Eyepiece-type full-color electro-holographic display for binocular vision

Head-mounted type 3-D displays are expected to be useful with Augmented Reality techniques to provide visual information. However, because these displays use the stereoscopic method to provide 3-D vision, observers tend to experience eye discomfort when viewing 3-D images due to the disparity between accommodation and convergence. Electro-holography is a rival technique that displays holograms on electrical devices such as a spatial light modulator and enables observers to view ideal 3-D images in comfort for many hours. In the current study, we applied the holography technique to an eyepiece-type display in order to solve the disparity problem. Our system can represent 3-D images at arbitrary depths and displays large reconstructed images by using a Fourier transform optical system. We also adopted the time division color method to reconstruct full-color images. In computer generated holography, holograms for each color are calculated considering with the distance between their wavelength. In this paper, we describe our calculation algorithm and report the fabrication of an eyepiecetype full color electro-holographic display for binocular vision. To confirm the effectiveness of the proposed system, the reconstructed images were evaluated both objectively and subjectively. Results of experiments show that reconstructed full-color images are located at the correct depth.