Patent ID: 6782225
Filing Date: 2004-08-24
Classification: G03G

Abstract:
In a developing device comprising a plurality of developing sections each including a developer carrier that causes a developer deposited thereon to form a magnet brush and contact an image carrier, said developer carrier comprising: a rotatable nonmagnetic sleeve; and a stationary magnet roller accommodated in said sleeve and including a magnetic pole for scooping up the developer to said sleeve, a magnetic pole for conveying said developer deposited on said sleeve, and a main magnetic pole for causing said developer to rise on said sleeve in a form of the magnet brush; wherein said plurality of developing sections include at least one developing section in which a flux density of said main magnetic pole in a normal direction has an attenuation ratio of 40% or above and at least one developing section in which said flux density has an attenuation ratio of 30% or below.