Reading barcodes using a laser scanner

I am talking about a project to add some more inteligence to the Roomba robotic vacuum.(the group isteh "hacking" part of

).

We want to a laser, and light sensor inside the Roomba and used it as a sensor to detect reflector targets that have barcodes on them. See these links for two sensor setups, but that don't try to detect bar codes'

and The goal is to have the robot determine its absolute position by spinning in place, and timing the detection of the reflective targets. The barcode is to allow the robot to know which of the targets it has detected. I was thinking of a system that started with a single stripe of reflective tape, which was followed by a series of either more reflective tape, or a missing stripe of tape to indicate binary 0's and

1's.

I see the scribbler robot has the ability to detect barcodes using its line-following sensors;

. I see that it uses a different system of encoding the digit. It does it by wide-strip vs. a thin-strip. It also has some other digits to determine which way the robot is scanning the code, but we won't need that, since we know the direction the robot will spin (clockwise)

I have a few questions;

Is there an advantage to the wide-strip / thin-strip system in our appication?

Any other projects out there that use this sort of laser-sensor in a barcode system?

Any more advice regarding our project? (you can put it on that web site if you wish)

Joe Dunfee