US 7,561,838 B2
Developing apparatus featuring magnetic seal members disposed in developer delivery regions
Tomoyuki Sakamaki, Toride (Japan); and Kazukiyo Akashi, Kashiwa (Japan)
Assigned to Canon Kabushiki Kaisha, Tokyo (Japan)
Filed on Aug. 28, 2006, as Appl. No. 11/510,637.
Claims priority of application No. 2005-259969 (JP), filed on Sep. 07, 2005.
Prior Publication US 2007/0053725 A1, Mar. 08, 2007
Int. Cl. G03G 15/08 (2006.01)
U.S. Cl. 399—269 8 Claims
OG exemplary drawing
 
1. A developing apparatus, which develops an electrostatic image on an image bearing member by using a developer containing magnetic particles, said developing apparatus comprising:
a developer container, which contains the developer;
a first developer carrying member that is rotatably disposed in said developer container, and carries and transports the developer toward a first development area;
a second developer carrying member that is rotatably disposed in a vicinity of said first developer carrying member in said developer container, and carries and transports the developer delivered from said first developer carrying member in a developer delivery region toward a second development area;
a first magnetic field generating member, which is disposed in said first developer carrying member and has a plurality of magnetic poles, said first magnetic field generating member having a first magnetic pole at a position facing the developer delivery region;
a second magnetic field generating member, which is disposed in said second developer carrying member and has a plurality of magnetic poles, said second magnetic field generating member having a second magnetic pole that is different in polarity from said first magnetic pole at a position facing the developer delivery region;
a first magnet member disposed in a vicinity of an axial end of said first developer carrying member along a peripheral surface of said first developer carrying member without facing said first magnetic pole; and
a second magnet member disposed in a vicinity of an axial end of said second developer carrying member along a peripheral surface of said second developer carrying member without facing said second magnetic pole, a surface facing said second developer carrying member in a downstream end area of said second magnet member in a rotating direction of said second developer carrying member being identical in polarity with said second magnetic pole.