Development of the viewing distance measuring device in smartphone use
Min-Won Seo, Wonjae Kim, Jun-Min Kim, Jeong‐Min Hwang, Jong-Mo Seo · 2017
In this paper, a low-cost lens fabrication method using a micro chamber produced by a three-dimensional (3-D) printer is presented. The shape of polydimethylsiloxane (PDMS) membrane was controlled by adjusting the pressure inside the chamber. On top of the shaped membrane, an ultraviolet-curable resin was poured. Depending on the pressure inside the chamber and the shape of the chamber lid, three types of lenses could be made: a bi-convex lens, a plano-convex lens, and a concave lens. This method can reduce the cost of making pilot or evaluation devices in healthcare service.