Path: utzoo!mnetor!uunet!husc6!psuvax1!gondor.cs.psu.edu!przemek
From: przemek@gondor.cs.psu.edu (Przemyslaw Klosowski)
Newsgroups: comp.arch
Subject: Re: Unix in ROM [was Re: Jerry Pournelle on UNIX (From BYTE)]
Message-ID: <3225@psuvax1.psu.edu>
Date: 19 Jan 88 18:39:08 GMT
References: <9601@tekecs.TEK.COM> <4530001@hpsrlc.HP.COM>
Sender: netnews@psuvax1.psu.edu
Reply-To: przemek@gondor.cs.psu.edu (Przemyslaw Klosowski)
Organization: Penn State University, University Park, PA
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In article <4530001@hpsrlc.HP.COM> darrylo@hpsrlc.HP.COM (Darryl Okahata) writes:

>     How advanced have liquid-crystal lenses become?  It would be
>interesting to see if liquid-crystal lenses could someday be used to
>replace CD servo mechanisms.  Basically, the LCD lens would remain
>physically fixed in place, and the focal point would be moved in 3D space,
>not in 2D space (i.e., along the focal axis) like glass-type lenses.
>
I don't think liquid crystal lenses are a good alternative because they 
do not exist :^) LQ are good for shutters (modulated transmission).

There is though a non-mechanical design: phase-arrayed semiconductor lasers. 
Remember that the function of the lens is focus the laser on a particular 
spot of the sample. The same effect can be obtained by modulating the phase 
of the light emitted from an array of emitters. Big radars work alreadu 
this way. 

				przemek@psuvaxg.bitnet
				psuvax1!gondor!przemek