Patent ID: 7725061
Filing Date: 2010-05-25
Classification: G03G

Abstract:
1. A developing apparatus comprising: a developer container, which contains a developer having magnetic particles; a first developer carrying member, which is rotatably disposed, and carries and transports the developer in the developer container to develop an electrostatic image formed on an image bearing member; a second developer carrying member, which is rotatably disposed in a same rotational direction as said first developer carrying member, and carries and transports the developer delivered from said first developer carrying member to develop the electrostatic image formed on the image bearing member; a first magnetic field generating member, which is disposed in said first developer carrying member, and which has a plurality of magnetic poles including at least a first magnetic pole provided in proximity to and opposite to said second developer carrying member; a second magnetic field generating member, which is disposed in said second developer carrying member, and which has a plurality of magnetic poles including a second magnetic pole, and which is provided substantially opposite to said first magnetic pole and is different in polarity from said first magnetic pole; a first magnet member, which is disposed at an axial end of said first developer carrying member, proximate to and substantially circumferentially conforming with a portion of a peripheral surface of said first developer carrying member without being opposed to said first magnetic pole; and a second magnet member, which is disposed at an axial end of said second developer carrying member, proximate to and substantially circumferentially conforming with a first portion of a peripheral surface of said second developer carrying member without being opposed to said second magnetic pole, wherein a surface of said second magnet member is disposed opposite to the peripheral surface of said second developer carrying member and has a same polarity as said second magnetic pole, at least at an end area downstream in the rotational direction of said second developer carrying member; and a magnetizable member, which is disposed at the axial end of said second developer carrying member and at least partially overlapping said second magnet member in an axial direction of said second developer carrying member, proximate to and substantially circumferentially conforming with a second portion of the peripheral surface of said second developer carrying member.