A study of photomask correction method in area-forming rapid prototyping system

Purpose - The purpose of this paper is to present a novel photomask auto-correction method for the area-forming rapid prototyping (RP) system. Design/methodology/approach - A digital light processing (DLP) projector was used in this research as a light source to generate the photomask image. A set of optical lenses were mounted in front of the DLP to rescale the photomask image. The rescaled photomask image was collected into a computer via a camera. By using the technique of image processing, the actual size of the photomask was then calculated. The designed size of the photomask image was eventually achieved by adjusting the relative locations of the lenses. Findings - It was found that this proposed photomask auto-correction method can produce a more accurate dimension of the photomask image and perform with higher efficiency than the manual calibration processes. Originality/value - The paper is believed to be the first work to use the image-processing technique to calibrate the photomask of an area-forming RP system, as well as to employ a method of adjusting the relative position between the lenses to rescale the photomask image size.