Last summer I built my own movie projector for total cost of about 100 dollars. In this article I explain how you too can build one for nearly the same price.
The idea is to strip a LCD monitor to takeout the LCD panel and place the stripped panel on top of an overhead projector. The panel should be placed approximately 1 cm above the OHP glass surface. Since overhead projectors emit a lot of heat, it is important to keep the LCD panel cool by placing a fan that can blow air in-between the stripped LCD panel and OHP glass surface.
The main parts needed for this project are the following:
1. An overhead projector
Nowadays you can buy an Overhead Projector (OHP) at eBay or Craigslist for around $50. I prefer craigslist because you do not have to pay any shipping charges and the seller resides in the same local area. Since overhead projectors are very heavy items they usually incur higher shipping charges. For a bright picture quality you many want to buy an OHP that has atleast 2500+ lumens output. Lumen is the unit of measure that measures the brightness of the OHP light output. I bought a 3M 9700 OHP with 4200 lumens for $50 at Craigslist. The 3M 9700 OHP is equipped with a triplet projection lens. A triplet lens is a special lens that is composed of 3 lenses (thus the name triplet). Triplet lenses can project superior image quality.
2. A 15” inch LCD monitor
It is important that the LCD monitor that you buy is strippable. Not all LCD monitors are easy to strip. To see a list of LCDs that can be stripped for the project, please visit this link. You should be able to buy an old 15 inch LCD monitor for around $50.
3. A small fan (used in computers)
You can buy a small CPU fan for a dollar or two at the local discount computer store.
Depending on how cheap you can get the above items, the cost of your projector may vary. You may want to also consider building an enclosure for your LCD panel so that your LCD panel and circuit boards are all neatly and securely placed inside the enclosure. The enclosure can also help you to reduce any light leakages. The idea is to only allow the OHP light through the LCD panel. Reducing any unwanted light can greatly improve your image quality.
I was very pleased with the results I got from my projector. I was able to project a 120 inch diagonal screen with excellent image clarity. Further increase in screen size is possible, but this is at the expense of image quality.
If you are still not clear what I am talking about, you can check the following pictures and videos to get a better idea. You may also want to read the forum at lumenlab.com which contain a wealth of resources in building a home made movie projector. Good Luck.
Stripped LCD panel inside the custom built enclosure to prevent light leakage.
My Projector in Action (click video to play)