Patent ID: 9522490
Filing Date: 2016-12-20
CPC Classification: B29C,B41M

Claim Text:
1. A method of forming a three-dimensional image, the method comprising: forming a colored image on one surface of a thermally expandable sheet where a thermally expandable layer is formed on a surface of a base sheet; forming a second print image on a region of the other surface of the thermally expandable sheet with a photothermal conversion material, wherein the second print image is a mirror image of the colored image, and the region of the other surface corresponds to the colored image on the one surface; and forming a three-dimensional image of the colored image by selectively expanding the thermally expandable layer with thermal energy that is generated in the second print image by irradiating the thermally expandable sheet with light from the other surface of the thermally expandable sheet; wherein, in the forming of the colored image on the one surface of the thermally expandable sheet, a density of a display color of a first part of the colored image is set as a first density and a density of a display color of a second part of the colored image is set as a second density which is higher than the first density according to a bulge height of the thermally expandable layer in consideration of a change of the density of the display color of the first and second parts of the colored image caused by the expansion of the thermally expandable layer, so that an originally planned density of the display colors set in the first part and the second part of the colored image is achieved even after the expansion of the thermally expandable layer when the colored image is formed, wherein the originally planned density of the display color of the first part of the colored image after the expansion is equal to the originally planned density of the display color of the second part of the colored image after the expansion, and wherein the bulge height of the thermally expandable layer in a region corresponding to the second part of the colored image after the expansion is to be higher than the bulge height of the thermally expandable layer in a region corresponding to the first part of the colored image after the expansion; and wherein, in the forming of the second print image on the other surface of the thermally expandable sheet, a density of the second print image containing the photothermal conversion material is set such that the bulge height of the thermally expandable layer becomes a planned arbitrary height after forming the three-dimensional image of the colored image.