U.S. patent application number 13/316886 was filed with the patent office on 2012-06-28 for recording media cassette, recording apparatus.
This patent application is currently assigned to SEIKO EPSON CORPORATION. Invention is credited to Kazumasa Harada, Kazutoshi Matsuzaki, Kazuhisa Nakamura, Atsuhiko Takeuchi, Kensuke Tamai.
Application Number | 20120161381 13/316886 |
Document ID | / |
Family ID | 46315665 |
Filed Date | 2012-06-28 |
United States Patent
Application |
20120161381 |
Kind Code |
A1 |
Nakamura; Kazuhisa ; et
al. |
June 28, 2012 |
Recording Media Cassette, Recording Apparatus
Abstract
A recording media cassette includes a lower tray that stores
recording media therein, and an upper tray that stores recording
media therein and is mounted on the lower tray so as to be
detachable from the lower tray.
Inventors: |
Nakamura; Kazuhisa;
(Nagano-ken, JP) ; Tamai; Kensuke; (Nagano-ken,
JP) ; Matsuzaki; Kazutoshi; (Nagano-ken, JP) ;
Takeuchi; Atsuhiko; (Nagano-ken, JP) ; Harada;
Kazumasa; (Nagano-ken, JP) |
Assignee: |
SEIKO EPSON CORPORATION
Tokyo
JP
|
Family ID: |
46315665 |
Appl. No.: |
13/316886 |
Filed: |
December 12, 2011 |
Current U.S.
Class: |
271/9.11 ;
271/145 |
Current CPC
Class: |
B65H 2405/332 20130101;
B65H 2801/06 20130101; B65H 1/266 20130101; B65H 2402/32
20130101 |
Class at
Publication: |
271/9.11 ;
271/145 |
International
Class: |
B65H 3/44 20060101
B65H003/44; B65H 1/00 20060101 B65H001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 24, 2010 |
JP |
2010-287063 |
Claims
1. A recording media cassette comprising: a lower tray that stores
recording media therein; and an upper tray that stores recording
media therein and is mounted on the lower tray so as to be
detachable from the lower tray.
2. The recording media cassette according to claim 1, wherein the
upper tray is slidably displaceable with respect to the lower tray
in a state in which the upper tray is mounted on the lower tray,
and the upper tray is in a state of being restrained by the lower
tray when the upper tray is located in a feedable position of the
upper tray within a slidably displaceable area of the upper
tray.
3. The recording media cassette according to claim 2, wherein the
upper tray is slidably displaceable by means of a driving unit, the
upper tray is in a state of being restrained by the lower tray, and
the upper tray is released from the state of being restrained by
the lower tray by the driving unit.
4. The recording media cassette according to claim 2, wherein the
upper tray is slidably displaceable to a position outside of an
area for storing the recording media in the lower tray.
5. The recording media cassette according to claim 1, wherein the
upper tray is configured to be independently detachably mounted in
the main body of a recording apparatus that performs recording on
the recording media in a state in which the upper tray is removed
from the lower tray.
6. A recording apparatus comprising: the recording media cassette
according to claim 1; a recording media feeding device that feeds
the recording media from the recording media cassette; and a
recording unit that performs recording on the recording media.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present invention relates to recording media cassettes
that are detachably mounted in the main body of an apparatus.
Further, the present invention relates to recording apparatuses,
such as facsimile machines or printers, having a recording media
feeding device that feeds recording media from the recording media
cassette.
[0003] 2. Related Art
[0004] Sheet cassettes that are detachably mounted in the main body
of an apparatus are commonly used. In particular, JP-A-2006-273565
and JP-A-2007-91445 disclose a detachable sheet cassette (tray)
having a dual-container configuration composed of upper and lower
sheet containers. A sheet container that stores sheets therein in a
recording apparatus is generally called various names, including
"cassette", "tray" and so forth. In the following description, an
entire unit that is detachably mounded in the main body of the
apparatus is referred to as a "cassette", while each sheet
container that is provided in the cassette is referred to as a
"tray".
[0005] In the sheet cassette having a dual-tray configuration as
mentioned above, an upper tray is slidably and rotatably movable
relative to a lower tray. The sheet cassette can be switched
between a state in which the sheets can be fed from the upper tray
and a state in which the sheets can be fed from the lower tray by
slidably moving the upper tray. Further, a space for storing sheets
in the lower tray is opened by turning the upper tray.
[0006] With such a dual-tray configuration of a sheet cassette,
however, it is not possible to remove the upper tray from the lower
tray. Accordingly, it is not always useful for a user who does not
frequently use the upper tray, since the upper tray reduces the
capacity for storing sheets in the lower tray. Further, an
additional action to turn the upper tray is necessary when loading
sheets into the lower tray.
SUMMARY
[0007] An advantage of some aspects of the invention is that the
usability of a sheet cassette having a multiple-tray configuration
composed of upper and lower trays is further improved.
[0008] According to an aspect of the invention, there is provided a
recording media cassette of a first example, which includes a lower
tray that stores recording media therein and an upper tray that
stores recording media therein and is mounted on the lower tray so
as to be detachable from the lower tray.
[0009] With this configuration, the recording media cassette having
a multi-tray configuration is composed of a lower tray and an upper
tray. Since the upper tray is detachable from the lower tray, the
capacity for storing the recording media in the lower tray
increases when the upper tray is removed, thereby further improving
usability in using the lower tray. Moreover, a space for storing
the recording media in the lower tray is fully opened when the
upper tray is removed, thereby further improving operability in
loading the recording media into the lower tray.
[0010] There is provided the recording media cassette of a second
example according to the first example, in which it is preferable
the upper tray is slidably displaceable by means of a driving unit
in a state in which the upper tray is mounted on the lower tray,
the upper tray is in a state of being restrained by the lower tray
when the upper tray is located in an active area of the upper tray
by the driving unit within a slidably displaceable area of the
upper tray, and the upper tray is released from the state of being
restrained by the lower tray when the upper tray is located in an
inactive area of the upper tray by the driving unit.
[0011] With this configuration, the upper tray is slidably
displaceable by means of a driving unit, the upper tray is in a
state of being restrained by the lower tray when the upper tray is
located in an active area of the upper tray, and the upper tray is
released from being in the restrained state when the upper tray is
located in an inactive area, thereby ensuring the upper tray to be
slidably displaced in the active area by means of the driving
unit.
[0012] There is provided the recording media cassette of a third
example according to any one of the first and second examples, in
which it is preferable the upper tray is slidably displaceable to a
position outside of an area for storing the recording media in the
lower tray.
[0013] With this configuration, the upper tray is provided to be
slidably displaceable to a position outside of an area for storing
the recording media in the lower tray. Accordingly, the area for
storing the recording media in the lower tray can be fully opened,
thereby facilitating an operation in loading the recording media
into the lower tray to a great extent.
[0014] There is provided the recording media cassette of a fourth
example according to any one of the first to third examples, in
which it is preferable the upper tray is configured to be
independently detachably mounted in the main body of a recording
apparatus that performs recording on the recording media in a state
in which the upper tray is removed from the lower tray.
[0015] With this configuration, the upper tray is configured to be
independently detachably mounted in the main body of a recording
apparatus that performs recording on the recording media in a state
in which the upper tray is removed from the lower tray.
Accordingly, the recording media can be fed from the upper tray
without using the lower tray, thereby further improving
usability.
[0016] There is provided a recording media feeding device that
feeds the recording media in a fifth example, in which it is
preferable the recording media feeding device includes the
recording media cassette according to any one of the first to
fourth examples. According to another aspect of the invention,
there is provided a recording apparatus including a recording unit
that performs recording on the recording media, and the recording
media feeding device according to the fifth example. With those
configurations, the same effect can be achieved as that according
to any one of the first to fourth examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention will be described with reference to the
accompanying drawings, wherein like numbers reference like
elements.
[0018] FIG. 1 is a side sectional view which shows a sheet
transportation path in a printer according to one embodiment of the
invention.
[0019] FIG. 2 is a perspective view of a sheet cassette according
to one embodiment of the invention.
[0020] FIG. 3 is a perspective view of a section of an essential
part of the sheet cassette according to one embodiment of the
invention.
[0021] FIGS. 4A and 4B are perspective views of an edge guide
according to one embodiment of the invention.
[0022] FIGS. 5A and 5B are perspective views of an edge guide
according to one embodiment of the invention.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0023] An embodiment of the invention will be described below with
reference to FIGS. 1 to 5. FIG. 1 is a side sectional view which
shows a sheet transportation path in an ink jet printer
(hereinafter referred to as a "printer") 1 which is an example of a
"recording apparatus" of the invention. FIG. 2 is a perspective
view of a sheet cassette 100 which is an example of a "recording
media cassette" of the invention. FIG. 3 is a perspective view of a
section of an essential part of the sheet cassette 100. In
addition, the rightward direction in FIG. 1 is a sheet feeding
direction, while a direction perpendicular to the sheet feeding
direction is a sheet width direction.
[0024] FIGS. 4A and 4B are perspective views of an edge guide 52,
showing a state in which a guide surface of the guide is at a
normal position (first state) and a state in which the guide
surface of the guide is at an elevated position (second state),
respectively. Further, FIGS. 5A and 5B are perspective views of an
edge guide 52', showing a state in which a guiding height of a
guide surface is at a normal position (first state) and a state in
which the guiding height of the guide surface is at an elevated
position (second state), respectively.
1. Overall Configuration of Printer
[0025] An overall configuration of the printer 1 will be described
below with reference to FIG. 1. The printer 1 includes a feeding
device 2 in the bottom portion of the apparatus. The feeding device
2 is configured to feed sheets (cut sheets in general) as an
example of the "recording media" one by one toward an output
stacker (not shown in the figure) disposed on the rear side of the
apparatus (left side in FIG. 1) after a recording unit 4 has
performed recording (ink jet recording).
[0026] Components disposed on the sheet transportation path will
now be described in further detail. The feeding device 2 includes a
sheet cassette 100, a pick up roller 16, guide roller 20 and a
separation unit 21.
[0027] The sheet cassette 100, in which a plurality of sheets P can
be set in a stacked state, is removably mounted in the main body of
the apparatus from the front side with respect to the feeding
device 2. The sheet cassette 100 includes two sheet containers,
that is, a lower tray 50 which is disposed on the lower side
thereof and constitutes a base of the sheet cassette 100, and an
upper tray 60 which is disposed above the lower tray 50 and is
slidably movable between a feedable position and a stand-by
area.
[0028] In FIG. 1, the sheets stored in the lower tray 50 and the
upper tray 60 are denoted by P1 and P2, respectively (hereinafter
collectively referred to as "sheet P" as long as the sheets do not
have to be individually identified).
[0029] The pick-up roller 16 which is rotated by a motor (not shown
in the figure) is provided on a pivot member 17 that pivotally
moves about a pivot shaft 18. When the upper tray 60 has been slid
to the rear-most position (in a retracting direction of the sheet
cassette 100, which is the leftward direction in FIG. 1), that is,
when the upper tray 60 is in a stand-by area, the pick-up roller 16
comes into contact with the uppermost sheet P1 stored in the lower
tray 50 and rotates so as to feed the uppermost sheet P1 from the
lower tray 50.
[0030] Moreover, when the upper tray 60 has been slid to the
front-most position, which is the abutment position (in a mounting
direction of the sheet cassette 100, which is the rightward
direction in FIG. 1), that is, when the upper tray 60 is in a
feedable position, the pick-up roller 16 comes into contact with
the uppermost sheet P2 stored in the upper tray 60 and rotates so
as to feed the uppermost sheet P2 from the upper tray 60.
[0031] When the upper tray 60 is positioned in the feedable
position (as shown in FIG. 1), the separating slope 54 of the lower
tray 50 extends toward the leading end of the sheets stored in the
upper tray 60 beyond the front inner wall of the upper tray 60 such
that the separating slope 54 serves as a separation unit when the
sheets are fed from the upper tray 60. That is, the separating
slope 54 of the lower tray 50 is used as a common separation unit
for the lower tray 50 and the upper tray 60.
[0032] A freely rotatable guide roller 20 is disposed at a position
downstream of the separating slope 54. Further, a separation unit
21 composed of a separation roller 22 and a driving roller 23 is
disposed at a position downstream of the guide roller 20. The
separation roller 22 has an outer periphery made of an elastic
material and is capable of pressingly contacting the driving roller
23 while being in a state in which a predetermined rotation
resistance is applied by a torque limiter mechanism. Accordingly,
the subsequent sheets P are not permitted to be fed with the
uppermost sheet P passing between the separation roller 22 and the
driving roller 23, thereby preventing double feeding of the sheets
P. The driving roller 23 is rotated by a motor, which is not shown
in the figure, in the direction by which the sheets P are fed
downstream.
[0033] A first intermediate feeder 25 is disposed at a position
downstream of the separation unit 21. The first intermediate feeder
25 is composed of a driving roller 26 that is rotated by a motor,
which is not shown in the figure, and an assisting roller 27 that
is driven by the driving roller 26 so as to nip the sheet P
therebetween such that the sheet P is fed further downstream. In
addition, reference numeral 29 denotes a driven roller that reduces
a passing load which is generated when the sheet P (particularly,
the trailing edge of the sheet P) passing along a curved
turn-around path.
[0034] Further, a second intermediate feeder 31 is disposed at a
position downstream of the driven roller 29. The second
intermediate feeder 31 is composed of a driving roller 32 that is
rotated by a motor, which is not shown in the figure, and an
assisting roller 33 that is driven by the driving roller 32 so as
to nip the sheet P therebetween such that the sheet P is further
fed downstream.
[0035] A recording unit 4 is disposed at a position downstream of
the second intermediate feeder 31. The recording unit 4 includes a
transportation unit 5, a recording head 42, a lower sheet guide 39
and an output unit 6. The transportation unit 5 is composed of a
transportation driving roller 35 that is rotated by a motor and a
transportation driven roller 36 that is supported by the upper
sheet guide 37 so as to be in pressing contact with and driven by
the transportation driving roller 35. When the sheet P enters the
transportation unit 5, the transportation driving roller 35 rotates
so that the sheet P is fed downstream in an accurate manner while
being nipped between the transportation driving roller 35 and the
transportation driven roller 36.
[0036] The recording head 42 is disposed at the bottom of the
carriage 40. The carriage 40 is actuated by a motor, which is not
shown in the figure, so as to reciprocate in a main scanning
direction while being guided by a carriage guide shaft 41 that
extends in the main scanning direction (the direction extending
across the drawing of FIG. 1 between the front side and the back
side of the drawing). In addition, the carriage 40 is of a
so-called off carriage type in which ink cartridges are not loaded.
The ink cartridges (not shown) are separately provided from the
carriage 40, so that ink is supplied from the ink cartridges to the
recording head 42 via ink supply tubes (not shown).
[0037] A lower sheet guide 39 is disposed at a position opposite
the recording head 42 such that a distance between the sheet P and
the recording head 42 are defined by the lower sheet guide 39.
Further, an output unit 6 is provided at a position downstream of
the lower sheet guide 39 so as to output the sheet P on which
recording has been performed.
[0038] The output unit 6 is composed of an output driving roller 44
that is rotated by a motor, which is not shown in the figure, and
an output driven roller 45 that is in contact with and driven by
the output driving roller 44 and is configured to output the sheet
P on which recording has been performed by the recording unit 4
toward a stacker provided on the front side of the apparatus, which
is not shown in the figure.
2. Details of Sheet Cassette
[0039] While the printer 1 is briefly described above, the sheet
cassette 100 will be further described below in detail with
reference to FIGS. 2 and 3. The lower tray 50 is provided on the
bottom 50a with the edge guide 51 (FIG. 1), which is slidably
movable in the sheet feeding direction (that is, sheet length
direction), such that the position of the trailing edge of the
sheet P1 is aligned with the edge guide 51.
[0040] Moreover, the lower tray 50 is further provided with the
edge guide 52, which is slidably movable in a direction
perpendicular to the sheet feeding direction (that is, sheet width
direction), such that the position of one side edge of the sheet P1
is aligned with the edge guide 52. The other side edge is aligned
with a side wall 50b (FIG. 2) of the lower tray 50. In other words,
the side wall 50b of the lower tray 50 serves as a fixed edge
guide.
[0041] A guide surface 51a of the edge guide 51 that defines the
position of the trailing edge of the sheet P1 is formed as a slope
that is substantially parallel with the separating slope 54 such
that the leading end of a stack of sheets is aligned with the
separating slope 54 when the edge guide 51 abuts the trailing edge
of the sheet P1. The edge guide 52 that defines the position of the
side edge of the sheet P1 will be described later in detail.
[0042] A high friction member 53 is placed on the bottom 50a of the
lower tray 50 at a position corresponding to the contact point
between the pick-up roller 16 and the sheet P1. The high friction
member 53 holds the stack of sheet during feeding of a sheet so
that the whole stack of sheets is not fed downstream by the pick-up
roller 16.
[0043] Similarly to the lower tray 50, the upper tray 60 is
provided with an edge guide 61 that is slidably movable in the
sheet length direction and an edge guide 62 that is slidably
movable in a sheet width direction on the bottom 60a. Further, a
high friction member 64 is placed at a position corresponding to
the contact point between the pick-up roller 16 and the sheet
P2.
[0044] A movable mechanism of the upper tray 60 will now be
described. The upper tray 60 includes a slide member 65 and a tray
base 66 such that the slide member 65 is slidably movable in the
sheet feeding direction and the opposite direction with respect to
the side walls 50b and 50c of the lower tray 50.
[0045] A tray base 66 is provided to form a space for storing the
sheets. The tray base 66 is rotatable about rotation shafts 66a on
both sides thereof in a direction indicated by the arrow r with
respect to the sliding member 65. In addition, a rotation limit of
the upper tray 60 (tray base 66) according to this embodiment is
greater than 90 degrees and smaller than 180 degrees. That is, when
the upper tray 60 has been turned to the maximum extent, a space
for storing the sheets in the lower tray 50 is opened so that the
sheets can be stored in the lower tray 50.
[0046] As shown in FIG. 3, a rack 65a is formed on the lower side
of one side face of the sliding member 65 so that the rack 65a
meshes with a pinion gear 55 that is provided on the lower tray 50.
That is, the sliding member 65 (the upper tray 60) is configured to
be slidably displaced as the pinion gear 55 rotates.
[0047] The pinion gear 55 is capable of meshing with a driving gear
(not shown) provided on the main body of the printer 1, when the
sheet cassette 100 is mounted in the main body of the printer 1.
The driving gear is rotated by a motor, which is not shown in the
figure, thereby driving the sliding member 65 (the upper tray
60).
[0048] A locking member 65b is formed on the sliding member 65 at a
position slightly ahead of the rack 65a. The locking member 65b is
configured to be put under a restraining rail 50d that is formed on
the lower tray 50. When the locking member 65b is put under the
restraining rail 50d (the locking member 65b is on the A side with
respect to the position L indicated in FIG. 3, which is hereinafter
referred to as "active area" of the upper tray 60), the rack 65a
meshes with the pinion gear 55 while the locking member 65b is put
under the restraining rail 50d, thereby restraining the sliding
member 65 (the upper tray 60) so as not to be removed from the
lower tray 50. Accordingly, the upper tray 60 is placed at a
position which permits feeding of the sheets from the upper tray
60.
[0049] On the other hand, when the locking member 65b is ahead of
the restraining rail 50d without being engaged with the restraining
rail 50d (the locking member 65b is on the B side with respect to
the position L indicated in FIG. 3, which is hereinafter referred
to as "inactive area" of the upper tray 60), the rack 65a is not
meshed with the pinion gear 55 while the locking member 65b
disengages the restraining rail 50d, thereby allowing the sliding
member 65 (the upper tray 60) to be removed from the lower tray 50
(as shown by the virtual line and reference numeral 60' in FIG. 2).
The inactive area of the upper tray 60 according to this embodiment
is a position at which the upper tray 60 has been slid to the
front-most position.
[0050] As mentioned above, the sheet cassette 100 having a
multi-tray configuration composed of the lower tray 50 and the
upper tray 60 is configured such that the upper tray 60 is
removable from the lower tray 50. Consequently, the capacity for
the sheets in the lower tray 50 increases when the upper tray 60 is
removed, thereby further improving usability of the lower tray 50.
Moreover, the space for storing the sheets in the lower tray 50 is
fully opened when the upper tray 60 is removed, thereby further
improving operability in loading the sheets into the lower tray
50.
[0051] In this embodiment, the upper tray 60 is slidably
displaceable by means of driving units such as the rack 65a, the
pinion gear 55 and a motor that drives the pinion gear 55 (not
shown). In addition to that, the upper tray 60 is in a state of
being restrained by the lower tray 50 in the active area of the
upper tray 60, and the upper tray 60 is released from being in the
restrained state in the inactive area. As a result, the upper tray
60 can be slidably displaced in a reliable manner without causing
disengagement of the rack 65a from the pinion gear 55 in the active
area.
[0052] Moreover, although the upper tray 60, when in the stand-by
position, is located above the space for storing the sheets in the
lower tray 50 in this embodiment, the upper tray 60 may be
configured in other embodiments to be slidably displaceable to a
position outside of the space for storing the sheets in the lower
tray 50 so that the space for storing the sheets in the lower tray
50 can be fully opened without turning or removing the upper tray
60.
[0053] Furthermore, the upper tray 60 may be configured in other
embodiments to be detachably mounted in the main body of the
printer 1 separately from the lower tray 50, so that the sheets can
be fed from the upper tray 60 without using the lower tray 50,
thereby further improving usability.
3. Details of Edge Guide
[0054] The edge guide 52 that is provided on the lower tray 50 will
be further described in detail with reference to FIGS. 4 and 5. As
described above, the space for storing the sheets in the lower tray
50 increases when the upper tray 60 is removed from the lower tray
50, which enables the increased number of the sheets to be stored
in the lower tray 50. However, if a guiding height of the edge
guide 52 that is provided on the lower tray 50 remains the same,
the sheets stored in the lower tray 50 cannot be guided in an
appropriate manner after the upper tray 60 is removed.
[0055] Accordingly, the edge guide 52 that is provided on the lower
tray 50 according to this embodiment is configured such that the
guiding height of the guide surface is adjustable. More
specifically, as shown in FIGS. 4A and 4B, the edge guide 52
includes a base 52a that slides along the bottom of the lower tray
50, an upright portion 52b formed integrally with the base 52a so
as to be mounted upright on the base 52a, a plate member 52c that
is rotatable with respect to the upright portion 52b about a
rotation shaft 52e and a biasing unit, which is not shown in the
figure, that biases the plate member 52c in a direction indicated
by the arrow C1.
[0056] Reference numeral 52d denotes the guide surface along which
the sheet edge is guided. The guiding height of the guide surface
52d is configured to increase as the plate member 52c rotates in
the direction indicated by the arrow C1, from a first state shown
in FIG. 4A to a second state shown in FIG. 4B.
[0057] More specifically, when the upper tray 60 is usually mounted
on the lower tray 50, the plate member 52c engages the bottom of
the upper tray 60, that is, the plate member 52c is pressed down,
thereby retaining the first state as shown in FIG. 4A.
[0058] Then, when the upper tray 60 is removed from the lower tray
50 as shown by reference numeral 60' in FIG. 2, the plate member
52c disengages from the upper tray 60. As a result, the plate
member 52c is rotated by a biasing force from the biasing unit and
switched to the second state as shown in FIG. 4B, thereby changing
(increasing) the guiding height of the guide surface 52d from h0
(FIG. 4A) to h1 (FIG. 4B) (h1>h0).
[0059] That is, the guiding height of the guide surface 52d is
adjustable and the guiding height of the edge guide 52 increases as
the capacity for the sheets in the lower tray 50 increases, thereby
enabling the increased number of stacked sheets to be accommodated.
As a result, the sheet can be fed in an appropriate manner without
causing a feeding problem such as skew feeding.
[0060] Moreover, in this embodiment, the sheet guide surface 52d is
formed by the plate member 52c that is rotatable about the rotation
shaft 52e such that the guiding height of the guide surface 52d can
be adjusted by rotation of the plate member 52c. Accordingly, a
switching mechanism for the guiding height of the guide surface 52d
can be achieved in a simple configuration at low cost.
[0061] In addition to that, the rotation shaft 52e is formed to be
perpendicular to the guide surface 52d in this embodiment such
that, when the plate member 52c rotates about the rotation shaft
52e, the edge of the sheets is aligned with a single surface of the
guide surface 52d in both the first state and the second state.
Accordingly, a smooth, flat or seamless guide surface is provided
during setting of the sheets without causing a problem, such as
that the sheet gets stuck, in both the first state and the second
state.
[0062] Further, since the guiding height of the guide surface 52d
decreases when the edge guide 52 engages the upper tray 60 and the
guiding height of the guide surface 52d increases when the edge
guide 52 disengages from the upper tray 60 in this embodiment, the
guiding height of the guide surface 52d increases without needing a
specific operation. Accordingly, the sheet cassette with high
usability can be achieved. In addition, the upper tray 60 according
to this embodiment remains in engagement with the edge guide 52
(the plate member 52c) when the upper tray 60 is mounted on the
lower tray 50, regardless of the position where the upper tray 60
is located in the slidable area.
[0063] Although the above-mentioned embodiment has been described
that the guiding height of the guide surface 52d is configured to
be changed between two states, that is, a lower state (FIG. 4A) and
a higher state (FIG. 4B), the guiding height maybe changed in a
stepwise manner for example by defining several height positions,
or alternatively, the guiding height may be continuously changed.
In such cases, it is desirable to provide a holding unit so as to
retain the predetermined guiding height.
[0064] Another embodiment will be described with reference to FIGS.
5A and 5B. The same configurations as those of FIGS. 4A and 4B are
referenced by the same reference numerals, while the configurations
corresponding to but different from those of FIGS. 4A and 4B are
referenced by the same reference numerals with a prime mark.
[0065] In FIGS. 5A and 5B, the edge guide 52' includes a base 52a,
an upright portion 52b' formed integrally with the base 52a so as
to be mounted upright on the base 52a, a plate member 52c' that is
rotatable with respect to the upright portion 52b' about rotation
shaft bearings 52f and a biasing unit, which is not shown in the
figure, that biases the plate member 52c' in a direction indicated
by the arrow C2. The rotation shaft bearing 52f is a bearing that
supports a shaft (not shown) formed on the upright portion
52b'.
[0066] Reference numerals 52d-1 and 52d-2 denote guide surfaces
along which the sheet edge is guided. In a first state shown in
FIG. 5A, the guide surface 52d-1 formed by the upright portion 52b'
constitutes a guide surface of the edge guide 52'. The guiding
height in this configuration is h0.
[0067] Then, as the plate member 52c' rotates in the direction
indicated by the arrow C2, thereby deploying the guide surface
52d-2 that is formed by the plate member 52c' on the guide surface
52d-1, the overall guiding height changes (increases) to h1
(h1>h0) from a first state shown in FIG. 5A to a second state
shown in FIG. 5B.
[0068] Accordingly, also in this embodiment, the guiding height of
the edge guide 52' increases as the capacity for the sheets in the
lower tray 50 increases, thereby enabling the increased number of
stacked sheets to be accommodated. As a result, the sheet can be
fed in an appropriate manner without causing a feeding problem such
as skew feeding.
[0069] Similar to the edge guide 52, which has been described with
reference to FIGS. 4A and 4B, the edge guide 52' of this embodiment
may be configured to retain the first state, which is achieved by
the plate member 52c' engaging the bottom of the upper tray 60,
that is, being pressed down by the upper tray 60. Accordingly, the
first state is not limited to a state in which the plate member
52c' has been fully rotated downward and is in close contact with
the upright portion 52b' as shown in FIG. 5A, but also may be a
state in which the plate member 52c' has been rotated to a certain
extent in a direction indicated by the arrow C2 from the state
shown in FIG. 5A.
[0070] In addition, the plate member 52c' in the second state shown
in FIG. 5B may be inclined to a certain extent toward the first
state in order to facilitate downward rotation of the plate member
52c' when the plate member 52c' is pressed down by the upper tray
60 in the state shown in FIG. 5B.
[0071] Furthermore, although the first state and the second state
have been described to be switched by means of the edge guides 52
and 52' engaging with/disengaging from the upper tray 60, a holding
unit, for example, may be separately provided so that the first
state and the second state are retained by the holding unit and
such retained state is released by an operation of a user.
[0072] Although the edge guides 52 and 52' have been described as
to guide the side edge of the sheets, it is needless to say that
the above edge guide may apply to an edge guide for the trailing
edge of the sheets (shown by reference numeral 51 in FIG. 1).
[0073] The entire disclosure of Japanese Patent Application No:
2010-287063, filed Dec. 24, 2010 is expressly incorporated by
reference herein.
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