Electrophotography – Image formation – Development
Reexamination Certificate
1999-10-27
2002-01-08
Royer, William J. (Department: 2852)
Electrophotography
Image formation
Development
C399S240000
Reexamination Certificate
active
06337963
ABSTRACT:
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a wet image-forming apparatus, and in particular, to a wet image-forming apparatus employing a liquid developer used in an electrophotographic printer.
(b) Description of the Related Art
A conventional wet image-forming apparatus shown in
FIG. 1
includes a developing roller
11
which rotates in a direction shown by an arrow “b” for developing electrostatic latent images formed on a photoreceptor B, a developing blade
12
for removing toner particles on the developing roller
11
, a brush roller
13
a
for removing the toner particles from the developing blade
12
, a manifold
14
for supplying a liquid developer to the developing roller
11
, a reservoir
15
a
for storing the liquid developer in order to dip the brush roller
13
a
in the liquid developer during printing, a shield
17
for controlling the flow of the liquid developer, a squeezing roller
18
for removing the excessive developer on the photoreceptor B during the printing and for cleaning the photoreceptor B immediately before the stopping of the apparatus, a wiping blade
19
which is pressed against the squeezing roller
18
during the cleaning of the photoreceptor B, a squeezing support
20
which supports the squeezing roller
18
and the wiping blade
19
and shifts the vertical positions thereof with respect to the developing roller
11
, and a developing support
21
for supporting the developing roller
11
, the manifold
14
, the reservoir
15
a
and the other elements.
Because of a difference between the electrified potential of the photoreceptor B and the developing potential V
D
applied to the developing roller
11
, an electric field which is reverse to that of the exposed portion of the photoreceptor B is generated on the non-exposed portion of the photoreceptor B during the printing. The electric field causes the toner particles to adhere to the developing roller
11
in a reverse image developing process. The apparatus of
FIG. 1
has a disadvantage in that it is difficult to keep a developing gap constant, and also in that the developing roller
11
requires cleaning. For cleaning purposes, the developing blade
12
is pressed against the outer peripheral surface of the developing roller
11
to remove the toner particles, while the toner particles adhering to the developing blade
12
are removed with the brush roller
13
a
. The brush roller
13
a
is manufactured by incorporating synthetic insulating resin fibers, such as rayon and nylon, on a cylindrical member. The reservoir
15
a
is also made of an insulating material.
As described above, the toner particles adhering to the developing blade
12
are removed with the brush roller
13
a
. Accordingly, the toner particles are gradually accumulated on the brush roller
13
a.
When the accumulation of toner particles becomes excessive, the brushing roller
13
a
can no longer remove the toner particles adhering to the developing blade
12
. The developing roller
11
under these conditions cannot be sufficiently cleaned.
If the liquid developer in the reservoir
15
a
is depleted upon the completion of printing, the toner particles adhering to the brush roller
13
a
are dried and coagulated, causing an increase in torque when the brush roller
13
a
is rotated. The dried and coagulated toner particles can cause damage to the developing blade
12
in the next printing.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of the present invention is to provide a wet image-forming apparatus which prevents toner particles contained in a liquid developer from accumulating on a brush roller to overcome the above problems in the conventional art.
The present invention provides a wet image-forming apparatus including: a developing roller which rotates in a first direction for developing electrostatic latent images formed on a photoreceptor with a liquid developer; a developing blade disposed in contact with a surface of the developing roller for removing toner particles adhering to the surface of the developing roller after developing; a brush roller which rotates in the first direction for removing the toner particles from the developing blade; and a reservoir which stores the liquid developer for accommodating both of the developing blade and the brush roller to dip both in the liquid developer, wherein the developing roller, the brush roller and the reservoir are applied with a common developing voltage.
In accordance with the wet image-forming apparatus of the present invention, toner particles that adhere to the developing blade can be mechanically and electrically prevented from accumulating. Cleaning of the developing roller can be accomplished effectively because substantially the same voltages as the developing voltage are applied to the brush roller and the reservoir.
The above and other objects, features and advantages of the present invention will be more apparent from the following description.
REFERENCES:
patent: 5893012 (1999-04-01), Schubert et al.
patent: 6094553 (2000-07-01), Shima
patent: 55-71354 (1953-11-01), None
patent: 10-274885 (1998-10-01), None
Japanese Office Action issued Sep. 5, 2000 in a related application with English translation of relevant portions.
Ostrolenk Faber Gerb & Soffen, LLP
Royer William J.
LandOfFree
Toner recovery system with electrical potential separation... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Toner recovery system with electrical potential separation..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Toner recovery system with electrical potential separation... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2817882