The patent mentioned in the article is specifically for continuous SLA printing (no pauses for lifting/peeling between layers), which the photon and other similarly-priced models don't do. I have one of the cheap SLA printers, and the lifting can occupy over half the printing time depending on layer height/resin type. The continuous printing machines seem to start in the several-thousand-dollar range.
You'd think laser printers would be prior art - a rotating mirror (usually a hexagon) was exactly how older laser printers would scan across the drum to form out the print.
