U.S. patent application number 16/223646 was filed with the patent office on 2019-06-27 for sheet conveying apparatus, image reading apparatus and image forming apparatus.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Takuya Yamaguchi.
Application Number | 20190193970 16/223646 |
Document ID | / |
Family ID | 66949948 |
Filed Date | 2019-06-27 |
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United States Patent
Application |
20190193970 |
Kind Code |
A1 |
Yamaguchi; Takuya |
June 27, 2019 |
SHEET CONVEYING APPARATUS, IMAGE READING APPARATUS AND IMAGE
FORMING APPARATUS
Abstract
Disclosed is a sheet conveying apparatus including an opening
and closing member rotatable; a rotating member provided on the
opening and closing member and which is rotatable by a sheet; and
an assist member which is provided on the opening and closing
member, and is at a first position when the opening and closing
member is at the closed position, and is at a second position when
the opening and closing member is at the open position, wherein the
assist member urges the rotating member toward the opening and
closing member side when the assist member is at the second
position.
Inventors: |
Yamaguchi; Takuya;
(Nagareyama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
66949948 |
Appl. No.: |
16/223646 |
Filed: |
December 18, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 2402/441 20130101;
B65H 3/06 20130101; B65H 2511/51 20130101; B65H 3/0684 20130101;
B65H 2553/81 20130101; B65H 2553/612 20130101; B65H 2801/06
20130101; B65H 2601/11 20130101; B65H 2511/528 20130101; B65H 5/062
20130101; B65H 7/04 20130101; B65H 1/14 20130101; B65H 2511/515
20130101 |
International
Class: |
B65H 7/04 20060101
B65H007/04; B65H 3/06 20060101 B65H003/06; B65H 5/06 20060101
B65H005/06 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 25, 2017 |
JP |
2017-247537 |
Claims
1. An apparatus comprising: an opening and closing member
configured to be rotatable and configured to be located at a closed
position and an open position; a rotating member rotatablely
provided on the opening and closing member and configured to be
rotatable by a sheet; and an assist member provided on the opening
and closing member, the assist member being configured to be
located at a first position when the opening and closing member is
located at the closed position and configured to be located at a
second position when the opening and closing member is located at
the open position, wherein the assist member is configured to be
displaceable from the first position to the second position by a
weight of the assist member with a rotation of the opening and
closing member from the close position toward the open position,
wherein the assist member is configured to urge the rotating member
toward a side of the opening and closing member when the assist
member is located at the second position.
2. The apparatus according to claim 1, wherein the assist member is
provided on the opening and closing member such that the assist
member is rotatable, the assist member being configured to be
separated from the rotating member when the assist member is
located at the first position, the assist member being configured
to rotate from the first position to the second position by the
weight of the assist member according to a movement of the opening
and closing member from the closed position to the open position so
that the assist member presses the rotating member and urges the
rotating member toward the side of the opening and closing
member.
3. The apparatus according to claim 1, wherein a center of rotation
of the rotating member is disposed at a lower portion of the
opening and closing member when the opening and closing member is
located at the closed position.
4. The apparatus according to claim 1, wherein a direction of a
rotational moment by the weight of the assist member is switched
while the opening and closing member is moved from the closed
position to the open position.
5. The apparatus according to claim 1, wherein the opening and
closing portion comprises an accommodating portion configured to
accommodate the rotating member.
6. The apparatus according to claim 1, wherein a conveying unit is
located in a vicinity of the rotating member, the conveying unit
having a conveying member which conveys a sheet, the conveying unit
being configured to be detachably attachable to the opening and
closing member.
7. The apparatus according to claim 1, wherein an abutting portion
of the assist member, which presses the rotating member is of a
circular arc shape.
8. The apparatus according to claim 1, wherein, a center of gravity
of the rotating member is disposed in a vicinity of a center of
rotation of the rotating member when the opening and closing member
is located at the closed position.
9. The apparatus according to claim 2, wherein a center of gravity
of the assist member is disposed in a vicinity of a center of
rotation of the assist member when the opening and closing member
is located at the closed position.
10. The apparatus according to claim 2, wherein a center of gravity
of the assist member is moved from one side of a center of rotation
of the assist member to the other side of the center of the
rotation of the assist member in a horizontal direction while the
opening and closing member is moved from the closed position to the
open position.
11. The apparatus according to claim 2, wherein the assist member
rotates in the direction opposite to that of the rotational member
to urge the rotational member toward the side of the opening and
closing member when the opening and closing member is moved from
the closed position to the open position.
12. The apparatus according to claim 2, wherein the assist member
rotates in the same direction as that of the rotational member to
urge the rotational member toward the side of the opening and
closing member when the opening and closing member is moved from
the closed position to the open position.
13. The apparatus according to claim 1, further comprising a sheet
supporting portion configured to support the sheet to be conveyed;
and a sensor configured detect a rotation of the rotating member,
the rotating member is rotated by the sheet on the sheet supporting
portion.
14. The apparatus according to claim 13, wherein a rotation center
of the rotating member is above the sheet supporting portion in a
state that the opening and closing member is located at the closed
position.
15. The apparatus according to claim 1, wherein the assist member
is configured not to act on the rotating member when the assist
member is located at the first position.
16. An image reading apparatus which reads an image of a sheet,
comprising: an opening and closing member configured to be
rotatable and configured to be located at a closed position and an
open position; a rotating member rotatablely provided on the
opening and closing member and configured to be rotatable by the
sheet; an assist member provided on the opening and closing member,
the assist member being configured to be located at a first
position when the opening and closing member is located at the
closed position and configured to be located at a second position
when the opening and closing member is located at the open
position, wherein the assist member is configured to be
displaceable from the first position to the second position by a
weight of the assist member with a rotation of the opening and
closing member from the close position toward the open position;
and a reading portion configured to read an image formed on a
sheet, wherein the assist member is configured to urge the rotating
member toward a side of the opening and closing member when the
assist member is located at the second position.
17. An image forming apparatus which forms an image on a sheet,
comprising: an opening and closing member configured to be
rotatable and configured to be located at a closed position and an
open position; a rotating member rotatablely provided on the
opening and closing member and configured to be rotatable by a
sheet; an assist member provided on the opening and closing member,
the assist member being configured to be located at a first
position when the opening and closing member is located at the
closed position and configured to be located at a second position
when the opening and closing member is located at the open
position, wherein the assist member is configured to be
displaceable from the first position to the second position by a
weight of the assist member with a rotation of the opening and
closing member from the close position toward the open position;
and an image forming portion configured to form an image on a
sheet, wherein the assist member is configured to urge the rotating
member toward a side of the opening and closing member when the
assist member is located at the second position.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to an apparatus having a
rotating member for detecting the presence or absence of a
sheet.
Description of the Related Art
[0002] An image forming apparatus that performs recording on a
sheet using an electro-photographic method, such as an
electro-photographic copying machine, has an image reading
apparatus having an image reading portion, an image forming portion
that forms a toner image on an image bearing member such as a
photosensitive drum, and a sheet conveying apparatus for conveying
a sheet from a feeding tray or the like.
[0003] Such a sheet conveying apparatus has a mechanism for
detecting whether sheets are stacked on the sheet stacking tray.
Such sheet detection mechanism has, for example, a detection flag
rotatable by its own weight provided in the sheet conveyance path.
When a sheet is set on the sheet stacking tray, the sheet detection
flag is pushed by the leading end of the sheet and is rotated to
release light shielding of the photo interrupter to recognize the
presence of the sheet. Conversely, when there are no sheets, the
sheet detection flag blocks the light of the photo interrupter to
recognize the sheet absence state. In this way it is possible to
determine the presence or absence of a sheet.
[0004] Further, in the sheet conveying apparatus as described
above, when a situation occurs in which a sheet is jammed during
conveyance, the sheet conveying path can be exposed so that the
jammed sheet can be removed. For this purpose, the sheet conveying
path is configured by the apparatus main body and an opening and
closing member rotatable with respect to the apparatus main body.
When the sheet is jammed, the jammed sheet can be removed by
exposing the conveying path by rotating the opening and closing
member.
[0005] In the above configuration, when the opening and closing
member is rotated to expose the sheet conveying path, the sheet
detection flag rotates by its own weight and retracts to come into
contact with the surface of the opening and closing member.
However, when the opening and closing member opens excessively, the
opening and closing member may collide with peripheral objects such
as a wall surface of an installation place. Thus, the rotational
angle is limited to a predetermined range. In such a case, even if
the opening and closing member is rotated and the sheet conveying
path is completely exposed, the sheet detection flag may not be
retracted inside the surface of the opening and closing member and
may remain projected from the surface of the opening and closing
member. In such a state, if a replacement operation or the like of
a member located in the vicinity of the sheet detection flag is
performed, the sheet detection flag may be damaged.
[0006] In order to solve the above problem, the configuration is
proposed by Japanese Patent Application Laid-Open No. 2010-64851,
for example, in which a weight portion for generating a rotational
moment about a rotational axis is provided in a sheet detection
flag. When the sheet conveying path is exposed by rotating the
opening and closing member, a rotational moment is generated by the
weight portion so that the sheet detection flag abuts against the
surface of the opening and closing member to retract the sheet
detection flag inside the surface of the opening and closing
member.
[0007] However, as disclosed in Japanese Patent Application
Laid-Open No. 2010-64851, when the weight portion is provided on
the sheet detection flag, it is necessary to adjust the inclination
angle of the flag based on the relationship of the rotational
moment occurring on the flag, and the angle formed by the sheet
detection flag and the sheet stacking tray may become small. In
such a case, the reactive force of the sheet detection flag due to
its own weight becomes large, and the sheet may easily buckle when
the thin sheet is set.
[0008] Another method for preventing the sheet detection flag from
protruding from the surface of the opening and closing member at
the time of an operation of maintenance may be considered, in which
when the opening and closing member is closed, the sheet detection
flag is provided such that the center of rotation of the detection
flag is located at an upper position of the opening and closing
member. In this manner, when the opening and closing member is
rotated to expose the conveying path, the sheet detecting flag is
easily hidden by the opening and closing member.
[0009] However, when the center of rotation of the sheet detection
flag is located at an upper position of the opening and closing
member, the distance between the sheet detection flag and the sheet
stacking tray becomes large so that it is necessary to lengthen the
sheet detection flag. Especially, if the feeding tray has a lift-up
configuration, it becomes necessary to further lengthen the sheet
detection flag. When the rotating radius of the sheet detection
flag becomes large, it is necessary to provide a cutout in the
guide member such as the opening and closing member in order to
avoid the trajectory of the rotation of the flag, which causes a
decrease in strength.
SUMMARY OF THE INVENTION
[0010] According to the present invention,
[0011] an apparatus comprising:
[0012] an opening and closing member configured to be rotatable and
configured to be located at a closed position and an open
position;
[0013] a rotating member rotatablely provided on the opening and
closing member and configured to be rotatable by a sheet; and
[0014] an assist member provided on the opening and closing member,
the assist member being configured to be located at a first
position when the opening and closing member is located at the
closed position and configured to be located at a second position
when the opening and closing member is located at the open
position, wherein the assist member is configured to be
displaceable from the first position to the second position by a
weight of the assist member with a rotation of the opening and
closing member from the close position toward the open
position,
[0015] wherein the assist member is configured to urge the rotating
member toward a side of the opening and closing member when the
assist member is located at the second position.
[0016] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a view schematically showing an overall
configuration of an image reading apparatus with a sheet conveying
apparatus.
[0018] FIG. 2 is a view schematically showing a configuration of a
document tray and a conveying unit of the sheet conveying
apparatus.
[0019] FIG. 3 is a plan view of a feeding portion and a separating
portion of the sheet conveying apparatus.
[0020] FIG. 4 is a perspective view of a vicinity of a document
setting detection sensor of the sheet conveying apparatus.
[0021] FIG. 5 is a cross-sectional view of an assist member in the
vicinity of the document setting detection sensor of the sheet
conveying apparatus.
[0022] FIG. 6 is a perspective view of an abutting portion of a
flag member and an assist abutting portion of an assist member when
the opening and closing guide of the sheet conveying apparatus is
closed.
[0023] FIGS. 7A, 7B and 7C are views showing movements until a
document is set and fed to a document tray of the sheet conveying
apparatus.
[0024] FIG. 8 is a view schematically showing a state in which the
opening and closing guide of the sheet conveying apparatus is
opened.
[0025] FIG. 9A is a view schematically showing the positions of a
flag member and an assist member in a state in which the opening
and closing guide of the sheet conveying apparatus is closed, and
FIG. 9B a view schematically showing the positions of a flag member
and an assist member in a state in which the opening and closing
guide of the sheet conveying apparatus is opened.
[0026] FIG. 10 is a perspective view showing a positional
relationship between a conveying unit and a flag member in a state
in which the opening and closing guide of the sheet conveying
apparatus is opened.
[0027] FIG. 11A is a view schematically showing the positions of a
flag member and an assist member in a state in which the opening
and closing guide of the sheet conveying apparatus is closed in the
second embodiment, and FIG. 11B is a view schematically showing the
positions of a flag member and an assist member in a state in which
the opening and closing guide of the sheet conveying apparatus is
opened in the second embodiment.
[0028] FIG. 12A is a view schematically showing the positions of a
flag member and an assist member in a state in which the opening
and closing guide of the sheet conveying apparatus is closed in the
third embodiment, and FIG. 12B is a view schematically showing the
positions of a flag member and an assist member in a state in which
the opening and closing guide of the sheet conveying apparatus is
opened in the third embodiment.
DESCRIPTION OF THE EMBODIMENTS
First Embodiment
[0029] In the first embodiment, an image reading apparatus
including a sheet conveying apparatus that conveys a document,
which is a sheet, will be described by way of an example.
[0030] <Image Reading Apparatus> FIG. 1 schematically shows
the overall configuration of the image reading apparatus. This
image reading apparatus has the image reading portion 200 and the
sheet conveying apparatus 80.
[0031] The sheet conveying apparatus 80 feeds the documents S one
by one onto the platen 18 made of transparent glass. Further, the
sheet conveying apparatus 80 is configured to be openable and
closable with respect to the image reading portion 200, and
operates to press a document placed on the platen 18.
[0032] The image reading portion 200 optically reads an image of a
document conveyed by the sheet conveying apparatus 80 or an image
of a document placed on the platen 18, photo-electrically converts
the image, and inputs the image as image information. The image
reading unit 200 has the contact image sensor 24 as a first reading
portion that reads an image of one side of a moving document
conveyed on the platen 18. The contact image sensor 24 is fixed at
a predetermined position (the position shown in FIG. 1) on the
sheet conveying apparatus 80, and reads an image of one side of a
document conveyed on the platen 18.
[0033] Further, the image reading apparatus has a second reading
portion that reads an image of the other side of the document. The
second reading portion includes the movable scanner unit 204 with
the lamp 202, the mirror 203, etc., the mirrors 205 and 206, the
lens 207, the image sensor 208, and the like. The second reading
portion is provided on the image reading portion 200. The second
reading portion stops the scanner unit 204 at a predetermined
position (solid line position shown in FIG. 1), and reads an image
of the other side of the document conveyed on the platen 18 above
the scanner unit 204. Further, while moving the scanner unit 204
along the platen 18, the second reading portion reads an image of
the other side of the document placed on the platen 18.
[0034] <Sheet Conveying Apparatus> The sheet conveying
apparatus 80 has the document tray 11 at an upper position. The
document tray 11 serves as a sheet supporting portion on which
documents S are placed, and the documents S placed on the document
tray 11 are sequentially fed from the uppermost document by the
feeding roller 1. The fed documents S are separated and fed one by
one by the conveying roller 3 and the separation roller 4. When
separately fed document S passes over the platen 18 of image
reading portion 200, an image of document S is read by either or
both of the scanner unit 204 and the contact image sensor 24. The
document S from which the image has been read is discharged onto
the discharge tray 19 by the discharge roller 16.
[0035] FIG. 2 schematically shows the configuration of the document
tray 11 and the conveying unit. On the document tray 11, the
document width regulating plate 10 for regulating the movement of
the stacked document S in the width direction of the document S is
provided. Further, the document tray 11 is configured to be able to
be lifted up and down by a driving portion (not shown). The feeding
roller 1 is rotatable around the shaft 13. Further, the roller 1 is
also rotatable about the shaft 5 by the arm 2 so as to be capable
of being lifted up and down with respect to the document S stacked
on the document tray 11.
[0036] The opening and closing guide 6, which is an opening and
closing member, is provided with the flag member 100 serving as an
actuator of the document setting detection sensor 102 for detecting
the presence or absence of a document on the document tray 11. The
document setting detection sensor 102 uses a photo interrupter and
detects that a sheet has been set on the document tray 11 when the
optical axis is blocked by the flag member 100 (hereinafter
referred to as sensor ON). Conversely, when the optical axis is not
blocked by the flag member 100 (hereinafter referred to as sensor
OFF), it is detected that a document is not set on the document
tray 11.
[0037] The arm 2 is provided with the actuator 90 of the feeding
position detection sensor 91 which determines a lifted position
(document feeding position) of the document tray 11. The feed
position detection sensor 91 uses a photo interrupter, and when the
sensor is ON, the sheet feeding is possible. Conversely, when the
sensor is OFF, it is necessary to lift up the document tray 11 by a
driving portion (not shown).
[0038] FIG. 3 is a plan view of the feeding portion and the
separating portion. The pulleys 8 and 9 are provided on the feeding
roller 1 and the conveying roller 3, respectively. The timing belt
7 is stretched on the pulleys 8 and 9 and transmits the driving
force of the motor M (see FIG. 2) to the feeding roller 1. The arm
2 is urged by the spring clutch 12. When the motor M rotates
forward, the arm 2 descends and contacts the top surface of the
documents on the document tray 11. Further, when the motor M
rotates forward, the feeding roller 1 and the conveying roller 3
rotate in the direction for feeding the documents and feed the
documents. When the motor M rotates in the reverse direction, the
spring clutch 12 is locked to lift up the arm 2.
[0039] (Document Setting Detection Mechanism) Next, a document
setting detection mechanism provided in the sheet conveying
apparatus will be described. FIG. 4 is a perspective view of the
vicinity of the document setting detection sensor.
[0040] The document setting detection sensor 102 is held by the
opening and closing guide 6. The flag member 100 has two flag shaft
portions 101 held by the opening and closing guide 6. The flag
shaft portions 101 are held by the bearing portion 103 of the
opening and closing guide 6 such that one of the flag shaft
portions 101 can freely rotate and the other of the flag shaft
portions 101 can freely rotate and move upward. The flag member 100
has the actuator portion 104. When the document S is set, the
actuator portion 104 is pressed by the leading end of the document
S so that the flag member 100 rotates about the flag shaft portions
101.
[0041] The flag member 100 has the detection portion 105 which
detects that the document S has been set by the detection portion
105 blocking the light of the document set detection sensor 102
when the detection portion 105 rotates about the flag shaft
portions 101. In addition, the flag member 100 has the protruding
portion 107. The position of the center of gravity of the flag
member 100 is determined such that a rotational moment is generated
around the flag shaft portion 101 in the clockwise direction
(direction of arrow A) in FIG. 4 when the opening and closing guide
6 is closed. As a result, the protruding portion 107 contacts the
flag stopper portion 108 provided on the opening and closing guide
6, whereby the posture of the flag member 100 in the rotational
direction is determined.
[0042] The flag member 100 has the cylindrical flag abutting
portion 109. As will be described later, the flag abutting portion
109 is pressed by the assist member 110. Further, the center of
gravity position of the flag member 100 is located at a position
slightly away (about 0.2 mm) from the flag shaft portions 101 (the
center of rotation of the flag member 100) in the horizontal
direction. Therefore, the moment generated at the flag member 100
is extremely small.
[0043] The assist member 110 is rotatably attached to the opening
and closing guide 6 and the assist member 110 is displaceable
between a first position and a second position in accordance with
opening and closing operations of the opening and closing guide 6.
The assist member 110 has two assist shaft portions 111 held by the
opening and closing guide 6. The assist shaft portions 111 are
rotatably held by the bearing portions 112 of the opening and
closing guide 6. The assist member 110 has the cylindrical assist
abutting portion 113. As will be described later, the assist
abutting portion 113 has a function of pressing the flag abutting
portion 109 when the opening and closing guide 6 is opened.
[0044] Two weights 114 are attached to the assist member 110. The
weights 114 in the present embodiment are made of SUM material
having a diameter of 6 mm and a length of 12 mm. The two weights
114 are disposed on both sides of the assist shaft portions 111
such that the direction of the rotational moment of the assist
member 110 by one of the weights 114 is opposite to that by the
other of the weights 114.
[0045] FIG. 5 is a cross-sectional view of the assist member 110 in
the vicinity of the document setting detection sensor 102. The
position of the center of gravity of the assist member 110 is so
determined that a moment is generated in the counterclockwise
direction (direction of arrow B) with respect to the assist shaft
portion 111 as shown in FIG. 5 when the open and close guide 6 is
closed. The assist abutting portion 115 provided on the assist
member 110 abuts against the stopper portion 116 provided on the
opening and closing guide 6, whereby the posture of the assist
member 110 in the rotational direction is determined. At this time,
the assist member 110 is located at the first position, and the
position of the center of gravity is located at a position slightly
away (about 0.2 mm) from the center of rotation of the assist shaft
portions 111 in the horizontal direction. As a result, the moment
generated to the assist shaft portions 111 is extremely small.
[0046] FIG. 6 is a perspective view of the flag abutting portion
109 of the flag member 100 and the assist abutting portion 113 of
the assist member 110 when the opening and closing guide 6 is
closed.
[0047] The flag abutting portion 109 is provided at a position
distant from the rotational center axis of the flag shaft portions
101. The flag abutting portion 109 has a cylindrical shape with a
diameter of 3 mm, and is provided in parallel with the flag shaft
portions 101. The assist abutting portion 113 is provided at a
position away from the center axis of the assist shaft portions
111. The assist abutting portion 113 has a cylindrical shape with a
diameter of 8 mm, and is provided in parallel with the assist shaft
portions 111.
[0048] When the opening and closing guide 6 is closed, the flag
abutting portion 109 and the assist abutting portion 113 are
separated from each other while keeping a constant clearance
without coming into contact with each other. In this state, the
assist member 110 does not act on the flag member 100. As the
opening and closing guide 6 is opened, the relative positional
relationship between the flag shaft portions 101 and the assist
shaft portions 111 is changed as described later. As a result, the
flag abutting portion 109 and the assist abutting portion 113 abut
against each other.
[0049] FIGS. 7A, 7B and 7C are schematic views showing movements
until a document is set and fed to the document tray 11.
[0050] Before the document S is set, the flag member 100 is held
with an inclination of about 83.degree. with respect to the
stacking surface of the document tray 11 (FIG. 7A). When the
document S is set by a user, the flag member 100 starts to rotate
in the clockwise direction about the flag shaft portions 101 by the
actuator portion 104 being pressed by the document S.
[0051] When the flag member 100 rotates by about 25.degree., the
document S goes under the flag member 100 (FIG. 7B). At this time,
the detection portion 105 blocks the light of the document setting
detection sensor 102, thereby detecting that the document S has
been set. By making the angle of the flag member 100 with respect
to the setting direction of the document S as close to 90.degree.
as possible, it is easy to detect even a document with low
stiffness such as a thin paper without buckling.
[0052] When the document S is detected, the document tray 11 is
lifted up by a document tray lifting motor (not shown) and is moved
to a predetermined position (FIG. 7C). Thereafter, the feeding
operation is performed by the feeding roller 1. After a
predetermined number of sheets are fed, the document tray 11 is
lifted down by the document tray lifting motor (not shown) and is
moved to the initial position. The flag member 100 also returns to
the initial position and the operations are completed. During this
series of operations, the flag member 100 and the assist member 110
are not brought into contact with each other. The reason is that
when the sheet is detected, since the flag member 100 rotates in
the clockwise direction in FIG. 7, the flag abutting portion 109
rotates in a direction to retract from the assist abutting portion
113.
[0053] Further, in the present embodiment, as shown in FIG. 7, the
flag shaft portions 101, which are the center of rotation of the
flag member 100, are positioned at lower positions of the opening
and closing guide 6 in the vertical direction in a state where the
opening and closing guide 6 is located at the closed position. With
this configuration, even if the angle of the flag member 100 with
respect to the setting direction of the document is made as close
as possible to 90.degree., it is not necessary to lengthen the flag
member 100.
[0054] (Operations of Flag Member When Opening and Closing Guide is
Opened) Next, the operations of the flag member 100 when the
opening and closing guide 6 is opened will be described. For
example, when a paper jam occurs in the reading apparatus, or when
replacing parts during maintenance, the work is done with the
opening and closing guide 6 being opened upward. FIG. 8 is a
schematic diagram showing a state in which the opening and closing
guide 6 is opened. The opening and closing guide 6 is held so as to
be rotatable around the rotational shaft 117 with respect to the
reading apparatus main body. When a user rotates the opening and
closing guide 6 to open it, the document conveying path is exposed.
At this time, the opening angle should be large enough because a
certain amount of space is required from the viewpoint of
workability, but if the opening angle is too large, the opening and
closing guide 6 may collide with peripheral objects such as a wall
surface of an installation place. Therefore, the opening angle of
the opening and closing guide 6 is set to an angle at which the
work is possible and the collision with surrounding objects is
avoided. Then, the opening and closing guide 6 is held in a
self-standing state for work to be easily done when the opening and
closing guide 6 is opened.
[0055] With the opening operations of the opening and closing guide
6, the assist member 110 acts on the flag member 100. When the
opening and closing guide 6 is located at the open position, the
assist member 110 presses the flag member 100 so that the flag
member 100 is urged toward the opening and closing guide 6. Next,
the action of the assist member 110 on the flag member 100 when the
opening and closing guide 6 is opened and closed will be described
in detail.
[0056] FIGS. 9A and 9B are schematic views showing the positions of
the flag member 100 and the assist member 110 when the opening and
closing guide 6 is closed and opened. FIG. 9A shows a state in
which the opening and closing guide 6 is located at a closed
position, and FIG. 9B shows a state in which the opening and
closing guide 6 is located at an open position.
[0057] In a state where the opening and closing guide 6 is closed,
as described above, the flag member 100 and the assist member 110
are held in a state in which a slight moment is generated in the
counterclockwise direction (direction of arrow C) due to their own
weights without contacting each other.
[0058] As the opening and closing guide 6 is opened, the position
of the assist shaft portion 111 with respect to the flag shaft
portion 101 relatively moves in the counterclockwise direction, and
the position of the assist shaft portion 111 in the vertical
direction becomes almost the same as the position of the flag shaft
portion 101. On the other hand, the flag member 100 and the assist
member 110 try to maintain the posture determined by the position
of the center of gravity. Therefore, the assist member rotates in
the clockwise direction because of the gravity, and the assist
abutting portion 113 abuts against the flag abutting portion 109 to
generate a force in the direction perpendicular to each tangent
(direction of arrow D). As a result, a moment is generated at the
flag member 100 in the clockwise direction (the direction of the
arrow E) with respect to the flag shaft portion 101 and the flag
member 100 rotates against the moment in the counterclockwise
direction (the direction of the arrow F) due to its own weight.
[0059] The flag member 100 continues to rotate until the assist
member 110 abuts against the assist stopper portion 118 provided on
the top surface of the opening and closing guide 6. At this time,
the assist member 110 is located at the second position, and as
shown in FIG. 9B, the flag member 100 is completely retracted
inside the guide surface of the opening and closing guide 6. Even
if the opening and closing guide 6 is opened further, since the
rotation of the assist abutting portion 113 is restricted by the
assist stopper portion 118, the flag abutting portion 109 is never
pushed further. When the opening and closing guide 6 is completely
opened and the opening and closing guide 6 becomes in the
self-standing state, the operation of opening is completed. When
closing the opening and closing guide 6, the opening and closing
guide 6 returns to the initial state by the reverse procedure.
[0060] Since both the flag abutting portion 109 of the flag member
100 and the assist abutting portion 113 are formed in a circular
arc configuration, the contact points are gradually moved while
rotating as the opening and closing guide 6 is opened.
[0061] As described above, when the opening and closing guide 6 is
opened, the flag member 100 is pressed and moved by the assist
member 110 so that the flag member 100 is completely retracted
inside the guide surface of the opening and closing guide 6.
Therefore, it is possible to reduce the risk that the worker
damages parts by contacting the flag member 100 with hands or other
parts during jam recovering or maintenance operations.
[0062] As a specific example, the effect of replacing the conveying
unit 121 for conveying a sheet will be described. FIG. 10 is a
perspective view showing the positional relationship between the
conveying unit 121 and the flag member 100 when the opening and
closing guide 6 is opened.
[0063] When the opening and closing guide 6 is opened, the flag
member 100 retracts inside the surface of the opening and closing
guide 6 as described above. In the embodiment of FIG. 10, an
accommodating portion for accommodating the flag member 100 is
formed in the opening and closing guide 6 with the groove portion
119 and the protection rib 120. When the opening and closing guide
6 is opened, the flag member 100 is pressed by the assist member
110, so that the flag member 100 is retracted into the groove
portion 119 provided in the opening and closing guide 6, and the
flag member 100 is protected by the protection rib 120 which
surrounds the flag member 100.
[0064] The conveying unit 121 has conveying members such as the
feeding roller 1, the arm 2 and the conveying roller 3. The
conveying unit 121 requires maintenance when it is used for a long
time. Therefore, the conveying unit 121 is detachably attachable to
the opening and closing guide 6. At the time of maintenance, the
opening and closing guide 6 is opened, the conveying unit 121 is
pulled out in the direction substantially perpendicular to the
plane of the drawing in the figure, and each roller is exchanged.
In pulling out the conveying unit 121, if the flag member 100
protrudes from the guide surface, the flag member 100 may collide
with the conveying unit 121 so that the flag member 100 may be
damaged. However, in the configuration of the above-described
embodiment, since the flag member 100 is retracted inside the guide
surface of the opening and closing guide 6, the risk thereof can be
reduced. Therefore, in the present embodiment, the flag member 100
is disposed in the vicinity of the conveying unit 121 so as to
reduce the size of the apparatus.
[0065] The flag member 100 is retracted inside the guide surface of
the opening and closing guide 6 by the assist member 110, and the
flag shaft portion 101, which is the center of rotation of the flag
member 100, is arranged to a lower position in the vertical
direction when the opening and closing guide 6 is closed, so that
the length of the flag member 100 can be reduced.
[0066] In the present embodiment, the conveying unit 121 is taken
as an example, but the above configuration is also effective when
other replacement parts such as other conveying rollers and sensors
are present in the vicinity of the flag member 100. The above
configuration is also effective not only at the time of maintenance
but also when there is an operation to open the opening and closing
guide 6 such as jam recovering.
[0067] In this embodiment, the flag member 100 is completely
retracted inside the guide surface of the opening and closing guide
6, but a certain effect can be obtained even when the flag member
100 is not completely retracted.
[0068] Further, in the present embodiment, an example in which the
document tray 11 has the lift-up configuration is described, but a
similar effect can be obtained with a fixed tray which does not
have the lift-up configuration.
[0069] Further, in the present embodiment, the assist member 110
has the weight 114. However, a certain effect can be obtained even
when the weight is not provided.
[0070] Further, in the present embodiment, the sheet conveying
apparatus having the flag member 100 and the assist member 110 is
used for the image reading apparatus. However, the sheet conveying
apparatus can be used for an image forming apparatus having an
image forming portion for forming an image on a sheet.
Second Embodiment
[0071] In the embodiment described above, when the opening and
closing guide 6 is opened, the assist member 110 presses the flag
member 100 while the assist member 110 and the flag member 100 are
rotating in the same direction. However, the flag member 100 can be
retracted while the assist member 110 and the flag member 100 are
rotating in the opposite directions with each other as described
next.
[0072] FIGS. 11A and 11B are schematic views showing the positions
of the flag member 100 and the assist member 110 when the opening
and closing guide 6 is located at the closed position and at the
open position in the second embodiment. FIG. 11A shows a state in
which the opening and closing guide 6 is closed, and FIG. 11B shows
a state in which the opening and closing guide 6 is opened.
[0073] When the opening and closing guide 6 is closed, the flag
member 100 is held by a stopper portion (not shown) in a state in
which a slight moment is generated in the counterclockwise
direction (direction of arrow C) by its own weight. On the other
hand, the assist member 110 is held by the second stopper portion
122 in a state in which a moment is generated in the clockwise
direction (direction of arrow G) by its own weight. The flag member
100 and the assist member 110 are held without contacting each
other.
[0074] As the opening and closing guide 6 is opened, the relative
position of the assist shaft portion 111 in the vertical direction
with respect to the position of the center of gravity of the assist
member 110 changes. When the opening and closing guide 6 is opened
to a predetermined angle, the rotational moment due to the position
of the center of gravity of the assist member 110 is switched from
the clockwise direction (the direction of the arrow G) to the
counterclockwise direction (the direction of the arrow H).
[0075] Therefore, the assist abutting portion 113 abuts against the
flag abutting portion 109, so that a force is generated in the
direction perpendicular to each tangent (direction of arrow I). As
a result, a moment is generated at the flag member 100 in the
clockwise direction (the direction of the arrow E) with respect to
the flag shaft portion 101 so that the flag member rotates against
the moment in the counterclockwise direction (the direction of the
arrow F) due to its own weight. The flag member 100 rotates until
the assist member 110 abuts against the assist stopper portion 118.
At this time, the flag member 100 is completely retracted inside
the guide surface of the opening and closing guide 6.
[0076] As described above, similarly to the first embodiment, when
the opening and closing guide 6 is opened, the flag member 100 is
completely retracted inside the guide surface of the opening and
closing guide 6 by being pressed and moved by the assist member
110. With this configuration, it is possible to reduce the risk
that the flag member 100 is damaged due to a worker contacting the
flag member 100 with a hand or a part during jam recovery or
maintenance operations.
Third Embodiment
[0077] In the embodiment described above, the direction of the
rotational moment due to the weight of the assist member 110 is
switched while the opening and closing guide 6 is moving from the
closed position to the open position. However, when the opening and
closing guide 6 is opened, the direction of the rotational moment
due to the weight of the assist member 110 may continue to be the
same.
[0078] FIGS. 12A and 12B are views for explaining the operations of
the flag member 100 and the assist member 110 provided in the
opening and closing guide 6 in the third embodiment. FIG. 12A shows
a state in which the opening and closing guide 6 is located at a
closed position, and FIG. 12B shows a state in which the opening
and closing guide 6 is located at an open position.
[0079] As shown in FIGS. 12A and 12B, the flag member 100 is
configured to be rotatable around the flag shaft portion 101, and
the assist member 110 is configured to be rotatable around the
assist shaft portion 111. When the opening and closing guide 6 is
located at the closed position, the assist abutting portion 113 of
the assist member 110, which is suspended by its own weight is
located at a position where the assist abutting portion 113 does
not act on the flag abutting portion 109 of the flag member
100.
[0080] When the opening and closing guide 6 moves from the closed
position of FIG. 12A to the open position of FIG. 12B, both the
assist member 110 and the flag member 100 rotate in the clockwise
direction, and the assist abutting portion 113 presses the flag
abutting portion 109 so that the flag member 100 is retracted
inside the guide surface of the opening and closing guide 6. With
this configuration, it is possible to obtain the same effect as the
above-described embodiment.
[0081] 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 such modifications and
equivalent structures and functions.
[0082] This application claims the benefit of Japanese Patent
Application No. 2017-247537, filed Dec. 25, 2017, which is hereby
incorporated by reference herein in its entirety.
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