JPH11116134A - Post-treating device for paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet post-treating device which can preclude frequent stop of device caused by full-sensing when sheets are exhausted. SOLUTION: A sheet post-treating device is equipped with a sheet exhaust tray on which sheets exhausted from an image forming device 1 are stacked and a full sensing means 51 which senses whether sheets are stacked fully on the tray, wherein further a full judging means is furnished which allows stacking of sheets to continue for at least a specified time from when the full condition of the exhaust tray is sensed and then stops the operation of the sheet post-treating device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet post-processing apparatus applied to an image forming apparatus such as a printer, a copying machine, a facsimile, and the like.

[0002]

2. Description of the Related Art There is known a sheet post-processing apparatus for performing post-processing of a sheet formed and discharged by an image forming apparatus. The post-processing of the sheet by the sheet post-processing apparatus includes a stacking process for sorting the sheets by a predetermined number of sheets, a stapling process for binding the sheets by a predetermined number of sheets, and the like. Stacked and stapled sheets are stacked in the output tray.To prevent the stacked sheets from overflowing and disturbing the alignment of the sheets, the sheets on the output tray Fullness detecting means for detecting a stacked state, for example, a full state of sheets, is provided in the paper discharge tray.

A technique relating to this full detecting means is disclosed in
No. -58545. According to this publication, a paper discharge device detects that a stacking height of sheets on a paper discharge tray is equal to or higher than a predetermined set height and detects fullness, and a paper discharge tray. Full release means for detecting that the loading height of the upper sheet has decreased to a loading height sufficiently lower than the set height and detecting full release, and the full detection means and full release means, Each detection of full and full release is performed.

[0004]

Since the sheet immediately after being discharged to the paper discharge tray may be curved on the paper discharge tray due to heat or the like, it is detected that the paper discharge tray is full. If it is stopped immediately, after a while the paper post-processing device stops, the loaded paper sinks under its own weight, the paper is no longer curved, the output tray is no longer full, and the paper can be loaded again. Become. Therefore, when the discharge of the paper is started again, the operation of detecting the fullness of the discharge tray and stopping the paper post-processing apparatus is repeated several times, which is inconvenient in use.

When a large amount of paper is discharged by a network printer or the like, the operator usually outputs the paper at a position far from the paper post-processing apparatus. It is inconvenient for the processing apparatus to stop repeatedly, and improvement is desired.

In the technique described in the above-mentioned publication, the fullness and the release of fullness of the discharge tray are respectively detected. However, when the fullness of the discharge tray is detected, the sheet post-processing device is stopped. ing. Accordingly, the operation / stop of the sheet post-processing device is repeated according to the full state of the sheet discharge tray. Further, in the above-described configuration, in order to detect each of the full state and the full state release, the full state detection unit and the full state release unit are required. For example, two sensors are required, which complicates the configuration and reduces the cost. There is also a problem that this is the case.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a sheet post-processing apparatus which can prevent frequent stoppage of the apparatus due to detection of a full state when a sheet is discharged.

[0008]

According to the first aspect of the present invention,
In a sheet post-processing apparatus having a sheet discharge tray for stacking sheets discharged from the image forming apparatus and a full detecting means for detecting whether or not the sheet stacked on the sheet discharge tray is full, The apparatus is provided with a fullness judging means for continuing the stacking of the sheets for at least a predetermined time from the time when the paper tray is full, and thereafter stopping the operation of the sheet post-processing apparatus.

According to a second aspect of the present invention, in the sheet post-processing apparatus according to the first aspect, the fullness determining means adjusts the length of the predetermined time according to the processing speed of the image forming apparatus.

According to a third aspect of the present invention, in the sheet post-processing apparatus according to the first aspect, the fullness judging means adjusts the length of the predetermined time according to the size of the sheet.

According to a fourth aspect of the present invention, in the sheet post-processing apparatus according to the first, second or third aspect, the sheets discharged from the image forming apparatus are stapled, and the stapled sheet bundle is discharged. A staple unit to be stacked on the tray; and a selection unit that selects one of an operation and a non-operation of the staple unit. From the point when the paper tray is full,
The operation of the stapling means is continued until at least a predetermined number of stapling processes are completed, and thereafter, the operation of the sheet post-processing apparatus is stopped.

[0012] The invention according to claim 5 is the invention according to claims 1, 2, 3, and 4.
Alternatively, in the paper post-processing apparatus described in 4, the up-down driving unit moves up and down the discharge tray in accordance with the stacking amount on the discharge tray.

According to a sixth aspect of the present invention, there is provided a stapling device for stapling a sheet ejected from an image forming apparatus, a selecting device for selecting one of an operation and a non-operation of the stapling device, and a stapling device. When the operation is selected, the paper ejected from the image forming apparatus is stacked, and when the operation of the stapling unit is selected, a paper output tray for loading a stapled sheet bundle and a paper output tray. A paper post-processing apparatus having vertical drive means for vertically moving a paper discharge tray in accordance with a load amount, and full detection means for detecting whether a paper or a bundle of paper stacked on the paper discharge tray is full or not. , The stacking of sheets or a bundle of sheets is continued until the number of sheets stacked on the sheet ejection tray reaches a predetermined number from the detection of the fullness of the sheet ejection tray. When the number reaches a predetermined number, it is configured to have a full determination means for stopping the operation of the sheet post-processing apparatus.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a paper post-processing apparatus to which the present invention is applied will be described. In FIG. 1, reference numeral 1 denotes
A copying machine as an image forming apparatus, and reference numeral 2 indicates a sheet post-processing apparatus mounted on a side of the copying machine 1. Inside the paper post-processing device 2, a transport path 4 for directly transporting the paper from the copying machine 1 to the paper output tray 3, and binding the paper from the copying machine 1, that is, stapling, that is, the paper output tray 3
A staple unit 5 serving as a staple unit for discharging paper to the printer and a reversing conveyance path 6 for reversing the front and back of the sheet from the copying machine 1 are provided.

The paper inlet of the transport path 4 is connected to the paper outlet of the copying machine 1. A reversing conveyance path 6 branches from an intermediate portion of the conveyance path 4, and the copier 1
There is provided a switching claw 7 for switching the transport direction of the sheet from the transport path 4 to one of the transport path 4 and the reverse transport path 6.

In the transport path 4, a paper sensor 10 for detecting the passage of the paper, a pair of carry-in rollers 11 for receiving the paper from the copying machine 1, a switching claw 7, a pair of transport rollers 12 for transporting the paper, and a transport for the paper A pair of discharge rollers 13 for discharging the paper from the path 4 to the paper discharge tray 3 are arranged in order from the upstream side to the downstream side. The discharge roller 13 includes a driving roller 13a and a driven roller 13b that is driven to rotate.
It is composed of The driven roller 13b has a paper ejection guide portion 15 supported so as to swing about a shaft 14.
, And is rotatable about the shaft 14 together with the paper ejection guide portion 15. That is,
The driven roller 13b is in contact with the driving roller 13a while being pressed against the driving roller 13a by its own weight.

In the vicinity of the paper discharge port of the transport path 4, one end contacts the upper surface of the paper stacked on the paper discharge tray 3, and
A paper surface lever 18 swingably supported by the device 7 and a paper surface sensor 19 for detecting the other end of the paper surface lever 18 are provided. Paper lever 18 and paper sensor 1
9, the height of the paper discharge tray 3 is adjusted such that the upper surface of the paper stacked on the paper discharge tray 3 is always at a fixed position with respect to the discharge roller 13.

The reverse transport path 6 is a first reverse transport path 6 a for transporting the sheet from the copying machine 1 to the staple unit 5.
And transporting the sheet to the transport path 4 with the sheet turned over.
And the reverse transport path 6b. In the first reversing conveyance path 6a, a reversing guide 20 and a pair of conveyance rollers 21 for conveying a sheet are disposed, respectively. The transport roller 21 is composed of a brush-like driving roller 21a and a driven roller 21b that is driven to rotate. The drive roller 21a is rotatable in the normal and reverse directions. When performing the staple process, the drive roller 21a rotates in the normal direction to transfer the paper to the staple unit 5.
When the reversing process is performed, the sheet is once rotated forward to draw a part of the sheet into the staple unit 5, and then rotated reversely to be transported from the rear end of the sheet to the transport path 4. Reference numeral 22 denotes a sheet sensor for detecting the trailing edge of the sheet for detecting the sheet conveyance timing during the reversing process.

The paper discharge tray 3 is supported by a base 26 via a shift direction guide member 25 for supporting the paper discharge tray 3 movably in a direction perpendicular to the paper discharge direction. The base 26 is formed by attaching the base 26 to the sheet post-processing device 2.
Up and down guide member 2 that movably supports the up and down direction
7 and is supported by the sheet post-processing device 2. The vertical guide member 27 is supported by a guide rail 28 extending in the vertical direction of the sheet post-processing device 2. In the vicinity of the lower end of the guide rail 28, a lower limit sensor 29 for detecting a lower limit of the base 26 is provided.

The shift driving means 4 for driving the shift direction guide member 25 and the vertical direction guide member 27
5 and a vertical drive means 46 (see FIG. 3) are provided. By driving these driving means, the paper discharge tray 3 is moved in the vertical direction of the paper post-processing device 2 and in the direction perpendicular to the paper discharge direction.

The paper surface sensor 19 and the lower limit sensor 29 constitute a full state detecting means.
When both the sheet 9 and the sheet level sensor 19 are turned on, it is determined that the stacked state of the sheets on the sheet discharge tray 3 is full.

As shown in FIGS. 1 and 2, a staple unit 5 aligns a staple tray 30 on which sheets from the copying machine 1 are placed with a sheet in a sheet width direction, that is, a direction orthogonal to the sheet conveyance direction. Jogger fence 3 to do
1 and a reference fence 32, a staple 33 for binding a part of the paper and performing a stapling process, and a paper discharge claw for transporting the bound paper in a bundle (hereinafter referred to as a paper bundle) to the paper discharge tray 3. 34 and the paper discharge nail 34 are fixed,
It mainly comprises a paper discharge belt 35 for driving the paper discharge claw 34.

In the vicinity of the surface of the discharge belt 35, a discharge claw 3 is provided.
A paper ejection claw sensor 36 for detecting the position of No. 3 is provided. If the paper size is different, the position of the paper discharge claw 33 is adjusted based on the output of the paper discharge claw sensor 36 so that the rear end position of the paper is always constant.

Next, the operation of the sheet post-processing apparatus 2 will be briefly described. In the post-processing of the sheet by the sheet post-processing apparatus 2, a sort / stack process in which the sheet from the copying machine 1 is directly discharged to the discharge tray 3, and the sheet from the copying machine 1 is bound and discharged to the discharge tray 3. There are three types of processing: a staple process and a reversal process of reversing the paper from the copier 1 and discharging the paper to the paper discharge tray 3. The selection of this processing is performed by the selection means 47 described later.

First, the sort / stack processing will be described. When this sort / stack processing is selected, the switching claw 7 is at the position shown by the solid line in FIG. 1, and the paper discharged from the copying machine 1 is transported through the transport path 4 and
Is discharged to the discharge tray 3. When the sheets from the copying machine 1 are sequentially discharged to the discharge tray 3, the sheet lever 18
Rises, that is, swings in the direction of arrow A in the figure, and the paper surface sensor 19 detects this. The discharge tray 3 is lowered by the driving of the vertical drive means 46 so that the upper surface of the paper is always at a constant position, and is always maintained at an appropriate height. Each time the number of sheets stacked on the discharge tray 2 reaches a predetermined number, the shift driving unit 45 drives the discharge tray 3 in a direction orthogonal to the sheet discharge direction to sort the sheets. I do.

Next, the stapling process will be described.
When this stapling process is selected, the switching claw 7
The sheet ejected from the copying machine 1 at the position indicated by the two-dot chain line is guided to the first reverse conveyance path 6 a and conveyed to the staple unit 5. At this time, the leading end of the switching claw 7 is in a state of light contact with the reversing guide 20, but the sheet is conveyed so as to push the switching claw 7 away. The paper discharge claw 34 is driven by the paper discharge belt 35 based on the output value of the paper discharge claw sensor 36 so that the rear end of the paper is always at a fixed position with respect to the conveyance roller 21. Moved up.

At the same time as the leading edge of the sheet abuts on the sheet ejection claw 34, the trailing end of the sheet is stacked on the staple tray 30 while being pressed toward the staple tray 30 by the drive roller 21a. Further, the paper is moved toward the reference fence 32 by the jogger fence 31 and is aligned in a direction orthogonal to the transport direction. Therefore, the sheets are stacked on the staple tray 30 in a state in which they are in contact with the reference fence 32 and the sheet discharge claws 34, respectively. The same operation is repeated every time a sheet is conveyed to the staple tray 30, and the sheets are stacked in a aligned state to form a sheet bundle.

When all the sheets to be stapled on the staple tray 30 are stacked, a stapling operation is performed on the sheet bundle by the staple 33, and the discharge roller 13 is discharged by the discharge claw 34.
Conveyed toward. Subsequently, the sheet bundle is discharged to the discharge tray 3 by the discharge rollers 13 and stacked on the discharge tray 3. The sheet bundle is sequentially stacked on the sheet discharge tray 3 until a predetermined number of copies is reached. Then, as in the case of the sort / stack process, the sheet discharge tray 3 is lowered so that the upper surface of the sheet bundle is always at a fixed position.

Next, the inversion process will be described. When this reversing process is selected, the switching claw 7 is located at the position shown by the two-dot chain line in FIG. 1 similarly to the case of the staple process, and the sheet discharged from the copying machine 1 While being guided to the path 6a, it is transported along the first reverse transport path 6a. At this time, the tip of the switching claw 7 is in a state of light contact with the reversing guide 20, but the sheet is conveyed through the first reversing conveyance path 6a so as to push the switching claw 7 away.

When the paper sensor 22 detects that the trailing edge of the paper has passed the switching claw 7, the transport roller 21 rotates in the reverse direction, and the trailing edge of the paper is transported toward the second reverse transport path 6b. Is done. By the switchback of the paper, the front and back of the paper are reversed. The sheet returns from the second reverse conveyance path 6 b to the conveyance path 4, is conveyed along the conveyance path 4, and is discharged to the discharge tray 3 by the discharge rollers 13. Output tray 3
When the sheets are stacked, they are moved up and down and shifted as in the case of the sort / stack processing. At the time of the reversing process, the paper discharge claw 34 is retracted to a position where it does not interfere with the leading edge of the sheet conveyed to the first reversing conveyance path 6a.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 3, the control means of the above-described sheet post-processing apparatus 1, for example, the input side of the CPU 50 includes various sensors 10, 22, and 36 and a selection means 47 for selecting a sheet post-processing method. Has various drive units 9 and 1
1, 12, 13, 21, 33, 34, etc. are connected respectively. The selecting means 47 is provided on an operation panel (not shown), and includes a switch for selecting any one of sort / stack processing, stapling processing, and inversion processing. Further, the CPU 50 can exchange the number of sheets with the copying machine 1 during sort / stack processing, the number of stapled copies during staple processing, the number of copies, the paper size, and the like.
Signals such as processing speed are communicated.

The paper surface sensor 19 and the lower limit sensor 29 constitute a fullness detecting means 51, and the output of the fullness detecting means 51 is output to the CPU 5 via the fullness determining means 52.
Input to 0. The fullness judging means 52 detects a fullness of the paper output tray 3 by the tray lowering timer 53 for lowering the paper output tray 3 according to the stacked amount of paper on the paper output tray 3 and the fullness detecting means 51. At this time, a full delay timer 54 is provided for delaying the output of the full detection to the CPU 50 by a predetermined time Ta.

The tray lowering timer 53 is provided for the discharge tray 3
When a predetermined amount of paper is stacked on the paper discharge tray 3 and the ON state of the paper surface sensor 19 continues for a predetermined time Tb, a signal for lowering the paper discharge tray 3 is sent to the CPU 50. Output. Here, the predetermined time Tb
Will be described. During the paper ejection operation, the paper ejection tray 3
Each time the paper is ejected, the leading edge of the paper raises the paper surface lever 18 to turn on the paper surface sensor 19.
8, the paper surface sensor 19 is turned off. However, when the sheets are stacked on the sheet discharge tray 3 and the stacking amount reaches a predetermined amount, the sheet surface sensor 19 is kept on even after the paper surface lever 18 is lowered. That is, by detecting a case where the ON state of the paper surface sensor 19 has continued for a predetermined time, it is determined that the paper stacking amount on the discharge tray 3 has reached the predetermined amount.

Therefore, the predetermined time Tb is a threshold value for detecting the amount of paper loaded on the paper output tray 3 and a threshold value for lowering the paper output tray 3 in accordance with the amount of paper loaded. is there. This predetermined time Tb is usually set to 2 to 3 seconds, and is set to approximately 2 seconds in the present embodiment. By appropriately setting the predetermined time Tb, the sheet discharge tray 3 can be lowered before the sheet overflows from the sheet discharge tray 3.

The full delay timer 54 starts counting up, that is, starts counting from the time when the full state is detected, and outputs a full state detection signal to the CPU 50 after a predetermined time Ta, for example, 20 to 30 seconds. In the present embodiment, the count-up time by the first full delay timer 63a, that is, the predetermined time Ta is set to approximately 25 seconds.

The delay time of the full delay timer 54, that is, the predetermined time Ta, will be described in detail. At the time of stacking the paper on the paper output tray 3, if the end of the paper is curved due to heat or the like and a gap is generated between the stacked paper surfaces, the fullness of the paper output tray 3 is detected. Thereafter, as time elapses, the paper stacked on the paper discharge tray 3 sinks under its own weight, so that the paper stacking height decreases by the amount of the sink and the fullness is released. Then, since the sinking allows the stacking to be performed again, even if the paper discharge tray 3 is detected to be full at the time of stacking the sheets, the sheets are stacked in advance by the amount by which the sheets sink. After the full state is detected, the stacking is continued for a predetermined time Ta after the full state is detected, in order to stack the amount of sinking sheets. Therefore, the predetermined time Ta is a time for loading beforehand by the amount of sinking after full detection, and is for delaying the output of the full detection signal.

Next, the operation of the discharge tray 3 when the sheets are stacked and when the discharge tray is full when the sort / stack processing or the reverse processing is selected will be described with reference to the flowcharts shown in FIGS. . In step A1, the sheets are discharged to the discharge tray 3 and stacked.
In step A2, it is detected whether or not the paper surface sensor 19 is turned on, that is, whether or not a predetermined amount of paper is stacked on the paper discharge tray 3. If the paper surface sensor 19 is on, the process proceeds to step A4, and if not, the process proceeds to step A3. For example, the paper loading height is approximately 10 m
m, the paper surface sensor 19 is set to be turned on, and the process proceeds to step A4 when the paper stacking height reaches approximately 10 mm. If the paper stacking height has not reached approximately 10 mm, the process proceeds to step A3. In step A3,
The time counter of the tray lowering timer 53 is reset.

In step A4, the tray lowering timer 5
3 starts counting, and proceeds to step A5. continue,
In step A5, it is determined whether or not the time T1 measured by the tray lowering timer 53 has reached a predetermined time Tb. That is, it is determined whether or not Tb ≦ T1 is satisfied. If the time T1 has reached the predetermined time Tb, the process proceeds to step A6. If the time T1 has not reached the predetermined time Tb, the process returns to step A2.

In step A6, the tray lowering timer 5
The timer 3 is reset, and the process proceeds to step A7. In step A7, the discharge tray 3 is lowered by a predetermined amount, and the process proceeds to step A8. At this time, for example, the paper ejection tray 3 is
Lower by 0 mm.

In step A8, it is detected whether or not the lower limit sensor 29 is ON, that is, whether or not the discharge tray 3 has been lowered to the lower end of the guide rail 28. If the lower limit sensor 29 is on, the process proceeds to step A9, and if not, the process returns to step A1.

In step A9, since both the paper surface sensor 19 and the lower limit sensor 29 are turned on, the full state of the paper discharge tray 3 is detected.
This includes the state where the paper is curved. By the way, when the paper discharge tray 3 is detected to be full, there is a gap between the top surface of the paper stacked on the paper discharge tray 3 and the discharge roller 13. Paper can be ejected. For example, assuming that the gap is approximately 10 mm, the gap can be discharged. Therefore, when the full state is detected, some paper discharge can be continued without stopping the operation of the paper post-processing apparatus 1 immediately. The paper discharge is continued and the process proceeds to step A10.

In step A10, the full delay timer 54
, And the process proceeds to step A11. continue,
In step A11, it is determined whether or not the time T2 measured by the full delay timer 54 has reached a predetermined time Ta.
That is, it is determined whether or not Ta ≦ T2 is satisfied.
If the time T2 has reached the predetermined time Ta, the process proceeds to step A12. If the time T2 has not reached the predetermined time Ta, the process returns to step A1. In step A12, the time counter of the full delay timer 54 is reset, the operation of the sheet post-processing device 1 is stopped, and a series of controls is ended.

Accordingly, by delaying the stop of the sheet post-processing device 2 due to the discharge tray being full by a predetermined time Ta,
The number of stoppages of the sheet post-processing device 2 due to the discharge tray being full can be reduced, and frequent stoppages of the sheet post-processing device 2 can be prevented.
It is possible to detect that the discharge tray is full. In particular, when outputting a sheet from a place remote from the sheet post-processing device 2,
Since the number of stoppages of the sheet post-processing device 2 due to the discharge tray being full is reduced, usability can be improved. Further, since the paper surface sensor 19 and the lower limit sensor 29 which have been conventionally used for the full state detection are used, there is no need to separately add a sensor, so that a simple configuration is sufficient and the cost is low.

In the present embodiment, the sheet stacking amount after the full state is detected is controlled by time, but the predetermined time Ta is set based on the sheet stacking amount per unit time. Therefore, the paper stacking amount after the full detection may be controlled by the number of sheets instead of the time. When the number of sheets is controlled, the load amount can be controlled more accurately.

Next, a second embodiment of the present invention will be described with reference to FIGS. In these figures, FIG.
5 to 5 are denoted by the same reference numerals as those used in FIGS. 3 to 5, description thereof will be omitted, and different points will be described. In some cases, the sheet post-processing device 2 is connected to a copying machine 1 having a different processing speed. In this case,
The paper output per unit time is different,
It is necessary to set the delay time of the output of the full detection signal to the CPU 50 according to the processing speed.

As shown in FIG. 6, the CPU 50 is connected to a processing speed input means 60 for inputting a processing speed of a copying machine to which the sheet post-processing apparatus 2 is connected, and a fullness judging means 61. The processing speed input means 60 is provided on an operation panel (not shown) and includes a plurality of selection switches. In the present embodiment, the processing speed of the copying machine 1 is 30
It supports CPM or 60 CPM in two ways,
By pressing the switch 60a for 30 CPM and the switch 60b for 60 CPM,
The processing speed of the copying machine 1 can be input. Note that CPM is a unit indicating the number of copies per minute, and 30 CPM means that 30 copies are made per minute.

The fullness judging means 61 includes a tray lowering timer 62 for lowering the discharge tray 3 in accordance with the stacking amount of sheets on the discharge tray 3, and a processing speed of the copying machine 1 when a fullness is detected. And a full delay timer 63 for delaying the output of the full detection to the CPU 50 for a predetermined time. The full delay timer 63 delays the output of the full detection to the CPU 50 for a predetermined time Tc when the processing speed of the copying machine 1 is 30 CPM and the full state is detected.
And the processing speed of the copying machine 1 is 60
A second full delay timer 63b for delaying the output of the full detection to the CPU 50 by a predetermined time Td when the full load is detected.

The first full delay timer 63a starts counting up, that is, starts counting from the time when the full state is detected, and outputs a full state detection signal to the CPU 50 after a predetermined time Tc, for example, 50 to 60 seconds. The second full delay timer 63b counts up from the time when full is detected,
That is, the timer starts counting, and a predetermined time Td, for example, 20
After 30 seconds, a full detection signal is output to the CPU 50. In the present embodiment, the count-up time by the first full delay timer 63a, that is, the predetermined time Tc is approximately 5
At 5 seconds, the count-up time by the second full delay timer 63b, that is, the predetermined time Td is set to approximately 25 seconds. In FIG. 6, other input members and other output members are the same as those shown in FIG.

Next, the operation of the output tray 3 when the sheets are stacked and the output tray is full when the sort / stack process or the reverse process is selected will be described with reference to the flowchart shown in FIG. Note that, in the same figure, steps B1 to B9 correspond to step A shown in FIG.
Since the control contents are the same as those in 1 to A9, their illustration and description are omitted.

At step B10, the processing speed of the copying machine 1 is determined. That is, the input from the processing speed input means 60 is determined. At this time, if the switch 60a is pressed, it is determined that the processing speed of the copying machine 1 is 30 CPM, and the process proceeds to step B11. If the switch 60b is pressed, the processing speed of the copying machine 1 is 60 CPM. If it is determined that there is, the process proceeds to step B14.

At step B11, time measurement by the first full delay timer 63a is started, and the routine proceeds to step B12.
Subsequently, in step B12, the first full delay timer 6
It is determined whether the time T3 measured by 3a has reached a predetermined time Tc. That is, it is determined whether or not Tc ≦ T3 is satisfied. When the time T3 has reached the predetermined time Tc, the process proceeds to step B13, and when the time T3 has not reached the predetermined time Tc, the process returns to step B1. In step B13, the time counter of the first full delay timer 63a is reset, the operation of the sheet post-processing device 1 is stopped, and a series of controls is ended.

On the other hand, in steps B14, 15, 16
The same control as in steps B11, 12, and 13 is performed. Start timing by the second full delay timer 63b,
It is determined whether the time T4 measured by the second full delay timer 63b has reached a predetermined time Td,
Judge for d ≦ T4. The counted time T4 is a predetermined time T
d, the second full delay timer 63b
Is reset, and the operation of the sheet post-processing apparatus 1 is stopped. If the time T4 has not reached the predetermined time Td, the process returns to step B1.

In the present embodiment, the input condition of the processing speed of the copying machine 1 is set in two ways. However, the present invention is not limited to this.
A plurality of input conditions for the processing speed of the copying machine 1 may be prepared.
Further, the input condition of the processing speed of the copying machine 1 may be variably set, and the predetermined time may be variably set accordingly.

Accordingly, when the processing speed of the copying machine 1 is different, the predetermined time Tc, Td is selected in accordance with the processing speed, so that one sheet post-processing apparatus 2 can perform a plurality of copying at different processing speeds. Machine 1 can be supported. Therefore, frequent stoppage of the sheet post-processing apparatus 2 for a plurality of copying machines 1 having different processing speeds can be prevented, and the versatility of the sheet post-processing apparatus 2 can be improved.

Further, a modification of the second embodiment will be described with reference to FIGS. In these drawings, the same members as those shown in FIGS. 6 and 7 are denoted by the same reference numerals as those used in FIGS. 6 and 7, and the description thereof is omitted, and different points will be described. In the second embodiment, the case where the processing speed of the copying machine 1 is different has been described, but in the present embodiment, the case where the size of paper on which an image is formed is different will be described. Even when the paper size is different, the paper discharge amount per unit time is different, so it is necessary to set the delay time of the output of the full detection signal to the CPU 50 according to the paper size.

As shown in FIG. 8, the CPU 50 is connected to a paper size input means 64 for inputting the size of the paper on which an image is formed in the copying machine 1. The paper size input unit 64 is provided on an operation panel (not shown), and includes a plurality of selection switches. In the present embodiment, the size of the paper is divided by the length of the paper in the paper discharge direction. When the length of the short side of the A4 size paper is L, the length of the paper in the paper discharge direction is less than L. Or the length of the paper in that direction is L
The switch 64a corresponds to the case of less than L, and the switch 64a corresponds to the case of L or more.
By pressing b respectively, it is possible to input the paper size.

The fullness judging means 61 includes a tray lowering timer 62 and a CPU 50 for detecting the fullness according to the sheet size.
And a full delay timer 65 for delaying the output to the CPU for a predetermined time. The full delay timer 65 is used when the length of the sheet in the sheet discharging direction is less than L, and when full is detected, the output of the full detection to the CPU 50 is performed for a predetermined time Te.
A third full-delay timer 65a for delaying the output and a case where the length of the sheet in the sheet discharging direction is L or more, and when a full state is detected, output of the full-state detection to the CPU 50 for a predetermined time Tf
And a fourth full delay timer 65b for delaying.

The third full delay timer 65a starts counting up, that is, starts counting from the time when the full state is detected, and outputs a full state detection signal to the CPU 50 after a predetermined time Te, for example, 20 to 30 seconds. The fourth full delay timer 65b counts up from the time when full is detected,
That is, the timer starts counting, and the predetermined time Tf, for example, 50
After 60 seconds, a full detection signal is output to the CPU 50. In the present embodiment, the count-up time by the third full delay timer 65a, that is, the predetermined time Te is approximately two.
At 5 seconds, the count-up time by the fourth full delay timer 65b, that is, the predetermined time Tf is set to approximately 55 seconds. In FIG. 8, other input members and other output members are the same as those shown in FIG.

Next, the operation of the discharge tray 3 when the sheets are stacked and when the discharge tray is full when the sort / stack processing or the reverse processing is selected will be described with reference to the flowchart shown in FIG. 4, steps C1 to C9 correspond to step A shown in FIG.
Since the control contents are the same as those in 1 to A9, their illustration and description are omitted.

In step C10, the size of the sheet on which the image is formed in the copying machine 1 (the length of the sheet in the sheet discharging direction) is determined. That is, the input from the paper size input unit 64 is determined. At this time, the switch 64a
Is pressed, it is determined that the length of the paper in the paper discharge direction is less than L, and the process proceeds to step C11. If the switch 64b is pressed, the length of the paper in the paper discharge direction is L or more. It proceeds to step C14.

In step C11, the third full delay timer 65a starts counting time, and the flow advances to step C12.
Subsequently, at step C12, the third full delay timer 6
It is determined whether the time T5 measured by 5a has reached a predetermined time Te. That is, it is determined whether or not Te ≦ T5 is satisfied. If the time T5 has reached the predetermined time Te, the process proceeds to step C13. If the time T5 has not reached the predetermined time Te, the process returns to step C1. In step C13, the time counter of the third full delay timer 65a is reset, the operation of the sheet post-processing device 1 is stopped, and a series of controls is ended.

On the other hand, in steps C14, 15, and 16,
Control similar to that of steps C11, C12, and C13 is performed. The time counting by the fourth full delay timer 65b is started,
It is determined whether the time T6 measured by the fourth full delay timer 65b has reached a predetermined time Tf,
It is determined that Tf ≦ T6, and the counted time T6 is equal to the predetermined time T.
f, the fourth full delay timer 65b
Is reset, and the operation of the sheet post-processing device 1 is stopped. If the time T6 has not reached the predetermined time Tf, the process returns to step C1. Therefore,
When the paper sizes are different, by selecting the predetermined times Te and Tf according to the paper size, one paper post-processing apparatus 2 can cope with the case where the paper sizes are different. Therefore, frequent stoppage of the sheet post-processing apparatus 2 can be prevented even when the sheet sizes are different, and the versatility of the sheet post-processing apparatus 2 can be improved.

In the present embodiment, the input conditions of the paper size are two types. However, the present invention is not limited to this, and a plurality of input conditions of the paper size may be prepared. When a plurality of paper size input conditions are prepared, a plurality of predetermined times corresponding to the conditions are also prepared. Further, although the paper size is classified according to the length in the paper discharge direction, the input condition of the paper size may be set according to the paper size and the direction of conveyance.

Further, a third embodiment of the present invention will be described with reference to FIGS. In FIG. 10, other input members and other output members are the same as those shown in FIG. 3, so that illustration thereof is omitted, and different points will be described.
In the first and second embodiments, the operation when the discharge tray is full when the sort / stack processing or the reverse processing is selected has been described. In the present embodiment, the discharge tray when the staple processing is selected is described. The operation of the discharge tray 3 when it is full will be described.

As shown in FIG. 10, the CPU 50 is connected to a fullness judging means 70 for adjusting the timing of outputting this fullness detection signal to the CPU 50 when fullness is detected. The fullness judging means 70 includes a tray lowering timer 71 for lowering the discharge tray 3 in accordance with the stacked amount of the sheet bundle on the discharge tray 3, a staple copy number counter 72 for counting the number of stapled copies, A staple copy number setting counter 73 for setting the number of copies of the sheet bundle to be discharged to the discharge tray 3 from the time when the discharge tray 3 is detected to be full to the time when a full detection signal is output to the CPU 50; ing.

The staple copy number counter 72 is provided between the staple unit 5 and the discharge roller 13.
The sheet bundle sensor includes a sheet bundle sensor for detecting the passage of the sheet bundle, and a counting counter connected to the sheet bundle sensor.
Each time the sheet bundle is ejected, the number of sheets in the sheet bundle is counted.

The staple copy number setting counter 73 is provided in a part of the control unit of the sheet post-processing apparatus 2. The staple copy number setting counter 73 sets the number of paper bundles to be stacked on the paper discharge tray 3 after detecting the fullness. The number of staples is set by the weight of the paper bundle stacked on the paper discharge tray 3. This corresponds to substantially the same number of copies as the stack of sheets corresponding to the stacking height to be loaded. The number of copies set by the staple copy number setting counter 73 is set to 4 to 5 copies, and is set to 4 copies in the present embodiment.

Hereinafter, the control by the full judgment means 70 at the time of full detection will be described with reference to the flowchart shown in FIG. In step D1, it is determined whether the sheet post-processing apparatus 2 performs staple processing. That is, it is determined whether or not the staple process is selected by the selection unit 47. If the staple process has not been selected, the process proceeds to step D2, where the sheet post-processing apparatus 2 performs a process other than the staple process, that is, performs a sort / stack process or a reverse process. In this case, the flowchart shown in FIGS.
The control contents of the flowchart shown in FIG.

On the other hand, if the stapling process is selected, the process proceeds to step D3, where the stapled sheet bundle is discharged to the discharge tray 3, and the sheet bundle is sequentially stacked on the discharge tray 3. The process proceeds to step D4, where it is determined whether or not the paper surface sensor 19 is turned on, that is, whether or not a predetermined amount of paper bundles are stacked on the paper discharge tray 3. If the paper surface sensor 19 is on, the process proceeds to step D6. If it is not turned on, the process proceeds to step D5, where the time counter of the tray lowering timer 71 is reset.

In step D6, the tray lowering timer 7
The time counting by 1 is started, and the process proceeds to Step D7. continue,
In step D7, the time T1 measured by the tray lowering timer 71 is compared with a predetermined time Tb for lowering the discharge tray 3, and whether the time T1 has reached the predetermined time Tb is determined. Is determined. That is,
It is determined whether Tb ≦ T1 is satisfied. Time T
If 1 has reached the predetermined time Tb, the process proceeds to step D8, and if the time T1 has not reached the predetermined time Tb, the process returns to step D4.

In step D8, the tray lowering timer 7
The timer counter of 1 is reset, and the process proceeds to step D9. In this step D9, the discharge tray 3 is lowered by a predetermined fixed amount, and the process proceeds to step D10. At this time, for example, the paper ejection tray 3 is
Lower by 0 mm.

At step D10, it is detected whether or not the lower limit sensor 29 is ON, that is, whether or not the discharge tray 3 has been lowered to the lower end of the guide rail 28. If the lower limit sensor 29 is on, the process proceeds to step D11, and if not, the process returns to step D3.

In step D11, the paper surface sensor 19
Since both the lower limit sensor 29 and the upper limit sensor 29 are turned on, the full state of the discharge tray 3 is detected. Since the full state at this time includes the state where the sheet bundle is curved, the state is changed from this state. Further, as time elapses, stacking is possible as much as the stack of sheets stacked on the sheet discharge tray 3 sinks under its own weight. Therefore, the CPU temporarily waits for the output of a full detection signal to the CPU 50, continues the discharge of the sheet bundle, and proceeds to step D12.

At step D12, counting of the sheet bundle by the staple copy number counter 72 is started.
Proceed to 13. Subsequently, in step D13, the number of copies P1 by the staple copy number counter 72 and the number of copies Pa by the staple copy number setting counter 73, for example,
The number of copies is compared with four copies to determine whether the number of copies P1 has reached the set number of copies Pa. That is, it is determined whether Pa ≦ P1 is satisfied. If the number of copies P1 has reached the set number Pa, the process proceeds to step D14. If the number of copies P1 has not reached the set number Pa, the process returns to step D3. In step D14, the count counter of the staple copy number counter 72 is reset, the operation of the sheet post-processing device 1 is stopped, and a series of controls is ended.

As described above, in the case of performing the stapling process, even if it is detected that the paper output tray 3 is full, the stacking of the sheet bundle is continued in anticipation of the amount by which the sheet bundle sinks by its own weight. Frequent stoppage of the sheet post-processing device 2 can be prevented, and an appropriate discharge tray full condition can be detected. In the stapling process, since the stapling is performed inside the sheet post-processing apparatus 2, the time required for the stapling process varies, and it is difficult to set the amount of time the sheet bundle sinks by its own weight. However, by setting the amount of sinking by the number of sheets in the sheet bundle, the number of stoppages of the sheet post-processing device 2 due to the fullness detection can be reliably reduced.

Further, a fourth embodiment of the present invention will be described with reference to FIGS. In FIG. 12, other input members and other output members are the same as those shown in FIG. 3, so that illustration thereof is omitted, and different points will be described.
In the present embodiment, the amount by which the sheet bundle sinks under its own weight is set by the number of sheets. The details will be described below with reference to the drawings.

As shown in FIG. 12, the CPU 50 is connected to a fullness judging means 80 for adjusting the timing of outputting this fullness detection signal to the CPU 50 when fullness is detected. The fullness judging means 80 includes a tray lowering timer 81 for lowering the paper output tray 3 in accordance with the amount of paper loaded on the paper output tray 3, and a number counting device for counting the number of papers output from the copying machine 1. It is composed of a counter 82 and a sheet number setting counter 83 for presetting the number of sheets to be stacked on the sheet discharge tray 3 from the start of sheet stacking to the full state.

The number-of-sheets counter 82 includes a first counter for counting the number of sheets when performing the sort / stack processing and the reversing processing, and a second counter for counting the number of sheets when performing the staple processing. It is configured.
The first counter counts the number of sheets based on the sheet detection by the sheet sensor 19, and the second counter counts the number of sheets based on the sheet sensor 22.
, The number of sheets is counted based on the sheet detection by.

The sheet number setting counter 83 is provided in a part of the control section of the sheet post-processing apparatus 2. The number-of-sheets setting counter 83 sets the number of sheets to be stacked on the discharge tray 3 after detecting the fullness. The number of sheets is determined by the stacking height at which the sheets stacked on the discharge tray 3 sink by their own weight. This is equivalent to substantially the same number of sheets as the number of sheets. The number of sheets set by the number-of-sheets setting counter 83 is set to 20 to 30 sheets, and is set to about 25 in this embodiment.

Hereinafter, the control by the fullness judging means 80 at the time of fullness detection will be described with reference to the flowchart shown in FIG. In step E1, it is determined whether or not to perform staple processing by the sheet post-processing apparatus 2. That is, it is determined whether or not the staple process is selected by the selection unit 47. If staple processing is not selected,
Proceeding to step E2, the paper post-processing device 2 performs processing other than stapling, that is, sort / stack processing or inversion processing.

In step E2, the sheets are discharged onto the discharge tray 3 and stacked. In step E3, counting of the number of sheets by the first counter of the sheet number counter 82 is started, and the process proceeds to step E4. Subsequently, in step E4, it is detected whether or not the paper surface sensor 19 is turned on, that is, whether or not a predetermined amount of paper is stacked on the paper discharge tray 3. If the paper surface sensor 19 is on,
Proceed to step E6. If not, step E5
And at step E5, the tray lowering timer 8
The timer 1 and the number counter 82 are reset. Note that the control contents from step E6 to step E9 are the same as the control contents from step D6 to step D9 in the flowchart shown in FIG. 11, and therefore description thereof will be omitted.

At step E10, it is detected whether or not the lower limit sensor 29 is ON, that is, whether or not the discharge tray 3 has been lowered to the lower end of the guide rail 28. If the lower limit sensor 29 is on, the process proceeds to step E11, and if not, the process returns to step E5.

In step E11, the paper surface sensor 19
Since both the lower limit sensor 29 and the upper limit sensor 29 are turned on, the full state of the paper discharge tray 3 is detected. The full state at this time includes the state in which the sheet is curved. The paper can be stacked as much as the paper stacked on the discharge tray 3 sinks by its own weight as time passes. Therefore, the CPU temporarily waits for a full detection signal to be output to the CPU 50, continues paper discharge, and proceeds to step E.
Proceed to 12.

At step E12, the number S1 counted by the number counter 82 counted at step E3.
And the number Sa set by the number setting counter 83, for example, approximately 25 sheets, and the counted number S1 is set to the set number Sa.
It is determined whether or not has been reached. That is, it is determined whether or not Sa ≦ S1 is satisfied. When the counted number S1 has reached the set number Sa, the process proceeds to step E13. When the counted number S1 has not reached the set number Sa, step E13 is performed.
Return to 1. In step E13, the number counting counter 82
Is reset, the operation of the sheet post-processing device 1 is stopped, and a series of controls is ended.

On the other hand, if the staple processing is selected in step E1, the process proceeds to step E14. In step E14, the switching claw 7 is switched to convey the sheet from the copying machine 1 to the staple unit 5, and E
The program then proceeds to step E15, in which the number counter 8
In step E16, the counting of the number of sheets by the second counter is started, and the sheets conveyed to the staple unit 5 are sequentially stacked on the staple tray 30.
Proceed to.

In step E16, the staple tray 3
It is determined whether or not a predetermined number of sheets set in advance on the stacker 0 are stapled by the staple 33. If the binding process is performed normally, step E1
Then, if the binding process has not been performed, the process returns to step E1.

In step E17, the stapled sheet bundle is discharged to the discharge tray 3, and the sheet bundle is sequentially stacked on the discharge tray 3, and the process proceeds to step E18. continue,
In step E18, as in the case of the control in step E4, ON / OFF of the paper surface sensor 19 is detected. If the paper surface sensor 19 is ON, the process proceeds to step E20. Also,
If not, the process proceeds to step E19,
In step 19, the time counter and the number counter 82 of the tray lowering timer 81 are reset.

At step E20, similarly to the control at step E6, time measurement by the tray lowering timer 81 is started, and the routine proceeds to step E21. Subsequently, step E21
Then, similarly to the control in step E7, the time T1 measured by the tray lowering timer 81 is compared with a predetermined time Tb for lowering the discharge tray 3, and it is determined whether Tb ≦ T1 is satisfied. The counted time T1 is a predetermined time T
b, the process proceeds to step E8, where the time T1 is counted.
If has not reached the predetermined time Tb, step E18
Return to

By managing the amount of paper loaded on the paper discharge tray 3 by the number of papers, the number of papers can be changed according to the processing speed of the copying machine 1, the paper size, or the staple processing. It is not necessary to change the control conditions for the subsidence. Therefore, various settings of the sheet post-processing device 2 are simplified, and operability can be improved. Further, even if a full state is detected during the stacking, the stacking of the sheets or the sheet bundle is continued until the number of sheets stacked on the discharge tray 3 reaches the set number of sheets Sa. Can be prevented. Further, after the detection of the full state, a number of sheets are stacked on the discharge tray 3 in consideration of the sinking of the sheets on the discharge tray 3, and thereafter, the operation of the sheet post-processing device is stopped. Even if the stacking height is lowered due to the sinking of the set sheets, the sheets can be stacked to the normal full detection height, and an appropriate discharge tray full state can be detected.

In this embodiment, as a counter for counting the number of sheets, a first counter used for performing the sort / stack processing and the inversion processing, and a second counter used for performing the staple processing. However, by counting the number of sheets based on the sheet detection by the sheet sensor 10, the number of sheets in each process can be counted by one counter.

In the embodiment described above, an example in which the sheet post-processing apparatus of the present invention is applied to a copying machine has been described.
Of course, the sheet post-processing apparatus of the present invention may be applied to an image forming apparatus such as a printer and a facsimile.

[0092]

As described above, according to the first aspect of the present invention, the paper is stacked on the paper output tray for at least a predetermined time from the time when the paper output tray is detected to be full. Since the operation of the post-processing device is stopped, even if the stacking height of the stacked sheets is lowered due to the sinking of the stacked sheets, it is possible to detect an appropriate discharge tray full taking into account the sinking of the sheets. Further, the number of stoppages of the sheet post-processing device due to the discharge tray being full can be reduced, and frequent stoppage of the sheet post-processing device can be prevented. In particular, when the sheet is output from a place distant from the sheet post-processing apparatus, the number of times the sheet post-processing apparatus is stopped due to a full discharge tray is reduced, so that usability can be improved. Further, in order to perform the control by the fullness judging means, the fullness detecting means is used, and it is not necessary to separately add a sensor or the like, so that the configuration is simple and the cost is low.

According to the second aspect of the present invention, the length of the predetermined time for stacking the sheets after detecting the fullness of the discharge tray is adjusted according to the processing speed of the image forming apparatus. It is possible to cope with the image forming apparatus, prevent frequent stoppage of the sheet post-processing apparatus for a plurality of image forming apparatuses having different processing speeds, and improve the versatility of the sheet post-processing apparatus.

According to the third aspect of the present invention, the length of the predetermined time for stacking sheets after detecting the fullness of the sheet ejection tray is adjusted according to the sheet size. This makes it possible to prevent the sheet post-processing device from frequently stopping when the sheet size is different, thereby improving the versatility of the sheet post-processing device.

According to the fourth aspect of the present invention, when the staple process is performed, the stacking of at least a predetermined number of sheets is continued from the time when the discharge tray is detected to be full. Since the operation of the apparatus is stopped, the amount of paper bundles stacked on the paper output tray can be loaded on the paper output tray in anticipation of sinking by its own weight, and an appropriate amount of paper bundles can be loaded. . Also, by setting the amount by which the sheet bundle sinks under its own weight by the number of sheets in the sheet bundle, the number of times the sheet post-processing apparatus stops due to full detection can be reliably reduced even if the staple processing time varies.

According to the fifth aspect of the present invention, even when a large number of sheets are stacked on the discharge tray, the present invention is applied to the discharge tray that moves up and down according to the amount of stacking on the discharge tray.
The number of stoppages of the sheet post-processing apparatus due to the discharge tray being full is greatly reduced, so that frequent stoppage of the sheet post-processing apparatus can be prevented, and the usability can be improved. In particular, when a large number of sheets are stacked on the discharge tray, the stacking height of the sheet is significantly changed due to the sinking of the sheet. .

According to the sixth aspect of the present invention, even if a full state is detected during the stacking, the stacking of the sheets or the sheet bundle is continued until the number of sheets stacked on the discharge tray 3 reaches a predetermined number. Frequent stoppage of the sheet post-processing device can be prevented. In addition, after the full state is detected, the output tray is loaded with a number of sheets in consideration of the sinking of the sheets on the output tray, and thereafter, the operation of the sheet post-processing device is stopped. Even if the stacking height is lowered due to the sinking of paper, sheets can be stacked to the normal full detection height, and an appropriate discharge tray full state can be detected. Further, by managing the amount of sheets loaded on the output tray by the number of sheets, the sheet sinks depending on the case where the processing speed of the image forming apparatus is different, the case where the sheet size is different, or the case where staple processing is performed. Since there is no need to change the management conditions for the minutes, various settings of the sheet post-processing apparatus can be simplified, and operability can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a sheet post-processing apparatus.

FIG. 2 is a front view of the staple unit.

FIG. 3 is a schematic block diagram of a control unit of the sheet post-processing apparatus.

FIG. 4 is a flowchart illustrating control of a discharge tray when the discharge tray is full.

FIG. 5 is a flowchart illustrating control of the discharge tray when the discharge tray is full.

FIG. 6 is a block diagram illustrating a main part of a control unit of a sheet post-processing apparatus according to a second embodiment.

FIG. 7 is a flowchart illustrating control of a discharge tray when the discharge tray is full according to the second embodiment.

FIG. 8 is a block diagram illustrating a main part of a control unit of a sheet post-processing apparatus according to a modification of the second embodiment.

FIG. 9 is a flowchart illustrating control of a discharge tray when the discharge tray is full according to a modification of the second embodiment.

FIG. 10 is a block diagram illustrating a main part of a control unit of a sheet post-processing apparatus according to a third embodiment.

FIG. 11 is a flowchart illustrating control of a discharge tray when the discharge tray is full according to the third embodiment.

FIG. 12 is a block diagram illustrating a main part of a control unit of a sheet post-processing apparatus according to a fourth embodiment.

FIG. 13 is a flowchart illustrating control of a discharge tray when the discharge tray is full according to a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copier (image forming apparatus) 2 Paper post-processing apparatus 3 Paper discharge tray 5 Staple unit 46 Vertical drive means 47 Selection means 50 CPU 51 Fullness detection means 52 Fullness determination means 53 Tray lowering timer 54 Fullness delay timer 60 Processing speed input Means 64 Paper Size Input Means 72 Staple Set Count Counter 73 Staple Set Counter 82 Sheet Count Counter 83 Sheet Set Counter

Claims (6)

[Claims] A sheet discharge tray on which sheets discharged from the image forming apparatus are stacked; and a sheet detecting means for detecting whether or not the sheets stacked on the sheet discharge tray are full. The post-processing apparatus further includes a full determination unit configured to cause the stacking of the sheets to be continued for at least a predetermined time from the time when the discharge tray is full, and then to stop the operation of the sheet post-processing apparatus. Paper post-processing device. 2. The sheet post-processing apparatus according to claim 1, wherein said full judgment means adjusts the length of said predetermined time according to the processing speed of said image forming apparatus. 3. The sheet post-processing apparatus according to claim 1, wherein said full judgment means adjusts the length of said predetermined time according to the size of said sheet. 4. A stapling means for stapling sheets discharged from the image forming apparatus and stacking the stapled sheet bundle on the discharge tray; and operating or not operating the stapling means. Selection means for selecting either one of the stapling means, and when the operation of the stapling means is selected, the fullness judging means detects at least a predetermined number of copies of the staple 4. The sheet post-processing apparatus according to claim 1, wherein the operation of the stapling unit is continued until the processing is completed, and thereafter, the operation of the sheet post-processing apparatus is stopped. 5. The sheet post-processing apparatus according to claim 1, further comprising up-down drive means for vertically moving said sheet discharge tray in accordance with the amount of paper loaded on said sheet discharge tray. 6. A stapling means for stapling a sheet discharged from the image forming apparatus, a selecting means for selecting one of an operation and a non-operation of the stapling means, and a non-operation of the stapling means are selected. And a stacking tray for stacking the staple-processed sheet bundle when the operation of the stapling unit is selected. Paper having up / down driving means for vertically moving the paper discharge tray in accordance with the amount, and full detection means for detecting whether or not the paper stacked on the paper discharge tray or the paper bundle is full; In the post-processing device, after the discharge tray is detected to be full, the paper or the upper side of the paper is stacked until the number of sheets stacked on the discharge tray reaches a predetermined number. A sheet post-processing apparatus, comprising: a full judgment unit for continuing the stacking of the sheet bundle and stopping the operation of the sheet post-processing apparatus when the number of sheets reaches a predetermined number.