JPS572047A - Two color electrostatic recording method - Google Patents

Abstract

PURPOSE:To obtain a two color toner image which is free from color mixture, by reversely developing the first electrostatic latent image as a negative latent image, and normally developing the second electrostatic latent image as a positive latent image, so that a toner of the second developing agent does not adhere to a residual image of the first electrostatic latent image. CONSTITUTION:In case of recording a printed matter consisting of different colors, such as a slip, etc. having ruled lines, data, etc., the surface of a photoconductive substance 15 on a substrate 14 is equally charged by a charger 16. Subsequently, the first electrostatic latent image is formed by negative-exposing by the first light beam 17, and it is reversely developed by the first toner 18 which has been positively charged. Subsequently, positive exposure is executed by the second light beam 19, and it is normally developed by the second toner 20 which has been negatively charged. For instance, the first laser beam from a laser light source 6 is irradiated to a photoconductive drum 1, an information signal is modulated by a light modulator 7, it is polarized by a rotary mirror 8, scanned and exposed through a lens 9, a negative latent image is formed, and is reversely developed by a developing device 21. Subsequently, a format film 3 is positive-exposed by the second light beam 19 and is developed. In this way, a picture which is free from color mixture of two color toners 18, 20 is transferred on a recording paper 11.