I am doing a physics project for my high school course. My project is to explain how a resistive touchscreen works.I have no engineering knowledge.
From a description I found on computerworld.com (it's the most elaborate one I could find)...
It consists of a top flexible, bendable film and a rigid bottom film (usually glass), separated by a air gap. The two films are lined with transparent conducting materials (usually ITO), perpendicularly placed to one another.
It's analog resistive ("analog"-measures a change in value, not limited to the binary choice between complete presence or absence)
When pressed, the top and bottom films (more specifically, the conducting linings) make contacts, and thus a circuit is formed.
The voltage is measured. Assuming the current that goes through this "circuit" is constant, the resistance varies proportionally with the voltage.
This is the tricky, kinda shaky part that the author just glossed over: with the voltage measured, the X and Y coordinates of the touch position is calculated based on the amount of resistance at the point of contact.
What determines the voltage measured (and thus the resistance calculated from voltage and current)?
What are the conducting layers lined perpendicularly?
If the whole resistive touchscreen is "analog resistive", why then "this analog voltage is processed by analog-to digital converters (ADC) to create a digital signal that the device's controller can use as an input signal from the user"? (ALSO, ISN'T "DIGITAL" THE OPPOSITE OF ANALOG?)