Projection Screen Inspired by Human Skin for Use in Pseudo Windows

When we consider viewing the surface of human skin, the skin gives us a sense of natural depth, while, in contrast, the surface of a plastic does not. In our research program, learning from the structure of human skin, we fabricated screens which consist of multilayers made of translucent sheets coated with TiO2 nanoparticles. The feeling of natural depth from the screen can be considered to come from the multiply-observed images produced by phase differences due to the translucent multi layers. Additionally, we think that the feeling of natural depth from our 3D imaging screen comes from the reflection/diffusion differences of light depending on its wavelength as well as human skin. This is because that the spectral distribution measurements of these translucent sheets suggest that blue light with short wavelength is scattered on the surface of the first layer, while red light with long wavelength permeates to the under layers. The screen has a number of potential applications, since it is easy to prepare, low cost, and applicable to a large area. One of promising candidates is, of course, in the application as 3D projection screen. This is because 2D images projected on the screen can be automatically transformed into 3D images with a stereoscopic background. And considering that this system is applicable to not only reflection type but also transmission type, one of interesting candidates is for use in pseudo windows. By connecting an external camera, the screen can be utilized as a pseudo window on a real wall. The pseudo window can be expected to provide an open feeling while keeping high heat insulation, sound insulation, and privacy.