Electrophotography – Image formation – Development
Reexamination Certificate
2002-09-18
2004-03-02
Lee, Susan S. Y. (Department: 2852)
Electrophotography
Image formation
Development
C399S240000
Reexamination Certificate
active
06701111
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Application No. 2002-1886, filed Jan. 12, 2002, in the Korean Industrial 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 liquid image developing system, and more particularly, to a liquid image developing system having a simplified structure using a high-concentration developer.
2. Description of the Related Art
In general, liquid image developing systems form an electrostatic latent image corresponding to a desired image by scanning light on a photosensitive body, developing the electrostatic latent image using a developer in which powder-shaped toner is mixed with a liquid solvent, and printing the developed electrostatic latent image on a paper.
FIG. 1
is an example of a conventional image developing system, disclosed in U.S. Pat. No. 5,255,058. As shown in
FIG. 1
, the conventional image developing system includes a photoconductive drum
10
charged at a predetermined voltage by a photoconductor charging apparatus
14
, and an imaging apparatus
16
(i.e., a laser scanning apparatus) to form an electrostatic latent image of a desired image by scanning light onto the charged photoconductive drum
10
and creating a relative voltage difference. The image developing system also includes a developer supplying unit to develop the electrostatic latent image by supplying a developer to the photoconductive drum
10
, and an intermediate transfer member
30
to transfer the developed image onto the photoconductive drum
10
and print the transferred image onto a paper
72
.
The developer supplying unit prepares the developer with a toner concentration of less than 3% solid and supplies the developer between the photoconductive drum
10
and a development roller
38
. For this purpose, the developer supplying unit includes concentration cartridges
82
and
84
containing a concentrated developer with a toner concentration of 25% solid, a solvent cartridge
86
containing pure solvent, and toner reservoirs
55
,
57
,
59
, and
61
to mix the concentrated developer from the concentration cartridges
82
and
84
with the solvent from the solvent cartridge
86
and preparing a developer with a uniform concentration of about 2-3% solid. The developer supplying unit further includes a multicolor liquid developer spray assembly
20
to pump the developing solvent prepared in the toner reservoirs
55
,
57
,
59
, and
61
to pumps
90
,
92
,
94
, and
96
, respectively, and to supply the developer to the development roller
38
, and a collecting unit to collect excess developer left after the electrostatic latent image is developed. In addition, the collecting unit includes a collection container
50
to collect the developer supplied between the development roller
38
and the photoconductive drum
10
and to return the developer to the toner reservoirs
55
,
57
,
59
, and
61
for each color, and a squeeze roller
26
to impress the photoconductive drum
10
on which the image is developed, and to squeeze the solvent contained in the developed image. The collecting unit further includes a separator
66
to collect the squeezed developer through the collection container
50
, to separate color toner from the collection container
50
and to return the solvent to a solvent reservoir
65
.
In the above structure, in order to perform a development operation, a developer having four colors, such as yellow (Y), magenta (M), cyan (C), and black (K), with a toner concentration of about 2-3% solid, is provided in the toner reservoirs
55
,
57
,
59
, and
61
. Of course, in the case of a system developing a single color, such as black, only one developer is required. In order to prepare a developer for each color, the developer supplying unit fabricates a developer with a corresponding concentration by supplying the concentrated developer and the pure solvent from the concentration cartridges
82
and
84
and the solvent cartridge
86
to the toner reservoirs
55
,
57
,
59
, and
61
, respectively. For this purpose, each of the toner reservoirs
55
,
57
,
59
, and
61
measures the concentration of the developer that is mixed according to a concentration sensor (not shown). Likewise, when the developer is prepared, the development operation begins. First, the photoconductor charging apparatus
14
charges the photoconductive drum
10
to a predetermined potential. In this state, the imaging apparatus
16
scans light on the charged photoconductive drum
10
to form an electrostatic latent image of a desired image. Subsequently, the pumps
90
,
92
,
94
, and
96
operate such that the developer provided in the toner reservoirs
55
,
57
,
59
, and
61
is supplied between the development roller
38
and the photoconductive drum
10
through the multicolor liquid developer spray assembly
20
, thereby forming the electrostatic latent image. The developed image is transferred to the intermediate transfer member
30
and is printed directly onto the paper
72
if the developed image is formed of only one color. However, if a color image is implemented by overlapping a developer having a plurality of colors, the charge, exposure, and development operations are repeated for each of the colors. For example, if there are four colors, such as yellow (Y), magenta (M), cyan (C), and black (K), the developed image for each color is overlapped on the intermediate transfer member
30
. The overlapped color image is printed onto the paper
72
passing through a space between the intermediate transfer member
30
and an impression roller
71
.
However, the structure of the system in the operations from preparing the developer to supply and collect the developer is considerably complicated. For this reason, a concentrated high-concentration developer cannot be directly used in the development operation, and instead a low-concentration developer (less than 3% solid) is used in the development operation. If the developer with a low concentration is used, mobility is improved, and thus a difference in density of toner throughout the image is reduced. However, as described above, the concentrated developer and solvent in each of the cartridges
82
,
84
, and
86
, are sent to the toner reservoirs
55
,
57
,
59
, and
61
, and mixed with a developer with the low concentration, and thus an electrostatic latent image is developed having the developer with a low concentration. Then, the solvent contained in the developed image is squeezed and collected so that the developer has a high concentration suitable for printing. To make things worse, the size and cost of embedded devices further amplify the problems of this complicated structure.
Thus, in order to solve these problems, a new image developing system is required.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a liquid image developing system having an improved structure in which a high-concentration developer is smoothly used in a development operation without requiring squeezing.
Additional objects 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 other objects of the present invention are achieved by providing a liquid image developing system, including a development container to store a developer having a charge; a photosensitive body; a development roller partially soaked in the developer in the development container and to rotate to form a development nip with the photosensitive body; a depositing portion to attach the developer to a surface of the development roller; a metering portion to regulate the developer attached to the development roller at a uniform thickness at a first end of the development nip; and a cleaning portion to clean the surface of the development roller at a second end of the development nip; wherein the cleaning p
Kim Jong-woo
No Kwang-ho
Park Woo-young
Lee Susan S. Y.
Samsung Electronics Co. LTD
Staas & Halsey , LLP
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