus according to an embodiment of the present invention. It is a schematic front sectional view of a sheet post-processing apparatus according to an embodiment of the present invention. It is a figure which shows the control hardware constitutions (a) and the work data (b) of the sheet post-processing apparatus according to the embodiment of the present invention. FIG. 3 is a side view illustrating a schematic configuration of a drive mechanism for an offset roller and a conveyance roller of the sheet post-processing apparatus according to the embodiment of the present invention. FIG. 5 is a plan view of the sheet post-processing apparatus of FIG. 4. FIG. 5 is an enlarged side view showing an offset roller portion of the sheet post-processing apparatus of FIG. 4. It is explanatory drawing of a structure of the clamp mechanism of the sheet | seat post-processing apparatus of FIG. 5A and 5B are diagrams for explaining an operation example of the copying machine and the sheet post-processing apparatus according to the embodiment of the present invention. 6 is a flowchart illustrating an operation example of the copier and the sheet post-processing apparatus according to the embodiment of the present invention. 6A and 6B are diagrams for explaining another operation example of the copying machine and the sheet post-processing apparatus according to the embodiment of the present invention. 6 is a flowchart showing another example of the operation of the copier and the sheet post-processing apparatus according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrophotographic recording part 2 ... Original board 4 ... Double-sided unit 18 ... Photosensitive drum 19 ... Transfer roller 23 ... Fixing part 25 ... Paper discharge path 28 ... Double-side inversion path 31 ... Platen glass 121 ... Working data 130 ... Serial interface part 135 ... Stack tray elevating motor 150 ... Offset home position sensor 160 ... Bunch discharge home position sensor 208 ... Sheet discharge unit 230 ... Sheet bundle discharge sensor 400 ... Sheet post-processing device 401 ... Sheet receiving unit 403 ... Inlet sensor 405 ... Conveying roller 406 ... offset roller arm 406a ... round hole 407 ... offset roller 410 ... post-processing tray 411 ... rear end stopper 412 ... gripper pawl 413 ... clamp mechanism 413a ... home position 413b ... bundling position 415 ... sheet discharge sensor 416a ... side edge alignment position 16m ... Offset home position 416t ... Binding position 418 ... Square axis 420 ... Stapler unit 421 ... Stack tray 430 ... Sheet bundle discharge motor 431 ... Conveyance motor 432 ... Offset motor 433 ... Pick-up solenoid 434 ... Clamp solenoid 435, 437 ... Belt 439 ... Pinion 441 ... Rack 442, 443 ... Pulley 444 ... Rack support member 445 ... Cross direction moving device 446 ... Conveyance direction moving device 447 ... Moving device 451 ... Pinion 452 ... Rack

Claims (13)

A sheet post-processing control method in an image forming apparatus having a sheet post-processing device including a post-processing unit that performs post-processing on a sheet discharged on a post-processing tray at a predetermined post-processing position,
When performing sheet post-processing by the sheet post-processing apparatus,
When the specified sheet size matches the sheet size of the sheet fed from the sheet feed stage of the image forming apparatus, the size does not match the discharge position on the post-processing tray for the post-processing target sheet. Shifting the discharge position on the post-processing tray relative to the sheet to a position deviating from the post-processing position of the post-processing means;
Continue the image forming operation of the succeeding sheet that matches the size,
A sheet post-processing control method, comprising: causing the post-processing unit to execute the post-processing after all the sheets to be post-processed are discharged onto the post-processing tray.   The sheet post-processing control method according to claim 1, wherein the shifting direction is a direction orthogonal to a sheet conveyance direction.   3. The sheet post-processing control method according to claim 1, wherein the shifting direction is a sheet conveyance direction. In an image forming apparatus having a sheet post-processing device including a post-processing unit that performs post-processing on a sheet discharged on a post-processing tray at a predetermined post-processing position.
A sheet feeding means for feeding a sheet on which an image is formed by the image forming apparatus from a sheet feeding stage;
Image forming means for forming an image on a fed sheet;
Sheet size detection means for detecting the sheet size fed from the paper feed stage;
Sheet size comparison means for comparing the detected sheet size with the sheet size designated for the image forming process target image;
A sheet post-processing device that post-processes a sheet fed from the sheet feeding stage in accordance with the processing content instructed by the image forming apparatus;
Control means for controlling the image forming means and the sheet post-processing apparatus;
When the sheet size comparison unit detects that the fed sheet size does not match the designated sheet size, and when the fed sheet is discharged to the sheet post-processing device, a post-processing target A sheet position changing means for shifting a discharge position on the post-processing tray for a non-matching sheet to a position outside the post-processing position of the post-processing means with respect to the sheet discharge position on the post-processing tray with respect to Prepared,
The control means shifts the non-size-matched sheets by the sheet position changing means and continues the image forming operation of the succeeding sheets whose sizes match, so that all sheets to be post-processed are discharged to the post-processing tray. Then, the post-processing is executed by the post-processing unit.   The image forming apparatus according to claim 4, wherein the post-processing performed by the post-processing unit includes a binding operation for binding the sheet bundle.   The image forming apparatus according to claim 4, wherein the sheet position changing unit includes a shift unit that shifts the sheet discharged to the sheet post-processing apparatus in a direction substantially orthogonal to the discharge direction.   7. The image forming apparatus according to claim 5, wherein the sheet position changing unit includes a conveying unit that conveys the sheet discharged to the sheet post-processing apparatus in the same direction as the discharging direction and in the opposite direction. apparatus.   The post-processing performed by the post-processing unit is post-processing for performing a sheet bundle binding operation, and the control unit determines that the sheet size fed by the sheet size comparing unit does not match the designated sheet size. 5. The image forming apparatus according to claim 4, wherein when the image is detected, if the staple position is not the sheet corner but one side of the sheet is designated, the staple position is changed to the sheet corner. In a sheet post-processing apparatus including a post-processing unit that is connected to the image forming apparatus and performs post-processing on a sheet discharged from the image forming apparatus onto a post-processing tray at a predetermined post-processing position.
Control means for controlling post-processing of discharged sheets;
When the non-matching sheet is discharged from the image forming apparatus, the post-processing unit sets the discharge position on the post-processing tray for the non-matching sheet with respect to the sheet discharge position on the post-processing tray for the post-processing target. Sheet position changing means for shifting to a position deviating from the post-processing position,
The control means shifts the non-size-matching sheets by the sheet position changing means, and continues to discharge the subsequent sheets whose sizes match, and all the sheets to be post-processed are discharged to the post-processing tray. Further, the post-processing device is configured to cause the post-processing means to execute the post-processing. The sheet post-processing apparatus according to claim 9, wherein the post-processing performed by the post-processing unit includes a binding operation for binding the sheet bundle. The sheet post-processing apparatus according to claim 9, wherein the sheet position changing unit includes a shift unit that shifts the discharged sheet in a direction substantially orthogonal to the discharge direction. The sheet post-processing apparatus according to claim 9 or 10, wherein the sheet position changing unit includes a conveying unit that conveys the discharged sheet in the same direction and in the opposite direction to the discharging direction. The post-processing performed by the post-processing unit is a post-processing for performing a sheet bundle binding operation, and when the control unit shifts the non-size-matched sheet by the sheet position changing unit, the staple position is at the corner of the sheet. The sheet post-processing apparatus according to claim 9 , wherein, when one side of the sheet is designated, the staple position is changed to a corner of the sheet.

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