100% LOADED

The iPod Touch finally dropped yesterday. Rejoice!! I will leave to others the comments on the price vs. the low memory, how the early iPhone adopters may have gotten the short-end, etc. Instead, I want to speculate on how Apple might be pulling-off the multi-touch functionality.

Most “true” multi-touch system out there right now, such as Microsoft Surface or Reactable, use a projector and a vision system built around Frustrated Total Internal Reflection (FTIR). This requires a big machine or setup to allow enough distance for the projector to display the image on the screen. The bigger the screen, the farther away the projector needs to be. Of course, you can offset this if your projector has really good optics and can focus-in closer, but most commercial products out there bottom out at around 2′ or 3′ feet.

So how do the iPhone and iPod Touch do it?

Certainly, these devices are way too thin to be doing any kind of optical trickery, so the answer (I think) must lie in a tried-and-true technology most of us have been using for years. I suspect it’s resistive touch screen panels. This is what is used on ATMs and interactive kiosks.

I’ve had a chance to play around with a couple of iPhones lately, and it struck me that all the gestures are either one (tap) or two fingers (pinch). This makes perfect sense, since you really can’t hold on to the device and perform a three-finger gesture. That would be like trying to hit ctrl-alt-tab-shift-F12 on your keyboard using only one hand.

You don’t need multi-touch. It should be more like bi-touch or duo-touch.

I’ve been racking my brain on this one for months, but the final clue came yesterday with this graphic shown on the Apple website. As you can see, it shows two points being touched over two “mystery” layers on top of this cool grid that has two bumps on it corresponding to the touch points. Eureka!!!

If all you need is two touch points at the most, you just throw-on two resistive “layers” over the LCD and you can use either hardware or software techniques to ignore the extra touch points. If the “top” layer senses one finger, the “bottom” layer agrees. If you put down a second finger, the “top” layer ignores it and the “bottom” layer can take over the tracking for it. Shear genius, Apple.

I’m not saying that, yes, this is how Apple is doing it… but at least, this is probably how I would have done it. It’s a tried-and-true technology, it’s inexpensive, and it’s really all you need to do hardware-wise to build such a great product around.

Yet another example of Apple’s incredible vision, innovation, and ability to use current technology and materials in very creative ways. I guess there’s no more need for a transitional product like the “WidePod”.

This means the Zune is done, by the way.

iPod Touch and iPhone are trademarks of Apple Inc. Image is Copyright © 2007 Apple Inc. Zune is a trademark of Microsoft.