JP4662423B2 - Sheet processing apparatus and image forming apparatus having the same - Google Patents

Description

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

  2. Description of the Related Art Conventionally, in image forming apparatuses such as copying machines, printers, facsimiles, and composite devices thereof, the image forming apparatus main body performs binding processing on sheets discharged from the image forming apparatus main body after image formation is completed. A sheet processing apparatus that performs processing is known.

  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 After such processing is finished, the sheet is discharged onto a sheet or a sheet bundle (hereinafter referred to as sheet (bundle)) stack tray (sheet stacking means).

  Further, in general, the sheet processing apparatus is often arranged on the side of the image forming apparatus main body, but the sheet processing apparatus main body does not protrude from the image forming apparatus by being arranged at the upper part of the image forming unit. Such a configuration is known that can achieve space saving (see, for example, Patent Document 1).

JP 2001-72311 A

  By the way, in such a conventional sheet processing apparatus, since the stack tray for stacking processed sheets (bundles) is provided below the sheet discharge port, the sheet stacking amount of the stack tray is determined from the stack tray. The amount is limited according to the distance to the sheet discharge port, and when this distance is short, the sheet stacking amount is reduced.

  Here, when the sheet processing apparatus is built in a composite printer having a mode (function) such as a recent copying machine, printer, facsimile, etc., when the sheet stacking amount is small, the mode of the copying machine, printer, facsimile, etc. When each sheet is output corresponding to the above, there is a problem that the sheet immediately reaches the sheet discharge port and closes the sheet discharge port.

  Therefore, the present invention has been made in view of such circumstances, and provides a sheet processing apparatus capable of saving space and stacking a large amount of sheets, and an image forming apparatus including the sheet processing apparatus. It is intended.

The present invention relates to a sheet processing apparatus for processing a sheet after image formation, in which the processed sheet is stacked and stored in a space formed in the image forming apparatus and covered with an upper surface. A plurality of sheet stacking units, a lifting unit that lifts and lowers the plurality of sheet stacking units independently from each other, and a process of stacking the sheets that are transported in a predetermined transport direction when processing the sheets after the image formation A sheet stacking unit; a driving unit that generates a driving force for moving the plurality of sheet stacking units by the elevating unit; and a sheet stacking unit positioned at an upper portion of the plurality of sheet stacking units, When the torque of the driving unit in the movement of the sheet stacking unit located on the upper part exceeds a predetermined torque, the transmission of the driving force from the driving unit to the lifting unit is regulated. And regulating means for,
By detecting the sheet stacking means located in the upper part, the detection means for detecting that the sheet stacking means located in the upper part has reached the upper limit position, and the sheet stacking means positioned in the upper part by the lifting / lowering means After the movement in the direction is started, when the detection unit detects that the upper sheet stacking unit has reached the upper limit position within a predetermined time, the driving unit is stopped, and the detection unit detects the predetermined unit. When the sheet stacking unit located at the upper part is not detected in time, a control unit that stops the driving unit after the predetermined time has passed, and a sheet processed by the processing sheet stacking unit is transferred to the processing sheet stacking unit. From the home position located upstream in the predetermined conveying direction, the sheet stack located downstream from the home position in the predetermined conveying direction. By moving the discharge position which can be discharged to the means, said a discharge means for discharging the sheet on the sheet stacking means, provided in the discharge means, sheet holding means for holding the sheet on the processing sheet stacking means When, wherein the discharge means, when the sheet is discharged, after the sheet on the treated the treated sheet stacking means is moved to the discharge position which can be discharged to the sheet stacking means, the home position The sheet holding means holds the sheet until the discharge means moves to a position where the sheet can be discharged to the sheet stacking means, and the discharge means returns to the home position. The holding of the sheet is released so that the sheet is stacked on the sheet stacking unit, and the lifting unit is configured to discharge the sheet by the discharging unit. Is characterized in that than preparative outlet moving the sheet stacking means located on the top upward.

  According to the present invention, a space for moving the sheet stacking means is provided above the sheet discharge port.

  As in the present invention, space can be saved by providing sheet stacking means in the sheet processing apparatus housed in the space formed in the image forming apparatus and moving the sheet stacking means above the sheet discharge port. In addition, a large amount of sheets can be stacked. In addition, this makes it possible to discharge and stack a large amount of sheets according to the mode such as copy, printer, facsimile, etc., and to provide an apparatus optimal for office needs.

  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 illustrating a configuration of an image forming apparatus including a sheet processing apparatus according to an embodiment of the present invention. In FIG. 1, 500 is an image forming apparatus, 500A is an image forming apparatus body, and 120 is an image. A reader unit (image input device) provided on the upper surface of the forming apparatus main body 500A for reading a document image and converting it into image data, 300 an automatic document feeder (ADF) provided on the upper surface of the reader unit 120, and 400 A sheet processing apparatus 200 performs processing of discharged sheets after an image is formed by the image forming apparatus main body 500A. The sheet processing apparatus 200 has a plurality of types of sheet cassettes 204 and 205, and image data is visible on the sheet by a print command. A printer unit that is an image forming unit that outputs an image.

  In the image forming apparatus 500 having such a configuration, when an original image is read to form an image, first, unillustrated originals stacked on the automatic original feeder (ADF) 300 are firstly placed one by one. It is sequentially conveyed onto the platen glass surface 102 of the reader unit.

  Next, when the document is conveyed to a predetermined position on the platen glass surface 102, the lamp 103 of the reader unit 120 is turned on, and the scanner unit 104 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 this irradiation light, and this latent image is developed by the developing device 203, and 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. The toner image transferred to the sheet S is fixed by the fixing unit 207, and then the sheet S is discharged from the paper discharge unit 208.

  Next, after the image formation is completed as described above, the sheet S discharged from the paper discharge unit 208 is conveyed to the sheet processing apparatus 400, and sorted, bound, and the like according to an operation mode designated in advance by the sheet processing apparatus 400. Is carried out and loaded on a desired tray (stack tray 421 or stack tray 422).

  Next, the sheet processing apparatus 400 will be described.

  As shown in FIG. 1, the sheet processing apparatus 400 is accommodated in the space SP formed in the side portion of the image forming apparatus main body 500A without protruding from the image forming apparatus main body 500A, and in addition to the sorting operation for sorting the sheets. For example, as shown in FIG. 2, a processing tray for processing sheets S sequentially discharged from the image forming apparatus main body 500 has a stapling function that is a binding operation by the stapler unit 420 shown in FIG. 410 and a stack tray (lower bin) 421 and a stack tray (upper bin) 422 for finally stacking a sheet bundle processed on the processing tray 410, and process a sheet bundle of a number corresponding to the number of documents. Formed on the tray and discharged to the stack tray (lower bin) 421 or stack tray (upper bin) 422 for each sheet bundle, And it is configured and controlled to allow mounting.

  Here, such a configuration and control is realized by the fact that a plurality (two in the present embodiment) of stack trays 421 and 422 can be moved up and down independently, and has a configuration that has not existed before. Further, by configuring and controlling in this way, it is possible not only to copy jobs but also to separately stack the stack trays 421 and 422 when outputting away from an image forming apparatus such as a printer or a facsimile machine. Can contribute greatly.

  In the example shown in FIG. 1, a reader unit and an automatic document feeder (ADF) are drawn on the upper part of the main body of the image forming apparatus, but without these, the sheet processing apparatus 400 is the image forming apparatus (or printer unit). It goes without saying that it is located at the top. Obviously, this can save space.

  Next, the configuration of the sheet processing unit 400 will be described.

  In FIG. 2, reference numeral 401 denotes a sheet receiving unit that receives the sheet S discharged from the image forming apparatus main body 500 </ b> A. The sheet S received by the sheet receiving unit 401 is detected by the entrance sensor 403, and then the conveyance roller 405 and The sheet is conveyed by the offset roller 407, and thereafter conveyed onto a processing tray 410 as a processing sheet stacking unit provided in the sheet processing unit 400B for processing the sheet 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 serving as a sheet conveying means constituted by a cylindrical member is an elastic body having elasticity close to rubber, such as rubber or foam, and the offset roller 407 is illustrated in FIG. It is held by an offset roller holder 406 so as to be movable up and down around an offset shaft 511 shown.

  The offset roller holder 406 can be moved up and down by a pickup solenoid 433 with the offset shaft 511 as a fulcrum. That is, the offset roller 407 can be raised and lowered via the solenoid arm 512, the lever holder 513, the separation lever 514, and the offset roller holder 406 by turning on and off the pickup solenoid 433.

  When the offset roller 407 conveys the sheet S to the processing tray 410, a pickup solenoid 433 serving as a position control unit is turned on, and the solenoid arm 512, the lever holder 513, the separation lever 514, and the offset roller holder 406 are turned on. Thus, the sheet S is moved to an upper position that does not hinder the conveyance of the sheet S, whereby the sheet S is conveyed onto the processing tray 410 without being obstructed by the offset roller 407.

  Further, as shown in FIG. 4, the offset roller 407 includes a timing belt 523, a roller gear 524, an idler gear 525, an offset gear 526, an offset pulley 527, and a timing belt 522 by a conveyance motor 431 capable of driving the conveyance roller 405. When the transport motor 431 rotates, it rotates in the transport direction (forward rotation) by an amount corresponding to the rotation amount of the transport motor 431, or rotates in the direction opposite to the transport direction (hereinafter referred to as reverse rotation). It is supposed to).

  In this embodiment, when the sheet bundle discharge sensor 415 shown in FIG. 2 detects the conveyed sheet, the pickup solenoid 433 is turned off, so that the offset roller 407 moves in the sheet conveying direction. While rotating, it descends by its own weight, lands (contacts) on the sheet, and after conveying the sheet for a predetermined time, it reverses when a predetermined time elapses.

  By reversing in this way, the trailing edge of the sheet is erected at the upstream end of the processing tray 410 in the conveyance direction, and the sheet trailing edge stopper 411 as a regulating member that regulates the position of the sheet S in the sheet conveyance direction. The sheet S is aligned in the conveying direction.

  In FIG. 4, reference numeral 416 denotes a positioning wall as a side end regulating member that regulates the position of the end of the sheet in the direction orthogonal to the sheet conveyance direction (hereinafter referred to as the width direction), and 420 denotes the vicinity of the positioning wall of the processing tray 410 The offset roller 407 is a positive unit as a driving unit that constitutes a moving unit together with the offset roller 407. The stapler unit is a stapling unit that performs stapling on a sheet bundle formed on the processing tray 410. The offset motor 432 that can be rotated in reverse direction is moved in the width direction via the offset motor gear 432 a, the offset pinion 516, and the offset rack 515, and can approach the positioning wall 416.

  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 conveying direction is conveyed in the direction of the positioning wall 416 by the frictional force of the offset roller 407. Then, while the curl is corrected by the paper press 510, positioning in the width direction is performed by bringing the sheet end face into contact with the positioning wall 416. After the sheet S hits the positioning wall 416, the offset roller 407 moves by a predetermined amount in the direction of the positioning wall 416 while sliding on the sheet and stops.

  Here, 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 that rotates in the sheet conveying direction as shown in FIG. After that, as shown in FIG. 5B, 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.

  5 and FIG. 6, FIG. 7, and FIG. 22, which will be described later, are different from FIG. 4 described above and are explained using a configuration in which the offset roller 407 is arranged inside the offset roller holder 406. However, this difference in configuration is merely a design difference, and there is no difference in function and operation from the configuration shown in FIG.

  Thereafter, as shown in FIG. 5C, the offset roller 407 is moved to the positioning wall 416 side along the offset shaft 511 while being in contact with the sheet S, whereby the end portion in the width direction of the sheet S is obtained. Is pressed by the positioning wall 416, and the sheet S is aligned in the width direction.

  On the other hand, in FIG. 4, reference numeral 412 denotes a sheet clamp member as a sheet (bundle) holding unit that presses the rear end portion of the aligned sheet S from above by the urging force of the urging unit 560. When the trailing end alignment of the sheet performed after the alignment in the width direction is completed, and thereafter the offset roller 407 is lifted by the pickup solenoid 433 as shown in FIG. Thus, the aligned sheet S is pressed from above as shown in FIG.

  Then, by pressing the sheet S from above, the sheet S previously discharged (conveyed) to the processing tray 410 is not affected by the subsequent feeding by the sheet S that is sequentially fed thereafter. It can be held at a predetermined position.

  The sheet clamp member 412 rotates upward as shown in FIG. 7A 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. 8, reference numeral 413 denotes a sheet bundle discharge member exemplified as discharge means for discharging the processed sheet bundle to the stack tray (lower bin) 421 or the stack tray (upper bin) 422. This sheet bundle discharge member 413 FIG. 9 shows a state in which the sheet clamp member 412 is rotatably held, and the aligned sheet bundle or the stapled sheet bundle after alignment is held by the sheet clamp member 412. The stack tray (lower bin) 421 or the stack tray (upper bin) 422 provided on the downstream side of the processing tray 410 is moved.

  Further, when the sheet bundle discharge member 413 reaches the leading end portion of the processing tray 410, which is the sheet discharge position indicated by the solid line in the drawing, the sheet bundle discharge member 413 holds the sheet bundle SA by the sheet clamp member 412 on the stack trays 421 and 422. Then, the sheet bundle SA is dropped by returning to the sheet rear end stopper 411 while releasing the holding of the sheet clamp member 412 with respect to the sheet bundle SA. With this configuration, stable stacking performance with a small angle (about 9 degrees) as in the present embodiment is limited without providing a stack tray angle of about 30 degrees as in the past. It is possible to achieve in a limited space.

  The sheet bundle SA discharged and stacked on the stack trays 421 and 422 is pressed by a pressing member 421A as a sheet pressing unit shown in FIG. In addition, by pressing the sheet bundle SA with the pressing member 421A in this way, not only the sheet stacking performance is prevented from being lowered due to the curling of the sheet, but also the stacking performance such that the stacked sheet is pushed and the stacking position is shifted by the succeeding sheet. Can be prevented. As a result, it is possible to achieve stable loading performance with a small angle as in the present embodiment in a limited space without providing a stack tray angle of about 30 degrees as in the conventional case as described above. It becomes possible.

  Here, a pin A553a and a pin B554a suspended from a slide gear A553 and a slide gear B554 that rotate via a belt 551 and a pulley gear 552 by driving the sheet bundle discharge motor 430 shown in FIG. The sheet bundle discharging member 413 moves in a guide slit (not shown) formed in the sheet bundle discharging member 413 while rotating integrally with the gear B554.

  With this configuration, the sheet bundle discharge member 413 is moved to the stack tray (1 lower bin) 421 or the stack tray (2 upper bin) 422 shown in FIG. 8B by the sheet bundle discharge motor 430. 8 is moved back and forth along the slide rail 555 to a position where the sheet is discharged and a home position in the vicinity of the sheet trailing edge stopper 411 shown in FIG. The sheet bundle discharge member 413 is normally fixed at the home position by excitation of the sheet bundle discharge motor 430.

  In FIG. 10, 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, whereby the sheet clamp member 412 is rotated upward via the lever 434a and the release lever portion 412a provided on the sheet clamp member 412.

  As shown in FIG. 11A, the pressing member 421A receives power through a press member 556, a lever member 557, and a coil spring 558 by a cam B 554b installed under the slide gear B 554, and rotates. It comes to move. Further, when no power is transmitted, the pressing member 421A is in a state of being retracted from the sheet stacking surface of the stack trays 421 and 422 by the return coil spring 559 as shown in FIG. It is supposed to be located.

  With such a configuration, the pressing member 421 </ b> A is configured so that the sheet bundle discharging member 413 discharges the sheet bundle to the stack trays 421 and 422 by rotating the slide gear A <b> 553 and the slide gear B <b> 554 by the rotation of the bundle discharging motor 430. When the pressing of the pressing member 556 by the cam B 554b is released, the pressing member 421A is in a state in which the sheet bundle can be dropped onto the stack trays 421 and 422 with respect to the sheet stacking surface by the return coil spring 559.

  Thereafter, the sheet bundle falls on the stack trays 421 and 422, and the cam B554b below the slide gear B554 operates the press member 556 just before the sheet bundle discharge member 413 returns to the rear end stopper 411, and the lever member 557, The pressing member 421A is rotated via the coil spring 558, and the sheet bundle is held by the pressing member 412A.

  By the way, in this embodiment, after the sheet S is moved in the width direction as described above, the offset roller 407 is reversely rotated again to complete the alignment operation in order to correct the deviation in the sheet conveyance direction. As a result, high-precision matching is realized. When the specified number of sheets have been aligned, the clamp solenoid 434 closes the sheet clamp member 412 to hold the sheet bundle.

Next, driving of the stack trays 421 and 422 will be described with reference to FIG. First, the preparative Reimota 530, belt 531, pulley 532, via the rotary shaft 533, power is transmitted to the worm gear A534, worm b535 in the rotating shaft at both ends. Next, power is transmitted from the worm gear a534 to the gear 2a538 from the gear 1a537 formed integrally with the worm wheel a536 and the worm wheel a536, and from the gear 3a539 formed integrally with the gear 2a538 to the rack a540. The

  Power is transmitted from the worm gear b535 to the worm wheel b541 and the gear 1b542 formed integrally with the worm wheel b541 to the gear 2b544, and the power is transmitted from the gear 3b543 formed integrally with the gear 2b544 to the rack b545. The stack trays 421 and 422 can be moved up and down by the transmission of power as described above.

  In FIG. 12, reference numeral 560 denotes a clutch a that rotates in conjunction with the pulley 532. A coil spring 561 is wound around the clutch a 560, and a clutch b 562 is wound around the opposite side of the coil spring 561. Further, a pin 563 that is press-fitted into the rotary shaft 533 is fitted into the groove of the clutch b562. With this configuration, a desired torque is transmitted to the rotary shaft 533, and the rotary shaft 533 is thus inserted. The power is transmitted to the worm gear a 534 and the worm gear b 535 at both ends of the rotating shaft via.

  By the way, when the stack trays 421 and 422 are provided in a sheet stacking space SP1 to be described later so as to be able to move up and down as in the present embodiment, the stack trays 421 and 422 rise without stopping at a predetermined position for some reason. In the case of continuing, not only the stack trays 421 and 422 or the sheets stacked on the stack trays 421 and 422 hit the upper stack tray, but also the uppermost stack tray (upper bin) 422 or the sheet is the sheet stacking space. There is a risk that it will hit the bottom surface (see FIG. 1) of the reader unit 120, which is the top surface of SP1. For this reason, in the present embodiment, an upper limit sensor 547 is provided as an example of a sensor for regulating the movement of the stack tray (upper bin) 422 as described later.

  However, for example, when foreign matter is mixed on the stack tray (upper bin) or a large amount of sheets are stacked, before the stack tray (upper bin) 422 is detected by the upper limit sensor 547, There is a possibility that a foreign object or a sheet hits the upper surface of the sheet stacking space SP1.

  Here, if the stack tray (upper bin) 422 continues to rise after the foreign object or sheet hits in this way, the foreign object, sheet, or stack tray (upper bin) 422 may be damaged. In this embodiment, as described above, the coil spring 561 as an example of the restricting means is provided between the tray motor 530 and the stack tray (upper bin) 422 (421), and the stack tray (upper bin) 422 is provided. When the torque for raising the height becomes larger than a predetermined torque, the drive of the tray motor 530 is not transmitted to the stack tray (upper bin) 422.

  That is, when a foreign object or sheet hits the upper surface of the sheet stacking space SP1 and thereafter a load greater than the torque set by the coil spring 561 is generated, the pulley 532 that rotates in conjunction with the rotation of the tray motor 530 rotates the rotating shaft 533. The rotary shaft 533 as an example of a drive shaft that transmits the drive of the tray motor 530 to the stack tray (upper bin) 422 stops, and the stack tray (upper bin) 422 is further raised. Disappear. If the upper limit sensor 547 does not detect the stack tray (upper bin) 422 even after a predetermined time has elapsed, the CPU 100 described later stops driving the tray motor 530 and stack tray (upper bin). The ascent of 422 is stopped.

  As described above, when a foreign matter or a sheet hits the upper surface of the sheet stacking space SP1, the stack tray (upper bin) 422 is restricted by the coil spring 561, whereby the stack tray (upper bin) 422 or the stack tray (upper Bin) 422 can be prevented from being damaged.

  FIG. 23 shows another configuration in which the rising of the stack tray (upper bin) 422 is stopped when a foreign object or sheet hits the upper surface of the sheet stacking space SP1, and the like on the disk portion 562a of the clutch b562. An interval slit (encoder) is provided, and the encoder is detected by a rotation sensor 564 as an example of a sensor that detects the rotation of the rotation shaft 533.

  Here, in such a configuration, when foreign matter is mixed in before the stack tray (upper bin) 422 is fully raised, the load becomes heavy, and when the rotating shaft 533 stops at a load higher than the set torque, When the CPU 100 detects the ON / OFF operation of the rotation sensor 564, the drive of the tray motor 530 is stopped and the rise of the stack tray (upper bin) 422 is stopped.

  Next, the operation at the time of tray switching between the stack tray (lower bin) 421 and the stack tray (upper bin) 422 will be described.

  As described with reference to FIG. 12, the stack tray (lower bin) 421 and the stack tray (upper bin) 422 can be moved up and down independently by the tray motor 530 via the rack and pinion. In this way, each of them independently has a driving source, and by moving up and down, processed sheets discharged by the sheet bundle discharge member 413 are stacked into a stack tray (lower bin) 421 and a stack tray (upper bin). 422 can be selectively received.

  Normally, a plurality (n in this embodiment) of stack trays (sheet stacking means) are made to wait while sandwiching the sheet discharge port 400A of sheets discharged by the sheet bundle discharge member (discharge means). In the state shown in FIG. 1 or FIG. 2, since a space is provided below the stack tray (lower bin) 421, not only can a large number of sheets be stacked, but also when the stack tray (upper bin) 422 is retracted, Depending on the contents to be printed, the upper and lower bins can be switched and stacked on the upper bin, so that more sheets can be stacked.

  Here, when the stack tray (lower bin) 421 is in a position where the sheet can be received and the stack tray (upper bin) 422 is retracted to the upper side (FIG. 13A), the stack tray (upper bin) ) The movement of 422 to a position where the sheet below the sheet discharge port 400A can be received will be described.

  A lower limit sensor 546 capable of detecting a lower limit is provided below the stack tray (lower bin) 421. In this operation, the stack tray (lower bin) 421 is first lowered to a position detected by the lower limit sensor 546. At this time, the pressing member 421A moves to the retracted position (FIG. 13B).

  Next, the pickup solenoid 433 shown in FIG. 4 is turned on, and the electromagnetic clutch 517 is turned on with the offset roller 407 moved to the upper standby position via the offset roller holder 406 as shown in FIG. Thus, after the transport motor 431 is connected, the transport motor 431 is rotated by a predetermined amount, so that the gear portion 517a, the idler gear 518, the cam gear 519 of the electromagnetic clutch 517, as shown in FIG. The shutter 521 is lowered via the shutter lever 520.

  Then, the shutter 521 is lowered in this way, and the sheet discharge port 400A of the processing tray 410 is closed, whereby a guide surface at the rear end of the sheet is formed (FIG. 15A), and the stack tray (upper bin) 422 The sheets already stacked on the stack tray (upper bin) 422 during the movement are prevented from flowing back into the processing tray.

  Next, when the lowering of the shutter 521 is completed, the stack tray (upper bin) 422 starts to lower and stops at a position where the pressing member 421A is removed (FIG. 15B). Thereafter, the shutter 521 is raised, and the holding member 421A that has been retracted is moved to a state in which the sheet can be pressed while the shutter 521 is stopped at a desired position, and the stack tray (upper bin) 422 is moved again. When it is lifted and moved to the sheet receiving position, it stops (FIG. 16 (a)). By moving to this position, sheets can be received in the same manner as the stack tray (lower bin) 421.

  Next, when the stack tray (upper bin) 422 is in a position where the sheet can be received and the stack tray (lower bin) 421 is retracted to the lower side (FIG. 16A), the stack tray (lower The operation of the bin 421 to move to a position where the sheet can be received will be described.

  In this case, first, the pressing member 421A is returned to the retracted position, and the shutter 521 is lowered so that the sheets already stacked on the stack tray (upper bin) 422 do not flow backward from the sheet discharge port 400A toward the processing tray. (FIG. 16B). Thereafter, the stack tray (upper bin) 422 starts to rise, passes through the sheet discharge port 400A, and rises to the space SPU provided above the sheet discharge port 400A.

  Then, the stack tray (upper bin) 422 that moves to the space SPU provided above the sheet discharge port 400A in this manner is placed near the upper limit of the space SPU (in this embodiment, the bottom surface of the reader unit 120 (see FIG. When the upper limit sensor 547 provided in the vicinity 1) detects, the tray motor 530 stops and the stack tray (upper bin) 422 stops (FIG. 17A).

  Next, the shutter 521 is raised, and the shutter 521 is raised to a desired position to open the sheet discharge port 400A, and then stops (FIG. 17B). Next, the retracted holding member 421A is moved to a state where the sheet can be pressed, and stopped when the stack tray (lower bin) 421 is moved up to the sheet receiving position (FIG. 13A). By moving to this position, the stack tray (lower bin) 421 can receive sheets.

  Here, a plurality of stack trays 421 and 422 are provided so as to be able to move up and down independently in the sheet processing apparatus 400 housed in the space SP (see FIG. 1) formed in the side portion of the image forming apparatus main body 500A. At the same time, by selectively stacking sheets on the stack trays 421 and 422, even when the sheet processing apparatus 400 is built in a composite printer having modes such as a copying machine, a printer, and a facsimile, space can be saved. And in which mode the sheet is output can be easily distinguished. This also makes it possible to carry out stacking according to the mode such as copy, printer, facsimile, etc., and to provide an apparatus optimal for office needs.

  Further, by moving the stack tray (upper bin) 422 above the sheet discharge port 400A, the stack trays 421 and 422 can be moved up and down in the space SP formed in the side portion of the image forming apparatus main body 500A. The space SPU above the sheet discharge port 400A in the sheet stacking space SP1 can be used as a sheet stacking space, whereby a large number of sheets can be stacked.

  Here, when the space SPU above the sheet discharge port 400A is used as a sheet stacking space as described above, it is preferable to provide the sheet discharge port 400A substantially at the center in the height direction of the sheet stacking space SP1. By providing the sheet discharge port 400A at such a position, a large amount of sheets can be stacked using the sheet stacking space SP1 efficiently.

  In the above description, the case where two stack trays as sheet stacking means are provided has been described. However, a plurality (n) of stack trays are provided, and a plurality of spaces SPU above the sheet discharge port 400A are provided. By making (n-1) stack trays movable among (n) sheet stacking means, it is possible to stack a large number of sheets efficiently using the limited sheet stacking space SP1. .

  Further, as in the present embodiment, the sheet discharge port 400A is used as a common sheet discharge port in modes such as a copying machine, a printer, and a facsimile, and sheets are selectively transferred from the common sheet discharge port 400A to a plurality of stack trays. By discharging, space can be saved and the height dimension can be suppressed. Furthermore, the sheet discharge port 400A is used as a common sheet discharge port, and the sheet is discharged from the sheet discharge port 400A to the stack tray by one sheet bundle discharge member 413, thereby simplifying the configuration. And cost reduction can be achieved.

  As shown in FIG. 18A, a sub-tray 421a as a spare sheet stacking unit is accommodated in the downstream end of the stack trays 421 and 422 in the sheet discharge direction so as to be drawn out. Here, the stack trays 421 and 422 are arranged so as not to protrude from the image forming apparatus main body 500A, and A4, B5, letter size (or smaller size sheets) having a high user frequency can be stacked as they are. It has become.

  On the other hand, when stacking large size sheets such as A3, B4, and legal, the sub-tray 421a stored inside the stack trays 421 and 422 is pulled out as necessary. In this embodiment, another sub-tray 421b is slidably provided on the sub-tray 421a, and the two sub-trays 421a and 421b are pulled out as shown in FIG. 18B according to the sheet size. Thus, it is possible to load the sheets satisfactorily. The other stack tray 422 (upper bin) has the same configuration.

  FIG. 19 is a block diagram showing the configuration of the control unit of the sheet processing apparatus 400 having such a configuration, and 100 is 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 FIG. 20 and FIG. The CPU 100 controls each unit while reading this program.

  The CPU 100 has a built-in RAM 121 in which work data and input data are stored. The CPU 100 performs control by referring to data stored in the RAM 121 based on the above-described program and the like. 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 above-described program and the like.

  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 </ b> A (control unit) and also transmits an image via the serial interface unit (I / O) 130. Each unit is controlled based on the control data sent from the forming apparatus main body 500A (the control unit).

  Since the image forming apparatus main body 500A knows the size of the sheet discharged from the sheet discharge unit 208, the control unit of the sheet processing apparatus 400 including the microcomputer system performs serial communication with the control unit of the image forming apparatus main body 500A. By doing so, it is possible to grasp the size of the sheet inserted on the processing tray 410.

  Accordingly, each time the sheet S is discharged (conveyed) from the image forming apparatus main body 500A, the control unit (CPU 100) of the sheet processing apparatus 400 grasps the size and controls the offset motor 432, thereby controlling the offset roller 407. The amount of movement in the width direction can be controlled. As a result, the offset roller 407 moves by an amount corresponding to the size of the sheet S inserted on the processing tray 410, and the side portion of the sheet can be reliably brought into contact with 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 (tray motor) (see FIG. 12) until the uppermost surface of the stacked sheet bundle substantially coincides with the processing tray 410.

  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 500A is started, the CPU 100 (see FIG. 19) of the sheet processing apparatus 400 checks whether or not a sheet discharge signal is received from the image forming apparatus main body 500A (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 holder 406 is pulled up.

  Next, the conveyance motor 431 is turned on (S120), and the conveyance roller 405 installed in the middle of the sheet discharge path enables the sheet to be conveyed in the same direction as the sheet discharge direction of the image forming apparatus main body 500A. 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 500A (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. 5A, 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 the sheet clamp installed at the home position in the vicinity of the sheet trailing edge stopper 411 as shown in FIG. Open member 412. 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 sheet trailing edge abuts against the sheet trailing edge stopper 411 takes into account the skew of the sheet S generated when the sheet is fed from the image forming apparatus main body 500A. The amount of rotation is such 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. That is, the offset roller 407 is reversely rotated for a predetermined time even after the sheet S is conveyed by a distance for contacting the sheet S with the trailing edge stopper 411.

  Thereby, the sheet S can be reliably brought into contact with the rear end stopper 411. When the sheet S abuts against the trailing edge stopper 411 while being reversely rotated for a predetermined time as described above, the offset roller 407 is idled (slip) on the sheet.

  Next, the sheet size to be discharged is checked based on the size information from the image forming apparatus main body 500A (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 amount of offset movement, which is the amount of movement in the width direction of the sheet S, required for pressing the sheet to the positioning wall 416 is calculated (S210).

  Next, the offset motor 432 is driven to start the offset movement of the offset roller 407 (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. 7B so as not to be a load of movement of the sheet S.

  As a result of such an offset movement operation of the offset roller 407, as shown in FIG. 5C, the sheet hits the positioning wall 416, whereby the sheet S is aligned in the width direction. The offset roller 407 slides on the sheet S slightly after the sheet S abuts against the positioning wall 416 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 in this way, 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, the sheet clamp member 412 is closed as shown in FIG. 6B, and the aligned sheet S is held and held. As a result, the sheet S discharged first is discharged next. It is possible to prevent the sheet from being carried by the used sheet.

  Next, as shown in FIG. 6B, 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).

  Next, it is checked whether or not the sheet S accommodated on the processing tray 410 is the last sheet corresponding to the last page of the copy document (S270), and based on the information sent from the image forming apparatus main body 500A. If it is determined that the sheet S is not the final sheet S (N in S270), the process returns to S100 and the next sheet discharge signal sent from the image forming apparatus main body 500A is received, and the final sheet S is stored in the processing tray 410. Until the above flow is repeated.

  With this configuration, each time the sheet S is discharged from the image forming apparatus main body 500A, the control unit (CPU) of the sheet processing apparatus 400 grasps the size of the sheet S and is suitable for the sheet S. The offset movement amount is calculated. As a result, the sheet S in contact with the offset roller 407 is subjected to the 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 stapler unit 420 is driven and the stapling process is executed at the staple position shown in FIG. 22 (S290).

  Next, when the stapling process is not selected (N in S280), 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 as shown in FIG. The sheet bundle SA is advanced in the direction of the stack tray 421 while being held by the sheet clamp member 412, and the sheet bundle SA is discharged (S300).

  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.

  Here, as described above, the rotation amount of the offset roller 407 when the sheet trailing edge abuts against the sheet trailing edge stopper 411 is changed from the point where the conveyance of the sheet S is stopped to switch back to the sheet trailing edge stopper 411. In other words, the offset roller 407 is moved to a predetermined distance even after the sheet S is conveyed by a distance that abuts the sheet trailing edge stopper 411 by the reverse rotation of the offset roller 407. By reversing the time, the sheet S can be reliably brought into contact with the sheet trailing edge stopper 411.

  Thereby, the position of the sheet S in the sheet conveying direction can be stably aligned with a simple configuration that does not require many members. Further, since the sheet is not discharged so as to be skipped, the sheet can be stably conveyed with little fluctuation.

  In the description so far, when stapling a sheet bundle, the offset roller 407 is operated as a sorting unit, and the stapling process is performed after the sheet bundle abuts against the positioning wall 416. When the stapling process is not performed, the sheet bundle may be discharged without being sorted by the offset roller 407.

  In this embodiment, the stapler unit 420, which is an example of a binding unit for binding the sheet bundle SA, is fixed and disposed near the positioning wall 416. However, the present invention is not limited to this. Alternatively, the stapler unit 420 may be movable and movable in the sheet conveying direction or the width direction.

  The movable stapler unit 420 is used as described above, and the stapler unit 420 can be moved in the sheet conveyance direction or the width direction, so that the sheet bundle SA in the sheet conveyance direction or the width direction can be separated. Staple processing can be performed at a place or a plurality of places.

  Further, in the present embodiment, the offset roller 407 and the offset motor 432 are used as the sheet conveying unit and the driving unit that constitute the moving unit that moves the sheet S in the width direction, but the present invention is not limited thereto. The same effect can be obtained even if the moving means is constituted by the sheet conveying means configured so that the member itself moves in the conveying direction and conveys the sheet, and the driving means for moving the sheet conveying means having such a configuration in the width direction. Is obtained.

  Furthermore, in this embodiment, the CPU performs control while the CPU reads the program written on the ROM (or RAM) shown in the flowcharts of FIGS. 20 and 21, but the hardware performs the processing on the control program. Even if configured in this way, the same effect can be obtained.

  In the above description, the case where the control of the stacking trays 421 and 422, the stapling operation control, and the like is performed by the control unit (CPU 100) of the sheet processing apparatus 400 has been described, but the present invention is not limited to this. Alternatively, the control may be performed by a control unit provided in the image forming apparatus main body.

  Further, as described above, the sheet processing apparatus 400 is accommodated in the space SP formed in the image forming apparatus without protruding, which depends on the size of the stack trays 421 and 422 depending on the size of the sheet to be processed. It goes without saying that the case where the tip protrudes from the image forming apparatus main body 500A is included.

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 operation | movement of the said offset roller, and the movement of a sheet | seat accompanying it. The 1st figure explaining operation | movement of the said sheet clamp member. The 2nd figure explaining operation of the above-mentioned sheet clamp member. The figure explaining the drive mechanism of the sheet bundle discharge member of the said sheet processing apparatus. FIG. 4 is a diagram illustrating a state where the sheet bundle discharge member discharges a sheet bundle to a stack tray. The figure explaining the drive mechanism of the sheet clamp member of the said sheet processing apparatus. The figure explaining the drive mechanism of the pressing member of the said sheet processing apparatus. The figure explaining the drive mechanism of the stack tray of the said sheet processing apparatus. FIG. 4 is a first diagram illustrating movement of a stack tray (lower bin), a stack tray (upper bin), and a shutter of the sheet processing apparatus. The figure explaining the drive mechanism of the shutter of the said sheet processing apparatus. FIG. 6 is a second diagram illustrating the movement of the stack tray (lower bin), stack tray (upper bin), and shutter of the sheet processing apparatus. FIG. 9 is a third diagram illustrating the movement of the stack tray (lower bin), stack tray (upper bin), and shutter of the sheet processing apparatus. FIG. 10 is a fourth diagram illustrating the movement of the stack tray (lower bin), stack tray (upper bin), and shutter of the sheet processing apparatus. The figure explaining the structure of the stack tray (lower bin) of the said sheet processing apparatus, and a stack tray (upper bin). The block diagram which shows the structure of the control part of the said sheet processing apparatus. 6 is a flowchart for explaining a part of the sheet processing operation of the sheet processing apparatus. 7 is a flowchart for explaining the remaining part of the sheet processing operation of the sheet processing apparatus. The figure which shows a mode that the sheet | seat offset by the said offset roller was stapled. The figure explaining the other mechanism which regulates the raise of the stack tray of the said sheet processing apparatus.

Explanation of symbols

100 CPU
200 Printer unit 400 Sheet processing device 400A Sheet discharge port 400B Sheet processing unit 407 Offset roller 410 Processing tray 411 Sheet rear end stopper 412 Sheet clamp member 413 Sheet bundle discharge member 416 Positioning wall 420 Stapler unit 421 Stack tray (lower bin)
422 Stack tray (upper bin)
500 Image forming apparatus 500A Image forming apparatus main body 530 Tray motor 533 Rotating shaft 547 Upper limit sensor 561 Coil spring 564 Rotation sensor S Sheet SA Sheet bundle SP Space SP1 formed on the side of the image forming apparatus main body Sheet stacking space SPU Sheet discharge port Upper space

Claims (3)

In a sheet processing apparatus that processes a sheet after image formation,
A plurality of sheet stacking units that are arranged in the vertical direction and stored in a space formed in the image forming apparatus and whose upper surface is covered , and stacks processed sheets;
Elevating means for elevating and lowering the plurality of sheet stacking means independently of each other ;
A processing sheet stacking unit that stacks the sheet transported in a predetermined transport direction when processing the sheet after the image formation;
A driving unit that generates a driving force for moving the plurality of sheet stacking units by the lifting unit;
Among the plurality of sheet stacking means, provided in the upper sheet stacking means, and when the torque of the drive unit in the movement of the sheet stacking means located in the upper part exceeds a predetermined torque, the drive unit Restriction means for restricting transmission of driving force to the lifting means;
Detecting means for detecting that the sheet stacking means located in the upper part has reached an upper limit position by detecting the sheet stacking means located in the upper part;
After the upper and lower sheet stacking means starts moving toward the upper limit position, the detection means detects that the upper sheet stacking means has reached the upper limit position within a predetermined time. A control unit that stops the driving unit and stops the driving unit after elapse of the predetermined time when the detection unit does not detect the sheet stacking unit located in the upper portion within the predetermined time by the detection unit;
The sheet processed by the processing sheet stacking unit is transferred from the home position positioned upstream of the processing sheet stacking unit in the predetermined transport direction to the sheet stacking unit positioned downstream of the home position in the predetermined transport direction. A discharge means for discharging the sheet to the sheet stacking means by moving to a discharge position where the discharge is possible ;
A sheet holding unit that is provided in the discharge unit and holds a sheet on the processing sheet stacking unit;
The discharge unit moves the sheet on the processed sheet stacking unit processed to the discharge position where the sheet can be discharged to the sheet stacking unit, and then moves to the home position. The sheet holding unit holds the sheet until the discharge unit moves to a position where the sheet can be discharged to the sheet stacking unit, and the sheet is held when the discharge unit returns to the home position. The holding of the sheet is released so as to be stacked on the stacking unit, and the lifting unit moves the sheet stacking unit located above the sheet discharge port through which the sheet is discharged by the discharge unit upward. Sheet processing apparatus. The sheet processing apparatus according to claim 1, wherein a space for moving the sheet stacking unit located at the upper part is provided above the sheet discharge port. An image forming apparatus comprising: an image forming unit; and the sheet processing apparatus according to claim 1 or 2 that processes a sheet after an image is formed by the image forming unit.

Images