JP3422236B2 - 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 laminated paper (plain paper, coated paper, OHP (overhead projector) sheet, glossy paper, cut sheet such as glossy film, or envelope), which is the highest grade. The present invention relates to a sheet feeding device that feeds sheets one by one. 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. 23, when the paper feed device 1 using the pad separation system is used in a printer, the fed paper P1 is conveyed while being pinched by the conveyance rollers 2 and 3, Although the printing is performed by the printing unit 4, the paper P1 is not normally completely removed from the paper feeding device when the transportation of the paper P1 by the transportation rollers 2 and 3 is started.

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 separated from each other when the conveyance of the paper P1 by the conveyance rollers 2 and 3 is started. Is pressed, the paper P1
Is in a state where the rear part thereof is pinched 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 rollers 2 and 3.

If such a load (that is, back tension) is large, the feeding accuracy of the paper by the conveying rollers 2 and 3 is deteriorated, and the printing quality is also deteriorated. It is desirable that the pressure contact force of is as small as possible. However, if 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.

24 (a) to 24 (e) 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-mentioned problem, that is, the next sheet of paper gradually enters the pressure contact portion between the paper feed roller and the separation pad and the paper cannot be separated, is once solved. Also seems to.

[0020]

In the conventional mechanism shown in FIG. 24, the lever 22 is rotatably driven by the urging force of the spring 26 when the next sheet S2 is pushed back. If the biasing force of the spring 26 is small, the next-order sheet S2 may not be surely pushed back.

If the biasing force of the spring 26 is increased, the next sheet S2 may be surely pushed back. However, the lever 22 has the highest sheet S1.
When the sheet is fed, the sheet S1 has to be pushed by the sheet S1 to escape as shown in FIGS. 24 (c) and 24 (d). Therefore, 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 above-mentioned conventional mechanism, in order to reduce the load (back tension), the spring 2 is used.
Although the urging force of 6 has to be reduced, if the urging force of the spring 26 is reduced, the next sheet S2 is not necessarily pushed back reliably, and as a result, the sheets can be reliably fed one by one. There is a risk that it will not be possible.

An object of the present invention is to solve the above problems and to make it possible to surely push back the next paper without increasing the load by using the separation pad system, thereby ensuring the paper. An object of the present invention is to provide a sheet feeding device that can feed sheets one by one.

[0024]

In order to achieve the above object, a sheet feeding device according to a first aspect of the present invention is a sheet feeding device which rotates normally during a sheet feeding operation and which is the uppermost sheet held in a stacked state of a plurality of sheets. The uppermost sheet to be fed by the paper feed roller, which contacts and feeds the paper, and the paper which is urged toward the paper feed roller and pinches the paper to feed the paper. And the separation pad for separating the next paper from the next paper and the trailing edge of the uppermost paper fed by the paper feed roller are passed, and then rotated backward so that the leading edge of the next paper is the paper feed roller. And a paper return lever that pushes back the next paper toward the rear so as to be located behind the contact portion with the separation pad, and the rearward rotation of the paper return lever causes the paper feed roller to rotate. It is characterized by being driven by reverse rotation.

According to a second aspect of the present invention, in the paper feeding device according to the first aspect, the paper feed roller is reversely rotated before the forward rotation, and the reverse rotation causes the paper return lever to rotate backward. It is characterized by moving.

According to a third aspect of the present invention, in the sheet feeding device according to the first or second aspect, the sheets held in the stacked state face a contact portion between the sheet feeding roller and the separation pad. It is characterized in that it is held in an inclined state in a direction in which it can slide down.

[0027]

According to the paper feeding device of the present invention, the paper feeding device rotates in the normal direction during the paper feeding operation, and comes into contact with the uppermost sheet of the sheets held in the stacked state of a plurality of sheets to feed the sheet. Laura,
And a separation pad that is urged toward the paper feed roller and pinches the paper between the paper feed roller and the top paper to be sent by the paper feed roller from the next paper. Therefore, at the time of the paper feeding operation, only the uppermost paper is fed.

After the trailing edge of the uppermost sheet fed by the sheet feed roller has passed, the sheet return lever is rotated backward to separate the leading edge of the next sheet from the sheet feed roller. The next-order sheet is pushed back toward the rear so as to be positioned rearward of the contact portion with the pad.

At this time, since the backward movement of the paper return lever is driven by the reverse rotation of the paper feed roller, the next paper is surely pushed back.

Therefore, according to this paper feeding device, the next paper is gradually (cumulatively) entered into the contact portion between the paper feed roller and the separation pad, and the paper cannot be separated. It can be surely prevented.

As described above, according to the paper feeding apparatus of the first aspect, the separation pad method is used to reliably feed the sheets one by one without increasing the above-mentioned load (back tension). be able to.

According to the paper feeding apparatus of the second aspect, in the paper feeding apparatus of the first aspect, the paper feeding roller reverses once before the forward rotation, and the reverse operation causes the paper return lever to move backward. Since it is configured to rotate to, 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, it can be reliably returned once. .

Therefore, if the paper feed operation is performed as it is while the paper has entered between the paper feed roller and the separation pad for some reason (for example, skewed paper or paper head). It is possible to prevent the occurrence of defective printing.

According to the sheet feeding device of the third aspect, in the sheet feeding device of the first or second aspect, the sheets held in the stacked state are a contact portion between the sheet feeding roller and the separation pad. Since it is configured to be held in a slanting direction in a direction in which it can slide down toward the top, when the uppermost sheet is fed, the next sheet also contacts the feed roller and the separation pad. It becomes easier to glide toward.

In such a situation, if it is assumed that the next paper is not pushed back by the paper return lever, the next paper is gradually pushed to the pressure contact portion between the paper feed roller and the separation pad as described above. The situation occurs in which (cumulatively) entry is made and the sheets cannot be separated.

On the other hand, according to the sheet feeding device of the third aspect, the second sheet is surely pushed back by the configuration of the first or second aspect.
The holding state of the sheet can be inclined to a direction in which the sheet can slide down toward the contact portion between the sheet feeding roller and the separation pad, and the inclination angle is increased (for example, 45 ° or more). be able to.

Therefore, according to the sheet feeding device of the third aspect, the installation area can be reduced.

[0038]

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 paper feeding apparatus according to the present invention, and FIG. 2 is a view showing an example of attachment to a printer, and a partially omitted side view showing a part thereof.

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 (FIG. 2) are set on the hopper 130 in a stacked state.

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 cut side view showing the main part of the paper feeding device, that is, mainly the paper feeding roller unit, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3, and FIG. A sectional view and FIG. 6 are partially omitted plan views of FIG.

In these drawings, reference numeral 121 denotes a paper feed 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 the 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 mainly through a bush 122 as shown in FIG. That is, the paper feeding roller 121 and the bush 122 are the same as the paper feeding roller shaft 11.
It cannot rotate with respect to 0. 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 (see FIG. 2). The leading edge Pa of the set paper P is supported and aligned by abutting the back surface (support surface) 152 of the separation pad holder 151 and the surface 152a of the sub-frame, which will be described later.

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. 5, that is, in the direction in which the paper P is brought into contact with the paper feed roller 121. However, as shown in FIGS. Cam followers 134 are formed at both ends of the cam 130.
Is a hopper cam 135 fixed to the paper feed roller shaft 110.
(See FIG. 1) the rotation thereof is restricted. As shown in FIGS. 5 and 6, a pad 1 similar to a separation pad described later is provided on the upper surface of the tip of the hopper 130.
36 are provided. Note that in FIGS. 8, 9, and 10, the surface 152a of the sub-frame 140 is a support surface of the leading edge of the paper P stacked on the hopper 130.

Reference numeral 150 is 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 that of the paper feed roller 121 with respect to the paper P. 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 μ
1>μ2> μ3.

As shown in FIGS. 7 and 8, the separation pad holder 151 includes a pad support portion 153 to which the separation pad 150 is fixed, and a support surface (rear surface) 152 portion of the above-mentioned sheet front end which is integral with the pad support portion 153. The sub-frame 140 has an arm portion 154 formed integrally therewith, and the shafts 155 provided on both sides of the rear end of the arm portion 154 fit into the track holes 140a of the sub-frame 140.
Is rotatably attached to.

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. 5, that is, in the direction of bringing the separation pad 150 into contact with the sheet feeding roller 121. Is the protrusion 157
(See FIGS. 7 and 8) are formed, and the protrusion 157 is formed.
However, as shown in FIG. 4, its rotation is regulated by abutting on a pin 141 (see FIG. 8) which is a pad regulating means provided on the sub-frame 140. With the protrusion 157 in contact with the pin 141, the separation pad 150 is located on the rotation path of the arc portion 121 a of the paper feed roller 121.

In FIGS. 3 to 5 and 9, 160
Is an idle roller, and 161 is an idle roller holder. Incidentally, 170 is a cover of the paper feed roller 121,
It is attached to the subframe 140.

The idle roller holder 161 has a substantially ring shape having a hole 161a at its center. A shaft 163 is provided below one side surface of the idle roller holder 161, and the idle roller 160 is rotatably supported by the shaft 163. In FIG. 9, 163
a is a retaining hook.

As shown in FIG. 9, the idle roller holder 161 is formed with a pair of claws 161b and 161b. These claws 161b and 161b are formed on the sub-frame 14a.
The idle roller holder 161 is attached to the sub-frame 140 by lightly fitting with the long holes 142, 142 provided at 0. As shown in FIGS. 4 and 5, a pair of pins 161c and 161c are provided above and below the other side surface of the idle roller holder 161, respectively. As shown in FIGS. Track holes 143, 14 formed in the frame 140
It fits slidably with respect to 3. further,
As shown in FIG. 4, the paper feed roller shaft 110 and the bush 122 are inserted into the hole 161a of the idle roller holder 161, and the diameter of the hole 161a is formed larger than the outer diameter of the corresponding portion 122a of the bush 122. Has been done.

Therefore, the idle roller holder 161
The pins 161c, 161c have track holes 143,
By being guided by 143, the arrow a in FIG.
Slidable in the direction of 1, a2, and therefore also
The idle roller 160 can also slide in the directions of arrows a1 and a2.

As shown in FIGS. 3, 4, and 9, a spring receiving portion 164 is provided above the idle roller holder 161.
Is provided, and a roller spring (tensile coil spring) 165 as a roller urging unit is provided so as to straddle the spring receiving portion 164. This roller spring 16
5 is attached to the sub-frame 140 by locking both ends thereof to the hooking portions 144 and 144 (see FIG. 9) formed on the inner surface of the sub-frame 140. Therefore, the idle roller holder 161 is constantly urged in the direction of arrow a1 in FIG. 5 by the roller spring 165. Cam 12 formed on
Its movement is restricted (by abutting against 3). The biasing force of the roller spring 165 is set smaller than the biasing force of the pad spring 156. Therefore, the idle roller 160 does not push down the separation pad 150.

On the other hand, a cam follower 166 is formed above one side surface of the idle roller holder 161, and the cam follower 166 comes into contact with and separates from the cam 123 (see FIGS. 3 to 5) formed on the bush 122 described above. As a result, the idle roller holder 161 moves in the direction of arrow a1 or a2, and therefore the idle roller 160 also moves in the direction of arrow a1 or a2. That is, in this embodiment, the idle roller retracting mechanism is composed of the idle roller holder 161 and the cam 123, and the operation of the cam 123 causes the leading end of the sheet to be fed to separate the pad 150. And the idle roller 160, the idle roller 160 is separated from the separation pad 150, and after the leading edge of the paper passes between the separation pad 150 and the idle roller 160, the arc portion 121a of the paper feed roller 121 The idle roller 160 is separated from the separation pad 15 before the contact between the separation pad 150 and the separation pad 150 is released.
The shape of the cam 123 is configured so as to be brought into contact with 0.

In FIGS. 3, 4, 9, and 10, reference numeral 180 denotes a paper return lever.

The paper return lever 180 has a base portion 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 tubular base portion 181, and the torsion spring 18 is attached to the small diameter portion 181a.
2 is attached (the small diameter portion 181a is the torsion spring 18).
Second coil portion 182a). One arm 182b of the torsion 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 18
0 is in the neutral position shown in FIGS. 3 and 9 when no external force acts on it, but when an external force (an external force of the disk 124 of the bush 122 described later or an external force of the fed sheet) acts, the spring 182 is attached. When it rotates clockwise or counterclockwise in FIG. 3 against the force and the external force stops acting, it returns to the neutral position by the urging force of the spring 182. Therefore, the biasing force of the spring 182 is a biasing force (weaker biasing force than the prior art) that can return the sheet return lever 180 to the neutral position when the sheet return lever 180 is no longer applied with an external force. There is enough.

As shown in FIG. 4, the bush 122 includes:
A disk 124 is integrally formed at a position corresponding to the sheet return lever 180 as an operating body that operates the sheet return lever 180. As shown in FIGS. 3 and 11, the disc 124 is provided with a recess 124a, and the sheet return lever 180 in the neutral position described above is inserted into the recess 124a. . Therefore, when the bush 122 rotates (feed roller shaft 1
10 rotates), the corner portion 124b or 124c of the disk 124 abuts the lever 180, and the lever 180 is rotationally driven clockwise or counterclockwise in FIG. When rotated in the clockwise direction, the paper is pushed back as will be described later, and at this time, the separating pad 150 described above is separated from the idle roller 160 by the separating mechanism described below. There is.

The separation mechanism is mainly composed of the paper return lever 180 and the separation lever 190 (FIG. 1) incorporated in the lower surface of the pad support portion 153 of the separation pad holder 151.
2)) and.

12 (a) and 12 (b) show a separation lever 190.
FIG. 7 is a perspective view showing a state in which the above is incorporated into a separation pad holder 151. In addition, in this figure, the top and bottom are drawn upside down in order to make it easy to understand the assembled state.

The separating lever 190 has a shaft 191, a spring receiving portion 192, and a projecting piece 193.

On the other hand, the separation pad holder 151 has a bearing hole 151a, a bearing groove 151b, and a window 151c.
And spring receiving holes 151d, 151d are formed.

The separating lever 190 has its projection 193 inserted into the window 151c so that the shaft 191 receives the bearing hole 1.
The separation pad holder 151 is attached to the separation pad holder 151 so as to be rotatable around the shaft 191 by being fitted in the bearing groove 151b and the bearing groove 151b.

In FIG. 9B, reference numeral 194 is a coil spring, which is formed by partially increasing the winding diameter.
4a is formed.

The coil spring 194 is attached to the separation pad holder 151 by engaging both ends thereof with the spring receiving holes 151d, 151d, and the spring receiving portion 192 of the separating lever 190 is pressed downward in FIG. Has become. Therefore, the spacing lever 190 is biased by the coil spring 194, and the protrusion 193 thereof is normally in contact with the lower edge 151f (see FIG. 8) of the window 151c of the separation pad holder 151 (see FIGS. 3 and 4). But one piece
93 is rotatable within a range in which it can move within the window 151c. Note that 151e is a protrusion that engages with the step portion 194a and prevents the coil spring 194 from coming off.

On the other hand, as shown in FIG. 10, a protrusion cam 184 is formed on the paper return lever 180 described above, and the separation pad holder 151 is a sub-frame as shown in FIGS. 3, 4, and 9. When it is assembled into the cam 140, the protruding piece 193 of the separation lever 190 causes the protruding cam 18 to move.
It is designed to be positioned in the rotation orbit of No. 4. Therefore, as will be described later, when the paper return lever 180 rotates clockwise in FIG. 3, the protruding cam 184 causes the protruding piece 193 to move.
, Which causes the pad 150 to be pushed down and separated from the idle roller 160.

In FIGS. 1 and 3, reference numeral 200 is a synthetic resin sheet as a biasing member. This sheet 20
The upper end 201 of 0 is fixed to the guide 171 fixed to the cover 170 of the paper feed roller. In the free state, the sheet 200 is in a linear state as shown by a chain double-dashed line in FIG. It is designed to bend. Conversely, this sheet 200 urges the sheets P stacked on the hopper 130 toward the sheet supporting surface 130a of the hopper 130.

The sheet feeding device of this embodiment is provided with a hopper holding mechanism for restricting the rotation of the hopper 130, in addition to the above-mentioned hopper cam 135 (see FIG. 1).

The hopper holding mechanism mainly consists of the holding lever 2
10 (see FIGS. 3 and 13).

In FIG. 3, reference numeral 102 denotes a pin projecting from the side wall 101 (see FIG. 1) of the frame 100, and the holding lever 210 is rotatably attached to the side wall 101 by this pin 102. A tension spring (not shown) is provided between the rear end 211 of the holding lever 210 and the side wall 101. The tension spring always urges the holding lever 210 in the clockwise direction in FIG. Since the hopper cam 135 is located on the rotation track, it is rotated counterclockwise when the tip 212 contacts the hopper cam 135 as shown in FIG. A protrusion 213 is formed in the middle of the holding lever 210, and the protrusion 213 can be engaged with and disengaged from the recess 138 formed at the side end of the hopper 130. That is, when the holding lever 210 rotates in the clockwise direction, the protrusion 213 engages with (enters) the recess 138 and the hopper 1 moves.
When the upward movement of 30 (clockwise rotation in FIG. 3) is restricted and the holding lever 210 rotates counterclockwise, the projection 213 is removed from the recess 138 and the hopper 130 can be moved upward. The hopper holding mechanism is provided on both sides of the hopper 130.

Next, the operation of the above-described paper feeding device will be described.

First, the standby state will be described.

During standby, as shown in FIG. 3, the hopper 130 is pushed down because the cam follower 134 of the hopper 130 is in contact with the hopper cam 135 (see FIG. 5).

The paper feed roller 121 has a linear portion 121b.
Is in a state of facing the paper P, and the paper feed roller 12
1 does not contact 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. 5), but as shown in FIG. By the contact, the rotation is restricted, and it stops at the position shown in FIGS. 3 and 5. Therefore, the biasing force of the pad spring 156 does not act on the idle roller 160. Further, at this time, the separation pad 150 has the arc portion 121 of the paper feed roller.
It is located in the rotation orbit of a.

The cam 123 of the bush 122 and the cam follower 166 of the idle roller holder 161 are not in contact with each other, so that the idle roller 160 is in contact with the separation pad 150 by the urging force of the roller spring 165.

The paper return lever 180 is in the neutral position and is in the recess 124a of the bush 122.

Projecting cam 184 of the paper return lever 180
And the protrusion 193 of the separation lever 190 are not in contact with each other or are in slight contact with each other.

The protruding piece 193 of the separating lever 190 is in contact with the lower edge 151f of the window 151c of the separation pad holder 151.

The tip end 212 of the holding lever 210 of the hopper holding mechanism is in contact with the hopper cam 135, so that the projection 213 of the holding lever 210 has the projection 213.
It is in a state of being removed from the concave portion 138.

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 description, 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, and the hopper cam 135
Also starts rotating.

(Iii) As shown in FIG. 14, the paper feed roller shaft 110, the paper feed roller 121, and the bush 12 are provided.
2. When the hopper cam 135 rotates by a predetermined angle and the contact between the hopper cam 135 and the cam follower 134 of the hopper 130 is released, the hopper 130 is momentarily pushed up by the hopper spring 133 (see FIG. 5) and the paper P is also pushed up. Then, the uppermost sheet P1 is fed to the sheet feeding roller 121.
Is pressed against the circular arc portion 121a. Since the hopper 130 and the paper P are momentarily pushed up, even if the upper paper comes off the support surfaces 152 and 152a, it hardly descends, and as shown in the figure, the paper is sandwiched between the hopper 130 and the paper feed roller 121. .

The separation pad holder 151 (that is, the separation pad 150) is in the same state as the standby state described above. The cam 123 of the bush 122 and the cam follower 166 of the idle roller holder 161 are not yet in contact with each other, and the idle roller 160 is in contact with the separation pad 150 by the urging force of the roller spring 165. The paper return lever 180 is rotated by the bush 122 so that the disk 12 is rotated.
It is pushed by the corner portion 124c (see FIG. 3) of No. 4 and rotates in the counterclockwise direction to come out of the recess portion 124a so that the tip thereof is along the peripheral surface 124d of the disc 124. Therefore, the projection cam 184 of the paper return lever 180 is completely separated from the protrusion 193 of the separation lever 190. The separation lever 190 and the holding lever 210 remain in the same state as the standby state.

(Iv) Further, as the paper feed roller shaft 110 continues to rotate, the arc portion 121a of the paper feed roller 121 and the uppermost paper P1 are in contact with each other as shown in FIG. Paper P1 is separation pad 150
Sent to. At this time, the paper P2, which is next to the paper P1, is adsorbed by the action of static electricity, or the frictional force acts between the paper P1 and the paper P2. However, the leading edge P2a of the sheet P2 is separated by the separation pad 15
When it hits 0, its movement is hindered and it 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. In addition, as you can see from now on, "the next paper"
In addition, the lower-order sheet P3 and the like are included, but in order to avoid complication of the description, the term "the lower-order sheet P3 and the like" is simply included unless necessary. To

At this time (the time shown in FIG. 15), the slope 123a of the cam 123 of the bush 122 contacts the cam follower 166 of the idle roller holder 161, but the leading end P1a of the uppermost sheet P1 is still idle roller 160.
Does not reach the contact portion T between the separation pad 150 and the separation pad 150. The contact portion T is an arc portion 121 of the sheet feeding roller 121.
a coincides with the contact portion between the separation pad 150 (see FIG. 1).
8).

The other members are described in (ii) above.
It remains in the same state as i).

(V) Further, as the paper feed roller shaft 110 continues to rotate, as shown in FIG.
The arcuate portion 121a of 21 presses the separation pad 150 via the uppermost sheet P1. Thereby, the separation pad 1
50 is pressed down in the direction of arrow b1 against the urging force of the pad spring 156, and at the same time, the urging force of the pad spring 156 pinches the uppermost sheet P1 with the arc portion 121a of the sheet feeding roller 121. That is, the paper P1 is sent while being pinched between the paper feed roller 121 and the separation pad 150. At this time, as described above, the next-order paper P2 may be likely to be sent together with the paper P1, but as described above, the friction coefficient between the paper feed roller 121 and the paper is μ1, and the separation pad 150 is If the coefficient of friction with the paper is μ2 and the coefficient of friction with the paper is μ3, then μ1>μ2> μ3.
As the sheet P1 and the sheet P2 are pressed by the arc portion 121a of the sheet feed roller and the separation pad 150 as the sheet 21 rotates, the movement of the sheet P2 is hindered by the frictional force between the sheet P2 and the separation pad 150. And the paper P is secondarily
Only the paper P1 is separated from the paper P1.

At this point (at the point shown in FIG. 16),
The cam follower 166 of the idle roller holder 161 is
The cam 123 is pushed up by the inclined surface 123a of the cam 123 and rides on the arc surface 123b of the cam 123. As a result, the idle roller 160 moves in the direction of arrow a2 and is separated from the separation pad 150, but the leading edge P1a of the uppermost sheet P1 is still idle roller 160.
Does not reach the contact portion T (see FIG. 15) between the separation pad 150 and the separation pad 150.

That is, when the leading edge P1a of the paper P1 to be fed passes between the separation pad 150 and the idle roller 160, the idle roller 160 has already been separated from the separation pad 150. Becomes

The other members are described in (ii) above.
It remains in the same state as i).

(Vi) By further continuing the rotation of the paper feed roller shaft 110, the paper P1 is further fed while being pinched by the paper feed roller 121 and the separation pad 150, as shown in FIG. The paper P1 is fed by rotating the paper return lever 180 counterclockwise, and the paper return lever 180 is rotated counterclockwise according to the paper P1 until the rear end of the paper P1 passes.

At this time (the time shown in FIG. 17), the cam follower 166 of the idle roller holder 161 has the cam 1
It is located near the end of the circular arc surface 123b of 23.

At this point, the paper feed roller shaft 110
Of the hopper cam 135 shown in FIG.
7, the tip 212 of the holding lever 210 of the hopper holding mechanism is disengaged from the hopper cam 135, and therefore, the protrusion 213 of the holding lever 210 of the hopper 130 is about to rotate clockwise in FIG. Front 13
By abutting against 9, the rotation in the clockwise direction is restricted (see the phantom line in FIG. 17).

The other members are described in (ii) above.
It remains in the same state as i).

(Vii) As the paper feed roller shaft 110 continues to rotate, as shown in FIG.
Is further fed while being pinched by the paper feed roller 121 and the separation pad 150.

At this time (the time shown in FIG. 18), the cam follower 166 of the idle roller holder 161 has the cam 1
23 slides down on the other inclined surface 123c, and thus the idle roller 1 is driven by the biasing force of the roller spring 165.
60 abuts the separation pad 150. However, at this point, the arc portion 121a of the paper feed roller 121 still has the paper P
The separation pad 150 is being pressed via 1.

That is, the arc portion 12 of the paper feed roller 121.
Before the contact between the sheet 1a and the separation pad 150 via the sheet P1 is released, the idle roller 160 moves the separation pad 150
Will come into contact with.

The other members are as described above in (vi).
However, the hopper 130 is pushed down by the hopper cam 135.

(Viii) Further, the paper feed roller shaft 110 rotates (just rotates once), and as shown in FIG. 19, the hopper 130 is completely pushed down by the hopper cam 135 and is in the standby state (the state shown in FIG. 3). Return to.

However, at this point, the paper P1 is not completely removed from the paper feeding device.

Therefore, the sheet P1 is in a state of being subjected to the load at the contact portion T (the state of being pulled backward) until the trailing edge of the sheet P1 passes through the contact portion T of the separation pad 150 and the idle roller 160. Then, the sheet is conveyed by the conveying rollers 2 and 3 shown in FIG.

In this case, the idle roller 160 is urged by the roller spring 165 toward the separation pad 150 to pinch the paper P1 with the separation pad 150. This is prevented even if the paper P2 tries to descend due to its own weight, is attracted to the paper P1 by the action of static electricity, or is sent together with the paper P1 due to the frictional force between the paper P1 and the paper P1.

(Ix) After the trailing edge of the sheet P1 fed and conveyed as described above is removed from the sheet feeding device, the sheet feeding operation is performed again if necessary. Since the hopper 130 of the paper device is inclined and a plurality of paper sheets P are set on the hopper 130 in a stacked state, once the paper feeding operation is performed as described above, as shown in FIG. The leading edge P2a of the second sheet P2 is the separation pad 1
It is in a lowered state until it is located near the contact portion T between the idler roller 160 and the idle roller 160. If the paper is a slippery film or the like, the tip P2a of the film may pass through the contact portion T. Therefore, if the paper feeding operation is repeated in this state, the next paper P3 or the like further enters between the paper feed roller 121 and the separation pad 150, and the next paper P4 further enters. And the idle rollers 160 are provided, the next paper that should not be sent passes through the contact portion T between the idle roller 160 and the separation pad 150, which is the maximum. A situation occurs in which it is sent (double-fed) together with the upper paper.

Therefore, in the paper feeding apparatus of this embodiment, before the paper feeding operation is performed, the paper 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-1) From the standby state described above (see FIGS. 3 and 19), the paper feed roller shaft 110 starts rotating (reverse rotation) in the counterclockwise direction. Therefore, the paper feed roller 121, the bush 122, and the hopper cam 135 also start reverse rotation.

As shown in FIG. 20, the paper feed roller shaft 110.
At the same time, when the paper feed roller 121, the bush 122, and the hopper cam 135 are reversed by a predetermined angle, the paper return lever 180 is pushed by the corner portion 124b of the disk 124 of the bush 122 to push back the leading edge P2a of the paper at the trailing edge 185. It rotates clockwise, and its projection cam 184 abuts the projection piece 193 of the separation lever 190 and pushes it down. The protruding piece 193 is provided with the window 151 of the separation pad holder 151.
Since it is in contact with the lower edge 151f of c, the separation pad 150 is also pushed down as a result, and the separation pad 150 is pushed by the separation roller 150 and the idle roller 160 as shown in the figure.
Will be separated from. In this way, the separation pad 15
0 is separated from the paper feed roller 121 and the idle roller 160 because, when the paper is a slippery film or the like as described above, the leading end P2a of the film has passed through the contact portion T. In such a case, the separation pad 150 and the paper feed roller 121 and the idle roller 160 are not separated from each other, and the paper P2
Even if the sheet return lever 180 pushes back the sheet, it cannot be pushed back smoothly.

The downward movement of the idle roller 160 is restricted by the cam follower 166 of the idle roller holder 161 contacting the cam 123.

At this time (at the time shown in FIG. 20), the cam follower 134 of the hopper 130 has the hopper cam 135.
The holding lever 210 of the hopper holding mechanism is rotated clockwise with the tip 212 of the holding lever 210 being disengaged from the hopper cam 135, and the projection 213 of the holding lever 210 is in contact with the hopper 130. The concave portion 138 is in a state of being inserted.

(I-2) As the paper feed roller shaft 110 continues to rotate in the reverse direction, the paper return lever 180 further rotates clockwise as shown in FIG.
At 5, the paper P2 is pushed back. The projection cam 184 of the paper return lever 180 abuts on the projection piece 193 of the separation lever 190 and keeps pressing it down. Therefore, the separation pad 150 causes the separation pad 150 to feed the feed roller 121 and the idle roller 160.
Remains separated from.

Since the cam follower 134 of the hopper 130 is in contact with the hopper cam 135,
It remains pressed down, and the protrusion 213 of the holding lever 210 also remains in the recess 138 of the hopper 130.

(I-3) Further, as the paper feed roller shaft 110 continues to rotate in the reverse direction, the paper return lever 180 further rotates clockwise as shown in FIG.
At 5, the paper P2 is completely pushed back. That is, the paper return lever 180 pushes the paper P2 back so that the front end P2a of the paper P2 reaches the rear of the support surfaces 152 and 152a. As a result, the sheet P2 receives the sheet P (that is, the sheet P2) by the hopper 130 due to its own weight.
By urging the sheet supporting surface 130a toward the sheet supporting surface 130a, the sheet is completely returned (dropped) onto the hopper 130.

At this point, the hopper cam 135 has the hopper 1
Since the hopper 130 tries to move up because it is disengaged from the cam follower 134 of 30, the hopper 130 does not move up but moves down because the projection 213 of the holding lever 210 has entered the recess 138 of the hopper 130. (The state shown in FIG. 22) remains as it is. Therefore, the dropping of the paper is surely performed. In addition, such a hopper 13
The holding operation of 0 changes the shape of the hopper cam 135, that is, even if the paper feed roller shaft 110 reverses as shown in FIG. 22, the shape is still in contact with the cam follower 134 (shape indicated by imaginary line 135 ′). It is also possible by However, with such a shape, the hopper 130 is pushed down quickly (lowers before reaching the state shown in FIG. 17) at the time of the above-described paper feeding operation, and a sheet is pushed by the pushing force of the hopper 130. This is not desirable because the contact period with the sheet feeding roller 121 may become insufficient and the sheet feeding operation itself may not be performed reliably.

By completely rotating the paper return lever 180 in the clockwise direction, the protruding cam 184 is in a state of being disengaged from the protruding piece 193 of the separating lever 190. Therefore, the separation pad 150 is allowed to move upward, but its upward movement is restricted by contacting the paper feed roller 121 at this point.

In this embodiment, as described above, the paper P2 is completely returned to the hopper 130. However, at least the leading end P2a of the next paper P2 is located between the idle roller 160 and the separation pad 150. If it is pushed back so that it is located rearward of the contact portion T, the above-mentioned cumulative entry 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. When the paper feed roller shaft 110 rotates in the forward direction after the paper return operation is performed, the paper return lever 180 causes the paper return lever 180 to rotate by the biasing force of the torsion spring 182 and the corner portion 124c of the disk 124 of the bush 122.
It is rotated counterclockwise by being pushed by, but at this time, the projection cam 184 of the paper return lever 180 is pressed.
Only contacts the lower surface of the protruding piece 193 of the spacing lever 190 and pushes it up (rotates the spacing lever 190 counterclockwise) to pass.

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

(A) A paper feed roller 121 that rotates in the normal direction during a paper feed operation and contacts the uppermost sheet P1 of the sheets P held in a stacked state of a plurality of sheets to feed the sheet P1, and the sheet feed roller 121. A separation pad 150 that is urged toward 121 and presses the paper between the paper feed roller 121 and the top paper P1 to be sent by the paper feed roller 121 from the next paper P2; Therefore, only the uppermost sheet P1 is fed during the sheet feeding operation.

Then, after the trailing edge of the uppermost sheet P1 fed by the sheet feeding roller 121 has passed, the sheet return lever 180 rotates rearward so that the leading edge P2a of the next sheet P2 is moved. Paper feed roller 121 and separation pad 15
A contact portion with 0 (refer to reference numeral T in FIG. 18. In this embodiment, as shown in FIG.
1 and the separation pad 150 are not actually in contact with each other, the sheet is pushed back. Therefore, the term “contact portion” in this specification refers to a portion where the sheet feeding roller and the separation pad should contact each other. The next paper P2 is pushed back toward the rear so that it is located rearward (see FIG. 22).

At this time, when the paper return lever 180 is rotated rearward, the paper feed roller shaft 110, that is, the paper feed roller 121 is rotated.
Since the sheet P2 is driven by reversing the sheet, the next sheet P2 is surely pushed back.

Therefore, according to this paper feeding device, the next paper P2 gradually (cumulatively) enters the abutting portion between the paper feeding roller 121 and the separation pad 150 (see symbol T in FIG. 18). Thus, it is possible to reliably prevent the situation where the sheets cannot be separated.

That is, according to the sheet feeding device of this embodiment, it is possible to reliably feed the sheets one by one without increasing the load (back tension) described above by using the separation pad method.

(B) The paper feed roller 121 reverses once before making one rotation, and by this reverse rotation, the paper return lever 180
Is configured to rotate rearward, so that even if the paper enters between the paper feed roller 121 and the separation pad 150 for some reason before the paper feed operation is started, this is surely performed once. Can be returned.

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 (for example, skewed paper or paper feed). Can be prevented in advance.

(C) Since the sheets P held in the stacked state are held in the inclined state in the direction in which they can slide down toward the contact portion between the sheet feeding roller 121 and the separation pad 150, When the uppermost paper P1 is fed, the next paper P2 also easily slides down toward the contact portion between the paper feed roller 121 and the separation pad 150.

In such a situation, the next paper P2
If the paper is not reliably pushed back by the paper return lever 180, the next paper P2 gradually (cumulatively) enters the pressure contact portion between the paper feed roller 121 and the separation pad 150, as described above. A situation occurs in which the sheets cannot be separated.

On the other hand, according to the paper feeding device of this embodiment, the next paper P2 is surely pushed back, so that the holding state of the paper P is set between the paper feed roller 121 and the separation pad 150. It is possible to make it in a slanting state in a direction in which it can slide down toward the abutting part, and to increase the slanting angle (for example, 45 ° or more).

Therefore, according to this paper feeding device, the installation area can be reduced.

(D) Since the sheets P are stacked in an inclined state, when the uppermost sheet P1 is fed, the next highest sheet P1 is fed.
2 also descends toward the paper feed roller 121,
The arc portion 121a of the paper feed roller 121 and the separation pad 150
When and are in pressure contact, the pressure contact portion prevents the next lower sheet P2 from descending (see FIG. 15 and the like).

Since the paper feed roller 121 is substantially D-shaped in a side view having the arcuate portion 121a and the straight line portion 121b, the pressure contact between the arcuate portion 121a and the separation pad 150 is released in the process of one rotation of the paper feed roller 121. Then, when the linear portion 121b comes into a state of facing the separation pad 150, that is, when the pressure contact portion disappears, the next paper P2 tries to descend, but at this time, the idle roller 160 causes the separation pad 15 to move.
Since it comes into contact with 0 and prevents the next paper P2 from descending,
The lowermost sheet P2 is prevented from descending (see FIG. 19).

After the trailing edge of the uppermost sheet P1 fed by the sheet feeding roller 121 has passed, the sheet return lever 180 pivots rearward so that the leading edge P2a of the next sheet P2 is moved. Since the next-order sheet P2 is pushed back toward the rear so as to be positioned behind the contact portion T between the idle roller 160 and the separation pad 150,
Although the paper feed roller 121 is a D-shaped roller and the paper P is stacked in an inclined state, the next paper P2
The situation where the paper gradually enters (cumulatively) into the pressure contact portion between the paper feed roller 121 and the separation pad 150 and the paper cannot be separated will not occur.

(E) According to the sheet feeding device of this embodiment, the separation pad 150 is formed by the arc portion 12 of the sheet feeding roller 121.
The pad urging means is provided because the pad regulating means 141 is provided separately from the idle roller 160 for regulating the movement of the separation pad 150 toward the paper feeding roller 121 when the paper P1 is not pressed between the pad P1 and the sheet la. The urging force of 156 is
It will be received by the pad regulation means 141.

Therefore, the contact force between the idle roller 160 and the separation pad 150 is obtained by the roller urging means 165, and the urging force by the roller urging means 165 is smaller than the urging force by the pad urging means 156. That is, the next paper P2 is the paper return lever 18
Since a relatively small biasing force that can prevent the movement of the next paper P2 can be prevented so as not to reach the position where it cannot be pushed back by the rotation of 0, the idle roller 160 and the separation pad 150 are provided. It is possible to reduce the nipping force of the paper due to, and as a result,
It is possible to reduce the load acting on the paper P1 after feeding the uppermost paper P1.

That is, according to the sheet feeding device of this embodiment, the sheets P stacked and held in the inclined state are reliably fed one by one without increasing the load (back tension) by using the separation pad method. Can be sent.

(F) Since the paper return lever 180 pivots backward and pushes back the next paper P2 toward the rear, a separation mechanism for separating the separation pad 150 from the idle roller 160 is provided. The paper P2 can be smoothly pushed back.

(G) The hopper 130 is a hopper that separates the paper P stacked on the hopper 130 from the paper feed roller 121 when the paper return lever 180 rotates rearward. Supporting surfaces 152 and 152a for supporting the leading ends of the sheets stacked on the hopper 130 are provided on the front side in the sheet feeding direction, and the sheet returning lever 180 is configured such that the leading end P2a of the next sheet P2 is supported on the supporting surface 152. Since the second paper P2 is pushed back so as to reach the rear of the second paper P1 and the second paper 152a, the leading end P2a of the second paper P2 pushed back is provided with the supporting surfaces 152 and 152a.
Will be supported by.

Therefore, the above-described cumulative entry of the next-order sheet P2 can be prevented more reliably.

(H) Since the sheet P stacked on the hopper 130 is provided with the sheet 200 as an urging member for urging the sheets P toward the sheet supporting surface 130a of the hopper 130, the sheet 200 is pushed back to the next position. The paper P2 of the
Will be dropped on the hopper 130 by
The leading edge of the next sheet P2 pushed back is surely supported by the support surface 1
It will be supported by 52.

Therefore, the above-described cumulative entry of the next-order sheet P2 can be prevented more reliably.

(I) When the leading edge of the paper P1 to be fed passes between the separation pad 150 and the idle roller 160, the idle roller 160 is separated from the separation pad 150 (see FIG. 16), and the paper P1 After the leading edge passes between the separation pad 150 and the idle roller 160, before the contact between the arcuate portion 121a of the paper feed roller 121 and the separation pad 150 via the sheet is released, the idle roller 1
Since the idle roller retracting mechanism for bringing the 60 into contact with the separation pad 150 (see FIG. 18) is provided, the following operational effects are obtained.

That is, during the paper feeding operation, the paper feeding roller 121
Is rotated and the uppermost sheet P1 is fed, and when the leading edge of the sheet P1 tries to pass through the contact portion between the arcuate portion 121a of the sheet feed roller 121 and the separation pad 150, the idle roller 160 moves the separation pad 150. When the idle roller 16 is pressed against the separation pad 150,
0 becomes a resistance against the sheet P1 which is about to pass.

On the other hand, according to the sheet feeding device of the embodiment, when the leading edge P1a of the sheet P1 to be fed passes between the separation pad 150 and the idle roller 160, the idle roller 160 is separated from the separation pad. Since the retracting mechanism that separates the sheet from 150 is provided, the idle roller 160 does not become a resistance against the sheet that is about to pass.

In the retracting mechanism, after the leading edge of the paper P1 passes between the separation pad 150 and the idle roller 160, the arc portion 121a of the paper feed roller 121 and the separation pad 1 are separated.
Since the idle roller 160 is brought into contact with the separation pad 150 before the contact with the sheet 50 via the paper is released, the contact between the arc portion 121a of the paper feed roller 121 and the separation pad 150 via the paper is released. And the top paper P1
At the same time, the next paper P2 will not be sent.

(J) Since the idle roller retracting mechanism is provided on the shaft 110 of the paper feed roller and is operated by the cam 123 that rotates together with this shaft 110, the structure can be simplified. For example, the structure can be simple as compared with the case where it is operated by a solenoid or the like.

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.

[0153]

According to any of the sheet feeding devices of claims 1 to 3, the separation pad system can be used to reliably feed the sheets one by one without increasing the load (back tension). .

Further, according to the paper feeding apparatus of the second aspect, even if the paper enters between the paper feeding roller and the separation pad for some reason before the paper feeding operation is started, this is ensured. Can be returned to once.

According to the paper feeding device of the third aspect, the installation area can be reduced.

[0156]

[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 diagram showing an example of how the paper feeding device is attached to the printer, and a partially omitted side view showing a part of the device.

FIG. 3 is a partially cut side view showing a main part of the sheet feeding device, that is, mainly a sheet feeding roller unit.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a sectional view mainly showing a paper feed roller, a hopper, and the like.

6 is a partially omitted plan view of FIG.

FIG. 7: Separation pad 150 and separation pad holder 15
1 is a perspective view of FIG.

FIG. 8: Separation pad holder 151 and subframe 1
The perspective view of 40.

9 is a perspective view mainly showing an idle roller holder 161 and a sub frame 140. FIG.

FIG. 10 is a perspective view mainly showing a paper return lever 180 and a subframe 140.

FIG. 11 is a side view showing a disc 124 of the bush 122.

12A and 12B are perspective views showing a mounting state of the separation lever 190.

FIG. 13 is a side view of a holding lever 210.

FIG. 14 is an operation explanatory view.

FIG. 15 is an operation explanatory view.

FIG. 16 is an operation explanatory view.

FIG. 17 is an operation explanatory view.

FIG. 18 is an operation explanatory view.

FIG. 19 is an operation explanatory view.

FIG. 20 is an operation explanatory view.

FIG. 21 is an operation explanatory view.

FIG. 22 is an operation explanatory view.

FIG. 23 is an explanatory diagram of a conventional technique.

24A to 24E are explanatory views of a conventional technique.

[Explanation of symbols]

P paper P1 topmost paper P2 Secondary paper 121 paper feed roller 130 hoppers 150 separation pad 180 Paper return lever

Continuation of front page (56) References JP-A-59-217538 (JP, A) JP-A-8-217280 (JP, A) JP-A-6-234437 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) B65H 3/52 B41J 13/00 B65H 3/06 B65H 3/46

Claims (3)

(57) [Claims] 1. A paper feed roller that rotates normally during a paper feed operation and contacts the uppermost sheet of the sheets held in a stacked state of a plurality of sheets and feeds the sheet, and a sheet feed roller attached to the sheet feed roller. A separation pad that separates the uppermost sheet to be sent by the sheet feeding roller from the next sheet by pressing the sheet between the sheet feeding roller and the sheet feeding roller, and the sheet is fed by the sheet feeding roller. After the trailing edge of the uppermost sheet has passed, it is rotated rearward so that the leading edge of the next sheet is located behind the contact portion between the sheet feeding roller and the separation pad. And a paper return lever that pushes the paper back toward the rear, and the backward rotation of the paper return lever is driven by the reverse rotation of the paper feed roller. 2. The paper feeding device according to claim 1, wherein the paper feeding roller is temporarily rotated in the reverse direction before the forward rotation, and the paper return lever is rotated backward by the reverse rotation. 3. The sheets held in the stacked state are held in an inclined state in a direction in which the sheets can slide down toward a contact portion between the sheet feeding roller and the separation pad. Alternatively, the sheet feeding device described in 2.