THREE-DIMENSIONAL PRINTER, THREE-DIMENSIONAL PRINTING METHOD, AND THREE-DIMENSIONALLY PRINTED ARTICLE

摘要

A three-dimensional printer and a method for manufacturing a three-dimensionally printed article preferable for halftone printing and color printing, for example, drawing a map on a three-dimensional article such as a landform model or a building model, drawing a hazard map, and writing a character. When a conventional ink-jet coloring device is used, if the jet nozzle is placed at a safe distance from the rugged surface of a three-dimensional article so as to prevent the jet nozzle bumps against the rugged surface, the jetted ink spreads and the hence the printing accuracy seriously degrades. According to the invention, halftone printing is effected as follows. The height spaced from the surface of a three-dimensional article by the focal length of the laser beam application head is used as a reference of the gradation value. The laser application head is moved vertically from the reference height according to the gradation value. The laser beam is given an application energy per unit area needed to develop the color of thermosensitive ink or to fuse a thermally fusable ink onto the area to which the laser beam is applied on the surface of the three-dimensional article which the area varies with the vertical movement of the application head. Thus, the print area is varied to express a desired gradation value. In such a way, halftone printing on a three-dimensional article is realized, and drawing a fine pattern such as a character is possible.