Method and apparatus for ink jet printing on rigid panels

An apparatus for printing on surfaces of substrates with UV curable ink from an ink jet printhead onto a rigid substrate formed of a material that has a tendency to at least temporarily deform in the direction of printhead if exposed to radiant curing energy while at a printing station comprising:

• a substrate support defining a substrate supporting plane at a printing station;
• a printhead track extending parallel to the plane having a printhead carriage moveable thereon;
• at least one ink jet printhead on the carriage;
• at least one UV curing head on the carriage, adjacent to and moveable with the printhead, and sufficiently close to the ink jet printhead to freeze dots of ink in position on the substrate when jetted thereon from the printhead;
• and
• the UV curing head being configured to emit sufficient UV energy to substantially cure the ink jetted onto the substrate without heating and thermally deforming, even temporarily while at the printing station, a substrate formed of such a material, so that the surface of the material being printed upon does not move from the plane for printing.

An apparatus for printing on substrates having a tendency to deform when exposed to energy from a curing head comprising:

• a substrate support to support a substrate for printing thereon;
• a printhead track extending transversely of the support having a printhead carriage moveable thereon;
• a drive operative to impart longitudinal movement between a substrate on the support and the track;
• a carriage motor operative to move the carriage in a scanning motion transversely on the track;
• at least one ink jet printhead on the carriage;
• a controller operative to control the drive, the carnage motor and the printhead, to selectively jet UV curable ink onto a substrate on the support from the printhead with the carriage moving bidirectionally in successive transverse rows as the track incrementally moves longitudinally relative to the substrate;
• a pair of cold-UV curing heads on the carriage, one on each side of the printhead sufficiently close to the printhead to freeze dots of ink in position on the substrate upon having been jetted thereon from the printhead while imparting sufficiently low thermal energy to the substrate in the vicinity of the printhead to avoid even temporary deformation of the substrate where ink is being jetted thereon;
• and
• the controller being operative to control the curing heads to activate the curing head on the trailing side of the printhead and deactivate the curing head on a leading side of the printhead as the printhead is printing.