JPH0748045A - Paper feeding device - Google Patents

Abstract

PURPOSE:To surely supply each separated paper sheet by forming a feeding-out roller to an eccentric peripheral surface, successively increasing the press contact force at a nipping part between the sending-out roller and a separation roller, and adjusting the load of a torque limitter. CONSTITUTION:A paper feeding device is equipped with a feeding-out roller 14 having a half-moon-shaped section, separation roller 15 for separating the feeding-out roller 14, and a torque limitter 20 engaged with the separation roller 15. The feeding-out roller 14 is formed to an eccentric peripheral surface, and the press contact force of a nipping part between both the rollers 14 and 15 is successively increased. In this stage where a sheet S1 intrudes into the nipping part, the state where no sheet S1 can be sent by the load of the torque limitter 20 is set. Further, preparatory separation is carried out when at least three sheets S1 intrude into the nipping part, and at most two sheets S1 are nipped in the nipping part. Further, the press contact force is increased in the next stage, and the sheet S1 in contact with the separation roller 15 is transferred reversely, and the sheet S1 in contact with the sending-out roller 14 is sent in the normal direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device provided in a recording device such as an electrophotographic copying machine, and more particularly to a paper feeding device for feeding transfer materials of various materials.

[0002]

2. Description of the Related Art A transfer sheet used for image recording in an electrophotographic copying machine or the like is usually housed in a detachable sheet feeding cassette and automatically fed to the copying machine main body.

Sheets stacked and accommodated in a paper feed cassette are separated from the upper layer one by one by the action of a well-known half-moon roller and separation claws and fed to an image forming section.

On the other hand, in the case of manually feeding a large number of stacks, since the above-mentioned separating claw cannot be used because cardboard such as OHP sheets and postcards cannot be passed, a circular drive roller is pressed against this and the torque limiter is used. A method of separating and feeding each sheet one by one by the action of the connected separation roller,
For example, a method in which a circular driving roller and a friction pad that is pressed against the circular driving roller separate the sheets one by one to feed the sheets is used.

[0005]

However, the sorting device using the circular driving roller and the sorting roller or the friction pad keeps the sheet sandwiched even after the sorting.

As a means for releasing the sheet from the sandwiched state immediately after it is conveyed, it is well known that the half-moon roller is used, but it is used as a separating roller using a separating claw. This has been proposed in the publication of JP-A-55-165837.

Further, the proposal in Japanese Patent Publication No. 58-2146 is intended only to increase the conveying force for thin paper sheets by forming a half-moon shape, and the roller itself cannot be expected to have a separating action. Absent.

For this reason, since the resist feed roller downstream of the drive roller requires a large conveying force, it is not possible to use a simple resist feed roller due to the operation of the shutter, resulting in a high cost. ing.

The problems of the conventional sheet feeding device having the half-moon roller and the separating roller are listed below.

(1) The sheet separating section by the conventional separating roller (retard roller, reverse roller) system with a torque limiter does not necessarily separate into three sheets when three or more sheets enter there, and the sheet is double-fed. May occur.

(2) When the sheet enters the separating roller that is rotating in the reverse direction, there is a problem that the sheet tip is broken and the sheet is injured.

(3) In the paper feeding apparatus having the paper feeding roller pair and the resist shutter on the downstream side of the feeding of the nip portion of the half-moon roller and the separating roller, the sheet is lightly held by the paper feeding roller pair and the resist shutter is used. To contact the
The sheet conveying force of the pair of sheet feeding rollers should be kept low, and the conveying load of the nip portion by the half-moon roller should be made less than the sheet conveying force. For this reason, the separating part uses a separating claw. However, the method using a separating claw has a drawback that a narrow cardboard such as a postcard cannot be passed.

(4) As a pair of paper feed rollers, generally, an elastic rubber roller is used on the driving side and a hard resin roller is used on the driven side. Then, after the sheet is fed by the pair of sheet feeding rollers, the sheet is abutted against a sheet leading end stop member (registration shutter) for timing the sheet, and the sheet is sandwiched by the pair of feeding rollers and slip-rotated. Was there. In this method, if the frictional force of the pair of paper feed rollers is too large, a loop is formed while the sheet is in contact with the registration shutter, and the position of the leading edge of the re-fed sheet during image formation becomes inaccurate. Further, if the frictional force of the pair of paper feed rollers is too small, the sheet cannot be reliably fed. In particular, the elastic rubber roller of the pair of paper feed rollers is greatly affected by environmental temperature and humidity changes, and if this is used on the drive side, stable feeding cannot be performed.

Further, when the elastic rubber roller on the driving side slips between the sheets, the sheet surface is soiled.

As a result of solving these problems and improving the present invention, the present invention can be used with a pair of resist type paper feed rollers utilizing a simple shutter, and is fed from a half-moon roller and a separating roller with a torque limiter. The paper device is configured to ensure the separation and feeding of sheets, stabilizes the separation of small size thick paper such as postcards, and is not affected by the environmental temperature and humidity, and the sheet feeding device does not stain the sheets. It is intended to be provided.

[0016]

The above-mentioned object is to provide a delivery roller having a half-moon-shaped cross section in which a part of the circumference is cut off,
In a sheet feeding device provided with a separating roller that comes into contact with and separates from the sending roller and a torque limiter that engages with the separating roller, the circumferential surface of the sending roller is driven and rotated to be pressed against the circumferential surface of the separating roller. Then, the sheet is fed to the nip position between the delivery roller and the sorting roller after the sorting roller is rotated in the driven direction.

Further, in the paper feeding device of the present invention, the peripheral surface of the delivery roller is formed as an eccentric surface, and pressure changing means for sequentially increasing the pressure contact force of the nip portion between the delivery roller and the separating roller is provided. In the first step in which the sheet enters the nip portion, it is set such that one sheet cannot be fed due to the load of the torque limiter, and when three or more sheets enter the nip portion, preparatory separation is performed to perform the nip portion. Nip two sheets or less, and in the second step thereafter, increase the pressure contact force to feed one sheet in contact with the separating roller in reverse and feed one sheet in contact with the delivery roller in order. It is characterized by being fed.

Further, the above-mentioned object is to provide a delivery roller having a half-moon-shaped cross section with a part of the circumference cut away, a separating roller which comes into contact with and separates from the delivery roller, and a torque limiter which engages with the separating roller. In a sheet feeding device including a sheet feeding roller pair provided on a downstream side of a nip portion between a sheet feeding roller and a separating roller in a sheet feeding direction, a cutout surface of the sheet feeding roller when the sheet is fed by the sheet feeding roller pair. Is arranged so as to face the separation roller at a distance, and is arranged at a position where it does not come into contact with the sheet.

Further, in the sheet feeding device of the present invention, when the sheet is fed by the pair of feeding rollers, the upper part of the peripheral surface of the separating roller is restricted to a position where it does not come into contact with the sheet fed by the pair of feeding rollers. The sheet feeding force of the pair of sheet feeding rollers is larger than the sheet friction load in the separated state between the feeding roller and the separating roller.

Furthermore, in the paper feeding device of the present invention, the lower drive roller of the paper feed roller pair is made of a hard resin member, and the upper driven roller is made of a rubber member having elasticity. It is a thing.

Furthermore, the sheet feeding device of the present invention is provided with a reversing conveyance path that feeds out one sheet from a sheet bundle stored in a sheet feeding cassette disposed below the image forming section and bends the sheet. In the sheet feeding device that conveys to the image forming unit by the pair of conveying rollers, among the pair of conveying rollers, a drive roller that is connected to a drive source and is driven to rotate is formed of a hard resin member, and is pressed against the drive roller. The driven roller that is driven to rotate is formed of a rubber member having elasticity, and the drive roller is provided inside the curved reverse conveyance path.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet feeding device of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of the main part of an image forming apparatus provided with a manual paper feed tray and a paper feed cassette. In the figure, 1 is a photosensitive drum (image forming body), 2 is a charger, 3
Is a developing device, 4 is a transfer device, 5 is a separator, and 6 is a peeling claw.

The paper feeding apparatus according to the present invention is a paper feeding cassette, a multi-sheet manual paper feeding tray, an intermediate stacker capable of recording on both sides, a paper feeding tray of an automatic document feeder, and the like. Although it is applicable to a paper stacker, the manual paper feeding device 10 and the cassette paper feeding device 30 will be described below as an example.

The sheets S1 are stacked and placed on the sheet placing tray (feeding stacker) 11 and the sheet lifting plate (pushing member) 12 of the manual sheet feeding device 10. The rotation shaft 12A of the sheet lifting plate 12 is a fixed frame body of the manual paper feeding device 10.
It is supported by both side plate portions 13 and one of its shaft ends is connected to a drive source and can be swung by a paper feed signal. A half-moon roller 14 is rotatably supported on the upper portions of both side plates of the fixed frame body 13. The half-moon roller 14 has a half-moon-shaped cross section in which a part of the circumference is cut out, and a rubber ring having a predetermined friction coefficient is wound and pressure-contacted to the outer peripheral surface thereof. A toothed gear for driving rotation is attached to one shaft end of the half-moon roller 14, which is driven and rotated by a driving source and a position gear train (not shown), and by a solenoid operated by a sheet feeding signal. Stops one rotation and rotates intermittently.

At the lower left portion of both side plates of the fixed frame body 13 in the figure, a bearing portion 15A is provided which allows a support plate 16 for supporting a reverse roller (scrolling roller) 15 to swing. A spring 17 is hooked around the right end of the support plate 16 in the figure and near the right end of the fixed frame body 13, and the swingable support plate 16 is attached to the bearing portion 15.
It is biased counterclockwise around A. Above support plate
A rising tip portion 16A near the right end of 16 comes into contact with a cushion member 18 adhered to the back surface side of the fixed frame body 13 to stop the swinging and the upper limit position of the reverse roller 15 supported by the support plate 16. Are regulated.

The reverse roller 15 is a torque limiter.
Equipped with 20 coaxially, it is configured to rotate when it receives a rotational force above a specified value, and to stand still or reverse at a rotational force below that.

As described above, the fixed frame 13 holds the sheet lifting plate 12, the half-moon roller 14 and the bearings of the support plate 16 on both side plate portions, and the holding surface 16B near the tip of the sheet S. A lower guide surface is formed by an abutting stop surface 16C at the leading end of the sheet S1 and a guide surface 16D toward the downstream side of feeding of the sheet S.

When the half-moon roller 14 is not driven, the plane portion 14A of the half-moon roller 14 comes to a lower side as shown in the figure to be in a stopped state, and is separated from the reverse roller 15. An upper guide plate 19 is fixed above the reverse roller 15. The sheet guide surface 19A on the lower side of the upper guide plate 19 has a shape that does not hinder the rotation of the half-moon roller 14 and is positioned below the flat portion 14A, and the upper guide of the sheet S to be fed. Forming a surface.

Sheet loading tray 11 and sheet lifting plate 12
When the bundle of sheets S1 placed on the upper surface starts to swing by the paper feed signal, the sheet lifting plate 12 and the half-moon roller 14 are driven and rotated to sandwich the sheet, and the sheet starts to be fed. The sheet is fed to a pressure contact position with the reverse roller 15, and at this nip position, only the uppermost one sheet S1 is separated and fed, and the sheet guide surface of the upper guide plate 19 is fed.
It passes through the gap between 19A and the guide surface 16D of the support plate 16, and is fed to the second feeding roller pair (registration roller pair) 21 on the downstream side.

The second feeding roller pair 21 is a lower driving roller.
21A and the driven roller 21B above are lightly pressed and held. The drive roller 21A is made of a hard resin member, and the driven roller 21B is made of a rubber member having soft elasticity.

Immediately after the downstream side of the second feeding roller pair 21, there is provided a registration sensor 22 composed of a swingable actuator 22A and a photo interrupter 22B, and detects the leading edge of the sheet S1 passing therethrough. To do.

A registration shutter 23, which is swingable about the same axis as the driven roller 21B, is disposed further downstream of the registration sensor 22. The registration shutter 23 is driven and oscillated after a lapse of a predetermined time by a timer after the leading edge of the sheet S1 fed by the second feeding roller pair 21 is detected by the registration sensor 22 and the leading edge of the sheet S1 is swung. The stopper portion 23A having the rising shape at the upper end portion rises to block the sheet feeding path. The leading end of the sheet S1 hits the stopper portion 23A to form a slight loop, and the second feeding roller pair 21 is in the slip drive state. The resist shutter 23 is connected to a solenoid (not shown), but when the solenoid is OFF, the stopper portion 23A is projected to the sheet feeding surface by the urging of a tension spring (not shown).

A third paper feed roller pair 24 is disposed downstream of the registration shutter 23.

When the sheet S1 stops, the second pair of feeding rollers 21 slips with respect to the sheet S1.
When the solenoid is turned on according to the timing of transferring the image on the photoconductor drum 1 and the resist shutter 23 is retracted from the feeding path by suction of the plunger, the second feeding roller pair 21 feeds again. Sheet S to start
1 is fed to the transfer area. During this time, the photosensitive drum 1
The toner image is formed on the upper part of the toner by the charging by the charging device 2, the image exposure of the original by the scanning optical system L, and the development by the developing device 3 successively.

Then, the second feeding roller pair 21 feeds at the above-mentioned timing, and the sheet S1 is conveyed to the transfer area by the transfer device 4 at the peripheral speed of the photoconductor drum 1 and the photoconductor drum 1 is conveyed. The toner image formed on the sheet 1 is the sheet S
1 is transferred. Sheet S1 on which the toner image is transferred
Is separated from the peripheral surface of the photosensitive drum 1 by the separator 5 and the peeling claw 6, and is accommodated in a paper discharge tray outside the machine or an intermediate tray inside the machine via a conveyance means, a fixing device, and a paper discharge means (not shown). .

On the other hand, below the image forming section, a sheet feeding cassette 30 is arranged so as to be detachable. Upper paper cassette
Reference numeral 30 includes a housing 31, a movable intermediate plate 32, and a separation claw 33. The sheets S2 stacked and stored in the housing 31 of the sheet feeding cassette 30 are moved to the illustrated position by the urging force of the movable intermediate plate 32 in the counterclockwise direction in the figure with both corners thereof being pressed by the separating claws 33. Is held.

Reference numeral 34 denotes a half-moon roller for sending out the sheet S2, which makes one revolution in the counterclockwise direction to contact the sheet S2 with its circumferential surface, and the uppermost one sheet S2.
Is separated into a loop by the separation claw 33 and is sent out to the second paper feed roller pair 35 on the downstream side.

The second paper feed roller pair 35 is arranged in the middle of the U-turn section of the reversing conveyance path, and the driving roller 35A is in contact with the inside of the U-turn path and the driven roller 35B is in contact with the outside of the U-turn path. ing. The drive roller 35A is made of a hard resin member, and the driven roller 35B is made of a flexible rubber member.

FIG. 2 is a sectional view of an essential part for explaining the sheet separating and feeding process by the half-moon roller 14 and the reverse roller 15 according to the present invention. FIG. 2A shows the initial state, in which the reverse roller 15 rotates the sheet S in the reverse direction with respect to the sheet feeding direction.
It works to return the tip of 1. FIG. 2B shows the state of sheet feeding by the sheet lifting plate 12 and the rotation start of the half-moon roller 14, and FIGS. 2C and 2D show the half-moon roller.
14 shows the separated feeding state by 14 and the reverse roller 15.

When the number of sheets S1 sent out by the rotating half-moon roller 14 and the sheet lifting plate 12 pressed against the half-moon roller 14 by the pressing force P1 is one, the half-moon roller 14 and the sheet S1 at the nip position are Since a torque exceeding the specified value is transmitted to the reverse roller 15 by the frictional force of the reverse roller 15, the reverse roller 15 is also driven to rotate to feed the sheet S1. However, when the number of sheets S1 fed into the nip position is two or more, the torque of the torque limiter 20 increases the sheet S1.
Therefore, the reverse roller 15 overcomes the frictional force between the two, and the reverse roller 15 stands still or reverses to prevent the sheet S1 other than the sheet S1 from being fed.

The sheet S after finishing the judgment of the sheet S1
1 is nipped and fed by the second pair of feeding rollers 21. Thereafter, as shown in FIG. 2D, the half-moon roller 14 is stopped at the rotation angle where the flat portion 14A is located at the lower portion and the pressure contact with the reverse roller 15 is released. Above flat part 14A
Is above the sheet guide surface 19A of the upper guide plate 19 and does not hinder the feeding of the sheet S1.

As described above, the sheet S1 nipped and fed by the second feeding roller pair 21 which is constantly rotating in this manner has the stopper portion 23A at the leading edge after the sheet leading edge is detected by the registration sensor 22 as described above. The tip position is regulated by contacting the standing resist shutter 23. afterwards,
Subsequently, the third paper feed roller pair 24 feeds the image to the image transfer area.

In the state where the leading edge of the sheet S1 is in contact with the registration shutter 23, the second feeding roller pair 21 is lightly pressed against the intermediate portion of the sheet S1 and slip-rotates with the sheet S1. Even when the trailing edge of the sheet S1 does not pass the position where the half-moon roller 14 and the reverse roller 15 face each other, the sheet S1 is kept in the state in which the pressure between the rollers 14 and 15 is released. The sheet S1 slidably contacts the smooth upper guide plate 19, but does not slidably contact the friction surface of the half-moon roller 14, so that the second feeding roller pair 21 is not subjected to an extra load and has a small driving force. Surely seat S
It is possible to deliver 1.

FIG. 3 is a cross-sectional view of the half-moon roller 14 according to the present invention.

The half-moon roller 14 for manual feeding has a drive shaft portion 14
B, a half-moon roller portion 14C, and an elastic member 14D having a thickness of about 2 mm in the shape of a wide rubber band covering the peripheral surface of the half-moon roller portion 14C. The outer diameter of the half-moon roller 14 including the elastic member 14D is the half-moon roller when the sheet S1 reaches the vicinity of the nip portion between the half-moon roller 14 and the reverse roller 15 from the position A where the sheet S1 is first pressed. The minimum radius is 22 mm up to the position B on the circumference of 14 (in the range of about 58 ° in the drawing), and it is in light contact with the reverse roller 15, but the radius is gradually increased until the uppermost sheet S1 is separated and fed. (Range of about 76 ° in the figure) Maximum radius at position C
With a thickness of 24 mm, it has a peripheral surface shape that increases the nip pressure.

FIG. 4 is a sheet separation feeding characteristic diagram showing the relationship between the torque value of the torque limiter 20 and the pressing load P2 of the half-moon roller 14 and the reverse roller 15.

In the figure, in the area (A) on the left side, the pressing load P2 is too large and the half-moon roller 14 has two or more sheets S.
1 will be sent, and one sheet S at the nip
This is a range where only 1 can be separated and fed. On the other hand, the region (C) on the right side of the drawing is a range in which the pressing load P2 is too small, and the frictional force on the peripheral surface of the half-moon roller 14 is small, so that one sheet S1 cannot be fed. The area (B) at the center of the drawing is the sheet 2
This is the range in which sheets can be separated and separated into one sheet. The two boundary areas with diagonal lines on both sides are areas where separation and feeding are uncertain.

However, in the conventional separating means, the pressing load P2 is set so as to enter the area (B) shown in FIG. 4, but when three or more sheets are fed into the nip portion, it is not always necessary. I didn't judge it to one.

Therefore, in the present invention, by combining the half-moon roller 14 and the reverse roller 15 having the torque limiter 20, the half-moon roller 14 and the reverse roller 15 are brought into contact with each other before the sheet plunges in the separating portion. To reverse the reverse roller 15. Next, as shown in FIG.
By changing the radius of the half-moon roller 14, first, in the initial stage of rotation, the sheet S1 is pressed under the condition of the region (C) of the light pressing load P2 to separate the sheet S1. 1 in this area (C)
The sheet S1 cannot be sent reliably, so the half-moon roller
The pressing load P2 is gradually increased by the peripheral surface of which the radius of 14 is gradually increased, and gradually shifts to the region (B), and stable judgment is performed in this region (B). That is, during the transition from the area (C) to the area (B), preliminary separation is performed, and then two or less sheets are reliably separated and fed in the area (B).

By doing so, even when three or more sheets enter the separating section, only one sheet can be reliably separated and fed. Further, since the leading edge of the sheet that enters the separating section is gripped by the light pressing load P2, the defect that the leading edge of the sheet is folded by the width of the reverse roller 15 does not occur.

Next, the driving roller 21 of the second feeding roller pair 21
A and the driven roller 21B will be described.

In the paper feeding apparatus, in which the leading edge of the sheet conveyed by the second feeding roller pair 21 is stopped by the registration shutter 23 and the slip conveyance is performed by the second feeding roller pair 21, If the frictional force of the feeding roller pair 21 is too large, the sheet forms a loop near the registration shutter 23, and if the frictional force is too small, the sheet cannot be conveyed. In particular, if the second feeding roller pair 21 is a rubber roller, the rubber roller is greatly affected by changes in the surrounding environment, and stable conveyance cannot be performed. Further, if the rubber roller slips, the surface of the sheet pressed against the rubber roller is soiled. Since the sheet conveying roller shown in the sheet conveying device of Japanese Patent Application Laid-Open No. 58-224948 is a rubber-loaded roller mixed with resin, a roller mark is attached to the sheet surface when slipping.

In the second feeding roller pair 21 of the present invention, the driving roller 21A on the lower side of the conveying path is made of a hard resin roller, and the upper driven roller 21B which is pressed against the driving roller 21B is made of an elastic rubber roller. Stable transportation is possible without being affected by environmental changes such as humidity. Moreover, even if the sheet pressed against the drive roller 21A slips, the back surface of the sheet is not soiled because the roller 21A is made of hard resin.

Table 1 shows changes in the sheet conveying force depending on the environment of temperature and humidity.

[0056]

[Table 1]

As shown in Table 1, the drive roller 21A was made of a hard resin polypropylene (PP), and the driven roller 21B was made of an elastic rubber ethylene propylene rubber (EPDM). With this combination, there is little change in the pressing load at a temperature of 10 ° C to 30 ° C and a humidity of 10% to 80%, which proves that the stability of roller conveyance is good for stabilizing registration. In particular, even at high temperature and high humidity, it is excellent in stability, and is a main cause of producing good registration even if the "stiffness" of the sheet is weak, even though the loop is easily formed.

Further, when the cassette is fed, the drive roller 35A made of hard resin is arranged inside the curved passage in the middle of the U-turn-shaped reversing conveyance path, and the driven roller 35B made of elastic resin is arranged outside the curved path. When a sheet is jammed in the reversing path, the outer driven roller 35B is separated from the outer guide plate 36 to open the conveyance path and the sheet S is opened.
When taking out the sheet 2, the sheet S2 wound around the hard resin peripheral surface of the drive roller 35A can be easily slid and taken out.

[0059]

As described above, the paper feeding device of the present invention has the following excellent effects.

(1) It is possible to stably separate and feed three or more sheets fed to the separating / feeding section by the feeding roller and the separating roller with the torque limiter, and finely adjust the pressing load. Is also unnecessary.

(2) The leading edge of the sheet does not break during the above-described separate feeding.

(3) It is possible to stably separate and feed narrow paper such as postcards.

(4) The sheet feeding stability is not impaired even when the temperature and humidity of the second feeding roller pair changes, and the durability is excellent.

(5) The slip conveyance by the second pair of feeding rollers and the resist shutter can be reliably and stably carried out, and the timing feeding of the sheet is stable.

(6) The back surface of the sheet is not soiled by the second feeding roller that rotates in a slip manner with respect to the sheet.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an image forming apparatus including a manual paper feed tray and a paper feed cassette according to the present invention.

FIG. 2 is a sectional view of an essential part for explaining a sheet separating / feeding process by the paper feeding device according to the present invention.

FIG. 3 is a sectional view of a half-moon roller according to the present invention.

FIG. 4 is a characteristic diagram showing a relationship between a torque value in a sheet separating portion and a pressing load applied by a half-moon roller.

[Explanation of symbols]

 10 Manual Paper Feeding Device 11 Sheet Loading Tray (Paper Feeding Stacker) 12 Sheet Lifting Plate (Pushing Member) 13 Fixed Frame Body 14 Half Moon Roller (Feeding Roller) 15 Reverse Roller (Split Roller) 16 Support Plate 17 Spring 19 Upper Guide Plate (paper feed guide plate) 20 Torque limiter 21 Second feeding roller pair (registration roller pair) 21A Driving roller 21B Followed roller 22 Registration sensor 23 Registration shutter 24 Third feeding roller pair 30 Cassette paper feeding device 31 Housing 32 Movable Middle Plate 33 Separation Claw 34 Half Moon Roller 35 Second Paper Feed Roller Pair 35A Drive Roller 35B Driven Roller S1, S2 Sheet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Susumu Tashiro Konica Co., Ltd. 2970 Ishikawacho, Hachioji City, Tokyo

Claims (7)

[Claims] 1. A paper feed provided with a delivery roller having a half-moon-shaped cross section in which a part of a circumference is cut out, a separating roller contacting with and separating from the delivering roller, and a torque limiter engaging with the separating roller. In the apparatus, the peripheral surface of the delivery roller is driven to rotate, presses against the peripheral surface of the separation roller, and the separation roller is driven to rotate forward, and then the sheet is fed to the nip position between the delivery roller and the distribution roller. A paper feeding device characterized by the above. 2. A paper feed provided with a delivery roller having a half-moon-shaped cross section in which a part of the circumference is cut out, a separating roller contacting and separating from the delivering roller, and a torque limiter engaging with the separating roller. In the apparatus, a peripheral surface of the delivery roller is formed as an eccentric peripheral surface, pressure change means for sequentially increasing a pressure contact force of a nip portion between the delivery roller and the separating roller is provided, and a sheet enters the nip portion. In the step of (1), it is set that one sheet cannot be fed due to the load of the torque limiter, and when three or more sheets enter the nip portion, preparatory separation is performed and two or less sheets are nipped in the nip portion. In the second step after that, the contact pressure is increased to feed one sheet in contact with the separating roller in reverse and feed one sheet in contact with the delivery roller in order. The paper feeding device characterized in that. 3. A delivery roller having a half-moon-shaped cross section in which a part of the circumference is cut out, a separation roller that comes into contact with and separates from the delivery roller, a torque limiter that engages with the distribution roller, and the delivery roller. In a sheet feeding device provided with a pair of sheet feeding rollers provided on the downstream side of the separating roller in the sheet feeding direction, when the sheet is fed by the pair of sheet feeding rollers, the cutout surface of the sheet feeding roller is provided with A sheet feeding device, characterized in that the sheet is arranged so as to face the roller separately and not come into contact with the sheet. 4. A delivery roller having a half-moon-shaped cross section in which a part of the circumference is cut out, a separating roller that comes into contact with and separates from the delivery roller, a torque limiter that engages with the separating roller, and the delivery roller. In a sheet feeding device provided with a pair of sheet feeding rollers provided on the downstream side of the separating roller in the feeding direction of the nip portion, when the sheet is fed by the pair of sheet feeding rollers, the peripheral surface of the separating roller is set to the sheet. A paper feeding device characterized by being regulated in a position where it does not come into contact with the paper. 5. A delivery roller having a half-moon-shaped cross section in which a part of the circumference is cut out, a separation roller that comes into contact with and separates from the delivery roller, a torque limiter that engages with the distribution roller, and the delivery roller. In a paper feeding device provided with a paper feeding roller pair provided on the downstream side in the feeding direction of a separating roller and a nip portion, in the paper feeding roller pair, the driving roller is made of a hard resin member and the driven roller is elastic. A sheet feeding device formed of a rubber member having a sheet. 6. The sheet feeding device according to claim 1, wherein the sheet feeding device is a multi-sheet manual feeding device. 7. An image forming apparatus according to claim 1, wherein one sheet is sent out from a sheet bundle accommodated in a sheet feeding cassette disposed below the image forming unit, and the reversing conveying path for curving the sheet and a pair of conveying rollers form the image. In the sheet feeding device for transporting the sheet to a sheet, a drive roller of the transport roller pair that is connected to a drive source and is driven to rotate is formed of a hard resin member, and a driven roller that is driven to rotate by being pressed against the drive roller is made elastic. A sheet feeding device, which is formed of a rubber member having the driving roller and is provided inside the curving reverse conveying path.