IMAGE FORMING METHOD AND CONDUCTIVE MAGNETIC RESIN CARRIER FOR DEVELOPER

摘要

PURPOSE:To improve the electrifying characteristic of a photosensitive body and to maintain the good electrical conductivity of a developer over a long time by replenishing the amt. of developer with specific resin carrier particles meeting the amt. of the small-diameter carrier particles migrated to a photosensitive body side into the developer. CONSTITUTION:The developer consisting of the conductive magnetic resin carrier having the small-diameter carrier particle component and an insulating toner is brought into contact with the surface of the photosensitive body and while a voltage is impressed thereto, the photoconductive layer near the surface facing a developing means is irradiated with selected light from the light transmissive base side. The inside of the developer is replenished with the small-diameter carrier particles of the amt. meeting the amt. of the small-diameter carrier particles migrated to the photosensitive body side by repeating the formation of the toner images corresponding to the photoirradiation on the photosensitive body. The conductive magnetic resin carrier consists of the particles obtd. by forming conductive layers on the surfaces of carrier cores consisting of the magnetic material particulate dispersed and deposited into a binder resin and has the average grain size in a 20 to 100mum range. The grain size distribution thereof is such that the carrier particles of the grain sizes below half the average grain sizes of the carrier occupy 5 to 40wt.%.