• 한국정보디스플레이학회:학술대회논문집
• /
• 2002.08a
• /
• pp.1005-1008
• /
• 2002

The authors introduce 3D display systems developed in our laboratories for recent ten years. Those are mainly realized by several technologies in holography: electro-holography. holographic stereogram, holographic optical elements (HOE) and hologram screen. We are currently focusing the development of 3D projection screen without glasses. Powerful directionality of the light beam is required for 3D projection screen unlike 2D type. We succeeded in achieving the superior diffractive efficiency of hologram screen that is based on the advanced volume holography. This technology is extensively useful to retrieve the Bragg condition of volume hologram in the three-dimensional space. Owing to this technology we could establish the principle of multi-view projection screen and have confirmed the case of 4 viewing points.

• Journal of Information Display
• /
• v.3 no.3
• /
• pp.1-11
• /
• 2002

Multi-view function is important to three-dimensional displays without dedicated glasses. It is the reason that the observers earnestly desire to change their positions freely. Multi-viewing is also principal to the reality of three-dimensional (3D) image displayed on the screen. The display of projection type has the advantage that the number of viewing points can be easily increased according to the number of projectors. The authors research on multi-view projection display with hologram screen. Powerful directionality of the diffracted beam from hologram screen is required unlike two-dimensional (2D) display. We developed a new method that all diffracted beams satisfied the same Bragg condition and became sufficiently bright to observe the 3D image under usual indoor light. The principle is based on the essential Bragg diffraction in the three-dimensional space. Owing to such three-dimensional Bragg diffraction we achieved an excellent hologram screen that could be multiple reconstructed in spite of single recording. This hologram screen is able to answer arbitrary numbers of viewing points within wide viewing zone. The distortion of 3D image becomes also sufficiently small with the method of dividing the cross angle between illumination and diffraction beam.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.8
• /
• pp.76-81
• /
• 1998

This paper presents a new method to synthesize a digital hologram that meets the resolution of a currently manufactured LCD while capable of displaying a 3-D object. That is accomplished by segmenting a hologram, resulting in relaxed sampling constraint. We show that the segmentation of a hologram enables us to utilize the planewave approximation and, unlike in a holographic stereogram, it does not require projection process, but directly takes fourier transform of horizontally sliced 2-D images that constitute a 3-D object, which makes it possible to reconstruct a higher resolution image with depth information. We also show that proposed hologram contains data significantly smaller than the conventional hologram does, which is quite useful for constructing wide-viewing hologram. Finally, simulation results obtained by both methods are compared.

• The Journal of the Korea Contents Association
• /
• v.12 no.12
• /
• pp.597-604
• /
• 2012

In order to actualize the third dimension form, hologram is coming to attention because it has no restriction on viewing position and is capable of natural visual expression. Although hologram technology is the best method to embody 3D image without glasses, it is not commercialized due to several technological problems. Currently used hologram technology in concerts or exhibitions are images flashed on a 2-dimensional transparent screen by HD projectors which is similar to hologram technology, not truly same. In this research, we make 3D contents for Holographic projection and use these contents to present art that can interact with spectators. As a result of the exhibition, attendance showed satisfaction on inspection form, allowing spectators to move around the screen and view it both sides; moreover, they were enterprising to interact with the videos played according to their movements. Therefore, we are able to implement a sensible and spatio-temporal artwork along with interesting space production and represent a intimate and interactive space with the public.

• KIPS Transactions on Software and Data Engineering
• /
• v.10 no.10
• /
• pp.429-438
• /
• 2021

In recent, realistic content has been applied in various ways due to the development of display technology and hologram, the final realistic content technology, have been used limitedly in accordance with the growing public demand. However, most realistic content requires additional devices of HMD (head mounted device) or glasses type, and other realistic content display technologies deliver a single image plane in the experience space to the user, providing a monotonous content experience. Various realistic contents with hologram technology are introduced in this work. In addition, we propose an interaction based realistic hologram service based that combines projection mapping and floating holograms. Projection-mapped screens and multi-floating hologram device provide a three-dimensional volumetric space with extended depth orientation from the user's point of view, while allowing users' entire and partial motions to be recognizable through multiple sensors.

• Proceedings of the Optical Society of Korea Conference
• /
• 2009.10a
• /
• pp.331-332
• /
• 2009

We present an analysis on the quality factors of the Fourier hologram generated from multiple orthographic view images of three-dimensional object. In the analysis, we analyze both the maximum size of the reconstructed object and its spatial resolution. For the maximum size of the reconstruction, we found that the main factor is the orthographic projection angle interval. Too large projection angle interval causes overlapping in the reconstruction space domain. For the spatial resolution, there are three factors, i.e. the capturing lens array pitch which determines the spatial sampling rate of the original three-dimensional objects, the maximum orthographic projection angle, and the spatial frequency bandwidth of the object. The dominant factor is determined by the relationship between those three factors.

• International journal of advanced smart convergence
• /
• v.8 no.1
• /
• pp.18-23
• /
• 2019

The image projected onto the screen of the floating hologram is no more than a two-dimensional image. Although it creates an illusion that an object appears to float in space as it moves around while showing its different parts. This paper has proposed a novel method of floating 3D hologram display to view stereoscopic three-dimensional images without putting on glasses. The system is comprised of a sharkstooth scrim screen, projector, polarizing filter for the projector, and a polarizing film to block the image projected from the sham screen. As part of the polarization characteristics, the background image and the front object have completely been separated from each other with the stereoscopic 3D effect successfully implemented by the binocular disparity caused by the distance between the two screens.

• Journal of Broadcast Engineering
• /
• v.19 no.6
• /
• pp.866-876
• /
• 2014

Generating of digital hologram of video contents with computer graphics(CG) requires natural fusion of 3D information between real and virtual. In this paper, we propose the system which can fuse real-virtual 3D information naturally and fast generate the digital hologram of fused results using multiple-GPUs based computer-generated-hologram(CGH) computing part. The system calculates camera projection matrix of RGB-Depth camera, and estimates the 3D information of virtual object. The 3D information of virtual object from projection matrix and real space are transmitted to Z buffer, which can fuse the 3D information, naturally. The fused result in Z buffer is transmitted to multiple-GPUs based CGH computing part. In this part, the digital hologram of fused result can be calculated fast. In experiment, the 3D information of virtual object from proposed system has the mean relative error(MRE) about 0.5138% in relation to real 3D information. In other words, it has the about 99% high-accuracy. In addition, we verify that proposed system can fast generate the digital hologram of fused result by using multiple GPUs based CGH calculation.

• Korean Journal of Optics and Photonics
• /
• v.20 no.3
• /
• pp.175-181
• /
• 2009

Holographic lithography is one of the potential technologies for next generation lithography which can print large areas (6") as well as very fine patterns ($0.35{\mu}m$). Usually, photolithography has been developed with two target purposes. One was for LCD applications which require large areas (over 6") and micro pattern (over $1.5{\mu}m$) exposure. The other was for semiconductor applications which require small areas (1.5") and nano pattern (under $0.2{\mu}m$) exposure. However, holographic lithography can print fine patterns from $0.35{\mu}m$ to $1.5{\mu}m$ keeping the exposure area inside 6". This is one of the great advantages in order to realize high speed fine pattern photolithography. How? It is because holographic lithography is taking holographic optics instead of projection optics. A hologram mask is the key component of holographic optics, which can perform the same function as projection optics. In this paper, Surface-Relief TIR Hologram Mask technology is introduced, and enables more robust hologram masks than those previously reported that were formed in photopolymer recording materials. We describe the important parameters in the fabrication process and their optimization, and we evaluate the patterns printed from the surface-relief TIR hologram masks.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.437-440
• /
• 2003

Computer-generated holograms of real existing are synthesized by using a series of projection images of an incoherently illuminated object. The principle of computer tomography is applied to obtain the 3-D Fourier spectrum of the object. A Fresnel hologram is calculated directly from the 3-D Fourier spectrum. Experimental results with simulation are presented and some optical properties of reconstructed images are discussed.