Patent ID: 8103199
Filing Date: 2012-01-24
Classification: G03G

Abstract:
1. A developing device, comprising: a developing roller provided facing an image bearing member; and a toner layer thickness control member configured to control an amount of a toner adhered to the developing roller, so that an electrostatic latent image formed on the image bearing member is developed with the toner to form a toner image, wherein the following relationships are satisfied: wherein Dv (μm) represents a volume average particle diameter of the toner, Ra (μm) represents an arithmetical mean roughness of the developing roller in a longitudinal direction, Rz (μm) represents a ten-point mean roughness of the developing roller in a longitudinal direction, and RSm (μm) represents a mean length of roughness curve elements of the developing roller, and the toner has a ratio (Dv/Dn) of a volume average particle diameter (Dv) to a number average particle diameter (Dn) from 1.8 to 2.5.