JPS60247265A - Two-color electrophotographic printing method - Google Patents

Abstract

PURPOSE:To maintain 2-color toner images correct without being affected by each other by setting the ratio of an amt. of the first developing toner to be electrostatically charged to that of the second toner to the prescribed range in the 2-color electrophotographic process. CONSTITUTION:The ratio of an amt. X1, of the first developing toner to be electrostatically charged to that X2 of the second toner is set to the range of X1/ X2=1.5-10 in the 2-color electrophotography. Since the charged amt. X1 of the first toner is large, the first toner adheres fastly, it is never dropped off by the attachment of the second toner of opposite polarity.

Description

Detailed Description of the Invention (a) Technical field The present invention relates to an electrophotographic apparatus, particularly an electrophotographic apparatus that exposes and develops a plurality of images on a drum or belt-like photoreceptor and transfers them to a transfer material such as paper. It relates to a printing method and is used, for example, in two-color electrophotography.

(b) Prior Art In the conventional electrophotographic printing method, one light source and one photoreceptor are used for one image exposure.

When converting a multicolor electronic filter'L°1 to rt F 2+, prepare 5 light sources and photoreceptors for the number of colors and sequentially overlay the colors, or expose the photoreceptor to light.・By repeating the process of developing and transferring to the transfer material as many times as necessary, the colors are applied over and over to obtain the desired multicolor electrophotograph.In this conventional method, the toner is fixed for each color, so
Even if each type of toner has the same amount of charge, there is a particular problem) 4 Nakatsu L:. However, the first problem with this method is that it is difficult to accurately superimpose images and it takes a long time to process! Recently, a method has been developed in which toners of different colors with different polarities are developed one after another on a photoconductor, which is made by sequentially laminating a photoconductive layer and an insulating layer on the surface of a conductive support, and then the transfer is carried out all at once. is about to be put into practical use. However, if toners with the same charge amount as conventional ones are used in such multicolor electrophotography, the image of the initially ordered (first color) toner will be replaced by the toner image developed next (second color). It has been found that the disadvantage is that the image is affected by the image and is stripped off, destroying the image.

(C) Purpose of the Invention The present invention provides a method for developing two color toners sequentially on one multilayer photoreceptor without the toners influencing each other.
An object of the present invention is to provide a two-color electrophotographic printing method that can correctly retain images.

(d) Structure of the present invention In order to achieve this object, the printing method of the two-color electrophotographic device of the present invention includes a photoconductive layer on the surface of a conductive support.
A two-color electronic system in which image signals of two colors are sequentially formed on a photoreceptor formed by sequentially laminating insulating layers, and a first developing toner and a second developing toner are sequentially adsorbed onto the photoreceptor and then transferred. In the photograph, when the charge amount of the first developing toner is x1 and the charge amount of the second developing toner is x2, Xl/X2 is set to 1.5 to 10. .

(Small) Function of the present invention The first development which is developed first among the image signals having two polarities formed on the photoreceptor formed by sequentially laminating a photoconductive layer and an insulating layer on the surface of the conductive support. Since the toner has a large amount of charge, it adheres firmly to the photoreceptor. The second one is developed later.
Since the amount of charge of the developing toner is 1/1.5 to 1/10 smaller than that of the first developing i-toner, it can be applied to the photoreceptor without stripping off the first developing toner of the opposite polarity that has previously adhered. is absorbed on top.

(g) Effects of the present invention As explained in detail above, in the present invention, two colors with different polarities are adsorbed onto a photoreceptor formed by successively laminating an insulating layer on the light guide side on the surface of a conductive support. Among the toners, the first developed toner that is attracted first has a larger amount of charge and therefore adheres firmly to the photoreceptor, while the second developed toner that is developed later has a smaller amount of charge, so the second developed toner of the opposite polarity adheres to the photoreceptor. 1 Since the developed toner is adsorbed onto the photoreceptor without peeling it off, each image is correctly retained, making clear two-color printing possible.

Patent applicant: Japan Steel Works, Ltd. Representative: Manko Tateno 5-

Claims (1)

[Claims] Image signals of two colors are sequentially formed on a photoreceptor formed by sequentially laminating a photoconductive layer and an insulating layer on the surface of a conductive support, and a first developing toner and a second developing toner are used. In two-color electrophotography in which images are sequentially adsorbed onto a photoconductor and then transferred, when the charge amount of the first developing toner is ×1 and the charge amount of the second developing toner is ×2, Xi /X2 = A two-color electrophotographic printing method characterized in that the setting is from 1.5 to 10.