P‐4.8: Unidirectional Observable Aero Signage Display Using Dye‐doped Corner Cube Prisms Which Enable to Make Transparent from Back Side

Abstract

Suppose that you look Arabic numerals on transparent glass windows or in the air. Which does it mean ‘85’ or ‘28’? You end up watching the mirrored images when you view from back side. So let us make the mirrored image invisible. To solve mirrored image problems of an aero signage which means images are floating in the air, our research group has utilized dye‐doped prisms and total internal reflection in optics. You know that water is generally colorless and transparent but the water in a bath tub is little blue. The color changes depending on the depth of water. The deeper, the darker water becomes blue. This is the reason why some color is generated in the dye‐doped material. In 2021, we presented a unidirectional observable display using letterings made by intaglio printings for arranging dye‐doped tiny prisms on a glass window. You can watch these colored letterforms from front and transparent pixels from back. But this 2021 model has a little defect that colors are less vivid because of color generating mechanism by twice reflection in conventional optical prisms using transparent materials for making transparent from back side. In this paper, the authors show an aero signage display using dye‐doped corner cube prisms which can lengthen light paths in the prism by multi‐times reflections to avoid the semi‐transparent problem which means colors are not vivid.