| 摘要 |
PURPOSE:To obtain a vivid and bright image by satisfying specific conditions in the relation between the quantity of a magnetic material in a toner and the particle size of the magnetic material. CONSTITUTION:A latent image holding body holding a latent image on the surface and a toner carrier carrying an insulating toner are arranged a certain gap apart from each other in a developing part. The toner is applied to the toner carrier by a magnetic means, and this applied layer has the thickness controlled to a value smaller than the gap of the toner carrier and is carried to the developing part, and the image is developed while applying an alternating electric field to the toner carrier. In this case, the relation between wt% magnetic material quantity Y in the toner and a particle size Xmum is selected to satisfy Y<=60X<1.23> (0.01<=X<=5). As the result, a vivid and bright picture is obtained with an ultrafine magnetic material satisfying the relation. |
