In order to realize a new and innovative automotive lighting technology, Bosch collaborates with specialist partners AUDI AG, Osram AG, Karlsruhe Institute of Technology (KIT) and ZKW Lichtsysteme GmbH on the funded BMBF project “iLaS” (intelligent laser based adaptive headlight system), FKZ 13N13087. In the course of this project a new high-resolution laser technology will be developed in order to make roadway illumination even more flexible and highly versatile in all situations – without blinding oncoming traffic or drivers ahead.
This new technology uses a laser beam scanning unit, which continuously scans over a phosphor converter by means of a MEMS micro mirror. The so generated scan pattern is projected onto the road through secondary optics.
Let’s have a closer look on the principle setup of this new laser technology: A blue laser diode with a wavelength of around 450 nanometers radiates its light onto a quickly moving MEMS micro mirror with a diameter in the millimeter range – developed by Bosch. The mirror is a micro-optical system that features electro-mechanical control and is made of silicon. It is very sturdy and ensures a very long durability. The MEMS micro mirror deflects the light towards a phosphor converter, containing conversion and scattering particles embedded in a matrix. The resulting mix of scattered blue light and converted light can be tuned to yield white light. With the synchronized combination of tilting the MEMS micro mirror and controlling the laser power, any desired light pattern can be produced on the converter and projected onto the road like a slide in a slide projection. The light pattern will be modified according to information obtained by high performance driver assistance sensors, such as camera, LIDAR, RADAR, etc. and merged by an ECU in order to calculate an adaptive and intelligent light distribution.
In contrast to existing LED headlamp technologies, scanning micro mirror based systems generate a continuous light distribution without “jumping” boundaries of the illuminated area when single LED segments are switched on or off. Another crucial advantage is their ability to redistribute the light flux as required allowing for a high average utilization of the installed light sources and low energy consumption.
The laser technology would enable a complete new market for MEMS products. Being one of the MEMS pioneers and by far the world’s largest automotive MEMS supplier with the experience of more than 7 billion MEMS sensors (automotive and consumer), Bosch fulfills all conditions to step successfully into the application field of scanning micro mirrors for intelligent automotive headlights.