Browse Topic: Light emitting diodes (LEDs)

Items (962)
This ARP covers three common light sources, incandescent, electroluminescent and light emitting diode that, when NVG filtered, can be used to illuminate NVG compatible aerospace crew stations. It is recognized that many other different light sources can also be used for this purpose. Also see 2.1.1 for other SAE documents that cover particular applications within the crew station environment. This ARP sets forth recommendations for the design of NVG compatible lighting, utilizing these light sources, that will meet the requirements of MIL-L-85762 Lighting, Aircraft, Interior, Night Vision Imaging System (NVIS) Compatible. This also includes the replacement document MIL-STD-3009: Lighting, Aircraft, Night Vision Imaging System (NVIS) Compatible. Although this ARP concentrates on lamp light sources for illumination, the information contained within this ARP may be directly applied to incandescent, electroluminescent and light emitting diode information display devices. Regardless of the
A-20A Crew Station Lighting
The scope of this SAE Aerospace Information Report (AIR) is to discuss factors affecting visibility of aircraft navigation and anticollision lights, enabling those concerned with their use to have a better technical understanding of such factors, and to aid in exercising appropriate judgment in the many possible flight eventualities
A-20B Exterior Lighting Committee
The purpose of this document is to serve as a resource to aerospace designers who are planning to utilize Wavelength Division Multiplexed (WDM) interconnects and components. Many WDM commercial systems exist and they incorporate a number of existing, commercially supported, standards that define the critical parameters to guide the development of these systems. These standards ensure interoperability between the elements within these systems. The commercial industry is motivated to utilize these standards to minimize the amount of tailored development. However, since some of the aerospace parameters are not satisfied by the commercial devices, this document will also try to extend the commercial parameters to those that are necessary for aerospace systems. The document provides cross-references to existing or emerging optical component and subsystem standards. These parameter definitions, test methods, and procedures typically apply to telecommunications application and in some cases
AS-3 Fiber Optics and Applied Photonics Committee
ARP6366 defines a comprehensive and widely-accepted set of specification guidelines to be considered by those seeking to use or design fiber optic sensors for aerospace applications. Some of the most common applications for fiber optic sensing within aerospace include inertial guidance and navigation (gyros) and structural monitoring (temperature, strain, and vibration sensing). Common sensor infrastructure elements include: transmitting and receiving opto-electronics (e.g., sources and receivers); multiplexing and demultiplexing optics; optical cabling; and signal processing (both hardware and firmware/software
AS-3 Fiber Optics and Applied Photonics Committee
This document is intended for connectors typically found on aerospace platforms and ground support equipment. The document provides the reasons for proper fiber optic cleaning, an in-depth discussion of available cleaning methods, materials, packaging, safety, and environmental concerns. Applicable personnel include: Managers Designers Engineers Technicians Trainers/Instructors Third Party Maintenance Agencies Quality Personnel Purchasing Shipping/Receiving Production
AS-3 Fiber Optics and Applied Photonics Committee
This document is intended for discrete and integrated digital, wavelength division multiplexing (WDM), and analog/radio frequency (RF) photonic components developed for eventual transition to aerospace platforms. The document provides the reasons for verification of photonic device life test and packaging durability. The document focuses on pre-qualification activity at the optical component level to achieve TRL 6. The recommended tests in this document are intended to excite typical failure mechanisms encountered with photonic devices in an aerospace operating environment, and to build confidence that a technology is qualifiable during a program’s engineering and manufacturing development phase. This recommended practice is targeting components to support electrical-to-optical, optical-to-electrical, or optical-to-optical functionality. Passive optical waveguide, fiber optic cable, and connector components that are integral to a photonic package are included. Component and photonic
AS-3 Fiber Optics and Applied Photonics Committee
This document draws from, summarizes, and explains existing broadly accepted engineering best practices. This document defines the process and procedure for application of various best practice methods. This document is specifically intended as a standard for the engineering practice of development and execution of a link loss power budget for a general aerospace system related digital fiber optic link. It is not intended to specify the values associated with specific categories or implementations of digital fiber optic links. This document is intended to address both existing digital fiber optic link technology and accommodate new and emerging technologies. The proper application of various calculation methods is provided to determine link loss power budget(s), that depend on differing requirements on aerospace programs. A list of parameters is provided as guidance for aerospace fiber optics applications along with a check list to help assure that appropriate parameters and
AS-3 Fiber Optics and Applied Photonics Committee
From televisions to smartphones, organic light-emitting diodes (OLEDs) are finding their way into many everyday devices. For use in displays, blue OLEDs are also required to supplement the primary colors — red and green. Especially in blue OLEDs, impurities give rise to strong electrical losses, which could be partly circumvented by using highly complex and expensive device layouts
This SAE Recommended Practice provides the methods of measurements for electrical and photometric characteristics of LED packages. It provides procedures, requirements, and guidelines for the methods of the measurement of luminous flux and color maintenance of LED devices (packages, arrays, and modules) for ground vehicle lighting applications
Lighting Standard Practices Committee
Temporal light modulation (TLM), colloquially known as “flicker,” is an issue in almost all lighting applications, due to widespread adoption of LED and OLED sources and their driving electronics. A subset of LED/OLED lighting systems delivers problematic TLM, often in specific types of residential, commercial, outdoor, and vehicular lighting. Dashboard displays, touchscreens, marker lights, taillights, daytime running lights (DRL), interior lighting, etc. frequently use pulse width modulation (PWM) circuits to achieve different luminances for different times of day and users’ visual adaptation levels. The resulting TLM waveforms and viewing conditions can result in distraction and disorientation, nausea, cognitive effects, and serious health consequences in some populations, occurring with or without the driver, passenger, or pedestrian consciously “seeing” the flicker. There are three visual responses to TLM: direct flicker, the stroboscopic effect, and phantom array effect (also
Miller, NaomiIrvin, Lia
To ensure adequate visibility without excessive glare, vehicle headlights are designed to use a specific source of illumination. The optical designs of headlights gather the luminous flux produced by the light source to produce a useful beam pattern that meets the relevant requirements and standards for vehicle forward lighting. With the advent of solid state, light emitting diode sources for general illumination, an increasing number of LED replacement headlight bulb products has emerged over the past decade. In most cases, these LED replacement bulbs are not permitted for legal use on public roadways, but some countries have begun to permit specific LED replacement bulbs to be used legally on the road for specific makes, models and production years of certain vehicles. If they can be demonstrated to produce a beam pattern that meets the photometric requirements for a legal headlight, they are permitted to be used legally for on-road use. In the present paper we present photometric
Bullough, John D.Skinner, Nicholas P.
A research team led by Lawrence Berkeley National Laboratory (Berkeley Lab) has developed “supramolecular ink,” a new technology for use in OLED (organic light-emitting diode) displays or other electronic devices. Made of inexpensive, Earth-abundant elements instead of costly scarce metals, supramolecular ink could enable more affordable and environmentally sustainable flat-panel screens and electronic devices
This document includes recommendations of installations of adequate landing and taxiing lighting systems in aircraft of the following categories: a Single engine personal and/or liaison type b Light twin engine c Large multiengine propeller d Large multiengine turbojet e Military high-performance fighter and attack f Helicopter g Electric Vertical Takeoff and Landing (EVTOL) and Urban Air Mobility (UAM
A-20B Exterior Lighting Committee
A single strand of fiber has the flexibility of cotton and the electric conductivity of a polymer, called polyaniline. The newly developed material showed good potential for wearable e-textiles. Researchers tested the fibers with a system that powered an LED light and another that sensed ammonia gas
Trends in automotive lighting are moving toward vehicle exterior lights, which will communicate with drivers and surroundings. The small size, lower power consumption, high efficiency, and substantially long life make LEDs a leading light source in automotive lighting applications. Losses in optical power for InGaN-based LEDs can be reduced up to 45% compared to AlGaInP, and phosphor-converted color LEDs can contribute to stable light output over the lifetime. Color LEDs will fulfill different requirements such as uniformity in color and luminance. Additionally, the mixing of different colors with white will underline the exterior features and aesthetic design of vehicles
Janeva Azdejkovic, MersidaDenis, XavierMatsuyama, YujiMiyairi, Hiroshi
Researchers from the Disruptive & Sustainable Technologies for Agricultural Precision (DiSTAP) and the Critical Analytics for Manufacturing Personalized-Medicine (CAMP) Interdisciplinary Research Groups (IRG) of the Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, have developed the world’s smallest LED. It enables the conversion of existing mobile phone cameras into high-resolution microscopes. Smaller than the wavelength of light, the new LED was used to build the world’s smallest holographic microscope, paving the way for existing cameras in everyday devices such as mobile phones to be converted into microscopes with modifications to the silicon chip and software. This technology also represents a significant step forward in the miniaturization of diagnostics for indoor farmers and sustainable agriculture
Imagine a thin, digital display so flexible that you can wrap it around your wrist, fold it in any direction, or even curve it over your car’s steering wheel. Well, imagine no more — researchers at the Pritzker School of Molecular Engineering (PME) at the University of Chicago have designed such a material; it can even bend in half or stretch to more than twice its original length — and still emit a fluorescent pattern
Batteries and humans like to be at room temperature. Thermal-management systems make sure that happens - while maximizing efficiency. When General Motors unveiled the 2025 Cadillac Escalade IQ, the EV luxury SUV with a 24-module Ultium battery pack providing more than 200 kWh of energy that contributes to an estimated 450 miles (724 km) of range and up to 750 hp, the company enumerated an array of technology features, ranging from the 55-in. total diagonal LED display powered by the Qualcomm Snapdragon Platform to the Four-Wheel Steer capability, which reduces the turning diameter of the SUV by more than 6.5 feet (to 39 ft, 4 ins). And there is a suite of other features. But among all that there was another feature perhaps not as glamorous as the sort of equipment in a luxury EV that will sticker at an estimated $130,000: a heat pump
Vasilash, Gary S.
Researchers have designed a thin, digital display that can bend in half or stretch to more than twice its original length while still emitting a fluorescent pattern. The material has a wide range of applications, from wearable electronics and health sensors to foldable computer screens
More pixels! This is a major trend in the display industry. The benefits of 8K or higher resolution TVs may be debatable. For eye catching applications such as AR/VR glasses, more and therefore smaller pixels are required for technical feasibility. Screen door effects and pixel inhomogeneities are easily visible and disturbing for the user on displays that sit closely to the viewer’s eye. μ-LEDs are considered an innovative technology for very high resolutions with pixel sizes of less than 10 μm and equally small pixel pitches. In general, they have the potential to be a groundbreaking display technology – provided production challenges can be solved. Just like OLED displays, μ-LEDs are an emissive display technology, i.e., each single subpixel is in itself a light source. Luminance and color variations between the individual pixels are likely. As this strongly influences the visual quality of the displays, a quality control and calibration of the displays is necessary not only in the
A research team from the National University of Singapore (NUS) Faculty of Science, led by Professor Liu Xiaogang from the Department of Chemistry, has developed a 3D imaging sensor that has an extremely high angular resolution — it can distinguish points of an object separated by an angular distance, of as little as 0.0018°. The sensor operates on a unique angle-to-color conversion principle, allowing it to detect 3D light fields across the X-ray to visible light spectrum
This AS covers subsonic and supersonic Mach meter instruments which, when connected to sources of static (Ps), and total (Pt), or impact (Pt-Ps), pressure provide indication of Mach number. These instruments are known as Type A. This AS also covers servo-operated repeater or digital display instruments which indicate Mach number when connected to the appropriate electrical output of a Mach transducer of Air Data Computer. These instruments are known as Type B
A-4ADWG Air Data Subcommittee
Super-cooled large drops present serious threats to aviation safety and as a result, the problem has been addressed by the FAA with the additional icing certification requirement. SLD clouds often consist of bi-modal drop size spectra leading to great challenges when it comes to simulating and characterizing these conditions in situ and in icing wind tunnels. Legacy instrumentation for measuring drop size distributions and liquid water content has been challenged under these conditions. In this report, a high-resolution particle imaging instrument is described; this instrument addresses the need for measuring drop size distributions and liquid water content over a wide range of drop sizes (10 to 2500 μm or larger). A high-throughput megapixel digital camera is used to record shadow images of the particles. High-quality illumination of the particle field is provided with high-power LED illumination with driving electronics designed to provide pulse durations as short as 25ns with
Bachalo, William DonManin, JulienPayne, GregoryFidrich, MichaelIbrahim, Khalid
As LEDs replace traditional lighting systems, they bring more smart capabilities to everyday lighting. While you might use your smartphone to dim LED lighting at home, researchers have taken this further by tapping into dynamically controlled LEDs to create a simple illumination system for 3D imaging
Headlamps should illuminate the traffic scene ahead of the vehicle in such a way that the driver can operate the vehicle safely and in a relaxed manner. At the same time, negative effects on drivers of other vehicles, pedestrians and other people should be minimized. Various technical parameters such as beam pattern, mounting height, headlamp aiming, and source spectrum can be tuned to find the necessary compromise. The physiology of the vision system under specific nighttime conditions strongly influences these factors and how headlamps can be best optimized for visibility and comfort. The SAE Improved Roadway Illumination task force collected and reviewed relevant research on these topics. This document is a comprehensive summary of this information. The goal is to enable lighting experts, advocacy groups, and non-experts (journalists, consumer organizations, car drivers) to better understand the benefits and tradeoffs of improved roadway lighting with modern headlamp technology. It
Road Illumination Devices Standards Committee
The ability to control light using a semiconductor device could allow low-power, relatively inexpensive sources like LEDs or flashlight bulbs to replace more powerful laser beams in new technologies such as holograms, remote sensing, self-driving cars, and high-speed communication
Synthetic fuels derived from renewable power sources, so-called e-fuels, will play a crucial role in achieving climate-neutral future mobility because they can be used in the existing fleets and in hard-to-decarbonize applications. In particular e-fuels that contain oxygen in their chemical structure can also burn more cleanly in terms of soot formation. For compression-ignition engines, polyoxymethylene dimethyl ethers (PODEs or OMEs) are among the most promising candidates for such oxygenated e-fuels. Here, we investigated the characteristics of injection and combustion of OME3-5 mixture compared to n-dodecane, a reference diesel-like fuel. Both single and multi-injection, comprising a short pilot injection, is used. Experiments were performed in a single-cylinder optically accessible Bowditch-type engine, injecting with 1500 bar pressure with a 3-hole injector (Spray B of the Engine Combustion Network). Liquid and vapor penetration were measured by imaging the spray illuminated by a
Wiesmann, FrederikBauer, EsraKaiser, Sebastian A.Lauer, Thomas
Sequential turn signals are becoming more common, partly because of the availability of the detailed temporal and spatial control of light that is allowed by LED sources. They seem to be popular with drivers, and some human factors considerations suggest that they may more effectively convey information about intended maneuvers. This research was designed to investigate possible benefits by presenting experimental participants with a variety of sequential and static turn signals under realistic field conditions. The experimental tasks were based on possible encounters at four-way intersections. Passenger cars were statically positioned to represent such encounters. Participants were seated in one of the vehicles and were asked to make simple but meaningful judgments about intended turns by the other vehicles. Visual conditions were realistic in terms of the viewing geometry and photometry. Experiments were conducted in the day and at night. Three experiments were performed. In two of
Flannagan, MichaelWaragaya, TakeshiKita, Yasushi
Automotive megatrends such as connected, autonomous and electrified vehicles are driving penetration of automotive electronic technology in every vehicle subsystem. However, these electronic units need to be interfaced with input/output devices from outside world. The same need to be interfaced with a robust and reusable architecture conforming to automotive norms. When generic electronic control units (ECUs) need to be reused across diverse vehicle families and segments, it is desirable that every ECU pin interfaced with the outside world needs to be capable of performing multiple tasks. This is particularly true of digital outputs (such as solenoids, lamps, on/off motors etc.) and digital inputs (such as command switches, pushbuttons, pressure switches, thermal switches etc.) Current smart switch peripheral ICs can be used only as outputs and cannot be configured as inputs whenever demanded by application requirements. Also, these smart switch architectures provide conservatively
Vaidya, Vishwas Manohar
Army Research Laboratory, Adelphi, MD Developing single photon UV detection for compact chemical and biological sensors. This report summarizes the main lines of effort for the Electro-Optics Materials Research (EOMR) program including its goals and major accomplishments, focusing on the past 5 years. This EOMR program was an effort within 601102A.31B.1 titled “Optoelectronic and Integrated Photonic Materials and Device Research” for FY16-FY19 and 611102A.AA8.1 titled “Photonic Materials and Device Research” for FY20-FY21. The focus of this EOMR for most of the program was to develop novel semiconductor optoelectronic devices to reduce the size, weight, power, and cost (SWaP-C) of chemical and biological detection and identification systems. Specifically, the program addressed the need for high sensitivity photodetectors in the near-UV (NUV) spectrum between 300 and 350 nm for biological agent detection using light-induced fluorescence techniques employed by the Tactical Biological
This SAE Aerospace Recommended Practice (ARP) contains the general requirements and test procedures for Dual Mode (NVIS Friendly visible and Covert) exterior lighting for most rotorcraft and fixed wing aircraft and could be applicable to ground vehicles that desire a Dual Mode lighting system
A-20B Exterior Lighting Committee
This SAE Standard provides the minimum requirements for automotive or RV, seven position, self-draining trailer tow connector interface. The procedures included within this specification are intended to cover the test methods, design, and performance requirements of the electrical interface of the seven-position trailer tow connector in low voltage (0 to 20) road vehicle applications
Connector Systems Standards Committee
Two-dimensional materials, which consist of just a single layer of atoms, can be packed together more densely than conventional materials, so they could be used to make transistors, solar cells, LEDs, and other devices that run faster and perform better. One issue holding back these next-generation electronics is the heat they generate when in use. Conventional electronics typically reach about 80 °C, but the materials in 2D devices are packed so densely in such a small area that the devices can become twice as hot. This temperature increase can damage the device
MIT engineers are taking a modular approach with a LEGO-like design for a stackable, reconfigurable artificial intelligence chip. The design comprises alternating layers of sensing and processing elements, along with light-emitting diodes (LED) that allow for the chip’s layers to communicate optically. Other modular chip designs employ conventional wiring to relay signals between layers. Such intricate connections are difficult if not impossible to sever and rewire, making such stackable designs not reconfigurable
Most signal and marking lighting devices have light sources (bulbs), which can be based on either filament or LED technology. To assure field replacement, it is important that light source types employed be readily available in normal service channels. This document defines the physical, electrical, and photometric characteristics necessary to achieve a proper replacement for popular types of signal and marking light sources. Some of the design characteristics in this document are listed solely for the sake of standardization and are not intended to describe the performance of lighting devices (lamp assemblies) on the vehicle. Halogen filament light sources suitable for signal and marking lighting are specified in SAE J2560
Lighting Standard Practices Committee
Surveillance video accurately depicts the dynamic state of the target vehicle, which is critical digital media forensics evidence in determining vehicle speed. However, the discontinuous time-domain video (DT video), video with variable frame rate, frame drop, frame skipping is common in proprietary video files, significantly disrupting the accuracy and reliability of traffic accident data. The goal of this study is to come up with a new and useful device and method for examiners to employ in DT video to determine vehicle speed. To begin, the LED Ruler’s structure and layout were designed to reconstruct a vehicle’s trajectory. Then, to determine its speed, a step-by-step detailed explanation and procedure of the vehicle speed analysis method were shown. Finally, the proposed method’s accuracy was verified in calibration testing and accident cases using LED Ruler
Wei, RanLi, PingfanYu, Zhuopin
The Grainger College of Engineering at the University of Illinois at Urbana–Champaign was established in 1868. The department has historically spearheaded worldwide innovation in technology with inventions such as the transistor, the integrated circuit, the LED, the first web browsers (Mosaic and Netscape), and (JavaScript) — all produced by students, faculty, or alumni of the college
Researchers have developed a temporary tattoo that uses organic light-emitting diodes (OLEDs) and is applied in the same way as water-transfer tattoos. The OLEDs are fabricated onto temporary tattoo paper and transferred to a new surface by being pressed onto it and dabbed with water
This SAE Aerospace Recommended Practice (ARP) describes the recommended performance levels for equipment located on the aircraft exterior which produces radiant energy which will provide desired information when viewed with NVIS goggles. These performance intensities, normally stated in candelas for visible light, are modified to consider the goggle spectral response range. Where necessary, location of the equipment on the airplane is specified. The spectral emission characteristics may or may not include visible light. Whether or not visible energy is emitted, this document will refer to these items of equipment as "lights
A-20B Exterior Lighting Committee
This SAE Recommended Practice provides test procedures, requirements, and guidelines for rear fog lamp systems
Signaling and Marking Devices Stds Comm
MIT engineers are taking a modular approach with a LEGO-like design for a stackable, reconfigurable artificial intelligence chip. The design comprises alternating layers of sensing and processing elements, along with light-emitting diodes (LED) that allow for the chip’s layers to communicate optically. Other modular chip designs employ conventional wiring to relay signals between layers. Such intricate connections are difficult if not impossible to sever and rewire, making such stackable designs not reconfigurable
Used in products ranging from brake lights to billboards, LEDs are ideal components for backlighting and displays in electronic devices because they are lightweight, thin, energy-efficient, and visible in different types of lighting. Micro LEDs, which can be as small as 2 micrometers and bundled to be any size, provide higher resolution than other LEDs. Their size makes them a good fit for small devices such as smartwatches but they can be bundled to work in flat-screen TVs and other larger displays. LEDs of all sizes, however, are brittle and typically can only be used on flat surfaces
This document contains guidance for designers, specifiers, regulatory personnel, purchasers, managers, and others who specify or use optical simulations of aircraft lights. All aircraft lighting will be considered interior, flight deck, and exterior lighting. Guidance on standard methods of analysis and presentation of data will be provided. Although this document concentrates on lighting, many of the principles covered will be helpful in other types of optical simulation, such as for displays, non-visible radiation, etc
A-20B Exterior Lighting Committee
The EU projects reaching net-zero emissions by 2050, thus reducing CO2 emissions is a priority in the European Climate Law published in 2021. The transport sector is the second contributor to CO2, responsible for around 26% of EU greenhouse gasses emissions. In 2020, GHG (greenhouse gas) emissions from transport in the EU have dropped by 12.7% due to the COVID-19 pandemic. As society comes back to normality, vehicles use is increasing again. To reach the emission targets, new vehicles can introduce CO2-reducing eco-innovative technologies. So far, these technologies accepted under WLTP are light-emitting diodes and efficient alternators. Nevertheless, many other technologies have potential as eco-innovations. In the past, eco-innovative technologies have contributed to reducing EU CO2 emissions. In 2018, the fleet of newly registered cars with eco-innovations saved around 11000 tonnes of CO2. An increasing tendency is seen in 2019: 21000 tonnes of CO2 were saved at fleet level. During
Gil-Sayas, SusanaDi Pierro, GiuseppeSerra, SimoneFontaras, GeorgiosLodi, ChiaraCurrò, Davide
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