Owing to the limited spatio-temporal resolution of display devices, dynamic holographic three-dimensional displays suffer from a critical trade-off between the display size and the visual angle. Here we show a projection-type holographic three-dimensional display, in which a digitally designed holographic optical element and a digital holographic projection technique are combined to increase both factors at the same time. In the experiment, the enlarged holographic image, which is twice as large as the original display device, projected on the screen of the digitally designed holographic optical element was concentrated at the target observation area so as to increase the visual angle, which is six times as large as that for a general holographic display. Because the display size and the visual angle can be designed independently, the proposed system will accelerate the adoption of holographic three-dimensional displays in industrial applications, such as digital signage, in-car head-up displays, smart-glasses and head-mounted displays.

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We demonstrate a method of enlarging the viewing zone for holography that has holograms with a pixel structure. First, aliasing generated by the sampling of a hologram by pixel is described. Next the high-order diffracted beams reproduced from the hologram that contains aliasing are explained. Finally, we show that the viewing zone can be enlarged by combining these high-order reconstructed beams from the hologram with aliasing.

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We describe a method in which holograms can be produced by calculation from images captured by integral photography (IP). We present a basic algorithm obtained by simulating IP reconstruction, in which conditions are set so as not to cause aliasing in the holograms after the calculations. To reduce the calculation load, we also propose a way to limit the range of calculation considering the distribution of light and a way to shift the optical field on the exit plane of microlenses in a lens array. Finally, by optical experiments, we confirm that three-dimensional images can be reconstructed from holograms calculated from an integral photograph of a real object captured with an IP camera.

We propose a method to reduce the color moire fringes that are attributable to the structure of a color flat-panel display in integral three-dimensional imaging. The method uses two types of optical low-pass filter, diffuser and defocus. The effectiveness of the method was confirmed in an experiment. We describe a way to design these filters with moire's residual energy and video signal energy as indices and demonstrate the validity of the model, which combines two filters to reduce moire fringes.