The Cairo hackerspace needed a projector for a few presentations during their Internet of Things build night, and of course Friday movie night. They couldn’t afford a real projector, but these are hackers. Of course they’ll be able to come up with something. They did. They found an old slide projector made in West Germany and turned it into something capable of displaying video.
The projector in question was a DIA projector that was at least forty years old. They found it during a trip to the Egyptian second-hand market. Other than the projector, the only other required parts were a 2.5″ TFT display from Adafruit and a Nokia smartphone.
All LCDs are actually transparent, and if you’ve ever had to deal with a display with a broken backlight, you’ll quickly realize that any backlight will work, like the one found in a slide projector. By carefully removing the back cover of the display, the folks at the Cairo hackerspace were able to get a small NTSC display that would easily fit inside their projector.
After that, it was simply a matter of putting the LCD inside the display, getting the focus right, and mounting everything securely. The presentations and movie night were saved, all from a scrap heap challenge.
A few years back I built a small still projector made from a high intensity LED flashlight element, a cheap digital picture key chain and one of those business card sized Fresnel magnifiers from the drug store. This worked as a primitive art projector and lettering guide and It cost less than $15!
Hats off to these guys.
Not a bad idea at all! I did not know it’s this easy.
Especially when one can get high-power LEDs for peanuts these days on ebay.
I have to test it with some phone LCD :)
Got the same idea, expect with a longer cable back to the phone.
Dedicated Snake projector anyone?
you should post a video of making that :)
I pray the guy who put this together quoted the great Burt Gummer. “Doing what I can with what I got.”
I bet you could do the same with an over head projector like they used to use in gradeschool, just by setting the LCD where the transparency would go.
Done that, it works. I even got the over head projectors (yes multiple) for free as they didn’t use them anymore.
Same. Quality was terrible, but what will you do when you want to watch movies and you’re 14.
Heat was definitely an issue, so I had 120mm fans hooked on a jumped computer PSU blowing air in between the LCD and the over head projector glass (propped it with 4 little blocks)
Once upon a time, Apple even made a large LCD panel designed to fit on an overhead projector to display Apple ][ output to your entire class. I got one from a surplus sale but it was SO lousy in quality that I eventually tossed it.
I imagine it would have doe the job, though, for a class of 4-th graders. :)
This isn’t it, but it was similar:
https://www.gcsurplus.ca/ic-ci/images/FS311039-177397.jpg
And, actually, it probably was made by InFocus and not by Apple, but it was clearly intended for the Apple ][
I just recently pulled one of those to bits. They actually have three lcd panels one, for each colour.
The Fresnel lens was fun to play with as well.
TI and HP each made LCD panels for overhead projectors, these would plug into a “Teachers Edition” of a popular big screen calculator. As the TI-83 and its variants are still popular in High School and Colleges, I suspect those are still available.
Oh! here is one on TAS (That Auction Site)
http://www.ebay.com/itm/New-Texas-Instruments-TI-Viewscreen-Overhead-Projector-Screen-80-81-82-83-LCD-/121086819512?pt=Calculators&hash=item1c31563cb8
Now that’s a hack!
I’ve seen home-made projectors like this, the problem is the heat from the projector degrades the LCD display.
You should add a small cooling fan above the screen or change the halogen bulb with super-bright LED or car Xenon light
14$?!?!??! what a stupid missleading post.
100 Egyptian pounds = 13.98 US Dollar , what is wrong?
TFT is for $44 + shiping…
It was donated by a member , but any way we made this before with an old smartphone
I worked for a electronics lab of a high school in México City, and I helped students to build their own projectors using the same technique described here. We mainly used the display found in the Sony PS One. It was in 2003.
The two most important things:
1) Heat dissipation
2) Optics!!!
We achieved great projectors, of course these were large, heavy, noisy and a little expensive. But we learnt and enjoyed a lot.
With a very good optics, we got a projection of more than 100 inches with an acceptable quality.
Very nice memories!