JP3456124B2 - Paper feeder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stack of papers (plain paper, coated paper, OHP (overhead projector) sheet, glossy paper, cut sheet such as glossy film), one from the top. The present invention relates to a sheet feeding device that feeds each sheet. The present invention mainly relates to a sheet feeding device suitable for a printer or the like.

[0002]

2. Description of the Related Art Generally, as a sheet feeding device, a claw separation system and a pad separation system are known.

In the claw separation method, as is well known, the tip corners of the stacked sheets are locked to the claws, and the paper feed roller is arranged behind the claws (downstream in the paper feeding direction). , By rotating the paper feed roller, the uppermost paper is bent between the paper feed roller and the claw portion, and the uppermost paper is moved to the next position by utilizing the fact that this bending reaches the limit. This is a method in which only the topmost sheet is fed by separating it from the other sheets.

On the other hand, in the pad separation method, as is well known, the friction coefficient between the paper feed roller and the paper is μ1,
When the friction coefficient between the separation pad and the paper is μ2 and the friction coefficient between the papers is μ3, the paper feed roller and the separation pad are configured and rotated so that the relationship of μ1>μ2> μ3 is established. This is a method in which the uppermost sheet and the next sheet are separated by pinching the sheet between the sheet feeding roller and the separation pad that is pressed against the sheet, and only the uppermost sheet is fed.

In any of these methods, when the surface of the uppermost sheet comes into contact with the rotating sheet feeding roller and the uppermost sheet moves, the back surface of the uppermost sheet is on the other side of the contact portion. And the surface of the next paper will come into sliding contact with each other, and therefore, the surface of the next paper will have a thin scratch due to the sliding contact, and if the paper is glossy paper or a glossy film, the thin scratch will be slightly noticeable. .

Further, in the case of the claw separation system, the sliding contact portion (that is, the thin scratched portion) is located behind the claw portion, that is, the rear side of the uppermost sheet so that the uppermost sheet can be flexed. It is located in the area, which is not preferable.

On the other hand, in the case of the pad separation method, although a thin scratch is caused by sliding contact, this thin scratch only attaches to the front end of the surface of the next paper, and therefore is not normally located in the print area. .

Therefore, from the viewpoint of the above-mentioned thin scratches,
The pad separation method is superior.

However, the pad separation method has the following drawbacks.

For example, as shown in FIG. 16, when the paper feed device 1 using the pad separation method is used in a printer, the fed paper P1 is conveyed while being pinched by the conveying roller pairs 2 and 3. The printing means 4 prints, but at the time when the conveyance of the sheet P1 by the pair of conveying rollers 2 and 3 is started, the sheet P1 is not normally completely removed from the sheet feeding device.

On the other hand, in the pad separation system, the above μ1
>Μ2> μ3, that is, when the frictional force between the paper feed roller and the paper is f1, the frictional force between the paper and the separation pad is f2, and the frictional force between the paper and the paper is f3, f
Since the paper feed roller and the separation pad must be pressed against each other so that the relationship of 1>f2> f3 is established, the paper feed roller and the separation pad are started when the conveyance of the paper P1 by the conveyance roller pair 2 and 3 is started. When and are pressed together, the paper P
In No. 1, the rear part is pressed by the paper feed roller and the separation pad.

Therefore, the sheet P1 is conveyed under a load (pulled rearward) under the load of the pressure-holding portion until the trailing edge of the paper P1 passes through the pressure-holding portion between the paper feed roller and the separation pad. It will be conveyed by the roller pairs 2 and 3.

If such a load (that is, back tension) is large, the feeding accuracy of the paper by the pair of conveying rollers 2 and 3 is deteriorated and the printing quality is also deteriorated. Therefore, this load, that is, the paper feeding roller and the separation pad. The pressure contact force with
It is desirable to make it as small as possible. However,
When the pressure contact force is small, there is a drawback that the next paper sheet gradually enters the pressure contact portion between the paper feed roller and the separation pad every time the paper feed operation is repeated, and the paper sheets cannot be separated.

A sheet medium aligning mechanism described in Japanese Patent Laid-Open No. 7-53062 is a solution to these problems.

FIGS. 17A to 17E are views showing the structure and operation of this mechanism.

In the figure, 18 is a paper feed roller, 24 is a separation pad, and 22 is a lever.

The lever 22 is rotatably supported by a pivot A as shown in FIG. 3C, and is urged clockwise by a cantilever spring 26 that presses the arm 22c.

According to this mechanism, when the paper feed roller 18 rotates in the clockwise direction as shown in FIGS. 8B to 8E, the uppermost sheet S1 at the pressure contact portion between the paper feed roller 18 and the separation pad 24. Is separated from the next highest sheet S2, and only the highest sheet S1 is fed as shown in FIG. On this occasion,
The lever 22 is pushed by the sheet S1 and escapes as shown in FIGS. Then, even if the next sheet S2 (and further the next sheet S3) enters or is about to enter the pressure contact portion between the paper feed roller 18 and the separation pad 24, the trailing end of the previous sheet S1 is the lever 22. When the lever 22 passes the upper end, the lever 22 is rotated clockwise by the urging force of the cantilever spring 26, and the next sheet S2 (and further the next sheet S3) is pushed back as shown in FIG. Becomes

Therefore, according to this mechanism, the above problem, that is, the problem that the next sheet gradually enters the pressure contact portion between the paper feed roller and the separation pad and the paper cannot be separated is solved. Also seems to get.

[0020]

However, in the above-mentioned conventional mechanism (FIG. 17), as is apparent from FIGS. 17D and 17E, the sheet feeding roller 18 and the sheet feeding roller 18 are operated during the pushing back operation of the next sheet S2. Since the separation pad 24 is pressure-contacted with the separation pad 24, if the leading edge of the next sheet S2 has already entered this pressure-contacting portion, the lever 22 can surely push it back. The biasing force of the spring 26 must be increased. However, lever 2
When the uppermost sheet S1 is fed, as shown in FIG.
As shown in (c) and (d), the sheet S1 must be pushed to escape and it is not desirable to increase the biasing force of the spring 26. When the biasing force of the spring 26 is increased, the feeding force of the sheet S1, that is, the pressure contact force between the sheet feeding roller 18 and the separation pad 24 is set so that the lever 22 is pushed by the uppermost sheet S1 and escapes. This is because it must be increased, and then the original purpose of reducing the load (back tension) cannot be achieved.

That is, in the conventional mechanism described above, in order to reduce the load (back tension), the urging force of the spring 26 must be reduced. If the urging force of the spring 26 is reduced, the next seat S2 is reduced. However, there is a problem in that it may not be surely pushed back, and as a result, two or more sheets may be fed.

An object of the present invention is to solve the above problems, reduce the load by using a separation pad system, and surely feed sheets one by one. To provide.

[0023]

In order to achieve the above object, a paper feeding apparatus according to a first aspect of the present invention is a paper feeding roller which is driven to rotate normally during a paper feeding operation, and feeds in contact with the paper feeding roller. Plural sheets of paper to be stacked are sandwiched between a hopper that presses the paper toward the paper feed roller when the paper feed roller rotates normally and a paper feed roller when the paper feed roller rotates normally. The separation pad separates the uppermost sheet to be fed by the sheet feeding roller from the next sheet, and separates the uppermost sheet from the sheet feeding roller after the sheet is fed by the sheet feeding roller by a predetermined amount. A protruding position that protrudes toward the sheet feeding roller in a side view, as compared with the surface facing the sheet feeding roller,
When the leading edge of the uppermost sheet passes through the pinching portion between the paper feed roller and the separation pad, it is in the retracted position, and the leading edge of the uppermost sheet moves the pinching portion. After passing, after the separation pad has passed before the separation pad is separated from the paper feed roller, the stopper protruding in front of the pressure unit and the trailing edge of the uppermost sheet fed by the paper feed roller have passed, rotates backward and a paper return lever pushes toward the sheet next order in the rear, the paper feed low
La reverses once before the forward rotation, and by this reverse rotation
The paper return lever is pivoted rearward .
The sheet feeding device according to claim 2 is driven to rotate normally during the sheet feeding operation.
Feeding roller that feeds
Multiple sheets of paper should be stacked and fed when the feed roller rotates in the forward direction.
The hopper that presses the paper against the rollers, and the paper
Pinch the paper between the paper and the paper feed roller
Allows the top paper to be fed by the paper feed roller.
Separate the paper from the next paper, and put the top paper on the paper feed roller.
Separation pack that separates from the paper feed roller
From the surface of the separation pad facing the paper feed roller.
Also, when viewed from the side,
Out it was not retracted position and the Toridoku, paper feed roller and the separation pad
When the leading edge of the topmost sheet passes through the pinching part of
At the retracted position, the leading edge of the topmost sheet passes through the pinching section.
After separating, before the separation pad separates from the paper feed roller
A stopper protruding in front of the pressing portion,
If the trailing edge of the topmost paper fed by the paper feed roller is
After passing, rotate backward to move the next sheet of paper backward.
And a paper return lever for pushing back the separation pad.
Is fed by the operation of the cam installed on the shaft of the paper feed roller.
It is characterized by being separated from the roller. Claim 3
The paper feeding device is a paper feeding roller that is driven to rotate normally during the paper feeding operation.
And the paper to be fed in contact with this paper feed roller
Several sheets are stacked and face the paper feed roller when the paper feed roller rotates forward.
When the hopper that presses the paper in contact with the paper feed roller
By pressing the paper between the paper feed roller and
Whether the top paper to be sent by the roller is the next paper
And the top paper is fed by a specified amount by the paper feed roller.
Separation pad that separates from the paper feed roller after
Side view from the surface of the release pad facing the paper feed roller
The protruding position that protrudes toward the paper feed roller and the retracted position that does not protrude.
It can be placed in the retracted position, and it is a pinching part between the paper feed roller and separation pad
When the leading edge of the uppermost sheet passes through the
Yes, after the top edge of the top sheet has passed the pinching section,
Before the separation pad is separated from the paper feed roller, the clamping pressure is applied.
Stopper that projects in front of the
The trailing edge of the topmost paper fed by the printer has passed
After that, rotate backward to push back the next sheet of paper backward
A paper return lever is provided, and the operation of the stopper is
Characterized by being linked with the rotation of the axis of the paper feed roller
It

The term "predetermined amount" as used herein means that when the paper feeding device is used in, for example, a printer such as that shown in FIG. The feed amount required to reach the pair of transport rollers 2, 3). The side view means that the sheet is viewed from the axial direction of the sheet feeding roller.

According to a fourth aspect of the present invention, there is provided a paper feeding device according to the first aspect.
In the paper feeding device of 2 or 3 , the hopper is
It is characterized in that it is arranged in a downward slope toward the separation pad.

According to a fifth aspect of the present invention, there is provided the paper feeding device according to the first aspect.
In the sheet feeding device described in 2, 3, or 4 , the hopper is a hopper that separates the sheets stacked in the hopper from the sheet feeding roller when at least the sheet return lever rotates backward. At the front of the hopper in the paper feeding direction, there is provided a supporting surface for supporting the leading end of the paper stacked on the hopper. It is characterized by pushing back the next paper so as to reach.

A paper feeding device according to a sixth aspect of the present invention is the paper feeding device according to the second aspect.
The sheet feeding device described in 3, 4, or 5 is characterized in that the sheet feeding roller reverses once before the forward rotation, and the sheet returning lever rotates backward due to this reverse rotation.

The sheet feeding apparatus according to claim 7, wherein the claim 1,
3, 4, 5, or 6 , the separation pad is separated from the paper feed roller by the operation of a cam provided on the shaft of the paper feed roller.

The paper feeding device according to claim 8 is the paper feeding device according to claim 1,
The sheet feeding device described in any one of items 2, 4, 5, 6, and 7 is characterized in that the operation of the stopper is interlocked with the rotation of the shaft of the sheet feeding roller.

[0030]

According to the paper feeding device of the first aspect, the paper feeding roller that is driven to rotate normally during the paper feeding operation, and a plurality of sheets to be fed in contact with the paper feeding roller are stacked. By pinching the paper between the hopper that presses the paper toward the paper feed roller when the paper feed roller rotates forward and the paper feed roller when the paper feed roller rotates normally, the paper should be fed by the paper feed roller. Since the upper sheet is provided with a separation pad for separating the upper sheet from the next sheet, only the uppermost sheet is fed during the paper feeding operation.

Since the separation pad is separated from the paper feed roller after the uppermost paper has been fed by the paper feed roller by a predetermined amount, the above-mentioned load (back tension) is almost eliminated or very small. It will be small.

When the separation pad is separated from the paper feed roller after the uppermost paper is fed by the paper feed roller by a predetermined amount,
When the uppermost sheet is conveyed by the conveying means in the latter stage,
There is a case where the next-order sheet is fed together with the highest-order sheet because the second-order sheet is attracted to the highest-order sheet by the action of static electricity or due to a frictional force between the sheets.

However, according to the paper feeding apparatus of the first aspect, the separation pad is separated from the paper feeding roller after the leading edge of the uppermost paper has passed the pinching portion between the paper feeding roller and the separation pad. Before, the stopper protrudes to the paper feed roller side in a side view from the surface of the separation pad facing the paper feed roller in front of the pressing portion, so that the stopper prevents passage of the next paper. This is prevented, and as a result, only the uppermost sheet is conveyed. When the leading edge of the uppermost sheet passes through the pinching portion between the sheet feeding roller and the separation pad, this stopper is in the retracted position, which is the non-projecting position. There is no inhibition.

In this way, the next paper, which is prevented from passing by the stopper, is pushed back toward the rear by the paper return lever that rotates backward after the trailing edge of the uppermost paper has passed. Become.

As a result, the next paper sheet gradually (cumulatively) enters the pressure contact portion between the paper feed roller and the separation pad,
The situation that the sheets cannot be separated will not occur.

As described above, according to the sheet feeding device of the first aspect, the sheets can be reliably fed one by one even though the load can be reduced by using the separation pad method. be able to. Further, according to claim 1.
According to the paper feeding device, the paper feeding roller is arranged before the forward rotation.
Once it reverses, the paper return lever moves backward
Since it is configured to rotate in one direction, the paper feeding operation is started.
For some reason, the paper will not
Even if it got in between, surely return it once
You can Therefore, for some reason
Make sure that it is inserted between the paper roller and the separation pad.
Problems that may occur if the paper feeding operation is performed as it is
It is possible to prevent (for example, defective cueing of paper) from occurring.
Wear. Further, according to the sheet feeding device of claim 2,
The release pad is formed by a cam provided on the shaft of the paper feed roller.
Since it is configured to move away from the paper feed roller,
Separation pads can be separated at desired timing
At the same time, the structure can be simplified. For example,
When configured to operate with a solenoid, etc.
The separation pad is separated at a more reliable timing than
It can be made simple and has a simple structure.
Wear. According to the paper feeding device of claim 3,
The operation of the topper is linked with the rotation of the shaft of the paper feed roller.
Since it is configured, push the stopper at the desired timing.
It can be ejected or retracted, and the structure is simple.
It is possible to insist. For example, with a solenoid
More reliable than when configured to operate by
To project or retract the stopper at various times
It is possible to have a simple structure.

According to the paper feeder of claim 4 ,
In the paper feeding device of 1, 2, or 3 , the hopper is arranged in a downwardly inclined shape toward the separation pad, and therefore, when the uppermost sheet is fed, the next highest sheet is fed. Also, it becomes easy to slide down toward the pressing portion between the paper feed roller and the separation pad. Further, when the separation pad is separated from the paper feed roller after the uppermost paper has been fed by the paper feed roller by a predetermined amount, the next most paper is more easily fed together with the uppermost paper.

However, according to the sheet feeding device of the fourth aspect , the second sheet is prevented from passing by the stopper due to the configuration of the first, second , or third aspect described above, and the sheet return lever. As a result, the sheet is pushed back toward the rear, so that even if the inclination angle of the hopper is increased, it is possible to feed the sheets one by one.

Therefore, according to the sheet feeding device of the fourth aspect , the inclination angle of the hopper is increased (for example, 45).
It is possible to reduce the installation area.

According to the paper feeder of claim 5 ,
1, 2, 3, or 4 , the hopper is a hopper that separates the sheets stacked in the hopper from the sheet feed roller when at least the sheet return lever rotates backward. With that, of this hopper,
A support surface for supporting the leading edge of the sheets stacked on the hopper is provided in the front of the sheet feeding direction, and the sheet return lever is arranged so that the leading edge of the next sheet reaches the rear side of the supporting surface. Since it is configured to push back the first sheet of paper, the leading end of the next sheet of paper that has been pushed back is supported by the support surface.

Therefore, the above-mentioned cumulative intrusion of the next paper is surely prevented.

According to the paper feeder of claim 6 ,
In the paper feeding device of 2, 3, 4, or 5 , since the paper feeding roller is reversely rotated before the forward rotation, and the paper return lever is rotated backward by the reverse rotation. Even if the paper has entered between the paper feed roller and the separation pad for some reason before the paper feed operation is started, the paper can be reliably returned once.

Therefore, for some reason, if the paper feed operation is performed as it is while the paper is inserted between the paper feed roller and the separation pad, a trouble (for example, a misfeed of the paper) may occur. Can be prevented.

[0044] According to the sheet feeding apparatus according to claim 7, claim
In the sheet feeding device described in 1, 3, 4, 5, or 6 , the separation pad is separated from the sheet feeding roller by the operation of a cam provided on the shaft of the sheet feeding roller. The separation pad can be separated at the timing of, and the structure can be simplified. For example, the separation pad can be separated at a more reliable timing, and a simple structure can be achieved, as compared with the case where it is operated by a solenoid or the like.

According to the paper feeder of claim 8 ,
In the sheet feeding device described in 1, 2, 4, 5, 6, or 7 , since the operation of the stopper is interlocked with the rotation of the shaft of the sheet feeding roller, the stopper is projected or ejected at a desired timing. It can be evacuated and the structure can be simplified. For example, the stopper can be projected or retracted at a more reliable timing, and a simple structure can be achieved, as compared with the case where it is operated by a solenoid or the like.

[0046]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of a sheet feeding device according to the present invention, and FIG. 2 is a partially omitted side view showing an example of attachment to a printer.

As shown in FIG. 1, the sheet feeding device SF is
A frame 100, a paper feed roller shaft 110 rotatably supported by the frame, and a pair of paper feed roller units 120, 12 attached to the paper feed roller shaft 110.
0 ′ and a hopper 130 rotatably attached to the frame 100.

An edge guide 131 slidable in the width direction of the paper 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. There is.

Such a sheet feeding device SF is shown in FIG.
It is built into the printer as shown in. In FIG.
Reference numerals 2 and 3 are a pair of transport rollers for transporting the sheet, 4 is a print head for printing on the sheet, 5 and 6 are a pair of discharge rollers for discharging the printed sheet, and 8a and 8b are sheet guides.

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

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

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

FIG. 3 is a partially cutaway side view showing the essential parts of the paper feeding device, that is, the paper feeding roller inside the paper feeding roller unit, the separation pad, and the periphery thereof, and FIG.
FIG. 4 is a view on arrow IV in FIG.

In these drawings, reference numeral 121 denotes a sheet feeding roller, which is formed in a substantially D shape in a side view and has an arc portion 121a and a straight portion 121b, and at least an arc portion 121.
The surface of a and the surface of the straight portion 121b are formed of a high friction material (for example, rubber). This paper feed roller 121
Is fixed to the paper feed roller shaft 110 via a bush 122. That is, the paper feed roller 121 and the bush 122 cannot rotate with respect to the paper feed roller shaft 110. The paper feed roller shaft 110 is rotatably driven by exactly one rotation during a paper feed operation by a driving unit (not shown) via a gear 111 (see FIG. 1) fixed to the shaft end thereof.

The hopper 130 has a shaft 13 as shown in FIG.
It is rotatably attached to the frame 100 by 2. Reference numeral 137 is a paper feed tray, which is attached to the printer. A plurality of sheets of paper P are set in a stacked state on the hopper 130 and the paper feed tray 137. The leading edge Pa of the set paper P is the back surface (support surface) 152 of the separation pad holder 151 described later.
Are supported and aligned by abutting against.

Reference numeral 140 denotes a frame of the paper feed roller unit 120 (hereinafter referred to as a subframe), and a hopper spring (compression spring) 133 is provided between the subframe 140 and the tip of the hopper 130. Therefore, the hopper 130 is always urged by the hopper spring 133 in the clockwise direction in FIG. 2, that is, in the direction in which the paper P is pressed against the paper feed roller 121, but as shown in FIGS. 4 and 11 (a1). Cam followers 134 are formed at both ends of the hopper 130, and the rotation of the cam followers 134 is restricted by contacting the hopper cams 135 (see FIG. 1) fixed to the paper feed roller shaft 110. . Note that, as shown in FIG. 2, a pad 136 similar to a separation pad described later is provided on the upper surface of the tip end portion of the hopper 130.

FIG. 5 is a diagram showing the details of the sub-frame 140. FIG. 5A is a plan view and FIG. 5B is a sectional view taken along line bb in FIG.
FIG.

The sub-frame 140 is an integrally molded product,
Track portions 142, 142 for rotatably supporting a receiving portion 141 of the hopper spring 133 and a separation pad holder 151 described later (only one is shown in FIG. 1B).
And a restricting portion 143 for restricting rotation of a stopper 160 described later, and a receiving portion 14 of a pad spring 156 described later.
4 and shafts 145a and 145b for rotatably supporting a sheet return lever 180 described later.

2 to 4, 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 coefficient of friction with respect to the paper P is smaller than that of the paper feed roller 121. Further, each of the friction coefficients is made of a material having a friction coefficient larger than that between the 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, then μ1>μ2> μ3. There is.

6A and 6B are diagrams showing details of the separation pad holder 151. FIG. 6A is a plan view, FIG. 6B is a left side view when FIG. A is a front view, and FIG. FIG. 4B is a right side view of FIG.

The separation pad holder 151 is the separation pad 1
It has a pad support portion 153 to which 50 is fixed, a support surface (rear surface) 152 of the above-mentioned sheet front end which is integral with the pad support portion 153, and an arm portion 154 which is integrally formed with the pad support portion 153. Shafts 155 and 155 provided on both sides of the rear end
Is rotatably attached to the sub-frame 140 by being fitted into the track holes 142, 142 of the sub-frame 140.

As shown in FIG. 2, a pad spring (compression spring) 156 as a pad urging means is provided between the lower surface of the pad support portion 153 and the sub-frame 140. Therefore, the separation pad holder 151 is always urged by the pad spring 156 in the clockwise direction in FIG. 2, that is, in the direction of bringing the separation pad 150 into contact with the paper feed roller 121. Has a protrusion 157 (see FIGS. 6 and 3), and this protrusion 157 is attached to the paper feed roller shaft 110 via the bush 122 as shown in FIGS. Also, a pad cam 158 that serves as a pad restriction means
By contacting with (see FIG. 7), the rotation thereof is regulated. As shown in FIG. 7, the pad cam 158 has a large diameter portion 158a and a small diameter portion 158b. When the protrusion 157 contacts the large diameter portion 158a, the separation pad 150 separates from the paper feed roller 121. When the protrusion 157 is disengaged from the large diameter portion 158a (pushed down) and cannot come into contact with it at all, the separation pad 150 is rotated clockwise (pushed up) by the urging force of the pad spring 156. ) The sheet can be pressed against the sheet feeding roller 121.

In FIGS. 3 and 4, 160 is a stopper. FIG. 8 is a diagram showing the details of the stopper 160.
Is a right side view, (b) is a rear view, and (c) is a left side view.

The stopper 160 is an integrally molded product and has a cylindrical base 161, a claw 162, and an arm 163. The cylindrical base 161 is provided with a shaft 159 protruding from the separation pad holder 151. By lightly fitting
It is rotatably attached to the separation pad holder 151. As shown in FIG. 4, a torsion coil spring 164 as a stopper urging unit is attached to the cylindrical base 161. One end 165 of this torsion coil spring 164
However, the stopper 160 is always biased in the counterclockwise direction in FIG. 3 by being hooked on the spring hooking portion 151a of the separation pad holder 151 and the other end 166 being hooked on the claw portion 162. As shown in FIG.
Abuts against the above-mentioned restriction portion 143, or
As shown in (b5), the arm portion 163 has the hopper 13
The rotation is restricted by abutting 0. As shown in FIG. 3, the separation pad holder 15
1 is pushed down, the lower portion of the claw portion 162 is the regulating portion 1.
43, or the arm 163 of the arm 163 contacts the hopper 130 as shown in FIG. 13 (b5), the stopper 160 is rotated clockwise against the urging force of the spring 164. The upper portion of the claw portion 162 is more than the surface 150 a of the separation pad 150 facing the paper feed roller 121,
In side view (as viewed from the axial direction of the paper feed roller shaft 110 as shown in FIG. 3), it projects toward the paper feed roller 121. That is, it takes a protruding position. As shown in FIG. 12B3, when the separation pad holder 151 is pushed up and its arm portion 163 does not abut on the hopper 130, the stopper 160 keeps the lower portion of its claw portion 162 abutting on the regulating portion 143. It rotates counterclockwise, and the claw portion 162 does not project from the facing surface (hereinafter referred to as the pad surface) 150a. That is, it takes the retracted position.

180 in FIGS. 3, 4 and 9.
Is a paper return lever.

This paper return lever 180 has its base 1
81 is formed in a tubular shape having a C-shaped cross section, and by utilizing its elasticity, the tubular base portion 181 is fitted to the shafts 145a and 145b formed in the subframe 140, thereby rotating the subframe 140. It is possible to install. A small diameter portion 181a is formed on the cylindrical base portion 181, and a torsion coil spring 182 is attached to the small diameter portion 181a (the small diameter portion 181a is inserted into the coil portion 182a of the torsion coil spring 182). One arm 182b of the torsion coil spring 182 is inserted into a hole 183 formed in the paper return lever 180 and locked by the lever 180, and the other arm 182c is formed at both ends of receiving grooves 146, 146 formed in the subframe 140. Is supported, and the central portion is hooked on the hook 147 to be locked to the sub-frame 140. Therefore, the lever 180 is in the neutral position shown in FIG. 3 when no external force acts on it, but when the external force (the external force of the disk 124 of the bush 122 described later or the external force of the fed paper) acts, the lever 182 is attached. When it rotates clockwise or counterclockwise in FIG. 3 against the force and no external force acts, the restoring force of the spring 182 causes the spring 182 to return to the neutral position.

As shown in FIGS. 3 and 4, the bush 122
A disk 124 is integrally formed at a position corresponding to the paper return lever 180. As shown in FIGS. 3 and 10, the disc 124 is provided with a recess 124a, and the paper return lever 180 in the neutral position described above is inserted into the recess 124a. . Therefore, when the bush 122 rotates (when the paper feeding roller shaft 110 rotates), the corner 12 of the disk 124 is rotated.
4b or 124c abuts the lever 180, which causes the lever 180 to rotate clockwise or counterclockwise in FIG. When rotated in the clockwise direction, the paper is pushed back as described later.

In FIGS. 1 and 2, reference numeral 170 denotes a cover of the paper feed roller 121, which is attached to the subframe 140.

In FIGS. 3 and 4, reference numeral 190 is an idle roller. The idle roller 190 has a disc shape, and is located on the side of the paper feed roller 121.
It is rotatably attached to 2. The circumferential surface 191 of the idle roller 190 is located outside the linear portion 121b of the sheet feeding roller 121 in a side view.

Next, the operation of the paper feeding apparatus as described above will be described mainly with reference to FIGS. Figure 1
1 to 14, FIGS. (A1) to (a8) mainly show the relationship between the hopper cam 135 and the hopper 130, and (b1) to (b8) mainly show the sheet feeding roller 121.
A pad cam 158, a separation pad holder 151,
The relationship with the stopper 160 is shown, and (c1) to (c
8) mainly shows the relationship between the disc 124 and the paper return lever 180. Although the paper P is omitted in the drawings other than the drawings (b1) and (b2), the paper P is actually set on the hopper 130 as shown in the drawings (b1) and FIG. There is.

First, the standby state will be described.

3 and 11 (a1) (b1) (c)
1) shows the state during standby.

During standby, as shown in FIGS. 3 and 11 (a1), since the cam follower 134 of the hopper 130 is in contact with the hopper cam 135, the hopper 13
0 is pushed down.

As shown in FIG. 9 (b1), the paper feed roller 12
In No. 1, the linear portion 121b is opposed to the paper P, and the paper feed roller 121 is not in contact with the paper P.

Therefore, in this state, the paper P can be easily set on the hopper 130.

The separation pad holder 151 (that is, the separation pad 150) is biased in the clockwise direction in FIG. 3 by the pad spring 156 (see FIG. 2), but as shown in FIG. 3 and FIG. The rotation of the part 157 is restricted by the contact of the part 157 with the large diameter part 158a of the pad cam 158. Therefore, the separation pad 150 is separated from the paper feed roller 121 and is pushed down to a position where it cannot contact the paper feed roller 121 at all.

The stopper 160 is the torsion coil spring 16
4 (see FIG. 4), it is urged in the counterclockwise direction in FIG. 11 (b1), but the lower part of the claw portion 162 is pushed down by the separation pad holder 151 being pushed down as described above. It comes into contact with 143 and rotates largely clockwise, and the upper portion of the claw portion 162 projects toward the paper feed roller 121 side from the pad surface 150a. That is, it is in the protruding position.

The paper return lever 180 is shown in FIG. 3 and FIG.
As shown in 1 (c1), it is in the neutral position, and its tip is in the recess 124a of the disc 124.

Next, the paper returning operation and the paper feeding operation will be described.

(I) In this embodiment, first, the paper returning operation is performed.

However, for convenience of explanation, it is easier to understand the paper returning operation after the paper feeding operation described in the following (ii) is performed, so that it will be described later.

(Ii) In FIG. 3, the paper feed roller shaft 11
0 starts rotating clockwise. Therefore, the paper feed roller 121, the bush 122 (disc 124), the hopper cam 135, and the pad cam 158 also start rotating.
Since the rotation angles (phases) of these respective parts are always the same, they will not be described below unless otherwise necessary.

(Iii) As shown in FIG. 11 (b2),
When the pad cam 158 rotates together with the paper feed roller shaft 110 by a predetermined angle and the projection 157 of the separation pad holder 151 comes off the large diameter portion 158a of the pad cam 158, the separation pad holder 151 moves upward due to the urging force of the pad spring 156.
The protrusion 157 contacts the small diameter portion 158b. As a result, the pad surface 150a of the separation pad 150 is positioned on the rotation path of the arcuate portion 121a of the paper feed roller 121.

Since the stopper 160 also moves upward with the upward movement of the separation pad holder 151 (that is, the upward movement of the shaft 159), the stopper 160 is released from the contact with the restricting portion 143. (See FIG. 4), it rotates counterclockwise. However, the rotation is restricted by the arm portion 163 contacting the hopper 130, and the tip 162a of the claw portion 162 still has the pad surface 1.
It projects above 50a.

At this point, the contact between the hopper cam 135 and the cam follower 134 of the hopper 130 has not been released, as shown in FIG. 11 (a2). In addition, FIG.
As shown in (c2), the paper return lever 180 has the disk 1
Although it is pushed by the corner portion 124c of 24 to rotate in the counterclockwise direction, its tip is not removed from the recess 124a.

(Iv) As shown in FIG. 12 (a3), when the hopper cam 135 further rotates together with the paper feed roller shaft 110 and the contact between the hopper cam 135 and the cam follower 134 of the hopper 130 is released, the hopper spring 133 ( (See FIG. 2), the hopper 130 is momentarily pushed up, the paper P is also pushed up, and the uppermost paper P1 is pressed against the arc portion 121a of the paper feed roller 121. Since the hopper 130 and the paper P are momentarily pushed up, even if the upper paper is disengaged from the support surface 152, it hardly descends, and as shown in the figure, the hopper 130 and the paper feed roller 121.
It will be sandwiched between and.

At this point in time, as shown in FIG. 12B3, the arc portion 121a of the sheet feeding roller has the pad surface 150.
Therefore, the arc portion 121a of the sheet feeding roller 121 presses the separation pad 150. Accordingly, the separation pad 150 causes the pad spring 156 (see FIG. 2).
It is pushed counterclockwise against the urging force of the sheet feeding roller 12 by the urging force of the pad spring 156.
It is pressed against the first circular arc portion 121a. In addition, as a result, the protrusion 157 of the separation pad holder 151 has the pad cam 158.
Is separated from the small diameter portion 158b.

Further, as a result of the upward movement of the hopper 130, the contact between the hopper 130 and the arm portion 163 of the stopper 160 is released, so that the stopper 160 rotates counterclockwise until it comes into contact with the regulating portion 143. , Claw 16
2 is a retracted position where it does not project above the pad surface 150a.

As shown in FIG. 12 (c3), the paper return lever 180 is pushed by the corner portion 124c of the disc 124 and rotated counterclockwise to come out of the recess 124a and its front end is disc-shaped. The state is along the peripheral surface of 124.

(V) As the paper feed roller shaft 110 continues to rotate, as shown in FIGS. 12B4 and 15 (partially enlarged enlarged view of FIG. 12B4), an arc portion of the paper feed roller 121 is formed. 121a and the uppermost paper P1 are in contact with each other, so that the paper P1 is separated from the separation pad
Then, the sheet is pressed between the arc portion 121a of the sheet feeding roller 121 and the separation pad 150. That is, the uppermost sheet P1 is fed while being pinched between the sheet feeding roller 121 and the separation pad 150.

At this time, as shown in FIG. 15, a friction force acts between the paper P1 and the paper P2 because the next paper P2 is attracted to the paper P1 by the action of static electricity. As a result, the sheet P2 may be sent together with the sheet P1, but the movement of the sheet P2 is hindered by the leading edge P2a thereof hitting the separation pad 150, and the sheet P2 can be temporarily separated from the sheet P1. Similarly, even if the lower-order sheet P3 or the like is sent, it can be separated in the same manner.

Further, as described above, the paper feed roller 121
The coefficient of friction between the paper and the paper is μ1, the coefficient of friction between the separation pad 150 and the paper is μ2, and the coefficient of friction between the papers is μ.
When it is set to 3, μ1>μ2> μ3, and therefore, as the paper feed roller 121 rotates, 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. , The paper P2 is the separation pad 15
The movement of the sheet P is blocked by the frictional force between the sheet P and the sheet 0, the sheet P1 is secondarily separated from the sheet P1, and only the sheet P1 is fed. Similarly, even if the lower-order sheet P3 or the like is sent, it can be separated in the same manner. As will be understood from the following, the "next-order sheet P3" includes the lower-order sheet P3 and the like. However, in order to avoid complication of the description, the "lower-order sheet P3" is included unless necessary. etc"
Including the above, we will simply call it the "next-generation paper."

In this way, the paper is nipped by the paper feed roller 121 and the separation pad 150 that rotate in the normal direction, so that the uppermost paper P1 to be sent by the paper feed roller 121 is separated from the next paper P2. Then, only the uppermost sheet P1 is fed.

At this time, since the stopper 160 is already in the retracted position, it does not interfere with the sheet P1 to be fed.

That is, when the front end P1a of the paper P1 to be fed passes between the separation pad 150 and the idle roller 160, the stopper 160 is already in the retracted position.

(Vi) Further, the paper feed roller shaft 110 continues to rotate, and as shown in FIG. 13 (a5), the hopper cam 13
5 again contacts the cam follower 134 of the hopper 130, and the hopper 130 is pushed down.

At this point in time, as shown in FIG. 13B5, the separation pad 150 is still in pressure contact with the paper feed roller 121 via the paper P1.
The uppermost sheet P1 continues to be fed by the paper feed roller 121, and the leading edge P1a thereof has already been fed.
1 and the separation pad 150 have passed through the pinching portion.

The stopper 160 is rotated clockwise when the hopper 130 is pushed down and the arm portion 163 is pushed down, and the tip 162a of the claw portion 162 projects onto the pad surface 150a. Therefore, the tip 162a of the claw portion 162 comes into contact with the back surface of the uppermost sheet P1.

That is, the tip 162a of the stopper 160
After the leading edge P1a of the uppermost sheet P1 passes through the pinching portion between the paper feed roller 121 and the separation pad 150, the separation pad 150 moves the paper feed roller 121 as described below (FIG. 13B6). Before it is separated from the front side of the pinching portion, it protrudes above the pad surface 150a (front side in the sheet feeding direction).

As shown in FIG. 13C5, the paper P1 is fed by rotating the paper return lever 180 counterclockwise, and the paper return lever 180 is fed by the paper return lever 180 until the rear end of the paper P1 passes. Accordingly, it is rotated counterclockwise.

(Vii) Further, the paper feed roller shaft 110 continues to rotate, and as shown in FIG.
The large-diameter portion 158 a of 58 abuts against the protrusion 157 of the separation pad holder 151 again, the separation pad holder 151 is pushed down, and the separation pad 150 is separated from the paper feed roller 121.

At this point of time, the leading edge of the sheet P1 has reached the conveying roller pair 2 and 3 which is the conveying means in the subsequent stage, and hence the sheet P1 can be conveyed by the conveying roller pairs 2 and 3 thereafter.

The stopper 160 is the separation pad holder 15
When 1 is pushed down, the lower portion of the claw portion 162 comes into contact with the regulating portion 143 and pivots largely clockwise,
The upper portion of the claw portion 162 projects more toward the paper feed roller 121 than the pad surface 150a. At this time, the claw portion 162
The tip end 162a of the paper feed roller 121 and the circumferential surface of the paper feed roller 121 overlap each other in a side view, and the tip end 162 of the claw portion 162.
a is still in contact with the back surface of the paper P1.

Therefore, as described above, the paper feed roller 1
21 and the separation pad 150 are separated from each other, whereby the next paper P2 slides down by its own weight, and even if the leading end P2a of the paper P2 tries to pass between the pad surface 150a and the paper feed roller 121, this is reliably prevented. The Rukoto.

In the process in which the uppermost sheet P1 is conveyed by the conveying roller pairs 2 and 3 in the subsequent stage, the next highest sheet P2 is adsorbed to the sheet P1 by the action of static electricity, or the sheet P1 and the sheet P1 are conveyed between them. Even if the paper P1 is sent by frictional force, this is prevented.

It should be noted that the hopper 130 is still in the depressed state as shown in FIG. 13 (a6), and the paper return lever 180 is in the state of the paper P as shown in FIG. 13 (c6).
It remains rotated counterclockwise by 1.

(Viii) Further, when the paper feed roller shaft 110 further rotates and makes one full rotation from the standby state described above, the respective members become as shown in FIGS. 14 (a7) (b7) (c7).
The state is the same as the standby state (states shown in FIGS. 11 (a1) (b1) (c1)).

However, at this point, the sheet P1 is not completely removed from the sheet feeding device, and is conveyed by the pair of conveying rollers 2 and 3 shown in FIG. 2 as described above. Become.

Also in this case, the stopper 160
, The upper part of the claw portion 162 is still protruding from the pad surface 150a toward the paper feed roller 121 side, so that the next paper P2 tries to slide down by its own weight, or the paper P
Even if the sheet 1 is attracted by the action of static electricity or is sent together with the sheet P1 due to the frictional force with the sheet P1,
This is prevented.

As described above, the paper feed roller 121
The idle roller 190 is provided on one side (the right side in FIG. 4).
Is provided, and its circumferential surface 191 is located outside the linear portion 121b of the paper feed roller 121 in a side view,
Further, a disk 124 is provided on the other side (left side in FIG. 4) of the paper feed roller 121, and its outer peripheral surface (mainly corner portions 124b and 124c) is seen from the side.
Since the sheet P1 is located outside the linear portion 121b of the sheet 1 (see FIG. 7 (c7) and FIG. 3), when the sheet P1 is conveyed by the pair of conveying rollers 2 and 3, the sheet P1 is made of a high friction material. Since the paper roller 121 does not come into contact with the paper roller 121, or if it comes into contact with the paper roller 121, the contact with the paper roller 121 made of a high-friction material does not increase the load on the conveyance of the paper P1.

(Ix) After the trailing edge P1b of the sheet P1 fed and conveyed as described above is removed from the sheet feeding device as shown in FIG. 14B7, the sheet feeding operation is performed again as necessary. However, once the paper feeding operation is performed as described above, the leading end P2a of the next paper P2 has entered the space between the separation pad 150 and the paper feeding roller 121. There is. In particular, in the sheet feeding device of this embodiment, since the hopper 130 is arranged in a downward slope toward the separation pad, the leading edge P2a of the next paper P2 is located between the separation pad 150 and the paper feed roller 121. It is easy to get into This tendency is promoted when the paper is a slippery film or the like.

Therefore, when the paper feeding operation is repeated in such a state, the next paper P3 or the like is further fed to the paper feeding roller 121.
Between the sheet and the separation pad 150, and the next sheet enters again. As a result, the sheet is accumulated, and as a result, even if the stopper 160 is provided, the next sheet should not be sent. There is a possibility that a sheet of paper may be sent together with the uppermost paper (double-fed).

Therefore, in the sheet feeding device of this embodiment, before the sheet feeding operation, the sheet returning operation is first performed in (i) as described above. That is, this paper return operation is
Prior to the above-mentioned operation (ii), the operation is performed as follows.

The paper returning operation is as follows.

(I) The standby state described above (see FIG.
1) (b1) (c1), or FIG. 14 (a7) (b7)
14 (a8) (b8) from the state shown in (c7).
As shown in (c8), the paper feed roller shaft 110 rotates counterclockwise (reverse rotation).

As a result, as shown in FIG. 14 (c8), the paper return lever 180 moves the corner portion 124b of the disc 124.
It is pushed by and rotates clockwise (rearward), and the trailing edge 185
Push back the front edge P2a of the paper.

At this time, the projection 1 of the separation pad holder 151
The sheet 57 remains in contact with the large-diameter portion 158a of the pad cam 158, and therefore the separation pad 150 remains in a state of being separated from the sheet feeding roller 121, so that the sheet P2 is smoothly pushed back.

As shown in FIGS. 14 (a8) and 14 (c8), since the cam follower 134 of the hopper 130 is in contact with the hopper cam 135 and is still pressed down, the pushed-back paper P2 remains in the hopper 130. Easy to fall on.

In this embodiment, the hopper cam 1
By further rotating the paper feed roller shaft 110 in the range in which 35 does not come off the cam follower 134, the paper return lever 180 is rotated further rearward (the tip of the lever 180 rotated further rearward as shown in FIG. Virtual line 18
The sheet P2 is completely pushed back onto the hopper 130. That is, the paper return lever 180
Pushes the sheet P2 back so that the front end P2a of the sheet P2 reaches behind the support surface 152. As a result, the paper P2
Will be completely returned (dropped) onto the hopper 130 due to its own weight. Thus, FIG.
When the paper feed roller shaft 110 is further reversed from the state shown in (b8), the protrusion 157 of the separation pad holder 151 is
The pad cam 158 is disengaged from the large-diameter portion 158a, and thus the separation pad 150 and the paper feed roller 121 are pressed against each other. At this time, however, the leading edge of the paper P2 has already been pushed back to the rear of the pressed contact portion. , Paper P
The push-back operation of No. 2 is not adversely affected.

As described above, it is possible to completely return the paper P2 onto the hopper 130.
If the leading edge P2a of at least the next-order sheet P2 is pushed back so as to be positioned behind the pressure contact position between the sheet feed roller 121 and the separation pad 150, the above-mentioned cumulative approach is prevented.

After the paper returning operation as described above is performed,
The paper feed roller shaft 110 rotates in the normal direction, and after the standby state described above, the paper feed operation after (ii) is performed.

According to the paper feeding device as described above, the following operational effects can be obtained.

(A) A paper feed roller 121 that is driven to rotate normally during a paper feed operation, and a plurality of sheets of paper P to be fed in contact with the paper feed roller 121 are stacked, and the paper feed roller 121 rotates in the normal direction. By pinching the paper P between the hopper 130 that sometimes presses the paper P toward the paper feed roller 121 and the paper feed roller 121 when the paper feed roller 121 rotates normally, the paper should be fed by the paper feed roller 121. Since the upper pad P1 is provided with the separation pad 150 for separating the upper paper P2 from the next paper P2, only the uppermost paper P1 is fed during the paper feeding operation.

Since the separation pad 150 is separated from the paper feed roller 121 after the uppermost paper P1 is fed by the paper feed roller 121 by a predetermined amount, the above-mentioned load (back tension) is almost eliminated. Even so, it will be extremely small.

In the case of the paper feeding device of this embodiment, the paper P
When the sheet 1 is conveyed by the pair of conveying rollers 2 and 3, the idler roller 190 which is a free roller, the stopper 160, the sheet returning lever 180, and the disc 124 can come into contact with the rear portion of the sheet P1. Only (the pad cam 158 and the projection 157 of the separation pad holder 151 are outside the sheet passage area as apparent from FIG. 4 and therefore do not contact the sheet), and these respective members merely contact the sheet P1. However, since the paper is not clamped as in the conventional case, the load (back tension) acting on the paper P1 is almost eliminated or extremely small. The spring 182 urging the sheet return lever 180 is only for returning the lever 180 to the neutral position when no external force acts on it.
Since it is not for returning the sheet, the contact force of the lever 180 with the sheet P1 by the spring 182 can be made extremely small.

When the separation pad 150 is separated from the paper feed roller 121 after the uppermost paper P1 has been fed by the paper feed roller 121 by a predetermined amount, when the uppermost paper P1 is conveyed by the conveying means in the subsequent stage, The next-order sheet P2 is attracted to the upper-order sheet P1 by the action of static electricity, or the friction force between the sheets causes the next-order sheet P2 to arrive.
2 may be sent together with the uppermost sheet P1.

However, according to the paper feeding device of this embodiment, the separation pad 150 feeds paper after the leading edge P1a of the uppermost paper P1 passes through the pinching portion between the paper feed roller 121 and the separation pad 150. Before separating from the roller 121,
Since the stopper 160 projects toward the paper feed roller 121 side in a side view from the pad 150a in front of the pinching portion, the stopper 160 allows the next paper P to be conveyed.
2 is prevented from passing, and as a result, only the uppermost sheet P1 is conveyed. When the leading edge P1a of the uppermost sheet P1 passes through the pinching portion between the sheet feeding roller 121 and the separation pad 150, the stopper 160 is at the retracted position, which is the non-projecting position, so this is the highest level. Paper P1
It does not hinder the passage of the tip P1a.

In this way, the next-order sheet P2, the passage of which is prevented by the stopper 160, is directed rearward by the sheet return lever 180 which rotates rearward after the trailing edge P1b of the uppermost sheet P1 has passed. Will be pushed back.

As a result, the next paper P2 gradually (cumulatively) enters the pressure contact portion between the paper feed roller 121 and the separation pad 150, and the paper cannot be separated.

As described above, according to the paper feeding device of this embodiment, it is possible to reliably feed the sheets one by one even though the load can be reduced by using the separation pad method. it can.

(B) The hopper 130 is separated by the separation pad 150.
Since the uppermost sheet P1 is fed, the secondmost sheet P2 also slides down toward the nip between the sheet feeding roller 121 and the separation pad 150. Easier to do. Further, the uppermost sheet P1 is the paper feed roller 1.
When the separation pad 150 is separated from the paper feed roller 121 after being fed by the predetermined amount by the sheet 21, the uppermost sheet P1 and the next sheet P2 are more easily fed.

However, according to the paper feeding apparatus of this embodiment, the passage of the next paper P2 is prevented by the stopper 16
Since it is prevented by 0 and is pushed back toward the rear by the paper return lever 180, even if the inclination angle of the hopper 130 is increased, it is possible to feed the paper one by one.

Therefore, according to the sheet feeding device of this embodiment, the installation area can be reduced by increasing the inclination angle of the hopper (for example, 45 ° or more).

(C) The hopper 130 is a hopper that separates the sheets stacked on the hopper 130 from the paper feed roller 121 at least when the sheet return lever 180 is rotated rearward. A support surface 152 that supports the leading edge of the sheets stacked on the hopper 130 is provided in the front of the sheet feeding direction, and the sheet return lever 180 is configured such that the leading edge P2a of the next sheet P2 is behind the supporting surface 152. Since the next-order sheet P2 is pushed back so as to reach, the leading end P2a of the pushed-back next-order sheet P2 is supported by the support surface 152.

Therefore, the above-described cumulative entry of the next-order sheet P2 is surely prevented.

(D) The paper feed roller 121 is reversely rotated before the forward rotation, and the paper return lever 180 is rotated backward by this reverse rotation, so that the paper feed operation is started before the paper feed operation is started. Even if the paper has entered between the paper feed roller 121 and the separation pad 150 for some reason, it can be reliably returned once.

Therefore, if the paper feed operation is performed as it is while the paper is inserted between the paper feed roller 121 and the separation pad 150 for some reason, a trouble (for example, a defective feeding of the paper) will occur. It can be prevented.

(E) Since the separation pad 150 is separated from the paper feed roller 121 by the operation of the pad cam 158 provided on the shaft 110 of the paper feed roller, the separation pad 150 is separated at a desired timing. In addition, the structure can be simplified. For example, as compared with a case where the separation pad 15 is configured to be operated by a solenoid or the like, the separation pad 15
It is possible to separate 0s and to have a simple structure.

(F) Since the operation of the stopper 160 is interlocked with the rotation of the shaft 110 of the sheet feeding roller, the stopper 160 can be projected or retracted at a desired timing, and the structure can be simplified. Can be planned. For example, the stopper can be projected or retracted at a more reliable timing, and a simple structure can be achieved, as compared with the case where it is operated by a solenoid or the like.

(G) As shown in FIG. 11 (b1), since the stopper 160 is in the projecting position during standby, the leading edge of the paper passes between the paper feed roller 121 and the separation pad 150 for some reason. The situation that it ends up is prevented.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be appropriately made within the scope of the gist of the present invention.

For example, the paper feed roller is not limited to the D-shaped side view, but may be a round roller.

[0144]

According to any of the sheet feeding devices of claims 1 to 8, it is possible to reliably feed the sheets one by one even though the load can be reduced by using the separation pad method. it can.

Further, according to the sheet feeding device of the fourth aspect , the installation area can be reduced by increasing the inclination angle of the hopper.

According to the sheet feeding device of the fifth aspect, the cumulative entry of the next sheet is surely prevented.

According to the sheet feeding device of the first or sixth aspect , if the sheet is fed between the sheet feeding roller and the separation pad for some reason, the sheet feeding operation is performed as it is. It is possible to prevent a defect (for example, defective cueing of paper) from occurring.

According to the paper feeding device of the second or seventh aspect , the separation pads can be separated at a desired timing and the structure can be simplified.

According to the sheet feeding device of the third or eighth aspect , the stopper can be projected or retracted at a desired timing, and the structure can be simplified.

[0150]

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a paper feeding device according to the present invention.

FIG. 2 is a partially omitted side view showing an example of attachment of a paper feeding device to a printer.

FIG. 3 is a partially cut side view showing a main part of the sheet feeding device, that is, a sheet feeding roller mainly inside the sheet feeding roller unit, a separation pad, and the periphery thereof.

FIG. 4 is a partial omission IV arrow view in FIG.

FIG. 5 is a diagram showing details of a subframe 140, (a)
Is a plan view, (b) is a cross-sectional view taken along the line bb in FIG.

FIG. 6 is a view showing details of a separation pad holder 151,
(A) is a plan view, (b) is a left side view when FIG. (A) is a front view, (c) is a right side view when (a) is a front view.

FIG. 7 is a side view of the pad cam 158.

8A and 8B are diagrams showing details of the stopper 160, where FIG. 8A is a right side view, FIG. 8B is a rear view, and FIG. 8C is a left side view.

9 is a perspective view mainly showing a paper return lever 180 and a subframe 140. FIG.

FIG. 10 is a side view showing a disc 124 of the bush 122.

11 (a1) (b1) (c1) (a2) (b2)
(C2) is an operation explanatory view.

FIG. 12 (a3) (b3) (c3) (a4) (b4)
(C4) is an operation explanatory view.

13 (a5) (b5) (c5) (a6) (b6)
(C6) is an operation explanatory view.

14 (a7) (b7) (c7) (a8) (b8)
(C8) is an operation explanatory view.

FIG. 15 is an explanatory view of the operation, and is an enlarged view with a part omitted in FIG. 12 (b4).

FIG. 16 is an explanatory diagram of a conventional technique.

17A to 17E are explanatory views of a conventional technique.

[Explanation of symbols]

P paper P1 topmost paper P2 Secondary paper 110 Paper feed roller shaft 121 paper feed roller 121a arc part 121b Straight part 130 hoppers 150 separation pad 150a Pad surface (opposing surface) 152 support surface 158 Pad Cam 160 stopper 180 Paper return lever

Continuation of front page (56) Reference JP-A-59-217538 (JP, A) JP-A-8-81078 (JP, A) JP-A-6-234437 (JP, A) JP-A-8-217280 (JP , A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65H 1/02 B65H 3/06 330 B65H 3/32 B65H 3/52

Claims (8)

(57) [Claims] 1. A sheet feeding roller that is driven to rotate normally during a sheet feeding operation, and a plurality of sheets to be fed in contact with the sheet feeding roller are stacked, and the sheet feeding roller is rotated when the sheet feeding roller rotates normally. The uppermost paper to be fed by the paper feed roller is separated from the next paper by pinching the paper between the hopper that presses the paper toward and the paper feed roller when the paper feed roller rotates normally. , The separation pad that is separated from the paper feed roller after the uppermost paper is fed by the paper feed roller by a predetermined amount, and is closer to the paper feed roller side than the surface of the separation pad facing the paper feed roller. A protruding position that protrudes and a retracted position that does not protrude can be provided, and when the leading edge of the uppermost sheet passes through the pinching portion between the paper feed roller and the separation pad, it is in the retracted position and the leading edge of the uppermost sheet. After passing through the clamping unit, the separation pad is After passing through the stopper that protrudes in front of the pressing unit before separating from the paper roller and the trailing edge of the uppermost sheet fed by the sheet feeding roller, rotate backward and move to the next position. and a paper return lever pushes toward the paper backward, the paper feed roller is temporarily reversed before the forward rotation, reverse
The paper feeding device , wherein the paper return lever is rotated backward by turning . 2. A paper feeding roller which is driven to rotate normally during a paper feeding operation.
And multiple sheets of paper to be fed in contact with this paper feed roller.
Stacked for facing the paper feed roller when the paper feed roller rotates in the forward direction
Nip the paper between the hopper that presses the paper and the paper feed roller when the paper feed roller rotates normally.
By pressing, the top to be fed by the feed roller
Paper is separated from the next paper, and the top paper is fed.
After feeding a predetermined amount by the roller, separate from the paper feeding roller
That the separation pad, than the opposing surfaces of the feed roller of the separation pad, the side
In the plan view, the protruding position that protrudes toward the paper feed roller and the protruding position
Can be set to a different retracted position.
When the leading edge of the uppermost sheet passes through the pressure section, the retracted position
And the leading edge of the uppermost sheet has passed the pinching section.
After the before said separation pad is between away from the paper feed roller
The stopper protruding in front of the pressing unit and the trailing edge of the topmost sheet fed by the sheet feeding roller are
After passing, rotate backward to move the next sheet of paper backward.
A paper return lever for pushing back the separation pad, and the separation pad is a cover provided on the shaft of the paper feed roller.
A paper feeding device characterized in that it is separated from the paper feeding roller by the operation of the system. 3. A paper feeding roller which is driven to rotate normally during a paper feeding operation.
And multiple sheets of paper to be fed in contact with this paper feed roller.
Stacked for facing the paper feed roller when the paper feed roller rotates in the forward direction
Nip the paper between the hopper that presses the paper and the paper feed roller when the paper feed roller rotates normally.
By pressing, the top to be fed by the feed roller
Paper is separated from the next paper, and the top paper is fed.
After feeding a predetermined amount by the roller, separate from the paper feeding roller
That the separation pad, than the opposing surfaces of the feed roller of the separation pad, the side
In the plan view, the protruding position that protrudes toward the paper feed roller and the protruding position
Can be set to a different retracted position.
When the leading edge of the uppermost sheet passes through the pressure section, the retracted position
And the leading edge of the uppermost sheet has passed the pinching section.
After the separation pad is separated from the paper feed roller,
The stopper protruding in front of the pressing unit and the trailing edge of the topmost sheet fed by the sheet feeding roller are
After passing, rotate backward to move the next sheet of paper backward.
A paper return lever for pushing back is provided, and the operation of the stopper is interlocked with the rotation of the shaft of the paper feed roller.
A paper feeder that is characterized by 4. The hopper is arranged so as to be inclined downward toward the separation pad.
The paper feeding device according to 1, 2, or 3 . 5. The hopper is a hopper that separates the paper stacked in the hopper from the paper feed roller when at least the paper return lever is rotated rearward, and the paper feed of the hopper is performed. At the front in the direction, there is provided a supporting surface for supporting the leading edge of the sheets stacked on the hopper, and the sheet return lever is arranged so that the leading edge of the next sheet reaches the rear side of the supporting surface. 5. The paper feeding device according to claim 1, 2, 3, or 4 , wherein the paper feeding device is pushed back. Wherein said feed roller, said once inverted before forward, claim 2,3,4 the sheet return lever by the reverse rotation, characterized in that rotates backward or 5,
The paper feeder described. 7. The feeding unit according to claim 1, 3, 4, 5, or 6, wherein the separation pad is separated from the feeding roller by the operation of a cam provided on the shaft of the feeding roller. Paper equipment. 8. The operation of the stopper is interlocked with the rotation of the shaft of the paper feed roller .
2, 4, 5, 6, or 7, the sheet feeding device.