Integrated area-light sources in RCL pave the way for new automotive signal lighting applications

Approaches like 'hidden until lit' describe trends in automotive interior lighting applications, where the light sources remain hidden until they are needed or turned on. Integrating the light source behind semi-transparent surfaces makes them practically invisible when not in use. This trend is now arriving at a high pace in automotive exterior lighting applications. The lighting designers try to hide the light sources either behind black surfaces or behind any individually designed surfaces (like e.g. technical patterns or gradient designs). This requires entirely new possibilities for integrating future lighting solutions. To support this trend, we have developed a rear combination lamp (RCL) prototype based on ams OSRAM's ALIYOS™ technology combined with LEONHARD KURZ's capabilities for In-Mold Decoration (IMD) and Functional Foil Bonding (FFB) Adhesive process. The RCL´s outer lens gets a semi-transparent colored surface via IMD. The ALIYOS™ LED-foils are integrated on the back side of the outer lens by FFB Adhesive and are thereby invisible due to the decorated surface. Only when the lighting function is turned on, the lighting signature becomes visible. The FFB Adhesive process has been further optimized to allow the integration of the LED-foil on 2.5D curved surfaces as well as the stitching of several LED-foils next to each other. Thanks to the transparency of the ALIYOS™ technology, additional light solutions can be placed directly behind the emissive area of the ALIYOS™ LED-foil. This combination of both technologies — the LED-area light source with traditional approaches based on latest developments of ams-OSRAM's SYNIOS™ LED family - allows for boosted light emission for functions such as stop, turn indicator and reverse lighting, respectively. Indication of autonomous driving within the RCL is demonstrated. Based on the RCL prototype, simulation results and measurement data will be discussed. This combined approach allows for more dynamic and customizable lighting solutions, enhancing both the aesthetic and functional aspects of automotive lighting design.