JP2000289877A - Paper feed device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely separate paper sheet one by one and carry it by small carrying force quickly and smoothly by movably providing a claw means supporting the moving means side of the extreme end of a paper sheet bundle between a first position positioned at feeding the paper sheet and a second position positioned at setting the paper sheets. SOLUTION: This paper feed device is constituted of an extreme end regulation member 303, a moving roller 304, a pressure connection plate 305, a presser plate 306, and a supporting claw 307, and the supporting claw 307 is arranged so as to contact with the angle part of the extreme end of documents. Further the supporting claw 307 is provided so as to support the underside of the extreme end part of a document bundle 302 on a tray 301, and in this case, the supporting claw 307 is movably provided between a first position and a second position, and at feeding the document, the supporting claw 307 is set on the first position, and the lowermost document of the document bundle 302 is pulled out from the supporting claw 307 by the moving roller 304 to carry it. Meanwhile, at setting the documents, the supporting claw 307 is set on the second position, and the documents inserted in the arrow mark are easily put in the supporting claw 307.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeder for separating and feeding sheets one by one from a stacked sheet bundle.

[0002]

2. Description of the Related Art Various printers such as laser printers and thermal printers, facsimile machines, copiers and the like are provided with a paper feeding device for feeding paper such as originals and transfer paper. Many sheets are stacked and held on a tray of a sheet feeding device, and the sheets are separated and sent out one by one from the sheet bundle.

Conventionally, such a paper feeder has been
A friction pad system that separates a bundle of sheets and feeds the sheets one by one by utilizing the difference between the frictional force between the sheets and the frictional force between the friction pad and the sheets. Various principles and methods, such as an air method for separating the sheet bundle and feeding the sheets one by one, and a separation claw method for separating the sheet bundle and separating the sheets one by one by using the separation claw using the elasticity of the sheet. Are known.

[0004]

However, in the above-described conventional paper feeder which separates and conveys paper one by one, for example, in the above-mentioned friction pad system, the paper is narrowed between a friction pad and a roller. Separates while transporting only the paper that comes into contact with the roller from the plurality of papers. For this reason, the transport means must have a transport force that overcomes the frictional force of the friction pad, and the driving source of the transport means is increased in size, leading to an increase in manufacturing costs and damage to paper.

On the other hand, there has been proposed a document feeder equipped with a paper feeder provided with a regulating plate for restricting the supply of paper to the friction pad. However, this method has not yet provided a means for realizing the reduction of the conveying force itself.

Further, in the air-type sheet feeding apparatus, since air is blown between the sheets to separate the sheets or to take out the sheets by suction, the sheet conveying force does not increase. However, fans and ducts that generate air are expensive, which leads to an increase in manufacturing cost, and not only increases the size of the apparatus but also causes noise in the intake and exhaust of the fans.

Further, in the paper feeder of the separation claw type, the paper contacting with the claw means is moved and deformed into a loop while being moved by utilizing the elasticity of the paper, so that the paper end is extracted from the claw means and conveyed. . However, since this method is greatly affected by the characteristics of paper elasticity, for example, the allowable range for changes in the environmental conditions such as temperature and humidity, which change the characteristics of the paper, and changes in physical conditions such as the thickness of the paper and the direction of the streaks is narrow. Paper mistakes and double feeds are likely to occur.

In the separation claw method, the vicinity of the claw means is a free space for forming a paper loop. Therefore, in the case of an "upside-down" sheet feeding device that feeds the topmost sheet one by one from the sheet bundle, the tray or the sheet bundle is pushed down by hand to securely insert the leading edge of the sheet into the claw means when setting the sheet. Needed to set the next paper. In addition, when the paper is set in the “lower-out” sheet feeding device that feeds the lowermost sheet one by one from the sheet bundle, the leading edge of the sheet falls into the free space due to the weight of the sheet bundle, and the sheet enters the claw means satisfactorily. However, there has been a problem that paper breakage such as broken ears, skew feed accompanying the breakage, and multi-sheet feed occur.

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned drawbacks of the prior art, and it is an object of the present invention to be able to surely separate sheets one by one and to convey quickly and smoothly with a small conveying force. An object of the present invention is to provide a small and inexpensive sheet feeding device.

[0010]

To achieve the above object, according to the present invention, there is provided a sheet feeding apparatus for separating and feeding sheets one by one from a sheet bundle. Tip regulating means for regulating the tip of the bundle;
A moving unit that is positioned upstream of the leading end regulating unit in the sheet feeding direction and that contacts a sheet and moves the leading end of the sheet to the upstream side in the sheet feeding direction to form a sheet loop; And a claw means for supporting the moving means side of the leading end of the sheet bundle, wherein the claw means is located at a first position at the time of sheet feeding and at a second position at the time of sheet setting. And a second position is a position retracted from the first position.

According to a second aspect of the present invention, in the paper feeder of the first aspect, the moving means includes a first position located at the time of feeding the paper, and a retracted position at the time of paper setting. It has a second position to be located, and retreats from the first position to the second position simultaneously with the claw means.

According to a third aspect of the present invention, in the paper feeder of the first aspect, the moving means is constituted by a roller having a rotating shaft and a contact portion which comes into contact with the sheet, and a cross section of the roller perpendicular to the rotating shaft. Is characterized by being non-circular.

According to a fourth aspect of the present invention, there is provided a sheet feeding device for separating and feeding sheets one by one from a sheet bundle, and a tray for stacking and holding the sheet bundle, and a leading end regulating means for regulating a leading end of the sheet bundle. A movement that is positioned upstream of the leading end regulating unit in the sheet feeding direction and below the sheet bundle, contacts the lowest sheet in the sheet bundle, and moves the leading end of the sheet to the upstream side in the sheet feeding direction to form a sheet loop. Means, pressing means for pressing the sheet bundle from the upper side to the lower side, and claw means for supporting the lower side of the leading end of the sheet bundle, wherein the claw means is located at a first position which is located at the time of sheet feeding. And a second position located at the time of setting a sheet, wherein the second position is a position retracted from the first position.

In the present invention, both the moving means and the claw means, or at least the claw means, are at the position moved in the paper bulging direction at the time of setting the paper, that is, at the position retracted from the insertion path of the paper to be set. In addition, it is possible to prevent the occurrence of a setting failure such that the leading end of the paper does not enter the claw means during the paper setting and the occurrence of a paper passing failure.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments shown in the drawings. FIG. 1 is a side view of a copier equipped with an automatic document feeder using a paper feeder according to a first embodiment of the present invention, and FIG. 2 is a schematic configuration diagram showing an internal structure of a copier main body. is there.

<< Copier Body >> First, the schematic configuration and operation of the copier body will be described.

The copying machine shown in FIG. 1 reads an image on a document surface, temporarily stores it in a memory, performs various image editing processes as needed, and forms an image on a sheet by a well-known electrophotographic method. This is called a digital copying machine. This copying machine comprises a copying machine main body 10 and an automatic document feeder 20 located thereon.

As shown in FIG. 2, an image of an original set on an original platen glass (platen glass) 111 is read by a CCD sensor 117 which is an image reader built in the copying machine main body 10, and the digital image is read. The data is converted into data and stored in the memory of the control unit. The copy operation is performed by reading the image data,
For example, the process is executed by adding a change in the page order, an image inversion process, or a copy process on both sides.

In the copying machine body 10, the optical system 11
An illumination lamp (exposure lamp) 112 which is arranged directly below the platen glass 111 on which the original is placed and illuminates the original placed on the platen glass 111, and a reflection mirror for polarizing the optical path of the reflected light of the original 113, 114,
115, lens 116 having focusing and zooming functions, C
CD sensor 117, optical system motor 11 for driving the optical system
8 and a shading correction plate 119 installed on the platen glass 111 to correct the sensitivity variation of the CCD sensor 117.

At the left end of the platen glass 111, a document reference plate 101 for positioning the document in the transport direction is arranged. The operator places the document on the platen glass 111 with the image surface facing down. One end is set according to the original scale 101. The optical system 11 illuminates the image of the set document while scanning it, and reads the reflected light through the lens 116 with the CCD sensor 117.

When scanning this image, the CCD sensor 11
7 first reads the shading correction plate 119,
The variation of each pixel of the CD sensor 117 is corrected. Thereafter, the exposure lamp 11 is driven by driving the optical system motor 118.
2 and the reflecting mirrors 113, 114 and 115 are slid and set at the document reference position SP. Then, the exposure lamp 112 and the reflection mirror 113
For a peripheral speed V of 1 (constant irrespective of the same magnification and magnification), V /
It moves in the direction of arrow b at a speed of m (m; copy magnification).
At the same time, the reflection mirrors 114 and 115 move in the direction of the arrow b at a speed of V / 2 m, so that an image is read with the optical path length kept constant.

The LD 131 is a semiconductor laser (LD) for converting image data read by the CCD sensor 117 and processed by the image processing unit 12 into a laser beam, and exposing the photosensitive drum 121 to the laser beam. The laser light emitted from the LD 131 is transmitted to the polygon scanner 1 rotating at a high speed.
The light is reflected by the polygon mirror 135, is polarized by the toroidal lens 136 and the fθ lens 137, is reflected by the folding mirrors 138a, 138b, and 138c and is exposed on the photosensitive drum 121.

On the outer peripheral surface of the photosensitive drum 121, a developing device 122, a separating claw 123, a cleaning device 124 and the like are arranged. Further, a fixing roller upper 176, a fixing roller lower 177, and a discharge roller pair 178 are provided on the left side of the photosensitive drum 121 in the drawing.

An upper, middle, and lower cassette 151, 152, and 153 are loaded below the center of the copying machine body 10, respectively. A pickup roller 154, a feeding roller 155, and a separation roller 15 are respectively loaded in each cassette.
6 are arranged. In addition, the code | symbol "171,172,1"
Reference numeral 73 denotes a transport roller pair, and reference numeral 174 denotes a timing roller pair. In addition, the manual feed tray 161
Are provided so that they can be opened and closed freely.
2. A feed roller 163 and a separation roller 164 are provided.

A plurality of reflection sensors 102 are arranged in the optical system 11 to detect the size of a document set on the platen glass 111. Since the arrangement of the sensors and the mechanism for detecting the size are known technologies, detailed descriptions thereof will be omitted.

When a copy start key (not shown) is pressed by the operator, the sheets set in the upper, middle, and lower cassettes 151, 152, 153 based on the size of the original read by the reflection type sensor 102. Select the required paper from the bundle. Thereafter, only the pickup roller 154, the feed roller 155, and the separation roller 156 of the selected cassette are driven and rotated by a feed motor (not shown), and only the uppermost sheet of the set sheet bundle is conveyed downstream. Here, as a mechanism for separating a plurality of sheets into one sheet, a separation mechanism similar to a friction pad method using a conveyance roller 155 and a separation roller 156 is employed, but this is also a known technique. , And a detailed description thereof will be omitted.

The paper separated into one by the separation mechanism is
It is transported by a transport roller pair 171, 172, 173,
It enters the nip of the timing roller pair 174 that has stopped rotating. The transport roller pair 171, 172, 173 and the timing roller pair 174 are driven and transmitted from a feed motor (not shown) for driving and rotating the separation mechanism. The timing roller pair 174 corrects the skew of the leading end of the sheet,
In addition, a clutch (not shown) is provided on the drive transmission path to measure the timing of entering the image transfer section, so that rotation or stop can be switched.

Further, the conveying roller pairs 171, 172, 17
3 also has a clutch (not shown) on each roller shaft,
It is possible to rotate or stop the transport roller pairs 171, 172, 173 independently of each other and irrespective of the driving of a feeding motor (not shown).

A sensor 175 is disposed between the pair of conveying rollers 173 and the pair of timing rollers 174. The sensor 175 detects the leading edge of the sheet conveyed from the pair of conveying rollers 173, and after a predetermined time, the sensor 175 detects the leading edge of the sheet. Of the transport roller pairs 171 to 173, only the roller that presses the sheet is turned off by stopping the clutch (not shown).
At this time, the timing roller pair 174 is stopped by the action of a clutch (not shown), and the sheet
A loop is formed by being fed a little longer than the distance between the nip of the timing roller pair 174 and the nip of the timing roller pair 174, so that skew of the timing roller pair 174 can be corrected. The upstream conveying path 179 of the timing roller pair 174
Needless to say, the paper path is partially widened to form a paper loop.

On the other hand, the image data of the original is read by the optical system 11, passes through the image processing section 12 having a storage medium and capable of image inversion processing, and the photosensitive drum 121 rotated in the direction a by the P / H section 13. Is exposed to laser light. The photosensitive drum 121 is charged by the charging charger 125, and has a characteristic of removing the electric charge in a portion irradiated with the laser beam, and a toner having the same polarity as the electrostatic latent image adheres to the portion from which the electric charge has been removed. It is possible to make it. The timing at which the leading edge of the sheet reaches the photosensitive drum 121 is measured, and P /
The H unit 13 irradiates image data to the photosensitive drum 121 charged in advance by the charging charger 125. The developing device 122 having the toner attaches the toner to the portion of the photosensitive drum 121 irradiated with the laser beam, and
Then, the image is transferred onto the transfer paper surface by the transfer charger 126.

The transfer paper after the desired transfer is completed
3, the leading end is separated from the surface of the photosensitive drum 121, and at the same time, the sheet is separated without being wound around the photosensitive drum 121 by performing the AC discharge by the separating charger 127.

The transfer paper onto which the toner has been transferred is heated and pressed by the upper and lower fixing rollers 176 and 177, and is discharged out of the copying machine body 10 by a discharge roller pair 178.

A transporting section 18 for transporting to the switchback section 19 is provided upstream of the discharge roller pair 178. The transport unit 18 includes a switching claw 181 driven by a solenoid (not shown), transport rollers 182 and 183, and transport guides 184 and 185.

The switchback unit 19 includes a transport roller 191 that can be rotated forward and backward by a drive source (not shown).
Driven roller 1 which is arranged opposite thereto and is not driven
92, a pair of transport rollers 193 configured to be rotatable only in a direction for transporting the transfer paper downstream, and transport guides 194, 19
5 and the detection sensor 196.

The operator selects double-sided copying,
When the copy start key is pressed, the sheet is conveyed to the switchback unit 19 by switching the switching claws 181 after performing the above-described transfer processing. After a predetermined time from the detection of the leading edge of the transfer paper by the detection sensor 196, the conveyance roller 191 is rotated in the direction of arrow c, and the rear end of the paper conveyed by the conveyance roller 191 is detected by the detection sensor 196 for a predetermined time. After a lapse of time, after the trailing edge of the sheet has passed over the mylar 197 for preventing reverse feeding, the conveying roller 191 is rotated in a direction opposite to the direction c, and
Transport to The paper reversed by the switchback unit 19 is transported upstream of the timing roller pair 174 by the transport roller pairs 141 and 142, and the transfer process is performed again to perform the transfer process on both the front and back surfaces of the paper. ing.

<< Automatic Document Conveying Apparatus >> Next, the schematic structure and operation of the automatic document conveying apparatus will be described. FIG.
FIG. 2 is a schematic configuration diagram illustrating an internal structure of the automatic document feeder.

As shown in FIG. 3, an automatic document feeder (A
The DF) 20 includes a sheet feeding device 30 and further includes a registration roller pair 205, a transport belt unit 206, a reversing roller 207, a discharge roller pair 208, and a discharge tray 209.

The ADF 20 includes a transport belt unit 206
Are arranged on the copying machine main body 10 so as to face the platen glass 111, and a hinge fitting 210 provided on the back side in the figure.
Thereby, the surface of the platen glass 111 can be opened. For convenience of explanation, the platen glass 111 and the document reference plate 101 on the copying machine main body 10 side are also shown in FIG.

The original D as the paper to be fed is placed on the tray 301 of the paper feeding device 30 with the first page facing upward.
It is loaded and held on top. When the copy start key is pressed by the operator, the documents are separated and sent out one by one from the document stack stacked on the tray 301. The sent original is aligned at the leading end by a pair of registration rollers 205 and sent to a transport belt unit 206.

The transport belt 211 is a platen glass 11
1 is endlessly stretched between the drive roller 212 and the driven roller 213 so as to cover the entire surface. A large number of backup rollers 2 are provided inside the conveyor belt 211 to press the conveyor belt 211 against the platen glass 111.
14 is installed rotatably. Conveyor belt 211
Is rotated in the direction of arrow d, and the original is
The leading edge of the document is set to a reference position SP for starting exposure, which is a boundary between the platen 1 and the platen glass 111.

After a predetermined exposure is completed by the optical system 11, the sheet is discharged and stored in a discharge tray 209 by a reversing roller 207 and a discharge roller 208.

The reversing roller 207 is a pinch roller 215,
216, and a switching claw 217 for switching the paper path to reverse the original in the original double-side mode.

When the original double-sided mode is selected, the original supplied from the tray 301 is transferred to the transport belt unit 206.
Is set to the reference position SP, and the first surface is exposed. After the exposure is completed, the original is turned over by the reversing roller 207, set again at the reference position SP, and the second surface is exposed. After the exposure is completed, the sheet is turned upside down again by the reversing roller 207, and is discharged and stored in the discharge tray 209 by the reversing roller 207 and the discharge roller 208.

As described above, the ADF 20 is provided with the original single-sided copy operation and the original double-sided copy operation, is configured to be selectable by the operator on the operation panel (not shown), and operates when a plurality of originals are set. Performs the above-described document feeding operation sequentially, and when the number of copies is set by an operator, reads image data once for one document by the optical system 11 and performs a predetermined number of readings using a storage medium (not shown). It is a mechanism to transfer.

<< Sheet Feeder >> Next, the structure and operation of the sheet feeder according to the present invention will be described.

FIG. 4 is a plan view of the sheet feeding device according to the present invention. FIG. 5 is a side view of the sheet feeding device shown in FIG.
5 is a side view of the sheet feeding device shown in FIG. 4 as viewed from the direction of arrow P in FIG.

The paper feeding device 30 shown in FIGS. 4 to 6 separates and sends out originals from the original bundle 302 one by one.

In the first embodiment, as shown in the plan view of FIG.
4. The pressing plate 305, the pressing plate 306, and the support claws 307 are arranged so as to contact the corners of the leading edge of the document. The direction in which the leading end of the document is moved to the upstream side by the moving roller 304 is a predetermined angle smaller than 90 degrees with respect to the direction opposite to the sheet feeding direction (the direction of document conveyance by the conveyance roller 310). It was set to be deflected toward the center. In other words, the loop is formed by moving the corner of the leading end of the document in the conveying direction in a direction deflected toward the center of the document by a predetermined angle smaller than 90 degrees with respect to the direction opposite to the document feeding direction. There is an advantage that a stable loop can be formed regardless of the size of the document. Also, paper such as a normal manuscript has streaks, and the ease of loop formation varies depending on the direction of the streaks.
The streaks usually appear in the width direction or the longitudinal direction of the paper.
Therefore, if the predetermined angle smaller than 90 degrees is set to 45 degrees, it is possible to eliminate the influence of the streaks.

The tray 301 is formed on the upper surface of the center of the casing of the ADF 20 so that the bottom is substantially horizontal.
An original bundle 302 loaded thereon is held. The leading end regulating member 303 regulates the leading end of the document bundle 302 stacked and held on the tray 301, and has a flat surface with which the leading end of the document bundle 302 comes into contact. The operator abuts the original bundle 302 against the leading end regulating member 303 and
By placing the original on the document 1, the leading ends of the original can be aligned. The tray 301 has a fixed guide 313,
A movable guide 314 is provided which is movable in a direction perpendicular to the document feeding direction in accordance with the width of the document.

Further, the tray 301 is supported by the support claws 307.
The lower surface of the leading end of the upper document bundle 302 is supported. The support claw 307 is provided integrally with the lower end of the front end regulating member 303 so as to extend to the upstream side so that the front end and the lower surface of the original bundle 302 can be held at the same time without any gap. It has become. Support claw 30
7, as shown in the drawing, a substantially horizontal first surface 311 that comes into contact with the leading end of the document bundle 302 and a second surface 312 that is located on the opposite side and that has a tapered surface that decreases in the sheet feeding direction. Have. As a result, the leading end of the document is
Can be smoothly fed in the paper feeding direction along the second surface 312 side. Note that the support claw 307 and the tip regulation member 303 do not necessarily have to be integral. When the support claws 307 and the tip regulation member 303 are separate bodies, there is an effect that the number of the support claws 307 can be set freely.

The moving roller 304 has a rotating shaft and is constituted by a roller having a non-circular cross section perpendicular to the axis. The moving roller 304 is positioned upstream of the leading end regulating member 303 in the sheet feeding direction, and contacts the lowermost original of the original bundle 302 stacked and held on the tray 301 to move the leading end of the original upstream. It has a configuration that can be performed. The moving roller 304 is located on the upstream side in the sheet feeding direction of the leading end regulating member 303, and the bundle of originals 3 stacked and held on the tray 301.
In this configuration, the leading end of the original can be moved to the upstream side by contacting the lowermost original 02. Therefore, the lowermost document of the document bundle 302 is
4 causes the support claw 307 to be pulled out.

As shown in FIG. 7 (a side view of the sheet feeding device from the direction of arrow P in FIG. 4), in the sheet feeding device 30 according to the first embodiment, the support claws 307 are driven by a drive (not shown). It is movably supported by the device in the directions of arrows e to f in FIG. That is, the position of the support claw 307 is set to the first position moving in the e direction and the second position moving in the f direction. At the time of document feeding, the support claw 307 is moved in the direction of arrow e in the figure to be set at the first position indicated by the broken line in FIG. 7, and the lowermost document of the document bundle 302 is moved from the support claw 307 by the moving roller 304. Pull out and transport.
On the other hand, at the time of document setting, the support claw 307 is moved in the direction of arrow f in the figure and set at the second position indicated by the solid line in the figure, so that a document inserted in the direction of arrow in the figure can be easily inserted into the support claw 307. .

The tray 301 has moving rollers 30 on it.
4, the leading end of the document is moved to the upstream side, so that the document swells toward the moving roller 304 side to form an opening 316 for forming a loop. Here, the opening 316 is for providing a space where the document forms a loop. Thereby, a loop can be formed satisfactorily in the space without being disturbed.

The moving roller 304 has a rotating part 308 having a rotating shaft and a contact part 309 for contacting the original. The moving roller 304 is configured to rotate in a direction indicated by an arrow in FIG. 7 by rotation driving means such as a motor (not shown). The shape of the moving roller 304 is not limited to the illustrated one.

As the contact portion 309, various materials such as rubber, foamed resin, and sponge can be used so that the coefficient of friction between the original and the original has a relatively large value. The range in which the contact portion 309 of the moving roller 304 is formed can be appropriately set according to the size of the loop to be formed.

The pressing plate 305 is arranged above the moving roller 304 so as to press and separate the original bundle 302 toward the moving roller 304. The pressure contact plate 305 is configured to be able to apply or release a pressure contact force by a spring member or the like to the upper surface of the document bundle 302 at a predetermined timing.

On the upstream side of the pressure contact plate 305, there is provided a pressing plate 306 for preventing the original from moving to the upstream side. The pressing plate 306 moves the moving roller 304 to the original bundle 302.
When only the leading end of the original is moved to the upstream side by contacting the lowermost original, the original itself is prevented from shifting to the upstream side. The pressing plate 306 is used to hold the original bundle 3
02 is provided so as to be pressed from above in a direction substantially orthogonal to the sheet feeding direction, and similarly to the pressure contact plate 305, a pressing force by a spring member or the like is applied to or released from the upper surface of the document bundle 302 at a predetermined timing. It is configured to be able to. Note that, instead of the above-described pressing plate 306, a configuration in which a member that abuts on the upstream end surface of the document bundle 302 and regulates the movement of the document itself to the upstream side may be provided.

A feed roller 315 is provided at a substantially central portion of the leading end of the tray 301 in the feeding direction of the document, close to the lower surface of the document bundle 302. The leading end of the document extracted from the tray 301 is positioned between the lower surface of the document bundle 302 and the feeding roller 31.
5 is to enter the gap. Feed roller 31
The surface of 5 is processed with rubber, a resin material, or the like so as to have a predetermined frictional force with the document.

The original bundle 30 of the feed roller 315
A second pressing plate 317 is provided above the sheet bundle 2 so as to be able to apply or release a pressing force by a spring member or the like to the upper surface of the document bundle 302 at a predetermined timing. . The second pressing plate 317 presses the document bundle 302 against the feed roller 315 when the document is fed, so that one separated document is guided to the transport roller 310 without fail.

A transport roller 310 composed of a pair of rollers rotatable by a rotation driving means (not shown) rotates at a predetermined timing, and the original sent from the feed roller 315 is further fed to the transport roller 310 in the paper feed direction. The ADF 20 is transported toward the registration roller pair 205 of the ADF 20 disposed on the side.

The paper feeder 30 of the first embodiment is configured as described above, and its operation will be described below with reference to FIGS.
1 (both are side views of the sheet feeding device from the direction of arrow P in FIG. 4). The flexible member 318 shown in FIGS. 8 to 11 presses the loop of the sheet formed by the operation of the moving roller 304 in a direction to eliminate the loop with a force smaller than the loop forming force of the moving roller 304. Things. The reason why the pressing force is made smaller than the loop forming force is to avoid a situation in which a loop cannot be formed on the sheet. This flexible member 318 is
It is formed in the shape of a tongue so that it extends from the end of the bottom portion of the bottom portion 01 of the downstream portion in the sheet feeding direction to the space where the loop is formed. That is, the flexible member 318 is a cantilever, and the other end is fixed to the bottom of the tray so that the free end is located on the moving roller 304 side. Also,
The flexible member 318 has a flexible plate shape,
In the vicinity of the free end, an external force elastically bends a predetermined distance. By this elastic force, the flexible member 3
Reference numeral 18 is configured to be able to apply the above-described appropriate pressing force by contacting a swollen document by forming a loop. Moreover, as described above, since the free end of the flexible member 318 is on the moving roller 304 side, the elastic force can be reliably applied to the loop at a position that does not hinder the formation of the loop. As a material of the flexible member 318, for example, a metal leaf spring having a predetermined elasticity is used, but a resin plate or the like can also be used.

First, the original bundle 302 composed of a plurality of originals to be copied is placed on the sheet feeding device 30 such that the leading end of the original bundle 302 comes into contact with the leading end regulating member 303 and the first surface 311 of the supporting claw 307. It is placed on the tray 301. At this time, the support claw 307 is in the second position, that is, f in FIG.
Sheltered in the direction. The pressing plate 305 and the pressing plate 30
6. The second pressing plate 317 is separated from the document bundle 302 and retracted to a predetermined upper position.

When a copy start key (not shown) is pressed, the support claws 307 move in the direction e in FIG.
And the pressing plate 305 and the pressing plate 3
06, the second pressing plate 317 is moved downward by a driving means (not shown). In this manner, the original bundle 302 on the tray 301 is given a predetermined pressing force by the pressing plate 305 and the second pressing plate 317 and a predetermined pressing force by the pressing plate 306.

Next, the moving roller 304 is rotated by a predetermined angle in the direction of the arrow in the figure. At this time, a contact pressure is generated between the lowermost document of the document bundle 302 on the tray 301 and the moving roller 304 due to the pressing force of the pressing plate 305, so that the leading end of the document has a frictional force with the moving roller 304. As a result, the support claw 307 is pulled out from the first surface 311 side and moves to the upstream side. The pressing force of the pressing plate 306 has a function of preventing the document itself from shifting to the upstream side (FIG. 8).

When the document is further moved to the upstream side, a loop is formed in the space at the leading end of the document so as to protrude downward from the opening 316 (FIG. 9). 9, 10). Further, since a predetermined pressing force is applied to the upper surface of the document bundle 302 by the pressing plate 306, the document itself is prevented from moving upstream from the point where the pressing force is applied as described above. It is also possible to stably form a loop having a desired size.

The moving roller 304 further rotates in the direction of the arrow in the figure, and the document separates from the contact portion 309 of the moving roller 304 and is extended flat (FIG. 11). At this time, the pressing plate 3
Since the pressing force of the original 05 on the original bundle 302 is maintained, there is no gap above the support claws 307, that is, between the first surface 311 and the original bundle 302. Therefore, the leading end of the original is It is extracted below 307, that is, on the second surface 312 side.

At the same time as one document is extracted from the document bundle 302, a feed roller 315 positioned on the second surface 312 side is used.
Starts to rotate. The pressing plate 305 moves upward to release a predetermined pressing force on the document bundle 302. At this time, the tray 301 is pressed by the pressing force of the second pressing plate 317.
Since a contact pressure is generated between the lowermost document of the upper document bundle 302 and the feed roller 315, the leading end of the document is moved in the paper feed direction by the rotation of the feed roller 315, and Sent.

When the leading end of the document reaches the transport roller 315, the rotation of the moving roller 304 stops. Also, the second
The pressing plate 317 and the pressing plate 306 move upward, and the application of the predetermined pressing force and pressing force to the document bundle is released. Therefore, the document being conveyed is prevented from being rubbed by the contact pressure of the moving roller 304, and is nipped and conveyed by the conveying roller 315 toward the registration roller pair 205 of the ADF 20 which is arranged smoothly in the paper feeding direction. Is done.

By repeating this series of operations, the tray 301
Conveys all originals placed on top. Then, when the last document is conveyed, the rotation of the moving roller 304 stops, and the support claws 307 retreat in the f direction.

As described above, according to the first embodiment, the support pawl 307 is movably supported, and the first position at the time of document feeding and the second position at the time of document setting are set. Therefore, with the support claw 307 set at the first position, the lowermost document bundle 302 is separated and fed one by one while forming a loop, while the support claw 307 is set at the second position. Documents can be set on the tray 301 in this state. Therefore, the leading edge of the document is reliably guided into the support claw 307 without performing a troublesome operation such as pushing down the tray 301 or the document bundle 302, and a feeding failure such as a multi-sheet feeding or an oblique feeding due to a broken ear at the time of setting is greatly reduced. Paper feeding reliability.
Also, with a compact and inexpensive configuration, it is possible to quickly and smoothly convey the documents separated from the document bundle 302 one by one in the paper feeding direction.

<< Paper Feeding Device According to Another Embodiment >> FIG.
FIG. 5 is a side view of the sheet feeding device according to the second embodiment as viewed from the direction of arrow P in FIG.

In the sheet feeding device 30 shown in FIG. 12, the same components as those in the first embodiment are denoted by the same reference numerals, and the detailed description is omitted. The feature of the second embodiment is that, unlike the first embodiment, both the moving roller 304 and the support claws 307 move. That is, the moving roller 304 and the supporting claw 307 are supported by a driving device (not shown) so as to be simultaneously movable in the directions of arrows e to f in the drawing. As the positions of the moving roller 304 and the support claw 307, a first position where both are moving in the e direction and a second position where both are moving in the f direction are set. At the time of paper feeding, the moving roller 304 and the support claw 307 are moved in the direction of arrow e in the figure to move the first
And the lowermost sheet of the sheet bundle 2 is pulled out from the support claw 307 by the moving roller 304. On the other hand, at the time of sheet setting, the moving roller 304 and the support claw 307 are moved in the direction of arrow f in the figure to be set at the second position shown by the solid line in the figure, and the sheet inserted in the direction of the arrow in the figure is
7 easy to put. The operation of the sheet feeding device 30 according to the second embodiment is the same as that of the first embodiment except that the moving roller 304 moves together with the support claws 307, and thus the description thereof is omitted.

FIG. 13 is a plan view of a sheet feeding device according to the third embodiment. In the sheet feeding device 30 shown in FIG. 13, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The features of the third embodiment are different from the first embodiment,
Pressing plate 305, tip regulating member 303, moving roller 30
4. Pressing plate 306, support claw 307, second pressing plate 317
Is located in the direction perpendicular to the document feeding direction, that is, near the leading end in the width direction. If you do this,
The arrangement of the driving means and the driving force transmitting means (not shown) becomes easy, and the entire sheet feeding device can be made compact. Further, a configuration in which a pair of movable guides 314 are provided on the tray 301 and the document is placed on the tray 301 so that the center of the document in the width direction of the document coincides with the tray 301 regardless of the width of the document may be adopted. Become.

It should be noted that the present invention is not limited to only the above-described embodiments, and various modifications can be made by those skilled in the art within the technical concept of the present invention.

For example, in the above embodiment, the tray 3
Although the “lower feeder” feeder that feeds the lowermost originals one by one from the original stack 302 on the document stack 01 has been described, the present invention is not limited to this. It is needless to say that the present invention can also be applied to an "upside-out" sheet feeding device that feeds the top document one by one.

[0076]

According to the present invention, at the time of setting the paper, at least the claw means is at the position retracted from the insertion path of the set paper, so that the leading end of the paper does not have to perform a troublesome operation such as pushing down the tray or the bundle of paper. The feeding is reliably guided into the claw means, and feeding failures such as a large number of feedings and an oblique feeding due to a broken edge at the time of setting are greatly reduced, and the reliability of paper passing can be improved.

[Brief description of the drawings]

FIG. 1 is a side view of a copying apparatus to which an automatic document feeder using a sheet feeder according to the present invention is attached.

FIG. 2 is a schematic configuration diagram showing an internal structure of a copying machine main body.

FIG. 3 is a schematic configuration diagram showing an internal structure of the automatic document feeder.

FIG. 4 is a plan view of the sheet feeding device according to the present invention.

FIG. 5 is a side view of the sheet feeding device according to the present invention.

FIG. 6 is a side view of the sheet feeding device according to the present invention as viewed from the direction of arrow P in FIG. 4;

FIG. 7 is a diagram illustrating an operation of the sheet feeding device according to the present invention.

FIG. 8 is a diagram illustrating the operation of the sheet feeding device according to the present invention.

FIG. 9 is a diagram illustrating the operation of the sheet feeding device continued from FIG. 8;

FIG. 10 is a diagram illustrating the operation of the sheet feeding device continued from FIG. 9;

FIG. 11 is a diagram illustrating the operation of the sheet feeding device following FIG. 10;

FIG. 12 is a diagram illustrating an operation of the sheet feeding device according to the second embodiment.

FIG. 13 is a plan view of a sheet feeding device according to a third embodiment.

[Explanation of symbols]

 10: Copier body 20: Automatic document feeder (ADF) 30: Paper feeder 301: Tray 302: Document bundle 303: Tip regulating member 304: Moving roller 305: Press plate 306: Press plate 307: Supporting claw 310: Transport Roller 315: Feeding roller 317: Second pressing plate

Claims (4)

[Claims] In a paper feeder for separating and feeding sheets one by one from a sheet bundle, a tray for stacking and holding the sheet bundle, leading end regulating means for regulating a leading end portion of the sheet bundle, and feeding of the leading end regulating means. A moving unit that is positioned on the upstream side in the paper direction, contacts the paper, moves the leading end of the paper to the upstream side in the paper feeding direction, and forms a paper loop, and a pressing unit that presses the paper bundle toward the moving unit. Claw means for supporting the moving means side of the leading end of the sheet bundle, wherein the claw means has a first position located at the time of sheet feeding and a second position located at the time of sheet setting. 2. The sheet feeding device according to claim 1, wherein the second position is a position retracted from the first position. 2. The image forming apparatus according to claim 1, wherein the moving unit has a first position located at the time of sheet feeding and a second position retracted from the first position and located at the time of sheet setting. 2. The sheet feeding device according to claim 1, wherein the sheet feeding device retreats from a first position to the second position. 3. The apparatus according to claim 1, wherein said moving means is constituted by a roller having a rotating shaft and a contact portion which comes into contact with a sheet, and a cross section of said roller perpendicular to the rotating shaft is non-circular. Paper feeder. 4. A paper feeder for separating and feeding sheets one by one from a sheet bundle, a tray for stacking and holding the sheet bundle, a leading end regulating means for regulating a leading end of the sheet bundle, and a supply of the leading end regulating means. A moving unit that is positioned upstream in the sheet direction and below the sheet bundle, contacts a sheet at the bottom of the sheet bundle and moves the leading end of the sheet to the upstream side in the sheet feeding direction to form a sheet loop; Pressing means for pressing downward from the side, and claw means for supporting the lower side of the leading end of the sheet bundle,
The claw means has a first position located at the time of sheet feeding and a second position located at the time of sheet setting, wherein the second position is a position retracted from the first position. Paper feeder.