The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 04, 2003
Filed:
Nov. 20, 2000
Shuuichi Endoh, Kanagawa, JP;
Osamu Endou, Kanagawa, JP;
Yoshihiro Abe, Chiba, JP;
Masahide Harada, Tokyo, JP;
Nobuhiko Umezawa, Kanagawa, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A developing device for an image forming apparatus of the present invention includes an image carrier performing endless movement while carrying a developer in the form of a layer thereon, and a regulating member for regulating the thickness of the layer Toner stored in the developing device is covered with an additive whose particle size is less than 2 &mgr;m. The regulating member is implemented as a doctor roller having a surface roughness Rz equal to or greater than the above particle size, but smaller than 2 &mgr;m. The doctor roller is pressed against a developing roller or developer carrier by a preselected pressure, forming a nip for development The developing device reduces irregular development ascribable to impurities caught at a regulating position assigned to the doctor roller more than a conventional developing device using a doctor blade as a regulating member. In addition, the developing device obviates irregular development in the form of fine stripes ascribable to stripe-like irregularities formed in the developer layer existing on the developing roller.