High-density generation of directional images can provide natural 3D images. Directional images are orthographic projections of a 3D scene into specific directions. A number of directional images projected into different horizontal directions are simultaneously displayed into the corresponding horizontal directions with nearly parallel rays. When the number of directional images becomes large enough and the display angle pitch becomes small enough, rays from a 3D scene are virtually reconstructed. A slanted lenticular sheet technique is used to construct a thin-type natural 3D display which can generate high-density directional images. A slanted lenticular sheet is attached to a high-resolution LCD panel to construct a 2D array of 3D pixels. One 3D pixel consists of 3M x N color sub-pixels to generate M x N rays having different horizontal proceeding directions. The lenticular sheet is slanted so as to differentiate all horizontal distances from the same color sub-pixels to the axis of a lenticle in each 3D pixel. The LCD panel having the resolution of 3,840 x 2,400 is used to construct 320 x 400 3D pixels and each 3D pixel emits rays into 72 different horizontal directions with the horizontal angle pitch of 0.38° by setting M = 12 and N = 6. The slant angle was determined by considering the directivity of directional images.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.