Color moiré reduction and resolution enhancement of flat-panel integral three-dimensional display.

Color moiré occurs owing to the subpixel structure of the display panel in the integral three-dimensional (3D) display method, deteriorating the 3D-image quality. To address this, we propose a method for reducing the color moiré and improving the 3D-image resolution, simultaneously, by combining multiple 3D images. In the prototype system, triple 3D display units with lens arrays closely attached to 8K-resolution display panels are optically combined. By controlling the color moiré of the 3D image generated on each display and shifting and combining the elemental lenses constituting the lens array, sufficient reduction in the color moiré is realized, while suppressing the deterioration of the 3D-image quality, at a distant position from the lens array in the depth direction, along with an approximately two-fold enhancement of the resolution near the lens array.

Measurement of static convergence and accommodation responses to images of integral photography and binocular stereoscopy.

Static convergence and accommodation responses were measured by comparing integral photography images, binocular stereoscopic images, and real objects in a measurement range from 450 to 900 mm. The experimental results were evaluated with a multiple comparison test. It was found that six of the ten observers did not have an accommodation-convergence conflict in viewing integral photography in the range. Moreover, the required resolution was found to be 0.7 or more and less than 1.4 cycles per degree for inducing accommodation. In conclusion, integral photography can provide a natural 3D image that looks like a real object.

Integral 3D display using multiple LCD panels and multi-image combining optical system.

We present a method to display an integral three-dimensional (3D) image without gaps between multiple display active areas by using multiple liquid crystal display (LCD) panels and multi-image combining optical systems (MICOS). We designed a MICOS to improve the resolution characteristics and decrease the luminance unevenness corresponding to the viewpoint. Furthermore, we developed a method for correcting the distortion of the integral 3D image by using image processing. We prototyped an integral 3D display using four 8K dual-green (8KDG) LCD panels and the improved MICOSs. The prototype display achieved to magnify the display area about 5.66 times more than when a single LCD panel was used.

Cross talk elimination using an aperture for recording elemental images of integral photography.

A major problem with integral photography using a lens array is overlapping recordings (cross talk) between elemental images. Another problem is the decrease in the number of pixels in the elemental images. We describe two methods (including analyses) of manipulating the aperture of a telecentric optical system to improve these problems. The first method locates the aperture on the focal plane of a field lens. The advantage of this method is that cross talk can be reduced without changing the size of the whole optical system. The second method establishes a telecentric optical system between objects and the lens array. The advantage of this method, even though the whole optical system becomes bigger, is that cross talk can be completely eliminated. In addition, the number of pixels in the elemental images can be increased by varying the aperture position sequentially with respect to time. We also describe how cross talk is reduced in both methods by taking diffraction into consideration. Experimental results are presented to verify this reduction.

Calculation of holograms from elemental images captured by integral photography.

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.

Viewing-zone enlargement method for sampled hologram that uses high-order diffraction.

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.