With smartphones increasingly displacing desktop and laptop computers, they also increasingly are used for presentations. However, image details are often hard to make out – the display is simply too small. A new LED projector could help: You position the smartphone in a small cradle on a coffee table, for instance, and it projects the image onto the table top: crisp, bright and DIN A4 size. If a user wants to zoom in on a portion of the picture, they can swipe the projection with their finger the same way they would swipe a display screen – the projected image can be controlled using the same principle as the display itself.
The special thing about the LED projector: the entire image displayed is crisp and clear – even if projected at a very fl at angle with the beams striking the table surface at a diagonal. Usually, this would distort the picture and make it blurry in places. The researchers who developed the projector at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena were able to solve this problem, though: “Our projector consists of hundreds of tiny microprojectors in an array, each of which generates a complete image“, explains Marcel Sieler, a scientist at IOF. “This technology, known as ‚array projection,' is modeled on nature – on the compound eye found in some insects – and with it for the fi rst time we can create very thin and bright LED projection systems with tremendous imaging properties.“
In the most simple case of vertical projection onto a level surface, each of these tiny projectors casts the same image onto the viewing surface. Hundreds of individual images overlap to create a sharp and bright overall picture. But if the device is positioned at an angle to the “screen“, each little projector shines a slightly different image. Just how these individual images will have to look in order