by: Andrew Seltz

Mix big screen home theater dreams with a skimpy budget and you

have the makings of a fantastic do-it-yourself project. Just think of

how impressed all your friends will be watching blockbuster movies on

a video projector you made with your own 2 hands. It was just these

motivations that landed me in front of my web browser digging for

information for this project. There are a lot of cheesy websites that

promise the moon and sell you a plastic magnifying lense and the

instructions to stick a television into a box and put this lens on the

front. You will get an image, but it will look like you made it

yourself. - dark, and blurry. Is there any way to make this work? The

short answer is yes. A video projector is essentially a high

resolution LCD video screen with a really bright light shining through

it and a projector lense enlarging onto the screen. New portable

models use very tiny, and expensive, LCDs along with sophisticated

light sources and high quality lenses. If you are willing to end up

with a projector that isn't quite so tiny, you can scavenge the parts

you need from an LCD computer monitor and add some electronic

components and relatively inexpensive lenses. For $200-$500 you should

be able to create a high resolution bright projector that will really

impress your friends.

The parts you need are:

High resolution LCD computer monitor

Projector lens (and possibly 2 fresnel lenses depending on the plans you use)

Cooling fan(s) - bright lights get hot when you shove them in a box

Bright lightsource (one approach to the project is to use an old overhead projector)

Electrical power supply

There are dozens of websites with step-by-step plans for free or for

sale. Some sell parts that you'll need. Two that I've found to be

excellent are LumenLab and the DIY Projector Company. They both sell

parts and parts kits. LumenLab sells a very nicely produced PDF

instruction guide with detailed plans. DIY offers plans free, but

expects that you'll buy one of their kits to actually make the

projector. They both use the LCD in a box with a lamp approach.

InventGeek has a great article explaining the whole process in depth

including the theory behind projectors. I recommend you check it out.

The DenGuru website shows another approach to the project. They use an

old overhead projector for both the lightsource and lens. You strip

the LCD panel out of its frame and lay it on the projector like a

transparency. Ugly, but it works! Check out their tutorial.

Break out your toolkit and get busy - and let's be safe out there

people!