Patent ID: 6792234
Filing Date: 2004-09-14
Classification: B82Y,G03G

Abstract:
A developing device comprising:a developer carrier configured to convey a developer, which includes toner and a magnetic carrier, deposited thereon and causing, in a developing zone, said developer to form a magnet brush with a main magnetic line of force issuing from a main magnetic pole, which is positioned inside said developer carrier, said toner being fed to an image carrier in said developing zone; a first metering member positioned upstream of the developing zone in a direction of developer conveyance and configured to regulate an amount of the developer being conveyed by said developer carrier toward said developing zone; a space configured to collect part of the developer removed by said first metering member; a toner hopper adjoining said space configured to replenish fresh toner to said developer carrier; a second metering member positioned upstream of said first metering member in the direction of developer conveyance; and a gap formed between said second metering member and said developer carrier configured to prevent, when a toner content of the developer on said developer carrier increases in order to increase a thickness of said developer forming a layer on said developer carrier, an increment of said developer carrier from passing; wherein a condition in which the developer and the fresh toner contact each other varies in accordance with the toner content of said developer present on said developer carrier for thereby varying a condition of replenishment of said fresh toner to said developer, and a peak of at least one auxiliary magnetic line of force is positioned between the developing zone and said first metering member.