IMAGE FORMING APPARATUS

摘要

During an image formation period from a start of image formation until an end of image formation in an image forming operation for forming an image on one recording material, a developing bias application unit applies a developing bias to a developer bearing member and a supply bias application unit applies a supply bias to a developer supply member, such that, at the start of image formation, the absolute value of the developing bias is greater than the absolute value of the supply bias, and in the exact center or the latter half of the image formation period, the developing bias and the supply bias have equal potential, whereupon the absolute value of the developing bias becomes smaller than the absolute value of the supply bias, until the end of image formation.

主权项

1. An image forming apparatus forming an image on a recording material, comprising:
a developer bearing member that bears a developer and develops an electrostatic latent image formed on an image bearing member to form a developer image when a developing bias is applied thereto; a developing bias application unit that applies a developing bias to the developer bearing member; a developer supply member that is provided so as to make contact with the developer bearing member and supplies a developer to the developer bearing member when a supply bias is applied thereto; and a supply bias application unit that applies a supply bias to the developer supply member, the image forming apparatus being configured such that the developer bearing member and the developer supply member move in the same direction in a contact region where the members contact each other, wherein during an image formation period from a start of image formation until an end of image formation in an image forming operation for forming an image on one recording material, the developing bias application unit applies a developing bias to the developer bearing member and the supply bias application unit applies a supply bias to the developer supply member so that, at the start of image formation, the absolute value of the developing bias is greater than the absolute value of the supply bias, and in the exact center or the latter half of the image formation period, the developing bias and the supply bias have equal potential, whereupon the absolute value of the developing bias becomes smaller than the absolute value of the supply bias, until the end of image formation.