Colors are playing an increasingly important role in the automotive sector. Consumers can not only choose the exterior color of the vehicle, you can also tailor the interior lighting to the customer’s individual taste. Thanks to the very wide blue color range of the new RGB MultiLED from Osram Opto Semiconductors, lighting designers have a virtually unlimited choice of colors for ambient lighting, including customer-specific colors. Color design now covers cluster lighting to an increasing extent, notably in combined instruments such as speedometers and RPM indicators, in infotainment and GPS displays, as backlighting for switches and in accent, ambient and trim lighting. Vehicles are fast becoming objects of individual design.
The main feature of the new MultiLED from Osram is a very broad blue color range with a wavelength of 447 to 476nm and high brightness. Deep saturated blue tones can now be produced thanks to the use of three LED chips in red, green and blue (RGB). Other properties of the MultiLED, such as its integrated ESD (electrostatic discharge) protective diode (2 kilovolts), its improved corrosion resistance, and its longtime market availability, make these LEDs ideal for use in automobiles. The MultiLED was developed specifically for applications in the automotive sector and meets all the requirements of an automotive certified component.
All shades of blue
The new MultiLED consists of a red chip, a green chip and a blue chip (RGB LED). At 370 millicandelas (mcd), the blue is much brighter than in other multi-chip LEDs on the market. This brightness is a significant advantage because the sensitivity of the human eye causes the color blue to be perceived as darker than it actually is.
"The new LED can offset this darker perception so that customer brightness requirements can be met for all color ranges," said David Rousseau, LED Product Marketing Manager at Osram Opto Semiconductors. "What’s more, a short-wave blue color has a pleasant saturated appearance. We have now succeeded in implementing this color range in an RGB LED version."
The three independently controllable LED chips in blue, red and green in the MultiLED are available in different brightness groups thanks to finely defined grouping (known as binning). They can be individually combined to produce a large color spectrum. All three chip colors are the product of leading-edge technology: blue and green in UX:3 technology, red in the latest thin-film technology. The light is extracted from the chip with very high efficiency, resulting in high luminous intensity. In the upper blue wavelength range, for example, a level of up to 560 millicandelas is achieved at an operating current of 20 mA. Luminous intensity in candelas (cd) corresponds to luminous flux in lumens (lm) emitted by a light source in a particular solid angle. The typical thermal resistance between the chip and the solder point is 127 K/W for blue and green, and 96 K/W for red.