Patent ID: 8744303
Filing Date: 2014-06-03
Classification: G03G

Abstract:
1. A developing device comprising: a developer bearing member configured to bear a developer including toner and a magnetic carrier and to develop an electrostatic image formed on an image bearing member; a developing container including a developing chamber and an agitation chamber, the developing chamber being configured to store the developer to be supplied to the developer bearing member in a position where the developing chamber faces the developer bearing member and to collect the developer supplied to the developer bearing member in the position where the developing chamber faces the developer bearing member, the agitation chamber being configured to communicate with the developing chamber at both ends thereof to form a circulation path to agitate the developer; a conveyance member arranged in the developing chamber and configured to convey the developer; a first magnet member arranged in the developing container on a side of one end of the developer bearing member on a downstream side in a developer conveyance direction of the developing chamber, opposite the developer bearing member along a circumferential direction of the developer bearing member, and configured to magnetically seal the one end of the developer bearing member; and a second magnet member arranged in the developing container on a side of the other end of the developer bearing member on an upstream side in the developer conveyance direction of the developing chamber, opposite the developer bearing member along the circumferential direction of the developer bearing member, and configured to magnetically seal the other end of the developer bearing member such that a magnetic flux density formed by the second magnet member on a surface of the developer bearing member is less than a magnetic flux density formed by the first magnet member.