JP2001058739A - Sheet aligning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet aligning device of simple configuration for aligning the sheets fed facing up in the sequence from the first page into the page-by- page arrangement. SOLUTION: From an image forming device, recording sheets in up-facing condition in the sequence from the fist page are fed at certain intervals. The fed sheets are transported by a first roller 311, second roller 312, and third roller 313. The transport by the second roller 312 and third roller 313 is stopped at the timing the trailing edge of the sheet comes over a springup machine 320, and its plate 321 is allowed to hop up (Fig. (b)). The plate 321 is restored at the timing the leading edge of the next recording sheet intrudes under the trailing edge of the sheet sprung up by the plate 321, and the transport by the second roller 312 and third roller 313 is resumed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet aligning apparatus, and more particularly, to a sheet aligning apparatus such as a copying machine.
The present invention relates to a sheet aligning device that arranges printed recording sheets that are sequentially discharged starting from the first page in the page order.

[0002]

2. Description of the Related Art In recent years, a composite image forming apparatus which can be used not only as a copying machine but also as a printer or a facsimile has been widely used. By the way, it is preferable that sheets (sheets) processed by the image forming apparatus are arranged in the order of pages in consideration of the user's trouble of rearranging each sheet.
This processing includes, for example, print processing when used as a printer and automatic document feeder (ADF) attached to the image forming apparatus when used as a copying machine.
(Auto Document Feeder)) to carry the document to the reading position.

In the case where the above-mentioned composite type image forming apparatus is used as a printer, a recording sheet is sequentially formed on the basis of image data transmitted from a personal computer connected to the image forming apparatus, usually starting from the first page. It is common to print. The recording sheet immediately after printing usually has its print surface facing upward, and if the recording sheets are discharged and stacked as they are, the order of the pages will be reversed. Therefore, conventionally, a method has been devised in which a printed recording sheet is inverted by a so-called switchback mechanism, and the printed surface is turned downward and stacked.

In the ADF, a document at a reading position usually has a reading surface facing downward. Therefore, the AD that transports from the first page to the reading position
In F, the read originals are discharged as they are (downward) to a discharge tray provided adjacent to the reading position, so that the read originals can be stacked in page order. it can.

Here, a system for performing processing from the first page, such as the above-described image forming apparatus or ADF, will be described below.
We say "first page system".

[0006]

However, the switchback mechanism in the above-described image forming apparatus introduces a recording sheet into the conveyance path of a dead end path, and takes out the introduced recording sheet so that the trailing end of the recording sheet is first. This is relatively complicated, such as inversion. Therefore, adopting the switchback mechanism increases the cost of the entire apparatus. Further, when the transport path is complicated, a so-called paper jam is likely to occur.

Further, in the above-mentioned ADF, the installation area of the image forming apparatus is increased due to the discharge tray projecting sideways, and the installation place is restricted accordingly. For this reason, an ADF has been developed that discharges a document that has been read by making a U-turn into a discharge tray provided above the reading position. However, in this case, since the document is inverted by the U-turn, the page order of the documents stacked on the discharge tray is reversed. This problem can be solved by adding the above-mentioned switchback mechanism to the U-turn discharge type ADF, but in that case, the same problem as that of the above-described image forming apparatus newly occurs.

In view of the above problems, the present invention is applied to an image forming apparatus, an ADF, or the like that employs a first page system, and can arrange processed sheets in the order of pages with a simple configuration. The purpose is to provide.

[0009]

In order to achieve the above-mentioned object, a sheet aligning apparatus according to the present invention comprises: first conveying means for receiving a plurality of sheets sequentially fed and conveying them at intervals; A second conveying unit that is provided downstream of the first conveying unit and conveys the sheet conveyed by the first conveying unit further downstream; and a conveying speed of both the first conveying unit and the second conveying unit. Transport speed control means for controlling the rear end of one sheet and the front end of the subsequent sheet to overlap, and when the rear end of the one sheet and the front end of the subsequent sheet overlap, the one sheet And a displacing means for displacing the rear end in a specific direction and aligning the overlapping relationship between the two sheets in page order.

Further, the transport speed control means controls the transport speed of the second transport means to be lower than the transport speed of the first transport means, so that the trailing edge of the one sheet and the subsequent sheet are controlled. Is characterized in that the tip is polymerized. Further, the transport speed control means overlaps the trailing edge of the one sheet and the leading edge of the succeeding sheet by temporarily stopping the transport by the second transport means.

The first conveying means includes a pair of conveying rollers including a first roller in contact with the first surface of the sheet and a second roller in contact with the second surface of the sheet. A member that is attached to the same shaft as the first roller and protrudes from the peripheral surface of the first roller, and rotates in synchronization with the first roller, so that the one sheet that has passed through the first roller Is characterized in that the rear end is displaced by being hit by the protruding portion.

Here, the first surface of the sheet refers to, for example, a surface on which the image is formed when an image is formed on only one side of the sheet in an image forming apparatus such as a copying machine,
Documents (sheets) in the automatic document feeder (ADF)
In the case where only one surface of the sheet is to be read, the surface to be read is referred to, and the second surface of the sheet refers to the surface opposite to the first surface.

The displacing means is provided between the first conveying means and the second conveying means so that the sheet is conveyed in a curved manner so that the first surface is wound outside. It is a sheet guide member. Further, the displacement means is a flip-up means disposed between the first transport means and the second transport means, and flips up the second surface of the one sheet toward the first surface. Means.

The sheet aligning device may further include a sheet stacking unit installed at a position lower than the second conveying unit, wherein the sheet stacking unit for stacking a sheet to be discharged and a sheet rear end. Before passing through the second conveying means, having a stopper that abuts on the leading edge of the sheet,
The second conveying means is a discharge roller for discharging a sheet, and includes a pair of discharge rollers arranged vertically, and a lower discharge roller projects more toward the sheet stacking means than an upper discharge roller. It is characterized by the following.

Further, the position of the stopper is changed according to the length of the discharged sheet in the conveying direction. Further, the sheet stacking means has a contact member that comes into contact with a trailing end of the discharged sheet, and a distance between the stopper and the contact member is set to be longer than a length of the sheet in the conveyance direction. It is characterized by the following.

Further, the sheet aligning apparatus further comprises a prohibition unit for prohibiting the control by the conveyance speed control unit, and when the prohibition by the prohibition unit is executed,
Continuously until the discharge of a series of sheets is completed, the transport speed of the first transport unit and the transport speed of the second transport unit are controlled to be substantially the same. The sheet aligning device is a device that forms a part of an automatic document feeder connected to an image forming device, and includes a plurality of sheets on which information is recorded on a first surface, from a first page. The image forming apparatus is a sheet aligning device that sequentially receives the sheets that have been conveyed to the reading position and the first surface of which has been read by the image forming apparatus at the reading position.

Further, the sheet aligning apparatus is a sheet aligning apparatus for receiving a sheet having an image formed on a first surface in order from a first page, which is a sheet discharged from the image forming apparatus. .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sheet aligning apparatus according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing the overall configuration of an image forming system to which the present invention is applied. As shown in the figure, the image forming system is configured by connecting an ADF 2 and a sheet aligning device 3 to an image forming apparatus 1. In this embodiment, the image forming apparatus and the sheet aligning apparatus are configured as separate apparatuses, but the sheet aligning apparatus may be configured as a part of the image forming apparatus.

The image forming apparatus 1 is a so-called composite digital image forming apparatus having a print function, a facsimile function, and a copy function. When used as a printer, the image forming apparatus 1 temporarily stores image data transmitted from a personal computer in a memory,
When used as a facsimile receiver, image data transmitted from the other party's transmitter is temporarily stored in a memory, and if necessary, various image editing processes are performed on the image data. An image is formed on a recording sheet by an electrophotographic method, and the recording sheet on which the image is formed is discharged from the discharge unit 11 to the sheet aligning device 3. When the image forming apparatus 1 is used as a copy machine, A
The image of the document conveyed onto the platen glass 12 (FIG. 2) by the DF2 is read by an image reader (not shown), and the read image data is temporarily stored in a memory. It is formed and discharged from the discharge unit 11. In any case, the recording sheet discharged from the discharge unit 11 passes through the inside of the sheet aligning device 3 and the sheet discharge tray 331 of the sheet aligning device 3.
Is discharged and collected. Note that the image forming apparatus 1
After forming an image on one side of the recording sheet, it has a double-sided printing function of inverting the recording sheet inside and forming an image on the other side.

An operation panel 14 (FIG. 9) is provided at a predetermined position on the upper surface of the image forming apparatus 1. On the operation panel 14, a copy / facsimile switching key for switching between a copy mode and a facsimile mode, a numeric keypad for inputting the number of copies, a two-sided / single-sided switching key for switching between two-sided copy and one-sided copy, and an instruction to start copying. A copy start key, a facsimile start key for instructing the start of facsimile transmission, and other various keys are provided.

FIG. 2 is a diagram mainly showing the internal structure of the ADF 2. Note that the ADF 2 employs a first page system that sequentially processes documents from the uppermost document of a bundle of documents set upward. As shown in FIG.
The DF 2 separates a plurality of documents D set on the document set tray 201 one by one and feeds the document D at a predetermined timing. A document transport unit 230 that transports the document D onto the surface of the platen glass 12 installed at the top of the apparatus 1 and accurately stops the document D at the document reading position, and is read by the image reader of the image forming apparatus 1 at the document reading position. And a document discharge unit 250 that discharges the original D after stacking and stacks it on the stack unit 202.

When a document is pushed and set in the direction of arrow A in the figure along the mounting surface of the document set tray 201, the pickup roller 211 of the document separating unit 210
The document is lifted upward at the leading edge. The lifted pickup roller 211 contacts the uppermost document and presses the document bundle. The document D set on the document set tray 201 is fed out by a pickup roller 211, and is separated by a separating roller 212 and a separating pad 213.
The sheets are separated one by one, sent downward along the guide 214, and further sent to the document feeder 230 by a pair of registration rollers 215.

The document D sent by the registration rollers 215 is conveyed to the document reading position on the platen glass 12 by the conveyance belt 231 of the document conveyance section 230 and stopped. The document D is read by the image reader of the image forming apparatus 1 at the document reading position,
1, the document is sent to the document discharge unit 250. FIG.
3 shows an enlarged view of the document discharge section 250 and its vicinity.

As shown in FIG. 1, the document discharge unit 250
First roller 2 including a pair of rollers 251a and 251b
51, a second roller 252 including a pair of rollers 252a and 252b, and a third roller 253 including a pair of rollers 253a and 253b. The portions of the first to third rollers for nipping the document (hereinafter, the abutting portion of the pair of rollers, and the portion for nipping the sheet-like material is referred to as a “nip portion”) are smoothly connected. Paper discharge path 254
Is provided. As shown in the figure, the paper discharge path 254 is curved in a C shape. The paper discharge path 254 is formed by guide members 255 to 257 and a back 258 a of a switching claw 258 (described later).

The guide member 259 and the guide member 25
6 form an inversion path 260. Conveyor belt 23
The document D sent to the document discharge unit 250 by the
The first roller 251, the second roller 252, and the third roller 253 convey the sheet 254 and discharge the sheet to the stack unit 202.

When a so-called double-sided copy for reading the back side of the original D is performed, the original D is sent to the reversing path 260 by the switching claw 258 and is again rotated by the transport belt 231 which rotates in the reverse direction. )
The document is transported to the upper document reading position. When the reading of the back side is completed, the document D is discharged to the stack unit 202 by the above-described discharge operation.

As described above, the originals set upward on the original set tray 201 are sequentially conveyed to the original reading position from the uppermost original (ie, the original of the first page), and are sequentially transferred to the stack unit 202. Is discharged and accumulated. At this time, when a two-sided copy is performed, the original set on the original set tray 201 is inverted and discharged to the stack unit 202. Therefore, the order of the pages of the original stacked on the stack unit 202 is the original order. Set tray 20
It is the same as set to 1. However, if the original is discharged to the stack unit 202 as it is when only one side of the original is read (ie, in the case of a single-sided copy), the order of the pages of the original stacked on the stack unit 202 is the original set It will be the opposite of what was set on the tray 201. This is because the second page discharged upward is superimposed on the first page discharged upward, and the third page document is stacked on the second page.

Therefore, in the ADF 2 according to the present embodiment, in the case of one-sided copying, the document discharging operation of the document discharging unit 250 is executed as follows to align the page order of the discharged documents. I have to. The paper discharging operation will be described with reference to FIGS. Although not described above, a sensor SE25a is provided at the entrance of the paper discharge path 254 of the document discharge section 250, so that the leading end and the rear end of the document introduced into the paper discharge path 254 are detected. Is done. In addition, a sensor SE25b is provided immediately before the exit of the paper discharge path 254, and thereby detects the trailing end of the finally discharged document, as described later.
Further, the first roller 251 and the second roller 252 are driven by the first motor 261 (FIG.
3 are driven to rotate by using the second motor 262 (FIG. 9) as a drive source.

FIG. 4 shows the sensor SE25a and the sensor SE2.
5B is a time chart showing the detection timing of FIG. 5B and the start / stop timing of the first motor 261 and the second motor 262. First, when the leading end of the document D1 of the first page is detected by the sensor SE25a (A1), both the first motor 261 and the second motor 262 are started (C1).
1, E1). As a result, the document D1 is transferred to the paper discharge path 25.
4 is conveyed. The transport speed of the document by the first to third rollers is the same as the transport speed by the transport belt 231.

The rear end of the conveyed document D1 is the sensor SE.
When the detection is made by the first roller 25a (A2), the second motor 262 is stopped when a predetermined time T1 has elapsed from the time of the detection (E2), whereby the conveyance of the document D1 by the third roller 253 is stopped. This time T1 is the second time after the trailing edge of the document has passed the detection position of the sensor SE25a.
This is the time required for the roller 252 to go a little too far.

That is, when the second motor is stopped (E
2) like the original D2 in FIG.
2 is the document of the second page), but the trailing edge of the document is the second page.
The paper discharge path 254 between the roller 252 and the third roller 253 is located immediately adjacent to the second roller 252 and stops. At this time,
The trailing end of the document that has passed through the nip portion of the second roller 252 is displaced in the direction of the guide member 257 by the waist of the document itself, and contacts the guide member 257. In this case, the original has a reading surface (first surface) facing the guide member 257. In other words, the guide member 257 is provided so that the document is conveyed while curving so that the reading surface (first surface) is wound outside.

In this state, the first roller 251 and the second
When the document D2 of the second page is conveyed by the rollers 252 and is fed out from the nip portion of the second rollers 252,
The front of the document D2 of the second page is superimposed on the rear of the document D1 of the first page (the document D2 and the document D in FIG. 3).
3). Then, when the leading end of the document D2 of the second page is detected by the sensor SE25a (A
When the predetermined time T2 has elapsed from 3), the second motor 262 is restarted (E3). This predetermined time T2 is:
This is the time required from when the leading edge of the document passes the detection position of the sensor SE25a to when it reaches the position immediately before the third roller 253. That is, the leading edge of the document is the sensor SE25a.
When the time T2 elapses after the detection, the front of the document is regarded as overlapping the rear of the preceding document.

When the conveyance by the third roller 253 is restarted by the activation of the second motor 262, the original D1 of the first page and the original D2 of the second page are stacked in a state where a part thereof is overlapped. Conveyed to the unit 202. When the rear end of the document D2 of the second page is detected by the sensor SE25a (A4), the second motor 262 is stopped after a lapse of time T1 from the detection point (E4), and the third roller 25 is stopped.
3 stops, and the document D2 of the second page stops.

In the same manner, a plurality of originals fed to the original discharge section 250 at regular intervals by the conveyor belt 231 are separated by a third roller 253 and a second roller 252.
Are discharged to the stack unit 202 in a state where the front surface of the succeeding document is superimposed on the rear surface of the back surface of the preceding document. First, the leading end of the discharged document comes into contact with a document stopper 203 provided in the stack portion 202, and after a while, the rear end of the discharged document has a third position.
The roller 253 exits the nip. That is, the distance L1 from the nip portion of the third roller 253 to the intersection of the document stopper 203 and the mounting surface 202a of the stack portion 202 is set to be shorter than the length of the document to be discharged in the transport direction. I have.

The rear end of the third roller 253 that has exited the nip portion does not fall on the mounting surface 202a of the stack portion 202 and stays near the nip portion of the third roller 253.
This is because the two forces described below mainly support the rear end (rear portion) of the document. First, while being held between the third rollers 253, the third rollers 2
This is the so-called waist force of a document that has not been released from 53. Second, the rollers 25 constituting the third roller 253
Reference numeral 3b denotes a force for supporting the document from below. Third roller 25
The two rollers constituting No. 3 are arranged such that the lower roller 253b projects toward the stack portion 202 side from the upper roller 253a. Therefore, the roller 253
b is located closer to the stack portion 202 than the contact portion between the rollers 253b and 253a (that is, the nip portion of the third roller 253), and the top supports the document placed thereon. Because it becomes.

While the third roller 253 is rotating, the frictional force acting between the peripheral surface of the upper roller 253a of the third roller 253 and the trailing edge of the document acts to lift the trailing edge of the document. Therefore, this also makes it easier for the rear end to stay near the nip portion of the third roller 253. Meanwhile, the third
The roller 253b on the lower side of the roller 253 acts to pull down the document when the trailing edge of the document contacts the peripheral surface. However, until the discharge of the last document is completed, at least one document is always held between the third rollers 253, and the held document is the lowest order of other documents discharged so far. , The other document is prevented from contacting the lower roller 253b. Therefore, the lower roller 253b does not act to pull down the trailing end of the document until the last document is discharged.

When the reading of the original proceeds and the last original is sent to the original discharge section 250 by the transport belt 231, even if the trailing end of the last original is detected by the sensor SE25a (A5), the second motor 262 is not stopped, and the conveyance by the third roller 253 is continued. When the trailing edge of the last document is detected by the sensor SE25b (B2), a predetermined time T3 from the time of the detection is detected.
At the elapse of time, both the first motor 261 and the second motor 262 are stopped (C2, E5), and a series of sheet discharging operations by the document discharging unit 250 ends. The predetermined time T3 is a time required from when the trailing edge of the document passes through the detection position of the sensor SE25b to when it completely passes through the nip portion of the third roller 253. A document (not shown) for detecting a document on the document set tray 201 is determined to be the last document fed by the pickup roller 211 immediately before the sensor is turned off.

When the rear end of the last original has passed through the third roller 253 and all the originals have been discharged to the stack portion 202, of the two forces supporting the rear end of the original, the force due to the waist of the original is used. As a result, the trailing end of the bundle of originals drops, and the bundle of originals falls on the original stopper 203 and the side wall 202 facing the original stopper 203 of the stack unit 202.
b and are accumulated in a bow shape.

When double-sided copying is performed, the first page of the original is detected by the sensor SE25a until the trailing edge of the last original passes through the third roller 253. Both the first motor 261 and the second motor 262 are continuously operated. As a result, the transport belt 231
Documents sent at an interval from are transported through the paper discharge path 254 while maintaining the interval, are discharged to the stack unit 202, and are stacked.

Next, the sheet aligning device 3 (FIG. 1) will be described in detail. Recording sheets on which images have been formed are fed into the sheet aligning apparatus 3 from the discharge unit 11 of the image forming apparatus 1 at regular intervals. When the image forming apparatus 1 is used as a printer or as a copier,
When a one-sided copy is made using the DF2, the recording sheets are usually sent to the sheet aligning device 3 sequentially from the first page. The recording sheet is fed with the image forming surface facing upward. As described above, in the image forming apparatus 1, the image is formed only on one side of the recording sheet, and the image forming surface (first surface) is directed upward, and the recording sheet of the first page is discharged from the discharge unit 11 in order from the first page. Below,
This is called "single-sided mode". On the other hand, an image is formed on both sides of the recording sheet, the odd numbered pages are directed downward, and the discharge unit 1 sequentially starts from the recording sheet on which the image of the first page is formed.
The mode for discharging from 1 is hereinafter referred to as a “double-sided mode”. For example, when one-sided copying is instructed from the operation panel 14, the one-sided mode is set, and when two-sided copying is instructed, the two-sided mode is set.

FIG. 5 is a view mainly showing the internal structure of the sheet aligning apparatus 3. As shown in FIG. As shown in FIG.
Includes a sheet transport unit 310 and a sheet stacking unit 330. The sheet transporting unit 310 includes the first roller 31
It has a first roller 312 and a third roller 313, and a transport path 314 is formed horizontally so as to guide the recording sheet to each roller.

The first roller 311 is, as shown in FIG.
A plurality of rollers 311ar (four in this example) is the shaft 3
11as and an upper roller 311a fixed to 11as and a plurality of rollers 311br (four in this example)
and a lower roller 311b fixed to the lower roller bs. The lower roller 311b is disposed immediately below the upper roller 311a.

The second roller 312 has the same configuration as the first roller 311. The third roller 313 is an upper roller 31
The configuration is the same as that of the first roller 311 except for the positional relationship between the lower roller 3a and the lower roller 313b. That is, as shown in FIG. 5, the lower roller 313b is provided so as to protrude more toward the sheet stacking unit 330 than the upper roller 313a.

The first roller 311 is connected to the first motor 3
15 (FIG. 9) as a drive source, and the second roller 312 and the third roller 313 are respectively driven to rotate by a second motor 316 (FIG. 9) as a drive source. At the entrance of the transport path 314, a sensor SE31a is provided, and thereby, the leading edge and the trailing edge of the recording sheet introduced into the transport path 314 are detected. Further, a sensor SE31b is provided immediately before the exit of the transport path 314, and as described later, the rear end of the recording sheet discharged last is detected.

Immediately after the first roller 311 on the downstream side in the recording sheet conveyance direction, a sheet flip-up device 320 is provided. The bouncing machine 320, as shown in FIG.
It has a plurality of flip-up plates 321 (three in this example), and the flip-up plate 321 has a shaft 322 with both ends pivotally supported.
(The pivot portion is not shown). The shaft 322 is provided below the transport path 314,
A lever 323 is fixedly attached to one end of the shaft 322. Shaft 3 of lever 323
A tension spring 3 is provided between one end of the sheet conveying unit 310 and the other end opposite to the hook 324 fixed to the housing of the sheet conveying unit 310.
25 are provided. The lever 323 is constantly pulled downward by the action of the tension spring 325. Also, the solenoid 326 has its plunger 326
a The tip is provided so as to contact the lower surface of the lever 323.

The flip-up plate 321 is normally in a horizontal state as shown in the drawing so as not to hinder the conveyance of the recording sheet (this horizontal position is hereinafter referred to as a "standby position"). When the solenoid 326 is activated (turned on) and the plunger 326a is displaced upward, the plunger 32
6a pushes up the lever 323, and the shaft 322
Rotates in the direction of arrow B, and accordingly, the flip-up plate 3
Similarly, the motor 21 rotates by a predetermined angle (the position rotated by the predetermined angle is hereinafter referred to as a “flip-up position”). At this time, the flip-up plate 321 is moved from the leading end thereof to the transport path 314.
And the recording sheet above the flip-up plate 321 is flipped up. When the solenoid 326 is turned off, the plunger 326a retreats, whereby the lever 323 is pulled down by the pulling force of the tension spring 325, the shaft 322 rotates in the direction opposite to the arrow B, and the flip-up plate 321 stands by. Return to position.

Returning to FIG. 5, the sheet stacking section 330 has a sheet discharge tray 331 for stacking recording sheets discharged from the sheet transport section 310. The sheet discharge tray 331 is provided so as to be inclined so that the rear side in the conveying direction of the recording sheet becomes lower.
It is installed at a position lower than the nip portion of the tenth third roller 313.

A slit (not shown) is provided in the center of the sheet discharge tray 331 in the width direction (perpendicular to the paper surface) in the longitudinal direction of the sheet discharge tray 331 (the left-right direction of the paper surface). The sheet stopper 332 is provided so as to be movable in the direction of arrow C by using as a guide. The sheet stopper 332 is provided for the sheet discharge tray 3.
A stopper moving mechanism 33 provided inside the apparatus below 31
3 moved. This stopper moving mechanism 333
Is a known feed screw mechanism, and the feed screw 334 is rotated by a motor 336 via a timing belt 335. A nut 337 engaged with the feed screw 334 is fixed to the sheet stopper 332, and the sheet stopper 332 is moved along the slit.

By the stopper moving mechanism 333, the sheet stopper 332 is positioned according to the length LS of the recording sheet handled by the sheet aligning device 3 (ie, fed from the image forming apparatus 1) in the transport direction. The sheet stopper 332 is positioned at a position where the distance L2 from the point P where the sheet stopper 332 intersects with the sheet placement surface 331a of the sheet discharge tray 331 to the nip portion of the third roller 313 is equal to or less than LS. At this time, the inclination angle of the sheet discharge tray 331 and the sheet discharge tray 331 and the third position are set such that the distance L3 from the point P to the point Q where the sheet placing surface 331a and the rear side wall 338 intersect is equal to or longer than LS. The height difference between the roller 313 and the nip portion is set.

In the above example, the sheet stopper 33
Positioning of the sheet stopper 332 is performed by continuously moving the sheet stopper 332 in the longitudinal direction of the sheet discharge tray 331 by the feed screw mechanism 334. However, the present invention is not limited to this, and may be, for example, as follows. That is, a concave portion is provided at a position corresponding to the above-described positioning position of the sheet discharge tray 331. Then, the sheet stopper is formed in a shape such that a part thereof is fitted into the recess. A sheet stopper is fitted into a concave portion at a positioning position corresponding to a recording sheet for use.

The operation of the above-described sheet aligning apparatus 3 when the image forming apparatus 1 forms an image in the single-sided mode will be described with reference to FIGS. FIG. 7 is a diagram illustrating a state where the recording sheet S is conveyed by the first roller 311 to the third roller 313, and FIG.
1A is a time chart showing the detection timing of a sensor SE31b, the start / stop of a first motor 315 and a second motor 316, and the ON / OFF timing of a solenoid 326.

First, when the leading end of the first page of the recording sheet S1 is detected by the sensor SE31a (F
1) Both the first motor 315 and the second motor 316 are started (H1, J1). As a result, the recording sheet S1 is transported along the transport path 314 (FIG. 7A). The transport speed of the recording sheet by the first to third rollers is:
It is the same as the conveyance speed of the recording sheet by the discharge unit 11 (FIG. 1) of the image forming apparatus 1.

When the trailing edge of the conveyed recording sheet S1 is detected by the sensor SE31a (F2), the second motor 316 is driven after a lapse of a predetermined time T11 from the time of the detection.
Is stopped, and the solenoid 326 is turned on (J2, K1). The time T11 is a time required from the time when the rear end of the recording sheet passes through the detection position of the sensor SE31a to the time when the rear part of the recording sheet reaches above the flip-up machine 320. More specifically, after the trailing edge of the recording sheet passes the detection position of the sensor SE31a, the flip-up device 3
This is the time required to reach above the 20 shafts 322.

With the above-mentioned stop of the second motor 316,
The conveyance of the recording sheet S1 by the second roller 312 and the third roller 313 is stopped at the timing when the rear end comes above the shaft 322 of the flip-up machine 320, and the flip-up plate 321 is moved from the standby position to the flip-up position. And jump up. As a result, as shown in FIG. 7B, the rear portion of the recording sheet S1 is flipped up by the flip-up plate 321 in a stopped state.

When the sensor SE31a detects the leading end of the second page of the recording sheet S2 (F3),
When a predetermined time T12 has elapsed from that time, the second motor 31
6 is restarted (J3), and the solenoid 326 is turned off (K2). The predetermined time T12 is a time required from the time when the leading end of the recording sheet passes the detection position of the sensor SE31a to the time when the leading end of the recording sheet slightly passes over the shaft 322 of the flip-up machine 320. That is, when the time T12 elapses after the leading end of the recording sheet is detected by the sensor SE31a, it is considered that the front part of the recording sheet has slipped under the rear part of the preceding recording sheet, and the front part and the rear part are overlapped. In order to match, the flip-up plate 321 is returned to the standby position.

When the conveyance by the second roller 312 and the third roller 313 is restarted by the activation of the second motor 316, a part of the recording sheet S1 of the first page and the recording sheet S2 of the second page become partially. The sheet is conveyed to the sheet discharge tray 331 in the stacked state (FIG. 7C). Second
When the rear end of the page recording sheet S2 is detected by the sensor SE31a (F4), a time T1 from the detection point is detected.
After one elapse, the second motor 316 is stopped (J4), the conveyance by the second roller 312 and the third roller 313 is stopped, the solenoid 326 is turned on (K3), and the rear end of the recording sheet S2 is flipped up.

In the same manner, a plurality of recording sheets fed to the sheet aligning apparatus 3 at a fixed interval from the discharge section 11 of the image forming apparatus 1
In the transport path 314 between the rollers 312, the sheet is discharged to the sheet discharge tray 331 in a state in which the rear part of the preceding recording sheet (second surface) is overlapped with the front part of the next succeeding recording sheet (first surface). Is discharged.

The discharged recording sheet is the ADF described above.
2, the document is stored above the sheet discharge tray 331 in the same state as the document discharged to the stack unit 202. That is, the leading end contacts the sheet stopper 332,
The rear end is accumulated with the rear end positioned on the lower roller 313b of the third roller 313. This is because the relationship between the distance between the nip portion of the third roller 313 and the sheet stopper 332 with respect to the length of the recording sheet is as described above.
The relationship between the length of the document and the distance between the nip portion of the third roller 253 and the document stopper is the same, and the upper roller 313a and the lower roller 313b constituting the third roller 313 This is because the positional relationship is similar to the positional relationship between the upper and lower rollers 253a and 253b of the third roller 253.

When the image formation on the recording sheet proceeds and the last recording sheet is sent from the discharge unit 11 of the image forming apparatus 1 to the sheet conveying unit 310, the trailing end of the last recording sheet is detected by the sensor SE31a. Even (F
5), the second motor 316 is not stopped, and the second roller 31
The conveyance by the second and third rollers 313 is continued. When the trailing edge of the last recording sheet is detected by the sensor SE31b (G2), the first motor 315 and the second motor 316 after a predetermined time T13 from the detection.
Are stopped (H2, J5), and a series of sheet discharging operations by the sheet aligning device 3 ends. This predetermined time T13
Is the time required from when the trailing edge of the recording sheet passes through the detection position of the sensor SE31b to when it completely passes through the nip portion of the third roller 313.

The trailing end of the last recording sheet is the third roller 31
And all the recording sheets pass through the sheet discharge tray 3
When the recording sheet bundle is discharged to the ADF 2, the trailing end of the recording sheet bundle falls to the sheet placing surface 331a, as in the case of the ADF 2. At this time, as described above, the distance L3 from the point P where the sheet stopper 332 intersects with the sheet placing surface 331a of the sheet discharge tray 331 to the point Q where the sheet placing surface 331a intersects with the rear side wall 338 is: Since the length is set so as to be equal to or longer than the length LS of the recording sheet in the transport direction, unlike the case of the ADF 2, the dropped recording sheet bundle is stacked while being extended almost straight without being bowed.

When the image forming apparatus 1 forms an image in the double-sided mode, after the front end of the first recording sheet is detected by the sensor SE31a, the rear end of the last recording sheet is the third end. Until the roller 313 passes,
Both the first motor 315 and the second motor 316 are continuously operated. As a result, the recording sheets sent from the discharge unit 11 at an interval are conveyed along the conveyance path 314 while maintaining the interval, discharged to the sheet discharge tray 331, and accumulated.

FIG. 9 shows a control section of the image forming system.
FIG. 4 is a block diagram illustrating a schematic configuration of a portion related to control of a document discharge unit 250 and a sheet alignment device 3 of the ADF 2. As shown in the figure, the CPU 13 includes a sensor SE25a, a sensor SE25b, a sensor SE31a, and a sensor SE31.
b, the operation panel 14, the ROM 15, and the RAM 16 are connected, and the CPU 13 includes a first motor 261,
Second motor 262, first motor 315, second motor 31
6 and the operation of the solenoid 326.

The ROM 15 stores a program for performing the above-described control and the above-described predetermined times T1 to T3, T11 to T13.
And other values required for the control. RAM 16
Various control variables, the number of copies set from the operation panel 14, various modes set, and the like are temporarily stored and serve as a work area when the program is executed.

FIG. 10 is a flowchart showing the control operation of the entire image forming system executed by the CPU 13. When the image forming system is powered on,
Initial settings of each part in the image forming system, such as clearing the storage contents of the RAM 16, are performed (step S1). Next, there is a copy processing start instruction or a fax transmission processing start instruction issued from the operation panel 14, or a print processing start instruction from a personal computer or a fax reception processing start instruction from a facsimile machine as a partner machine. (Step S2), the internal timer is started (step S3). The processing time of the routine of steps S3 to S8 of the main routine is set by the internal timer.

Steps S4 to S8 subsequent to step S3 are executed when necessary according to the instruction received in step S2. In step S4, ADF2
From the original set tray 201 to the stack unit 2
The document feeding process up to 02 is performed. In step S5, the recording sheets are taken out one by one from the paper feed cassette in the image forming apparatus 1 and conveyed to the image forming position.
The process of discharging from is performed.

In step S6, a process for forming a toner image on the recording sheet conveyed as described above is performed. In step S7, the sheet aligning device 3 receives the recording sheet discharged from the discharge unit 11 of the image forming apparatus 1 and discharges the recording sheet to the sheet discharge tray 331.

In step S8, when the image forming apparatus 1 is used as a facsimile, transmission processing from the present image forming system and reception processing from the facsimile apparatus as the partner machine are performed. In step S9, it is determined whether or not the process accepted in step S2 has been completed. If it is determined that the process has been completed, the process returns to step S2 to wait for a process start instruction. If not, the process proceeds to step S10. After waiting for the end of the internal timer, the process returns to step S3.

FIG. 11 shows a document discharge section 250 (FIG. 3) constituting the ADF 2 in the processing in step S4 in FIG.
9 is a flowchart showing a subroutine of the document discharge process of FIG. When the document feeding process by the ADF 2 is started, regarding the document discharge unit 250, first, when the sensor SE25a detects the leading edge of the document of the first page (Yes in step S401), the first motor 261 and the second motor 262 are detected. Is started (steps S402 and S403).

Next, when the sensor SE25a detects the trailing end of the document (Yes in step S404), the timer for document discharge processing is reset and started (step S4).
05), when the timer counts the predetermined time T1 (Yes in step S406), the second motor 262
Is stopped (step S407), and the conveyance of the original by the third roller 253 is interrupted.

When the sensor SE25a detects the leading edge of the document following the one whose transport has been interrupted (Yes in step S408), the timer is reset and started (step S409). When the predetermined time T2 is counted (step S41)
0) The second motor 262 is started (step S411), assuming that the front of the succeeding document overlaps the rear of the document whose conveyance is interrupted (step S411), and the conveyance of the document by the third roller 253 is restarted. In this state, the document whose conveyance has been interrupted and the subsequent document are conveyed to the stack unit 202 in a state where the documents are partially overlapped.

In the following step S412, step S4
It is determined whether or not the original detected in step 08 is the original of the last page.
Returning to 404, thereafter, the processing of steps S404 to S411 is repeated, while if it is the last page (Yes),
Proceed to step S413. In step S413, after waiting for the sensor SE25b to detect the trailing edge of the last page of the document, the timer is reset and started (step S414). When the timer counts the predetermined time T3 (Yes in step S415). Then, the first motor 261 and the second motor 262 are stopped assuming that the trailing end of the last page of the document has passed the third roller 253 (steps S416 and S417), and a series of document discharge processing ends.

FIGS. 12 and 13 show a subroutine of the sheet discharging process (step S7) in the flowchart of FIG. First, in the flowchart of FIG. 12, it is determined whether or not the one-sided mode is set. If it is determined that the one-sided mode is set (Yes in step S71)
In step s), the overlapping discharge processing is performed (step S7).
2) If it is determined that the one-sided mode is not set, that is, if the two-sided mode is set (step S71)
No), a normal discharge process is performed (step S71).

FIG. 13 shows a flowchart of the above-described superposition discharge processing. When the discharge of the recording sheet from the discharge unit 11 is started by the image forming apparatus 1, first, the control waits until the sensor SE31a detects the leading edge of the recording sheet of the first page (Yes in step S701), and the first motor 315 and the second motor 316 are started (step S
702, S703).

Next, when the sensor SE31a detects the trailing edge of the recording sheet (Yes in step S704), the timer for the overlap discharge processing is reset and started (step S705), and the timer sets the predetermined time T11 as described above. After accounting (Yes in step S706),
The second motor 316 is stopped (step S707), and the second
The conveyance of the recording sheet by the roller 312 and the third roller 313 is interrupted, the solenoid is turned on (step S708), and the rear end of the recording sheet is flipped up by the flip-up plate.

Then, the leading end of the recording sheet succeeding the recording sheet whose conveyance has been interrupted is detected by the sensor SE31a.
Is detected (Yes in step S709), the timer is reset and then started (step S710), and when the timer counts the predetermined time T12 (step S711), the subsequent sheet is added to the rear of the recording sheet whose conveyance is interrupted. Assuming that the front portion of the recording sheet to be read has entered, the solenoid is turned off (step S712), the flip-up plate is returned to the standby position, a part of both sheets is overlapped, and the second motor 316 is started. (Step S713), the second roller 312 and the third roller 313
Of the recording sheet is restarted. In this state, the recording sheet whose conveyance has been interrupted and the subsequent recording sheet are conveyed to the sheet discharge tray 331 in a state where the recording sheets are partially overlapped.

In the following step S714, step S7
In step 09, it is determined whether the detected recording sheet is the last page of the recording sheet.
o), returning to step S704;
4 to S713 are repeated. On the other hand, in the case of the last page (Yes), the process proceeds to step S715. Step S
At 715, after waiting for the sensor SE31b to detect the trailing edge of the recording sheet of the last page, the timer is reset and started (step S716), and the timer counts the predetermined time T13 (step S717).
Yes), the trailing edge of the recording sheet of the last page is the third
The first motor 315 is regarded as having passed through the roller 313.
And the second motor 316 is stopped (step S71).
8, S719), and ends the series of recording sheet superimposed discharge processing.

FIG. 14 shows a flowchart of the normal discharging process. A recording sheet discharging unit 1 by the image forming apparatus 1
When the discharge from the sensor 1 is started, first, the sensor SE31a
Detects the leading edge of the recording sheet of the first page (Yes in step S731), starts the first motor 315 and the second motor 316 (steps S732 and S73).
3).

Thereafter, both the first motor 315 and the second motor 316 are continuously operated, and when the last page of the recording sheet is fed from the image forming apparatus 1 (step S7).
(Yes in 34), and waits until the sensor SE31b detects the rear end of the recording sheet of the last page (step S7).
35), the timer for the normal discharge process is started after resetting (step S736).

When the timer counts the predetermined time T13 (Yes in step S737), it is considered that the rear end of the recording sheet of the last page has passed the third roller 313, and the first motor 315 and the second motor Both are stopped (steps S738 and S739), and the normal discharge process of a series of recording sheets is completed. FIG. 15 is a diagram illustrating a part of another embodiment of the sheet conveying unit 310, and corresponds to FIG. The sheet transport unit 400 according to the other embodiment has basically the same configuration as the sheet transport unit 310 except that a flip-up device 320 is removed and a flip-up roller described later is added. Therefore, the same reference numerals are given to the constituent members of the common portion, the description thereof will be omitted, and the description will focus on the different portions.

As shown in FIG. 15, the sheet conveying section 400
A plurality of (three in this example) flip-up rollers 410 are fixedly attached to the shaft 311as of the first roller 311 between the rollers 311ar. The flip-up roller 410 is a roller 311 constituting the upper roller 311a.
A plurality of (eight in this example) protrusions 412 are formed on the peripheral surface of a roller 411 having substantially the same diameter as the ar. When the shaft 311as is rotated, the flip-up roller 410 rotates similarly to the roller 311ar.

In the case of the sheet conveying section 400, similarly to the case of the sheet conveying section 310, the first motor 315 for driving the first roller 311 is driven by the discharging speed of the discharging section 11 of the image forming apparatus 1 by the first roller 311. The recording sheet is driven at a rotation speed that is the same as the recording sheet conveyance speed Va according to FIG. On the other hand, the second motor 316 is
A rotation speed Ra such that the conveyance speed of the recording sheet by the twelfth and third rollers 313 becomes the conveyance speed Va;
Rotation speed Rb such that conveyance speed Vb is lower than Va
The operation is switched between the second speed and the second speed.

The operation of the sheet aligning apparatus 3 provided with the above-described sheet conveying section 400 when the image forming apparatus 1 forms an image in the one-sided mode will be described with reference to FIGS. FIG. 16 shows the first roller 3 as in FIG.
FIG. 17 is a diagram illustrating a state in which the recording sheet S is conveyed by the first to third rollers 313. FIG.
a, Detection timing of sensor SE31b and first motor 3
15 is a time chart showing the start / stop timing of the second motor 316 and the start / stop / shift of the second motor 316.

First, when the leading end of the first page of the recording sheet S1 is detected by the sensor SE31a (M
1) Both the first motor 315 and the second motor 316 are started (R1, W1). At this time, the second motor 316
Is controlled to Rb. As a result, the recording sheet is conveyed along the conveyance path 314.
Roller 311, second roller 312, and third roller 31
As shown in FIG. 16A, the recording sheet is conveyed in a bow between the first roller 311 and the second roller 312 because there is a difference in conveyance speed between the first roller 311 and the second roller 312.

The trailing edge of the conveyed recording sheet is
When detected by E31a (M2), the second motor 316 is stopped when a predetermined time T21 has elapsed from the time of the detection (W2), whereby the conveyance by the second roller 312 and the third roller 313 is stopped. This time T
Reference numeral 21 denotes a time required from when the trailing edge of the recording sheet passes through the detection position of the sensor SE31a to when it passes through the nip portion of the first roller 311.

The conveyance is stopped, and the trailing end is the first roller 3
The recording sheet that has passed through the nip portion of No. 11 has
The protrusion 41 of the flip-up roller 410 that is continuously rotating
It is jumped up by 2 (FIG. 16 (b)).
The leading end of the recording sheet S2 of the second page is the sensor S
When detected by E31a (M3), the second motor 316 is restarted and the rotation speed of the second motor 316 is controlled to Ra when the predetermined time T22 has elapsed from that point (W3). The predetermined time T22 is a time required from the time when the leading edge of the recording sheet passes through the detection position of the sensor SE31a to the time when the leading edge of the recording sheet that is one step ahead is sufficiently advanced.

When the second motor 316 is restarted as described above, the bowing state of the recording sheet S1 is gradually eliminated, and the rear portion overlaps the front portion of the succeeding recording sheet S2. Then, the two recording sheets are conveyed to the sheet discharge tray 331 (FIG. 1) in an overlapping state (FIG. 16C). Further, when a predetermined time T23 has elapsed from the time (M3) when the leading end of the recording sheet S2 is detected by the sensor SE31a, the rotation speed of the second motor 316 is reduced (W4). This predetermined time T23 is a period after the leading edge of the recording sheet has passed the detection position of the sensor SE31a.
This is the time required until the second roller 312 reaches just before the nip portion. In this state, the recording sheet S2 is
12, the recording sheet S
1, the recording sheet S2 has a bow shape.

Then, the rear end of the recording sheet S2 is
When detected by E31a (M4), a predetermined time T2
After one elapse, the second motor 316 is stopped (W5), and the rear end of the recording sheet S2 is flipped up by the flip-up roller. Thereafter, similarly, a plurality of recording sheets fed from the discharge unit 11 of the image forming apparatus 1 to the sheet aligning apparatus 3 at a fixed interval are transported along a transport path 314 between the first roller 311 and the second roller 312. Then, the recording sheet is discharged to the sheet discharge tray 331 in a state where the front part (the first surface) of the next succeeding recording sheet is superimposed on the rear part of the back surface (the second surface) of the preceding recording sheet.

When the image formation on the recording sheet progresses and the last recording sheet is sent from the discharge section 11 of the image forming apparatus 1 to the sheet conveying section 400, even if the leading end of the recording sheet is detected by the sensor SE31a ( M5), 2nd
The motor 316 is not decelerated, and the rear end of the recording sheet is detected by the sensor SE31a (M
6), the second motor 316 is not stopped, and the second roller 31
The conveyance by the second and third rollers 313 is continued at the conveyance speed Va.

When the trailing edge of the last recording sheet is detected by the sensor SE31b (N2), the first motor 315 is driven after a lapse of a predetermined time T24 from the detection.
And both the second motor 316 are stopped (U2, W6),
A series of sheet discharging operations by the sheet aligning device 3 ends. During the predetermined time T24, the rear end of the recording sheet is detected by the sensor SE.
This is the time required from passing the detection position of 31b to completely passing through the nip portion of the third roller 313.

When the image forming apparatus 1 forms an image in the double-sided mode, after the front end of the first recording sheet is detected by the sensor SE31a, the rear end of the last recording sheet is the third end. Until the roller 313 passes,
The fact that both the first motor 315 and the second motor 316 are continuously operated is the same as in the case of the above-described sheet conveying unit 310.

In the example described with reference to the time chart of FIG. 17, after the trailing edge of the recording sheet is detected by the sensor SE31a (M2, M4) T21, the leading edge of the next succeeding recording sheet is detected by the sensor SE31a. The second motor 316 is stopped until a predetermined time T22 elapses after the detection (time period (a)).
6 may be continuously operated with the rotation speed Rb. The interval between the recording sheets to be sent and the conveying speed Va
By determining the transport speed Vb (<Va) in accordance with the above, a part of the continuous recording sheets can be overlapped without stopping the transport by the second roller 312 and the third roller 313. .

FIG. 18 is a perspective view showing a part of the configuration of a modified example of the above-mentioned sheet conveying section 400. The sheet conveying unit 500 according to the present modified example is different from the sheet conveying unit 4 in that a flip-up protrusion 510 is provided instead of the flip-up roller 410.
This is basically the same configuration as 00. Therefore, the same reference numerals are given to the constituent members of the common portion, the description thereof will be omitted, and the description will focus on the different portions.

As shown in FIG. 18, the upper roller 311a
Shaft 311as, between rollers 311ar,
A plurality (three in this example) of flip-up projections 510 are fixedly attached. The height of the tip of the flip-up protrusion 510 from the axis of the shaft 311as is higher than the height of the peripheral surface of the roller 311ar from the axis. FIG.
FIG. 16 is a diagram illustrating a state in which the recording sheet S is conveyed by the first roller 311 to the third roller 313, and corresponds to FIG. Further, the sheet transport unit 500 is controlled in the same procedure as the sheet transport unit 400 described with reference to FIG.

That is, also in the case of the sheet conveying section 500, the first
By making the transport speed Vb of the second roller 312 and the third roller 313 slower than the transport speed Va of the roller 311,
The recording sheet is bent in a bow shape (FIG. 19A). When the trailing end of the bent recording sheet passes through the nip portion of the first roller 311, the conveyance by the second roller 312 and the third roller 313 is temporarily stopped, and the rotating flip-up protrusion 510 is used to move the rear end of the recording sheet. The end is flipped up (FIG. 19B). Below the back of the record sheet that jumped up,
The front portion of the next recording sheet is fed in, and then the conveyance by the second roller 312 and the third roller 313 is restarted to partially overlap the recording sheets. (FIG. 19C).

In the example shown in FIG. 18, all the three flip-up projections 510 are aligned in the same direction. May be arranged 180 ° apart from each other. FIG. 20 is a diagram illustrating a part of another embodiment of the sheet conveying unit 310, and corresponds to FIG. The sheet transport section 600 according to the other embodiment is an application of the configuration of the document discharge section 250 of the ADF 2 described above. That is, a part of the conveyance path is curved, and in the curved section, the front part of the recording sheet succeeding the rear part of the recording sheet is overlapped. The sheet conveying unit 600 includes a first roller 311 and a second roller 312.
The configuration is basically the same as that of the sheet conveying unit 310 except that the arrangement relationship with the sheet conveying unit 310 differs.

To explain in more detail, the first roller 3
The conveyance path between the roller 11 and the second roller 312 is
11 and the sheet guide 612 so as to be curved (FIG. 20A). When a predetermined time has elapsed from the time when the trailing edge of the recording sheet is detected by the sensor SE31a, the transport by the second roller 312 and the third roller 313 is temporarily stopped, assuming that the trailing edge has passed the nip portion of the first roller 311. Is done. The rear end of the recording sheet whose conveyance has been stopped is displaced in the direction of the sheet guide 611 due to its own waist, and comes into contact with the sheet guide (FIG. 20B).

The leading end of the following recording sheet is the sensor SE31.
When a predetermined time elapses from the point of time when the recording sheet is detected as “a”, the front part of the subsequent recording sheet is regarded as overlapping the rear part of the recording sheet in contact with the sheet guide 611, and the second
The conveyance by the roller 312 and the third roller 313 is restarted, and the two recording sheets are kept in a partially overlapped state.
The sheet is conveyed to the sheet discharge tray 331 (FIG. 20).
(C)).

Although the present invention has been described based on the embodiments, it goes without saying that the present invention is not limited to the above-described embodiments. (1) In the above embodiment, the case where the present invention is applied to an image forming system having a digital image forming apparatus has been described as an example. However, the present invention is applied to an analog image forming apparatus (copier). Is also applicable. (2) In the above embodiment, the single CPU provided in the image forming apparatus controls the image forming apparatus, the ADF, and the sheet alignment apparatus. However, the present invention is not limited to this.
A CPU may be individually provided for each device, and control of the entire system may be performed while exchanging control signals between the CPUs. (3) The sheet aligning apparatus according to the present invention is not limited to the application to the image forming system as described above. That is, in the case of single-sided copying, the sheet is such that the first side and the second side are distinguished from each other, such as the side on which an image is formed and the other side, and are fed at a predetermined interval. Applicable to devices that need to align sheets.

[0099]

As described above, according to the sheet aligning apparatus according to the present invention, the conveying speeds of the first and second conveying means are controlled such that the rear end of one sheet and the front end of the succeeding sheet are overlapped. And a displacing means for displacing the rear end of the one sheet in a specific direction when the rear end of the one sheet and the front end of the subsequent sheet overlap. With only a simple configuration, it is possible to arrange the overlapping relationship between the two sheets in page order. Thereby, for example, when accepting a sheet on which an image such as a document is recorded on one side and a sheet fed sequentially from the first page, the displacement unit moves the rear end of one sheet in a specific direction, that is, By displacing in the direction of the surface on which the image is recorded, the overlapping relationship between the one sheet and the subsequent sheet is aligned in the page order.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an overall configuration of an image forming system according to an embodiment.

FIG. 2 is a schematic diagram mainly showing an internal structure of an ADF constituting the image forming system.

FIG. 3 is an enlarged view of a document discharge section of the ADF shown in FIG. 2 and its vicinity.

FIG. 4 is a time chart showing the timing of the operation of the document discharge section.

FIG. 5 is a schematic diagram mainly showing an internal structure of a sheet aligning apparatus constituting the image forming system.

FIG. 6 is a perspective view showing a schematic structure of a first roller and a flip-up machine of the sheet aligning device.

FIG. 7 is a diagram illustrating a state in which a recording sheet is conveyed in a sheet conveyance unit of the sheet alignment apparatus.

FIG. 8 is a time chart showing the operation timing of the sheet aligning apparatus.

FIG. 9 is a block diagram illustrating a schematic configuration of a portion related to control of an ADF document discharge unit and a sheet alignment device in the control unit of the image forming system.

FIG. 10 is a flowchart illustrating a control operation of the entire image forming system.

FIG. 11 is a flowchart for controlling the document discharge unit.

FIG. 12 is one of flowcharts for controlling the sheet aligning apparatus.

FIG. 13 is a flowchart for performing a superposition discharge process in the sheet alignment apparatus.

FIG. 14 is a flowchart for performing a normal discharge process in the sheet aligning apparatus.

FIG. 15 is a perspective view showing a part of a configuration of a sheet aligning apparatus according to another embodiment of the sheet aligning apparatus.

FIG. 16 is a diagram illustrating a state in which a recording sheet is conveyed in a sheet conveying unit of a sheet aligning apparatus according to another embodiment.

FIG. 17 is a time chart showing operation timings of the sheet aligning apparatus according to the other embodiment.

FIG. 18 is a perspective view showing a part of a configuration of a modified example of the sheet aligning apparatus according to the other embodiment.

FIG. 19 is a diagram illustrating a state in which a recording sheet is conveyed in a sheet conveying unit of a sheet aligning apparatus according to the modification.

FIG. 20 is a view for explaining a sheet aligning apparatus according to still another embodiment of the sheet aligning apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 image forming apparatus 2 automatic document feeder (ADF) 3 sheet aligning device 13 CPU 15 ROM 16 RAM 25 a sensor SE 25 b sensor SE 31 a sensor SE 31 b sensor SE 202 stack unit 203 document stopper 250 document discharge unit 251 first roller 251 a , 251b Roller 252 Second Roller 252a, 252b Roller 253 Third Roller 253a, 253b Roller 257 Guide Member 258a Switching Claw Back 261 First Motor 262 Second Motor 311 First Roller 311a Upper Roller 311as Shaft 311b Lower Roller 312 Second Roller 313 Third roller 313a Upper roller 313b Lower roller 315 First motor 316 Second motor 320 Jump-up machine 330 Sheet stacking unit 331 Sheet discharge tray 32 sheet stopper 333 stops moving mechanism 338 rear sidewall 400 sheet conveying portion 410 upturning roller 411 roller 412 projecting 500 the sheet conveying unit 510 splashing projections 600 sheet conveying portion 611 sheet guide 612 sheet guide

Claims (12)

[Claims] A first conveying unit that receives a plurality of sheets sequentially fed and conveys the sheets at an interval; and a sheet provided downstream of the first conveying unit and conveyed by the first conveying unit. A second conveying unit that conveys the sheet further downstream; and a conveying unit that controls the conveying speed of both the first conveying unit and the second conveying unit so that the rear end of one sheet and the front end of the subsequent sheet overlap. Speed control means, when the trailing edge of the one sheet and the leading edge of the succeeding sheet overlap, displace the trailing edge of the one sheet in a specific direction, and align the overlapping relationship of both sheets in page order And a sheet aligning device. 2. The conveyance speed control means controls the conveyance speed of the second conveyance means to be slower than the conveyance speed of the first conveyance means, thereby controlling the rear end of the one sheet and the subsequent sheet. 2. The sheet aligning apparatus according to claim 1, wherein the leading end of the sheet is superposed. 3. The apparatus according to claim 1, wherein the conveyance speed control means temporarily stops the conveyance by the second conveyance means so that the rear end of the one sheet and the front end of the next sheet overlap. The sheet aligning device as described in the above. 4. The first transport unit includes a pair of transport rollers including a first roller in contact with a first surface of the sheet and a second roller in contact with a second surface of the sheet. A member mounted on the same axis as the first roller and protruding from the peripheral surface of the first roller;
The synchronous rotation with the first roller causes the rear end of the one sheet that has passed through the first roller to be displaced by being hit by a protruding portion.
Item 5. The sheet aligning device according to Item 1. 5. The apparatus according to claim 5, wherein the displacement unit includes a first transport unit and a second transport unit.
4. A sheet guide member provided so that the sheet is curved and conveyed so that the first surface thereof is wound outward between the conveying means. Item 5. The sheet aligning device according to Item 1. 6. The apparatus according to claim 6, wherein said displacement means comprises a first transport means and a second transport means.
4. A flip-up means disposed between the conveying means, and the flip-up means for flipping the second surface of the one sheet toward the first surface. 1
Item 5. The sheet aligning device according to Item 1. 7. The sheet aligning device, further comprising: a sheet stacking unit installed at a position lower than the second conveying unit, wherein the sheet stacking unit stacks discharged sheets; Before passing through the second conveying means, the sheet has a stopper which comes into contact with the leading end of the sheet. The second conveying means is a discharging roller for discharging the sheet, and a pair of discharging rollers arranged vertically. The sheet aligning apparatus according to any one of claims 1 to 6, further comprising a roller, wherein a lower discharge roller projects more toward the sheet stacking unit than an upper discharge roller. 8. The sheet aligning apparatus according to claim 7, wherein a position of the stopper is changed according to a length of the discharged sheet in a conveying direction. 9. The sheet stacking means has a contact member that contacts a trailing end of a discharged sheet, and a distance between the stopper and the contact member is set to be longer than a length of the sheet in the sheet conveyance direction. 9. The method according to claim 7, wherein
The sheet aligning device as described in the above. 10. The sheet aligning apparatus further includes a prohibition unit for prohibiting the control by the conveyance speed control unit, and when the prohibition by the prohibition unit is executed, until a series of sheets are discharged. 10. The sheet aligning apparatus according to claim 1, wherein the conveying speed of the first conveying unit and the conveying speed of the second conveying unit are controlled to be substantially the same. 11. The sheet alignment device is a device that forms a part of an automatic document feeder connected to an image forming device, and includes a plurality of sheets having information recorded on a first surface thereof. 10. A sheet aligning device that receives a sheet that is sequentially conveyed to a reading position from one page and that has completed reading of the first surface by the image forming apparatus at the reading position. 3. The sheet aligning device according to 1. 12. The sheet aligning apparatus according to claim 1, wherein the sheet aligning apparatus is a sheet aligning apparatus that sequentially receives, from a first page, sheets on which an image is formed on a first surface, the sheets being discharged from an image forming apparatus. The sheet alignment device according to claim 1.