US Patent 7488572 Image formation method

An image formation method comprising exposing a photothermographic material 10 having an image-forming layer and a back layer with a light having a wavelength of 700-850 nm and subjecting it to development in a heat development apparatus provided with a preheating section A, a heat development section B and a gradual cooling section C, wherein the photothermographic material 10 has at least one coated layer obtained by applying a coating solution containing 20 weight % or more of an organic solvent, and the heat development section B is provided with heating members 15 on image-forming layer side 10a and back layer side 10b and transportation rollers only on the image-forming layer side 10a with respect to the photothermographic material 10 to be transported in the apparatus. There is provided an image formation method utilizing a photothermographic material, which can form images showing less generation of density unevenness, high contrast and high maximum density without causing physical deformation.