Patent ID: 7738821
Filing Date: 2010-06-15
Classification: G03G

Abstract:
1. An image forming apparatus comprising a latent image carrying body having a latent image forming surface which is an outer surface of a solid figure formed by arranging a first closed curve present on a plane in a continuously and repeatedly juxtaposed fashion in a direction orthogonal to the plane and on which an electrostatic latent image corresponding to an image to be formed is formed, and developer supply means for supplying a developer charged in a predetermined polarity to the latent image forming surface so as to cause the developer to adhere to the latent image forming surface at positions corresponding to the electrostatic latent image, the image forming apparatus forming the image on a recording medium by means of the developer adhering to the latent image forming surface, wherein the developer supply means comprises: a developer carrying body having a developer carrying surface which is an outer surface of a solid figure formed by arranging a second closed curve present on the plane in a continuously and repeatedly juxtaposed fashion in the direction orthogonal to the plane and which carries the developer charged in the polarity thereon and faces the latent image forming surface in a predetermined developing area, and adapted to move the developer carrying surface such that an arbitrary point on the developer carrying surface moves unidirectionally on a locus having the same shape as that of the second closed curve; upstream developer transport means having an upstream transport surface disposed in such a manner as to face, with a predetermined distance therebetween, a portion of the developer carrying surface located upstream of the developing area with respect to a moving direction of the developer carrying surface, and adapted to form, in a space between the upstream transport surface and the developer carrying surface, upstream transport electric fields for moving the developer charged in the polarity on the upstream transport surface at a predetermined upstream transport speed from an upstream side toward a downstream side with respect to the moving direction of the developer carrying surface; and downstream developer transport means having a downstream transport surface disposed in such a manner as to face, with a predetermined distance therebetween, a portion of the developer carrying surface located downstream of the developing area with respect to the moving direction of the developer carrying surface, and adapted to form, in a space between the downstream transport surface and the developer carrying surface, downstream transport electric fields for moving the developer charged in the polarity on the downstream transport surface at a downstream transport speed higher than the upstream transport speed from the upstream side toward the downstream side with respect to the moving direction of the developer carrying surface.