silver@cup.portal.com (Jim B Howard) (08/17/90)
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$) do. I think.
tuv@pmafire.UUCP (Mark Tovey) (08/17/90)
In article <32906@cup.portal.com> silver@cup.portal.com (Jim B Howard) writes: > > >I wonder if it would be possible to take one of the better made pocket >LCD TV's , such as the Sony Watchman, and remove the LCD element far >enough away to allow the insertion of a really bright backlight, such >as a small quartz lamp or something, and then focus the light with a >few simple lenses to give you a large projected color image. > >(quite a long sentence, eh?) > >I've experimented with taking cheap calculators apart, and removing the >foil backing from the LCD element, shiing a flashlight through it, >and using an overhead projector lens assembly to put the image on the wall. >It works fine, very readable. I've even done this with my old Casio >7000 graphing calculator. The question is, do they attach the >LCD elements of those little TV's so strangely that there is no chance >of relocating it enough to do what I propose? I don't want to spend >299$ 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. > Sharp makes just such a unit (~ $3000 to $4000). It is a very nice system, designed to be portable and set in seconds. There is no convergence involved, just point and focus. The resolution is still somewhat low so it doesn't work to well with computer graphics but is just fine for normal video applications. There are other manufacturers currently making similar systems (I believe Kodak is one of them) but the Sharp is considered to be the best one on the market today.
jws@thumper.mlb.semi.harris.com (James W. Swonger) (08/18/90)
The problem you are going to have to beat is how to get rid of the heat from your projection source. Any light bright enough to make a decent projection display is going to throw off a lot of heat. You will have to block or remove the IR from hitting the LCD display or it will quit working. They don't like temperature extremes.
ron@vicorp.com (Ron Peterson) (08/18/90)
In article <32906@cup.portal.com> silver@cup.portal.com (Jim B Howard) writes: > > >I wonder if it would be possible to take one of the better made pocket >LCD TV's , such as the Sony Watchman, and remove the LCD element far >enough away to allow the insertion of a really bright backlight, such >as a small quartz lamp or something, and then focus the light with a >few simple lenses to give you a large projected color image. > >(quite a long sentence, eh?) > >I've experimented with taking cheap calculators apart, and removing the >foil backing from the LCD element, shiing a flashlight through it, >and using an overhead projector lens assembly to put the image on the wall. >It works fine, very readable. I've even done this with my old Casio >7000 graphing calculator. The question is, do they attach the >LCD elements of those little TV's so strangely that there is no chance >of relocating it enough to do what I propose? I don't want to spend >299$ 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
fmgst@unix.cis.pitt.edu (Filip Gieszczykiewicz) (08/18/90)
<The problem you are going to have to beat is how to get rid of the heat <from your projection source. Any light bright enough to make a decent <projection display is going to throw off a lot of heat. You will have to <block or remove the IR from hitting the LCD display or it will quit <working. They don't like temperature extremes. Greetings. I recently made curing unit for a dentist. It uses 4 300Watt halogen lamps and 4 IR filters. The lamps were $20 each and the filters $40. The filter looks like ordinary thick, bluish-tint glass that just _loves_ to shatter :-( Heat should not be the problem. (I can get a 200Watt 12V lamp) -- _______________________________________________________________________________ "The Force will be with you, always." It _is_ with me and has been for 10 years Filip Gieszczykiewicz "A man without a dream is like a fish without water." FMGST@PITTVMS or fmgst@unix.cis.pitt.edu "My ideas. ALL MINE!!"
esmith@goofy.apple.com (Eric Smith) (08/19/90)
In article <29520@unix.cis.pitt.edu> fmgst@unix.cis.pitt.edu (Filip Gieszczykiewicz) writes: > <The problem you are going to have to beat is how to get rid of the heat > <from your projection source. Any light bright enough to make a decent > <projection display is going to throw off a lot of heat. You will have to > <block or remove the IR from hitting the LCD display or it will quit > <working. They don't like temperature extremes. ... > Greetings. I recently made curing unit for a dentist. It > uses 4 300Watt halogen lamps and 4 IR filters. The lamps > were $20 each and the filters $40. > > The filter looks like ordinary thick, bluish-tint glass that > just _loves_ to shatter :-( > > Heat should not be the problem. (I can get a 200Watt 12V lamp) Heating the glass isn't the problem. The problem is the liquid crystal BETWEEN the two layers of glass. They generally don't work well at high (or low) temperatures. -- Eric L. Smith Opinions expressed herein do not necessarily reflect those esmith@apple.com of my employer, friends, family, computer, or even me! :-)
ken@argus.UUCP (Kenneth Ng) (08/20/90)
In article <32906@cup.portal.com>, silver@cup.portal.com (Jim B Howard) writes:
: I've experimented with taking cheap calculators apart, and removing the
: foil backing from the LCD element, shiing a flashlight through it,
: and using an overhead projector lens assembly to put the image on the wall.
: It works fine, very readable. I've even done this with my old Casio
: 7000 graphing calculator. The question is, do they attach the
: LCD elements of those little TV's so strangely that there is no chance
: of relocating it enough to do what I propose? I don't want to spend
: 299$ to get one of those things and find out they've welded the element
: in place.
Interesting idea, one word of caution is to keep the LCD panel cool
from the heat of the lamp. I know some panels that will turn completely
black if they get too warm.
--
Kenneth Ng: Post office: NJIT - CCCC, Newark New Jersey 07102
uucp !andromeda!galaxy!argus!ken *** NOT ken@bellcore.uucp ***
bitnet(prefered) ken@orion.bitnet or ken@orion.njit.edufmgst@unix.cis.pitt.edu (Filip Gieszczykiewicz) (08/20/90)
<> <> The filter looks like ordinary thick, bluish-tint glass that <> just _loves_ to shatter :-( <> <> Heat should not be the problem. (I can get a 200Watt 12V lamp) < <Heating the glass isn't the problem. The problem is the liquid crystal <BETWEEN the two layers of glass. They generally don't work well at <high (or low) temperatures. <-- <Eric L. Smith Opinions expressed herein do not necessarily reflect those <esmith@apple.com of my employer, friends, family, computer, or even me! :-) < Greetings. That's the point! The IR filter removes almost all of the heat, so all that gets to the LCD layer is pure white light - the best kind :-) (I have feeling I am going to _have_ to try this....;-) -- _______________________________________________________________________________ "The Force will be with you, always." It _is_ with me and has been for 10 years Filip Gieszczykiewicz "A man without a dream is like a fish without water." FMGST@PITTVMS or fmgst@unix.cis.pitt.edu "My ideas. ALL MINE!!"
wallwey@snoopy.Colorado.EDU (WALLWEY DEAN WILLIAM) (08/22/90)
Does anybody know the resolution of these hand-held small color LCD TVs?? Does the sharp LCD projection TV use the same size and resolution LCD, or is it designed better for projection. Has anybody seen the sharp projection TV?? If so, what do you think of it??? I wish I had thought of this!!! -Dean ****************************************************************************** *-Dean Wallwey wallwey@snoopy.colorado.edu or wallwey@128.138.238.103 * *"If people drove cars like they run computers, 5% of the driving population * *would die every business day in automobile accidents!" * * #define DISCLAIMER \ * * The above comments are my own and not necessarly that of my employer or\ * * school. grammer, spelling errors, real heavy flames > NULL * ******************************************************************************
siegman@sierra.STANFORD.EDU (siegman) (08/22/90)
Working from memory here, but I _think_ I recall reading that some major commerical aerospace firm -- Hughes? -- was actually buying el cheapo Radio Shack LCD TVs and taking 'em apart in order to use the LCD displays as low-cost light modulators in some optical computing or optical data processing research project. So I _think_ they can be taken apart successfully...