Title:
IMAGE FORMING DEVICE
Document Type and Number:
Japanese Patent JP3026644
Kind Code:
B2
Abstract:
PURPOSE: To obtain a two-color image which is stable over the lapse of time by making first toner smaller than second toner and making its particle size distribution uniform.
CONSTITUTION: The toner used for a first developing device 5 is smaller than the toner used for a second developing device 8 and its particle size distribution satisfies the relationship of a mean particle size in volumetric average ≤ 1.2. A latent image formed on a photosensitive body 2 by carrying out negative exposure based on first image information by the use of a first exposure device 4 after the uniform electrification by the use of a first electrostatical changing device 3 is made to a first developed image by the first developing device 5. Thereafter, a second electrostatical charging device 6 is activated to carry out uniform electrification again from the position above the first developed image, negative exposure is carried out based on second image information by a second exposure device 7, and the second developing device 8 transsites the toner to the latent image by the application of DC bias. At this time, since the attaching of toner to the photosensitive body 2 is strengthened by the conditions of the toner in the course of the first development, the toner is hardly scattered.
More Like This:
Inventors:
Tomotoshi Nakahara
Hisao Murayama
Ichiro Komuro
Hisao Murayama
Ichiro Komuro
Application Number:
JP18117791A
Publication Date:
March 27, 2000
Filing Date:
July 22, 1991
Export Citation:
Assignee:
株式会社リコー
International Classes:
G03G9/087; G03G15/01; G03G15/09; (IPC1-7): G03G15/01; G03G9/087; G03G15/09
Domestic Patent References:
| JP6456461A | ||||
| JP63294579A | ||||
| JP63149662A | ||||
| JP2132459A | ||||
| JP2208674A | ||||
| JP63301066A | ||||
| JP3181952A | ||||
| JP2302772A |
Attorney, Agent or Firm:
Toru Kabayama (1 person outside)