US 6,389,245 B2 · Developing device and image forming apparatus

Abstract

A developing device includes a developer bearing member for bearing and conveying a developer having a toner and a carrier, a first magnetic pole arranged in the developer bearing member, a second magnetic pole arranged in the developer bearing member, a polarity of the second magnetic pole being opposite to a polarity of the first magnetic pole. The second magnetic pole is adjacent to the first magnetic pole and is arranged on a downstream side of the first magnetic pole in a moving direction of the developer bearing member. A regulating member regulates a layer thickness of the developer borne by the developer bearer. The regulating member is arranged in the vicinity of the second magnetic pole and a concentration detector for detecting a concentration of the toner in the developer.

Claims30

Dependent claims

A developing apparatus comprising:

a developing bearing member for bearing a developer having a toner and a carrier to convey the developer to a developing portion;
magnetic field generating means disposed in said developer bearing member for generating a magnetic field, wherein said magnetic field generating means includes a first magnetic pole and a second magnetic pole disposed adjacently to and downstream of said first magnetic pole in a moving direction of said developer bearing member, said second magnetic pole having a same polarity as said first magnetic pole;
a regulating member for regulating a layer thickness of the developer borne on said developer bearing member;
and
detecting means for detecting information corresponding to a magnetic permeability of the developer,
wherein, said regulating member is disposed in a vicinity of said second magnetic pole.

3 more elements

Dependencies are inferred from the claim text.

Developing device and image forming apparatus

Life of this patent

Developing device and image forming apparatus

Life of this patent

Abstract

Claims30