| 摘要 |
<p>PURPOSE:To attain fog-free high image density by enhancing the electrostatic chargeability of a magnetic toner in a developing unit without utilizing the triboelectric charge of both magnetic and nonmagnetic toners. CONSTITUTION:In a developer consisting of a magnetic toner (A) contg. at least a resin and a magnetic substance and a nonmagnetic toner (B) contg. at least a resin and a colorant, the nonmagnetic toner content of the developer is regulated to 0.2-5.0wt.% and the relations of 1.0 <Qa/Qb<10.0 and 0.8< Db/Da<1.2 are satisfied between the volume average particle diameters Da, Db (mum) of the toners A, B and between the amts. of electric charges Qa, Qb (muC/cm<3>) on the toners A, B. The objective developer is obtd.</p> |
