Title: Cooling apparatus of an image forming apparatus
Abstract: A cooling apparatus of an electrophotographic image forming apparatus includes a cooling fan and a first opening. The cooling fan emits heat in the electrophotographic image forming apparatus to an outside of the electrophotographic image forming apparatus, is installed in any one of two frames that are opposite to each other so as to support a fusing unit, is disposed in a direction where a paper is discharged from the fusing unit, and allows internal air to flow out. The first opening is formed in a first frame that is opposite to a second frame in which the cooling fan is installed, and allows external air to flow into the electrophotographic image forming apparatus. The cooling apparatus is applied to a dry or wet electrophotographic image forming apparatus. The cooling apparatus emits heat generated from a fusing unit to the outside without affecting temperatures of a photosensitive drum and a developer unit so as to prolong a usable period of the photosensitive drum and improve an image quality. Also, waste toner is not congealed so as to reduce a load exerted on the cooling apparatus and the developer unit.
Patent Number: 6,892,040 Issued on 05/10/2005 to Ahn, et al.
| Inventors:
|
Ahn; Byung-sun (Gyeonggi-do, KR);
Kim; Dong-woo (Seoul, KR);
Baek; Jung-gee (Busan, KR)
|
| Assignee:
|
Samsung Electronics Co., Ltd. (Suwon-Si, KR)
|
| Appl. No.:
|
256170 |
| Filed:
|
September 27, 2002 |
Foreign Application Priority Data
| Feb 07, 2002[KR] | 2002-7024 |
| Current U.S. Class: |
399/92 |
| Intern'l Class: |
G03G 021/20 |
| Field of Search: |
399/92- 94
165/89
|
References Cited [Referenced By]
U.S. Patent Documents
| 5189473 | Feb., 1993 | Negoro et al.
| |
| 6173132 | Jan., 2001 | Kida et al.
| |
| 6219504 | Apr., 2001 | Matsuzaki et al.
| |
| Foreign Patent Documents |
| 8-063084 | Mar., 1996 | JP.
| |
| 10268735 | Oct., 1998 | JP.
| |
| 2000029283 | Jan., 2000 | JP.
| |
| 2000235338 | Aug., 2000 | JP.
| |
| 2000293089 | Oct., 2000 | JP.
| |
| 2001013856 | Jan., 2001 | JP.
| |
Primary Examiner: Grimley; Arthur T.
Assistant Examiner: Gleitz; Ryan
Attorney, Agent or Firm: Staas & Halsey LLP
Claims
1. A cooling apparatus of an image forming apparatus having a body having a bottom,
a fusing unit, and opposite frames disposed on opposite sides of the bottom to
support the fusing unit, comprising:
a paper discharging unit disposed higher than the fusing unit with respect to
the bottom to communicate with the fusing unit through a paper feeding path;
a cooling fan which emits heat in the image forming apparatus to an outside of
the image forming apparatus, is installed in one of the opposite frames, is disposed
on the paper feeding path between the fusing unit and the paper discharging unit
in a first direction, in which a sheet of paper is discharged from the fusing unit,
and induces air from the image forming apparatus to flow to the outside; and
a first opening that is positioned on the paper feeding path in the other frame
other than the one of the opposite frames in which the cooling fan is installed,
the cooling fan drawing external air through the first opening, into the image
forming apparatus, and across the fusing unit in the first direction.
2. The cooling apparatus of claim 1, wherein the image forming apparatus comprises
a developer unit, and the first opening is disposed between the developer unit
and the fusing unit.
3. The cooling apparatus of claim 1, wherein
a second opening is positioned in the one of the opposite frames in which the
cooling fan is installed; and
the cooling fan draws external air from the second opening, across the fusing
unit, in the first direction.
4. The cooling apparatus of claim 3, wherein the second opening is disposed between
the developer unit and the fusing unit.
5. The cooling apparatus of claim 3, wherein an area of the first opening is
greater than that of the second opening.
6. The cooling apparatus of claim 1, wherein the cooling fan is disposed above
the fusing unit and below the paper discharging unit with respect to the bottom
of the body of the image forming apparatus.
7. A cooling apparatus of an image forming apparatus having a frame containing
a bottom, a developer unit, and a fusing unit, the cooling apparatus comprising:
a paper discharging unit disposed higher than the fusing unit with respect to
the bottom to discharge a sheet of paper toward an outside of the image forming
apparatus through a paper feeding path, the paper feeding path being defined from
the developer unit to the fusing unit to the paper discharging unit;
a cooling fan mounted on the frame and disposed between the fusing unit and the
paper discharging unit to discharge internal air contained in the image forming
apparatus to the outside of the image forming apparatus; and
an opening positioned on the frame and disposed on the paper feeding path between
the developer unit and the fusing unit, the cooling fan drawing external air from
the opening, across the fusing unit, in a direction of the paper feeding path,
when the cooling fan operates.
8. The cooling apparatus of claim 7, wherein the cooling fan has a height higher
than that of the fusing unit and lower than that of the paper discharging unit
from the bottom of the frame.
9. The cooling apparatus of claim 8, wherein the fusing unit comprises a fusing
roller having a longitudinal axis, and the cooling fan has a center higher than
the longitudinal axis of the fusing roller of the fusing unit from the bottom of
the frame.
10. The cooling apparatus of claim 7, wherein the frame comprises first and second
side frames disposed on opposite ends of the fusing unit, and the cooling fan is
disposed on the first side frame, and is adjacent to one of the opposite ends of
the fusing unit.
11. The cooling apparatus of claim 7, wherein the cooling fan and the opening
forms an air flow from the opening to the cooling fan through the fusing unit when
the cooling fan operates.
12. The cooling apparatus of claim 11, wherein the air flow does not move toward
the developer unit.
13. The cooling apparatus of claim 11, wherein the fusing unit comprises a body
having first and second ends disposed adjacent to both ends of the fusing unit,
and the air flow moves from the first end of the fusing unit to the second end
of the fusing unit by passing the fusing unit.
14. The cooling apparatus of claim 13, wherein the first and second ends are
disposed opposite sides of the fusing unit with respect to a longitudinal axis
of the fusing unit perpendicular to a direction from the developer unit to the
fusing unit, and the cooling fan is disposed adjacent to the second end of the
fusing unit while the opening is disposed adjacent to the first end of the fusing unit.
15. The cooling apparatus of claim 11, wherein the internal air disposed around
the fusing unit moves toward the cooling fan.
16. The cooling apparatus of claim 11, wherein the external air flowing into
the inside does not flow toward the developer unit when the cooling fan operates.
17. A cooling apparatus of an image forming apparatus having a frame containing
a bottom, a developer unit, and a fusing unit, comprising:
a paper discharging unit disposed higher than the fusing unit with respect to
the bottom to discharge a sheet of paper toward an outside of the image forming
apparatus through a paper feeding path;
a cooling fan mounted on the frame and disposed between the fusing unit and the
paper discharging unit to discharge internal air contained in the image forming
apparatus to the outside of the image forming apparatus; and
an opening formed on the frame and disposed between the developer unit and the
fusing unit to allow external air to flow into an inside of the image forming apparatus
toward the fusing unit when the cooling fan operates,
wherein the frame comprises first and second side frames disposed on opposite
ends of the fusing unit,
the cooling fan is disposed on the first side frame and adjacent to one of the
opposite ends of the fusing unit, and
the opening is disposed on the second side frame and adjacent to another one
of the opposite ends of the fusing unit.
18. A cooling apparatus of an image forming apparatus having a frame comprising
a bottom, a developer unit, and a fusing unit, the cooling apparatus comprising:
a paper discharging unit disposed higher than the fusing unit with respect to
the bottom to discharge a sheet of paper toward an outside of the image forming
apparatus through a paper feeding path;
a cooling fan mounted on the frame and disposed between the fusing unit and the
paper discharging unit to discharge internal air contained in the image forming
apparatus to the outside of the image forming apparatus; and
an opening formed on the frame and disposed between the developer unit and the
fusing unit to allow external air to flow into an inside of the image forming apparatus
toward the fusing unit when the cooling fan operates
wherein the cooling fan and the opening forms an air flow from the opening to
the cooling fan through the fusing unit when the cooling fan operates,
the fusing unit comprises a body having first and second ends, and
the first and second ends are disposed toward the developer unit and the paper
discharging unit, respectively, and the air flow passes over the body of the fusing
unit from the first end to the second end.
19. A cooling apparatus of an image forming apparatus having a frame containing
a bottom, a developer unit, and a fusing unit, comprising:
a paper discharging unit disposed higher than the fusing unit with respect to
the bottom to discharge a sheet of paper toward an outside of the image forming
apparatus through a paper feeding path;
a cooling fan mounted on the frame and disposed between the fusing unit and the
paper discharging unit to discharge internal air contained in the image forming
apparatus to the outside of the image forming apparatus; and
an opening formed on the frame and disposed between the developer unit and the
fusing unit to allow external air to flow into an inside of the image forming apparatus
toward the fusing unit when the cooling fan operates
wherein the cooling fan and the opening forms an air flow from the opening to
the cooling fan through the fusing unit when the cooling fan operates, and
the internal air disposed around the developer unit moves toward the cooling
fan through the fusing unit.
20. A cooling apparatus of an image forming apparatus having first and second
opposing side walls, and a paper feeding path passing a developer unit, a fusing
unit, and a paper discharging unit in order, the cooling apparatus comprising:
a cooling fan disposed on the first side wall, on the paper feeding path between
the fusing unit and the paper discharging unit, higher than one of the developer
unit and the fusing unit with respect to the paper feeding path between the developer
unit and the fusing unit; and
an opening disposed on the second side wall, on the paper feeding path, between
the fusing unit and the developer unit, the cooling fan drawing external air from
the opening, across the fusing unit, in a direction of the paper feeding path.
21. The cooling apparatus of claim 20, wherein the image forming apparatus comprises
first and second side frames disposed both sided of the paper feeding path, and
the cooling fan is formed on the first side frame while the opening is formed on
the second side frame.
22. A cooling apparatus of an image forming apparatus having a paper feeding
path passing a developer unit, a fusing unit, and a paper discharging unit in order,
the cooling apparatus comprising:
a first side wall of the image forming apparatus, having a first opening positioned
on the paper feeding path between the developer unit and the fusing unit;
a second side wall of the image forming apparatus opposing the first side wall;
and
a cooling fan, positioned on the second side wall, on the paper feeding path,
between the fusing unit and the paper discharging unit, and drawing external air
from the first opening across the fusing unit in a direction of the paper feeding
path.
23. The cooling apparatus according to claim 22, wherein:
the second side wall has a second opening positioned between the developer unit
and the fusing unit; and
the cooling fan draws external air from the second opening across the fusing
unit.
24. A cooling apparatus of an image forming apparatus having a paper feeding
path passing a developer unit, a fusing unit, and a paper discharging unit in order,
the cooling apparatus comprising:
first and second opposing side walls of the image forming apparatus, having an
opening positioned between the developer unit and the fusing unit on one of the
first and second side walls; and
a cooling fan, positioned on one of the first and second side walls, on the paper
feeding path, between the fusing unit and the paper discharging unit, and drawing
external air from the opening across the fusing unit in a direction of the paper
feeding path.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Patent Application No. 2002-7024,
filed Feb. 7, 2002, in the Korean Intellectual Property office, the disclosure
of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrophotographic image forming apparatus,
and more particularly, to a cooling apparatus for lowering a temperature of a body
that is increased by heat generated from a fusing apparatus.
2. Description of the Related Art
A electrophotographic apparatus generally forms a latent electrostatic image
on
a photosensitive medium, such as a photosensitive belt or a photosensitive drum,
develops the latent electrostatic image with toner, and transfers the developed
latent electrostatic image to a sheet of paper to form an image.
The electrophotographic apparatus is classified into one of wet and dry electrophotographic
printers according to a kind of toner. The dry electrophotographic printer uses
powdered toner while the wet electrophotographic printer uses a liquid developer
containing volatile liquid carrier toner. The wet electrophotographic printer can
perform quality printing, compared to the dry electrophotographic printer, and
prevent damage occurring due to harmful toner dust.
FIG. 1 is a cross-sectional view of a conventional dry electrophotographic image
forming apparatus 100. FIG. 2 is a perspective view explaining an airflow
generated by a cooling apparatus 170 shown in FIG. 1.
Referring to FIG. 1, the dry electrophotographic image forming apparatus
100 includes a developer unit 120, a transfer unit 130, a
fusing unit 140, a paper supplying unit 160, and the cooling apparatus 170.
The developer unit 120 coats a latent electrostatic image formed on a
photosensitive drum 121 by a laser scanning unit 110 with a developer
supplied from a developer tank 122 to form a toner image.
The transfer unit 130 is installed so as to be disposed opposite to the
photosensitive drum 121 to rotate together with the photosensitive drum
121. A sheet of paper P is inserted between the photosensitive drum 121
and the transfer unit 130 and simultaneously, the toner image formed on
the photosensitive drum 121 is transferred to the paper.
The fusing unit 140 is installed in a paper discharging pathway and fuses
the toner image which has been transferred to the paper by the transfer unit 130
to the paper by predetermined heat and pressure.
The paper supplying unit 160 supplies the paper P, to which the toner
image will be transferred, to a transfer nip between the photosensitive drum 121,
on which the toner image has been formed, and the transfer unit 130. The
paper supplying unit 160 includes a pickup roller 161 and transfer
rollers 162 and 163. The pickup roller 161 picks up the paper
P stacked on a tray 152 supported by a spring 153 in a cassette 151
that is installed to be detached from and attached to a printer body, and supplies
the picked-up paper P into a printer body. The transfer rollers 162 and
163 transfer the paper P which has been picked up by the pickup roller 161
inside the printer body.
The cooling apparatus 170 maintains a temperature in the dry electrophotographic
image forming apparatus 100 to a predetermined temperature by lowering the
temperature increased by heat that is generated in the fusing unit 140 and
is spread around. The cooling apparatus 170 is installed on a front frame
181 (See FIG. 2) to be disposed between the fusing unit 140 and the
developer unit 120 and includes a first opening 172 and a cooling
fan 171. The first opening 172 is formed in a back frame 182
(See FIG. 2). The cooling fan 171 allows external air having a low
temperature to flow into the printer body through a second opening 173 which
is formed in a side frame 183 that is installed to be perpendicular to the
front and back frames 181 and 182.
When the cooling fan 171 operates, a pressure difference occurs in the
printer body of the dry electrophotographic image forming apparatus 100.
Due to the pressure difference, when the external air having the low temperature
flows into the printer body through the first and second openings 172 and
173, internal air whose temperature is increased by heat generated from
the fusing unit 140 is discharged outside. As a result, the temperature
in the printer body drops so as to be maintained at the predetermined temperature.
Referring to FIG. 2, the external air induced through the first and second
openings 172 and 173 by an operation of the cooling fan 171
flows in A, B, and D directions and then flows out through the cooling fan 171.
When the cooling fan 171 operates, air may flow in C and E directions
because of airflow characteristics. Heat generated in the fusing unit 140
is transmitted through C and D directions to the developer unit 120. Thus,
temperatures of the developer unit 120 and the photosensitive drum 121
are increased.
An increase in the temperature of the photosensitive drum 121 causes a
reduction of a usable period of the photosensitive drum 121. In particular,
if a temperature of toner is 55° C. or more, characteristics of toner are
changed. Thus, a density of an image quality deteriorates.
Also, due to an increase in a temperature of a waste toner storage (not shown),
toner is fused to the waste toner storage, or characteristics thereof are changed,
resulting in congelation of the toner. As a result, a load exerted on the cooling
apparatus may sharply increase and internal parts of the printer body may be damaged.
SUMMARY OF THE INVENTION
To solve the above and other problems, it is an object of the present invention
to provide a cooling apparatus of an electrophotographic image forming apparatus
which is improved so as to keep an image clear by lowering a temperature in the
electrophotographic image forming apparatus without increasing a temperature of
a developer unit.
Additional objects and advantageous of the invention 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 invention.
Accordingly, to achieve the above and other objects, there is provided
a cooling apparatus of an electrophotographic image forming apparatus including
a cooling fan and a first opening. The cooling fan emits heat in the electrophotographic
image forming apparatus to an outside of the electrophotographic image forming
apparatus, is installed in any one of two frames that are disposed opposite to
each other so as to support a fusing unit, is disposed in a direction where a sheet
of paper is discharged from the fusing unit, and allows internal air to flow out.
The first opening is formed in a frame that is disposed opposite to a frame in
which the cooling fan is installed, and allows external air to flow into the electrophotographic
image forming apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the present invention will become
more apparent and more readily appreciated from the following description of the
preferred embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a cross-sectional view of a conventional dry electrophotographic image
forming apparatus;
FIG. 2 is a perspective view explaining an airflow formed by a cooling apparatus
shown in FIG. 1;
FIG. 3 is a cross-sectional view of a dry electrophotographic image forming
apparatus having a cooling apparatus according to an embodiment of the present invention;
FIG. 4 is a perspective view explaining an airflow formed by the cooling apparatus
shown in FIG. 3; and
FIG. 5 is a perspective view explaining airflow formed by a cooling apparatus
according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiments
of the present invention, examples of which are illustrated in the accompanying
drawings, wherein like reference numerals refer to the like elements throughout.
The embodiments are described in order to explain the present invention by referring
to the figures.
FIG. 3 is a cross-sectional view of a dry electrophotographic image forming
apparatus
200 having a cooling apparatus
270 according to an embodiment
of the present invention. It is understood that the cooling apparatus
270
according to the present invention is not limited to the dry electrophotographic
image forming apparatus but can be applied to a wet electrophotographic image forming apparatus.
Referring to FIG. 3, the dry electrophotographic image forming apparatus
200 (hereinafter, referred to as an "image forming apparatus") includes
a developer unit
220, a transfer unit
230, a fusing unit
240,
a paper supplying unit
260, and the cooling apparatus
270.
The developer unit
220 coats (develops) a latent electrostatic image formed
on a photosensitive drum
221 by a laser scanning unit
210 with a
developer supplied from a developer tank
222 to form a predetermined toner image.
The transfer unit
230 is installed so as to be disposed opposite to the
photosensitive drum
221 to rotate together with the photosensitive drum
221. A sheet of paper P is inserted between the photosensitive drum
221
and the transfer unit
230 and simultaneously, the toner image formed on
the photosensitive drum
221 is transferred to the paper P.
The fusing unit
240 fuses the toner image which has been transferred to
the paper P by the transfer unit
230 to the paper P by predetermined heat
and pressure. The paper P is discharged from the fusing unit
240 to an outside
of the electrophotographic image forming apparatus
200 through a paper discharging
unit
292.
The paper supplying unit
260 supplies the paper P to a transfer nip between
the photosensitive drum
221 and the transfer unit
230. The paper
supplying unit
260 includes a is pickup roller
261 and transfer rollers
262 and
263. The pickup roller
161 picks up the paper P loaded
on a tray
252 supported by a spring
253 in a cassette
251
that is installed to be detached from and attached to a printer body, and supplies
the paper P into the printer body. The transfer rollers
262 and
263
transfer the paper P which has been picked up by the pickup roller
61 into
the printer body.
The cooling apparatus
270 lowers a temperature in the image forming apparatus
200 which is increased by heat generated in the fusing unit
240,
and includes a cooling fan
271 and a first opening
272.
FIG. 4 is a perspective view explaining an airflow formed by the cooling apparatus
shown in FIG.
3. Referring to FIGS. 3 and 4, the cooling fan
271
is installed in a front frame
281 in which one end of the fusing unit
240
is installed. The cooling fan
271 is positioned in a direction where the
paper P is discharged from the fusing unit
240 and is adjacent to a side
frame
283 which is perpendicular to the front frame
281. The paper
discharging unit
292 may be disposed on the side frame
283 or between
the side frame
283 and the fusing unit
240. The cooling fan
271
may be disposed between the fusing unit
240 and the paper discharging unit
292 or the side frame
283.
The cooling fan
271 is higher than the fusing unit
240 from the
bottom of the image forming apparatus
200. The first opening
272
is formed in a back frame
282 that is disposed opposite to the front frame
281, but it is possible to form the first opening
272 between the
developer unit
220 and the fusing unit
240.
The cooling fan
271 is installed in the direction where the paper is discharged
from the fusing unit
240, and the first opening
272 is formed in
a first frame that is disposed opposite to a second frame in which the cooling
fan
271 is installed.
In particular, it is possible that the first opening
272 is formed between
the developer unit
220 and the fusing unit
240. External air, which
flows through the first opening
272, passes through the fusing unit
240
and the cooling fan
271 to the outside of the image forming apparatus
200
so that a temperature in the developer unit
220 is not affected by heat
generated from the fusing unit
24 when a temperature in the image forming
apparatus
200 is lowered by the external air.
In this embodiment of the present invention, the cooling fan
271 is formed
in the front frame
281, and the first opening
272 is formed in the
back frame
282. However, the cooling fan
217 may be formed in the
back frame
282, and the first opening
272 may be formed in the front
frame
281.
Since air in the image forming apparatus
200 flows out with an operation
of the cooling fan
271, an internal pressure in the image forming apparatus
200 becomes lower. Thus, external air, which has an external pressure higher
than the internal pressure, flows through the first opening
272 into the
image forming apparatus
200.
The external air, which has flowed into through the first opening
272,
flows in an F direction, passes through the fusing unit
240 and the cooling
fan
272, and flows in an H direction to the outside of the image forming
apparatus
200.
Here, the external air flows out with heat generated from the fusing unit
240
and heat in the image forming apparatus
200. As a result, the temperature
in the image forming apparatus
200 drops.
FIG. 5 is a perspective view explaining airflow formed by a cooling apparatus
according to another embodiment of the present invention. Referring to FIG. 5,
a basic structure is the same as the structure shown in FIG.
4. However,
a second opening
273 is formed in the front frame
281, in which the
cooling fan
271 is installed, to be disposed opposite to the first opening
272 formed on the back frame
282.
The external air flows through the first opening
272 in the F direction
(see FIG. 4) and toward the cooling fan
271. Here, since the external air
flows through the first opening
272 to the cooling fan
271 that is
diagonal to the first opening
272, the external air may not smoothly flow
to the fusing unit
240 that is positioned toward the front frame
281.
Thus, it may be difficult to effectively discharge the heat generated by the fusing
unit
240.
Therefore, as show in FIG. 5, the second opening
273 is formed
in the front frame
281, in which the cooling fan
271 is installed,
and between the developer unit
220 and the fusing unit
240.
The external air, which has flowed through the second opening
273, flows
in a G direction, and flows out through the cooling fan
271 in the H direction.
Thus, the external air can flow throughout the fusing unit
240.
Here, it is possible that an area of the first opening
272 is wider
than that of the second opening
273. The external air flowing through the
first opening
272 in the F direction can effectively lower the temperature
in the image forming apparatus
200.
The first and second openings
272 and
273 are not limited to a
rectangular shape as shown in the embodiment of the present invention and may have
various shapes which can allow the external air to flow into the image forming
apparatus
200.
As described above, the cooling apparatus of the image forming apparatus according
to the present invention emits heat generated from the fusing unit to the outside
without affecting the temperature of the photosensitive drum and the developer
unit so as to prolong a usable period of the photosensitive drum and improve image
quality. Also, waste toner is not congealed so as to reduce a load exerted on the
cooling apparatus and the developer unit.
Although a few preferred embodiments of the present invention have been
shown and described, it would be appreciated by those skilled in the art that changes
may be made in this embodiment without departing from the principles and spirit
of the invention, the scope of which is defined in the claims and their equivalents.
*
