<title>Composite holographic screens for the stereoscopic or multiview color image display</title>

Abstract

The transmission type holographic screen is a special kind of scatterer, which is used to concentrate the light from the projected image into small size spot (viewing zone). As a result, different images can be delivered to each observer's eyes and it is possible to display the stereoscopic images. The most serious problem related with the holographic screen is its high dispersion and aberrations which cause the viewing zone distortions and poor color reproduction in the displayed image, especially in the screen corners. Both of the above mentioned drawbacks become more prominent when the screen size becomes larger. To compensate the screen dispersion, a diffuser in the form of a long narrow stripe directed to the reference beam axis is used for an object. The length and position of the diffuser are calculated to make the reconstructed images of it for all wavelengths of the white light projector to be superposed in the viewing zone. To solve the aberrations problem, a big size screen was composed by mosaicking many sub-screens which were recorded individually in the specially optimized setup. For example, when the sub- screen is recorded for the edge part of the screen, the diffuser was tilted different direction to provide proper superposition of the reconstructed diffuser images. For each sub-screen, the diffuser is tilted such that it is in nearly the same plane with the reference beam axis. The sub-screens are recorded on the holographic photoplates PFG-01 (Russia) with an optical set-up optimized for each sub-screen by adjusting the diffuser position and its tilt angle. All necessary parameters are calculated by considering the light beam path for different wavelengths in the visible spectrum. The size of each sub-screen is 40 X 30 cm2. Eight sub- screens are mosaicked to obtain a composite holographic screen with size 80 X 120 cm2. The screens have been used to display the full color stereoscopic images from slide projectors. The distances between the projector and the composite screen, and the screen and a viewer are set to 4 m and 3.5 m, respectively.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.