JP2003002501A - Sheet processing device and image forming device equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processing device capable of improving the sheet processing efficiency and an image forming device equipped with the same. SOLUTION: Sheets to be carried to the sheet processing device 101 are temporarily held in holding passages 23 and 41 branched from a carrying passage 22 for carrying sheets to the sheet processing means 101, and the number of sheets held in the holding passages 23 and 41 is changed according to the size of the sheets or the sheet processing motion of the sheet processing means 101 by a control means. As a result, the number of sheets can be set so that the sheets can be processed by the size or the sheet processing motion without stopping the device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet processing apparatus and an image forming apparatus including the same, and more particularly to a sheet processing apparatus having a standby path for waiting a sheet to be processed next when processing the sheet.

[0002]

2. Description of the Related Art Some image forming apparatuses such as conventional copying machines and laser beam printers are equipped with a sheet processing apparatus for performing binding processing and folding processing on sheets after image formation. Here, as such a sheet processing apparatus, for example, as shown in Japanese Patent Laid-Open No. 10-194582, a processing tray that staples sheets as needed, and a sheet is received and accommodated in bundles. Some are equipped with a stack tray.

FIG. 20 shows the structure of such a conventional sheet processing apparatus. In the figure, reference numeral 238 is a processing tray, 224 is a stack tray, and a stapler 222 for binding staples around the processing tray 238, a jogger 221 for aligning sheets while moving in the front and back directions, and conveying sheets. Transport path 206, a standby path (hereinafter referred to as a buffer path) 208 for temporarily retracting the sheet from the transport path 206, a buffer roller 209 for transporting the sheet in the buffer path, and a discharge roller pair for discharging the sheet to the processing tray 238. 217, 218,
A pair of bundle discharge rollers 232 and 233 for transferring the sheet bundle on the processing tray to the stack tray 224 is provided.

When the sheet discharged from the image forming apparatus (not shown) is conveyed into the sheet processing apparatus, for example, when the staple mode is set, the sheet first passes through the conveying path 206 and is discharged from the discharging roller. Pair 217,21
8 to the processing tray 238, and then the jogger 221 aligns the sheets. At this time, the bundle discharge roller pair 2
32 and 233 are separated from each other and do not interfere with the discharging operation and the aligning operation.

Next, the final sheet of the sheet bundle is the processing tray 23.
When the sheets are aligned in step 8, the stapler 222 performs staple binding processing. Note that, after such staple binding processing is performed, the sheet bundle currently in the processing tray 238 is discharged to the stack tray 224 by the bundle discharge rollers 232 and 233 so that the next sheet can be discharged onto the processing tray 238. Perform processing to

By the way, the next sheet cannot be received until the processing tray 238 is emptied after such processing (stapling processing, bundle discharging processing) is completed.
While performing such processing, the output sheet is temporarily passed through the buffer path 208 by the buffer roller 209.
I'm trying to make it wait (buffering).

Then, after that, when the processing tray 238 becomes empty, the sheet waiting in the buffer path 208 and the sheet to be discharged next are overlapped at the same time so that the sheet to be discharged next comes first. , Discharge roller pair 21
7, 218, the sheet is discharged to the processing tray 238, and the sheet is reversely fed so that the trailing edge of the sheet is abutted against the trailing edge stopper 220 provided at the end of the processing tray 238 for alignment.

[0008]

By the way, in the conventional sheet processing apparatus having such a configuration and the image forming apparatus including the same, the processing time varies depending on the set mode and the size of the sheet to be processed. That is, the processing time is longer in the staple sort mode than in the sort mode without stapling, and the number of sheets that need to be buffered during that time is also increased accordingly.

At the same processing time, A4, B5, L
Half size sheets such as TR are A3, B4, LD
Since the productivity is generally higher than that of a large size sheet such as R, the number of sheets to be buffered also increases. Therefore, if the buffering number N is set to correspond to the longest processing time in all modes and sizes,
The number of sheets that can be processed without stopping the image forming apparatus is N, and even if the processing time and size are shorter than that, the number is N.
You will not be able to set less.

If the number of buffering sheets cannot be set in accordance with all modes and sizes in this manner, the number of sheets to be buffered is more than the required number of sheets, so that the sheet processing efficiency deteriorates.

On the other hand, conventionally, there is a case of processing a sheet bundle in which a large size sheet and a half size sheet having different lengths in the conveying direction are mixed, and in this case, the sheet bundle is discharged to a processing tray and then fed back to the rear end. The sheet is aligned by abutting against the end stopper 220, but at this time, if the difference in distance between the rear end position of each size of the sheet and the rear end stopper 220 is too large, the sheet does not come into contact with the rear end stopper 220. There was a problem that the misalignment occurred.

Therefore, the present invention has been made in view of the above circumstances, and it is a first object of the present invention to provide a sheet processing apparatus capable of improving sheet processing efficiency and an image forming apparatus including the sheet processing apparatus. It is intended. A second object of the present invention is to provide a sheet processing apparatus capable of preventing the occurrence of misalignment when processing a sheet bundle in which sheets of different sizes are mixed, and an image forming apparatus including the sheet processing apparatus.
Is the purpose of.

[0013]

SUMMARY OF THE INVENTION The present invention is a sheet processing apparatus provided with a sheet processing means for processing a sheet, and a conveying path for conveying the sheet to the sheet processing means. A standby passage for temporarily holding the sheet toward the sheet processing means, and a control means for changing the size of the sheet or the number of sheets to be kept waiting in the standby passage according to the sheet processing operation by the sheet processing means And are provided.

Further, according to the present invention, a first position is provided at a branch point between the conveying passage and the standby passage, and the sheet is introduced into the standby passage, and the sheet is passed through without being introduced into the standby passage. A passage switching unit that can switch to the second position is provided, and the control unit responds to the size of the sheet or the sheet processing operation by the sheet processing unit so as to change the number of sheets to be put on standby in the standby passage. It is characterized in that the timing for moving the passage switching means in the first position to the second position is changed.

Further, the present invention comprises size detecting means for detecting the size of the sheet, and the control means comprises the path switching means at the first position according to the sheet size information from the size detecting means. It is characterized by changing the timing of moving to a position.

The present invention further comprises setting means for setting the size of the sheet or sheet processing operation by the sheet processing means, and the control means is the sheet size information from the setting means or the sheet processing operation. The timing for moving the passage switching means at the first position to the second position is changed according to the above.

Further, the present invention is characterized in that the sheet processing means is staple binding means for staple binding a sheet bundle.

Further, the present invention is characterized in that the front sheet processing means is punching means for punching a sheet bundle.

Further, the present invention is characterized in that the sheet processing means is a gluing binder for gluing a sheet bundle and binding.

Further, the present invention comprises a conveying means for pulling the sheet into the waiting passage and sending the sheet drawn into the waiting passage to the conveying passage, and the control means makes the waiting passage wait for sheets of different sizes. At this time, the driving of the conveying means is controlled so that the rear ends of the respective sheets are close to each other.

The present invention further comprises a conveying means for pulling the sheet into the standby passage and sending out the sheet drawn into the standby passage to the conveying passage, wherein the control means is a confluence point of the conveying passage and the standby passage. Then, the drive of the conveying means is controlled so that the rear ends of the sheets passing through the conveying path and the standby path are close to each other.

Further, the present invention is an image forming apparatus comprising an image forming section for forming an image on a sheet and a sheet processing apparatus for processing the sheet image-formed by the image forming section, wherein the sheet processing apparatus is the above-mentioned. It is characterized by being described in any of the above.

Further, as in the present invention, the sheet facing the sheet processing apparatus is temporarily made to stand by in the standby passage branched from the conveying passage for conveying to the sheet processing means, and the size of the sheet or the sheet processing means is controlled by the control means. By changing the number of sheets to be made to stand by in the standby path according to the sheet processing operation by the sheet processing operation, the number of sheets that can be processed without stopping the apparatus is set for each sheet size or each sheet processing operation. .

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

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

In the figure, 300A is a copying machine and 300
Is a copying machine main body, and the copying machine main body 300 includes a platen glass 906 as a document placing table, for example, an image forming unit 300B for forming an image by an electrophotographic method, and an automatic document feeding for feeding a document to the platen glass 906. A feeding device 500 and the like are provided.

Further, in the figure, 1 is a finisher which is a sheet processing apparatus, 2 is a pair of entrance rollers provided in the sheet receiving port 1a of the finisher 1, 3 are conveying rollers, 31 is a first sheet detecting sensor, and 50 is A punch unit that punches holes near the trailing edge of the conveyed sheet, 5
Is a buffer roller, and this buffer roller 5 and the pressing rollers 12, 13, 1 which are in pressure contact with this buffer roller 5.
The sheet is nipped by 4 and conveyed.

Further, 4 is an entrance path, 11 is a first switching flapper for directing the sheet that has passed through the entrance path 4 to the non-sort path 21 or the sort path 22, and 10 is a sheet for temporarily storing the sheets flowing to the sort path 22 and the sort path 22. A second switching flapper 40, which is a passage switching unit provided at a branch point from the half buffer path 23 that is a standby passage for (holding) the sheets, temporarily stores the sheets that flow to the sort path 22 and the sort path 22 (standby). Is a third switching flapper which is a passage switching means provided at a branch point from the large buffer path 41 which is a standby passage for (1).

Note that the half buffer path 23 and the large buffer path 41 have entrances at their ends so that a sheet can be drawn in by a buffer roller 5 which is a conveying means and the drawn sheet can be sent out to a sort path 22 which is a conveying path. It is connected to pass 4.

Here, the half buffer path 23 is formed around the buffer roller 5 so that half size sheets such as A4, B5 and LTR can be stored. Further, a part of the large buffer path 41 is formed around the buffer roller 5, and the half buffer path 23
It is configured to be extended longer than that, and is capable of storing large size sheets such as A3, B4, and LDR.

Further, 6 is a conveying roller provided in the sort path 22, 130 is a processing tray which is an intermediate tray for performing alignment and stapling after temporarily stacking sheets (bundles), and 7 is a processing tray 130. A discharge roller for discharging sheets, 150 is a swing guide, 180b is supported by the swing guide 150, and a bundle discharge lower roller 180a arranged on the processing tray 130 when the swing guide 150 is moved to the closed position. A bundle discharge upper roller that cooperates to discharge the sheets on the processing tray 130 to the stack tray 200.

Further, 101 is a stapler 101 which is a sheet processing means for performing a staple binding process on a sheet bundle stacked on the processing tray 130.
Is moved to the binding position by a driving means (not shown).

Further, 200 is a stack tray, 201 is a sample tray, and these two trays 200, 2
01 is used properly depending on the situation, the lower stack tray 200 is selected when receiving copy output, printer output, etc., and the upper sample tray 201 is sample output, interrupt output, stack tray overflow output, function sorting. It is designed to be selected when receiving output, job mixed output, and the like.

By the way, in the present embodiment, the copying machine 300A can be set to the non-sort mode, the sorting mode, etc., and the finisher 1 can be set to the copying machine 30A.
The sheet is processed according to the mode set by 0A.

Next, the flow of the sheet P in each mode of the finisher 1 will be described.

First, the non-sort mode will be described.
In this mode, first, when the user sets the non-sort mode by the operation unit shown in FIG. 18 of the copying machine main body 300, which will be described later, the sheet P is discharged from the discharging roller 399 of the copying machine main body 300 as shown in FIG. This sheet P
Is a pair of entrance rollers 2, a conveyance roller 3, a buffer roller 5
And the non-sort path 2 by the first switching flapper 11 which has been moved to the position shown in the figure by a solenoid (not shown).
1 is transported.

After that, when the sheet detection sensor 34 detects the trailing edge of the sheet P, the discharge roller 9 rotates at a speed suitable for stacking, and the sheet P is discharged to the sample tray 201.

Next, the staple sort mode will be described.

When the staple sort mode is set,
As shown in FIG. 3, the sheet discharged from the copying machine main body 300 is moved by the entrance roller pair 2, the conveying roller 3, the buffer roller 5, and the first to third flappers 10, 11, and 40 that have moved to the positions shown in FIG. After passing through the sort path 22, the sheet is discharged onto the processing tray 130 by the discharging roller 7.

In the figure, reference numeral 170 denotes a retractable tray which is provided below the bundle discharge lower roller 180a and which advances and retreats in the sheet conveying direction while substantially following the inclination of the processing tray 130. When the sheet is discharged toward the processing tray 130, it is in a protruding state as shown in FIG. The protruding / retracting tray 170 thus prevents the leading edge of the sheet P from hanging down when the sheet P is discharged by the discharging roller 7 and thereby causing a return failure, and also prevents the sheet on the processing tray from becoming defective. The alignment of P can be improved.

On the other hand, the sheet P discharged toward the processing tray 130 starts to move by its own weight toward a rear end stopper 131 shown in FIG. The rotation of is to facilitate movement. After this, the sheet P
When the rear end surely contacts the rear end stopper 131 and stops, the rotation of the paddle 160 is also stopped, and the alignment member 140 performs alignment in the width direction that is a direction orthogonal to the ejection direction of the ejected sheet P.

Next, when all the sheets P of the first copy are discharged onto the processing tray 130 and aligned as described above, the swing guide 150 swings downward as shown in FIG. The bundle discharge upper roller 180b is the bundle discharge lower roller 180
The sheet bundle PA is sandwiched together with a and the sheet bundle PA is fixed. Then, the stapler 101 staples the sheet bundle PA with the sheet bundle PA fixed in this way.

By the way, after the sheet bundle PA is stapled in this way, in order to discharge the next sheet P to the processing tray 130, the above processing (sheet bundle stapling processing, bundle discharging processing) is performed, and the processing tray 130 is emptied. I have to

Here, the sheet P is discharged from the copying machine main body 300 unless the copying machine 300A is stopped during this process. In such a case, the copying machine 30
In order not to reduce the productivity of 0, the half buffer path 23 is discharged before the sheet P discharged from the copying machine main body 300 is discharged to the processing tray 130 while the sheet P is processed as described above. Alternatively, it is necessary to perform buffering for temporarily storing in the large buffer path 41.

Next, the buffering operation will be described according to the sheet size. First, the case of buffering a half size sheet will be described.

In this case, the first sheet PH1 discharged from the copying machine main body 300 is the sheet PH shown in FIG.
1 for introducing 1 into the half-pass path 23 in the standby passage
After being guided to the half buffer path 23 by the second switching flapper 10 that has moved to the position, the second switching flapper 10 winds the buffer roller 5 and stops after the predetermined distance from the second sheet detection sensor 32.

Next, when the second sheet PH2 advances from the first sheet detection sensor 31 by a predetermined distance, the buffer roller 5 rotates as shown in FIG. After the sheets PH2 of the eyes are overlapped with each other so as to be ahead by a predetermined distance based on the rear end,
As shown in (3), it is wound around the buffer roller 5 and stopped again when it has advanced a predetermined distance from the second sheet detection sensor 32.

Then, when the third sheet PH3 advances from the first sheet detection sensor 31 by a predetermined distance, the buffer roller 5 rotates again, and the sheet PH3 is already waiting in the half buffer path 23. Before the leading edge reaches the second switching flapper 10, the second switching flapper 10 feeds the sheet shown in FIG. 7 to the half buffer path 23 before the leading edge reaches the second switching flapper 10. To the second position where it passes without being introduced into the
1, PH2 and PH3 are sent out to the sort path 22 that conveys the sheet to the stapler 101.

The half-sized sheet PH1,
Half buffer path 2 where PH2 and PH3 are saved
3 is the feeding direction, and half-size sheets PH1 and PH
2, PH3 has a length suitable for the dimension, and the next sheet does not enter before stopping the sheets PH1, PH2, PH3 in the half buffer path.

On the other hand, when buffering a large size sheet, as shown in FIG. 8, the second switching flapper 10 moves the sheet P to the second position for directing the sheet P to the sort path 22, and the third switching flapper 40 moves the sheet P to the sheet P. The sheet PL1 discharged from the copying machine main body 300 is moved to the first position which leads to the large buffer path 41.
Enters the large buffer path 41 and stops at a predetermined distance from the third sheet detection sensor 42. The transport roller 43 of the large buffer path 41 is designed to rotate in conjunction with the buffer roller 5.

Then, when the next sheet PL2 advances from the first sheet detection sensor 31 by a predetermined distance, the buffer roller 5 and the conveying roller 43 rotate, and as shown in FIG. Sheet PL2 is superposed so as to precede by a predetermined distance based on the rear end,
As shown in the figure, it is wound around the buffer roller 5 and stopped again when it advances from the third sheet detection sensor 42 by a predetermined distance.

Subsequently, when the third sheet PL3 advances from the first sheet detection sensor 31 by a predetermined distance, the buffer roller 5 and the conveying roller 43 rotate again, and as shown in FIG. 10, the sheet PH3 is already in the large buffer. The sheets PH1 and PH2 waiting on the path 41 are fed while being superposed so as to precede the sheets PH1 and PH2 by a predetermined distance with the trailing edge as a reference,
Before the tip reaches the third switching flapper 40, the third
The switching flapper 40 moves to a second position where the sheet shown in the same figure is passed without being introduced into the large buffer path 41 and is moved to a position, whereby three sheets PH1,
PH2 and PH3 come to be sent to the sort path 22.

Large size sheets PH1 and PH
The large buffer path 41 in which PH2 and PH3 are retracted is a large size sheet PH1, PH2, in the feeding direction.
It has a length suitable for the size of PH3, so that the large sheets PH1 and PH can be placed in the large buffer path.
2, PH3 is certainly accommodated.

By the way, in this embodiment, the sheets P of different sizes can be stapled. Even in such a case, the sheet P
The sheet P discharged from the copying machine main body 300 is subjected to the buffering before being discharged to the processing tray 130 during the processing (1).

Here, when buffering the sheets P of different sizes in this way, first, as in the case of the large size sheet, the first sheet PM1 is stored in the large buffer path 41 as shown in FIG. Stop at. Then, after that, the same operation is performed so that the second sheet PM2 precedes the first sheet PM1 with the trailing edge as a reference.

At this time, when the first sheet PM1 is the half size and the second sheet PM2 is the large size, the stop position of the first sheet PM1 is the third sheet detection sensor 42 as shown in FIG. It is controlled by the first sheet detection sensor 31 so as to be located upstream of the above.

Here, the stop position is the second sheet P.
M2 is conveyed by the buffer roller 5, and at the same time, the buffer roller 5 and the conveying roller 43 are rotated, so that the first sheet P
When M1 overlaps with the second sheet PM2, the second sheet PM2 precedes with the trailing edge as a reference, and
The rear ends of the sheets PM1 and PM2 are set to be close to each other. Note that the same setting is made when buffering the third sheet PM3.

On the contrary, when the first sheet PM1 is large size and the second sheet PM2 is half size, FIG.
As shown in, the sensor 31 controls the stop position of the first sheet PM1 to be located downstream of the sensor 42.

Here, the stop position is the second sheet P.
M2 is conveyed by the buffer roller 5, and at the same time, the buffer roller 5 and the conveying roller 43 are rotated, so that the first sheet P
When M1 overlaps with the second sheet PM2, the second sheet PM2 precedes with the trailing edge as a reference, and
The rear ends of the sheets PM1 and PM2 are set to be close to each other. Note that the same setting is made when buffering the third sheet PM3.

When the sheets P having different sizes are stapled as described above, the rear end of the sheet P is set to be close to each other in the large buffer path 41.
In other words, when waiting for sheets of different sizes in the large buffer path 41, the drive of the buffer roller 5 and the transport roller 43 is controlled so that the trailing ends of the sheets come close to each other, and thereafter the sheet bundle When the sheet is discharged to the processing tray 130 and the trailing edge is abutted against the trailing edge stopper 131, the difference in the distance between the trailing edge position of each sheet and the trailing edge stopper 130 can be reduced. This can prevent the occurrence of misalignment when processing a sheet bundle in which sheets of different sizes are mixed.

The above is the buffering operation according to the size, and the following is common description regardless of the size.

By the way, during such a buffering operation, the sheet bundle on the processing tray 130 is discharged onto the stack tray 200 as shown in FIGS. At this time, the retractable tray 170 moves to the home position (see FIG. 12) before the sheet bundle PA leaves the bundle discharge rollers 180a and 180b in order to drop the sheet bundle PA onto the stack tray 200.

Also, at this time, as shown in FIG. 13, the swing guide 150 receives the three sheets P by the bundle discharge rollers 180a and 180b while swinging downward, and thereafter, as shown in FIG. And the trailing edge of the sheet P is the discharge roller 7.
If the bundle discharge rollers 180a and 180b are rotated in the reverse direction before the trailing end abuts the trailing end stopper 131, as shown in FIG.
As shown in FIG. 5, the swing guide 150 moves up.

As a result, the bundle discharging upper roller 180b is
Move away from the seat surface. The fourth and subsequent sheets P are
Similar to the operation of the first copy, it is discharged onto the processing tray through the sort path. After the third copy, the same operation as the second copy is performed,
The set number of sets are stacked on the stack tray 200, and the process ends.

Next, the sort mode will be described.

When the user sets the original on the RDF 500, designates the sort mode by the operation section shown in FIG. 18 to be described later, and turns on the start key (not shown), the entrance roller 2 and the conveying roller 3 perform staple sort. Similar to the mode, the sheets are rotated as shown in FIG. 16 to stack the sheets on the processing tray 130. Here, after a small number of sheets are stacked on the processing tray while aligning the sheets P on the processing tray 130 by the aligning member 140, the swing guide 150 swings downward as shown in FIG. A small number of sheet bundles are conveyed in a bundle by bundle discharge rollers 180a and 180b.

Here, the sheet P sent next passes through the first switching flapper 10 and is wound around the buffer roller 5 in the same manner as the operation described in the staple sort mode, and the processing tray 130 after the bundle discharge is completed. Is discharged to. It should be noted that the number of the small number of bundles to be discharged is preferably 20 or less through experiments. Regarding this number, the number of originals ≧ the number of sheets discharged in a bundle ≦ 20 is satisfied.

Therefore, when setting the program, for example, when the number of sheets to be discharged in the bundle is set to 5, when the number of originals is 4, the bundle is discharged in units of 4 sheets. If the number of originals is 5 or more,
For example, when the number of sheets is 14, the sheets are divided into 5 sheets + 5 sheets + 4 sheets, aligned, and discharged in a bundle.

By the way, in the above description, the number of buffering sheets is 3 for both half and large size while the sheet bundle processing (staple processing, bundle discharge processing) is performed in the staple sort mode and the sort mode. In the present invention, the number of buffered sheets can be changed according to the above sheet processing operation, in other words, according to the time spent for sheet processing.

For example, four sheets are used in the two-point staple mode, which is the sheet processing operation that takes the longest time, three sheets in the one-point staple mode, which takes the next longest, and two sheets in the sort mode that does not perform stapling. There is.

In this embodiment, as shown in FIG. 18, the finisher 1 is provided so that the number of buffered sheets can be changed according to the sheet processing operation.
When it is determined that the one-place staple mode is set based on the setting information from the operation unit 102, which is a setting unit that sets the sheet processing operation, the control unit 100 that controls the half buffer path 23 or the large buffer path 41. After temporarily storing the three sheets, the second switching flapper 10 and the third switching flapper 40 are switched from the above-described first position to the second position.

As a result, in the one-place staple mode, the number of sheets to be buffered can be three,
The number of sheets corresponding to the time spent for sheet processing can be buffered, and the sheet processing efficiency is improved.

Further, the number of buffering sheets may be reduced depending on the sheet size, for example, in the case of the large size which is low in productivity, the number of buffering sheets may be smaller than the half size.

In this case, the control means 100 first determines the sheet size based on the sheet size signal from the sheet size detection means 103 provided in the sheet path 22 or the sheet size information from the operation unit 102. To do so.

Thereafter, for example, when the one-place staple mode is set, three sheets are temporarily stored in the half buffer path 23 when the sheet is half size, and when the sheet is large size. Temporarily stores two sheets in the large buffer path 41, then
The switching flapper 10 and the third switching flapper 40 are switched from the first position to the second position. As a result, the number of sheets corresponding to the sheet size can be buffered, and the sheet processing efficiency is improved.

As described above, by changing the number of sheets to be buffered according to the sheet size or the sheet processing operation, in other words, the sheet is located at the first position according to the sheet size or the sheet processing operation. By changing the timing of moving the second switching flapper 10 and the third switching flapper 40 to the second position and changing the number of sheets to be buffered, the apparatus is not stopped for each sheet size or each sheet processing operation. It is possible to set the number of sheets that can be processed in.

Next, a second embodiment of the present invention will be described.

FIG. 19 is a diagram showing the structure of the sheet processing apparatus according to this embodiment. In addition, in FIG.
The same reference numerals as those in FIG. 7 indicate the same or corresponding portions.

In the figure, 44 is a straight path which is a conveying path connecting the inlet roller 2 to the discharge roller 7,
47 is a large buffer path, and this large buffer path 47 partially overlaps the half buffer path 23. Reference numeral 46 is a fourth switching flapper provided at a branch point between the straight path 44 and the large buffer path 47.

Next, the buffering of the large size sheet in this embodiment having such a structure will be described.

While the sheet processing by the stapler 101 or the like is being performed, first, the first sheet P of the next sheet bundle is
1 is an action of each flapper 10, 11, and 46, first from the entrance roller 2 through the conveying roller 3, the buffer roller 5 and the like,
The tip stops before the discharge roller 7 reaches a predetermined amount. At this time, the rear end is out of the entrance roller 2. Then, the second sheet P2 enters the straight path 44 by the rotation of the flapper 46, and when the leading edge passes the straight path roller 45,
The sheet P1 is again conveyed by the conveying roller 3, the buffer roller 5, and the like.

Here, in the present embodiment, the straight path 44 and the large buffer path 47 have two merging points.
The first sheet P1 and the second sheet P2 are stacked so that the second sheet P2 precedes with the trailing edge as a reference, and then the sheet is discharged onto the processing tray 130 by the sheet discharge roller 7.
The subsequent processing is the same as that of the above-described first embodiment.

On the other hand, when the sheets P having different sizes are stapled, the control means 100 controls the buffer roller 5, and the straight path 44 and the large buffer path 47.
The two sheets P1 and P2 are overlapped with each other at the confluence portion so that the rear end of the half size sheet is close to the rear end of the large size sheet. This can prevent the occurrence of misalignment when processing a sheet bundle in which sheets of different sizes are mixed.

When the sheets are buffered in this way, the first sheet P is originally placed on the processing tray.
1 is stacked above the second sheet P2, and the desired page order cannot be obtained. Therefore, for example, the image forming apparatus 300 stores the output image information in a memory unit (not shown) so as to match the page order, and converts the image according to the first and second sheets or the number of sheets to be buffered. I try to do it.

Although the case where the stapler is used as the sheet processing means has been described so far, the present invention is not limited to this, and a puncher (punch means) for collectively punching the sheet bundle as the sheet processing means is used. Alternatively, a gluing binder for gluing one end portion of the sheet bundle and binding may be used. Here, the puncher and the gluing binder are already widely known, and a description thereof will be omitted.

[0086]

As described above, according to the present invention, the number of sheets to be made to stand by in the waiting path is changed according to the sheet size or the sheet processing operation by the sheet processing means, or each sheet size is changed. The sheet processing efficiency can be improved by setting the number of sheets that can be processed without stopping the apparatus for each sheet processing operation.

Further, when processing a sheet bundle in which sheets of different sizes are mixed, by stacking sheets of different sizes so that their rear ends are close to each other,
It is possible to prevent the occurrence of misalignment.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating a sheet flow in a non-sort mode of the finisher.

FIG. 3 is a first diagram illustrating a sheet flow in the staple sort mode of the finisher.

FIG. 4 is a second diagram illustrating a sheet flow in the staple sort mode.

FIG. 5 is a third diagram illustrating the flow of (half-size) sheets in the staple sort mode.

FIG. 6 is a fourth diagram illustrating the flow of (half-size) sheets in the staple sort mode.

FIG. 7 is a fifth diagram illustrating a (half-size) sheet flow in the staple sort mode.

FIG. 8 is a sixth diagram illustrating the flow of (large size) sheets in the staple sort mode.

FIG. 9 is a seventh diagram illustrating the flow of (large size) sheets in the staple sort mode.

FIG. 10 is an eighth diagram illustrating the flow of (large size) sheets in the staple sort mode.

FIG. 11 is a diagram illustrating a sheet flow when stapling sheets of different sizes in the staple sort mode.

FIG. 12 is a diagram illustrating another flow of sheets when stapling sheets of different sizes in the staple sort mode.

FIG. 13 is a first diagram showing the operation of the processing tray unit in the staple sort mode.

FIG. 14 is a second diagram showing the operation of the processing tray unit in the staple sort mode.

FIG. 15 is a third diagram showing the operation of the processing tray section in the staple sort mode.

FIG. 16 is a first diagram illustrating a sheet flow in a sort mode of the finisher.

FIG. 17 is a second diagram illustrating a sheet flow in the sort mode.

FIG. 18 is a control block diagram of the finisher.

FIG. 19 is a diagram showing a configuration of a sheet processing apparatus according to a second embodiment of the present invention.

FIG. 20 is a diagram showing a configuration of a conventional sheet processing apparatus.

[Explanation of symbols]

1 finisher 5 buffer rollers 10 Second switching flapper 22 Sort Path 23 Half Buffer Pass 40 Third switching flapper 41 Large Buffer Pass 44 straight pass 47 Large Buffer Pass 101 stapler 100 control means 102 Operation unit 103 sheet size detection means 300A copier 300B image forming unit 300 Copier body P sheet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B65H 37/02 B65H 37/02 3F108 37/04 37/04 D G03G 15/00 534 G03G 15/00 534 F Term (reference) 2H072 AA07 AA23 AA34 AB06 CA01 CB01 CB03 CB05 FB01 GA02 GA08 GA09 HB07 JA02 JA04 3F048 AA00 AB01 BA07 BB03 CA03 CC02 DA06 DB11 DC00 EB22 CB24 CA05 AC02 CB12 CA01 CB12 CA01 CB12 CA01 CB12 CA01 KA03 KA07 LA02 LA07 LA14 LB03 3F108 GA02 GA04 GB01 GB07 HA02 HA13 HA32

Claims (10)

[Claims] 1. A sheet processing means for processing a sheet,
In a sheet processing apparatus having a transport passage for transporting the sheet to the sheet processing means, a standby passage for branching from the transport passage and temporarily waiting the sheet facing the sheet processing means, the size of the sheet, Alternatively, a sheet processing apparatus comprising: a control unit configured to change the number of sheets waiting in the standby path according to a sheet processing operation performed by the sheet processing unit. 2. A first passage, which is provided at a branch point between the conveying passage and the standby passage and introduces the sheet into the standby passage.
A passage switching unit that can switch between a position and a second position that allows the sheet to pass therethrough without being introduced into the standby passage is provided, and the control unit changes the number of sheets waiting in the standby passage. 2. The sheet processing apparatus according to claim 1, wherein the timing for moving the passage switching means at the first position to the second position is changed according to the size of the sheet processing operation or the sheet processing operation by the sheet processing means. . 3. A size detection means for detecting the size of the sheet is provided, and the control means moves the passage switching means at the first position to the second position according to the sheet size information from the size detection means. The sheet processing apparatus according to claim 2, wherein the timing of changing the sheet is changed. 4. A setting means for setting the size of the sheet or a sheet processing operation by the sheet processing means, the control means comprising sheet size information from the setting means,
3. The sheet processing apparatus according to claim 2, wherein the timing for moving the path switching means at the first position to the second position is changed according to the sheet processing operation. 5. The sheet processing apparatus according to claim 1, wherein the sheet processing unit is a staple binding unit that staples a sheet bundle. 6. The front sheet processing means is a punch means for punching a sheet bundle.
The sheet processing apparatus according to claim 1. 7. The sheet processing apparatus according to claim 1, wherein the sheet processing unit is a gluing binder that glues a sheet bundle to perform bookbinding. 8. A conveyance means for pulling a sheet into the standby passage and feeding the sheet drawn into the standby passage to the conveyance passage, wherein the control means respectively waits for sheets of different sizes in the standby passage. The sheet processing apparatus according to any one of claims 1 to 7, wherein the driving of the transporting unit is controlled so that the rear ends of the sheets of the sheet are close to each other. 9. A conveyance unit that draws a sheet into the standby passage and sends the sheet drawn into the standby passage to the conveyance passage, wherein the control unit conveys the sheet at a confluence of the conveyance passage and the standby passage. 8. The sheet processing apparatus according to claim 1, wherein the driving of the conveying unit is controlled so that the trailing ends of the sheets passing through the passage and the standby passage are close to each other. 10. An image forming apparatus, comprising: an image forming unit for forming an image on a sheet; and a sheet processing apparatus for processing the sheet on which the image is formed by the image forming section, wherein the sheet processing apparatus is the one according to claim 1. Any one of to 9
An image forming apparatus according to item 1.