| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a toner and a developer which are used to develop an electrostatic image in a device including a hybrid non-replenishing developing system and which have characteristics carefully controlled to give the quality of almost the same printed matter as that of offset printing. SOLUTION: The developer is a mixture of carrier particles and toner particles containing one binder, at least one coloring material, and if necessary, one or more kinds of additives, and the developer has 35 to 60μC/g triboelectric charges and -0.5 to -1.0 fC/μm charge distribution (Q/D). The distribution is substantially a single peak form and the peak width smaller than 0.5 fC/μm and preferably than 0.3 fC/μm. The conductivity of the developer ranges 1×10-11 to 10×10-15 mho/cm measured at 30 V voltage. The carrier particles in the developer have preferably 65 to 90μm average particle diameter and has the grain size distribution in which <2.0% of the whole carrier particles have <38μm particle size. The ratio of the carrier diameter at the median of the volume to the toner diameter at the median of the volume is about 10:1.</p> |
