Illuminating ideas

Few areas of automotive development have changed as dramatically and as quickly as lighting. Audi has long been a leader in the field and continues to push the envelope, developing new technologies that literally turn night into day. With the coming of the new Audi A8, cutting-edge lighting again plays a significant role, with the technologies of Audi laser light and HD Matrix LED high beams used together for the very first time.

This revolutionary combination produces a clarity of light and an intelligent system that is safer for road users than ever before. But what does it actually mean?

Originally developed for use in motorsport, Audi laser light doubles the range of the high beam.

A small laser module in each headlight generates a light cone that extends several hundred metres as a spotlight. The monochromatic and coherent blue laser beam has a wavelength of 450 nanometers. A phosphor converter transforms it into white light suitable for road use with a colour temperature of 5500 Kelvin. Translated to plain language, this is the perfect condition for the human eye. As a result, drivers enjoy greater contrast and the eyes are not strained and tire less quickly. The laser spot, which is active at speeds of 70km/h and above, also offers significant visibility and safety advantages. The laser spot dims automatically if the camera mounted on the windscreen detects other cars within its range.

Matrix LED headlights produce the high beam with tiny light-emitting diodes that are bundled in common reflectors or lenses. With the new A8, each headlight integrates 32 small, individually controllable light-emitting diodes. They are arranged in two rows in a common housing. Thanks to the new configuration and to a low beam that is also variable, the HD Matrix LED headlights create a light that is again, perfectly suited to the human eye, while producing extraordinary illumination.

When the light switch is set to Automatic and the high beams are on, the system is switched on outside of urban areas at speeds of 30km/h and above. As soon as the camera on the windscreen detects other vehicles or city limits, the controller switches off individual LEDs or dims them in 64 stages, creating several million possible light patterns. The Matrix LED light masks out other vehicles while continuing to fully illuminate the areas between and around to them.

The LEDs in the Matrix LED headlights also assume the function of cornering lights, shifting the focal point of the light along the curve. This occurs shortly before the wheel is turned, based on predictive route data provided by MMI navigation plus. In addition, LEDs are maintenance-free and designed to last the life of the car. 

At the other end of the car, Audi offers optional OLED lighting as part of the package when ordering the HD Matrix headlights with laser light. The OLED lighting (organic light-emitting diode, uses two electrodes in each unit – at least one of which is transparent – incorporating numerous extremely thin layers of organic semiconductor materials. A low DC voltage between 3 and 4 volts causes these layers, which are 200 times thinner than a human hair, to illuminate.

 Unlike point light sources such as LEDs, OLEDs are surface light sources. Their light achieves a new level of homogeneity, and dimming is continuously variable. It does not not require any reflectors, light guides or similar optical parts, making OLED units efficient, lightweight and perfectly homogeneous.

In the A8, each OLED unit is divided into multiple segments that light up with varying brightness. The outer corners generate the tail light, the inner surfaces generate the brake light. The illuminated surface sections are delimited from one another with extreme precision. Dividing the OLEDs into small, individually controllable segments arranged in three dimensions enables entirely new lighting scenarios.