63 research outputs found

    An autostereoscopic device for mobile applications based on a liquid crystal microlens array and an OLED display

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    In recent years, many experimental and theoretical research groups worldwide have actively worked on demonstrating the use of liquid crystals (LCs) as adaptive lenses for image generation, waveform shaping, and non-mechanical focusing applications. In particular, important achievements have concerned the development of alternative solutions for 3D vision. This work focuses on the design and evaluation of the electro-optic response of a LC-based 2D/3D autostereoscopic display prototype. A strategy for achieving 2D/3D vision has been implemented with a cylindrical LC lens array placed in front of a display; this array acts as a lenticular sheet with a tunable focal length by electrically controlling the birefringence. The performance of the 2D/3D device was evaluated in terms of the angular luminance, image deflection, crosstalk, and 3D contrast within a simulated environment. These measurements were performed with characterization equipment for autostereoscopic 3D displays (angular resolution of 0.03 )

    Three-dimensional media for mobile devices

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    Cataloged from PDF version of article.This paper aims at providing an overview of the core technologies enabling the delivery of 3-D Media to next-generation mobile devices. To succeed in the design of the corresponding system, a profound knowledge about the human visual system and the visual cues that form the perception of depth, combined with understanding of the user requirements for designing user experience for mobile 3-D media, are required. These aspects are addressed first and related with the critical parts of the generic system within a novel user-centered research framework. Next-generation mobile devices are characterized through their portable 3-D displays, as those are considered critical for enabling a genuine 3-D experience on mobiles. Quality of 3-D content is emphasized as the most important factor for the adoption of the new technology. Quality is characterized through the most typical, 3-D-specific visual artifacts on portable 3-D displays and through subjective tests addressing the acceptance and satisfaction of different 3-D video representation, coding, and transmission methods. An emphasis is put on 3-D video broadcast over digital video broadcasting-handheld (DVB-H) in order to illustrate the importance of the joint source-channel optimization of 3-D video for its efficient compression and robust transmission over error-prone channels. The comparative results obtained identify the best coding and transmission approaches and enlighten the interaction between video quality and depth perception along with the influence of the context of media use. Finally, the paper speculates on the role and place of 3-D multimedia mobile devices in the future internet continuum involving the users in cocreation and refining of rich 3-D media content

    ํˆฌ๋ช…ํ•œ ๋งค์งˆ์—์„œ์˜ ๊ด‘ ๊ฒฝ๋กœ ๋ถ„์„์„ ์ด์šฉํ•œ ์ง‘์•ฝ์  3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด

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    ํ•™์œ„๋…ผ๋ฌธ (๋ฐ•์‚ฌ)-- ์„œ์šธ๋Œ€ํ•™๊ต ๋Œ€ํ•™์› : ์ „๊ธฐยท์ปดํ“จํ„ฐ๊ณตํ•™๋ถ€, 2017. 2. ์ด๋ณ‘ํ˜ธ.๋ณธ ๋ฐ•์‚ฌํ•™์œ„ ๋…ผ๋ฌธ์—์„œ๋Š” ๊ด‘ํ•™์ ์œผ๋กœ ํˆฌ๋ช…ํ•œ ๋งค์งˆ์—์„œ์˜ ๊ด‘ ๊ฒฝ๋กœ ๋ถ„์„์„ ๋ฐ”ํƒ•์œผ๋กœ ์ง‘์•ฝ์ ์ธ 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ์„ ๊ตฌํ˜„ํ•˜๋Š” ์ ‘๊ทผ ๋ฐฉ๋ฒ•์— ๋Œ€ํ•˜์—ฌ ๋…ผ์˜ํ•œ๋‹ค. 3์ฐจ์› ์˜์ƒ ์žฅ์น˜๋ฅผ ๊ตฌ์„ฑํ•˜๋Š” ์š”์†Œ์™€ ์‹œ์ฒญ์ž ์‚ฌ์ด์˜ ๋ฌผ๋ฆฌ์ ์ธ ๊ฑฐ๋ฆฌ๋ฅผ ์ค„์ด๋Š” ๊ฒƒ์€ ์ง‘์•ฝ์ ์ธ 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ์„ ๊ตฌํ˜„ํ•˜๋Š” ์ง๊ด€์ ์ธ ๋ฐฉ๋ฒ•์ด๋‹ค. ๋˜ํ•œ, ๊ธฐ์กด ์‹œ์Šคํ…œ์˜ ํฌ๊ธฐ๋ฅผ ์œ ์ง€ํ•˜๋ฉด์„œ ๋” ๋งŽ์€ ์–‘์˜ 3์ฐจ์› ์˜์ƒ ์ •๋ณด๋ฅผ ํ‘œํ˜„ํ•˜๋Š” ๊ฒƒ ๋˜ํ•œ ์ง‘์•ฝ์  3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ์„ ์˜๋ฏธํ•œ๋‹ค. ๋†’์€ ๋Œ€์—ญํญ๊ณผ ์ž‘์€ ๊ตฌ์กฐ๋ฅผ ๊ฐ€์ง„ ์ง‘์•ฝ์  3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ์„ ๊ตฌํ˜„ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๋‹ค์Œ์˜ ๋‘ ๊ฐ€์ง€ ๊ด‘ํ•™ ํ˜„์ƒ์„ ์ด์šฉํ•œ๋‹ค. ๋“ฑ๋ฐฉ์„ฑ ๋ฌผ์งˆ์—์„œ์˜ ์ „๋ฐ˜์‚ฌ ํŠน์„ฑ๊ณผ ์ด๋ฐฉ์„ฑ ๋ฌผ์งˆ์—์„œ์˜ ๋ณต๊ตด์ ˆ ํŠน์„ฑ์ด๋‹ค. ๊ฐ€์‹œ๊ด‘ ์˜์—ญ์—์„œ ๋น›์„ ํˆฌ๊ณผ์‹œํ‚ค๋Š” ๋‘ ๋งค์งˆ์˜ ๊ณ ์œ  ๊ด‘ํ•™ ํŠน์„ฑ์„ ๊ธฐ์กด์˜ 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ์— ์ ์šฉํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๊ด‘ ๊ฒฝ๋กœ ์ถ”์ ์„ ํ†ตํ•˜์—ฌ ๋ถ„์„ํ•œ๋‹ค. ๊ด‘ ๋„ํŒŒ๋กœ์˜ ์ „๋ฐ˜์‚ฌ ํŠน์„ฑ์€ ์ง‘์•ฝ์  ๋‹ค์ค‘ ํˆฌ์‚ฌ 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ์„ ๊ตฌํ˜„ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ์‚ฌ์šฉํ•œ๋‹ค. ํˆฌ์‚ฌ ๊ด‘ํ•™๊ณ„์˜ ์˜์ƒ ์ •๋ณด๋Š” ๊ด‘ ๋„ํŒŒ๋กœ๋กœ ์ž…์‚ฌ, ๋‚ด๋ถ€์—์„œ ์ „๋ฐ˜์‚ฌ๋ฅผ ํ†ตํ•˜์—ฌ ์ง„ํ–‰ํ•˜๊ณ , ์ด์— ์ˆ˜ํ‰ ํˆฌ์‚ฌ ๊ฑฐ๋ฆฌ๋Š” ๊ด‘ ๋„ํŒŒ๋กœ์˜ ๋‘๊ป˜๋กœ ์ œํ•œ๋œ๋‹ค. ๋‹ค์ˆ˜์˜ ์ „๋ฐ˜์‚ฌ ์ดํ›„ ์˜์ƒ ์ •๋ณด๋Š” ๊ด‘ ๋„ํŒŒ๋กœ์˜ ์ถœ์‚ฌ ๋ฉด์„ ํ†ตํ•ด ๋น ์ ธ๋‚˜๊ฐ€๊ณ , ๋ Œ์ฆˆ์— ์˜ํ•˜์—ฌ ์ตœ์  ์‹œ์ฒญ ์ง€์ ์—์„œ ์‹œ์ ์„ ํ˜•์„ฑํ•œ๋‹ค. ๊ด‘ ๋„ํŒŒ๋กœ ๋‚ด๋ถ€์—์„œ์˜ ๊ด‘ ๊ฒฝ๋กœ๋ฅผ ๋“ฑ๊ฐ€ ๋ชจ๋ธ์„ ํ†ตํ•˜์—ฌ ์กฐ์‚ฌํ•˜๊ณ , ์ด๋ฅผ ํ†ตํ•ด ๋‹ค์ˆ˜์˜ ํˆฌ์‚ฌ ๊ด‘ํ•™๊ณ„๋กœ๋ถ€ํ„ฐ ์ƒ์„ฑ๋œ ๋‹ค์ˆ˜์˜ ์‹œ์  ์˜์ƒ์ด ์™œ๊ณก๋˜๋Š” ๊ฒƒ์„ ๋ถ„์„ํ•˜๊ณ  ๋ณด์ •ํ•œ๋‹ค. 10๊ฐœ์˜ ์‹œ์ ์„ ์ œ๊ณตํ•˜๋Š” ์ง‘์•ฝ์  ๋‹ค์ค‘ ํˆฌ์‚ฌ 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ์„ ํ†ตํ•ด ์ œ์•ˆ๋œ ๋ฐฉ๋ฒ•์„ ๊ฒ€์ฆํ•œ๋‹ค. ํ–ฅ์ƒ๋œ ๋Œ€์—ญํญ ํŠน์„ฑ์„ ๊ฐ€์ง„ ๋‹ค์ค‘ ํˆฌ์‚ฌ 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด์™€ ๋‹ค์ค‘ ์ดˆ์  ํ—ค๋“œ ๋งˆ์šดํŠธ ๋””์Šคํ”Œ๋ ˆ์ด ๊ตฌํ˜„์„ ์œ„ํ•œ ์ด๋ฐฉ์„ฑ ํŒ์„ ์ด์šฉํ•œ ํŽธ๊ด‘ ๋‹ค์ค‘ํ™” ๋ฐฉ๋ฒ•์„ ์ œ์•ˆํ•œ๋‹ค. ๋น›์˜ ํŽธ๊ด‘ ์ƒํƒœ, ์ด๋ฐฉ์„ฑ ํŒ์˜ ๊ด‘์ถ• ๋ฐฉํ–ฅ์— ๋”ฐ๋ผ ๊ด‘ ๊ฒฝ๋กœ๊ฐ€ ๋‹ฌ๋ผ์ง„๋‹ค. ์ธก๋ฉด ๋ฐฉํ–ฅ์œผ๋กœ์˜ ๊ด‘ ๊ฒฝ๋กœ ์ „ํ™˜์€ ๋‹ค์ค‘ ํˆฌ์‚ฌ 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ๊ธฐ์ˆ ๊ณผ ๊ฒฐํ•ฉํ•˜์—ฌ ์‹œ์ ์„ ์ธก๋ฉด ๋ฐฉํ–ฅ์œผ๋กœ ๋‘ ๋ฐฐ๋กœ ์ฆ๊ฐ€์‹œํ‚จ๋‹ค. ๊นŠ์ด ๋ฐฉํ–ฅ์œผ๋กœ์˜ ๊ด‘ ๊ฒฝ๋กœ ์ „ํ™˜์€ ํ—ค๋“œ ๋งˆ์šดํŠธ ๋””์Šคํ”Œ๋ ˆ์ด์—์„œ ๋‹ค์ค‘ ์ดˆ์  ๊ธฐ๋Šฅ์„ ๊ตฌํ˜„ํ•œ๋‹ค. ๊ด‘ ๊ฒฝ๋กœ ์ถ”์  ์‹œ๋ฎฌ๋ ˆ์ด์…˜์„ ํ†ตํ•ด ์ด๋ฐฉ์„ฑ ํŒ์˜ ๋ชจ์–‘, ๊ด‘์ถ•, ํŒŒ์žฅ ๋“ฑ์˜ ๋‹ค์–‘ํ•œ ํŒŒ๋ผ๋ฏธํ„ฐ ๋ณ€ํ™”์— ๋”ฐ๋ฅธ ๊ด‘ ๊ฒฝ๋กœ ์ „ํ™˜์„ ๋ถ„์„ํ•œ๋‹ค. ๊ฐ๊ฐ์˜ ๊ธฐ๋Šฅ์— ๋งž๋„๋ก ์„ค๊ณ„๋œ ์ด๋ฐฉ์„ฑ ํŒ๊ณผ ํŽธ๊ด‘ ํšŒ์ „์ž๋ฅผ ์‹ค์‹œ๊ฐ„์œผ๋กœ ๊ฒฐํ•ฉํ•˜์—ฌ, ๋‹ค์ค‘ ํˆฌ์‚ฌ 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด์™€ ๋‹ค์ค‘ ์ดˆ์  ํ—ค๋“œ ๋งˆ์šดํŠธ ๋””์Šคํ”Œ๋ ˆ์ด์˜ ๋Œ€์—ญํญ์ด 2๋ฐฐ ์ฆ๊ฐ€ํ•œ๋‹ค. ๊ฐ ์‹œ์Šคํ…œ์— ๋Œ€ํ•œ ์‹œ์ž‘ํ’ˆ์„ ์ œ์ž‘ํ•˜๊ณ , ์ œ์•ˆ๋œ ๋ฐฉ๋ฒ•์„ ์‹คํ—˜์ ์œผ๋กœ ๊ฒ€์ฆํ•œ๋‹ค. ๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ๊ด‘ ๋„ํŒŒ๋กœ์™€ ๋ณต๊ตด์ ˆ ๋ฌผ์งˆ์„ ์ด์šฉํ•˜์—ฌ ๊ทธ ๊ด‘ ๊ฒฝ๋กœ๋ฅผ ๋ถ„์„, ๋Œ€ํ˜•์˜ ๋‹ค์ค‘ ํˆฌ์‚ฌ 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ๊ณผ ๊ฐœ์ธ ์‚ฌ์šฉ์ž์˜ ํ—ค๋“œ ๋งˆ์šดํŠธ ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ์˜ ํฌ๊ธฐ๋ฅผ ๊ฐ์†Œ์‹œํ‚ค๊ณ , ํ‘œํ˜„ ๊ฐ€๋Šฅํ•œ ์ •๋ณด๋Ÿ‰์„ ์ฆ๊ฐ€์‹œํ‚ค๋Š” ๋ฐฉ๋ฒ•์„ ์ œ์•ˆํ•œ๋‹ค. ๊ด‘ ๋„ํŒŒ๋กœ์™€ ์ด๋ฐฉ์„ฑ ํŒ์€ ๊ธฐ์กด์˜ 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ๊ณผ ์‰ฝ๊ฒŒ ๊ฒฐํ•ฉ์ด ๊ฐ€๋Šฅํ•˜๋ฉฐ, ์ œ์•ˆ๋œ ๋ฐฉ๋ฒ•์€ ํ–ฅํ›„ ์†Œํ˜•๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ์ค‘๋Œ€ํ˜• 3์ฐจ์› ๋””์Šคํ”Œ๋ ˆ์ด ์‹œ์Šคํ…œ์˜ ์ง‘์•ฝํ™”์— ๊ธฐ์—ฌํ•  ์ˆ˜ ์žˆ์„ ๊ฒƒ์œผ๋กœ ๊ธฐ๋Œ€๋œ๋‹ค.This dissertation investigates approaches for realizing compact three-dimensional (3D) display systems based on optical path analysis in optically transparent medium. Reducing the physical distance between 3D display apparatuses and an observer is an intuitive method to realize compact 3D display systems. In addition, it is considered compact 3D display systems when they present more 3D data than conventional systems while preserving the size of the systems. For implementing compact 3D display systems with high bandwidth and minimized structure, two optical phenomena are investigated: one is the total internal reflection (TIR) in isotropic materials and the other is the double refraction in birefringent crystals. Both materials are optically transparent in visible range and ray tracing simulations for analyzing the optical path in the materials are performed to apply the unique optical phenomenon into conventional 3D display systems. An optical light-guide with the TIR is adopted to realize a compact multi-projection 3D display system. A projection image originated from the projection engine is incident on the optical light-guide and experiences multiple folds by the TIR. The horizontal projection distance of the system is effectively reduced as the thickness of the optical light-guide. After multiple folds, the projection image is emerged from the exit surface of the optical light-guide and collimated to form a viewing zone at the optimum viewing position. The optical path governed by the TIR is analyzed by adopting an equivalent model of the optical light-guide. Through the equivalent model, image distortion for multiple view images in the optical light-guide is evaluated and compensated. For verifying the feasibility of the proposed system, a ten-view multi-projection 3D display system with minimized projection distance is implemented. To improve the bandwidth of multi-projection 3D display systems and head-mounted display (HMD) systems, a polarization multiplexing technique with the birefringent plate is proposed. With the polarization state of the image and the direction of optic axis of the birefringent plate, the optical path of rays varies in the birefringent material. The optical path switching in the lateral direction is applied in the multi-projection system to duplicate the viewing zone in the lateral direction. Likewise, a multi-focal function in the HMD is realized by adopting the optical path switching in the longitudinal direction. For illuminating the detailed optical path switching and the image characteristic such as an astigmatism and a color dispersion in the birefringent material, ray tracing simulations with the change of optical structure, the optic axis, and wavelengths are performed. By combining the birefringent material and a polarization rotation device, the bandwidth of both the multi-projection 3D display and the HMD is doubled in real-time. Prototypes of both systems are implemented and the feasibility of the proposed systems is verified through experiments. In this dissertation, the optical phenomena of the TIR and the double refraction realize the compact 3D display systems: the multi-projection 3D display for public and the multi-focal HMD display for individual. The optical components of the optical light-guide and the birefringent plate can be easily combined with the conventional 3D display system and it is expected that the proposed method can contribute to the realization of future 3D display systems with compact size and high bandwidth.Chapter 1 Introduction 10 1.1 Overview of modern 3D display providing high quality 3D images 10 1.2 Motivation of this dissertation 15 1.3 Scope and organization 18 Chapter 2 Compact multi-projection 3D displays with optical path analysis of total internal reflection 20 2.1 Introduction 20 2.2 Principle of compact multi-projection 3D display system using optical light-guide 23 2.2.1 Multi-projection 3D display system 23 2.2.2 Optical light-guide for multi-projection 3D display system 26 2.2.3 Analysis on image characteristics of projection images in optical light-guide 34 2.2.4 Pre-distortion method for view image compensation 44 2.3 Implementation of prototype of multi-projection 3D display system with reduced projection distance 47 2.4 Summary and discussion 52 Chapter 3 Compact multi-projection 3D displays with optical path analysis of double refraction 53 3.1 Introduction 53 3.2 Principle of viewing zone duplication in multi-projection 3D display system 57 3.2.1 Polarization-dependent optical path switching in birefringent crystal 57 3.2.2 Analysis on image formation through birefringent plane-parallel plate 60 3.2.3 Full-color generation of dual projection 64 3.3 Implementation of prototype of viewing zone duplication of multi-projection 3D display system 68 3.3.1 Experimental setup for viewing zone duplication of multi-projection 3D display system 68 3.3.2 Luminance distribution measurement of viewing zone duplication of multi-projection 3D display system 74 3.4 Summary and discussion 79 Chapter 4 Compact multi-focal 3D HMDs with optical path analysis of double refraction 81 4.1 Introduction 81 4.2 Principle of multi-focal 3D HMD system 86 4.2.1 Multi-focal 3D HMD system using Savart plate 86 4.2.2 Astigmatism compensation by modified Savart plate 89 4.2.3 Analysis on lateral chromatic aberration of extraordinary plane 96 4.2.4 Additive type compressive light field display 101 4.3 Implementation of prototype of multi-focal 3D HMD system 104 4.4 Summary and discussion 112 Chapter 5 Conclusion 114 Bibliography 117 Appendix 129 ์ดˆ ๋ก 130Docto

    Optical simulation, modeling and evaluation of 3D medical displays

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    ํŽธ๊ด‘ ๋‹ค์ค‘ํ™”๋ฅผ ์ด์šฉํ•˜์—ฌ ํ–ฅ์ƒ๋œ ๊ธฐ๋Šฅ์„ ์ œ๊ณตํ•˜๋Š” ๋„ํŒŒ๊ด€ ๊ธฐ๋ฐ˜์˜ ๊ทผ์•ˆ ๋””์Šคํ”Œ๋ ˆ์ด

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    ํ•™์œ„๋…ผ๋ฌธ (๋ฐ•์‚ฌ) -- ์„œ์šธ๋Œ€ํ•™๊ต ๋Œ€ํ•™์› : ๊ณต๊ณผ๋Œ€ํ•™ ์ „๊ธฐยท์ •๋ณด๊ณตํ•™๋ถ€, 2021. 2. ์ด๋ณ‘ํ˜ธ.This dissertation presents the studies on the optical design method that enhances the display performance of see-through waveguide-based near-eye displays (WNEDs) using the polarization multiplexing technique. The studies focus on the strategies to improve the crucial display performances without compromising a small form factor, the most attractive merit of the WNEDs. To achieve this goal, thin and lightweight polarization-dependent optical elements are devised and employed in the WNED structure. The polarization-dependent devices can allow multiple optical functions or optical paths depending on the polarization state of the input beam, which can break through the limitation of the waveguide system with the polarization multiplexing. To realize the function-selective eyepiece for AR applications, the proposed devices should operate as an optically transparent window for the real scene while performing specific optical functions for the virtual image. The proposed devices are manufactured in a combination structure in which polarization-dependent optical elements are stacked. The total thickness of the stacked structure is about 1 mm, and it can be attached to the waveguide surface without conspicuously increasing the form factor of the optical system. Using the proposed polarization-dependent devices, the author proposes three types of novel WNED systems with enhanced performance. First, the author suggests a compact WNED with dual focal planes. Conventional WNEDs have an inherent limitation that the focal plane of the virtual image is at an infinite distance because they extract a stream of collimated light at the out-coupler. By using the polarization-dependent eyepiece lens, an additional focal plane can be generated with the polarization multiplexing in addition to infinity depth. The proposed configuration can provide comfortable AR environments by alleviating visual fatigue caused by vergence-accommodation conflict. Second, the novel WNED configuration with extended field-of-view (FOV) is presented. In the WNEDs, the maximum allowable FOV is determined by the material properties of the diffraction optics and the substrate. By using the polarization-dependent steering combiner, the FOV can be extended up to two times, which can provide more immersive AR experiences. In addition, this dissertation demonstrates that the distortion for the real scene caused by the stacked structure cannot severely disturb the image quality, considering the acuity of human vision. Lastly, the author presents a retinal projection-based WNED with switchable viewpoints by simultaneously adopting the polarization-dependent lens and grating. The proposed system can convert the viewpoint according to the position of the eye pupil without mechanical movement. The polarization-dependent viewpoint switching can resolve the inherent problem of a narrow eyebox in retinal projection displays without employing the bulky optics for mechanical movement. In conclusion, the dissertation presents the practical optical design and detailed analysis for enhanced WNED based on the polarization multiplexing technique through various simulations and experiments. The proposed approaches are expected to be utilized as an innovative solution for compact wearable displays.๋ณธ ๋ฐ•์‚ฌํ•™์œ„ ๋…ผ๋ฌธ์—์„œ๋Š” ํŽธ๊ด‘ ๋‹ค์ค‘ํ™” ๊ธฐ๋ฒ•์„ ์ด์šฉํ•˜์—ฌ ๋„ํŒŒ๊ด€ ๊ธฐ๋ฐ˜์˜ ์ฆ๊ฐ•ํ˜„์‹ค ๊ทผ์•ˆ ๋””์Šคํ”Œ๋ ˆ์ด์˜ ์„ฑ๋Šฅ์„ ํ–ฅ์ƒ์‹œํ‚ค๋Š” ๊ด‘ํ•™ ์„ค๊ณ„ ๋ฐ ์ด์— ๋Œ€ํ•œ ๋ถ„์„์— ๋Œ€ํ•ด ๋…ผ์˜ํ•œ๋‹ค. ๋ณธ ์—ฐ๊ตฌ๋Š” ๋„ํŒŒ๊ด€ ๊ธฐ๋ฐ˜ ๊ทผ์•ˆ ๋””์Šคํ”Œ๋ ˆ์ด์˜ ๊ฐ€์žฅ ํฐ ์žฅ์ ์ธ ์†Œํ˜• ํผ ํŒฉํ„ฐ๋ฅผ ์œ ์ง€ํ•˜๋ฉด์„œ ๋””์Šคํ”Œ๋ ˆ์ด ์„ฑ๋Šฅ์„ ๊ฐœ์„ ํ•˜๋Š” ๊ฒƒ์— ์ค‘์ ์„ ๋‘”๋‹ค. ์ด๋ฅผ ์œ„ํ•ด ๊ธฐ์กด ๊ด‘ํ•™ ์†Œ์ž์— ๋น„ํ•ด ๋งค์šฐ ๊ฐ€๋ณ๊ณ  ์–‡์€ ํŽธ๊ด‘ ์˜์กดํ˜• ๊ฒฐํ•ฉ๊ธฐ ๊ด‘ํ•™ ์†Œ์ž๊ฐ€ ์ƒˆ๋กญ๊ฒŒ ์ œ์•ˆ๋˜๋ฉฐ, ์ด๋Š” ์ž…์‚ฌ๊ด‘์˜ ํŽธ๊ด‘ ์ƒํƒœ์— ๋”ฐ๋ผ ๋…๋ฆฝ์ ์ธ ๊ด‘ ๊ฒฝ๋กœ ์ œ์–ด๋ฅผ ๊ฐ€๋Šฅ์ผ€ ํ•˜์—ฌ ํŽธ๊ด‘ ๋‹ค์ค‘ํ™”๋ฅผ ํ†ตํ•ด ํ–ฅ์ƒ๋œ ์„ฑ๋Šฅ์„ ์ œ๊ณต ํ•  ์ˆ˜ ์žˆ๋‹ค. ๋˜ํ•œ ์‹ค์ œ ์˜์ƒ์˜ ๋น›์€ ๊ทธ๋Œ€๋กœ ํˆฌ๊ณผ ์‹œํ‚ด์œผ๋กœ์จ ์ฆ๊ฐ•ํ˜„์‹ค์„ ์œ„ํ•œ ์†Œ์ž๋กœ ํ™œ์šฉ ๊ฐ€๋Šฅํ•˜๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ ์ œ์•ˆํ•˜๋Š” ํŽธ๊ด‘ ์˜์กดํ˜• ๊ฒฐํ•ฉ๊ธฐ ๊ด‘ํ•™ ์†Œ์ž๋Š” ๊ธฐํ•˜ํ•™์  ์œ„์ƒ(geometric phase, GP)์— ๊ธฐ๋ฐ˜ํ•˜์—ฌ ๋™์ž‘ํ•œ๋‹ค. GP ๊ธฐ๋ฐ˜์˜ ๊ด‘ํ•™์†Œ์ž๊ฐ€ ์„œ๋กœ ์ง๊ตํ•˜๋Š” ์›ํ˜• ํŽธ๊ด‘ ์ž…์‚ฌ๊ด‘์— ๋Œ€ํ•ด ์ƒ๋ณด์ ์ธ ๊ธฐ๋Šฅ์„ ์ˆ˜ํ–‰ํ•˜๋Š” ๊ฒƒ์„ ์ด์šฉํ•˜์—ฌ, ๋‘ ๊ฐœ ์ด์ƒ์˜ GP ์†Œ์ž์™€ ํŽธ๊ด‘ ์ œ์–ด๋ฅผ ์œ„ํ•œ ๊ด‘ํ•™ ํ•„๋ฆ„๋“ค์„ ์ค‘์ฒฉ ์‹œํ‚ด์œผ๋กœ์จ ์ฆ๊ฐ•ํ˜„์‹ค ๊ฒฐํ•ฉ๊ธฐ ๊ด‘ํ•™ ์†Œ์ž๋ฅผ ๊ตฌํ˜„ํ•  ์ˆ˜ ์žˆ๋‹ค. ์ด๋“ค ๊ด‘ํ•™์†Œ์ž๋Š” ๋งค์šฐ ์–‡๊ธฐ ๋•Œ๋ฌธ์—, ๋ณธ ์—ฐ๊ตฌ์—์„œ ์ œ์ž‘๋œ ํŽธ๊ด‘ ์˜์กดํ˜• ๊ฒฐํ•ฉ๊ธฐ ๊ด‘ํ•™ ์†Œ์ž์˜ ์ด ๋‘๊ป˜๋Š” 1 mm ์ˆ˜์ค€์œผ๋กœ ํผ ํŒฉํ„ฐ ์ œ์•ฝ์œผ๋กœ๋ถ€ํ„ฐ ์ž์œ ๋กญ๋‹ค. ๋˜ํ•œ ํ‰ํ‰ํ•œ ํ•„๋ฆ„ ํ˜•ํƒœ์ด๋ฏ€๋กœ, ํ‰ํŒํ˜• ๋„ํŒŒ๊ด€์— ๋ถ€์ฐฉํ•˜๊ธฐ ์‰ฝ๋‹ค๋Š” ์ด์ ์„ ์ง€๋‹Œ๋‹ค. ๊ณ ์•ˆ๋œ ํŽธ๊ด‘ ์˜์กดํ˜• ๊ฒฐํ•ฉ๊ธฐ ๊ด‘ํ•™ ์†Œ์ž๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ์„ธ ๊ฐ€์ง€ ์œ ํ˜•์˜ ์ƒˆ๋กœ์šด ๋„ํŒŒ๊ด€ ๊ธฐ๋ฐ˜์˜ ๊ทผ์•ˆ ๋””์Šคํ”Œ๋ ˆ์ด ๊ตฌ์กฐ๋ฅผ ์ œ์•ˆํ•œ๋‹ค. ์ฒซ ๋ฒˆ์งธ๋Š” ์ž…์‚ฌ๊ด‘์˜ ํŽธ๊ด‘ ์ƒํƒœ์— ๋”ฐ๋ผ ํˆฌ๋ช… ๊ด‘ํ•™ ์ฐฝ ๋˜๋Š” ์˜ค๋ชฉ ๋ Œ์ฆˆ๋กœ ์ž‘๋™ํ•˜๋Š” ํŽธ๊ด‘ ์˜์กดํ˜• ๊ฒฐํ•ฉ๊ธฐ ๋ Œ์ฆˆ๋ฅผ ์ ์šฉํ•˜์—ฌ ๊ฐ€์ƒ ์˜์ƒ์— ๋Œ€ํ•ด ์ด์ค‘ ์ดˆ์ ๋ฉด์„ ์ œ๊ณตํ•˜๋Š” ์‹œ์Šคํ…œ์ด๋‹ค. ์ œ์•ˆ๋œ ๊ตฌ์กฐ๋Š” ๊ธฐ์กด์˜ ๋„ํŒŒ๊ด€ ๊ธฐ๋ฐ˜ ๊ทผ์•ˆ ๋””์Šคํ”Œ๋ ˆ์ด๊ฐ€ ๋ฌดํ•œ๋Œ€ ์œ„์น˜์— ๋‹จ์ผ ์ดˆ์ ๋ฉด์„ ์ œ๊ณตํ•จ์œผ๋กœ์จ ๋ฐœ์ƒํ•˜๋Š” ์‹œ๊ฐ์  ํ”ผ๋กœ ๋ฐ ํ๋ฆฟํ•œ ์ฆ๊ฐ•ํ˜„์‹ค ์˜์ƒ์˜ ๋ฌธ์ œ๋ฅผ ์™„ํ™”ํ•  ์ˆ˜ ์žˆ๋‹ค. ๋‘ ๋ฒˆ์งธ๋กœ๋Š” ์ž…์‚ฌ๊ด‘์˜ ํŽธ๊ด‘ ์ƒํƒœ์— ๋”ฐ๋ผ ๊ด‘ ๊ฒฝ๋กœ๋ฅผ ์ขŒ์ธก ๋˜๋Š” ์šฐ์ธก์œผ๋กœ ์ œ์–ดํ•  ์ˆ˜ ์žˆ๋Š” ํŽธ๊ด‘ ๊ฒฉ์ž๋ฅผ ํ™œ์šฉํ•˜์—ฌ ๊ฐ€์ƒ ์˜์ƒ์˜ ์‹œ์•ผ๊ฐ์„ ๊ธฐ์กด๋ณด๋‹ค ์ตœ๋Œ€ 2๋ฐฐ๊นŒ์ง€ ํ™•์žฅํ•  ์ˆ˜ ์žˆ๋Š” ์‹œ์Šคํ…œ์„ ์ œ์•ˆํ•œ๋‹ค. ์ด๋Š” ๋‹จ์ผ ๋„ํŒŒ๊ด€ ๊ธฐ๋ฐ˜ ๊ทผ์•ˆ ๋””์Šคํ”Œ๋ ˆ์ด์—์„œ ์˜์ƒ ๊ฒฐํ•ฉ๊ธฐ (imaging combiner)๋กœ ํ™œ์šฉ๋˜๋Š” ํšŒ์ ˆ ์†Œ์ž์˜ ์„ค๊ณ„ ๋ณ€์ˆ˜์— ์˜ํ•ด ์ œํ•œ๋˜๋Š” ์‹œ์•ผ๊ฐ ํ•œ๊ณ„์ ์„ ๋ŒํŒŒํ•  ์ˆ˜ ์žˆ๋Š” ๊ตฌ์กฐ๋กœ ์ปดํŒฉํŠธํ•œ ํผ ํŒฉํ„ฐ๋กœ ๋”์šฑ ๋ชฐ์ž…๊ฐ ์žˆ๋Š” ๋Œ€ํ™”๋ฉด ์ฆ๊ฐ•ํ˜„์‹ค ์˜์ƒ์„ ์ œ๊ณตํ•  ์ˆ˜ ์žˆ๋‹ค. ๋งˆ์ง€๋ง‰์œผ๋กœ ์œ„์—์„œ ์ œ์•ˆ๋œ ๋‘ ๊ฐ€์ง€ ํŽธ๊ด‘ ์˜์กดํ˜• ๊ด‘ํ•™ ์†Œ์ž๋ฅผ ๋ชจ๋‘ ์‚ฌ์šฉํ•˜์—ฌ ์‹œ์  ์ „ํ™˜์ด ๊ฐ€๋Šฅํ•œ ๋„ํŒŒ๊ด€ ๊ธฐ๋ฐ˜์˜ ๋ง๋ง‰ ํˆฌ์‚ฌํ˜• ๋””์Šคํ”Œ๋ ˆ์ด ๊ตฌ์กฐ๋ฅผ ์ œ์•ˆํ•œ๋‹ค. ํŽธ๊ด‘ ๋‹ค์ค‘ํ™”๋ฅผ ํ†ตํ•ด ๋‹ค์ค‘ ์ดˆ์ ๋“ค์„ ์„ ํƒ์ ์œผ๋กœ ํ™œ์„ฑํ™”ํ•จ์œผ๋กœ์จ, ํ™•์žฅ๋œ ์‹œ์ฒญ์˜์—ญ์„ ์ œ๊ณตํ•˜๋Š” ๋™์‹œ์— ๋™๊ณต ํฌ๊ธฐ ๋ณ€ํ™” ๋˜๋Š” ์›€์ง์ž„์— ์˜ํ•œ ์ด์ค‘ ์˜์ƒ ๋ฌธ์ œ๋ฅผ ์™„ํ™”ํ•  ์ˆ˜ ์žˆ๋‹ค. ๋˜ํ•œ ๊ธฐ๊ณ„์  ์›€์ง์ž„ ์—†์ด ์‹œ์  ๊ฐ„์˜ ๊ณ ์† ์ „ํ™˜์ด ๊ฐ€๋Šฅํ•˜๋‹ค๋Š” ์žฅ์ ์„ ์ง€๋‹ˆ๊ณ  ์žˆ๋‹ค. ๋ณธ ๋ฐ•์‚ฌํ•™์œ„ ๋…ผ๋ฌธ์—์„œ ์ œ์‹œํ•œ ํŽธ๊ด‘ ๋‹ค์ค‘ํ™”๋ฅผ ํ™œ์šฉํ•œ ์ƒˆ๋กœ์šด ๊ฒฐํ•ฉ๊ธฐ ๊ด‘ํ•™ ์†Œ์ž ๋ฐ ๊ด‘ํ•™ ๊ตฌ์กฐ๋“ค์€ ๋„ํŒŒ๊ด€ ๊ธฐ๋ฐ˜ ๊ทผ์•ˆ ๋””์Šคํ”Œ๋ ˆ์ด์˜ ํ–ฅ์ƒ๋œ ์„ฑ๋Šฅ์„ ์ œ๊ณตํ•˜๋Š” ํ•ด๊ฒฐ์ฑ… ๋ฐ ์ƒˆ๋กœ์šด ๊ฐ€๋Šฅ์„ฑ์œผ๋กœ ์ œ์‹œํ•  ์ˆ˜ ์žˆ์„ ๊ฒƒ์ด๋ผ ๊ธฐ๋Œ€๋œ๋‹ค.Abstract i Contents iii List of Tables vi List of Figures vii Chapter. 1 Introduction 1 1.1 Augmented reality near-eye display 1 1.2 Key performance parameters of near-eye displays 4 1.3 Basic scheme of waveguide-based near-eye displays 22 1.4 Motivation and purpose of this dissertation 33 1.5 Scope and organization 37 Chapter 2 Dual-focal waveguide-based near-eye display using polarization-dependent combiner lens 39 2.1 Introduction 39 2.2 Optical design for polarization-dependent combiner lens 42 2.2.1 Design and principle of polarization-dependent combiner lens 42 2.2.2 Prototype implementation 48 2.3 Waveguide-based augmented reality near-eye display with dual-focal plane using polarization-dependent combiner lens 51 2.3.1 Implementation of the prototype and experimental results 51 2.3.2 Performance analysis and discussion 57 2.4 Conclusion 69 Chapter 3 Extended-field-of-view waveguide-based near-eye display via polarization-dependent steering combiner 70 3.1 Introduction 70 3.2 Optical design for polarization-dependent steering combiner 73 3.2.1 Principle of polarization grating 73 3.2.2 Principle of polarization-dependent steering combiner 76 3.2.3 Analysis and verification experiment for real-scene distortion 77 3.3 Waveguide-based augmented reality near-eye display with extended-field-of-view 81 3.3.1 Field-of-view for volume grating based waveguide technique 81 3.3.2 Implementation of the prototype and experimental results 84 3.3.3 Performances analysis and discussion 87 3.4 Conclusion 92 Chapter 4 Viewpoint switchable retinal-projection-based near-eye display with waveguide configuration 93 4.1 Introduction 93 4.2 Polarization-dependent switchable eyebox 97 4.2.1 Optical devices for polarization-dependent switching of viewpoints 97 4.2.2 System configuration for proposed method 100 4.2.3 Design of waveguide and imaging combiner 105 4.3 Compact retinal projection-based near-eye display with switchable viewpoints via waveguide configuration 114 4.3.1 Implementation of the prototype and experimental results 114 4.3.2 Performance analysis and discussion 118 4.4 Conclusion 122 Chapter 5. Conclusion 123 Bibliography 127 Appendix 135Docto

    Head Tracked Multi User Autostereoscopic 3D Display Investigations

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    The research covered in this thesis encompasses a consideration of 3D television requirements and a survey of stereoscopic and autostereoscopic methods. This confirms that although there is a lot of activity in this area, very little of this work could be considered suitable for television. The principle of operation, design of the components of the optical system and evaluation of two EU-funded (MUTED & HELIUM3D projects) glasses-free (autostereoscopic) displays is described. Four iterations of the display were built in MUTED, with the results of the first used in designing the second, third and fourth versions. The first three versions of the display use two-49 element arrays, one for the left eye and one for the right. A pattern of spots is projected onto the back of the arrays and these are converted into a series of collimated beams that form exit pupils after passing through the LCD. An exit pupil is a region in the viewing field where either a left or a right image is seen across the complete area of the screen; the positions of these are controlled by a multi-user head tracker. A laser projector was used in the first two versions and, although this projector operated on holographic principles in order to obtain the spot pattern required to produce the exit pupils, it should be noted that images seen by the viewers are not produced holographically so the overall display cannot be described as holographic. In the third version, the laser projector is replaced with a conventional LCOS projector to address the stability and brightness issues discovered in the second version. In 2009, true 120Hz displays became available; this led to the development of a fourth version of the MUTED display that uses 120Hz projector and LCD to overcome the problems of projector instability, produces full-resolution images and simplifies the display hardware. HELIUM3D: A multi-user autostereoscopic display based on laser scanning is also described in this thesis. This display also operates by providing head-tracked exit pupils. It incorporates a red, green and blue (RGB) laser illumination source that illuminates a light engine. Light directions are controlled by a spatial light modulator and are directed to the usersโ€™ eyes via a front screen assembly incorporating a novel Gabor superlens. In this work is described that covered the development of demonstrators that showed the principle of temporal multiplexing and a version of the final display that had limited functionality; the reason for this was the delivery of components required for a display with full functionality

    Perceptually Optimized Visualization on Autostereoscopic 3D Displays

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    The family of displays, which aims to visualize a 3D scene with realistic depth, are known as "3D displays". Due to technical limitations and design decisions, such displays create visible distortions, which are interpreted by the human vision as artefacts. In absence of visual reference (e.g. the original scene is not available for comparison) one can improve the perceived quality of the representations by making the distortions less visible. This thesis proposes a number of signal processing techniques for decreasing the visibility of artefacts on 3D displays. The visual perception of depth is discussed, and the properties (depth cues) of a scene which the brain uses for assessing an image in 3D are identified. Following the physiology of vision, a taxonomy of 3D artefacts is proposed. The taxonomy classifies the artefacts based on their origin and on the way they are interpreted by the human visual system. The principles of operation of the most popular types of 3D displays are explained. Based on the display operation principles, 3D displays are modelled as a signal processing channel. The model is used to explain the process of introducing distortions. It also allows one to identify which optical properties of a display are most relevant to the creation of artefacts. A set of optical properties for dual-view and multiview 3D displays are identified, and a methodology for measuring them is introduced. The measurement methodology allows one to derive the angular visibility and crosstalk of each display element without the need for precision measurement equipment. Based on the measurements, a methodology for creating a quality profile of 3D displays is proposed. The quality profile can be either simulated using the angular brightness function or directly measured from a series of photographs. A comparative study introducing the measurement results on the visual quality and position of the sweet-spots of eleven 3D displays of different types is presented. Knowing the sweet-spot position and the quality profile allows for easy comparison between 3D displays. The shape and size of the passband allows depth and textures of a 3D content to be optimized for a given 3D display. Based on knowledge of 3D artefact visibility and an understanding of distortions introduced by 3D displays, a number of signal processing techniques for artefact mitigation are created. A methodology for creating anti-aliasing filters for 3D displays is proposed. For multiview displays, the methodology is extended towards so-called passband optimization which addresses Moirรฉ, fixed-pattern-noise and ghosting artefacts, which are characteristic for such displays. Additionally, design of tuneable anti-aliasing filters is presented, along with a framework which allows the user to select the so-called 3d sharpness parameter according to his or her preferences. Finally, a set of real-time algorithms for view-point-based optimization are presented. These algorithms require active user-tracking, which is implemented as a combination of face and eye-tracking. Once the observer position is known, the image on a stereoscopic display is optimised for the derived observation angle and distance. For multiview displays, the combination of precise light re-direction and less-precise face-tracking is used for extending the head parallax. For some user-tracking algorithms, implementation details are given, regarding execution of the algorithm on a mobile device or on desktop computer with graphical accelerator

    Fundamentals of 3D imaging and displays: a tutorial on integral imaging, light-field, and plenoptic systems

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    There has been great interest in researching and implementing effective technologies for the capture, processing, and display of 3D images. This broad interest is evidenced by widespread international research and activities on 3D technologies. There is a large number of journal and conference papers on 3D systems, as well as research and development efforts in government, industry, and academia on this topic for broad applications including entertainment, manufacturing, security and defense, and biomedical applications. Among these technologies, integral imaging is a promising approach for its ability to work with polychromatic scenes and under incoherent or ambient light for scenarios from macroscales to microscales. Integral imaging systems and their variations, also known as plenoptics or light-field systems, are applicable in many fields, and they have been reported in many applications, such as entertainment (TV, video, movies), industrial inspection, security and defense, and biomedical imaging and displays. This tutorial is addressed to the students and researchers in different disciplines who are interested to learn about integral imaging and light-field systems and who may or may not have a strong background in optics. Our aim is to provide the readers with a tutorial that teaches fundamental principles as well as more advanced concepts to understand, analyze, and implement integral imaging and light-field-type capture and display systems. The tutorial is organized to begin with reviewing the fundamentals of imaging, and then it progresses to more advanced topics in 3D imaging and displays. More specifically, this tutorial begins by covering the fundamentals of geometrical optics and wave optics tools for understanding and analyzing optical imaging systems. Then, we proceed to use these tools to describe integral imaging, light-field, or plenoptics systems, the methods for implementing the 3D capture procedures and monitors, their properties, resolution, field of view, performance, and metrics to assess them. We have illustrated with simple laboratory setups and experiments the principles of integral imaging capture and display systems. Also, we have discussed 3D biomedical applications, such as integral microscopy

    Scalable multi-view stereo camera array for real world real-time image capture and three-dimensional displays

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    Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2004.Includes bibliographical references (leaves 71-75).The number of three-dimensional displays available is escalating and yet the capturing devices for multiple view content are focused on either single camera precision rigs that are limited to stationary objects or the use of synthetically created animations. In this work we will use the existence of inexpensive digital CMOS cameras to explore a multi- image capture paradigm and the gathering of real world real-time data of active and static scenes. The capturing system can be developed and employed for a wide range of applications such as portrait-based images for multi-view facial recognition systems, hypostereo surgical training systems, and stereo surveillance by unmanned aerial vehicles. The system will be adaptable to capturing the correct stereo views based on the environmental scene and the desired three-dimensional display. Several issues explored by the system will include image calibration, geometric correction, the possibility of object tracking, and transfer of the array technology into other image capturing systems. These features provide the user more freedom to interact with their specific 3-D content while allowing the computer to take on the difficult role of stereoscopic cinematographer.Samuel L. Hill.S.M
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