IE 11 is not supported. For an optimal experience visit our site on another browser.

Transparent sensor could turn your wall into a camera

Film fluroresence
The film sensor (right) with image projected on it, and its output (bottom left)Optics Express

A new type of image sensor has been developed by Austrian researchers that takes the form of a transparent film that could be placed over windows, walls, or displays. It's still very much a work in progress, but could represent the shape of webcams to come.

Many are familiar with the frustrations of user-facing cameras. Perhaps the most irritating thing is that you can't look someone in the eye when you video chat — a nice problem to have, to be sure, but still a problem. And with things like the Kinect and Leap changing how we interact with computers, having an actual camera stuck to your monitor or phone seems distinctly 20th century.

This new form of sensor may be a hint at how devices of the future see us: By detecting the light patterns cast on just about any surface — though it's so early in development that they haven't even given it a name yet (unless "thin-film luminescent concentrator" counts).

The transparent film intercepts a tiny amount of the light passing through it, channeling to the edges of the sheet. There, an array of photosensors picks it up — and by some complicated math that computes what is bright and dark depending on the way the light hits different sensors, they can reconstruct the image striking the whole sheet.

The research lab's test setup, projecting an image onto the sensor.Optics Express

Of course, the image would have to be focused on the display itself, the way an image has to be in focus on a piece of film or a traditional image sensor. Since you can't put a huge lens in front of the display (or project the image directly onto the film, as shown in their test setup), chances are this new sensor will be getting a fairly fuzzy picture of what's in front of it.

But you don't need a sharp picture for every purpose: Gestures could be detected, for instance, or the general ambient light, or the location of the user — all without a "real" camera. And it doesn't have to be on a screen; It could easily be put on a window or desk, making those into light-sensitive surfaces.

Right now the resolution is extremely limited, it only produces greyscale images, and there's a lot of noise. But this is just a proof of concept; Improving the quality is the next step (though it is hardly a trivial one).

The paper describing the technology, by Alexander Koppelhuber and Oliver Bimber of Johannes Kepler University Linz in Austria, appeared in Optics Express and can be downloaded for free from the journal.

via Gizmag

Devin Coldewey is a contributing writer for NBC News Digital. His personal website is