IMAGE FORMING APPARATUS, DEVELOPING DEVICE, AND IMAGE FORMING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a device for image formation which use an image carrier like an amorphous silicon drum such that the volume resistivity of the surface layer is adjusted to about 109to 1014Ωcm and perform excellent image formation without causing fogging nor a decrease in image density even when two-component contact development is carried out in an alternating electric field, an image forming method, and a developing device which is provided for the image forming apparatus.

SOLUTION: The image forming apparatus has the image carrier 1 which has an electrostatic latent image formed on its surface and the developing device 4 which develops the electrostatic latent image with a developer containing a toner and a magnetic carrier carried on a developer carrier 41 having a magnetic field generating means inside at a development part where the image carrier 1 and developer face each each other in contact while a developing bias including a DC voltage on which an AC voltage is superposed is applied; and the image carrier 1 has a low-resistance layer of 109to 1014Ωcm and the developer carrier 41 has a plating coating layer formed on its surface by plating, the product σ×d of the volume resistance value σ of the developer carrier 41 and the layer thickness (d) of the plating coating layer satisfying a condition of 1×10-6Ωcm2≤σ×d≤≤1×105Ωcm2.

COPYRIGHT: (C)2004,JPO