JPH08133493A - Document feeding device, and image forming device equipped with the document feeding device - Google Patents

Abstract

PURPOSE: To provide a document feeding device capable of giving the desired feeding load to the documents, and surely feeding the document even when the number of the documents on a document tray is small. CONSTITUTION: A document feeding device is provided with a document tray to load the documents, a semicircular paper feeding roller 8 to turn and feed the documents on the document tray, and a sheet document stopper 19 as a feeding load giving means to energize the document on the paper feeding roller 8 side. This sheet document stopper 19 consists of a partitioning member and a weight member 19b. The weight member 19b is not brought into contact with the paper feeding roller 8 even when no document are on the document loading table, and is provided with a projecting part 19c which overlaps the outer circumferential turning locus on the document side of the paper feeding roller 8. Even when the number of the documents on the document tray is small, the projecting part 19c of the weight member 19b surely energizes the document on the paper feeding roller 8 side to give the desired feeding load to the document and the paper feeding roller 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder, and more particularly, a document feeder used in an image forming apparatus such as a copying machine, a printer or a facsimile, and an image forming apparatus equipped with the document feeder. It relates to the device.

[0002]

2. Description of the Related Art As is generally known in the prior art, a document feeding device urges a document placed on a document placing table in order to reliably feed the document by a feeding means. A weight member serving as a feeding load applying unit is provided.

The weight member of this document feeder is shown in FIG.
As shown in FIG. 3, in order to prevent vibration and noise from coming into contact with the half-moon roller as a feeding means when there is no original on the original table, the rotation path of the half-moon roller is It is configured to have some space.

[0004]

However, in the conventional example as described above, even when there is no document on the document table,
Since the weight member has a slight space with respect to the rotation path of the half-moon roller, when the number of originals on the original table is small, the weight member cannot sufficiently urge the originals toward the half-moon roller, There is a problem that there is a possibility that the document may not be properly fed.

[0005]

According to the present invention, a document placing table (4) on which a document is placed, and a feeding means (8) for rotating and feeding the document on the document placing table (4). The feeding means (8)
A document feeding device (2) comprising a feeding load imparting means (19) for urging the document toward the side, wherein the feeding load imparting means (19) is on the document placing table (4). Even if there is no document on the paper, it does not come into contact with the feeding means (8),
Further, it is characterized in that it is provided with a projecting portion (19c) which overlaps with the outermost peripheral rotation locus of the feeding means (8) on the document side.

Further, the document feeder (2) of the present invention is characterized in that the projecting portion (19c) of the feeding load applying means (19) is formed of a rubber-like elastic member.

Furthermore, the image forming apparatus (1) of the present invention reads the image of the original document feeding device (2) and the original document fed from the original document feeding device (2) to obtain a desired image on the sheet. And an image forming unit (G) that forms the image.

[0008]

Even when the number of originals on the original placing table (4) is small, the projecting portion (19c) of the feeding load applying means (19) surely urges the originals toward the feeding means (8), Then, a desired feeding load is applied to the feeding means (8) so that the feeding means (8) reliably feeds the original on the original placing table (4).

The reference numerals in the above parentheses are for the purpose of comparison with the drawings and do not limit the structure of the present invention in any way.

[0010]

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

In FIG. 1, R is a sheet material conveying device.
The DF (circulation type document feeder of the present invention) 2 has a document tray 4 as a document placing table above and a wide belt 7 wound around a driving roller 36 and a turn roller 37 below the document tray 4. It is done. The wide belt 7 is in contact with the platen 3 of the copying machine main body 1, and the original tray 4
The sheet original P placed on the upper side is conveyed and placed at a predetermined position on the platen 3, or the sheet original P on the platen 3 is carried out onto the original tray 4.

Further, a pair of width direction regulating plates 33 are arranged on the document tray 4 so as to be slidable in the width direction of the sheet document P, and the width direction of the sheet document P placed on the document tray 4 is set. Restricting the stability of the sheet original P during feeding,
Consistency is ensured when carrying out onto the document tray 4. The width direction restricting plate 33 has a built-in jogging mechanism, and presses the sheet originals P carried out on the original tray 4 one by one against the original reference guide 33 to further improve the consistency. Further, the original tray elevating mechanism causes the original tray 4 to move around the swing center 40 as shown in FIG.
It is possible to swing between the positions shown in FIG.

Adjacent to the document tray 4, a half-moon-shaped sheet feeding roller 5 and a stopper 21 which is moved up and down by a stopper solenoid (not shown) are provided, and the sheet document is set on the document tray 4. P is restricted by the protruding stopper 21 so that it cannot move downstream.

When the copying conditions are input through the operation unit of the copying machine 1 and a start key (not shown) is pressed, the stopper 21 sinks to open the path of the sheet document P, and the sheet document P is fed. The paper roller 5 is fed and advances to the downstream portion. At this time, the partition member 22 connected to a partition member motor (not shown) built in the document reference guide 33 on the document tray rotates and rides on the uppermost sheet document P, and the unprocessed document and the processed document are processed. To distinguish.

At the downstream side of the stopper 21, there is disposed a first separating section composed of a conveying roller 38 and a separating belt 6 which constitute a separating section, and each of them rotates in the direction of the arrow and advances from the document tray 4. The sheet originals P are separated sheet by sheet and conveyed further downstream.

A weight 20 is provided above the stopper 21, so that the number of sheet originals P on the original tray 4 is small and the sheet originals P are separated by the feeding force of the paper feed roller 5. If the sheet solenoid P cannot be advanced to, the sheet solenoid P is moved downward by a weight solenoid (not shown) to sandwich the sheet document P between the sheet document P and the sheet feeding roller 5, thereby improving the feeding force of the sheet feeding roller 5.

Original feed paths (a), (b), and (c) are constructed from the separating parts 6, 38 to the platen 3 (see FIG. 4), and the original feed paths (a), (a). B),
(C) is bent and connected to the conveyance path on the platen 3, and guides the sheet document P onto the platen 3. Further, in the vicinity of the paper feed roller 5, the sheet document P placed on the document tray 4 is placed.
An entrance sensor 23, which is a transmissive optical sensor for detecting the presence / absence of the presence or absence, is arranged.

On the left side of the main body of this RDF 2, a large roller 1
0 is provided, and the platen 3 to the large roller 10 are
Document discharge paths (e) and (f) extending around the outer circumference of the document tray and extending above the document tray 4 are formed (see FIG. 4). Further, a document reversing path (e) for branching from the upper side of the large roller 10 of the document discharging paths (e) and (f) to reverse the front and back sides of a double-sided document (see FIG. 4), The downstream portion of the document reversing path (e) joins the document feeding path (b). On the downstream side of the document output path (to),
A relay roller 44 and a paper discharge roller 11 are provided. Then, the sheet original P conveyed through the original discharge paths (e) and (e) is carried out to the uppermost part of the original stack P on the original tray 4. The wide belt 7 arranged above the platen 3 conveys and places the sheet document P at a predetermined position on the platen 3, and carries out the document from the platen 3 after image reading. A feeding roller 9 is provided at the confluence of the document feeding paths (a), (b) and (c) and the document reversing path (e). The feeding roller 9 forms a loop on the arrived sheet document P to prevent the sheet document P from skewing. In the vicinity of the upstream side of the feeding roller 9, the sheet feeding sensor 2 which is a transmissive optical sensor for detecting the front end and the rear end of the sheet document P.
5, the document feeding paths (a), (b),
It is also possible to detect the original document P that has passed either the conveyance path of (C) or the original reversing path (E). A registration sensor 39, which is a transmissive optical sensor that detects the trailing edge of the sheet original P, is disposed downstream of the feeding roller 9. A reversing sensor 26, which is a transmissive optical sensor for detecting the sheet document P carried out from the platen 3, is arranged below the large roller 10 in the document discharge paths (e) and (e). In the document discharge path (f) between the roller 10 and the discharge roller 11, the transmission that detects the passage of the sheet document P that has passed through the document discharge path (f) and is discharged onto the document tray 4. A paper discharge sensor 27, which is a mold type optical sensor, is provided.

A reversing flapper 34 for switching the path is provided at a portion branched from the document discharge paths (e) and (f) to the document reversing path (e). This reverse flapper 3
4 is by turning on / off the reverse flapper solenoid
The path is switched by swinging between the solid line position and the dotted line position in the figure.

Further, on the right side of the main body of the RDF 2, there are provided a second document separating means for conveying the sheet document from the right end of the platen glass on the image reading portion on the platen 3, a second document feeding path (h), ( (I) and (n) (see FIG. 4).

The document tray 4 is adapted to swing in conjunction with the vertical swinging operation of the document tray 4 with the positions shown in FIGS. 1 and 2 as the upper limit and lower limit positions. As shown in FIG. 2, when the document tray 4 is at the lower limit position, a half-moon shaped second paper feed roller (feeding means) 8 and a conveyance roller 15 constituting a second separation unit are adjacent to the lower limit position. A separation belt 14 is provided. Then, the rollers 8 and 15 and the separation belt 14 rotate in the direction of the arrow to separate the sheet originals P advancing from the original tray 4 sheet by sheet and convey them further downstream.

In FIG. 5, the stopper 21 and the short arm 41 integral therewith are rotatable about the support shaft 12, and the pin of the support shaft 12 is engaged with the recess of the operating member 13. . The stopper 21 can be rotated to the chain line position by rotating the operating member 13 in the clockwise direction. The actuating member 13, whose intermediate portion is rotatably supported by the support shaft 12, is urged counterclockwise by the tension spring 42, and its rotation is restricted by the stopper 57. The lower end of the operating member 13 is connected to the stopper solenoid 24 via a connecting member 43.

The document tray 4 is configured to have an upper limit position or a lower limit position depending on the size of the document placed on the tray and the input conditions of the image forming apparatus. When the tray 4 reaches the lower limit position, the above-mentioned stopper 21 of the tray 4 conveys the sheet document P placed on the tray 4 in a bundle by a certain distance to the second separating means 14 and 15.

The sheet originals P conveyed in a bundle are always "paper present" by the transmission type optical sensors 28a and 28b which are arranged near the upstream side of the second separating means and detect the presence or absence of the sheet originals.
Is conveyed to a position where is detected (see FIG. 3). When the bundle conveyance is completed, the sheet document stopper 19 as the feeding load applying means is configured to be placed on the sheet document P.

A second feeding roller 16 is arranged downstream of the second separating means 14 and 15. The second feeding roller 16 forms a loop on the arrived sheet document P to prevent the sheet document P from skewing. A second paper feed sensor 30, which is a transmissive optical sensor for detecting the front end and the rear end of the sheet document P, is disposed near the upstream side of the second feeding roller 16. Further, there is a relay roller 17 on the downstream side, and a transmissive optical sensor 18 for detecting the leading end position of the sheet document P is provided in the second feeding path (nu) shown in FIG.
Is provided. The document detection signal of the light sensor 18 is sent to a controller (not shown), and the controller controls the sheet feeding timing of the sheet material on which an image is formed in the image forming apparatus.

Next, the structure and operation of the sheet original document stopper 19 as the feeding load applying means will be described.

[1]. A case will be described in which the number of image forming copies is set to 1 in the image forming apparatus 1 with the input key.

In this case, the sheet document stopper 19 (partitioning member 19a, weight member 19b) remains placed on the sheet document P as shown in FIG. 3, and is ejected by the sheet ejection roller 11. The sheet originals are regulated so as not to enter the second separating portions 14 and 15.

As shown in FIGS. 6 to 8, the sheet original stopper 19 can be swung by using two weight members 19b fixed to the rotating shaft 31 and a parallel pin 32 on the rotating shaft 31 ( (See FIG. 6), and two partition members 19a attached to the partition member (see FIG. 7). Of these, the partition members 19 a are arranged at both ends of the document tray 4. The weight member 19b is arranged on the second feeding roller 8 having a half-moon shape.

The partition member 19a and the weight member 19
The relative positions of b, the second paper feed roller 8 and the document tray 4 and the operating states are as follows.

(A). A case where the number of sheet originals is three or less will be described.

First, the sheet document stopper 19 descends on the sheet document P stacked on the document tray 4, and the sheet document P is separated and fed. At this time, it becomes a separation delay,
If the sheet original does not reach the separation sensor 29 even after a predetermined time has elapsed, the downward biasing force of the sheet original stopper 19 increases (hereinafter referred to as retry), and the conveying force increases. That is, the rotating shaft 31 is rotated by a predetermined amount by the motor M whose rotation is controlled by the controller (see FIG. 7), and the rotating shaft 3 is rotated.
The weight member 19b fixed to 1 urges the document downward.

After the image flow reading at the predetermined position is completed, the sheet original P is ejected onto the original tray 4 by the paper ejection roller 11. At this time, there is no sheet original on the original tray 4 and 2
Since the one partition member 19a is swingably attached to the rotary shaft 31, it is in contact with the document tray 4 by its own weight. Then, the two weight members 19b
Is the rotation locus of the second paper feed roller 8 at the position facing the second paper feed roller 8 (the outermost peripheral rotation locus in the upper part of FIG. 7).
And are located with a slight gap to prevent vibration and noise. Further, the weight member 19b is provided with ribs 19c at both ends in the width direction (left and right direction in FIG. 9) that slightly overlaps with the rotation locus of the second sheet feeding roller 8 (projection portion) (see FIG. 9). Is bent to contact the roller 8 so that the conveying force can be increased even when retrying when the number of originals on the original tray 4 is small (even 3 or less).

The partition member 19a has a screw hole for tightening the screw 36 so that its own weight can be adjusted (see FIG. 6).

(B). A case where there are four or more sheet originals will be described.

Also in this case, as in the case of (a), the sheet document stopper 19 is lowered on the sheet document P stacked on the document tray 4, and the sheet document P is separated and fed. At this time, if the sheet original does not reach the separation sensor 29 after a predetermined time has elapsed due to separation delay, the downward biasing force of the sheet original stopper 19 increases (hereinafter referred to as a retry), and the conveying force increases. ing.

After the image flow reading at the predetermined position is completed, the sheet original P is discharged onto the original tray 4 by the paper discharge roller 11. At this time, since there are one or more sheet originals on the original tray 4, and two partition members 19a are swingably attached to the rotary shaft 31, they are in contact with the bundle of sheet originals by their own weights. (See Figure 3). The ribs 19c of the two weight members 19b are in contact with the sheet original bundle. At the time of retry, the sheet original stopper 19
When is at the lower limit (when the number of sheets is small), the originals are curved due to overlap to increase the downward biasing force, and when other than the lower limit (when the number of sheets is large), the stack of sheet originals is pressed toward the lowermost direction. The carrying power is increasing.

At this time, as shown in FIG. 3, the stopper 21 conveys the sheet original P to the second separating portions 14 and 15, and returns to the initial position after the conveyance. Also, every time the sheet document is discharged from the discharge roller 11 onto the document tray 4, the stopper 21 causes the second end of the rear end of the sheet document to move to the second position.
Of the sheet document P on the document tray 4
The consistency in the transport direction of the paper is improved (Figs. 10 and 1).
1).

[2]. A case will be described in which the number of image forming copies is set to n copies by the input key in the image forming apparatus 1 (one copy of a sheet original is circulated n times).

In this case, as shown in FIGS. 10 and 11, the sheet original stopper 19 is retracted upward until the sheet original is (n-1) circulated, and the first sheet original of the nth circulation is set. When the document is reloaded on the document tray 4, it is placed on the sheet document and regulates the entry of the first sheet document into the second separating portions 14 and 15.

The sheet document stopper 19 is arranged and arranged as described above, and its relative position and operating state are as follows.

(C). A case where the sheet document is completely (n-1) circulated will be described.

At the time of retry, the sheet original stopper 19 standing by above presses the bundle of sheet originals on the original tray 4 for a predetermined time to increase the conveying force, and then stands by again above.

(D). When the sheet document is completely circulated (n-1), the same functions as those in (a) and (b) are performed.

At this time, as shown in FIG. 3, the stopper 21 conveys the sheet original P to the second separating portions 14 and 15 and returns to the initial position after the conveyance. In addition, the stopper 21 outputs the sheet original to the paper discharge roller 1.
Each time the sheet document is discharged from the document tray 1 to the document tray 4, the trailing edge of the sheet document is pushed toward the second separating portions 14 and 15 to improve the consistency of the sheet document P on the document tray 4 in the conveying direction. (FIGS. 10 and 11).

At the end of n circulation, as shown in FIG. 12, the leading edge of the sheet original P is regulated by the sheet original stopper 19. After that, the document tray 4 moves upward,
Stop at the upper limit position. <Other Embodiments> Next, a second embodiment of the present invention will be described.

In the above embodiment, the weight member 19b has the rib 19c integrally formed, but the rib-shaped elastic member (rubber) may be vulcanized and bonded. <Image Forming Apparatus> Next, the overall configuration of a copying machine using the above-described document feeding apparatus will be described with reference to the sectional view of FIG.

In FIG. 14, reference numeral 200 denotes an upper cassette, and the sheets (recording media) in the cassette 200 are separated and fed one by one by the action of the separating claw and the feeding roller 201 and guided to the registration roller 206. Reference numeral 202 denotes a lower cassette, and the sheets (recording media) in the cassette 202 are separated and fed one by one by the action of the separating claw and the sheet feeding roller 203 and guided to the registration roller 206.
Reference numeral 204 denotes a manual feed guide, which is a roller 20 for each sheet.
It is guided to the registration roller 206 via 5. A sheet stacking device (deck type) 208 includes an intermediate plate 208a that moves up and down by a motor or the like, and the sheets on the intermediate plate are separated and fed one by one by the action of a sheet feeding roller 209 and a separating claw, and a conveying roller 210. Be led to.

Reference numeral 212 is a photosensitive drum, 213 is a reading optical system, 214 is a developing device, 215 is a transfer charging device, and 216 is a separating charging device, and constitute an image forming section G.

Reference numeral 217 is a conveying belt for conveying the image-formed sheet, 218 is a fixing device, 219 is a conveying roller,
220 is a flapper. The sheet on which the image is formed is guided to the discharge roller 221 by the flapper 220 and is conveyed into the sorter 222. A discharge tray may be attached instead of the sorter.

An intermediate tray 300 stocks the sheet on which the image is formed once when the image is formed on both sides of the sheet or when the image is formed on one side of the sheet. 301 is a carrying roller, 302 is a carrying belt, 303 is a flapper, 304 is a carrying belt, 30
Reference numeral 5 is a conveyance roller. Pass 306 for double-sided copying
The sheet is guided to the intermediate tray 300 through the sheet. At this time, the image surface of the sheet faces upward. In the case of multiple copying, the sheet is guided to the intermediate tray 300 through the path 307. At this time, the image surface of the sheet faces downward.

The sheets stacked on the intermediate tray 300 are
Auxiliary rollers 309 and 310, forward / reverse separation roller pair 311
By the action of, the sheets are separated one by one from below and are re-fed. The re-fed sheets are conveyed by the conveying rollers 313, 314,
It is guided to the image forming unit via the roller 315, the roller 210, and the registration roller 206. After the image is formed, it is discharged in the same manner as described above.

According to the number of copies set for one document placed on the platen (glass) 3, first one side is copied, and these are stacked on the intermediate tray 300. After that, the front and back of the original document on the platen (glass) 3 are reversed, and the original is guided again on the platen (glass) 3 to read this image for the number of copies. The read image of the original is formed on a sheet that is re-fed from the intermediate tray 300 each time the image is read. They are sorted in page order by the sorter 222.

On the other hand, there is also a method in which each time the original document is circulated by the original document feeder 2, only one copy of the original document is produced. According to this method, even when making copies of a plurality of copies, a copy group in which the page order is uniform can be sequentially obtained.
Even without a sorter, the required number of copies can be obtained separately. When performing double-sided copying by this method, both sides of one original are continuously read, the front and back sides of the sheet are continuously copied and discharged, and then the same is applied to both sides of the next original.
By repeating this many times, a group of divided double-sided copy sheets can be obtained.

[0055]

As described above, according to the present invention, the feeding load applying means does not come into contact with the feeding means even when there is no original on the original placing table, and the original of the feeding means. Since the protruding portion that overlaps the outermost peripheral rotation locus on the side is provided, even if the number of originals on the original mounting table is small, the originals are not moved to the feeding means side by the protruding portion of the feeding load applying means. A desired feeding load can be applied between the original and the feeding means by pressing, and the original can be reliably fed by the feeding means.

Further, since the image forming apparatus of the present invention is equipped with the document feeding device capable of reliably feeding the document as described above, the document feeding failure does not occur, and the image forming apparatus can be fed to the image forming apparatus. The reliability can be significantly improved.

[Brief description of drawings]

FIG. 1 is a first configuration diagram of a document feeder according to an embodiment of the present invention.

FIG. 2 is a second configuration diagram thereof.

FIG. 3 is a third configuration diagram thereof.

FIG. 4 is a diagram of the same transportation route.

FIG. 5 is an enlarged view of a main part of the document feeding device.

FIG. 6 is a side view showing an embodiment of a partition member of the feeding load applying means according to the present invention.

FIG. 7 is an operation explanatory view of the feeding load applying means according to the present invention.

FIG. 8 is an attached state view of a feeding load applying means according to the present invention.

FIG. 9 is a perspective view of essential parts showing an engagement state between a weight member and a feeding means of the feeding load applying means according to the present invention.

FIG. 10 is a fourth view of the document feeder according to the embodiment of the present invention.
Configuration diagram of.

FIG. 11 is a fifth view of the document feeder according to the embodiment of the present invention.
Configuration diagram of.

FIG. 12 is a sixth view of the document feeder according to the embodiment of the present invention.
Configuration diagram of.

FIG. 13 is a perspective view of a main part showing an engagement state of a conventional weight member and a feeding unit.

FIG. 14 is a configuration diagram of an image forming apparatus including the document feeding apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus (copying machine) 2 Original feeding device 4 Original placing table (original tray) 8 Feeding means (second paper feeding roller) 19 Feeding load applying means (sheet original stopper) 19c Projecting part (rib) G Image forming section

Claims (3)

[Claims] 1. A document placing table on which a document is placed, a feeding means for rotating and feeding the document on the document placing table, and a feeding load applying means for urging the document toward the feeding means. In the document feeding apparatus including :, the feeding load applying unit does not contact the feeding unit even when there is no document on the document placing table, and the document of the feeding unit is An original feeding device, characterized in that it is provided with a protruding portion that overlaps the outermost peripheral rotation locus on the side. 2. The document feeder according to claim 1, wherein the projecting portion of the feeding load applying means is formed of a rubber-like elastic member. 3. The document feeder according to claim 1, and an image of a document fed from the document feeder,
An image forming apparatus comprising: an image forming unit that forms a desired image on a sheet.