Sheet processing apparatus and image forming apparatus

A sheet processing apparatus includes a stapler configured to staple a bundle of sheets by driving a staple into the sheet bundle; a cutting mechanism configured to cut off portions of staples driven into the sheet bundle; a storage portion configured to store cut-off portions of staples; a lid mounted on the storage portion capable of opening and closing; an open and closed state detecting portion configured to detect open and closed state of the lid; a collecting portion configured to collect cut-off portions of staples from the storage portion; and a lid opening and closing portion configured to open the lid when cut-off portions of staples are collected, wherein after the lid opening and closing portion has performed a lid opening and closing motions, if the open and closed state detecting portion detects that the lid is not closed, the lid opening and closing portion repeats a lid opening and closing operation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sheet processing apparatus and an image forming apparatus capable of cutting off end portions of staples used for binding sheets, and more particularly to a sheet processing apparatus and an image forming apparatus capable of surely closing the lid which is opened when the cut-off end portions of staples are disposed of.

2. Description of the Related Art

An image forming apparatus, such as a copying machine and printer, can include a sheet processing apparatus adapted to selectively perform a stapling process or a punching process to sheets on which an image has been formed, so as to reduce work required for the stapling process or the like on image carrying sheets.

The conventional sheet processing apparatus which can perform a stapling process, can include a stapler capable of stapling a sheet bundle at one or more than one points.

In such a sheet processing apparatus, a predetermined number of image carrying sheets are transported to the process  tray, and the sheets are aligned. Then, the stapler is moved to a predetermined position at an edge of the aligned sheet bundle, and the stapler drives staples into the sheet bundle to bind the sheets.

When sheets are bound, if a small number of sheets is bound together using long-leg staples, two end portions of each staple overlap one another. To prevent the overlapping of staple legs, conventional staplers have a mechanism to cut off surplus legs. More specifically, when staples are driven through the sheet bundle, they extend to the air on the opposite side of the sheet bundle. With respect to the extending staple, only the portions of staples necessary for stapling are preserved, and after surplus portions are cut off, the remaining portions are clinched to fasten the sheets together (refer to Japanese Patent Application Laid-Open No. 2001-105347, for example).

In such a stapler, cut-off end portions H of staples are accumulated in a storage box510provided at a stapler501as shown inFIG. 20. If a stapling job is continuously performed, the storage box510becomes full. In this case, it is necessary to store the cut-off end portions H of staples into a large capacity storage box600before the storage box510becomes full.

When the cut-off end portions H of staples are stored in the large capacity storage box600, the storage box510is moved above the large capacity storage box600, and the open-close lid520provided for the movable box510is opened.  As the open-close lid520is opened, the cut-off end portions H of staples fall from the storage box510into the large capacity storage box600and collected therein.

In the conventional sheet processing apparatus and image forming apparatus, after the cut-off waste end portions H are collected in the large capacity storage box600, the open-close lid520is closed, and then the stapler501starts a stapling operation.

However, when the staple end portions H are collected into the large capacity storage box600, the staple end portions H sometimes can be caught in the open-close lid520. In this case, the open-close lid520cannot be completely closed, and a space is made between the storage box510and the open-close lid520. Under this condition, if the stapling operation is performed and the cut-off end portions H accumulate in the storage box510, the end portions H can drop off through the space between the storage box510and the open-close lid520.

Also in a stapling operation, the open-close lid520can open for some reason. If the open-close lid520opens, the staple end portions H are scattered from the storage box510.

SUMMARY OF THE INVENTION

The present invention is directed to a sheet processing apparatus and an image forming apparatus in which the open-close lid can be unfailingly closed.

According to an aspect of the present invention, a  sheet processing apparatus includes a stapler configured to staple a bundle of sheets by driving a staple into the sheet bundle; a cutting mechanism configured to cut off end portions of a staple driven into the sheet bundle; a storage portion storing cut-off end portions of staples; a lid mounted on the storage portion capable of opening and closing; an open and closed state detecting portion configured to detect open and closed states of the lid; a collecting portion configured to collect cut-off end portions of staples from the storage portion; and a lid opening and closing portion configured to open the lid when the cut-off staple portions are collected from the storage portion to the collecting portion, wherein after the lid opening and closing portion has performed a lid opening and closing operation of a lid opening motion and then a lid closing motion, if the open and closed state detecting portion detects that the lid is not closed, the lid opening and closing portion repeats the lid opening and closing operation.

According to another aspect of the present invention, the image forming apparatus includes an image forming portion configured to form an image on a sheet; and a sheet processing apparatus configured to process a sheet having an image formed by the image forming portion, wherein the sheet processing apparatus is as described above.

According to an embodiment of the present invention, after the end portions of staples temporarily stored in the storage portion are collected into the collecting portion, if it is detected that the lid is still open, the lid is opened  and closed again, and the sheet processing apparatus can cause cut-off staple portions adhering to the lid to fall into the collecting portion. Consequently, the lid can be closed assuredly. Thus, it is possible to prevent cut-off staple portions from dropping off through the space between the storage portion and the lid, so that the ease of use of the apparatus is improved.

DETAILED DESCRIPTION OF THE EMBODIMENTS

First Exemplary Embodiment

FIG. 1is a diagram showing a structure of a copying machine as an example of an image forming apparatus including a sheet processing apparatus according to an embodiment of the  present invention.

FIG. 1shows a copying machine1A as the image forming apparatus. The copying machine1A is formed by mounting a sheet processing apparatus10to a copying machine main body1. In the copying machine1A, when an image forming operation is started, a toner image is formed on a photosensitive drum3, which constitutes an image forming portion1B. The toner image is transferred onto a sheet S supplied from a paper supply portion2.

The sheet S, onto which the toner image has been transferred, is sent to a fixing device4. The fixing device4fixes the toner image on the sheet, and then the sheet S is discharged with a pair of discharge rollers5to the sheet processing apparatus10.

The sheet processing apparatus10accepts one sheet S after another as they are discharged from the copying machine main body1. The sheet processing apparatus10performs a bundling process of aligning and bundling accepted sheets into a sheet bundle, and a stapling process of stapling the sheet bundle together. Other processes on the sheet bundle, such as sorting, punching, and book binding, are also performed in the sheet processing apparatus10. This sheet processing apparatus10includes a buffer roller22A and a process tray unit25A having a process tray serving as a paper stacking portion, which will be described below.

While sheets on a process tray25are being processed, the buffer roller portion22A stacks one or more sheets up which  are on stand-by for the next process. After the on-going process is completed, the buffer roller portion22A transfers the sheet or sheets on stand-by toward the process tray25. The buffer roller portion22A includes a buffer roller22and a plurality of small buffer rollers23to press the sheet against the buffer roller22.

The process tray unit25A includes the process tray25, a pair of discharge rollers24, aligning members32, and a return paddle31. The process tray25temporarily accumulates, aligns, and staples the sheets. The pair of discharge rollers24discharges sheets onto the process tray25. The process tray unit25A also includes a binding unit50A equipped with a stapler50. The stapler50fastens a bundle of sheets when necessary by driving staples into the sheets stacked on the process tray25.

The process tray25can be an inclined tray with its downstream side (on the left ofFIG. 1) located at a higher position and its upstream side (on the right ofFIG. 1) at a lower position. A rear end aligning member30is located at the lower end of the tray. When a sheet is discharged to the process tray25by the discharge roller pair24, the discharged sheet slides down the process tray25under the sheet's own weight and also by the action of the paddle31until it comes into contact with the rear-end aligning member30.

The aligning members32include the front-side aligning member and the rear-side aligning member which can move in the back and forth direction independently of each other.  Thus, the sheets are aligned in the direction of the sheet width perpendicular to the conveying direction of the sheet bundle. When the user operates the buttons on the operation display portion214in the copying machine main body1shown inFIG. 2, the front side of the copying machine main body1where the user is standing (the side where the user can see the screen image as shown inFIG. 2) is here referred to as the front side and the opposite rear side as the rear side.

InFIG. 1, there are a stack tray40and a sample tray41, which are used separately as the occasion demands. For example, the stack tray40located below is used to receive copy output and print output. The sample tray41located above is used to receive sample output, interrupt output, output at time of stack tray overflow, function sort output, and output in mixed job process. The two trays40and41are supported such that they are capable of self-moving in the vertical direction independently of each other.

A pivoting guide26is capable of swinging in the directions shown by arrows a, and an upper roller29is supported by the pivoting guide26. When the pivoting guide26swings downward and comes to the closed position, the upper roller29and a lower roller28, arranged on the process tray25, jointly serve in a pair as bundle discharge rollers for discharging a sheet bundle onto the stack tray40along the process tray.

When a sheet is normally discharged onto the process tray25, the pivoting guide26is placed in an open state (the state in which the bundle discharge rollers28,29are separate  from each other) as shown inFIG. 1, so that the pivoting guide26does not present an obstacle to the discharge and the fall of the sheets onto the process tray25, and also to a subsequent aligning process. When a sheet bundle is discharged from the process tray25to the stack tray40, the pivoting guide26moves to a closed state (the state in which the upper discharge roller29is in contact with the sheet bundle).

The flow of a sheet S in the above sheet processing apparatus10will be described next.

For example, when a staple sort mode is specified from the operation display portion214in the copying machine main body1shown inFIG. 2, a sheet S discharged from the copying machine main body1is sent to the sort path P by way of a pair of transfer rollers21and the buffer roller22, and by switching a flapper (not shown).

The sheet S sent to the sort path P is discharged onto the process tray25by the discharge roller pair24. The discharged sheet S slides down the process tray25on the sheet's own weight and also by the action of the return paddle31, until the trailing end of the sheet comes into contact with the rear end aligning member30. As a result, the trailing ends of the sheets are aligned. Furthermore, the sheets are aligned in the sheet width direction by the aligning members32.

When all sheets of a first copy have been discharged onto the process tray25and aligned, the pivoting guide26goes down and the upper roller29comes to rest on the bundle of sheets to fix the sheet bundle. Then, the stapler50staples the sheet  bundle. The sheet bundle which has been processed on the process tray25is discharged onto the stack tray40by the pair of bundle discharge rollers28,29.

The stapler50is arranged close to the rear end aligning members30, and can move in the direction of the sheet width (the front-rear direction of the sheet processing apparatus). The stapler50staples the sheet bundle by driving staples into an end portion of the sheet bundle aligned along the rear end aligning member30. The staple driving operation is driven by a DC brush motor (not shown), and, interlocked with this stapling operation, surplus portions of staples are cut off.

FIGS. 3A and 3Bshow a cutting mechanism for cutting off surplus end portions of staples. End portions of a staple152have passed through the sheet bundle, and a cutter portion151cuts off surplus end portions of the staple152. This cutting mechanism is mounted on the binding unit50A.

When a predetermined number of sheets are stacked on the process tray, the stapler (not shown) drives a staple152into a sheet bundle, and the end portions of the staple extend from the sheet bundle as shown inFIG. 3A.

Because the end portions of the staple152extending beyond the line (Z) are surplus made in a step of bending the staple, they are cut off by moving the cutter portion151in the direction of arrow (Y). As shown inFIG. 3B, by moving the cutter portion151, the two surplus portions of the staple152are cut off almost simultaneously at a same distance from the  top surface of the sheet bundle.

After the end portions are cut off by the cutter portion151, the remaining portions of the staple152are bent and the stapling process is completed. The processes from the staple driving operation to the staple cutting and the end-portion bending are driven by a DC brush motor (not shown).

The end portions cut off as described are conveyed as surplus through a transfer pathway (not shown) and temporarily stored in a storage portion51provided in the binding unit50A shown inFIG. 4. The cut-off tip portions of staples (hereafter referred to as cut-off portions) fall by gravity in the storage portion51and accumulate in the lower area of the storage portion51.

An open-close lid52is provided which can be opened and closed at the bottom of the storage portion51. The open-close lid52is closed to prevent cut-off staple portions from falling during a stapling operation. An opening lever53for opening and closing the open-close lid52is attached to the open-close lid53, and is urged upward by a spring (not shown).

A release cam54pushes down the opening lever53. This release cam54is rotated in the direction of an arrow b by a driving force transmitted from a driving motor210through a pulley belt55so that the opening lever53can be pushed down against the force of the spring. By pushing down the opening lever53by a lid opening and closing portion210A including the release cam54and the driving motor210, the open-close  lid52can be opened. In this embodiment, the lid opening and closing portion210A is arranged at the front side of the sheet processing apparatus, which is the home position of the binding unit50A. The lid opening and closing portion210A opens the open-close lid52above the staple waste box60which is similarly arranged at the front side of the sheet processing apparatus10. The lid opening and closing portion210A can also be provided on the binding unit50A. By this arrangement, the open-close lid52can be opened or closed at any optional position.

When the cut-off staple portions stored in the storage has accumulated close to or reached a maximum capacity of the storage portion51during a stapling process (job), the storage portion51is moved above the staple waste box60.

After this, when the release cam54is rotated, due to a shape of the release cam54, the opening lever53is pushed down against the force of the spring as shown inFIG. 5. As a result, the open-close lid52rotates in the direction of an arrow c around an axis52aserving as a fulcrum. Accordingly, cut-off portions of staple freely fall into the staple waste box60as shown in the direction of an arrow d.

Subsequently, as shown inFIG. 3, when the release cam54further rotates and passes a point of action, the opening lever53rotates upward according to the shape of the release cam54and by the force of the spring. The open-close lid52turns in the direction of an arrow e inFIG. 6and goes from the open state to a closed state as described with reference  toFIG. 4. With respect to the release cam54shown inFIGS. 4 to 6, an angle A indicates a phase angle of the cam face when the open-close lid52transfers from the closed state to the open state, and an angle B indicates a phase angle of the cam face when the open-close lid52transfers from the open state to the closed state.

As described above, when the open-close lid52moves to the closed state, a lid open-close sensor208(shown inFIG. 11) detects the closed state of the open-close lid52. The lid open-close sensor208is includes, for example, a micro-switch to detect the open and closed state of the open-close lid52which will be described below with reference toFIG. 11. When the open-close lid52moves to the closed state, the open-close lid52pushes down a micro-switch to change the signal. The micro-switch is arranged in the storage portion51at the open end side of the open-close lid52.

FIGS. 7A and 7Bare diagrams showing a state when the storage portion51is moved above the staple waste box60as described above.FIG. 7Ashows the state in which the stapler50is at rest in the rear side stapling position in the two-point stapling mode. Note that this stapler50is configured to move on a moving rail97in the front-rear direction (sheet-width direction) driven by a stapler moving motor. The stapler moving motor can be a stepping motor (not shown) which constitutes a moving portion.

FIG. 7Bshows the state in which the storage portion51has moved above the staple waste box60integrally with the  stapler50according to an amount of cut-off staple portions stored in the storage portion51. When cut-off staple portions stored in the storage portion51are collected, the storage portion51is moved above the staple waste box60. Then, the open-close lid52is opened to collect the cut-off staple portions into the staple waste box60.

In this embodiment, the staple waste box60is arranged near the waiting position (home position) during a standby period for the job on the stapler50. This waiting position is set at the foremost front of the sheet processing apparatus10.

Meanwhile, the staple waste box60is supported by a support plate61as shown inFIG. 8. The support plate61can move in the vertical direction. When the staple waste box is filled with staple end portions, the support plate61, while supporting the staple waste box60, descends under the weight of the staple waste box60. When the staple cut-off portions accumulated in the staple waste box60exceed a certain amount, the user is supposed to dismount the staple waste box60from the support plate61and dispose of the staple cut-off portions.

To efficiently dispose of cut-off portions of staples accumulated in the staple waste box60, it is necessary to detect an amount of staple portions stored in the staple waste box60. After the cut-off portions of stapes have been discarded, it is also necessary to check if the staple waste box60is set surely in the support plate61.

To detect the amount of cut-off staple waste stored  in the staple waste box60, the support plate61is provided with a detection flag63. The support plate61is also provided with a detection lever64for checking if the staple waste box60is set in the support plate61.

In this embodiment, the staple waste box60is adapted to be set in the support plate61from the side, and the detection lever64is urged by a spring (not shown) in a direction opposite to the setting direction of the staple waste box60.

Therefore, if the staple waste box60is not set in the support plate61, the detection lever64can rotate in a direction that its distal end gets into the inside of the support plate as shown inFIG. 9, which will be described later. When the staple waste box60is set, the detection lever64rotates along a groove60aon a side of the staple waste box60against the force of the spring in the direction in which the staple waste box60is set.

On the other hand, on the sheet processing apparatus side, a detecting sensor62is provided which detects the positions of the detection flag63and the detection lever64to determine the amount of staple end portions and detects whether the staple waste box60is set. In this embodiment, as the detecting sensor62, a reflection type sensor is used to detect a state of the object by receiving different signals between when the detection object is in a predetermined position relative to the light-emitting surface and when it is not in the predetermined position.

For example, the detecting sensor62generates and  outputs different signals between when the detection object is in the vicinity of line L1adjacent to the detecting sensor62, and when the detection object is in the vicinity of line L2which is remote from the line L1. Hereinafter, a signal output when the detection object is in the vicinity of the line L1, is referred to as a first signal, and a signal output when the detection object is in the vicinity of the line L2is referred to as a second signal.

For example, as shown inFIG. 9, when the staple waste box60is not set in the support plate61, the detecting surface65of detection lever64, which is not yet rotated, is in the vicinity of the line L1. In this case, a first signal is output from the detecting sensor62.

As shown inFIG. 10, when the staple waste box60and the support plate61descend as the cut-off portions H of staples accumulate in the staple waste box60, along with them, the detecting surface66of the detection flag63also descends and comes to the vicinity of the line L1. In this case, a first signal is output from the detecting sensor62.

FIG. 8shows that the cut-off portions H of staples in the staple waste box60have not yet reached a predetermined amount, and the staple waste box60is set in the support plate61. The detecting surface65of the detection lever64is rotated pressed by the staple waste box60, and the detecting surface65of the detection lever64is in the vicinity of the line L2. In this case, a second signal is output from the detecting sensor62.

Based on a detection result, when a first signal is received, a control portion201shown inFIG. 11(which will be described below) causes the operation display portion214(refer toFIG. 2) to display a necessary message, such as an alert to the user. In this embodiment, one detecting sensor not only detects whether the staple waste box60is set but also detects the amount of cut-off portions H of staples in the staple waste box60so that the system configuration can be configured to be simple.

FIG. 11is a control block diagram of a sheet processing apparatus10as described above. InFIG. 11, a control portion201controls the processes in the sheet processing apparatus10. The control portion201includes a CPU, a ROM for storing programs and a weighting table, and a RAM used to temporarily store data (all not shown).

This control portion201receives signals from a staple position sensor204, a release cam phase sensor205, a full-state sensor101, a stapler home position sensor207, a lid open-close sensor208, and other detecting sensors213. The full-state sensor101is formed by a reflection type sensor similar to the above sensor62inFIGS. 8 to 10.

A communication control portion202controls communication between an image forming control portion203in the copying machine1and the sheet processing apparatus10. A counting portion211counts a number of stapling times during a stapling job. A stored amount calculating portion212calculates an amount of cut-off staple portions in the storage  portion51from, for example, a counting result of the counting portion211and a weighting table stored in the ROM (not shown). A lid open-close counter215counts a number of opening and closing operations of the lid52.

The control portion201supplies a control signal to a motor control circuit209based on the above detection information. Based on this control signal, a motor control portion209generates a control signal for a driving motor210(refer toFIG. 4) and operates the driving motor210to rotate the release cam54. Alternatively, a DC brush motor (not shown) can be driven to perform a stapler clinching motion in a stapling operation.

If the control portion201determines according to a signal from the lid open-close sensor208that the open-close lid52is not completely closed, as described below, the control portion201displays this information on the operation display portion214through the communication control portion202and the image forming control portion203.

Meanwhile, in this embodiment, the capacity of the storage portion51for storing cut-off staple portions is set at 200 copies of a book. Therefore, the storage portion51can store cut-off staple portions when stapling 100 sheet bundles in two-point stapling mode, or 200 sheet bundles in one-point stapling mode. However, the number of copies that can be set for one job is larger than the above capacity. Therefore, if a set number of sheet bundles is too large for the storage portion51to store the staple cut-off portions, the cut-off portions  can overflow from the storage portion51halfway in a stapling job.

A process of preventing cut-off staple portions from overflowing from the storage portion51during a stapling job is described with reference toFIG. 12. In the present embodiment, control in performing this process is described with regard to a case where the process is carried out by the control portion201. However, this process can also be controlled directly from the image forming control portion203in the copying machine main body1without using the control portion201.

For example, when a staple sort mode is specified for a job from the operation display portion214shown inFIG. 2, it is determined whether a bundle of sheets stacked on the process tray25has been stapled (step S501). In this case, because the mode for stapling is in effect, a stapling operation is carried out. When the stapling operation has been carried out, the decision in S501is YES, and the stapling counter at the counting portion211is incremented by one (step S502).

It is determined whether the stapling job has been completed (step S503). If the job has been completed (YES in step S503), the process is terminated. If there is a subsequent job (NO in step S503), it is determined whether the stapling counter has reached 200 (step S504).

When the stapling counter has reached 200 (YES in step S504), a process of discarding (collecting) cut-off staple portions (step S505) is performed, which will be described later.  When the process of discarding the cut-off staple portions is completed, the process returns to step S501.

Referring to the flowchart inFIG. 13, a process of collecting the cut-off portions from the storage portion51into the staple waste box60is described.

When the stapling counter reaches 200, the stapler50is moved to its home position (refer toFIG. 7) (step S511). Note that the home position is set at the foremost front position of the sheet processing apparatus10inFIG. 1as has been described. The stapler home position sensor207detects that the stapler50comes to the home position.

Next, the value (N) on the lid open-close counter215is set to 0 (refer toFIG. 11). The lid open-close counter215counts the number of an opening and closing operation of the open-close lid52(step S512). After this operation, when the stapler50reaches the home position, the driving motor210is started to open the open-close lid52(step S513). Then, a predetermined waiting time passes until the cut-off staple portions fall from the storage portion51into the staple waste box60(step S514). In this embodiment, a waiting period lasts two seconds, which is enough for all of the cut-off staple portions to fall from the storage portion51into the staple waste box60. When a predetermined time passes, the open-close lid is closed (step S515).

The cut-off portions of staples fall from the storage portion51into the staple waste box60. However, during a closing motion of the open-close lid52, the cut-off portions  of staples sometimes remain adhering to the open-close lid and get caught between the open-close lid52and the storage portion51. In this case, since the open-close lid52cannot be completely closed, a gap appears between the open-close lid52and the storage. If the next stapling operation is performed under this condition, cut-off staple portions that are newly accumulated can come out through the gap.

For this reason, in this embodiment, if it is determined that the open-close lid52is still open, the control portion201controls the above-described lid opening and closing portion210A to perform an opening and closing operation of the open-close lid52five times at most. By repeating an opening and closing of the open-close lid52, the open-close lid52is vibrated enough to cause the cut-off staple portions adhering to the open-close lid to fall into the staple waste box60.

After the open-close lid is closed, the lid open-close counter is incremented (step S516). Then, the above-described lid open-close sensor208determines whether the open-close lid52is closed (step S517). If it is determined that the open-close lid52is closed (YES in step S517), the stapler50is again moved to the stapling position (step S518) and is set ready for a subsequent stapling job. After this operation, the stapling counter is cleared (step S519).

On the other hand, if it is determined that the open-close lid52is not closed, in other words, the open-close lid52is in an open state (NO in step S517), the lid open-close  counter215showing the number of times of opening and closing the open-close lid52is checked. If the value on the lid open-close counter215has not reached five (5) (NO in step S520), the process returns to step S513. After the opening motion of the open-close lid52is performed, the closing motion of the open-close lid52is carried out (step S515).

When the number of times of opening and closing the open-close lid52has reached five (5) (YES in step S520), in other words, when the open-close lid52cannot be closed even if the opening and closing motion has been repeated five times, an alarm message appears on the operation display portion214, urging the operator to check the cut-off staple portions in the storage portion51(step S521). Thus, cut-off staple portions are disposed of before the capacity of the storage portion51is exceeded, so that the cut-off portions of staples are prevented from overflowing from the storage portion51.

When the job is completed, the stapler50returns to the home position, and the stapling counter is cleared. After this operation, the cut-off staple portions accumulated in the storage portion51are collected in the staple waste box60, and the stapler is set ready for the next job. By this process, the storage portion51is emptied before the next job is started.

Thus, after the cut-off portions H of staples have been collected from the storage portion51into the staple waste box60, if it is detected that the open-close lid52is not closed, the opening and closing operation of the open-close lid52is retried. Accordingly, the cut-off staple portions adhering to  the open-close lid52can fall into the staple waste box60. Therefore, the open-close lid52can be closed surely, and as a result, the cut-off staple portions can be prevented from coming out through the gap between the storage portion51and the open-close lid52, so that the ease of use of the stapler is improved.

In the foregoing description, if it is detected that the open-close lid52is open, an operation of opening and closing the open-close lid52is carried out five times. In each operation of opening and closing the lid52, first the open-close lid52is opened and after waiting a certain period of time, the open-close lid52is closed.

However, an embodiment of this invention is not limited to the above-described process. The operation of opening and closing the open-close lid52can be carried out, for example, five times continuously. During the operation, cut-off staple portions adhering to the open-close lid52can fall into the staple waste box60.

Another process is described with reference to the flowchart inFIG. 14in which cut-off staple portions adhering to the open-close lid52can fall into the staple waste box60.

In this case, when the stapling counter reaches 200, to begin with, the stapler50is moved to the home position (step S611). Then, when the stapler50reaches the home position, the open-close lid52is opened (step S612). A predetermined waiting time passes until cut-off staple portions fall from the storage portion51into the staple waste box (step S613). Then,  the open-close lid52is closed (step S614).

Next, it is determined whether the open-close lid52is closed (step S615). When the open-close lid52is closed (YES in step615), the stapler50is again moved to the stapling position (step S616) to be ready for a subsequent stapling job. Then, the stapling counter is cleared (step S617).

On the other hand, if it is determined that the open-close lid52is not closed (NO in step S615), the open-close lid52is continuously opened and closed a predetermined number of times (five times in this embodiment) (step S618). Then, it is determined whether the open-close lid52is closed (step S619). At this time, if it is determined that the open-close lid52is not closed (NO in step S619), an alarm message is displayed on the operation display portion214, urging the operator to check the cut-off staple portions in the storage portion51(step S620). However, when it is determined that the open-close lid52is closed (YES in step S619), the process returns to S616.

In the above description, in order to detect the amount of cut-off staple portions stored in the storage portion51, detection is performed based on the position of the cut-off staple waste box60as shown inFIG. 8.

However, this invention is not limited to the above-mentioned embodiment. As shown inFIG. 15, for example, the amount of cut-off staple portions stored in the storage portion51can be determined directly by the full-state sensor101when the sensor101detects a dotted line (a) which indicates  the top of the cut-off portions H of staples. In this case, as the full-state sensor101, a reflection type sensor as described above is used, but the other type of a sensor can also be used.

A process of collecting cut-off staple portions using this full-state sensor101is described with reference to the flowchart inFIG. 16.

When the staple sort mode is specified for a stapling job from the operation display portion214as shown inFIG. 2, it is determined whether stapling has been performed on a bundle of sheets stacked on the process tray25(step S561). In this case, since the specified mode is stapling, the sheet bundle is stapled. When stapling is completed (YES in step S561), it is determined if the stapling job is finished (step S562).

When the job is finished (YES in step S562), the process is terminated. If there is a subsequent job (NO in step S562), the full-state sensor101determines whether the storage portion51is full (step S563). The full-state sensor101determines that the storage portion51is full when it detects the dotted line (a) that indicates the top of the cut-off staple portions inFIG. 15.

When the storage portion51is determined to be full (YES in step S563), a process of discharging (collecting) the cut-off staple portions is carried out (step S564). When the process of discharging the cut-off staple portions is completed, the process returns to step S561. The process of discarding the cut-off staple portions in step S564is similar to the  process from steps S511to S516described in the flowchart inFIG. 13. If the storage portion51is not full (NO in step S5623), the process returns to step S561.

The process of detecting the closed state of the open-close lid52when the staple sort mode has been selected on the operation display portion214is described with reference to the flowchart inFIG. 17.

It is determined whether the staple sort mode has been selected (step S531). If the staple sort mode has not been selected (NO in step S531), this process is terminated. On the other hand, if the staple sort mode has been selected (YES in step S531), it is determined whether the open-close lid52is open (step S532).

If the open-close lid52is closed (NO in step S534), the staple sort mode is set (step S535). On the other hand, if it is determined that the open-close lid52is open though the closing motion of the open-close lid52has been performed (YES in step S532), the alarm message as shown inFIG. 2, for example, is displayed on the operation display portion214(step S533).

Then, it is again determined whether the open-close lid52(step S534) is closed. If the open-close lid52remains open (YES in step S534), the process returns to step S533. When it is determined that the open-close lid is closed (NO in step S534) after the user removes the cut-off staple portions adhering to the open-close lid52, the staple sort mode is set (step S535). By performing those steps in the stapling  operation, the open-close lid52can be prevented from remaining open.

Incidentally, if the open-close lid52opens for some reason while a stapling job is underway, the cut-off staple portions are scattered from the storage portion51. Therefore, if the open-close lid52opens while a stapling job is being carried out, the process shown inFIG. 8is executed.

If the lid open-close sensor208determines that the open-close lid52is open while a stapling job is being carried out (YES in step S551), the job underway is suspended (step S552). Then, the process of disposing of the cut-off staple portions is carried out (step S553). Since this process has been already described, its description is omitted here. Next, the suspended job is resumed (step S554).

Thus, when it is determined that the open-close lid52is open during the execution of the stapling job, the job is suspended. The job is resumed after the open-close lid52is closed, so that the cut-off staple portions are prevented from scattering from the storage portion51.

In this embodiment, when cut-off staple portions have piled up in the staple waste box60, the user takes out the staple waste box60by pulling the staple waste box60from the sheet processing apparatus10in the direction to the front side, and discards the cut-off staple portions. In order to improve the operability of the apparatus, the range of opening and closing motion of the open-close lid52should not interfere with the dismounting direction of the staple waste box60.

To this end, an intermediate fixing guide67can be provided between the storage portion51and the staple waste box60as shown inFIG. 19, so that the open-close lid52can open and close within the intermediate fixing guide67. By this arrangement, the staple waste box60can be easily pulled out regardless of the state of the open-close lid52, and thus, the ease of use of the stapler50and the staple waste box60are improved.

In the above description, a micro-switch is used as an example for the lid open-close sensor208, but it can be configured such that when the open-close lid52is closed completely, a flag is detected. Further, an optical sensor can be used for the lid open-close sensor208, which has a light-emitting portion and a light-receiving portion arranged respectively at the front side and the rear side of the sheet processing apparatus10. In this configuration, the open and closed states of the open-close lid52can be monitored. Furthermore, in the foregoing description, the driving motor210is used as an example for the lid opening and closing portion210A to drop the cut-off staple portions from the open-close lid52. However, a vibration source can be installed to vibrate the open-close lid52when the open-close lid52is open.

This application claims priority from Japanese Patent Application No. 2006-032882 filed Feb. 9, 2006, which is hereby incorporated by reference herein in its entirety.