posted on Jan, 15 2007 @ 06:17 PM
No, it will have to be much much more than just some sort of transmitter mounted on a camera. Remember, this doesn't have any sort of smarts to it.
It's just ink that absorbs radio waves of some particular frequency range most likely due to some sort of ferrous particulates they've mixed in to
So how do you read ink marks with light? Remember, radio waves are just really low frequency light. The same sorts of things apply, although the means
by which you do it change.
If I'm reading a mark, I'll have to "look at" a spot that's significantly smaller than the smallest feature I'm trying to see. Imagine trying to
read a print book, for example, when I my scanner has a dot size the size of a BB. I'm not going to be able to resolve letters, just that some sort
of print is there. I won't be able to tell if it's letters or small pictures, for example. This is why higher resolution LCD screens on your PC can
show more details. What sort of picture could you show with, say, 10 really big pixels? Not much detail there.
The same thing applies to reading some sort of bar code. My resolution has to be significantly smaller than the smallest bar in the code, or it will
all run together into a blur.
Since he's reading the marks with some sort of radio device, his resolution is limited, because radio waves are pretty big compared to bars in a bar
code. In general, you can't focus a spot of RF smaller than twice the wavelength due to physics. The wavelength of your microwave is about 12
centimeters. So, you could, with a nice dish antenna, get a focal spot of about 24 cm diameter. That's not very small, I could tattoo the entire side
of the cow and only get a few bars. I need to get a lot tighter than that! Looking at a book here with my calipers, I see that the guard bars on the
UPC code are about 0.87mm. The smallest bars are a lot thinner than that, but I can't measure it with my caliper. So, in order to read a 0.87mm
series of bars, I'd need a spot size about half that so I can see the spaces and bars clearly. Let's say 0.40mm for a spot size. The wavelength to
scan that bar code with a radio beam would be half THAT, or about 0.20mm. That's 1.4THz, if I didn't slip a decimal place.
That's not off the shelf, and this guy's not using it.
I'm leaving out all the fun part where you have to focus the beam so that it's still small at 4 feet, and how the guy scans it at that distance.
The easy way is some sort of contact reader, where you can have your pickup's size limit the aperture of the scan spot. I CAN see him doing this.
That would be something you could go buy.
Like I say, the phrasing they're using sounds fishy. It will be interesting to see if it ends up making it to market, maybe they've circumvented
physics in some new way, but this is a technology incubator company going for funding.