An analytical model for scanning-projection based stereolithography

There is a growing need for effective small scale production methods. Projection stereolithography (PSL) is a technological response to such a demand. In PSL, Experience shows a decrease in resolution as area of exposure increases. A relatively novel hybrid method, scanning-projection stereolithography (SPSL) is presented in this work. This method is based on previous work by a number of authors, utilizing a combination of scanning and projection to manufacture large parts with relatively high-resolution. A modelling method to investigate the total energy received by individual pixels on resin surface is considered for both PSL and SPSL. The modelling shows near identical energy distribution for both methods. The modelling results were attempted to verify experimentally. Four patterns with circular and rectangular features were exposed with both methods. The resulting cured layers were compared via microscopic observation and measurements. Sample measurements show SPSL has a slightly better resolution using an inherently non-uniform exposure system. In large area exposure, SPSL provided less stitching and overlap issue.