Patent ID: 8548364
Filing Date: 2013-10-01
Classification: G03G

Abstract:
1. A developing device comprising: a magnetic field generating unit that generates a magnetic field; and a cylindrical developer holder, to which a voltage is applied, that surrounds the magnetic field generating unit and rotates, the cylindrical developer holder: having an outer circumferential surface having a plurality of grooves that extend in a direction of a rotational axis, the outer circumferential surface being capable of holding developer including a magnetic substance by using the magnetic field generated by the magnetic field generation unit, an electrical resistance of an inner wall surface of each of the grooves being higher than an electrical resistance of the magnetic substance included in the developer; and supplying the developer to an image holder that holds an electrostatic latent image, wherein an anodizing film is formed on the inner wall surface, and the anodizing film is not formed on a surface of a part of the developer holder other than the plurality of grooves.