US Patent 11458685 Large array stereolithography with efficient optical path

A three-dimensional printing system for fabricating a three-dimensional article includes a resin vessel, a motorized platform, an imaging bar, a movement mechanism, a servicing module, and a controller. The motorized platform has an upper surface for supporting the three-dimensional article. The imaging bar has an array of light emitters arranged along a transverse axis which emitting light downwardly from an exit surface. The controller is configured to: operate the motorized build plate, the movement mechanism, and the imaging module to complete fabrication, and periodically during fabrication operate the movement mechanism to position the imaging bar in the servicing module to clean resin residue from the imaging bar.