German researchers develop world's thinnest pico projector

Posted by Trent Nouveau

German researchers have developed what is being billed as the world's "thinnest" pico video projector.

The prototype device measures just six millimeters thick, but is capable of rendering images 10 times brighter (11 lumens) than current projectors of a similar size. 

So, how does it work?

Well, the mini-pico boasts an array of carefully shaped microlenses, each with its own miniature liquid-crystal display (LCD).

"Increasing the brightness of a projection normally means increasing the area of the light source used," explained Marcel Sieler, a researcher at the Fraunhofer Institute for Applied Optics and Precision Engineering.

"But to increase the area in this way requires a thicker lens to focus the larger image. As the area of the light source increases, so does the volume of the lens."

As such, Sieler and his team developed a new class of lens that focuses light from a (relatively) larger source while remaining thin.

Each lens - and there are 45 in the prototype - includes an LCD with 200x 200 pixels behind it.

The light passing through each LCD is focused through a lens, while images are neatly superimposed on top of others to produce a final picture.

It should be noted that Sieler and his team are currently working to reduce the LCD pixel size from  8.5 microns each to less than three microns.

(Via MIT Technology Review)