Skip to main content

Integrated communicating Solid-State Light Engine (ISLE) for use in Automotive Forward Lighting and information exchange between vehicles and infrastructure

Exploitable results

The state of the art in lighting is an electric bulb. But these bulbs cannot be modulated, so they are of no use for communication. White light-emitting diodes (LEDs) are in existence today and could serve for both purposes. A standard incandescent bulb achieves 20 lumens per watt (lm/W) while automotive xenon lamp technology provides 90 lm/W. Solid-state technology currently achieves up to 40 lm/W in laboratory quantities and about 20 lm/W in series production. New records are established every three months. The theoretical limit of 200 lm/W means that the solid-state source achieves greater efficiency than the best existing light source. More efficient lighting systems would mean an enhanced brightness on the road while reducing fossil fuel emissions through lower power consumption. The ISLE project aims to develop a new manufacturing technology to produce a new generation of headlamps for vehicles, which is the base for a future car-to-car or of car-to-infrastructure communication system. The point is to define the ability of an LED system to provide communication modes for other vehicles or traffic safety devices - measured by the new ability to communicate during different driving conditions. The following results have been achieved: 1. Samples of white LED have been manufactured performing with a correlated colour temperature below 4300 K. On the way to this, a suitable submount for the LED-chip had to be designed. It had to perform optimal thermal conductance and provide a minimum of light absorption. Since monochromatic LED-chip radiation had to be transformed into white light, a unique converter material was also to be composed. All single components had then be brought together, always considering methods suitable for mass production. 2. The communication concept has been implemented and its feasibility was approved in the laboratory and at the complete system. The concept was based on a frequency shift keying technology (FSK). The clou of this concept ensures together with the electronically driving concept no light loss either with or without sending data. 3. An electronic driver circuit on a lower scale integration (SMD-technology) with all necessary functionality was developed. From the experience made during the project development, an integrated circuit (ASIC) performing all functionality of the electronic driver circuit has been developed for automotive application and has now been introduced to the market. 4. The integrated optical concept was turned into a complete headlamp including driving (high) and passing (low) beam. Also an alternative modular optical concept was designed and its performance simulated. Following the experience made within this project, the modular optical concept would have advantages for large scale mass production. 5. A novel concept of laminating high reflective coating on plastic material was developed. It was found, that this concept has advantages compared to a metalisation layers normally used to make reflectors in terms of higher absolute reflectance. 6. A high dynamic heating and cooling system operating with pressurised water for controlling the temperature in injection moulding tools was developed, which takes advantage of a new ultrasonic based water flow measurement.