ABSTRACT
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. The feasibility of the system is demonstrated by an experimental system composed of a planar and a spherical screen with a collimating lens. In addition, accommodation properties of the proposed system are demonstrated according to the depth modulation method.
ABSTRACT
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. Two multi-projection methods are proposed based on reflection type integral imaging and multi-view method. Especially, the reflection type multi-view-based system is realized with a curved anisotropic diffuser. High resolution see-through 3D display can be realized with the proposed methods. They can be used in various applications with the two multi-projection methods. In order to show the augmented reality features, real objects and virtual 3D images are presented at the same time in the experimental setup.
ABSTRACT
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. The polarization modulation of the image from a single projection unit enables us to generate two viewing zones at different positions. For realizing full-color images at each viewing zone, a polarization-based temporal multiplexing technique is adopted with a conventional polarization switching device of liquid crystal (LC) display. Through experiments, a prototype of a ten-view multi-projection 3D display system presenting full-colored view images is implemented by combining five laser scanning projectors, an optically clear calcite (CaCO3) crystal, and an LC polarization rotator. For each time sequence of temporal multiplexing, the luminance distribution of the proposed system is measured and analyzed.
ABSTRACT
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. Also, if the system is constructed properly, it is possible to generate view images with inter-pupillary gap and satisfy the super multi-view condition. We explain the principle of the proposed system and verify its feasibility with simulations and experimental results.
ABSTRACT
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. In addition, we deduce an equivalent model of such a light-guide to simplify the analysis of the image distortion in the light-guide. From the equivalent model, the focus of the image is adjusted, and pre-distorted images for each projection unit are calculated by two-step image rectification in air and the material. The distortion-compensated view images are represented on the exit surface of the light-guide when the light-guide is located in the intended position. Viewing zones are generated by combining the light-guide projection system, a vertical diffuser, and a Fresnel lens. The feasibility of the proposed method is experimentally verified and a ten-view 3D display system with a minimized structure is implemented.
ABSTRACT
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. In addition, dynamic vertical and horizontal motion parallax can be given according to the tracked position of the viewer. As the depth-fusing effect is not dependent on the viewing distance, accommodation cue and motion parallax are provided for a wide range of viewing position. We demonstrate the feasibility of our proposed method by experimental system.
ABSTRACT
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. In this paper, we propose the volume using the layers of switchable diffusers to implement the active-type Lamina 3D display system. Because the diffusing rate of the layers has no relation with the polarization state, the polarizer wheel is applied to the proposed system in purpose of making the sectioned image synchronized with the diffusing layer at the designated location. The imaging volume of the proposed system consists of five layers of polymer dispersed liquid crystal and the total size of the implemented volume is 24x18x12 mm3(3). The proposed system can achieve the improvements of viewing qualities such as enhanced depth expression and widened viewing angle.
ABSTRACT
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. By adopting projection optics to the depth encoding system, reconstructed 3D images can be scaled like images of 2D projection displays. 3D reconstruction characteristics of the polarization-encoded images are analyzed with simulation and experiment. The experimental system is also demonstrated to show feasibility of the proposed method.
Subject(s)
Imaging, Three-Dimensional/instrumentation , Refractometry/instrumentation , Signal Processing, Computer-Assisted/instrumentation , Equipment DesignABSTRACT
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. In this paper, we analyzed the various projection geometries of multi-projection systems, and explained the different depth-expression characteristics for each individual projection geometry. We also demonstrated the depth-expression characteristic of an experimental multi-projection system.
ABSTRACT
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. Meanwhile, light reflected by a concave mirror-array becomes Bragg mismatched light, and is integrated into three-dimensional images without the fill factor problem. The optical characteristics of the DHOE are examined by measuring diffraction efficiencies, and the feasibility of the fill-factor-improved InIm is verified by a concave mirror-array and DHOE.
Subject(s)
Holography/instrumentation , Imaging, Three-Dimensional/instrumentation , Optical Phenomena , DiffusionABSTRACT
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. Instead of reducing the size of hogel, the lateral resolution of holographic stereograms can be enhanced by printing overlapped hogels, which makes it possible to take advantage of multiplexing property of the volume hologram. We built a holographic printer, and recorded two holographic stereograms using the conventional and proposed overlapping methods. The images and movies of the holographic stereograms experimentally captured were compared between the conventional and proposed methods. The experimental results confirm that the proposed hogel overlapping method improves the lateral resolution of holographic stereograms compared to the conventional holographic printing method.
Subject(s)
Computer-Aided Design , Holography/instrumentation , Image Enhancement/instrumentation , Imaging, Three-Dimensional/instrumentation , Models, Theoretical , Computer Simulation , Equipment Design , Equipment Failure Analysis , Light , Scattering, RadiationABSTRACT
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.
ABSTRACT
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. The occlusion effect between 2D images and 3D images is realized by using a compensation mask for 2D images and the elemental images. The principle of proposed system is experimentally verified.
Subject(s)
Image Enhancement/instrumentation , Imaging, Three-Dimensional/instrumentation , Lighting/instrumentation , Refractometry/instrumentation , Equipment Design , Equipment Failure Analysis , Systems IntegrationABSTRACT
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. To overcome the limitation of the pinhole interval, we use a color filter pinhole array on a display panel and a projection-type integral imaging scheme. The use of a color filter pinhole array and the projection scheme can enlarge the region of one elemental image and improve the resolution and ray density remarkably. This paper presents the experimental results of the proposed method and a comparison with conventional methods.
Subject(s)
Color , Computer-Aided Design , Filtration/instrumentation , Lighting/instrumentation , Liquid Crystals/chemistry , Equipment Design , Equipment Failure AnalysisABSTRACT
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. However, in the proposed method, the real and the virtual modes can be displayed simultaneously by generating multiple elemental image layers within the depth of field of a single projector. To embody the proposed method, the system specifications, such as the focal lengths of lenses and the distance between components, must be designed carefully. In this paper, we define and calculate the system factors and present the design role of the system. The feasibility of the proposed method is demonstrated with experimental results.
ABSTRACT
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. We demonstrate the feasibility of our proposal by the experiment.
Subject(s)
Imaging, Three-Dimensional/instrumentation , Refractometry/instrumentation , Signal Processing, Computer-Assisted/instrumentation , Equipment Design , Equipment Failure Analysis , Feasibility StudiesABSTRACT
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. With such unique characteristic, 3D/2D conversion or even the simultaneous display of 3D and 2D images is also possible. The prototype was fabricated by the aluminum coating and the polydimethylsiloxane molding process. We could experimentally verify the 3D/2D conversion and the display of 3D image on 2D background with the fabricated prototype.
Subject(s)
Image Processing, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Polymers/chemistry , Algorithms , Aluminum/chemistry , Dimethylpolysiloxanes/chemistry , Equipment Design , Light , Optics and Photonics , Scattering, RadiationABSTRACT
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. The feasibility of the proposal is proved by the experiments.
ABSTRACT
A water extract of Panax notoginseng Buck F.H. Chen. (Arialiaceae) root (PN) is being used as a therapeutic agent to stop haemorrhages and as a tonic to promote health in Korean and Chinese medicine. The pharmacokinetic profiles of PN have not been accurately investigated. The preliminary aim was to elucidate the pharmacokinetic features of PN. First, the prevention of neutrophil functions was assessed. PN inhibited neutrophil functions, including degranulation, superoxide generation and leukotriene B4 production, without any effect on 5-lipoxygenase activity. PN reduced nitric oxide (NO) and prostaglandin (PG)E2 production in mouse peritoneal macrophages stimulated with lipopolysaccharide (LPS) while no influence on the activity of inducible NO synthase (iNOS), cyclo-oxygenase-2 (COX-2) or cyclo-oxygenase-1 (COX-1) was observed. PN significantly reduced mouse paw oedema induced by carrageenan. The results indicate that PN exerts antiinflammatory effects related to the inhibition of neutrophil functions and NO and PGE2 production, which could be due to a decreased expression of iNOS and COX-2.
