U.S. patent application number 13/101852 was filed with the patent office on 2011-11-10 for paper feeding cassette and image forming apparatus.
This patent application is currently assigned to Toshiba Tec Kabushiki Kaisha. Invention is credited to Masahiro Ohno, Yousuke Ushiyama.
Application Number | 20110272879 13/101852 |
Document ID | / |
Family ID | 44901432 |
Filed Date | 2011-11-10 |
United States Patent
Application |
20110272879 |
Kind Code |
A1 |
Ushiyama; Yousuke ; et
al. |
November 10, 2011 |
PAPER FEEDING CASSETTE AND IMAGE FORMING APPARATUS
Abstract
According to one embodiment, a paper feeding cassette includes a
sheet storing section, side guides, and a sheet tray. The sheet
storing section stores a sheet to be fed. The side guides move in
the width direction orthogonal to a sheet feeding direction from
the sheet storing section and regulate movement of a sheet end at
least to one side in the width direction. The sheet tray lifts a
downstream side end in the sheet feeding direction from the inside
of the sheet storing section on the lower surface of the sheet
stored in the sheet storing section. A through-hole including at
least a passing area in the width direction of the side guides is
provided in the sheet tray. At least a part of an edge that is
present on the downstream side in the sheet feeding direction,
faces the through-hole, and extends in the width direction moves
closer to the sheet feeding direction as the part of the edge moves
further away from the sheet center in the width direction to an end
side.
Inventors: |
Ushiyama; Yousuke;
(Shizuoka-ken, JP) ; Ohno; Masahiro;
(Kanagawa-ken, JP) |
Assignee: |
Toshiba Tec Kabushiki
Kaisha
Tokyo
JP
Kabushiki Kaisha Toshiba
Tokyo
JP
|
Family ID: |
44901432 |
Appl. No.: |
13/101852 |
Filed: |
May 5, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61333183 |
May 10, 2010 |
|
|
|
61333181 |
May 10, 2010 |
|
|
|
Current U.S.
Class: |
271/227 ;
271/171; 271/253 |
Current CPC
Class: |
B65H 1/266 20130101;
B65H 2601/2531 20130101; B65H 2511/22 20130101; B65H 2405/1117
20130101; B65H 2511/22 20130101; B65H 2220/04 20130101; B65H
2220/01 20130101; B65H 2511/12 20130101; B65H 3/0607 20130101; B65H
2511/12 20130101; B65H 2403/60 20130101 |
Class at
Publication: |
271/227 ;
271/171; 271/253 |
International
Class: |
B65H 1/04 20060101
B65H001/04; B65H 7/02 20060101 B65H007/02; B65H 9/00 20060101
B65H009/00 |
Claims
1. A paper feeding cassette comprising: a sheet storing section
configured to store a sheet to be fed; side guides configured to
move in a width direction orthogonal to a sheet feeding direction
from the sheet storing section and regulate movement of a sheet end
at least to one side in the width direction; and a sheet tray
configured to lift a downstream side end in the sheet feeding
direction from an inside of the sheet storing section on a lower
surface of the sheet stored in the sheet storing section, a
through-hole including at least a passing area in the width
direction of the side guides being provided in the sheet tray and
at least a part of an edge that is present on the downstream side
in the sheet feeding direction, faces the through-hole, and extends
in the width direction moving closer to the sheet feeding direction
as the part of the edge moves further away from a sheet center in
the width direction to an end side.
2. The paper feeding cassette according to claim 1, wherein the
sheet tray includes a supporting section main body configured to
support the sheet and a sheet guide section that extends downward
from the supporting section main body, and the edge is an edge of
the sheet guide section.
3. The paper feeding cassette according to claim 2, wherein a lower
end face of the sheet guide section faces down and is parallel to
the supporting section main body.
4. The paper feeding cassette according to claim 3, wherein the
sheet guide section tilts downward from the supporting section main
body, and an angle formed by the supporting section main body and
the sheet guide section is 145.degree. in sectional view of the
sheet guide section taken along in the sheet feeding direction.
5. The paper feeding cassette according to claim 3, wherein the
sheet guide section curves downward from the supporting section
main body.
6. The paper feeding cassette according to claim 3, wherein the
sheet guide section extends downward vertically from the supporting
section main body.
7. The paper feeding cassette according to claim 1, wherein the
sheet tray has a flat plate shape, and the edge in contact with the
through-hole is an end face of the sheet tray that faces a
side.
8. The paper feeding cassette according to claim 1, further
comprising a sheet sensor configured to emit light to the
downstream side in the sheet feeding direction on the sheet on the
sheet tray and receive reflected light, wherein an opening for
sensor through which the light emitted from the sheet sensor passes
is provided on the downstream side in the sheet feeding direction
of the edge in the sheet tray.
9. The paper feeding cassette according to claim 8, wherein a
section of the edge corresponding to the sheet center side in the
width direction is present further on the upstream side in the
sheet feeding direction than the opening for sensor, and a section
of the edge corresponding to the sheet end side in the width
direction is present on the width direction from the opening for
sensor.
10. The paper feeding cassette according to claim 1, wherein at
least a pair of the side guides are provided and the side guides
are opposed to each other in the width direction and regulate
movement of sheet both ends in the width direction.
11. The paper feeding cassette according to claim 1, wherein a
cushion material is provided on at least one of the upstream side
in the sheet feeding direction on a lower surface of the sheet tray
and a bottom of the paper feeding cassette opposed to the upstream
side in the sheet feeding direction on the lower surface of the
sheet tray.
12. The paper feeding cassette according to claim 1, wherein the
paper feeding cassette is drawn out in the width direction from an
apparatus that houses the paper feeding cassette.
13. An image forming apparatus comprising: a sheet storing section
configured to store a sheet to be fed; side guides configured to
move in a width direction orthogonal to a sheet feeding direction
of the sheet stored in the sheet storing section from an inside of
the sheet storing section and regulate movement of a sheet end at
least to one side in the width direction; and a sheet tray
configured to lift a downstream side end in the sheet feeding
direction from the inside of the sheet storing section on a lower
surface of the sheet stored in the sheet storing section, a
through-hole being formed in an area including at least a passing
area in the width direction of the side guides and at least a part
of an edge that is present on the downstream side in the sheet
feeding direction of the through-hole and extends in the width
direction moving closer to the sheet feeding direction as the part
of the edge moves further away from a sheet center in the width
direction to an end side.
14. The apparatus according to claim 13, wherein the sheet tray
includes a supporting section main body configured to support the
sheet and a sheet guide section that extends downward from the
supporting section main body, and the edge is an edge of the sheet
guide section.
15. The apparatus according to claim 14, wherein a lower end face
of the sheet guide section faces down and is parallel to the
supporting section main body.
16. The apparatus according to claim 15, wherein the sheet guide
section tilts downward from the supporting section main body, and
an angle formed by the supporting section main body and the sheet
guide section is 145.degree. in sectional view of the sheet guide
section taken along in the sheet feeding direction.
17. The apparatus according to claim 15, wherein the sheet guide
section curves downward from the supporting section main body.
18. The apparatus according to claim 15, wherein the sheet guide
section extends downward vertically from the supporting section
main body.
19. The apparatus according to claim 15, wherein the sheet tray has
a flat plate shape, and the edge in contact with the through-hole
is an end face of the sheet tray that faces a side.
20. The apparatus according to claim 13, further comprising a sheet
sensor configured to emit light to the downstream side in the sheet
feeding direction on the sheet on the sheet tray and receive
reflected light, wherein an opening for sensor through which the
light emitted from the sheet sensor passes is provided on the
downstream side in the sheet feeding direction of the edge in the
sheet tray.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority from U.S. provisional application 61/333,183, filed on May
10, 2010; and U.S. provisional application 61/333,181, filed on May
10, 2010; the entire contents of which are incorporated herein by
reference.
FIELD
[0002] Embodiments described herein relate generally to a technique
for stacking sheets using a paper feeding cassette.
BACKGROUND
[0003] FIG. 24 is a perspective view of a paper feeding cassette
3A.
[0004] The paper feeding cassette 3A in the past of an image
forming apparatus includes a cassette case 4 configured to store
sheets, side guides 31A and 31B configured to slide in a sheet
width direction (a Y direction), and a sheet tray 5A on which the
sheets are stacked. The paper feeding cassette 3A feeds the sheets
to the image forming apparatus in the right direction in FIG. 24.
In FIG. 24, the sheet feeding direction from the paper feeding
cassette 3A to the image forming apparatus is represented as X
direction. In FIG. 24, the sheet width direction orthogonal to the
sheet feeding direction (the X direction) and the up-down direction
(a Z direction) is represented as Y direction. Through-holes 9A
including at least passing areas in the sheet width direction of
the side guides 31A and 31B are provided in the sheet tray 5A. A
cushion material 53 is provided on an upstream side in the sheet
feeding direction on the lower surface of the sheet tray 5A. When
the paper feeding cassette 3A is present in the image forming
apparatus, a downstream side in the sheet feeding direction of the
sheet tray 5A is lifted upward. When the paper feeding cassette 3A
is drawn out from the image forming apparatus, the sheet tray 5A
drops to a bottom 45 of the paper feeding cassette 3A. The cushion
material 53 eases the impact between the sheet tray 5A and the
bottom 45 of the paper feeding cassette 3A when the sheet tray 5A
drops.
[0005] FIG. 25 is an enlarged plan view of an edge 521A on the
downstream side in the sheet feeding direction of the sheet tray
5A.
[0006] Among edges that face the through-holes 9A of the sheet tray
5A, the edge 521A on the downstream side in the sheet feeding
direction extends in the sheet width direction.
[0007] FIG. 26 is a sectional view of the paper feeding cassette 3A
taken along a YZ plane in a position (A) shown in FIG. 25. FIG. 27
is a sectional view of the paper feeding cassette 3A taken along an
XZ plane in a position (B) shown in FIG. 25.
[0008] When the paper feeding cassette 3A is drawn out from the
image forming apparatus, the sheet tray 5A drops to the bottom 45
of the paper feeding cassette 3A. If a small number of sheets are
stacked on the sheet tray 5A, the cushion material 53 is held
between the sheet tray 5A and the bottom 45 of the paper feeding
cassette 3A. As shown in FIG. 27, the downstream side in the sheet
feeding direction of the sheet tray 5A is lifted upward. Therefore,
a space S having a sufficient size is formed below the
through-holes 9A. When a user inserts a sheet onto the sheet tray
5A from the upstream side in the sheet feeding direction to the
downstream side in the sheet feeding direction, both ends in the
width direction of the sheet hang down to the space S below the
through-holes 9A.
[0009] When the user moves the sheet to the downstream side in the
sheet feeding direction in this state, for example, both the ends
in the width direction of the sheet hung down from the sheet tray
5A enter under the edge 521A of the sheet tray 5A to be caught by
the edge 521A. Therefore, setting properties of the sheet is
deteriorated. If both the ends in the width direction of the
hung-down sheet strongly come into contact with the edge 521A, it
is likely that a bend occurs in the sheet. If the bend occurs in
the sheet, it is likely that a paper jam occurs in the image
forming apparatus.
[0010] If the cushion material 53 is not provided on the lower
surface of the sheet tray 5A or, even if the cushion material 53 is
provided, if the sheet tray 5A fells down to the bottom 45 of the
paper feeding cassette 3A because a large number of sheets are
stacked on the sheet tray 5A, a sheet hangs down from the upper
surface of the sheet tray 5 by at least the depth of the
through-holes 9A or by a space between the sheet tray 5A and the
bottom 45 of the paper feeding cassette 3A. Therefore, in these
cases, the sheet is caught by the edge 521A when the sheet is set
and a bend occurs in the sheets. These problems tend to occur, in
particular, if the sheet is easily bent or the sheet is warped in
advance.
DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a diagram of the configuration of an image forming
apparatus;
[0012] FIG. 2 is a perspective view of a paper feeding
cassette;
[0013] FIG. 3 is a schematic plan view of a sheet tray in which
areas of a main supporting section and sub-supporting sections are
shown;
[0014] FIG. 4 is a sectional view of the sheet tray;
[0015] FIG. 5 is an enlarged sectional view of a lower surface end
of the main supporting section;
[0016] FIG. 6 is a perspective view of a driving mechanism;
[0017] FIG. 7 is a sectional view of a state in which a lifting
lever lifts the sheet tray upward;
[0018] FIG. 8 is a sectional view of a state in which the lifting
lever releases the lifting of the sheet tray;
[0019] FIG. 9 is a sectional view of a state in which the sheet
tray drops to a cassette case;
[0020] FIG. 10 is a perspective view of the sheet tray for
explaining the shape of the sub-supporting sections;
[0021] FIG. 11 is an enlarged view of the sub-supporting section
present on a distal end side in a cassette inserting direction;
[0022] FIG. 12 is a sectional view of the sub-supporting section
taken along an XZ plane;
[0023] FIG. 13 is a plan view of the sheet tray;
[0024] FIG. 14 is a sectional view of a paper feeding cassette in a
position (C) shown in FIG. 13;
[0025] FIG. 15 is a sectional view of a modification of the
sub-supporting section;
[0026] FIG. 16 is a sectional view of a modification of the
sub-supporting section;
[0027] FIG. 17 is a sectional view of a modification of the
sub-supporting section;
[0028] FIG. 18 is a perspective view of a paper feeding
cassette;
[0029] FIG. 19 is an enlarged perspective view of a sub-supporting
section;
[0030] FIG. 20 is a sectional view of the paper feeding cassette
taken along the XZ plane in a position (D) shown in FIG. 19;
[0031] FIG. 21 is a sectional view of a state in which a scoop-up
section enters a hole;
[0032] FIG. 22 is a plan view of a width-direction scoop-up
section;
[0033] FIG. 23 is diagram of the width-direction scoop-up section
viewed from an arrow (E) direction shown in FIG. 22;
[0034] FIG. 24 is a perspective view of the paper feeding
cassette;
[0035] FIG. 25 is an enlarged plan view of an edge on a downstream
side in a sheet feeding direction of a sheet tray;
[0036] FIG. 26 is a sectional view of the paper feeding cassette
taken along a YZ plane in a position (A) shown in FIG. 25; and
[0037] FIG. 27 is a sectional view of the paper feeding cassette
taken along the XZ plane in a position (B) shown in FIG. 25.
DETAILED DESCRIPTION
[0038] In general, according to one embodiment, a paper feeding
cassette includes a sheet storing section, side guides, and a sheet
tray. The sheet storing section stores a sheet to be fed. The side
guides move in the width direction orthogonal to a sheet feeding
direction from the sheet storing section and regulate movement of a
sheet end at least to one side in the width direction. The sheet
tray lifts a downstream side end in the sheet feeding direction
from the inside of the sheet storing section on the lower surface
of the sheet stored in the sheet storing section. A through-hole
including at least a passing area in the width direction of the
side guides is provided in the sheet tray. At least a part of an
edge that is present on the downstream side in the sheet feeding
direction, faces the through-hole, and extends in the width
direction moves closer to the sheet feeding direction as the part
of the edge moves further away from the sheet center in the width
direction to an end side.
First Embodiment
[0039] A first embodiment is explained below with reference to the
drawings.
[0040] FIG. 1 is a diagram of the configuration of an image forming
apparatus 1.
[0041] The image forming apparatus 1 is a MFP (Multi Function
Peripheral). The image forming apparatus 1 includes a control
section 2, a display section 11, an image reading section 12, a
sheet feeding section 13, and an image forming section 14. The
control section 2 includes a processor 21, a memory 22, a HDD (Hard
Disk Drive) 23, and an ASIC (Application Specific Integrated
Circuit) 24 and controls the entire image forming apparatus 1. The
display section 11 includes an operation input section 111
configured to receive an operation input. The display section 11
displays, for example, setting of the image forming apparatus 1 and
receives the operation input. The image reading section 12 is an
ADF (Auto Document Feeder) and reads an original document. The
sheet feeding section 13 includes plural paper feeding cassettes 3
configured to store sheets, pickup rollers 131 configured to pick
up the sheets from the paper feeding cassettes 3 one by one, sheet
sensors 132 configured to detect presence or absence of the sheets
in the paper feeding cassettes 3, a conveying path 133 for
conveying the sheets to the image forming section 14, and paper
feeding rollers 134 configured to feed the sheets picked up by the
pickup rollers 131 to the conveying path 133. The image forming
section 14 includes a transfer belt 141 configured to transfer a
toner image onto the sheet conveyed from the sheet feeding section
13 and a fixing device 142 configured to heat and press the sheet
and fix the toner image on the sheet.
[0042] FIG. 2 is a perspective view of the paper feeding cassette
3. In FIG. 2, the upward direction is represented as Z direction, a
sheet feeding direction from the paper feeding cassette 3 to the
image forming apparatus 1, which is a direction orthogonal to the Z
direction, is represented as X direction, and the width direction
of sheets stacked on the paper feeding cassette 3, which is a
direction orthogonal to the X and Z directions, is represented as Y
direction.
[0043] The paper feeding cassette 3 includes a cassette case 4 (a
sheet storing section), side guides 31A, 31B, 32A, and 32B, an end
guide 33, a sheet tray 5 (a tray), and a tray driving mechanism 6
(FIG. 6).
[0044] The cassette case 4 stores sheets to be fed to the image
forming apparatus 1. The cassette case 4 includes walls 41 to 44
and a bottom 45. Ends of the walls 41 to 44 are connected to one
another vertically. Among the walls 41 to 44, the wall 41 provided
near the pickup roller 131 (FIG. 1) extends in the sheet width
direction and regulates movement of the sheets in a downstream side
in the sheet feeding direction. The sheets are stored in a space
surrounded by the wall 41, the side guides 31A, 31B, 32A, and 32B,
the end guide 33, and the sheet tray 5. The bottom 45 is connected
to the lower ends of the walls 41 to 44 and closes an opening
surrounded by the walls 41 to 44.
[0045] The side guides 31A, 31B, 32A, and 32B extend in the sheet
feeding direction. The side guides 31A and 31B are opposed to each
other in the sheet width direction across the sheet tray 5. The
side guides 32A and 32B are provided further on an upstream side in
the sheet feeding direction than the side guides 31A and 31B and
opposed to each other in the sheet width direction not across the
sheet tray 5. The side guides 31A, 31B, 32A, and 32B slide in the
sheet width direction. The bottoms of the side guides 31A and 32A
on the inner side in FIG. 2 are connected to each other via a
tabular member. The bottoms of the side guides 31B and 32B on the
front side in FIG. 2 are also connected to each other via a tabular
member. When the side guides 31A and 31B on one side are moved to
the center side in the sheet width direction of the cassette case
4, the side guides 31A and 31B on the other side also move to the
center side in the sheet width direction of the cassette case 4. A
user moves the side guides 31A, 31B, 32A, and 32B to the center
side in the sheet width direction of the cassette case 4 according
to a sheet size to regulate the movement of the sheets in the sheet
width direction using the side guides 31A, 31B, 32A, and 32B.
[0046] The end guide 33 is provided in the center in the sheet
width direction of the cassette case 4 and opposed to the wall 41
across the sheet tray 5. The end guide 33 slides in the sheet
feeding direction. In FIG. 2, the end guide 33 and the side guides
31A and 31B are present in positions for regulating, in cooperation
with the wall 41, movement of A4-size sheets in the sheet feeding
direction and the sheet width direction.
[0047] The sheet tray 5 lifts the downstream side end in the sheet
feeding direction on the lower surface of the sheets and causes the
pickup roller 131 to pick up a sheet. Through-holes 9 including at
least passing areas in the sheet width direction of the side guides
31A and 31B are provided in the sheet tray 5. The sheet tray 5
includes a main supporting section 51 and sub-supporting sections
52.
[0048] The main supporting section 51 is provided on the center
side in the sheet width direction of the cassette case 4 and
extends in the sheet feeding direction. The main supporting section
51 supports the lower surface of the sheets and turns up and down
around the upstream side in the sheet feeding direction.
[0049] FIG. 3 is a plan view of the sheet tray 5 in which areas of
the main supporting section 51 and the sub-supporting sections 52
are shown.
[0050] The main supporting section 51 is provided between the
through-holes 9, i.e., on the center side in the sheet width
direction of the cassette case 4. The main supporting section 51
includes a main body section 511 that extends in the sheet feeding
direction, a bridging section 512 that extends from the upstream
side in the sheet feeding direction of the main body section 511 to
both sides in the sheet width direction, side sections 513 that
extend from sides near the walls 42 and 44 of the bridging section
512 to both sides in the sheet feeding direction along the walls 42
and 44, and standing sections 514 (see FIG. 2) that stand from the
walls 42 and 44 sides of the side sections 513 along the walls 42
and 44.
[0051] The sub-supporting sections 52 extend from the downstream
side in the sheet feeding direction of the main supporting section
51 to both the sides in the sheet width direction and are connected
to the downstream end in the sheet feeding direction of the side
section 513. The sub-supporting sections 52 extend over the passing
areas of the side guides 31A and 31B and support the downstream
side in the sheet feeding direction of the sheets.
[0052] FIG. 4 is a sectional view of the sheet tray 5.
[0053] A cutout section 515 is provided on the upstream side in the
sheet feeding direction of the standing section 514. A rotation
fulcrum 46 that projects from the walls 42 and 44 opposed to the
standing section 514 is inserted through the cutout section 515.
The sheet tray 5 turns up and down around the rotation fulcrum 46.
On the lower surface of the main supporting section 51, an upstream
side end 516 in the sheet feeding direction approaches and
separates from the bottom 45 of the cassette case 4 according to
the turning of the main supporting section 51. As shown in FIG. 5
in enlargement, a cushion material 53 is fixed to the upstream side
end 516 of the main supporting section 51.
[0054] FIG. 6 is a perspective view of the tray driving mechanism
6.
[0055] The tray driving mechanism 6 lifts the downstream side in
the sheet feeding direction of the sheet tray 5 upward when the
paper feeding cassette 3 is present in the image forming apparatus
1. The tray driving mechanism 6 includes a lifting lever 61, a
drive coupling shaft 62, and a lever driving section 63. The
lifting lever 61 lifts the downstream side in the sheet feeding
direction of the sheet tray 5 upward. The drive coupling shaft 62
is connected to the lower end of the lifting lever 61 and extends,
in the sheet width direction, to the distal end side in an
inserting direction of the paper feeding cassette 3 into the image
forming apparatus 1. In the drive coupling shaft 62, a coupling 621
is provided on the distal end side in the cassette inserting
direction. The lever driving section 63 includes a driving coupling
631 coupled to the coupling 621. The lever driving section 63 turns
the lifting lever 61 via the drive coupling shaft 62.
[0056] When the paper feeding cassette 3 is present in the image
forming apparatus 1, the lever driving section 63 turns the lifting
lever 61 upward via the drive coupling shaft 62 and, as shown in
FIG. 7, lifts the downstream side in the sheet feeding direction of
the sheet tray 5 upward. When the paper feeding cassette 3 is drawn
out from the image forming apparatus 1, the couplings 621 and 631
are uncoupled. As shown in FIGS. 8 and 9, the downstream side in
the sheet feeding direction of the sheet tray 5 drops. At that
point, the cushion material 53 enters between the sheet tray 5 and
the bottom 45 of the cassette case 4, eases the impact of the drop
of the downstream side in the sheet feeding direction of the sheet
tray 5, and prevent the sheet tray 5 from forcefully colliding
against the bottom 45 of the cassette case 4 to cause large
sound.
[0057] If a small number of sheets are placed on the sheet tray 5,
when the paper feeding cassette 3 is drawn out from the image
forming apparatus 1, the cushion material 53 enters between the
sheet tray 5 and the bottom 45 of the cassette case 4, whereby the
downstream side in the sheet feeding direction of the sheet tray 5
is lifted.
[0058] FIG. 10 is a perspective view of the sheet tray 5 for
showing edges 521.
[0059] The sub-supporting sections 52 on the downstream side in the
sheet feeding direction of the sheet tray 5 include the edges 521
that face the through-holes 9 and extend in the sheet width
direction.
[0060] FIG. 11 is an enlarged view of the sub-supporting section 52
provided on the distal end side in the cassette inserting
direction.
[0061] In the sub-supporting section 52 provided on the distal end
side in the cassette inserting direction, an opening for sensor 522
is provided between the edge 521 and the wall 41. If there is no
sheet on the sheet tray 5, light emitted from the sheet sensor 132
provided above the sheet tray 5 passes through the opening for
sensor 522 and, after reflecting on the bottom 45 of the cassette
case 4, passes through the opening for sensor 522 again and is
received by the sheet sensor 132. The sheet sensor 132 detects
presence or absence of sheets according to whether the emitted
light is blocked by the sheets. Alternatively, the sheet sensor 132
detects whether the number of remaining sheets is equal to or
smaller than a fixed number according to whether the emitted light
is blocked by an actuator configured to operate if the number of
sheets is equal to or smaller than the fixed number.
[0062] The sub-supporting section 52 includes a sub-supporting
section main body 523 (a supporting section main body) configured
to support sheets and a sheet guide section 524 that extends
downward from the upstream side in the sheet feeding direction of
the sub-supporting section main body 523. The edge 521 of the
sub-supporting section 52 is the edge 521 of the sheet guide
section 524. At least a part of the edge 521 tilts to move closer
to the sheet feeding direction as the part of the edge 521 moves
further away from the sheet center to an end side in the width
direction. A section corresponding to the sheet center side in the
sheet width direction in the edge 521 is provided further on the
upstream side in the sheet feeding direction than the opening for
sensor 522. A section corresponding to the sheet end side in the
sheet width direction in the edge 521 is provided on the sheet
width direction from the opening for sensor 522. The edge 521 of
the sub-supporting section 52 on the proximal end side in the
cassette inserting direction tilts to move closer to the sheet
feeding direction as the edge 521 moves further away from the sheet
center to the end side in the sheet width direction (FIG. 10).
[0063] As shown in FIG. 11, the sheet guide section 524 is also
provided at a corner 54 of the main supporting section 51 and the
sub-supporting section 52. The sheet guide section 524 at the
corner 54 curves in an arcuate shape in plan view. The main
supporting section 51 includes a sheet guide section 517 that
curves downward from the main body section of the main supporting
section 51. The sheet guide section 517 is connected to the sheet
guide section 524 of the sub-supporting section 52 at the corner
54. An edge 518 of the main supporting section 51 is the edge 518
of the sheet guide section 517.
[0064] FIG. 12 is a sectional view of the sub-supporting section 52
taken along an XZ plane.
[0065] The sheet guide section 524 curves downward from the
sub-supporting section 52. A lower end face 525 of the sheet guide
section 524 faces down and is parallel to the sub-supporting
section main body 523. The sheet guide section 524 is formed by,
for example, bending and drawing the sheet tray 5. The sheet guide
section 517 of the main supporting section 51 has structure same as
that of the sheet guide section 524 of the sub-supporting section
52.
[0066] FIG. 13 is a plan view of the sheet tray 5.
[0067] At least a part of the edge 521 of the sheet tray 5 tilts to
move closer to the sheet feeding direction as the part of the edge
521 moves further away from the sheet center to the end side in the
sheet width direction. The action performed by the edge 521 when
the user places the downstream side in the sheet feeding direction
of a sheet on the sheet tray 5 and moves the sheet to the
downstream side in the sheet feeding direction in a state in which
both ends in the sheet width direction hang further downward than
the sheet tray 5 is explained below.
[0068] When the sheet is present in a position (i) on the upstream
side in the sheet feeding direction on the main supporting section
51 of the sheet tray 5, the sheet hangs further downward as the
sheet moves further away in the sheet width direction from the edge
518 of the main supporting section 51.
[0069] When the sheet is moved to the downstream side in the sheet
feeding direction by the user and, as indicated by (ii), comes into
contact with the edge 521 of the corner 54, a part of the
downstream side in the sheet feeding direction of the sheet is
scooped up onto the sub-supporting section 52 along the arcuate
edge 521 of the corner 54.
[0070] FIG. 14 is a sectional view of the paper feeding cassette 3
taken along the XZ plane in a position (C) shown in FIG. 13.
[0071] When the sheet further moves to the downstream side in the
sheet feeding direction from the position of (ii), the edge 521
tilts to move closer to the sheet feeding direction as the edge 521
moves further away from the sheet center to the end side in the
sheet width direction. As shown in FIG. 14 and indicated by (iii)
and (iv) shown in FIG. 13, according to the movement of the sheet
to the downstream side in the sheet feeding direction, the sheet is
gradually scooped up by the edge 521 and moves onto the
sub-supporting section 52. When the sheet moves to a position in
contact with the wall 41, the downstream side end in the sheet
feeding direction of the sheet entirely moves onto the main
supporting section 51.
[0072] As explained above, in this embodiment, when the sheet is
inserted onto the sheet tray 5 and the sheet is moved to the
downstream side in the sheet feeding direction, the hung-down
portions of the sheet can be gradually scooped up onto the
sub-supporting section 52 by the edge 521. Therefore, in this
embodiment, setting properties of the sheet in the paper feeding
cassette 3 can be improved. In this embodiment, since the sheet is
gradually scooped up, it is possible to prevent the sheet from
strongly coming into contact with the sub-supporting section 52.
Therefore, it is possible to prevent a bend of the sheet and
suppress a sheet jam caused by the bent sheet conveyed into the
image forming apparatus 1.
[0073] The lower end face 525 of the sheet guide section 524 faces
down and is parallel to the sub-supporting section main body 523.
Therefore, it is possible to satisfactorily prevent the sheet from
entering the lower side of the sheet guide section 524 compared
with a case where the lower end face 525 faces the outer side of
the sub-supporting section 52. Since the sheet guide section 524
curves downward from the sub-supporting section main body 523, it
is possible to more satisfactorily prevent the sheet from entering
the lower side of the sheet guide section 524.
[0074] As shown in FIG. 15, a sheet guide section 524B may tilt
downward from the sub-supporting section main body 523. In
sectional view of the sheet guide section 524B viewed from the
sheet width direction, an angle formed by the sub-supporting
section main body 523 and the sheet guide section 524B may be
145.degree..
[0075] As shown in FIG. 16, a sheet guide section 524C may extend
downward vertically from the sub-supporting section main body
523.
[0076] As shown in FIG. 17, a sub-supporting section 52D may be
formed in a flat plate shape. An edge 521D may be an end face 526
of the sub-supporting section 52D that faces a side.
[0077] The sheet tray 5 may include only the sub-supporting section
52 on one side.
Second Embodiment
[0078] A paper feeding cassette according to a second embodiment is
explained below. Sections having the same functions as those in the
first embodiment are denoted by the same reference numerals and
signs and explanation of the sections is omitted.
[0079] FIG. 18 is a perspective view of a paper feeding cassette
3E.
[0080] The paper feeding cassette 3E includes a cassette case 4E,
the side guides 31A, 31B, 32A, and 32B, the end guide 33, a sheet
tray 5E, and the tray driving mechanism. Among these components,
the side guides 31A, 31B, 32A, and 32B, the end guide 33, and the
tray driving mechanism are the same as those in the first
embodiment.
[0081] As in the first embodiment, the edge 521 of the
sub-supporting section 52 provided on one end side in the sheet
width direction (the proximal end side in the cassette inserting
direction) tilts to move closer to the sheet feeding direction as
the edge 521 moves further away from the sheet center to the end
side in the sheet width direction. The edge 521 scoops up one end
side in the sheet width direction of a sheet onto the
sub-supporting section 52.
[0082] FIG. 19 is an enlarged perspective view of a sub-supporting
section 52E on the other end side in the sheet width direction (the
distal end side in the cassette inserting direction).
[0083] On a bottom 45E of the cassette case 4E, a projecting
section 47 is provided further on the upstream side in the sheet
feeding direction than the sub-supporting section 52E. The
projecting section 47 extends in the sheet width direction over
passing areas of the side guides 31A and 31B. The projecting
section 47 includes a slope 471 that faces the upstream side in the
sheet feeding direction.
[0084] In the sub-supporting section 52E, a cutout section 527
recessed to the downstream side in the sheet feeding direction is
provided on the upstream side in the sheet feeding direction. Light
emitted from the sheet sensor 133 (FIG. 1) is made incident on the
bottom 45E of the cassette case 4E through a space S1 surrounded by
the cutout section 527.
[0085] The sheet tray 5E includes an elastic sheet 7 fixed on the
sub-supporting section 52E by, for example, bonding by an adhesive.
Unlike the sub-supporting section 52 on one end side in the sheet
width direction, the sub-supporting section 52E on the other end
side in the sheet width direction scoops up the other end side in
the sheet width direction of a sheet onto the sub-supporting
section 52E using the elastic sheet 7 and the slope 471. In the
projecting section 47, a section corresponding to the cutout
section 527 in the sheet width direction is higher in the Z
direction than a section corresponding to the elastic sheet 7 in
the sheet width direction.
[0086] The elastic sheet 7 includes an elastic sheet main body
section 71 fixed on the sub-supporting section 52E and a scoop-up
section 72 that is bent downward from the elastic sheet main body
section 71 and extends downward from the sub-supporting section
52E. The scoop-up section 72 extends from the passing area of the
side guide 31A to the cutout section 527 in the sheet width
direction. The scoop-up section 72 includes a
sheet-feeding-direction scoop-up section 721 and a width-direction
scoop-up section 722.
[0087] The width-direction scoop-up section 722 is formed by
bending, in the sheet feeding direction, an end of the
sheet-feeding-direction scoop-up section 721 that extends in the
sheet width direction. The width-direction scoop-up section 722
tilts with respect to the sheet feeding direction and enters the
inside of the space S1 surrounded by the cutout section 527.
[0088] FIG. 20 is a sectional view of the paper feeding cassette 3E
taken along the XZ plane in a position (D) shown in FIG. 19. The
sub-supporting section 52E and the sheet-feeding-direction scoop-up
section 721 are shown in the figure.
[0089] The sub-supporting section 52E includes a tongue section 528
that is bent downward from the sub-supporting section main body 523
configured to support a sheet on the sub-supporting section 52E.
The tongue section 528 is formed by, for example, bending and
drawing the sheet tray 5.
[0090] The sheet-feeding-direction scoop-up section 721 is formed
by bending the elastic sheet main body section 71 downward. A base
portion of the sheet-feeding-direction scoop-up section 721 is
fixed on the tongue section 528 by bonding. This makes it possible
to stabilize an angle of the sheet-feeding-direction scoop-up
section 721 at an angle same as an angle of the tongue section
528.
[0091] In this embodiment, as in the first embodiment, for example,
if the number of sheets on the sheet tray 5E is small, a cushion
material is held between the bottom 45E of the cassette case 4E and
the sheet tray 5E, whereby the downstream side in the sheet feeding
direction of the sheet tray 5E is lifted upward. At this point, the
top end of the slope 471 is present in a position higher than the
bottom end of the sheet-feeding-direction scoop-up section 721.
[0092] When a sheet is moved to the downstream side in the sheet
feeding direction by a user, as indicated by (i), first, the other
end side in the sheet width direction of the sheet hung down from
the sheet tray 5E comes into contact with the slope 471 and is
lifted upward by the slope 471.
[0093] When the sheet is moved to the downstream side in the sheet
feeding direction by the user, as indicated by (ii), the other end
side in the sheet width direction of the sheet is lifted further
upward by the sheet-feeding-direction scoop-up section 721. The
other end side in the sheet width direction of the sheet is finally
scooped up onto the sub-supporting section 52E by the
sheet-feeding-direction scoop-up section 721 according to the
movement of the sheet to the downstream side in the sheet feeding
direction and supported by the sub-supporting section 52E.
[0094] On the bottom 45E of the cassette case 4E, a hole 48 is
provided between the projecting section 47 and a section under the
sub-supporting section 52E. As shown in FIG. 19, the hole 48
includes a first hole 481 that extends in the sheet width direction
in plan view and a second hole 482 that is bent to the sheet
feeding direction side in plan view. As shown in FIG. 21, when the
sheet tray 5E falls down to the bottom 45E, the
sheet-feeding-direction scoop-up section 721 enters the first hole
481 that extends in the sheet width direction. The width-direction
scoop-up section 722 enters the second hole 482 that is bent to the
sheet feeding direction side.
[0095] As shown in FIG. 21, the hole 48 pierces through the bottom
45E. An elastic sheet regulating surface 483 is provided on the
wall surface on the downstream side in the sheet feeding direction
of the hole 48. The elastic sheet regulating surface 483 tilts with
respect to the sheet feeding direction and faces the upstream side
in the sheet feeding direction. When the scoop-up section 72 enters
the hole 48, the elastic sheet regulating surface 483 regulates a
projecting direction of the scoop-up section 72 on the rear surface
side of the bottom 45E to a direction in which the scoop-up section
72 avoids a structure 81 provided on the rear surface side of the
bottom 45E. In this embodiment, the elastic sheet regulating
surface 483 bends the scoop-up section 72 to the upstream side in
the sheet feeding direction. The elastic sheet regulating surface
483 guides the projecting direction of the scoop-up section 72 on
the rear surface side of the bottom 45E to the upstream side in the
sheet feeding direction. The elastic sheet regulating surface 483
regulates a projection amount of the scoop-up section 72 on the
rear surface side of the bottom 45E to an amount equal to or
smaller than a predetermined amount.
[0096] FIG. 22 is a plan view of the width-direction scoop-up
section 722. FIG. 23 is a diagram of the width-direction scoop-up
section 722 viewed from an arrow (E) direction shown in FIG.
22.
[0097] When a sheet is inserted onto the sheet tray 5E in the sheet
width direction, the width-direction scoop-up section 722 lifts
upwards the downstream side end in the sheet feeding direction of
the sheet hung down to the inside of the space S1 surrounded by the
cutout section 527 and prevents the sheet from being caught by the
cutout section 527.
[0098] According to the second embodiment, it is possible to
provide, for example, techniques (1) to (5) explained below.
(1) A paper feeding cassette including:
[0099] a sheet storing section configured to store a sheet to be
fed, the sheet storing section including a projecting section that
projects from the bottom of the sheet storing section and extends
in the width direction of the sheet and has a slope that faces an
upstream side in a sheet feeding direction from the inside of the
sheet storing section;
[0100] side guides that are provided further on the upstream side
in the sheet feeding direction than the projecting section and
extend in the width direction, slide in the width direction, and
regulate movement of the sheet at least to one side of the width
direction; and
[0101] a sheet tray in which a through-hole including at least a
passing area in the width direction of the side guide is provided,
the sheet tray including a supporting section that lifts a
downstream side end in the sheet feeding direction on the lower
surface of the sheet stored in the sheet storing section and an
elastic sheet including a scoop-up section that extends downward
from the supporting section and fixed to the supporting
section.
(2) The paper feeding cassette of (1), wherein
[0102] a cushion material is fixed on the upstream side in the
sheet feeding direction on the lower surface of the sheet tray and,
when there is no sheet on the sheet tray, the cushion material is
held between the bottom and the sheet tray, whereby the downstream
side in the sheet feeding direction of the sheet tray is lifted
upward, and
[0103] the top end of the slope is present in a position higher
than the bottom end of the scoop-up section.
(3) The paper feeding cassette of (1), wherein the hole where the
scoop-up section enters when the sheet tray falls down to the
bottom is provided between the projecting section and a section
under the supporting section on the bottom. (4) The paper feeding
cassette of (3), wherein the hole pierces through the bottom and
includes an elastic sheet regulating surface configured to regulate
a projecting direction of the scoop-up section on the rear surface
side of the bottom. (5) The paper feeding cassette of (1), further
including:
[0104] a rotation fulcrum configured to rotate the sheet tray
around the upstream side in the sheet feeding direction of the
sheet tray;
[0105] a tray driving mechanism configured to lift the downstream
side in the sheet feeding direction of the sheet tray upward;
and
[0106] a cushion material fixed near the rotation fulcrum on the
lower surface of the sheet tray and configured to ease the impact
of collegian of the sheet tray and the bottom when the tray driving
mechanism releases lifting of the sheet tray and the sheet tray
drops to the bottom.
[0107] As explained above in detail, according to the technique
described in this specification, it is possible to provide a
technique for stacking sheets using a paper feeding cassette.
[0108] While certain embodiments have been described, these
embodiments have been presented by way of example only, and are not
intended to limit the scope of invention. Indeed, the novel
apparatus, methods and system described herein may be embodied in a
variety of other forms; furthermore, various omissions,
substitutions and changes in the form of the apparatus, methods and
system described herein may be made without departing from the
sprit of the inventions. The accompanying claims and their
equivalents are intended to cover such forms or modifications as
would fall within the scope and spirit of the inventions.
* * * * *