A digital lithography system including a droplet source (printhead) for
selectively ejecting liquid droplets of a phase-change masking material,
and an imaging system for capturing (generating) image data representing
printed features formed by the ejected liquid droplets. The system also
includes a digital control system that detects defects in the printed
features, for example, by comparing the image data with stored image
data. The digital control system then modifies the printed feature to
correct the defect, for example, by moving the printhead over the defect
and causing the printhead to eject droplets onto the defect's location.
In one embodiment, a single-printhead secondary printer operates in
conjunction with a multi-printhead main printer to correct defects.