Color toner for electrophotography, and a combined set of color toners for electrophotography using the same, color developing agent for electrophotography using the same, method for forming color images using the same, and device for forming color images using the same

A method for forming color images comprising:

• a step for forming an electrostatic latent image on an electrostatic latent image carrier;
• a step for developing the electrostatic latent image by using a color toner for an extreme bottom layer and a color toner for an upper layer so as to form a visible image on the electrostatic latent image carrier;
• a step for transferring the visible image on the electrostatic latent image carrier onto a recording medium for forming a combined transferred image which comprises a multiple layers, and an extreme bottom layer of the multiple layer is disposed on the recording medium;
• and
• a step for flash fixing the combined transferred image;
• wherein the color toner for electrophotography comprises a coloring agent and an infrared ray absorbent and exhibits contrast ratio of 35% to 95% and used in an extreme bottom layer of a multi-color image formed by laminating at least two types of toners selected from black toner, magenta toner, yellow toner, and cyan toner.

An apparatus for forming color images comprising:

• an electrostatic latent image carrier;
• means for forming an electrostatic latent image on the electrostatic latent image carrier;
• means for developing the electrostatic latent image using a color toner for electrophotography;
• means for transferring the visible image onto a recording medium;
• and
• means for flash fixing the image transferred onto the recording medium;
• wherein the color toner for electrophotography comprises a coloring agent and an infrared ray absorbent and exhibits contrast ratio of 35% to 95% and used in an extreme bottom layer of a multi-color image formed by laminating at least two types of toners selected from black toner, magenta toner, yellow toner, and cyan toner.

An apparatus for forming color images comprising:

• an electrostatic latent image carrier;
• means for forming an electrostatic latent image on the electrostatic latent image carrier;
• means for developing the electrostatic latent image using a color toner for an extreme bottom layer and a color toner for an upper layer so as to form a visible image on the electrostatic latent image carrier;
• means for transferring the visible image on the electrostatic latent image carrier onto a recording medium for forming a combined transferred image which comprises a multiple layers, and an extreme bottom layer of the multiple layer is disposed on the recording medium;
• and
• means for flash fixing the combined transferred image on the recording medium;
• wherein the color toner for electrophotography comprises a coloring agent and an infrared ray absorbent and exhibits contrast ratio of 35% to 95% and used in an extreme bottom layer of a multi-color image formed by laminating at least two types of toners selected from black toner, magenta toner, yellow toner, and cyan toner.