Sheet processing apparatus and image forming apparatus including the same

A sheet processing apparatus includes an intermediate stacking portion which temporarily stacks, thereon, a sheet conveyed thereto; a discharge portion which discharges sheet stacked on the intermediate stacking portion; an aligning member which is provided downstream of the discharge portion in a sheet conveying direction and has a sheet holding surface capable of holding the lower surfaces of the sheet and a sheet aligning surface capable of abutting against end portions of the sheet in the widthwise direction orthogonal to the sheet conveying direction, the aligning member being movable in the widthwise direction; a first stacking portion which is provided below the aligning member and stacks, thereon, a sheet discharged from the discharge portion; and a second stacking portion which is provided above the aligning member and stacks, thereon, a sheet conveyed thereto; wherein a standby position of the aligning member is at a position more inward than the outermost position in the widthwise direction, within the range through which the aligning member is movable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sheet processing apparatus capable of selectively performing processing to sheets received from the main body of an image forming apparatus.

2. Description of the Related Art

Conventionally, among image forming apparatuses such as copying machines and printers, there have been image forming apparatuses including sheet processing apparatuses capable of successively receiving sheets on which images have been formed and selectively performing, on the sheets, processing such as binding. For example, Japanese Patent Application Laid-Open No. 2005-263488 discloses a sheet processing apparatus which is structured such that sheets are discharged to and stacked on an intermediate stacking portion through an intermediate roller, then are aligned at their end portions on the intermediate stacking portion and, then, are subjected to binding processing through a binding device, such as a stapler. Then, joggers for aligning the end portions of the sheets, which are constituents of the intermediate portion, are evacuated to positions having, therebetween, a width greater than the sheet width, and the sheets which have been subjected to the binding processing through the stapler are stacked on a stack tray under the intermediate stacking portion.

Further, there are sheet processing devices including plural trays, in order to sort sheets according to the applications, in addition to binding functions such as staplers. For example, if plural trays as aforementioned are provided in the aforementioned sheet processing apparatus at an upper portion thereof, this will increase the size of the entire apparatus. However, by placing the aforementioned plural trays near the upper portions of the joggers, it is possible to structure the entire apparatus to have a reduced size.

However, in the case of structuring the apparatus as described above, when the joggers are evacuated to the outermost positions within the range through which the joggers are movable, there is induced the problem that the joggers interfere with removal of sheets stacked on the tray just above the joggers, thereby making it difficult to remove sheets.

Further, when the joggers are evacuated to the outermost positions within the range through which the joggers are movable, as described above, there is induced the problem of degradation of the viewability of sheets stacked on the tray under the joggers in a vertical direction.

SUMMARY OF THE INVENTION

The present invention provides a sheet processing apparatus which increases the viewability of sheets and makes it easier to remove sheets, while having trays for sorting sheets which are provided above joggers in a vertical direction for reducing the size of the apparatus.

In order to attain the aforementioned object, a sheet processing apparatus according to the present invention includes an aligning member which aligns a conveyed sheet and is movable in a widthwise direction orthogonal to a sheet conveying direction to align the conveyed sheet in the widthwise direction; and a stacking portion which is provided below a position of the conveyed sheet to be aligned by the aligning member and stacks the aligned sheet, wherein the aligning member can move more outwardly than an end portion of the stacking portion in the widthwise direction, and wherein a standby position of the aligning member, where the aligning member is on standby without operating, is at a position more inwardly by a predetermined amount than the outermost position in the widthwise direction, within the range through which the aligning member is movable.

The present invention also provides a sheet processing apparatus includes an aligning member which aligns a conveyed sheet and is movable in a widthwise direction orthogonal to a sheet conveying direction to align the conveyed sheet in the widthwise direction; and a stacking portion which is provided above a position of the conveyed sheet to be aligned by the aligning member and stacks, thereon, a sheet conveyed thereto, wherein the aligning member can move more outwardly than an end portion of the stacking portion in the widthwise direction, and wherein a standby position of the aligning member, where the aligning member is on standby without operating, is at a position more inwardly by a predetermined amount than the outermost position in the widthwise direction, within the range through which the aligning member is movable.

According to the present invention, it is possible to provide a sheet processing apparatus which increases the viewability of sheets stacked on the stacking portion below the aligning member and makes it easier to remove sheets from the stacking portion above the aligning member, while reducing the size of the entire sheet processing apparatus.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, with reference to the drawings, preferred embodiments for carrying out the present invention will be exemplarily described in detail. However, the sizes, materials, shapes and relative positions of components described in the embodiments should be properly changed according to the structure of the apparatus to which the invention is applied and according to various conditions, and the scope of the present invention is not intended to be limited to the following embodiments.

First Embodiment

FIG. 1is an external view of a sheet processing apparatus according to a first embodiment, andFIG. 2is a schematic cross-sectional view illustrating an image forming apparatus connected to the sheet processing apparatus according to the first embodiment.

The sheet processing apparatus1according to the first embodiment is connected to the main body of the image forming apparatus as illustrated inFIG. 2and selectively performs predetermined processing such as stapling on sheets on which images have been formed. Although there is exemplified, in this case, a stapler (binding unit) as a process unit which performs processing on the aforementioned sheets, the process unit is not limited thereto. For example, the process unit can be other process units, such as a punching unit which performs punching and a folding unit which performs folding, or appropriate combinations of these process units. The main body of the image forming apparatus includes an image forming portion2which forms images on sheets, and an image reading portion3which is connected to the image forming portion2and reads information written on originals.

As illustrated inFIG. 2, the image forming portion2separately feeds a plurality of sheets S stacked on a sheet cassette4, one by one, through a feeding roller6and a separately-conveying roller7and conveys them to an image forming processing unit9through a conveying guide8.

The image forming processing unit9forms images (toner images) through an electrophotographic system. More specifically, light is directed from a laser scanner11to a photosensitive drum10as an image bearing member to form an image, then the aforementioned image is developed through toner, and the toner image is transferred to a sheet S.

The sheet S to which the toner image has been transferred from the photosensitive drum10is conveyed to a fixing device12which applies heat and a pressure thereto to fix the image.

The sheet S on which the image has been fixed is conveyed to a face-up conveying path14or a switch-back conveying path15which turns sheets upside down, wherein the switching between the face-up conveying path14and the switch-back conveying path15is performed by a conveying-path switching flapper13.

The sheet transferred to the switch-back conveying path15is conveyed by a switch-back convey roller16until the rear end of the sheet passes through a reversing flapper17. Thereafter, the switch-back conveying roller16is reversed, so that the aforementioned sheet is conveyed at a state where it is turned upside down such that its end which has been placed at the rear side is placed at the tip-end side. At this time, the reversing flapper17is switched over, so that the sheet which has been turned is conveyed to a face-down conveying path18.

The face-up conveying path14and the face-down conveying path18are merged with each other before a discharge roller19. Sheets guided to the face-up conveying path14and sheets which have been conveyed from the switch-back conveying path15and passed through the face-down conveying path18are both discharged from the image forming portion2through the discharge roller19.

The image reading portion3is constituted by a scanner portion21and an automatic document feeding portion (hereinafter, referred to as an ADF)22, as illustrated inFIG. 2. The ADF22separately feeds plural originals stacked on a original stack tray23, one by one, through a feeding roller24to cause them to pass through a original reading position25at which an optical carriage27in the scanner portion21stays. Further, the ADF22can be opened or closed rearwardly about a hinge (not illustrated) at the rear side of the apparatus and is opened and closed when an original is placed on a original-base-plate glass26.

The scanner portion21includes the movable optical carriage27and reads information written on originals. In the scanner portion21, the optical carriage27reads information written on the original placed on the original-base-plate glass26while scanning the original in a horizontal direction, and a CCD28performs photoelectric conversion on the read information. Further, during reading the original by the aforementioned ADF22, the optical carriage27stays at the original reading position25and reads the information written on the original being conveyed, as described above.

FIG. 3is a schematic cross-sectional view for describing the structure of the sheet processing apparatus1. The sheet processing apparatus1, which is connected to a side surface of the main body of the image forming apparatus, receives sheets discharged from the image forming portion2through the discharge roller19and performs stapling processing thereon.

As illustrated inFIG. 3, the sheet processing apparatus1has an intermediate conveying roller31. A discharge upper roller32and a discharge lower roller33constitute a discharge portion which discharges sheets which have been processed by a stapler (process unit) which will be described later. An intermediate stacking portion34temporarily stacks the aforementioned received sheets thereon. A first stack tray35as a first stacking portion stacks, thereon, sheets which have been subjected to stapling (aligning) processing and discharged through the discharge rollers32and33or sheets have been discharged therethrough without being subjected to stapling (aligning) processing. An aligning roller36performs aligning of the conveying direction of sheets stacked on the intermediate stacking portion34. The aligning roller36is movable upwardly and downwardly with respect to the sheet stacking surface of the intermediate stacking portion34. When the aligning roller36is descended, it abuts against the surface of the sheets on the intermediate stacking portion34and moves the sheets and, when the aligning roller36is ascended, it is evacuated to a position at which it does not interfere with the conveying of sheets to the intermediate stacking portion34. The sheet processing apparatus1further has a first aligning reference wall37in the sheet conveying direction and a conveying guide38above the intermediate stacking portion34. Downstream of the discharge rollers32and33, there is provided a stack-height detection flag39which abuts against the upper surface of the sheets stacked on the first stack tray35and detects the height of the stack. The discharge upper roller32can be spaced apart from the discharge lower roller33until it reaches the position designated by the broken line. When the rollers are spaced apart from each other, the stack-height detection flag39can be moved to the position designated by the broken line by being pushed upwardly by the roller32.

The sheet processing apparatus1has a second stacking portion which stacks the aforementioned received sheets thereon, in addition to the aforementioned first stacking portion. In this case, the sheet processing apparatus1has a second stack tray44and a third stack tray45which enables sorting the aforementioned sheets thereinto and stacking the sheets thereon, as the second stacking portion. The stack trays44and45are provided above an aligning member, in a vertical direction, which will be described later. A switching member41is provided at the inlet of the apparatus for conveying sheets to the upper stack trays44and45. By switching over the orientation of the switching member41, the sheets fed to the sheet processing apparatus1are fed to a stapling conveying path42or a sorting conveying path43. Then, the conveying path is switched over through a sorting member46which is provided in the sorting conveying path43, and the sheets are discharged to and stacked on the second stack tray44or the third stack tray45as the upper stack tray, through the corresponding discharge roller.

FIG. 4is a perspective view illustrating the intermediate stacking portion34, at the downstream side in the sheet conveying direction. A reference-side jogger51and an aligning-side jogger52, which is an aligning member that performs aligning operation in the widthwise direction orthogonal to the sheet conveying direction, are also illustrated inFIG. 4. The joggers51and52have sheet holding surfaces51aand52acapable of holding the lower surfaces of sheets and sheet aligning surfaces51band52bcapable of abutting against the end portions of the aforementioned sheets in the widthwise direction, respectively. The joggers51and52can be moved in the widthwise direction of sheets for aligning sheets in the widthwise direction and constitute the aligning portion in cooperation with a driving portion which will be described later. Further, the aforementioned first stack tray35is provided under the joggers51and52, while the aforementioned second and third stack trays44and45are provided thereabove in the vertical direction (seeFIG. 3). There is a second aligning reference wall53in the widthwise direction orthogonal to the sheet conveying direction. A stapler54binds the bundle of sheets which have been aligned.

The aforementioned reference-side jogger51and the aligning-side jogger52exist downstream of the discharge rollers32and33in the sheet conveying direction and are shaped to form substantially an angular-U shape in such a way as to support the upper and lower surfaces of sheets S. Further, the joggers51and52are structured to be moved among plural positions illustrated inFIG. 5, in the sheet-widthwise direction, by the driving portion. In this case, the joggers51and52are moved by the driving portion and the controlling portion, among evacuation positions illustrated inFIG. 5A, reception positions illustrated inFIG. 5Band alignment positions illustrated inFIG. 5C. The evacuation positions illustrated inFIG. 5Aare positions at which the sheet holding surfaces51aand52bare evacuated outwardly from the sheet conveying path, and the sheet holding surfaces of the joggers exist outwardly from the width of sheets S, in order to enable discharging, to the stack tray35, sheets which have been subjected to stapling processing. The reception positions illustrated inFIG. 5Bare positions at which the sheet holding surfaces51aand52bsupport the lower surfaces of sheets S, and the sheet aligning surfaces51band52bhave, therebetween, a width greater by a predetermined amount than the width of sheets S for preventing the convey of sheets from being hindered, when the sheets S have been conveyed to the intermediate stacking portion34. The alignments position illustrated inFIG. 5Care positions at which the sheet aligning surfaces51band52babut against the end portions of sheets S being held by the sheet holding surfaces51aand52bfor aligning the sheets, and the sheets S have been moved until they abut against the second aligning reference wall53for aligning the sheets. In the present embodiment, the reference-side jogger51is stopped at the reception position illustrated inFIG. 5Bby a stopper (not illustrated), when it has been moved to substantially the same position as that of the second aligning reference wall53, as will be described later. Thereafter, only the aligning-side jogger52is moved to the alignment position illustrated inFIG. 5c. Namely, the reception position and the alignment position of the reference-side jogger51are the same position. It goes without saying that the reception position and the alignment position of the reference-side jogger51can be set to be different from each other.

The aforementioned joggers51and52are positioned at power-on or during standby between jobs at a home position which is set to be more inwardly by a predetermined amount than the outermost position (the evacuation position) within the range through which the joggers51and52are movable.

FIG. 6is a view illustrating the driving portion and the guide for the joggers51and52. Referring toFIG. 6, a pulley67, a pulley66and a timing belt68are driven by a jogger motor64as the driving portion. Sliders71and72are secured to the timing belts68, the slider72and the aligning-side jogger52are secured to each other, and the slider71and the reference-side jogger51are coupled to each other through a spring70. The joggers51and52can be moved in the widthwise direction of sheets (in the lateral direction in the figure) by being guided by the guide69, and the positions of the joggers51and52are detected by a jogger-position sensor62. The reference-side jogger51and the aligning-side jogger52are moved from the evacuation positions to the reception positions, in synchronization with each other, through the movement of the timing belt68. The reference-side jogger51is stopped by the stopper (not illustrated), when it has been moved to substantially the same position as that of the second aligning reference wall53. Thereafter, only the slider71is moved along with the aligning-side jogger52since the spring70is stretched, until the aligning-side jogger52reaches the alignment position. Accordingly, in this case, the reference-side jogger51exists at the same position as that of the second aligning reference wall53, at the alignment position.

Next, with reference toFIG. 7andFIG. 8, there will be described a sheet processing operation by the sheet processing apparatus1.

During standby (S101), the home positions of the joggers51and52are set to the reception positions (FIG. 5B). If the sheet processing apparatus1receives a print signal (S102) from the image forming portion2, the controlling portion61provided in the sheet processing apparatus1drives the jogger motor64to move the joggers51and52to the evacuation positions (FIG. 5A) on the basis of information from the jogger-position sensor62(S103). Next, the joggers51and52are to be moved to the reception positions (FIG. 5B), but if the joggers are moved to the reception positions at this state, they may impinge on the stack-height detection flag39depending on the position of the stack-height detection flag39. Therefore, before operating the joggers51and52, the controlling portion61drives a roller spacing motor65to move the discharge upper roller32to a spacing position on the basis of information from a roller space sensor63(S104) for ascending the stack-height detection flag39. This causes the stack-height detection flag39to move to the inside of the substantially-angular-U shape formed by the joggers51and52, which prevents the joggers51and52from impinging on the stack-height detection flag39even when the joggers51and52are moved. At this state, the joggers51and52are moved to the reception positions (S105) and, after the movement, the discharge upper roller32is temporarily restored to the conveying position from the spacing position (S106). However, the stack-height detection flag39is left within the substantially-angular-U shape by being supported by the lower surfaces of the joggers51and52.

Before a sheet is conveyed to the inside of the sheet processing apparatus, a conveying motor100is activated (S107) to rotate the conveying roller in the apparatus. When a sheet is conveyed to the sheet processing apparatus1(S108), the sheet is conveyed to the stapling conveying path42through the switching member41and then is discharged to the intermediate stacking portion34through the intermediate conveying roller31. The first sheet to be processed is certainly conveyed toward the substantially-angular-U shape formed by the joggers51and52, since the discharge upper roller32is positioned at the convey position. After the tip end of the first sheet is conveyed to the joggers51and52, the discharge upper roller32is moved to the spacing position (S109) so that it is evacuated, which prevents the sheet from being further conveyed after the rear end of the sheet is passed through the intermediate conveying roller31and also prevents the discharge upper roller32from interfering with the movement of the sheet caused by subsequent aligning operations. Accordingly, until the completion of aligning of a predetermined number of sheets to be processed, after the first sheet, the discharge upper roller32is held at the spacing position.

Sheets are aligned one by one (S110) and, when a sheet is stacked on the intermediate stacking portion34, the sheet is aligned in the widthwise direction through the movement of the joggers51and52. At this time, the reference-side jogger51is fixed at the position at which the sheet aligning surface51bis flashed with the second aligning reference wall53. Then, the aligning-side jogger52is moved, in the direction orthogonal to the sheet conveying direction, to the alignment position (FIG. 5C) at which the sheet abuts against the second aligning reference wall53for aligning the sheet in the widthwise direction.

Next, the aligning roller36is descended to abut against the surface of the sheet and then is rotated in the direction opposite from the sheet conveying direction to move the sheet until it abuts against the first aligning reference wall37, thereby aligning the sheet in the sheet conveying direction.

A second sheet is conveyed (S111) and aligned (S112) with the discharge upper roller32held at the spacing position, as described above.

The same operations as the aforementioned operations are repeatedly performed until the predetermined number of sheets to be stapled is reached (S113). After the completion of aligning of the last sheet, the conveying motor100is stopped (S114), and the stapler54is driven to bind the bundle of the aforementioned sheets which have been aligned (S115). Thereafter, the discharge upper roller32is moved to the conveying position (S116), then the conveying motor100is activated (S117) to convey the aforementioned bundle of sheets and, further, the joggers51and52are evacuated to the evacuation positions (FIG. 5A) at which their lower surfaces have, therebetween, a width greater than the width of the sheets (S118). Thus, the bundle of sheets is dropped to and staked on the stack tray35. Although, in the present embodiment, there has been described the structure of the sheet processing apparatus1which is provided with the controlling portion61, the controlling portion61can be provided integrally with a controlling portion (not illustrated) provided in the main body of the image forming apparatus for controlling the entire image forming apparatus, such that the controlling portion61directly controls the sheet processing apparatus1from the main body of the image forming apparatus.

Hereinafter, there will be described the operations which are performed by the apparatus, after a job which has been subjected to stapling processing is discharged to the stack tray35.

The upper stack trays44and45have a width (a length in the sheet-widthwise direction) set to enable stacking a sufficient number of sheets thereon, and are positioned at subsequently the same positions as the positions of the joggers51and52at the reception positions (FIG. 5B). The reception positions of the joggers are set to positions which have, therebetween, a width greater by a predetermined amount than the width of sheets. This is because a tray having the same width as that between the reception positions of the joggers enables stacking a sufficient number of sheets thereon. The width of the trays is set to be a smallest possible value as described above, which improves the viewability of sheets stacked on the first stack tray35, makes it easier to remove sheets stacked on the second stack tray44and enables reduction of the size of the apparatus. However, the second stack tray44is installed near and right above the joggers51and52in the vertical direction. Therefore, when the joggers51and52exist at the outermost evacuation positions (FIG. 5A), the joggers are largely protruded from an end of the second stack tray44in the sheet-widthwise direction as illustrated inFIG. 9, which causes the reference-side jogger51to interfere with the removal of sheets from the second stack tray at its front side.

In cases where processing of a next job is successively performed after the completion of the aforementioned job, the same sequence as the aforementioned sequence is repeatedly performed (S119). Further, in cases where the job is completed at this time, the conveying motor is stopped (S120), and the joggers51and52are moved to the reception positions (FIG. 5B) as the home positions. Accordingly, the reference-side jogger51is positioned at substantially the same position as an end portion of the second stack tray44. This prevents the reference-side jogger51from interfering with the removal of the sheets stacked on the second stack tray44as illustrated inFIG. 1, thereby making it easier to remove the sheets. Further, at the reception position, the reference-side jogger51is substantially hidden under the second stack tray44, thereby making it easier to check the sheets stacked on the first stack tray35. Although, in this example, there is exemplified a case where the jogger51is positioned at the same position as that of an end portion of the second stack tray44at the home position, the present invention is not limited thereto, and the jogger51can be positioned more inwardly than the end portion of the second stack tray44, for example. Similarly to a description above, when the jogger51, at the home position, is positioned at the same position as that of an end portion of the first stack tray35, or at more inwardly than the end portion of the first stack tray35, thereby making it easier to check the sheets stacked on the first stack tray35.

When the joggers51and52are moved to the reception position, similarly to when the first job is processed, the discharge upper roller32is spaced apart from the discharge lower roller (S121) to ascend the stack-height detection flag39and, thereafter, the joggers51and52are moved to the reception positions (S122). Then, the discharge roller is descended (S123) and is restored to a standby state (S124).

As described above, in the present embodiment, the home positions of the joggers51and52is set to positions more inwardly by a predetermined amount than the evacuation positions which are the outermost positions within the range through which the joggers51and52are movable. This can provide a sheet processing apparatus capable of improving the viewability of sheets stacked on the first stack tray35and making it easier to remove sheets from the second stack tray44, while reducing the size of the entire sheet processing apparatus.

Further, the home positions of the joggers51and52are set to the reception positions thereof, which improves the viewability of the first stack tray35and makes it easier to access the second stack tray44, in comparison with cases where the home positions are set to the evacuation positions as inFIG. 9.

Further, in this case, the joggers51and52are moved in conjunction with each other and, accordingly, the aligning-side jogger52exists at the home position when the reference-side jogger51has been moved to the home position. However, in the case where the sheet processing apparatus is connected to a side surface of the main body of the image forming apparatus and is structured to allow sheets stacked on the trays to be removed only at the front side or the side surface as the aforementioned sheet processing apparatus, the aligning-side jogger52which is positioned in the rear side of the apparatus does not affect the accessibility of sheets when sheets are removed, even when the aligning-side jogger52exists at the outermost evacuation position. Therefore, in this case, it is preferable to structure the apparatus such that only the reference-side jogger51positioned in the sheet-removal side is moved to the home position (the reception position) which is more inwardly by a predetermined amount than the evacuation position, in order to prevent the removal of sheets from being hindered.

Second Embodiment

FIG. 10is an external view illustrating a sheet processing apparatus according to a second embodiment.

As inFIG. 1A, in the present embodiment, there are provided upper stack trays44and45having stacking surfaces which are provided with cutout portions71at their sides which are accessed when sheets stacked thereon are removed. This makes it easier to remove sheets on these trays by grasping the end portions of the sheets. Further, a reference-side jogger51, which is provided near the cutout portions of the aforementioned trays, is formed to have a shape which conforms to the aforementioned cutout portions71, which prevents it from blocking the cutout portion71of the stack tray44at a home position illustrated inFIG. 10. In this case, as inFIG. 1A, the reference-side jogger51has no sheet aligning surface51band has only upper and lower surfaces at its downstream side, so that the end surfaces of sheets abut against the aligning surface51bat its upstream side, while the lower surfaces of the sheets are supported by the sheet holding surface51afrom the upstream side to the downstream side thereof. This enables aligning similarly to in the aforementioned first embodiment. This can make it easier to access the sheets stacked on the stack tray44.

Third Embodiment

FIG. 11is a perspective view illustrating a sheet processing apparatus according to a third embodiment.

As inFIG. 11, in the present embodiment, there is provided, at the sheet-removal side, a reference-side jogger51constituted by a moving portion72movable in the sheet-widthwise direction, and a rotating portion73which is movable along with the aforementioned moving portion72and rotatable with respect to the aforementioned moving portion72. The rotating portion73is structured such that it can be rotated about a supporting point74with respect to the moving portion72in the direction in which sheets stacked on the aforementioned jogger51are accessed. Further, the rotating portion73is biased through a spring (not illustrated) in the direction of an arrow illustrated inFIG. 11A.

In the present embodiment, similarly to in the aforementioned second embodiment, there are provided stack trays44and45having stacking surfaces which are provided with cutout portions71at their sheet-removal sides. When the reference-side jogger51exists at a home position as inFIG. 11A, the rotating portion73in the reference-side jogger51is exposed through the cutout portions71. However, since the rotating portion73can be rotated with respect to the moving portion72, the rotating portion73can be rotated inwardly as inFIG. 11Bwhen sheets are removed, which enables certainly grasping the sheets S. This can make it easier to access to the sheets stacked on the second stack tray44. Similarly to a description above, this can make it easier to check sheets stacked on the first stack tray35.

Other Embodiments

Although, in the aforementioned embodiments, there have been exemplified cases where the apparatus is structured such that the joggers at the opposite sides in the sheet-widthwise direction are moved with respect to the second aligning reference wall for aligning sheets in the widthwise direction, the present invention is not limited thereto. For example, even when the apparatus is structured such that both the joggers are moved with respect to a center portion in the sheet-widthwise direction served, the present invention is effective. Further, there have been exemplified structures provided with joggers for aligning sheets in the widthwise direction at the opposite sides in the widthwise direction, the present invention is not limited thereto. For example, in cases where aligning is performed with respect to a single side in the sheet-widthwise direction, the apparatus can be structured such that the aforementioned jogger can be provided only at the other side in the widthwise direction, and the present invention can be applied to this structure for offering the same effects.

Further, although, in the aforementioned embodiments, there have been exemplified two stack trays as a second stacking portion which is provided above the aforementioned aligning portion, the present invention is not limited thereto. It is necessary only to provide at least one stacking portion, and it is possible to provide a single stacking portion or three or more stacking portions.

Further, although, in the aforementioned embodiments, there has been exemplified a copying machine as an image forming apparatus, the present invention is not limited thereto, and it is possible to employ other image forming apparatuses, such as a scanner, a printer or a facsimile. Also, it is possible to employ other image forming apparatuses, such as a compound machine having combined functions of these image forming apparatuses. The present invention can be applied to a sheet processing apparatus used with such an image forming apparatus for offering the same effects.

Further, although, in the aforementioned embodiments, there has been exemplified a sheet processing apparatus which is detachably connected to an image forming apparatus, the present invention is not limited thereto. For example, it is possible to employ a sheet processing apparatus including an image forming apparatus formed integrally therewith, and the present invention can be applied to such a sheet processing apparatus for offering the same effects.

This application claims the benefit of Japanese Patent Applications No. 2007-015797, filed Jan. 26, 2007, No. 2008-008739, filed Jan. 18, 2008 which are hereby incorporated by reference herein in their entirety.