JP2002087688A - Sheet treatment device and image forming device equipped with this - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet treatment device capable of increasing sheet treatment speed and an image forming device equipped with the sheet treatment device. SOLUTION: A sheet delivered after an image is formed is loaded on a sheet loading means, and the sheets loaded on the sheet loading means are aligned in the direction perpendicularly crossing to the sheet delivery direction with a pair of alignment means 412. A sheet bundle loaded on the sheet loading means is stapled with a staple means 419, and when the sheet bundle stapled with the staple means 419 is delivered, a pair of alignment means 412 is moved in the position where the distance between a pair of alignment means 412 does not come in contact with the sheet with a control means controlling the alignment action of the alignment means 412, and the time shunting to the position where a pair of alignment means 412 accepts the next sheet is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet processing apparatus and, more particularly, to sheet alignment performed before processing such as binding and punching of sheets (bundles) stacked on sheet stacking means.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a sheet on which an image is formed is discharged to a sheet processing apparatus.
There is a type in which a sheet bundle is stacked on a stack tray after performing a binding process or the like on a sheet discharged in a sheet processing apparatus.

In such a sheet processing apparatus, for example, when staple processing is performed, first, sheets discharged from the image forming apparatus are stacked on an intermediate processing tray, and one sheet is discharged. Each time, the sheet discharge direction and the direction orthogonal thereto are aligned on the intermediate processing tray. The matching of the discharge direction
Rotation of a flexible rubber paddle or belt makes contact with the sheet, and alignment in the direction orthogonal to the sheet discharge direction is performed by contacting the alignment plates with both side edges of the sheet. .

After the sheets are aligned in this manner, when one bundle of sheets is stacked on the intermediate processing tray, stapling is performed by the stapler unit. And, after the stapling process is performed in this way,
The sheet bundle of the intermediate processing tray is discharged to a stack tray by a bundle discharge roller or a bundle discharge belt.

[0005]

However, in such a conventional sheet processing apparatus, after the staple processing is performed, the alignment plate is moved to a position where the next sheet can be received. During this time, the next sheet cannot be discharged to the intermediate processing tray. For this reason, it is necessary to stop image formation by the image forming apparatus or to delay sheet discharge, and the sheet processing speed is reduced.

Accordingly, the present invention has been made in view of such circumstances, and has as its object to provide a sheet processing apparatus capable of increasing the sheet processing speed and an image forming apparatus having the same. It is.

[0007]

According to the present invention, there is provided a sheet processing apparatus for processing a sheet to be discharged, wherein a sheet stacking means for stacking the discharged sheet and a sheet stacked on the sheet stacking means are provided. A pair of alignment means for performing alignment in a direction orthogonal to the sheet discharging direction, staple means for stapling a sheet bundle stacked on the sheet stacking means, and control means for controlling alignment operation of the alignment means. When discharging the sheet bundle stapled by the stapling means, the control means
It is characterized in that the pair of aligning means is controlled so as to be moved to a position where the distance between the pair of aligning means does not contact the sheet.

Further, the invention is characterized in that the control means controls to start moving the pair of alignment means before discharging the sheet bundle.

In the present invention, the control means controls the pair of aligning means to stop at a position substantially in contact with the sheet when the bundle is discharged without performing the stapling. It is assumed that.

According to the present invention, there is provided an image forming apparatus comprising: an image forming section; and a sheet processing apparatus for processing a sheet discharged after an image is formed by the image forming section. It is characterized by any one of the above.

Further, as in the present invention, the sheet discharged after the image is formed is stacked on the sheet stacking means, and the sheet stacked on the sheet stacking means by the pair of aligning means in the sheet discharging direction. The alignment is performed in the direction orthogonal to. Then, the sheet bundle stacked on the sheet stacking unit is stapled by the stapling unit, and when the sheet bundle stapled by the stapling unit is discharged, the pair of aligning units is controlled by the control unit that controls the aligning operation of the aligning unit. The distance between the pair of aligning means is shifted to a position where the pair of aligning means does not contact the sheet, so that the time required for the pair of aligning means to retreat to the position for receiving the next sheet is shortened.

[0012]

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

FIG. 1 is a diagram showing a configuration of an image forming apparatus provided with a sheet processing apparatus according to the present embodiment.

In FIG. 1, reference numeral 500 denotes an image forming apparatus. The image forming apparatus 500 has an image reader 200 and a printer 300, and is provided between the image reader 200 and the printer 300 as an image forming unit. A finisher 400 as a sheet processing apparatus is provided.

Here, the image reader 200 includes a scanner unit 104 and a document feeder 100.
The document feeder 100 separates the document set upward, feeds it one sheet at a time sequentially from the first page to the left, conveys it onto the platen glass 102 via a curved path, and reads the document. The original is discharged to a discharge tray 112.

The scanner unit 104 has a lamp 103 for irradiating the original conveyed on the platen glass 102 with light. The light emitted from the lamp 103 onto the original is reflected by the original and then reflected by a mirror. 105,1
06, 107, image sensor 1 via lens 108
09 to read the original image.

On the other hand, the printer 300 is provided with an exposure control unit 110 for outputting a laser beam corresponding to an image of a document subjected to image processing after being read by the image sensor 109. The laser beam is applied to the photosensitive drum 111 so that an electrostatic latent image is formed on the photosensitive drum 111.

Further, thereafter, the electrostatic latent image on the photosensitive drum 111 is developed by a developing unit 113 to form a toner image. The toner image is stored in cassettes 114 and 115, a manual paper feed unit 125 described later, The transfer unit 116 transfers the sheet to a sheet fed from any one of the sheets 124.

The sheet on which the toner image has been transferred as described above is subjected to a fixing process when passing through the fixing unit 117, and the sheet having passed through the fixing unit 117 is guided to a discharge roller 118, where the toner image is transferred. The sheet is discharged from the printer 300 by the discharge roller 118 with the transferred surface facing downward (face down).

Here, by discharging the sheet face-down in this manner, image formation is performed sequentially from the first page, such as when using the document feeder 100 or when printing an image output from a computer. The correct page order. When images are formed on both sides of the sheet, the sheet that has passed through the fixing unit 117 is
After being guided to the paper discharge path 122 by 21, it is switched back to the double-sided conveyance path 124, and thereafter, an image is formed on the back surface by the operation described above.

On the other hand, the sheet discharged from the discharge roller 118 is sent to the finisher 400.
In the present embodiment, the finisher 400
Performs a stapling operation on a sheet.

FIG. 2 is a view showing the structure of the finisher 400. In FIG. 2, reference numeral 419 denotes a staple unit for performing staple processing on sheets, 421 denotes an inclined bundle discharge belt, and this bundle discharge belt 421. The sheet (bundle) discharged on a low-friction intermediate processing tray, which is a sheet stacking unit (not shown), and then stapled by a stapling unit 419 is stacked on a stack tray 411.
It is for discharging up. The intermediate processing tray is provided at a position several millimeters higher in parallel with the bundle discharge belt 421.

The bundle discharge belt 421 has a bundle discharge lever 421A. When the bundle discharge belt 421 makes a revolving motion, the bundle discharge lever 421A operates.
The sheet bundle on which the stapling process has been performed is pushed up in the upper right direction, and is discharged onto the stack tray 411 moving to a predetermined stacking position. Note that the stack tray 411 moves up and down in accordance with the sheet stacking amount.

Reference numeral 417 denotes a fan-shaped return roller.
The return roller 417 rotates and comes into contact with the sheet discharged onto the intermediate processing tray, and moves the sheet in the lower left direction. Then, by moving the sheet in the lower left direction, the end of the sheet is moved to the stopper plate 418.
And the staple unit 41 with respect to the sheet whose end portion abuts against the stopper plate 418 in this manner.
Reference numeral 9 denotes a stapling process.

Reference numerals 412A and 412B denote alignment plates as a pair of alignment means for restricting both side edges of the sheet on the intermediate processing tray, and are provided on the near side and the back side. Also, 42
0 indicates that after the sheet is discharged onto the stack tray 411,
This is a paper pressing member that suppresses the upper surface of the sheet. By lowering the stack tray 411 by a predetermined amount and then raising the stack tray 411, the upper surface of the sheet is pressed by the paper pressing member 420. This prevents the sheet being pushed out from being pushed rightward by the sheet discharged onto the stack tray 411 next.

In the finisher 400 configured as described above, after the sheet received from the printer 300 is sent to the paper discharge roller 415 via the path 416, the sheet discharge belt 421 is inclined by the paper discharge roller 415. The sheet discharged upward and further discharged is shown in FIG.
As shown in (2), it falls in the lower left direction along the bundle discharge belt 421 (intermediate processing tray) provided diagonally.

After the sheet falls, the return roller 417 rotates in the direction of the arrow, so that the friction member 417a provided in the arc of the return roller 417 is discharged onto the bundle discharge belt 421. It comes into contact with S. As a result, the sheet S moves in the lower left direction, and the end comes to abut against the stopper plate 418 as shown in FIG.

Then, after the end of the sheet S is brought into contact with the stopper plate 418, the staple unit 41
9, a stapling process is performed on the sheets on the bundle discharge belt 421. Note that the bundle discharge belt 421 may not be long enough to stack the sheets. Therefore, the bundle discharge belt 421 is provided with a stacking auxiliary plate 421B, which allows the length of the sheet stacking surface of the intermediate processing tray. I try to make up for the shortage.

On the other hand, the sheets on the intermediate processing tray on which stapling has been performed as described above are caused to rotate the bundle discharge belt 421 in the direction of the arrow so that the bundle discharge belt 42 is rotated.
The sheet is discharged onto a stack tray 411 by a bundle discharge lever 421A provided in the stack tray 411 as shown in FIG. In addition,
At this time, the bundle discharge lever 421A moves in a notch provided in the intermediate processing tray.

At this time, the stack tray 411 moves up and down in accordance with the sheet stacking amount.
11 is pressed down by the paper pressing member 420 by lowering the stack tray 411 by a predetermined amount and then raising it.
11 is prevented from being pushed rightward by the sheet discharged onto the sheet 11.

FIG. 6 is a control block diagram of the image forming apparatus 500. In the figure, reference numeral 150 denotes a CPU circuit unit. The CPU circuit unit 150 controls the document feeder 100 according to a program stored in the ROM 151 and settings of the operation unit 1.
1. Image reader controller 201 for controlling image reader 200, image signal controller 202, printer controller 301 for controlling printer 300, finisher controller 401 for controlling finisher 400, and external I / F 20
3 is controlled.

Here, the external I / F 203 is an interface from the computer 204 for developing print data into an image and outputting it to the image signal control unit 202. Also, the image sensor 109 (FIG. 1) is sent from the image reader control unit 201 to the image signal control unit 202.
(See FIG. 1), and the image output from the image signal control unit 202 to the printer control unit 301 is input to the exposure control unit 110 (see FIG. 1). Note that 15
Reference numeral 2 denotes a RAM used as an area for temporarily storing control data and a work area for operations involved in control.

FIG. 7 is a diagram showing the configuration of the image signal control unit 202. In FIG. 7, reference numeral 205 denotes an image processing unit which performs an image correction process and an editing process according to the settings of the operation unit 1. . The image read by the image sensor 109 is output to the printer control unit 301 via the image processing unit 205, the line memory 206, and the page memory 207. The hard disk 208 is used as needed, for example, when changing the page order.

FIG. 8 is a diagram for explaining a sensor and a motor in the finisher 400. In FIG.
1, M2 are first and second motors, and the first motor M1
Drives the discharge roller 415 and the return roller 417, and the second motor M2 controls the bundle pressing member 420 and the bundle discharge belt 4
21 is driven. Note that the first motor M1 is a step motor, and the amount of rotation is constantly managed by the finisher control unit 401 as control means.

The discharge roller 415 is driven by a first motor M1 via a one-way clutch 425, and the return roller 417 is driven by a first motor M1 via a one-way clutch 426. In the present embodiment, the first motor M
When 1 rotates forward, only the discharge roller 415 rotates in the direction of discharging the sheet, and when it rotates reversely, the return roller 417 rotates.
Only the sheet rotates in a direction to hit the sheet against the stopper plate 418.

The bundle discharge belt 421 is driven by a second motor M2 via a one-way clutch 422, and the bundle pressing member 420 is driven by a second motor M2 via a one-way clutch 424. In the present embodiment, only the bundle discharge belt 421 rotates when the second motor M2 rotates forward, and only the bundle pressing member 420 rotates when the second motor M2 rotates reversely. Then, as described above, the discharge rollers 41
5 and the return roller 417, the bundle discharge belt 421, and the bundle holding member 420 are driven by one motor M1 and M2, respectively, whereby cost reduction can be achieved.

S3 is a sensor for detecting whether or not the return roller 417 is at the home position. This sensor S3 detects a flag (not shown) attached to the rotating shaft of the return roller 417, thereby detecting the return. Roller 41
7 detects whether or not it is at the home position.

A sensor S2 is provided in the path 416 and detects a sheet to be discharged.
Detects the leading edge of the sheet, a detection signal is input to the finisher control unit 401 (see FIG. 6), whereby the finisher control unit 401 activates the discharge roller 415 and decelerates the discharge roller 415 at a timing described later. ,
It is designed to stop.

S5 is a sensor for detecting sheets on the bundle discharge belt 421, and S11 is
11 is a sensor that detects a sheet on the sheet 11. S8 is a sensor for detecting whether or not the bundle discharge lever 421A is at the home position.

The position shown in FIG.
7. The home position of the bundle discharge lever 421A.
The home position of the bundle discharge lever 421A is slightly to the right of the stopper plate 418.

The return roller 417 makes exactly one turn in the direction of the arrow starting from the home position every time one sheet is discharged. When the return roller 417 is rotating, the discharge roller 415 does not rotate due to the above-described configuration.

When the bundle is discharged, the bundle discharge belt 42
1 is rotated by half, but at this time, the stack tray 41
Numeral 1 is controlled to a position which is a distance suitable for dropping the sheet bundle when discharging the bundle. However, in this state, the upper surface of the sheet bundle stacked on the stack tray 411 is placed on the trajectory of the bundle discharge lever 421A. It hits the stacked sheet bundle.

Therefore, when the bundle discharge lever 421A is substantially parallel to the linear portion of the bundle discharge belt 421 (substantially parallel to the intermediate processing tray not shown) as shown in FIG. (2) The motor M2) is temporarily stopped, and the stack tray 411 is lowered. When the stack tray 411 descends, the remaining rotation is performed to stop at the home position. This prevents the bundle discharge lever 421 </ b> A from entangling the sheets on the stack tray 411 and prevents the bundle discharge belt 42
It is possible to prevent the trailing end of the sheet bundle from remaining on top of the sheet bundle.

FIG. 10 shows matching plates 412A and 412B.
FIG. 3 is a diagram for explaining the driving mechanism of FIG. 3, in which M3 is a third motor M3, M4 that drives the rear alignment plate 412A.
Is a fourth motor M4 for driving the front matching plate 412B. Note that when the motors M3 and M4 rotate in the black arrow direction, the respective units rotate in the black arrow direction, and when the motor rotates in the white arrow direction, the respective units rotate in the white arrow direction.

S6 is a sensor for detecting whether or not the rear alignment plate 412A is at the home position, and S7 is a sensor for detecting whether or not the front alignment plate 412B is at the home position. In addition, these matching plates 412
A and 412B can perform offset stacking in which the state where sheets S are stacked on the stack tray 411 is distributed to the near side and the back side as shown in FIG.

When staple processing is performed by the staple unit 419, the alignment plate 412B on the front side is used.
Is set to the foremost side, and the bundle discharge belt 421 is set.
Each time the sheet is discharged upward, the third motor M3 is driven to push the rear-side alignment plate 412A against the sheet, thereby aligning the sheet by abutting the sheet against the alignment plate 412B. .

When performing the offset discharge without performing the stapling process, each of the alignment plates 412A and 412B is set at a distance corresponding to the sheet width, and the sheets are placed on the bundle discharge belt 421 in this state. Each time the sheet is discharged, one of the alignment plates 412A and 412B is pressed against the sheet, so that the sheet is aligned with the alignment plates 412A and 412B.
The sheet is aligned by contacting the other side of the sheet.

Further, each time the bundle is discharged, the alignment plate 412
A, the position of 412B is the near side, the back side, the near side, the back side ...
By alternately shifting as described above, the sheet bundle stacked on the stack tray 411 can be set in an offset (shifted) state for each bundle.

It is to be noted that whether or not the offset sheet is to be discharged can be appropriately set by the user through the operation unit 1 of the image forming apparatus 500, and the setting contents are transmitted from the CPU circuit unit 150 to the finisher control unit 401. Notified to
The finisher 400 operates accordingly.

Here, the timing of driving the alignment plates 412A and 412B and the return roller 417 will be described. As described above, the return roller 417 moves the sheet in the sheet discharging direction to perform alignment in the sheet discharging direction, and
Reference numerals 12A and 412B act to move the sheet in a direction perpendicular to the sheet discharging direction and perform alignment in a direction perpendicular to the sheet discharging direction.

When the return roller 417 and the alignment plates 412A and 412B act in different directions,
If both operations overlap, the seat will be adversely affected. For this reason, the operation of the alignment plates 412A and 412B
At the time when the operation of Step 17 is completed, the sheet is controlled so as to contact the sheet. In the present embodiment, the matching plate 41
The sheets 2A and 412B are aligned so as not to damage the sheet S as described later, and to prevent the sheet from being forcibly pressed in order to prevent variation due to a reaction force.

FIG. 12 is a view for explaining a mechanism for raising and lowering the stack tray 411. M5 is a fifth motor for raising and lowering the stack tray 411.
A sensor 11 detects that 11 has reached the upper limit, and a sensor S12 detects that the stack tray 411 has reached the lower limit. When the fifth motor M5 rotates in the black arrow direction, each part rotates in the black arrow direction, and the fifth motor M5 rotates.
Each part rotates in the white arrow direction when rotates in the white arrow direction.

S10 is a height sensor 423 for detecting the height of the sheets stacked on the stack tray 411.
The flag 423 normally protrudes outward as shown in FIG. 13, but when the stack tray 411 is raised and comes into contact with the sheets S stacked on the stack tray 411, As shown in FIG. 14, it is pushed inward. The height of the sheets S stacked on the stack tray 411 can be detected by detecting the flag 423 pressed in this way by the height sensor S10.

In the present embodiment, the stack tray 411 is moved down after the bundle is discharged, but this is because the bundle discharge lever 421A does not contact the sheet on the stack tray 411 as described above. Therefore, after the bundle is discharged, the stack tray 411 is lowered to a position where the height sensor S10 is not detected.

The reason for raising the stack tray 411 after lowering the stack tray 411 is to raise the stack tray 411 so that the upper surface of the newly discharged stack of sheets is discharged to the next bundle discharge position. To move it. Also, before the lowering operation after the bundle is discharged, the bundle holding member 4
Reference numeral 20 rotates clockwise, and operates so as to press the sheets on the stack tray 411.

By the way, for example, when the finisher 400 is to be made compact as shown in FIG.
The distance between the paper discharge roller 415 and the sensor S2 becomes shorter. On the other hand, considering the stackability when the discharge roller 415 discharges the sheet onto the bundle discharge belt 421, the sheet is conveyed at a high speed by the discharge roller 415 during the conveyance of the sheet, and the rear end of the sheet is discharged by the discharge roller 415. At the time of exiting
It is desirable to prevent the sheet from jumping over the bundle discharge belt 421 by decelerating the sheet.

Here, when decelerating with reference to the rear end, a method of decelerating according to the detection of the rear end of the sheet is usually employed. However, as described above, the paper discharge roller 415 and the sensor S
2 is short, the sheet is bundled with the discharge belt 421.
Even if it can be prevented from jumping over, it may not be enough to improve the loadability.

Next, the drive control of the paper discharge roller 415 for obtaining a better stacking performance with a compact finisher will be described with reference to the flowchart shown in FIG.

First, the finisher control unit 401 has a CPU
The sheet size information is received from the circuit unit 150, and the sheet ejection roller 415 determines whether the sheet to be ejected is a sheet of a standard size (S101). When it is determined that the sheet is the standard size (Y in S101), it is next determined whether or not the sensor S2 is on (the leading edge of the sheet passes) (S102). If the sensor S2 is on, (S
102), driving of the paper discharge roller 415 (the first motor M
1) is turned on (S103).

Next, as described above, the finisher control unit 401 which manages the rotation amount of the first motor M1 provides
It is determined whether the discharge roller 415 has been rotated by the first motor M1 by an amount corresponding to the sheet size (S10).
4). Then, when it is determined that the discharge roller 415 has rotated by an amount corresponding to the size (Y in S104), after a time corresponding to the sheet size has elapsed, the discharge roller 415 is decelerated (S105) and stopped (off). (S106).

The time according to the sheet size is
The setting is made in consideration of the sheet size and the deceleration time of the paper discharge roller 415 so that the trailing edge of the sheet comes out immediately before the paper discharge roller 415 stops in step S106. Accordingly, it is possible to prevent the discharged sheet from flying too far on the bundle discharge belt 421.

On the other hand, if it is determined in step S101 that the sheet is not the standard size, that is, it is a free size sheet (N in S101), it is determined whether or not the sensor S2 is turned on (the leading end of the sheet passes) (S107). When the sensor S2 is turned on (Y in S107), the discharge rollers 41
5 is turned on (S108). And the sensor S2
Is turned off (the trailing edge of the sheet passes) (S1
09, Y), the paper discharge roller 415 is decelerated (S11).
0) and stop (turn off) (S111).

Next, control of bundle discharge by the bundle discharge belt 421 in the finisher 400 will be described with reference to the flowchart shown in FIG.

First, as an initial operation before the image forming operation, it is determined whether there is a sheet on the bundle discharge belt 421 (intermediate processing tray) based on the sensor S5 (S121). Then, when there is a sheet on the intermediate processing tray (S121)
(Y), it is determined whether or not the sheet is the second original drawing (S122). Here, the second original drawing is a thin and rigid sheet used for drafting and the like.

It should be noted that whether or not the sheet is the second original drawing is determined, for example, when the manual sheet feeding unit 125 (see FIG. 1) is used, the setting for using the manual sheet feeding unit 125 is set on the image forming apparatus side. Then, the screen of the operation unit 1 of the image forming apparatus 500 changes to the state shown in FIG. 17B, and when the material key 1a is pressed on this screen, the state shown in FIG.

When the second original key 1b is pressed on this screen, it is considered that the second original is fed from the manual paper feeder 125, and the image forming apparatus 500 sends the finisher 4
When the sheet is transferred to 00, the image forming apparatus 500 notifies the finisher 400 of the material information and the sheet feeding unit information in association with the sheet.

Thus, the finisher 400 can determine whether or not the sheet on the intermediate processing tray is the second original drawing. FIG. 17A shows a screen of the operation unit in the normal standby mode in the copy mode, in which the number of image forming units set by the operation unit 1 and the like are displayed.

Next, when it is determined that the sheet on the intermediate processing tray is not the second original (N in S122), the bundle discharge belt 421 is driven to discharge the bundle (S123), and the image forming apparatus 500 Output a standby signal to the
6). Then, in response to the standby signal from finisher 400, image forming apparatus 500 starts forming an image on a sheet.

Here, since the second original drawing is stiff and is not suitable for bundle discharge, the user is asked to remove the bundle from the intermediate processing tray without discharging the bundle. For this reason,
If it is determined that the sheet is the second original drawing (Y in S122), an intermediate processing tray overflow signal is output to the image forming apparatus 500 as a signal for activating a display for prompting the image forming apparatus to perform the display (S124). ).

Then, the image forming apparatus 500 which has received the intermediate processing tray overflow signal displays on the operation section 1 a message "Please remove the sheet from the intermediate processing tray." Next, the process waits until there are no more sheets on the bundle discharge belt 421 (intermediate processing tray). When there are no more sheets (N in S125), a standby signal is output to the image forming apparatus 500 (S126). If there is no sheet on the intermediate processing tray in step 121 (N in S121), a standby signal is output to the image forming apparatus 500 (S126).

Next, after outputting the standby signal as described above, each of the variables S, N, and T is set to 0 (S12).
7). Here, the variables S and N are variables for monitoring the sheet so as not to be overloaded on the intermediate processing tray, and the variable T is mainly used for discharging the OHP sheet when the OHP sheet is discharged. This is a variable to prevent the sheet from being adversely affected.

Next, the type information of the material of the sheet discharged from the image forming apparatus 500 is received, and it is determined whether or not the sheet is the second original (S128). First, one sheet received from the image forming apparatus 500 is discharged onto the intermediate processing tray (S129), and a weighting count for a variable S described later is performed (S130).

Then, the size information of the next sheet to be received is received from the image forming apparatus 500, and it is determined whether or not the width of the sheet already stacked on the intermediate processing tray is different from the width of the next sheet to be received (S131). If the widths do not differ (N in S131), it is next determined whether stapling is not performed on the currently received sheet, that is, whether or not the sheet is in the non-staple mode (S132).

Here, when the setting of the image forming job is the non-staple mode, it is determined whether or not the sheet discharged onto the intermediate processing tray in step S129 has been fed from the manual paper feed unit 125 (step S129). S133).
If the sheet is fed from the manual feed unit 125 (Y in S133), one is added to the variable T (S13).
4), it is determined whether or not the variable T has become 2 (S13)
5).

When the variable T becomes 2 (Y in S135), that is, when sheets are continuously
If the sheets have been fed, the bundle discharge belt 421 is driven to discharge the bundle (S136). If the job has not been completed at this time (N in S156), the process returns to step S127. If it is determined in step S133 that the sheet is not a sheet fed from the manual sheet feeding unit 125 (N in S133), the variable T is set to 0 (S137), and step S13 to be described later is executed.
Proceed to 8. Also, if the variable T has not become 2 in step S135 (N in S135), the step S
Proceed to 138.

Here, the manual paper feed unit 125 is designed to be able to feed various types of sheets including OHP sheets, but the OHP sheets are more likely to be charged with static electricity than ordinary paper. For this reason, if 30 sheets of ordinary paper are bundled and discharged to the stack tray 411, the sheets on the stack tray 411 will not be adversely affected, but if only 30 sheets of OHP sheets are bundled and discharged, The sheet on the stack tray 411 may be shifted due to the synergistic effect of weight and static electricity. Therefore, when two sheets continuously fed from the manual sheet feeding unit 125 to which an OHP sheet may be fed,
A bundle is discharged to prevent it.

On the other hand, if the width of the sheet stacked on the intermediate processing tray is different from the width of the next sheet to be received in step S131 (Y in S156), the bundle is discharged (S13).
6). If the mode is not the non-staple mode in step S132 (N in S132), that is, if the mode is the staple mode, it is determined whether or not the variable S has become 60 or more (S138).

When the variable S is not equal to or greater than 60, that is, when the variable S is less than 60 (N in S138), it is determined whether or not the variable is a break based on a job separation signal from the image forming apparatus 500 (S140). Here, when the job is a break (Y in S140), the bundle is discharged (S136). If it is determined that the variable S is equal to or greater than 60 (Y in S138), the current stapling is prohibited (S139), and the bundle is discharged (S136). The prohibition of stapling is released after receiving the delimiter signal.

If it is determined in step S128 that the image is the second original drawing (Y in S128), the image forming apparatus 5
The sheet received from 00 is discharged onto the intermediate processing tray (S141), and 1 is added to the variable N (S142). Then, a weighting count is performed on the variable S (S14).
3) It is determined whether the variable N has reached 15 (S14).
4).

If the variable N has not become 15 (N in S144), it is determined whether or not the variable S has become 60 or more (S145). (N in S 145), it is determined whether or not it is a break based on a job break signal from the image forming apparatus (S 146). If it is not a job break (N in S146), the process returns to step S128.

If it is a job break (Y in S146), an intermediate processing tray overflow signal is output to the image forming apparatus 500 (S147). Accordingly, as described above, the image forming apparatus 500 performs a display for removing the sheet on the intermediate processing tray.

Thereafter, until the sheet is removed from the bundle discharge belt 421 (intermediate processing tray) (S1
48, Y), an intermediate processing tray sheet presence signal is output to the image forming apparatus 500 (S149). While the intermediate processing tray overflow signal is being received and the intermediate processing tray sheet present signal is being received, the image forming apparatus 500
Does not start the next image forming job.

When the variable N becomes 15 in step S144 (Y in S144) and when the variable S becomes 60 or more in step S145 (Y in S145), the intermediate processing tray reaches the limit of the stacking amount. If it has reached, an overflow signal for the intermediate processing tray is output to the image forming apparatus 500 (S150).

Thereafter, until the sheet is removed from the bundle discharge belt 421 (intermediate processing tray) (S14).
8Y), an intermediate processing tray sheet presence signal is output to the image forming apparatus 500 (S149). Also at this time, the image forming apparatus 500 performs a display requesting that the sheet on the intermediate processing tray be removed.

If the processing has proceeded to step S129 and subsequent steps (in the case of a sheet other than the second original drawing),
The aligning plates 412A and 412B perform the aligning operation according to the sheet size and rotate the return roller 417 clockwise. When the process proceeds to the process after step S141 (in the case of the second original drawing), the stacking of the sheets is performed. The alignment plates 412A and 412B are retracted to a position where they do not interfere, so that the alignment operation is not performed, and the return roller 417 is not driven. FIG. 18 shows the state of the second original drawing S when the second original drawing S is discharged onto the bundle discharge belt 421.

Next, the weighting count in steps S130 and S143 will be described with reference to the flowchart shown in FIG.

The sheet length (length in the conveyance direction) based on the size information of each sheet received from the image forming apparatus 500
Is determined to be not more than 297 mm (S151). If the sheet length (length in the conveying direction) is not more than 297 mm (Y in S151), 2 is added to the variable S (S152).

If the sheet length is longer than 297 mm (N in S151), it is determined whether the sheet length is 364 mm or less (S153). If the sheet length is 364 mm or less (Y in S153), 3 is added to the variable S (S153). S154).
When the sheet length is longer than 364 mm (S15
(N of 3), 4 is added to the variable S (S155).

By weighting the count value in accordance with the sheet length in this manner, it is possible to stack up to the number of sheets suitable for the bundle discharge on the intermediate processing tray when performing the bundle discharge. Is not carried out, the stacking on the intermediate processing tray can be performed so that the sheets are not scattered.

Next, control of the stack tray 411 in the finisher 400 will be described with reference to the flowchart shown in FIG.

After the start of copying, the stack tray 411 is controlled so that the height sensor S10 for detecting the sheet height of the stack tray 411 is turned on. Then, the sheet received from the image forming apparatus 500 is
A bundle discharge process (S161) is performed in which the bundle discharge belt 421 is driven by the forward rotation of the motor M2 to discharge the bundle, and the bundle pressing member 420 is rotated in the reverse direction to hold the paper on the stack tray 411. .

Then, the stack tray 411 is lowered (S162), and it is detected by the lower limit sensor S12 (see FIG. 12) whether or not the stack tray 411 has reached the lower limit (S163). Here, the stack tray 411
Does not reach the lower limit, that is, when the lower limit sensor S12 is not turned on (N in S163), the height sensor S1
0 is turned off (see FIG. 13) or not (S1).
64) If the height sensor S10 has not been turned off (N in S164), the process returns to step S162.

When the height sensor S10 is turned off (Y in S164), the stack tray 411 is stopped, and after a lapse of a predetermined time, the stack tray 4 is stopped.
11 is raised (S165). And the height sensor S
When 10 is turned on (see FIG. 14) (Y in S166),
Further, the stack tray 411 is raised (S167),
When the stack tray 411 rises by a predetermined amount (Y in S168), the stack tray 411 is stopped (S169).

Here, the fifth motor M5 for raising and lowering the stack tray 411 is a DC motor, and by inputting the number of pulses from an encoder provided on the axis of the DC motor, the finisher control unit 401
11 can be monitored. Fifth motor M5
Can be configured with a stepping motor and monitoring with an input clock is also possible.

On the other hand, when the stack tray 411 reaches the lower limit in step S163, that is, when the lower limit sensor S12 is turned on (Y in S163), a stacker overflow signal is output to the image forming apparatus (S170), and the stack tray is output. 411 is stopped (S171). In addition,
The image forming apparatus 500 that has received this signal displays “Remove the paper from the stack tray” on the operation unit 1 after the job is completed.

Thereafter, it is determined whether or not there is a next job to be discharged (S172). If there is a next job (Y in S172), the bundle is continuously discharged (S17).
3) If there is no next job to be discharged (S172)
N), and waits until the height sensor S10 is turned off (S
174), when it is turned off (Y in S174), the stacker overflow signal is turned off (S175).

As described above, when the lower limit is reached while the stack tray 411 is being lowered, the jobs (for example, the computer 204) that cannot be stopped at the time of detection of the lower limit without performing the raising operation of steps S165 and S167.
Of the bundle corresponding to the job received from the printer).

Here, the stack tray 4 suitable for bundle discharge
The position 11 will be described. If the distance from the bundle discharge belt 421 to the stacking surface on the stack tray 411 is too large, the stackability of the sheet bundle on the stack tray 411 is poor. Further, since the leading edge of the sheet while being discharged to the paper discharge roller 415 follows a trajectory as shown in FIG.
If the distance is too short, the leading end of the sheet abuts on a steeply inclined portion of the stacking surface of the stack tray 411, and there is a possibility that a jam may occur during the conveyance of the paper discharge roller 415.

Therefore, steps S162 to S1 described above are performed.
By the lowering and raising control in 69, the distance between the bundle discharge belt 421 and the stacking surface on the stack tray 411 is set to a distance that does not easily cause a jam and that the stacking property is good.

In the present embodiment, the stack tray 41
The upper surface of the upper sheet is detected by the height sensor S10. In such a configuration, if the upper surface of the sheet cannot be detected while the stack tray 411 is descending, the bundle discharge belt 421 and the stack tray 411 are not detected. The precise distance from the upper loading surface cannot be controlled.

Here, the thickness of the bundle may be controlled by estimating the thickness of the bundle based on the number of discharged sheets. However, in the case where the thickness of the sheet is various and the thickness of the bundle does not reach the estimated thickness. There is. If a bundle that is thicker than expected is discharged, as described above, the distance between the bundle discharge belt 421 and the stacking surface of the stack tray 411 becomes short, and there is a possibility that a jam occurs.

Therefore, when the lower limit is reached while the stack tray 411 is being lowered, the stack bundle 411 is discharged without performing the raising operation of the stack tray 411 under the control of steps S170 to S173. This can prevent the occurrence of a jam, and furthermore, since the sheet bundle discharged at this time is the last bundle, even if the stackability is somewhat poor, there is no significant effect.

In this embodiment, in order to make the finisher 400 compact and low-cost, the bundle discharge belt 421 is slightly shorter. Therefore, A4
When processing a long sheet such as an R or A3 size sheet, a portion of the sheet S that did not fit on the discharge belt 421 is supported on the stacker tray 411 as shown in FIG.

When the image forming apparatus 500 starts an image forming job in the staple mode, the sensor S11 detects that sheets are stacked on the stack tray 411.
Is detected, the image forming apparatus 500 displays on the operation unit 1 the message "Please remove the sheet from the stack tray."

This is because when the stapled sheet bundle is stacked on the stack tray 411, the staple portions overlap and the stackability is not very good, and the image forming job is performed in a state where sheets are not stacked on the stack tray 411 as much as possible. Because I want to start.

However, since the image forming apparatus 500 is used not only in the copy mode but also in the printer mode,
The image forming job (including staple processing and bundle discharge processing) can be started even if the sheet is not removed in consideration of the fact that the user is not present.

When the image forming apparatus has completed 30 image forming jobs continuously in the staple mode, the image forming job is temporarily interrupted, and the operation unit displays "Please remove sheets from stack tray." In addition to the display, a sheet is removed from the stack tray 411 and the sensor S11 is turned off to wait for the restart of the image forming job.

Next, the sheet alignment operation in the present embodiment will be described with reference to a timing chart shown in FIG.

When the sensor S2 detects a sheet received from the image forming apparatus 500, the finisher control unit 401
First, the first motor M1 rotates forward, whereby the sheet S is stacked on the intermediate processing tray by the sheet discharging roller 415 as shown in FIG. 3 (sheet discharging 1). Thereafter, the second motor M2 rotates in the reverse direction, whereby the return roller 417 rotates, and the sheet is aligned (returned) in the sheet discharging direction as shown in FIG.

Next, the third motor M3 rotates forward, and for example, the rear alignment plate 412A moves to a position corresponding to the size of the sheet S received in advance from the image forming apparatus 500, and the sheet S is discharged in the sheet discharging direction. (Alignment 1). Thereafter, the third motor M3 rotates in the reverse direction, whereby the alignment plate 412A retracts to a position for receiving the next sheet (retreat 1).

Here, as described above, in the present embodiment, when aligning the sheet S in the direction orthogonal to the sheet discharging direction, the aligning plate 412A prevents the aligning plate 412A from forcibly pressing the sheet. 412B is moved within a range where the distance from the sheet 412B is wider than the sheet width.
When the sheets are aligned in this manner, the alignment plate 412
By preventing the sheet from being forcibly pressed by A, the sheet can be prevented from being damaged, and variation due to the reaction force can be prevented.

By the way, when the alignment plate 412A is aligned so as not to forcibly press the sheet, particularly when the length of the sheet in the transport direction is long, when aligning the sheet, as shown in FIG. The sheet is pushed out of the center in the sheet discharging direction, and the sheet is inclined as shown in a state A shown by a solid line.

However, even if the sheet S is inclined as described above,
When the next sheet is discharged onto the sheet in such a skewed state, and is subsequently aligned in the sheet discharge direction by the return roller 417, the sheet skewed due to friction with the next sheet is indicated by a broken line. The state shown in FIG.

Thereafter, the sheets are continuously discharged, and for the (n-1) th sheet (discharge n-1),
After performing (return n-1), (alignment n-1), and (evacuation n-1), when the n-th sheet is discharged, similarly to the operation for the previous sheet (discharge n), (Return n) and (Match n) are performed. At this time, if an instruction to staple the n sheets has been received from the image forming apparatus 500 in advance, the finisher control unit 401 does not perform the retracting operation of the alignment plate 412A, as shown in FIG. Then, the second motor M2 is rotated in the reverse direction to rotate the return roller 417, and the discharge direction alignment operation is performed (return n + 1).

Thus, even when the n-th sheet is inclined as shown in the state A by the aligning operation by the aligning plate 412A, the return roller 417 is operated so that the sheet S rotates around the fulcrum A, and B is matched. With such a configuration, the sheets can be aligned even when the sheets are not forcibly pushed by the alignment plate 412A. With this configuration, the number of return operations is reduced as compared with the related art, which is advantageous in terms of durability, power consumption, and processing time.

On the other hand, after such (return n + 1) is completed, the stapling unit 41 according to the stapling instruction.
9 operates to perform a stapling operation. Thereafter, when the third motor M3 rotates in the reverse direction and the alignment plate 412A starts retreating to the position for receiving the next sheet (retreat n + 1), the second motor M2 also rotates forward and starts the bundle discharge operation ( Bundle ejection).

In this embodiment, the bundle discharge operation is started at least at a position where the alignment plate 412A does not come into contact with the sheets stacked on the intermediate processing tray after the alignment plate 412A starts retreating. It is when it reaches. Note that before starting the bundle discharge operation, the alignment plate 412
Even if A is retracted, since the sheet bundle is stapled by the staple unit 419, there is no fear that the sheet bundle will be dislodged even if the bundle discharge operation is performed thereafter.

Then, as described above, the staple unit 4
19, the alignment plate 412A is at least at a position where it does not come into contact with the sheets stacked on the intermediate processing tray, in other words, a pair of alignment means 412A, 41
When the bundle discharge operation is started when the interval of 2B reaches a position where the sheet does not contact the sheet, as in the related art, for example, as shown in FIG. Compared with the configuration in which the plate 412A is retracted, the time for the alignment plate 412A to retract to a position where the next sheet can be received can be shortened.

As a result, the discharge of the first sheet of the next job can be accelerated, and the sheet processing operation can be accelerated. It should be noted that the alignment plate 412A may be retracted to a position where the next sheet can be received during the period from the start of the bundle discharge to the end of the bundle discharge.
The evacuation time of 12A can be shortened, and the same effect can be obtained.

On the other hand, when the bundle discharging operation is completed as described above, the second motor M2 rotates in the reverse direction to perform the bundle holding operation (bundle holding). Next, after the fifth motor M5 rotates in reverse and the stack tray 411 descends, the second motor M2 rotates forward again to move the bundle discharge belt 421 to the home position (bundle pushing home). After this, the stack tray 411 is raised by the forward rotation of the fifth motor M5,
It stops at a position based on the detection of the sensor S10.

The next sheet is received by the alignment plate 4.
This is possible when the bundle pushing belt 421 is at the home position with the 12A retracted (sheet discharge 1). It is necessary that the stack tray 411 has been lifted at the end of the sheet discharge. By repeating these operations, continuous paper can be received.

In the above description, the timing for performing stapling has been described. If there is no instruction to perform stapling, the processing of (return n + 1) and (staple) is performed as shown in FIG. The operation excluding is performed. It should be noted that there is no problem even if the processing of (return n + 1) is omitted, since there is no particular limitation on the consistency when no stapling is performed.

When the bundle discharging means is operated without performing the operation by the stapling means, the aligning plate 412A is retracted after the bundle discharging is completed as shown in FIG. I have. In other words, when the bundle is discharged, the alignment plate 412A is stopped at a position substantially in contact with the sheet, so that it is possible to prevent the aligned bundle from falling apart when the bundle is discharged. If the stapling is not performed, the retreat time of the alignment plate 412A is shorter than the staple time, and thus does not cause a delay in the sheet discharging operation.

[0124]

As described above, when a sheet bundle stapled by the stapling means is discharged, the pair of aligning means is positioned at a position where the interval between the pair of aligning means is not in contact with the sheet. By moving, the evacuation time of the aligning means can be shortened, and the sheet processing speed can be increased.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an image forming apparatus including a sheet processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a finisher that is the sheet processing apparatus.

FIG. 3 is a diagram illustrating a state in which sheets are stacked on an intermediate processing tray (bundle discharge belt) of the finisher.

FIG. 4 is a diagram illustrating a state in which a sheet stacked on the intermediate processing tray abuts against a stopper plate.

FIG. 5 is a diagram illustrating a state in which sheets stacked on the intermediate processing tray are discharged to a stack tray by a bundle discharge belt.

FIG. 6 is a control block diagram of the image forming apparatus.

FIG. 7 is a block diagram of an image signal control unit provided in the image forming apparatus.

FIG. 8 is a diagram illustrating a sensor and a motor in the finisher.

FIG. 9 is a diagram illustrating a temporary stop position of a bundle discharge lever provided on the bundle discharge belt.

FIG. 10 is a diagram illustrating a driving mechanism of an alignment plate provided in the finisher.

FIG. 11 is a diagram illustrating a positional relationship of an alignment plate when sheets are offset stacked on the stack tray.

FIG. 12 is a view for explaining a stack tray elevating mechanism.

FIG. 13 is a view for explaining a state before a stack tray of a height sensor provided in the finisher is lifted.

FIG. 14 is a view for explaining a state when the stack tray of the height sensor is raised.

FIG. 15 is a flowchart showing drive control of a discharge roller in the finisher.

FIG. 16 is a flowchart showing bundle discharge control by a bundle discharge belt in the finisher.

FIG. 17 is a diagram illustrating a screen for setting materials of the image forming apparatus.

FIG. 18 is a diagram illustrating a state of the second original drawing when the second original drawing is discharged onto the bundle discharge belt.

FIG. 19 is a flowchart showing a weight count in the finisher.

FIG. 20 is a flowchart illustrating control of a stack tray in the finisher.

FIG. 21 is a diagram illustrating a state of a sheet when the sheet is discharged by the discharge roller.

FIG. 22 is a diagram illustrating a state where a long sheet is supported by the stacker tray.

FIG. 23 is a timing chart showing a sheet alignment operation of the finisher.

FIG. 24 is a diagram showing a change in the state of a sheet in the sheet alignment operation.

FIG. 25 is a timing chart showing a sheet aligning operation of a conventional finisher.

FIG. 26 is a timing chart showing the bundle discharging operation of the finisher.

[Explanation of symbols]

 400 Finisher 411 Stack tray 412, 412A, 412B Alignment plate 415 Discharge roller 417 Return roller 419 Staple unit 420 Bundle pressing member 421 Bundle discharge belt 500 Image forming apparatus S Sheet

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yuzo Matsumoto 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 3F054 AA01 AC01 BA04 BB01 BF08 BH13 BH14 DA01 3F108 GB01 GB07 HA02 HA32

Claims (4)

[Claims] 1. A sheet processing apparatus for processing a discharged sheet, comprising: a sheet stacking unit for stacking the discharged sheet; and a direction orthogonal to the sheet discharging direction with respect to the sheet stacked on the sheet stacking unit. A pair of aligning means for performing the alignment, a stapling means for stapling the sheet bundle stacked on the sheet stacking means, and a control means for controlling the aligning operation of the aligning means. When discharging the sheet bundle, the control unit controls the pair of alignment units to move to a position where the interval between the pair of alignment units does not contact the sheet. Sheet processing equipment. 2. The sheet processing apparatus according to claim 1, wherein the control unit controls the pair of alignment units to start moving before discharging the sheet bundle. 3. The apparatus according to claim 2, wherein the control unit controls the pair of alignment units to stop at a position substantially in contact with the sheet when the bundle is discharged without performing the stapling. Item 2. The sheet processing apparatus according to Item 1. 4. An image forming apparatus, comprising: an image forming unit; and a sheet processing device that processes a sheet discharged after an image is formed by the image forming unit. 3. An image forming apparatus according to any one of 3.