Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!vicorp!ron
From: ron@vicorp.com (Ron Peterson)
Newsgroups: sci.electronics
Subject: Re: Big Screen Projector from tiny LCD TV ?
Message-ID: <1990Aug17.220136.13502@vicorp.com>
Date: 17 Aug 90 22:01:36 GMT
References: <32906@cup.portal.com>
Reply-To: ron@vicorp.COM (Ron Peterson)
Distribution: usa
Organization: V. I. Corporation, Amherst, Massachusetts
Lines: 43

In article <32906@cup.portal.com> silver@cup.portal.com (Jim B Howard) writes:
>
> 
>I wonder if it would be possible to take one of the better made pocket
>LCD TV's , such as the Sony Watchman, and remove the LCD element far
>enough away to allow the insertion of a really bright backlight, such
>as a small quartz lamp or something, and then focus the light with a 
>few simple lenses to give you a large projected color image.
> 
>(quite a long sentence, eh?)
> 
>I've experimented with taking cheap calculators apart, and removing the
>foil backing from the LCD element, shiing a flashlight through it,
>and using an overhead projector lens assembly to put the image on the wall.
>It works fine, very readable.  I've even done this with my old Casio 
>7000 graphing calculator.   The question is, do they attach the 
>LCD elements of those little TV's so strangely that there is no chance
>of relocating it enough to do what I propose?  I don't want to spend 
>299$ to get one of those things and find out they've welded the element
>in place. 
> 
>This is a very simplified method of achieving what those expensive TV
>projectors (such as the Sharp one ~ 5000$) do.  I think.
> 
I've tried this with a cheap ($30) black&white lcd tv (a no longer
manufactured Casio model I think) and it works fairly well.  Using
a good lens is desirable.  The resolution of the tv was only about
200x200 so the pixels got to looking very blockish when I projected
an eight foot wide picture.  The lcd screen is seperable from the
rest of the tv in this unit so it was fairly easy to use a slide
projector to backlight it.  I used the lens from my 35mm camera to
project the image.
   So the main question would be "can the lcd be removed or access to
the back of it gained somehow?"  Probably the only way to find out
is do it---with your own or someone elses.  Be careful of any mounting
arrangements for the lcd panel itself.  If it connects to the circuitry
through the same little spongy fingers that are used in watches and
calculators, they are almost immpossible to realign once they've
been moved.
  I think a unit could be constructed for MUCH less than the $8000 that
Sharp is asking for.  I'd be interested in hearing of any experiments
in this area.
                       ron@vicorp.COM