Re: Laser x-y game

Here is something I saved back in 1988:

Hedley

Path: imagen!sun!decwrl!labrea!agate!pasteur!ames!nrl-cmf!ukma!tut.cis.ohio-state.edu!cs.utexas.edu!sm.unisys.com!aero!venera.isi.edu!paris.ics.uci.edu!orion.cf.uci.edu!cbell2
From: cbell2@orion.cf.uci.edu (Chris Bell)
Newsgroups: sci.electronics
Subject: Re: deflection systems
Keywords: General Scanning Galvos
Message-ID: <1239@orion.cf.uci.edu>
Date: 6 Dec 88 19:32:37 GMT
References: <Dec.3.22.05.26.1988.9928@topaz.rutgers.edu> <1372@cseg.uucp> <Dec.6.06.33.54.1988.4315@topaz.rutgers.edu>
Organization: University of California, Irvine
Lines: 30

In article <Dec.6.06.33.54.1988.4315@topaz.rutgers.edu> hobbit@topaz.rutgers.edu ($ *Hobbit*) writes:
>Professional shows use multiple x-y pairs of GS's better positional-feedback
>galvos -- they're not only fast as hell, they provide exact feedback about
>where they are, and you can build your driver accordingly. They also cost
>something like $700 per. Since GS is apparently still the only company
>making these things [someone please correct me if I'm wrong] they can get
>away with this pricing scheme.
>

Yes. I do work for a company called LOGIC+ (logic plus) which does portable
laser graphics shows. We use GS galvonometers. They are pretty good, but not
as good as we would like. All of the feedback in the world won't do you
any good if the thing just won't slew fast enough. We have, with our own
custom amplifiers, a bandwidth of about 1500hz from these guys.
Eventually, we will be adding a digital control feedback control system
with a very large power ampilfier to coax more bandwidth. However, even 1500hz
does not give you very much bandwidth to scan a vectored x-y image that has
a lot of corners. (I mean a picture, not an abstract art work). As a result,
we use multiple coordinated scanners. (We do a piece from the Star Wars trench
scene that is very busy. 1 scanner gets the trench, 2 others handle Skywalkers
x wing and vaders tie.) Fun stuf ;-)

Later.

Guy
~The Interrupt Master~

hedley@8x8.com | 8x8, Inc
hedley@netcom.com | Santa Clara, CA. (408) 654-0883
Received on Wed May 28 22:37:36 1997