Multi-pass UV inkjet printer for outputting high glossy varnish and printing method using the same

A printing method using a multi-pass ultraviolet (UV) inkjet printer for outputting high glossy varnish, the UV inkjet printer including an inkjet module for performing a printing job by moving back and forth across the printer, the inkjet module having a varnish print head for outputting varnish on a substrate, the printing method comprising:

• providing a side UV light irradiation device at a side of the inkjet module and a front UV light irradiation device in front of the inkjet module not overlapped by the varnish print head, wherein a width of the side UV light irradiation device in a direction parallel with the varnish print head is less than a width of the varnish print head, and wherein the width of the area not overlapped by the varnish print head and the side UV light irradiation device in a direction perpendicular to the varnish print head is greater than the width of one pass;
• during output of the varnish, dividing each print region in data to be printed into a plurality of passes and activating the side UV light irradiation device and the front UV light irradiation device at the same time, wherein the irradiation power of the side UV light irradiation device is less than that of the front UV light irradiation device, such that when the substrate is being conveyed forward, varnish outputted on the substrate in a nth pass is passed under the side UV light irradiation device for shaping during or after a n+1th pass performed by the UV inkjet printer;
• and
• passing the varnish outputted on the substrate in the nth pass under the front UV light irradiation device for complete curing during or after a n+2th pass.