Liquid crystal devices (LCDs) are one of ideal devices for spatial light modulators (SLMs) and they have a future to become practical devices for displaying holographic images in real time. In this paper, process, characteristics and driving methods of the LCTV based SLMs (LCTV・SLMs) that aim for fine pixel structures are presented. The affection of the pixel structures to the image quality is studied experimentally in the electro-holographic system.
The authors propose a stereovision 3D-display system using holographic optical element (HOE). The HOE of this system is used for holographic screen. Each parallax image is projected onto this screen overlap each other and is distributed to each view area by diffraction quality of HOE. Because observer can see 3D-images. This system uses many LCD that number is equal to viewpoints. Because even if the number of viewpoints increase, resolution of each viewpoint isn't decline. The viewpoint of this system is wide focus, because observer can see 3D image freely. Observer doesn't fix his face and eye.
Holographic 3D color printer is one of ideal three-dimensional display apparatuses. To obtain distortion free and full-parallax three-dimensional image, two-dimensional images which have horizontal and vertical parallaxes should be printed into very small elementary holograms. Furthermore, by recording Lippmann type hologram, the image can be reconstructed by a white light source. The elementary holograms is partitively recorded by R, G, B Laser. So, the reconstructed image can be observed with true color. The light reconstructed from holographic recording material BB-PAN is shifted to shorter wavelength than recording wavelength.
In this paper we consider about wavelength dependence to the position of reconstructed image, viewing angle and the color balance of the image and propose the most suitable method to improve the characteristics of the reconstructed image.
The reproduction of image reality, including colors, glosses, textures, shades and 3-D effects, is very important in the visual telecommunication systems. In this paper, we present a method to reproduce the images of two-dimensional object under various illumination conditions. In the method, an image sequence is captured with rotating the object, and diffused and specular components are separated. Using these components and assumed observation geometry, new images are synthesized using the technique of light-ray arrangement, as if observed under different illumination. The images synthesized by the proposed method are displayed by a CRT as moving images and a holographic stereogram. The experimental results show that the effectiveness of the proposed image conversion.
For practical 3-D computer generated holograms (CGH), it is important to display surface model shaded images like computer graphics (CG). We propose a simple process to obtain 3-D data for CGH from two CG images. The first image is just a shaded CG image. The second image is a depth cued image, i.e. image intensity is modulated by the depth of the object. This process is applicable not only modeled CG images, but also manually drawn images. Experimental results are also reported.
A simulation system for analyzing the reconstruction characteristics of hologram is developed. The orientation and intensity of reconstructed beam are calculated using Kirchhoffs theory of diffraction, and the results are visualized. Some examples are demonstrated to show the effectiveness of the system.
The logical neuron has some different characteristics in comparison with the threshold type neuron. It is defined that each neuron has a truth table inside and its output is decided by the logic of input according to the truth table. Also, the logical neural field is defined as interconnection of the several logic neuron. Meanwhile, all logic and multi-input element can be realized by the shadow casting method and an array of computer-generated Fresnel holograms. In this paper, we propose the one dimensional optical-logic neural field using computer-generated Fresnel hologram and show some basic experimental results.
Computer-generated hologram (CGH) is made for three dimensional image reconstruction of a virtual object. Error diffusion method is used to improve the reconstructed image. The selection of diffusion coefficient exerts an influence to the image quality of the reconstructed image. In this article, diffusion coefficient is optimized by using genetic algorithm (GA). Diffusion coefficient searched by GA is able to decrease the mean square error of the reconstructed image by 10% compared with it searched by the stochastic method.