Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!mintaka!bloom-beacon!sao
From: sao@athena.mit.edu (Andy Oakland)
Newsgroups: comp.graphics
Subject: Re: TIs 3D Display
Summary: Same principle as old spinning-disc TV's
Message-ID: <1990Oct5.193803.13819@athena.mit.edu>
Date: 5 Oct 90 19:38:03 GMT
References: <1990Oct1.160621.5445@infonode.ingr.com> <1990Oct1.143245.753@jarvis.csri.toronto.edu> <1990Oct1.212142.18501@morrow.stanford.edu>
Sender: daemon@athena.mit.edu (Mr Background)
Organization: Massachusetts Institute of Technology
Lines: 17

In article <1990Oct1.212142.18501@morrow.stanford.edu> rick@pangea.Stanford.EDU (Rick Ottolini) writes:
>Didn't the first versions of TV in the 1920's use mechanical scanners
>before magnetic beams were perfected?

It's true; I've seen one of these monsters.  Imagine a big (~3')
spinning disc, punched with holes.  At the top of the disc, a neon (?) 
bulb was behind it, and a translucent screen a few inches square was
in front.

The bulb flickered in time with the incoming video signal, the 
disc spun, and the holes in the disc were arranged so that the bulb 
showed through progressively lower scanlines.

The resulting image was about the size of a postage stamp.  Amazing.

	:Andy Oakland
	sao@athena.mit.edu