I have one more gadget besides the ones I listed in my last column, and that is an iPod video. It’s extravagant, or at least it was when it was new — I only have it because my wife gave it to me for Christmas a few years ago. It’s my second favorite gift from her, the most favorite being the roll around toolbox she got me not long after we were married.
I happened to run across (over on Instructables, of course) a bunch of DIY passive iPod projectors. They don’t plug in, and as shown in the diagram they simply use mirrors and lenses to project the image on the wall. Since the light source is the iPod backlight they’re not that bright, so the room has to be dark and the projector has to be close to the wall in order for it to be visible.
They generally use a lens from a slide projector, and a glass hand mirror. As noted in many of the comments, for a relatively small amount of money you could buy a small LCD panel and hook it up with a video cable to get a much more usable device that would also include sound. Used LCD projectors are available pretty cheap on Ebay. However, these comments miss the point. This is a good opportunity to build a simple optics project and learn a little about lenses and focal points. This would be a great demo or project for a middle school science class. And, there’s never anything wrong with breaking out the duct tape and hot glue gun to build something from scratch that does something useful.
I can think of two improvements to this. First would be to use a front surface mirror instead of a regular glass mirror. The glass mirror gives at least two reflections, one from the glass surface and one from the painted mirror on the back. The front surface mirror only gives one reflection.
The other improvement would be to eliminate the mirror altogether and have the iPod project directly into the mirror. This could be done by cutting the iPod hole in the back of the box instead of the top, and adding a bracket on the back into which you place the iPod.
Next time: How about a really large touchscreen, ala Minority Report? Stay tuned…