LASER-BASED 3-D VOLUMETRIC DISPLAY SYSTEM - THE IMPROVED 2ND GENERATION

NRaD, the RDT&E Division of the Naval Command, Control and Ocean Surve illance Center (NCCOSC), has developed its second generation device fo r displaying data, information and scenes in a three-dimensional volum e of image space. The device incorporates a 36-inch diameter double he lix that spins at approximately 10 revolutions per second, providing a means to address a cylindrical volume. Under computer control, a lase r beam is directed to illuminate certain discrete volume points (voxel s) on the helix needed to create a scene. The laser light scatters fro m the surface of the helix, so, to the observer, each voxel appears to emanate from specific points in space. Each point has x-y coordinates determined by the position of the laser beam, and a z coordinate dete rmined by the height of the point on the helical surface. Any point wi thin the cylindrical image volume can be computer-addressed to appropr iately synchronize the laser beam, the Acousto-Optic (AO) Scanner and the phase of the helix, as shown in figures 1 and 8. Using a novel Aco usto-Optic (AO) Random-Access Scanner, up to 40 thousand laser-generat ed voxels refreshed at 20 Hz per color are projected onto the reflecti ve surface of the rotating helix. (This is about 10 times more than th e current state of the art.) The higher resolution allows improved col or images, updated in real time, for group viewing with the naked eye (see the optical head in figure 8).