Patent ID: 8649714
Filing Date: 2014-02-11
Classification: G03G

Abstract:
1. A development device comprising: a cylindrical developer bearer to carry by rotation two-component developer including toner and magnetic carrier particles to a development range where the developer bearer faces a latent image bearer to develop a latent image formed thereon; a magnetic field generator disposed inside the developer bearer for generating magnetic force; a developer regulator disposed upstream from the development range in a rotational direction of the developer bearer and facing a circumferential surface of the developer bearer across a regulation gap for adjusting an amount of the developer carried on the developer bearer; a supply compartment from which the developer is supplied to the developer bearer, the supply compartment disposed adjacent to the developer bearer and extending in an axial direction of the developer bearer; a developer agitator provided in the supply compartment for transporting the developer in the axial direction of the developer bearer; a collection compartment to which the developer is collected after the developer passes through the development range; a pre-regulation portion adjacent to and upstream from the developer regulator in the rotational direction of the developer bearer; and a developer mobility adjuster that makes mobility of the developer in the pre-regulation portion higher on an upstream side in a developer conveyance direction in the supply compartment than on a downstream side in the developer conveyance direction in the supply compartment, wherein: the magnetic field generator includes multiple magnetic poles arranged in the rotational direction of the developer bearer, the multiple magnetic poles including an attraction pole for attracting the developer from the supply compartment to the circumferential surface of the developer bearer, the attraction pole of the magnetic field generator generates an attractive magnetic flux on the circumferential surface of the developer bearer, and the developer mobility adjuster shifts a peak density position in a direction normal to the circumferential surface of the developer bearer of the attractive magnetic flux on an upstream side in the developer conveyance direction in the supply compartment to a downstream side in the rotational direction of the developer bearer.