A detection and control method of resin liquid-level of stereolithography apparatus

Purpose - The purpose of this paper is to detect and control the liquid-level of stereolithography apparatus precisely. Design/methodology/ approach - A brightness-variable laser source is adopted to remove the computational error of divider and a closed-loop circuit is set to measure the terminal voltage directly proportional to the output current of photosensitive devices. It employs a sinking-block device to control the liquid-level. Findings - The precise calibration result of this detecting device indicates that the resolution of the liquid-level detection can reach ±1.5μm. Originality/value - This sinking-block style liquid-level control device can allow for the liquid-level wave reduced from ±45 to ± 15μm.