Long-range 3D display using a collimated multi-layer display.

We propose a long-range three-dimensional (3D) display using a collimated optics with multi-plane configuration. By using a spherical screen and a collimating lens, users observe the collimated image on the spherical screen, which simulates an image plane located at optical infinity. By combining and modulating overlapped multi-plane images, the observed image is located at desired depth position within the volume of multiple planes.

See-through multi-projection three-dimensional display using transparent anisotropic diffuser.

We propose a see-through multi-projection three-dimensional (3D) display using a transparent anisotropic diffuser. By immersing a metal-coated anisotropic diffuser into index matching oil which has the same refractive index of anisotropic diffuser, a transparent anisotropic diffuser is implemented. The reflectance of the transparent anisotropic diffuser is analyzed with the transfer matrix.

Computational multi-projection display.

A computational multi-projection display is proposed by employing a multi-projection system combining with compressive light field displays. By modulating the intensity of light rays from a spatial light modulator inside a single projector, the proposed system can offer several compact views to observer. Since light rays are spread to all directions, the system can provide flexible positioning of viewpoints without stacking projectors in vertical direction.

Viewing zone duplication of multi-projection 3D display system using uniaxial crystal.

We propose a novel multiplexing technique for increasing the viewing zone of a multi-view based multi-projection 3D display system by employing double refraction in uniaxial crystal. When linearly polarized images from projector pass through the uniaxial crystal, two possible optical paths exist according to the polarization states of image. Therefore, the optical paths of the image could be changed, and the viewing zone is shifted in a lateral direction.

Compact multi-projection 3D display system with light-guide projection.

We propose a compact multi-projection based multi-view 3D display system using an optical light-guide, and perform an analysis of the characteristics of the image for distortion compensation via an optically equivalent model of the light-guide. The projected image traveling through the light-guide experiences multiple total internal reflections at the interface. As a result, the projection distance in the horizontal direction is effectively reduced to the thickness of the light-guide, and the projection part of the multi-projection based multi-view 3D display system is minimized.

Real-mode depth-fused display with viewer tracking.

A real-mode depth-fused display is proposed by employing an integral imaging method in the depth-fused display system with viewer tracking. By giving depth-fusing effect between a transparent display and a floated planar two-dimensional image generated by the real-mode integral imaging method, a three-dimensional image is generated in front of the display plane unlike conventional depth-fused displays. The viewing angle of the system is expanded with a viewer tracking method.

Implementation of active-type Lamina 3D display system.

Lamina 3D display is a new type of multi-layer 3D display, which utilizes the polarization state as a new dimension of depth information. Lamina 3D display system has advanced properties - to reduce the data amount representing 3D image, to be easily made using the conventional projectors, and to have a potential being applied to the many applications. However, the system might have some limitations in depth range and viewing angle due to the properties of the expressive volume components.

Reflection-type integral imaging system using a diffuser holographic optical element.

A reflection-type integral imaging (InIm) system using a diffuser holographic optical element (DHOE) is proposed for improving the fill factor of displayed three-dimensional images. The DHOE performs an optical function similar to that for a conventional diffuser only for Bragg matched light, while Bragg mismatched light passes through the DHOE. Elemental images projected under Bragg matching condition are scattered by the DHOE.

Lamina 3D display: projection-type depth-fused display using polarization-encoded depth information.

In order to realize three-dimensional (3D) displays, various multiplexing methods have been proposed to add the depth dimension to two-dimensional scenes. However, most of these methods have faced challenges such as the degradation of viewing qualities, the requirement of complicated equipment, and large amounts of data. In this paper, we further developed our previous concept, polarization distributed depth map, to propose the Lamina 3D display as a method for encoding and reconstructing depth information using the polarization status.

Depth-expression characteristics of multi-projection 3D display systems [invited].

A multi-projection display consists of multiple projection units. Because of the large amount of data, a multi-projection system shows large, high-quality images. According to the projection geometry and the optical configuration, multi-projection systems show different viewing characteristics for generated three-dimensional images.

Bi-sided integral imaging with 2D/3D convertibility using scattering polarizer.

We propose a two-dimensional (2D) and three-dimensional (3D) convertible bi-sided integral imaging. The proposed system uses the polarization state of projected light for switching its operation mode between 2D and 3D modes. By using an optical module composed of two scattering polarizers and one linear polarizer, the proposed integral imaging system simultaneously provides 3D images with 2D background images for observers who are located in the front and the rear sides of the system.

Depth-fused display with improved viewing characteristics.

We propose a depth-fused display (DFD) with enhanced viewing characteristics by hybridizing the depth-fusing technology with another three-dimensional display method such as multi-view or integral imaging method. With hybridization, the viewing angle and expressible depth range can be extended without changing the size of the volume of the system compared to the conventional DFD method. The proposed method is demonstrated with experimental system.

Resolution enhancement of holographic printer using a hogel overlapping method.

We propose a hogel overlapping method for the holographic printer to enhance the lateral resolution of holographic stereograms. The hogel size is directly related to the lateral resolution of the holographic stereogram. Our analysis by computer simulation shows that there is a limit to decreasing the hogel size while printing holographic stereograms.

Integral imaging using a color filter pinhole array on a display panel.

We propose methods of enhancing pinhole-type integral imaging ray density, resolution, and expressible depth range using a color filter pinhole array on a liquid crystal display panel with a projection scheme. A color filter structure on a liquid crystal display panel acts as pinhole array in integral imaging with separation of color channels. In conventional pinhole-type integral imaging, the resolution, viewing angle, and ray density are limited by the pinhole interval, the width and thickness of the pinhole structure, and the gap between the display panel and the pinhole array.

Polarization distributed depth map for depth-fused three-dimensional display.

We propose a polarization distributed depth map (PDDM) which can be used in a depth-fused three-dimensional (DFD) display. PDDM is obtained from a conventional depth map using a polarization switching device and shows different polarization states for each pixel depending on the depth position of corresponding pixel. The proposed DFD system using PDDM is composed of three devices which are projection-type display, polarization switching device, and polarization-selective scattering screens.

Projection-type integral imaging system using multiple elemental image layers.

A projection-type integral imaging system is proposed using multiple elemental image layers obtained from a single projector. In a conventional projection-type integral imaging system, only one display mode among real, virtual, and focused modes can be displayed selectively with a single projector. Plural projectors must be used for the generation of multiple elemental image layers.

3D/2D convertible projection-type integral imaging using concave half mirror array.

We propose a new method for implementing 3D/2D convertible feature in the projection-type integral imaging by using concave half mirror array. The concave half mirror array has the partially reflective characteristic to the incident light. And the reflected term is modulated by the concave mirror array structure, while the transmitted term is unaffected.

Integral imaging system using a dual-mode technique.

A new integral imaging system is proposed that uses a dual-mode technique, in which the elemental lens of the lens array is used not only as a convex lens but also as a convex mirror. The integral imaging system using dual modes can represent the real and the virtual integrated images simultaneously with improved viewing parameters. The lens array coated with thin aluminum is used to balance the ratio between the reflectance and the transmittance of lens array.

Inhibitory effect of Panax notoginseng on nitric oxide synthase, cyclo-oxygenase-2 and neutrophil functions.

A water extract of Panax notoginseng Buck F.H. Chen.