| 摘要 |
Ink jet printing is provided onto rigid panels (15) such as office partitions, which may have surfaces (16) that are contoured, textured, made of three-dimensional material, or are otherwise variably spaced from the plane of the panel, such that the distance between a printing element (30, 130, 130a-130d) and the point on the surface on which ink is to be deposited is not always the same or exactly predictable. Preferably, panels (15) are printed using ultraviolet (UV) light curable ink, which is first at least partially cured with UV light and then may be subjected to a heating step to more completely cure and dry the ink to remove, by evaporation, further curing or otherwise, the uncured monomers. The panel surface (16) may be contoured by quilting or molding processes. Print head to panel spacing is adjustable to maintain a predetermined constant distance from the printing element to the surface of the panel where the ink is to be applied. Each of a plurality of print heads (130a-130d) may be independently moveable to control the spacing of the print heads from the substrate surface. Sensors (40, 138) on the print head carriage (129) measure the distance from the print head carriage to the surface of the substrate being printed. The position or focal length of the UV light curing head (23, 123) may be varied to maintain focus of the UV light on the ink on a contoured surface of the substrate. UV curing heads may be located on the print head carriage, one on each side of the print heads, and activated alternately as the carriage reciprocates, to spot cure and freeze the dots of ink immediately after being deposited on the substrate. Cold UV sources may be used to prevent heat deformation of flat or contoured substrates during printing, thereby making spot curing on heat-sensitive substrates such as foam-board possible.
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