Patent ID: 7991319

Claim:
An image forming apparatus, comprising: a latent image carrier that carries an electrostatic latent image; a housing that stores toner inside; a toner carrier roller that is shaped approximately like a cylinder, is mounted to the housing rotatably about a rotational axis, rotates while carrying toner on a surface thereof to convey the toner to an opposed position facing the latent image carrier outside the housing, and is provided, on the surface thereof, with a plurality of convex sections which are regularly arranged in an axial direction parallel to the rotational axis and in a circumferential direction orthogonal to the axial direction and parallel to a circumferential surface of the toner carrier roller and a concave section which surrounds the convex sections; a seal member that is arranged in abutting contact with the surface of the toner carrier roller moving from the outside the housing toward the inside the housing at a position downstream of the opposed position in a rotation direction of the toner carrier roller to prevent toner leakage from the inside the housing; a moving mechanism that relatively moves the toner carrier roller relative to the seal member in the axial direction; and a controller that is adapted to control a rotation of the toner carrier roller by executing a predetermined rotation mode, has two rotation modes in which relative positions of the seal member and the toner carrier roller in the axial direction differ by an odd number multiple of half the arrangement pitch, and selectively executes either one of the two rotation modes, wherein the convex sections are arranged in the axial direction at a specified arrangement pitch, and a relative movement amount of the toner carrier roller relative to the seal member in the axial direction by the moving mechanism is equal to or larger than half the arrangement pitch.