One-way Observable Window Signage Using Interference Colors of Transparent Optical Films with Birefringence

Abstract

A window signage or sign is a cost effective way to attract attention from streets. Assume that you draw something on the glass window from both sides. It is difficult to understand your drawing correctly since one observes the mirrored text and graphics from opposite side. It stands to reason that someone observes mirrored imaging according to the direction of viewing if you draw something on the transparent material. The authors have researched one-way observable window display system which enables to make images invisible form back side. In this paper, we propose the window signage display to avoid mirrored image problems using interference colors of transparent optical films.