- #1
genxium
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Our professor gave us a lecture about sensors tonight, but I'm kind of confused about the principals of capacitive touch screen.
As the attached figure shows, when finger touches the screen , capacitance is formed between finger and the ITO bars, but is it true for all the ITO bars?
It's well known that parallel aligned plates can form a capacitor, and [itex]C=\frac{\epsilon A}{d}[/itex] , [itex]A[/itex] is the so called "effective area", in high school I was told that [itex]A[/itex] is the "aligned projected area", according to this, if my finger has no "projected area" that intersects with some far away ITO bars, can I tell that there's no capacitance formed between my finger and these far away ITO bars?
As the attached figure shows, when finger touches the screen , capacitance is formed between finger and the ITO bars, but is it true for all the ITO bars?
It's well known that parallel aligned plates can form a capacitor, and [itex]C=\frac{\epsilon A}{d}[/itex] , [itex]A[/itex] is the so called "effective area", in high school I was told that [itex]A[/itex] is the "aligned projected area", according to this, if my finger has no "projected area" that intersects with some far away ITO bars, can I tell that there's no capacitance formed between my finger and these far away ITO bars?