JP2851923B2 - Sheet material transport device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus, and more particularly, to a sheet conveying apparatus for simultaneously loading a plurality of sheets on a predetermined processing apparatus. The present invention relates to a document conveying device mounted on a machine or a reader.

[Conventional technology]

A typical example of this type of apparatus is a document feeder. This case will be described as an example.

Equipped with a document feeder in an image forming apparatus such as a copying machine,
It is known that, when a document is automatically fed continuously to a platen for copying, for example, images of two documents are arranged side by side on one side of one recording medium (copy paper) and copied.

FIG. 5A shows an example of an image forming apparatus that performs the above-described copying.

In FIG. 1, reference numeral 100 denotes a copying machine main body, and a document feeder 200 is mounted on a platen 101 serving as an image reading unit.

The document feeder 200 includes a stacking tray 201 for stacking the document bundle S, a separation unit 202 for separating the documents S ′ one by one from the document bundle S on the stacking tray 201, and a separation unit 202 for separating the documents S ′. A transport roller 203 for transporting the original S ′ to the platen 101; a sensor 204 disposed between the transport roller 203 and the separation unit 202 for detecting the original S ′;
The apparatus is provided with a full-surface belt 205 for setting the original S 'conveyed from 03 on the platen 101, and a discharge roller 206 for discharging the original S' on the platen 101 onto a discharge tray 206.

In the image forming apparatus, first, the original bundle S is set with the image surface facing upward (see FIG. 5A).

Next, the separation unit 202 rotates in response to a copy process start signal, separates the lowermost document S 'of the document bundle S by one, and abuts the leading end of the document S' on the transport roller 203 (see FIG. ).

Next, the conveyance roller 203 and the full-surface belt 205 are rotated forward to convey the document S ′ in the direction of the platen 101, and once the rear end of the document S ′ has passed through the conveyance roller 203, the conveyance roller 203 and the full-surface belt 205 are stopped once. (See FIG. C).

Next, the entire surface belt 205 is rotated in the reverse direction and stopped when the rear end of the document S 'abuts on the transport roller 203 (see FIG. 4D).

Next, the separation unit 202 is rotated to separate the second document S ', and the leading end of the document S' is abutted against the transport roller 203 (see FIG. 3E).

Next, when the second original S 'reaches a predetermined position on the platen 101 by rotating the conveying roller 203 and the full-surface belt 205 forward again, the full-surface belt 205 is stopped (see FIG. 5F).

As a result, two originals S ′ are placed on the platen 101 in a state of being arranged side by side. Thereafter, when the image of the original S 'is read (see FIG. 9G), the images of the two originals S' are copied on one side of one copy sheet.

After the reading is completed, the original S 'on the platen 101 is discharged onto the discharge tray 206 by rotating the entire surface belt 205 and the discharge roller 207 forward (see h in FIG. 4).

[Problems to be solved by the invention]

However, as is apparent from the enlarged view of the nip portion of the transport roller 203 shown in FIG. 6, it is difficult to abut the rear end of the first original S 'and the front end of the second original S'. A gap corresponding to the width X of the nip portion occurs.

As a result, the original S 'set on the platen 101
Between them, a space with a width equivalent to the gap X is created,
There was a drawback that a defect occurred during copying.

For example, as shown in FIG. 7, the size of the document S 'l ₁
And then, also when the gap between l _2, 'when copying to the copy paper twice the size of one sheet document S' document S will protrude is shifted ₂ minutes l from the image reading area, the first sheet In this case, the shaded area (l ₂ ) of the original S ′ was missing from the copied image.

[Means (and action) for solving the problem]

According to the present invention, when the preceding sheet material is conveyed, the second sheet conveying / rotating means is rotated for a predetermined time so that the rear end of the sheet material remains in the nip portion of the second sheet conveying / rotating means. Control means for rotating the second sheet conveying rotation means to simultaneously convey the preceding sheet and the succeeding sheet while the leading end of the next sheet material is inserted into the nip portion. , Thereby reducing the gap between sheet materials, eliminating missing image information,
Or minimized.

〔Example〕

Hereinafter, an embodiment of the sheet conveying apparatus of the present invention will be described with reference to the drawings.

<First Embodiment> FIG. 1 shows a first embodiment of the present invention, and is a cross-sectional view schematically showing a copying machine having a document feeder to which the present invention is applied, and FIG. 2 is an enlarged view of a nip portion. is there.

In FIG. 1, reference numeral 10 denotes a copying machine main body, and a document feeder 12 as a document feeder is mounted on a platen 11 serving as an image reading unit.

The document feeder 12 has a stacking tray 13 for stacking the document bundle S, and a document S ′ from the document bundle S on the stacking tray 13.
Separating section 14 (conveying roller 14a, separation belt 14b) for separating sheets S one by one, a substantially U-shaped guide 15 for guiding the separated document S 'to the platen 11, and the guide 15 is disposed at an appropriate position. A transport roller 16 for transporting the original S 'to the platen 11 and an entire belt 17 for setting the original S' at a predetermined position on the platen 11 are provided.

Here, on the downstream side of the stacking tray 13, a semicircular paper feed roller is provided.
And a sensor 19 for detecting the leading end of the document S '.

Also, the transport roller 14a of the separation unit 14 rotates counterclockwise in FIG. 1, and the separation belt 14b rotates counterclockwise similarly to the vicinity of the transport belt 14a.

A sensor 20 for detecting passage of the document S 'is disposed upstream of the transport roller 16 of the guide 15.

The entire surface belt 17 includes a driving roller 17a disposed on one end side (left side in FIG. 1) of the platen 11, a driven roller 17b disposed on the other end side (right side in FIG. 1) of the platen 11, and a driving roller 17a. And a transport belt 17c wound around the driven roller 17b. And drive roller 17a
One end of a drive shaft 21a of a drive motor 21 is connected to the drive shaft 17a 'of the
The c travels in the direction of the solid arrow shown in FIG. A clock counter 22 is connected to the other end of the drive shaft 21a, and a photo interrupter 23 is arranged close to the clock plate 22. The photo interrupter 23 counts the number of slits provided on the clock plate 22 to control the amount of movement of the conveyor belt 17c.

At the other end of the platen 11, a substantially U-shaped guide 23 and a paper discharge roller 24 are provided, and the original S 'on the platen 11 is discharged onto a paper discharge tray 25 arranged on the transport belt 17a. Paper. At an appropriate position of the guide 23, a sensor 26 for detecting the document S 'is arranged.

 Next, the operation of the above configuration will be described.

First, a case where two originals S 'are simultaneously placed on the platen 11 will be described.

(1) The original is placed on the tray 13 with the image facing upward.

(2) When the copy start button (not shown) of the main body 10 is pressed, the feed roller 18 and the separation unit 14 rotate to separate the lowermost document by one sheet and convey it toward the roller 16.

(3) When a predetermined time passes after the leading edge of the document passes the sensor 20, the separating unit 14 and the roller 18 stop. As a result, the first document is applied to the stopped roller 16 at its leading end, forms a predetermined loop, and stands by (FIG. 1 (b)). Thereby, the course of the document is corrected.

(4) When the separation unit 14 and the roller 18 stop, the transport roller 16
And the entire belt 17 rotates forward in the direction of the arrow, and the document
Start conveying in the direction.

(5) When the rear end of the document passes through the sensor 20 and enters the nip portion of the transport roller 16, the roller 16 and the belt 17 are stopped (FIG. 1 (c)). The feed amount is controlled by counting the amount of advance of the document after the trailing end of the sensor 20 has passed by the photointerrupter 23 of the slit of the clock plate 21 of the motor 21. If it is determined from the count of the timer that the trailing edge of the sheet document has approached the stop position, the feeding speed is reduced (voltage application to the motor is reduced) to facilitate positioning of the sheet document.

(6) When the rear end of the first original is held by the nip (FIGS. 1 (c) and 2), the roller 18 and the separation unit 14 rotate again, and the second original is continued. Is separated and conveyed by the same operation as in the above (3), and the leading end is applied to the roller 16 to form a predetermined loop and wait (FIG. 1 (d)). (As can be seen here, (FIG. 2 (a))
It can be seen that the document interval Y with the second document is smaller than the interval X in FIG. )
The distance Y is further reduced by bringing the rear end stop position of the first sheet closer to the upstream side of the nip of the roller 16. Y =
It is also possible to set it to 0. Since the second sheet is about to enter the nip portion by the reaction force of the loop, if the rear end of the first sheet protrudes upstream from the nip portion, “Y
= 0 ", the second sheet is guided by a" wedge-shaped portion "formed by the outer circumferences of the upper and lower rollers 16,16.
The sheet comes into contact with the rear end of the second sheet (FIG. 2B). After the rotation of the roller 16, the second sheet enters by the force of the loop.

(7) When the separation unit 14 and the roller 18 stop, the roller 16 and the belt 17 rotate forward again to convey two documents in the direction of the platen 11 (FIG. 1 (e)).

(8) When the trailing edge of the second document passes through the sensor 20 and reaches a predetermined position on the platen, the roller 16 and the belt 17 stop (first).
Figure (f). Also in this case, the feed amount is determined by counting the slits of the clock plate 21 by the sensor 23. As a result, the two originals are placed on the platen 11 at very small intervals.

(9) When the document placement is completed, the optical system (not shown) of the copying machine main body 10 starts scanning. The scanning is performed successively on the first and second originals. In accordance with the reading, only one sheet material (corresponding to the total length of the first and second originals) is separated and fed from the cassette 301 by the transport roller 302. The separated sheet material stands by a registration roller 303, and is fed in accordance with the position of the developed image on a photosensitive drum (on which the read images of the first and second originals are projected) 304. Can be As a result, two original images are formed on one copy sheet. By repeating this operation, a plurality of copies can be obtained. In addition, 305 is a fixing unit, and 307 is a paper discharge tray.

(10) After reading is completed, the belt 17 and the roller 24 rotate,
The two originals on the platen are discharged onto the tray 25 (first
Figure (g)).

The above operation is repeated until there are no more documents on the tray 13. In this way, the trailing edge of the preceding document is stopped in the nip,
By touching the leading edge of the subsequent document, the document can be placed at a predetermined position with a minimum gap between a plurality of documents.

 Here, operations (4) and (5) are considered.

The conveyance speed of the preceding document from the formation of the front end loop to the rear end nip position is now the same as the normal conveyance speed, but this speed is slower than the normal conveyance speed, and the accuracy of the stop position in the rear end nip is reduced. May be increased. Further, the conveyance speed may be reduced after the trailing edge of the preceding document has passed through the sensor 20 to improve the accuracy of the stop position in the nip at the trailing edge.

<Other Embodiments> In the above embodiment, the loading tray 13 is used as the document feeder 12.
And a paper discharge tray 25 are separately provided, but a device that returns the fed document S 'to the same stacking tray 13 again may be used.

Further, the case where two originals S 'are fed and copied on the platen 11 is shown, but three or four originals S' may be fed to the platen 11 for copying.

In the case where the images of a plurality of originals S 'are formed on the same surface of the same recording medium and formed only on one side (front side) of the recording medium (in the case of single-sided copying), the recording medium is placed inside the printer. , And can be applied to the case of double-sided copying in which images of a plurality of originals S ′ are also formed on the back side.

Also, the case where the present embodiment is applied to a copying machine has been described.
Of course, the present invention can be applied to a laser beam printer, an image reader (reading device), and the like.

 Here, an example of a two-sided copying machine will be described.

Reference numeral 400 denotes an upper cassette. Sheets in the cassette are separated and fed one by one by the action of a separation claw and a feeding roller 401, and are guided to a registration roller 406. Reference numeral 402 denotes a lower cassette, which is separated and fed one by one by the action of a sheet separating claw and a feeding roller 403 in the cassette and guided to the registration roller 406. A manual guide 404 guides sheet materials one by one to a registration roller 406 via a roller 405. 408
Is a sheet stacking device (decick type) having a middle plate 408a which is raised and lowered by a motor or the like, and the sheet on the middle plate is a feeding roller.
The sheet is fed and separated one by one by the action of the separation claw 409 and the separation claw and guided to the conveyance roller 410.

412 is a photosensitive drum, 413 is a reading optical system, 414 is a developing device, 4
Reference numeral 15 denotes a transfer charger, and 416, a separation charger, which constitutes an image forming unit.

417, a conveying belt for conveying the sheet material on which the image is formed, 418, a fixing device, 419, a conveying roller, and 420, a flapper. The sheet material on which the image is formed is guided to the discharge roller 421 by the flapper 420 and is conveyed into the sorter 422. In some cases, a discharge tray is mounted instead of the sorter.

An automatic document feeder 430 positions the documents one by one on a platen 431 and reads them by the optical system.

For one document placed on the platen, an image is formed on the photosensitive drum according to the set number of copies, and the sheet material for the number of copies is formed from any of cassettes 400, 402, and deck 408. , Each time an image is formed on the photosensitive drum. The registration between the image on the photosensitive drum and the sheet material is performed by registration rollers 406.

When the required number of copies are formed, the original is discharged from the platen, and the next original is positioned on the platen. Hereinafter, the same applies.

Reference numeral 500 denotes an intermediate tray, which stocks a sheet material on which an image has been formed once when forming an image on both sides of the sheet material or when forming an image on one side of the sheet material (multiple). 501 is a transport roller, 502 is a transport belt,
503 is a flapper, 504 is a transport belt, and 505 is a transport roller. In the case of duplex copying, the sheet is guided to the intermediate tray 500 through the path 506. The sheet has the image side facing up. In the case of multiple copies, intermediate tray 5 passes through path 507
Guide the sheet material to 00. The sheet material has the image side facing down.

The sheet material stacked on the intermediate tray 500 is
09, 510, the sheet is separated one by one from below by the action of the forward / reverse separation roller pair 511 and re-fed. The re-fed sheet material is guided to the image forming unit via conveyance rollers 513, 514, 515, a roller 410, and a registration roller 406. After image formation, the paper is discharged in the same manner as described above.

One-sided copies are first made according to the number of copies set for one document placed on the platen, and they are stacked on the intermediate tray 500. After that, the original is reversed on the platen and guided again on the platen, and this image is read by the number of copies. The read image is formed on a sheet material re-fed from the intermediate tray 500 every time the image is read. They are sorted by the sorter 422 in page order.

On the other hand, there is also a method in which only one copy is created each time a document is rotated by the automatic document feeder. According to this method, even when a plurality of copies are made, a copy group having the same page order can be obtained in order, so that a necessary number of copies can be obtained separately without a sorter. When making a two-sided copy in this manner, one side of the original is continuously read, the two sides of the sheet are continuously copied and ejected, and then the same procedure is performed on both sides of the next original. By repeating the process many times, a divided double-sided copy group is obtained.

The above is the description of each embodiment of the present invention according to the present invention, but the present invention is not limited to this example.

For example, in positioning the original, a timer may be counted in accordance with the original size information after the leading end of the original is detected by the center 20 (provided downstream of the roller 16), or the count may be started from the start of rotation of the roller 16. May be.

〔The invention's effect〕

As described above, according to the present invention, it is possible to reduce the gap between sheet materials and eliminate or minimize the loss of image information.

Further, unlike the conventional example, the drive system does not perform the forward / reverse rotation operation for combining the two originals, so that the configuration of the drive system can be simplified, and the operation time and processing time can be reduced.

[Brief description of the drawings]

1 (a) is a front sectional view of one embodiment of the present invention, FIGS. 1 (b) to 1 (g) are explanatory diagrams of the operation, and FIG. 2 (a) is an embodiment of the present invention. 2 (b) is an enlarged view showing another nip state, FIG. 3 is a block diagram, FIG. 4 is a front sectional view of another embodiment, and FIG. 5 (a). 5 (h) are explanatory views of the operation of the conventional example, FIG. 6 is an enlarged view showing a nip state of the conventional example, and FIG. 7 is a plan view showing a copying state of the conventional example. 10 Copy machine body 11 Platen 12 Document feeder 13 Loading tray 14 Separation section 16 Transport roller 20 Sensor

Claims (1)

(57) [Claims] A first sheet conveying rotation unit for conveying the sheet material; and a second sheet conveying rotation unit for conveying the sheet material from the first sheet conveying rotation unit in a predetermined processing position direction. In the sheet material transporting apparatus, when the preceding sheet material is transported, the second sheet transport rotating means is rotated in one direction for a predetermined time so that the rear end of the sheet material is in the nip portion of the second sheet transport rotating means. The second sheet conveying / rotating means is rotated in one direction while the leading end of the next sheet is inserted into the nip, and the preceding sheet and the succeeding sheet are simultaneously conveyed. A sheet conveying device including a control unit for causing the sheet to be conveyed.