JP6157075B2 - Sheet processing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet processing apparatus for receiving a sheet discharged from an image forming apparatus such as a copying machine or a printer, selectively processing the received sheet, and discharging and stacking the sheet, and an image forming apparatus including the sheet processing apparatus. Relates to the device.

  2. Description of the Related Art Conventionally, a sheet processing apparatus that receives a sheet discharged from an image forming apparatus such as a copying machine or a printer and selectively performs processing such as binding processing and sorting processing on the received sheet is known.

  As such a sheet processing apparatus, a plurality of sheets are temporarily stacked on an intermediate stacking tray provided in the apparatus to form a sheet bundle, and a binding process is performed on the sheet bundle. A configuration in which the sheets are sequentially discharged and stacked on the stacking tray is widely used.

  Further, in Patent Document 1, in order to enable processing of a sheet that is long in the conveyance direction, the sheet exits from the lower side of the intermediate stacking tray to the extension of the intermediate stacking tray, and the downstream end of the sheet on the intermediate stacking tray in the conveying direction. The structure which provided the auxiliary tray which supports a part (front-end | tip part) from the downward direction is disclosed.

JP 2002-265123 A

  However, the retractable auxiliary tray is generally stored below the intermediate stacking tray during standby, and protrudes above the stacking tray when supporting sheets on the intermediate stacking tray. For this reason, if the end of the sheet stacked on the stacking tray is at a position higher than a predetermined position due to curling or the like, the auxiliary tray may be placed on the stacking tray when the auxiliary tray protrudes above the stacking tray. There is a risk of colliding with the rear end of the sheet. In this case, the already loaded sheets on the stacking tray and the sheets on the intermediate processing tray may be disturbed.

In addition, a detection unit that detects the upper surface position of the sheets stacked on the stacking unit is provided, and the detection unit erroneously detects the pressing unit when the stacking drive unit that moves the stacking unit up and down is controlled based on the detection unit. There is. In this case, there is a possibility that the lifting / lowering operation of the loading unit based on the detection unit may be performed inappropriately.

One aspect of the sheet processing apparatus according to the present invention includes an intermediate stacking unit that temporarily stacks the conveyed sheets, a processing unit that processes the sheets stacked on the intermediate stacking unit, and the intermediate stacking unit. Discharging means for discharging the stacked sheets, stacking means for stacking the sheets discharged by the discharging means, a stacking wall surface against which an upstream end portion in the discharging direction of the sheets stacked on the stacking means abuts, and the intermediate stacking means And an auxiliary unit that is movable between a supporting position that supports a downstream end portion in the discharge direction of the sheets stacked on the intermediate stacking unit, and a retracted position that is retracted inside the stacking wall surface. A first upper position that regulates the upper surface of the sheet stacked on the stacking unit below the movement region to the support position of the auxiliary unit and a retreat position that is retracted from above the sheet are taken. For the detection by the possible pressing means, the detection means for detecting the upper surface position in the vicinity of the upstream end in the discharge direction of the sheets stacked on the stacking means, the stacking drive means for raising and lowering the stacking means, and the detection means Control means for controlling the stack driving means based on the control means, the control means moving the pressing means to the first upper position before moving the auxiliary means to the support position, When the pressing means is located at the first upper position, the control means does not control the stack driving means based on detection by the detection means.

According to the present invention, it is possible to prevent the detection unit that detects the upper surface position of the sheets stacked on the stacking unit from erroneously detecting the pressing unit.

Sectional view of an image forming apparatus provided with a sheet processing apparatus Block diagram of control unit of image forming apparatus Schematic cross section of sheet processing equipment Block diagram of control unit of sheet processing apparatus Sectional view of the main processing part of the sheet processing apparatus Explanatory drawing of an in / out tray in a sheet processing apparatus Operational diagram of the in / out tray in the sheet processing apparatus Perspective view of an intermediate stacking tray in a sheet processing apparatus Top view of processing alignment unit in sheet processing apparatus Explanatory drawing of the sheet pressing member which concerns on this embodiment Explanatory drawing of the sheet pressing member which concerns on this embodiment (A) (b) (c) is an operation explanatory view of the sheet pressing member according to the present embodiment. (A) (b) (c) is an operation explanatory view of a sheet pressing member and a retracting tray according to the present embodiment. (A) (b) (c) is an operation explanatory view of a sheet pressing member and a retracting tray according to the present embodiment. Operation flow chart at the time of bundle discharge according to the present embodiment

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the following embodiments should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions. Therefore, unless specifically stated otherwise, the scope of the present invention is not intended to be limited thereto.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. In addition, what attached | subjected the same code | symbol is the same structure, The duplication description about these shall be abbreviate | omitted suitably.

<Overall configuration of image forming apparatus>
A monochrome / color copying machine as an image forming apparatus will be described with reference to FIG. The monochrome / color image forming apparatus includes a copying machine main body 900 (hereinafter simply referred to as “main body”) of a monochrome / color copying machine (hereinafter simply referred to as “copying machine”) and a sheet processing apparatus 100. The sheet processing apparatus 100 is connected to a main body 900 and includes a side stitching processing apparatus 190 and a saddle stitching processing apparatus 135 as sheet stacking processing apparatuses. For this reason, the sheet discharged from the main body 900 can be processed online. Note that the sheet processing apparatus 100 may be used as an option. For this reason, the main body 900 can be used alone. Further, the sheet processing apparatus 100 and the main body 900 may be integrated.

  The sheet supplied from the cassettes 909a and 909b in the main body 900 is transferred with toner images of four colors by an image forming unit composed of yellow, magenta, cyan, black photosensitive drums 914a to 914d, and the like. The toner image is fixed and discharged outside the apparatus.

  FIG. 2 is a block diagram of an image forming apparatus control unit that controls the image forming apparatus. As illustrated in FIG. 2, the CPU circuit unit 630 includes a CPU 629, a ROM 631, and a RAM 650. The CPU circuit unit 630 controls the document feeder control unit 632, the image reader control unit 633, the image signal control unit 634, the printer control unit 635, the finisher control unit 636, and the external interface 637. The CPU circuit unit 630 performs control according to the program stored in the ROM 631 and the setting of the operation unit 601.

  The document feeder control unit 632 controls the document feeder 950. The image reader control unit 633 controls the image reader. The printer control unit 635 controls the main body 900. A finisher control unit 636 serving as a control unit controls the sheet processing apparatus 100. In the present embodiment, a configuration in which the finisher control unit 636 is mounted on the sheet processing apparatus 100 as a control unit will be described. However, the configuration is not limited thereto, and the main body 900 is provided integrally with the CPU circuit unit 630. The sheet processing apparatus 100 may be controlled.

  The RAM 650 is used as an area for temporarily storing control data and a work area for operations associated with control. The external interface 637 is an interface from the computer 620 and develops print data into an image and outputs the image to the image signal control unit 634. An image read by the image sensor is output from the image reader control unit 633 to the image signal control unit 634, and an image output from the image signal control unit 634 to the printer control unit 635 is input to the exposure control unit.

<Overview of sheet processing apparatus>
The overall configuration of the sheet processing apparatus 100 according to the present embodiment will be described with reference to the cross-sectional view of FIG.

  The sheet discharged from the main body 900 is delivered to the inlet roller pair 102 of the sheet processing apparatus 100. At this time, the entrance sensor 101 simultaneously detects the sheet delivery timing. The sheet conveyed by the entrance roller pair 102 is detected by the detection sensor 104 while passing through the conveyance path 103. Then, it is detected how much the conveyance position of the conveyed sheet is deviated in the direction perpendicular to the conveyance direction (hereinafter referred to as sheet width direction) with respect to the target conveyance position. Subsequently, the sheet is conveyed to the shift unit 108. The shift unit 108 is movable in the sheet width direction while conveying the sheet by the shift roller pair 105 and 106. Therefore, the sheet can be transported at the target transport position by moving the shift unit 108 by a predetermined amount in the sheet width direction in consideration of the detected transport position deviation in the sheet width direction. Thereafter, the sheet is transferred to the conveyance roller 110 and the separation roller 111, and subsequently transferred to the buffer roller pair 115.

  Here, when the sheet is discharged to the upper stacking tray 136, the upper path switching member 118 is brought into a broken line state in FIG. 3 by a driving means such as a solenoid (not shown). Then, the sheet conveyed from the buffer roller pair 115 is guided to the upper path conveying path 117 and is discharged to the stacking tray 136 by the upper discharge roller 120. When the sheet is not discharged to the stacking tray 136, the upper path switching member 118 is in a solid line state in FIG. The sheet conveyed by the buffer roller pair 115 is guided to the bundle conveyance path 121. Thereafter, the paper is sequentially transferred to the buffer roller pair 122 and the bundle conveying roller pair 124.

  Here, when the sheet is saddle stitched, the saddle path switching member 125 is brought into a broken line state in FIG. 3 by a driving means such as a solenoid (not shown). The sheet conveyed from the bundle conveying roller pair 124 is guided to a saddle path 133 and conveyed to a saddle stitching processing device (saddle unit) 135 by a saddle entrance roller pair 134. Next, after the sheets are temporarily stacked on the saddle stitching processing device 135, the sheet bundle is subjected to saddle stitching processing and discharged to the outside. Since the saddle stitching process is a general process, a detailed description thereof is omitted here.

  On the other hand, when the sheet is discharged to the lower stacking tray 137, the saddle path switching member 125 is in the solid line state of FIG. Then, the sheet conveyed from the bundle conveying roller pair 124 is guided to the lower path 126 and transferred to the lower discharge roller pair 128 as conveying means. Here, when performing the side stitching process on the sheet, the sheet is discharged to the intermediate stacking tray 138 by the lower discharge roller pair 128. The intermediate stacking tray 138 is an intermediate stacking unit that temporarily stacks sheets. Then, after sequentially discharging the sheets to be discharged in the intermediate stacking tray 138, a side binding process is performed on a sheet bundle composed of a plurality of sheets. The sheet bundle after the binding process is discharged to the stacking tray 137 by a bundle discharge roller pair 130 as discharge means. The stacking tray 137 is a stacking unit that stacks the sheets discharged by the bundle discharge roller pair 130. The sheet binding process in the intermediate stacking tray 138 will be described in detail later.

  When the sheets are discharged to the stacking tray 137 without performing the side stitching process, the sheet conveyed from the lower discharge roller pair 128 is directly transferred to the bundle discharge roller pair 130 and discharged to the stacking tray 137.

  Inside the stacking tray 137 is provided a stacking tray lifting / lowering motor M137 (see FIG. 4) as stacking drive means for moving the stacking tray 137 up and down. Further, a paper surface detection sensor S137 as a detection unit for detecting the upper surface position of the sheet is provided in the vicinity of the base upstream of the stacking tray in the discharge direction. The paper surface detection sensor S137 detects the height position of the upstream end portion (rear end portion) in the discharge direction of sheets such as paper stacked on the stacking tray 137. Based on the detection result detected by the paper surface detection sensor S137, the stacking tray lifting motor M137 is driven to control the height direction position of the stacking tray 137.

  An in / out tray unit 400 is disposed below the intermediate stacking tray 138. When the sheets are temporarily stacked on the intermediate stacking tray 138, the protruding / extracting tray unit 400 functions as an extension of the intermediate stacking tray 138 and supports a sheet that is longer than the intermediate stacking tray by supporting the stacking. To do. That is, the loading / unloading tray unit 400 is placed between the intermediate stacking tray 138 and the stacking tray 137 at a support position that supports the downstream end (leading end) of the sheets stacked on the intermediate stacking tray 138 in the discharge direction. 5)).

  A stacked sheet pressing unit 500 as a pressing unit is disposed below the bundle discharge roller pair 130. The sheet pressing unit 500 functions to press the rear end portion of the sheet abutted against the stacking wall surface 170 (see FIG. 5) from above. The stacked sheet pressing unit 500 mainly functions to press the sheets on the stacking tray 137 when the sheets are discharged from the bundle discharge roller pair 130 to the stacking tray 137.

  Details of the in / out tray unit 400 and the stacked sheet pressing unit 500 will be described later.

  Next, the control configuration of the sheet processing apparatus 100 will be described. FIG. 4 is a functional block diagram illustrating a configuration of a part related to the finisher control unit 636 serving as a control unit. As shown in FIG. 4, the finisher control unit 636 includes a microcomputer (CPU) 701, a RAM 702, a ROM 703, an input / output unit (I / O) 705, a communication interface 706, and a network interface 704. Various sensor signals are input to the input port of the I / O 705. The output port of the I / O 705 is connected to each drive system via a control block (not shown) and various drivers. A conveyance control unit 707 controls various processes related to sheet conveyance such as conveyance position adjustment. The intermediate stacking tray control unit 708 controls various processes for stacking and aligning sheets on the intermediate stacking tray 138. The binding processing unit 709 controls the binding processing applied to the sheet. A stacked sheet pressing control unit 710 controls various processes for pressing sheets on the stacking tray 137. The stacking tray control unit 711 controls the raising and lowering processes of the stacking trays 136 and 137.

<Description of the intermediate stacking tray>
Next, the intermediate stacking tray unit will be described with reference to FIGS.

  The intermediate stacking tray 138 temporarily stacks sheets and stacks and aligns the sheets. Then, after performing a side binding process on the stacked sheets, the sheet bundle is discharged onto the stacking tray 137. As shown in FIG. 5, the intermediate stacking tray 138 is disposed with the downstream side (left side in FIG. 5) inclined upward and the upstream side (right side in FIG. 5) inclined downward with respect to the sheet bundle discharge direction. Yes. A rear end stopper 150 is disposed at the lower end on the upstream side of the intermediate stacking tray 138. A bundle discharge roller pair 130 is disposed at the downstream end of the intermediate stacking tray 138. The bundle discharge roller pair 130 is rotatable by a bundle discharge drive motor M130 (see FIG. 4), and has a function of discharging a sheet bundle on the intermediate stack tray 138 to the stack tray 137. The discharged sheets are sequentially stacked on the stacking tray 137 such that the trailing end of the sheet abuts against the stacking wall surface 170 due to the inclination of the stacking tray 137.

  One upper bundle discharge roller 130 b constituting the bundle discharge roller pair 130 is configured at an end portion of the upper opening / closing guide 149. The upper opening / closing guide 149 can be rotated about the support shaft 154, and is rotated in the vertical direction by driving the upper opening / closing guide motor M149. Therefore, the upper bundle discharge roller 130b can be brought into and out of contact with the lower bundle discharge roller 130a as the upper opening / closing guide 149 rotates. When the sheets are stacked on the intermediate stacking tray 138, the bundle discharge roller pair 130 is in a separated state. When the sheets are discharged to the stacking tray 137, the bundle discharge roller pair 130 is in a joined state with the sheets interposed therebetween.

  An in / out tray unit 400 is disposed below the intermediate stacking tray 138. As described above, when the sheets on the intermediate stacking tray 138 are supported, as shown in FIG. 6B, the sheet protrudes on the extension of the intermediate stacking tray 138, and during other standbys, as shown in FIG. 6C. Are stored below the intermediate stacking tray 138. The in / out tray unit 400 includes an in / out tray base 402 and a sheet support unit 401 as shown in FIG. A slide shaft 410 is passed through the in / out tray base 402, and driving of the rotary link 403 is provided from an in / out drive motor M400 via a belt 411. As shown in FIGS. 7A, 7 </ b> B, and 7 </ b> C, when the rotation link 403 rotates, the retracting tray base 402 moves along the slide shaft 410 by the amount corresponding to the sliding direction of the rotation path. Also, an in / out tray home sensor S400 for detecting the home position of the in / out tray unit 400 is disposed in the vicinity of the upstream side of the movable range of the in / out tray base 402.

  A pull-in paddle 131 is disposed above the intermediate stacking tray 138. The sheet discharged from the lower discharge roller pair 128 to the intermediate stacking tray 138 is first guided to the belt roller 158 by the drawing paddle 131. As shown in FIG. 8, a plurality of drawing paddles 131 are fixed along a drive shaft 157 rotated by a paddle drive motor M155. Then, the paddle drive motor M155 rotates in the counterclockwise direction (the direction opposite to the sheet discharge direction) in FIG. 8 at an appropriate timing.

  Next, the sheet delivered to the belt roller 158 is conveyed toward the rear end stopper 150 by the belt roller 158. The sheet is abutted against the trailing end stopper 150 so that the sheet conveyance direction is aligned. The belt roller 158 is wound around the outer periphery of the first discharge roller 128 a constituting the first discharge roller pair 128, and is sandwiched between the sandwiching rollers 162 and 163 provided at the tip of the belt moving member 161. Then, the belt roller 158 rotates counterclockwise following the rotation of the first discharge roller 128a in such a positional relationship that the lower portion of the belt roller 158 contacts the uppermost sheet stacked on the intermediate stacking tray 138. Further, by moving the belt moving member 161 from the belt moving motor M167 via the rack gear 164 in the direction of the arrow, the shape of the belt roller 158 can be changed, and the position in contact with the uppermost sheet can be changed up and down. Can do. The position of the belt moving member 161 is controlled by the belt moving home sensor S168 while detecting the edge of the belt moving member 161.

  On both sides of the intermediate stacking tray 138 in the sheet width direction, alignment plates 340 and 341 for aligning the side edges in the width direction orthogonal to the conveying direction of the sheets stored in the intermediate stacking tray 138 are disposed. As shown in FIG. 9, the alignment plates 340 and 341 are arranged on the surface of the intermediate stacking tray 138 so as to face both side edges in the sheet width direction. In addition, in order to press and support the sheet-side end surface, each of the alignment surfaces 340a and 341a is perpendicular to the surface of the intermediate stacking tray 138. The left and right alignment plates 340 and 341 include alignment plate drive motors M340 and M341 that can be driven independently. Therefore, the alignment plates 340 and 341 can be independently moved along the width direction of the sheet via the timing belts 343 and 344 from the front end pulley of the drive motor. Here, sensors S340 and S341 for detecting respective home positions are arranged for the alignment plates 340 and 341, and the positions of the alignment plates 340 and 341 are controlled by the respective motors and sensors. Therefore, when the alignment plates 340 and 341 are moved to predetermined positions, the sheets are sandwiched and alignment in the width direction of the sheets is possible. When the alignment plates 340 and 341 do not operate, they stand by at respective home position positions set at both ends.

  A stapler 132 is disposed on the extension on the rear end stopper 150 side of the intermediate stacking tray 138. The stapler 132 that is a binding unit is a device that binds the end portion of the sheet bundle by a clinch motor M132 (see FIG. 5), and a metal needle that is a fastening member is attached to the end portion of the sheet bundle on the intermediate stacking tray 138. Fasten the driven sheet bundle.

  A stacked sheet pressing unit 500 is disposed below the bundle discharge roller pair 130. 10 and 11 are detailed views of the stacked sheet pressing unit 500. FIG. The stacked sheet pressing unit 500 is provided with two pressing portions 510 that are portions for directly pressing the sheets on the stacking tray 137 along the sheet width direction. The pressing unit 510 is driven by the sheet pressing unit driving motor M500 and rotates about the rotation shaft 514, thereby rotating the rear end portion of the sheet on the stacking tray 137 from the stacking wall surface 170 to the upper position. It works to hold down from.

  The driving by the sheet pressing unit driving motor M500 is transmitted from the leading pulley 523 provided on the shaft of the sheet pressing unit driving motor M500 to the pulleys 522, 521, and 520 through the timing belts 526, 525, and 524. Since the pulley 520 and the rotating shaft 514 are driven and transmitted by parallel pins, the rotating shaft 514 is driven to rotate by driving the sheet pressing portion driving motor M500.

  The pressing portion 510 includes a pressing member 511, a drive transmission member 512, and a pressing spring 513. The pressing member 511 is configured to be rotatable relative to the drive transmission member 512 about the axis of the rotation shaft 514. Note that the relatively rotatable range is limited to a certain angle. The drive transmission member 512 is configured to be rotationally driven together with the rotation shaft 514 via a parallel pin. The drive transmission member 512 has a sensor flag 512a. One pressing portion 510 is provided with a sheet pressing portion HP sensor S500 corresponding to the sensor flag 512a of the drive transmission member 512, and controls the rotational position of the pressing portion 510 together with the sheet pressing portion driving motor M500. Yes. The pressing spring 513 is a tension spring and is spanned between the pressing member 511 and the drive transmission member 512. The torque acting on the drive transmission member 512 is transmitted to the pressing member 511. Therefore, the drive transmission member 512 is rotated with the rotation of the rotation shaft 514, and the rotational torque is transmitted to the pressing member 511 via the pressing spring 513. Therefore, the pressing member 511 is also rotated at the same time.

  Therefore, as shown in FIGS. 12A, 12B, and 12C, the pressing member 511, the drive transmission member 512, and the pressing spring 513 move the rotating shaft 514 until the pressing member 511 contacts the sheet S on the stacking tray 137. Rotates around the central axis. After the pressing member 511 contacts the sheet S on the stacking tray 137 (see FIG. 12B), the pressing member 511 stops rotating, and the pressing member 511 and the drive transmission member 512 rotate relatively ( (Refer FIG.12 (c)). At that time, the drive transmission member 512 continues to rotate while pulling the pressing spring 513. Therefore, the tension of the spring generated by the tension is converted into torque and transmitted to the pressing member 511, and acts as a force for pressing the sheet.

<Operation of sheet holding unit when discharging sheets from intermediate stacking tray>
Next, an operation when a sheet (or sheet bundle) is discharged from the intermediate stacking tray 138 will be described. FIGS. 13 and 14 are explanatory diagrams of operations of the sheet pressing unit 500 and the retracting tray unit 400. FIG. FIG. 15 is a flowchart showing the flow of the operation.

First, the operation of the sheet pressing unit 500 when discharging a sheet will be described. When a sheet is discharged from the intermediate stacking tray 138, a pressing position (second upper position) for pressing the sheet S before the sheet S ′ discharged by the discharge roller pair 130 collides with the sheet S on the stacking tray 137. ) Until the pressing portion 510 is rotated (see FIG. 13A). This is a position for preventing the sheet S ′ discharged from the intermediate stacking tray 138 from pushing out the already stacked sheet by colliding (contacting) with the sheet S on the stacking tray 137. Has a pressing force acting on the stacking tray 137 from above (see FIG. 13B).

  Subsequently, immediately before the trailing edge of the sheet S ′ to be discharged passes through the bundle discharge roller pair 130, the pressing portion 510 is retracted to the home position (retreat position) before protruding from the stacking wall surface 170 (FIG. 13). (See (c)). This is to prevent the discharged sheet S ′ from dropping above the pressing portion 510 and disturbing the stacking.

When the discharge is completed, in order to stack the next sheet on the intermediate stacking tray, it is necessary to project the in / out tray unit 400 to a support position for supporting the sheet (a position protruding from the stacking wall surface 170). Here, before moving the in / out tray unit to the support position, the sheet pressing unit 500 protrudes again from the stacking wall surface 170 (see FIG. 14A). At this time, the position of the sheet pressing unit 500 is a regulation position (first upper position) that regulates the upper surface of the already stacked sheets stacked on the stacking tray 137 below the moving area to the support position of the appearing and tray unit 400. is there.

  Since the sheet pressing unit 500 is in a restricting position for restricting the upper surface of the already stacked sheets below the moving region to the support position of the appearing / extracting tray unit 400, the upper and lower surfaces of the sheets on the stacking tray 137 move to the supporting position. Interference with the tray unit 400 is eliminated. Therefore, even if the in / out tray unit 400 protrudes from the stacking wall surface 170, the in / out tray unit 400 can be reliably protruded without disturbing the already stacked sheets at the front end (see FIG. 14B).

  When the in / out tray unit 400 protrudes from the stacking wall surface 170, stacking of the next sheet on the intermediate stacking tray 138 is started. Further, the sheet pressing unit 500 returns to the home position (retracted position) before protruding from the stacking wall surface 170 (see FIG. 14C).

  Here, when the sheet pressing unit 500 is in a position protruding from the stacking wall surface 170 (regulation position or pressing position), control is performed so that the upper surface position of the sheet on the stacking tray is not detected by the paper surface detection sensor S137. doing. This is because the regulation position and the pressing position of the sheet pressing unit 500 and the sheet upper surface detection position of the sheet surface detection sensor S137 are both at the rear end side of the sheet, and the sheet pressing unit 500 from which the sheet surface detection sensor S137 protrudes is erroneously detected. This is to prevent that.

  Further, the moving distance from the home position of the sheet pressing unit 500 to the restriction position (the amount of rotation of the pressing portion 510) is set shorter than the moving distance from the home position to the pressing position. This is set to a minimum amount that ensures the protrusion of the appearing tray unit 400 in order to quickly restart the detection of the upper surface position of the sheet by the paper surface detection sensor S137.

  Next, an operation flow will be described with reference to FIG. When the binding job is started (step S1), first, it is monitored whether each drive part of the sheet processing apparatus (finisher) is at a predetermined home position, and an initial process is performed to move a non-home position to the home position. Is executed (step S2).

  After the initial process, if the print job is a job that performs a binding process, the sheet pressing unit 500 is moved to a restriction position below the moving area to the support position of the retracting tray unit 400 (step S3). Subsequently, the in / out tray unit 400 is moved to the sheet support position (step S4). When the retracting tray unit 400 is moved to the sheet support position, the sheet pressing unit 500 is returned to the home position (retracted position) (step S5).

  Thereafter, the conveyance of the print sheet is started (step S6), and after the sheets are temporarily stacked on the intermediate stacking tray 138 (step S7), the sheet bundle is bound (step S8). When the binding process is completed, the sheet pressing unit 500 is moved to a pressing position for pressing the sheets on the stacking tray 137 (step S9). Subsequently, the in / out tray unit 400 is moved to the home position (retracted position) (step S10).

  When each movement is completed, the discharge of the sheet bundle is started (step S11). After a certain time has elapsed after the discharge starts, the sheet pressing unit 500 is moved to the home position (retracted position) before the discharge of the sheet bundle is completed (step S11). Step S12). That is, the sheet pressing unit 500 is moved to the home position before the sheet bundle discharged by the bundle discharge roller pair 130 contacts the already stacked sheet bundle on the stacking tray 137. When the discharge of the sheets is completed (step S13), it is determined whether or not the discharged sheet bundle is the final bundle (step S14). If it is not the final bundle, the process returns to step S3, and the sheet pressing unit 500 is again moved to the restriction position. Move to. If the sheet is the final bundle, the process proceeds to step S15 to end the binding job.

  As described above, according to the present embodiment, the rear end portion of the sheets stacked on the stacking tray 137 is restricted to the restriction position below the movement region to the support position of the appearance tray unit 400, so that the appearance tray During the projecting operation of the unit 400, the intrusion tray unit 400 can be reliably projected without colliding with the sheets on the stacking tray 137. As a result, the sheets can be stacked with good consistency without disturbing the sheets on the intermediate stacking tray 138 and the sheets on the stacking tray 137.

M137 ... stacking tray lift motor M400 ... retracting drive motor S137 ... paper surface detection sensor 100 ... sheet processing device 128 ... lower discharge roller pair 130 ... bundle discharge roller pair 130a ... lower bundle discharge roller 130b ... upper bundle discharge roller 132 ... stapler 135 ... Saddle stitching processing devices 136, 137 ... stacking tray 138 ... intermediate stacking tray 170 ... stacking wall surface 190 ... flat stitching processing device 400 ... retracting tray unit 500 ... sheet pressing unit 510 ... pressing part 511 ... pressing member 512 ... drive transmission member 513 ... Pressing spring 514... Rotating shaft 636. Finisher control unit 900... Main body 914a to 914d.

Claims (7)

Intermediate stacking means for temporarily stacking conveyed sheets;
Processing means for processing sheets stacked on the intermediate stacking means;
Discharging means for discharging the sheets stacked on the intermediate stacking means;
Stacking means for stacking sheets discharged by the discharging means;
A stacking wall surface against which the upstream end of the sheet stacked on the stacking unit abuts;
Between the intermediate stacking means and the stacking means, it is possible to move between a support position for supporting the downstream end portion in the discharge direction of the sheets stacked on the intermediate stacking means and a retreat position retracted inside the stacking wall surface. Auxiliary means,
A first upper position that regulates the upper surface of the sheet stacked on the stacking unit below a movement region to the support position of the auxiliary unit, and a pressing unit that can take a retreat position retracted from above the sheet; ,
Detecting means for detecting an upper surface position in the vicinity of the upstream end portion in the discharge direction of the sheets stacked on the stacking means;
Stacking drive means for raising and lowering the stacking means;
Control means for controlling the stacking drive means based on the detection of the detection means,
The control means moves the pressing means to the first upper position before moving the auxiliary means to the support position,
The sheet processing apparatus according to claim 1, wherein when the pressing unit is located at the first upper position, the control unit does not control the stack driving unit based on detection by the detection unit.   The control unit is configured to discharge a sheet stacked on the stacking unit below the first upper position before the sheet discharged by the discharge unit contacts the sheet stacked on the stacking unit. The sheet processing apparatus according to claim 1, wherein the pressing unit is moved to a second upper position where the upstream end is pressed from above onto the stacking unit.   The moving distance of the pressing means from the retracted position to the first upper position of the pressing means is shorter than the moving distance of the pressing means from the retracted position to the second upper position. The sheet processing apparatus according to claim 2.   The control unit is configured to perform the pressing operation after the sheet discharged by the discharge unit comes into contact with the sheet stacked on the stacking unit and before the sheet discharged by the discharge unit completes stacking on the stacking unit. The sheet processing apparatus according to claim 1, wherein a unit is moved to the retracted position.   5. The sheet processing apparatus according to claim 1, wherein the control unit moves the auxiliary unit to the support position before a sheet is stacked on the intermediate stacking unit.   The control means performs the processing of the sheets stacked on the intermediate stacking means after the processing means performs processing on the auxiliary means before starting the discharge of the sheets stacked on the intermediate stacking means by the discharge means. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is moved to the retracted position.   An image forming unit that forms an image on a sheet, and a 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.

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