Fraunhofer develops new lighting technology to improve road safety and freer vehicle design

According to foreign media reports, Fraunhofer researchers have developed a new lighting technology that not only exceeds the legal and automotive industry requirements for lighting performance and functionality, but is also more efficient, more compact, and more flexible in installation than current systems. The newly developed headlights allow designers to design non-traditional cars more freely, while also benefiting drivers and automakers.

(Image source: Fraunhofer official website)

Scientists at the Fraunhofer International Institute for Optics (IOF) will present a second functional prototype of a segmented high-beam unit based on a multi-aperture projector that minimizes light scatter. Its 200,000 micro-optical elements focus the light optimally in the direction of the vehicle's travel. The lighting segments can be deactivated individually or in groups as required without delay. In combination with modern automotive sensor technology, this effectively prevents high-beam headlights from blinding oncoming drivers. In addition, the design requires significantly less installation space than conventional systems. Not only does it dim the light for oncoming vehicles, it also protects pedestrians, such as cyclists who are not equipped with lights, from the bright light, thus increasing safety for all road users.

"We developed the headlight as part of the WISA project SSL (Structured Spot Light)," said Stephanie Fischer, research assistant at Fraunhofer IOF's Micro-Optical Systems Division. "This is a commercial internal research project that enables cross-institute pre-competitive research and lays the foundation for sub-industry development projects." The project relies on a group of consultants from automakers and parts suppliers. They provide the required parameters for high and low beams as well as mechanical design requirements. Participating members include well-known brands such as Audi, Hella, Trilux and Osram.

(Image source: Fraunhofer official website)

In the coming years, automakers will have more creative freedom when designing headlights. Because the system has a very small installation depth, and the size and shape allow for greater freedom in installation. Therefore, designers can freely decide whether to install the headlights on the outer edge of the front of the car or install them in a narrow strip in the middle of the front of the car. Stephanie Fischer said, "Headlights don't have to be rectangular, designers can choose any other shape they want. In the past, larger optical components required more space and restricted car design." In addition, the new system increases LED light output. For example, when set to low beam, only 35% of the light output is lost, improving the energy balance of the vehicle and increasing the level of acceptance of automotive applications.

The high beam unit consists of two modules, each containing seven individually controllable LED clusters. Four collimating lenses direct the light of the LED clusters onto two series-connected lens arrays. These micro-optics handle the distribution of the light from the individual LEDs. Thousands of micro-lenses precisely direct the light to the respective lighting segments. Each lighting segment controls 24 LEDs individually and can be switched on or off in less than a second.

For the first time, Fraunhofer IOF uses rectangular polymer lenses of different sizes for more precise optical modeling. The smallest variant is 0.045 mm x 0.180 mm. Fraunhofer has also developed its own new production method for rectangular lenses, the "High Five" grayscale lithography system. High Five not only produces extremely fine microstructures, but also creates relatively large profile depths (100μm) to optimize the use of LED brightness. Fraunhofer IOF has now successfully realized the first prototype of a low-beam headlight module. If all components are fully developed, the 8,000 microlenses will give the car optimal visibility at night and in bad weather conditions.