bluuebunny/crossref_metadata_2025 huggingface dataset:
Radio propagation models for differential GNSS based on dense point clouds
Authors: Kubelka Vladimír , Dandurand Philippe , Babin Philippe , Giguère Philippe , Pomerleau François
Published: September 2020

Accurate geolocation of mobile equipment operating in outdoor environments is an increasingly important question in robotics and automation. Modern geolocation systems, however, rely on the crucial ability for a mobile device to receive specific radio signals at all times. As such geolocation systems are increasingly deployed in harsh or difficult environments, for example, in the presence of tall buildings or dense forest, it becomes critical to predict how the environment will impact the propagation of these radio signals. To this effect, we present a new signal propagation model that can determine what areas would be favorable for global navigation satellite system (GNSS) positioning, based on a prior three‐dimensional (3D) point cloud map of the environment. Our model can predict both the number of usable satellites for a GNSS receiver and the strength of the reference radio signal used in the differential GNSS scenario. Contrary to others, it takes into account both signal occlusion and absorption mechanisms, given the geometry and density of the point cloud map. We designed two rugged mobile data‐collecting platforms, both to generate the 3D maps of the environment, as well as to gather various ground truth for GNSS satellite and local radio signals. Environments used for our field deployments included a boreal forest, a subarctic forest and diverse industrial areas. Experimental results indicate that our model performs well in both structured and unstructured environments, with median errors of 1.10 for the predicted number of satellites and for the strength of the differential GNSS correction signals.
Heavy metal contamination and ecological risk in sediment from typical suburban rivers
Authors: Cui Song , Gao Shang , Zhang Fuxiang , Fu Qiang , Wang Min , Liu Dong , Li Kunyang , Song Zihan , Chen Pengyu
Published: September 2020

The environmental pollution and ecological risk of riverine systems are of growing concern in China and worldwide. Previous studies have mainly focused on urban and rural rivers. However, suburban rivers differ from urban and rural rivers as they are subject to complex pollution sources, random discharge of domestic garbage, improper handling of agricultural means of production and imperfect municipal engineering facilities; thus, identifying the complex pollution sources and ecological risk in suburban rivers might help improve environmental quality and inform management decisions. The occurrence and spatial distribution of six heavy metals were investigated and analysed. The average concentrations of target heavy metals in surface sediments were in the order of Zn (1,198.7) > Cr (84.6) > Pb (40.0) > Cu (25.6) > Ni (11.8) > Cd (0.5) (mg/kg, dry weight). The concentrations of all heavy metals in the study area except Ni and Pb were significantly higher (p < .05) than the environmental background values. The pollution load index (PLI) indicated that the sediments were “moderately polluted”, which was mainly caused by Zn and Cd. The potential ecological risk index (RI) showed that there was a “high” ecological risk of heavy metals in sediments, of which Cd accounted for 83% of the RI. A principal component analysis coupled with Pearson's correlations indicated that Pb and Zn were mainly associated with domestic, traffic and agricultural sources; Cr, Cu and Ni were mainly derived from traffic and natural sources, and Cd was likely from coal combustion and agricultural sources. The results from this study will provide the scientific knowledge needed to control and manage the emissions or discharge from multiple heavy metal pollution sources and identify their potential ecological risk in the sediment of suburban rivers.
Operational efficiency of equipment system drives environmental and economic performance of surface coal mining—A sustainable development approach
Authors: Rai Sheo Shankar , Murthy Vemavarapu M. S. R. , Sukesh Nalamasa , Sairam Teja Akkiraju , Raval Simit
Published: September 2020

Improving operational efficiency (OE) of mining processes can ensure the sustainable development of the coal mining sector. The selection of equipment systems and the adoption of efficient mining methods are critical for achieving OE in mining. Planning and simulation of mining operations is a complex and dynamic process that requires deeper domain knowledge and application of computer‐based technology. Computer‐aided simulation of mining operations can help identify the most appropriate equipment system and innovative mining methods that can achieve the highest level of OE. OE has got a direct and positive impact on environmental efficiency (EE) defined in terms of reduction in emissions of GHG, TSP, and PM10, and cost efficiency (CE) defined by a reduction in unit operating cost (₹/m3). In an Indian study for a large dragline operated surface coal mine, a 40% gain in OE in terms of mining rate (m3/hr) resulted in a gain in EE with an annual reduction of GHG, TSP, and PM10emission by 26%, 47%, and 52%, respectively, and CE improved by over 33% vis‐a‐vis the existing operation without the infusion of any additional resource.
3‐2: Invited Paper: A Wide Color Gamut LCD with a Polarized Laser Backlight
Authors: Komura Shinichi , Okuda Koichi , Onoda Ken , Kijima Hiroaki , Tagaya Akihiro , Kikutani Takeshi , Koike Yasuhiro
Published: September 2020

We have developed a 17.3‐inch 8K wide color gamut in‐plane switching LCD (IPS‐LCD) with a polarized laser backlight. By applying a zero—zero‐birefringence polymer, the polarized laser backlight emits polarized light with 88% polarization. The IPS‐LCD with the developed polarized laser backlight achieves a wide color gamut with high efficiency.
3‐5: Late‐News‐Paper: A Two‐Dimensionally Aligned Array with 1‐μm Pixel Pitch Using Ferroelectric Liquid Crystal Pixels for Holography Application
Authors: Aso Shintaro , Isomae Yoshitomo , Aoshima Ken-ichi , Higashida Ryo , Funabashi Nobuhiko , Shibasaki Junichi , Ishinabe Takahiro , Shibata Yosei , Machida Kenji , Fujikake Hideo , Kikuchi Hiroshi
Published: September 2020

We developed stacked two‐layered electrodes having predesigned patterns that applied two different voltages across the electrodes’ surfaces and fabricated ferroelectric liquid crystal (FLC) arrays using the electrodes showing clear checkered pattern with a 1 × 1‐μm pitch. Furthermore, we demonstrated a holographic 3D image reconstruction using the FLC array.
5‐2: Invited Paper: Computational Eyeglasses and Near‐eye Displays with Focus Cues
Authors: Wetzstein Gordon
Published: September 2020

In emerging VRIAR applications, the primary interface between the user and the digital world is the near‐eye display. However, today's VR/AR systems struggle to provide natural and comfortable viewing experiences, partly due to their fixed focal plane designs. In this paper, we discuss gaze‐contingent varifocal display designs for next‐generation computational near‐eye displays. Moreover, we discuss how the same technology components, eye tracking and focus‐tunable optics, can help presbyopes see the real world better. As humans age, they gradually lose the ability to accommodate, or refocus, to near distances because of the stiffening of the crystalline lens. This condition, known as presbyopia, affects nearly 20% of people worldwide. Here, we discuss the design and implementation of a new presbyopia correction, autofocals, to externally mimic the natural accommodation response, combining eye tracker and depth sensor data to automatically drive focus‐tunable lenses. With extensive user studies, we demonstrate that autofocals improve visual acuity over conventional monovision eyeglasses and task performance over progressives.
6‐4: Late‐News Paper: Realizing Deep Blue Emission in Blue Phosphorescent Organic Light‐Emitting Diodes
Authors: Sun Jinwon , Jeong Hyein , Lyu Jaejin
Published: September 2020

The origin of spectrum broadening in blue phosphorescent organic light‐emitting diodes (OLEDs) was investigated in order to improve color purity of the OLED device aiming to realize efficient blue phosphorescent OLED with deep blue emission. Assuming the formation of exciplex between host and guest (H‐G) material from intermolecular charge transfer (CT) state of the two, the experiment was performed controlling the distance between H‐G for the verification. The exciplex formation was observed dependent on the distance of H‐G, indicating that the spectrum broadening occurred due to H‐G CT state. The critical distance to avoid H‐G CT state was found which can be further utilized in designing host and dopant materials for blue phosphorescent OLEDs. The EL efficiency and the stability of the blue phosphorescent device were enhanced by 1.2 and 5 times, respectively, by minimizing H‐G CT state.
7‐4: Late‐News‐Paper: Development of High‐mobility Top‐gate IGZTO‐TFT and Suppression of Threshold Voltage Shift in Short Channel Utilizing Laser Irradiation Process
Authors: Nakata Mitsuru , Ochi Mototaka , Takei Tatsuya , Tsuji Hiroshi , Miyakawa Masashi , Nishiyama Kohei , Nakajima Yoshiki , Shimizu Takahisa
Published: September 2020

Top‐gate self‐aligned thin‐film transistors (TFTs) with a high carrier mobility of 31 cm2/Vs were developed using the oxide semiconductor In‐Ga‐Zn‐Sn‐O. The threshold‐voltage shift in short‐channel top‐gate TFTs was suppressed by application of a laser irradiation process to reduce the resistance of the source/drain regions
8‐4: Invited Paper: Flexible glass Substrate for OLED Lightning Application ans Efficient Internal Light Extraction for OLED Lightning Devices
Authors: Chowdhury Dipak , Woo Kwang-je , Kong Bo-Kyung , Lee Joo-young , Yoon Hong , Mlejnek Michal
Published: September 2020

We discuss application of Corning® Willow® Glass for OLED Lighting integrated substrate which includes an internal light extraction layer for high efficacy. Two technologies – (1) glass carrier, and (2) edge healing, needed for successful product development will be discussed.
10‐1: Invited Paper: High Dynamic Range Mini‐LED and Dual‐Cell LCDs
Authors: Hsiang En-Lin , Huang Yuge , Yang Qian , Wu Shin-Tson
Published: September 2020

Two high dynamic range displays: dual‐cell LCD and mini‐LED backlit LCD, are investigated. In a dual‐panel display, the parallax error at large viewing angles is analyzed and mitigated by a newly proposed splitting algorithm. Besides, the image qualities of mini‐LED backlit LCD are compared with OLED under different display brightness, ambient reflectance, and ambient light illuminance. The halo effect of mini‐LED based LCD becomes less noticeable as the ambient light brightness increases.
11‐3: Distinguished Paper: Advanced Methods for Safe Visualization on Automotive Displays
Authors: Axmann Benjamin , Langner Frank , Blankenbach Karlheinz , Vogelmann Matthaeus , von Gaisberg Adrian , Strobel Lukas , Bauer Jan
Published: September 2020

Camera‐Monitor‐Systems, such as rear‐view and side mirrors, are becoming increasingly important. These systems must fulfill high safety requirements. Today's approaches deal with supervision of data and voltages. This paper introduces new methods of advanced monitoring of panel electronics and optical output. These measurements are correlated with images/video to be displayed.
12‐2: High‐Performance OLED Microdisplays Made with Multi‐Stack OLED Formulations
Authors: Hamer John , Kondakova Marina , Spindler Jeffrey , Cupello Robert , Hamer Suzannah , Andre Michael , McClurg Scott , Pleten Anatole , Primerano Bruno , Scott David , Scherer George , Stickel Scott
Published: September 2020

High‐performance OLED microdisplays have been developed using multi‐stack white OLED architectures for high brightness and long lifetime. This approach also provides additional degrees of design freedom which can be used to reduce power, balance sub‐pixel currents, and increase color gamut. Examples with 3, 4, and 5 stacks are shown.
12‐3: Organic Light‐emitting Diode Microdisplay with a 32:9 Aspect Ratio for Wide Field of View
Authors: Lee Hyunkoo , Cho Hyunsu , Byun Chun-Won , Kang Chan-mo , Shin Jin-Wook , Choi Sukyung , Kwon Byoung-Hwa , Cho Nam Sung , Cho Ara , Kim Hokwon , Cho Jeong , Park Sang Hyun , Kim Minseok , Park Soon-gi , Kim Youngjoon , Ha Jeonghun , Kim Jaehyeok
Published: September 2020

Microdiplay is one of critical factors to determine the performance of AR glasses. A white OLED with tandem structure have been developed for OLED microdiplays. The device has driving voltage of 6.9 V for 1,000 cd/m2 and maximum current efficiency of 19.5 cd/A. Using developed white OLED structure, we have successfully demonstrated a white OLED microdisplay with a 32:9 aspect ratio. This large aspect ratio can be helpful for improving field of view of AR glasses using a pin mirror lens.
13‐3: Improvement of Blue Pixels in OLED Panels with more Efficient Fluorescent and TADF Emitters
Authors: Baumann Thomas , Budzynski Matthias , Kasparek Christian , Dueck Sebastian , Ochsmann Julian
Published: September 2020

The missing high‐efficiency Blue OLEDs are still the bottleneck for the power consumption in today’s OLED panels. One way to improve the efficiency of the blue pixel is the use of narrow‐type fluorescent emitters in a classical fluorescent stack for top‐emission OLED devices where the optical cavity effect favors narrow over a broader emission. In this paper, we will show how narrow‐type fluorescent emitters can deliver >30% efficiency improvement over traditional commercial fluorescent blue emitters to reach >200 cd/A/CIEy in top‐emission devices. For further efficiency increase, those fluorescent emitters can be combined with TADF emitters which can increase the internal quantum efficiency from 25% to 100%. In order to make such a hyper‐fluorescent system work efficiently, the combination of TADF and fluorescent emitter has to be chosen carefully as they have to match the materials perfectly.
16‐4: Late‐News Paper: High Color Gamut Mini‐LED Backlight Demon based on Dual‐Emissive Perovskite Quantum Dots Films
Authors: Li Fei , Ji Honglei , Xu Huaishu , Bai Zelong , Liu Ruikuo , Li Jing , Zhong Haizheng
Published: September 2020

In this work, the green and red dual emissive perovskite quantum dot embedded composite films with photoluminescence quantum yield of about 85%, transmittance of about 90% and narrow band emissions were successfully fabricated and integrated with Mini‐LEDs for LCD backlight applications.
16‐5: Late‐News Paper: High Flux Stable Perovskite Quantum Dots‐Polymer Composite for Down‐Converting Applications
Authors: Sinatra Lutfan , Lutfullin Marat , Lentijo-Mozo Sergio , Bakr Osman M.
Published: September 2020

Perovskite Quantum Dots have excellent optical properties but low stability under high flux irradiation. In this work, a method to synthesize perovskite QDs‐polymer composite will be presented to overcome the high flux stability problem. As compared to pristine perovskite QDs, the perovskite QDs‐polymer composite shows higher stability under high flux condition in a long term.
17‐2: A method of improving image contrast based on Dual Cell display
Authors: Zhao Yizhuo , He Tao , Chen Yinhong , Zhou Mingzhong
Published: September 2020

Based on the Dual cell structure display, this paper proposes an effective contrast enhancement scheme. By using the lower cell to control the backlight brightness, local dimming is realized at the pixel level. Combined with spatial filtering, the ghosting problem of the Dual cell structure display is solved.
17‐4: Evaluate and Upgrade Picture Quality of Local Dimming Mini‐LED LCD
Authors: Chen Chun-Chi , Qiu Young-Yuan , Zheng Wei-Wei , Yu Gang , Chiu Chung-Yi , Zhao Bin , Zhang Xin
Published: September 2020

Picture quality can be improved by mini‐LED backlight, but it will case halo issue, so we need a simulation tool to check the picture quality, then we can fine tune the parameter of design for better picture quality. In this paper we develop a system to simulate the picture quality of mini LED backlight LCD and analyze the halo issue. We simulated LC optics by LCD master, then we evaluated the optical performance of mini‐LED backlight with local dimming function by Matlab , and last we simulated the picture gotten by human eye in different the distance and angle of viewer. Through this system we can simulate the picture quality of mini‐LED backlight, and we can fine tune the parameter of design for making the picture quality better.
18‐4: Invited Paper: Switchable Lightfield Displays for Automotive Applications
Authors: Fattal David , Hohmann Kai
Published: September 2020

Lightfield displays are of great interest to enhance the automotive user experience if they can meet specific usability constraints. We introduce Diffractive Lightfield Backlighting as a novel, low‐cost and flexible technology to implement an auto‐grade Lightfield display with attractive properties such as simple 2D/3D switch, intrinsic light control and switchable privacy.
21‐1: Invited Paper: 5291‐ppi Microdisplay Using CAAC‐IGZO FET with Channel Length of 60 nm
Authors: Shishido Hideaki , Katsui Shuichi , Kobayashi Hidetomo , Nakagawa Takashi , Tamatsukuri Yuki , Uesaka Shogo , Nagata Takaaki , Aoyama Tomoya , Okazaki Yutaka , Ikeda Takayuki , Yamazaki Shunpei
Published: September 2020

For high‐definition microdisplays with more than several thousands of pixels per inch (ppi), c‐axis‐aligned crystal indium‐gallium‐zinc oxide (CAAC‐IGZO) field‐effect transistors (FETs) are effective devices. Based on such a viewpoint, we have fabricated a 5291‐ppi organic light‐emitting diode (OLED) display using CAAC‐IGZO FETs with a channel length of 60 nm.
22‐4: Development of Rolled Long Ultra‐thin Glass and Its Mass Production Technology
Authors: Mori Hiroki , Takimoto Hiroshi , Hasegawa Yoshinori
Published: September 2020

Ultra‐thin glass is unique flexible material. We have established mass production process of long(1km) rolled ultra‐thin glass by developments of forming, cutting and winding technologies. The rolled long glass realizes roll to roll process in production line for new electronics devices (or new material) with high productivity.
23‐2: Distinguished Paper: Wrap‐around Electrodes for MicroLED Tiled Displays
Authors: Pastel David , Peterson Richard , Buchholz Tetyana , Tadesse Haregewine , Vaddi Rajesh , Kuo Kuan Ting , Garner Sean , Khan Sijan , Curtis Jamie
Published: September 2020

The authors have developed a process to create wrap‐around electrodes (WAE) on glass for use in tiled microLED display applications. The electrodes have small size and spacing, low resistance, and good reliability. In addition, an opaque overcoat protects the edges of the tiles and reduces seam visibility. These electrodes allow bezel free tiled operation for high resolution displays.
25‐1: Multi‐bit MIP(Memory‐in‐Pixel)‐based Pixel Circuit of CMOS Backplane for Micro‐LED Display
Authors: Seong Jewoo , Jang Jinwoong , Lee Jaehoon , Lee Myunghee
Published: September 2020

The Micro‐LED display is getting more attention in AR/MR (Augmented/Mixed Reality) applications. The display size of 0.5 to 0.7‐inch is preferred with 5,000 or higher PPI (Pixel Per Inch). Due to the pixel density and size, a CMOS (Complementary Metal‐Oxide‐Silicon) backplane is a preferred solution for driving the pixelized micro‐LEDs. This paper proposes a multi‐bit MIP‐based pixel circuit with PWM driving for a CMOS backplane in order to minimize power dissipation. it also provides an estimation of the minimum achievable pixel size based on the CMOS process node.
26‐4: Late‐News Paper: Super‐Light Smart Glasses Using a Thin Plastic Light Guide Plate
Authors: Hirano Shigenobu , Nakamura Naoki , Itoh Masahiro , Sudoh Yoshifumi , Okazaki Shun , Momma Susumu , Ohsugi Shiori , Yamada Masamichi , Maki Takashi , Hasegawa Aino , Igarashi Norikazu , Kameyama Kenji , Katano Yasuo
Published: September 2020

We have developed a binocular type AR smart glasses using a thin plastic light guide plate with multi‐stage micro mirror and an intermediate image temple optical system. Its load on the nose is less than 25 g and a field of view of 40 degrees.
27‐4:Late‐News Paper:Key Materials for High‐Performance Solution‐Process OLEDs
Authors: Iida Koichiro , Gorohmaru Hideki , Ishibashi Koichi , Shoji Yoshiko
Published: September 2020

We are accelerating the development of materials for the solution‐process OLEDs. High‐performance small molecules for EML and platform polymers with reduced the molecular weight for HIL/HTL have been developed as the best practice for high‐resolution printed OLED panels. Further, no‐diffusible p‐dopants have been successfully developed that are key materials for improving the performances of OLEDs produced by solution processes.
28‐4: Investigation of Moiré Interference in Pinhole Matrix Fingerprint on Display Technology
Authors: Zeng Yang , Lu Feng , Yao Qijun , Yu Haochi , Zhang Qing , Su Xiaoyue
Published: September 2020

We have investigated the Moiré interference in pinhole based fingerprint on display technology. The origin of the phenomenon is identified as the interference between discrete OLED pixels and the object outline. A countermeasure is given to overcome its impact on the identification of miniature fingerprint features.
30‐4: MicroLED Display Technology Trends and Intellectual Property Landscape
Authors: Virey Eric H. , Baron Nicolas , Bouhamri Zine
Published: September 2020

We have analyzed the most recent trends in μLED display intellectual property landscape. After a decade of low activity, filings have been growing exponentially since 2012. This analysis identifies key technologies, highlights unusual solutions, and provides insights on the status of μLED developments.
30‐5: Late‐News Paper: Glass‐based High brightness AMLED using Dual Gate Coplanar a‐IGZO TFT
Authors: Choi Jin-Woo , Song Dae-Ho , Chun Hyung-Il , Kim Min-Woo , Yang ByungChoon , Hong Jong-Ho , Kim Hyo-Min , Jang Jin , Jo Sung-Chan
Published: September 2020

In this study, we report the high‐brightness 1.53 inch 130 PPI active‐matrix light‐emitting diode display (AMLED). Dual gate coplanar amorphous indium‐gallium‐zinc‐oxide (a‐IGZO) thin film transistor (TFT) is applied for the high brightness micro LED display. The micro LEDs optimized for the a‐IGZO TFT backplane are fabricated, and the low‐temperature eutectic bonding is applied to prevent thermal bonding damage.

Finally, the glass based AMLED over ~ 10,000 cd/m2 is demonstrated, using the dual gate coplanar a‐IGZO TFT.
32‐2: Improvement in Directional Cubic Convolution Image Interpolation
Authors: Liu Xiaolei , Sun Jiankang , Yan Guixin , Lu Yaoyu , Xue Yachong , Li Gang , Chen Lili , Zhang Hao
Published: September 2020

Compared with traditional methods, edge‐based interpolation algorithm can generate high‐resolution images with rare edge artifacts. However complex textured regions produce morphological distortion at the same time, resulting in a HD image looks unnatural. In this paper, we analyze the disadvantages of the best performing edge‐based interpolation (DCCI) algorithm and propose a novel adaptive edge‐based interpolation algorithm, which use both 2‐D texture entropy and directional gradient to eliminate the distortion. It turns out that this method can effectively improve the image quality.
33‐1:Invited Paper:Tabletop True 3D Display Systems based on Projection Light Field and Integral Imaging
Authors: Wang Qiong-Hua , Li Hai-Feng , Xia Yun-Peng , Li Shuang , Ren Hui , Ni Li-Xia
Published: September 2020

In this paper, we introduce two tabletop true 3D display systems based on the projection light field and integral imaging. In the projection light field tabletop system, a dual‐panoramic camera is used for multi‐face real time tracking and achieving full parallax, and gesture‐based interaction by Leap Motion is also added for free and accurate interaction. In the integral imaging system, an optimized compound lens array is designed to improve the viewing angle of the 3D image, and the liquid light diffuser is proposed to increase the depth of field of the 3D image.
33‐3: Viewing Angle Enhanced DMD Holographic Display with Reduced Speckle Noise
Authors: Lee Byounghyo , Yoo Dongheon , Jeong Jinsoo , Lee Dukho , Lee Byoungho
Published: September 2020

Holographic displays give users a realistic experience by allowing them to perceive three‐dimensional (3D) images without any visual aids such as glasses. However, in a holographic display using liquid crystal based spatia/light modulator (LC‐SLM), the pixel pitch is not small enough so that the images are realized in limited areas. In addition, the slow framerate of LC‐SLM makes temporal multiplexing practically impossible. We propose holographic display using digital micromirror device (DMD) and apply temporal multiplexing method. The proposed system enhances viewing angle through temporally switched directional illuminations. Besides, the DMD's sufficient framerate provides significant reduction in speckle noise of holograms. We experimentally show the feasibility of proposed method by reconstructing holograms of 3D objects.
37‐1: Yield Statistics for Fault Tolerant Micro LED Displays
Authors: Ahmed Khaled
Published: September 2020

Millions of μLEDs are transferred from donor wafers and integrated onto TFT backplanes to fabricate a μLED display. To guarantee that the number of defective pixels is zero, a fault‐tolerant design (e.g. redundancy) may be adopted. In this work, the required redundancy level is estimated for a given display resolution, and yields for the μLED donor wafers and the transfer process of μLED to the backplane. This is done using a novel mathematical yield model that is derived from first principles statistics. It is shown that without redundancy the wafer and transfer yields need to be > 99.9999% to hit a display line yield of 80%. With redundancy, the required wafer and transfer yields can be as low as 99.5% with 3× redundancy. The model results may be used to assess the capital requirements and the risk involved in fabricating μLED displays.
37‐4: Micro LED Defect Analysis via Photoluminescent and Cathodoluminescent Imaging
Authors: Behrman Keith , FouilIoux Julie , Ireland Terry , Fern George R , Silver Jack , Kymissis Ioannis
Published: September 2020

Ultra‐high resolution micro LED displays are emerging as a viable technology for self‐emissive displays. One challenge for displays with millions of pixels is process control and defect analysis during LED fabrication and transfer. Here we investigate two non‐destructive test methods, photoluminescent and cathodoluminescent imaging, and compare them to electroluminescent images to verify LED fidelity and evaluate these methods as potential tools for defect analysis.
40‐4: Cost‐Efficient Polymer Flat Lens for Chromatic Aberration Correction in Virtual Reality Displays
Authors: Zhan Tao , Zou Junyu , Xiong Jianghao , Liu Xiaomin , Chen Hao , Liu Sheng , Dong Yajie , Wu Shin-Tson
Published: September 2020

An optical chromatic aberration correction method for virtual reality displays is demonstrated. With a cost‐efficient ultra‐broadband liquid crystal flat lens based on the Pancharatnam‐Berry phase, the proposed method can reduce the lateral color breakup by more than 10 times. Both simulation and experimental results are presented and discussed.
40‐5: Distinguished Paper: A Scanning Waveguide Display with 100° of FOV
Authors: Xiong Jianghao , Tan Guanjun , Yin Kun , Zhan Tao , Wu Shin-Tson
Published: September 2020

A novel scanning waveguide display is proposed and experimentally realized. The core component, an off‐axis reflective lens array with f‐number of 0.75, is fabricated by photo‐alignment technique combined with cholesteric liquid crystal. The system has a diagonal field of view of 100°, exceeding theoretical limit of traditional waveguide displays.
41‐3: 17.3 Inch UHD Resolution AMOLED Panel Fabricated by Ink Jet Printing Process
Authors: Chen Peng-Yu , Chen Chien-Chuan , Lin Yu-Syuan , Li Chun-Han , Hsieh Hsieh-Tsung , Lu Hsueh-Hsing , Chiang Sin-Shen , Cheng Robin , Chen Nick. CC. , Jen KR , Hsu Daniel. CM. , Sun Ming-Wei , Kuo Joanne , Tsai Leo
Published: September 2020

We fabricated a 17.3 inch AMOLED panel by using of the inkjet printing process. The panel resolution is UHD (3840x2160) and the pixel density is 255ppi (pixel per inch).The pixel design of the panel is real RGB side‐by‐side pixel arrangement. We demonstrated that the high resolution OLED panel could be realized with high efficiency material usage by inkjet printing process. Uniformity of top emission OLED structure and device performance including the luminous efficiency and the device lifetime is also discussed in our study.
42‐1: A Controller IC for On‐display Touch and Multi‐Fingerprint Sensor
Authors: Kim Min Gyu , Kim Sunkwon , Choi Youngkil , Kim Kang Joo , Song Uijong , Ahn Sewoong , Lee Yilho , Kim Yunjeong , Jeong Moonsuk , Lee Jongsung , Lee Hee Bum , Park Yongjin , Cheon SuHyun , Lee Sungmok , Choi Sungoh , Choi Yoon-Kyung
Published: September 2020

This paper presents a controller IC with on‐display capacitive sensor for touch and multi fingerprint function. Single sensor and the IC enable both touch and fingerprint without additional area or sensor. Fully balanced multi‐channel driving technique with proposed method removes column offset to maximize the immunity to display and external noise. Prototype IC is fabricated in a 65nm CMOS technology. This work achieves 31.6dB SNR with 0.7mmϕ stylus and 120Hz frame rate with 14x10 pixels TSP in touch mode, and 32dB SNR with 0.2mm cover glass and 200ms scan time in multi‐fingerprint mode with 5cmx3.5cm area.
43‐2: Application of Liquid Extraction Surface Analysis (LESA)‐NanoESI‐Orbitrap‐MS to a Degradation Analysis of Organic EL Elements
Authors: Takano Hikaru , Akiyama Tsuyoshi , Shioji Hirotaka , Shibamori Takahiro , Muraki Naoki
Published: September 2020

Liquid extraction surface analysis (LESA)‐NanoESI‐Orbitrap‐mass spectrometry is successfully applied to small‐molecular based OLEDs devices for the first time. It is revealed that NanoESI is possible to detect the molecular ion of unstable metal complexes and that LESA enables to detect deteriorated species of TPBi covered with the electrode.
45‐1: Invited Paper: Multi‐Spliced LCDs for Foldable Mobile Device ‐ Seamless Technology and Applications
Authors: Wu Yung-Hsun , Tsai Chia-Hao , Cheng Chang-Chiang , Hsu Yu Chun , Yang Chiulien
Published: September 2020

This article presents the use of spliced LCD displays on foldable mobile devices. In order to achieve a perfect spliced display, we need to use a four‐sided narrow border design LCD and visual seamless technology. The article introduces two new techniques for ultra narrow borders and uses these two techniques to overcome the rainbow pattern and textual continuity of the seam edges between two adjacent LCD displays.
47‐2: Solid State Projection Display Based on Angular Color Projection and MicroLED
Authors: Wang Yong-Jing , Miller John L.
Published: September 2020

A novel projection light engine structure based on Angular Color Projection (ACP) technology and MicroLED is proposed. This system uses three monochrome RGB MicroLED panels or sub panels to display information in spatially separated color zones. Patented projection optics based on ACP is utilized to merge the RGB zones into a full color picture. Preliminary design and evaluation show that compact, high‐resolution, low‐cost and highly efficient micro projectors are achievable by eliminating the transferring of mass amounts of color pixels needed in a conventional MicroLED display. All optical components can be glued together by automation onto the MicroLED face plate. Therefore, a Full Solid State Projection Display without discrete optical components is achievable. This technology enables a projection light engine with similar size of a CMOS camera used in a modern smart phone. It could greatly increase the applications of projection and Near to Eye (NTE) displays in smart phones and AR/VR glasses.
48‐2: Design Strategies of Fluorescent Dopants toward Pure Blue for Highly Efficient Top Emission OLEDs
Authors: Takahashi Ryota , Ito Hirokatsu , Nakano Yuki , Shirasaki Yoshinao , Masuda Tetsuya , Mase Kazuma , Kawamura Yuichiro , Kuma Hitoshi
Published: September 2020

A blue dopant (BD) emitting pure blue fluorescence was created on new design strategies that combined specific partial molecular structures to reduce peak shoulder of the fluorescence spectrum. The top emission organic light emitting diode using the new BD achieved L/J/CIEy=201, which was about 10% higher than the conventional BD.
49‐3: Late‐News Paper: Hybrid Capacitor Type Organic Electrochromic Device for Multicolor Representation
Authors: Liang Zhuang , Nakamura Kazuki , Kobayashi Norihisa
Published: September 2020

In this paper, we designed a novel multicolor electrochromic (EC) device having hybrid capacitor electrochromic device based on 4,4 ’‐biphenyl dicarboxylic acid diethyl ester and phenothiazine molecule with carbon electrode. The EC properties of the device were analyzed and discussed for the possibility to multicolor representation.
50‐1: Invited Paper: Color/White Light Output, Luminance Contours, and Colour Volume
Authors: Poynton Charles , LeHoty David A.
Published: September 2020

Commercial digital image interchange standards (such as sRGB and BT.709/BT.1886) are universally based upon additive RGB. However, frame‐sequential color projectors (such as 1‐DLP) projectors have for many years used a white segment that affords higher luminance for white and high‐luminance/low‐chroma colours (sometimes called “white boost”), at the expense of introducing large color errors with respect to the interchange standard. In this work we show that luminance contours characterize loss of color accuracy, and we estimate available color gamut at the interface of created content and display.
51‐3: Efficient InP/ZnS Quantum Dot Light‐emitting Diodes with Improved Electron Confinement
Authors: Wu Zhenghui , Zhang Wenda , Liu Pai , Wang Kai , Sun Xiao Wei
Published: September 2020

Highly delocalized electrons and parasitic emissions are serious problems in InP/ZnS quantum dot light emitting diodes. This work provided several approaches from the perspective of device design and physical mechanism to address the above problems. As a result, high efficiency InP/ZnS quantum dot light emitting diodes were achieved.
55‐3: Efficient, Low Haze Light Extraction for OLED Displays Using Micro‐Optic Patterns Imprinted on Glass
Authors: Kuksenkov Dmitri V. , Kang Casey , Lynn Christopher M. , Timofeev Nikolay T. , Aguilar Alejandro , Joos Felipe M. , Ishikawa Tomohiro , Mlejnek Michal
Published: September 2020

A novel design and application technique for light extraction in OLED displays are described, using micro‐optic patterns formed on the underside of an encapsulation glass. The design produces negligible haze and is fully compatible with the use of circular polarizers. A relative increase in brightness of 56% is demonstrated for a mobile phone display.
56‐1: Invited Paper: Research on Commercial Foldable AMOLED and Relevant Technologies
Authors: SHI Shiming , LI Zhao , TSAI Paoming , DONG Liming , WANG Dawei , SHI Yongxiang , DU Shuang , CAI Peng , GAO Meiling , ZHENG Meizhu , WANG Haoran
Published: September 2020

In this work, a commercial foldable display of 8.0‐inch 2K AMOLED(Active Matrix Organic Light‐emitting Diode) was developed for foldable smart phones. By considering commercial requirements for a brand new product, fundamental performances are introduced. By new design concepts, display and touch performances are guaranteed, while the foldable reliabilities are also achieved to a commercial goal. Not only how to improve the bending abilities, but also the mechanical abilities of foldable display module are discussed. In bending performance, the endurance of dynamic folding and static folding are treated by different ways. The materials and layer stacks optimization are discussed. The root causes of the deformation in foldable display are analyzed. Solutions for the out‐folding display is suggested.
56‐2: Thin Foldable AMOLED Module with Excellent Low‐Temperature‐Bendability and Pencil Hardness
Authors: Murao Takehiro , Kikuchi Ryo , Tsuchida Kenichiro , Togashi Yasuyuki , Sakai Akira , Hasegawa Masahiro , Yamada Miho , Watanabe Noriko , Yasuda Yuki , Smeeton Tim M. , Boardman Edward A.
Published: September 2020

We explored the effect of thickness and slip property of OCA and developed simulations which succeeded perfectly in reproducing OCA behavior at both room and low temperature. Finally, we developed foldable OLED modules with excellent low‐temperature bendability and pencil hardness. We also mentioned thin coating polarizer for the future products.
59‐3: A Novel Transflective 31.5‐inch IGZO‐TFT LCD with a Twisted‐VA Mode
Authors: Sasaki Takahiro , Hakoi Hiroyuki , Hashimoto Junichi , Ni Ming , Otsubo Masashi , Sato Takashi , Shimada Shinji , Minoura Kiyoshi
Published: September 2020

We have developed a novel transflective LCD providing good visibility under various circumstances and high productivity. To obtain high image qualities in both transmissive and reflective modes, the panel designs for the transflective LCD with a twisted VA mode were examined. We adopted them into a prototype and successfully fabricated a 31.5‐inch IGZO‐TFT LCD.
62‐2: Deep‐Red and Near‐Infrared OLEDs with High Efficiency and Long Lifetime for Display and Light‐Source Applications
Authors: Seo Satoshi , Tomida Airi , Watabe Takeyoshi , Kawano Yuta , yamaguchi Tomoya , Tominaga Tetsuaki , Inoue Hideko , Ohsawa Nobuharu , Yamazaki Shunpei
Published: September 2020

A deep‐red OLED satisfying the BT.2020 standard achieved an extremely high external quantum efficiency (EQE) over 30% and long lifetime. Furthermore, a near‐infrared OLED with an emission peak around 800 nm, a maximum EQE of 7.2%, and less degradation was demonstrated. This efficiency is the best among reported near‐infrared OLEDs.
64‐1: Separating Specular Reflection from Diffuse Haze for ePaper Using the Extended Variable‐Aperture Source Method
Authors: Hertel Dirk , Kelley Edward F. , Penczek John
Published: September 2020

Specular reflections often interfere when viewing displays. Anti‐glare surfaces reduce specular reflections but introduce diffuse haze. Predicting ambient contrast requires separating these components. Decreasing aperture size in the variable aperture source method separated specular from diffuse reflection, thus quantifying how anti‐glare surfaces effectively mitigate disturbing glare on electrophoretic ePaper displays.
66‐1: Invited Paper: Liquid‐Crystal Mixture with a Composition Including Highly Reliable Fluorinated Diluter and RM Monomer for PSVA and PI‐less IPS LCDs
Authors: Mizusaki Masanobu , Okazaki Tsuyoshi , Okamoto Kazuo , Shibata Toshihiro
Published: September 2020

We developed a high reliable diluter 3HFFH3 for LC compositions and a reactive mesogen (RM)‐monomer carrying a polarized UV absorption unit, chalcone. As the diluter does not carry a vinyl group, a trade‐off between response property and reliability could be solved, and we succeeded to fabricate the PSVA cell that showed fast response speed and high voltage holding ratio. In addition, we also succeeded to fabricate the PI‐less IPS cell owing to use the RM‐monomer carrying the chalcone unit combined with the diluter 3HFFH3.
66‐5: Late‐News‐Paper: Fast Response Texture Free Polymer Stabilized Vertically Aligned Liquid Crystal Displays
Authors: Lim Yong-Woon , Jang Won Hyuk , Jeong Cheolsu , Kim Hyeon Hwan
Published: September 2020

We propose a polymer stabilized vertical aligned (PSVA) liquid crystal (LC) mode with 12‐domains having a center gap (CG) of 6 μm. In the conventional PSVA LC mode, the pixel is divided either into high or low sub‐pixel and the respective sub‐pixel has 4 domains for wider viewing and high quality visibility. However, difficulty in texture control and slow response time in the low sub‐pixel with the long axis remains. In addition to eliminating the major cause of texture irregularity, the proposed 12‐domains PSVA LC mode is divided into 4‐domains and 8‐domains in the high and the low sub‐pixels having CG, respectively. In the proposed 12‐domains PSVA LC mode, the LC director is well defined the multi‐directional tilted direction through the azimuthal angles in the domains and the brightness and viewing angle are similar to the conventional PSVA LC mode. In particular, the rising response time is faster while the falling response time is similar to the conventional PSVA LC mode due to additional center bar inside of pixels. Moreover, high quality visibility is achieved.
67‐3: ColorNet: A Neural Network‐Based System for Consistent Display of Brand Colors for Video
Authors: Walker Erica Black , Smith Dane Hudson , Lineberger John Paul , Mayer Michelle Leigh , Mayes Emma Elizabeth , Sanborn Andrew Thomas
Published: September 2020

When watching sports on screen, fans recognize inconsistencies in their team colors. ColorNet is an artificial intelligence (AI) technology that ingests live video, adjusts each frame pixel‐by‐pixel, and outputs color corrected video in real‐time ensuring accurate brand colors. In this study, ColorNet is demonstrated using Clemson University's orange, Pantone 165.
69‐2: Transparent Conductive Hybrid Cathode Structure for Top‐Emitting Organic Light‐Emitting Devices
Authors: Quan Wei , Wu Chang-Yen , You Juanjuan , Wang Linlin , Song Wenfeng , Shen Yongqi , Luo Chengyuan , Yu Donghui , Bo Bin , Sun Li , Shih Huai-Ting , Wu Zhongyuan
Published: September 2020

There is an increasing attention paid to improving transparent conductive electrodes for applications in highly transparent and large area displays. We optimized top‐emitting blue organic light‐emitting diodes (TE‐BOLEDs) using hybrid cathode consisting of a thermally evaporated Mg/Ag capped with IZO. The device of cd/A/CIEy which used the hybrid cathode improved by 20% more than that with the identical organic layers and conventional Mg/Ag cathode. Meanwhile the transparency increased by 13% and sheet resistance decreased by half. Balancing the device performance, transparency and resistivities, different hybrid cathode structure could meet various requirements.
71‐3: Meeting Optical Testing Challenges of High‐Resolution µLED‐Displays
Authors: Steinel Tobias , Wolf Martin
Published: September 2020

Novel display technologies come with new measurement challenges to meet the highest quality standards in mass production. Here we shine light on these challenges and discuss innovative testing solutions to assure highest display quality in production takt times. We present how single pixel analysis can improve display quality by using a statistical approach to nonuniformity of luminance as well as color metrology on sub‐pixel level. Applications for smartphone displays and microdisplays are discussed emphasizing the challenges of very small pixels and pixel pitches. Finally, calibration of light measuring devices are challenged with respect to the specific spectral properties of µLEDs and OLEDs.
74‐2: Diffracted Image Retrieving with Deep Learning
Authors: Baek Seungin , Koh Eunkyung , Lee Sang-Gu , Park Byong-Ug , Yoo Jewon , Kim Daewook , Choi Soojin , Son Hyunjin , Cho Hyunguk , Kim Yongjo
Published: September 2020

We investigated deep image‐to‐image regression models to retrieve diffracted and/or defocused images induced from optical components. For the purpose, a quantitative metric for strength of diffraction/defocus and optical simulation method have been devised. The quality of retrieved images has been improved by optimizing optical components, and by modifying the deep model.
75‐3: Highly Collimated Backlight for Liquid Crystal Displays
Authors: Berteloot Brecht , Beeckman Jeroen , Stuyven Gert , Vermeirsch Koenraad , Blomme Tom , Neyts Kristiaan
Published: September 2020

In this work, we present the design of a collimated backlight design that can be used for a liquid crystal display. The design is based on a hexagonal array of white light emitting diodes (LEDs) in combination with two arrays of lenses. Ray tracing simulations show a full width ‐ half maximum (FWHM) collimation angle of 2.8º with a uniformity of 73%. A prototype of this design has been fabricated and its performance has been analyzed. Compared to a standard backlight, the collimated backlight provides a 4.2 times better contrast ratio for a twisted nematic (TN) liquid crystal (LC) panel. In combination with a diffusor in front of the LC panel, the contrast ratio under a wide viewing angle is improved by a factor of 10 and the color shift is reduced by 79%.
76‐3: Ultra‐High‐Efficiency OLED Display by 3D Pixel Configuration
Authors: Visser Robert Jan , Chen Chung-Chia , Bang Hyunsung , Lin Wan-Yu , Xu Lisong , Yu Gang , Kwak B. Leo , Chen Yi-Ting , Wen Sheng-Wen , Liao Po-Hsiang , Lee Chang-Cheng , Lee Wei-Kai , Huang Chun-Wei , Su Guo-Dong , Lin Hoang Yan , Wu Chung-Chih
Published: September 2020

Exploring beyond our previously published work on 3D pixel configuration for high light out‐coupling in OLED devices, we will report on configurations wherein the transparent conductive oxide is the top electrode. This can lead to substantially greater EQE (> 3.5x) over the current baseline OLED, by combining it with the previously‐reported patterned, index‐matched filler and the reflective mirror on PDL bank. In addition, we will report on simulation work that expands beyond the pixel level to include the functional layers, e.g., TFE, touch, OCAs, and polarizer, above the pixel. Such results will elucidate the full, device‐level impact of the novel 3D OLED subpixel architectures and instructions on design principles for maximum OLED device performance.
82‐4: Invited Paper: Speckle Reduction in Laser Projectors by Angular, Wavelength, and Polarization Diversities
Authors: Yamada Hirotaka , Moriyasu Kengo , Sato Hiroto , Hatanaka Hidekazu , Yamamoto Kazuhisa
Published: September 2020

Speckle reduction by angular, wavelength, and polarization diversities are widely used to suppress speckle, but they are not fully understood yet. This paper summarizes these speckle reduction methods and shows novel experimental results and theoretical analysis, including the dependency of angular and wavelength diversities.
84‐3: Invited Paper: Advanced Cover Window and Thin‐film Encapsulation Technologies for Foldable AMOLED Display
Authors: Chen Glory , Yeh Shu-Tang , Ho Jia-Chong , Lee Cheng-Chung , Kuo Chen-Kuan , Kuo Hao-Fei , Wu Yu-Hsun , Yang Wen-Hsin , Lin Chih-Wei , Yu Kuo-Hsuan , Wang Chih-Haw
Published: September 2020

Foldable AMOLED enable some component technologies integration and continuously improvement. A roll to roll process integrated cover window with circular polarizer show the high mechanical strength and R3mm folding ability with AMOLED panel. And also, the advanced solution‐coated gas barrier is proposed to OLED thin film encapsulation for new flexible AMOLED form factor applications.
84‐4: New Barrier Fabrication Method based on an Infiltration Technology for Flexible OLED Displays
Authors: Kim Seung Hun , Song Seung Yong , Kim Soo Youn , Chang Moon Won , Kwon Hyo Jeong , Sung Myung Mo , Chu Hye Yong
Published: September 2020

In this work, new barrier fabrication method is proposed to make the barrier layer for blocking the permeation of an oxygen and water and for improving the flexibility. To do this, infiltration technology is implemented to fabricate an in/organic hybrid thin barrier layer for flexible OLED displays. In/organic hybrid layer shows the good WVTR property (~10‐5 g/m2·day), the flexibility after a folding test and the good reliability for the life time test. From the results, this method can be applied to flexible OLED displays for improving the performance.
85‐3: In‐Cell Optical Compensation Technology for OLED Demura Application
Authors: Qin Yunke , Ding Xiaoliang , Li Yangbing , Wang Wenjuan , Zhang Zhen , Zhang Ping , Zhao Fangyuan
Published: September 2020

An in‐cell optical compensation (IOC) technology is verified. The whole device presents a sandwich structure, in which bottom‐emission AMOLED and optical sensor were fabricated onto different substrates and jointed together by adhesive. By optimizing cathode layer, a portion of light could pass through the cathode and be detected by sensor.