Cheap naked chips snap a perfect picture

(say that title 3 times fast)

07 October 2009 by Paul Marks
Magazine issue 2729.

HOW can image sensors - the most complicated and expensive part of a digital camera - be made cheaper and less complex? Easy: take the lid off a memory chip and use that instead.

As simple as it sounds, that pretty much sums up a device being developed by a team led by Edoardo Charbon, of the Technical University of Delft, in the Netherlands. In a paper presented at an imaging conference in Kyoto, Japan, this week, the team say that their so-called "gigavision" sensor will pave the way for cellphones and other inexpensive gadgets that take richer, more pleasing pictures than today's devices. Crucially, Charbon says the device performs better in both very bright light and dim light - conditions which regular digital cameras struggle to cope with.

While Charbon's idea is new and has a patent pending, the principle behind it is not. It has long been known that memory chips are extremely sensitive to light: remove their black plastic packages to let in light, and the onrush of photons energises electrons, creating a current in each memory cell that overwhelms the tiny stored charge that might have represented digital information. "Light simply destroys the information," says Martin Vetterli, a member of the EPFL team.

A similar effect occurs aboard spacecraft: when energetic cosmic rays hit a cell in an unprotected memory chip they can "flip" the state of the cell, corrupting the data stored in the chip.

What Charbon and his team have found is that when they carefully focus light arriving on an exposed memory chip, the charge stored in every cell corresponds to whether that cell is in a light or dark area. The chip is in effect storing a digital image.

more:
http://www.newscientist.com/article/mg20427295.100-cheap-naked-chips-snap-a-perfect-picture.html
If correct, the future of digital photography...

Wonder how big they can make these?

SHeeeait

Right now, the cells in DRAMs are quite a bit smaller than a wavelength
of visible light.

Tesha

Way back when you could buy RAM in packages with lids that were easily peeled off a lot of people were making this kind of camera. But at .016 or .064 Megabyte resolution the picture was rather primitive...

The use of noise in image processing is also common and built into most still and video compression algorithms. In DVDs for example the noise in a picture is often stripped out, which can create a very unnatural looking picture, but then different noise is reintroduced back into the picture and everything looks fine again.

It sounds to me as if they are taking the very noisy high resolution picture from the memory chip and extracting the final photograph from that.