JPH1045271A - Sheet feeding device, and image forming device having the sheet feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the contamination of edge in a separated sheet by alternately arranging a feeding means to a separating means, and providing an elastic member deformed by the stiffness of a sheet on the side contacting the sheet of the separating means. SOLUTION: A feed roller 11 and a separating pad 12 constitute a switch back route-side separating part. The separating pad 12 opposed to semicircular feed roller 9 and feed roller 11 rotated counterclockwise has an elastic member 150 easily elastically deformable by the rigidity of a sheet and an urethane rubber sheet-like elastic layer 151 fixed to the circumferential surface thereof, and it is arranged so as to alternately overlap the feed roller 11. Although the overlap quantity is differed depending on the frictional coefficient on the circumferential surface of the feed roller 11 or the separating pad 12 or the separating pressure, it is generally 0.2-0.5mm, and to realize a lighter pressure, 0mm is also included herein.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeder applicable to an image forming apparatus such as a copying machine and an LBP, and an image forming apparatus provided with the sheet feeder. TECHNICAL FIELD The present invention relates to a sheet feeding device capable of separating and feeding a sheet without causing the toner or ink adhered to another sheet, and an image forming apparatus including the sheet feeding device.

[0002]

2. Description of the Related Art Conventionally, a sheet feeding apparatus has been applied to an automatic document feeder which places an original (sheet) on an image reading section of an image forming apparatus such as a copying machine and automatically feeds the original. A plurality of documents stacked on the mounting table are separated and fed one by one from a separation unit.

FIG. 23 is a vertical sectional front view showing an example of this type of separation unit. The retractable shutter 203, which strikes the sheet P on the tray 201, is
From the sheet feeding direction (arrow 21).
4) In order to feed the plurality of sheets P on the tray 201 one by one in order from the bottom sheet, a weight bun 204 pressing the pickup roller 202 and a half-moon-shaped pickup roller 202 rotating counterclockwise are used. , And the separation paper feed roller 206 and the separation belt 208
As shown in the plan view of FIG. 24, the separation belt 208 alternately arranged with the separation feeding roller 206 is wound around the separation drive pulley 207 and the separation driven pulley 209 as shown in the plan view of FIG. The separation belt 208 rotates the separation drive pulley 207 fixed to the separation belt drive shaft 211, which is driven by a drive motor (not shown) by a drive transmission means (not shown) such as a drive gear, so that the separation belt 208 turns the sheet P into a sheet. It moves in the opposite direction to the feeding direction 214 to prevent the second and subsequent sheets from entering.
The separation driven pulley 209 can freely rotate with respect to the separation driven shaft 210, and when the separation belt 208 is driven, the separation driven pulley 209 rotates (follows). Reference numeral 205 denotes a regulating plate that guides the sheet outside the area of the separation belt 208.

The outer circumference of the paper feed roller 206 is formed of a rubber material having a higher friction coefficient than the separation belt 208.
Further, since the peripheral speed is slightly higher than that of the separation belt 208, only the lowermost sheet can be fed while the second and subsequent sheets of the sheet bundle are blocked by the separation belt 208. Note that this feeding force is proportional to the amount of overlap 212 between the separation belt 208 and the separation paper feed roller 206. However, if the amount of overlap is too large, the sheet becomes wavy between the separation paper supply roller 206 and the separation belt 208. Then, the paper feeding load increases and the paper feeding becomes defective. On the other hand, if the overlap amount is too small, the second and subsequent sheets cannot be blocked, resulting in double feeding.
It is about 5 mm.

Further, as shown in FIG.
A plurality of separation belts 208 and separation paper feed rollers 206 are arranged almost symmetrically with respect to the sheet center 213 in order to respond to the sheet thickness, and a separation pair (separation (separation) in which the interval between the separation belt 208 and the separation paper supply rollers 206 is reduced in the thrust direction. Belt 2
08-2, separation paper feed rollers 206-3). (There are various combinations of the number of separation belts, separation paper feed rollers, and separation pairs, but these are cited as examples of conventional technology.)

[0006]

However, in the above-mentioned prior art, as shown in FIG. 25, when a sheet P to be fed is a document on which toner or ink output from a copying machine or LBP is fixed. Moves the bottom sheet P ₁ to the arrow 2
When feeding in the direction of 14, the nip pressure (separation pressure) strongly concentrates on the back surface (lower surface in the figure) or the end surface of the _second document P2 blocked by the separation belt 208 in the separation nip area 215. it allows for the surface toner 216 fixed (upper surface in the figure) is attached to move with friction with the lowermost sheet P _1, there is a risk that occurs scumming (edge stain).

Accordingly, an object of the present invention is to provide a separating means for separating sheets one by one by providing an elastic member so that the separating means does not concentrate a strong separating pressure, and a light and uniform separating pressure can be obtained. An object of the present invention is to provide a sheet feeding device capable of preventing edge contamination of a sheet and an image forming apparatus provided with the sheet feeding device.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has been made in consideration of the above circumstances, and includes sheet loading means for loading sheets, delivery means for delivering the loaded sheets from the sheet loading means, and delivery means. A sheet feeding device configured by: a separating unit that separates the sheets sent out by the unit one by one; and a feeding unit that feeds the separated sheets in cooperation with the separating unit from the separating unit. ,
The feeding unit is disposed alternately with respect to the separating unit in a direction intersecting the sheet feeding direction, and the separating unit is provided on a side in contact with the sheet.
The sheet feeding device has an elastic member that is deformed by the rigidity of the sheet.

The elastic member preferably has an elastic layer on the surface of the elastic member, the elastic layer being in contact with the sheet.

Further, the overlap between the contact surface of the separating means with the sheet and the contact surface of the feeding means with the sheet may be more than 0 mm and 0.5 mm or less.

Preferably, the elastic member is a sponge, and the elastic layer is rubber.

The coefficient of friction of the feeding means is preferably larger than the coefficient of friction of the elastic layer.

Preferably, the sponge is a urethane foam sponge, and the rubber is a urethane rubber.

Further, it is preferable that the feeding means is a feeding roller.

Further, the feeding means may be a feeding belt.

Further, it is preferable that the separating means has a contact member which comes into contact with the outer peripheral surface of the feeding means.

Further, a retard roller cooperating with the feeding means may be provided.

Also, a sheet stacking means for stacking sheets, a sending means for sending out the stacked sheets from the sheet stacking means, and a separating means for separating and feeding the sheets sent by the sending means one by one. And a separating unit that includes a feeding unit that drives the sheet in a feeding direction and a separating unit that prevents double feeding of the sheet. The separating unit is elastically deformable. The sheet feeding device is characterized by being alternately arranged in a non-contact manner with the feeding means.

Any one of the above-described sheet feeding apparatuses, image reading means for reading an image of a sheet fed by the sheet feeding apparatus, image forming means for forming an image based on the read image, An image forming apparatus comprising:

An image reading means for reading an image on a sheet, an image forming means for forming an image based on the read image, and a sheet material for forming an image in the image forming means are fed to the image forming means. An image forming apparatus comprising any one of the sheet feeding devices.

[Operation] In the above construction, the sheets stacked on the sheet stacking means are sent out from the sheet stacking means by the feeding means, and the sheets are separated one by one in cooperation with the separating means and the feeding means. Feed. The feeding means,
The separation unit is disposed alternately with respect to the separation unit in a direction intersecting with the sheet feeding direction, and the separation unit includes an elastic member on a side in contact with the sheet, whereby the separation is performed. Since the means is deformed by the rigidity of the sheet, a uniform separating pressure can be formed with a light pressure to prevent edge contamination of the sheet.

The elastic layer on the surface of the elastic member is in contact with the sheet.

Further, the overlap between the contact surface of the separating means with the sheet and the contact surface of the feeding means with the sheet is more than 0 mm and not more than 0.5 mm. , The overlap amount decreases due to the seat stiffness.

Further, since the elastic member is a sponge and the elastic layer is a rubber, the elastic deformation is excellent.

Since the coefficient of friction of the feeding means is larger than the coefficient of friction of the elastic layer, the separated sheet is reliably fed.

Also, since the sponge is a urethane foam sponge and the rubber is a urethane rubber, a uniform load can be obtained and the residual strain is small.

Further, the feeding roller serving as the feeding means rotates to feed the sheet.

Further, the feeding belt serving as the feeding means rotates to feed the sheet.

Then, the contact member of the separating means comes into contact with the outer peripheral surface of the feeding means to separate and separate the sheet.
Feed.

Further, the provision of the retard roller cooperating with the feeding means further ensures the separation of the sheet.

Then, the sheets stacked on the sheet stacking means are sent out from the sheet stacking means by the feeding means, and the separating means and the feeding means constituting the separating section cooperate to separate the sheets one by one. Feed. The feeding means,
Since the separating means is arranged alternately with respect to the separating means in a direction intersecting the sheet feeding direction, and the separating means is elastically deformable, the separating means is deformed by the rigidity of the sheet. In addition, it is possible to form a uniform separation pressure with a light pressure to prevent edge contamination of the sheet.

Further, the image reading means reads the image of the sheet fed by the above-mentioned sheet feeding apparatus, and the image forming means forms an image based on the read image.

Further, the sheet material is fed to the image forming means for forming an image based on the image read by the image reading means, so that the image is formed in the image forming apparatus.

[0034]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 2 shows an example of an image forming apparatus main body to which a sheet feeding apparatus (hereinafter referred to as "automatic original feeding apparatus") 2 according to the present invention can be applied. An image forming apparatus (hereinafter referred to as “copier main body”) 900 includes a platen glass 3 as a document reading unit, a light source (reading unit) 907, a lens system 908, a paper feeding unit 909, and an image forming unit (hereinafter “image”). 902). Documents P are fed one by one to the platen glass 3 by the automatic document feeder 2.

The paper feeding section 909 has cassettes 910 and 911 which accommodate sheets (hereinafter, referred to as “sheet material”) S and are detachable from the apparatus main body 900 and a deck 913 arranged on a pedestal 912. The image forming unit 902 includes a developing device 91 including a cylindrical photosensitive drum 914.
5, a transfer charger 916, a separation charger 917, a cleaner 918, a primary charger 919, and the like. On the downstream side of the image forming unit 902, a transport device 920,
A fixing device 904, a discharge roller 905, and the like are provided. The discharged sheet material S is classified as necessary by a sheet classification device 922 connected to the copying machine main body 900. Reference numeral 930 indicates a control device (CPU) of the copier main body 900.

Next, the operation of the image forming apparatus will be described.

When a sheet feed signal is output from a control device 930 provided on the apparatus main body 900, the cassette 91 is output.
The sheet material S is fed from the deck 0, 911 or the deck 913. On the other hand, light reflected from a light source 907 applied to a sheet (hereinafter, referred to as “document”) P placed on the platen glass 3 is reflected by a photosensitive drum 914 via an optical system 908.
Is irradiated. The photosensitive drum 914 is charged in advance by a primary charger 919, and is irradiated with light to form an electrostatic latent image, and then a developing device 915 forms a toner image.

The sheet material S fed from the paper feeding unit 909
The skew is corrected by the registration rollers 901, and the skew is sent to the image forming unit 902 at a further adjusted timing. In the image forming unit 902, the toner image on the photosensitive drum 914 is transferred to the sheet material S sent by the transfer charger 916, and the transferred sheet material S is opposite in polarity to the transfer charger 916 by the separation charger 917. And is separated from the photosensitive drum 914. Then, the separated sheet material S is transported to the fixing device 904 by the transport device 920, and the unfixed transfer image is permanently fixed to the sheet material S by the fixing device 904. The sheet material S on which the image is fixed is discharged from the apparatus main body 900 by the discharge roller 905. In this manner, the sheet material S fed from the sheet feeding unit 909
Is formed and discharged.

Next, the sheet feeder (automatic original feeder 2) according to the present invention will be described. FIG. 1 is a vertical sectional front view of the automatic document feeder 2. In the figure,
On the platen glass 3 of the copying machine main body 900, a forward / reversely rotatable transport belt (endless belt) 20 wound around a driving roller 17 and a driven roller 19 and guided by a roller 21 is provided. A plurality of originals P are placed on the original placing table 5, and are aligned in such a manner that the width direction is regulated by a pair of width regulating plates 7. The recycle lever 10 placed on the original P indicates a member for distinguishing between the original P that has not been fed and the fed original P that is discharged onto the original placing table 5 after feeding. Reference numeral 6 denotes a shutter (moving means) that receives and aligns the leading end of the document P, and retreats below the document table 5 during paper feeding. Reference numeral 9 denotes a half-moon-shaped feeding means (hereinafter, referred to as a "feeding roller").
The document P is rotated at the time of paper feeding and the document P is sent out from the lowermost side of the document P.

On the downstream side of the feed roller 9, a feeding means (hereinafter referred to as "feed roller") rotating in the document feeding direction.
11 and a separation unit including separation means (hereinafter referred to as a “separation pad”) 12 for preventing the entry of a document above the lowermost sheet, and one sheet of the document P sent out by the feed roller 9 is provided. Separately and transport. Further on the downstream side, a pair of registration rollers 13 and 15 composed of a reversing roller (a driving roller) 13 and a driven roller 15 in contact therewith.
And feeds the document P onto the platen glass 3 at a predetermined timing. The document P conveyed onto the lipletn glass 3 by the rotation of the conveyance belt 20 and stopped at a predetermined position is fixedly read by manipulating the light source 907 in the direction of the arrow.

The first transport path 1 is formed by the transport path including the separation units 11 and 12 and the pair of registration rollers 13 and 15.
6 are constituted. The first transport path 16, the transport belt 20, the discharge path 26, and the like constitute a switchback path TS for transporting the document P to the reading position by switchback and discharging.

After completion of the fixed reading, the original P
By the reverse rotation of 0, the sheet is conveyed to the flapper 25 while being guided by the rollers 22 and 23 via the conveying path outside the reversing roller 13. The flapper 25 reverses the document P when reading both sides of the document P and guides the document P to the platen glass 3. In the case of single-side reading, the flapper 25 guides the document P to the discharge roller pair 29 via the discharge path 26. Reference numeral 27 denotes a sensor for detecting the document P passing through the discharge path 26. The document P discharged by the discharge roller pair 29 is placed on a document P that has not been fed on the document table 5 and is separated by the recycle lever 10 to be distinguished.

The original placing table 5 is rotatable about the support shaft 4 to the inclined position shown in FIG. 1 and the horizontal position shown in FIG. In position
The document P is conveyed to the platen glass 3 on the first conveyance path 16 as described above, and at the position shown in FIG. 3, the document P is transferred from the rear end side of the document P to the platen glass 3 via the second conveyance path 45. It is designed to be transported. The light source 9
Reference numeral 07 moves to a position indicated by a solid line in FIG. 3 in accordance with switching between the flow reading and the fixed reading described later.

The second transport path 45, the transport belt 20
The discharge path 26 and the like constitute a closed path path TC that transports the document P to a reading position in a closed loop and discharges it. A document transport unit T that transports the document P to the reading position and discharges the document P by the switchback path TS, the transport belt 20, and the closed path TC.
S, TC, and 20 are configured. Reference numeral 77 denotes a document transport unit T that transports the document P sent by the delivery roller 36.
S, TC, and a supply unit for supplying to TC and 20 are shown.

Members similar to those described above are also provided on the rear end side of the document table 5, respectively. 37 is a guide plate, 36 is a half-moon-shaped feeding roller, and 39 is a document P feeding roller 36. Reference numeral 40 denotes a conveying roller that rotates in the document feeding direction, and 41 denotes a separation pad that prevents entry of a document equal to or more than the lowermost sheet.

On the downstream side of the separation section of the CP (closed path side) comprising the feeding roller 40 and the separation pad 41, the platen glass 3 on which the separated document P is set as the reading position
A second transport path 45 for transporting to the second transport path is provided. The second transport path 45 includes a transport roller pair 43, a registration sensor 48, a registration roller pair 46, a feed roller pair 4
7, respectively.

A moving guide for guiding the document P to the platen glass 3 or guiding the document P on the platen glass 3 is provided between the upper roller of the feed roller pair 47 and the second roller 19 of the transport belt 20. A member 50 is provided.
Reference numeral 51 denotes a manual feed tray for manually feeding the original P into the automatic document feeder 2; 52, a manual feed roller;
Reference numeral 49 denotes a guide plate for a manual document.

Next, the operation of the shutter 6 and the document table 5 when feeding the document P will be described.

4 to 6, a frame 31 and a support member 32 integral with the frame 31 are provided on both sides of the document table 5.
Are fixed, and the support member 32 is rotatable about the support shaft 4. The bent piece 3la provided on the frame 31 is pushed down by a driving pin 35a provided at a free end of a driving member (elevating means) 35 and descends. The driving member 35 is connected to the frame member 30.
It is fixed to both ends of a connecting shaft 33 provided in (FIG. 1), and is rotated by a driving source such as a motor. The drive member 35 and the drive source constitute an elevation drive device that moves the document table 5 up and down. The reference numeral 32b shown in FIG.
A hole through which the feed roller 9 extends upward is shown.

When the original P is fed from the rear end side (flow reading is performed in order to execute high-speed reading), the driving pin 35 is rotated to drive the driving pin 35a.
Presses the bent piece 3la of the frame 31. As a result, the document table 5 is moved from the inclined state of FIG.
It is rotated to the horizontal state of (c).

In FIG. 4, a support shaft 5 integral with a shutter 6 is shown.
5 is a support portion 63a integral with the block 63 (see FIG. 6).
Is mounted to be rotatable. Numeral 60 denotes a solenoid for driving the shutter 6, and its operating member 60a
The other end of the connecting member 61 pivotally supported at one end is provided with a pin 5
9 is fixed. The pin 59 is engaged with a long hole provided at a free end of the arm 57.
It is rotatable about the support shaft 57a.

A lower end of a driven member 56 having a free end fixed to the support shaft 55 is opposed to the pin 59.
The shutter 6 is urged in a clockwise direction in FIG. 4, that is, a direction in which the shutter 6 extends from the document table 5 by a tension spring 62 having both ends locked by the shutter 6 and the connecting member 61.

When the document P on the document table 5 is transported along the first transport path 16 (to make a plurality of copies,
4A, the shutter 6 functions as a normal shutter, and the amount of protrusion from the document table 5 is small as shown in FIG. When a feed start signal from the control device 930 (FIG. 2) is supplied to the solenoid 60 and the solenoid 60 is operated, the arm 57 is moved to the position shown in FIG.
Is rotated clockwise. As a result, the driven member 56 is pressed by the pin 59 and rotates counterclockwise as shown in FIG. At the same time, when the shutter 6 integrated with the arm 57 rotates in the same direction, the shutter 6 is retracted from the upper surface of the document table 5 (FIG. 4B). In this state, several sheets of the document P are conveyed to the separation units 11 and 12 by the rotation of the feed roller 9.

5 and 6, a block 63 supporting the shutter 6 is movably supported by a guide shaft 65. Reference numeral 32a denotes a guide piece which engages with and guides the protrusions 6a at both ends of the shutter 6 when the shutter 6 returns to the original position shown in the figure. In the state of FIG. Thus, the projection 6a is in a state of being pressed against the guide piece 32a.

Reference numeral 66 denotes a pulse motor (batch transport motor 6) for moving the shutter 6 along the upper surface of the document table 5.
6), the output gear 6 being fixed to the output shaft.
6a meshes with the pulley gear 67. Pulley gear 6
7 and a plurality of pulleys 69a, 69b, 6
A belt 70 is wound around 9 c, and a part thereof is connected to the block 63. As a result, the motor 66 rotates according to the length of the document P, and the shutter 6
Moves in the longitudinal direction (front-back direction) of the document table 5.

The original P is transferred from the rear end to the second transport path 45.
When the document is conveyed to the side, while the shutter 6 is held at the position shown in FIG. 4A, the document table 5 is lowered to the horizontal state as described above (FIG. 4C). When the guide piece 32a of the support member 32 integrated with the document table 5 rotates in the downward direction, the protrusion 6a of the shutter 6 pressed against the guide piece 32a follows the same direction (clockwise in FIG. 4). ).

As a result, the shutter 6 is moved from the document table 5
4C, the amount of protrusion of the shutter 6 is increased as shown in FIG. 4C. In this state, the shutter 6 is driven by the motor 66 and moved to the second feed roller 36 side, so that the document P is conveyed in a bundle, and the second feed roller 36, the second separation unit 40, 41 allows the paper to be fed to the second transport path 45 (see FIG. 5).

As described above, when the shutter 6 functions as the bundle transporting means, by increasing the amount of protrusion of the shutter 6, the end of the original P placed on the original placing table 5 (the leading end) is curled. Even if there is, the end is engaged with the shutter 6 and the bundle P can be stably conveyed. Documents P fed by the second feed roller 36 and separated one by one by the separation units 40 and 41 are conveyed onto the platen glass 3 as a reading unit via the second conveyance path 45. Furthermore, the manuscript P
Is read by the light source 907 stopped at a predetermined position indicated by a broken line while being conveyed by the conveyance belt 20,
The document is discharged onto the document table 5 via the discharge path 26.

In FIG. 1, when the original P is read in a stream, the light source 907 as the reading means is moved to a predetermined position indicated by a broken line. At a position above the light source 907, both end portions of the conveyor belt 20 are pressed against the lip platen glass 3 by a pair of pressing members 110. As a result, even if the side edge of the transport belt 20 has a wavy shape due to the temporal change due to the use of the transport belt 20, the side edge of the document P is lifted up, thereby preventing a reading failure.

FIG. 7 shows the shutter 6 and the weight 39 for pressing and partitioning the originals P bundled by the shutter 6. 7A, the document P placed on the document placing table 5 is regulated by moving the pair of width regulating plates 7 by manual operation. The document P is aligned in the width direction (Y direction) by the reciprocating movement of the jog member 117 provided on one width regulating plate 7 in the width direction.

The weight 39 has a base rotatably mounted on the support shaft, and is capable of moving up and down so as to press the unfeeded original P ₀ on the original mounting table 5 against the feed roller 36. When, it has been fixed to the base support shaft 39a, to regulate as shown in (b) FIG tip end of the original P ₁ of the first round to be discharged is fed onto the document P ₀ from the document table 5 And a partition member 39B.

FIG. 8 shows the operation panel 120 of the copier main body 900 and the automatic document feeder 2. 1
Reference numeral 25 denotes a start button, reference numeral 121 denotes a stop key 121 for stopping the feeding of the document P, and reference numeral 22 denotes a flow reading adjustment key 122.

FIG. 9 shows a drive system of the automatic document feeder 2.

Reference numeral 95 denotes a recycle motor for driving a recycle lever 10 for separating the fed document P from the fed document P. 101 denotes a weight S for moving the pressing member 8 up and down.
L and 92 are separation motors; 92a and 92b are separation motor encoders (hereinafter the same) composed of a rotating disk and a U-shaped sensor for detecting the number of rotations of the rotation disk; A clutch transmitting to the unit 40; a belt motor 91 for driving the transport belt 20;
1a and 91b are separation motor encoders, 93 is a reversing motor for driving the reversing roller 13, 93a and 93b are reversing motor encoders, and 98a and 98b are registration roller pairs.
3 and 15, driven roller encoders; 99, a discharge motor driving the discharge roller pair 29; 99a, 99b, a discharge motor encoder; 66, a bundle transport motor for moving the shutter 6; The tray lifting motor to be moved, 105 is a partition member SL for moving the partition member 39B up and down, 106 is a weight SL for moving the pressing member 39A up and down, 107a and 107b are transport roller pair encoders, and 109 is a CP register for driving the registration roller pair 46. The motors 109a and 109b indicate CP registration motor encoders.

FIG. 10 is a block diagram relating to the control of the automatic document feeder 2. The sensors (arranged in the main part of the automatic document feeder 2 shown in FIG. 1) connected to the control device (CPU) 100 of the automatic document feeder 2 are connected. In FIG. 1, reference numeral 71 denotes an empty sensor for detecting the presence or absence of a document P on the document table 5, reference numeral 72 denotes a separation sensor, reference numeral 73 denotes a pre-registration sensor for detecting a registered document P, and reference numeral 74 denotes a pre-registration sensor.
Is a post-registration sensor, 75 is a reversing sensor for detecting the document P passing through the reversing roller 13, 42 is a separation sensor on the CP side, 48 is a registration sensor, and 79 is a paper feed sensor.

Referring to FIG. 11, the operation in the flow reading mode when the document P is flow read will be described.

A tray down process is performed to move the document tray 2 to the lower limit position (draftseq1), and a document bundle transport process is performed to move the document bundle P to the right (dr).
aftseq2), and thereafter, a jog (X jog) in the bundle conveying direction of the original bundle P is performed, and then a jog in the width direction (Y jog) is sequentially performed (draftseq3). Perform separation processing (d
raftseq4).

Thereafter, the clockwise sheet feeding process (draftseq) is performed so that the original is placed one stream upstream from the image to be read.
5) is performed, and upon receiving a document exchange (start of flow reading) trigger from the main body 900, reading of an image is performed on the main body 100.
In order to perform this operation while the optical system 133 is fixed at a predetermined position, a document flow reading process is performed (draftseq6), and the document is moved to a position of a fixed image destination at a predetermined speed. afterwards,
The document is discharged onto the document tray 2 by performing clockwise discharge processing (draftseq7).

Also, during clockwise separation processing to be described later (dra
If the final document determination in ftseq4) is negative, the right side separation process for the next document is activated during the right-side paper feed process (draftseq5) in the next step, thereby enabling continuous document feeding. Further, clockwise discharge processing (draftse)
q7) After the end, if the original is the last original, the tray up process (draftseq8) is performed to return the original tray 2 to the initial position. In addition, the original flow reading process (draft)
seq6) When a plurality of images are to be formed after the end, the main body 100 returns the light source 907 to the home position on the weekly image destination side, and then performs fixed reading by moving the light source 907 a desired number of times. It is possible.

Next, a driving mechanism of the width regulating plate 7 will be described with reference to FIG.

A pair of width regulating plates 7 are mounted on both sides of the original placing table 5 so as to be movable in the width direction (arrows 86 and 87). A document size detection sensor (document size recognizing means) 80 composed of a rotary volume is provided at the center of the document table 5.
The pinion 81 is fixed to the 0 output shaft 80a.
At a position on the opposite side of the pinion 81, a pair of racks 82 mesh with each other, and the bases thereof are fixed to the width regulating plates 7, respectively. Thus, when the width regulating plate 7 is manually moved so that the width regulating plates 7 abut on both sides of the placed document P, the rotary volume 80 rotates according to the width size of the document P. Then, the size of the document P is automatically detected.

FIG. 13 shows the relationship between the size of the original P placed on the original placing table 5 and the rotation angle of the rotary volume 80. The size of the document P placed on the document P is detected. A side jog (Y jog) SL is provided inside one of the width regulating plates 7,
One end of a pair of links 115 is pivotally connected to the connecting lever 113 connected thereto. The above link 115
Are pivotally connected to the jog member 117, respectively.
As a result, when the side jog SL112 is turned on / off, the jog member 117 reciprocates in the width direction of the document table 5 and aligns the placed document P in the width direction.

Next, the structure and operation of the separation unit that separates and feeds a plurality of documents P stacked on the document table 5 one by one will be described.

FIG. 14 shows a feeding roller (feeding means) 11 and a separating pad (separating means) 12 which constitute a separating section on the switchback path side TS. An elastic member (hereinafter, referred to as a "sponge member") 150, which can be easily elastically deformed due to the rigidity of the sheet, is provided on the separation pad 12 facing the half-moon-shaped feed roller (feeding means) 9 and the feed roller 11 which rotates counterclockwise. And a urethane rubber sheet-like elastic layer (hereinafter referred to as “rubber layer surface”) 151 on the outer peripheral surface.
Are fixed, and are alternately overlapped with the feed roller 11 as shown in FIG.

The overlap amount varies depending on the friction coefficient of the outer peripheral surface of the feed roller and the separation pad 12 and the separation pressure, but is generally 0.2 to 0.5 mm. 0 mm is included for the purpose. The paper feed roller 11 has a higher coefficient of friction than the rubber layer surface 151 of the separation pad 12, and blocks sheets equal to or larger than the lowermost sheet by the separation pad 12 and feeds only the lowermost sheet. The sponge is a urethane foam sponge, and the foam air chamber (cell) is relatively uniform, so that a uniform load can be obtained with respect to the amount of compressed load and the residual strain is small.

The rubber layer 151 on the surface is made of a material to which ink, toner, pencil stains and the like of a sheet material separated by urethane rubber are unlikely to adhere. A sheet is adhered or welded to the sponge. Moreover, you may apply a liquid thing to a sponge. Further, in the case of feeding a sheet material to which the sheet material to be separated adheres, such as silicon oil, a silicon-based rubber having good compatibility with silicon oil may be used. The material of the surface of the rubber layer, urethane-based rubber, silicon-based rubber is described as a representative in the description of the present embodiment, but requires a certain level of friction coefficient or more to prevent paper, The material is not limited to the above rubber as long as it is a material that is hard to adhere to, such as durability and ink. Furthermore, although a rubber layer is described, other materials having the same effect (in terms of prevention) as rubber, such as seagull suede and felt, may be used. FIG. 16 shows the lowermost sheet P ₁ of the sheet bundle P.
It is a figure which separates and feeds. Next sheet P ₂ of the lowermost sheet P ₁ is blocked by the separation nip 153.

FIG. 17 shows the separation nip 1 viewed from the arrow 152.
It is an enlarged view of 53 parts. The bottom paper P ₁ is the sponge member 1
50, the sponge member 150 can be easily deformed, so that it is elastically deformed with respect to the initial state (two-dot chain line). The amount of deformation depends on the stiffness of the sheet and the amount of the sheet bundle entering, but the restoring force arrow 1 that is going to return to the original
Since 54 is small per unit area, and is a space due to non-contact with the feed roller 11 on the opposite side, it is possible to form a uniform separation pressure with light pressure. With the above structure, it as high separation pressure dirt toner or ink is fixed on the lowermost sheet P ₁ adheres transferred to the rear surface or the end surface of the next sheet P ₂ (the edge stain) occurs is concentrated In addition, reliable separation and feeding can be performed with light pressure.

FIG. 18 shows the separation sections 40 and 41 on the closed path path side TC composed of the second transport path 45, the transport belt 20 and the discharge path 26 (FIGS. 1 and 3). A half-moon-shaped delivery roller 36 that rotates clockwise similarly to the above-described separation unit on the switchback path side TS.
(Feeding means), feeding roller 40 (feeding means),
A sponge member 160 that can be easily elastically deformed and a urethane-based rubber sheet-like layer 161 are fixed to the outer peripheral surface of the separation pad 41 (separation means) facing the feed roller 40, and are alternately arranged to overlap. You. The separation pressure here is also light and uniform, as in the case of the TS-side separation section, so that reliable separation and feeding can be performed without edge contamination. <Second Embodiment> FIG. 19 is a cross-sectional view showing details of a separating portion according to a second embodiment.

As in the first embodiment, the half-moon-shaped feeding roller 9 rotating counterclockwise and the paper feeding belt 162
Roller 163 and the driven roller 16 for rotating the
4 winds the paper feed belt 162 and drives the roller pulley 163 in the direction of the arrow in the figure to rotate the paper feed belt 162 to feed the sheet. On the opposite side of the paper feed belt 162, a separation pad similar to that of the first embodiment, comprising a sponge member 150 that can be easily elastically deformed and a urethane-shaped rubber sheet-like layer 151 on the outer peripheral surface, alternately overlaps. Be placed.

Here, the separation nip 165 is formed in a wide range in the paper feeding direction by using the belt-shaped paper feeding belt 162 as the feeding means, so that the separation pressure can be further reduced to be uniform and the first embodiment. As in the case of the first embodiment, reliable separation and feeding can be performed without edge contamination. <Third Embodiment> FIG. 20 is a sectional view showing details of a separating portion according to a third embodiment.

As in the first embodiment, the separation pad for feeding out the sheet in the feeding direction by the semi-lunar-shaped feeding roller 9 and the feeding roller 11 rotating in the counterclockwise direction to prevent the second and subsequent sheets from entering. Reference numeral 12 denotes a sponge member 150 that can be easily elastically deformed, and a urethane-shaped rubber sheet-like layer 151 on the outer peripheral surface, and a fixed member that is alternately overlapped with the feed roller 11 is disposed. Outside, contact members (hereinafter referred to as "members")
165 is in contact with the paper feed roller 11 so as to press it.

FIG. 21 is a view as seen from the arrow 152.
The sponge member 150 alternately overlaps with the paper feed roller 11, and the member 165 is in contact with the paper feed roller 11. That is, the sponge member 150 serves to prevent the second and subsequent sheets from entering under light pressure such that edge contamination does not occur, and the nip portion between the sheet feeding roller 11 and the member 165 is formed by a known so-called Duplo system. Since the separation effect is exerted, reliable separation and feeding can be realized by the double effect, and edge contamination does not occur.

The member 165 is a Duplo pad and an elastic member (for example, a rubber material). However, since the entry of the second and subsequent sheets is prevented by the sponge material 150, the member 1
In the case of 65, a rigid body (for example, resin) having a low friction coefficient enough to obtain a feeding force may be used, or a contact or pressure contact with the paper feed roller 11 may be used. <Fourth Embodiment> FIG. 22 is a cross-sectional view showing details of a separating portion according to a fourth embodiment.

As in the first embodiment, a feed roller 9 and a paper feed roller 11, which rotate counterclockwise, and a separation pad 12 are arranged on the opposite side. The roller 166 is a retard roller, which is driven by a transmission means (not shown) from the paper feed roller 11 in a direction A (sheet return direction) through a torque limiter (not shown) in the drawing. Since the torque is larger, the motor normally follows and rotates in the B direction. When two or more sheets enter the nip between the roller 166 and the paper feed roller 11, torque is transmitted because the friction between the sheets is low, and the sheet rotates in the direction A to eject the second and subsequent sheets to prevent double feeding. .

Here, the pressure between the roller 166 and the paper feed roller 11 is made smaller than the pressure of the ordinary well-known retard system, thereby preventing edge contamination of the sheet. When the second sheet or more passes through the nip between the roller 166 and the paper feed roller 11, the separation pad 12 similar to that of the first embodiment is disposed, so that the second and subsequent sheets are prevented from entering. Can be. Edge contamination on the separation pad 12 does not occur because of light pressure. Here, the separation pad 12 is the retard roller 1
Although it is located downstream of 66, it is the same on the upstream side and is not limited to this.

The sheet feeder according to the present invention has been described with reference to the automatic document feeder 2 as an example. However, the present invention is not limited to this. 909, the sheet feeding apparatus according to the present invention can be applied. In this case, even when the back surface of the sheet (sheet material) on which the image has been once formed on one side is used for forming a new image, occurrence of edge contamination of the sheet can be prevented as in the case described above.

[0087]

As described above, according to the present invention, the feeding means is arranged alternately with respect to the separating means, and
By providing the separating means so as to be elastically deformable due to the rigidity of the sheet, the separating means forms a light pressure and a uniform separating pressure without concentrating a strong separating pressure. Can be prevented, and the quality of the sheet can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a first embodiment of a sheet feeding apparatus according to the present invention.

FIG. 2 is a vertical sectional side view showing an example of an image forming apparatus to which the sheet feeding apparatus can be applied.

FIG. 3 is a view for explaining the operation of the sheet feeding apparatus of FIG. 1;

4A and 4B are explanatory diagrams of the operation of the mounting table member of FIG. 1, wherein FIG. 4A is a side view of a shutter unit and a document mounting table when a document is fed from a switchback path, and FIG. FIG. 3C is a side view of the shutter unit and the document table when the document is fed from the closed path.

FIGS. 5A and 5B are explanatory views of the operation of the mounting table unit, wherein FIG. 5A is a side view of the shutter unit and the document mounting table when a document is conveyed from a switchback path, and FIG. 5C is a block diagram of FIG. FIG.

FIG. 6 is a plan view of a shutter unit and a driving unit of the sheet feeding device according to the present invention.

FIGS. 7A and 7B are diagrams of a document placing table and a weight portion of the sheet feeding apparatus according to the present invention, wherein FIG. 7A is a plan view thereof and FIG. 7B is a side view of FIG.

FIG. 8 is a plan view of an operation panel of the sheet feeding device according to the present invention.

FIG. 9 is a longitudinal sectional view showing a configuration of a drive system of the sheet feeding device according to the present invention.

FIG. 10 is a block diagram relating to control of a sheet feeding apparatus according to the present invention.

FIG. 11 is a flowchart of a flow reading mode of the sheet feeding apparatus according to the present invention.

FIG. 12 is a plan view of a width regulating plate of the sheet feeding device according to the present invention and a driving unit thereof.

FIG. 13 is a correlation diagram between a document size and a rotary volume of the sheet feeding apparatus according to the present invention.

FIG. 14 is a longitudinal sectional view illustrating an example of a separation unit of the sheet feeding apparatus according to the invention.

FIG. 15 is an arrow view illustrating an example of a separation unit of the sheet feeding apparatus according to the invention.

FIG. 16 is a diagram illustrating an example of a sheet state in a separation unit of the sheet feeding device according to the invention.

FIG. 17 is a detailed view illustrating a configuration of a separation unit of the sheet feeding device according to the invention.

FIG. 18 illustrates a separation unit (TC side) of the sheet feeding apparatus according to the invention.
FIG.

FIG. 19 is a longitudinal sectional view illustrating a configuration of a separation unit of the sheet feeding device according to the second embodiment.

FIG. 20 is a longitudinal sectional view illustrating a configuration of a separation unit of a sheet feeding device according to a third embodiment.

FIG. 21 is an arrow view showing a configuration of a separation unit of the sheet feeding device.

FIG. 22 is a longitudinal sectional view illustrating a configuration of a separation unit of a sheet feeding device according to a fourth embodiment.

FIG. 23 is a longitudinal sectional view showing a configuration of a separation unit of a conventional sheet feeding apparatus.

FIG. 24 is a plan view showing a configuration of a separation unit of the sheet feeding device.

FIG. 25 is a detailed view showing a configuration of a separation unit of the sheet feeding device.

[Explanation of symbols]

 2 Sheet feeding device (automatic document feeding device) 3 Document reading means (platen glass) 5 Document mounting table 6 Moving means (shutter) 7 Width regulating plate 9 Feeding means (feeding roller) 11 Separating section (feeding means) (Feeding roller) 12 Separation part (separation means) (separation pad) 36 Delivery means (delivery roller) 40 Separation part (feeding means) (feeding roller) 41 Separation part (separation means) (separation pad) 150 Elastic member ( Sponge member) 151 elastic layer (rubber layer surface) 160 sponge member 161 elastic layer (rubber layer surface) 165 contact member (member) 166 retard roller 900 image forming apparatus (copier main body) 902 image forming means (image forming section) 907 Document reading means (light source) 908 Document reading means (lens system) P sheet (document) S sheet (sheet material)

Claims (13)

[Claims] 1. A sheet stacking means for stacking sheets, a sending means for sending the stacked sheets from the sheet stacking means, a separating means for separating the sheets sent by the sending means one by one, and the separation Feeding means for feeding the separated sheet in cooperation with the means from the separating means;
In the sheet feeding device configured by the above, the feeding unit is disposed alternately with respect to the separating unit in a direction intersecting a direction in which the sheet is fed, and the separating unit is provided with the sheet and A sheet feeding device comprising an elastic member that is deformed by the rigidity of a sheet on a contact side. 2. The sheet feeding device according to claim 1, wherein the elastic member has an elastic layer in contact with a sheet on a surface of the elastic member. 3. An overlapping amount between a contact surface of the separating unit with the sheet and a contact surface of the feeding unit with the sheet,
The sheet feeding device according to claim 1, wherein the sheet feeding device is more than 0 mm and 0.5 mm or less. 4. The sheet feeding device according to claim 2, wherein the elastic member is a sponge, and the elastic layer is a rubber. 5. The sheet feeding device according to claim 2, wherein a coefficient of friction of the sheet feeding means is larger than a coefficient of friction of the elastic layer. 6. The sheet feeding device according to claim 4, wherein the sponge is a urethane foam sponge, and the rubber is a urethane rubber. 7. The sheet feeding device according to claim 1, wherein the feeding unit is a feeding roller. 8. The sheet feeding device according to claim 1, wherein the feeding unit is a feeding belt. 9. The sheet feeding apparatus according to claim 1, wherein the separating unit includes a contact member that contacts an outer peripheral surface of the feeding unit. 10. The sheet feeding device according to claim 1, further comprising a retard roller that cooperates with the feeding unit. 11. A sheet stacking means for stacking sheets,
A sheet device comprising: a sending unit that sends out the stacked sheets from the sheet stacking unit; and a separating unit that separates and feeds the sheets sent by the sending unit one by one. A sheet feeding means driven in a sheet feeding direction, and a separating means for preventing double feeding of sheets. The separating means is elastically deformable, and is alternately arranged in a non-contact manner with the feeding means. Sheet feeding device. 12. The sheet feeding device according to claim 1, image reading means for reading an image of a sheet fed by the sheet feeding device, and an image based on the read image. An image forming apparatus, comprising: an image forming unit that forms an image. 13. An image reading means for reading an image on a sheet, an image forming means for forming an image based on the read image, and a sheet material for forming an image in the image forming means is fed to the image forming means. An image forming apparatus comprising: the sheet feeding device according to any one of claims 1 to 11.