JP4471720B2 - Sheet processing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet processing apparatus capable of reliably aligning side edges along a sheet conveying direction of a sheet, and an image forming apparatus including the sheet processing apparatus.

  Conventionally, when the sheet processing apparatus aligns (aligns) the sheet width (direction intersecting the sheet conveying direction), the sheet S conveyed in the arrow A direction to the processing tray 600 as shown in FIG. The sheet S was abutted against the abutting wall 603 by moving the width regulating plate 602 by a predetermined amount on the processing tray 600 in the arrow B direction orthogonal to the sheet conveying direction. The width regulating plate 602 moves by receiving a driving force of a motor (not shown) via a rack and a pinion. Note that the alignment of the sheet widths also means alignment of one end surface (hereinafter referred to as “side end”) Sa of the sheet S.

  The amount of movement of the width regulating plate 602 is set to a distance that is further pushed, for example, by about 2 mm to about 3 mm from the position at which the side end of the sheet S along the sheet conveyance direction hits the abutting wall 603. That is, the width restricting plate 602 moves to a position narrowed by about 2 mm to about 3 mm from the width size of each sheet (the length of C in FIG. 21).

  However, in the conventional sheet post-processing apparatus provided with the width regulating plate 602, the movement amount of the width regulating plate 602 is further determined to be about 2 mm to about 3 mm from the position where the side edge of the sheet S is abutted against the abutting wall 603. Therefore, when the sheet S that has been conveyed is an upper curl with both ends facing upward, or a lower curl with both ends facing downward, the width C of the sheet is equal to the amount of curling of the sheet S. When the width is narrower than the actual width and the predetermined width-adjusting amount of the width regulating plate 602, there is a problem that the sheet cannot be reliably abutted against the abutting wall 603, and the width alignment accuracy is significantly lowered.

  If the movement amount of the width regulating plate 602 is about 2 mm to about 3 mm or more, an overload is applied to the motor that moves the width regulating plate when a normal sheet that is not curled is pushed in, and the motor may step out. . For this reason, in the conventional sheet processing apparatus, the sheet is pushed by the width regulating plate 602 by a distance (about 2 mm to about 3 mm) that does not cause the motor to step out.

  Further, when the sheet comes into contact with the regulating plate 602, when the sheet curls upward, the sheet slightly floats from the processing tray 600 along the curl, and conversely, when the sheet curls down, the sheet follows the curl. There is a problem that the width alignment accuracy is remarkably lowered due to a slight rise from the processing tray 600.

  In addition, since the conventional sheet processing apparatus pushes the entire side edge of the sheet with the width regulating plate 602, there is a problem that the width alignment accuracy cannot be increased if there is a variation in the sheet size at the time of sheet cutting.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet post-processing apparatus that improves the alignment accuracy of the side edges of a sheet.

To achieve the above object, a sheet processing apparatus of the present invention includes a stacking means sheet is stacked, the the surface of the sheet stacked on the stacking means in contact, the sheet in a direction crossing the sheet conveying direction a moving means for moving the a side end positioning means for receiving the side edge of the sheet canceller moved in the intersecting direction by the moving means, separable therefrom the side edge positioning means distribution in the vicinity to said stacking means comprising a pressing means which is set, wherein the pressing means includes a pressing portion for pressing the side edge of the sheet is received on the side edge positioning means to the stacking means direction, the sheet is moved by said moving means A guide surface that guides a side end portion between the pressing portion and the stacking unit, and the moving unit moves the side end portion of the sheet along the guide surface between the pressing unit and the stacking unit. Between By moving, it is characterized by pressing the side edge portions of the sheet pressed state to the pressing portion in the side end positioning means.

In the sheet processing apparatus of the present invention, said pressing means, by riding up the previous SL moving means have a slope portion for separating said moving means from the sheet, the moving means is moved in the crossing direction sheet Is moved in the intersecting direction, the side end portion of the sheet is pressed against the side end positioning means, and then moved in the intersecting direction so as to ride on the slope portion so as to be separated from the sheet. It has become.

The sheet processing apparatus of the present invention includes an upstream end positioning unit that is provided upstream of the moving unit in the sheet conveying direction and receives and positions an upstream end of the sheet in the sheet conveying direction, and the moving unit includes the upstream end of the sheet . Is positioned in contact with the upstream end positioning means to position the upstream end of the sheet , and then the side end of the sheet is positioned with respect to the side end positioning means.

In the sheet processing apparatus of the present invention, the moving means is a roller that can be rotated forward and backward, and can discharge the sheets stacked on the stacking means in the sheet conveying direction.

In the sheet processing apparatus of the present invention, the contact position of the moving means in contact with the sheet is set to a predetermined distance away from the side edge of the sheet which is brought into contact with the side end positioning means.

In the sheet processing apparatus of the present invention, when the sheet is conveyed with respect to the said side edge, the contact position of the moving means in contact with the sheet, as will be set from the side edge of the sheet at the same distance away It has become.

In the sheet treatment apparatus of the present invention, the distance between the side end positioning means and the side edge of the sheet when different by the sheet, the contact position of the moving means in contact with the sheet, the side edge positioning means and the sheet of The wider the distance from the side end, the farther from the side end positioning means.

  In order to achieve the above object, an image forming apparatus of the present invention comprises: an image forming unit that forms an image on a sheet; and a sheet processing device that processes a sheet on which an image has been formed by the image forming unit. The processing apparatus is the sheet processing apparatus according to any one of the above.

  In the sheet processing apparatus of the present invention, the side edge of the sheet moved by the moving means is guided between the pressing means and the stacking means by the inclined portion formed in the pressing means. The sheet is guided to the guide surface and entered between the pressing unit and the stacking unit, and is pressed against the stacking unit by the pressing unit and is brought into contact with the side end positioning unit in a flat state. Therefore, the side edge alignment accuracy can be improved.

  In the sheet processing apparatus according to the present invention, the moving means in which the side edge of the sheet is in contact with the side end positioning means is separated from the sheet by the floating portion of the pressing means. In addition, since the loop formed on the sheet can be opened without substantially shifting the position of the sheet in contact with the side end positioning wall, the alignment accuracy of the side edges of the sheet can be improved.

  In the sheet processing apparatus of the present invention, after the upstream end of the sheet is aligned by the upstream end positioning unit, the side end of the sheet is positioned by the side end positioning unit, so that the alignment accuracy of the side end of the sheet is improved. be able to. In addition, since both the upstream end and the side end of the sheet are aligned by a common moving means, the structure can be simplified.

  The sheet processing apparatus of the present invention can simplify the structure because the moving means not only aligns the side edges of the sheet but also performs the operation of discharging the sheet.

  In the sheet processing apparatus according to the present invention, the moving means comes into contact with a substantially constant position from the side edge of each sheet regardless of the sheet width. Even if the distance to contact with the sheet is different, the distance by which the pressing means presses the side edge of the sheet against the side edge positioning means can be substantially constant regardless of the size of the sheet, and the sheet side edge alignment accuracy is improved. be able to. Further, if the floating means is provided in the pressing means, the loop amount formed until the moving means is separated from the sheet can be made substantially the same regardless of the width size of the sheet. As a result, the sheet side edge alignment accuracy can be increased.

  In the sheet processing apparatus of the present invention, when the sheet is conveyed with reference to the side edge, the contact position of the moving means is always set to the same position. Stand-by at a substantially constant position, the pressing means makes the distance pressed after the side edge of the sheet abuts the side edge positioning means, regardless of the sheet size, and the sheet side edge alignment accuracy Can be increased. Further, if the floating means is provided in the pressing means, the loop amount formed until the moving means is separated from the sheet can be made substantially the same regardless of the width size of the sheet. As a result, the sheet side edge alignment accuracy can be increased.

  In the sheet processing apparatus of the present invention, when the distance between the side edge positioning means and the side edge of the sheet differs depending on the sheet, the contact position of the moving means that contacts the sheet is the same as the side edge positioning means and the side edge positioning means. The wider the distance from the side edge of the sheet, the farther the distance from the side edge positioning means is set. Therefore, even if the distance until the side edge of the sheet contacts the side edge positioning means differs depending on the size of the sheet. The pressing distance after the pressing means abuts the side edge of the sheet against the side edge positioning means can be made substantially constant regardless of the size of the sheet, and the side edge alignment accuracy of the sheet can be improved. Further, if the floating means is provided in the pressing means, the loop amount formed until the moving means is separated from the sheet can be made substantially the same regardless of the width size of the sheet. As a result, the sheet side edge alignment accuracy can be increased.

  Hereinafter, embodiments of the present invention will be described 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 the figure, an image forming apparatus A performs post-processing of a sheet discharged from the image forming apparatus main body 500, an automatic document feeder (ADF) 300 provided on the upper surface of the image forming apparatus main body 500, and the image forming apparatus A. For example, a sheet post-processing apparatus 400 is provided as a sheet processing apparatus.

  A rail member 440 is provided below the sheet post-processing apparatus 400. The sheet post-processing apparatus 400 can be pulled out obliquely with respect to the conveyance direction by the rail member 440 to replenish the staples of the stapler unit 420.

  In FIG. 1, a reader unit (image reading device) 120 converts a document into image data. For example, the printer unit 200 which is an image forming unit has a plurality of types of sheet cassettes 204 and 205, and outputs image data as a visible image on a sheet in accordance with a print command.

  In the image forming apparatus A having such a configuration, when an original image is read to form an image, first, an original document stacked on the automatic document feeder (ADF) 300 is converted into an automatic document feeder (ADF). ) 300 are sequentially conveyed onto the platen glass surface 102 one by one.

  Next, when the document is conveyed to a predetermined position on the glass surface 102 in this way, the lamp 103 of the reader unit 120 is turned on, and the scanner 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 the irradiation light, and the latent image is developed by the developing device 203. As a result, a toner image is formed on the photosensitive drum 202.

  Next, the sheet S is conveyed from the sheet cassettes 204 and 205 in synchronization with the leading edge of the toner image, and the toner image is transferred onto the sheet S by the transfer unit 206. Thereafter, the toner image transferred to the sheet S is fixed by the fixing unit 207. After the toner image is fixed in this way, the sheet S is sent from the paper discharge unit 208 to the sheet post-processing apparatus 400.

  Then, the sheet S output from the paper discharge unit 208 is conveyed to the sheet post-processing device 400, and processing such as sorting and binding is performed according to the operation mode designated in advance by the sheet post-processing device 400.

  The sheet post-processing apparatus 400 includes a stapling function that is a binding operation by a staple unit in addition to a sorting operation for sorting sheets. As shown in FIG. 2, the sheet post-processing apparatus 400 finally stacks a processing tray 410 that processes the sheets S sequentially discharged from the image forming apparatus main body 500 and a sheet bundle processed on the processing tray 410. A stack tray 421 and the like are provided, and a number of sheet bundles corresponding to the number of documents are formed on the processing tray 410, and each sheet bundle is discharged to the stack tray 421.

  In the figure, a sheet receiving unit 401 receives a sheet S discharged from the image forming apparatus main body 500. After the sheet S received by the sheet receiving unit 401 is detected by the entrance sensor 403, the sheet S is conveyed by a conveying roller 405 and a moving unit such as an offset roller 407, and thereafter is a sheet stacking unit as shown in FIG. For example, it is discharged onto the processing tray 410. Note that the sheets S stacked on the processing tray 410 are detected by the sheet bundle discharge sensor 415 shown in FIG.

  Here, the offset roller 407 is held up and down by an offset roller arm 406 that can move in the vertical direction about a shaft 406a shown in FIGS. The offset roller 407 moves upward via the offset roller arm 406 when the sheet S is discharged to the processing tray 410. As a result, the sheet S is discharged onto the processing tray 410 without being interrupted by the offset roller 407.

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

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

  Therefore, after the entrance sensor 403 detects the leading edge of the sheet, the pickup solenoid 433 is turned off when a predetermined time set in advance according to the sheet size has elapsed. Then, the offset roller 407 descends by its own weight and lands on the sheet, and then rotates in the sheet conveying direction for a predetermined time, and reverses for a predetermined time when a predetermined time elapses.

  Then, the reversely rotating offset roller 407 abuts the trailing end of the sheet against, for example, a sheet trailing end stopper 411, which is an upstream end positioning unit erected at the upstream end of the processing tray 410 in the conveying direction. Consistency.

  In FIG. 4, for example, a side end positioning wall 416, which is a side end positioning unit, is a wall that serves as an alignment position reference for the end of the sheet S in a direction that intersects the sheet conveyance direction (hereinafter referred to as the width direction). The stapler unit 420 is disposed in the vicinity of the side end positioning wall 416 of the processing tray 410 and performs a stapling process on the sheet bundle formed on the processing tray 410. The offset roller 407 is moved in the width direction via the pinion 423 and the rack 424 by driving of the offset motor 432, and can approach the side end positioning wall 416.

  When the offset roller 407 approaches the side end positioning wall 416, the sheet S that is abutted against the sheet trailing edge stopper 411 and aligned in the conveyance direction by the rotation of the offset roller 407 stops rotating and contacts the sheet S. As the offset roller 407 is moved in the sheet width direction (arrow K direction), the offset roller 407 is moved to follow the offset roller 407 by the frictional force of the offset roller 407 to perform positioning in the width direction. It has come to be.

  The sheet S is guided by the guide surface 700d of the sheet pressing member 700, which is the pressing means shown in FIGS. 4 and 12, just before coming into contact with the side end positioning wall 416, and enters between the pressing piece 700b and the processing tray 410. The side end positioning wall 416. The guide surface 700d is an inclined surface that approaches the processing tray 410 as it approaches the side end positioning wall 416.

  As shown in FIGS. 4 and 12, the sheet pressing member 700 is rotatably provided on the shaft 406 a, and for example, a pressing piece 700 b that is a pressing portion that presses the sheet by its own weight, and the lower surface of the offset roller arm 406. For example, a floating piece 700c, which is a floating portion in which the inclined surface 700a to be received is formed, is also formed.

  The offset roller 407 moves the sheet S by a predetermined distance and abuts against the side end positioning wall 416, and then considers that the sheet S is skewed in the image forming apparatus main body 500. The sheet S is conveyed by about 5 mm or more.

  As a result, a loop is formed at the side end portion of the sheet S abutted against the side end positioning wall 416. The sheet pressing member 700 is slightly pushed up by this loop. In addition, when the offset roller 407 moves in a direction approaching the side end positioning wall 416, the lower surface of the offset roller arm 406 rides on the inclined surface 700a of the sheet pressing member 700 as shown in FIG. And gradually separated (E) from the sheet S.

  At the same time, the sheet pressing member 700 that has pressed the sheet S by its own weight is loaded by the weight of the offset roller unit (406, 407, 431b, etc.) 435 itself due to the offset roller arm 406 climbing upward. As a result, the force with which the sheet pressing member 700 presses the side edge of the sheet against the processing tray 410 is increased.

  As described above, the offset roller 407 is lifted from the sheet and the force by which the sheet pressing member 700 presses the vicinity of the side edge of the sheet against the processing tray 410 is increased. Therefore, in the state where the vicinity of the side edge of the sheet is fixed, the loop D is Opened in the direction of arrow H. As a result, the sheet is reliably aligned with the side end thereof being in contact with the side end positioning wall 416, and skew in the sheet width direction is corrected.

  It will be described that the sheet post-processing apparatus 400 according to the present embodiment can form the loop in the same manner regardless of the width size of the sheet.

  As described above, in the sheet post-processing device 400 of this embodiment, the offset roller 407 moves the sheet S in a direction (sheet width direction) that intersects the sheet conveyance direction of the image forming apparatus main body, thereby positioning the side edges. The skew in the width direction is corrected by abutting against the wall 416 and looping (bending) the sheet S in the vicinity of the sheet pressing member 700.

  By the way, the sheet is fed into the sheet post-processing apparatus 400 with the sheet width center aligned with the width center of the conveyance path. A so-called sheet is conveyed on the basis of the center. On the other hand, the amount of movement of the offset roller 407 in the sheet width direction is such that the offset roller unit (406, 407, 431b, etc.) 435 rides on the slope 700a of the sheet pressing member 700 from the sheet width center (conveyance path width center). The distance to rise is always the same regardless of the width size of the sheet. For this reason, if the offset roller 407 is made to stand by at the center of the width of the sheet and alignment in the width direction of the sheet is performed, the following problems occur.

  That is, the side edge of the sheet is closer to the side edge positioning wall 416 as the sheet width size is larger. On the other hand, the movement amount of the offset roller 407 in the sheet width direction is always the same regardless of the sheet width size, as described above. For this reason, for example, a wide sheet such as a large size sheet has a longer time for forming a loop after being brought into contact with the side end positioning wall 416, and the sheet width is larger than that of a large size sheet. A loop larger than a narrow sheet is formed, and the sheet pressing member 700 is pressed on the processing tray 410 to cause a jam, and the side edges of the sheet may not be aligned.

  In view of this, the offset roller 407 in the sheet post-processing apparatus 400 of the present embodiment, as shown in FIGS. It waits at a certain position (X). This position is called a contact position because the offset roller is in contact with the sheet. Therefore, even if the distance (Y) until the side edge of the sheet comes into contact with the side edge positioning wall 416 is different, the offset roller unit (406, 407, 431b, etc.) 435 rides on the slope 700a of the sheet pressing member 700, and the amount of loop formed until the offset roller 407 moves away from the sheet can be made substantially the same regardless of the width size of the sheet. . As a result, the sheet post-processing apparatus 400 of the present embodiment can perform stable side edge alignment regardless of the sheet width size, and can improve side edge alignment accuracy.

The value of X is preferably slightly increased as the width of the sheet is increased. That is, when the width of the sheet is large, the sliding area of the sheet is increased, and the sliding resistance is large. Therefore, the offset roller 407 makes the offset until the side edge of the sheet contacts the side edge positioning wall 416. The roller 407 may slide somewhat with respect to the sheet, and the amount of loop may be reduced, and the sheet width may not be accurately aligned. Therefore, the amount of offset roller 407 is expected to slide relative to the sheet, and the value of X is slightly increased according to the width size of the sheet, thereby securing the sheet loop amount and increasing the sheet width alignment accuracy. This can be further improved. That is, the sheet post-processing apparatus 400 as the sheet processing apparatus has a contact position added with an amount of sliding while the offset roller 407 as the moving unit moves the sheet to the side end positioning wall 416 as the side end positioning unit. Therefore, even if the offset roller 407 slides on the sheet, the side end of the sheet can be reliably aligned with the side end positioning wall 416, and the alignment accuracy of the side end can be improved.

  In the above description, the case where the sheet is conveyed to the sheet post-processing apparatus 400 with the width center of the conveyance path coincident with the width center of the sheet has been described. However, as shown in FIG. In the case of a sheet conveyed to the sheet post-processing apparatus 400 so as to coincide with one side of the conveyance path (so-called one-side reference), the distance (Y) in FIG. 11 is the same regardless of the width size of the sheet. For this reason, the offset roller 407 may always stand by at a distance X from the side edge of the sheet, that is, at a distance (Y + X) from the side edge positioning wall 416, regardless of the width size of the sheet.

  In any case, it is preferable that the offset roller 407 is at a position of a distance X from the Sa side end of the sheet as shown in FIGS. 10 and 11 immediately before contacting the sheet.

  The description of the sheet post-processing operation will be continued.

  The sheet discharged onto the processing tray 410 is conveyed to the stack tray 421 (see FIGS. 1 to 3) by an offset roller 407 that rotates in the sheet conveying direction as shown in FIG. 6 (b), the sheet is returned to the sheet trailing edge stopper 411 by the reverse rotation of the offset roller 407, and the trailing edge is abutted against the sheet trailing edge stopper 411 to align the trailing edge.

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

  On the other hand, in FIG. 5, the sheet clamp member 412 presses the rear end portion of the aligned sheets S against the processing tray 410 from above by a biasing force by a biasing unit (not shown). After the alignment of the trailing edge of the sheet, as shown in FIG. 7A, after the offset roller 407 is lifted by the pickup solenoid 433, the sheet clamp member 412 holds the aligned sheet S in FIG. Press from above as shown in (b). As a result, the sheet S previously discharged to the processing tray 410 is held at a predetermined position without being influenced by the accompanying sheet S that is sequentially fed thereafter.

  The sheet clamp member 412 is held at a position rotated upward as shown in FIG. 8A so that the sheet S can be received while the offset roller 407 is reversely rotated. Further, when the sheet S is moved in the width direction together with the offset roller 407 in order to align the rear end of the sheet, the sheet clamp member 412 does not become a load of movement of the sheet S as shown in FIG. Is held at a position rotated upward.

  In FIG. 5, the sheet bundle discharge member 413 discharges the processed sheet bundle to the stack tray 421. The sheet bundle discharge member 413 holds the sheet clamp member 412 in a freely rotatable manner, and holds the aligned sheet bundle or the aligned and stapled sheet bundle by the stapler unit 420 by the sheet clamp member 412. In this state, as shown in FIG. 9, it moves in the direction of the stack tray 421 provided on the downstream side of the processing tray 410.

  Further, after this, when the leading end of the processing tray 410, which is the sheet discharge position indicated by the solid line in FIG. 9, is reached, the holding of the sheet bundle SA by the sheet clamp member 412 on the stack tray 421 is released, and the sheet bundle SA is stacked. The paper is discharged to the tray 421.

  As shown in FIG. 5, when the power of the sheet bundle discharge motor 430 is transmitted through the rack and the pinion, the sheet bundle discharge member 413 has a position for discharging the sheet to the stack tray 421 and the vicinity of the rear end stopper 411. It is designed to reciprocate between the home position. The sheet bundle discharge member 413 is normally fixed at the home position by excitation of the sheet bundle discharge motor 430.

  In FIG. 5, the clamp solenoid 434 rotates the sheet clamp member 412. The clamp solenoid 434 is turned on when the rotation is stopped after the offset roller 407 conveys the sheet and when the offset roller 407 moves in the sheet width direction, and rotates the sheet clamp member 412 upward via the lever 434a. It is supposed to be moved.

  When the alignment processing for the designated number of sheets is completed, the clamp solenoid 434 closes the sheet clamp member 412 and causes the sheet clamp member 412 to hold the sheet bundle.

  FIG. 13 is a block diagram illustrating a configuration of a control unit of the sheet post-processing apparatus 400. The CPU 100 has a ROM 110 therein, and programs and the like corresponding to control procedures shown in FIGS. 14 and 15 described later are stored in the ROM 110. The CPU 100 controls each unit while reading this program.

  Further, the CPU 100 has a RAM 121 in which work data and input data are stored, and the CPU 100 performs control with reference to data stored in the RAM 121 based on the program. Further, each sensor such as an inlet sensor 403 and a sheet bundle discharge sensor 415 is connected to the input port of the CPU 100. The CPU 100, based on the state of these sensors, conveys the conveyance motor 431 connected to the output port according to the program. Each load of the offset motor 432, the sheet bundle discharge motor 430, the pickup solenoid 433, the clamp solenoid 434, and the like is controlled.

  In addition, the CPU 100 includes a serial interface unit (I / O) 130. When the CPU 100 exchanges control data with the image forming apparatus main body 500 (control unit thereof), the serial interface unit (I / O) 130 is provided. Each unit is controlled based on control data sent from the image forming apparatus main body 500 (control unit thereof).

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

  Whenever the sheet S is discharged from the image forming apparatus main body 500, the control unit (CPU 100) of the sheet post-processing device 400 grasps the size of the sheet S and controls the offset motor 432, thereby controlling the sheet of the offset roller 407. The offset roller 407 is controlled so as to move away from the sheet to a position corresponding to the contact position where the offset roller contacts. As a result, the offset roller 407 contacts the sheet when moved by an amount corresponding to the width of the sheet discharged onto the processing tray 410, and moves the sheet S by moving by a preset sheet width. It abuts against the side end positioning wall 416. Further, the CPU 100 moves the offset roller 407 by a substantially constant amount in the direction of the side end positioning wall 416 regardless of the sheet width, thereby correcting the skew in the width direction of the sheet by forming a loop on the end surface of the sheet S. .

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

  In the following description of the flowchart, it is assumed that the sheet is conveyed based on the center reference described above.

  First, when an image forming operation by the image forming apparatus main body 500 is started, the CPU 100 (see FIG. 13) of the sheet post-processing apparatus 400 checks whether a sheet discharge signal is received from the image forming apparatus main body 500 (see FIG. 13). S100). At this time, the offset roller 407 stands by at a center position that matches the center reference of the conveyed sheet. This position is called a standby position. A position where the offset roller 407 contacts the sheet is referred to as a contact position. A position at a distance X from the side edge Sa of the sheet in FIG. The standby position and the contact position may be the same or different.

  Here, when the sheet discharge signal is received (YES in S100), the CPU 100 turns on the pickup solenoid 433 (see FIG. 4) (S110), pulls up the offset roller 407 supported by the offset roller arm 406, The offset motor 432 is moved to a contact position (see FIGS. 6A and 10) according to the sheet size. FIG. 10A shows an example in which the standby position of the offset roller 407 matches the contact position. FIG. 10B shows an example in which the width of the sheet is larger than that in FIG. 10A. When the offset roller 407 moves by a distance Z from the standby position indicated by the broken line, the offset roller 407 starts from the side edge Sa of the sheet. It moves to the contact position which is the position of the distance X. FIG. 10C shows an example in which the sheet width size is larger than that in FIG. 10B. The offset roller 407 has a longer distance Z from the standby position indicated by the broken line than in the case of FIG. Is moved from the side edge Sa of the sheet to a contact position at a distance X.

  Next, the CPU 100 turns on the conveyance motor 431 (see FIG. 4) (S120), and the conveyance roller 405 installed in the middle of the pass can convey the sheet in the same direction as the paper discharge direction of the image forming apparatus main body 500. Like that. When the leading edge of the first sheet passes through the inlet sensor 403 (see FIG. 3) and turns on the inlet sensor 403 (YES in S130), the first sheet reaches the conveying roller 405 and is conveyed from the conveying roller 405. In response to the force, the image forming apparatus main body 500 leaves the sheet discharge unit 208 (see FIG. 1) (YES in S140) and is passed to the sheet post-processing apparatus 400.

  Next, the CPU 100 conveys the sheet to the processing tray 410 by the conveying roller 405 and turns off the pickup solenoid 433 before the sheet is completely removed from the conveying roller 405 (S150), and sets the offset roller 407 under its own weight. Land on top. Thereafter, as shown in FIG. 6A, the CPU 100 controls the transport motor 431 to transport the sheet S to a predetermined position downstream in the sheet transport direction by the offset roller 407 (S160). When the sheet S is conveyed to a predetermined position on the downstream side in the sheet conveying direction (YES in S160), the CPU 100 stops the rotation of the conveying motor 431 (S170) and stops conveying the sheet S.

  Next, the CPU 100 turns on the clamp solenoid 434 when the rotation of the offset roller 407 stops (S180), and as shown in FIG. 6B, the sheet clamp member installed near the rear end stopper 411. Open 412. Thereafter, the CPU 100 controls the rotation of the transport motor 431 in the direction opposite to the transport direction, and pulls back the sheet S from the predetermined position downstream in the sheet transport direction to the upstream side by the offset roller 407 (S190). The end is brought into contact with the rear end stopper 411.

  Note that the rotation amount of the offset roller 407 when the trailing edge of the sheet abuts against the trailing edge stopper 411 takes into account the skew of the sheet S that occurs when the sheet S is fed from the image forming apparatus main body 500. It is set so that the sheet can be conveyed a little more than the distance from the switchback point where the conveyance to the downstream side in the sheet conveyance direction is stopped and the upstream side is pulled back to the rear end stopper 411.

  Next, the CPU 100 checks the sheet size to be discharged based on the size information from the image forming apparatus main body 500 (S200), and the distance Y from the sheet side end to the side end positioning wall 416 is determined according to the discharged sheet size. Then, an offset movement amount is calculated by adding the distance α (not shown) for forming a loop on the sheet (S210).

  Then, the CPU 100 controls the offset motor 432 (see FIG. 4), and moves the offset roller 407 to the side end positioning wall 416 through the pinion 423 and the rack 424 as shown in FIG. The offset is moved (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 toward the side end positioning wall 416 by the frictional force of the offset roller 407.

  At this time, the sheet clamp member 412 is rotated upward as shown in FIG. 8B so as not to be a load of movement of the sheet S. Further, even if the sheet clamp member 412 is directed upward, it does not interfere with the offset roller 407 and the offset roller arm 406.

Next, the offset roller 407 moves by a distance α while slightly sliding on the sheet S ( S220 ) even after the sheet S is abutted against the side edge positioning wall 416, and loops on the side edge of the sheet S. Form. Further, the offset roller 407, the upper take the slope 700a of the offset roller unit 435 is the sheet pressing member 700 by moving the side end positioning wall 416 direction Ri, separated from the sheet S. Further, almost simultaneously with the separation, the sheet pressing member 700 receives the weight of the offset roller unit 435 and presses the sheet to the processing tray 410. As a result, the sheet S is released from the loop while being pressed against the processing tray 410 by the sheet pressing member 700, and the alignment of the side edges of the first sheet S is completed.

  Next, when the alignment of the first sheet S is completed in this way, the CPU 100 turns on the pickup solenoid 433 (see FIG. 4) (S240), and moves the offset roller 407 as shown in FIG. After lifting, the clamp solenoid 434 (see FIG. 5) is turned off (S250). As a result, the sheet clamp member 412 is closed as shown in FIG. 7B, and the aligned sheet S is sandwiched and held on the processing tray 410. As a result, it is possible to prevent the sheet S discharged first from being transported downstream in the sheet conveyance direction by the next discharged sheet.

  Next, the CPU 100 controls the offset motor 432 so that the offset roller 407 lifted by the pickup solenoid 433 is in the standby position described in (S100) as shown in FIG. 7B. Return to the home position (S260).

  Thereafter, the CPU 100 checks whether or not the sheet S accommodated on the processing tray 410 is the last sheet corresponding to the last page of the copy original (S270), and the information sent from the image forming apparatus main body 500 is checked. If it is determined that the sheet S is not the final sheet S (NO in S270), the process returns to S100 to receive a sheet discharge signal sent from the image forming apparatus main body 500, and the last sheet S is stored in the processing tray 410. The above flow is repeated until it is done.

  Thus, each time the sheet S is discharged from the image forming apparatus main body 500, the control unit (CPU) of the sheet post-processing apparatus 400 grasps the width size of the sheet S and is suitable for the offset standby position for the sheet S. And the offset amount can be calculated, and the sheet S in contact with the offset roller 407 can be fed to the side end positioning wall 416 by feeding a substantially constant amount regardless of the sheet size.

  On the other hand, when the CPU 100 determines that the sheet is the final sheet (YES in S270), a sheet bundle corresponding to the copy document is formed on the processing tray 410, and therefore whether or not the stapling process is selected next. (S280), if it is selected (YES in S280), the staple unit 420 is driven to execute the stapling process (S290).

  Next, when the staple process is not selected (NO in S270) or after the staple process is completed, the CPU 100 controls the sheet bundle discharge motor 430 (see FIG. 5) to grip the sheet bundle with the sheet clamp member 412. The sheet bundle discharging member 413 (see FIGS. 5 and 9) is advanced toward the stack tray 421 to discharge and move the sheet bundle SA (S300).

  The CPU 100 operates the clamp solenoid 434 to release the grip of the sheet bundle by the sheet clamp member 412, discharges the sheet bundle to the stack tray 421 (S310), controls the sheet bundle discharge motor 430, and controls the sheet. The bundle discharging member 413 is returned to the home position (S320). Further, after that, the CPU 100 stops the conveyance motor 431 (S330) and turns off the pickup solenoid 433 (S340) to stop the rotation of the conveyance roller 405 and the offset roller 407, and lowers the offset roller 407. Terminate the process.

  In this embodiment, the CPU performs control while the CPU reads the program written on the RAM (or ROM) shown in the flowcharts of FIGS. 14 and 15, but the hardware performs the processing on the control program. Even if configured, the same effect can be obtained.

  In this embodiment, the sheet pressing member 700 presses the sheet against the processing tray 410 at almost the same timing as the offset roller 407 moves away from the sheet, but the inclined surface 700a of the sheet pressing member 700 is used. Of course, the offset roller 407 may be separated from the sheet after the sheet pressing member 700 is pressed by the offset roller unit 435 (see FIG. 4) by changing the shape of the sheet.

  As described above, in the sheet post-processing apparatus 400, the offset roller 407 that conveys the sheet contacts the upper surface of the sheet and moves the sheet in a direction that intersects the sheet conveying direction of the image forming apparatus A, so Abutting and forming a loop to correct the skew of the side edge of the sheet, and further moving in the same direction, climbing on the floating piece 700c (slope 700a) of the sheet pressing member 700, separating from the sheet, The loop of the sheet is released. Further, when the offset roller 407 rides on the inclined surface 700 a of the sheet pressing member 700, the sheet pressing member 700 presses the sheet against the processing tray 410 almost simultaneously with the release of the sheet loop.

  In (S110) of the above flowchart, the offset roller 407 is moved to the contact position. However, the offset roller 407 is not moved to the contact position and is kept at the standby position, and the contact position is calculated in (S210). May be.

  In the sheet post-processing apparatus 400 according to the above embodiment, the offset roller 407 forms a loop on the sheet, and the sheet pressing member 700 puts the sheet on the processing tray 410 at almost the same timing as the offset roller 407 moves away from the sheet. When the offset roller 407 does not need to be separated from the sheet, such as when the loop is not generated or when the loop is small, as shown in FIGS. For example, a sheet pressing member 710 may be used.

  The sheet pressing member 710 is provided on a support shaft 711 provided on a fixing member (not shown) so as to be rotatable in the sheet conveying direction. The sheet pressing member 710 also has a guide surface 710 d for guiding the sheet between, for example, a pressing piece 710 b and a processing tray 410, which is a pressing portion that presses the sheet by its own weight. Note that the offset roller 407 may be provided to be rotatable with respect to the shaft 406a.

  Hereinafter, the operation will be described focusing on the sheet pressing member 710. The sheet discharged onto the processing tray 410 is conveyed to the stack tray side by an offset roller 407 that rotates in the sheet conveying direction as shown in FIG. 18A, and then as shown in FIG. 18B. 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 abutted against the trailing edge stopper 411 to be aligned.

  Then, as shown in FIG. 18C, the offset roller 407 is moved to the side end positioning wall 416 side along the shaft 406a while being grounded to the sheet S. The portion moves along the guide surface 710d of the sheet pressing member 710 and is pressed by the side end positioning wall 416 while being pressed against the pressing piece 710b of the sheet pressing member 710, and the sheet S is aligned in the width direction. . By installing the sheet pressing member 710 in this way, it is possible to always press the sheet at the time of alignment in the width direction of the sheet, so that the fluctuation of the sheet at the time of alignment is reduced and the alignment of the sheet bundle is improved. Can do.

  As shown in FIG. 19A, after the offset roller 407 is lifted by the pickup solenoid 433 shown in FIG. 4, the aligned sheet S is moved by the sheet clamp member 412 as shown in FIG. I try to hold it from above. As a result, the sheet S previously discharged to the processing tray 410 can be held at a predetermined position without being affected by the subsequent feeding by the sequentially fed sheets S. .

  The sheet clamp member 412 rotates upward as shown in FIG. 20 (a) so that the sheet S can be received when the offset roller 407 is reversely rotated to align the end portion. When the sheet S moves in the width direction together with the offset roller 407, the sheet S is rotated upward as shown in FIG.

  As shown in FIG. 9, the sheet clamp member 412 holds the aligned sheet bundle, or another sheet provided on the downstream side of the processing tray 410 while holding the stapled sheet bundle after alignment. It is conveyed in the direction of the stack tray 421 which is a stacking means.

  Further, after this, when the leading end of the processing tray 410, which is the sheet discharge position indicated by the solid line in the figure, is reached, the holding of the sheet bundle SA by the sheet clamp member 412 on the stack tray 421 is released, and the sheet bundle SA is stacked. The paper is discharged to the tray 421.

  As described above, the sheet pressing member 710 can always press the sheet at the time of alignment in the width direction of the sheet, so that the sheet is not disturbed at the time of alignment and the alignment of the sheet bundle can be improved. .

As described above, when the sheet post-processing apparatus includes the sheet pressing member 710, the sheet pressing member 710 guides the side end portion of the sheet that is moved by the offset roller 407 by the guide surface 710d formed on the sheet pressing member 710. Therefore, even for a curled sheet, the sheet is guided by the guide surface 710d to enter the lower portion of the sheet pressing member 710, and is pressed against the processing tray 410 by the sheet pressing member 710. The sheet can be brought into contact with the side end positioning wall 416 in a flat state, and the sheet side end alignment accuracy can be improved. Note that the sheet post-processing apparatus also has the same effect when it includes the sheet pressing member 700 described above.

  In the description so far, the side edge of the sheet is positioned after the upstream end of the sheet is brought into contact with the sheet trailing end stopper 411 by the offset roller 407. However, the pressing member 710 described above is used. In the case where the sheet is positioned, the offset roller 407 abuts the side end of the sheet against the side end positioning wall 416 and positions the side end of the sheet, and then the upstream end of the sheet abuts against the sheet trailing end stopper 411. The same effect can be obtained when the CPU of the control unit controls the sheet processing operation of the offset roller or the like.

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

FIG. 3 is a cross-sectional view of the image forming apparatus including the sheet post-processing apparatus according to the embodiment of the present invention along the sheet conveying direction. FIG. 2 is a cross-sectional view along the sheet conveyance direction in the sheet post-processing apparatus of FIG. 1. It is a figure which shows a mode that a sheet | seat is discharged to the processing tray of the sheet | seat post-processing apparatus of FIG. FIG. 2 is a schematic plan view of a driving mechanism portion of an offset roller and a conveyance roller of the sheet post-processing apparatus of FIG. 1. FIG. 2 is a schematic front view of a drive mechanism for an offset roller, a conveyance roller, a sheet bundle discharge member, and a sheet clamp member of the sheet post-processing apparatus of FIG. 1. FIG. 2 is a diagram for explaining the operation of an offset roller and the accompanying movement of the sheet in the sheet post-processing apparatus of FIG. 1. (A) It is a figure which the offset roller is conveying the sheet | seat downstream. FIG. 6B is a diagram illustrating that the offset roller conveys the sheet to a predetermined position on the downstream side and then conveys the sheet toward the sheet trailing edge stopper. (C) It is a figure which the offset roller is conveying the sheet | seat toward the side end positioning wall. FIG. 2 is a diagram for explaining the operation of an offset roller and the accompanying movement of the sheet in the sheet post-processing apparatus of FIG. 1. (A) It is a figure of the state which left | separated from the sheet | seat after the offset roller butted the sheet | seat on the side end positioning wall. (B) It is a figure of the state which an offset roller returns to a standby position. FIG. 8 is a diagram for explaining the operation of the sheet clamp member in the sheet post-processing apparatus of FIG. 1. (A) It is a figure which shows the position of a sheet clamp member when an offset roller abuts a sheet | seat on a sheet | seat trailing edge stopper. (B) It is a figure which shows the position of a sheet clamp member when an offset roller abuts a sheet | seat on a side end positioning wall. FIG. 2 is a diagram illustrating a state in which a sheet bundle discharge member discharges a sheet bundle to a stack tray in the sheet post-processing apparatus of FIG. 1. The figure shows a case where the standby position of the offset roller with respect to the sheet fed to the sheet post-processing apparatus with the sheet width center aligned with the width center of the conveyance path is set at a position away from the side edge of the sheet. is there. (A) It is a figure when the width | variety of a sheet | seat is narrow. (B) It is a figure when the width | variety of a sheet | seat is wider than (a). (C) It is a figure that the width | variety of a sheet | seat is wider than (b). FIG. 10 is a diagram when the standby position of the offset roller with respect to a sheet fed to the sheet post-processing apparatus with the side edge of the sheet aligned with one side of the conveyance path is set at a position away from the side edge of the sheet. (A) It is a figure when the width | variety of a sheet | seat is narrow. (B) It is a figure when the width | variety of a sheet | seat is wider than (a). (C) It is a figure when the width | variety of a sheet | seat is wider than (b). FIG. 5 is a view corresponding to a view of FIG. 4 viewed from the left side, and is a view showing a relationship between an offset roller unit and a sheet pressing member. It is a block diagram which shows the structure of the control part of a sheet | seat post-processing apparatus. 6 is a flowchart for explaining a part of the sheet processing operation of the sheet post-processing apparatus. It is a flowchart following FIG. It is a schematic plan view of the drive mechanism part of the sheet | seat pressing member of another embodiment, an offset roller, and a conveyance roller. It is a figure which shows the relationship between the sheet | seat pressing member and offset roller unit of other embodiment. FIG. 10 is a diagram for explaining the operation of the offset roller and the accompanying sheet movement in the sheet post-processing apparatus including another sheet pressing member. (A) It is a figure which the offset roller is conveying the sheet | seat downstream. FIG. 6B is a diagram illustrating that the offset roller conveys the sheet to a predetermined position on the downstream side and then conveys the sheet toward the sheet trailing edge stopper. (C) It is a figure which the offset roller is conveying the sheet | seat toward the side end positioning wall. FIG. 19 is a diagram for explaining the operation of the offset roller and the accompanying sheet movement in the sheet post-processing apparatus of FIG. 18. (A) It is a figure of the state which left | separated from the sheet | seat after the offset roller butted the sheet | seat on the side end positioning wall. (B) It is a figure of the state which an offset roller returns to a standby position. FIG. 19 is a diagram for explaining the operation of the sheet clamp member in the sheet post-processing apparatus of FIG. 18. (A) It is a figure which shows the position of a sheet clamp member when an offset roller abuts a sheet | seat on a sheet | seat trailing edge stopper. (B) It is a figure which shows the position of a sheet clamp member when an offset roller abuts a sheet | seat on a side end positioning wall. It is a schematic perspective view of the conventional sheet post-processing apparatus.

Explanation of symbols

A Image forming apparatus S Sheet SA Sheet bundle 100 CPU
200 Printer unit (image forming means)
300 Automatic document feeder 400 Sheet post-processing device (sheet processing device)
401 Sheet receiving portion 407 Offset roller (moving means)
410 Processing tray (loading means)
411 Sheet rear end stopper (upstream side positioning means)
412 Sheet clamp member 416 Side end positioning wall (side end positioning means)
420 Stapler unit 500 Image forming apparatus main body 700 Sheet pressing member (pressing means)
700a Slope 700b of sheet pressing member 700c Pressing piece 700c Floating piece (floating part)
700d Guide surface 710 Sheet pressing member (pressing means)
710b Pressing piece 710d Guide surface 711 Support shaft

Claims (8)

A stacking means on which sheets are stacked;
A moving means for moving the sheet in a direction in contact with the surface of the sheet stacked on the stacking means and intersecting the sheet conveying direction;
And the side edge positioning means for receiving the side edge of the sheet canceller moved in the intersecting direction by the moving means,
A pressing means disposed in the vicinity of the side end positioning means so as to be able to contact and separate from the loading means,
The pressing unit includes a pressing unit that presses a side end of the sheet received by the side end positioning unit in the stacking unit direction, and a side end of the sheet that is moved by the moving unit and the stacking unit. A guide surface for guiding between the means and
The moving means moves a side edge of the sheet along the guide surface between the pressing portion and the stacking means, and moves the side edge of the sheet pressed by the pressing portion to the side edge. A sheet processing apparatus, wherein the sheet processing apparatus is pressed against positioning means . Said pressing means, have a slope portion for separating said moving means from the sheet by riding up said moving means,
The moving means moves in the intersecting direction to move the sheet in the intersecting direction, presses the side end portion of the sheet against the side end positioning means, and then moves the sheet while moving in the intersecting direction. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is separated from the sheet by riding on a slope portion . An upstream end positioning unit that is provided upstream of the moving unit in the sheet conveyance direction and receives and positions an upstream end of the sheet in the sheet conveyance direction;
Said moving means, after positioning the upstream end of the sheet upstream edge of the sheet is brought into contact with the upstream end positioning means, according to claim, characterized in that positioning the side edge of the sheet on the side end positioning means 1 Or the sheet processing apparatus of 2. 4. The sheet processing according to claim 1, wherein the moving unit is a roller capable of forward and reverse rotation, and the sheet stacked on the stacking unit can be discharged in a sheet conveying direction. 5. apparatus. Contact position of said moving means in contact with the sheet, any of claims 1 to 4, characterized in that it is set to a predetermined distance away from the side edge of the sheet which is brought into contact with the side end positioning means The sheet processing apparatus according to claim 1. When the sheet is conveyed with respect to the said side edge, the contact position of the moving means in contact with the sheet, 1 to claim, characterized in that it is set to the same distance away from the side edge of the sheet the sheet processing apparatus according to any one of 4. When the distance between the side end positioning means and the side edge of the sheet differs by the sheet,
The contact position of the moving means that comes into contact with the sheet is set at a position farther from the side end positioning means as the distance between the side end positioning means and the side end of the sheet is wider. Item 6. The sheet processing apparatus according to Item 5 . Image forming means for forming an image on a sheet;
A sheet processing apparatus for processing a sheet on which an image is formed by the image forming unit,
The sheet processing apparatus, an image forming apparatus which is a sheet processing apparatus according to any one of claims 1 to 7.

Images