Display Sharp 3D Images in the Air Using Low Resolution Liquid Crystal Panels

A relatively simple screen is provided for large size sharp 3D display. It consists of only a micro-lens array (MLA) and two low resolution liquid crystal panels, one panel for amplitude modulation while another panel for phase modulation. A parallel illuminating laser beam is first modulated by the two panels and then focused into point light source array (PLSA) by MLA. Voxels are recreated via constructive interference of light waves from the PLSA. The intensity of a voxel is proportional to the square of the number of point light sources that shed light on it and the brightness of each point light source. A little away from a voxel the intensity of the light field decreases dramatically due to mismatch of phase. With quantities of voxels large and sharp discrete 3D images could be displayed in the air within a large volume. As an example, 3D image quality for a particular object under particular screen parameters was analyzed.