Patent ID: 11794411

Abstract:
A method for 3D printing a part in a layer-wise manner includes providing a pool of polymerizable liquid in a vessel over a build window and positioning a downward-facing build platform in the pool, thereby defining a build region above the build window. The method includes selectively curing a volume of polymerizable liquid in the build region by imparting electromagnetic radiation through the build window to form a printed layer of the part adhered to the build platform and scanning at least a portion of the build window with monochromatic, polarized light along a plane of incidence. The method includes measuring a change in intensity and polarity of the light to obtain information about the printed layer. The method includes raising the build platform to a height of a next layer to be printed and modifying the electromagnetic energy imparted into the next layer based upon the obtained information to print a next layer. The imparting, scanning, measuring, raising and modifying steps are repeated until the part is printed.