From: brucec@phoebus.labs.tek.com (Bruce Cohen)
Subject: Re: Integrated laser arrays for Eyephones
Date: 6 Nov 91 20:17:55 GMT
Organization: Computer Research Lab, Tektronix Inc.




In article <1991Nov6.024051.367@milton.u.washington.edu> 
70353.3056@CompuServe.COM (Christopher Fry) writes:

> Bravo! You get a standing ovation from me for this message! I've heard 
> unsustantiated talk about cutting down needed pixels by decreasing res from 
> the fovea out, but had no idea that the savings were potentially so dramatic.
> 100K -> 150 K pixels is no more than current LCD's can put out. With 
> "distorting" lenses we can leave them in the regular array as they're 
> manufactured for TV yet present the eye with varying resolution. But those 
> LCD's are TOO BIG to move quickly with low weight motorsso we're back to some 
> kind of integerated-optics light sources, be they LED's or microlasers. Only 
> now we need a LOT less than my original proposal.

So don't move the arrays.  Instead, move the distorting lenses.  There
are compensating mirror systems for telescopes moved by motors which can
make several compensations a second (see last month's (Nov.) Scientific
American article on trends in astronomy), and there are lens systems for
motion compensation of hand-held film and video cameras.  The state of
the art for the camera systems when they were first introduced in the
late '60s was control system rolloff at about 10 hertz.  Anyone know
how fast the current systems are?

> Once we've got the display itself, a bunch of clever graphics software needs 
> to be written. I expect each pixels to take considerably longer to draw than 
> regular-array square pixels [and remember, we need to fill an oval, not a 
> rectangle].  If our general-purpose hardware still isn't fast enough for 
> manipulating those 150K pixels, then this sounds like an ideal candidate for 
> special purpose parallel hardware. 

One way to solve this problem is to spend memory on it: make the frame
buffer match the maximum resolution over the whole field of vision, use
ordinary algorithms on a fast standard processor to write the pixels,
then use special hardware on the video output side to filter output to
the display with the filter kernel based on where in the field of vision
the pixel is.

------------------------------------------------------------------------
Speaker-to-managers, aka
Bruce Cohen, Computer Research Lab        email: brucec@crl.labs.tek.com
Tektronix Laboratories, Tektronix, Inc.                phone: (503)627-5241
M/S 50-662, P.O. Box 500, Beaverton, OR  97077