JP2003182923A - Sheet treatment device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably stack and adjust sheets by keeping the drawing force of a knurling belt 190 to be constant even when the coefficient of friction of the knurling belt 190 is degraded during a long use. <P>SOLUTION: A sheet treatment device comprising a treatment tray 130 having a stopper part 131 to receive and stack discharged sheets, the knurling belt 190 which is stretched over a discharge roller 7a to draw the sheets on the treatment tray 130 to the stopper part 131, and a traction motor 192 to tract one end of the knurling belt 190 in a predetermined direction further comprises a height detecting means 195 to detect the height of the stacked sheet, and a counting means to count the number of the sheets drawn into the stopper part by the knurling belt 190. When feeding the sheets by the knurling belt 190, the traction motor 192 is controlled so that the drawing force of the sheets by the knurling belt 190 is constant by the height of the sheets detected by the height detecting means and the number of the sheets counted by the counting means 195. <P>COPYRIGHT: (C)2003,JPO

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 performing processing such as stapling processing on a sheet on which an image has been formed, and an image forming apparatus including the sheet processing apparatus.

[0002]

2. Description of the Related Art Generally, as a sheet processing apparatus, a sheet having an image formed thereon is aligned and focused, and if necessary, a first processing means for stapling a part of the sheet bundle and an aligned sheet bundle. Alternatively, as for the apparatus in combination with the second processing means for receiving and accommodating the staple-stitched sheet bundle for each bundle, for example, there are already many techniques including the technique disclosed in JP-A-11-199123. Things have been proposed and implemented. FIG. 7 shows a schematic configuration of a matching unit in a conventional sheet processing apparatus of this type.

In FIG. 7, a conventional sheet processing apparatus receives a pair of carry-out rollers 701 including a lower carry-out roller 701a for carrying out a sheet P from a sort path 700 and a carry-out roller 701b, and receives and aligns the carried-out sheet P. A processing unit 800 that has a first processing unit that collects and bundles a part of the sheet bundle as needed, and a stack tray 900 that stores and stacks the sheet bundle discharged after the processing for each bundle And configure.

A knurled belt 702 is wound around the lower unloading roller 701a of the unloading roller pair 701 at several positions in the axial direction between the unloading roller 701b and the sheet guides are provided at appropriate positions between the knurled belts 702. 703 is arranged.

The processing unit 800 has a processing tray 801 that is inclined by positioning the downstream side (upper left side in the figure) upward and the upstream side (lower right side in the figure) downward with respect to the discharge direction of the sheet P. And a stopper portion 802 at the upstream end, a pair of left and right aligning members 803 in the sheet width direction, and a pair of lower and upper bundle discharge rollers 804 arranged on the downstream side of the processing tray 801.
and a lower bundle discharge roller 804a having a bundle discharge roller pair 804 composed of a and 804b and an upper bundle discharge roller 804b on the lower surface of the front end portion.
With respect to the upper bundle discharge roller 804b, a swinging guide 805 that supports the upper bundle discharge roller 804b so that the upper bundle discharge roller 804b can be contacted with and separated from the upper bundle discharge roller 804b.
Have 06 and.

In this case, the lower and upper bundle discharge rollers 804a and 804b of the pair of bundle discharge rollers 804 have swing guides 805.
By the swing control of the upper bundle discharge roller 804b with respect to the lower bundle discharge roller 804a, the sheet P from the discharge roller pair 701 is received on the processing tray 801 in the open state.
At the end of the acceptance, the lower bundle discharge roller 804a is brought into contact with the upper bundle discharge roller 804b to be in a closed state, and the lower bundle discharge roller 804a is driven to rotate clockwise, so that the received sheet P is processed. After being urged so as to be pulled back to the upstream stopper portion 802 side, that is, the upstream side, on 801 it is separated again.

The sheet P urged to the upstream side continues the pullback action by the rotational drive of the pull-in paddle 806 and is aligned by the operation of each aligning member 803, and the rotation of the knurled belt 702 thereto. The sheet P is brought into contact with the stopper portion 802 through the sheet guides 703 by adding the feeding action of the sheet end portion by the above, and the alignment operation is completed in this manner.

As shown in FIG. 7, the knurled belt 702 is wound around the discharge roller 701a on the lower side between the carry-out rollers 701, that is, the discharge tray 701a on the processing tray 801 side so as to be rotatable, and A floating roller 791 is provided which rotates in contact with the lower inner peripheral surface of the knurled belt 702, and the processing tray 80 is provided at the time of the paddle and aligning operation described below, particularly at the start of the aligning operation performed subsequent to the paddle operation.
According to the height h of the sheets P stacked in 1, the floating roller 7
By driving 91 to the rear side in the figure by a stepping motor 792, the pulling force of the stacked sheet bundle toward the uppermost stopper 802 is kept constant.

The sheet P discharged from the pair of carry-out rollers 701 has its own weight and a retractable paddle described later.
Due to the action of 806 and the feeding action on the lower surface side of the knurled belt 702, the trailing edge of the sheet P becomes
While being guided downward by the 703, the stopper 802
It slides on the processing tray 801 until it abuts against the abutting support surface 802a. The abutting sheet P is aligned in the width direction of the sheet by the aligning unit 803 to form a sheet bundle.

The sheet bundle aligned on the processing tray 801 is bound, if necessary, at the aligning position, and then the upper bundle discharge roller 804b is brought into contact with the lower bundle discharge roller 804a. And this time, the lower bundle discharge roller 804
By rotating a in a counterclockwise direction, the processed sheet bundle is discharged onto the stack tray 900.

[0011]

However, the knurled belt 702 moves the floating roller 791 to the rear side in the figure by the stepping motor 792 according to the sheet height h of the sheets P stacked on the processing tray 801 shown in FIG. When the knurled belt has a low friction coefficient on the surface due to durability etc., it is necessary to keep the pulling force of the stacked sheet bundle toward the uppermost stopper 802 side constant by driving it. It was not possible to obtain the pull-in force of, and this was a cause of alignment failure and stacking failure.

Therefore, an object of the present invention is to keep the pulling force of the knurled belt constant even when the friction coefficient of the knurled belt is lowered due to durability or the like, and enable more stable stacking and alignment of sheets. Is.

[0013]

In order to achieve the above object, a typical constitution of the present invention is a stacking means having a stopper portion for receiving and stacking discharged sheets, and a stretching roller that stretches the sheet. Height detection for detecting the height of stacked sheets in a sheet processing apparatus including a belt member that pulls sheets on the stacking unit to the stopper unit and a pulling unit that pulls one end of the belt member in a predetermined direction A means and a counting means for counting the number of sheets drawn into the stopper portion by the belt member, and at the time of sheet feeding by the belt member, the height of the sheet detected by the height detecting means, and From the number of the sheets counted by the counting means, the pulling force of the sheets by the belt member is kept constant. And controlling the pull stage.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment) A sheet processing apparatus according to the present invention and an image forming apparatus having the same will be described in detail with reference to the drawings. 1 is a schematic view of an image forming apparatus having a sheet processing apparatus, FIG. 2 is a schematic view of a sheet processing apparatus, FIG. 3 is a view showing a moving mechanism of a knurled belt, and FIG. 4 is a drawing of a knurled belt. It is a figure which shows the relationship between force and pulling amount, and FIG. 5 is a figure which shows a mode of a knurling belt and a moving mechanism.

First, an image forming apparatus equipped with the sheet processing apparatus according to the present invention will be described. FIG. 1 is an overall sectional view schematically showing a schematic configuration of an image forming apparatus (copying apparatus) including a sheet processing apparatus.

In the apparatus configuration shown in this figure, the image forming apparatus 300 comprises a document placing table 401 such as a platen glass for reading the automatically fed copy source document D, a light source 402 and a lens system 403. Document reading unit 400, image forming sheet feeding unit 500, image forming unit 600, and sheet processing for processing and stacking image-formed sheet P discharged from pair of discharge rollers 302 The device 1 and the like are provided.

The feeding section 500 is provided with cassettes 501 and 502 on which the sheets P are placed and which are detachably attached to the apparatus main body, and a deck 504 which is arranged on a pedestal 503. The image forming unit 600 includes a cylindrical photosensitive drum 601, a primary charger 602 around the photosensitive drum 601, an exposure unit 603, a developing unit 604, and a transfer charger 6.
05, a separation charging device 606, a cleaner 607, and the like are provided, and a fixing device 608 is arranged downstream of the image forming unit 600 via a conveying device 301.

Next, the operation of the image forming apparatus 300 having the above configuration will be described. When a feeding signal is output from the control device 310 in the apparatus main body, feeding of the sheet P is started from the cassette 501, 502 of the feeding unit 500 or the deck 504. On the other hand, the image of the document D placed on the document placing table 401 is read by the light from the light source 402, and is irradiated onto the surface of the photosensitive drum 601 through the lens system 403. The photoconductor drum 601 is previously charged by the primary charger 602, an electrostatic latent image is formed on the drum surface by irradiation of the reading light, and the electrostatic latent image is developed by the toner of the developing device 604. By that,
A corresponding toner image is formed.

The sheet P fed from the feeding unit 500 is fed to the image forming unit 600 with its skew being corrected by the registration rollers 505 and the timing thereof being adjusted. Next, in the image forming section 600, the toner image on the surface of the photoconductor drum 601 is transferred onto the sheet P by the transfer charger 605, and then the sheet P onto which the toner image is transferred is separated by the separation charger 606. It is charged to the opposite polarity and separated from the surface of the photosensitive drum 601.

After that, the sheet P is conveyed to the fixing device 608 by the conveying device 301, and the transferred image is permanently fixed by the fixing device 608. Then, the sheet P on which the image is formed in this manner is discharged to the sheet processing apparatus 1 side by the discharge roller pair 302.

Next, the sheet processing apparatus according to the present invention will be described. FIG. 2 is an overall sectional view schematically showing a schematic configuration of the sheet processing apparatus.

In the configuration of the sheet processing apparatus (hereinafter referred to as "finisher") 1 shown in FIG. 2, 2 is an inlet roller pair for receiving the sheet P discharged from the discharge roller pair 302 of the image forming apparatus 300. Reference numeral 3 denotes a first conveying roller pair that conveys the received sheet P, and 31 denotes a sheet detection sensor on the entrance side that detects passage of the sheet P. Further, reference numeral 50 is a punch unit for making a hole near the rear end of the conveyed sheet. Reference numeral 5 denotes a roller having a relatively large diameter (hereinafter referred to as “buffer roller”) which is arranged on the way of conveyance, and each pressing roller arranged around the outside.
At 12, 13, and 14, the sheet P is pressed against the roll surface and conveyed.

Reference numeral 11 is a first switching flapper, which can select a non-sort path 21 and a sort path 22. 10 is a second switching flapper, which is a sort path 22.
And the buffer path 23 for temporarily storing the sheet P. 33 is a sensor for detecting the sheet P in the non-sort path 21, and 32 is a sensor for detecting the sheet P in the buffer path 23.

Reference numeral 6 denotes a second conveying roller pair of the sort path 22. 129 temporarily stacks the sheets P, aligns the stacked sheets P, and staples the staple unit 100.
It is a processing unit including a processing tray 130 which is a first stacking unit provided for performing a stapling process by a stapler 101 (stitching unit). On the discharge end side of the processing tray 130, one discharge roller that constitutes a bundle discharge roller pair that is a bundle transfer unit, here, a lower discharge roller 180a as a fixed side is arranged. Reference numeral 7 denotes a first discharge roller pair which is arranged in the sort path 22 and has a tension roller for discharging the sheet P onto the processing tray 130.
A second discharge roller pair 9 is disposed on the non-sort path 21 and discharges the sheet P onto the sample tray 201.

180b is supported by the swing guide 150, and when the swing guide 150 reaches the closed position, it is pressed against the lower discharge roller 180a to press the sheet P on the processing tray 130. Upper discharge rollers for discharging a bundle onto the stack tray 200 which is the second stacking means. Reference numeral 40 denotes a stack stacking guide that supports the rear end (rear end in the stack discharge direction) edge of the stack of sheets stacked on the stack tray 200 and the sample tray 201, and also serves as the exterior of the sheet processing apparatus 1 here. ing.

Next, the processing unit 129 including the processing tray 130 will be described in detail with reference to FIGS. 3 and 4. The processing unit 129 includes a processing tray 130 and a stopper portion 13.
1, alignment means 140, swing guide 150, pull-in paddle 160, bundle discharge roller pair 180, and knurled belt (endless belt-shaped feed member) as a belt member that is rotationally driven by the above-mentioned first discharge roller pair 7. It is composed of 190 and.

The processing tray 130 is inclined by positioning the downstream side (upper left side in the figure) upward and the upstream side (lower right side in the figure) downward with respect to the discharge direction of the sheet bundle. The sheet guides 130c are set at the lower end which is the upstream side and arranged at predetermined intervals in the sheet width direction.
The knurled belt 190 and the above-mentioned stopper portion 131 are arranged, and a stacking height detecting means 195 is provided in the vicinity of the stopper portion 131.

Further, in the middle portion, the aligning means 140 is arranged so as to occupy the outer positions corresponding to the left and right sides of the sheet P. Further, a swing guide 150 including a drawing paddle 160 and a bundle discharge roller pair 180 is arranged in an upper part which is also a downstream side, specifically, in a substantially upper region part of the processing unit configuration.

The knurled belt 190 is formed by forming anti-slip knurls on the entire outer periphery and molded into a required diameter, and is an endless belt having flexibility that is deformable in the rotational direction.
As shown in FIG. 3, the first discharge roller pair 7 is wound around the discharge roller 7a on the lower side, that is, the discharge tray 7a on the processing tray 130 side so as to be rotatable, and inside the lower portion of the knurled belt 190. Floating roller 191 that rotates in contact with the peripheral surface
Is rotatably provided on a pulling arm 196 as a moving means.

The pulling arm 196 extends above the processing tray 130 and below the first discharge roller pair 7 on the rear end support surface 131a side of the processing tray at a predetermined angle with the processing tray 130, and the rack 196a. Are integrally formed. The rack 196a and the gear portion 192a provided on the drive shaft of the traction motor 192 as the traction means are fitted. The towing motor is a pulse motor, and the rotation amount of the motor is determined by a pulse signal given to the motor, and the floating roller 191 is towed by an amount corresponding to the rotation amount of the motor, as shown in FIG. The distance H between the knurled belt 190 and the processing tray 130 is changed.

That is, when the floating roller 191 is pulled by the pulling motor 192 in the direction of arrow X in the figure, the knurled belt
190 is deformed and retracted (indicated by a broken line in FIG. 3A) in a direction of being pulled inside the upper sheet guide 130c away from the processing tray 130 and the sheet bundle, and when retracted to the maximum,
It will get inside the sheet guide 130c. When the floating roller 191 is driven in the opposite arrow Y direction, the knurled belt 190 and the processing tray 130 come close to each other, and the knurled belt 190 and the processing tray 130 come into contact with each other at the leading end.

When the sheet P is discharged onto the processing tray 130, the knurled belt 190 is in a position where it does not contact the processing tray 130. Immediately after the sheet P is discharged to the processing tray 130, the knurled belt 190 moves to the contact position and feeds the sheet P toward the stopper portion 131. And at the start of the matching operation that follows the paddle operation,
When the floating roller 191 is pulled by the pulling motor 192 in the direction of the arrow X in the figure, the knurled belt 190 is separated from the sheet P so that the abutting of the sheet P against the rear end support surface 131a is not obstructed during the alignment operation. Become.

When the aligning operation is completed and the next sheet is discharged to the processing tray 130, the floating roller 191 is driven again in the direction of the arrow Y in the drawing, and the knurl 190 comes into contact with the sheet P. At this time, by the stacking height detection means 195,
The height of the sheet bundle stacked on the processing tray is roughly detected, and the contact amount between the sheet P and the knurled belt 190 is constant regardless of the height of the sheet bundle, that is, after the stopper 131 of the sheet P abuts. The position of the floating roller 191 is controlled so that the pulling force to the end support surface 131a becomes constant. That is,
Floating roller when the knurled belt 190 contacts the sheet P as a large number of sheets are stacked and the stacking height becomes higher.
The position of 91 moves in the direction of the arrow X in the figure.

The pulling force of the knurled belt 190 is such that the sheet height is constant and the sheet P and the knurled belt are
Even when the contact pressure of 190 is constant, as shown in FIG.
It is generally known that the pulling force decreases as the total number of pulled-in sheets P increases. This is because the knurled belt 190 pulls in the sheet P, and the surface of the knurled belt 190 is scraped, resulting in a decrease in the coefficient of friction. However, in order to keep the pulling force of the sheet P constant, a predetermined pulling force can be obtained by increasing the contact pressure of the knurled belt to the uppermost position.

FIG. 4 shows an example of the relationship between the number of durable knurled belts and the pull-in force. In order to obtain the predetermined pull-in force F, the total number of the sheets P pulled by the knurled belt 190 is counted by the counting means in the memory of the knurled belt control means (not shown) by the pulse motor
The knurled belt 190
Depending on the total number of sheets pulled in, for example, as shown in FIG. 5, by changing from A1 to A4, the pulling force can be controlled to be substantially constant.

Since the reduction of the pulling force of the knurled belt 190 is almost constant, if the relation between the total number of pulled-in sheets, the pulling-in force, and the pulling amount is obtained as data in advance, the durability will be improved and the friction of the knurled belt will be increased. Even if the coefficient decreases and the pulling force decreases as a result, by controlling the pulling amount, it is possible to maintain the same pulling force as in the initial stage.

In this way, the sheet P discharged from the first discharging roller pair 7 is moved by the own weight of itself and the action of the retracting paddle 160, and the feeding action on the lower surface side of the knurled belt 190 to the rear side of the sheet P. Edges of each sheet guide 130c
While being guided to the lower side by the above, it slides on the processing tray 130 until it abuts against the abutting rear end support surface 131a of the stopper portion 131.

Further, at the upper end of the processing tray 130,
As described above, one lower discharge roller 180a that constitutes the bundle discharge roller pair 180 is arranged, and the lower surface front end portion of the swing guide 150 abuts against the lower discharge roller 180a. The other upper discharge roller 180b that is in contact is arranged, and each of these discharge roller pairs 180a, 180b is
A drive motor (not shown) can rotate in the forward and reverse directions. The sheets P processed by the processing tray 130 are bound by the binding unit 100 as necessary, and then discharged to the stack tray 200 by the bundle discharge roller pair 180 described above.

In the present embodiment, the height of the sheets stacked on the processing tray is directly detected by the stacking height detecting means. However, the number of sheets stacked on the processing tray is counted, and the count is calculated in advance. There is no problem even if the sheet height is estimated by using the relationship between the number of sheets and the stacking height obtained through experiments. Since the sheet thickness is extremely thin, it is not necessary to control the knurl height for each sheet, and in some cases, even if the height is changed for every plural sheets (for example, every five sheets or every ten sheets). Well, the invention is in no way limited to this embodiment.

(Other Embodiments) In the above-described embodiment, the knurled belt 190 is wound around the discharge roller 7a on the processing tray 130 side so as to be rotatable and is in contact with the lower inner peripheral surface of the knurled belt 190. It is assumed that the floating roller 191 that freely rotates about the pulling arm 196 is rotatably provided. However, the present invention is not limited to this, and as shown in FIG. 6, the tension roller pair 193 is replaced by the first discharge roller pair 7. Alternatively, the knurled belt 190 may be deformed by the floating roller 191.

Further, in the above-mentioned embodiment, the copying machine is exemplified and explained as the image forming apparatus, but the present invention is not limited to this, and it may be a facsimile machine or a printer.

[0042]

As described above, in the present invention, the height detecting means for detecting the height of the stacked sheets, and the counting means for counting the number of sheets pulled into the stopper portion by the belt member, When the sheet is fed by the belt member, the drawing force of the sheet by the belt member is calculated from the height of the sheet detected by the height detecting means and the number of sheets counted by the counting means. Since the pulling means is controlled so as to be constant, even if the friction coefficient of the belt member is reduced due to durability etc., the pulling force of the belt member is kept constant and more stable stacking and alignment of sheets is possible. Can be

[Brief description of drawings]

FIG. 1 is a schematic diagram of an image forming apparatus having a sheet processing apparatus.

FIG. 2 is a schematic diagram of a sheet processing apparatus.

FIG. 3 is a diagram showing a moving mechanism of a knurled belt.

FIG. 4 is a diagram showing a relationship between a pulling force and a pulling amount of a knurled belt.

FIG. 5 is a diagram showing a state of a knurled belt and a moving mechanism.

FIG. 6 is an explanatory diagram of another embodiment.

FIG. 7 is a diagram showing a moving mechanism of a conventional knurled belt.

[Explanation of symbols]

D ... manuscript P ... Sheet 1 ... Sheet processing device 2 ... Inlet roller pair 3 ... First transport roller pair 5 ... Buffer roller 6 ... Second transport roller pair 7 ... 1st discharge roller pair 7a ... Ejection roller 9 ... Second discharge roller pair 10… Second switching flapper 11 ... 1st switching flapper 12 ... pressing roller 13 ... pressing roller 14 ... pressing roller 21… Non-sorted path 22… Sort path 23… Buffer pass 31… Sheet detection sensor 32… Sensor 33… Sensor 40… Bundle loading guide 50… Punch unit 100 ... Staple unit 101 ... Stapler 129… Processing unit 130… Processing tray 130c… Sheet guide 131… Stopper 131a ... Rear end support surface 140… Matching means 150… Swing guide 160… retract paddle 180… Bundle discharge roller pair 180a ... Lower discharge roller 180b ... Upper discharge roller 190… Knurled Belt 191 ... Floating roller 192 ... Traction motor 192a ... Gear section 193 ... tension roller pair 195… Height detection means 196 ... Towing arm 196a ... Rack 200… Stack tray 201… Sample tray 300… Image forming device 301… Conveyor 302… Ejection roller pair 310… Control device 400… Original scanning section 401… manuscript table 402… Light source 403… Lens system 500… Feeding department 501 ... cassette 502 ... cassette 503 ... Pedestal 504… Deck 505 ... Registration roller 600 ... Image forming unit 601 ... Photosensitive drum 602… Primary charger 603 ... Exposure part 604 ... Developer 605 ... Transfer charger 606 ... Separating charger 607 ... Cleaner 608 ... Fixer

Claims (5)

[Claims] 1. A stacking unit having a stopper unit for receiving and stacking discharged sheets, a belt member stretched by a stretching roller to draw the sheet on the stacking unit to the stopper unit, and one end of the belt member. In a sheet processing apparatus having a pulling unit that pulls in a predetermined direction, a height detecting unit that detects the height of stacked sheets, and a count that counts the number of sheets pulled into the stopper unit by the belt member. Means, and in the sheet feeding by the belt member, the height of the sheet detected by the height detection means, the number of sheets counted by the counting means, from the sheet by the belt member A sheet processing apparatus, wherein the pulling means is controlled so that the pulling force is constant. 2. A stacking unit having a stopper unit for receiving and stacking discharged sheets, a belt member stretched by a stretching roller to draw the sheet on the stacking unit to the stopper unit, and one end of the belt member. In a sheet processing apparatus having a pulling means for pulling in a predetermined direction, a counting means for counting the number of sheets pulled into the stopper portion by the belt member, and a sheet feeding by the belt member, The stacking height of sheets is estimated from the number of sheets counted by the counting means, and the pulling means is controlled so that the pulling force of the sheets by the belt member becomes constant. Sheet processing equipment. 3. The sheet processing apparatus according to claim 1, wherein when the pulling unit operates and the belt member is pulled, the belt member moves substantially upward from the stacking unit. Characteristic sheet processing device. 4. The sheet processing apparatus according to claim 1, wherein the pulling means is in contact with the inner peripheral surface of the belt member and is driven to rotate, and the floating roller in a predetermined direction. A sheet processing apparatus comprising: a moving unit that moves the sheet. 5. An image forming unit for forming an image on a sheet, and the sheet processing apparatus according to claim 1, wherein the sheet on which the image is formed by the image forming unit is discharged and processed.
An image forming apparatus comprising: