| 摘要 |
PURPOSE:To develop an electrostatic latent image low in potential to obtain a toner image high in density and image quality by using a magnetic carrier of spherical sintered ferrite particles having roughness due to primary particles on the surface, a specified median diameter, a specified apparent density, and a specified electric resistance. CONSTITUTION:The developer is composed of an electrically conductive toner and the magnetic carrier of the spherical sintered ferrite particles having roughness due to primary particles on the surface, and having a median diameter of 30-50mum, an apparent density of <=2.6g/cc, and a resistance of 6-72X10<4>OMEGA measured in the form of a magnetic brush. Since such a ferrite carrier is small in specific gravity and small in saturated magnetic flux density, the magnetic brush is soft, and a torque necessary for rotating magnets inside a sleeve, the electric characteristics of the magnetic brush can be stabilized for a long term, and an amt. of spent toner to be produced can be reduced. The use of the spherical sintered particles having roughness due to the primary particles on the ferrite surface can prevent brush marks perfectly. |
