1. Touch-Sensitive Screen
By Rory Pettitt (Woo!)

2. What is a Touch-
Sensitive Screen?
I will be going over Multi-Touch, rather than
Mono-Touch.
A Multi-Touch screen allows people to control
information with their fingertips (Or other body
parts)
It accomplishes this via Mutal Capacitance, this
requires two layers of material. One carries
current and the other sensing lines.

3. How touch sensing
works:
1) The screen register touch. (2) Raw data is
captured. (3) Background noise is removed. (4)
Pressure Points are measured. (5) Touch areas
are established. (6) Exact coordinates are
calculated.

4. Continued
For a MTS to interpret the raw data it has to go
through seveal steps:
(1) Signals travel from the touch sreen to the
processor as electrical impulses. (2) The processor
then uses a piece of software to analyze the data to
determing the feature of each touch: Including size,
shape and location (If Necessary). (3) The processor
uses gesture-interpretation software to determine
which gesture the person made. (4) The processor
relays you instruction to the program in use.

5. The Mutual Capacitance
Screen
The MCS is made of several layers, in order:
LCD Display Layers, Glass Substrate, Sensing
Lines, Driving Lines, Bonding Layer, protective
cover and anti-Reflective Coating.

6. Driving/Sensing Lines
The circuitry can sense changes at each point
along the grid. This grid is the combination of
Driving/Sensing lines, Vertical and Horizontal
respectively.
Every point on the grid generates its own signal
when touched, when then relays the signal
generated to the processor.