1. Field of the Invention
The present invention relates to an apparatus for forming an image, such as a color laser printer.
2. Background Art
As an apparatus for forming a multicolor image, such as a four-color image, on a recording medium, such as recording paper, a tandem type apparatus has been known, which has, for each of colors, a photoreceptor, an exposing unit for exposing the photoreceptor to form an electrostatic latent image on the surface thereof, and a developing unit for developing the electrostatic latent image by attaching a charged developer on the surface of the photoreceptor having the electrostatic latent image formed thereon. A four-cycle type apparatus has also been known, which has one pair of an exposing unit and a photoreceptor, and plural developing unit for the respective colors arranged around the photoreceptor.
The four-cycle type apparatus is not suitable for speeding up the image formation because the exposing and developing steps of the photoreceptor are sequentially carried out with changing colors. In the tandem type apparatus, on the other hand, the exposing and developing steps of the photoreceptors can be simultaneously carried out for the colors, and a multicolor image can be formed by sequentially transferring the developers attached on the photoreceptors corresponding to the respective colors on a recording medium. Therefore, the tandem type apparatus for forming a multicolor image exhibits a color image forming speed equivalent to the case of a monochrome image, and is suitable for high-speed image formation.