From: Christopher Fry <70353.3056@CompuServe.COM>
Subject: Re: Integrated laser arrays for Eyephones
Date: 05 Nov 91 02:05:19 EST



>I'm not aware of any current research into eye-tracking displays: who's 
>doing this?  

Iscan Inc, 125 Cambridge Park Drive, Cambridge, MA, USA 02138
(617) 868-5353

I saw these guys at a trade show about 2 years ago. They had 2 models:
a desktop mounted mondel that was a video camera sitting at the base of your 
comupter screen looking up at your face. It might have had motors in it to 
track your head. It output the position of your pupils. As I recall, their
demo was to highlight text that you looked at, and scroll it as need be.
Their second model was mounted like the rear-view mirror clipped onto glasses 
frames that's used by bicyclists. It contained a tiny TV camera. 

>Head mounted displays, to my mind DO NOT qualify as a good
>way to reduce pixel counts, even with high-resolution areas (see below).

Isn't the ideal to have an eye-tracking display mounted on the head?
Big movements handled by your head motions. Little movements by something 
small and light. 

The fast-light, 2-d tilt mirrors developed for aiming the lasers in 
laser-light shows may find some application here. If we can tolerate delays as
long as 100MS [Stampe's numbers, sounds long to me but I haven't done the 
experiments] then the laser aiming mirrors are plenty fast enough. Probably 
not quite light enough, though.

>Here are some numbers on the advantages of eye-tracking displays over
>the standard head-mounted eyephones: [...]

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.

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.