Patent ID: 6889025

Claim:
A color image forming apparatus, comprising: a light source; a photosensitive medium having a layer to be electrically charged and upon exposure to the light source, an electric potential difference is generated at an electrically charged area of the layer; a light exposure unit converting an electrical signal of an image data to be formed to an optical signal and projecting the converted optical signal to the photosensitive medium to form an electrostatic latent image by utilizing the electric potential difference; a developing unit comprising developers each having developing rollers and toner-supplying rollers to develop the electrostatic latent image on the photosensitive medium with color toners, wherein the developers are fixed near to the photosensitive medium where each developing roller maintains a predetermined developing gap with respect to the photosensitive medium; a high voltage switching unit supplying the developing rollers and the toner-supplying rollers with a high voltage that is required during a developing operation, the high voltage being consecutively supplied to each of the developers in an order of colors where the development of the electrostatic image is performed consecutively in respective colors; and a plus voltage-supplying unit supplying the photosensitive medium with a plus(+) voltage to reduce an electric potential difference between the photosensitive medium and the developing rollers of non-operated developers during the developing operation, wherein a toner image and/or the electrostatic image of different colors formed on the photosensitive medium is not attracted to the developing rollers of the non-operated developers.