Patent Publication Number: US-6661995-B2

Title: Sheet processing apparatus and image forming apparatus provided with the same

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a sheet processing apparatus in which jam processing or staple replacement is easy and cost may be reduced and an image forming apparatus provided with this. Also, the invention relates to a sheet processing apparatus in which stapler means may readily be removed and an image forming apparatus provided with this. In particular, the present invention relates to means for performing a stapling process to sheets on which an image has been formed. 
     2. Related Background Art 
     In some cases, a conventional image forming apparatus such as a copying machine, a printer and a facsimile machine is provided with a sheet processing apparatus for picking up sheets on which an image has been formed one by one and a stapling process is performed to the sheets in order to reduce time and labor to be needed for stapling the sheets such as pieces of copying paper on which an image has been formed. 
     There is known a type of such a sheet processing apparatus, which is provided on a side surface of the sheet discharge port side of the image forming apparatus body, aligns the sheets that were printed in the image forming apparatus before being fed from the discharge port, thereafter performs the stapling process, and discharges the sheets. 
     Also, in general, a stapling mechanism section for performing the above stapling process is located in an interior of an outer shell of the sheet processing apparatus. Such a type is known in which, in the case where the jam processing or the staple replacement is to be performed in the stapling mechanism section, an outer shell lid is opened and the jam processing or the staple replacement is performed. 
     However, in the sheet processing apparatus having the stapling function, since the stapling mechanism is arranged in the interior of the outer shell of the sheet processing apparatus, the user has to perform the jam processing or the staple replacement by actually opening the outer shell lid upon the jam processing or the staple replacement in the stapler section. 
     Also, in the sheet processing apparatus having such a staple function, since the stapler is fixed by screws to the interior of the outer shell of the sheet processing apparatus, it is necessary to remove the stapler after removal of the screws by opening the outer shell lid upon the stapler replacement or, depending upon the situation, even in the case of the jam processing or the staple replacement. 
     For this reason, a large number of time and labor are required by the user upon the jam processing or the staple replacement and the manipulation property is inferior due to the processing in the interior of the outer shell. Also, since the lid is provided on the outer shell, the structure is complicated to increase the cost, disadvantageously. 
     SUMMARY OF THE INVENTION 
     Accordingly, in view of the above-described situation, an object of the present invention is to provide a sheet processing apparatus in which the jam processing or the staple replacement is easy and the cost therefor may be reduced and an image forming apparatus provided with the sheet processing apparatus. 
     Also, an object of the present invention is to provide a sheet processing apparatus in which a stapler (stapler means) may be removed with ease and an image forming apparatus provided with the sheet processing apparatus. 
     According to the present invention, there is provided a sheet processing apparatus provided with stapler means for performing a stapling process to a sheet bundle, characterized in that the stapler means comprises a detachably mountable staple cartridge, and a cover that forms an outer appearance of the stapler means and serving also as an outer shell of the sheet processing apparatus, and the stapler means is provided in an apparatus body selectively movably between a stapling position for stapling the sheet bundle and a position for replacing the staple cartridge. 
     Further, according to the present invention, there is provided a sheet processing apparatus provided with stapler means for performing a stapling process to a sheet bundle, characterized in that the stapler means is detachably mounted on the apparatus body and provided movably to a position where the stapler means is removable. 
     Further, the present invention is characterized in that the stapler means is held with a constant force in each position of the position for stapling the sheet bundle and the position for replacing the staple cartridge. 
     Further, the present invention is characterized in that the stapler means is held with a constant force in the position for stapling the sheet bundle. 
     Further, the present invention is characterized in that the stapler means is held in the two positions with a constant force when the stapler means is located in the position for stapling the sheet bundle and in the position where the stapler means is removable. 
     Further, the present invention is characterized in that the stapler means is provided rotatably to the apparatus body. 
     The present invention further comprises holding means provided in the stapler means for holding the stapler means detachably to the apparatus body, characterized in that the holding means is in the condition that the stapler means may be removed from the apparatus body when the stapler means is moved to the position where the stapler means is removable. 
     Further, the present invention is characterized in that the holding means is a shaft member that is engaged elastically with the apparatus body for holding the stapler means and that, when the holding means is moved to the position where the stapler means is removable, is operable to release the elastic engagement with the apparatus body and to move to the position where the stapler means is removable. 
     Further, the present invention is characterized in that the shaft member is provided in a position where the shaft member is not visible from the outside until the stapler means is moved to the removable position. 
     The present invention further comprises mounting guide means for guiding the stapler means to a predetermined held position of the apparatus body, characterized in that the holding means is a shaft for guiding the stapler means along the mounting guide section to the predetermined held position and for pivotally supporting the stapler means movably between the position for stapling the sheet bundle and the removable position in the predetermined held position and is operable to remove the stapler means along the mounting guide section from the apparatus body when the stapler means is moved to the removable position. 
     Further, the present invention is characterized in that a cutaway portion if formed for removing the stapler means away from the apparatus body along the mounting guide section when the stapler means is moved to the removable position. 
     Further, the present invention is characterized in that a jam process cover is provided and, in the case where the jam process cover is opened or in the case where the stapler means is not in the stapling position for stapling the sheet bundle, the stapler means is inoperative. 
     Further, the present invention is characterized in that the stapler means and the apparatus body are connected to each other through an electric cable connector, and a connector for the stapler means and a connector for the apparatus body are detachably mountable. 
     Further, the present invention is characterized in that the stapler means is provided with a connector connected to the connector on the side of the apparatus body and provided retractably to the apparatus body, and the stapler means is removed while drawing the connector on side of the apparatus body when the stapler means is to be removed. 
     The present invention is characterized by further comprising return means for returning the connector on the side of the body removed from the stapler means to the apparatus body after the stapler means has been removed. 
     The present invention further comprises a sheet stacking section for stacking the sheet bundle to which the stapling process is performed; and alignment means for performing alignment of the sheet stacked on the sheet stacking section, characterized in that the alignment operation is possible by the alignment means when the apparatus body side connector is removed from the stapler means that has been removed. 
     According to the present invention, there is provided an image forming apparatus provided with an image forming section and a sheet processing apparatus for performing stapling process to a sheet on which an image is formed by the image forming section, characterized in that the sheet processing apparatus is produced in accordance with any one of the above descriptions. 
     Further, the present invention is characterized in that the sheet processing apparatus is disposed above the image forming apparatus body. 
     The present invention further comprises a paper feed cassette received detachably in the image forming apparatus body and an operation section provided in the image forming apparatus body, characterized in that a sheet conveying direction in the stapler means of the sheet processing apparatus and any one of a mounting direction of the paper feed cassette and a direction toward the operating section are the same. 
     Further, the present invention is characterized in that, when the stapler means of the sheet processing apparatus is in a staple cartridge replacement position, the staple cartridge replacement direction is in a direction close to the sheet conveying direction in comparison with the position for stapling the sheet. 
     Further, the present invention is characterized in that the stapler means is provided with a staple cartridge removal knob for removing the staple cartridge, and that the staple cartridge removal knob is visually observable in any one of the mounting direction of the paper feed cassette and a direction toward the operating section. 
     The present invention is characterized by including a first sheet stacking section for stacking tentatively the sheet on which an image is formed by the image forming section and a alignment means for performing the alignment of the sheet stacked on the first sheet stacking section. 
     As described above, according to the present invention, the cover forming the outer appearance of the stapler means is provided to serve as a part of the outer shell of the apparatus body and the stapler means is provided in the apparatus body, movably selectively in the position where the sheet bundle is bound and the position where the staple cartridges are replaced, to thereby make it possible to facilitate the jam processing or the staple replacement and to reduce the cost. 
     Also, the stapler means is maintained by the holding member so as to be detachably mounted to the apparatus body and able to move between the position where the sheet bundle may be bound and the position where the bundle may be removed. On the other hand, the holding means may perform the operation for removing the stapler means from the interior of the apparatus body when the stapler means is moved to the position where the bundle means may be removed, thereby making it possible to readily remove the stapler means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is a schematic cross-sectional view showing a whole structure of a laser beam printer that is an example of an image forming apparatus provided with a sheet processing apparatus according to a first embodiment of the present invention; 
     FIGS. 2A and 2B are views illustrating the structure of the sheet processing apparatus and motions of the respective parts in the case where a sheet conveyed from the printer body forwarded to the sheet processing apparatus; 
     FIGS. 3A and 3B are a plan view and a side elevational view of a primary part of the sheet processing apparatus; 
     FIGS. 4A and 4B are views showing a condition that the sheet bundle falls down when a slide guide provided in the sheet processing apparatus is located in a home position; 
     FIGS. 5A,  5 B and  5 C are views illustrating motions of the respective parts in a stapling operation of the sheet processing apparatus; 
     FIGS. 6A and 6B are views showing a condition where the sheets are aligned by the slide guide; 
     FIGS. 7A and 7B are views as viewed in a direction shown by an arrow A of FIG. 3A; 
     FIG. 8 is a view showing a structure of a stapler provided in the sheet processing apparatus; 
     FIG. 9 is a side elevational view of the sheet processing apparatus; 
     FIGS. 10A and 10B are views showing a staple operational position of the stapler and a rotational position thereof; 
     FIG. 11 is a perspective view showing a user access direction to the sheet processing apparatus; 
     FIGS. 12A and 12B are views showing the rotational operation of the stapler; 
     FIG. 13 is a perspective view showing a condition that a jam processing cover provided on the sheet processing apparatus is opened; 
     FIGS. 14A,  14 B and  14 C are views showing a procedure for removing the stapler; 
     FIGS. 15A and 15B are views showing a procedure after the stapler has been removed from the sheet processing apparatus; 
     FIG. 16 is a view showing a structure of a stapler section of a sheet processing apparatus according to a third embodiment of the present invention; 
     FIG. 17A is a view showing a condition of the stapler section in which a stapler is moved to the rotary position; 
     FIG. 17B is a view showing a condition of the stapler section in which a jam processing cover is opened; 
     FIGS. 18A and 18B are perspective views showing a sheet processing apparatus in accordance with a fourth embodiment of the present invention; 
     FIG. 19 is a view showing a structure of a driver section of the stapler provided in the sheet processing apparatus; 
     FIGS. 20A and 20B are views showing a rotational operation a stapler in a sheet processing apparatus in accordance with a fifth embodiment of the present invention; 
     FIGS. 21A and 21B are views showing the operation for removing the stapler; 
     FIGS. 22A and 22B are views showing a procedure after the stapler has been removed away from the sheet processing apparatus body; 
     FIGS. 23A,  23 B and  23 C are views showing a stapler removal operation in a sheet processing apparatus in accordance with a sixth embodiment of the present invention; and 
     FIGS. 24A and 24B are views showing a procedure after a stapler has been removed away from the sheet processing apparatus. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present invention will now be described in detail with reference to the accompanying drawings. 
     FIG. 1 is a schematic cross-sectional view showing a whole structure of a laser beam printer that is an example of an image forming apparatus provided with a sheet processing apparatus according to a first embodiment of the present invention. 
     In FIG. 1, symbol  100 A denotes a laser beam printer and reference numeral  100  denotes a laser beam printer body (hereinafter referred to as a printer body). The laser beam printer  100 A is connected independently to a computer or a network such as a LAN, forms an image (print) on a sheet by a predetermined image forming process on the basis of a print signal, image information or the like fed from the computer or the network and discharges the sheet. 
     Also, reference numeral  300  denotes a sheet processing apparatus. This sheet processing apparatus  300  is arranged on the upper portion of the printer body  100  and is adapted to stack sheets discharged from the printer body  100  to the outside on a first stacking section  300 B with their image surface in face down through a conveyer section within the sheet processing apparatus, and then align the sheets by a alignment means  301  to be described later. The sheet processing apparatus  300  bundles the sheets for every predetermined job, staples the sheets at one position or a plurality of positions, and discharges and stacks the sheets onto a second stacking section  325 , or discharges and stacks the sheets simply in a face down manner onto the second stacking section  325 . 
     In this case, the sheet processing apparatus  300  and the printer body  100  are electrically connected to each other through a cable connector (not shown). Also, the sheet processing apparatus  300  has a casing portion  300 A for receiving the respective parts and is adapted to be detachably mountable to the printer body  100 . 
     With respect to the structure of each part of the printer body  100 , the conveying path of a sheet S to be delivered will now be described. 
     In the printer body  100 , a plurality of sheets S are laid within a feeding cassette  200  so that the uppermost sheet S 1  may be separated and conveyed one by one by various rollers. In the sheet S that has been conveyed from the feeding cassette  200 , a toner image is transferred to a top surface in an image forming section  101  for forming a toner image by a so-called laser beam type image forming process, and subsequently heat or pressure is applied in a fixing device  120  on a downstream side in accordance with a predetermined print signal that has been fed from the computer or the network, to thereby permanently fix the toner image. 
     Subsequently, the sheet S on which the image has been fixed is folded back in a substantially U-shaped conveying path to discharging rollers  130  so that the image surface of the sheet S is turned over. Thus, the sheet is discharged in the face down manner from the printer body  100  under the condition that the image surface faces downwardly. 
     In this case, the sheet S is selected to be discharged to a face down (FD) discharging section  125  provided in an upper portion of the printer body  100  by, for example, the discharging rollers  130 , or to be discharged to the second stacking section  325  of the sheet processing apparatus  300 , in response to the position of a flapper  150  of the printer body  100  which rotates on the basis of a control signal from the control section (not shown). 
     The operation of the sheet processing apparatus  300  and each section in the case where the sheet S that has been conveyed from the sheet processing apparatus  300  and the printer body  100  is conveyed toward the sheet processing apparatus  300  will now be described with reference to FIGS. 2A,  2 B,  3 A and  3 B. 
     In FIGS. 2A and 2B, symbol  330   a  denotes an sheet discharging upper roller, symbol  330   b  denotes a sheet discharging lower roller, symbol M denotes a jogger motor as a drive source, reference numeral  322  denotes a paddle, and reference numeral  323  denotes a reference wall against which the sheet rear end is to be abutted. In this case, as shown in FIGS. 2A and 2B, the pair of the discharging rollers  330  composed of the sheet discharging upper roller  330   a  and the sheet discharging lower roller  330   b  is arranged on the upper side on the downstream side in the sheet conveying direction of the above-described flapper  150 , and is rotatably driven by a drive motor (not shown). 
     Also, the sheet discharging upper roller  330   a  is pivotally supported to an arm  330   c  rotatable about a paddle shaft  350 . The jogger motor M is a motor for driving each slide guide  301  and  302  to be described later. In this embodiment, a stepping motor is used as the jogger motor M. 
     Also, a plurality of paddles  322  are made of elastic material such as rubber and fixed to the paddle shaft  350  in a direction perpendicular to the sheet conveying direction. Then, when the sheet is discharged from the printer body  100 , the paddles are rotated clockwise by the drive of the paddle shaft  350  so that the sheet S is moved in the opposite direction to the sheet conveying direction to be brought into contact with and aligned with the reference wall  323 . 
     Also, as shown in FIGS. 3A and 3B, in the sheet processing apparatus  300  according to this embodiment, the slide guide  301  and the slide guide  302  to be described in detail later are provided as alignment members for performing the alignment in a width direction of the sheet. Also, in FIGS. 3A and 3B, symbol H denotes a stapler that is a stapler means for stapling the sheet bundle thereby performing the stapling process to the sheet bundle, and the stapler H is arranged and fixed on the side of the slide guide  301  for performing the stapling at the upper left corner portion of the image surface of the sheet on which the image has been formed, thereby stapling each sheet. 
     Then, the sheet processing apparatus  300  with such a structure is adapted to perform the staple process on the basis of a command outputted from a computer or the like. In the case where such a staple process is to be performed, first of all, the flapper  150  is rotated in the counterclockwise direction by a solenoid (not shown) as shown in FIG. 2A before the sheet to be stapled is discharged by convey rollers  121  provided in the printer body  100 , so that the sheet path is switched over to the side of the sheet processing apparatus. 
     Thus, the sheet S is conveyed to the sheet processing apparatus  300  by means of the convey rollers  121 . Then, the sheet S that has been thus conveyed to the sheet processing apparatus  300  causes a flag  391  of an inlet sensor  390  to rotate clockwise so that the flag  391  causes the light to pass through a photo sensor  392  to thereby detect the passage of the sheet S. Thereafter, the sheet S is conveyed upwardly by means of a pair of inlet rollers  363 . 
     By the way, in this embodiment, this sheet processing apparatus  300  is adapted to discharge and stack the sheets onto the second stacking section  325  after stapling and also discharge and stack the sheets onto the second stacking section  325  simply in a face down manner. 
     The operation for discharging and stacking the sheet onto the second stacking section  325  in the face down manner will now be described. 
     In this case, as shown in FIG. 4A, the bottom surfaces of the slide guide  302  on the left side and the slide guide  301  on the right side to the sheet conveying direction are retracted to positions where the bottom surfaces are not brought into contact with the sheet S to be conveyed, i.e., outside positions deviated by a predetermined amount from the widthwise direction of the sheet S so as not to support the sheet S. 
     Accordingly, the sheet that has been conveyed by the pair of inlet rollers  363  is passed through the pair of the staple rollers  320 , thereafter conveyed by means of the pair of sheet discharging rollers  330  through an opening of the stapler H, and dropped toward the second sheet discharge section  325  as shown by an arrow of FIG.  4 B and shown in FIG.  2 B. 
     The operation for discharging and stacking the sheet onto the second stacking section  325  after stapling will now be described. 
     In this case, in the slide guides  301  and  302 , reference pins  303  and  304  provided on the wall surfaces of the slide guides  301  and  302  are retracted to positions so as not to interfere with the sheet S to be conveyed as shown in FIG.  3 A. 
     Also, in this case, the slide guides  301  and  302  are located in such a position that an interval of end surfaces of the bottom surfaces thereof is smaller than a width of the sheet S, and the two slide guides  301  and  302  are located in such a position so that the first stacking section  300 B for supporting the sheet S to be introduced may be formed. 
     Accordingly, the sheet that has been conveyed by the pair of inlet rollers  363  is passed through the pair of staple rollers  320 , thereafter conveyed by the pair of sheet discharging rollers  330  through the opening of the stapler H, and conveyed onto the guide surface of the first sheet stacking section  300 B constituted by the slide guides  301  and  302 . 
     In this case, as shown in FIG. 5A, the guide surface of the first sheet stacking section  300 B is slanted at a predetermined angle to the horizontal direction to form slant angles which are different between an upstream side and the downstream side in the sheet conveying direction. More specifically, a bent portion  300 C that is bent at a slant angle α between a predetermined region on the upstream side and a predetermined region on the downstream side is formed. Incidentally, there is provided such a bent portion  300 C to thereby prevent the flexure of the central portion of the sheet S that is not guided by the respective slide guides  301  and  302 . 
     On the other hand, immediately after the first sheet has been thus conveyed onto the top surface defined by the slide guide  301  and  302 , as shown in FIG. 5B, the arm  330   c  is rotated counterclockwise so that the sheet discharging upper roller  330   a  pivotally supported to the arm  330   c  is retracted upwardly to thereby space the pair of sheet discharging rollers. 
     Also, the drive connected to the pair of sheet discharging rollers  330  simultaneously therewith is interrupted and the rotation of the sheet discharging upper roller  330   a  and the sheet discharging lower roller  330   b  is stopped. As a result, when the rear end of the sheet S is completely passed through the pair of staple rollers  320 , the sheet S is returned back in the opposite direction to the conveying direction by the gravitational force and is moved in the direction toward the reference wall  323 . 
     Subsequently, only the slide guide  302  on the left side is operated, the alignment operation in the width direction of the sheet S laid on the first sheet stacking section  300 B is started. More specifically, the slide guide  302  is driven by the motor M and is moved to the right side of FIGS. 3A and 3B so that the reference pins  304  provided in the slide guide  302  are brought into contact with the left side surface of the sheet S to thereby push the sheet S on the side of the slide guide  301 . 
     Then, the right side surface of the sheets is brought into abutment with the reference pins  303  provided in the slide guide  301  to thereby perform the alignment in the widthwise direction of the sheet. The sheet S is set so that the sheet S is in contact with the reference pins  303  and brought into the staple position set in the aligned position. After the alignment, the slide guide  302  is moved in a direction of expanding wider than a width of the sheet S so as to be ready to convey the next sheet in the waiting position again. 
     The structures of the slide guides  301  and  302  will now be described in detail. 
     As is shown in FIGS. 3A and 3B, each slide guide  301 ,  302  is guided by four guide pins, which are guide pins guide pins  313   a  provided in a mold frame and  313   b  provided on a plate frame, so as to be reciprocatingly movable in right and left directions of FIGS. 3A and 3B, i.e., a direction (width direction) perpendicular to the sheet conveying direction and at the same time to be moved by the drive force from the jogger motor M. 
     Also, each slide guide  301  and  302  exhibits a U-shaped form in cross-section by each guide wall section for guiding both sides of the sheet S and support sections for supporting the top and bottom surfaces of the sheet S as shown in FIG. 3B as viewed from the downstream side in the sheet conveying direction. Each sheet to be discharged onto the first sheet stacking section  300 B by the lower surface of the U-shape is supported and the central portion in the widthwise direction of the sheet S is not supported. 
     Furthermore, a slide rack section  310  having a spur gear that is engaged with a stepped gear  317  is provided on the slide guide  302 . A slide rack  312  having a spur gear that is engaged with the stepped gear  317  is also mounted on the slide guide  301 . 
     In this case, the slide rack  312  is provided to be movable relatively to the slide guide  301  through a coil spring  314 . Incidentally, this spring  314  is brought into contact with the slide guide  302  at one end side and brought into contact with the slide rack  312  at the other end side so that the slide guide  301  and the slide rack  312  are biased in a direction of expansion. Also, the slide rack  312  has an angular hole portion  312   a  for moving an emboss portion  301   a  to the side of the slide guide  301 . 
     Furthermore, the two reference pins  303  made of metal that is superior in anti-wear property are provided on the side wall of the slide guide  301  and the two reference pins  304  are provided on the side wall of the slide guide  302 , respectively. When the sheet is aligned, as described above, the slide guide  302  is moved so that the reference pins  304  and  303  are brought into contact with both side end surfaces  305  and  306  of the sheet. 
     Also, the slide guides  301  and the slide guide  302  are supported in a height direction by the stepped gear  317  and the jog plate frame F. 
     The operation of each slide guide  301  and  302  will now be described. 
     When the power source is turned on for the sheet processing apparatus  300 , the pair of staple rollers  320  starts to rotate, and subsequently, the jogger motor M rotates to rotate the stepped gear  317  so that the slide rack section  310  of the slide guide  302  is driven to retract to the outside. 
     Also, with respect to the slide guide  301 , when the jogger motor M rotates and the stepped gear  317  rotates, first of all, the slide rack  312  is moved relatively, and the angular hole portion  312   a  of the slide rack  312  is brought into contact with the right side end surface of the emboss portion  301   a  of the slide guide  301  shown in FIGS. 3A and 3B. Thereafter, the slide guide  301  is depressed by the angular hole portion  312   a  and retracted to the outside. 
     A slit portion  301 S is provided in the slide guide  301 . When the slit portion  301 S is moved through a predetermined retracted distance, as shown in FIG. 4B, the photo sensor  316  receives light. At this time, the jogger motor M stops. This position will be hereinafter referred to as a “home position”. 
     On the other hand, when a signal for introducing the sheet S into the sheet processing apparatus  300  is inputted from the printer body  100 , the jogger motor M rotates so that the slide guides  301  and  302  are moved inwardly and stop in the position where the width between the slide guides is greater by a predetermined amount d than the width of the sheet S to be introduced as shown in FIGS. 3A and 3B. In this position, the stopper  301   b  is in contact with the guide pin  313   a  so that the slide guide  301  could not be moved further inwardly. This position will be hereinafter referred to as a “waiting position”. Incidentally, in the waiting position, the side surface of the slide guide  301  becomes the reference position of the alignment operation. 
     In this embodiment, in the case where the size (width) of the sheet S is the maximum size of the sheet that may pass through, the waiting positions of the slide guides  301  and  302  are set so that the gaps on both sides have the predetermined amounts d, d. 
     Incidentally, in the case where the sheet having a narrower width than that of the above-described sheet is to be aligned in alignment, the slide guide  302  is moved rightward corresponding to this, so that the gap on the left side in the waiting position shown in FIGS. 3A and 3B is always kept at the predetermined amount d. On the other hand, in this case, the gap between the sheet and the slide guide  302  is expanded by half the amount that becomes narrower by the predetermined amount d. 
     On the other hand, as shown in FIGS. 6A and 6B, after the completion of the alignment in the widthwise direction by the slide guides  301  and  302 , both slide guides  301  and  302  are retracted somewhat outwardly so that the limit in the alignment direction of the sheet S is kept rough and the sheet S may be moved in the sheet conveying direction. Thereafter, as shown in FIG. 5B, the paddles  322  are rotated clockwise about the paddle shaft  350  through one turn in contact with the top surface of the sheet S whereby the sheet S is brought into contact with the reference wall  323  for alignment. 
     Then, with such an operation, the alignment in the sheet conveying direction and the widthwise direction is possible. Incidentally, in order to keep such aligned condition, stamp means  400  for depressing the sheet S aligned by moving up and down a lever  400   b  provided with a frictional member  400   a  as shown in FIGS. 7A and 7B that are views as viewed in a direction indicated by an arrows A′ of FIG. 3A is provided in the vicinity of the right end surface of the sheet kept aligned as shown in FIGS. 6A and 6B. 
     In this case, the stamp means  400  is provided with the lever  400   b  that rotates in the up and down direction. After the completion of the alignment operation, the lever  400   b  that has been rotated upwardly as shown in FIG. 7B is rotated downwardly and pushes the top surface of the sheet as shown in FIG. 7A before the sheet to be introduced next is brought into contact with the aligned sheet, whereby the aligned sheet is moved by the next sheet to thereby prevent the alignment from falling into disorder. 
     Incidentally, after the completion of the alignment of the first sheet in this manner, the second sheet is conveyed. However, in this case, since the pair of discharging rollers  330  are separated during the conveyance of the second sheet and the following sheets, when the trailing end of the sheet S is completely passed through the pair of staple rollers  320 , the sheet is returned back in the opposite direction by its gravitational force and moved toward the reference wall  323 . Incidentally, the alignment operation onward is the same as that of the first sheet and the explanation therefor will be omitted. 
     Then, such an operation is repeated. The operation for aligning the last (n-th) sheet (Sn) of one job is performed. Each reference pin  304  provided in the slide guide  302  causes the left side surface of the sheet to come into contact with each reference pin  303  of the slide guide  301 . Under the condition in FIGS. 6A and 6B in which the movement of the slide guide  302  is stopped, the position on the right trailing end is stapled by the miniaturized stapler H located in the right trailing end of the sheet bundle. 
     In this case, with such a structure and such an operation, the slide guide  301  is stopped in the reference position and not moved during the alignment operation of each sheet and only the slide guide  302  is moved so that the left side end portion of each sheet is aligned in the reference position. Accordingly, the stapling process by the stapler H arranged and fixed on the side of the slide guide  301  may be performed positively and accurately. 
     Furthermore, even if there is non-uniformity in width of each sheet to be conveyed in one job or the sheet size within one job is changed, for example, from LTR to A4, since the position of the left end portion of each sheet is aligned to be constant, the finishing of the stapling process by the stapler H is correct and neat to ensure the excellent effect. 
     On the other hand, when the staple operation is thus completed, as shown in FIG. 5C, the arm  330   c  is rotated clockwise so that the sheet discharging upper roller  330   a  pivotally supported to the arm  330   c  is moved downwardly to form the pair of the sheet discharging rollers  330 , and at the same time to drive the pair of sheet discharging rollers  330  to start the rotation of the sheet discharging upper roller  330   a  and the sheet discharging lower roller  330   b . Thus, the sheet bundle S is clamped by the pair of sheet discharging rollers  330  and is conveyed onto the first stacking section  300 B formed by the slide guides  301  and  302 . 
     Then, thereafter, when the sheet bundle S is completely discharged from the pair of sheet discharging rollers  330 , the jogger motor M is drivingly rotated so that the slide guide  302  is moved in an expanding direction from the condition shown in FIGS. 6A and 6B. Incidentally, upon the start of movement of the slide guide  302 , on the side of the slide guide  301 , the slide rack  312  is moved to the right side of FIGS. 6A and 6B and the slide guide  301  per se is not immediately moved. 
     Then, when the position of the slide guide  302  has passed through the waiting position shown in FIGS. 3A and 3B, the emboss portion  312   a  of the slide rack  312  is brought into contact with the end surface of the angular hole portion  310   a  of the slide guide  301 , the slide guide  301  starts to move to the right side of FIGS. 3A and 3B and both the slide guides  301  and  302  move. 
     Furthermore, thereafter, when the distance between the two slide guides  301  and  302  becomes close to the width of the sheet or wider than the width, the sheet bundle that has been subjected to the stapling and that is supported to the slide guides  301  and  302  falls downwardly as shown in FIG. 5C to be stacked on the second stacking section  325 . The structure of the printer body and the sheet processing apparatus according to this embodiment and a series of the operation thereof have been described above. 
     The structure of the stapler H located in the right trailing end of the sheet bundle will now be described. 
     As shown in FIG. 8, the stapler H according to this embodiment is composed of a stapler body  503 , a staple cartridge  504 , and a staple cover  505  that is a cover forming an outer appearance of the stapler H. 
     Incidentally, FIG. 9 is a right side elevational view of the sheet processing apparatus  300 . As shown in FIG. 9, the staple cover  505  has a structure also serving as an outer shell of the sheet processing apparatus body  300 D. 
     Then, thus, the staple cover  505  serves also as the outer shell of the sheet processing apparatus body  300 D whereby it is unnecessary to perform the jam process or the staple replacement by actually opening the outer shell lid during the jam process or the staple replacement in the stapler section to thereby make it possible to enhance the operationability and to reduce time and labor. Also, since it is unnecessary to provide the lid on the outer shell, the structure becomes simple and the cost therefor may be reduced. 
     Incidentally, in FIG. 9, reference numeral  507  is a staple cartridge removal knob. When the staple cartridge  504  is replaced, the staple cartridge  504  is replaced after the staple cartridge removal knob  507  is drawn out. 
     Also, the stapler H is provided rotatably (movably) about the shaft  506  in the sheet processing apparatus body  300 D as shown in FIG.  10 A. Namely, the stapler H may be moved selectively between the staple operating position shown in FIG.  10 A and the rotational position shown in FIG.  10 B and may be maintained in each position by a latch mechanism (not shown) in a click-sensing manner. 
     In this case, the user access direction of the printer body  100  and the sheet processing apparatus  300  according to this embodiment is a direction indicated by the arrow A of FIG. 11 in the direction toward the operation panel  501  that is the operational section of the printer body  100  and in the direction for removing the sheet feeding cassette  502  detachably mounted on the printer body  100 . 
     Then, the position of the staple cartridge removal knob  507  in the rotational position of FIG. 10B is a position close to the direction indicated by the arrow A that is the user access direction of the sheet processing apparatus  300  in accordance with this embodiment to the position in the staple operating position shown in FIG.  10 A. Incidentally, since the staple cartridge removal knob  507  is visually observable in either direction of a direction toward the operation panel  501  shown in FIG.  11  and the removal direction of the paper feed cassette  502 , the operation is facilitated. 
     The jam process in the stapler section of the sheet processing apparatus  300  with such a structure and the operation by the user when the staples of the stapler are expended will now be described. 
     When the staples of the stapler H have been expended, the user rotates the stapler H located in the staple operating position shown in FIG. 12A about the shaft  506  directly manually from the user access side as shown in FIGS. 12A and 12B, and moves the stapler H to the rotational position shown in FIG.  12 B. 
     Incidentally, although the stapler H is held in the staple operating position with a constant force by the latch mechanism (not shown) when the stapler H is in the staple operating position, the holding force of the latch mechanism is released when the stapler H is rotated manually and moved from the staple operating position. On the other hand, thereafter, when the stapler H is rotated to the rotational position, the stapler is again held with a constant force in a click-sensing manner by the latch mechanism (not shown). 
     In this case, if the stapler H is moved to the rotational position, then the direction of the staple cartridge removal knob  507  is directed close to the user access side to the staple operating position. 
     Accordingly, the user may easily draw out the staple cartridge removal knob  507  and replace the staple cartridges, as a result of which it is possible to enhance the operationability during the staple replacement. 
     By the way, in the sheet processing apparatus  300  with such a structure, a jam processing cover  508  for jam process in the conveyer section as shown in FIG. 13 is provided. When the jam process is performed, this jam processing cover  508  is opened. 
     However, in the case where the staple cover  505  serves also as the outer shell of the sheet processing apparatus body  300 D, when the jam processing cover  508  is thus opened, since the stapling section of the stapler H is exposed, it is desirable to disable the operation of the stapler H when the jam processing cover  508  is opened. Also, even if the stapler H is moved to the rotational position as described above, since the stapling section is exposed, it is also preferable to disable the operation of the stapler. 
     The operation by the user when the staple clogging occurs in the stapler section provided with the stapler H of the sheet processing apparatus  300  with such a structure according to a second embodiment of the present invention and the stapler H is broken down will now be described. 
     In this case, the user rotates the stapler H located in the staple operating position about the shaft  506  directly manually from the user access side as shown in FIGS. 10A and 12A, and moves the stapler H to the removal position shown in FIGS. 10B and 12B. 
     Incidentally, although the stapler H is held in the staple operating position with a constant force by the latch mechanism (not shown) when the stapler H is in the staple operating position, the holding force of the latch mechanism is released when the stapler H is rotated manually and moved from the staple operating position. 
     On the other hand, thereafter, when the stapler H is rotated to the removal position, a claw portion  601  that is a shaft member including a rotary center shaft  506  (see FIG. 8) projecting from the top surface of the staple cover  505  received in the sheet processing apparatus body as shown in FIG. 10A is exposed as shown in FIG.  10 B. 
     In this case, the claw portion  601  elastically engage the rotary center shaft  506  with the sheet processing apparatus body  300 D to form a holding means for holding the stapler H to the sheet processing apparatus body  300 D. Then, when the stapler H is moved to the removal position where the stapler H may be removed, the claw portion  601  is moved to the position where the elastic engagement with the sheet processing apparatus body  300 D is released and the stapler H may be removed, i.e., the exposed position shown in FIG.  10 B. 
     Incidentally, FIGS. 14A to  14 C are views showing a procedure for removing the stapler H kept in the condition that the stapler H is rotated to the removal position. In the case where the stapler H is to be removed, first of all, the claw portion  601  that has been rotated together with the stapler H (staple cover  505 ) as shown in FIG.  14 A and exposed is depressed from above. 
     In this case, the claw portion  601  may be flexed downwardly. When the claw portion is thus depressed from above, the claw portion  601  is flexed downwardly as shown in FIG.  14 B. Thus, the rotary center shaft  506  may be removed from an upper shaft hole  602  formed in the sheet processing apparatus body  300 D. 
     Then, after the rotary center shaft  506  has been thus drawn out of the upper shaft hole  602 , the stapler H may be removed from the sheet processing apparatus body  300 D by drawing the stapler H in the direction indicated by the arrow of FIG.  14 C. 
     Thus, the stapler H is provided detachably from the sheet processing apparatus body  300 D and movably between the staple operating position where the sheet bundle is to be bundled and the removal position. On the other hand, the stapler H is held detachably to the sheet processing apparatus body  300 D by the claw portion  601  including the rotary center shaft  506 . Furthermore, when the stapler H is moved to the removal position, the claw portion  601  is operated so that the stapler H may be removed. It is thus possible to readily remove the stapler H. 
     Incidentally, in this embodiment, in the staple operating position shown in FIG.  10 A and FIG. 12A, the claw  601  is covered in the interior of the sheet processing apparatus body. Normally, the claw portion  601  is thus covered in the sheet processing apparatus body to thereby make it possible to enhance the outer appearance of the sheet processing apparatus body  300 . 
     Also, this stapler H is provided with a cable connector  603  that is electrically connected to the connector  604  on the body side provided in the sheet processing apparatus body  300 D. Then, after the stapler H has been removed, the cable connector  603  extending from the side of the stapler H that is kept in the connected condition as shown in FIG.  15 A and the connector  604  on the side of the sheet processing apparatus body are removed as shown in FIG.  15 B. 
     By the way, in the sheet processing apparatus  300  with such a structure, a jam processing cover  508  for jam process in the conveyer section as shown in FIG. 13 is provided. When the jam process is performed, this jam processing cover  508  is opened. 
     However, in the case where the staple cover  505  serves also as the outer shell of the sheet processing apparatus body  300 D, when the jam processing cover  508  is thus opened, since the stapling section of the stapler H is exposed, it is desirable to disable the operation of the stapler H when the jam processing cover  508  is opened. Also, even if the stapler H is moved to the removal position as described above, since the stapling section is exposed, it is also preferable to disable the operation of the stapler. 
     A third embodiment of the present invention will now be described in which when the jam processing cover  508  is thus opened or the stapler H is moved to the rotational position, the stapler H is not operated. 
     FIG. 16 is a view showing a structure of the stapler section of the sheet processing apparatus according to this embodiment. 
     In FIG. 16, reference numeral  509  denotes an operation controlling switch for controlling the operation of the stapler H, reference numeral  512  denotes a rotatable link that is rotatable about a shaft  510 , and reference numeral  513  denotes a link lever rotatably held through a shaft  511  to the link  512 . Also, reference numeral  514  denotes a switch lever provided on the staple cover  505  of the stapler H and reference numeral  515  denotes a switch lever provided on a jam processing cover  508 . 
     Incidentally, the link  512  is biased in pressing contact with the switch lever  515  provided on the jam processing cover  508  by biasing means (not shown). Also, the link lever  513  is biased and brought into pressing contact with the switch lever  514  of the stapler H by the biasing means (not shown). 
     By the way, FIG. 16 shows a condition that the stapler H is located in the staple operating position. In this condition, the jam processing cover  508  is closed. At this time, the link lever  513  is depressed by the switch lever  514  of the stapler H so that the operating controlling switch  509  is turned on. Thus, the stapler H is kept in the operable condition. 
     On the other hand, FIG. 17A shows a condition of the stapler section when the stapler H is moved from the staple operating position to the rotational position. Under this condition, the link lever  513  depressed by the switch lever  514  of the stapler H is rotated in the direction indicated by the arrow around the shaft  511  by the biasing means (not shown). As a result, the operation controlling switch  509  is turned off and the stapler H is in an inoperative condition. Accordingly, even if the stapling section in the rotational position is exposed to the outside, the stapler H is no longer operated. 
     Also, FIG. 17B shows a condition in which the jam process cover  508  is opened. The link  512  depressed by the switch lever  515  of the jam process cover  508  in this condition is rotated about the shaft  510  so that the shaft  511  is moved in the direction indicated by the arrow. 
     Then, when the shaft  511  is thus moved, the link lever  513  is separated away from the operation controlling switch  509 , as a result of which the operation controlling switch  509  is turned off and the stapler H is in the inoperative condition. Accordingly, the stapler H is no longer operated even under the condition that the jam process cover  508  is opened and the stapling section is exposed to the outside. 
     A fourth embodiment of the present invention will now be described. 
     FIGS. 18A and 18B are perspective views showing the sheet processing apparatus according to this embodiment. Incidentally, in FIGS. 18A and 18B, the same reference numerals are used to indicate the corresponding parts or members as those of FIGS. 12A and 12B. 
     In this embodiment, when the staples of the stapler H are expended, the user may directly remove the stapler H, located in the staple operating position as shown in FIG. 18A, from the sheet processing body  300 D as shown in FIG.  18 B. Incidentally, the stapler H is normally held with a constant force by the latch mechanism (not shown) in the staple operating position. However, when the stapler is moved from the staple operating position manually, the holding force may be released. 
     Thus, the stapler H is removed to the outside so that the user may readily draw the staple cartridge removal knob  507  and may perform the replacement of the staple cartridges. Furthermore, as shown in FIG. 18B, the stapler H (of which stapling section) is provided in the lower portion whereby the staples  516  accumulated in the stapling section after the idle strike during the jam condition may readily be removed. 
     Also, in the stapler H in accordance with this embodiment, in the staple operating position as shown in FIG. 19, a gear train  517  in cooperation with a drive source of the sheet processing apparatus body  300 D and a gear  518  provided in the stapler H are engaged with each other. When the stapler H is removed from the sheet processing apparatus body  300 D, the engagement between the gear train  517  and the gear  518  is released so that the stapler H is not subjected to the drive. 
     Then, when the stapler H is thus removed from the sheet processing apparatus body  300 D, the transmission of the drive is disabled whereby when the stapler H is removed, even if the stapling section is exposed to the outside, the stapler H is no longer operated. 
     A fifth embodiment of the present invention will now be described. 
     FIGS. 20A and 20B are views showing a structure of a stapler section of a sheet processing apparatus in accordance with this embodiment. Incidentally, in FIGS. 20A and 20B, the same reference numerals are used to indicate the corresponding parts and members as those of FIGS. 10A and 10B. 
     In FIGS. 20A and 20B, reference numeral  506 A denotes the rotary center shaft of the stapler H forming the holding means for detachably holding the stapler H to the sheet processing apparatus body  300 D as desired. For example, a cutaway portion  506   a  having a D-cut shape is formed in the upper end portion of the rotary center shaft  506 A of the stapler H. Also, reference numeral  560  denotes a mounting groove that is a mounting guide section for guiding the stapler H to an upper shaft hole  602  and a lower shaft hole  602   a  (see FIGS. 14A to  14 C) formed in a predetermined holding position of the sheet processing apparatus body  300 D. During the mounting operation, the rotary center shaft  506 A of the stapler H is guided to the upper shaft hole  602  and the lower shaft hole  602   a  along the mounting groove  560 . 
     In this case, the width of this mounting groove  560  is narrower than a diameter of the rotary center shaft  506 . When the stapler H is in the staple operating position, a cutaway portion  506   a  that is cut away so as to be greater than the width of the mounting groove  560  as shown in FIG. 20A faces the mounting groove  560 . Then, under this condition since the rotary center shaft  506  is no longer introduced into the mounting groove  560 , the stapler H could not be drawn out. 
     On the other hand, in the case where the staple clogging takes place in the stapler H or the stapler H is broken down, the user directly manually rotate the stapler H from the staple operating position shown in FIG. 20A to the removal position shown in FIG. 20B about the rotation center shaft  506 . 
     Then, when the stapler H is removed and rotated to the removal position, the cutaway portion  506   a  of the rotary center shaft  506  is directed to the condition that the cutaway portion may be introduced into the mounting groove  560  as shown in FIG.  20 B. Incidentally, the stapler H is held with a constant force by the latch mechanism (not shown) in the staple operating position shown in FIG.  20 A. The stapler H may be rotated manually and when the stapler is moved from the staple operating position, the holding force is released. 
     Then, after the cutaway portion  506   a  is brought into such a direction, the stapler H is slid so as to be along the mounting groove  560  as shown in FIGS. 21A and 21B, the stapler H may be removed from the sheet processing apparatus body  300 D. 
     Thus, when the stapler H is moved to the removal position, the stapler H is adapted to be operated and removed from the sheet processing apparatus body  300 D along the mounting groove  560  so that the stapler H may readily be removed to the outside. 
     By the way, in this embodiment, the connector  604  on the side of the sheet processing apparatus body connected to the cable connector  603  of the stapler H is fixed at one end to the sheet processing apparatus interior and is mounted on the cable that may be drawn. Thus, when the stapler H is removed from the sheet processing apparatus body  300 D, the connector  604  on the apparatus body side is also drawn out to the outside together with the stapler H. 
     Incidentally, after the stapler H has been thus removed, when the connectors  603  and  604  connected to each other are separated as shown in FIG. 22A, the connector  604  on the apparatus body side is returned to the original portion as shown in FIG. 22B by the retracting force of the retracting means (not shown) for the cable  604 A into the apparatus body interior. 
     Then, the connector  604  on the sheet processing apparatus body side may be thus retracted to the outside so that the operationability of the connecting/disconnecting of the connectors  603  and  604  may be enhanced upon the mounting/detaching of the stapler H. 
     Incidentally, in the sheet processing apparatus according to this embodiment, the jam process cover  508  is provided as shown in FIG. 13 described above for the jam process in the conveyer section. Also, when the jam process cover  508  is opened during the jam process, or even under the condition that the stapling section of the stapler H is exposed to the outside, the operation limiting mechanism as shown in FIG. 16 described above is provided so that the sheet processing apparatus body is inoperative. 
     Furthermore, in the embodiment, during the replacement of the staplers, when the stapler is removed, the sheet processing apparatus body  300 D is inoperative. However, after the stapler H has been removed as described above, if the connector  603  is removed, the link lever  513  shown in FIG. 16 is adapted to be returned to the same condition as the case where the link lever  513  is pushed by the switch lever  514  shown in FIG. 16 by the retracting means (not shown) for retracting the cable  604 A into the interior of the apparatus. 
     Thus, the sheet processing apparatus body  300 D is operative, as a result of which even if the stapler H is removed, as descried above, after the alignment by the alignment means  301  has been performed, the stack mode is possible in which the sheet is discharged and stacked onto the second stacking section  325  simply in a face down manner. 
     A sixth embodiment of the present invention will now be described. 
     FIGS. 23A to  23 C are views illustrating the stapler removal operation in the sheet processing apparatus in accordance with this embodiment. 
     Incidentally, in this embodiment, the stapler H is disposed in the interior of the outer shell whereby the design of the outer appearance of the sheet processing apparatus body  300 D is enhanced. 
     Then, in such a sheet processing apparatus, when the staple clogging occurs in the stapler H arranged in the interior in the outer shell or the stapler H is broken down, first of all, the user opens an outer shell door  605 . Subsequently, the stapler H arranged in the interior is directly manually rotated from the staple operating position shown in FIG. 23B to the removal position shown in FIG.  23 C. 
     In this case, when the stapler H is thus rotated to the removal position, the claw portion  601  including the rotary center shaft  506  as shown in FIGS. 10A and 10B as described above is exposed to the outside. Incidentally, the stapler H is held with a constant force by the latch mechanism (not shown) in the staple operating position. However, if the stapler is moved from the staple operation position, the holding force is released. 
     Subsequently, when the claw portion  601  is depressed from above from this condition, the claw portion  601  is flexed downwardly as shown in FIG. 14B whereby the rotary center shaft  506  may be removed from the upper shaft hole  602  formed in the sheet processing apparatus body  300 D. 
     Incidentally, after the stapler H has been thus removed, the cable connector  603  extending from the side of the stapler H kept under the connected condition shown in FIG.  24 A and the connector  604  on the side of the sheet processing apparatus body are removed as shown in FIG.  24 B.