Capacitive Touch-Screens

By: Mason SchoonoverMEEN 3344

How it’s Made

• A capacitive touch screen is an all glass touch screen with a transparent metallic conductive coating.

• The LCD display is found beneath the glass and conductive layers.

How it Works• There is a low voltage charge that

is generated from the corners of the screen and distributed throughout the conductive layer.

• When a finger touches the screen it draws a minute amount of current, creating a drop in voltage.

• The device then pin points the location of the touch by the proportion of where the finger creates the drop in voltage on the screen.

Advantages and Disadvantages

Advantages• High touch resolution• High image clarity• Not affected by dirt, grease,

or moisture.

Disadvantages• Will only work when

touched by a conductive input.

• Some capacitive touch screens can have erratic behavior when touched by more than one input.

Interesting Facts• A 15” capacitive touch screen

costs about $2500.• It takes less than 3 ounces of

force to activate the touch screen.

• It is rated for 100,000,000 plus touches at each specific point on the screen.

• Capacitive touch screens have been developed into multiple touch systems.

Uses• ATMs• Public Access Kiosks• Phones• Computers• Gaming machines• Point of Sale• Industrial controls• Hand held electronics

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