Holographic Display System Combined a Reflective Liquid Crystal Display with a Special-Purpose Computer for Holography, HORN-4

摘要

Holography is a useful 3D image reconstruction technique since an object light can be reconstructed correctly. This technique has mainly two big problems, namely an enormous computational time for hologram and a minutely interference fringe of a hologram. To solve the enormous computational time we designed and built a special-purpose computer for holography, HORN (Holographic ReconstructioN). We designed and built latest HORN machine, HORN-4 with PLD (Programmable Logic Device) technology. HORN computers have pipeline architecture. In the HORN-4 system, we designed the pipeline by adopting our "recurrence formulas" algorithm that can calculate the phase on a hologram. As compared with traditional computational algorithms for hologram, our algorithm could integrate many computational units into PLD chip. We could obtain 48,000 grids hologram from a 3D-image composed of 415 points in about 0.45 sec using PentiumIII-500MHz with HORN-4. We need a device which can display the minutely interference fringe of a hologram. As the devices, transmissive LCD (Liquid Crystal Display) has been mainly used. We have used reflective LCD because reflective LCD can be generally made minutely as compared with transmmisive LCD. We have constructed a holographic display system combined a reflective LCD with HORN-4. We could observe animation of 3D image by this system.