Pixel chip sparks energy-efficient intelligent LED headlamps
Up to now, pixel systems have been based on a large number of individual LEDs. The project, which is 18 months old, is being funded to a total of seven million euros by the US Federal Ministry of Education and Research as part of its focus on ‘Integrated Microphotonics’ and will run until January 31, 2016. The aim of the project is to develop the technical principles for a new class of energy-efficient LED headlamps which may then provide the basis for adaptive front lighting systems. These systems will improve the illumination of the road ahead because they actively adapt the distribution of the light according to the driving and traffic situation without dazzling other road users.
The µAFS demonstrator shows that with only one LED chip it is possible to control 256 pixels individually. Source: Osram
The prototype was developed jointly by experts at the project coordinator Osram Opto Semiconductors, Osram Specialty Lighting, Infineon Technologies and the Fraunhofer Institute for Reliability and Microintegration IZM. In previous adaptive front lighting systems (AFS) one pixel corresponded to one LED component or one chip, whereas in this prototype one chip contains 256 pixels which can all be individually controlled. This is the first step to light sources with more than 1000 pixels. Osram Opto Semiconductors has developed the pixel chip with defined light patterns in the colors blue and white. The challenge was to define the light points during chip processing itself and enable them to be linked directly with the control system.
Infineon Technologies developed the electronic driver chip for directly controlling the numerous light points individually. As the specialist in mounting technology, Fraunhofer IZM made it possible to couple the light-emitting pixel chip with the controlling driver chip. By structuring the chip surface and attaching the converter for creating white light Osram Opto Semiconductors then completed the prototype. This demonstrator proves the feasibility of the first project objective as it exhibits a particularly high resolution which is what is needed for the light pattern to be adjusted dynamically and with a high degree of precision. In contrast to current LED-based AFS solutions, it will open up special automotive lighting options such as city lights and bad weather lights.
One of the next steps will be for the Osram Specialty Lighting business unit to transfer the prototype to a light module with electrical, mechanical and thermal interfaces. The two aspects of particular interest here are intelligent control and an appropriate connection to the vehicle bus to ensure extremely fine control of the light. µAFS project partners Hella, the lighting specialist, and Daimler, the car manufacturer, will then take over. Hella is responsible for the development of the optical system and the thermal management system, including the design of the complete headlight. Daimler has already contributed specifications and requirements with regards to the bus connection and optics within the project, and is responsible for detailed testing of the headlamp and therefore for the final process.
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