A Video Projector That Fits In Your Pocket

Sven-Erik writes "Video projectors able to project high-quality images will be embedded in your cellphones and laptops within two years. This is the promise of a new technology developed at Cambridge University. These pocket projectors will have no lenses and no light bulbs. Instead, these future battery-powered tiny projectors will rely on holographic technology and special algorithms. In 'Holograms enable pocket projectors,' Technology Research News explains that a 2D hologram will be created on a microdisplay and projected by using a laser beam. This has been possible because the researchers have written special algorithms which generates the holograms a million times faster than standard ones." Update: 07/03 21:21 GMT by T : Note that this text belongs to Roland Piquepaille and comes from his weblog; submitters, please strive to make your sources clear.

Watch for Apple

[fastdecade]

Apple will make this a standard component first, in the same way as they picked up on other trends and mainstreamed them, e.g. window-based UI, 17" screen, PDA.

Re:won't the small size also affect image quality?

[sploo22]

To the best of my knowledge, the loss of image quality with standard optical equipment occurs due to imperfections in the lens. With this method, there seems to be no actual refraction taking place - it all operates on wave interference. And I quote:

"No lenses are required -- the projected image is formed entirely by diffraction," said Cable.

Believe it or not, the cost is not likely to be that much higher, because there's no need for precision optics, just a tiny screen and a laser.

Re:Watch for Apple

[Anonymous Coward]

Apple is not "mainstream" .. the only thing they "mainstreamed" was the iPod.

They should be patented

[Anonymous Coward]

...These novel algorithms will be patented....

Of course, and they should be. 'Novel' applications like this one are completely non-obvious. That's what patents are for. All I'm saying is that I don't think anything is wrong with this company getting patents for it's work.

Re:won't the small size also affect image quality?

[Freudiandave]

The fact that it's easier to use won't make it cheaper. There's a novelty to it that will allow them to price it higher if they want. Just look at DVDs, which should be cheaper to produce VHS, for an example.

Re:Watch for Apple

[fastdecade]

Yeah, they certainly made a mes of the Newton. I'm not saying they succeeded in everything they kicked off, I'm just saying they put their butts on the line and go all-out with upcoming technologies.

In the case of Newton, they made it big news. There were PDAs before, mostly industrial, but Apple were making a big fanfare about being the first mainstream PDA.

As it happened, all the publicity backfired big time.

Re:Watch for Apple

[fastdecade]

Apple's not exactly mainstream, but it pushes technologies into the manistream. If I had a dollar for every "candy coloured" gadget that came out in the late nineties ...

Re:Oblig Star Wars Ref

[Tlosk]

You know the funny thing is I remember thinking to myself the first time I saw that why the holographic video was grainy, it seemed preposterous to me that they could have that sort of technology on R2D2 and yet have it be all grainy in appearance.

And now it seems incredibly prescient lol, given the millionfold increase in processing speed using the noise variance method described in the article, the trade off between graininess and speed actually becomes quite rational.

Can it be used as a computer display?

[Anonymous Writer]

The images were the same but contained different levels of noise. The researchers found that variation in noise levels affected people's perception of video quality more than the actual level of the noise.

I'm not familiar with holography, but doesn't the presence of noise mean that individual pixels won't be very clear? I suppose that would be okay for video, but what about using the projection as a computer display? Would it be good enough for text and fonts?

errr.. batteries?

[Anonymous Coward]

"Hey guys, check out this hologram I just got! Just give me a second for me to plug my wireless phone into an electrical socket, so that my batteries don't get completely drained in 15 seconds."

Kind of defeats the purpose, huh? Already when I start using my video camera is limits my cell phone usage. Imagine the energy requirements for a hologram projector.

Let's forget about putting all this stuff in cell phones... let's concentrate on actually getting this in a real projector of some sort before we start making high-faluting promises of having everything in our freaking cell phones.

Re:Well..

[aero6dof]

Go one step further and you might have a laptop with flip up lid that consists of little more that a reflective surface to shine the projector onto, flip the lid out of the way and have a presentation projector.

Some really exciting possibilities

[LeBlanc_Joey]

Maybe it would be possibe for a computer to use both this and one of those projected keyboards [alpern.org] you could have a tiny useful device.

Re:won't the small size also affect image quality?

[pVoid]

The quick answer is no.

The reason is that Holograms *use* diffraction as a means of creating the image. Diffraction is the phenomenon where if a light wave passes through a hole that is approximately the size of its wave length, it gets 'garbled' - or diffracted into unrecognizalbe patterns.

That's why you have a practical limit to the miniaturisation of lenses.

But aside from that, you have optical artifacts that occur even with normal SLR lenses. And that is because lenses are not perfectly 'stygmatic'. Which means, lenses don't actually do what they're supposed to, they only do it to a certain degree at which the eye can't differentiate.

If lenses were stygmatic, then the concept of 'depth of field' would not exist: everything in the picture would always be in focus.

Think of it this way, the rules playing on lenses and holograms are as different as the rules effective on analog vs digital. It might be the same medium, but it's an entirely different ballgame.