<title>Expansion of the image size and viewing zone in holographic display using liquid crystal devices</title>

Abstract

We are researching 3D display using Liquid Crystal Devices (LCDs) as spatial light modulators to control wavefront for reconstructed 3D holographic image. We have tried to expand the image size and viewing zone, especially on vertical direction. The image size depends on the size of LCD pixel, and the viewing zone depends on the number of LCD pixels. So we use half mirror to set up three-fine pixel LCDs continuously in horizontal direction. In our display of first step, we can see 14 mm in width of image size, under +/- 1.2 degree(s) in angle of horizontal viewing zone. But in vertical direction, since the number of LCD pixels are limited, the reconstructed image size and viewing zone become small in full- parallax off-axis holography. So we discard the vertical parallax, which makes the necessity for number of LCD pixels to diffract the wavefront too large. We use cylindrical lens to expand the vertical image size and adjust the image plane, under the condition of discarding the vertical parallax. And we set lenticular sheet on the image plane to get wide vertical viewing zone.