Patent ID: 7027761
Filing Date: 2006-04-11
Classification: G03G

Abstract:
1. A developer carriers, comprising: a developing sleeve for carrying and transporting a developer; and a magnetic roll disposed within said developing sleeve having a plurality of magnetic poles, wherein a width of a development pole forming a magnet brush to raise the developer in a developing region facing a latent image carrier is narrowed, a rising region of said developer in said developing region is narrowed to realize a narrow development nip, and a flux density attenuation ratio of said development pole is 40% or more, and a half-value width of a flux density of said development pole is 22° or less, and a flux density variation rate in a circumferential direction is 4.0 mT/Deg or more in a part where the flux density in at least half of a downstream side of a developer carrying direction from a peak magnetic force position of said development pole is 90% or less.