JPH06329273A - Paper feeding device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of no feeding or feed in piles in a sheet which is not tough in bending. CONSTITUTION:In a paper feeding device which is so constituted that a part of a feed roller 15 is provided while being extruded out of a stack surface 11a, sheets S are stacked over the stack surface 11a so as to be pressed from above by a presser member 16, and the stacked sheets S are delivered from below in order with the feed roller 15 rotated, and a projection section 11b is formed in the feed direction roughly at the center of the stack surface 11a in the width direction. And when the sheet S is set over the stack surface 11a, the sheet S is curved by the projection section 11b so as to be made tough in bending, so that the forward end of the sheet S is put on the feed roller 15 so as to be supported therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a printer, a copying machine,
It can be applied to scanners and facsimiles. More specifically, the present invention relates to a sheet feeding device that separates and feeds sheets for feeding in such a printer.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 13 and 14, for example, as shown in FIGS. 13 and 14, a sheet feeding roller 1 is provided so as to project from a stack surface 2 and the stack surface 2 is provided. Two
The sheets S are stacked on top and pressed by the pressing member 3 from above,
Some of the stack sheets S are sequentially fed out from below by the rotation of the paper feed roller 1.

[0003]

However, in such a conventional sheet feeding device, in the case of the sheet S which is not so stiff, the weight of the sheet S is applied to the sheet feeding roller 1 as shown in FIG. Therefore, if the pressing member 3 is weakly pressed, the frictional force between the sheet S and the sheet feeding roller 1 becomes small, and the sheet S becomes weak.
On the other hand, when the pressing member 3 is strongly pressed, the frictional force between the sheets S is increased and the sheets S are double-fed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to prevent occurrence of non-feeding or double feeding of a sheet that is not so rigid in the above-described sheet feeding device.

[0005]

Therefore, what is stated in claim 1 is, for example, as shown in the following illustrated embodiment,
Part of the paper feed roller 15 is projected from the stack surface 11a,
Sheets S are stacked on the stack surface 11a and are pressed by a pressing member 16 from above, and the stacked sheets S are sequentially sent out from below by the rotation of the above-mentioned sheet feeding roller 15.
In the above, the protrusion 11b is formed on the stack surface 11a in the sheet feeding direction so that the stack sheet S can be seated and the front end thereof can be placed on the sheet feeding roller 15.

According to a second aspect of the present invention, for example, as shown in the following illustrated embodiments, the sheet feeding device 1 according to the first aspect is described.
3, the protrusion 11b is formed to be gradually lower in the sheet feeding direction.

According to a third aspect of the present invention, for example, as shown in the following illustrated embodiments, the sheet feeding device 1 according to the first aspect is described.
3, the protrusion 11b is formed to be gradually wider in the sheet feeding direction.

[0008]

In the present invention, when the sheet S is set on the stack surface 11a, the protrusion 11 of the stack surface 11a
The sheet S is bent by b, and the waist is attached to the sheet S, and the front end of the sheet S is placed on the sheet feeding roller 15 and supported there.
Then, the pressing member 16 gently presses the front end of the sheet S from above, and the stack sheet S is sequentially fed out from below by rotation of the paper feed roller 15.

According to the second aspect, the stack surface 1
When the sheet S is set on the sheet 1a, much weight of the sheet S is put on the sheet feeding roller 15.

According to the third aspect, the stack surface 1
When the sheet S is set on the sheet 1a, the degree of bending in the sheet feeding direction is reduced.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a schematic diagram of the entire internal structure of a scanner including a sheet feeding device according to an embodiment of the present invention.

Reference numeral 10 in the drawing denotes the scanner body. The apparatus main body 10 includes a lower structure 11 and an upper structure 12 that can be opened and closed with respect to the lower structure 11.

A paper feeding device 13 according to the present invention, which is surrounded by a dotted line, is provided substantially at the center of the device body 10. The sheet feeding device 13 has a stack surface 11 a on the upper surface of the lower structure 11. The stack surface 11a extends to the right end of the lower structure 11 in the figure. The stack side 11
As shown in FIG. 3, a pair of side guides 14 that regulates the width direction of the sheet on both sides of the sheet feeding direction indicated by the arrow is provided on a.
14 is movably provided, and the protrusion 1 is provided at the center of its width.
1b is formed. The protrusion 11b is formed on the stack surface 11a.
The same height is formed in the sheet feeding direction from the rear end. The protrusion 1
The paper feed roller 15 is arranged in the vicinity of the front end of 1b. The paper feed roller 15 is appropriately supported by the lower structure 11, and is vertically moved in FIG. 4 by an appropriate means (not shown) so that a part of the paper feed roller 15 can be retracted from the stack surface 11a.

A pressing member 16 is provided above the paper feed roller 15 as shown in FIG. The pressing member 16 has a lever shape and is rotatably provided on the upper structure 12 about a support shaft 17, and a biasing member (not shown) imparts a counterclockwise rotational habit to the pressing member 16. The holding member 16
The regulating member 18 is arranged vertically on the left side of FIG. The regulating member 18 has a plate shape, and the seat abutting surface 18
a is formed and is appropriately supported by the upper structure 12.

On the other hand, on the left side of the paper feed roller 15 in the figure,
A separating roller 19 is provided by appropriately supporting the lower structure 11.
A separating blade 20 is arranged to face the separating roller 19 in the figure. The separating blade 20 is appropriately supported and provided by the upper structure 12 via a holder (not shown), and is pressed against the outer peripheral surface of the separating roller 19 by being urged by an urging member (not shown).

In the sheet feeding direction A of the sheet feeding device 13, a pair of conveying rollers 23, a contact glass 24, and a pair of sheet discharging rollers 26 are respectively arranged in the lower structure 11 or the upper structure 12.
The lower structure 11 is supported by
Inside, a reading mechanism 25 is provided below the contact glass 24, and a paper discharge tray 27 is detachably attached so as to project from the side surface of the lower structure 11 to the left in the drawing.

When the sheet S is set on the stack surface 11a, the sheet S is placed on the stack surface 11a. At that time, as shown in FIG. 2, the sheet S is bent by the protrusion 11b and attached to the waist, and as shown in FIG. 1, the front end of the sheet S is placed on the sheet feeding roller 15 and supported by it. . Then, as shown in FIG. 4, the front end of the sheet S is abutted against the sheet abutting surface 18a of the regulating member 18, and both side edges of the sheet S are sandwiched by the side guides 14 to regulate the movement in the width direction. Then, the upper structure 12
Is again set to the position shown in the figure, and the front end of the sheet S is lightly pressed by the pressing member 16 and pressed against the sheet feeding roller 15.

During sheet feeding, a driving force from a driving source (not shown) is appropriately transmitted to the sheet feeding roller 15 through a gear train so as to be rotationally driven in the counterclockwise direction in the figure, and the rotational driving force is also applied. Separating roller 19 via an idler gear (not shown)
And then rotate it counterclockwise. At that time, the paper feed roller 15 is raised to the position shown in the figure around the rotation shaft of the idler gear and pressed against the lower surface of the lowest sheet S, and the rotation of the sheet S causes the sheet S to be fed out, and the regulating member 18
Limit the number of sheets that can pass. Then, the sheets S fed out while being restricted are passed between the separating roller 19 and the separating blade 20 and separated, and are fed one by one in the sheet feeding direction.

Then, the sheet S is conveyed by the conveying roller pair 23, the reading surface of the sheet S is read through the contact glass 24 by the reading mechanism 25 during the conveyance, and after the reading, the sheet is discharged by the sheet discharging roller pair 26. The sheet is discharged onto the paper tray 27.

In the sheet feeding device 13 of the above-described embodiment, the protrusions 11b on the stack surface 11a are formed at the same height in the sheet feeding direction. However, as shown in FIG. 5, the protrusion 11b on the stack surface 11a may be gradually lowered in the sheet feeding direction. Then, the height of the sheet becomes high on the upstream side in the sheet feeding direction as shown in FIG. 6, and the height of the sheet S becomes low on the downstream side as shown in FIG. Then, the paper feed roll
Put a lot of weight of the sheet on LA 15.

Further, as shown in FIG. 8, it is more preferable to dispose a roller 30 slightly protruding from the upper surface in the sheet feeding direction of the protrusion 11b. Then, the frictional force between the protrusion 11b and the sheet S is reduced.

A sheet feeding device 1 of another embodiment shown in FIG.
In Example 3, the protrusion 11b on the stack surface 11a is gradually lowered in the sheet feeding direction, and the transport roller pair 23 is arranged at a position in the sheet feeding direction where the stack sheet S contacts. However, as shown in FIG. 9, the reading mechanism 25 may be arranged at a position in the sheet feeding direction where the stack sheets come into contact with each other. Then, the recording surface of the sheet is read in a flat state.

Further, a sheet feeding device 1 of another embodiment shown in FIG.
3, the stack surface 11a and the transport guide surface 11c in the sheet feeding direction are formed flat and the transport roller pair 23 is arranged. However, as shown in FIG. 10, the transport guide surface 11c
It may be configured such that the carrier roller pair 23 is disposed there by raising a little. Then, the transport roller pair 23 is brought closer to the paper feed roller 15 side to reduce the size.

Further, in all of the above-mentioned embodiments, the protrusion 11b is formed to have the same width in the sheet feeding direction. However,
As shown in FIG. 1, the protrusion 11b may be formed to be gradually wider in the sheet feeding direction. Then, when the sheet S is set on the stack surface 11a, the degree of bending of the sheet S in the sheet feeding direction is reduced as shown in FIG.

[0025]

According to the present invention, therefore, when a sheet is set on the stack surface in the sheet feeding device, the protrusion bends the sheet to make it lean, and the front end of the sheet is fed to the sheet feeding roller. Since it is placed on the roller and supported there, the frictional force between the sheet feeding roller and the sheet becomes large, and even if the pressing force of the pressing member is not increased, the stacking sheet is surely delivered from the bottom by rotation of the sheet feeding roller. Therefore, it is possible to prevent non-feeding and double feeding of a sheet that is not so stiff.

According to the second aspect, when the sheets are set on the stack surface, a large amount of the weight of the sheets is applied to the sheet feeding cassette, so that the frictional force between the sheet feeding roller and the sheets is further increased. be able to.

According to the third aspect of the present invention, when the sheets are set on the stack surface, the degree of bending of the stack sheets is reduced in the sheet feeding direction.
The reading position and the recording position can be arranged close to the paper feeding roller, which enables downsizing.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a sheet feeding device according to an embodiment of the present invention when viewed from a direction perpendicular to a sheet feeding direction.

FIG. 2 is a schematic configuration diagram of the sheet feeding device as seen from a front side in a sheet feeding direction.

FIG. 3 is a perspective view of the sheet feeding device.

FIG. 4 is an overall schematic configuration diagram of a scanner including the paper feeding device.

FIG. 5 is a schematic configuration diagram showing a paper feeding device according to another embodiment of the present invention when viewed from a direction perpendicular to the sheet feeding direction.

FIG. 6 is a state explanatory diagram on the upstream side in the sheet feeding direction showing a state in which sheets are set on the stack surface.

FIG. 7 is an explanatory diagram of a state on the downstream side in the sheet feeding direction.

FIG. 8 is a schematic configuration view of a paper feeding device according to still another embodiment of the present invention as viewed from a direction perpendicular to the sheet feeding direction.

FIG. 9 is a schematic configuration diagram showing a paper feeding device of still another embodiment of the present invention as seen from a direction perpendicular to the sheet feeding direction.

FIG. 10 shows a paper feeding device according to still another embodiment of the present invention,
It is a schematic structure figure seen from a direction at right angles to a sheet delivery direction.

FIG. 11 is a perspective view of a part of a paper feeding device according to still another embodiment of the present invention.

FIG. 12 is a perspective view showing a state in which sheets are set on the stack surface.

FIG. 13 is a schematic configuration diagram of a conventional sheet feeding device as seen from a direction perpendicular to a sheet feeding direction.

FIG. 14 is a schematic configuration diagram of the sheet feeding device as viewed from the front in the sheet feeding direction.

[Explanation of symbols]

 11a stack surface 13 sheet feeding device 15 sheet feeding roller 16 pressing member S sheet

Claims (3)

[Claims] 1. A part of a paper feed roller is projected from a stack surface, sheets are stacked on the stack surface and pressed by a pressing member from above, and a stack sheet is sequentially lowered by rotation of the paper feed roller. A sheet feeding device for feeding the stack sheet, wherein a protrusion is formed on the stack surface in the sheet feeding direction so that the stack sheet has a waist and a front end thereof is placed on the sheet feeding roller. 2. The sheet feeding device according to claim 1, wherein the protrusion is formed to be gradually lower in the sheet feeding direction. 3. The paper feeding device according to claim 1, wherein the protrusion is formed to be gradually wider in the paper feeding direction.