Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Display Devices”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Structural and optical analysis on europium doped AZrO{sub 3} (A=Ba, Ca, Sr) phosphor for display devices application

Behavior displayed by europium doped AZrO{sub 3} phosphor which was synthesized by solid state reaction method. For synthesis of BaZrO{sub 3}, SrZrO{sub 3} and CaZrO{sub 3} phosphor with fixed concentration of europium ion was calcination at 1000°C and sintered at 1300°C following intermediate grinding. Synthesized sample was characterized by X-ray diffraction analysis and crystallite sized was calculated by Scherer’s formula. From PL spectra of prepared phosphors shows intense emission centred at 612nm (red emission) with high intensity for SrZrO{sub 3}:Eu{sup 3+}. For europium doped BaZrO{sub 3} and CaZrO{sub 3} (613nm) phosphor shows less intense PL spectra as compared to SrZrO{sub 3}:Eu{sup 3+}. The strong emission peak of AZrO{sub 3}:Eu{sup 3+} phosphor is due to forced electric dipole transition of {sup 5}D{sub 0} to {sup 7}F{sub 2} centered at 612 and 613nm. It is characteristic red emission for europium ion. The excitation spectra of AZrO{sub 3}:Eu{sup 3+} phosphor mainly consists of the charge transfer and (CTB) of Eu{sup 3+} located in 200–350 nm centred at 254nm. The present phosphors can act as single host for red light emission in display devices. The CIE coordinates were calculated by Spectrophotometric method using the spectral energy distribution of the AZrO{sub 3}:Eu{sup 3+} sample.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

Characterization of crosstalk in stereoscopic display devices

Many different types of stereoscopic display devices are used for commercial and research applications. Stereoscopic displays offer the potential to improve performance in detection tasks for medical imaging diagnostic systems. Due to the variety of stereoscopic display technologies, it remains unclear how these compare with each other for detection and estimation tasks. Different stereo device shave different performance trade-offs due to their display characteristics. Among them, crosstalk is known to affect observer perception of 3D content and might affect detection performance. We measured and report the detailed luminance output and crosstalk characteristics for three different types of stereoscopic display devices. We recorded the effect of other issues on recorded luminance profiles such as viewing angle, use of different eye wear, and screen location. Our results show that the crosstalk signature for viewing 3D content can vary considerably when using different types of 3D glasses for active stereo dis-plays. We also show that significant differences are present in crosstalk signatures when varying the viewing angle from 0 degrees to 20 degrees for a stereo mirror 3D display device. Our detailed characterization can help emulate the effect of crosstalk in conducting computational observer image quality assessment evaluations that minimize costly and time-consuming human reader studies.

42 ENGINEERING↗
DOE OSTI2014

Lighted display devices for producing static or animated visual displays, including animated facial features

An illuminated display device with a base member with a plurality of cavities therein. Illumination devices illuminate the cavities and emit light through an opening of the cavities in a pattern, and a speaker can emit sounds in synchronization with the pattern. A panel with translucent portions can overly the base member and the cavities. An animated talking character can have an animated mouth cavity complex with multiple predetermined mouth lighting configurations simulative of human utterances. The cavities can be open, or optical waveguide material or positive members can be disposed therein. Reflective material can enhance internal reflectance and light emission.

42 ENGINEERING↗
DOE OSTI2019

Plasma-Based Ambient Desorption/Ionization Mass Spectrometry for the Analysis of Liquid Crystals Employed in Display Devices

Liquid-crystal displays (LCDs) are the most frequently used display technology worldwide these days. Due to the rather complex manufacturing process and purity requirements for the chemicals used, quality control and display failure analysis are important analytical tasks. Currently, the state-of-the-art techniques (e.g., high-performance liquid chromatography (HPLC), gas chromatography (GC) coupled to mass spectrometry (MS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), or high-resolution microscopy) are costly and time-consuming. Hence, a new pathway to precisely analyze liquid-crystalline materials and LCDs in their native state is reported. A new approach for direct analysis via plasma-based ambient desorption/ionization mass spectrometry (ADI-MS) offers an inexpensive and faster alternative. In this study, direct analysis in real time (DART), the low-temperature plasma (LTP) probe, and flowing atmospheric-pressure afterglow (FAPA) ADI sources coupled to high-resolution mass spectrometry (HR-MS) are compared based on their capabilities and performance for liquid-crystal analysis. These sources enable direct analyte desorption from a sample surface at ambient conditions and ionize the vaporized analyte molecules in a subsequent step. Primarily, the ionization capabilities of the three ADI sources are compared for individual liquid-crystal standards, mixtures of liquid crystals (LCs), and complex liquid crystal/additive mixtures applied in commercially available LCDs. Furthermore, direct surface analysis from a glass substrate is also performed with ADI-MS to compare their applicability to this type of sample matrix. .

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2014

Pr{sup 3+}–Yb{sup 3+} codoped Y{sub 2}O{sub 3} phosphor for display devices

Graphical abstract: Concentration dependence of UC emission intensity for (a) Pr{sup 3+} ions and (b) Yb{sup 3+} ions in doped/codoped Y{sub 2}O{sub 3} phosphors. - Highlights: • Upconversion emission bands with their enhanced emission intensity have been observed on codoping of Yb{sup 3+} ions. • By using Scherrer’s formula and Hall–Williamson plot, the presence of nano-structured crystallites have been identified. • The decay curve analysis for the emitting level has been performed. • The codoped phosphor proves its suitability in making the visible upconverter and display devices. - Abstract: Efficient green colour emitting Pr{sup 3+}–Yb{sup 3+} codoped Y{sub 2}O{sub 3} phosphor prepared by low temperature solution combustion process has been investigated under the excitation with a 980 nm diode laser. Several upconversion emission bands from Pr{sup 3+} ions with their enhanced upconversion emission intensity have been observed on codoping of Yb{sup 3+} ions in the Y{sub 2}O{sub 3}:Pr{sup 3+} system. To identify the phase formation, size of crystallites and strain present in synthesized sample, X-ray diffraction pattern has been recorded. The decay curve analysis for the emitting level has also been performed along with power dependence study to clear the upconversion process. The tunability of colour emitted from the codoped phosphor has been examined which proves its suitability for display devices.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Image Quality Characteristics of Handheld Display Devices for Medical Imaging

Handheld devices such as mobile phones and tablet computers have become widespread with thousands of available software applications. Recently, handhelds are being proposed as part of medical imaging solutions, especially in emergency medicine, where immediate consultation is required. However, handheld devices differ significantly from medical workstation displays in terms of display characteristics. Moreover, the characteristics vary significantly among device types. We investigate the image quality characteristics of various handheld devices with respect to luminance response, spatial resolution, spatial noise, and reflectance. We show that the luminance characteristics of the handheld displays are different from those of workstation displays complying with grayscale standard target response suggesting that luminance calibration might be needed. Our results also demonstrate that the spatial characteristics of handhelds can surpass those of medical workstation displays particularly for recent generation devices. While a 5 mega-pixel monochrome workstation display has horizontal and vertical modulation transfer factors of 0.52 and 0.47 at the Nyquist frequency, the handheld displays released after 2011 can have values higher than 0.63 at the respective Nyquist frequencies. The noise power spectra for workstation displays are higher than 1.2x10 -5 mm 2 at 1 mm -1 , while handheld displays have values lower than 3.7x10 -6 mm 2 . Reflectance measurements on some of the handheld displays are consistent with measurements for workstation displays with, in some cases, low specular and diffuse reflectance coefficients. The variability of the characterization results among devices due to the different technological features indicates that image quality varies greatly among handheld display devices.

47 OTHER INSTRUMENTATION↗
DOE OSTI2015

Upconversion luminescence in BaMoO{sub 4}:Pr{sup 3+} phosphor for display devices

The frequency upconversion is an important nonlinear optical property by which near infrared light is converted into the visible light. The BaMoO{sub 4}:Pr{sup 3+} powder phosphor has been synthesized by solid state reaction method. The upconversion emission bands are recorded under the excitation of 808 nm diode laser. The phase formation of the prepared phosphor has been identified by powder X-ray diffraction (XRD) technique. The upconversion emission mechanism and colour coordinate have been explained by using energy level and CIE (International Commission on Illumination) chromaticity diagram study, respectively.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Real-time data analysis for medical diagnosis using FPGA-accelerated neural networks

Real-time analysis of patient data during medical procedures can provide vital diagnostic feedback that significantly improves chances of success. With sensors becoming increasingly fast, frameworks such as Deep Neural Networks are required to perform calculations within the strict timing constraints for real-time operation. However, traditional computing platforms responsible for running these algorithms incur a large overhead due to communication protocols, memory accesses, and static (often generic) architectures. In this work, we implement a low-latency Multi-Layer Perceptron (MLP) processor using Field Programmable Gate Arrays (FPGAs). Unlike CPUs and Graphics Processing Units (GPUs), our FPGA-based design can directly interface sensors, storage devices, display devices and even actuators, thus reducing the delays of data movement between ports and compute pipelines. Moreover, the compute pipelines themselves are tailored specifically to the application, improving resource utilization and reducing idle cycles. We demonstrate the effectiveness of our approach using mass-spectrometry data sets for real-time cancer detection. We demonstrate that correct parameter sizing, based on the application, can reduce latency by 20% on average. Furthermore, we show that in an application with tightly coupled data-path and latency constraints, having a large amount of computing resources can actually reduce performance. Using mass-spectrometry benchmarks, we show that our proposed FPGA design outperforms both CPU and GPU implementations, with an average speedup of 144x and 21x, respectively. In our work, we demonstrate the importance of application-specific optimizations in order to minimize latency and maximize resource utilization for MLP inference. By directly interfacing and processing sensor data with ultra-low latency, FPGAs can perform real-time analysis during procedures and provide diagnostic feedback that can be critical to achieving higher percentages of successful patient outcomes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Dye and pigment-free structural colors and angle-insensitive spectrum filters

Optical spectrum filtering devices displaying minimal angle dependence or angle insensitivity are provided. The filter comprises a localized plasmonic nanoresonator assembly having a metal material layer defining at least one nanogroove and a dielectric material disposed adjacent to the metal material layer. The dielectric material is disposed within the nanogroove(s). The localized plasmonic nanoresonator assembly is configured to funnel and absorb a portion of an electromagnetic spectrum in the at least one nanogroove via localized plasmonic resonance to generate a filtered output having a predetermined range of wavelengths that displays angle insensitivity. Thus, flexible, high efficiency angle independent color filters having very small diffraction limits are provided that are particularly suitable for use as pixels for various display devices or for use in anti-counterfeiting and cryptography applications. The structures can also be used for colored print applications and the elements can be rendered as pigment-like particles.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Applications for alliform carbon

This invention relates to novel applications for alliform carbon, useful in conductors and energy storage devices, including electrical double layer capacitor devices and articles incorporating such conductors and devices. Said alliform carbon particles are in the range of 2 to about 20 percent by weight, relative to the weight of the entire electrode. Said novel applications include supercapacitors and associated electrode devices, batteries, bandages and wound healing, and thin-film devices, including display devices.

25 ENERGY STORAGE↗
DOE OSTI2016

Role of salt concentration in blend polymer for energy storage conversion devices

Solid Polymer Electrolytes (SPE) are materials of considerable interest worldwide, which serves dual purpose of electrolyte and separator between electrode compartments in renewable energy conversion/storage devices such as; high energy density batteries, electrochromic display devices, and supercapacitors. Polymer blend electrolytes are prepared for various concentration of salt (Ö/Li) with the constant ratio (0.5 gm) of each PEO and PAN polymers (blend polymer) using solution casting technique. Solid polymeric ionic conductor as a separator is the ultimate substitute to eliminate the drawback related to liquid and gel polymer ionic conductors. In the present work, solid polymer electrolyte film consisting of PEO, PAN and LiPF{sub 6} are examined for various concentration of lithium salt by keeping PEO/PAN blend ratio as a constant with a view to optimize the dominant salt concentration which could give the maximum conductivity at ambient temperature.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2022

Design and optimization of high temperature optocouplers as galvanic isolation

The commercial InGaN-based (blue and green) and AlGaInP-based (red) multiple quantum well (MQW) lighting emitting diodes (LEDs) were studied in a wide range of temperatures up to 800 K for their light emission and detection (i.e., LEDs operated under reverse bias as photodiodes (PDs)) characteristics. The results indicate the feasibility of integrating a pair of selected LEDs to fabricate high temperature (HT) optocouplers, which can be utilized as galvanic isolation to replace the bulky isolation transforms in the high-density power modules. A detailed study on LEDs and PDs were performed. The external quantum efficiency (EQE) of the LED and PDs were calculated. Higher relative external quantum efficiency (EQE) and lower efficiency droops with temperatures are obtained from the blue and green LEDs for display compared with the blue one for lighting and red LED for display. The blue for lighting and red for display devices show superior responsivity, specific detectivity (D*), and EQE compared with blue and green for display when operated as PDs. The results suggest that red LED devices for display can be used to optimize HT optocouplers due to the highest wavelength overlapping compared with others.

42 ENGINEERING↗
DOE OSTI2022

Portable aircraft controller devices and systems

A portable computerized device for an aircraft control system includes an input system for inputting commands, a device display for displaying information on the computerized device, a processor, a wireless communication module, and a non-transitory computer readable medium comprising computer executable instructions, the computer executable instructions configured to cause the processor to perform a method. The method can include detecting whether the portable computerized device is in a cockpit state such that the portable computerized device is in and/or docked to an aircraft cockpit or if the portable computerized device is in a remote state such that the portable computerized device is not in an aircraft cockpit or is not docked to an aircraft cockpit. If the portable computerized device is determined to be in a remote state, the method includes operating the remote device in a remote mode. If the portable computerized device is determined to be in a cockpit state, the method includes operating the device in a local mode.

Sahay, Prateek↗
DOE OSTI2018

Sol–gel Synthesis and Upconversion Luminescent Properties of Yb{sup 3+},Er{sup 3+},Eu{sup 3+} Triply-Doped in YVO{sub 4} Phosphors

Yb{sup 3+},Er{sup 3+},Eu{sup 3+} triply-doped in YVO{sub 4} with varying molar ratio of Er/Eu were synthesized in a sol–gel method with a subsequent heat treatment for the first time. The optimal molar ratio of Er/Eu for the maximum energy transfer efficiency was 1/39. After molar ratio, the influences of different heat treatment temperatures were also researched and the maximal heat temperature was 1300 °C. Besides, the properties of YVO{sub 4}:Yb{sup 3+},Er{sup 3+},Eu{sup 3+} upconversion phosphors were investigated by X-ray diffraction, scanning electron microscopy and photo luminescent spectra, respectively. In sum, XRD results indicate the crystal structure of as-prepared samples, which is the tetragonal phase of YVO{sub 4} with no other diffraction peaks. SEM images show the morphology of as-prepared samples, which are granular-like nanoparticles. PL spectra demonstrate the upconversion luminescence of as-prepared samples, which emit strong green lights (at 525 nm, 550 nm) and slight red lights (at 590 nm, 615 nm, 695 nm) under the NIR irradiation at 980 nm. Two strong green emissions are attributed to the {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2} and {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} transitions of Er{sup 3+} ions. Meanwhile, three slight red emissions are attributed to the {sup 5}D{sub 0}→{sup 7}F{sub 1}, {sup 5}D{sub 0}→{sup 7}F{sub 2} and {sup 5}D{sub 0}→{sup 7}F{sub 4} transitions of Eu{sup 3+} ions. All in all, the colorful emissions endow YVO{sub 4}:Yb{sup 3+},Er{sup 3+},Eu{sup 3+} phosphors great potential for some applications, such as display devices, bio-labeling and infrared detection.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Electro-optical properties of photochemically stable polymer-stabilized blue-phase material

Polymer-stabilized blue-phase liquid crystal (BPLC) comprising fluorinated compounds with high resistivity and photochemical stability is demonstrated. The Kerr constant, driving voltage, and response time of this BPLC are measured using an in-plane switching liquid crystal cell. At 20 °C, the measured total response time is faster than 0.7 ms and Kerr constant is 2 nm/V{sup 2}. This fluorinated BPLC material is a promising candidate for next-generation photonic and display devices, because it can be used in active matrix addressed devices.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2016

Structural origination of charge transfer complex nanostructures: Excellent candidate for field emission

Worldwide strategies for amalgamating rationally controlled one-dimensional organic nanowires are of fundamental importance for their applications in flexible, cheaper and lighter electronics. In this work we have fabricated large-area, ordered CuTCNQ (copper-7,7,8,8-tetracyanoquinodimethane) nano architecture arrays over flexible conducting substrate and discussed the rational growth and integration of nanostructures. Here we adopted the organic solid phase reaction (VLS) technique for the growth of organic hierarchies and investigated how field emission properties changes by tuning the nanostructures morphology i.e., by varying length, diameter, alignment and orientation over flexible substrate. The CuTCNQ nanowires with optimized geometry exhibit excellent high field emission performance with low turn-on and threshold field values. The result strongly indicate that CuTCNQ nanowires on flexible carbon cloth substrate are promising candidates for constructing cold cathode based emission display devices, vacuum nanoelectronics, and etc.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2013

High stability electron field emitters made of nanocrystalline diamond coated carbon nanotubes

We report enhanced life-time stability for the electron field emitters prepared by coating nanocrystalline diamond (NCD) on carbon nanotubes (CNTs). Upon overcoming the problem of poor stability in CNTs, the NCD-CNTs exhibit excellent life-time stability of 250 min tested at different applied voltages of 600 and 900 V. In contrast, the life-time stability of CNTs is only 33 min even at relatively low voltage of 360 V and starts arcing at 400 V. Hence, the NCD-CNTs with improved life-time stability have great potential for the applications as cathodes in flat panel displays and microplasma display devices.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2016

Synthesis, structure and photoluminescence properties of Sm{sup 3+}-doped BiOBr phosphor

Well-crystallized tetragonal layered BiOBr and Bi{sub 0.95}Sm{sub 0.05}OBr phosphors were prepared by the solid state method. These compounds were characterized using powder X-Ray diffraction and photoluminescence technique. In PL spectra, the electric dipole transitions dominate than other transitions which indicate that the Sm{sup 3+} ions occupy a site with an inversion center of BiOBr. CIE chromaticity diagram confirmed that these phosphors can be useful in the fabrication of red component in white light emitting diodes (WLEDs) for display device applications.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗