Never ending work in ALL-LED headlamps? How and why efficiency increase initiates adaption in reflection and projections systems

You are here: Homepage > Search

Never ending work in ALL-LED headlamps? How and why efficiency increase initiates adaption in reflection and projections systems

Stade, Florian / Scholl, Michael

Everybody likes the announced LED improvement, especially in the coming new technology of LED in low and high beams. Since a head lamp is designed for a defined flux of the LEDs and thus providing the required minima and maxima of photometry, there is a given small band of possible variation. The limits of the legal specifications are quickly reached due to the enormous improvement in efficiency of the LEDs. So the situation might occur that the system needs to be adapted. A possible solution could be e.g. to reduce the current or to reduce the number of the light emitting chips. The resulting effects will be discussed using the LED multi arrays in different light functions impacted by the increasing performances. The paper will show a broad analysis from investigations with the reflection and projection systems of the AUDI R8 ALL-LED headlamp. The concept of changing the number of active chips in an ALL LED headlamp is dependent on the used optical system. There are systems in which the concept works well like the projection system of the R8 LED Spot. Other systems like the R8 LED high beam are unsuitable for changing the number of chips and systems like the base light of the R8 LED are provisory fitted for a reduced number of chips. This system works with some limitations and slight modifications in the light distribution. The investigation finally shows that the system of an ALL LED Headlamp should be designed under consideration of the medium-term roadmap of the used LEDs very precisely. Although the system with a reduced chip number works, there is more work to do as only changing the LEDs for e.g. adapting the ECU.