| 摘要 |
PURPOSE:To obtain a developer not causing an abnormal image by using a developer of a mixture comprising high-resistivity magnetic toner particles containing fine magnetic particles and conductive magnetic particles each consisting of a core and a conductive layer coating the core, and rendering the volume average particle diameter of the conductive magnetic particles smaller than that of the toner particles. CONSTITUTION:The volume average particle diameter of the conductive magnetic particles 5b is made smaller than that of the magnetic toner particles 5a, and the particles 5b to be used are made by forming the coating layer having a resistivity of a specified value or lower, on the surface of each core, such as magnetite, thus permitting localization of the toner particles 5a, such as coating the particles 5b with the particles 5a, and magnetic aggregation of the particles 5b, to be prevented, and the obtained developer to prevent abnormal images, such as white spots, white bands, and whitening due to lack of the toner occurring on the ends of black solids. |
