A handheld transparent 3D display using a light-guide and holographic optical element

Transparent displays have the advantage of being able to superimpose arbitrary images onto real-world scenery, and they are attracting attention as an augmented reality technology. In terms of augmented reality expression, "acrylic stands" have recently become popular as lightweight and inexpensive products that allow for superposition with real space. An acrylic stand consists of an acrylic plate with a character or person printed on it. In this paper, we propose a highly portable autostereoscopic display resembling an acrylic stand, using Holographic Optical Elements (HOE), which are transparent optical elements, and an acrylic light guide plate. We investigate a transparent 3D display that combines three projectors, a light guide plate, and input/output HOEs that serve the roles of light ray control and screen. Through simulations, we confirmed that it is possible to create a glasses-free stereoscopic display using this system.