U.S. patent application number 12/787913 was filed with the patent office on 2011-02-24 for image forming apparatus.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Soo-Yong Jung, Su-Hwan Kim, Duk-Young LEE, Chan-Sik Park.
Application Number | 20110042890 12/787913 |
Document ID | / |
Family ID | 43604687 |
Filed Date | 2011-02-24 |
United States Patent
Application |
20110042890 |
Kind Code |
A1 |
LEE; Duk-Young ; et
al. |
February 24, 2011 |
IMAGE FORMING APPARATUS
Abstract
Disclosed is an image forming apparatus incorporating a
discharging unit that discharges a printing medium outside the
housing of the image forming apparatus, and which stacks the
discharged printing medium. The discharging unit includes a
discharging part arranged on the transportation path of the
printing medium in the housing, a stacking lever rotatably
supported on the housing and a driving unit that drives the
stacking lever to rotate. The discharging part discharges a
printing medium outside the housing, and stacks the discharged
printing medium on a stacking unit provided outside the housing.
The stacking lever guides the stacking of the printing medium in
the stacking unit. A control unit may be provided to control the
driving unit so as to vary the revolution position of the stacking
lever based on the discharged position of the printing medium
discharged by the discharging part.
Inventors: |
LEE; Duk-Young; (Suwon-Si,
KR) ; Jung; Soo-Yong; (Suwon-Si, KR) ; Kim;
Su-Hwan; (Suwon-Si, KR) ; Park; Chan-Sik;
(Suwon-si, KR) |
Correspondence
Address: |
STANZIONE & KIM, LLP
919 18TH STREET, N.W., SUITE 440
WASHINGTON
DC
20006
US
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-Si
KR
|
Family ID: |
43604687 |
Appl. No.: |
12/787913 |
Filed: |
May 26, 2010 |
Current U.S.
Class: |
271/314 ;
271/220 |
Current CPC
Class: |
B65H 31/02 20130101;
B65H 2404/63 20130101; B65H 2601/211 20130101; B65H 29/52 20130101;
B65H 2404/14211 20130101; B65H 2301/4223 20130101; B65H 2404/1421
20130101; B65H 2404/6112 20130101; B65H 2301/51214 20130101; B65H
2801/06 20130101 |
Class at
Publication: |
271/314 ;
271/220 |
International
Class: |
B65H 29/22 20060101
B65H029/22; B65H 31/00 20060101 B65H031/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 24, 2009 |
KR |
10-2009-0078410 |
Claims
1. An image forming apparatus, comprising: a housing; an image
forming unit disposed in the housing, the image forming apparatus
being configured to form an image on a printing medium; and a
discharging unit configured to discharge the printing medium
outside the housing, and to stack a discharged printing medium, the
discharging unit comprising: a discharging part disposed on a
printing medium transportation path in the housing, the discharging
part being configured to discharge the printing medium outside the
housing; a stacking unit on which printing media discharged outside
the housing are stacked; a stacking lever which is rotatably
disposed in the housing, the stacking lever being configured to
guide stacking of the printing medium in the stacking unit; a
driving unit configured to rotate the stacking lever; and a control
unit configured to control the driving unit so as to vary a
revolution position of the stacking lever based on a discharged
position of the printing medium being discharged by the discharging
part.
2. The image forming apparatus according to claim 1, further
comprising a discharging sensor disposed on the printing medium
transportation path, the discharging sensor being configured to
sense the discharging position of the printing medium, wherein the
control unit is configured to control the driving unit based on a
sensing result of the discharging sensor.
3. The image forming apparatus according to claim 2, wherein the
control unit controls the driving unit so that an end portion of
the stacking lever maintains an ascending state when a leading end
portion of the printing medium enters the stacking unit, and so
that the end portion of the stacking lever descends when a trailing
end portion of the printing medium enters the stacking, unit.
4. The image forming apparatus according to claim 1, wherein the
discharging part comprises: a discharging roller disposed on a
first rotation shaft rotatably arranged on the printing medium
transportation path, and an idle roller formed on a second rotation
shaft rotatably arranged on the printing medium transportation
path, the second rotation shaft extending parallel to the first
rotation shaft.
5. The image forming apparatus according to claim 1, wherein the
stacking lever comprises: a revolution shaft disposed in the
housing, and a lever member rotatable about the revolution shaft,
the lever member comprising an operating unit ascending and
descending by the driving unit and a pressing unit configured to
come into a pressing contact with the printing medium.
6. The image forming apparatus according to claim 5, wherein the
pressing unit of the lever member is formed to have at least one of
a rectilinear shape, a rounded shape having a rounded end, a step
shape and a bent shape bent toward the stacking unit as it extends
away from the revolution shaft toward end of the pressing unit.
7. The image forming apparatus according to claim 5, wherein the
stacking lever comprises: a second revolution shaft arranged in the
housing, a second lever member rotatably disposed on the second
revolution shaft, the second lever member comprising a second
operating unit interlocking with the operating unit of the lever
member to ascend and descend therewith and a second pressing unit
configured to come into a pressing contact with the printing medium
in a pressing direction opposite to a direction in which the
pressing unit of the lever member presses the printing medium, and
a link member which connects the operating unit of the lever member
and the second operating unit of the second lever member.
8. The image forming apparatus according to claim 5, wherein the
stacking lever comprises: a second revolution shaft arranged in the
housing, a second lever member rotatably disposed on the second
revolution shaft, the second lever member comprising a second
pressing unit configured to come into a pressing contact with the
printing medium in a pressing direction opposite to a direction in
which the pressing unit of the lever member presses the printing
medium, and a weight coupled to the second lever member, the weight
biasing the second pressing unit toward the pressing unit of the
lever member by its own weight.
9. The image forming apparatus according to claim 1, wherein the
driving unit comprises a solenoid having an operating rod that
ascends and descends by an electromagnetic force, the operating rod
being connected to an end portion of the stacking lever.
10. The image forming apparatus according to claim 1, wherein the
driving unit comprises: a driving source configured to supply a
rotation force, a cam member driven by the driving source to
rotate, the cam member being configured to regulate an ascending
height of an end of the stacking lever based on a rotational
position of the cam member, and an elastic member elastically
biasing the end of the stacking lever toward the earn member.
11. The image forming apparatus according to claim 1, wherein the
stacking lever comprises: a revolution shaft arranged in the
housing, and a plurality of lever members disposed to the
revolution shaft spaced apart from one another by a predetermined
interval, and respectively comprise an operating unit ascending and
descending by the driving unit, and a pressing unit pressing on the
printing medium, and wherein the control unit controls the driving
unit so that an end part of a lever member positioned in a central
part of the printing medium in its widthwise direction among the
plurality of lever members further descends in comparison to an end
part of another lever member positioned at an edge part of the
printing medium in the widthwise direction.
12. The image forming apparatus according to claim 11, wherein the
driving unit comprises: a driving source configured to supply a
rotational force, a plurality of cam members which are rotated by
the rotational force supplied by the driving source, the plurality
of cam members being configured to regulate an ascending height of
the operating unit of each of the plurality of lever members based
on a rotation position of the plurality of cam members, and a
plurality of elastic members which elastically bias the operating
unit of each of the plurality of lever members toward the cam
members.
13. The image forming apparatus according to claim 11, wherein the
driving unit comprises: a solenoid with an operating rod that
ascends and descends by an electromagnetic force, an
ascending/descending member which is interlocked with ascending and
descending of the operating rod to thereby ascend and descend, and
a plurality of elastic members provided between the
ascending/descending member and the operating unit of each of the
plurality of lever members to elastically bias the operating unit
of each of the plurality of lever members.
14. An image forming apparatus, comprising: a housing; an image
forming unit disposed in the housing, the image forming apparatus
being configured to form an image on a printing medium; and a
discharging unit configured to discharge the printing medium
outside the housing, and to stack discharged printing media, the
discharging unit comprising: an operating plate rotatably supported
in the housing; a driving unit disposed in the housing, the driving
unit being configured to drive the operating plate to rotate; a
discharging part supported on the operating plate, the discharging
part being configured to discharge the printing medium outside the
housing; a stacking unit in which the printing medium discharged
outside the housing by the discharging part is stacked; a stacking
lever supported on the operating plate, the stacking lever being
configured to guide stacking of the printing medium in the stacking
unit based on a rotational position variation of the operating
plate; and a control unit which controls the driving unit to vary a
revolution position of the stacking lever based on a discharged
position of the printing medium being discharged by the discharging
part.
15. The image forming apparatus according to claim 14, further
comprising a discharging sensor disposed on a transportation path
of the printing medium, the discharging sensor being configured to
sense the discharged position of the printing medium, wherein the
control unit is configured to control the driving unit based on a
sensing result of the discharging sensor.
16. The image forming apparatus according to claim 14, wherein the
control unit controls the driving unit so that an end portion of
the stacking lever maintains an ascending state when a leading end
portion of the printing medium enters the stacking unit, and so
that the end portion of the stacking lever descends when a trailing
end portion of the printing medium enters the stacking unit.
17. The image forming apparatus according to claim 14, wherein the
discharging part comprises: a discharging roller which formed on a
first rotation shaft supported on the operating plate, and an idle
roller formed on a second rotation shaft supported on the operating
plate, the second rotation shaft extending parallel to the first
rotation shaft.
18. The image forming apparatus according to claim 17, wherein the
operating plate is configured to revolve about the first rotation
shaft or about the second rotation shaft.
19. The image forming apparatus according to claim 14, wherein the
driving unit comprises a solenoid with an operating rod that
ascends and descends by an electromagnetic force, the operating rod
being connected to a side of the operating plate.
20. The image forming apparatus according to claim 14, wherein the
driving unit comprises: a driving source configured to supply a
rotational force; a cam member which is driven to rotate by the
rotational force supplied by the driving source, the cam member
being configured to regulate a revolution position of an end of the
operating plate based on a rotation position of the cam member, and
an elastic member configured to elastically bias the end of the
operating plate toward the cam member.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Korean Patent
Application No. 10-2009-0078410, filed on Aug. 24, 2009 in the
Korean Intellectual Property Office, the entire disclosure of which
is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates generally to an image forming
apparatus, and more particularly, to an image forming apparatus
employing a printing medium discharging unit capable of stably
discharging and stacking printing media.
BACKGROUND OF RELATED ART
[0003] An image forming apparatus such as, for example, a printer,
an electronic copier, a facsimile, a multifunction device and the
like forms an image on a printing medium by one or more of various
types of image forming processes, including, for example, an
electrophotographic, an ink jet, a heat transfer, or the like. An
image forming apparatus typically includes a discharging unit for
discharging a printing medium on which an image has been
formed.
[0004] In general, a discharging unit of an image forming apparatus
may include among others a discharging roller provided on the
discharging path of the printing medium, a stacker onto which the
printing media are stacked and a stacking lever that guide the
stacking of a printing medium discharged onto the stacker by the
discharging roller. The stacking lever is typically rotatably
disposed to a main body of the image forming apparatus, and
reciprocally rotates by the force of a printing medium being
discharged and by its own weight, allowing the stacking of the
print media without requiring a separate driving force to
downwardly press the printing medium.
[0005] In the discharging unit of the conventional image forming
apparatus configured as described above, since the speed at which
the movable end of the discharging lever descends by its own weight
is slow, the stacked order of a printing medium may become out of
the correct sequence in the case of a high speed discharging of
printing media. That is, a sheet that is later in sequence may
actually be stacked under the preceding sheet of printing medium.
Further, the printing medium that is stacked out of order may
prevent the printing medium that should have properly preceded it
from being properly stacked so that the preceding printing medium
may become turned over or may deviate from the stacker. Such
improperly stacked printing medium may then prevent subsequent
sheets of printing media from being discharged normally, and may
even cause a jam.
SUMMARY OF DISCLOSURE
[0006] Accordingly to an aspect of the present disclosure, there
may be provide an image forming apparatus that may include a
housing, an image forming unit and a discharging unit. The image
forming unit may be disposed in the housing, and may be configured
to form an image on a printing medium. The discharging unit may be
configured to discharge the printing medium outside the housing,
and may be configured to stack the discharged printing medium. The
discharging unit may comprise a discharging part disposed on the
transportation path of the printing medium in the housing for
discharging the printing medium outside the housing, a stacking
unit on which printing media discharged outside the housing are
stacked, a stacking lever which may be rotatably disposed in the
housing, and which may be configured to guide stacking of the
printing medium in the stacking unit, a driving unit configured to
rotate the stacking lever and a control unit configured to control
the driving unit so as to vary the revolution position of the
stacking lever based on the discharged position of the printing
medium being discharged by the discharging part.
[0007] The image forming apparatus may further comprise a
discharging sensor disposed on the transportation path of the
printing medium. The discharging sensor may be configured to sense
the discharging position of the printing medium. The control unit
may be configured to control the driving unit based on a sensing
result of the discharging sensor.
[0008] The control unit may control the driving unit so that an end
portion of the stacking lever maintains an ascending state when the
leading end portion of the printing medium enters the stacking
unit, and so that the end portion of the stacking lever descends
when the trailing end portion of the printing medium enters the
stacking unit.
[0009] The discharging part may comprise a discharging roller
disposed on a first rotation shaft rotatably arranged on the
printing medium transportation path and an idle roller formed on a
second rotation shaft rotatably arranged on the printing medium
transportation path, the second rotation shaft extending parallel
to the first rotation shaft.
[0010] The stacking lever may comprise a revolution shaft disposed
in the housing and a lever member rotatable about the revolution
shaft, the lever member comprising an operating unit ascending and
descending by the driving unit and a pressing unit configured to
come into a pressing contact with the printing medium.
[0011] The pressing unit of the lever member may be formed to have
at least one of a rectilinear shape, a rounded shape having a
rounded end, a step shape and a bent shape bent toward the stacking
unit as it extends away from the revolution shaft toward end of the
pressing unit.
[0012] The stacking lever may comprise a second revolution shaft
arranged in the housing, a second lever member rotatably disposed
on the second revolution shaft and a link member. The second lever
member may comprise a second operating unit interlocked with the
operating unit of the lever member to ascend and descend therewith
and a second pressing unit configured to come into a pressing
contact with the printing medium in a pressing direction opposite
to a direction in which the pressing unit of the lever member
presses the printing medium. The link member may connect the
operating unit of the lever member and the second operating unit of
the second lever member.
[0013] The stacking lever may comprise a second revolution shaft
arranged in the housing, a second lever member rotatably disposed
on the second revolution shaft and a weight coupled to the second
lever member. The second lever member may comprise a second
pressing unit that may be configured to come into a pressing
contact with the printing medium in a pressing direction opposite
to a direction in which the pressing unit of the lever member
presses the printing medium. The weight may bias the second
pressing unit toward the pressing unit of the lever member by its
own weight.
[0014] The driving unit may comprise a solenoid having an operating
rod that ascends and descends by an electromagnetic force. The
operating rod may be connected to an end portion of the stacking
lever.
[0015] The driving unit may comprise a driving source configured to
supply a rotation force, a cam member driven by the driving source
to rotate and an elastic member elastically biasing the end of the
stacking lever toward the cam member. The cam member may be
configured to regulate the ascending height of an end of the
stacking lever based on the rotational position of the cam
member.
[0016] The stacking lever may comprise a revolution shaft arranged
in the housing and a plurality of lever members disposed to the
revolution shaft. The plurality of lever members may be arranged to
be spaced apart from one another by a predetermined interval, and
may respectively comprise an operating unit ascending and
descending by the driving unit and a pressing unit pressing on the
printing medium. The control unit may control the driving unit so
that an end part of a lever member positioned in the central part
of the printing medium in its widthwise direction among the
plurality of lever members further descends in comparison to an end
part of another lever member positioned at an edge part of the
printing medium in the widthwise direction.
[0017] The driving unit may comprise a driving source configured to
supply a rotational force, a plurality of cam members which are
rotated by the rotational force supplied by the driving source and
a plurality of elastic members. The plurality of cam members may be
configured to regulate the ascending height of the operating unit
of each of the plurality of lever members based on the rotation
position of the plurality of cam members. The plurality of elastic
members may elastically bias the operating unit of each of the
plurality of lever members toward the cam members.
[0018] The driving unit may comprise a solenoid with an operating
rod that ascends and descends by an electromagnetic force, an
ascending/descending member which is interlocked with ascending and
descending of the operating rod to thereby ascend and descend and a
plurality of elastic members provided between the
ascending/descending member and the operating unit of each of the
plurality of lever members to elastically bias the operating unit
of each of the plurality of lever members.
[0019] According to another aspect of the present disclosure, an
image forming apparatus may be provided to include a housing, an
image forming unit disposed in the housing for forming an image on
a printing medium and a discharging unit configured to discharge
the printing medium outside the housing. The discharging unit may
stack discharged printing media, and may include an operating plate
rotatably supported in the housing, a driving unit disposed in the
housing for driving the operating plate to rotate, a discharging
part supported on the operating plate for discharging the printing
medium outside the housing, a stacking unit in which the printing
medium discharged outside the housing by the discharging part is
stacked, a stacking lever supported on the operating plate for
guiding the stacking of the printing medium in the stacking unit
based on the rotational position variation of the operating plate
and a control unit which may control the driving unit so as to vary
the revolution position of the stacking lever based on the
discharged position of the printing medium being discharged by the
discharging part.
[0020] The image forming apparatus may further comprise a
discharging sensor disposed on the transportation path of the
printing medium. The discharging sensor may be configured to sense
the discharged position of the printing medium. The control unit
may be configured to control the driving unit based on a sensing
result of the discharging sensor.
[0021] The control unit may control the driving unit so that an end
portion of the stacking lever maintains an ascending state when the
leading end portion of the printing medium enters the stacking
unit, and so that the end portion of the stacking lever descends
when the trailing end portion of the printing medium enters the
stacking unit.
[0022] The discharging part may comprise a discharging roller
formed on a first rotation shaft supported on the operating plate
and an idle roller formed on a second rotation shaft supported on
the operating plate. The second rotation shaft may extend parallel
to the first rotation shaft.
[0023] The operating plate may be configured to revolve about the
first rotation shaft or about the second rotation shaft.
[0024] The driving unit may comprise a solenoid with an operating
rod that ascends and descends by an electromagnetic force, and that
is connected to a side of the operating plate.
[0025] The driving unit may comprise a driving source configured to
supply a rotational force, a cam member that is driven to rotate by
the rotational force supplied by the driving source and an elastic
member. The cam member may be configured to regulate the revolution
position of an end of the operating plate based on the rotation
position of the cam member. The elastic member may be configured to
elastically bias the end of the operating plate toward the cam
member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Various features and advantages of the present disclosure
will become apparent and more readily appreciated from the
following description of several embodiments thereof, taken in
conjunction with the accompanying drawings, of which:
[0027] FIG. 1 is a schematic sectional view illustrating an image
forming apparatus according to an embodiment of the present
disclosure;
[0028] FIG. 2 is a partial sectional perspective view illustrating
a discharging unit according to an embodiment of the present
disclosure;
[0029] FIGS. 3 and 4 schematically illustrate operation states of
the discharging unit of FIG. 2;
[0030] FIGS. 5 and 6 schematically illustrate the operation of the
lever member of the discharging unit of FIG. 2;
[0031] FIG. 7 schematically illustrates a discharging unit
according to another embodiment of the present disclosure;
[0032] FIG. 8 is a schematic perspective view illustrating a
discharging unit according to another embodiment of the present
disclosure;
[0033] FIG. 9 schematically illustrates the operational state of
the discharging unit of FIG. 8;
[0034] FIG. 10 schematically illustrates a discharging unit
according to another embodiment of the present disclosure;
[0035] FIG. 11 is a schematic perspective view illustrating a
discharging unit according to another embodiment of the present
disclosure;
[0036] FIG. 12 schematically illustrates the bent shape of printing
media by a pressing unit of a lever member of the discharging unit
of FIG. 11;
[0037] FIG. 13 is a schematic perspective view illustrating a
discharging unit according to another embodiment of the present
disclosure;
[0038] FIG. 14 is a schematic perspective view illustrating a
discharging unit according to another embodiment of the present
disclosure;
[0039] FIG. 15 schematically illustrates operational state of the
discharging unit of FIG. 14; and
[0040] FIG. 16 schematically illustrates a discharging unit
according to another embodiment of the present disclosure.
DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS
[0041] Reference will now be made in detail to several embodiments,
examples of which are illustrated in the accompanying drawings,
wherein like reference numerals refer to like elements throughout,
repetitive descriptions of which may be omitted for brevity sake.
It should be also noted that in the drawings, the dimensions of the
features are not intended to be to true scale and may be
exaggerated for the sake of allowing greater understanding.
[0042] FIG. 1 is a schematic sectional view illustrating an image
forming apparatus according to an embodiment of the present
disclosure.
[0043] Referring to FIG. 1, an image forming apparatus according to
an embodiment may include a housing 1, an image forming unit 10
disposed inside the housing 1 for forming an image on printing
media M and a discharging unit 100 for discharging the printing
medium M outside the housing 1.
[0044] The image forming apparatus may further include a printing
medium supplying unit 30 mounted to the housing 1 for supplying the
printing medium M. The printing medium supplying unit 30 may be
detachably provided to an inner portion and/or to an outer portion
of the housing 1, and may supply the printing medium M to the image
forming unit 10. The printing medium M supplied through the
printing medium supplying unit 30 is transported toward the image
forming unit 10 through a transportation path 41.
[0045] According to an embodiment, the supplying unit 30 may
include a first supplying unit 31 used for an automatic supplying
of the printing medium M and a second supplying unit 35 used for a
manual supplying. The first supplying unit 31 may be provided
inside the housing 1, and may supply the printing medium M by the
rotation of a first pickup roller 33. The second supplying unit 35
may be disposed outside the housing 1, and may supply the printing
medium M to the transportation path 41 by the rotation of a second
pickup roller 37.
[0046] The transportation path 41 may be provided inside the
housing 1. The printing medium M supplied from the printing medium
supplying unit 30 may be transported along the transportation path
41. To that end, the transportation path 41 may include a plurality
of transporting rollers 43 and 45. According to an embodiment, in
the transportation path 41, the path through which the printing
media are supplied from the first and second supplying units 31 and
35 diverges into two paths while the remaining path for the forming
of image and for discharging the printing media is provided as a
single path. The image forming apparatus may further include a
plurality of sensors S1 and S2 for sensing the transportation
position of a printing medium being transported on the
transportation path 41.
[0047] The image forming unit 10 forms an image on the printing
medium M supplied from the supplying unit 30 along the
transportation path 41 through a predetermined image forming
process such as an electrophotographic type, a heat transfer type,
an inkjet type, or the like. The image forming apparatus according
to an embodiment shown in FIG. 1 is example of an image forming
apparatus employing the electrophotographic type image forming unit
10.
[0048] As shown in FIG. 1, according to an embodiment, the image
forming unit 10 may include a developing unit 11, a light scanning
unit 23 forming an electrostatic latent image, a transferring unit
21 transferring an image formed in the developing unit 11 onto a
printing medium and a fusing unit 25 fusing the image transferred
to the printing medium M. The developing unit 11 may include a
toner container 11 a in which toner T of a predetermined color is
accommodated, a photosensitive medium 13 on which the electrostatic
latent image is formed by the light beam L from the light scanning
unit 23, a charging unit 15 charging the photosensitive medium 13
to a predetermined electric potential, a developing roller 17
arranged to face the photosensitive medium 13 for developing using
toner T the electrostatic latent image on the photosensitive medium
13 into a developed image and a supply roller 19 for supplying the
toner T to the developing roller 17. The light scanning unit 23
scans a light onto the photosensitive medium 13 to form the
electrostatic latent image on the photosensitive medium 13. The
transferring unit 21 may be disposed to face the photosensitive
medium 13 between which the printing medium M transported through
the transportation path 41 is to be interposed, and may perform the
process transferring the developed image formed to the
photosensitive medium 13 to a supplied printing medium M. The image
transferred to the printing medium M by the transferring unit 21 is
fused onto the printing medium M by the fusing unit 25.
[0049] To that end, the fusing unit 25 may include a heat source
26, a heating roller 27, a surface of which is heated by the heat
generated by the heat source 26, a temperature sensor (not shown)
measuring a surface temperature of the heating roller 27 and a
fusing control unit (not shown) controlling the electrical power
supplied to the heat source 26 based on the surface temperature of
the heating roller 27 measured by the temperature sensor.
[0050] While in the above-described embodiment(s) the image forming
unit 10 is described as an electrophotographic type image forming
unit, but the image forming unit 10 may employ any other types of
image forming processes, including, for example, an ink jet type or
a heat transferring type. In addition, while, for the sake of
brevity, in FIG. 1 a monochromatic electrophotographic image
forming unit that employs toner of single color is depicted,
according to alternative embodiments, a color electrophotographic
color image forming unit of either a multi pass type or a single
pass type known to those skilled in the art that utilizes a
plurality of color toners may be employed.
[0051] Hereinafter, a discharging unit 100 according to several
embodiments of the present disclosure will be described in
references to FIGS. 2 to 16.
[0052] FIG. 2 is a partial sectional perspective view illustrating
a discharging unit 100 according to an embodiment of the present
disclosure. FIGS. 3 and 4 schematically illustrate the operational
states of the discharging unit of FIG. 2.
[0053] Referring to FIGS. 1-4, the discharging unit 100 according
to an embodiment may include a discharging part 110 discharging a
printing medium M, a stacking unit 120 in which the discharged
printing media M are stacked, a stacking lever 130, a driving unit
150 for rotating the stacking lever 130 and a control unit 170.
[0054] The discharging part 110 is disposed on a printing medium
transportation path 41 inside the housing 1, and discharges the
printing medium M outside the housing 1. The stacking unit 120 is a
space in which the printing media M discharged outside the housing
1 are stacked. The stacking lever 130 may be supported on the
housing 1 in such a manner it is capable of rotating reciprocally,
and guides the stacking of the printing media on the stacking unit
120.
[0055] The control unit 170 controls the driving unit 150 so that
the rotation position of the stacking lever 130 varies depending on
the discharged position of the printing medium M being discharged
by the discharging part 110.
[0056] According to an embodiment, the discharging unit 100 may
further include a discharging sensor 180 disposed on the
transportation path 41 for sensing the discharging of the printing
medium M. In such embodiment, the control unit 170 controls the
driving unit 150 based on the sensing result of the discharging
sensor 180. That is, as shown in FIG. 3, the control unit 170
controls the driving unit 150 so that the end part 139a (see FIG.
4) of the stacking lever 135 maintains an ascending state if the
leading end portion of the printing medium M enters the stacking
unit 120. As shown in FIG. 4, the control unit 170 controls the
driving unit 150 so that the end part 139a descends when the
trailing end portion of the printing medium M enters the stacking
unit 120.
[0057] The discharging part 110 may include a discharging roller
111 and an idle roller 113. The discharging roller 111 is supported
on the first rotation shaft 111a disposed on the transportation
path 41. The idle roller 113 is supported on the second rotation
shaft 113a disposed on the transportation path 41 parallel with the
first rotation shaft 111a.
[0058] The discharging roller 111 and the idle roller 113 may each
include a plurality of rollers supported respectively on the first
and second rotation shafts 111a and 113a spaced apart from one
another by a predetermined interval. With such configuration, each
of the discharging rollers 111 may be arranged to face a respective
corresponding one of the idling rollers 113 or may be arranged
between two idling rollers 113.
[0059] The stacking lever 130 may include a revolution shaft 131
rotatably supported by the housing 1 and a lever member 135
supported on the revolution shaft 131 so as to rotate with the
revolution shaft 131. The lever member 135 may include an operating
unit 137 that ascends and descends by the driving unit 150 and a
pressing unit 139 that comes into a contact with a printing medium
M being discharged.
[0060] According to an embodiment, the lever member 135 may be
configured as a pressing unit 139 having a rectilinear shape as
shown in FIG. 2, as a pressing unit having a rounded shape in which
an end part 139a is rounded as shown in FIG. 3, as a pressing unit
239 having its end portion bent toward the stacking unit 120 as
shown in FIG. 5, or a pressing unit 339 having a stepped shape as
shown in FIG. 6.
[0061] According to an embodiment, the driving unit 150 may include
a solenoid 151 with an operating rod 151a that ascends and descends
by an electromagnetic force, and which is connected to the
operating unit 137 of the stacking lever 130. With such
configuration, the lever member 135 moves with the ascending and
descending of the operating rod 151a to thereby pivot about the
revolution shaft 131.
[0062] FIG. 7 schematically illustrates a discharging unit
according another embodiment according to the present disclosure.
Referring to FIG. 7, the driving unit 150 may be configured as a
cam driving unit 155. The cam driving unit 155 may include a
driving source 156 supplying a rotation force, a cam member 157 and
an elastic member 159. The cam member 157 is driven by the driving
source 156, and regulates an ascending height of the operating unit
137 of the lever member 135. The elastic member 159 may be provided
to elastically bias the operating unit 137 toward the cam member
157. With the above configuring the driving unit 150, the pivoting
of the lever member 135 about the revolution shaft 131 can be
actively controlled. Accordingly, the trailing end portion of a
printing medium M can be pressed when the trailing end portion of
the printing medium is discharged to the stacking unit 120, and the
printing medium M can be stacked more rapidly in comparison to a
conventional lever member that operate by its own weight. Further,
by returning back the rotational position of the lever member 135
to the ascended position before the discharging of the subsequent
printing medium, the lever member 135 can be prevented from
interfering with the leading end portion of the subsequent printing
medium.
[0063] FIG. 8 is a schematic perspective view illustrating a
discharging unit according to another embodiment of the present
disclosure whereas FIG. 9 schematically illustrates the operational
states of the discharging unit of FIG. 8.
[0064] Referring to FIGS. 8 and 9, according to an embodiment, the
stacking lever 130 may include a first revolution shaft 131
disposed to the housing 1, a first lever member 135 rotatably
disposed to the first revolution shaft 131, a second revolution
shaft 144, a second lever member 145 and a link member 142. The
first lever member 135 includes a first operating unit 137
ascending and descending by the driving unit 150 and a first
pressing unit 139 pressing a printing medium.
[0065] The discharging unit according to the present embodiment has
the distinction of further including the second revolution shaft
144, the second lever member 145 and the link member 142 in
comparison to the discharging unit according to the previously
described embodiments.
[0066] The second lever member 145 is supported on to the second
revolution shaft 141, and includes a second operating unit 147
linked with the first operating unit 137 by the linking member 142
to ascend and descend and a second pressing unit 149 pressing the
printing medium from the opposite direction to the pressing
direction of the first pressing unit 139. The link member 142
connects the first operating unit 137 and the second operating unit
147, and transmits the driving force supplied from the driving unit
150 to the second lever member 145.
[0067] With the configuration described above, by supporting the
printing medium M being discharged to the stacking unit 120 from
the upper and lower directions, downward sagging of the leading end
of the next printing medium can be prevented, thereby guiding the
next printing medium to be stacked from a higher position than the
trailing end of the preceding printing medium. Accordingly, the out
of sequence stacking of the subsequent printing medium being
inserted under the preceding printing medium can be prevented.
[0068] FIG. 10 schematically illustrates a discharging unit
according to another embodiment of the present disclosure.
[0069] Referring to FIG. 10, according to an embodiment, a stacking
lever 130 may include a first revolution shaft 131 rotatably
supported on the housing 1, a first lever member 135 rotatably
disposed to the first revolution shaft 131, a second revolution
shaft 141, a second lever member 145 and a weight 144. The
discharging unit according to the embodiment has a distinction of
including the weight 144 instead of the link member 142 of the
previous embodiment of FIG. 8.
[0070] The weight 144 is disposed to the second lever member 145,
and biases the second pressing unit 149 toward the first pressing
unit 139. Accordingly, when the first pressing unit 139 ascends and
descends by the driving unit 150, the weight 144 ascends and
descends by the pressing force of the first pressing unit 139 and
by its own weight to support the lower side of the printing
medium.
[0071] FIG. 11 is a schematic perspective view illustrating a
discharging unit according to another embodiment of the present
disclosure. FIG. 12 schematically illustrates the bent shape of a
printing medium imparted by the pressing unit of the lever member
in FIG. 11.
[0072] Referring to FIGS. 11 and 12, a stacking lever 130 of the
discharging unit according to an embodiment may include a
revolution shaft 131 rotatably supported on the housing 1 and a
plurality of lever members 135 coupled to the revolution shaft 131
and spaced apart from one another by a predetermined distance
interval. Each of the plurality of lever members 135 may include an
operating unit 137 ascending and descending by the driving unit 150
and a pressing unit 139 for pressing a printing medium M.
[0073] With such configuration, the control unit 170 controls the
driving unit 150 so that an ends of the lever members 135b and 135c
positioned in the central part in the widthwise direction of the
discharged printing medium M among the plurality of lever members
135 further descends in comparison to the ends of the lever members
135a and 135d positioned at an edge part in the widthwise direction
of the printing medium M when the rear end part of the printing
medium M enters the stacking unit 120.
[0074] To that end, the driving unit 150 may include a driving
source 156, a cam rotation shaft 158, a plurality of cam members
157a through 157d supported on the cam rotation shaft 158 to be
spaced apart from one another by a predetermined interval and a cam
driving unit 155 that may include a plurality of elastic members
159a through 159d. The plurality of cam members 157a, 157b, 157c
and 157d rotate by the driving source 156, and regulates an
ascending height of the operating unit 137 of the respective
corresponding one of lever members 135a, 135b, 135c and 135d
depending on the rotation position. The plurality of elastic
members 159a, 159b, 159c and 159d elastically bias the operating
unit 137 of the respective corresponding one of lever members 135a,
135b, 135c and 135d toward the cam members 157a, 157b, 157c and
157d, respectively.
[0075] With the above described configuration, the present
embodiment varies the revolution angles of the plurality of lever
members as shown in FIG. 12 so that the air between the printing
medium currently being discharged and the printing medium
discharged immediately subsequently is allowed to escape when the
printing medium descends to the stacking unit. Accordingly, the
turning over of a printing medium, the position deviation and the
reversed stacking order of the printing media caused by the air
resistance during the stacking process can be prevented.
[0076] FIG. 13 is a schematic perspective view illustrating a
discharging unit according to another embodiment of the present
disclosure.
[0077] Referring to FIG. 13, the stacking lever 130 of the
discharging unit according to an embodiment may include a
revolution shaft 131 rotatably supported on the housing 1 and a
plurality of lever members 135 coupled to rotate with the
revolution shaft 131 and spaced apart from one another by a
predetermined interval. Each of the plurality of lever members 135
includes an operating unit 137 that ascends and descends by the
driving unit 150 and a pressing unit 139 for pressing a printing
medium M. In comparison to the previously described embodiments,
there is a distinction that the driving unit 150 according to the
present embodiment is changed. That is, the driving unit 150
includes a solenoid 151 driving an operating rod 151a to ascend and
descend by an electromagnetic force, an ascending/descending member
152 interlocked with the ascending and descending of the operating
rod 151a, and a plurality of elastic members 153a, 153b, 153c and
153d. The elastic members 153a, 153b, 153c and 153d are provided
between the ascending/descending member 152 and the operating unit
137 of each of lever member 135a, 135b, 135c and 135d to
elastically bias the operating unit 137 of each lever member 135a,
135b, 135c and 135d, respectively.
[0078] The plurality of elastic members 153a, 153b, 153c and 153d
may have different elastic coefficients or lengths. For example,
the elastic members 153b and 153c disposed to the central part may
have larger elastic coefficients or longer lengths than the elastic
members 153a and 153d disposed at the edge portion. Accordingly,
when the trailing end of the printing medium M enters the stacking
unit 120, the ends of the lever members 135b and 135c positioned at
the central part in the widthwise direction of the discharged
printing medium can further descend in compassion to the ends of
the lever members 135a and 135d positioned at the edge part in the
widthwise direction of the printing medium.
[0079] FIG. 14 is a schematic perspective view illustrating a
discharging unit according to another embodiment of the present
disclosure while FIG. 15 schematically illustrates the operational
states of the discharging unit of FIG. 14.
[0080] Referring to FIGS. 14 and 15, the discharging unit according
to the present embodiment may include an operating plate 201
rotatably disposed inside the housing 1, a driving unit 250 for
rotatably driving the operating plate 201, a discharging part 210,
a stacking unit (not shown) in which a printing medium discharged
outside the housing 1 is stacked, a stacking lever 230 and a
control unit 270. The operating plate 201 is supported on the
housing 1 rotatably about a revolution shaft 205, and is rotated by
the driving unit 250.
[0081] The discharging part 210 is also supported on the operating
plate 201, and discharges a printing medium outside the housing 1.
The discharging part 210 may include a discharging roller(s) 211
formed on a first rotation shaft 211 a supported on the operating
plate 201, and an idle roller(s) 213 formed on a second rotation
shaft 213a also supported on the operating plate 201 parallel with
the first rotation shaft 211a. Accordingly, the discharging part
210 can change the discharging direction of a printing medium
discharged between the discharging roller 211 and the idle roller
213 depending on the rotational position of the operating plate
201.
[0082] The stacking lever 230 supported on the operating plate 201
guides the stacking of the printing medium on the stacking unit by
varying its position depending on variation of the rotational
position of the operating plate 201.
[0083] The control unit 270 controls the driving unit 250 to vary
the revolution position of the stacking lever 230 depending on the
discharging position of the printing medium being discharged in the
discharging part 210. That is, the control unit 270 controls the
driving unit 250 so that the printing medium pressing end part of
the stacking lever 230 can maintain an ascending state when the
leading end portion of the printing medium enters the stacking
unit. The control unit 270 further controls the driving unit 250 so
that the printing medium pressing end part of the stacking lever
230 can descend when the trailing end portion of the printing
medium enters the stacking unit.
[0084] The discharging unit according to an embodiment may further
include a discharging sensor 280 disposed along the printing media
transportation path, which may sense the discharging of a printing
medium. In such an embodiment, the control unit 270 may control the
driving unit 250 based on the sensing result of the discharging
sensor 280.
[0085] The driving unit 250 may include a solenoid 251 including an
operating rod that extends and retracts by an electromagnetic
force, and that is connected to a side of the operating plate 201.
Alternatively, the driving unit 250 may include a cam driving unit
including a driving source, a cam member and an elastic member. The
cam driving unit may have the substantially same configuration as
the cam driving unit of the discharging unit according to the
embodiment described in reference to FIG. 7.
[0086] As described above, by proving the discharging part 210 and
the stacking lever 230 to the operating plate 201 that is
rotationally driven, the positions of the discharging roller 211
and the idle roller 213 configuring the discharging part 210 and
the position of the stacking lever 230 can be actively controlled,
thereby efficiently preventing the stacking errors.
[0087] FIG. 16 schematically illustrates a discharging unit
according to another embodiment of the present disclosure.
[0088] As shown in FIG. 16, the discharging unit according to an
embodiment may have the distinction of providing the revolution
shaft 205 of the operating plate 201 to be coaxial with the first
rotation shaft 211a or the second rotation shaft 213a. In the
example shown in FIG. 16 illustrates an example of the operating
plate 201 rotating about the second rotation shaft 213a. With such
a configuration, although the operating plate 201 rotates about the
second, rotation shaft 213a of the idle roller 213, since the
rotational shaft of the idle roller 213 does not vary, there is the
advantage that it is not necessary to change the configuration and
the disposition of the driving force transmitting unit if the
rotational driving force is transmitted to the idle roller from an
external driving source.
[0089] While a detailed structure of the control unit 150 or 250 is
not depicted in the figures herein, as would be readily understood
by those skilled in the art, the control unit may be, e.g., a
microprocessor, a microcontroller or the like, that includes a CPU
to execute one or more computer instructions to implement the
various control operations herein described and/or control
operations relating to other components of the image forming
apparatus, such as, for example, one or more of the print medium
supply device 30, the image forming unit 10, and, to that end, may
further include a memory device, e.g., a Random Access Memory
(RAM), Read-Only-Memory (ROM), a flesh memory, or the like, to
store the one or more computer instructions.
[0090] The image forming apparatus according to the embodiments
described above provides a driving unit rotating a stacking lever
to actively control the revolution of the stacking lever depending
on the discharging state of a printing medium. Accordingly, the
printing medium can be stably stacked even when discharging
printing media at a high speed.
[0091] According to one or more aspects of the present disclosure,
and according to one or more embodiments described herein, the
revolution angles of the a plurality of stacking levers disposed
along the widthwise direction of a printing medium may be
controlled independently so as to allow the air between two
consecutively discharged printing media to escape. Accordingly, the
turning over or the position deviation of a printing medium caused
by the air friction can be reduced.
[0092] According to one or more aspects of the present disclosure,
an operating plate rotatably disposed to a housing, and on which
the discharging roller(s), the idle roller(s), as well as the
stacking lever(s) are supported, may be provided to thereby change
the discharging direction of a printing medium being discharged
between the discharging roller and the idle roller. According to
such embodiments, the position of the operating plate may be
controlled depending on the discharging position of the printing
medium, thereby realizing a more stable discharging and stacking of
printing media.
[0093] While the present disclosure has been particularly shown and
described with reference to several embodiments thereof, it will be
understood by those of ordinary skill in the art that various
changes in form and details may be made thereto without departing
from the principles and spirit of the present disclosure, the
proper scope of which is defined in the following claims and their
equivalents.
* * * * *