Triathlete Guru on Building a Video Projector

As I’ve mentioned before, I’m not a guru yet. I’m not a guru when it comes to triathlons, and I’m definitely not a guru when it comes to electronics! So when I decided to build a video projector, I wasn’t 100% certain it was possible, especially not by me. Nevertheless I jumped headlong into the project…

I had entertained the idea of a DIY big screen tv a while back and had researched the idea on the internet, only to decide that most of the “plans” available online were bogus. The majority of the plans suggested that with the use of a tv, a big box, and a fresnel you could project the tv image to a wall. The obvious (to me at least) missing piece of the puzzle was “light”, how will the tv image be bright enough to show up on the wall? So I scraped the idea, at least for the time being…

After a year or so, a co-worker and friend of mine, Walt Howd came across an article and video on Tom’s Hardware titled “Supersize Your TV for $300: Build Your Own XGA Projector!”. In short, the approach in this article was to take a 15″ lcd monitor and remove the lcd from the casing and remove the backlight after which you set it on an overhead projector. I knew this was legitimate, not only since it was on Tom’s Hardware, but because I had seen something similar done before with an lcd panel that was manufactured explicitly for this purpose. However, I wasn’t real impressed with this approach. Then Walt came across a much better method which is documented at Lumenlab. This new approach involves building a “box” that the stripped lcd goes in along with several fresnels, a projector lens, and a 400w metal hallide bulb. So that’s the idea in a nutshell and since a picture is worth a 1000 words…

Getting the parts...
The first order of business is to get all the necessary parts. Ebay is a great source. Also, having lots of miscelaneous junk laying around never hurts…

Stripping lcd...
Stripping the LCD was the scariest part, any mistake could ruin the LCD

Expanding the work area
Once started, space quickly became an issue and I found my work space needed to expand…

Building the box...
I used scrap/salvaged wood to build my box. The dimensions are approximately 15″ wide, 11″ tall, and about 30″ long.

Box further along...
The interior of the box goes something like this: Reflector (mixing bowl), MH 400W bulb, Lexan heat shield, fresnel, lcd, fresnel, lcd brains, projector lens/focus box.

Building focus box frame...
The focus box allows the lens to move for focusing…

Focus box...
…just about done with the focus box.

First time...
Firing up the bulb for the first time. My bulb and ballast hasn’t arrived yet, the testing I’ve done has been with Walt’s bulb and ballast…

One of the 1st images!!
For the intial testing I used a colored transparency…


Later on I added the LCD, it was a relief to see it still working following the stripping of the LCD…

Blurry computer image...
This final image I hesitated to post as I didn’t set the camera on a tripod and it turned out really blurry. Trust me though, the image looked great in person!

posted at 12:48:00 on 12/17/04 by Tony Rigdon – Category: General