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Finally you can do something with that old LCD monitor you have in the garage.
You can turn it into a privacy monitor! It looks all white to everybody except you, because you are wearing "magic" glasses!
All you really have tohave is a pair of old glasses, x-acto knife or a box cutter and some solvent (paint thinner)




Here is what I used:
an LCD monitor of course
single use 3D glasses from the movie theater (old sunglasses are just fine)
paint thinner (or some other solvent such as toluene, turpentine, acetone, methyl acetate, ethyl acetate etc)
box cutter (and CNC laser cutter :) but that you don't really need, I'm sure x-acto knife and a steady hand would do just fine)
screwdriver or a drill
paper towels
superglue

Step 1: Take the monitor apart

Find an old monitor that you are willing to sacrifice.
Take off the plastic frame by unscrewing all screws from the back.

Step 2: Cut the polarized film

Most LCD monitors have two films on the glass - a polarized one to filter out the light you are not supposed to see, and a frosted anti-glare film. The anti-glare film we don't need, the polarized one we do - it is used for the glasses. 

So, grab you cutting tool and cut the films along the edge. Don't be afraid to press, metal wont scratch the glass, unless there is sand or other abrasives on it.

Then, start peeling. Make sure to save the polarized film, also remember the orientation.

Step 3: Clean the film adhesive

After you remove the film, the glue will likely remain stuck to the glass, so here comes the messy part.
With some solvent, soften the glue and wipe it off with paper towels.
I started with OOPS, but that was not fast enough so I got some paint thinner.
I found out that if you cover the screen with paper towels and then soak them in paint thinner you can let it sit longer and dissolve the adhesive without running and evaporating.
Scrape off the soft glue with a piece of plastic or wood.
Be careful not to get paint thinner on the plastic frame, because it will dissolve it.

Step 4: Monitor - done

After cleaning the adhesive, assemble everything back the way it was. Before even making the glasses, you can test the monitor with the polarized film!
Notice how the upper left corner looks clear, because it has the anti-glare film removed. That is the part we are going to use to make the glasses.

Step 5: Pop the lenses out

For the glasses, I used single use 3D glasses from the movie theater, but you can use whatever you want.
Pop out the lenses or take the glasses apart if you can.

Step 6: Scan, Trace, Cut

If you are going to use a cnc blade or laser cutter, scan and trace the parts.
You can find a local vinyl or laser cutting service, or you could send them to an online service like Outfab.com
I scanned the frames so I can use them as a reference for the lens orientation.
Remember, this is a polarized film so the angle is critical. Back and front also matters.
If you don't have access to a cnc cutter or you don't want to wait for an online service, you can probably tape the old lenses on the film and then cut them out with an x-acto knife.

Step 7: Reassemble glasses and enjoy!

Finally assemble the glasses and you are ready for some fun!
People might think you are crazy, staring at a blank white screen wearing sunglasses!
But I guess that makes it even more fun!
<p>Might there be a way to work this into a laptop that has an LCD display? That's what I'd like to take to the coffee shop!</p>
<p>Yes, laptops screens are made the same way.</p>
<p>I have an old flat screen monitor is would love to try this on. Is there a way to tell if it is an LCD, as opposed to other types listed in the comments?</p><p>Thanx!</p>
<p>yes it works for all LCD, cellphones and LED's. and TFT screen too. I did in my child hood with small &quot;digital calculator&quot;. None of my friend could use my calculator, But was master then in making calculations using the same calculator</p>
<p>It WILL NOT work on LEDs, TFTs, oLEDs, CRTs, or DLPs. It has to be an <br>LCD screen (Liquid Crystal Display), because the crystals work with <br>polarized light &amp; a polarized light filter (the film).</p>
<p>Betty, an LED monitor is still an LCD, it just uses white LEDs for backlighting instead of fluorescent backlighting. LCDs (which use TFT (thin film transistors)) polarize and then twist the polarized light allowing the light to pass through the outer polarized film at that specific pixel.</p>
<p>LEDs and TFTs are both still LCD monitors. DLP is a projector, not a monitor at all. Anything OLED is likely to be too new and very expensive, so I doubt anyone would try this trick on one.</p>
Did this year's ago with my calculator and watch - it's cool to see that the same thing works with a color lcd monitor! Nice instructable!
I did this to my watch too when I was in school.<br>I had the only lcd watch around with white numbers on a black background.<br>lcd watches were just becoming cheap and common. that was about 37 years ago....<br>
<p>Yep. You can reverse the polarized light filter too, so you get a negative image. On a calculator with black numbers, they would be white or light grey numbers, &amp; the background turns black.</p>
&quot;Year's&quot;? *shakes his robot fist at his autocorrect*
Lol
<p>Nice idea! One question though, I have the exterior layer peeling off with ease, leaving a nice glossy film layer on the monitor lcd. With difficulty, the glossy display can slowly be picked off in little pieces, revealing a nasty glue ridden surface. So, the glossy screen that comes off in little pieces is the polarized film? And how do I remove it with greater ease? Any input would help. Thanks.</p>
<p>Use an eraser(rubber) and gently clean the screen.</p>
<p>Put a few wet paper towels on it before trying to peel the thing off and let it hang out for a day or so making sure the paper towels stay damp. The whole thing will peel off in one big sheet.</p>
<p>If that doesn't work then try a hair drier to warm it up. Most commercial glues become tacky again if heated allowing the film to be peeled off far more easily when warm than they are at room temperature</p>
<p>Heat will destroy most LCD screens. The liquid crystals in it can't take much heat. Beware some LCDs have plastic, not glass in them, or layers of both. Solvents or paint thinner will destroy the plastic, &amp; ruin the screen.</p>
By &quot;wet&quot; I assume you mean wet with paint thinner.
<p>can it work tft moniter</p>
<p>yes it works for all LCD, cellphones and LED's. and TFT screen too. I did in my child hood with small &quot;digital calculator&quot;. None of my friend could use my calculator, But was master then in making calculations using the same calculator</p>
<p>It WILL NOT work on LEDs, TFTs, oLEDs, CRTs, or DLPs. It has to be an <br>LCD screen (Liquid Crystal Display), because the crystals work with <br>polarized light &amp; a polarized light filter (the film).</p>
<p>Awesome!!!! COOOL!!! What makes the screen white? The paint solvent? Or removing that layer of anti-glare?</p>
<p>The crystals in a Liquid Crystal Display polarize the light to one <br>direction or another, depending on their orientation, but doesn't <br>actually block light. But when that polarized light shines through a <br>polarized light filter (the film or glasses), it shows black or white <br>depending on the orientation of the crystals or the filters. Without the<br> polarized filter it's all just white polarized light. The polarized filter blocks all the light polarized in one direction, but allows light from the opposite polarization. The orientation of the crystals in the display, determines the polarization of the light for that pixel, then the light filter blocks or allows light through depending on the polarization of the light.</p>
<p>One of the anti-glare layers is polarized, and only lets through the &quot;intended&quot; light. Without it, everything bleeds all over everything else creating white.</p>
I think this needs 1 more hack to be really useful.<br>We need to figure out a way to feature an image on the white screen that gets filtered out by the glasses.<br>For instance, if instead of a white screen, anybody without glasses who walked into your office would see a spreadsheet, but with the glasses you wouldn't see the spreadsheet.<br>Too complex, or is it a possibility?
<p>Won't work. The crystals in a Liquid Crystal Display polarize the light to one direction or another, depending on their orientation, but doesn't actually block light. But when that polarized light shines through a polarized light filter (the film or glasses), it shows black or white depending on the orientation of the crystals or the filters. Without the polarized filter it's not possible for any image to be seen. The film he removed is a polarized light filter. So basically, he transferred the function it does from the screen, to the glasses. No matter were you place the filter, it will still polarize the light.</p>
<p>I love this!</p>
<p>Awesome project...Just loved it. I am definitely going to try it he he...</p>
<p>Awesome idea!</p>
<p>Awesome idea!</p>
<p>Can you use polarized sunglasses instead of putting the polarized film in the glasses?</p>
<p>I would really like to know as well. I have polarized sunglasses that I'd rather use than go through the trouble of making some. But also, it would mean that others with polarized glasses could also see your monitor. </p>
<p>it depends on the orientation. it will work only if your glasses coincidentally have the same orientation as the polarized film of the monitor.</p>
<p>you can try. polarized films and glasses works in the same way. but glass are great built quality.</p>
<p>Dude, your work has been featured on Ifunny!(or just someone that stole it from here)</p><p>http://ifunny.co/fun/AtYIdyGV?gallery=shuffle</p>
<p> Wow - this is definitely a super spy cool idea.</p>
<p>This is genius to say the least.</p>
<p>yaaaaaas i made it!</p>
<p>Awesome man !! Im going to try this...</p>
<p>Can you do this on an oled screen?</p>
No, it has to be LCD.
<p>dat reaalllll coool! im gonna try it!</p>
<p>Oooh. This is really cool. I am really debating on doing this or not; Does the monitor appear as clear and sharp as before? Thanks :)</p>
<p>It does if it is glossy. If the screen is matte you would need to remove the anti-glare film for it to be as sharp as new. You could also buy a polarizing film from Amazon. The one I used had an anti-glare film, which I had to remove.</p>
<p>Thanks! :) And seriously WELL DONE on winning!!! :D</p>
<p>Beautiful!! How long would it take to make this, and what is the estimated cost for the project??</p>
<p>Genius!!! I thought this was totally fake until I saw the video!</p>
<p>this idea is awesome , but I'm not brave enough to do this :(</p>

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Bio: I'm an electrical engineer interested in making stuff!
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