Patent ID: 6978109

Claim:
An image forming apparatus comprising: a developer carrier on which a developer is deposited in a form of a magnet brush, said magnet brush contacting an image carrier for developing a latent image formed on said image carrier, said developer carrier comprises a nonmagnetic sleeve and a magnet roller held stationary within said sleeve, said magnet roller including a magnetic pole for scooping up said developer to said developer carrier, a magnetic pole for conveying said developer, and a main magnetic pole for causing the developer to rise in a form of said magnet brush, said main magnetic pole has a flux density in a normal direction whose attenuation ratio is 40% or above, and a ratio of a distance between said image carrier and said developer carrier at a boundary of a nip for development to a distance at a position where said image carrier and said developer carrier are closest to each other is 1.5 or below.