U.S. patent application number 16/432516 was filed with the patent office on 2019-09-19 for sheet stacking apparatus, sheet feeding apparatus, image forming apparatus, and image forming system.
The applicant listed for this patent is CANON FINETECH NISCA INC.. Invention is credited to Shota Odajima.
Application Number | 20190283988 16/432516 |
Document ID | / |
Family ID | 63916021 |
Filed Date | 2019-09-19 |
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United States Patent
Application |
20190283988 |
Kind Code |
A1 |
Odajima; Shota |
September 19, 2019 |
SHEET STACKING APPARATUS, SHEET FEEDING APPARATUS, IMAGE FORMING
APPARATUS, AND IMAGE FORMING SYSTEM
Abstract
A sheet stacking apparatus includes a tray capable of stacking
plural sheets, and four wires with one end of each of them being
connected to a corresponding one of portions at four corners of the
tray. On the downstream side of the tray concerning a sheet feeding
direction, the other end of each of two wires is connected via
pulleys provided above the tray. A winding unit in the apparatus
vertically moves the tray hung by the four wires by winding up or
rolling down the two wires. On a side opposite to the side of the
tray where the connecting portion to which one end of each of the
two wires connected to the winding unit is connected, the other end
of each of the remaining two wires are connected via pulleys
provided above and below the tray, respectively.
Inventors: |
Odajima; Shota; (Yashio-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON FINETECH NISCA INC. |
Misato-shi |
|
JP |
|
|
Family ID: |
63916021 |
Appl. No.: |
16/432516 |
Filed: |
June 5, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15946074 |
Apr 5, 2018 |
10351369 |
|
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16432516 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 1/14 20130101; B65H
2403/544 20130101; B65H 2405/15 20130101; B65H 2801/06
20130101 |
International
Class: |
B65H 1/14 20060101
B65H001/14 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 27, 2017 |
JP |
2017-088573 |
Claims
1.-15. (canceled)
16. A sheet feeding apparatus comprising: a stacking unit capable
of stacking a sheet; a feeding unit configured to contact and feed
an uppermost sheet stacked by the stacking unit; a first lifting
unit configured to lift the stacking unit; a second lifting unit
different from the first lifting unit and configured to lift the
stacking unit; a third lifting unit different from the first
lifting unit and the second lifting unit and configured to lift the
stacking unit; and a roll-up unit configured to raise the stacking
unit by rolling up the first lifting unit and the second lifting
unit, and lowering the stacking unit by releasing the first lifting
unit and the second lifting unit, wherein the stacking unit
includes, in a conveyance direction, a first connecting portion, a
second connecting portion, and a third connecting portion, to which
the first lifting unit, the second lifting unit, and the third
lifting unit are, respectively, connected at a plurality of
positions, with respect to the conveyance direction, the second
connecting portion is provided on a downstream side of the third
connecting portion, and the first connecting portion is provided on
a downstream side of the second connecting portion, the first
lifting unit is provided to be connected to the first connecting
portion and to lift the first connecting portion by acting on the
first connecting portion when rolled up by the roll-up unit, the
second lifting unit is provided to be connected to the second
connecting portion and to lift the second connecting portion by
acting on the second connecting portion when rolled up by the
roll-up unit, and the third lifting unit is provided to be
connected to the second connecting portion at one end, to be
connected to the third connecting portion at the other end, and,
when the roll-up unit rolls up the first lifting unit and the
second lifting unit, to be drawn to the second connecting portion
lifted by an action of the second lifting unit and to lift the
third connecting portion by acting on the third connecting portion
on the stacking unit.
17. The apparatus according to claim 16, wherein in the second
connecting portion, a connecting point with the second lifting unit
and a connecting point with the third lifting unit are the
same.
18. The apparatus according to claim 16, wherein in the second
connecting portion, a connecting point with the second lifting unit
and a connecting point with the third lifting unit are different in
a predetermined range, and a distance between the connecting point
with the second lifting unit and the connecting point with the
third lifting unit is shorter than a distance between the first
connecting portion and the second connecting portion, and shorter
than a distance between the second connecting portion and the third
connecting portion.
19. The apparatus according to claim 16, further comprising: a
first support unit provided below the stacking unit and configured
to support the third lifting unit; and a second support unit
provided above the stacking unit and configured to support the
third lifting unit, wherein the third lifting unit drawn to the
second connecting portion lifts the stacking unit via the first
support unit and the second support unit.
20. The apparatus according to claim 19, wherein the stacking unit
can be vertically moved between the first support unit and the
second support unit.
21. The apparatus according to claim 20, wherein a position of the
second support unit is changeable in a direction of vertically
moving the stacking unit, and a lifting action of the second
lifting unit is adjusted by changing the position of the second
support unit.
22. The apparatus according to claim 19, wherein the first support
unit and the second support unit are pulleys.
23. The apparatus according to claim 16, further comprising a
driving unit configured to generate a driving force of rotating the
roll-up unit in a first direction and a second direction.
24. The apparatus according to claim 16, wherein the first lifting
unit, the second lifting unit, and the third lifting unit are,
respectively, connected to corresponding connecting portions at
positions outside a stacking region where the stacking unit can
stack the sheet.
25. The apparatus according to claim 16, wherein the stacking unit
includes concave portions between the first connecting portion and
the second connecting portion, and between the second connecting
portion and the third connecting portion, and the first connecting
portion, the second connecting portion, and the third connecting
portion are provided in beam-like convex portions formed by
providing the concave portions.
26. The apparatus according to claim 16, wherein in the conveyance
direction, a tail end of a sheet of a stackable maximum size is
positioned on an upstream side of the second connecting
portion.
27. An image forming apparatus comprising: a stacking unit capable
of stacking a sheet; a feeding unit configured to contact and feed
an uppermost sheet stacked by the stacking unit; an image forming
unit configured to form an image on the sheet fed by the feeding
unit; a first lifting unit configured to lift the stacking unit; a
second lifting unit different from the first lifting unit and
configured to lift the stacking unit; a third lifting unit
different from the first lifting unit and the second lifting unit
and configured to lift the stacking unit; and a roll-up unit
configured to raise the stacking unit by rolling up the first
lifting unit and the second lifting unit, and lowering the stacking
unit by releasing the first lifting unit and the second lifting
unit, wherein the stacking unit includes, in a conveyance
direction, a first connecting portion, a second connecting portion,
and a third connecting portion to which the first lifting unit, the
second lifting unit, and the third lifting unit are, respectively,
connected at a plurality of positions, with respect to the
conveyance direction, the second connecting portion is provided on
a downstream side of the third connecting portion, and the first
connecting portion is provided on a downstream side of the second
connecting portion, the first lifting unit is provided to be
connected to the first connecting portion and to lift the stacking
unit by acting on the first connecting portion when rolled up by
the roll-up unit, the second lifting unit is provided to be
connected to the second connecting portion and to lift the stacking
unit by acting on the second connecting portion when rolled up by
the roll-up unit, and the third lifting unit is provided to be
connected to the second connecting portion at one end, to be
connected to the third connecting portion at the other end, and,
when the roll-up unit rolls up the first lifting unit and the
second lifting unit, to be drawn to the second connecting portion
lifted by an action of the second lifting unit and to lift the
stacking unit by acting on the third connecting portion on the
stacking unit.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a sheet stacking apparatus
that feeds stacked sheets, a sheet feeding apparatus that includes
this sheet stacking apparatus, an image forming apparatus that
includes the sheet feeding apparatus, and an image forming
system.
Description of the Related Art
[0002] In image forming apparatuses such as a copying machine and a
printer, there is known an apparatus that includes a sheet storage
unit and a feeding mechanism such as a feeding roller which feeds
sheets stored in the sheet storage unit, and configured to feed the
sheets stored in the sheet storage unit to an image forming unit by
the feeding mechanism. In recent years, out of such image forming
apparatuses, the number of apparatuses each including a
large-volume sheet storage unit capable of supplying a large volume
of sheets as many as several thousand sheets increases.
[0003] Furthermore, in a recent print industry, needs (for example,
book jackets, double-page spreads of catalogs, or POP
advertisements) to perform printing on elongated paper rather than
plain paper of A3, A4, or the like have grown.
[0004] A lifter mechanism of a conventional sheet feeding apparatus
adopts an arrangement using wires and pulleys so as to implement a
simple and low-cost arrangement. However, the vertical moving
performance of a sheet stacking tray is degraded due to the
relationship between the barycenter of stacked sheets and the
hanging fulcrums of the wires. To cope with this, there has been
proposed a feeding apparatus that hangs and supports a sheet
stacking tray stably by providing wire fulcrums outside the
barycenters of sheet members of various sizes stacked on the sheet
stacking tray with respect to the barycenters (see Japanese Patent
Laid-Open No. 7-300245).
[0005] In the related art, however, the wire fulcrums are provided
in four portions of the front/rear end portions of the sheet
stacking tray and connected to different wires, and these four
portions are lifted by the driving force of a motor, requiring an
arrangement that fixes the wires to both the front/rear end
portions or an arrangement that winds up the wires. This requires a
space for including the arrangement that fixes or winds up the
wires in the front/rear of the sheet stacking tray, causing a
problem that the apparatus has to be increased in size.
SUMMARY OF THE INVENTION
[0006] Accordingly, the present invention is conceived as a
response to the above-described disadvantages of the conventional
art.
[0007] For example, a sheet stacking apparatus, a sheet feeding
apparatus, an image forming apparatus, and an image forming system
according to this invention are capable of vertically moving a
sheet stacking tray stably with a simple arrangement.
[0008] According to one aspect of the present invention, there is
provided a sheet stacking apparatus comprising: a stacking unit
capable of stacking a sheet; a restriction unit movable, in a
conveyance direction in which the sheet stacked by the stacking
unit is conveyed, in a restriction direction of restricting
movement of the sheet stacked by the stacking unit and a release
direction of releasing the restriction; a first lifting unit
configured to lift the stacking unit; a second lifting unit
different from the first lifting unit to lift the stacking unit; a
third lifting unit different from the first lifting unit and the
second lifting unit to lift the stacking unit; and a roll-up unit
configured to raise the stacking unit by rolling up the first
lifting unit and the second lifting unit, and lowering the stacking
unit by releasing the first lifting unit and the second lifting
unit, wherein the stacking unit includes, in the conveyance
direction, a first connecting portion, a second connecting portion,
and a third connecting portion to which the first lifting unit, and
the second lifting unit, and the third lifting unit are,
respectively, connected at a plurality of positions and an
elongated hole for the restriction unit to move, in the conveyance
direction, the second connecting portion is provided on a
downstream side of the third connecting portion, and the first
connecting portion is provided on the downstream side of the second
connecting portion, the first lifting unit is provided to be
connected to the first connecting portion and to lift the stacking
unit by acting on the first connecting portion when rolled up by
the roll-up unit, the second lifting unit is provided to be
connected to the second connecting portion and to lift the stacking
unit by acting on the second connecting portion when rolled up by
the roll-up unit, and the third lifting unit is provided to be
connected to the second connecting portion at one end, to be
connected to the third connecting portion at the other end, and
when the roll-up unit rolls up the first lifting unit and the
second lifting unit, to be drawn to the second connecting portion
lifted by an action of the second lifting unit and to lift the
stacking unit by acting on the third connecting portion on the
stacking unit.
[0009] According to another aspect of the present invention, there
is provided a sheet feeding apparatus comprising: a stacking unit
capable of stacking a sheet; a restriction unit movable, in a
conveyance direction in which the sheet stacked by the stacking
unit is conveyed, in a restriction direction of restricting
movement of the sheet stacked by the stacking unit and a release
direction of releasing the restriction; a feeding unit configured
to contact and feed an uppermost sheet stacked by the stacking
unit; a first lifting unit configured to lift the stacking unit; a
second lifting unit different from the first lifting unit to lift
the stacking unit; a third lifting unit different from the first
lifting unit and the second lifting unit to lift the stacking unit;
and a roll-up unit configured to raise the stacking unit by rolling
up the first lifting unit and the second lifting unit, and lowering
the stacking unit by releasing the first lifting unit and the
second lifting unit, wherein the stacking unit includes, in the
conveyance direction, a first connecting portion, a second
connecting portion, and a third connecting portion to which the
first lifting unit, and the second lifting unit, and the third
lifting unit are, respectively, connected at a plurality of
positions and an elongated hole for the restriction unit to move,
in a direction parallel to a long side of a sheet with a maximum
length stackable by the stacking unit, the second connecting
portion is provided closer to a side of the restriction direction
than the third connecting portion, and the first connecting portion
is provided closer to the side of the restriction direction than
the second connecting portion, the first lifting unit is provided
to be connected to the first connecting portion and to lift the
stacking unit by acting on the first connecting portion when rolled
up by the roll-up unit, the second lifting unit is provided to be
connected to the second connecting portion and to lift the stacking
unit by acting on the second connecting portion when rolled up by
the roll-up unit, and the third lifting unit is provided to be
connected to the second connecting portion at one end, to be
connected to the third connecting portion at the other end, and
when the roll-up unit rolls up the first lifting unit and the
second lifting unit, to be drawn to the second connecting portion
lifted by an action of the second lifting unit and to lift the
stacking unit by acting on the third connecting portion on the
stacking unit.
[0010] According to still another aspect of the present invention,
there is provided an image forming apparatus comprising: a stacking
unit capable of stacking a sheet; a restriction unit movable, in a
conveyance direction in which the sheet stacked by the stacking
unit is conveyed, in a restriction direction of restricting
movement of the sheet stacked by the stacking unit and a release
direction of releasing the restriction; a feeding unit configured
to contact and feed an uppermost sheet stacked by the stacking
unit; an image forming unit configured to form an image on the
sheet fed by the feeding unit; a first lifting unit configured to
lift the stacking unit; a second lifting unit different from the
first lifting unit to lift the stacking unit; a third lifting unit
different from the first lifting unit and the second lifting unit
to lift the stacking unit; and a roll-up unit configured to raise
the stacking unit by rolling up the first lifting unit and the
second lifting unit, and lowering the stacking unit by releasing
the first lifting unit and the second lifting unit, wherein the
stacking unit includes, in the conveyance direction, a first
connecting portion, a second connecting portion, and a third
connecting portion to which the first lifting unit, and the second
lifting unit, and the third lifting unit are, respectively,
connected at a plurality of positions and an elongated hole for the
restriction unit to move, in the conveyance direction, the second
connecting portion is provided on a downstream side of the third
connecting portion, and the first connecting portion is provided on
the downstream side of the second connecting portion, the first
lifting unit is provided to be connected to the first connecting
portion and to lift the stacking unit by acting on the first
connecting portion when rolled up by the roll-up unit, the second
lifting unit is provided to be connected to the second connecting
portion and to lift the stacking unit by acting on the second
connecting portion when rolled up by the roll-up unit, and the
third lifting unit is provided to be connected to the second
connecting portion at one end, to be connected to the third
connecting portion at the other end, and when the roll-up unit
rolls up the first lifting unit and the second lifting unit, to be
drawn to the second connecting portion lifted by an action of the
second lifting unit and to lift the stacking unit by acting on the
third connecting portion on the stacking unit.
[0011] According to still another aspect of the present invention,
there is provided an image forming system comprising: a sheet
feeding apparatus; and an image forming apparatus, wherein the
sheet feeding apparatus comprises: a stacking unit capable of
stacking a sheet; a restriction unit movable, in a conveyance
direction in which the sheet stacked by the stacking unit is
conveyed, in a restriction direction of restricting movement of the
sheet stacked by the stacking unit and a release direction of
releasing the restriction; a feeding unit configured to contact and
feed an uppermost sheet stacked by the stacking unit; a first
lifting unit configured to lift the stacking unit; a second lifting
unit different from the first lifting unit to lift the stacking
unit; a third lifting unit different from the first lifting unit
and the second lifting unit to lift the stacking unit; and a
roll-up unit configured to raise the stacking unit by rolling up
the first lifting unit and the second lifting unit, and lowering
the stacking unit by releasing the first lifting unit and the
second lifting unit, wherein the stacking unit includes, in the
conveyance direction, a first connecting portion, a second
connecting portion, and a third connecting portion to which the
first lifting unit, and the second lifting unit, and the third
lifting unit are, respectively, connected at a plurality of
positions and an elongated hole for the restriction unit to move,
in a direction parallel to a long side of a sheet with a maximum
length stackable by the stacking unit, the second connecting
portion is provided closer to a side of the restriction direction
than the third connecting portion, and the first connecting portion
is provided closer to the side of the restriction direction than
the second connecting portion, the first lifting unit is provided
to be connected to the first connecting portion and to lift the
stacking unit by acting on the first connecting portion when rolled
up by the roll-up unit, the second lifting unit is provided to be
connected to the second connecting portion and to lift the stacking
unit by acting on the second connecting portion when rolled up by
the roll-up unit, the third lifting unit is provided to be
connected to the second connecting portion at one end, to be
connected to the third connecting portion at the other end, and
when the roll-up unit rolls up the first lifting unit and the
second lifting unit, to be drawn to the second connecting portion
lifted by an action of the second lifting unit and to lift the
stacking unit by acting on the third connecting portion on the
stacking unit, and the image forming apparatus comprises an image
forming unit configured to form an image on the sheet fed by the
feeding unit.
[0012] The invention is particularly advantageous since it is
possible to vertically move a stacking tray stably with a simple
arrangement.
[0013] 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
[0014] FIG. 1 is a side sectional view showing the schematic
arrangement of an image forming apparatus that includes a sheet
feeding apparatus according to an exemplary embodiment of the
present invention;
[0015] FIG. 2 is a perspective view showing, in a state in which a
cover is removed, a main part of a sheet stacking unit according to
the first embodiment;
[0016] FIG. 3 is a perspective view showing the arrangement of
wires that hang a sheet stacking tray in the sheet stacking unit
according to the first embodiment;
[0017] FIG. 4 is a sectional view showing the arrangement of the
wires that hang the sheet stacking tray in the sheet stacking unit
according to the first embodiment;
[0018] FIG. 5 is a sectional view showing a state in which the
sheet stacking tray is lifted up in the sheet stacking unit
according to the first embodiment;
[0019] FIG. 6 is a perspective view showing, in a state in which a
cover is removed, a main part of a sheet stacking unit according to
the second embodiment;
[0020] FIG. 7 is a perspective view showing the arrangement of
wires that hang a sheet stacking tray in the sheet stacking unit
according to the second embodiment;
[0021] FIG. 8 is a sectional view showing the arrangement of the
wires that hang the sheet stacking tray in the sheet stacking unit
according to the second embodiment; and
[0022] FIG. 9 is a sectional view showing a state in which the
sheet stacking tray is lifted up in the sheet stacking unit
according to the second embodiment.
DESCRIPTION OF THE EMBODIMENTS
[0023] Exemplary embodiments of the present invention will now be
described in detail in accordance with the accompanying drawings.
However, the present invention is not limited to embodiments to be
described below, and a change and an addition may be made without
departing from the scope of the present invention.
[0024] In this specification, the terms "print" and "printing" not
only include the formation of significant information such as
characters and graphics, but also broadly include the formation of
images, figures, patterns, and the like on a print medium, or the
processing of the medium, regardless of whether they are
significant or insignificant and whether they are so visualized as
to be visually perceivable by humans.
[0025] Also, the term "print medium (or sheet)" not only includes a
paper sheet used in common printing apparatuses, but also broadly
includes materials, such as cloth, a plastic film, a metal plate,
glass, ceramics, wood, and leather, capable of accepting ink.
[0026] <Outline of Image Forming Apparatus (FIG. 1)>
[0027] FIG. 1 is a side sectional view showing the schematic
arrangement of an image forming system 1000 that forms an image in
accordance with an electrophotographic method according to an
exemplary embodiment of the present invention.
[0028] As shown in FIG. 1, the image forming system 1000 includes
an image forming apparatus (LBP) 900 and a paper deck 3000
connected to the image forming apparatus 900. The paper deck 3000
includes a control unit 41 with a CPU, a RAM, and a ROM, which
controls the paper deck 3000 in accordance with a command of a
controller 120 that controls the entire image forming system
1000.
[0029] The image forming apparatus 900 includes first to fourth
sheet feeding apparatuses 1001 to 1004 of the same arrangement that
feed sheets S and a sheet conveying apparatus 902 that conveys the
sheets S fed by the sheet feeding apparatuses 1001 to 1004 to an
image forming unit 901. The controller 120 provided in the image
forming apparatus 900 includes the CPU, the RAM, and the ROM in
order to control the respective units of the image forming system
1000. In addition, the controller 120 generates an image signal
upon receiving image data from the outside (for example, a PC or
the like) and outputs this to the image forming unit.
[0030] Each of the first to fourth sheet feeding apparatuses 1001
to 1004 includes a paper feed cassette 10 that stores the sheets S,
a pickup roller 11, and a separation/conveyance roller pair 25
constituted by a feed roller 22 and a retard roller 23. Each sheet
S stored in the paper feed cassette 10 is separated and fed by the
pickup roller 11 and the separation/conveyance roller pair 25 each
performing a vertical moving operation and rotating at a
predetermined timing. A feeding sensor 24 is arranged near the
downstream side of the roller 22 and retard roller 23 in a sheet
feeding direction. The feeding sensor 24 detects passage of the
sheets S, and transmits a detection signal to the controller
120.
[0031] The sheet conveying apparatus 902 includes conveyance roller
pairs 15, a pre-registration roller pair 130, and a registration
roller pair 110. The sheet S fed from each of the first to fourth
sheet feeding apparatuses 1001 to 1004 is passed through a sheet
conveyance path 108 by the conveyance roller pairs 15 and the
pre-registration roller pair 130, and then guided to the
registration roller pair 110. Subsequently, the sheet S is fed to
the image forming unit 901 at a predetermined timing by the
registration roller pair 110.
[0032] The image forming unit 901 includes, for example, a
photosensitive drum 112, a laser scanner 111, a developing device
114, a transfer charger 115, and a separation charger 116. Then, at
the time of image formation, laser light from the laser scanner 111
driven by an image signal from the controller 120 is deflected by a
mirror 113, and the photosensitive drum 112 that rotates in a
clockwise direction is irradiated with the laser light, forming an
electrostatic latent image on the photosensitive drum. Furthermore,
the electrostatic latent image thus formed on the photosensitive
drum is then visualized as a toner image by the developing device
114.
[0033] Subsequently, the toner image on the photosensitive drum is
transferred to the sheet S by the transfer charger 115 in a
transfer unit 112b. Furthermore, the sheet S to which the toner
image is thus transferred is conveyed to a fixing apparatus 118 by
a conveyance belt 117 after electrostatic separation from the
photosensitive drum 112 by the separation charger 116, and then
discharged by discharge rollers 119. Note that the image forming
unit 901 and the fixing apparatus 118 form an image on the sheet S
fed from a sheet feeding apparatus 30 (or the sheet feeding
apparatuses 1001 to 1004).
[0034] A discharge sensor 122 is arranged in a conveyance path
between the fixing apparatus 118 and the discharge rollers 119.
Based on a detection signal of the discharge sensor 122, the
controller 120 detects passage of the discharged sheet S.
[0035] Furthermore, in the above-described embodiment, the
description has been given by taking an image forming apparatus
(printer apparatus) having a single function as an example.
However, the present invention is not limited to this. The present
invention is also applicable to, for example, a copying machine
system that integrates an image reading apparatus (scanner
apparatus), the image forming apparatus, and an ADF device or may
be implemented by adopting a multifunctional system obtained by
further adding a facsimile function to the copying machine
system.
[0036] Furthermore, the description has been given assuming that
the image forming unit of the above-described image forming
apparatus includes a mechanism that forms an image in accordance
with the electrophotographic method. However, the present invention
is not limited to this. The present invention may be implemented by
adopting, for example, an image forming unit that forms an image in
accordance with an inkjet method.
[0037] An embodiment regarding the paper deck 3000 serving as a
large-volume deck will be described next by taking, as an example,
the paper deck 3000 as the sheet feeding apparatus 30 of the image
forming system 1000 configured as described above.
First Embodiment
[0038] FIG. 2 is a perspective view showing, in a state in which a
cover is removed, a main part of a paper deck 3000 according to the
first embodiment.
[0039] As shown in FIGS. 1 and 2, the paper deck 3000 includes an
apparatus main body 3000a, a large-volume deck storage 62
accommodated in the apparatus main body 3000a, and a sheet feeding
apparatus 30. The sheet feeding apparatus 30 feeds sheets S
stacked/stored in the large-volume deck storage 62 to an image
forming unit 901.
[0040] The sheet feeding apparatus 30 includes a paper stacking
tray (sheet stacking tray) 61 that stacks sheets S, a pickup roller
51 that feeds the sheets S stacked on the paper stacking tray 61,
and a separation/conveyance roller pair 31 constituted by a feed
roller 12 and a retard roller 13. The pickup roller 51 is arranged
near a leading end portion in a sheet feeding direction (the
direction of an arrow b) to be brought into tight contact with the
uppermost sheet on the paper stacking tray 61 by an appropriate
force. For this reason, the pickup roller 51 is provided above the
paper stacking tray 61, contacts the uppermost sheet of the sheets
S stacked on the raised paper stacking tray 61, and feeds the sheet
in the direction of the arrow b.
[0041] The paper stacking tray 61 can stack sheets and is supported
so as to undergo a vertical moving operation in a vertical
direction (a direction parallel to a gravity direction) by a
driving mechanism that includes a vertical moving motor (to be
described later). This vertical moving motor is desirably
configured to vertically move the paper stacking tray 61 by a
single motor. An upper surface detection sensor 50 is arranged on
the upstream side of the pickup roller 51 on the upper side of the
paper stacking tray 61. The upper surface detection sensor 50 is
located above the paper stacking tray 61 and detects an upper
surface 68 of the sheet S on the paper stacking tray. When the
paper stacking tray 61 is lowered the most, the paper stacking tray
61 contacts a base plate 63 of the sheet feeding apparatus 30. As
indicated by a dotted line 81 in FIG. 1, the paper stacking tray 61
rises when the volume of stacked sheets decreases.
[0042] The sheet feeding apparatus 30 includes the paper stacking
tray 61 and two pairs of side restriction members 82, 83, 84, and
85. The side restriction members 82, 83, 84, and 85 are arranged
such that side end positions 82a and 83a in a widthwise direction
(the direction of an arrow h in FIG. 2) perpendicular to the
feeding direction (the direction of the arrow b in FIG. 2) of the
sheets S stacked on the paper stacking tray 61 can be restricted,
and both of them can move in the widthwise direction.
[0043] In this embodiment, the pickup roller 51 is configured to be
brought into tight contact with the uppermost sheet of the sheets S
on the paper stacking tray by an appropriate force, as described
above. Each sheet S on the paper stacking tray 61 is separated and
fed by the pickup roller 51 and the separation/conveyance roller
pair 31 each performing a vertical moving operation and rotating at
a predetermined timing.
[0044] In a connecting portion 14 with an image forming apparatus
900 of the paper deck 3000, a connecting conveyance path 32 that
feeds the sheet S from the side of the paper deck 3000 to a
pre-registration roller pair 130 on the side of the image forming
apparatus 900 is arranged.
[0045] The two pairs of the side restriction members 82, 83, 84,
and 85 are configured to be able to guide the sheets S on the paper
stacking tray 61 by sliding up to the widths of all sheet sizes
compatible with specifications. That is, the side restriction
members are supported to be movable in a sheet widthwise direction
and restrict the both sides positions of the sheets S by contacting
the both end portions of the stacked sheets S. Note that a leading
end restriction unit 86 in FIG. 2 restricts the leading end portion
of each sheet S on the paper stacking tray 61.
[0046] In addition, a trailing end restriction member 87 is
arranged so as to restrict the trailing end portion of each sheet S
on the paper stacking tray 61. The trailing end restriction member
87 is supported to be movable in a direction parallel to the sheet
feeding direction (the direction of the arrow b) and restricts the
trailing end position of each sheet S. The trailing end restriction
member 87 is moved along an elongated positioning hole portion 61a
(FIG. 2) formed in the center portion of the paper stacking tray
61.
[0047] As shown in FIG. 2, when the pickup roller 51 is driven by a
driving motor (not shown) to rotate in a direction (the direction
of an arrow a) of feeding the sheets S, the uppermost sheet S is
fed in the direction of the arrow b. Consequently, the sheet S
contacts a nip portion of the separation/conveyance roller pair 31
adjacent to the exist side of the pickup roller 51.
[0048] When double feed of the sheets S fed by the pickup roller 51
occurs, the following operation is performed. That is, the retard
roller 13 that is driven to/rotates in a direction opposite to the
feed roller 12 that rotates in the same direction as the arrow a
(the direction of an arrow c) rotates in the same direction as the
feed roller 12 by the intervention of two or more sheets S in the
nip portion. Then, the second and subsequent sheets S in the nip
portion are pushed back to the direction of the paper stacking tray
61 by the retard roller 13, and only one uppermost sheet S is fed
to the direction of the arrow b by the feed roller 12.
[0049] When the sheet S is fed from the paper deck 3000 having the
above arrangement or one of the aforementioned first to fourth
sheet feeding apparatuses 1001 to 1004, the leading end of the
sheet S abuts against the nip portion of the pre-registration
roller pair 130. The pre-registration roller pair 130 is formed by
a pair of counter rollers and arranged on a conveyance path of the
sheet S to be rotatable in the direction of an arrow d in FIG. 2 by
a driving motor (not shown). The sheet S that once abuts against
the nip portion of the pre-registration roller pair 130 is conveyed
to the inside of the image forming apparatus 900 by the
pre-registration roller pair 130 that rotates in accordance with a
feeding timing.
[0050] Lifter Mechanism of Paper Stacking Tray 61
[0051] The vertical moving operation of the paper stacking tray 61
will be described here.
[0052] FIG. 3 is a perspective view showing the suspension
arrangement of wires for describing a lifter mechanism of the paper
stacking tray 61.
[0053] As shown in FIGS. 2 and 3, one end of each of four wires
70A, 70B, 72A, and 72B is connected to a corresponding one of four
wire connecting portions 73 and 75 provided in portions beam-like
extending from the four corners of the paper stacking tray 61, and
the paper stacking tray 61 is hung by the four wires. The paper
stacking tray 61 rises when a roll-up unit 90 connected to a motor
M rolls up the two wires 70A and 70B via a driving mechanism by a
driving force generated by the motor. On the other hand, the paper
stacking tray 61 lowers when the roll-up unit 90 rolls down the two
wires 70A and 70B.
[0054] As shown in FIGS. 2 and 3, the shape of the paper stacking
tray 61 prevents the two pairs of movable side restriction members
82, 83, 84, and 85 and the movable trailing end restriction member
87 from interfering with each other. That is, the paper stacking
tray 61 is shaped so as to include beams extending in a direction
(the direction of the arrow h) perpendicular to the sheet feeding
direction (the direction of the arrow b) in the front portion and
rear portion of the sheet feeding direction with respect to the
barycenter of the paper stacking tray 61 as the center, and a flat
plate that connects these two beams. Then, there is a concave space
between these two beams. On the other hand, an elongated
positioning hole portion 61a is formed in the center portion of the
flat plate.
[0055] Then, the side restriction members 82, 83, 84, and 85 can
move in the concave space, and the trailing end restriction member
87 can move in the elongated positioning hole portion 61a, making
it possible to guide the sheets S of a plurality of sizes. The four
wire connection portions 73 and 75 hanging the paper stacking tray
61 are installed on the same beam at the both ends of the front
portion and at the both ends of the rear portion, respectively, in
the sheet feeding direction of the paper stacking tray 61, and
provided on different beams at the both ends in the sheet feeding
direction (the direction of the arrow b).
[0056] Wire Arrangement
[0057] The arrangement of wires that vertically move the paper
stacking tray 61 will be described here.
[0058] The four wires 70A, 70B, 72A, and 72B for vertically moving
the paper stacking tray 61 are installed in the both end portions
of the paper stacking tray 61 in the widthwise direction (the
direction of the arrow h) with the same arrangement, as shown in
FIG. 3. The wire connecting portions of the paper stacking tray 61
include the front portion and the rear portion with respect to the
barycenter of the paper stacking tray 61 in the sheet feeding
direction (the direction of the arrow b).
[0059] FIG. 4 is a side sectional view showing a state in which the
paper stacking tray 61 is lowered. FIG. 5 is a side sectional view
showing a state in which the paper stacking tray 61 is lifted
up.
[0060] As shown in FIGS. 4 and 5, the other end of each of the two
wires 70A and 70B swaged on the lower side of the paper stacking
tray 61 by a swage portion (not shown) and connected to the two
wire connecting portions 73 in the front portion is connected to
the roll-up unit 90 via a plurality of pulleys 91 and 92. The
roll-up unit 90 rotates by driving a motor (not shown), vertically
moving the paper stacking tray 61.
[0061] On the other hand, the remaining two wires 72A and 72B
connected to the two wire connecting portions 75 in the rear
portion are connected on a side opposite to a lifting direction
(the direction of an arrow e) of the paper stacking tray 61 in the
wire connecting portion 73 via a plurality of pulleys 94, 95, 96,
and 97. The wires 72A and 72B may be arranged to be swaged on the
upper side of the paper stacking tray 61 by a swage portion (not
shown) and connected to the wire connecting portion 73. The wires
72A and 72B may also be arranged to be provided at a position
shifted in, for example, the direction of the arrow h or the
direction of the arrow b with respect to the wire connecting
portion 73. More specifically, the wires 72A and 72B may be
provided at a position in a range up to about 10% of the short side
of a stackable sheet with the maximum length in the direction of
the arrow h or a position in a range up to about 10% of the long
side of the stackable sheet with the maximum length in the
direction of the arrow b. If the wire connecting portion 73 is
lifted as a result of this, the wire connecting portion 75 linked
by the two wires 72A and 72B is also pulled and lifted up together.
Note that the wire connecting portion 73 and the wire connecting
portion 75 are linked by the wires 72A and 72B, and thus they are
always in the same direction regarding vertical moving operations
and have the same vertical moving amount. If the wire connecting
portion 73 is vertically moved, the wire connecting portion 75 is
also vertically moved together.
[0062] As shown in FIG. 5, when the roll-up unit 90 rolls up the
wires 70A and 70B, the paper stacking tray 61 is lifted up by the
wires 70A and 70B and raised, the wires 72A and 72B are pulled to
the wire connecting portion 73, and the wire connecting portion 75
is also lifted up.
[0063] Therefore, as can be seen in the arrangements shown in FIGS.
4 and 5, the paper stacking tray 61 can be vertically moved, by
driving the motor, between positions where the pulleys 91, 92, 96,
and 97 are provided and positions where the pulleys 94 and 95 are
provided. Since a distance from the wire connecting portion 73 to
the wire connecting portion 75 is long, the wires 72A and 72B may
extend, causing a bend in each wire. In this case, the pulleys 94
and 95 can change their positions in a vertical direction, making
it possible to adjust the bend in each wire by changing the
positions of the pulleys 94 and 95.
[0064] Therefore, according to the above-described embodiment, a
wire winding mechanism is only provided in the end portion of the
paper stacking tray on the downstream side of a sheet conveyance
direction, making it possible to making a space related to vertical
movement of the paper stacking tray smaller. This contributes to
downsizing of the paper deck. The above-described wire winding
mechanism and wire arrangement are provided on both sides in the
direction of the arrow h. It is only necessary, however, that at
least the one side includes the above-described mechanism.
Second Embodiment
[0065] In a case where an arrangement capable of stacking sheets
long in their conveyance direction, or so-called elongated sheets
is adopted, the center portion of a paper stacking tray easily
suffers from flexural deformation owing to the weight of the
stacked sheets. Therefore, in this embodiment, an arrangement for
preventing or at least reducing such flexural deformation will be
described, in addition to the above-described first embodiment.
[0066] FIG. 6 is a perspective view showing, in a state in which a
cover is removed, a main part of a paper deck 3000 according to the
second embodiment. Note that in FIG. 6, the same reference numerals
denote the same constituent elements as those that have already
been described in the first embodiment, and a description thereof
will be omitted.
[0067] As can be seen by comparing FIG. 6 with FIG. 2, in the
center portion of a paper stacking tray 61 according to this
embodiment, a beam 61m is provided in a direction (the direction of
an arrow h in FIG. 6) perpendicular to a sheet conveyance
direction. Then, other wire connecting portions are provided in the
end portions of the beam 61m in the direction of the arrow h.
[0068] Lifter Mechanism of Paper Stacking Tray 61
[0069] FIG. 7 is a perspective view showing the suspension
arrangement of wires for explaining a lifter mechanism of the paper
stacking tray 61 according to the second embodiment. Note that in
FIG. 7, the same reference numerals denote the same constituent
elements as those that have already been described in the first
embodiment, and a description thereof will be omitted. Only an
arrangement characteristic to this embodiment will be described
here.
[0070] As shown in FIG. 7, a plurality of wires 70A, 70B, 71A, 71B,
72A, and 72B are connected to respective wire connecting portions
73, 74, and 75 of the paper stacking tray 61, and the paper
stacking tray 61 is hung by these wires.
[0071] As shown in FIGS. 6 and 7, the paper stacking tray 61 is
shaped so as to include the beam 61m extending in the direction of
the arrow h near the center portion (a portion to be the barycenter
of the paper stacking tray 61) concerning the direction of an arrow
b. This beam 61m is desirably provided at a position in a range
corresponding to .+-.20% of a stackable sheet with the maximum size
from the center of a stackable sheet with the maximum length in a
direction parallel to the arrow b. Furthermore, the beam 61m is
provided in a place where movability of two pairs of side
restriction members 82, 83, 84, and 85 and a trailing end
restriction member 87 is not disturbed. In this embodiment, the
wire connecting portions 74 hanging the paper stacking tray 61 in
the beam 61m are provided in the end portions of the beam 61m in
the direction of the arrow h.
[0072] Wire Arrangement
[0073] A wire arrangement according to this embodiment that
vertically moves the paper stacking tray 61 will be described
here.
[0074] As shown in FIG. 7, the wire connecting portions 73, 74, and
75 of the paper stacking tray 61 are provided in the front portion,
intermediate portion, and rear portion of the paper stacking tray
61 concerning a sheet feeding direction (the direction of the arrow
b).
[0075] FIG. 8 is a side sectional view showing a state in which the
paper stacking tray 61 is lowered. FIG. 9 is a side sectional view
showing a state in which the paper stacking tray 61 is lifted
up.
[0076] As shown in FIGS. 7 and 8, the wire connecting portions 73
in the front portion are swaged on the lower side of the paper
stacking tray 61 by a swage portion (not shown). The other end of
each of the wires 70A and 70B, and the wires 71A and 71B connected
to the wire connecting portions 74 in the intermediate portion is
connected to a roll-up unit 90 via a plurality of pulleys 91, 92,
and 93. The paper stacking tray 61 is vertically moved by rotating
the roll-up unit 90.
[0077] The wires 72A and 72B connected to the wire connecting
portions 75 in the rear portion are connected in a direction
opposite to a hanging direction (the direction of an arrow e) of
the wire connecting portions 74 in the intermediate portion via a
plurality of pulleys 94, 95, 96, and 97. If the wire connecting
portions 74 in the intermediate portion are lifted, the wire
connecting portions 75 in the rear portion linked with the wire
connecting portions 74 in the intermediate portion by the wires 72A
and 72B are also pulled and lifted up together. Note that the wire
connecting portions 74 in the intermediate portion and the wire
connecting portions 75 in the rear portion are linked by the wires
72A and 72B, and thus they are always in the same direction
regarding vertical moving operations and have the same vertical
moving amount. Therefore, if the wire connecting portions 74 in the
intermediate portion are vertically moved, the wire connecting
portions 75 in the rear portion are also vertically moved
together.
[0078] As shown in FIG. 9, when the roll-up unit 90 rolls up the
wires, the paper stacking tray 61 is lifted up by the wires 70A,
70B, 71A, and 71B and raised, the wires 72A and 72B are pulled by
the wire connecting portion 74 in the intermediate portion, and the
wire connecting portion 75 in the rear portion is also lifted
up.
[0079] Therefore, as can be seen in the arrangements shown in FIGS.
8 and 9, the paper stacking tray 61 can be vertically moved, by
driving the motor, between positions where the pulleys 91, 92, 93,
96, and 97 are provided and positions where the pulleys 94 and 95
are provided.
[0080] Therefore, according to the above-described embodiment, in
addition to the arrangement described in the first embodiment, the
beam is provided in the intermediate portion of the paper stacking
tray, and the additional wire connecting portions are provided in
the end portions of the beam, making it possible to hang the
intermediate portion of the paper stacking tray as well by the
wires. Consequently, although the intermediate portion of the paper
stacking tray easily suffers from flexural deformation in a
downward direction owing to the weight of the stacked sheets, a
force added by a user, or the like, it is possible to prevent or
reduce a bend or deformation in the intermediate portion in the
downward direction by providing the wire connecting portions in the
intermediate portion to hang it by the wires.
[0081] If the beam in the intermediate portion of the paper
stacking tray is lifted up in a direction (upward direction)
opposite to a vertical direction due to an operation error by the
user, a portion which is not so tolerable in strength (for example,
the intermediate portion) may be deformed in the arrangement of the
first embodiment. In the arrangement of this embodiment, however,
the wire connecting portions in the rear portion are also raised in
the same manner when the intermediate portion is raised.
Consequently, a force of raising the intermediate portion upward is
canceled by a force of raising the wire connecting portions in the
rear portion with the intermediate portion, making it possible to
prevent or reduce deformation in the paper stacking tray in the
upward direction.
[0082] Note that an arrangement that provides one beam in the
intermediate portion of the paper stacking tray has been adopted in
the second embodiment. However, the present invention is not
limited to this. An arrangement that provides two or more beams in
the intermediate portion, and lifts these beams by wires may be
adopted. At this time, an arrangement that makes the interval
between the respective beams equal is desirable. This makes it
possible to prevent a bend or deformation in the intermediate
portion more reliably.
[0083] In any case, according to the arrangements of the
above-described embodiments, as shown in FIGS. 3 to 5 and FIGS. 7
to 9, there are the plurality of wire connecting portions (for
example, the connecting portions 73 and 74) to which the plurality
of wires are connected on the paper stacking tray. An arrangement
is adopted in which in these connecting portions, one wire is hung
in a direction of raising the paper stacking tray, and the other
wire is pulled in a direction opposite to the direction of raising
the paper stacking tray.
[0084] Furthermore, in the above-described embodiments, an
arrangement that provides a beam and lifts the beam by wires has
been adopted. However, the present invention is not limited to
this. For example, an arrangement that lifts, without providing any
beam, a stacking tray by providing it with wire connecting portions
may be adopted. This case has the advantage of being able to
vertically move the stacking tray while maintaining a balance with
a simpler arrangement.
[0085] Furthermore, in the above-described embodiments, an
arrangement that provides wires along a feeding direction of a
print medium has been adopted. However, the present invention is
not limited to this. An arrangement that provides wires in a
direction parallel to the long side of a stackable sheet with the
maximum size may be adopted.
[0086] Furthermore, in the above-described embodiments, an
arrangement that uses the paper deck and the image forming
apparatus independently has been adopted. However, the present
invention is not limited to this. An arrangement that incorporates
the paper deck in the image forming apparatus may be adopted.
[0087] 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.
[0088] This application claims the benefit of Japanese Patent
Application No. 2017-088573, filed Apr. 27, 2017, which is hereby
incorporated by reference herein in its entirety.
* * * * *