START DEVELOPER AND IMAGE FORMING APPARATUS USING THE SAME

PROBLEM TO BE SOLVED: To provide a start developer, capable of forming a clean thin layer more uniform in thickness and free of defects on a surface of a developer carrier, when it is supplied first to an empty developing device in an image forming apparatus adopting a magnetic one-component developing method and operation is started, and to provide an image forming apparatus that uses the start developer. SOLUTION: The start developer includes a first magnetic toner T1 whose charge amount, in a state with its being held on the surface of the developer carrier is 3.5-8.0 μC/g and a second magnetic toner T2 whose charge amount in the above state is 1.0-3.0 μC/g in the T1 to T2 weight ratio range of 95:5 to 98:2. The image forming apparatus uses a developer carrier, having a ten-point average surface roughness Rz of 2.0-6.0 μm as a developer carrier on which a thin layer is formed first with the start developer. COPYRIGHT: (C)2006,JPO&NCIPI