US20130193635A1

US20130193635A1 - Feeding apparatus

Info

Publication number: US20130193635A1
Application number: US13/750,113
Authority: US
Inventors: Takashi Awai; Tadashi Hanabusa; Akihiro Tomoda; Masahiro Kawanishi; Haruo Ishizuka
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2012-01-30
Filing date: 2013-01-25
Publication date: 2013-08-01
Also published as: JP6214165B2; JP2013177243A

Abstract

A feeding apparatus which is capable of increasing the number of stacked sheets without increasing a size of an apparatus is provided. The feeding apparatus includes a stopper member which is in contact with a leading edge of a sheet placed on a sheet stacking plate and blocks the sheet from entering a separation unit, and an actuating member which presses the stopper member in conjunction with a rotation of a holding member, and a movement distance of the actuating member is longer than a movement distance of the holding member.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present disclosure relates to a feeding apparatus, and particularly, to a feeding apparatus including a stopper member which is in contact with a sheet placed on a sheet stacking plate to block the sheet from entering a separation unit.
2. Description of the Related Art
Some of conventional image reading apparatuses include a document feeding apparatus in which documents placed on a document positioning plate are sent by a document feeding unit, separated by a separation unit sheet by sheet, and then fed to an image reading unit.
U.S. Pat. No. 6,792,241 discusses a conventional sheet feeding apparatus. The sheet feeding apparatus sends sheets placed on a sheet stacking plate by a sheet feeding unit. Then, the apparatus separates the sheets by a separation unit one by one to feed the sheets. The sheet feeding apparatus includes a holding member which is rotatably and pivotally supported above the sheet stacking plate and holds the sheet feeding unit to be able to contact with and separate from the sheet placed on the sheet stacking plate. Further, the sheet feeding apparatus includes a stopper member which is provided in a sheet feeding path through which the sheet sent by the sheet feeding unit passes, and which contacts with the sheet placed on the sheet stacking plate to block the sheet from entering the separation unit.
In the apparatus, when the holding member is rotated downward, the stopper member is pressed against the holding member, and is lowered with respect to the sheet stacking plate. In addition, after the stopper member is lowered, the stopper member is pressed against the sheet and is lowered when the sheet sent by the sheet feeding unit passes. According to the apparatus, the stopper member blocks the sheet sent by the sheet feeding unit from entering the separation unit in large amounts, and thus it is possible to maintain a sheet separation performance of the separation unit.
In U.S. Pat. No. 6,792,241, the holding member is configured to contact with the stopper member to directly press the stopper member. Therefore, a lowering movement distance (lowering stroke) of the holding member until the sheet feeding unit abuts on an uppermost sheet placed on the sheet stacking plate corresponds to a distance where the holding member presses the stopper member. In other words, the lowering movement distance of the holding member is to the same as the lowering movement distance of the stopper member. In U.S. Pat. No. 6,792,241, when the stopper member is lowered, it is necessary that a sheet regulating surface of the stopper member is lowered (is retracted) with respect to the sheet feeding path so as to allow the uppermost sheet to pass through the sheet feeding path. Therefore, it is necessary to set a height of the sheet regulating surface to a lowering movement distance of the stopper member or less.
In order to increase the number of sheets to be stacked, it is necessary to dispose the sheet regulating surface of the stopper member at a high position and to increase the lowering movement distance of the stopper member. Further, in order to decrease the size of the sheet feeding apparatus while maintaining the number of stacked sheets, it is necessary to decrease a movement distance of the holding member. As a result, according to the sheet feeding apparatus discussed in U.S. Pat. No. 6,792,241, if the number of stacked sheets increases, an issue of increase in an apparatus size may occur.

SUMMARY OF THE INVENTION

The present disclosure is directed to a feeding apparatus which is capable of increasing a number of sheets to be stacked without increasing a size of the apparatus.
According to an aspect disclosed herein, a feeding apparatus includes a feed roller configured to feed a sheet placed on a sheet stacking plate, a separation unit configured to separate the sheets fed from the feed roller, a holding member configured to hold the feed roller and the separation unit, and move the feed roller into a position to contact a sheet placed on the sheet stacking plate and a position separated from the sheet, a stopper member that is in contact with a leading edge of a sheet placed on the sheet stacking plate and configured to block the sheet from entering the separation unit, and an actuating member configured to move the stopper member according to a movement of the holding member, wherein a movement distance of the actuating member is greater than a movement distance of the holding member.
Further features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 1 is a perspective view of an image reading apparatus including a feeding apparatus according to an exemplary embodiment.

FIG. 2 is a perspective view illustrating a state in which the feeding apparatus is opened with respect to the image reading apparatus.

FIG. 3 is a cross sectional view illustrating a configuration of the feeding apparatus.

FIG. 4 is a perspective view illustrating a state in which a cover unit provided in the feeding apparatus is opened.

FIG. 5 is a cross sectional view illustrating the feeding apparatus according to an exemplary embodiment.

FIG. 6 is a perspective view illustrating a stopper member.

FIG. 7 is a cross sectional view illustrating a state in which a pickup arm is lowered.

FIG. 8 is a cross sectional view illustrating a state in which a pickup roller is rotated to send a sheet.

FIG. 9 illustrates the feeding apparatus as seen from a stacking tray side.

FIG. 10 illustrates the state in which the pickup arm is lowered as seen from the stacking tray side.

DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments, features, and aspects of the invention will be described in detail below with reference to the drawings.
FIG. 1 is a perspective view of an image reading apparatus including a feeding apparatus according to an exemplary embodiment disclosed herein. FIG. 2 is a perspective view illustrating a state in which the feeding apparatus is opened with respect to the image reading apparatus. FIG. 3 is a cross sectional view illustrating a configuration of the feeding apparatus. FIG. 4 is a perspective view illustrating a state in which a cover unit provided in the feeding apparatus is opened. FIG. 5 is a cross sectional view illustrating the feeding apparatus according to an exemplary embodiment.
As illustrated in FIGS. 1 and 2, a feeding apparatus 20 is installed in an upper portion of an image reading apparatus 60. The feeding apparatus 20 is installed so as to be able to open and close to a contact glass 61 provided to the upper portion of the image reading apparatus 60. The feeding apparatus 20 feeds a document (a sheet) toward a reading unit and presses a document (a sheet) placed on the contact glass 61.
As illustrated in FIG. 3, a U-turn path 21 having an approximately U shape is provided inside the feeding apparatus 20. A stacking tray 22 is provided at an upstream edge side of the U-turn path 21 in a sheet feeding direction. The stacking tray 22 is a sheet stacking plate which can stack a plurality of sheets. In addition, a feeding unit 10 is provided on the upstream edge of the U-turn path 21.
On the other hand, a discharge tray 23 is provided at a downstream edge side of the U-turn path 21. A discharge roller pair 24 for discharging the sheet to the discharge tray 23 is provided between the U-turn path 21 and the discharge tray 23. A conveyance roller pair 25 for conveying the sheet is provided in a middle of the U-turn path 21. A document edge sensor (not illustrated) for detecting a leading edge and a trailing edge of the sheet, is provided in the vicinity of the conveyance roller pair 25.
The reading unit 62 is a unit for reading an image of a sheet (document) conveyed on the contact glass 61. The reading unit 62 includes a contact image sensor provided below the contact glass 61. The contact image sensor includes a light emitting diode (LED) array (not illustrated), a SELFOC (registered trademark) lens (not illustrated), and a receiving element (not illustrated). The light emitting diode (LED) array is a light source for irradiating a surface of the sheet with light. The SELFOC lens forms an image on the receiving element with reflected light which is reflected on the surface of the sheet. Therefore, the reading unit 62 reads an image of the sheet (document).
In FIG. 4, a cover unit 30 is attached so as to be able to open and close to the feeding apparatus 20. When a sheet is jammed (paper jam occurs), the jammed sheet can be removed by opening the cover unit 30.
In FIG. 5, a pickup roller (a feed roller) 2 is provided in the feeding unit 10. The pickup roller 2 is a sheet feeding unit which is in contact with an uppermost sheet placed on the stacking tray 22, and sends the sheet downstream. The feeding unit 10 further includes a separation roller 4 and a separation pad 3 which is in pressure contact with the separation roller 4. The separation pad 3 and the separation roller 4 constitute a separation unit which separates the sheets sent by the pickup roller 2 one by one. Further, the feeding unit 10 includes a document presence/absence detection sensor 5 (see FIG. 7) for detecting an existence of a sheet (document) on the stacking tray 22.
In addition, the feeding unit 10 includes a stopper member 11 which is in contact with a leading edge of the sheet placed on the stacking tray 22, and blocks the sheets from entering the separation unit (including the separation pad 3 and the separation roller 4). The stopper member 11 is configured to be retracted downward the sheet feeding path when the sheet sent by the pickup roller 2 passes through the sheet feeding path.
FIG. 6 is a perspective view illustrating a configuration of the stopper member. The stopper member 11 includes a regulating surface 11 d which is in contact with the leading edge of the sheet placed on the stacking tray 22, and blocks the sheet from entering. A slope portion 11 a which is inclined in the sheet feeding direction is provided to an upper edge (leading edge) of the regulating surface 11 d. A pressing portion 11 c is provided to an upper edge (leading edge) of the slope portion 11 a.
The stopper member 11 can swing around a swing shaft 11 b. The stopper member 11 swings in a direction perpendicular to the sheet feeding direction around the swing shaft 11 b by pressing the pressing portion 11 c against a pressing piece 13 c of a stopper lever 13 described below. Therefore, the stopper member 11 is moved between a state in which the stopper member enters the sheet feeding path and a state in which the stopper member is retracted downward the sheet feeding path. A torsional coil spring 14 applies a force to the stopper member 11. Thus, when the pressing portion 11 c is not pressed by the pressing piece 13 c, the stopper member 11 is held at a position where the stopper member 11 enters the sheet feeding path and blocks the sheet from entering the separation unit (the separation pad 3 and separation roller 4).
The pickup arm 12 is movably supported to the cover unit 30. The pickup arm 12 is rotatably supported to a shaft 12 a (a first shaft) of the separation roller 4. The pickup arm 12 is a holding member for holding the pickup roller 2 to be able to contact with and separate from the sheet placed on the stacking tray 22 by rotating around the shaft 12 a. When the sheet placed on the stacking tray 22 is sent downstream, the pickup arm 12 is rotated in a direction of an arrow E in the drawing (see FIG. 5) to bring the pickup roller 2 into contact with the sheet.
The stopper lever 13 is engaged with the pickup arm 12. The stopper lever 13 is an actuating member for pressing the stopper member 11 in conjunction with a rotation of the pickup arm 12. When the pickup arm 12 is rotated downward, the pressing piece 13 c of the stopper lever 13 presses the pressing portion 11 c of the stopper member 11, and therefore the stopper member 11 is pressed down.
A series of operation contents, such as sheet feeding, image reading, and sheet discharging, which are performed in the image reading apparatus 60 illustrated in FIG. 1 will be described below.
Sheets are placed on the stacking tray 22 by an operator with a document surface (a surface to be read) thereof up. At that time, a leading edge position of the sheet is regulated by the stopper member 11. In addition, the document presence/absence detection sensor 5 detects that the sheets are placed on the stacking tray 22.
Subsequently, when the operator inputs an instruction to start a reading via an operation unit (not illustrated), firstly, a driving unit (not illustrated) rotates the pickup arm 12 in the direction of the arrow E in the drawing (see FIG. 5). Accordingly, the stopper lever 13 is rotated around a rotating shaft 13 a (a second shaft) in a direction of an arrow F in the drawing, in conjunction with the rotation of the pickup arm 12. As the stopper lever 13 is rotated downward, the stopper member 11 is pressed down by the stopper lever 13.
FIG. 7 is a cross sectional view illustrating a state in which the pickup arm 12 is lowered. FIG. 7 illustrates a state in which the pickup roller 2 is in contact with the uppermost sheet placed on the stacking tray 22 and the stopper member 11 is pressed down by the stopper lever 13.
FIG. 8 is a cross sectional view illustrating a state in which the pickup roller 2 is rotated to send a sheet. As illustrated in FIG. 8, the pickup roller 2 is rotated to send a sheet downstream. In this case, the regulating surface 11 d of the stopper member 11 is retracted downward the sheet feeding path. Therefore, the leading edge of the sheet enters the separation unit (the separation pad 3 and the separation roller 4) while pressing down the slope portion 11 a of the stopper member 11. The leading edge of the sheet passes through the stopper member 11, the sheet is separated by the separation roller 4 and the separation pad 3 one by one, and then sent to the U-turn path 21.
The sheet sent to the U-turn path 21 is conveyed along the U-turn path 21 by the conveyance roller pair 25. When the leading edge of the sheet is detected by the document edge sensor (not illustrated), a reading operation is started by a reading unit 62 which is installed on a reading position separated a predetermined distance from a detection position of the document edge sensor, after a predetermined time period elapses from the detection timing. At that time, the sheet is pressed against the reading unit 62 by a reading blank plate 26 (see FIG. 3).
Then, when a trailing edge of the sheet is detected by the document edge sensor (not illustrated), the reading operation is terminated by the reading unit 62 after a predetermined time period elapses from the detection timing. The sheet of which reading operation is terminated is discharged to the discharge tray 23 by the discharge roller pair 24.
When the trailing edge passes through the discharge roller pair 24, the sheet of which reading operation is terminated freely falls and is accommodated in the discharge tray 23 in the state in which the trailing edge of the sheet is held on the holing surface 23 a (see FIG. 3). The image reading apparatus 60 repeatedly performs the above-described operations until the document presence/absence detection sensor 5 detects that there is no sheet placed on the stacking tray 22.
FIG. 9 illustrates the feeding apparatus as seen from a stacking tray side. As illustrated in FIG. 9, the stopper lever 13 is disposed laterally to the pickup arm 12. The stopper member 11 can move between the state in which the stopper member enters the sheet feeding path and the state in which the stopper member is retracted downward the sheet feeding path. A guide member 31 guides a sheet to the U-turn path 21.
A configuration of the feeding unit 10 will be described in detail below with reference to FIGS. 5 and 9. The stopper lever 13 is rotated around the rotating shaft 13 a. A fulcrum 13 b of the stopper lever 13 is a part which is engaged with the pickup arm 12. The stopper lever 13 is provided with the pressing piece 13 c at a side opposite to the rotating shaft 13 a across the fulcrum 13 b. Accordingly, the stopper lever 13 is also rotated downward in conjunction with the operation that the pickup arm 12 is rotated downward. Therefore, the pressing piece 13 c of the stopper lever 13 presses the pressing portion 11 c of the stopper member 11, and the stopper member 11 is moved below the sheet feeding path.
According to the present exemplary embodiment of the present invention, the pressing piece 13 c is disposed downstream of the rotating shaft 13 a in the sheet feeding direction. A cam surface may be formed at a position in contact with the fulcrum 13 b of the pickup arm 12, and the fulcrum 13 b may move along the cam surface. In this configuration, the stopper lever 13 presses the stopper member 11 at the position at which a leading edge portion (protrusion) of the cam surface is in contact with the fulcrum 13 b.
According to the present exemplary embodiment, the stopper lever 13 is engaged with the pickup arm 12 to satisfy the following expression (1).
(b/a)×(C/D)>1 (1)
In the above expression (1), as illustrated in FIG. 5, a symbol “a” represents a distance from the shaft 12 a of the pickup arm 12 to the pressing piece 13 c of the stopper lever 13. A symbol “b” represents a distance from the shaft 12 a of the pickup arm 12 to the fulcrum 13 b of the stopper lever 13. A symbol “C” represents a distance from the rotating shaft 13 a of the stopper lever 13 to the pressing piece 13 c. A symbol “D” represents a distance from the rotating shaft 13 a of the stopper lever 13 to the fulcrum 13 b.
When the above expression (1) is satisfied, a downward movement distance Zd of the stopper lever 13 is longer than a downward movement distance Zp of the pickup arm 12. The downward movement distance of the stopper lever 13 represents a downward movement distance of the pressing piece 13 c. On the other hand, the downward movement distance of the pickup arm 12 represents a downward movement distance of the pickup arm 12 at a position corresponding to the stopper member 11 in the sheet feeding direction. For example, in a case where a=10.2 mm, b=16 mm, C=33.3 mm, and D=21.1 mm, the movement distance Zp of the stopper lever 13 is 5.6 mm whereas the movement distance Zd of the pickup arm 12 is 3.5 mm.
As illustrated in FIG. 5 or FIG. 9, when the pickup arm 12 is rotated in the direction of the arrow E according to the start of the reading operation, the stopper lever 13 presses the stopper member 11. At that time, the downward movement distance of the stopper lever 13 is amplified, with respect to the downward movement distance of the pickup arm 12. Then, the pickup arm 12 is lowered until the pickup roller 2 abuts on a sheet S. The stopper lever 13 is rotated downward according to lowering of the pickup roller 2. Further, the stopper member 11 which is pressed against the pressing piece 13 c of the stopper lever 13 swings in a direction G (a direction perpendicular to the sheet feeding direction), which is illustrated in FIG. 9. In addition, the regulating surface 11 d of the stopper member 11 is retracted downward the sheet feeding path. In this case, as illustrated in FIG. 7, the pressing piece 13 c of the stopper lever 13 is placed above the pickup arm 12. Accordingly, when a sheet is sent, an issue such as the sheet being caught in the pressing piece 13 c of the stopper lever 13 does not occur.
After the stopper member 11 is lowered to a predetermined position, the pickup roller 2 is rotated. Then, the sheet is sent and passes above the lowered stopper member 11.
The above-described operations are repeatedly performed until the document presence/absence detection sensor 5 detects that there is no sheet S placed on the stacking tray 22.
When the sending of the sheets by the pickup roller 2 is terminated, the pickup arm 12 is rotated upward. The pressing piece 13 c of the stopper lever 13 is also rotated upward according to the rotation of the pickup arm 12. As a result, since a pressing force from the pressing piece 13 c is released, the stopper member 11 is rotated upward with an urging force of the torsional coil spring 14.
FIG. 10 illustrates a state in which the pickup arm 12 is lowered when seen from the stacking tray side. As illustrated in FIG. 10, the pressing piece 13 c of the stopper lever 13 has a width capable of reliably pressing the pressing portion 11 c while the stopper member 11 is moved from a rising position to a lowering position.
According to the present exemplary embodiment, a lowering movement distance of the stopper member 11 can be amplified with respect to a lowering movement distance of the pickup arm 12. Therefore, if a height of the regulating surface 11 d of the stopper member 11 is increased, the lowering movement distance of the pickup arm 12 can be suppressed. Accordingly, the number of stacked sheets (documents) can be increased without increasing the size of the feeding apparatus. In addition, if the numbers of stacked sheets (documents) are the same, a height of the feeding apparatus may be lower than that of the conventional configuration.
According to the present exemplary embodiment, the stopper member 11 swings in the direction perpendicular to the sheet feeding direction. Therefore, a space for causing the stopper member 11 to swing in the sheet feeding direction is not necessary.
According to the present exemplary embodiment, the stopper member 11 and the stopper lever 13 are disposed only at a side of the pickup arm 12 in the sheet width direction. However, the stopper member 11 and the stopper lever 13 may be disposed at both sides of the pickup arm 12 in the sheet width direction.
Further, according to the present exemplary embodiment of the present disclosure, the pressing piece 13 c of the stopper lever 13 is disposed downstream of the rotating shaft 13 a in the sheet feeding direction. However, the pressing piece 13 c of the stopper lever 13 may be disposed upstream of the rotating shaft 13 a in the sheet feeding direction.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications, equivalent structures, and functions.
This application claims priority from Japanese Patent Application No. 2012-016714 filed Jan. 30, 2012, which is hereby incorporated by reference herein in its entirety.

Claims

What is claimed is:

1. A feeding apparatus comprising:

a feed roller configured to feed a sheet placed on a sheet stacking plate;

a separation unit configured to separate the sheets fed from the feed roller;

a holding member configured to hold the feed roller and the separation unit, and move the feed roller into a position to contact a sheet placed on the sheet stacking plate and a position separated from the sheet;

a stopper member that is in contact with a leading edge of a sheet placed on the sheet stacking plate and configured to block the sheet from entering the separation unit; and

an actuating member configured to move the stopper member according to a movement of the holding member, wherein a movement distance of the actuating member is greater than a movement distance of the holding member.

2. The feeding apparatus according to claim 1, further comprising:

a first shaft configured to rotatably support the holding member; and

a second shaft configured to rotatably support the actuating member,

wherein if a distance from the first shaft of the holding member to a portion where the stopper member is pressed by the actuating member is set to “a”, a distance from the first shaft to a portion where the holding member is engaged with the actuating member is set to “b”, a distance from the second shaft to the pressed portion is set to “C”, and a distance from the second shaft to the engaged portion is set to “D”, an expression of (b/a)×(C/D)>1 is satisfied.

3. The feeding apparatus according to claim 2, wherein the portion where the stopper member is pressed by the actuating member is provided downstream of the second shaft in a sheet feeding direction.

4. The feeding apparatus according to claim 1, wherein the stopper member and the actuating member are provided only at a side of the holding member in a sheet width direction.

5. The feeding apparatus according to claim 1, wherein the feed roller, the holding member and the actuating member are provided on an opposite side to the sheet stacking plate with respect to a sheet feeding path.

6. The feeding apparatus according to claim 1, further comprising a cover member configured to open and close a sheet feeding path,

wherein the feed roller, the holding member, and the actuating member are provided on the cover member.

7. The feeding apparatus according to claim 1, wherein the stopper member swings in a direction perpendicular to a sheet feeding direction.