PURPOSE: To obtain two colored electrostatic charge images having no clouding of colors by using coloring particles having mutually different electrostatic charging polarities, and contg. magnetic materials, and developing the electrostatic latent images of different polarities in image backing materials by the use of magnetic bias.
CONSTITUTION: Ferrite powder, a polyester resin, and a carbon black are mixed, and melted by heating. The molten mixture is ground to prepare a positive charging black developer. A negative charging red developer using iron powder, a polyester resin, and cinnabar is mixed and dispersed at an equal ratio therewith to prepare a composite developer for two colors. Electrostatic latent images (400V positive, 400V negative) are provided by positive and negative recording signals 2 on a dielectric drum 3 with an electrostatic recording stylus 1. The composite developer of two colors, black and red, is put in a magnetic brush developing device 5, and the developers are developed under the magnetic bias developed by an AC power source 12 by using AC electric fields. The polarities of the developers are unified by a corona charger 6, and the developers are transferred onto recording paper 7 by a corona charger 8 for transfer and are fixed, whereby the images of two colors having no photographic fogs are obtained.
ITAYA MASAHIKO
TANAKA MITSURU
| JPS5530625A | 1980-03-04 | |||
| JPS5659244A | 1981-05-22 |