Patent ID: 8075127

Claim:
A printing apparatus which performs printing on a medium, comprising: an ink-jet head which discharges an ink toward the medium, the ink containing a coloring component which is decolorizable by ultraviolet light and a curing component which is curable by the ultraviolet light, and a light amount of the ultraviolet light required for curing being smaller than a light amount of the ultraviolet light required for decolorization; a UV light source which radiates the ultraviolet light toward the medium; a movement mechanism which moves the medium in a predetermined direction relative to the ink-jet head and the UV light source to move a discharge area in which the ink-jet head discharges the ink and a radiation area in which the UV light source radiates the ultraviolet light; and a controller which receives any one of instructions of a plurality of operation modes including a printing mode and an erasing mode and which controls the ink-jet head and the UV light source in accordance with the instructed mode, wherein when the printing mode is selected, the controller controls the inkjet head and the UV light source to perform a printing process in which the ink-jet head discharges the ink toward the medium to deposit the ink to the medium, and the UV light source radiates the ultraviolet light, in a light amount that the coloring component is not decolorized, toward the ink deposited to the medium to cure the curing component; and when the erasing mode is selected, the controller controls the inkjet head and the UV source to perform an erasing process in which the UV light source radiates, toward the medium, the ultraviolet light in a light amount larger than the light amount of the ultraviolet light radiated during the printing process to decolorize the coloring component.