PURPOSE: To form a high-definition image without unevenness, roughness and fogging by forming a thin layer of toner particles having nearly spherical shape which perform triboelectrification on a developer carrier with a blade and making the toner fly to an electrostatic image carrier with DC electric field.
CONSTITUTION: The toner 28 in a developing device 27 is non-magnetic one component and it is obtained by adding additives such as silica to the spherical toner particles whose mean particle size is about 15 μm. It is conveyed to a stirring blade 31 and sprinkled on the developer carrier 29 at every fixed period. While the toner is electrostatically charged to be positive by a rubber blade 30 with the rotation of the carrier, the uniform thin layer of one or two layers is formed of the toner. When the thin layer comes to a position opposed to a photosensitive body 21, the toner is made to fly with the DC voltage applied between the carrier 29 and the toner layer to develop a latent image on the drum 21. Since the toner layer is extremely uniformly formed concerning electrostatic condition and layer thickness, the image which is very faithful to the latent image is obtained only with the DC electric field.
TAKASHIMA YUJI
KUNISHIGE HIDENORI
HAYASHI KAZUMASA
