U.S. patent application number 10/078701 was filed with the patent office on 2002-08-29 for sheet feeding apparatus, and image forming apparatus, image reading apparatus and communication apparatus using the sheet feeding apparatus.
Invention is credited to Miyamoto, Shigeo.
Application Number | 20020117796 10/078701 |
Document ID | / |
Family ID | 18906765 |
Filed Date | 2002-08-29 |
United States Patent
Application |
20020117796 |
Kind Code |
A1 |
Miyamoto, Shigeo |
August 29, 2002 |
Sheet feeding apparatus, and image forming apparatus, image reading
apparatus and communication apparatus using the sheet feeding
apparatus
Abstract
An object of the invention is to provide a sheet feeding
apparatus of a simple structure which is capable of stacking
discharged sheets in a discharged-sheet stacker in an aligned
manner without performing any complicated operation even when the
sheet size is changed. The common sheet guide is removably attached
to the cassette and comes in contact with the sheets stacked in the
cassette and the sheets stacked in the stacker. When the sheets in
the cassette are replaced with sheets of a different size, as the
common sheet guide is moved to come in contact with the edges of
the sheets, the common sheet guide is located at the position
capable of coming in contact with the edges of the sheets stacked
in the stacker. Therefore, it is possible to restrict the movement
of the sheets stacked in the stacker and to align the sheets with
each other.
Inventors: |
Miyamoto, Shigeo; (Nara-shi,
JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
18906765 |
Appl. No.: |
10/078701 |
Filed: |
February 21, 2002 |
Current U.S.
Class: |
271/3.14 |
Current CPC
Class: |
B65H 1/04 20130101; B65H
1/266 20130101; B65H 31/02 20130101; H04N 1/0062 20130101; B41J
13/106 20130101; H04N 1/00631 20130101; B41J 11/0055 20130101; B41J
13/103 20130101; H04N 1/00543 20130101; B65H 2404/74 20130101; H04N
1/00567 20130101; B65H 2405/3322 20130101; G03G 15/6552
20130101 |
Class at
Publication: |
271/3.14 |
International
Class: |
B65H 005/22 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 21, 2001 |
JP |
P2001-44849 |
Claims
What is claimed is:
1. A sheet feeding apparatus comprising: an apparatus body for
inserting sheets fed thereto and discharging the sheets; a feed
sheet stacking section, mounted to the apparatus body, for stacking
sheets to be fed to the apparatus body; and a discharged-sheet
stacking section, mounted to the apparatus body, for stacking
sheets discharged from the apparatus body, wherein the feed sheet
stacking section includes a feed sheet stack plate on which the
sheets to be fed are stacked so that an almost entire bottom
surface of the stack of the sheets is supported by the feed sheet
stack plate, the discharged-sheet stacking section includes a
discharged-sheet stack plate which extends substantially parallel
to the feed sheet stack plate and on which the discharged sheets
are stacked so that an almost entire bottom surface of the stack of
the sheets is supported by the discharged-sheet stack plate, and a
common sheet guide is provided on an upstream side from the feed
sheet stack plate in a sheet insert direction and on a downstream
side from the discharged-sheet stack plate in a sheet discharge
direction, the common sheet guide being movable in the sheet insert
direction and the sheet discharge direction, for guiding sheets by
coming in contact with edges of the sheets stacked in the feed
sheet stacking section and edges of the sheets stacked in the
discharged-sheet stacking section.
2. The sheet feeding apparatus of claim 1, wherein the feed sheet
stacking section and the discharged-sheet stacking section are
arranged at an upper position or a lower position relative to each
other, the sheet stacking section arranged at the upper position is
mounted so as to be angularly displaced relative to the sheet
stacking section arranged at the lower position, thereby enabling
supply and removal of sheets relative to the sheet stacking section
arranged at the lower position.
3. The sheet feeding apparatus of claim 1, wherein the feed sheet
stacking section and the discharged-sheet stacking section are
arranged at an upper position or a lower position relative to each
other, at least one of the sheet stacking sections being mounted to
the apparatus body so as to be capable of being pulled out from the
apparatus body, thereby enabling supply and removal of sheets
relative to the sheet stacking section arranged at the lower
position.
4. An image forming apparatus which utilizes the sheet feeding
apparatus of claim 1.
5. An image reading apparatus which utilizes the sheet feeding
apparatus of claim 1.
6. A communication apparatus which utilizes the sheet feeding
apparatus of claim 1.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a sheet feeding apparatus
which stacks a plurality of sheets such as cut sheets of paper,
transports the sheets one by one, and stacks the sheets after
processing. More particularly, the present invention relates to a
sheet feeding apparatus for use in an image forming apparatus of
the electrophotographic recording type or the thermal transfer type
for example, an image reading apparatus, or a communication
apparatus such as a facsimile apparatus.
[0003] 2. Description of the Related Art
[0004] FIG. 4 is a sectional view showing the basic structure of an
electrophotographic facsimile apparatus utilizing a prior art sheet
feeding apparatus. A plurality of sheets 87 stacked in a sheet
cassette 80 as a feed sheet stacking section are picked up one by
one by a pickup roller 111 for successive transportation to a
transfer section 19. Then, a toner image is transferred to each of
the sheets 87 transported to the transfer section 19. The toner
image on the sheet 87 is fixed by a fixing roller 120. The sheets
87 onto which images are thus fixed are discharged and stacked in a
discharged-sheet stacker 88 which is a discharged-sheet stacking
section. The sheet cassette 80 and the discharged-sheet stacker 88
are separately provided. The sheet cassette 80 maybe replaced
according to the size of sheets, or may be provided with
unillustrated movable guides respectively extending lengthwise and
widthwise of sheets for fitting to the size of sheets. In this
sheet feeding apparatus 3, for the purpose of stacking sheets 87 of
various sizes, the discharged sheet stacker 88 for stacking
discharged sheets is not provided with a member such as a guide
(stopper) which restricts the movement of the sheets 87.
[0005] The sheet feeding apparatus 3 may be used not only for an
image forming apparatus such as a facsimile apparatus but also for
an image reading apparatus such as a scanner. Specifically, sheets
stacked in the sheet feed stacking section are picked up one by one
for reading images formed thereon and then discharged to be stacked
in the discharged-sheet stacking section.
[0006] An example of such prior art sheet feeding apparatus is
disclosed in Japanese Unexamined Patent Publication JP-A 7-149452
(1995). This sheet feeding apparatus includes a plurality of sheet
cassettes correspondingly to the sizes of sheets. One of the
plurality of sheet cassettes is upwardly provided with a cassette
lid serving as a discharged-sheet stacking section. The sheets
discharged from a recording section are stacked on the cassette
lid. When the sheet cassette provided with the cassette lid is not
attached to the apparatus body of the sheet feeding apparatus, a
controller stops the discharging of sheets to prevent the dropping
of the sheets and the sheet jam during the discharging.
[0007] To stack the sheets after printing or reading and to
satisfactorily align the stacked sheets is an important issue which
may influence the subsequent processing for the sheets. However,
since the prior art sheet feeding apparatus is not provided with a
guide for restricting the movement of the sheets, the discharged
sheets freely move on the discharged-sheet stacking section, so
that the stacking positions of the sheets do not coincide with each
other. Moreover, the stacked sheets may often drop from the
discharged-sheet stacking section due to the pushing force of the
following sheets.
[0008] For preventing the sheets 87 from dropping, a guide may be
provided. Specifically, a guide which is so designed as to
correspond to the largest size of sheets among various sizes which
can be dealt with may be fixedly attached to the discharged-sheet
stacker 88. In this case, the provision of the guide prevents the
dropping of the sheets 87. However, when the sheets having a
smaller size are used, the sheets stacked on the discharged-sheet
stacking section cannot be controlled and aligned, similarly to the
case where the guide is not provided. Therefore, the discharged
sheets are stacked unacceptably irregularly, so that the sheets
need be manually aligned after the printing.
[0009] Japanese Unexamined Patent Publication JP-A 10-218466 (1998)
discloses a sheet feeding apparatus provided with a guide for
restricting the movement of discharged sheets. This sheet feeding
apparatus performs restriction of front edges of documents in
discharging the documents. Specifically, the document tray includes
a plurality of discharged-document stoppers (guides) provided
correspondingly to the sizes of documents and arranged along the
document transport direction. Each of the discharged-document
stoppers is movable between a restriction position for engaging
with the front edges of the discharged documents and a retreated
position for retreating from the front edges of the discharged
documents.
[0010] In this apparatus, the discharged-document stoppers, which
corresponds to the size of documents, is moved to the restriction
position by a driving motor for stacking the documents in an
aligned manner. Therefore, the structure for moving the
discharged-document stopper is complicated, which disadvantageously
increases the manufacturing cost. Moreover, to operate selected one
of the plural discharged-document stoppers, the work for inputting
the document size by the operator or means for detecting the
document size is required. Thus, in the case where the operator
inputs the document size, the operation efficiency is deteriorated,
whereas, in the case where the detection means is provided, the
structure becomes more complicated.
[0011] Another prior art sheet feeding apparatus which utilizes a
guide having a more simple structure than the above is disclosed in
Japanese Unexamined Patent Publication JP-A 6-144598 (1994), for
example. FIG. 5A is a perspective view showing the image forming
apparatus having the simply structured guide, and FIG. 5B is a
sectional view showing the sheet cassette of the image forming
apparatus of FIG. 5A.
[0012] In the image forming apparatus 50, the sheet cassette 70 is
removably attached to an apparatus body 60 where image forming is
performed. The sheet cassette 70 stores sheets 56 on which images
are to be formed. The sheet cassette 70 includes a cassette body 51
attached to the apparatus body 60, a slide portion 52, a slide lid
53 and a stopper 54. The slide portion 52 is slidably attached to
the cassette body 51. The sheets 56 are so stacked as to locate on
both of the slide portion 52 and the cassette body 51.
Specifically, with respect to each of the sheets 56 stacked in the
sheet cassette 70, the longitudinally front half of the sheet is
supported by the bottom plate of the cassette body 51, whereas the
rear half of the sheet is supported by the bottom plate of the
slide portion 52, for example. By moving the slide portion 52 in a
sliding manner toward or away from the apparatus body 60, the
cassette body 51 can be freely expanded or contracted, so that
sheets 56 of various sizes can be stored in the sheet cassette
70.
[0013] The slide lid 53 is attached so as to cover an upper portion
of the slide portion 52. The slide lid 53 is removably attached to
the slide portion 52. The slide lid 53 moves relative to the
apparatus body 60 together with the sliding movement of the slide
portion 52. The sheets 56 fed from the sheet cassette 70 into the
apparatus body 60 are discharged onto the slide lid 53. The slide
lid 53 is provided with the stopper 54 for preventing the
discharged sheets 56 from moving due to the discharging force.
Thus, the discharged sheets 56 hit against the stopper 54 so that
the movement is restricted.
[0014] In the prior art sheet feeding apparatus 50 shown in FIGS.
5A and 5B, when the slide portion 52 is slid, the sheet 56 rubs
against the bottom plate of the slide portion 52. As a result, the
sheet 56 may be stained or folded, which may lead to transport
failure. Further, since the respective front halves of the sheets
56 are stacked on the bottom plate of the cassette body 51 whereas
the respective rear halves are stacked on the bottom plate of the
slide portion 52, a large load is exerted on the slide portion,
which increases the likelihood of breakage of the slide portion
52.
SUMMARY OF THE INVENTION
[0015] It is, therefore, an object of the present invention to
provide a sheet feeding apparatus of a simple structure which is
capable of feeding sheets while preventing damage to the sheets and
transport failure and which is also capable of stacking discharged
sheets in a discharge tray as aligned even when sheets are replaced
with those having a different size.
[0016] The present invention provides a sheet feeding apparatus
comprising: an apparatus body for inserting sheets fed thereto and
discharging the sheets; a feed sheet stacking section, mounted to
the apparatus body, for stacking sheets to be fed to the apparatus
body; and a discharged-sheet stacking section, mounted to the
apparatus body, for stacking sheets discharged from the apparatus
body,
[0017] wherein the feed sheet stacking section includes a feed
sheet stack plate on which the sheets to be fed are stacked so that
an almost entire bottom surface of the stack of the sheets is
supported by the feed sheet stack plate,
[0018] the discharged-sheet stacking section includes a
discharged-sheet stack plate which extends substantially parallel
to the feed sheet stack plate and on which the discharged sheets
are stacked so that an almost entire bottom surface of the stack of
the sheets is supported by the discharged-sheet stack plate,
and
[0019] a common sheet guide is provided on an upstream side from
the feed sheet stack plate in a sheet insert direction and on a
downstream side from the discharged-sheet stack plate in a sheet
discharge direction, the common sheet guide being movable in the
sheet insert direction and the sheet discharge direction, for
guiding sheets by coming in contact with edges of the sheets
stacked in the feed sheet stacking section and edges of the sheets
stacked in the discharged-sheet stacking section.
[0020] According to the present invention, since the common sheet
guide comes in contact with the sheets stacked in the feed sheet
stacking section and the sheets stacked in the discharged-sheet
stacking section, the movement of each sheet can be restricted so
that the sheets can be aligned with each other. Further, the common
sheet guide is movably provided. Therefore, by appropriately moving
the common sheet guide, when the sheets to be stacked in each
stacking section are replaced with sheets having another size, it
is possible to stack the sheets so as to align them.
[0021] Further, since the feed sheet stack plate and the
discharged-sheet stack plate extend substantially parallel to each
other and the common sheet guide is arranged on the upstream side
from the feed sheet stack plate in the sheet insert direction and
on the downstream side from the discharged-sheet stack plate in the
sheet discharge direction, it is possible to collectively restrict
the movement of the sheets stacked in the feed sheet stacking
section and the sheets stacked in the discharged-sheet stacking
section.
[0022] For example, in the case where the sheets stored in the feed
sheet stacking section are replaced with sheets having a different
size from those of the initially stored sheets, the common sheet
guide can be moved to an appropriate position by bringing the
common sheet guide into contact with the newly inserted sheets,
thereby aligning the sheets stacked in the feed sheet stacking
section. At this time, the common sheet guide is moved to the
restriction position for restricting the movement of the sheets
stacked in the discharged-sheet stacking section and comes in
contact with the downstream edges in the sheet discharge direction
of the sheets stacked in the discharged-sheet stacking section.
[0023] Thus, just by bringing the common sheet guide into contact
with the sheets stored in the feed sheet stacking section, the
sheets in the discharged sheet stacking section can be aligned
without conducting any special operation. Further, the common sheet
guide can be composed of a single movable member and can be easily
located at a proper position by the sheet supplier in accordance
with the size of the sheets. Therefore, means for driving the
common sheet guide and means for detecting the sheet size need not
be provided, so that the sheet feeding apparatus can be have a
simple structure and the number of structural parts can be reduced.
Accordingly, the sheet feeding apparatus can be inexpensively
manufactured and can have the function of aligning sheets without
increasing the manufacturing cost.
[0024] Further, the almost entire bottom surface of the stack of
the sheets is supported by each of the stackplates. Therefore,
unlike the prior art apparatus which utilizes a slide member,
damage to the sheets due to the movement of the guide can be
prevented. By preventing damage to the sheets, failure in
transporting the sheets can also be prevented.
[0025] Further, in the invention it is preferable that the feed
sheet stacking section and the discharged-sheet stacking section
are arranged at an upper position or a lower position relative to
each other, the sheet stacking section arranged at the upper
position is mounted so as to be angularly displaced relative to the
sheet stacking section arranged at the lower position, thereby
enabling supply and removal of sheets relative to the sheet
stacking section arranged at the lower position.
[0026] According to the present invention, by the angular
displacement of the upper one of the sheet stacking sections, the
space between the upper sheet stacking section and the lower sheet
stacking section can be increased. Therefore, the supply and
removal of sheets can be easily performed without detaching the
upper sheet stacking section from the apparatus body.
[0027] Further, in the invention it is preferable that the feed
sheet stacking section and the discharged-sheet stacking section
are arranged at an upper position or a lower position relative to
each other, at least one of the sheet stacking sections being
mounted to the apparatus body so as to be capable of being pulled
out from the apparatus body, thereby enabling supply and removal of
sheets relative to the sheet stacking section arranged at the lower
position.
[0028] According to the invention, at least one of the feed sheet
stacking section and the discharged-sheet stacking section is
mounted to the apparatus body so as to be capable of being pulled
out from the apparatus body. Therefore, by pulling out the at least
one sheet stacking section from the apparatus body, the upside of
the lower stacking section can be made open, and thereby the supply
and removal of sheets can be easily performed.
[0029] Further, the invention provides an image forming apparatus
which utilizes the above-described sheet feeding apparatus.
[0030] Furthermore, the invention provides an image reading
apparatus which utilizes the above-described sheet feeding
apparatus.
[0031] Further, the invention provides a communication apparatus
which utilizes the above-described sheet feeding apparatus.
[0032] According to the invention, the image forming apparatus may
be, for example, a copying machine or a printer. The image reading
apparatus may be, for example, a copying machine or a scanner. The
communication apparatus may be, for example, a facsimile apparatus.
By utilizing the above-described sheet feeding apparatus for these
apparatuses, it is possible to feed sheets stacked in the feed
sheet stacking section and to stack discharged sheet in the
discharged-sheet stacking section. Since the sheets discharged to
the discharged-sheet stacking section are stacked so as to be
aligned with each other, the troublesome work of manually aligning
the sheets can be eliminated, which enhances the convenience.
[0033] According to the present invention, in storing sheets in the
feed sheet stacking section, when the common sheet guide is placed
at the restriction position for aligning sheets stacked in the feed
sheet stacking section, the common sheet guide is also placed at
the restriction position for the discharged-sheet stacking section
in accordance with the size of the sheets stored in the feed sheet
stacking section. Therefore, without performing any special work,
the sheets discharged to the discharged-sheet stacking section can
be controlled and aligned by the common sheet guide. Further, even
when a sheet size is changed, the work for manually aligning the
sheets can be eliminated. This facilitates the processing after the
discharging of the sheets.
[0034] Moreover, the sheet feeding apparatus can have a simple
structure and the number of structural parts can be reduced.
Accordingly, the sheet feeding apparatus can be inexpensively
manufactured and can have the function of aligning sheets without
increasing the manufacturing cost.
[0035] According to the invention, the supply and removal of sheets
can be easily performed without detaching the sheet stacking
section arranged at the upper position from the apparatus body.
Therefore, time is not spent for detaching the upper sheet stacking
section, which makes it possible to supply and remove sheets in a
short time.
[0036] According to the invention, at least one of the feed sheet
stacking section and the discharged-sheet stacking section is
mounted to the apparatus body so as to be capable of being pulled
out from the apparatus body. Therefore, by pulling out the at least
one sheet stacking section from the apparatus body, the upside of
the lower stacking section can be made open, and thereby sheets can
be easily performed supplied to or removed from the sheet stacking
section arranged at the lower position.
[0037] According to the invention, by utilizing the above-described
sheet feeding apparatus for an image forming apparatus, an image
reading apparatus or a communication apparatus, sheets can be
stacked in the discharged-sheet stacking section in an aligned
manner even when the sheet size is changed. Thus, the sheets need
not be manually aligned, which makes it possible to easily carry
out the following work and to provide enhanced convenience.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Other and further objects, features, and advantages of the
invention will be more explicit from the following detailed
description taken with reference to the drawings wherein:
[0039] FIG. 1 is a sectional view showing a sheet feeding apparatus
according to an embodiment of the present invention as
enlarged;
[0040] FIG. 2 is a sectional view showing the basic structure of a
laser facsimile apparatus utilizing the sheet feeding apparatus of
FIG. 1;
[0041] FIG. 3 is a sectional view showing a sheet feeding apparatus
according to another embodiment of the present invention as
enlarged;
[0042] FIG. 4 is a sectional view showing the basic structure of a
laser facsimile apparatus utilizing a prior art sheet feeding
apparatus; and
[0043] FIGS. 5A and 5B illustrate an image forming apparatus
utilizing another prior art sheet feeding apparatus, where FIG. 5A
is a perspective view showing the image forming apparatus and FIG.
5B is a sectional view showing the prior art sheet cassette.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Now referring to the drawings, preferred embodiments of the
invention are described below.
[0045] FIG. 1 is a sectional view showing a sheet feeding apparatus
according to an embodiment of the present invention as enlarged.
FIG. 2 is a sectional view showing the basic structure of a laser
facsimile apparatus utilizing the sheet feeding apparatus of FIG.
1. The laser facsimile apparatus 2 prints a read image on a sheet
supplied thereto and then discharges the sheet.
[0046] As shown in FIG. 2, the laser facsimile apparatus 2 includes
an operation section 11. The operation section 11 is provided with
various keys for inputting information by the operator, and a
display for providing information for the operator, thereby serving
as a man-machine interface. For example, by operating the operation
section 11, the operator can give the laser facsimile apparatus 2
an instruction to read an image of a document.
[0047] Plural sheets of documents formed with images to be read are
disposed on a document feeder 12 provided above an apparatus body
6. When an image-read instruction is given, the documents are fed,
one by one, to an image reading unit 113 by a separator roller 13,
and the image on each of the documents is read. After the image is
read, the document is transported by a document discharge roller
115 for discharge to a document discharge section 114. The document
discharge section 114 is provided with a document stacker (not
shown) for stacking the documents whose images have been read.
[0048] The sheet feeding apparatus 1 for feeding sheets 117 on
which images are to be formed is arranged at a lower portion of the
laser facsimile apparatus 2. The sheet feeding apparatus 1
comprises the apparatus body 6 including a pickup roller 111 for
transporting the sheets 117 and a record transport roller (not
shown), a sheet cassette 110 and a discharged-sheet stacker 118
both of which are arranged adjacent the apparatus body 6. The sheet
cassette 110, which is a feed sheet stacking section, stores a
plurality of sheets 117 as stacked. The staked sheets 117 are
picked up one by one by the pickup roller 111 for transportation to
a transfer section 19. In the transfer section 19, a toner image,
which is a visible image formed on a photosensitive drum 18, is
transferred to each of the sheets 117. The sheet 117 is then
transported to a fixing roller 120 and pressed against the fixing
roller 120 at a high temperature, so that the toner image is fused
and fixed onto the sheet 117. The sheets 117 on which images are
thus fixed are successively stacked in a discharged-sheet stacker
118 which is a discharged-sheet stacking section. In this way, the
sheets 117 travels along a sheet travel route 116 extending along
the above-described path. For purpose of avoiding complexity and
simple illustration, such means as a guide or a roller for
transporting the sheets 117 along the sheet travel route 116 is not
illustrated in FIG. 2.
[0049] The printing on each of the sheets 117 is performed as
follows. First,the photosensitive drum 18 is charged at a charge
section 112. Then, a laser beam 16 from a laser unit 15 is applied
to the photosensitive drum 18. Specifically, the laser beam 16 is
modulated in accordance with the information to be printed, and
becomes, by a non-illustrated polygon mirror, a scanning light for
scanning the photosensitive drum 18 over a width corresponding to
the sheet width. The laser beam 16 emitted from the laser unit 15
is reflected by reflective mirrors 14 to be directed to the
photosensitive drum 18. At this time, the laser beam 16 is in the
form of an ON/OFF pattern necessary for the image printing. The
surface potential of the photosensitive drum 18 charged at the
charge section 112 lowers at portions irradiated with the laser
beam. Thus, an electrostatic latent image corresponding to the
image to be printed is formed on the photosensitive drum 18.
[0050] Then, in a developer unit 17, toner particles adhere to the
photosensitive drum 18 in accordance with the electrostatic latent
image, forming a visible toner image. As described before, the
visible image is transferred to the sheet 117 at the transfer
section 19.
[0051] The sheet feeding apparatus 1 will be described below in
detail. As shown in FIG. 1, the sheet feeding apparatus 1 is
provided with the apparatus body 6 where sheets 117 are
transported, the sheet cassette 110, the discharged-sheet stacker
118 and a common sheet guide 119. By the pickup roller 111, the
sheets 117 are inserted along the insert direction indicated by the
arrow A into the image forming apparatus and then make a U-turn to
be discharged in the discharge direction indicated by the arrow
B.
[0052] The sheet cassette 110 includes a rectangular feed sheet
stack plate 110a, a press member 131 and a spring 130. The sheets
117 to be fed to the apparatus body 6 are stacked on the feed sheet
stack plate 110a so that an almost entire bottom surface of the
stack of sheets is supported by the feed sheet stack plate. The
feed sheet stack plate 110a includes a feed-side edge 110b rising
from the end closer to the apparatus body 6. The sheet cassette 110
is removably attached to the apparatus body 6 arranged
substantially horizontally. When the sheet cassette 110 is attached
to the apparatus body 6, the feed sheet stack plate 110a is held
substantially horizontally. The press member 131 together with the
spring 130 resiliently supports the almost entire bottom surface of
the stack of the sheets 117 stacked on the feed sheet stack plate
110a so as to bias the stack of the sheets 117 upward toward the
pickup roller 111. For example, the press member 131 biases the
sheets upward while keeping the horizontal posture of the sheets.
The sheets 117 biased upward are picked up one by one by the pickup
roller 111 and transported.
[0053] The discharged-sheet stacker 118, which is arranged above
the sheet cassette 110, includes a rectangular discharged-sheet
stack plate 118a and a discharged-sheet stacker handle 32. The
sheets 117 discharged from the apparatus body 6 are stacked on the
discharged-sheet stack plate 118a so that an almost entire bottom
surface of the stack of the sheets is supported by the
discharged-sheet stack plate. The discharged-sheet stack plate 118a
includes a discharge-side edge 118b rising from the end closer to
the apparatus body 6. The discharged-sheet stacker 118 is attached
to the apparatus body 6 so that the discharged-sheet stack plate
118a is held generally in parallel to the feed sheet stack plate
110a. The discharged-sheet stacker 118 is arranged above the sheet
cassette 110 and at a position deviated from the sheet cassette 110
in the discharge direction B relative to the apparatus body 6.
[0054] The common sheet guide 119 is attached to the sheet cassette
110 and the discharged-sheet stacker 118. The common sheet guide
119 is arranged adjacent the end of the feed sheet stack plate 110a
on the upstream side in the insert direction and adjacent the end
of the discharged-sheet stack plate 118a on the downstream side in
the discharge direction. The common sheet guide 119 is movable in
the insert direction A and in the discharge direction B.
[0055] The common sheet guide 119 includes a feed-side contact
plate 119a and a discharge-side contact plate 119b. The feed-side
contact plate 119a comes in contact with respective rear edges (the
upstream edges in the sheet insert direction A) of the sheets 117
stacked in the sheet cassette 110. The discharge-side contact plate
119b comes in contact with respective front edges (the downstream
edges in the sheet discharge direction B) of the sheets 117 stacked
in the discharged-sheet stacker 118.
[0056] Since the common sheet guide 119 comes in contact with the
sheets 117 stacked in the sheet cassette 110 and the sheets 117
stacked in the discharged-sheet stacker 118, the movement of the
sheets 117 discharged to the discharged-sheet stacker 118 can be
restricted, thereby the sheets 117 can be aligned with each
other.
[0057] In this embodiment, the sheet cassette 110 is arranged at a
position deviated from the discharged-sheet stacker 118 in the
sheet insert direction, as described above. For conformity to this
arrangement, the common sheet guide 119 has a stepped
configuration. Specifically, the common sheet guide 119 comprises
four plate members 119a, 119b, 119c and 119d adjacent ones of which
are connected perpendicularly to each other at respective ends. The
slide plate 119c of the common sheet guide 119 is attached to the
lower surface of the sheet cassette 110 movably relative to the
sheet cassette 110. The feed-side contact plate 119a is connected
to the slide plate 119c. The discharge-side contact plate 119b is
connected to the feed-side contact plate 119a via the adjustment
plate 119d attached to the lower surface of the discharged-sheet
stacker 118.
[0058] The common sheet guide is so arranged that the length of the
adjustment plate 119d equals to the deviation amount of the sheet
cassette 110 relative to the discharged-sheet stacker 118 in the
insert direction A. Therefore, when the feed-side contact plate
119a is brought into contact with the edges of the sheets 117
stacked in the sheet cassette 110, the discharge-side contact plate
119b is brought into contact with the edges of the sheets 117
stacked in the discharged-sheet stacker 118.
[0059] For example, in the case where the sheets 117 stored in the
sheet cassette 110 are replaced with sheets 117 having a different
size from those of the initially stored sheets 117, the common
sheet guide 119 can be moved to a proper position by bringing the
common sheet guide 119 into contact with the newly inserted sheets
117, thereby aligning the sheets 117 stacked in the sheet cassette
110. At this time, the common restriction guide 119 is moved to the
position for restricting the movement of the sheets 117 stacked in
the discharged-sheet stacker 118 and comes in contact with the
downstream edges in the sheet discharge direction of the sheets 117
stacked in the discharged-sheet stacker 118. Thus, just by bringing
the common sheet guide plate 119 into contact with the sheets 117
newly supplied in the sheet cassette 110, the sheets 117 in the
discharged-sheet stacker 118 can be aligned without conducting any
special operation.
[0060] The common sheet guide 119 can be composed of a single
movable member and can be easily located at a proper position by
sheet supplier in accordance with the size of the sheets.
Therefore, means for driving the common sheet guide 119 and means
for detecting the sheet size need not be provided, so that the
sheet feeding apparatus 1 can be have a simple structure and the
number of structural parts can be reduced.
[0061] Further, since the common sheet guide 119 is movable in the
insert direction A and in the discharge direction B, sheets 117
having a different size can be placed without the need for
replacing the sheet cassette 110 with another one. Furthermore, the
sheets 117 can be stacked in the discharged-sheet stacker 118 in an
aligned manner without conducting any complicated operation.
[0062] The discharged-sheet stacker 118 is provided with a
discharged-sheet stacker rotary shaft 31 which angularly
displaceably supports the discharged-sheet stacker 118 to the sheet
cassette 110 and the discharged-sheet stacker handle 32. The rotary
shaft 31, extending in parallel with a horizontal plane and
substantially perpendicularly to the discharge direction B, is
arranged at the upstream end 123 in the sheet discharge direction B
of the discharged-sheet stacker 118. With this arrangement, the
discharged-sheet stacker 118 is angularly displaceable about the
axis of the rotary shaft 31. In other words, the discharged-sheet
stacker 118 is angularly displaceably arranged so that the down
stream end in the sheet discharge direction B of the
discharged-sheet stacker 118 is kept away from or close to the
sheet cassette 110. When the discharged-sheet stacker 118 is
angularly displaced in the direction C for raising the downstream
end 124 in the sheet discharge direction B of the discharged-sheet
stacker 118, the space between the discharged-sheet stacker 118 and
the sheet cassette 110 is increased at the downstream side in the
sheet discharge direction B. The discharged-sheet stacker handle 32
is arranged at the downstream side 124 in the sheet discharge
direction B. Just by raising the stacker handle 32 by the user, the
discharged-sheet stacker 118 can be easily angularly displaced.
[0063] Although the discharged-sheet stacker 118 is so arranged as
to cover the sheet cassette 110 and supply of the sheet 117 to the
sheet cassette 110 may be apparently difficult, the
discharged-sheet stacker 118 can be angularly displaced as
described above. Therefore, the supply and removal of sheets 117
can be easily performed utilizing the increased space between the
sheet cassette 110 and the discharged-sheet stacker 118 without the
need for detaching the discharged-sheet stacker 118 from the
apparatus body 6. Moreover, since the discharged-sheet stacker 118
is angularly displaced about the upstream end 123 in the sheet
discharge direction, the upstream end 123 does not largely separate
from the apparatus body 6 even when the space is increased.
Therefore, it is possible to increase the space and to supply and
remove sheets 117 without preventing the discharge of the sheets
117.
[0064] Although the discharged-sheet stacker 118 is angularly
displaced in a raising manner in this embodiment, the discharged
sheet stacker 118 may be horizontally moved in the angular
displacement direction, or laterally about the apparatus body 6. In
other words, the discharged-sheet stacker 118 may be angularly
displaced about the axis perpendicular to the horizontal plane.
Alternatively, as shown in FIG. 3 showing a view of a sheet feeding
apparatus 1a of another embodiment of the invention, the
discharged-sheet stacker 118 may be pulled in the discharge
direction B. By such movement, sheets 117 can be easily supplied to
or removed from the sheet cassette 110 disposed below the
discharged-sheet stacker.
[0065] Moreover, in this embodiment, the sheets 117 are discharged
through the fixing roller 120 to drop onto the discharged-sheet
stacker 118. On the discharged-sheet stacker 118, the movement of
the sheets 117 is restricted by both of the discharge-side contact
plate 119b of the common sheet guide 119 and the discharge-side
edge 118b of the discharged-sheet stack plate 118a. Therefore, as
compared with the case where the sheets are aligned only by the
discharge-side contact plate 119b, the sheets 117 can be more
precisely aligned.
[0066] Further, the sheet cassette 110, the sheets 117 are stacked
so that the almost entire bottom surface of the stack sheets 117 is
supported by the feed sheet stack plate 110a of the sheet cassette
110 and are not stacked on the common sheet guide 119. Therefore,
unlike the prior art apparatus which utilizes a slide member, the
movement of the guide does not cause the sheet 117 to be stained or
folded. Since such damage to the sheet 117 can be prevented, the
transport failure of the sheet can also be prevented. Moreover,
since the press member 131 biases the sheets 117 upward while
keeping the horizontal posture of the sheets, the sheets 117 can be
prevented from bending.
[0067] The above-described structure is merely an example of the
present invention and may be modified in various ways without
departing from the scope of the invention. For example, although
the discharged-sheet stacker 118 is arranged as deviated downstream
in the discharge direction relative to the sheet cassette 110, this
positional relationship is not limitative of the present
invention.
[0068] Further, in the above-described embodiment, the common sheet
guide 119 is movable in the sheet insert direction A and the sheet
discharge direction B. However, the sheet feeding apparatus 1 may
further include another common sheet guide which is movable in a
direction perpendicular to the sheet insert direction A and the
sheet discharge direction B within a horizontal plane. With such an
arrangement, the sheets 117 discharged can be aligned both in the
longitudinal direction and in the widthwise direction.
[0069] Moreover, the feed sheet stack plate 110a and the
discharged-sheet stack plate 118a may be inclined relative to the
horizontal surface as long as they extend generally parallel to
each other. In such a case, the common sheet guide may be so
arranged as to be movable in the direction in which the feed sheet
stack plate 110a and the discharged-sheet stack plate 118a
extend.
[0070] Hereinabove, as an example of the invention, reference is
made to the sheet feeding apparatus 1, used in the facsimile
apparatus, for transporting sheets. However, the sheet feeding
apparatus is applicable to any apparatus having a structure for
feeding and discharging sheets. For example, the sheet feeding
apparatus of the invention is applicable to a communication
apparatus such as a facsimile apparatus, an image forming apparatus
such as a copying machine or a printer, an image reading apparatus
such as a scanner, or an information processing apparatus
integrally provided with a printer, providing the same advantages
as the above.
[0071] Further, sheets used for the embodiment may not be sheets of
paper but may be, for example, resin sheets for use with an OHP
(overhead projector).
[0072] The invention may be embodied in other specific forms
without departing from the spirit or essential characteristics
thereof. The present embodiments are therefore to be considered in
all respects as illustrative and not restrictive, the scope of the
invention being indicated by the appended claims rather than by the
foregoing description and all changes which come within the meaning
and the range of equivalency of the claims are therefore intended
to be embraced therein.
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