LEDs... is there anything they can’t do? Well yes, actually, there is. They can’t be something other than a point light source. That’s not ideal when it comes to flat – and increasingly thin – displays such as television and cell phone screens. How does one go about converting that three-dimensional point light source into a two-dimensional display, without losing much of its intensity? The answer could be found in a new machine that efficiently and inexpensively produces fiber optic film sheets.
The machine was designed by the Fraunhofer Institute for Production Technology in Germany. The plastic sheets it produces are 2x3 meters wide, yet the internal microstructures that distribute the light are mere micrometers in size.
The process starts by using specialized diamond tools to create a 2x2 millimeter-wide stamp, made from ultrathin nickel sheet. Then, like a dot matrix printer, that stamp is precisely guided as it treats the surface of the plastic sheet, populating it with the microstructures. It takes a few days for it to treat the entire surface, but this is far better than the weeks or even months required by previous methods.
After the sheet has been prepared, the machine can then test its optical structure. If changes are needed, they can be done on the spot. Once it’s up to snuff, the sheet is immersed in a nickel bath, and galvanized. From there, it can serve as the master for mass replication.
The researchers claim that the machine can produce fiber optic sheets for use in a wide variety of applications, including displays, architectural lighting, and automobile interior lighting.