Inkjet printers perform printing by ejecting ink onto a print media through one or more inkjet print heads. Because it becomes difficult to eject the ink through the inkjet print head when the viscosity of the ink is increased or the ink is cured by the evaporation of a solvent, conventional methods using various improved techniques for ink have been proposed in order to avoid any occurrence of curing of the ink, for example, to add an anti-evaporation agent to aqueous ink, or to use high-boiling point oily ink.
However, the use of those improved inks requires long drying time when a print media of low permeability is used. In addition, when the printed matter is contacted to a component part of the printer body during printing, or when the printed surfaces of the print medias stacked are contacted to each other immediately following the completion of printing, the printed image on the print media is disturbed. In order to prevent the occurrence of such disturbance, inkjet printers using UV-curing type ink have been proposed.
Such a conventional inkjet printer comprises an inkjet print head for ejecting an UV-curing type ink onto a print media, a carrying means for carrying the print media printed through the inkjet print head to an ultraviolet irradiation device, and the ultraviolet irradiation device for irradiating ultraviolet light (For example, see the patent document of Japanese laid open publication number JP-7-224241). This inkjet printer can avoid the occurrence of disturbance of the printed image on the print media even if user's fingers touch it, because in order to cure the ink the inkjet printer irradiates the ultraviolet light onto the UV-curing type ink, which has been ejected, on the print media.
However, this kind of the conventional inkjet printer requires the carrying means for carrying a printed print media after printing process to the irradiation position where the ultraviolet irradiation device is placed. It is further necessary to have a configuration in which the printed surface of the print media is not contacted to any component part of the carrying means during carrying the print media to the ultraviolet irradiation device. Furthermore, the conventional inkjet printers require a longer total-printing time because it must be necessary to perform the carrying process for the printed matter to the ultraviolet irradiation device and the irradiation process of ultraviolet light after the completion of the printing through the inkjet print head.
Moreover, the ultraviolet irradiation device in the conventional inkjet printer requires an ultraviolet lamp of high power because the ultraviolet irradiation device must irradiate the ultraviolet light of a predetermined amount to the entire print surface of the print media and it must be necessary to equip a heat protection means for protecting the device against a large heat generated by the ultraviolet lamp. Therefore the manufacturing cost of the conventional inkjet printer becomes high and the size thereof becomes large.
Accordingly, an object of the present invention is, with due consideration to the drawbacks of the conventional technique, to provide an inkjet printer and an ink curing method thereof capable of reducing a total printing time without incorporating any carrying means to carry a print media after the completion of a printing process.
In addition, another object of the present invention is to provide an inkjet printer and an ink curing method thereof using an ultraviolet irradiation device of a small size, a low cost, a low power consumption, and capable of reducing a total printing time without incorporating any carrying means to carry a print media after the completion of a printing process.