Having done a ton of research on DIY projection and having retrofitted a cheap lamp into an expensive DLP projector, I was intrigued by the idea of these “iPod' projectors.

On the face of it these are little more than the “100 inch TV kits” which is basically just a fresnel lens projecting using the power of the TV and nothing else. Using the backlight from a Zune or iPod seems like a joke and something that wouldn't work for any practical application. Or at the very least the image would be too dim to be useable.

I decided to give it a shot.

The main items in the build are a mirror and a lense from a slide projector. I had the lense from a slide projector project from a few years ago. Next I needed a chassis for the ZPJ. Everyone else uses cardboard but that seemed.... so ghetto. So I went to AC Moore and picked up both a little wooden box, and a mirror. The mirrors came in a set of 2 for like 2.29. and the box was 2 dollars. I decided to take the ZPJ a step further and since its shooting an image but no sound I decided to also utilize a cheap un-powered set of speakers. The thought was if you're using a projector to make a larger image you're probably sharing with someone and rather than sharing your earbuds (ick!) you may as well be able to hear it too.



So first I knew I'd need the mirror to sit at a 45 degree angle for this to work o I went to my favorite rapid prototyping material (popscicle sticks) and make cut the pieces that would support the mirror at the right angle. I then  traced the base of the lens onto the box so that I knew the size to cut the hole.





I cut the hole using a dremel routing bit since I didn't have the correct size hole saw. After a few minutes of horrific screeching I had a hole and a bit of grinding with the dremel got the hole into shape. Its not perfect but then this job didn't require precision.



Next I hot glued the mounts in place in the box, I then test fit the mirror and lense in place. Next using the a utility knife I cut out the area above the mirror where the Zune would sit. Since there was a lattice work on top of the box I decided to remove those as well and use an old hotel mag card to block the light escaping. I then tested the unit. The picture was dim but it did go into focus nicely. I plugged the speakers in to listen to it while testing it. The sound was tinny but thats not suprising for a pair of speakers that came free with a cheap walkman.







So it worked. Not great mind you but it worked. I decided to see if I couldn't optimize it a bit. There was the possibility that stray light was washing out the image so I decided to paint it black inside. I also decided to permanently mount the mag card to the top of the box.





I noticed that the mirror was starting to slip a bit so I then glued a small piece to wood to the based of the mirror holding it still so that it wouldn't slip. I decided not to glue the mirror in place so it could be removed for easy cleaning.

Next I decided to mount the speakers to the unit. Hot glue to the rescue. I hot glued the mag card in place and removed the hardware that held it together as a box and glued the whole thing together.





Here's the finished product.







Final thoughts. Though the concept is sound there isn't nearly enough light energy present in  tiny backlight to project any sizeable image. I found that the largest image is maybe 12 inches tops. It's also incredibly sensitive to what kind of screen you use. The wall I used initially was whitish but that yielded a dark image. I then tried a white box top and that did better. Also content is important. If you use it for cartoons with bright colors you will get a better image than if you were to use it to watch “Batman Begins”. I dare say it would be unwatchable.


This is the best photo I could get of the projected image. This is not retouched. It looks much better in person however. I speculate the other results pictures I've seen are processed in some way.

Though it doesn't work well it was an interesting experiment. I figure at the very least if it doesn't work well it may as well look cool. It's a pretty contraption at least. I may even find myself using it a bit if I can find a suitable projection surface that has hi gain. 

An interesting experiment nonetheless.

The rest of the photos can be seen in our gallery here.