Colour and White Light
By choosing the adequate combination of semiconductor materials, the LED manufacturers are able to control the emitted wavelength and therefore the colour of the emitted light
LED emits monochromatic light, which means that the light is at one specific wavelength or visible at one specific colour. White light is the mixture of all colours, and exactly the same principle is used to create white LED light. There are several methods used to produce white light with LEDs and more on the R&D horizon. Most white LEDs are built from a blue LED die covered with special phosphor. In operation, much of the blue light is converted to yellow, and the mixture of blue and yellow appears as white to the eye. Manufacturers provide a range of available colour temperatures by making changes in the phosphor composition, warm-white, neutralwhite and cold-white devices can be created in this way. Depending on the individual application, the light designer can choose the optimum colour of the light. For example, the bakery department will need more yellowish light in order to underline the freshly-baked character of the goods while this would be a no-go for the fresh fish department, which needs cold blue light in order to emphasise that the fish is well-cooled. The other method is to mix the three colours Red, Green and Blue, emitted by three individual LEDs mostly placed in an array. When dynamic colour or colour temperature is a requirement, a microcontroller-driven RGB LED assembly is used. By individually controlling the intensity of each LED it is possible to mix any colour within the so-called colour gamut. This means that the white point can also be adjusted as required. For an extended warm white gamut, additional amber LEDs may be preferred. Also, a lot of new RGBW (red-green-blue + white) arrays are available today. With this technique, white light at various colour temperatures on the Planckian locus can easily be reached. The full colour range is also available.
Ongoing rapid improvement of the LEDs efficacy
There are several existing LEDs from our portfolio with efficacy way over 100 lm/W. However latest lab results showed efficacy more than 250lm/W. The ongoing rapid improvement on the LED efficacy brings live new technologies like the new COBs (Chip on Board) from our portfolio. First OSRAM COB on market Soleriq™ E incorporates an easy to use metal core board and a large flux package. However to increase over all system efficacy in real lighting there are several factors to watch on LED selection like luminous flux depreciation, increasing junction temperature, optical losses and electronic control performance. We are ready to advise you with the expertise from our LightSpeed team on best suitable system solutions for your particular application.
Size and Package
Nearly everything is possible as LEDs are significantly smaller than all other light sources
The real advantage of the LED design is when art goes hand in hand with engineering. The avaialable wide LED package selections will give designers great advantage in size allowing them to create lighting systems and luminaries in almost any shapes and sizes required by an application. There are LEDs available from our portfolio in various PLCC packages like OSRAM DURIS offering optical efficency over 100lm/W at 5000K, CRI70 or mini powerfull JADE from Avago providing 3 W with luminous efficency of 112lm/W in a small package with 700 mA drive current and isolated heat sink and many others.
Directed Light Output
LEDs directed light output increase system efficiency, means there are no reflector losses because LED light is emitted only into one half of the space
There is constant applicational efficency improvement among our LED manufacturers to gain on optimisation of the light beam angles for particualar application needs. LEDs have natural advantages on light emission and directionality over standard “bulb” shaped incandescent lamps or fluorescent lamps which emit light in all directions - LED light is emitted only into one half space. Special families were optimized for retrofits and fixtures (e.g. fluorescent replacement) like OSRAM OSLON® SSL 80 and 150 suitable for professional down lights and luminaries as well outdoor lighting. The real benefit of this family is a technique bringing ideal balance of the CRI and luminus flux.
Robust to thermal, mechanical and vibrational shocks
LEDs incorporate no filament or fragile glass bulb that can be damaged due to mechanical vibrations and shocks. Product breakage is a fact of life in electric lamp transport, storage, handling, and installation. LEDs do not use any glass. LEDs mounted on a circuit board are connected with soldered leads that may be vulnerable to direct impact, but even that risk is mainly connected to Thru-Hole types. LED light fixtures may be especially appropriate in applications with a high probability of lamp breakage such as bridges, industrial areas, or stadiums. Beside needed roboustness for outdoor challenges LEDs have another important reliable advantage towards other light sources. They dont “burn out” like incadescent or other lamps. They just slowly lose their light output over the time.
Cold Temperature Operation
Cold temperatures present a challenge for fluorescent lamps
LEDs are available in wide area of different rugged packages with silicon encapsulation suitable for challenging outdoor operations at low temperatures and even offering water resistive types. They are used for example for street lighting, architectural lighting and any kind of outdoor entertainment like full color video screens. To start, for example, a fluorescent lamp at low temperature higher voltage is required and luminous flux is decreased. LEDs are most suitable for low temperature operations and its performance is inherently increased.
Environmental Impact with Negligible UV Emissions
Usage of LEDs reduce environmental impact
Average lifetime for the high flux LED is rather long which brings several advantages especially towards reducing resources required for the maintenance. LEDs use no mercury and less phosphorus than fluorescent lamps. Constant improvements on the efficacy and full electronic controllability are involving LED technology closely towards modern renewable energy concepts. These are the facts which make usage of LED technology a smart choice while reducing the footprint on the nature. LEDs emit light with negligible ultraviolet (UV) and very little infrared radiation.The lack of UV radiation makes them usefull for lighting applications not attractive to insects and very attractive for illumination of delicate objects such as artworks as well as materials subject to UV degradation.
Unaffected by Frequent Switching
LEDs reach full brightness instantly, with no re-strike delay
This characteristic is notable for example in vehicle brake lights as an important differentiator unlike other traditional light sources such as fluorescent or metal halide lamps. Traditional light sources will burn out sooner if switched on and off frequently. LED life and lumen maintenance are unaffected.