Developing device and image forming apparatus including the same
AssigneeRicoh Company, Ltd.
InventorsNobutaka Takeuchi, Kenzo Tatsumi
Life of this patent
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Abstract
In a developing device for an image forming apparatus of the present invention, a main magnetic pole for development has an angle of 60° or below between opposite pole transition points respectively positioned upstream and downstream thereof in a direction of developer conveyance. A flux density between the main magnetic pole and the magnetic pole downstream of the main magnetic pole in the normal direction has a peak value that is 80% of the maximum flux density of the main pole in the normal direction or above. With this configuration, it is possible to reduce various defective images at the same time.
Claims12
In a developing device comprising a developer carrier facing an image carrier, which carries a latent image thereon, via a gap to thereby form a developing zone between said developer carrier and said image carrier, said developer carrier comprising a main magnetic pole for development and magnetic poles respectively positioned upstream and downstream of said main magnetic pole in a direction of developer conveyance for conveying a developer, said developer forming a magnet brush on a surface of said developer carrier,
- said main magnetic pole has an angle of 60° or below between opposite pole transition points respectively positioned upstream and downstream of said main pole in said direction of developer conveyance, and
- a flux density between said main magnetic pole and the magnetic pole downstream of said main magnetic pole in a normal direction has a peak value that is 80% of a maximum flux density of said main pole in said normal direction or above.
In an image forming apparatus comprising a developing device comprising a developer carrier facing an image carrier, which carries a latent image thereon, via a gap to thereby form a developing zone between said developer carrier and said image carrier, said developer carrier comprising a main magnetic pole for development and magnetic poles respectively positioned upstream and downstream of said main magnetic pole in a direction of developer conveyance for conveying a developer, said developer forming a magnet brush on a surface of said developer carrier,
- said main magnetic pole has an angle of 60° or below between opposite pole transition points respectively positioned upstream and downstream of said main pole in said direction of developer conveyance, and
- a flux density between said main magnetic pole and the magnetic pole downstream of said main magnetic pole in a normal direction has a peak value that is 80% of a maximum flux density of said main pole in said normal direction or above.
Dependencies are inferred from the claim text.