Television screens are becoming increasingly flatter - some have even become almost as thin as a sheet of paper. Their size takes impressive dimensions, much to the delight of home cinema fans. Cellphones and laptops also have ever brighter and more brilliant displays. All of these developments owe their thanks to miniature light-emitting diodes LEDs that beam background lighting into a multitude of devices.
However, LED technology does have a disadvantage. It is a point light source. But displays are two-dimensional. So how does one distribute the light from an LED evenly on as large a surface as possible, without massive energy loss? At the Fraunhofer Institute for Production Technology IPT in Aachen, a truly one-of-a-kind machine is currently emerging. They will soon be producing fiber optic film that solves this problem and distributes the light two-dimensionally. What's so unusual and special about this: The films possess superficial structures measuring in the single-digit micrometer range, while the sheets themselves measure at two by one meter in size. This makes them the largest of their kind throughout the EU. In addition, they can be produced cost-effectively and with energy-efficiency in mass reproduction.
To do so, the researchers of IPT developed a process chain with which they can populate large-scale sheets with the necessary microstructures. It's an ultraprecise process, says Dr. Christian Wenzel, senior engineer at IPT. Using pinpoint accuracy, the machine must apply the smallest structures just a few micrometers in size onto the surface of the film in a periodic sequence. In order to produce the stamp, we use special diamond tools, explains Wenzel. The stamp consists of a gossamer-thin nickel sheet, and itself is also infinitesimal: Its surface equals at most two by two millimeters. Like a dot matrix printer, it must then process a sheet measuring two by one meter in size, guided by the ultraprecision machine. Within a
|Contact: Dr.-Ing. Christian Wenzel|