Integrated 3D display and imaging using dual purpose passive screen and head-mounted projectors and camera

We propose an integrated 3D display and imaging system using a head-mounted device and a special dual-purpose passive screen that can simultaneously facilitate 3D display and imaging. The screen is mainly composed of two optical layers, the first layer is a projection surface, which are the finely patterned retro-reflective microspheres that provide high optical gain when illuminated with head-mounted projectors. The second layer is an imaging surface made up of an array of curved mirrors, which form the perspective views of the scene captured by a head-mounted camera. The display and imaging operation are separated by performing polarization multiplexing. The demonstrated prototype system consists of a head-worn unit having a pair of 15 lumen pico-projectors and a 24MP camera, and an in-house designed and fabricated 30x24cm² screen. The screen provides bright display using 25% filled retro-reflective microspheres and 20 different perspective views of the scene using 5x4 array of convex mirrors. The real-time implementation is demonstrated by displaying stereo-3D content providing high brightness (up to 240 cd/m²) and low crosstalk (<4%), while 3D image capture is demonstrated by performing the computational reconstruction of the discrete free-viewpoint stereo pair displayed on a desktop or virtual reality display. Furthermore, the capture quality is determined by measuring the imaging MTF of the captured views and the capture light efficiency is calculated by considering the loss in transmitted light at each interface. Further developments in microfabrication and computational optics can present the proposed system as a unique mobile platform for immersive human-computer interaction of the future.