US Patent 7277649 Developing apparatus and image forming method

A developing apparatus for developing an electrostatic image with light chromatic toner and dark chromatic toner which have the same hue, the developing device includes a light color developing device for accommodating a developer containing the light chromatic toner and carrier to develop the electrostatic image; a dark color developing device for accommodating a developer containing the dark chromatic toner and carrier to develop the electrostatic image; light color developer supply container accommodating a developer containing the light chromatic toner and the carrier to be supplied to the light color developing device; and dark color developer supply container accommodating a developer containing the dark chromatic toner and the carrier to be supplied to the dark color developing device, wherein the developer in the light chromatic toner supply container and the developer in the dark chromatic toner supply container have carrier weight ratios which are different from each other.