Patent ID: 7565099
Filing Date: 2009-07-21
Classification: G03G

Abstract:
1. A developing device comprising: a container that contains toner particles that are for developing a latent image borne by an image bearing body; and a toner-particle bearing roller that has a helical groove portion on a surface thereof that is for bearing the toner particles, the helical groove portion having an inclination with respect to an axial direction and a circumferential direction of the toner-particle bearing roller and being formed having a uniform pitch in the axial direction, wherein: the latent image includes dot-like latent images which are formed respectively in regions divided into lattices; the lattices can be formed having a plurality of types of pitches in the axial direction; and a pitch of the groove portion in the axial direction is shorter than a longest pitch among a plurality of the types of the pitches of the lattices.