Getting started

What you need:

• A LCD/TFT screen of course
• A projection lens
• A fresnel lens (some designs use 2: one before and one after the LCD)
• A light source
• Some tools. The bare minimum is: a few screwdrivers, a drill and a saw.

The LCD/TFT screen
If you can find an old working TFT screen (preferably 15inch or smaller, it's OK if the backlight doesn't work anymore, we won't use it) you're good to go; if you can't find one, you can always buy a $/€150-200 15inch monitor, choose for one with a 1024*728 resolution (=cheaper) to display 720p HDTV or one that does 1280*1024 if you're going to use it as a display for your pc (for example for games). Remember: the lower the response time, the better (I recommend everything under 20ms).

Once you have got your screen, you need to have the TFT itself and the PCB that drives it. You begin by opening the housing (always unplug your monitor before opening it!) and removing the backlight, you don't need it. Carefully "peel" of the rest until you're left with only the TFT connected to its PCB (BE CAREFULL NOT TO BREAK THE TFT).

The projection lens
For optimal projection, you must use a triplet lens (3 lenses in 1) that is designed to project images because a regular lens will give "color shift": for example: instead of a white pixel, you will see a smear of the colors of the rainbow due to the differences in wavelength. With a triplet lens, you don't have that problem.

The fresnel lens
See this section of the site for more information on how to get fresnel lenses.

Light source
You need to use a lamp which is as small as possible, so a regular light bulb won't work. If you use a light bulb or another larger lamp, you won't get nice and crisp edges on your screen. I recommend that you use a "metal halide" lamp because it produces a high amount of light in a very small spot. These lamps give a lot of light and don't consume that much energy. Because of the low energy, the lamp also won't produce much heat.
Recommend lamps are around 250 and 400 Watts, the 250W type is small enough to build a reflector and a condenser lens on it so you can get a nice and bright image. The 400W type will provide an even brighter image but will need more cooling.

It's also possible to use a light source that covers the entire back of the LCD and gives a lot of light, this will avoid the search for a very small yet very effective lamp. However, by using a backlight, it's quite difficult to get an even lit image so it's recommended to use a small light source as described above.

The projection screen
You can buy a projection screen or you can make your own from a piece of cloth that is big enough. It's also possible to paint a wall white and project your image onto that.

The actual building process
All the info above is just general information, for the actual building and detailled information please go to www.DIYProjectorCompagny.com

*Note: pictures of LCD projector will be coming as soon as I get my hands on a digital camera. You can always send in your own pictures and I will put them on this site.