Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Post imaging process – finishing – or perfecting composition...
Reexamination Certificate
1998-01-14
2001-04-10
Rodee, Christopher D. (Department: 1753)
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Post imaging process, finishing, or perfecting composition...
C430S110100
Reexamination Certificate
active
06214512
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming method including the steps of developing an electrostatic latent image and transferring a toner image onto a belt transfer body.
2. Description of the Related Art
As conventional methods of visualizing an electrostatic latent image formed on a photoconductive photoreceptor or the like by using toner in the electrophotographic method, for example, a magnetic brush method described in U.S. Pat. No. 2,874,063, a cascade method described in U.S. Pat. No. 2,618,552, the powder cloud method described in U.S. Pat. No. 2,221,776, etc. have been known. Meanwhile, in cases where a multi-color image is obtained by the electronic needling method, a method in which colors are superposed successively for each color by repeating the charging, exposure, development and cleaning processes is used. In this method, a multi-color image is formed on a transfer drum having a drum shape, and thus the problem arose of the apparatus to house the drum. In order to solve this problem, making the image forming apparatus smaller has been attempted by using a flexible belt-shaped transfer body (hereinafter, referred to as “belt transfer body”).
As a developer for developing an electrostatic latent image using the electrophotographic method, a two-component developer composed of a toner and a carrier is often used. Various carriers are used in the two-component developer, typical examples being an electroconductive carriers such as iron oxide powder, and coat-type insulating carriers. Further, a toner, which is obtained by mixing a coloring material with a thermoplastic resin is generally used. Furthermore, various organic and inorganic fine powders added as additives give process adaptability by improving flow, charge, and cleaning properties, and the like. Examples of powders proposed for this use include fine powders of silicon oxide (silica), titanium oxide, alumina, and tin oxide. In particular, titanium oxide fine powder has been frequently used in recent years because of its excellent environmental reliability, electric charge exchangeability, and flowability when added to the toner externally.
In recent years, longer life of the developer is desired. Therefore, in order to lower non-electrostatic adhesion between the toner and carrier, and prevent contamination of the carrier by the toner, it is suggested that the surface of the carrier be coated with a fluorine-containing resin so that the life of the developer may be lengthened.
Further, the need for high image quality has increased in recent years, and thus various improvements in image forming apparatuses and developers have been tried in order to satisfy such needs. An image forming apparatus includes development, transfer, cleaning, and fixing process, but particularly in the transfer process, an image is deteriorated remarkably, and in an image forming apparatus using a belt transfer body, a sufficiently high image quality has not been yet obtained. Moreover, when an image is copied on plural sheets of paper with a low image density, the developer deteriorates, and thus problems arise such as the transfer efficiency being lowered.
SUMMARY OF THE INVENTION
The present invention solves the aforementioned problems. Namely, it is an object of the present invention to provide an image forming method which is capable of suppressing image deteriorations such as scattering of toner and unsatisfactory dot reproducibility occurring in the transfer process using a belt transfer body, as well as suppressing unsatisfactory transfer due to copying an image onto plural sheets of paper with a low image density, and lowering of transfer efficiency, and of obtaining a stable, high image quality even over a long period of use.
The inventors finished the present invention after making an examination to solve the aforementioned problems of the conventional technique. Namely, the present invention provides an image forming method having the steps of developing an electrostatic latent image on an electrostatic latent image carrying member using a toner layer on a developer carrying member, transferring the developed toner image onto a belt transfer body which is a first transfer body, and transferring the toner image formed on the belt transfer body onto a second transfer body. The image forming method is characterized in that surface resistance of the belt transfer body is 10
8
to 10
15
&OHgr;·cm, and the toner is composed of at least resin particles containing a binding resin and coloring material, and an additive, and the additive contains particles whose volume resistance of is 10
7
to 10
13
&OHgr;·cm.
REFERENCES:
patent: 2221776 (1940-11-01), Carlson
patent: 2618552 (1952-11-01), Wise
patent: 2874063 (1959-02-01), Greig
patent: 4859716 (1989-08-01), Ibsen et al.
patent: 4933251 (1990-06-01), Ichimura et al.
patent: 5429902 (1995-07-01), Saito et al.
patent: 5572304 (1996-11-01), Seto et al.
patent: 5778291 (1998-07-01), Okubo et al.
patent: 6-202428 (1994-07-01), None
patent: 8-211755 (1996-08-01), None
Ichimura Masanori
Imai Takashi
Ishihara Yuka
Takano Hiroshi
Fuji 'Xerox Co., Ltd.
Oliff & Berridg,e PLC
Rodee Christopher D.
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