Three-dimensional object printing

Abstract

A volume element (voxel) printing system for printing a three-dimensional object is provided. The system includes a first printhead group, at least one second printhead group, a conveyor and a control system. The first printhead group includes a plurality of first printheads configured to print a first voxel layer on a substrate. The second printhead group includes a plurality of second printheads located downstream from the first group and configured for printing a subsequent voxel layer on at least part of the first layer. The second printheads are reconfigurable as backup printheads for the first printheads in case of failure. The conveyor is configured to operatively convey the substrate past the printhead groups. The control system controls and monitors the printhead groups and the conveyor, and is configured to dynamically reconfigure the second printheads if failure of a first printhead is detected.

1 . A volume element (voxel) printing system for printing a three-dimensional object, the system comprising:
 a series of printhead groups, each printhead group having a plurality of printheads configured to print a voxel layer, a first layer printed by a first printhead group being printed on a substrate and subsequent layers printed by respective printhead groups following the first printhead group, each subsequent layer being printed upon a preceding layer printed by a preceding printhead group, the series of printhead groups also including redundant printhead groups not used during normal operation;   a conveyor to operatively convey the substrate past the printhead groups; and   a control system to control and monitor the printhead groups and the conveyor, and to dynamically reconfigure the printhead groups to remove faulty printhead groups from operation, and utilize one or more of the redundant printhead groups.   
   
   
       2 . The printing system of  claim 1 , wherein each printhead includes a plurality of micro-electromechanical nozzle arrangements configured to operatively eject a voxel therefrom, said voxel selected from the group consisting of a polymer, a metal, a metal alloy, a wax, an evaporative drying material, and a compound. 
   
   
       3 . The printing system of  claim 1 , wherein the printhead groups are configured to print simultaneously such that a plurality of different layers are simultaneously printed as the substrate is conveyed past the printheads. 
   
   
       4 . The printing system of  claim 1 , wherein the printhead groups are configured not to print on predetermined parts of a preceding layer to define a cavity for receiving a pre-formed object. 
   
   
       5 . The printing system of  claim 4 , having an insertion assembly for inserting pre-formed objects into the cavity during printing. 
   
   
       6 . The printing system of  claim 1 , wherein the printheads extend transversely across the conveyor relative to a conveying direction. 
   
   
       7 . The printing system of  claim 1 , having at least one curing assembly interspersed between the printheads to perform a curing process, said curing process selected from the group consisting of evaporative drying, freezing of voxels, ultra violet curing, printing of reagents, printing of catalysts, and printing of polymerization initiators. 
   
   
       8 . The printing system of  claim 1 , wherein a distance between each printhead group and the substrate or layer printed upon is constant for all printhead groups. 
   
   
       9 . The printing system of  claim 1 , wherein each printhead further has redundant nozzles which are utilized when nozzles fail in that printhead fail.