Multicolor image forming method preventing contamination of toner on an

Abstract

A multicolor image forming method in which a plurality of latent images are sequentially formed and developed on an image carrier on top of each other on the image carrier. The second and any successive color toners are developed in a non-contact manner. A developed image on a photoconductive element is prevented from being contaminated by subsequent developing stages and toner on the photoconductive element is prevented from contaminating the developer in the subsequent developing stages by reducing the amount of toner which improperly flies between the photoconductive element and the developing stages. Such a prevention of the flight of toner can be accomplished by keeping the potential of the toner on the photoconductive element within a predetermined threshold of the voltage of the toner in the subsequent developing stages. Also, properties of the various toners can reduce the improper flight of the toner such as by controlling the relative amounts of hydrophobic SiO.sub.2 within the toners, controlling the average volume particle size of the toners, controlling the average volume particle size and the average number particle size, and controlling the voltage difference between the toner on the photoconductive element and the toner in the subsequent developing stage(s).