3D object creation system comprising a plurality of layer groups

1. A three-dimensional object creation system comprising:

a plurality of stationary printhead layer groups, each layer group comprising at least one printhead for printing a respective layer of said object; and

a conveyor for conveying a partially-formed object past said layer groups, wherein said printheads are configured to print simultaneously such that a plurality of different layers are printed simultaneously by said layer groups,

wherein at least one layer group comprises a plurality of printheads.

2. The object creation system of claim 1 , wherein each printhead in said at least one layer group prints the same material.

3. The object creation system of claim 1 , wherein said at least one layer group comprises a first printhead for printing a first material and a second printhead for printing a second material in a same layer of said object.

4. The object creation system of claim 3 , wherein said first and second printheads are maintained at different temperatures.

5. The object creation system of claim 1 , wherein said layer groups are each positioned at different heights relative to said conveyor.

6. The object creation system of claim 5 , wherein a height difference between each layer group and its adjacent layer group is constant.

7. The object creation system of claim 6 , wherein the height difference is at least one volume element (voxel) height of the object.

8. The object creation system of claim 5 , wherein at least one layer group comprises a plurality of printheads, and said plurality of printheads within said at least one layer group are positioned at the same height relative to said conveyor.

9. The object creation system of claim 1 , wherein each layer is defined by a plurality of volume elements (voxels) of the object arranged in a regular array and wherein the voxels of each layer are printed so as to be offset by half a voxel relative to the voxels of adjacent layers in a conveying direction and/or a direction perpendicular to the conveying direction.

10. The object creation system of claim 1 comprising first layer group for printing a first layer and second layer group for printing a second layer, wherein the first layer group is dynamically reconfigurable to print at least part of the second layer and the second layer group is dynamically reconfigurable to print at least part of the first layer.

11. The object creation system of claim 1 further comprising a control system for controlling each layer group.

12. The object creation system of claim 1 , further comprising a robot for inserting pre-formed objects into the partially-formed object during printing.

13. The object creation system of claim 12 , wherein the pre-formed object is an electrical or mechanical device.

14. The object creation system of claim 13 , wherein at least one printhead prints electrical connections for the electrical device.

15. The object creation system of claim 12 , wherein the pre-formed object is a semiconductor device.

16. The object creation system of claim 12 , wherein said layer groups are configured to create one or more cavities in the partially-formed object, the or each cavity being configured for receiving a pre-formed object from said robot.

17. The object creation system of claim 1 , wherein said printheads extend transversely across said conveyor relative to a conveying direction.

18. The object creation system of claim 17 , wherein said layer groups are spaced apart along the conveying direction of the conveyor.