We propose a novel full-parallax 3D display system, called RePro3D, that is suitable for interactive 3D applications. The approach is based on retro-reflective projection technology in which several images from a projector array are displayed on a retro-reflective screen. When viewers look at the screen through a half mirror, they see a 3D image superimposed on the real scene without having to wear glasses. RePro3D has a sensor function to recognize user input, so it can support some interactive features, such as manipulation of 3D objects. In this paper, we describe the optical system of the high-density projector array. Then, we develop a prototype of RePro3D. The prototype shows parallax images that were displayed on a real scene from 42 different viewpoints. The user can touch the 3D image with his/her hands.
