Electrophotography – Image formation – Development
Reexamination Certificate
2000-03-02
2001-03-27
Moses, Richard (Department: 2852)
Electrophotography
Image formation
Development
C399S238000, C399S057000, C347S084000
Reexamination Certificate
active
06208822
ABSTRACT:
This application is based on Japanese Patent Applications Nos. 11-55297 and 11-105139 filed in Japan on Mar. 3, 1999, and on Apr. 13, 1999, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid material supplier for causing a liquid material, such as ink, to be held in a uniform thin layer on a surface of a liquid material holding member, such as a roller or belt, and to an image forming apparatus having the liquid material supplier incorporated therein.
2. Description of Related Art
A printer, an image forming apparatus, or the like using a liquid material such as a liquid ink is so constructed as to form the liquid ink adhering to a rotating roller as a liquid material holding member into a uniform thin layer by using a regulating blade, transfer the thin layer onto a form plate or an image carrying member, and then scrape the ink remaining on the rotating roller therefrom by using a removing blade.
FIG. 10
shows a conventional ink supplier
2
using such a removing blade. The ink supplier
2
comprises a container
4
for containing ink
6
. The ink
6
is supplied from an ink cartridge
8
to the container
4
. In the upper part of the container
4
, a roller
14
which rotates around a shaft
10
extending perpendicularly to the paper surface and in the direction indicated by the arrow
12
in the drawing is disposed such that the lowermost portion
16
of the roller
14
underlies an ink liquid level
18
, i.e., a part of the roller
14
is constantly immersed in the ink
6
. On the side portion of the roller
14
, a regulating blade
20
composed of a plate-like elastic member is provided fixedly. The regulating blade
20
protrudes generally tangentially to the roller
14
and downstream in the direction of rotation of the roller
14
to be in contact with the roller
14
. Another roller
22
is provided over the roller
14
in a contact relationship with the roller
14
. On the side portion of the roller
14
, there is further provided a removing blade
28
in a contact relationship with the roller
14
at a position downstream of a contact portion
24
with the regulating blade
20
and a contact portion
26
with the other roller
22
in the direction of rotation of the roller
14
. The removing blade
28
is formed of a single plate-like elastic member and directed generally tangentially to the roller
14
and upstream of the roller
14
in the direction of rotation of the roller
14
.
Next, a description will be given to the operation of the ink supplier
2
with reference to FIG.
10
. The ink
6
adhering to the surface of the roller
14
below the ink liquid level
18
is pumped up with the rotation of the roller
14
to reach a tip portion
24
of the regulating blade
20
. The ink
6
receives a given pressure from the tip portion
24
of the regulating blade
20
, whereby the surplus ink
6
is scraped off and removed by the regulating blade
20
and a thin layer of the ink
6
having a desired uniform film thickness in accordance with the tip pressure of the regulating blade
20
is formed on the surface of the roller
14
. Thereafter, the tin-film ink
6
is transferred, i.e., supplied to the surface of the other roller
22
rotating in the opposite direction (rotation indicated by the arrow
32
) to the roller
14
, while keeping contact with the roller
14
, at the contact portion (supply position)
26
. After that, the ink
6
remaining on the surface of the roller
14
reaches the tip portion
30
of the removing blade
28
. Since the tip portion
30
of the removing blade
28
is in contact with the roller
14
, while being oriented in such a direction (direction indicated by the arrow
12
) as to collide with the direction of rotation of the roller
14
, the remaining ink
6
is scraped off by the tip portion
30
to return into the container
4
. Accordingly, the ink
6
does not remain on the surface of the roller
14
after it has passed through the tip portion
30
of the removing blade
28
.
The refreshed surface of the roller
14
from which the remaining ink
6
has been scraped is immersed again in the liquid ink
6
by the rotating operation of the roller
14
to be prepared for another transfer to the roller
22
, i.e., another ink supply. In the ink supplier
2
with the conventional structure, therefore, the thin layer of the ink
6
is constantly formed on the surface portion of the roller
14
lying between the position
36
at which the roller
14
emerges from the ink liquid level and the position at which the surface of the roller
14
comes in contact with the tip portion
30
of the removing blade
28
regardless of whether an ink supply operation is being performed or halted. This particularly presents a problem when the time interval between the halting of the ink supply operation and the initiation of the subsequent ink supply operation is long. This is because the layer of the ink
6
dries during the long period of time and tends to stick to the surface of the roller
14
and there may be cases where an ink supply from the roller
14
to the roller
22
is not effected as desired due to the stuck ink
6
in the subsequent ink supply operations, with the result that a formed image is disturbed.
On the surface portion of the roller
14
lying between the regulating blade
20
and the removing blade
28
in the direction of rotation of the roller
14
, the ink is thinly spread out to have a large contact area with an outer atmosphere so that such drying is especially likely to occur.
OBJECT AND SUMMARY
It is therefore an object of the present invention to provide an improved liquid material supplier and an image forming apparatus comprising the same, whereby the foregoing problems are solved.
Another object of the present invention is to provide a liquid material supplier capable of effectively preventing a liquid material, such as ink, held on a surface of a liquid material holding member from drying and an image forming apparatus comprising the same.
The foregoing objects are attained by providing a liquid material supplier and an image forming apparatus comprising the same, the liquid material supplier comprising:
a liquid material holding member for holding a liquid material on a surface thereof, the liquid material holding member being rotatable in a predetermined direction and supplying, during rotation, the liquid material to a member to be supplied at a given supply position;
a driver for driving and rotating the liquid material holding member in the predetermined direction;
a supply station for supplying the liquid material to the surface of the liquid material holding member;
a regulating member for regulating the liquid material on the liquid material holding member to a specified thickness, the regulating member being disposed at a position downstream of the supply station and upstream of the supply position in the direction of rotation of the liquid material holding member;
a removing member for removing the liquid material from the surface of the liquid material holding member; and
a controller for selectively effecting a supply mode for supplying the liquid material from the liquid material holding member to the member to be supplied or a removal mode for removing the liquid material from the surface of the liquid material holding member.
In the supplier, the removing member may also be disposed at a position downstream of the supply station and upstream of the regulating member in the direction of rotation of the liquid material holding member. In this case, the controller preferably controls the removing member such that the removing member is brought away from the surface of the liquid material holding member in the supply mode and into contact with the surface of the liquid material holding member in the removal mode. More preferably, the removing member is disposed adjacent the supply station.
In the supplier, the controller may also control the driver such that the liquid material holding member is rot
Kitoba Utako
Sasai Kosuke
Takeda Katsuhiko
McDermott & Will & Emery
Minolta Co. , Ltd.
Moses Richard
LandOfFree
Liquid material supplier and image forming apparatus... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid material supplier and image forming apparatus..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid material supplier and image forming apparatus... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2511438