Patent ID: 6757510
Filing Date: 2004-06-29
Classification: G03G

Abstract:
A developing device comprising:a developer carrier; magnet brush forming means for causing a developer to rise on said developer carrier in a form of a magnet brush with a magnetic pole; and a developer storing member for storing the developer developed a latent image; wherein said magnet brush forming means comprises at least a first magnetic pole facing an image carrier carrying the latent image, which is to be developed by the magnet brush, and a second magnetic pole positioned downstream of said first magnetic pole in a direction of rotation of said developer carrier, and when the magnet brush formed by said first magnetic pole forms a nip between said magnet brush and the image carrier, a flux density in a direction normal to said developer carrier has an attenuation ratio of 40% or above while said second magnetic pole has an upstream half-value point located downstream of a point upstream of and angularly spaced from an edge of said developer storing member by 15Â°.