Patent Number: 7,103,305

Title: Developing apparatus for image forming apparatus

Abstract: A developing apparatus which uses a two-component developer consisting of a toner and carrier. The ratio between the amount of the developer M1 which is drawn onto a developing sleeve and refluxes while being regulated by a doctor blade, and the amount of the developer (drawn amount) M2 which passes through the doctor blade is M1/M2<10. The toner is a negatively-charged toner. In a charge amount distribution the number of toners of -1 fc/10 .mu.m or more is 20% or less of the total number of toners.

Inventors: Koike; Takayuki (Kanagawa, JP), Takeuchi; Nobutaka (Kanagawa, JP), Iwata; Nobuo (Kanagawa, JP), Muramatsu; Satoshi (Tokyo, JP), Matsumoto; Junichi (Kanagawa, JP)

Assignee: Ricoh Company, Ltd.

International Classification: G03G 15/09 (20060101)

Expiration Date: 9/05/02018