Computer-generated cylindrical rainbow hologram

Abstract

In this paper, we have investigated the computer-generated cylindrical rainbow hologram. Since general flat format hologram has the limited viewable area, we usually can not see the other side of the reconstructed object. There are some holograms to solve this problem. A cylindrical type hologram is well known as the 360 degrees viewable hologram. As the cylindrical holograms, there are two methods such as a multiplex hologram and a laser reconstruction 360 degrees hologram. Since the multiplex hologram consists of the many two-dimensional pictures, the reconstructed image is not the true three-dimension. In constant, a laser reconstruction 360 degrees hologram has the true three-dimensional effect. However, since the spatial resolution of the output device is not enough and the huge calculation amount, there are few reports on computer-generated cylindrical hologram. In our previous study, the computer-generated cylindrical hologram was realized as the Fresnel hologram. The calculation amount was too huge and took about 44 hours in the total calculation time, though we had used the several PCs. We propose the rainbow type computer-generated cylindrical hologram. To decrease the calculation amount, the rainbow hologram sacrifices the vertical parallax. Also, this hologram can reconstruct the image with white light. Comparison with the previous study of the Fresnel hologram, the calculation speed becomes 165 times faster. After the calculation, we print this hologram with the fringe printer, and evaluate reconstructed images.