U.S. patent application number 11/457515 was filed with the patent office on 2008-01-17 for paper cassette having manual paper feeder and image forming apparatus including the same.
Invention is credited to Young-min Kim, Sang-cheol Park.
Application Number | 20080012199 11/457515 |
Document ID | / |
Family ID | 38948455 |
Filed Date | 2008-01-17 |
United States Patent
Application |
20080012199 |
Kind Code |
A1 |
Kim; Young-min ; et
al. |
January 17, 2008 |
PAPER CASSETTE HAVING MANUAL PAPER FEEDER AND IMAGE FORMING
APPARATUS INCLUDING THE SAME
Abstract
A paper cassette having a manual paper feeder, and an image
forming apparatus including the same. The image forming apparatus
includes a paper cassette provided with a guide groove formed at a
portion of a front surface thereof and having a multi-stepped
widths corresponding to multiple width sheets of paper, and a case
having a cassette attachment part to insert the paper cassette.
Inventors: |
Kim; Young-min; (Suwon-si,
KR) ; Park; Sang-cheol; (Suwon-si, KR) |
Correspondence
Address: |
STANZIONE & KIM, LLP
919 18TH STREET, N.W., SUITE 440
WASHINGTON
DC
20006
US
|
Family ID: |
38948455 |
Appl. No.: |
11/457515 |
Filed: |
July 14, 2006 |
Current U.S.
Class: |
271/9.09 |
Current CPC
Class: |
B65H 1/266 20130101;
B65H 2407/21 20130101; B65H 2405/31 20130101; B65H 2402/46
20130101 |
Class at
Publication: |
271/9.09 |
International
Class: |
B65H 5/26 20060101
B65H005/26; B65H 3/44 20060101 B65H003/44 |
Claims
1. An image forming apparatus comprising: a paper cassette
including a guide groove formed at a portion of a front surface
thereof and having a at least one width portion corresponding to at
least one width of a sheet of paper; and a case having a cassette
attachment part to insert the paper cassette, wherein a sheet of
paper is manually fed through a space defined by the guide groove
and the cassette attachment part.
2. The image forming apparatus according to claim 1, wherein the
cassette attachment part is formed at a lower part of the case.
3. The image forming apparatus according to claim 1, wherein the
guide groove is formed at an upper part of the paper cassette.
4. The image forming apparatus according to claim 1, wherein the
guide groove has a multi-stage structure to guide sheets of paper
of various widths.
5. The image forming apparatus according to claim 1, wherein the
paper cassette comprises a resilient projection formed at an outer
surface, and the cassette attachment part of the case comprises a
threshold formed at a position spaced apart from the resilient
projection, at which the paper cassette is fully inserted into the
cassette attachment part, so that the resilient projection becomes
stopped by the threshold when the paper cassette is drawn out by a
predetermined distance.
6. The image forming apparatus according to claim 1, wherein the
cassette attachment part has a paper introduction port formed at a
portion corresponding to the guide groove of the paper cassette to
manually feed paper.
7. The image forming apparatus according to claim 6, further
comprising: guide members installed at the paper introduction port
to slide along a width of the paper introduction port.
8. The image forming apparatus according to claim 1, wherein the
case comprises a manual feed roller to convey the sheet of paper
manually fed through the space defined by the guide groove and the
cassette attachment part.
9. A paper cassette usable with an image forming apparatus, the
paper cassette comprising: a cassette body having an automatic
paper feeder to automatically feed paper into the image forming
apparatus; and a manual paper feeder integrally formed with a
portion of the cassette body to manually feed paper into the image
forming apparatus.
10. The paper cassette according to claim 9, wherein the manual
paper feeder comprises a guide groove formed at a portion of a
front surface of the cassette body and having a width corresponding
to the paper to enable manual feeding of the paper.
11. The paper cassette according to claim 10, wherein the guide
groove has a multi-stage structure having different widths
corresponding to paper of various widths.
12. The paper cassette according to claim 10, wherein guide members
are installed adjacent to the guide groove to be adjusted to the
width of the paper.
13. The paper cassette according to claim 10, wherein the cassette
body has a paper support surface formed at a portion thereof to
function as a support plate to support a bottom surface of the
paper manually fed into the guide groove.
14. An image forming apparatus, comprising: a case to contain a
paper cassette therein, the case including a cassette attachment
part formed at a front part thereof to slidably receive a paper
cassette; and a paper cassette comprising: an automatic paper
feeder portion to contain paper therein to be automatically fed
into the image forming apparatus, and a front wall portion having a
grooved portion formed at an upper surface thereof and facing the
cassette attachment part to receive paper manually fed
therebetween.
15. The image forming apparatus according to claim 14, wherein the
cassette attachment part comprises a paper introduction part
extending horizontally along an upper portion thereof to receive a
paper having a large width to be manually fed.
16. The image forming apparatus according to claim 15, wherein the
grooved portion comprises multi-stepped portions extending upwardly
and outwardly along the front wall portion to face the paper
introduction part, each multi-stepped portion having a different
width to receive paper of a corresponding width.
17. The image forming apparatus according to claim 16, wherein the
grooved portion is centrally disposed with respect to the front
wall portion.
18. The image forming apparatus according to claim 16, further
comprising: a pair of guide members slidable along the paper
introduction part to provide adjustable guides for papers of any
width to be manually fed into the image forming apparatus.
19. The image forming apparatus according to claim 18, further
comprising: a lever disposed below the guide groove to pull or push
the paper cassette in and out of the cassette attachment part.
20. The image forming apparatus according to claim 19, wherein the
front wall portion further comprises: an upper support surface
extending along an upper side thereof such that when the paper
cassette is pulled out of cassette attachment part by a
predetermined amount, the upper support surface provides a support
for a bottom of the paper being manually fed between the grooved
portion and the paper introduction part.
21. The image forming apparatus according to claim 20, wherein the
case comprises a pair of feed rollers to receive and transfer the
manually fed paper within the image forming apparatus.
22. The image forming apparatus according to claim 14, wherein the
cassette attachment part comprises: an elongated groove at opposite
sides thereof to guide the sliding of the paper cassette; and a
threshold extending from one inner side of thereof to contact a
portion of the paper cassette to limit the drawing out of the paper
cassette with respect thereof.
23. The image forming apparatus according to claim 21, wherein the
paper cassette comprises a resilient projection to be inserted into
the elongated groove to glide therein such that the resilient
projection engages with and is stopped by the threshold when slid
by a predetermined distance out of the cassette attachment
part.
24. An image forming apparatus, comprising: a front surface portion
comprising: a cassette attachment part formed therein to receive a
paper cassette, and a paper introduction portion formed along a
predetermined length of a horizontally extending portion of the
cassette attachment part to receive manually fed paper therein; and
a paper cassette comprising: a body portion to contain papers to be
automatically fed within the image forming apparatus, and a front
surface portion including a groove portion formed therein having
multi-stepped grooves facing opposite the paper introduction
portion to receive corresponding multiple sized manually fed paper
therebetween.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present general inventive concept relates to an image
forming apparatus and, more particularly, to a paper cassette
having a manual paper feeder and an image forming apparatus
including the same.
[0003] 2. Description of the Related Art
[0004] An image forming apparatus such as a duplicator, a printer,
a facsimile, and so on generally has two paper feeding methods,
i.e., an automatic paper feeding method of inserting a plurality of
sheets of paper into a paper cassette and automatically outputting
the paper, and a manual paper feeding method of manually inserting
a paper into a manual paper feeder when a sheet of a specific type
of paper is fed or several sheets of plain paper are fed one at a
time.
[0005] FIG. 1 is a perspective view of a conventional image forming
apparatus including a manual paper feeder.
[0006] Referring to FIG. 1, an image forming apparatus 10 includes
a manual paper feeder 20 having a paper insertion slot 22 laterally
formed at a case 11 to feed sheets of paper 16 one by one. A
cassette attachment part 13 is formed below the paper insertion
slot 22 to attach a paper cassette 18 for stacking sheets of paper
16.
[0007] Guide members 24 are installed at the paper insertion slot
22 to laterally slide to stably guide various sizes of recording
mediums such as an envelope, a label paper, an OHP film, a card
sheet, and so on.
[0008] Meanwhile, an image forming unit (not shown) for forming an
image on the sheet of paper 16 inserted through the paper insertion
slot 22 is installed in the image forming apparatus 10. A paper
discharge part 19 is formed at an upper end of the image forming
apparatus 10 to discharge the sheet of paper 16, on which an image
is formed, to an exterior of the image forming apparatus 10.
[0009] However, since the conventional image forming apparatus 10
has no support member for supporting a free end of the sheet of
paper 16 when the paper is fed through the manual paper feeder 20,
the sheet of paper 16 may unstably move sideways while being fed,
and the cassette attachment part 13, being in close proximity to
the paper insertion slot 22, takes away from the appearance of the
image forming apparatus.
[0010] In order to solve these problems, Korean Utility Model
Registration No. 20-0136727, entitled "Auxiliary Manual Paper
Feeding Device for Printer", discloses a foldable paper support
tray installed at a lower part of a manual paper feeding box to
function as a guide member. However, this additional guide member
increases manufacturing costs.
[0011] Meanwhile, since an intermediate part A between the cassette
attachment part 13 and the paper insertion slot 22 has a small
thickness and a small width, a molding material in which the
intermediate part A is formed may not be sufficiently formed of the
proper shape or size when a case 11 is injection-molded, thereby
causing deformation such as bending of the intermediate part A
after injection molding. When the deformed case 11 is used, the
guide members 24 cannot smoothly slide along the paper insertion
slot 22. In particular, such deformation adversely affects the
performance and appearance of the printer. Though reinforcement
ribs may be further formed at the intermediate part A, formation of
the reinforcement ribs in the limited space decreases injection
efficiency and makes the mold structure complex, thereby reducing
the lifespan of the mold.
SUMMARY OF THE INVENTION
[0012] The present general inventive concept provides an image
forming apparatus having a simplified structure as well as improved
performance due to removal of an intermediate part between a
cassette attachment part and a paper insertion slot.
[0013] Additional aspects and advantages of the present general
inventive concept will be set forth in part in the description
which follows and, in part, will be obvious from the description,
or may be learned by practice of the general inventive concept.
[0014] The present general inventive concept also provides an image
forming apparatus capable of reducing manufacturing costs by
employing a simple structure to guide paper, which is manually fed,
without additional guide members.
[0015] The present general inventive concept also provides a paper
cassette of an image forming apparatus including a manual paper
feeder.
[0016] Additional aspects and utilities of the present general
inventive concept will be set forth in part in the description
which follows and, in part, will be obvious from the description,
or may be learned by practice of the general inventive concept.
[0017] The foregoing and/or other aspects and utilities of the
present general inventive concept may be achieved by providing an
image forming apparatus including: a paper cassette provided with a
guide groove formed at a portion of a front surface thereof and
having a width corresponding to a sheet of paper; and a case having
a cassette attachment part for inserting the paper cassette. The
sheet of paper can be manually fed through a space defined by the
guide groove and the cassette attachment part.
[0018] The cassette attachment part may be formed at a lower part
of the case, and the guide groove may be formed at an upper part of
the paper cassette. In this case, the manually fed paper may be
readily seated on the guide groove by its own weight. In addition,
the guide groove may have a multi-stage structure to guide sheets
of paper having various widths.
[0019] The paper cassette may include a resilient projection formed
at its outer surface, and the cassette attachment part of the case
may include a threshold formed at a position, spaced apart from the
resilient projection, at which the paper cassette is fully inserted
into the cassette attachment part. Therefore, the resilient
projection can be hooked by the threshold when the paper cassette
is drawn out by a predetermined distance.
[0020] The cassette attachment part may have a paper introduction
port formed at its structure corresponding to the guide groove of
the paper cassette, to manually feed paper. In this case, the
apparatus may further include guide members installed at the paper
introduction port to facilitate lateral sliding along the paper
introduction port. Further, the case may include a manual feed
roller for conveying the sheet of paper manually fed through a
space defined by the guide groove and the cassette attachment
part.
[0021] The foregoing and/or other aspects and utilities of the
present general inventive concept may also be achieved by providing
a paper cassette of an image forming apparatus including: a
cassette body having an automatic paper feeder for automatically
feeding paper; and a manual paper feeder integrally formed with a
portion of the cassette body for manually feeding paper.
[0022] The manual paper feeder may include a guide groove formed at
a portion of a front surface of the cassette body and having a
width corresponding to the paper to enable manual feeding of the
paper. In this case, the guide groove may have a multi-stage
structure having different widths corresponding to paper of various
widths.
[0023] Guide members may be installed adjacent to the guide groove
to be adjusted to the width of the paper.
[0024] The cassette body may have a paper support surface formed at
a portion thereof to function as a support plate for supporting a
bottom surface of paper manually fed into the guide groove.
[0025] The foregoing and/or other aspects and utilities of the
present general inventive concept may also be achieved by providing
an image forming apparatus, including: a case to contain a paper
cassette therein, the case including a cassette attachment part
formed at a front part thereof to slidably receive a paper
cassette; and a paper cassette including an automatic paper feeder
portion to contain paper therein to be automatically fed into the
image forming apparatus, and a front wall portion having a grooved
portion formed at an upper surface thereof and facing the cassette
attachment part to receive paper manually fed therebetween.
[0026] The foregoing and/or other aspects and utilities of the
present general inventive concept may also be achieved by providing
an image forming apparatus, including: a front surface portion
including a cassette attachment part formed therein to receive a
paper cassette, and a paper introduction portion formed along a
predetermined length of a horizontally extending portion of the
cassette attachment part to receive manually fed paper therein; and
a paper cassette including a body portion to contain papers to be
automatically fed within the image forming apparatus, and a front
surface portion including a groove portion formed therein having
multi-stepped grooves facing opposite the paper introduction
portion to receive corresponding multiple sized manually fed paper
therebetween.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] These and/or other aspects and advantages of the present
general inventive concept will become apparent and more readily
appreciated from the following description of the embodiments,
taken in conjunction with the accompanying drawings of which:
[0028] FIG. 1 is a perspective view of a conventional image forming
apparatus including a manual paper feeder;
[0029] FIG. 2 is a perspective view of an image forming apparatus
in accordance with an embodiment of the present general inventive
concept;
[0030] FIG. 3 is a front view of the image forming apparatus of the
embodiment of FIG. 2;
[0031] FIG. 4 is a front view of an image forming apparatus in
accordance with another embodiment of the present general inventive
concept;
[0032] FIGS. 5A and 5B are side cross-sectional views of the image
forming apparatus of the embodiment of FIG. 2, a paper cassette of
which can be drawn therefrom by a predetermined distance;
[0033] FIG. 6 is a front view of an image forming apparatus in
accordance with still another embodiment of the present general
inventive concept, a paper cassette of which can drawn therefrom by
a predetermined distance; and
[0034] FIG. 7 is a cross-sectional view taken along line I-I' of
the image forming apparatus illustrated in FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Reference will now be made in detail to the embodiments of
the present general inventive concept, examples of which are
illustrated in the accompanying drawings, wherein like reference
numerals refer to the like elements throughout. The embodiments are
described below in order to explain the present general inventive
concept by referring to the figures.
[0036] FIG. 2 is a perspective view of an image forming apparatus
in accordance with an embodiment of the present general inventive
concept, FIG. 3 is a front view of the image forming apparatus of
the embodiment of FIG. 2.
[0037] Referring to FIGS. 2 and 3, an image forming apparatus 100
in accordance with an embodiment of the present general inventive
concept includes a case 111 having a cassette attachment part 111a
formed at a lower portion thereof, and a paper cassette 118 that
inserts into the cassette attachment part 111a.
[0038] As illustrated in FIGS. 2, 3, 5A and 5B, the paper cassette
includes a cassette body 118c having an automatic paper feeder 118e
therein, and a manual paper feeder 120 integrally formed on the
cassette body 118c. Therefore, a sheet of paper 116 can be
automatically fed into the case 111 through the automatic paper
feeder 118e, or manually fed into the case 111 through the manual
paper feeder 120.
[0039] The manual paper feeder 120 may include a guide groove 118a
formed at an upper part of the cassette body 118c, such as at a
part of a front surface of the cassette body 118c, for example, a
center part, a width of which corresponds to different sizes of
papers to be fed into the image forming apparatus 100. Therefore,
the sheet of paper 116 can be manually fed into the case 111
through the guide groove 118a. The guide groove 118a may
alternatively be formed at a lower part or at side parts of the
cassette body 118c, rather than at the upper part. However, in
order to correspond with a conventionally positioned paper feed
roller, the guide groove 118a is formed at the upper part or the
lower part of the cassette body 118c.
[0040] The guide groove 118a may have a multi-stage shape as
illustrated in FIGS. 2 and 3 in order to guide papers of various
sizes such as envelopes, postcards, 3.times.5 inch paper, B5, A5,
B4, A4, and so on. In other words, the guide groove 118a can
include a plurality of groove portions as illustrated in FIGS. 2
and 3. Here, the number and width of the multi-stage of the guide
groove 118a may be determined depending on the type of the sheet of
paper or papers 116 to be inserted. In addition, a lever 118b is
formed at a lower front part of the cassette body 118c, just below
the guide groove 118a, such that a user can grasp the lever 118b to
pull the paper cassette 118 out of the image forming apparatus 100
or push the paper cassette 118 into the image forming apparatus
100.
[0041] In addition, the cassette attachment part 111a of the case
111 has a shape corresponding to a cross-section of the paper
cassette 118 to be inserted therein. Further, a paper introduction
port 111b to manually feed a sheet of paper is formed at a surface
of the cassette attachment part 111a to correspond with the guide
groove 118a of the paper cassette 118. The paper introduction port
111b may have a width slightly larger than a maximum width of
recording media that can be manually fed, and may be integrally
formed with the cassette attachment part 111a.
[0042] The manual paper feeder 120 to feed sheets of paper 116 (or
other recording media) one by one is a part at which the sheet of
paper 116 is fed into the case 111. In this embodiment, a lower
surface and side surfaces of the manual paper feeder 120 are
defined by a bottom surface and side surfaces of the guide groove
118a of the paper cassette 118, and an upper surface of the manual
paper feeder 120 is defined by the paper introduction port 111b of
the case 111.
[0043] With the arrangement as described above, the paper
introduction port 111b formed at an upper surface of the cassette
attachment part 111a of the case 111 can guide a sheet of paper 116
having a width substantially equal to the width of the paper
introduction port 111b. In an alternative embodiment, the manual
paper feeder 120 may not include the paper introduction port 111b.
That is, the paper 116 can be fed through a space defined by the
guide groove 118a and the cassette attachment part 111a. In this
case, the manual paper feeder 120 is formed by a co-operation
between the paper cassette 118 and the cassette attachment part
111a such that different size spaces to feed paper are provided
therebetween. One surface of the manual paper feeder 120 is defined
by the cassette attachment part 111a formed at the case 111, and
another three surfaces of the manual paper feeder 120 are defined
by portions of the guide groove formed at the paper cassette 118,
such as, for example, the portions illustrated as positioned in the
middle of the cassette body 118c directly above the lever 118b.
[0044] However, in order to feed a sheet of paper 116 having a
larger width than the portions of the guide groove 118a formed at
the paper cassette 118, the guide groove 118a should also have a
portion that is formed at an upper end of the cassette body 118c
with a large width to correspond with the paper surface of the
introduction port 111b as illustrated in FIGS. 2 and 3. When the
outermost portion of the guide groove 118a has the large width to
correspond with the paper surface of the introduction port 111b, a
center part of the sheet of paper 116 may sag so that both sides
edges of the sheet of paper 116 become separated from edges of the
guide groove 118a, thereby causing the sheet of paper 116 to be
incorrectly guided. Therefore, the paper introduction port 111b
also includes a shape to form a groove portion having a large width
formed at the cassette attachment part 111a and directly above the
cassette body 118c to receive larger size sheets of paper 116.
[0045] FIG. 4 is a front view of an image forming apparatus in
accordance with another embodiment of the present general inventive
concept.
[0046] Referring to FIG. 4, an image forming apparatus 100 may
further include guide members 124, in addition to the features
described above with respect to the embodiment of FIGS. 2 and 3.
The guide members 124 laterally slide along the paper introduction
port 111b of the manual paper feeder 120 to enable insertion of
paper 116 of various sizes while guiding the inserted papers 116.
Though the guide groove 118a and the paper introduction port 111b
can guide standard sizes of paper 116 and smaller sizes such as
envelopes, postcards, and 3.times.5 inch, further installation of
the guide members 124 allows any size of paper 116, as well as the
standard sizes, envelopes, postcards, and 3.times.5 inch to be
smoothly guided.
[0047] FIGS. 5A and 5B are side cross-sectional views of the image
forming apparatus of the embodiment illustrated in FIG. 2, the
paper cassette 118 of which can be drawn therefrom. FIG. 5A
illustrates the paper cassette 118 being fully inserted into the
cassette attachment part 111a, and FIG. 5B illustrates the paper
cassette 118 being drawn from the cassette attachment part 111a to
the exterior thereof by a predetermined distance.
[0048] Referring to FIGS. 2, 5A and 5B, the cassette attachment
part 111a is formed at a lower part of the case 111, and the paper
cassette 118 is slidably inserted into the cassette attachment part
111a.
[0049] The case 111 includes a manual feed roller 131 rotatable by
a signal from a controller (not illustrated) to convey a manually
fed piece of paper 116 to an image forming unit (not illustrated)
installed in the image forming apparatus 100, and an idle roller
133 to rotatably engage with the manual feed roller 131 to generate
a friction force to convey the sheet of paper 116.
[0050] As illustrated in FIG. 5B, when the sheet of paper 16 is fed
in a state in which the paper cassette 118 is drawn out of the
image forming apparatus 100 by the predetermined distance, an upper
paper support surface 118d of the cassette body 118c functions as a
support member to support the manually fed paper 116. That is, the
paper support surface 118d of the cassette body 118c supports a
bottom surface of the manually fed paper 116. Therefore, when the
sheet of paper 116 is manually fed along the guide groove 118a, the
paper support surface 118d of the cassette body 118c supports a
bottom surface of the manually fed sheet of paper 116 to remarkably
reduce curling of the sheet of paper 116 as the manually fed paper
116 passes between the rollers 131 and 133.
[0051] While the paper cassette 118 may be freely drawn out of the
image forming apparatus 100 by a distance desired by a user to
support the paper 116 thereon at the paper support surface 118d, a
means to accurately position the paper cassette 118 at a position
at which sagging of the sheet of paper 116 can be minimized can
additionally be provided as described below with respect to FIGS. 6
and 7.
[0052] FIGS. 6 and 7 illustrate an example of a positioning unit to
accurately position the paper cassette 118 at a position at which
sagging of the sheet of paper 116 can be minimized. P FIG. 6 is a
front view of an image forming apparatus in accordance with still
another embodiment of the present general inventive concept, a
paper cassette of which can be drawn therefrom by a predetermined
distance, and FIG. 7 is a cross-sectional view taken along line
I-I' of the image forming apparatus illustrated in FIG. 6.
[0053] Referring to FIGS. 6 and 7, the paper cassette 118 is
slidably inserted into the cassette attachment part 111a of the
case 111.
[0054] The paper cassette 118 can include a resilient projection
140 formed at one side thereof, and the cassette attachment part
111a of the case 111 has an elongated groove 111c extending in a
longitudinal direction of the cassette attachment part 111a,
thereby allowing the resilient projection 140 to be inserted and
guided in the elongated groove 111c (see FIG. 6). While the
elongated groove 111c is optional in this embodiment, when the
elongated groove 111c is provided, a gap may be generated between
the side surface of the paper cassette 118, at which the resilient
projection 140 is formed, and the cassette attachment part 111a to
provide a lateral movement of the paper cassette 118 with respect
to the image forming apparatus 100. Therefore, in order to minimize
the lateral movement of the paper cassette 118, the elongated
groove 111c is formed at a portion of the cassette attachment part
111a, along which the resilient projection 140 moves, and the
remaining portions of the cassette attachment part 111a can have a
shape conforming to the paper cassette 118.
[0055] In addition, a threshold 111d can be formed at a
predetermined position within the elongated groove 111c of the case
111, along which the resilient projection 140 moves, such that the
resilient projection 140 can be stopped at a predetermined position
within the elongated groove 111c.
[0056] The resilient projection 140 can include a hollow
cylindrical part 143 projecting perpendicular to the side surface
of the paper cassette 118, a cap 141 inserted over an end opening
of the cylindrical part 143, and a spring 145 inserted into the
cylindrical part 143 to create an elastic force so that the cap 141
can move in contact with an inner surface of the case 111.
[0057] The resilient projection 140 has a predetermined elastic
force such that the resilient projection 140 is stopped by the
threshold 111d to prevent further movement of the paper cassette
118 when less than a predetermined force is applied. However, when
the predetermined force is applied to the cassette 118, the
resilient projection 140 rides over the threshold 111d such that
the paper cassette 118 can be fully drawn out of the image forming
apparatus 100. Therefore, the spring 145 installed in the resilient
projection 140 can have a low coefficient of elasticity and the
threshold 111d can have a smooth curved surface such that a user
can feel the stopping of the resilient projection 140 by the
threshold 111d, to appropriately position the paper cassette 118
and readily draw the paper cassette 118 out of the image forming
apparatus 118 to a desired position.
[0058] Hereinafter, operations of the image forming apparatus 110
in accordance with an embodiment of the present general inventive
concept will be described.
[0059] First, a user grips the lever 118b of the paper cassette 118
to draw out the paper cassette 118. At this time, the resilient
projection 140 formed at the side surface of the paper cassette 118
is elastically biased against the inner surface of the case 111 to
move in close contact with the elongated groove 111c.
[0060] Then, when the paper cassette 118 is drawn out to a
predetermined distance, the resilient projection 140 comes in
contact with the threshold 111d formed at the inner surface of the
case 111 to stop the cassette 118 at the drawn position of the
paper cassette 118.
[0061] Next, when a predetermined piece of paper 116 to be fed is
positioned over the guide groove 118a of a central upper portion of
the paper cassette 18, the sheet of paper 116 drops down to be
seated on the guide groove 118a by its own weight. The guide groove
118a has a multi-stage structure to feed paper 116 of various sizes
such as 3.times.5 inch paper, envelopes, postcards, and so on. A
rear end of the seated paper 116 becomes supported by an upper end
surface of the drawn paper cassette 118 to prevent the sheet of
paper 116 from curling while being fed into the case and then
between the manual feed roller 131 and the idle roller 133.
[0062] When the sheet of paper 116 is pushed into the case 111, the
paper is slid in with both sides being in close contact with
sidewalls of the guide groove 118a, and a front end of the sheet of
paper 116 is inserted between the manual feed roller 131 and the
idle roller 133. At this time, a controller (not illustrated)
rotates the manual feed roller 131 under the control of the image
forming apparatus 100 to convey the piece of paper 116 to the image
forming part (not illustrated). Since the conveyed paper 116 is
guided by the guide groove 118a and fed to an accurate position,
the sheet of paper 116 can be prevented from jamming or entering
the case 111 crookedly. Here, jamming refers to when a sheet of
paper gets caught along a conveyance path, and entering crookedly
refers to a case when the sheet of paper is fed into the case 111
at an angle with respect to a paper feeding direction.
[0063] Meanwhile, when the sheet of paper 116 has a different width
than the portions of the multi-stage guide groove 118a, the guide
members 124 installed at the paper introduction port 111b of the
manual paper feeder 120 can be laterally slid to be in harmony with
the width of the sheet of paper 116 to be fed. As a result, it is
possible to accurately feed the paper as if the paper was being
guided by the guide groove 118a.
[0064] As can be seen from the foregoing, an image forming
apparatus in accordance with embodiments of the present general
inventive concept has a simplified structure as well as improved
performance due to removal of an intermediate part between a
cassette attachment part and a paper insertion slot.
[0065] In addition, an image forming apparatus in accordance with
embodiments of the present general inventive concept is capable of
preventing a sheet of paper from jamming or skewing by forming a
paper guide groove having portions with various widths at an upper
surface of a paper cassette, thereby enabling accurate feeding of
the paper without an additional guide member.
[0066] Further, an image forming apparatus in accordance with
embodiments of the present general inventive concept is capable of
supporting a paper including a rear end thereof on an upper end of
the paper cassette drawn out of the image forming apparatus to a
predetermined distance to prevent the paper from curling while
being fed therein, by forming a resilient projection at a side of
the paper cassette and a threshold at an inner wall of the
case.
[0067] Although a few embodiments of the present general inventive
concept have been shown and described, it will be appreciated by
those skilled in the art that changes may be made in these
embodiments without departing from the principles and spirit of the
general inventive concept, the scope of which is defined in the
appended claims and their equivalents.
* * * * *