Electrophotography – Internal machine environment – Particle or contaminant control
Reexamination Certificate
2003-01-03
2004-12-21
Lee, Susan (Department: 2852)
Electrophotography
Internal machine environment
Particle or contaminant control
C399S105000
Reexamination Certificate
active
06834170
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of Korean Application No. 2002-29952, filed May 29, 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 a developing apparatus of a dry electrophotographic image forming apparatus, and more particularly, to a developing apparatus having a sealing member to prevent leakage of dry toner (hereinafter referred to as toner) contained in the developing apparatus.
2. Description of the Related Art
In general, a dry electrophotographic image forming apparatus contains toner and supplies the toner to a photoreceptor medium, such as a photoreceptor drum or the like, to develop a latent electrostatic image on the photoreceptor medium. Here, the toner is minute powder having a predetermined color and has to be contained in the developing apparatus except when being adhered to the latent electrostatic image. Therefore, the developing apparatus of the dry electrophotographic image forming apparatus using toner generally has a sealing member to prevent leakage of the toner.
FIG. 1
is an exploded perspective view of a conventional developing apparatus having sealing members. As shown in
FIG. 1
, the conventional developing apparatus includes a housing
100
which contains toner, and a blade
130
and a developer roller
120
which are respectively combined with the housing
100
. The conventional developing apparatus also includes sealing members
140
which are disposed on insides
102
of right and left walls
104
of the housing
100
and closely contact the blade
130
and the developer roller
120
to prevent the toner in the housing
100
from leaking.
The developer roller
120
is coupled to couplings
101
which are prepared in the right and left walls
104
of the housing
100
, to rotate. The developer roller adheres the toner in the housing
100
onto an outer circumference thereof, and supplies the toner to a photoreceptor drum (not shown) to develop a latent electrostatic image on the photoreceptor drum.
The blade
130
is conjoined with an upper surface
103
of the housing
100
in order to longitudinally contact the outer circumference of the developer roller
120
. Thus, the blade
130
rubs against the outer circumference of the developer roller
120
that is rotating to scrape away the toner excessively adhered onto the outer circumference of the developer roller
120
so as to form a toner layer having a predetermined thickness.
Here, a length L
2
of the developer roller
120
is smaller than an inner distance L
1
between the right and left walls
104
of the housing
100
, and a length L
3
of the bladed
130
is smaller than the length L
2
of the developer roller
120
. Thus, the toner may leak through gaps between right and left ends
121
of the developer roller
120
and the insides
102
of the right and left walls
104
of the housing
100
, and gaps between the blade
130
and the insides
102
of the right and left walls
104
of the housing
100
. Therefore, in order to prevent leakage of the toner, the sealing members
140
are disposed on the insides
102
of the right and left walls
104
of the housing
100
.
Since the sealing members
140
are generally formed of a sponge material, the sealing members
140
elastically and closely contact the outer circumference of the developer roller
120
, the blade
130
, and the insides
102
of the right and left walls
104
of the housing
100
.
According to the above-described structure, when the sealing members
140
, the blade
130
, and the developer roller
120
are sequentially combined with the housing
100
, the sealing members
140
closely contact the insides
102
of the right and left walls
104
of the housing
100
, the outer circumference of the developer roller
120
, and the blade
130
. Thus, gaps between the right and left ends
121
of the developer roller
120
and the insides
102
of the right and left walls
104
of the housing
100
, and gaps between the blade
130
and the insides
102
of the right and left walls
104
of the housing
100
are blocked to prevent leakage of the toner.
As described above, the length L
2
of the developer roller
120
is smaller than the inner distance L
1
between the right and left walls
104
of the housing
100
, and the length L
3
of the blade
130
is smaller than the length L
2
of the developer roller
120
. Thus, a contact width T
2
between the blade
130
and the sealing member
140
is smaller than a width T
1
of the sealing member
140
.
FIG. 2A
is a partial perspective view of the assembled conventional developing apparatus of
FIG. 1
, and
FIG. 2
is an enlarged view of portion C of FIG.
2
A.
FIG. 3A
is a cross-sectional view along cutting plane line A-A′ of
FIG. 2A
, and
FIG. 3B
is an enlarged view of portion D of FIG.
3
A.
As shown in
FIGS. 2A
,
2
B,
3
A, and
3
B, lower portions of a front part
141
(shown in
FIG. 1
) of the sealing members
140
closely contact the outer circumference of the developer roller
120
, and upper portions of the front part
141
of the sealing members
140
closely contact an inside surface
131
(shown in
FIG. 1
) of the blade
130
by the contact width T
2
.
A lower long side part
133
of the blade
130
has a bent portion
134
, perpendicular to the long side part
133
, in order to prevent the outer circumference of the developer roller
120
from being damaged due to contact with the blade
130
. Since the bent portion
134
raises the sealing member
140
, the sealing member
140
does not contact the outer circumference of the developer roller
120
at a portion in which the bent portion
134
is formed, thereby forming a gap
160
. Reference character “a” of
FIG. 2B
represents a portion of the sealing member
140
which does not contact the blade
130
, but is pulled and deformed in a direction
145
due to a portion of the sealing member
140
that contacts the blade
130
to be compressed, thereby forming a gap
150
between the sealing member
140
and the outer circumference of the developer roller
120
. As a result of the above, the toner in the housing
100
may leak through gaps
160
and
150
.
SUMMARY OF THE INVENTION
Accordingly, it is an aspect of the present invention to provide a developing apparatus having a sealing member which prevents deterioration of the sealing member due to compression and deformation of the sealing member.
Additional aspects and advantages 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.
The foregoing and/or other aspects of the present invention are achieved by providing a developing apparatus including a housing, a developer roller, a blade, and sealing members. The housing contains toner. The developer roller is combined with the housing to rotate and adheres the toner onto an outer circumference thereof to supply the toner out of the housing. The blade controls an amount of toner that is adhered onto the outer circumference of the developer roller. The sealing members are installed on both inside walls of the housing and closely contact the housing, the developer roller, and the blade to prevent the toner from leaking out. The sealing members include a first sealing member and a second sealing member. The first sealing member has a side part that elastically and closely contacts the inside walls of the housing and a short side part of the blade, and a front part that elastically and closely contacts the outer circumference of the developer roller. The second sealing member overlaps with the first sealing member and has a front part that elastically and closely contacts an inside surface of the blade and the outer circumference of the developer roller.
According to an aspect of the invention, the second sealing member further includes a horizontal slit which is cut along a contact line with a
Choi Sam-seuk
Han Cheol-young
Lee Susan
Samsung Electronics Co,. Ltd.
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