Patent ID: 6701114
Filing Date: 2004-03-02
Classification: G03G

Abstract:
A developing device for developing a latent image formed on an image carrier, comprising:a rotatable developer carrier formed of a nonmagnetic material; and magnetic field forming means for causing, in a developing region where said developer carrier faces the image carrier, a developer made up of toner and magnetic grains to rise on said developer carrier in a form of a magnet brush; a developer case for housing said magnetic field forming means, the developer case including a first doctor member, a predoctor member, and a developer chamber between said first doctor member and said predoctor member, said predoctor member extending toward said first doctor member at a doctoring end for shaving off an upper portion of the developer such that the shaved-off developer accumulates at a position upstream of said predoctor member, and such that during operation a point of accumulation of the shaved-off developer is substantially at an upstream edge of a port defined by said predoctor member and a toner hopper; wherein in the developing region the magnet brush on a surface of said developer carrier is caused to move at a higher speed than a surface of the image carrier in a same direction as and in contact with said surface of said image carrier, thereby developing the latent image, the toner of the developer is magnetic toner, and flux density set up in the developing region outside of the surface of said developer carrier in a normal direction has an attenuation ratio of 50% or above.