Step 1: Parts, Tools & Links
# Overhead projector - 20~50 Euro
One of the main parts is a overhead projector. You can find these things at schools, secondhand shops and websites like Marktplaats.nl or eBay.
Tips for buying:
1) Look for an brand projector, like 3M
2) Choose one with a high wattage lamp. I used a 250watt lamp, thats in daylight a bit weak, you can better look for an 400watt lamp.
3) A bigger glass plate can hold bigger LCD screens
4) Check the glass plate on damages
# LCD monitor - 25~50 Euro
The second main part is a LCD screen. I used a TFT computer monitor. There are a lot of screen sizes. Look for one that fits on the glass plate of your overhead projector. Bigger works too, but then you will lose some screen edges.
A lot of screens got a short FFC cable, thats called a 'FFC issue'. You need to extend the cable by replace it with a longer cable or extend the FFC cable with a solder iron. The easiest way is to find a screen with no FFC issues.
Tips for buying:
1) Search for one that fits on you overhead projector.
2) TFT computer screens are the easiest way. Laptop screens needs a controller, they are hard to find in Europe.
3) Look for screens with a broken backlight. You don't need that component for this projector.
4) Search on the internet for a type with no FFC issues. You can look in the database of Lumenlab or search with Google "LCD brand + model + ffc issue"
# Wood - 2~5 Euro
For making a frame that will hold the LCD screen.
# FFC cable - 15 Dollar
Only if you have a screen with a FFC issue. You can buy this one at the Lumenlab Store.
# UV & IR filter - 20 Euro
This will help cooling down the screen and prevents the screen is getting yellow.
# 2x Cooling fans - 10 Euro
These will help to keep the LCD screen cool. Simple computer fans, you can get these from old computers or buy it at a local computer shop.
# Gaffer tape - 10 Euro
This tape could be used for screen protection at the wooden frame.
# Aluminum foil - 1 Euro
To improve the light reflection.
# Solder iron
# Iron saw
Please read before you start a lot of information about building a projector. It prevents a lot of problems.
# Information about overhead projectors:
# Information about LCD screens
# Other overhead projector projects:
- http://www.neoweb.nl/tftbeamer/index.html (Dutch)
- http://www.dity.nl/forum/ (Dutch)
- http://gathering.tweakers.net/forum/list_messages/1091930 (Dutch)
Step 2: Stripping the LCD Screen
Start stripping the LCD screen. There are a lot of different screens, it could have different parts and and look not exactly the same. I describing here the basic steps.
Tips before you start:
- Make pictures to remind
- Watch out and be carefully
1) Disconnect all cables and wait a few minutes.
2) Put a towel or pillow on your desk for protecting the LCD screen from scratches.
3) Remove all screws, usually you can find these only at the back.
4) Lay down the screen on the towel on your desk and remove first the back cover and then the front cover.
5) You will have now something like this:
6) Disconnect all cables and remove the tape if needed. Do this with your hand and not with tools. It's very fragile.
7) Use a screwdriver to remove the power supply, the lcd controller and the OSD controller.
8) Remove the tiny screws from each side.
9) Remove carefully the plastic from the print, watch out for the brown plastic wires. If you damage this, your screen is dead.
10) Now you can remove safely the frame. (it's a 'click' system)
11) Wipe the LCD screen carefully out the white backlight plate.
- An other guide for Dutch readers
Step 3: Testing
Now we can test the screen on the overhead projector.
1) Lay down the screen on the overhead projector. Use something between the LCD screen and the glass plate to create some space. Watch out for scratches on the screen.
2) Connect the screen to the power supply, LCD controller and OSD controller.
3) Connect the LCD controller to your computer.
4) Turn it all on to test it.
Do this only a few minutes !!! Otherwise the screen gets very hot and will die !!!
Step 4: Making the Frame
Because all overhead projectors and screens got different sizes are there many ways to make a frame. I'll give here some tips:
1) Important is the cooling of the screen. Create enough space between the LCD screen and the glass plate (between 6-8cm). In my design I placed at the left and right side a 80x80mm cooling fan. To create a good airflow, one will blow in and the other blow out.
2) Make the screen hole in the middle.
3) Think about where you can place the power supply, LCD controller and OSD controller.
4) Paint it a nice color.
5) To improve the light reflection place some aluminum foil inside.
6) I placed some gaffer tape on the edges of the screen hole to protect the LCD screen.
7) Place the cooling fans on the frame and connect these wires together.
Step 5: The IR+UV Filter
To protect the LCD screen you'll need a IR (against heat) + UV (against fade) filter. You can buy these separately or an all in one glass. I've used the all in one. It's a small glass that needs to be placed a few centimeters above the lamp.
The easiest way to create a frame that will hold the glass above the lamp. Use iron or aluminum to make the frame. Don't use plastic or wood, because the frame gets very hot!
Open your overhead projector to look what the best way is to fit a frame above the lamp.
I've used a part from an old ATX computer power supply and made with a iron saw a hole for the filter.
Step 6: Building the Projector
Everything is now finished to build your projector.
1) Open the overhead projector to place the IR+UV filter with frame above the lamp.
2) Clean the glass plate.
3) Place the wooden frame at the projector.
4) Place the LCD screen on the frame.
5) Place the power supply, LCD controller and OSD controller on the frame.
6) Connect these to the screen.
7) Connect the wires from the cooling fans to the power supply. Do this only if there is a 12volt connector on it. Otherwise you need a universal 12volt adapter.
8) Connect the LCD controller to a computer.
9) You're done! The projector is finished.
Step 7: End Result
See the pictures below :)