Dual-mode Optical See-Through Integral Imaging 3D Display with Large Depth of Field

Conventional optical see-through integral imaging display system using holographic optical element (HOE) is actually in focused display mode whose central depth plane (CDP) is very close to the HOE plane, and the depth of field (DOF) of the system is limited to several centimeters around the HOE plane. In this paper, we proposed a dual-mode optical see-through integral imaging display system to reconstruct 3D images in both real and virtual display modes simultaneously and greatly extend the DOF. A dual-mode lens array HOE (DM-LAHOE) was specially designed by using two sets of lens arrays, and it featured as a lens array with positive focal length and negative focal length under the illumination of different probe beams. The designed DM-LAHOE can generate two CDPs away from the HOE plane. Hence, the real mode and virtual mode of the integral imaging display can be achieved simultaneously, and the DOF of the system was greatly improved by increasing the focal length of the recorded lens array and the number of CDPs. In the experiment, the DM-LAHOE with large focal lengths of +/- 14mm was fabricated, and the DOF of the proposed system was increased from 24.5mm to 190mm. The proposed dual-mode optical see-through integral imaging display system is expected to be applied in the fields of augmented reality display, vehicle display, window display, etc.