Browsing by Author "Wu, Jui-Yi"

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A 2D/3D Hybrid Integral Imaging Display by Using Fast Switchable Hexagonal Liquid Crystal Lens Array
(2017-01-01)
Lee, Hsin-Hsueh
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Huang, Ping-Ju
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Wu, Jui-Yi
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Hsieh, Po-Yuan
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Huang, Yi-Pai
The paper proposes a new display which could switch 2D and 3D images on a monitor, and we call it as Hybrid Display. In 3D display technologies, the reduction of image resolution is still an important issue. The more angle information offer to the observer, the less spatial resolution would offer to image resolution because of the fixed panel resolution. Take it for example, in the integral photography system, the part of image without depth, like background, will reduce its resolution by transform from 2D to 3D image. Therefore, we proposed a method by using liquid crystal component to quickly switch the 2D image and 3D image. Meanwhile, the 2D image is set as a background to compensate the resolution.. In the experiment, hexagonal liquid crystal lens array would be used to take the place of fixed lens array. Moreover, in order to increase lens power of the hexagonal LC lens array, we applied high resistance (Hi-R) layer structure on the electrode. Hi-R layer would make the gradient electric field and affect the lens profile. Also, we use panel with 801 PPI to display the integral image in our system. Hence, the consequence of full resolution 2D background with the 3D depth object forms the Hybrid Display.
A toroidal-lens designed structure for static type table-top floating image system with horizontal parallax function
(2017-07-01)
Chou, Ping-Yen
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Wu, Jui-Yi
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Hsieh, Po-Yuan
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Chen, Chun-Ho
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Yu, Zih-Sin
A new structure of horizontal parallax table-top floating image system with toroidal-lens optical film was developed. In this design, the circular arranged pico-projectors limit the angular resolution of this system and display the floating image for surrounding viewing zones. In addition, the pinhole array and toroidal-lens layer compose the optical film in the system and correspond with each other; both of them could be considered as a repeatable unit to control the spatial resolution of image. After passing through the optical film, the direction, position, shape, and divergence angle of light field could be controlled as fan ray, which has a widely scattered angle in latitude and high directivity in longitude direction. Moreover, to confirm the optical properties, the proposed structure was built in the commercially optical software, LightTools v8.3, which is widely used in the simulation of light distribution. Based on the imaging principle and the inverse light tracking method, displaying floating image with circular viewing zones would be achieved.
Image formation modeling and analysis of near-eye light field displays
(2019-04-01)
Qin, Zong
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Chou, Ping-Yen
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Wu, Jui-Yi
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Chen, Yu-Ting
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Huang, Cheng-Ting
Near-eye light field displays based on integral imaging through a microlens array provide attractive features like ultra-compact volume and freedom of the vergence-accommodation conflict to head-mounted displays with virtual or augmented reality functions. To enable optimal design and analysis of such systems, it is desirable to have a physical model that incorporates all factors that affect the image formation, including diffraction, aberration, defocusing, and pixel size. Therefore, in this study, using the fundamental Huygens-Fresnel principle and the Arizona eye model with adjustable accommodation, we develop an image formation model that can numerically calculate the retinal light field image with near-perfect accuracy, and experimentally verify it with a prototype system. Next, based on this model, the visual resolution is analyzed for different field of views (FOVs). As a result, a rapid resolution decay with respect to FOV caused by off-axis aberration is demonstrated. Finally, resolution variations as a function of image depth are analyzed based on systems with different central depth planes. Significantly, the resolution decay is revealed to plateau when the image depth is large enough, which is different from real-image type light field displays.
Matching Prescription & Visual Acuity: Towards AR for Humans
(2019-01-01)
Kim, Jonghyun
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Stengel, Michael
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Wu, Jui-Yi
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Boudaoud, Ben
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Spjut, Josef
Prescription AR: a fully-customized prescription-embedded augmented reality display
(2020-03-02)
Wu, Jui-Yi
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Kim, Jonghyun
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光電工程學系
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Department of Photonics
In this paper, we present a fully-customized AR display design that considers the user's prescription, interpupillary distance, and taste of fashion. A free-form image combiner embedded inside the prescription lens provides augmented images onto the vision-corrected real world. The optics was optimized for each prescription level, which can reduce the mass production cost while satisfying the user's taste. The foveated optimization method was applied which distributes the pixels in accordance with human visual acuity. Our design can cover myopia, hyperopia, astigmatism, and presbyopia, and allows the eye-contact interaction with privacy protection. A 169g dynamic prototype showed a 40 degrees x 20 degrees virtual image with a 23 cpd resolution at center field and 6 mm x 4 mm eye-box, with the vision-correction and varifocal (0.5-3m) capability. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Resolution enhanced light field near eye display using e-shifting method with birefringent plate
(2018-05-01)
Wu, Jui-Yi
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Chou, Ping-Yen
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Peng, Kuei-En
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Huang, Yi-Pai
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Lo, Hsin-Hsiang
Light field near eye displays (LFNED) can produce lightweight devices and address the accommodation-convergence conflict. However, low spatial resolution creates a poor immersive experience in LFNED. In addition, although many e-shifting devices have been proposed to enhance resolution in projection system, yet those devices are too bulky to be applied in an LFNED to keep it lightweight. In this paper, a compact e-shifting component is proposed to enhance image resolution in an LFNED by using a birefringent plate and twisted nematic switch cell. The proposed e-shifting device is a flat and thin component with only 2.6mm of thickness, which could be placed in the gap of an LFNED without increasing the thickness. The results show that the proposed components could be easily integrated in an LFNED with the result of resolution enhancement.
Resolution-enhanced light field displays by recombining subpixels across elemental images
(2019-05-15)
Qin, Zong
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Chou, Ping-Yen
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Wu, Jui-Yi
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Huang, Cheng-Ting
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Huang, Yi-Pai
Light field displays based on integral imaging feature ultra-compact volume and freedom of the vergence-accommodation conflict for advanced virtual reality and augmented reality devices; however, they currently suffer from low visual resolution. Considering that subpixels have an intrinsically tripled resolution compared with triad pixels, this Letter develops a subpixel-level algorithm by recombining subpixels with relatively small raytracing errors from different elemental images. As a result, based on a highly accurate image formation model, the resolution of a typical system (pixel size, 7.8 mu m; system thickness, 4.07 mm) is remarkably enhanced from 8.3 to 20.0 pixels per degree, for a gain of 2.41. In addition, the color breakup introduced by the chromatic subpixels is largely suppressed. (C) 2019 Optical Society of America
Revelation and addressing of accommodation shifts in microlens array-based 3D near-eye light field displays
(2020-01-01)
Qin, Zong
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Wu, Jui-Yi
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Chou, Ping-Yen
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Chen, Yu-Ting
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Huang, Cheng-Ting
In a 3D near-eye light field display using microlens arraybased integral imaging, the accommodation response is presumed to exactly coincide with the reconstructed depth plane (RDP) which, however, has been little examined. By employing a highly accurate image formation model to analyze retinal images, the accommodation response is revealed to significantly shift towards the central depth plane (CDP) because of defocusing. The shift is quantitatively characterized for various CDPs and RDPs with a preliminary verifying experiment to provide content producers an approach to address the accommodation shift to fully mitigate the vergence-accommodation conflict. (C) 2019 Optical Society of America