Patent ID: 7474322

Claim:
A multicolor image forming apparatus comprising: an ultraviolet radiation irradiator configured to irradiate ultraviolet radiation to an image display medium so as to color all types of photochromic compounds contained in a photoconductive layer; a first heater configured to temporarily heat the image display medium; a visible radiation irradiator configured to irradiate visible radiation to the image display medium, at wavelength corresponding to the maximum absorption wavelength of each of the photochromic compounds in a state of colored so as to selectively decolorize the photochromic compounds; and a second heater configured to temporarily heat the image display medium after irradiating the visible radiation, wherein the image display medium repeatedly forms a multicolor image, and the image display medium comprises: a photoconductive layer containing two or more types of photochromic compounds and an electron accepting compound; and a substrate, wherein the photochromic compounds have different maximum absorption wavelengths when colored.