JP2005306508A - Sheet treatment device and image formation device provided with this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet treatment device and an image formation device provided with this capable of enhancing piling up property of a sheet with a simple constitution. <P>SOLUTION: After the treatment of a sheet bundle SA is completed, the treated sheet bundle SA on a first sheet piling up means is retained by a sheet bundle retaining means 412 and the sheet bundle retaining means 412 is reciprocally moved to a retaining position for retaining the sheet bundle SA and a delivery position provided on a second sheet piling up means side of the first sheet piling up means 410 and delivering the sheet bundle SA to the second sheet piling up means 421 by a movement means 430. Then, after the sheet bundle retaining means 412 is moved from the retaining position to a direction of the second sheet piling up means and is stopped, the delivery position is made to a position where it is moved to an opposite direction by a predetermined distance. Thereby, after the sheet bundle retaining means 412 is once stopped, the sheet bundle SA is delivered. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet processing apparatus and an image forming apparatus including the sheet processing apparatus, and more particularly to a configuration for preventing a positional deviation of a sheet bundle that is discharged after being processed.

  Conventionally, in an image forming apparatus such as a copying machine, a printer, a laser printer, a facsimile, and a composite device thereof, a sheet that performs a process such as a binding process on a sheet discharged from the image forming apparatus main body. Some have a processing device.

  As such a sheet processing apparatus, a sheet stacking operation for transporting a sheet discharged from the image forming apparatus main body to a sheet processing unit, and stacking and aligning the discharged sheet in the sheet processing unit, and a sheet In some cases, processing such as stapling is performed.

  Furthermore, as shown in FIG. 16, for example, such a sheet processing apparatus discharges a sheet bundle from the processing tray 602 to the inclined stack tray 601 of the main body outside 600 by the bundle discharge unit 650 after processing the sheet. In this case, the sheet bundle can be aligned in one direction by its own weight due to the inclination of the stack tray 601 (see Patent Document 1).

  As another sheet processing apparatus, after an image-formed sheet is stored in the stacking unit, the sheet bundle is moved to a bundle, and thereafter, the sheet bundle is subjected to processing such as binding processing, and then the bundle is again bundled. An apparatus that moves and accommodates in a loading means is known (see Patent Document 2).

JP 2002-284425 A JP-A-7-257811

  However, in such a conventional sheet processing apparatus and an image forming apparatus including the sheet processing apparatus, when stacking sheet bundles on the inclined stack tray 601, the sheet bundles can be aligned by the inclination of the stack tray 601. When the sheet bundle is discharged to a substantially horizontal stack tray, the sheet bundle cannot be aligned due to its own weight drop. For this reason, depending on the inertial force and the condition of the sheet bundle, the position of the sheet bundle loaded on the stack tray after being discharged is not constant, and the stackability is deteriorated.

  In particular, in an unbound sheet bundle, the alignment in the sheet bundle is also easily shifted, and once shifted, it cannot be aligned again. That is, when discharging a sheet bundle to a substantially horizontal stack tray, it is difficult to stack the sheet bundle in an aligned state.

  Accordingly, the present invention has been made in view of such a current situation, and an object thereof is to provide a sheet processing apparatus capable of improving the stackability of sheets with a simple configuration and an image forming apparatus including the sheet processing apparatus. It is what.

  The present invention is provided with a first sheet stacking unit for stacking sheets to be processed and a downstream of the first sheet stacking unit in the sheet conveying direction, and after being processed on the first sheet stacking unit, the sheet is discharged. A sheet processing apparatus including a second sheet stacking unit configured to stack the sheet bundle to hold the processed sheet bundle on the first sheet stacking unit after the processing of the sheet bundle is completed. A holding unit, the sheet bundle holding unit, a holding position for holding the sheet bundle, and a second sheet stacking unit side of the first sheet stacking unit, and the sheet bundle is mounted on the second sheet stacking unit. Moving means for reciprocating between the discharge position and the discharge position to be discharged to the means, and the sheet bundle holding means is moved from the holding position to the second sheet stacking means by the moving means. After stopping to, it is characterized in that it has a position a predetermined distance in the opposite direction.

  Further, the present invention is characterized in that a holding release portion is provided at the discharge position to release the holding of the sheet bundle of the sheet bundle holding means as the sheet bundle holding means moves in the reverse direction. is there.

  According to the present invention, the discharge position is a position where the sheet bundle is stacked on the second sheet stacking unit by its own weight when the holding release unit releases the holding of the sheet bundle by the sheet bundle holding unit. It is characterized by being.

  According to the present invention, the sheet bundle holding means is movable to a first position for holding the sheet bundle and a second position for releasing the holding of the sheet bundle, and the holding release unit is configured to hold the sheet bundle. The sheet bundle holding means is moved from the first position to the second position as the means moves in the reverse direction.

  According to the present invention, the holding release unit is a recess formed at an end of the first sheet stacking unit on the second sheet stacking unit side, and the sheet bundle holding unit is in a direction opposite to the sheet bundle holding unit. A lever portion that moves in the recess as it moves is moved from the first position to the second position by contacting the lever portion with a side wall of the recess after the lever portion has moved the predetermined distance in the recess. It is characterized by moving to.

  According to the present invention, in the image forming apparatus, the image forming unit includes an image forming unit that forms an image on the sheet, and the sheet processing device according to any one of the above that processes the sheet on which the image is formed by the image forming unit. It is characterized by.

  The present invention also provides an image forming unit that forms an image on a sheet, a first sheet stacking unit that stacks sheets to be processed by the image forming unit, and a downstream side of the first sheet stacking unit in the sheet conveying direction. And a second sheet stacking unit that stacks the sheet bundle to be discharged after being processed on the first sheet stacking unit, and the processed first sheet stacking after the processing of the sheet bundle is finished. A sheet bundle holding means for holding a sheet bundle on the means; the sheet bundle holding means; a holding position for holding the sheet bundle; and a second sheet stacking means side of the first sheet stacking means, Moving means for reciprocally moving the sheet bundle to and from the discharge position for discharging the sheet bundle to the second sheet stacking means, wherein the sheet bundle holding means is moved from the holding position by the moving means. Second After stopping moving in the direction of the sheet stacking means, it is characterized in that it has a position a predetermined distance in the opposite direction.

  According to the present invention, when discharging a sheet bundle, the sheet bundle is temporarily stopped and then discharged, so that it is possible to eliminate the influence of the inertial force when discharging the sheet bundle. Can be made constant. Thereby, the sheet bundle can be aligned on the stack tray with a simple configuration, and the stackability of the sheets can be improved.

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

  FIG. 1 is a cross-sectional view showing a configuration of an image forming apparatus provided with a sheet processing apparatus according to an embodiment of the present invention, in which A is an image forming apparatus, 500 is an image forming apparatus main body, and 300 is an image. An automatic document feeder (ADF) 400 provided on the upper surface of the forming apparatus main body 500 is a sheet processing apparatus that processes sheets discharged from the image forming apparatus A.

  In the figure, reference numeral 120 denotes a reader unit (image input device) that converts a document into image data, and 200 includes a plurality of types of sheet cassettes 204 and 205, and the image data is converted into a visible image on the sheet by a print command. It is a printer unit which is an image forming unit to output.

  In the image forming apparatus A configured as described above, when an original image is read to form an image, first, the originals stacked on the automatic original feeder (ADF) 300 are sequentially placed on the platen glass one by one. It is carried on the surface 102.

  Next, when the document is conveyed to a predetermined position on the glass surface 102 in this way, the lamp 103 of the reader unit 120 is turned on, and the scanner unit 101 moves to irradiate the document. Then, the reflected light from the original is input to the CCD image sensor unit 109 through the mirrors 105, 106, 107 and the lens 108, and electrical processing such as photoelectric conversion is performed in the CCD image sensor unit 109, and normal digital processing is performed. Is given.

  Next, the image signal subjected to the electrical processing in this manner is converted into a modulated optical signal by the exposure control unit 201 of the printer unit 200, and irradiates the photosensitive drum 202. Then, a latent image is formed on the photosensitive drum 202 by the irradiation light, and the latent image is developed by the developing device 203. As a result, a toner image is formed on the photosensitive drum 202.

  Next, the sheet S is conveyed from the sheet cassettes 204 and 205 in synchronization with the leading edge of the toner image, and the toner image is transferred to the sheet S by the transfer unit 206. Thereafter, the toner image transferred to the sheet S is fixed by the fixing unit 207. After the toner image is fixed in this way, the sheet S is discharged from the paper discharge unit 208 to the outside of the apparatus.

  Then, the sheet S output from the paper discharge unit 208 is conveyed to the sheet processing apparatus 400, and processing such as sorting and binding is performed in accordance with an operation mode designated in advance by the sheet processing apparatus 400.

  When outputting sequentially read images on both sides of one sheet S, first, the direction switching member 209 is once switched in the solid line direction in the drawing for the sheet S on which the toner image is fixed on one side by the fixing unit 207. Then, the direction switching member 217 is switched to the broken line direction, and the direction switching member 213 is switched to the broken line direction, so that the sheet is conveyed to the reverse path 212 via the path 218.

  Next, after the trailing edge of the sheet passes through the direction switching member 213, the direction switching member 213 is switched to the solid line direction, and the rotation direction of the roller 211 is reversed to guide the sheet to the path 210, and then to the transfer unit 206. The sheet is conveyed to form an image on the back surface of the sheet S.

  On the other hand, the sheet processing apparatus 400 has a stapling function that is a binding operation by a stapling unit in addition to a sorting operation for sorting sheets, and is sequentially discharged from the image forming apparatus main body 500 as shown in FIG. A processing tray 410 for processing the sheet S and a stack tray 421 for finally stacking a sheet bundle processed on the processing tray 410 are provided, and a sheet bundle corresponding to the number of documents is placed on the processing tray 410. And is discharged to the stack tray 421 for each sheet bundle.

  In the figure, reference numeral 401 denotes a sheet receiving unit that receives the sheet S discharged from the image forming apparatus main body 500. The sheet S received by the sheet receiving unit 401 is detected by the entrance sensor 403, and then the conveyance roller. 405 and an offset roller 407, and then discharged onto a processing tray 410 as a first sheet stacking unit as shown in FIG. The sheets S stacked on the processing tray 410 in this way are detected by a sheet bundle discharge sensor 415 shown in FIG.

  Here, the offset roller 407 is held up and down by an offset roller arm 406 that can move up and down about a shaft 406 a shown in FIGS. 4 and 5, and when the sheet S is discharged to the processing tray 410. The sheet S is moved upward via the offset roller arm 406, whereby the sheet S is discharged onto the processing tray 410 without being obstructed by the offset roller 407.

  The offset roller arm 406 can be moved up and down by a pickup solenoid 433 with a shaft 406a as a fulcrum. That is, the offset roller 407 moves up and down when the pickup solenoid 433 is turned on / off.

  Further, as shown in FIG. 5, the offset roller 407 is driven via belts 431a and 431b by a conveyance motor 431 that drives the conveyance roller 405. When the conveyance motor 431 rotates, the conveyance motor 431 is driven. Rotate in the transport direction or in the opposite direction of the transport direction (hereinafter referred to as reverse rotation) by an amount corresponding to the amount of rotation.

  In the present embodiment, when the sheet bundle discharge sensor 415 detects a sheet, the pickup solenoid 433 is turned off, whereby the offset roller 407 is lowered by its own weight and landed on the sheet. Thereafter, the sheet rotates in the sheet conveying direction for a predetermined time, and reverses when the predetermined time elapses.

  By reversing in this way, the trailing edge of the sheet is brought into contact with the sheet trailing edge stopper 411 provided at the upstream end of the processing tray 410 in the conveying direction so as to align the sheet S in the conveying direction. ing.

  In FIG. 4, reference numeral 416 denotes a positioning wall serving as an alignment position reference at the end of the sheet in a direction orthogonal to the sheet conveyance direction (hereinafter referred to as the width direction), and 420 is disposed near the positioning wall of the processing tray 410. This is a stapler unit that performs a stapling process on a sheet bundle formed on the processing tray 410. The offset roller 407 is moved in the width direction via the rack and pinion by driving the offset motor 432, and close to the positioning wall 416. Can be done.

  When the offset roller 407 approaches the positioning wall 416 in this way, the sheet that is abutted against the sheet trailing edge stopper 411 and aligned in the conveyance direction moves to the positioning wall 416 by the frictional force of the offset roller 407. Thus, positioning in the width direction is performed. After the sheet S hits the positioning wall 416, the offset roller 407 moves and stops while sliding on the sheet.

  By providing such an offset roller 407, the sheet discharged onto the processing tray 410 is conveyed to the stack tray side by the offset roller 407 rotating in the sheet conveying direction as shown in FIG. 6B, the sheet is returned to the sheet trailing edge stopper 411 by the reverse rotation of the offset roller 407, and then the trailing edge is brought into contact with the trailing edge stopper 411 for alignment.

  In FIG. 6 and FIGS. 7 and 8 to be described later, unlike FIG. 4 described above, the offset roller 407 is described as having a configuration arranged inside the offset roller arm 406. This difference in configuration is merely a difference in design, and there is no difference in function and operation from the configuration shown in FIG.

  Thereafter, as shown in FIG. 6C, the offset roller 407 is moved to the positioning wall side along the shaft 406a while being grounded to the sheet S, so that the end in the width direction of the sheet S is positioned. The sheet S is pressed against the wall 416 and the sheet S is aligned in the width direction.

  On the other hand, in FIG. 5, reference numeral 412 denotes a sheet clamp member as sheet bundle holding means for pressing the rear end portion of the aligned sheet S from above by a biasing force by a biasing means (not shown). Then, as shown in FIG. 7A, after the offset roller 407 is lifted by the pickup solenoid 433, the aligned sheet S is moved by the sheet clamp member 412 as shown in FIG. 7B. It can be pressed from above. As a result, the sheet S previously discharged to the processing tray 410 can be held at a predetermined position without being affected by the subsequent feeding by the sequentially fed sheets S. .

  The sheet clamp member 412 rotates upward as shown in FIG. 8A so that the sheet S can be received when the offset roller 407 is reversely rotated, and is offset to align the ends. When the sheet S moves in the width direction together with the roller 407, the sheet S is rotated upward as shown in FIG.

  In FIG. 5, reference numeral 413 denotes a sheet bundle discharge member exemplified as a sheet bundle discharge unit for discharging the processed sheet bundle to the stack tray 421. The sheet bundle discharge member 413 allows the sheet clamp member 412 to turn freely. As shown in FIG. 9, the sheet bundle that is held and the aligned sheet bundle or the stapled sheet bundle that has been aligned and held by the sheet clamp member 412 is provided downstream of the processing tray 410. Further, the sheet moves in the direction of the stack tray 421 as the second sheet stacking means.

  Further, after this, when the leading end of the processing tray 410, which is the sheet discharge position indicated by the solid line in FIG. The paper is discharged to the tray 421.

  Here, the sheet bundle discharge member 413 discharges the sheet bundle to the stack tray 421 when power is transmitted through the rack and the pinion by the sheet bundle discharge motor 430 as the moving means as shown in FIG. It is possible to reciprocate between a position (discharge position) and a home position as a holding position for holding the sheet bundle in the vicinity of the sheet trailing edge stopper 411. The sheet bundle discharge member 413 is normally fixed at the home position by excitation of the sheet bundle discharge motor 430.

  In FIG. 5, reference numeral 434 denotes a clamp solenoid for rotating the sheet clamp member 412. This clamp solenoid 434 is used when the offset roller 407 stops rotating after conveying the sheet and when the offset roller 407 moves in the width direction. When moving, the sheet clamp member 412 is turned on, and the sheet clamp member 412 is rotated upward via a release lever portion 412 a provided on the lever 434 a and the sheet clamp member 412.

  In this embodiment, after the sheet S is moved in the width direction, the offset roller 407 is reversely rotated again to complete the alignment operation in order to correct the deviation in the sheet conveyance direction. High-precision matching is achieved. When the specified number of sheets have been aligned, the clamp solenoid 434 closes the sheet clamp member 412 to hold the sheet bundle.

  FIG. 10 is a block diagram showing the configuration of the control unit of the sheet processing apparatus 400 having such a configuration. Reference numeral 100 denotes a CPU exemplified as the control means in the present embodiment. Here, the CPU 100 has a ROM 110 therein, and programs and the like corresponding to control procedures shown in FIGS. 13 and 14 to be described later are stored in the ROM 110. The CPU 100 reads out and executes this program to control each unit.

  Further, the CPU 100 has a built-in RAM 121 in which work data and input data are stored, and the CPU 100 performs control with reference to data stored in the RAM 121 based on the program. Further, sensors such as an inlet sensor 403 and a sheet bundle discharge sensor 415 are connected to the input port of the CPU 100, and a conveyance motor 431, an offset motor 432, a sheet bundle discharge motor 430, and a pickup solenoid 433 are connected to the output port of the CPU 100. A motor such as a clamp solenoid 434 and a solenoid are connected. Based on the state of these sensors, the CPU 100 controls loads such as various motors and solenoids connected to the output port according to the aforementioned program.

  In addition, the CPU 100 includes a serial interface unit (I / O) 130, which transmits and receives control data to and from the image forming apparatus main body 500 (control unit thereof), and also transmits an image via the serial interface unit (I / O) 130. Each unit is controlled based on control data sent from the forming apparatus main body 500 (control unit thereof).

  Since the image forming apparatus main body 500 knows the size of the sheet discharged from the sheet discharge unit 208, the control unit of the sheet processing apparatus 400 performs serial communication with the control unit of the image forming apparatus main body 500 to perform processing. The size of the sheet inserted on the tray 410 can be grasped.

  Therefore, each time the sheet S is discharged from the image forming apparatus main body 500, the control unit (CPU 100) of the sheet processing apparatus 400 grasps the size of the sheet S and controls the offset motor 432 so that the offset roller 407 in the width direction is controlled. The movement amount can be controlled to be a movement amount according to the sheet size. As a result, the offset roller 407 moves by an amount corresponding to the size of the sheet discharged onto the processing tray 410, and the side edge of the sheet S can be reliably pressed against the positioning wall 416.

  In this embodiment, since the sheet bundle stacked on the stack tray 421 constitutes a part of the processing tray 410, when the sheet bundle SA is discharged from the processing tray 410, the stack tray 421 is discharged. Is lowered by a stack tray raising / lowering motor (see FIG. 10) until the uppermost surface of the stacked sheet bundle substantially coincides with the processing tray 410.

  In FIG. 11, 410 a is a recess formed on the top surface of the front end of the processing tray 410 and extending a predetermined distance in the direction opposite to the moving direction of the sheet bundle discharging member 413, and the sheet bundle discharging member 413 is disposed on the processing tray 410. After reaching the leading end, it is temporarily stopped, and then when returning to the home position, the lower end of the release lever portion 412a as the lever portion of the sheet clamp member 412 moves along the recess 410a. .

  When the sheet bundle discharging member 413 moves, the release lever portion 412a slides while being pressed against the processing tray 410, so that the release lever portion 412a moves to a position facing the recess 410a. Then, the release lever portion 412a elastically enters the recess.

  After that, when the sheet bundle discharge member 413 moves by a predetermined distance, the release lever portion 412a is locked to the side end of the concave portion 410a, and when the sheet bundle discharge member 413 further moves, the release lever portion 412a moves clockwise. The sheet clamp member 412 is rotated upward along with the rotation.

  That is, a recess 410a as a holding release portion is formed on the top surface of the front end of the processing tray 410, and when the sheet bundle discharge member 413 moves in the direction returning to the home position, the release lever portion of the sheet clamp member 412 is located at the side end of the recess 410a. By locking 412a, the sheet clamp member 412 rotates upward (moves) from the first position where the sheet bundle is held to the second position where the holding of the sheet bundle is released.

  Note that the predetermined distance for moving the sheet bundle discharge member 413 movable to the first position and the second position to rotate the sheet clamp member 412 upward is set when the holding by the sheet clamp member 412 is released. This is the distance at which SA falls on the stack tray due to its own weight.

  Then, when the sheet bundle SA is stacked on the stack tray in this way, the sheet bundle discharge member 413 is temporarily stopped and then the sheet bundle SA is dropped, thereby reducing the inertial force of the sheet bundle SA. As a result, the sheet bundle dropping position can always be kept constant. As a result, when the sheet bundle SA is placed on the substantially horizontal stack tray 421, misalignment due to the inertial force of the sheet bundle SA can be prevented, and misalignment between the sheet bundles can be prevented. The stackability of the sheet bundle SA can be improved.

  Next, the sheet processing operation of the sheet processing apparatus 400 of the present embodiment configured as described above will be described with reference to the flowcharts shown in FIGS.

  First, when an image forming operation by the image forming apparatus main body 500 is started, the CPU 100 (see FIG. 10) of the sheet processing apparatus 400 checks whether or not a sheet discharge signal is received from the image forming apparatus main body 500 (S100). ). If a sheet discharge signal is received (Y in S100), the pickup solenoid 433 is turned on (S110), and the offset roller 407 supported by the offset roller arm 406 is pulled up.

  Next, the conveyance motor 431 is turned on (S120), so that the conveyance roller 405 installed in the middle of the sheet discharge path can convey the sheet in the same direction as the sheet discharge direction of the image forming apparatus main body 500. Here, the leading edge of the first sheet passes through the inlet sensor 403 and turns on the inlet sensor 403 (Y in S130). Thereafter, the sheet reaches the conveying roller 405 and power is transmitted from the conveying roller 405 to the sheet. Then, when the sheet is separated from the paper discharge unit 208 (see FIG. 1) of the image forming apparatus main body 500 (Y in S140), the delivery of the sheet is completed.

  Next, while the sheet is conveyed to the processing tray 410 by the conveying roller 405, the pickup solenoid 433 is turned off before the sheet is completely removed from the conveying roller 405 (S150), and the offset roller 407 is landed on the sheet by its own weight. Let Thereafter, as shown in FIG. 6A, the sheet S is conveyed to a predetermined position by the offset roller 407 (S160). When the sheet S is conveyed to a predetermined position (Y in S160), the rotation of the conveyance motor 431 is stopped (S170), and the conveyance of the sheet S is stopped.

  Next, when the rotation of the offset roller 407 stops, the clamp solenoid 434 is turned on (S180), and as shown in FIG. 6B, the sheet clamp member 412 installed in the vicinity of the sheet trailing edge stopper 411 is moved. open. Thereafter, the conveyance motor 431 is rotated in the direction opposite to the conveyance direction, the sheet S is pulled back by the offset roller 407 (S190), and the sheet trailing edge is abutted against the sheet trailing edge stopper 411.

  Note that the rotation amount of the offset roller 407 when the trailing edge of the sheet abuts against the trailing edge stopper 411 takes into account the skew of the sheet S that is generated when the sheet S is fed from the image forming apparatus main body 500, and the sheet S is conveyed. The sheet is rotated so that it can be transported slightly more than the distance from the point of stopping and switching back to the sheet trailing edge stopper 411.

  Next, the sheet size to be discharged is checked based on the size information from the image forming apparatus main body 500 (S200), and the offset movement amount according to the size of the discharged sheet S, that is, the sheet S discharged onto the processing tray 410 is checked. The movement distance in the width direction of the sheet S necessary for pressing the sheet to the positioning wall 416 is calculated (S210).

  Thereafter, the offset roller 407 is offset to the positioning wall 416 via the rack and pinion by the offset motor 432 as shown in FIG. 6C (S220). Here, when the offset roller 407 moves in this way, the sheet S in contact with the offset roller 407 moves together with the offset roller 407 in the direction of the positioning wall 416 by the frictional force of the offset roller 407. At this time, the sheet clamp member 412 is rotated upward as shown in FIG. 8B so as not to be a load of movement of the sheet S.

  Next, after the offset roller 407 abuts the sheet S against the positioning wall 416, the offset roller 407 slides slightly on the sheet S and stops. Thereafter, in order to correct the misalignment in the transport direction after the offset movement, an alignment operation is performed in which the offset roller 407 is reversed again and the sheet S is pulled back (S230). Alignment is complete.

  Next, when the alignment of the first sheet S is completed as described above, the pickup solenoid 433 is turned on (S240), and the offset roller 407 is lifted as shown in FIG. Turn off (S250). As a result, as shown in FIG. 7B, the sheet clamp member 412 is closed and the aligned sheet S is held and held. As a result, the first discharged sheet S is discharged next. It is possible to prevent the sheet from being carried by the used sheet.

  Next, as shown in FIG. 7B, the offset roller 407 is moved back to the home position via the rack and pinion by the offset motor 432 in a lifted state (S260).

  It is checked whether or not the sheet S stored on the processing tray 410 is the last sheet corresponding to the last page of the copy original (S270), and the final sheet is based on the information sent from the image forming apparatus main body 500. When it is determined that the sheet is not S (N in S270), the process returns to S100 and the next sheet discharge signal sent from the image forming apparatus main body 500 is received, and until the final sheet S is stored in the processing tray 410, Repeat the flow.

  Thus, each time the sheet S is discharged from the image forming apparatus main body 500, the control unit (CPU) of the sheet processing apparatus 400 grasps the size of the sheet S and calculates an offset movement amount suitable for the sheet S. Thus, the sheet S in contact with the offset roller 407 is subjected to an alignment process based on the calculated movement amount and is aligned with the positioning wall 416.

  On the other hand, if it is determined that the sheet is the final sheet (Y in S270), a sheet bundle corresponding to the copy document is formed on the processing tray 410, so whether the stapling process is selected next. If it is selected (Y in S280), the stapling unit 420 is driven to execute the stapling process (S290).

  Next, when the stapling process is not selected (N in S270) or after the stapling process is completed, the sheet bundle discharging member 413 is replaced with the sheet bundle discharging motor 430 and the sheet bundle SA is set as shown in FIG. The sheet bundle SA is advanced in the direction of the stack tray 421 while being grasped by the sheet clamp member 412, and the sheet bundle SA is discharged and moved (S300).

  Next, when the sheet bundle discharge member 413 reaches the front end position of the processing tray 410, the sheet bundle discharge member 413 is temporarily stopped (S305). Then, by temporarily stopping the sheet bundle discharge member 413 in this way, the inertial force that acts on the sheet bundle SA at this point is eliminated.

  Thereafter, when the sheet bundle discharge member 413 moves in the direction returning to the home position, the lower end of the release lever portion 412a of the sheet clamp member 412 is the side end of the concave portion 410a (see FIG. 11) provided on the upper end surface of the processing tray 410 Accordingly, the sheet clamp member 412 that has gripped the sheet bundle SA is rotated upward to release (hold) the sheet bundle SA.

  When the nipping is thus released, the sheet bundle SA falls on the stack tray by its own weight. At this time, since the inertia force of the sheet bundle SA is hardly generated, the sheet bundle SA falls to a certain position on the stack tray, and thereby the sheet bundle SA is aligned on the stack tray. Loaded with.

  Next, the stack tray 421 is moved (lowered) in accordance with the discharge operation of the sheet bundle SA (S310), and then the sheet bundle discharge member 413 is returned to the home position (S320).

  Thereafter, the conveyance motor 431 is stopped to stop the rotation of the conveyance roller 405 and the offset roller 407 (S330), the pickup solenoid 433 is turned off (S340), and the offset roller 407 is lowered to complete a series of processing. To do.

  In this embodiment, a fixed stapler disposed near the positioning wall 416 is used to bind the sheet bundle. However, when a movable stapler is used, another portion of the sheet bundle is used. It is also possible to staple the plurality of locations.

  In this embodiment, the offset roller 407, which is a roller member, is used to align the sheet S. However, instead of the roller member, the member itself moves in the conveyance direction to convey the sheet. The same effect can be obtained by using a sheet orthogonal direction moving unit that moves in the direction orthogonal to the conveyance direction to move the sheet.

  Further, in the present embodiment, the CPU performs control while reading the program written on the RAM (or ROM) storing the program corresponding to the flowcharts of FIGS. 13 and 14, but the processing on the control program is performed. The same effect can be obtained even if the hardware is configured.

  In the above description, the sheet bundle discharge member 413 (sheet clamp member 412) is moved by transmitting the power of the sheet bundle discharge motor 430 via a rack and a pinion. For example, the power of the sheet bundle discharge motor 430 may be transmitted via a cam, and the power of the sheet bundle discharge motor 430 may be transmitted via a belt 451 as shown in FIG. . Furthermore, although the present invention is very effective with a substantially horizontal stack tray, it goes without saying that better alignment can be obtained even if it is employed in an apparatus having an inclined stack tray.

  In the description so far, the case where the CPU of the control unit provided in the sheet processing apparatus provided in the image forming apparatus controls the operation of the offset roller or the like has been described. It may be provided in the forming apparatus main body, and its CPU may control the sheet processing operation of the offset roller or the like.

1 is a cross-sectional view illustrating a configuration of an image forming apparatus including a sheet processing apparatus according to an embodiment of the present invention. The figure explaining the structure of the said sheet processing apparatus. The figure which shows a mode that a sheet | seat is discharged on the processing tray of the said sheet processing apparatus. The figure explaining the drive mechanism of the offset roller of the said sheet processing apparatus, and a conveyance roller. The figure explaining the drive mechanism of the offset roller of the said sheet processing apparatus, a conveyance roller, a sheet bundle discharge member, and a sheet clamp member. FIG. 6 is a first diagram illustrating the operation of the offset roller and the accompanying sheet movement. FIG. 9 is a second diagram illustrating the operation of the offset roller and the accompanying sheet movement. The figure explaining operation | movement of the said sheet clamp member. FIG. 4 is a diagram illustrating a state where the sheet bundle discharge member discharges a sheet bundle to a stack tray. The block diagram which shows the structure of the control part of the said sheet processing apparatus. The figure which shows the state before a sheet | seat is discharged on the processing tray of the said sheet processing apparatus. FIG. 4 is a diagram illustrating a state when the sheet bundle discharge member moves to a position where the sheet bundle is discharged to a stack tray. 6 is a flowchart for explaining a part of the sheet processing operation of the sheet processing apparatus. 6 is a flowchart for explaining the remaining part of the sheet processing operation of the sheet processing apparatus. The figure explaining the other structure of the said sheet processing apparatus. The figure explaining the structure of the conventional sheet processing apparatus.

Explanation of symbols

200 Printer Unit 400 Sheet Processing Device 407 Offset Roller 410 Processing Tray 410a Recess 411 Sheet Rear End Stopper 412 Sheet Clamp Member 412a (Sheet Clamp Member) Release Lever Unit 420 Stapler Unit 421 Stack Tray 430 Sheet Bundle Discharge Motor 500 Image Forming Device Main Body A Image forming apparatus S Sheet SA Sheet bundle

Claims (7)

A first sheet stacking unit configured to stack sheets to be processed; and a sheet bundle that is provided downstream of the first sheet stacking unit in the sheet conveying direction and processed on the first sheet stacking unit and then discharged. A sheet processing apparatus including a second sheet stacking unit for stacking;
A sheet bundle holding means for holding a sheet bundle on the processed first sheet stacking means after the processing of the sheet bundle is completed;
The sheet bundle holding unit is provided at a holding position for holding the sheet bundle and the second sheet stacking unit side of the first sheet stacking unit, and discharges the sheet bundle to the second sheet stacking unit. Moving means for reciprocating between the discharge positions;
With
The discharge position is a position moved by a predetermined distance in the opposite direction after the sheet bundle holding means is moved from the holding position toward the second sheet stacking means and stopped by the moving means. Sheet processing apparatus.   2. The sheet processing according to claim 1, wherein a holding release unit is provided at the discharge position to release the holding of the sheet bundle of the sheet bundle holding unit in accordance with the movement of the sheet bundle holding unit in the reverse direction. apparatus.   The discharge position is a position where the sheet bundle is stacked on the second sheet stacking unit by its own weight when the holding release unit releases the holding of the sheet bundle by the sheet bundle holding unit. The sheet processing apparatus according to claim 2.   The sheet bundle holding means is movable between a first position for holding the sheet bundle and a second position for releasing the holding of the sheet bundle, and the holding release portion is in a direction opposite to the sheet bundle holding means. 4. The sheet processing apparatus according to claim 2, wherein the sheet bundle holding unit is moved from the first position to the second position in accordance with the movement.   The holding release unit is a recess formed at an end of the first sheet stacking unit on the second sheet stacking unit side, and the sheet bundle holding unit is moved in the reverse direction of the sheet bundle holding unit. A lever portion that moves in the recess, and the lever portion moves from the first position to the second position by contacting the side wall of the recess after moving the lever portion in the recess for the predetermined distance. 5. The sheet processing apparatus according to claim 4, wherein   An image forming unit that forms an image on a sheet, and the sheet processing apparatus according to claim 1 that processes a sheet on which an image is formed by the image forming unit. Image forming apparatus. An image forming unit for forming an image on a sheet;
First sheet stacking means for stacking sheets to be processed by the image forming unit;
A second sheet stacking unit that is provided downstream of the first sheet stacking unit in the sheet conveying direction and stacks the sheet bundle that is discharged after being processed on the first sheet stacking unit;
A sheet bundle holding means for holding a sheet bundle on the processed first sheet stacking means after the processing of the sheet bundle is completed;
The sheet bundle holding unit is provided at a holding position for holding the sheet bundle and the second sheet stacking unit side of the first sheet stacking unit, and discharges the sheet bundle to the second sheet stacking unit. Moving means for reciprocating between the discharge positions;
With
The discharge position is a position moved by a predetermined distance in the opposite direction after the sheet bundle holding means is moved from the holding position toward the second sheet stacking means and stopped by the moving means. Image forming apparatus.

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