| 摘要 |
PURPOSE:To obtain the developer which forms images of a high density and is free from carrier attraction even if a toner having a low electrical conductivity is used by selecting the grain size distribution of the magnetic carrier at a specific value. CONSTITUTION:This developer is constituted of the toner having <=3.0 to 10<-10>s/cm electrical conductivity and the carrier in which 50% diameter of the weight average grain size is in an 80 to 100mum range, the difference in the grain size between 25% diameter D25 of the weight average grain size and 75% diameter D75 of the weight average grain size satisfies a 5 to 20mum range and the grain size distribution of <=250 mesh is adjusted to <=8wt.%. The developer to be used under the conditions of <1mm spacing between an image carrying member and a developer carrying member and <=500V developing potential difference is obtd. in this way. The high-density color images are thus obtd. without generating the carrier attraction, etc., of the developer even when the toner having the lower electrical conductivity is used. |
