JPH09100060A - Sheet processor and image forming device provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processor that is able to stabilize a sheet on a tray in a short time, and also to secure stable loadability, and an image former equipped with this processor. SOLUTION: A fact that sheets S loaded on a sheet storage means 103 have come to the specified number of sheets is detected by a sheet number detecting means, and simultaneously each size of the sheets S is detected by a sheet size detecting means, while in the case where a sheet keep control means has judged that the sheet S is larger than the specified size on the basis of a detection signal out of the sheet size detecting means, it operates a sheet keep means 106 at once so as to check the sheet S loaded on the sheet storage means 103. In addition, when it is so judged as not to be larger than the specified size, the sheet keep means 106 is operated when the loaded sheets S have come to the specified number of pieces on the basis of a detection signal out of the sheet number detecting means so as to hold the sheets S down.

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 for stacking sheets discharged from an image forming apparatus such as a copying machine or a laser printer in a sheet storing means, and an image forming apparatus including the sheet processing apparatus.

[0002]

2. Description of the Related Art Heretofore, there has been known a sheet processing apparatus which is attached to an image forming apparatus and which binds, collates, sorts, and stores sheets ejected after forming an image. In the processing device, the discharged sheets are selectively sorted and stacked on a stack tray which is a sheet storing means.

[0003]

By the way, in stacking sheets in such a conventional sheet processing apparatus,
Depending on the direction / amount of curl of the sheet, the amount of toner, the bending / swelling due to heat, etc., as shown in FIG. 21, between the stacked sheets Sl, S2, S3 or with the stack tray 103 of the lowermost sheet Sl. There is a problem in that the paper surface angle changes and the stacking property deteriorates significantly.

Further, particularly when the swelling or curling amount of the discharged sheet S is large, the air resistance of the sheet S2 becomes large as shown in FIG. 22, the state of the sheet S2 becomes unstable, and the stacked sheets are stable. The next sheet S is loaded before the time to change or the sheet S loaded earlier is not stable on the sheet storage tray 103,
As shown in FIG. 23, there is a problem that the stacking position of the sheet S in the horizontal direction (X) and the vertical direction (Y) is disturbed.

Therefore, the present invention has been made in order to solve such a problem, and it is possible to stabilize sheets on a tray in a short time and to obtain a stable stacking property, and a sheet processing apparatus. An object of the present invention is to provide an image forming apparatus provided with this.

[0006]

According to the present invention, in a sheet processing apparatus for stacking discharged sheets in a sheet storage means, a sheet pressing means for pressing the sheets stacked in the sheet storage means and the sheet storage means are provided. A sheet number detection unit that detects that a predetermined number of sheets have been stacked, a sheet size detection unit that detects the size of the sheet, and a sheet size determination unit that determines that the size of the sheet is larger than a predetermined size based on a detection signal from the sheet size detection unit The sheet pressing means is immediately operated, and when it is determined that the size is not larger than a predetermined size, the sheet pressing control means operates the sheet pressing means based on the detection signal from the sheet number detecting means. It is characterized by having done.

The present invention further comprises a sheet ejection detecting means for detecting that the sheet has been ejected, and the sheet pressing control means outputs the sheet ejection detecting means from the sheet ejection detecting means when it determines that the sheet is larger than a predetermined size. The sheet pressing means is operated immediately in response to the detection signal.

Further, according to the present invention, in a sheet processing apparatus for selectively sorting discharged sheets and sequentially stacking them on a plurality of sheet storage means, a sheet pressing means for pressing the sheets sequentially stacked on each of the sheet storage means. , A mode selecting means for selecting a mode for sorting the sheets, a sheet number counting means for counting the number of sheets stacked in the sheet storing means, and a case where the sort mode is selected by the mode selecting means. When it is determined that the number of stacked sheets has reached one set based on the counting information from the sheet number counting means, the sheet holding means is operated, and when the sort mode is not selected, the sheet number counting means A sheet for operating the sheet pressing means when it is determined that the number of stacked sheets reaches a predetermined number based on the count information. And e control means and is characterized by comprising a.

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 post-processing a sheet image-formed by the image forming section, The sheet processing apparatus is claim 1.
Alternatively, the sheet processing apparatus according to the second aspect is characterized.

With this structure, the number of sheets stacked in the sheet storing means is detected by the sheet number detecting means, and the sheet size is detected by the sheet size detecting means, while the sheet pressing control is performed. The means operates the sheet pressing means immediately when it determines that the sheet is larger than the predetermined size based on the detection signal from the sheet size detecting means, and presses the sheets stacked in the sheet storing means. When it is determined that the size is not larger than the predetermined size, the sheet pressing unit is operated to press the sheets when the number of stacked sheets reaches the predetermined number based on the detection signal from the sheet number detecting unit.

On the other hand, when the discharged sheets are selectively sorted, the number of sheets stacked in the sheet storage means is counted by the sheet number counting means, while the sheet pressing control means selects the sort mode by the mode selecting means. In this case, the sheet pressing means is operated when it is determined that the number of stacked sheets has reached the number of one set based on the counting information from the sheet number counting means. When the sort mode is not selected, the sheet pressing means is operated when it is determined that the number of stacked sheets reaches the predetermined number based on the counting information from the sheet number counting means.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the inside of a copying machine which is an example of an image forming apparatus to which the first embodiment of the present invention can be applied. In FIG. 1, 1 is a copying machine and a copying section 2 is shown. It has a built-in copying machine body 3. Here, the copying machine main body 3 includes a platen glass 5, a light source 6, and mirrors 7, 8, 9, 1.
Two cassettes 1 for storing 0, lens 11 and sheet S
2 and 13 and the deck 15 are provided.

Further, the copying machine side of the cassettes 12 and 13 is provided with a button-shaped projection (not shown) for notifying the copying machine 1 of the sheet size set in the cassettes 12 and 13. The copy machine 1 can recognize the sheet size by the arrangement of the buttons. Note that paper feed rollers 16, 17, and 19 are provided above the cassettes 12 and 13 and the deck 15, respectively.

On the other hand, a conveying section 20 is arranged downstream of the sheet feeding roller 19 of the deck 15, and a registration roller pair 21 is arranged downstream of the conveying section 20 and the sheet feeding rollers 16 and 17. ing. Further, a copying section 2 which is an image forming section is arranged downstream of the registration roller 21, and a conveyor belt 22 and a fixing device 23 are arranged downstream of the copying section 2.

A discharge roller pair 24, a flapper 25, and a discharge roller pair 26 are arranged downstream of the fixing device 23, and the sheet S is adjacent to the copying machine main body 3 downstream of the discharge roller pair 26. A sheet processing apparatus 27 having an automatic stapler unit 27b for stacking or stapling is provided. The copying machine main body 3 is provided with a re-conveying path 29 branched to the flapper 25, and the re-conveying path 29 includes an intermediate tray device 30. In the figure, S1, S2 and S3 are sensors.

By the way, the main body 3 of the copying machine is provided with an automatic document feeder (RDF) 31 on its upper part, and this automatic document feeder 31 has a document tray 32 on which a document M is stacked. A paper feed roller 33 that feeds the original M on the original tray 32 is disposed near the original tray 32, and a separating belt 35 that rotates counterclockwise is provided downstream of the paper feed roller 33. A conveyor belt 36 is provided.

Sheet size detecting sensors S37 and S39, which are sheet size detecting means for detecting the size of the original M, are arranged in the vicinity of the conveying belt 36 in a straight line in the lateral direction with respect to the direction of the original. A drive roller 40 and a driven roller 41 are provided downstream of the size detection sensors 37 and 39.
The conveyor belt 42 is stretched by.

Further, a flapper 45 is arranged at the document discharge portion on the left side of the conveyor belt 42.
Conveyance paths 46, 47, 49 that are switched and guided by a flapper 45 are provided around the. Here, a pair of conveying rollers 50, 51 or a discharge roller 52 is arranged in each of the conveying paths 46, 47, 49. In addition, S4 is
It is a circulation detection sensor that detects one circulation of the sheet.

As shown in FIG. 2, the sheet processing apparatus 27 is provided with a control unit 61. The control unit 61 has a CPU (central processing unit) 62, a ROM 63 storing a control program for controlling the CPU 62, and the like. A RAM 65 as a main recording device, an output interface (I / O output) 66 that outputs a control signal to a load such as a main motor, and an input interface (I / O input) 67 that inputs a detection signal from each sensor. have. The loads and sensors of the copying machine body 3 and the automatic document feeder 31 are also connected to each other through interfaces (not shown).

Here, the output interface 66 includes
Bundle transport motor Ml, swing motor M2, stepping motor 82, stapler motor M3, tray lifting motor M
4, the transport motor M5, and the first transport motor M6 are connected. A sheet pressing solenoid 107 for operating a sheet pressing lever 106, which will be described later, is connected to the output interface 66, and the control section 61 serves as a sheet pressing control means for the sheet pressing solenoid 1.
The sheet pressing lever 106 is operated via 07.

Further, the input interface 67 includes sheet detection sensors S5, S6, S8, a side plate HP (home position) sensor S7, a sheet level sensor 105, a micro switch 97, and a tray upper limit sensor S2.
0, sheet size detection sensors S37, 39 and sheet S
The sheet counter CT1 which is a sheet number detecting means for detecting that a predetermined number of sheets have been stacked and the discharge port 2 shown in FIG.
00, which is connected to a sheet trailing edge passage sensor S40 which is a sheet ejection detecting unit that detects that a sheet has been ejected.

On the other hand, the sheet processing apparatus 27, as shown in FIG. 3, is an engaging member 69 provided on the side surface of the copying machine main body 3.
The sheet processing apparatus 27 is positioned by having the swingable hook 70 that engages with the engaging member 69.

A carry-in port 71 for carrying in the sheet S discharged by the pair of paper discharge rollers 26 is provided on the side surface of the sheet processing device 27, and a first deflector 72 is provided downstream of the carry-in port 71. It is arranged. Further, a first conveyance path 73 is provided on the downstream side of the first deflector 72, and a conveyance roller pair 75 is arranged in the first conveyance path 73. Furthermore, a paper discharge roller pair 76 is disposed on the downstream side of the first transport path 73, and the paper discharge roller pair 76 is provided.
A processing tray 77 is disposed on the downstream side of.

Here, a part of the belt 79 is wound around the lower roller 76a of the paper discharge roller pair 76, and the lower end of the belt 79 is in contact with the processing tray 77. Further, on the processing tray 77, a movable lateral plate 80 that aligns the width direction of the sheet S and a positioning plate (not shown) are arranged. Further, a rack 81 is provided under the lateral plate 80. The rack 81 is provided and meshes with a pinion gear 83 driven by a stepping motor 82 disposed below the processing tray 77.

A stapler 85 is arranged near the processing tray 77, and the sheets S stacked on the tray 77 are bound by the stapler 85. Further, a paper discharge roller 86 is provided at the tip of the tray 77.
The paper discharge roller 86 is in contact with a rocking roller 89 arranged at one corner of a rocking guide 88 that is rockably supported by a shaft 87.

Further, the swing guide 88 is close to the guide lever 90 and is rotated by the swing motor M2.
3 is arranged, and the guide lever 9 is attached to the disc 93.
A pin 95 that engages with 0 is erected. Also, the disk 9
3, a leaf spring 96 having an L-shape in a front view is swingably supported. The switch 97 is provided near the leaf spring 96.
Are arranged.

Furthermore, a rail plate 99 extending in the horizontal direction is provided on the machine body frame 91, and a rotatable roller 101 provided on the snowboard guide 100 is supported by the rail plate 99. A tray moving base 102 is supported on the sludge guide 100 so as to be able to move up and down, and a stack tray 103 is provided on the moving base 102, the base end side of which is recessed and the sheets S are stacked.

The swing guide 88 has a sheet pressing lever 106 for pressing the sheet S against the sheets S stacked on the stack tray 103 and the sheet pressing lever 106.
A sheet pressing solenoid 107 for driving the sheet is provided. The sheet pressing lever 106 is normally raised by a spring or the like.

On the other hand, when the first deflector 72 is switched to the position shown by the broken line, the second deflector 110 is arranged at the end of the second conveying path 109 through which the sheet passes. Further, downstream of the second deflector 110, a bent third conveyance path 111 which is formed by the large roller 112 and communicates with the first conveyance path 73 is provided. In the figure, S5 and S6 are sheet detection sensors that detect the sheet S, and S8 is a sheet detection sensor that detects the presence or absence of the sheet S on the stack tray.

Next, the operation of discharging the sheet in the sheet processing apparatus thus constructed will be described with reference to the flow charts shown in FIGS.

When the power is turned on, the CPU 62 determines whether or not there is a sheet S on the stack tray 103 based on a signal from the sheet detection sensor S8 as shown in FIG. 4 (F
l), when it is determined that there is no sheet (N of Fl), the storage number counter (not shown) is cleared to 0 (F
2). After this, the width board 80 is at the home position (HP).
It is judged from the signal from the sensor S7 whether or not (F3).

When the cross plate 80 reaches the home position (HP) (N in F3), the swing motor M
2 is turned on (F4), and the disc 93 is rotated clockwise as indicated by the arrow in FIG. And thus, the disc 93
By rotating the pin 95, the pin 95 moves the guide lever 90.
The guide lever 90 is rotated clockwise while compressing the spring 92. Further, when the guide lever 90 rotates clockwise in this way, the swing guide 88 swings clockwise about the shaft 87 as a fulcrum, whereby the swing roller 89 and the paper discharge roller 86 are separated from each other. Become.

By the way, when the swing roller 89 and the paper discharge roller 86 are separated from each other in this way, the micro switch 97 is turned off (Y of F5), and when the micro switch 97 is turned off, the swing guide 88 of the CPU 62 is raised. Determine that After that, the rocking motor M2 is turned off (F6), and the rocking guide 88 is held in the raised state. As a result, the width board 80 can be moved toward the home position.

Next, the stepping motor 82 is turned on.
N (F7), the lateral board 80 is moved toward the home position, while the lateral board HP (home position) sensor S7 determines whether or not the lateral board 80 is located at the home position (HP). Judge (F8), width plate 8
When it is determined that 0 has moved to the home position (Y in F8), the stepping motor 82 is turned off (F9).

Next, after moving the width plate 80 to the home position in this way, the swing guide 88 is lowered to bring the swing roller 89 and the discharge roller 86 into pressure contact, so that as shown in FIG. It is determined whether the micro switch 97 is OFF (F10). At this time, since the micro switch 97 remains off (Y in F10), the swing motor M2 is turned on (Fll).

Here, the swing motor M2 is turned on in this way.
Then, the disk 93 rotates in the clockwise direction, and the pin 95 is released from the guide lever 90 to release the pressure on the guide lever 90. The guide lever 90 is compressed by the spring force of the spring 92. Swing counterclockwise. When the guide lever 90 swings in this way, the micro switch 97 turns on (F12), and the CPU 62 turns off the swing motor M2 by turning on the switch 97 (F13). When the cross plate 80 is at the home position (Y in F3), the micro switch 97 remains ON (N in F10).

On the other hand, after clearing the stored number counter (see F2 in FIG. 4), the CPU 62 turns on the tray elevating motor M4 in real time as shown in FIG. 6 (Fl).
4) Raise the stack tray 103 to the upper limit position. Then, when the stack tray 103 moves up to the upper limit position and the tray upper limit sensor S20 is turned on (Y in Fl5), the tray lifting motor M4 is reversely turned on for a predetermined number of clocks (Fl6). The elevating motor M4 rotates in the reverse direction and the stack tray 10
3 is lowered to a position where the sheet S can be stored. In addition,
After lowering the stack tray 103 in this manner, the tray lifting motor M4 is turned off (F17), and the lowering of the stack tray 103 is completed.

Here, in this way, the sheet processing apparatus 2
After completion of the initial processing of 7 and the like, when the document M is stacked on the document tray 32 and a start key (not shown) is turned on, a motor (not shown) is rotated to drive the sheet feeding roller 33 and the separation belt 35. And the conveyor belt 36 are driven counterclockwise.

As a result, the originals M stacked on the original tray 32 are fed by the paper feed roller 33, and separated and conveyed one by one from below by the separation belt 35 and the conveyance belt 36. After this, the original M is placed on the platen
And the transport belt 42, and the transport belt 42 transports and stacks the document at a reference position on the platen 5, and the lamp 6, the mirrors 7, 8, 9, 10, and the lens 11 read the image and copy it. An image is formed on the part 2.

On the other hand, the sheet S is fed by the paper feed rollers 16, 17, 19 from the cassette 12, 13 or the deck 15 selected by the selection switch (not shown), and the sheet S is further fed to the copying section 2 by the registration roller pair 21. The image is conveyed in synchronization with the formed image.

Then, the image of the sheet S is copied by the copying section 2 and is further conveyed to the fixing device 23 by the conveying belt 22. Then, the image of the sheet S is fixed by the fixing device 23, and in the case of one-sided copying, the sheet S is guided by the flapper 25 and conveyed to the sheet processing device 27 by the pair of paper discharge rollers 26. Also, in the case of multiple copy or double-sided copy,
The sheet S is branched and guided by the flapper 25 and is conveyed to the reconveyance path 29. Further, by the same operation as described above, the image is copied on the back surface of the sheet S, and the sheet processing apparatus 27
Transported to

By the way, the CPU 6 of the sheet processing apparatus 27
2 receives the start signal from the copying machine 3, turns on the carry motor M5 as shown in FIG. 7 (F20), while
The first transport motor M6 and the bundle transport motor Ml are turned on to drive each roller. Here, a mode switch SW which is a mode selection means provided in an operation unit (not shown) of the copying machine 3
Therefore, modes other than the binding mode (for example, collation for each original,
When the group / sort mode that performs sorting processing or the non-sort mode that does not perform collation processing) is selected, the copying machine 3
The more discharged sheet S is carried in through the carry-in port 71,
The first deflector 72 guides the first transport path 73 or the second transport path 109.

The division into the first conveyance path 73 or the second conveyance path 109 is made according to the operation mode and the sheet size. The sheet guided in the first conveyance path 73 is shown in FIG. As shown in the conveyance roller pair 75
Thus, the sheet guided to the discharge roller pair 76 and the sheet guided to the second transport path 109 are transported to the discharge roller pair 76 by the large roller 112 as shown in FIG.

After that, when the leading edge of the sheet S passes through the sheet detection sensors S5 and S6, the sheet detection sensors S5 and S6.
6 is turned on (Y in F21), and when it is detected that the leading edge of the sheet S has passed the sheet detection sensors S5 and S6, the CPU 62 calculates the conveyance distance.

That is, when the first transport path 73 is used,
The length (mm) of the sheet S to the distance (mm) from the sheet detection sensor S5 to the carry-in port 71 shown in FIG. 11, and the length (m) of the sheet S when the second conveyance path 109 is used.
m) from the sheet detection sensor S6 shown in FIG. 12 to the carry-in port 71 is subtracted to obtain the carry distance, while the carry speed is the same as that of the copying machine 3 by the carry distance thus obtained. The sheet S is conveyed by.

By the way, when the sheet S is conveyed in this way, the trailing edge of the sheet S eventually reaches the sheet detection sensors S5, S.
6 comes to pass, and when the trailing edge of the sheet S passes like this, the sheet detection sensor S that has been ON until then
When 5,5 and S6 are turned off (Y in F22) and the rear end of the sheet S is detected, the CPU 62
Switches the transport motor M5 to the same speed as the copying machine 3, and switches the first transport motor M6 and the bundle discharge motor M7 to the second discharge speed. The paper discharge speed differs depending on the paper size and the like.

As a result, the sheet S is positioned at a position where it comes into contact with the swing roller 89 and the discharge roller 86 as shown in FIG. 3, and the discharge roller 76a of the discharge roller pair 76 and the swing roller pair 89 are located. The sheet is discharged onto the stack tray 103 by the sheet discharge rollers 86 as shown in FIG.

On the other hand, after the sheet S is discharged in this manner, the CPU 62 starts a wait timer (not shown) (F23), and when the wait timer ends after a predetermined time has elapsed (Y in F24), the result shown in FIG. As shown in the figure, first, the number of stored sheets counter that counts the total number of sheets S discharged onto the stack tray 103 for each sheet storage and the sheet counter CT1 are incremented by 1 (F40), and then discharged onto the tray 103. Seat S
Is larger than a predetermined size based on the detection signals from the sheet size detection sensors S37 and S39 (F
41).

When it is determined that the sheet S is not larger than the predetermined size (N in F41), the number of sheets S stacked on the tray 103 becomes the predetermined number by the signal from the sheet counter CT1. It is determined whether or not (F42). Then, a signal that detects that the number of stacked sheets has reached the predetermined number is input from the sheet counter CT1, and when it is determined that the number of stacked sheets has reached the predetermined number (Y in F42), the sheet trailing edge passage sensor S40 is used. Sheet pressing solenoid 1 according to the sheet discharge detection signal of
07 is turned on (F43), and the sheet S discharged onto the stack tray 103 is pressed by the sheet pressing lever 106 as shown in FIG. At the same time, a sheet pressing timer (not shown) is started (F44), and when the sheet pressing timer ends after a predetermined time has passed (F45),
The sheet pressing solenoid 107 is turned off (F46), and then the sheet counter CT1 is cleared (F47).
In addition, when it is not the predetermined number (N of F42),
C processing is ended.

On the other hand, when it is determined that the sheet is larger than the predetermined size (Y in F41), the sheet larger than the predetermined size has large bulges and curls, and therefore the sheet discharge detection signal is output regardless of the number of sheets. Immediately, the sheet pressing solenoid 107 is turned on (F43), and the sheet S discharged onto the stack tray 103 is pressed by the sheet pressing lever 106 as shown in FIG.

By pressing the sheet S by the sheet pressing lever 106 in this way, even if the swelling or curling of the sheet S is large as shown in FIG. Since the sheet S is pressed by the lever 106, the sheets S can be stabilized on the stack tray 103 in a short time as shown in FIG. 16, and a stable stacking property can be obtained.

Here, after the C processing is completed in this manner, whether or not one circulation copy of the original M (hereinafter, one circulation processing of the original M is referred to as one cycle) is completed as shown in FIG. If it is determined (F25) that one cycle is not completed (N of F25), the CPU 62 checks the height of the stack tray 103 (F31), and then repeats the above-mentioned operations after F21. .

The tray height check is for lowering the stack tray by several mm in a unit of a predetermined amount when the number of sheets stored reaches a set number. However, this is not limited to the number of sheets, but the set number of sheets and the tray lowering amount are variable depending on the operation mode and the paper size. For example, in the non-sort mode in which binding processing is not performed, 5
The 2.5 mm stack tray descends every 7 sheets up to 0 sheets, and the stack tray descends every 18 sheets from 50 sheets or more.

On the other hand, when it is judged that the copying for one cycle is completed (Y of F25), it is judged whether or not the predetermined cycle is completed (F27), and if the predetermined cycle is completed (Y of F27). , The copy operation ends. If not completed (N in F27), the above-mentioned Fl
Through F17, the initial processing (F26) is performed, and the operation after F21 is repeated for the next job.

Next, the case where two sheets are discharged in the staple mode will be described.

When the staple mode is selected, CP
U62 first performs the same initial processing as in the flowcharts of FIGS. 4 to 6, and after receiving the start signal from the copying machine main body 3 after completion of the initial processing, turns on the carry motor M5 as shown in the flowchart of FIG. Do (F
500), the first transport motor M6 is turned on to drive each roller.

Then, the swing motor M2 rotates the disc 93 by a predetermined amount, and the pin 95 rotating integrally with the disc 93 swings the guide lever 90 clockwise. As a result, the swing guide 88 swings clockwise around the shaft 87, and the swing roller 89 and the paper discharge roller 86 are separated from each other. Then, the sheet S discharged from the copying machine 3 is carried in through the carry-in port 71, and is guided to the first transport path 73 by the first deflector 72. (Note that the first sheet S of the next job is guided to the second transport path 111 by switching the first deflector 72, and then stays in the second transport path 111, and overlaps with the second sheet S. Then, the leading edge of the sheet S is detected by the sheet detection sensors S5, S6.
When the sheet S is passed through, the sheet detection sensors S5 and S6 are turned on (Y in F501), which causes the CPU 62 to detect the sheet S.
It is determined that the leading edge of the sheet has passed the sheet detection sensors S5 and S6. After this, the sheet detection sensors S5 and S6 are turned off.
When it becomes FF (Y in F502), the CPU 62 causes the sheet S
It is determined that the rear end has passed the sensors S5 and S6, and a tray storage timer (not shown) is started (F503).

As a result, the sheet S is ejected by the paper ejection roller pair 7
6 is discharged across the processing tray 77 and the stack tray 103, and the widthwise plate 80 abuts the positioning plate to align the widthwise direction, and only in the clockwise direction with respect to the first sheet S. The rotating belt 79 abuts the base end portion of the processing tray 77 to align the front-back direction.

On the other hand, when the tray storage timer expires after a lapse of a predetermined time (Y in F504), the CPU 62 increments the storage number counter by +1 (F50).
5) Based on the signal from the circulation detection sensor S4, it is determined whether or not the copying process for one cycle is completed (F50).
6). When it is determined that the one-cycle copy process is not completed (N in F506), the process in F31 is performed.

When the copy process for one cycle is completed (Y in F506), the swing motor M2 is turned on (F5
07), rotate the disc 93 clockwise. By the rotation of the disc 93, the urging force of the guide lever 90 by the pin 95 disappears, and the guide lever 90 is urged counterclockwise by the spring 92. As a result, the guide lever 90 swings the leaf spring 96 counterclockwise, and when the micro switch 97 is turned on as shown in FIG. 18, (F508).
When the switch 97 is turned on, the CPU 62 stops the swing motor M2.

At this time, due to the swinging of the guide lever 90,
The swing guide 88 swings counterclockwise integrally with the guide lever 90, and the paper discharge roller 86 and the swing roller 89 come into contact with each other. Then, the CPU 62 causes a sensor (not shown) to
After confirming that the sheet S is on the processing tray 77, the stapler 85 is operated to perform the stapling process for binding the sheet bundle S (F510).

When the stapling process is completed (Y in F511), the CPU 62 turns on the bundle conveying motor Ml.
N (F512), discharge roller pair 86 and swing roller pair 8
9, the sheet bundle S is discharged onto the stack tray 103. Further, the CPU 62 turns on the tray lifting motor M4.
No (F513), and the stack tray 103 is lowered by the descending amount according to the stored number counter. For example, when the counter value is 15 sheets, 2.5 mm, when 17 sheets, 2.5 m
Set to descend by m.

Next, the CPU 62 controls the tray lifting motor M4.
Is turned off (F514). At this time, the CPU 62
Is configured to move the stack tray 103 and the snow guide 100 in the sheet width direction by a driving unit (not shown) to offset the sheet bundle S stacked on the stack tray 103 so that the staple needle portion does not swell.

Finally, the CPU 62 performs the above-mentioned initial processing (F515), and then performs the operations after the above-mentioned F9 for the next job. If the micro switch 97 is not turned on (N in F508), it is determined that there is a foreign substance on the processing tray 77, and the CPU 62 stops the system (F509).

By the way, in the first embodiment of the present invention described so far, the timing for pressing the sheet is controlled according to the size of the sheet, but the present invention is not limited to this. The timing of pressing the sheet can be controlled by the mode.

Next, such a second embodiment of the present invention will be described with reference to the flowchart shown in FIG. Note that in this embodiment, the flowcharts of FIGS. 4 to 7 in the first embodiment perform the same operation, so description thereof will be omitted, and only the C processing that is different from the first embodiment will be described. It shall be.

The CPU 62 increments the stored sheet number counter and sheet counter by +1 (FlOO) every time a sheet is stored, and then staples the sheet bundle in the operation mode selected by the mode switch SW of the copying machine 3. If the mode is not the staple mode (FlOl), and if it is not the staple mode (N of FlOl), it is determined whether it is the group / sort mode for collating and sorting sheets (F
10).

When the group / sort mode is determined (Y in F102), the sheet counter CT1 serving as a sheet number counting means for counting the number of sheets stacked on the stack tray 103 in the present embodiment. Based on the count value of, it is determined whether or not one cycle has ended depending on whether or not the number of sheets S stacked on each stack tray 103 has reached one set (FLO
4) When the number of sheets for one set is not reached, it is determined that one cycle is not completed (N of FlO4), and the process is completed.

On the other hand, when the number of sheets for one set is reached, it is judged that one cycle is completed (Y of FlO4), the sheet pressing solenoid 107 is turned on (F105), and the sheet S is pressed, and the sheet pressing timer is pressed. To start (F106). When the sheet pressing timer expires after a lapse of a predetermined time (Fl07), the sheet pressing solenoid 107 is set to 0FF (Fl08), the sheet counter CT1 is cleared (Fl09), and the process ends.

When the mode is the non-sort mode in which sheet discharge processing is performed (N in F102), the CPU 62 determines whether a predetermined number of sheets S have been stacked based on the value of the sheet counter CT1 (F103), and the stacked sheets are stacked. When the number of sheets reaches a predetermined number (Y of Fl 03), the processing after Fl 05 is performed. If the predetermined number is not reached (N in Fl 03), the process is terminated.

By the way, in the first and second embodiments of the present invention described so far, the sheet size,
Although the timing of pressing the sheet is controlled according to the operation mode, the present invention is not limited to this, and the timing of pressing the sheet may be controlled after the end of one sheet.

Next, the third embodiment of the present invention will be described with reference to the flow chart shown in FIG. In addition, in the present embodiment, the flowcharts of FIGS. 4 to 7 in the first embodiment perform the same operation, and therefore the description thereof will be omitted.

First, when the CPU 62 receives the start signal from the copying machine 3, the CPU 62 sets the carry motor M5 to 0N (F200), and the second carry motor M6 and the bundle carry motor Ml.
To 0N to drive each roller. As a result, the copying machine 3
The more discharged sheet S is carried in through the carry-in port 71,
The first deflector 72 guides the first transport path 73 or the second transport path 109.

After that, when the leading edge of the sheet S passes the sheet detecting sensors S5 and S6, the sheet detecting sensors S5 and S6.
6 is turned on (Y in F201), and when it is detected that the leading edge of the sheet S has passed the sheet detection sensors S5 and S6, the CPU 62 calculates the transport distance.

That is, when the first conveyance path 73 is used as described above, the distance (m) from the length (mm) of the sheet S to the sheet inlet sensor 71 shown in FIG.
m) and the length (mm) of the sheet S when the second conveyance path 109 is used, the sheet detection sensor S shown in FIG.
The distance (mm) from 6 to the carry-in port 71 is subtracted to obtain the transport distance, and the sheet S is transported at the same transport speed as that of the copying machine 3 by the transport distance thus obtained.

By the way, when the sheet S is conveyed in this way, the trailing edge of the sheet S eventually reaches the sheet detection sensors S5, S.
6 is passed, and when the trailing edge of the sheet S is passed, the sheet detection sensors S5 and S6 are turned off (Y in F202). Then, when it is detected that the trailing edge of the sheet S has passed, the CPU 62 switches the conveyance motor M5 to the same speed as the copying machine 3, and sets the first conveyance motor M6 and the bundle discharge motor M7 to the second discharge speed. Switch to. The paper discharge speed differs depending on the paper size and the like.

As a result, the sheet S is positioned at the position where it comes into contact with the swing roller 89 and the discharge roller 86 as shown in FIG. 3, and the discharge roller 76a of the discharge roller pair 76 and the swing roller pair 89 are positioned. The sheet is discharged onto the stack tray 103 by the sheet discharge rollers 86 as shown in FIG.

After the sheet S is discharged, the CPU 62 starts the weight timer (F203), and when the predetermined time elapses and the weight timer ends (Y of F204), the CPU 62 performs the above-described C processing of FIG. After performing this C processing, it is determined whether or not one copy cycle is completed (F
205) When it is determined that one cycle is not completed (N of F205), the CPU 62 causes the stack tray 103
After performing the height check (F211),
The operations after 1 are repeated.

When one cycle is completed (F2
(Y of 05), the sheet pressing solenoid 107 is turned on (F
206), the discharged sheet S is pressed onto the stack tray 103 as shown in FIG. At this time, the CPU
62 starts the sheet presser timer (F20
8) When the sheet pressing timer expires after a predetermined time has elapsed (Y of F208), the sheet pressing solenoid 107 is turned on.
FF is performed (F209).

After that, it is judged whether or not the predetermined cycle is finished (F212), and if the predetermined cycle is not finished (N of F212), an initial process is performed (F210), and then the process is repeated from F201. . After the end of the predetermined cycle (Y of F212),
The copy process ends.

[0082]

As described above, according to the present invention, the sheet pressing means is provided immediately when the sheets are larger than the predetermined size and when the number of stacked sheets reaches the predetermined number when the sheets are not larger than the predetermined size. It can be operated to hold down the sheet. Further, when the discharged sheets are selectively sorted, when the sorting mode is selected, the number of stacked sheets reaches one set, and when the sorting mode is not selected, the number of stacked sheets is a predetermined number. When it is determined that the sheet is pressed, the sheet pressing means can be operated to press the sheet. By pressing the sheet by the sheet pressing means in this manner, the sheet can be stabilized on the tray in a short time, and the state of the sheet after image formation (the direction and amount of curl, the degree of toner sticking, and the sheet due to heat) It is possible to obtain a stable stacking property regardless of bending, bulging, etc.

[Brief description of the drawings]

FIG. 1 is a diagram showing the inside of a copying machine which is an example of an image forming apparatus to which a first embodiment of the present invention can be applied.

FIG. 2 is a diagram showing a configuration of a control unit provided in a sheet processing apparatus adjacent to the copying machine.

FIG. 3 is an enlarged view of the inside of the sheet post-processing device.

FIG. 4 is a first flowchart showing an operation of the sheet processing apparatus when a sheet is discharged in the first embodiment of the present invention.

FIG. 5 is a second flowchart showing an operation at the time of discharging a sheet in the first embodiment.

FIG. 6 is a third flowchart showing an operation at the time of discharging a sheet according to the first embodiment.

FIG. 7 is a fourth flowchart showing an operation at the time of discharging a sheet according to the first embodiment.

FIG. 8 is a fifth flowchart showing an operation at the time of discharging a sheet in the first embodiment.

FIG. 9 is a diagram showing a state in which a sheet guided by a first conveyance path of the sheet processing apparatus is conveyed to a pair of discharge rollers.

FIG. 10 is a diagram showing a state in which a sheet guided by a second conveyance path of the sheet processing apparatus is conveyed to a pair of discharge rollers.

FIG. 11 is a diagram showing a distance from a sheet detection sensor to a carry-in port in the first transport path.

FIG. 12 is a diagram showing a distance from a sheet detection sensor to a carry-in port in the second transport path.

FIG. 13 is a diagram showing how sheets are discharged to a stack tray.

FIG. 14 is a diagram showing a state where a sheet presser presses a sheet discharged onto the stack tray.

FIG. 15 is a view showing a state before the sheet presser presses a sheet material having a large bulge or curl.

FIG. 16 is a view showing a state where the sheet presser presses the sheet material having the large bulge and curl.

FIG. 17 is a first flowchart for discharging two sheets in the staple mode.

FIG. 18 is a second flowchart for discharging two sheets in the staple mode.

FIG. 19 is a flowchart showing a second embodiment of the present invention.

FIG. 20 is a flowchart showing a third embodiment of the present invention.

FIG. 21 is a diagram showing a state where the above-mentioned sheet materials having large bulges and curls are stacked in the conventional sheet processing apparatus.

FIG. 22 is a view showing another state when stacking sheet materials having large bulges and curls in the conventional sheet processing apparatus.

FIG. 23 is a diagram showing a disorder of the stacking position when stacking sheet materials having large bulges and curls in the conventional sheet processing apparatus.

[Explanation of symbols]

 3 Copier 61 Control Unit 103 Stack Tray 106 Sheet Pressing Lever S Sheet S37, S39 Sheet Size Detection Sensor CT1 Sheet Counter SW Mode Switch

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location B65H 39/11 G03G 15/00 534 G03G 15/00 534 B41J 3/00 D

Claims (4)

[Claims] 1. A sheet processing apparatus for stacking discharged sheets in a sheet storage means, and a sheet pressing means for pressing the sheets stacked in the sheet storage means, and a predetermined number of the sheets stacked in the sheet storage means. The sheet number detecting means for detecting that the sheet size, the sheet size detecting means for detecting the size of the sheet, and the sheet presser immediately when it is determined that the sheet is larger than a predetermined size based on the detection signal from the sheet size detecting means. And a sheet pressing control unit that operates the sheet pressing unit based on a detection signal from the sheet number detecting unit when it is determined that the size of the sheet is not larger than a predetermined size. apparatus. 2. A sheet discharge detecting means for detecting discharge of the sheet, wherein the sheet pressing control means detects a signal from the sheet discharge detecting means when it is determined that the sheet is larger than a predetermined size. 2. The sheet processing apparatus according to claim 1, wherein the sheet pressing means is operated immediately in response to the instruction. 3. A sheet processing apparatus for selectively sorting discharged sheets and sequentially stacking the stacked sheets in a plurality of sheet storage means, and sheet pressing means for pressing the sheets sequentially stacked in each of the sheet storage means; A mode selecting means for selecting a mode for sorting the sheets, a sheet number counting means for counting the number of sheets stacked in the sheet storing means, and a sheet number when the sort mode is selected by the mode selecting means. When it is determined that the number of stacked sheets has reached one set based on the counting information from the counting means, the sheet pressing means is operated, and when the sort mode is not selected, the counting information from the sheet number counting means is used. Based on the above, when the number of stacked sheets is determined to be the predetermined number, the sheet pressing control means for operating the sheet pressing means The sheet processing apparatus characterized by comprising a. 4. An image forming unit for forming an image on a sheet,
An image forming apparatus comprising: a sheet processing apparatus that performs post-processing of a sheet on which an image is formed by the image forming unit, wherein the sheet processing apparatus is the sheet processing apparatus according to claim 1. Image forming apparatus.