JPH1179432A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce generation of a paper jam and a feed wrinkle by a simple structure, in a paper feeder with a space adjustable between a pair of the fellow paper feed means. SOLUTION: When a paper feed means 121 able to slide is placed in a position corresponding to paper of relatively broad width, a correction member 170 positioned between a pair of the fellow paper feed means into contact with paper largely curved in protruded shape as viewed from a paper feed direction to correct a curve thereof is constituted able to take refuge from between a pair of the fellow paper feed means. The correction member is always energized by an energizing means 172 toward non-refuge position a cover 122 is provided in the paper feed means 121 constituted able to slide, and the correction member takes refuge by coming into contact with this cover. A route of the fed paper is curved as viewed from an axial line direction of the paper feed means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device.
For example, the present invention relates to a sheet feeding device that feeds a sheet to an image forming apparatus such as a printer, a facsimile, and a copying machine.

[0002]

2. Description of the Related Art As a conventional paper feeding apparatus, for example, FIG.
The one shown in FIG.
No. 65684).

The paper feeder is provided at both ends of a common shaft 4 and drives sprockets Pa on both sides of the paper P (see FIG. 1B) to feed the paper P. 3 is provided.

According to the sheet feeding device having such a configuration, the sheet P receives a conveying force only on both sides Pa thereof. If no means is taken, as shown by a virtual line in FIG. The central portion Pc may be bent (curved) in a convex shape when viewed from the sheet feeding direction. Such bending is likely to occur when the width of the sheet P is relatively large. Further, such bending is not limited to the case where the paper feeding means is a sprocket,
This may also occur when there is a pair of paper feed rollers that drive the paper on both sides to feed the paper. In FIG. 7B, reference numeral 7 denotes a paper guide plate.

[0005] When the sheet central portion Pc is bent as described above, this may cause a paper jam or the generation of feed wrinkles.

Therefore, in the conventional apparatus shown in FIG. 6A, the guide roller 1 is provided at the center of the shaft 4 to prevent the above-described bending.

Further, at least one of the sprockets 2 and 3 is slidable with respect to the shaft 4, so that the interval between the sprockets 2 and 3 can be changed according to the sheet width. Therefore, between the guide roller 1 and the sprockets 2 and 3, the helical springs 5 and 5 having the same spring constant and length are mounted on the shaft 4, and even when the distance between the sprockets 2 and 3 changes, the guide rollers 1 was always located at the center between the sprockets 2 and 3.

[0008]

In the above-described conventional apparatus, the sprockets 2, 3 whose distance can be adjusted according to the sheet width are used.
A pair of helical springs 5 and 5 are provided on both sides of the guide roller 1 so that the guide roller 1 is always located at the center between the sprockets 2 and / or 3, so that the sprocket 2 (and / or 3, the same applies hereinafter) is connected to the springs 5 and 5. When the slider is slid against the urging force, some kind of locking means is required to hold the sprocket 2 at that position, and the structure becomes complicated.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and reduce the occurrence of paper jams and wrinkles with a simple structure despite the fact that the distance between a pair of paper feed means can be adjusted. It is an object of the present invention to provide a paper feeding device capable of performing the following.

[0010]

According to a first aspect of the present invention, at least one of a pair of sheet feeding means for feeding a sheet while contacting both sides of the sheet is provided. A sheet feeding device configured to be slidable in a sheet width direction corresponding to a sheet width, wherein when the slidable sheet feeding unit is located at a position corresponding to a relatively wide sheet, the pair of sheet feeding units; A correcting member that is located between the means and contacts a sheet that is greatly curved in a convex shape when viewed from the sheet feeding direction, and corrects the curvature. The correcting member can be retracted from between the pair of sheet feeding means. There is a feature.

According to a second aspect of the present invention, in the sheet feeding apparatus according to the first aspect, the correction member is constantly urged toward a non-retreat position by an urging means, and is configured to be slidable. The sheet feeding means is provided with a cover which covers the sheet feeding means and slides in the sheet width direction together with the sheet feeding means. When the cover comes into contact with the cover, the correcting member moves the biasing means from between the pair of sheet feeding means. And retreats against the urging force of

According to a third aspect of the present invention, there is provided a sheet feeding apparatus.
4. The sheet feeding device according to 2, 3 or 4, wherein a path of the sheet fed by the pair of sheet feeding units is curved as viewed from an axial direction of the sheet feeding unit.

[0013]

According to the first aspect of the present invention, a sheet is fed by a pair of sheet feeding means that comes into contact with both sides of the sheet. Since at least one of the pair of paper feeders is configured to be slidable in the paper width direction corresponding to the width of the paper, even if the paper is a relatively wide paper, a relatively narrow paper is used. Even this can be sent.

Since the sheet receives the conveying force only on both sides thereof, if the sheet is relatively wide, the central portion of the sheet may bend in a convex shape when viewed from the sheet feeding direction. According to the sheet feeding device described above, when the slidable sheet feeding unit is located at a position corresponding to a relatively wide sheet, the correction member is located between the pair of sheet feeding units and is convex when viewed from the sheet feeding direction. When the sheet comes into contact with a sheet that is largely curved in a shape, the curvature (bending) is corrected. Therefore, the occurrence of paper jams and feed wrinkles is reduced.

On the other hand, since the correcting member can be retracted from between the pair of sheet feeding means, when the slidable sheet feeding means is slid to a position corresponding to a relatively narrow sheet, the correcting member is moved. By evacuating,
It can be easily slid to that position and held in that position without any locking means.

That is, according to the paper feeder of the first aspect, the occurrence of paper jams and wrinkles is reduced with a simple structure despite the fact that the distance between the pair of paper feed means is adjustable. Can be.

According to the sheet feeding device of the second aspect, in the sheet feeding device of the first aspect, the straightening member is always directed to a non-retreat position (ie, a position where the bending of the sheet can be corrected) by the urging means. The paper feeding means, which is slidable and is slidable, is provided with a cover which covers the paper feeding means and slides in the paper width direction together with the paper feeding means. Is retracted from between the pair of paper feeding means against the urging force of the urging means. By sliding the slidable paper feeding means, the correcting member is automatically retracted. It is retracted to the position or is located at the non-retracted position. Further, since the correcting member is retracted by contacting the cover of the sheet feeding means, the rotation of the sheet feeding means is not hindered by the correcting member.

According to a third aspect of the present invention, in the sheet feeding apparatus according to the first, second, or third aspect, the path of the sheet fed by the pair of sheet feeding means is viewed from the axial direction of the sheet feeding means. Since the paper is curved, the degree of freedom in setting the paper path can be increased, but the occurrence of paper jams and feeding wrinkles can be reduced.

More specifically, in the conventional apparatus shown in FIG. 6A, the path of the fed sheet is linear when viewed from the direction of the axis 4 (when viewed from the width direction of the fed sheet). .

On the other hand, if the path of the sheet is curved, for example, if the sheet held in the inclined state can be fed from the inclined state to the horizontal state, the installation area of the sheet feeding device can be reduced. Can be. That is, the projection area can be reduced by the amount that the sheet is held in the inclined state.

However, if the path of the sheet is curved, the central portion of the sheet is more likely to bend near the curved portion.

On the other hand, if the straightening member is provided, the central portion of the sheet that is to be bent is corrected as described above, and the occurrence of paper jams and wrinkles is reduced.
The path of the sheet can be curved.

Therefore, according to the paper feeder of the third aspect, it is possible to reduce the occurrence of paper jams and feed wrinkles, although the degree of freedom in setting the paper path can be increased. Become.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

First, an example of a sheet feeding device which is a premise of the embodiment of the present invention will be described, and then the embodiment of the present invention will be described.

FIG. 1 is a perspective view showing an external appearance of an example of a sheet feeding apparatus which is a premise of the embodiment of the present invention, and FIG. 2 is a sectional view.

The sheet feeding device SF includes a frame 100,
Paper feed roller shaft 11 rotatably supported by this frame
0, a pair of feed roller units 120 and 120 ′ attached to the feed roller shaft 110, and a frame 10.
And a hopper 130 that is rotatably mounted with respect to zero.

An edge guide 131 slidable in the sheet width direction is attached to the hopper 130. One of the pair of paper feed roller units 120 and 120 ′ is connected to the edge guide 131 and is slidable along the paper feed roller shaft 110 together with the edge guide 131. I have.

Such a sheet feeding device SF is, for example, as shown in FIG.
As shown in the figure below. In FIG.
Reference numerals 12 and 13 denote transport roller pairs for transporting paper, 14 a print head for printing on paper, 15 and 16 a paper discharge roller pair for discharging printed paper, and 18a and 18b paper guides.

The hopper 130 is inclined as shown, and a plurality of sheets P (FIG. 2) are set thereon in a stacked state.

The edge guide 131 shown in FIG. 1 is slid in accordance with the width of the sheet set by the user to guide one side edge of the fed sheet. The other side edge is
It is guided by the side wall 101 of the frame 100. Therefore, the other sheet feeding roller unit 120 is connected to the sheet feeding roller shaft 1.
Do not slide on 10.

A pair of paper feed roller units 120 and 12
0 'is configured symmetrically and differs only in whether or not it slides. Therefore, only one sheet feed roller unit 120 will be described below.

Reference numeral 121 denotes a paper feed roller as a sheet feeding means, which has a substantially D-shape in side view having an arc portion 121a and a straight portion 121b.
The surface of a and the surface of the linear portion 121b are formed of a high friction material (for example, rubber). The paper feed roller 121 is provided with a cover 122. The cover 122 is attached to a sub-frame 140 described later.

The paper feed roller shaft 110 is driven to rotate just one rotation during the paper feed operation by a driving means (not shown) of the printer via a gear 111 (see FIG. 1) fixed to the shaft end. ing.

The hopper 130 is rotatably attached to the frame 100 by a shaft 132. Reference numeral 137 denotes a paper feed tray, which is attached to the printer. These hopper 130 and paper feed tray 137
A plurality of sheets of paper P are set in a stacked state on the top (see FIG. 2).
reference). The set sheet P is supported and aligned by the leading end Pd abutting against the back surface (support surface) 152 of the separation pad holder 151 described later.

Reference numeral 140 denotes a frame (hereinafter, referred to as a sub-frame) of the sheet feeding roller unit 120, and a hopper spring (compression spring) 133 is provided between the sub-frame 140 and the tip of the hopper 130. Accordingly, the hopper 130 is constantly urged by the hopper spring 133 in the clockwise direction in FIG. 2, that is, in the direction in which the sheet P comes into contact with the paper feed roller 121, but as shown in FIG. Has a cam follower 134
The cam follower 134 is in contact with a hopper cam 135 fixed to the paper feed roller shaft 110, thereby restricting the rotation of the cam follower 134. Note that a pad 136 similar to a separation pad described later is provided on the top surface of the tip of the hopper 130.

In FIG. 2, reference numeral 150 denotes a separation pad, which is fixed to the separation pad holder 151. The separation pad 150 is made of a material (for example, a material such as cork) whose friction coefficient with respect to the paper P is smaller than the friction coefficient of the paper feed roller 121. Each of the friction coefficients is made of a material having a friction coefficient larger than the friction coefficient between sheets. That is, if the friction coefficient between the paper feed roller 121 and the paper is μ1, the friction coefficient between the separation pad 150 and the paper is μ2, and the friction coefficient between the papers is μ3,
μ1>μ2> μ3.

The separation pad holder 151 holds the separation pad 1
A pad support portion 153 to which the sheet 50 is fixed, a support surface (rear surface) 152 at the leading end of the sheet integrated with the pad support portion 153, and an arm portion 154 formed integrally therewith are provided. The shafts 155 provided on both sides of the rear end are rotatably attached to the sub-frame 140 by fitting into the holes of the sub-frame 140.

A pad spring (compression spring) 156 is provided between the lower surface of the pad support 153 and the subframe 140 as pad urging means. Accordingly, the separation pad holder 151 is constantly urged by the pad spring 156 in the clockwise direction in FIG. 2, that is, in the direction in which the separation pad 150 is brought into contact with the paper feed roller 121, but the separation pad holder 151 is moved toward one side of the separation pad holder 151. Is formed with a projection (not shown).
The rotation is restricted by abutting on a pin (not shown) serving as a pad restricting means provided in the above. In a state where the protrusion is in contact with the pin, the separation pad 150 is
The paper feed roller 121 is located in the rotation orbit of the arc portion 121a.

Reference numeral 160 denotes an idle roller, which is pressed against the separation pad 150 by a biasing means (not shown) with a smaller biasing force than the pad spring 156.

The paper feeding device SF as described above is incorporated in the printer as described above, and is a driving means of the printer, and the paper feeding roller shaft 110 is driven by a gear 111 (see FIG. 1).
Is driven as follows, so that it operates as follows.

During standby, the hopper 130 is pushed down by the cam follower 134 of the hopper 130 contacting the hopper cam 135.
The paper feed roller 121 is in a state where the linear portion 121b faces the paper P, and the paper feed roller 121 is not in contact with the paper P.

Accordingly, in this state, the paper P can be easily set on the hopper 130, and the edge guide 131 is slid according to the width of the paper P to guide the side edges of the paper. can do. When the edge guide 131 is slid, the paper feed roller unit 120 'is also slid accordingly.

In the paper feed operation, the paper feed roller shaft 110 rotates clockwise in FIG. 2, and the paper feed roller 121 and the hopper cam 135 rotate together with the paper feed roller shaft 110 to rotate the hopper cam 135 and the cam follower 134 of the hopper 130. When the contact with the sheet P is released, the hopper 130 is pushed up by the hopper spring 133, and the sheet P is also pushed up. P1 is sent toward the separation pad 150. At this time, the sheet P2 is fed together with the sheet P1 because the next sheet P2 is attracted to the sheet P1 by the action of static electricity or a frictional force acts between the sheet P1 and the sheet P2. However, the sheet P2 may be temporarily separated from the sheet P1 because the movement of the sheet P2 is hindered by the tip P2a of the sheet P2 abutting against the separation pad 150. Similarly, even if a lower-order sheet P3 or the like is to be sent, it can be separated in the same manner.

Further, as the paper feed roller shaft 110 continues to rotate, the arc portion 121a of the paper feed roller 121 presses the separation pad 150 via the uppermost sheet P1, whereby the separation pad 150 is moved by the pad spring 156. The pad spring 156 is simultaneously pressed down against the urging force.
, The uppermost sheet P1 is pressed between the sheet feeding roller 121 and the arc portion 121a. That is, the paper P
1 is fed in a state of being pinched between the paper feed roller 121 and the separation pad 150. At this time, as described above, the next sheet P2 may be likely to be sent together with the sheet P1, but as described above, the friction coefficient between the sheet feeding roller 121 and the sheet is μ1, and the separation pad 150 is The coefficient of friction between paper and μ2, the coefficient of friction between paper μ3
Then, since μ1>μ2> μ3, when the paper P1 and the paper P2 are both pressed by the arc portion 121a of the paper feed roller and the separation pad 150 as the paper feed roller 121 rotates, The paper P2 is the separation pad 150
The movement is hindered by the frictional force between the sheet P1 and the sheet P1, and the sheet P2 is secondarily separated from the sheet P1, and only the sheet P1 is fed.

The feed roller shaft 110 makes one full rotation, the hopper 130 is pushed down by the hopper cam 135, and returns to the standby state (the state shown in FIG. 2).

At this time, the sheet P1 is not completely removed from the sheet feeding device, and the sheet P1 is not moved until its rear end passes through the contact portion between the separation pad 150 and the idle roller 160. In a state where a load is applied to the contact portion (a state where the transfer roller is pulled backward),
Will be transported.

In this case, since the idle roller 160 is urged toward the separation pad 150 by the roller spring 165 and presses the sheet P1 with the separation pad 150, the next roller already separated from the sheet P1 This prevents the sheet P2 from descending due to its own weight, or from being attracted to the sheet P1 by the action of static electricity or from being sent together with the sheet P1 by a frictional force with the sheet P1.

In the above-described paper feeder SF, if the paper P to be fed is a relatively wide paper (for example, A4 size paper), the paper P is supplied to both sides by paper feed rollers 121 and 121. Since only the conveying force is applied, the central portion (see the broken line Pc in FIG. 5) may be bent (curved) when viewed from the sheet feeding direction. Such bending is likely to occur when the paper P is a relatively stiff paper, such as glossy paper, and causes feed wrinkles and the like.

This embodiment has been made to solve such a problem.

FIG. 3A is a plan view showing a main part of this embodiment, FIG. 3B is a sectional view taken along line bb in FIG. 3A, and FIG. 3C is a plan view showing a retracted state. FIG. In these figures, the same parts as those shown in FIGS. 1 and 2 are denoted by the same reference numerals.

The feature of this embodiment is that the straightening member 170
Is provided.

FIGS. 4A and 4B mainly show the correction member 170. FIG. 4A is a view as viewed from the back side of FIG. 3A, FIG. 4B is a left side view when FIG. c) is FIG.
It is the figure seen from the back side of (c).

The correction member 170 is formed in a substantially plate shape as a whole, and a support plate 180 (not shown in FIGS. 3A and 3B) installed on the frame 100 (see FIG. 1).
Is mounted to be rotatable about a shaft 181.

A tension coil spring 172 as urging means is stretched between the spring hook 171 of the correction member 170 and the spring hook 182 of the support plate 180. Therefore, the correction member 170 is moved by the spring 172 in FIG.
7A, the rotation is restricted by the head 173 of the correction member 170 abutting against the stopper 183 formed on the support plate 180.

In this state, the leading end 174 of the correction member 170 is located on the slide track of the slidable paper feed roller unit 120 'as shown in FIG. 3B.

Therefore, the edge guide 131 is
3A, when the sheet feeding roller unit 120 'is slid to the right and the sheet feeding roller unit 120' is slid to the right, the cover 122 of the sheet feeding roller abuts on the side of the straightening member 170. As shown in FIG. 4C and FIG. 4C, the sheet is retracted from between the pair of sheet feeding rollers 120 against the urging force of the spring 172. At this time, the spring 172 extends while bending along the outer periphery of the cylindrical bearing portion 175 of the correction member 170.

That is, when the slidable sheet feeding roller unit 120 'is at a position corresponding to a relatively wide sheet as shown in FIG. When the slidable paper feed roller unit 120 'located between the paper feed rollers 121 is slid as shown in FIG. , 121.

Then, the non-retreat position, that is, FIG.
When the correction member 170 is at the position shown in FIG. 5B (correctable position), as shown in FIG. The curvature is corrected as shown by a virtual line Pc ′. When the paper P is a relatively stiff paper such as glossy paper, the central portion Pc is often greatly curved, and when the paper is a relatively stiff plain paper or the like, the paper P is greatly curved. Therefore, the leading end 174 of the correcting member 170 is arranged so as to contact and correct the sheet only when the sheet is greatly curved as shown by the broken line Pc. Therefore, the correction member 170 does not unnecessarily interfere with the weak paper and damage the paper.

The correction member 170 can be manually rotated without providing the spring 172 for the correction member. In this case, it is desirable to provide an operating lever integrally on the head of the correction member 172.

According to the above-described paper feeder, the following operation and effect can be obtained.

(A) The sheet P is fed by a pair of sheet feed means 121, 121 which come into contact with both side portions Pa of the sheet P. At least one of the pair of sheet feeding means (the sheet feeding roller 121 on the unit 120 'side, the same applies hereinafter) is configured to be slidable in the sheet width direction corresponding to the width of the sheet. This can be sent to a wide sheet or a relatively narrow sheet. In this embodiment, it is possible to handle from A4 size paper to postcard size paper. FIG. 3C shows a state in which a postcard is fed.

Since the sheet P receives the conveying force only on both side portions Pa, if the sheet P has a relatively large width, as shown in FIG. 5, the central portion Pc tries to bend in a convex shape when viewed from the sheet feeding direction. However, according to this paper feeder, when the slidable paper feed means is located at a position corresponding to a relatively wide paper, for example, as shown in FIG.
The correction member 170 is located between the pair of sheet feeding means, and the sheet P greatly curved convexly when viewed from the sheet feeding direction.
, The curvature (deflection) Pc becomes P
The correction is performed as shown in c ′. Therefore,
The occurrence of paper jams and feed wrinkles is reduced.

On the other hand, since the correction member 170 can be retracted from between the pair of sheet feeding means 121, 121, when the slidable sheet feeding means is slid to a position corresponding to a relatively narrow sheet, By retracting the correction member 170 (manually or automatically), the correction member 170 can be easily slid to the position, and the feeding means 121 can be provided without any locking means.
Can be held in that position.

That is, according to the paper feeder of this embodiment, although the interval between the pair of paper feed means 121 is adjustable, the occurrence of paper jams and wrinkles is reduced with a simple structure. Can be done.

(B) The correcting member 170 is provided with an urging means 172
3 (a), which is always biased toward the non-retreat position (ie, the position shown in FIG. 3 (a) where the curl of the sheet can be corrected). A cover 122 that slides in the paper width direction is provided together with the paper feeding means.
The correction member 17 is brought into contact with the cover 122.
0 is retracted from between the pair of sheet feeding means 121, 121 against the urging force of the urging means 172, so that the sheet feeding means 1 slidably formed.
By sliding 21, the correction member 170 is automatically retracted to the retracted position or is located in the non-retracted position. Therefore, the user's labor can be reduced.

The correction member 170 is retracted by contacting the cover 122 of the sheet feeding means, so that the rotation of the sheet feeding means 121 is not hindered by the correction member 170.

(C) As shown in FIG. 5, the path of the sheet fed by the pair of sheet feeding means is curved as viewed from the axial direction of the sheet feeding means, so that the degree of freedom in setting the sheet path is increased. However, paper jams and feed wrinkles can be reduced.

More specifically, in the conventional apparatus shown in FIG. 6A, the path of the fed sheet is linear when viewed from the axis 4 direction (when viewed from the width direction of the fed sheet). .

On the other hand, if the path of the sheet is curved, for example, as shown in FIG. 5, if the sheet held in the inclined state can be fed from the inclined state to the horizontal state, if the sheet is fed, The installation area can be reduced. That is, the projection area can be reduced by the amount that the sheet is held in the inclined state.

However, when the path of the sheet is curved as shown in FIG. 5, the central portion Pc of the sheet is more likely to bend near the curved portion.

On the other hand, if the straightening member 170 is provided, the central portion Pc of the sheet which is to be bent as described above is straightened as indicated by Pc ′, and the occurrence of paper jams and feed wrinkles is reduced. Therefore, the paper path can be curved.

Therefore, according to the paper feeder of this embodiment, it is possible to reduce the occurrence of paper jams and feed wrinkles, although the degree of freedom in setting the paper path can be increased. .

As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of the present invention.

[0075]

According to any one of the first to third aspects of the present invention, the occurrence of paper jams and wrinkles is reduced with a simple structure despite the fact that the distance between the pair of paper feeding means can be adjusted. Can be done.

Further, according to the paper feeding device of the second aspect, the correcting member is automatically retracted to the retracted position or located in the non-retracted position by sliding the slidable sheet feeding means. And
The effect is obtained that the rotation of the sheet feeding means is not hindered by the correction member.

According to the paper feeder of the third aspect, it is possible to reduce the occurrence of paper jams and feed wrinkles, although the degree of freedom in setting the paper path can be increased.

[0078]

[Brief description of the drawings]

FIG. 1 is an external perspective view of an example of a sheet feeding device as a premise of an embodiment of the present invention.

FIG. 2 is a sectional view of the same.

3A is a plan view showing a main part of one embodiment of the present invention, FIG. 3B is a cross-sectional view taken along line bb in FIG. 3A, and FIG.
FIG. 3 is a plan view showing a retracted state of the correction member.

4A and 4B are diagrams mainly showing a correction member 170, wherein FIG. 4A is a view as viewed from the back side of FIG. 3A, FIG. 4B is a left side view when FIG. FIG. 3C is a view from the back side of FIG.

FIG. 5 is an operation explanatory view.

FIGS. 6A and 6B are explanatory diagrams of a conventional technique.

[Explanation of symbols]

 P paper 121 paper feed roller (paper feeding means) 122 cover 170 straightening member 172 tension spring (biasing means)

Claims (3)

[Claims] 1. A sheet feeding device wherein at least one of a pair of sheet feeding means for feeding a sheet in contact with both side portions of the sheet is slidable in a sheet width direction corresponding to a width of the sheet. When the slidable sheet feeding means is at a position corresponding to a relatively wide sheet, the sheet feeding means is located between the pair of sheet feeding means, and comes into contact with a sheet which is greatly curved in a convex shape when viewed from the sheet feeding direction. And a straightening member for straightening the curved portion, wherein the straightening member is retractable from between the pair of sheet feeding means. 2. The correction member is constantly urged toward a non-retreat position by an urging means, and the slidable sheet feeding means is covered with the sheet feeding means and is moved in the sheet width direction together with the sheet feeding means. 2. A sliding cover is provided, and by contacting the cover, the correcting member is retracted from between a pair of sheet feeding means against the urging force of the urging means. Paper feeder. 3. The sheet feeding device according to claim 1, wherein a path of the sheet fed by the pair of sheet feeding units is curved as viewed from an axial direction of the sheet feeding unit.