Patent ID: 7306885

Claim:
A method for forming electrostatic latent images on a latent image carrier comprising: developing latent images using toners of different colors each in which a coloring agent selected from a group consisting of at least yellow, magenta, cyan, and black is internally added thereto and hydrophobic silica particles and metallic soap particles are externally added to toner mother particles to form toner images and, transferring the toner images to a recording medium, wherein color superposition of the toners is conducted during the development of latent images on the latent image carrier or during the transfer of the toner images to the recording medium after the development, wherein: an absolute value of a difference between work functions of two of said toners is 0.02 eV or more, the color superposition is conducted sequentially from a toner having the largest work function in descending order of work function of the toners, an absolute value of a difference between a work function of the toner mother particles and a work function of the metallic soap particles is 0.15 eV or less, and a work function of the latent image carrier is larger than the work function of the toner having the smallest work function.