Track lightingtypes

The prismatic and reflective polarization films are generally achieved using so called DBEF films manufactured and supplied by 3M.[30][31] These reflective polarization films using uniaxial oriented polymerized liquid crystals (birefringent polymers or birefringent glue) were invented in 1989 by Philips researchers Dirk Broer, Adrianus de Vaan and Joerg Brambring.[32]

LED backlights are often dimmed by applying pulse-width modulation to the supply current, switching the backlight off and on more quickly than the eye can perceive. If the dimming-pulse frequency is too low or the user is sensitive to flicker, this may cause discomfort and eyestrain similar to the flicker of CRT displays at lower refresh rates.[46] This can be tested by simply waving a hand in front of the screen; if it appears to have sharply-defined edges as it moves, the backlight is pulsing at a fairly low frequency. If the hand appears blurry, the display either has a continuously-illuminated backlight or is operating at a frequency too high to perceive. Flicker can be reduced (or eliminated) by setting the display to full brightness, although this can degrade image quality and increases power consumption.[citation needed]

The combination of LED dynamic backlight control[18] in combination with reflective polarizers and prismatic films (invented by Philips researchers Adrianus de Vaan and Paulus Schaareman[27] make these "LED" (LCD) televisions far more efficient than the previous CRT-based sets, leading to a worldwide energy saving of 600 TWh in 2017, equal to 10% of the electricity consumption of all households worldwide, or twice the energy production of all solar cells in the world.[28][29]

Because LEDs can be switched on and off more quickly than CCFLs and can offer a higher light output, it is theoretically possible to offer very high contrast ratios. They can produce deep blacks (LEDs off) and high brightness (LEDs on). However, measurements made from pure-black and pure-white outputs are complicated by edge-LED lighting not allowing these outputs to be reproduced simultaneously on screen.[clarification needed]

An integrated LED track head combines LEDs, optics, and thermal management system into a single housing. The LED driver is either co-located with other components or housed in a dedicated gear box. The luminaire comes with a die cast aluminum housing that serves double duty as the heat sink in some designs.

Track lightingfor kitchen Ceiling

Addressable track systems are typically accomplished by incorporating data lines. In this case, each track head should be capable of being controlled through a protocol such as 0-10V, DALI or DMX. Addressable lighting control can also be implemented through wireless networking. In this instance, the track luminaire incorporates a wireless communication module, which allows the luminaire to be controlled from a smartphone or handheld device through a wireless protocol such as ZigBee, Z-wave or Bluetooth.

Quantum dots are photoluminescent; they are useful in displays because they emit light in specific, narrow normal distributions of wavelengths. To generate white light best suited as an LCD backlight, parts of the light of a blue-emitting LED are transformed by quantum dots into small-bandwidth green and red light such that the combined white light allows a nearly ideal color gamut to be generated by the RGB color filters of the LCD panel. The quantum dots may be in a separate layer as a quantum dot enhancement film, or replace pigment-based green and red resists normally used in LCD color filters. In addition, efficiency is improved, as intermediate colors are no longer present and do not have to be filtered out by the color filters of the LCD screen. This can result in a display that more accurately renders colors in the visible spectrum. Companies developing quantum dot solutions for displays include Nanosys, 3M as a licensee of Nanosys, QD Vision of Lexington, Massachusetts, US and Avantama of Switzerland.[39][40] This type of backlighting was demonstrated by various TV manufacturers at the Consumer Electronics Show 2015.[41] Samsung introduced their first 'QLED' quantum dot displays at CES 2017 and later formed the 'QLED Alliance' with Hisense and TCL to market the technology.[42][43]

Track lighting systems provide the most flexible solution for ambient, task, accent lighting and wall washing in offices and hospitality spaces. Variable space layouts, variable room concepts and variable task needs in today’s commercial and hospitality environments call for dynamic, flexible lighting to create appealing, effective spaces. In open-plan offices, meeting rooms, libraries, halls and ballrooms, a lighting solution that adjusts to varying working conditions can boost concentration and motivation. In hotels, restaurants, bars, cafeterias, cafes, nightclubs and discotheques, lighting design must accommodate layout changes and space reconfigurations in order to keep up with the latest trends in hospitality design.

The rate at which heat is removed from the LED module depends on the ability of the heat sink to absorb thermal energy and dissipate it into the surrounding ambient air. The heat sink must be designed with an adequate surface area to ensure the volume of heat flow outpaces the load rate.

Commercial track lighting makes use of a track system created with one or more linear electrified tracks (rails) along which one or more light fixtures may be mounted. Most track systems are line voltage and capable of handling up to 2400 watts on single 20-amp, 120-volt circuit, allowing them to deliver long runs necessary for commercial and architectural applications. The tracks accommodate either one or multiple circuits and come in H-type (Halo compatible), L-type (Lightolier compatible), or J-type (Juno compatible) configurations. The most prevalent multiple-circuit tracks are 2-circuit rails which are designed for use when a higher load capacity is needed or two separately controlled circuits are required on one section of track. Multiple circuits sharing a neutral, however, can generate cross-circuit interferences and neutral harmonics. Some multiple-circuit tracks have independent neutrals, which eliminates harmonics and allows for flicker-free dimming. Tracks may include additional raceways that allow for one or more sets of data lines to run through.

An LED-backlit LCD is a liquid-crystal display that uses LEDs for backlighting instead of traditional cold cathode fluorescent (CCFL) backlighting.[1] LED-backlit displays use the same TFT LCD (thin-film-transistor liquid-crystal display) technologies as CCFL-backlit LCDs, but offer a variety of advantages over them.

The performance and reliability of the LED driver are system design considerations of critical importance. The amount of power delivered to the LED load must be tightly controlled to ensure consistent and predictable light quality. Since most track light fixtures installed in offices and hospitality spaces are intended to deliver task lighting, ripples in the output current provided to the LED load should be smoothed out to ensure flicker-free lighting. The LED load can be dimmed through phase control or constant current reduction (CCR). Selective control of LED luminaires mounted on a single circuit requires the track systems to be addressable.

Aside from light distribution, glare control is an important consideration in designing track luminaires. Directional luminaires are typically constructed to intentionally regress the position of the LED array. Beam control accessories such as honeycomb louvers, snoots and barn doors may be provided to eliminate high angle glare or soften aperture brightness.

The white LEDs in LED backlights may use special silicate phosphors, which are brighter but degrade faster.[37] The size of the LEDs is one of the factors that determines the size of the bezel of LED-backlit LCDs.[38]

AmazonTrack Lighting

Television sets described as "LED TVs" are LCD-based, with the LEDs dynamically controlled using the video information[17] (dynamic backlight control or dynamic "local dimming" LED backlight, also marketed as HDR, high dynamic range television, invented by Philips researchers Douglas Stanton, Martinus Stroomer and Adrianus de Vaan[18][19][20]

The evolution of energy standards and the increasing public expectations regarding power consumption made it necessary for backlight systems to manage their power. As for other consumer electronics products (e.g., fridges or light bulbs), energy consumption categories are enforced for television sets.[21] Standards for power ratings for TV sets have been introduced, e.g., in the US, EU, Australia,[22] and China.[23] A 2008 study[24] showed that among European countries power consumption is one of the most important criteria for consumers when they choose a television, as important as the screen size.[25]

Today’s LEDs deliver an exceptionally high efficacy. But even with LEDs, the tradeoff between color and efficacy still come into play. If luminous efficacy is an emphasis, light sources with a color rendering index (CRI) in the low to mid 80s are very likely to be used. However, the high source efficacy of LEDs affords us an opportunity to enjoy high color rendering lighting in virtually all applications. Task and accent lighting typically demands the use of light sources with a minimum CRI of 90, which means the spectral power distribution (SPD) of the light sources is balanced in exact proportions.

The amount of energy emitted as various wavelengths of the visible light spectrum also determines the apparent color (correlated color temperature, or CCT) of the light being produced by a source, which in turn affects the pleasantness of a space and subjective interpretation of brightness. LEDs can be specified in a nominal CCT of 2700K, 3000K, 3500K, 4000K, or 5000K. In LED lighting, the chromaticity consistency within the beam of light, and from luminaire to luminaire matters a lot to architectural and accent lighting. A higher level of color control on a particular group of LED must be exercised to keep variations of light color within defined acceptance criteria.

LEDTrack lighting

LED-backlit LCDs are not self-illuminating (unlike pure-LED systems). There are several methods of backlighting an LCD panel using LEDs, including the use of either white or RGB (Red, Green, and Blue) LED arrays behind the panel and edge-LED lighting (which uses white LEDs around the inside frame of the TV and a light-diffusion panel to spread the light evenly behind the LCD panel). Variations in LED backlighting offer different benefits. The first commercial full-array LED-backlit LCD TV was the Sony Qualia 005 (introduced in 2004),[12][13][14][15][16] which used RGB LED arrays to produce a color gamut about twice that of a conventional CCFL LCD television. This was possible because red, green and blue LEDs have sharp spectral peaks which (combined with the LCD panel filters) result in significantly less bleed-through to adjacent color channels. Unwanted bleed-through channels do not "whiten" the desired color as much, resulting in a larger gamut. RGB LED technology continues to be used on Sony BRAVIA LCD models. LED backlighting using white LEDs produces a broader spectrum source feeding the individual LCD panel filters (similar to CCFL sources), resulting in a more limited display gamut than RGB LEDs at lower cost.[citation needed]

A first dynamic "local dimming" LED backlight was public demonstrated by BrightSide Technologies in 2003,[33] and later commercially introduced for professional markets (such as video post-production).[34] Edge LED lighting was first introduced by Sony in September 2008 on the 40-inch (1,000 mm) BRAVIA KLV-40ZX1M (known as the ZX1 in Europe). Edge-LED lighting for LCDs allows thinner housing; the Sony BRAVIA KLV-40ZX1M is 1 cm thick, and others are also extremely thin.[citation needed]

Track rails are constructed of extruded aluminum. The live circuit and neutral conductors are made of heavy gauge copper and encased in extruded PVC insulators to prevent contact with aluminum extrusion. Tracks can be cut to custom length. They can also be joined together to form simple linear runs or complex configurations. Various connector options, including straight, “L”, “T”, “X” and adjustable push-in connectors, are available to mechanically and electrically join track sections together and provide design continuity throughout a space. A track system must be fully polarized and grounded throughout to ensure safe operation. Grounding is accomplished with a dedicated bus bar or through a grounding channel in the track. A current limiter is attached to a track system for limiting the amount of electrical load that can be placed on the circuit. Tracks can be surface mounted, recessed into the ceiling with special housing or clips, or pendant mounted from the ceiling using suspension stems.

Using PWM (pulse-width modulation), a technology where the intensity of the LEDs are kept constant but the brightness adjustment is achieved by varying a time interval of flashing these constant light intensity light sources,[26] the backlight is dimmed to the brightest color that appears on the screen while simultaneously boosting the LCD contrast to the maximum achievable levels, drastically increasing the perceived contrast ratio, increasing the dynamic range, improving the viewing angle dependency of the LCD and drastically reducing power consumption.[clarification needed]

Additionally a special diffusion panel (light guide plate, LGP) is often used to spread the light evenly behind the screen.

Full-array mini-LED backlights, consisting of several thousand WLEDs, were being researched for TVs and mobile devices in 2017.[36]

A 2016 study by the University of California (Berkeley) suggests that the subjectively perceived visual enhancement with common contrast source material levels off at about 60 LCD local dimming zones.[11]

Lamp-based LED luminaires, however, are not effective use of LED technology. The retrofit LED lamps incorporated in these fixtures must conform to the form factor and physical dimension of legacy light sources, which leads to compromise in thermal, electrical and optical design for LED systems. While lamp-based LED luminaires are still a common choice of design in entry-level track lighting systems, a solution that fulfils the requirement of high efficiency, high reliability, highly controllable, and high quality lighting calls for integrated design of LED lighting systems.

Backlit LCDs cannot achieve true blacks for pixels, unlike OLED and microLED displays. This is because even in the "off" state, black pixels still allow some light from the backlight through. Some LED-backlit LCDs use local dimming zones to increase contrast between bright and dim areas of the display, but this can result in a "blooming" or "halo" effect on dark pixels in or adjacent to an illuminated zone.[3]

A track light fixture, commonly known as a track head, is detachably engaged to the track via an adapter which communicates electrical current and control signals to the track head. Track rack heads come in forms of lamp-based LED luminaires and integrated LED luminaires. Lamp-based LED luminaires are track light fixtures that use retrofit LED lamps to create the desired beam of light. The retrofit LED lamps are typically directional lamps that use internal reflectors to provide various light distribution patterns ranging from narrow-beam-angle spotlighting to wide-beam-angle floodlighting. Directional lamps include parabolic aluminized reflector (PAR) lamps, bulged reflector (BR) lamps, and multifaceted reflector (MR) lamps. Among these types, PAR and BR lamps are self-ballasted systems that run off a line power, MR LED lamps are low voltage systems and must be powered by transformers that reduce the line voltage to, typically, 12 volts. Lamp-based track heads are commonly gimbal ring fixtures which are the simplest and most cost-effective of all the designs.

Track Lightingheads

Track lightingmodern

The most classic of all track head design is a cylinder. A cylinder track head typically includes a light engine that is an assembly of the LED module and aluminum heat sink. The LED module is a chip-on-board (COB) LED package or an array of high power LEDs or mid-power SMD LEDs solder mounted on a metal-core printed circuit board (MCPCB). The LED board is fully attached to the heat sink to ensure the heat dissipated by the LEDs can be spread out over a very large area. A thermal interface material (TIM) may be used to minimize thermal contact resistance at the interface.

LED backlights replace CCFL (fluorescent) lamps with a few to several hundred white, RGB or blue LEDs. An LCD with LED-Backlight may be edge- or direct-lit:[9]

Televisions that use a combination of an LED backlight with an LCD panel are sometimes advertised as LED TVs, although they are not truly LED displays.[1][2]

The local dimming method of backlighting allows to dynamically control the level of light intensity of specific areas of darkness on the screen, resulting in much higher dynamic-contrast ratios, though at the cost of less detail in small, bright objects on a dark background, such as star fields or shadow details.[10]

Mini LED displays are LED-backlit LCDs with mini-LED–based backlighting supporting over a thousand full array local dimming (FALD) zones, providing deeper blacks and a higher contrast ratio.[44] An example of a product that uses Mini LED backlighting is Apple's 2021 year 12.9 inch iPad Pro.[45]

An integrated LED luminaire uses LEDs in conjunction with thermal, electrical and optical components to enable high efficiency, long life system operation and effective delivery of light. A dedicated system allows to incorporate a full sized heat sink for effective transfer of the heat flux from the LED junction to the ambient air. An optical design that extracts and controls light directly from the source provides for highly efficient and precisely controlled optical distributions. Integrated design typically lends adequate spaces to accommodate driver and control circuitry which is significantly more complicated than that of traditional light sources.

LED track heads use lenses, reflectors, or a combination of them to regulate luminous flux from the light source. Total internal reflection (TIR) lenses are capable of producing smooth, rotationally symmetric beams with FWHM angular widths between 4 and 60 degrees with intense center beam candlepower (CBCP) for accent lighting or high illuminance uniformity for task or ambient lighting. TIR optics are also available in round or square lens arrays that provide individual optical control for an array of LEDs. The use of compound lens arrays enables miniaturization of optics and compact design of track luminaires. Tight beam control can also be accomplished with facet reflectors which take advantage of a large number of small surfaces (facets) to improve the reflection power and maximize the optical performance. Track lighting systems are also employed to provide uniform illumination and accenting of walls and vertical surfaces. The wall washing beam is usually achieved with asymmetric reflector systems.

LED-backlit LCDs have longer life and better energy efficiency than plasma and CCFL LCD TVs.[35] Unlike CCFL backlights, LEDs do not use mercury in their manufacture, which is an environmental pollutant. However, other elements (such as gallium and arsenic) are used in the manufacture of the LED emitters; there is debate over whether they are a better long-term solution to the problem of screen disposal.[citation needed]