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View Full Version : how does the notebook mousepad know.....


JBucc
09-20-2006, 01:31 PM
Whether or not it's a finger touching it? I tried to move it with my pen and my leather wallet, nothing. Freaky.

JBucc
09-20-2006, 01:35 PM
http://en.wikipedia.org/wiki/Touchpad

"Touchpads commonly operate by sensing the capacitance of a finger, or the capacitance between sensors. Capacitive sensors are laid out along the horizontal and vertical axis of the touchpad. The location of the finger is determined from the pattern of capacitance from these sensors. This is why they will not sense the tip of a pencil or other similar implement. Gloved fingers may be problematic (such as in a cleanroom environment) but can sometimes work. Moist or sweaty fingers can be problematic for those touchpads that rely on measuring the capacitance between the sensors."

DaFace
09-20-2006, 01:35 PM
http://www.thetartan.org/2004/3/1/scitech/howthingsworktrackpads

Basically, your fingers absorb a tiny amount of an electric current from the mousepad. When that change is detected, it knows where your fingers are. :)

DaFace
09-20-2006, 01:37 PM
After reading through that, the technology is strikingly similar to an ultra-safe table saw I read about a while back. Handyman or not, this thing is cool as hell:

http://www.sawstop.com/

Check out the "Hot Dog Demo" if nothing else.

JBucc
09-20-2006, 01:37 PM
I never even thought about it until just now. I guess I just assumed it sensed pressure or something.

JBucc
09-20-2006, 01:40 PM
After reading through that, the technology is strikingly similar to an ultra-safe table saw I read about a while back. Handyman or not, this thing is cool as hell:

http://www.sawstop.com/

Check out the "Hot Dog Demo" if nothing else.Whoa! That's awesome.

DaFace
09-20-2006, 01:45 PM
Yeah, as long as you don't mind dumping 3 grand on a tablesaw. Could be worth it for a finger, though.

This is cool enough that I think I'll post a thread in the lounge about it. :D