There are four main types of touch screen technologies: capacitive, resistive, infrared grid, and optical imaging. Capacitive touch screens, made popular by Apple devices, are the most responsive and rely on changes in electrical current when a finger touches the screen. Resistive touch screens use a mesh between the screen and touch panel to register touches. Infrared grid touch screens are not common and use infrared light to detect touches. Optical imaging touch screens are new and use corner image sensors and infrared lighting to detect touch locations.

1. Touch Screen Technologies

2. Types of Touch-screen
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Capacitive
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Resistive
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Infrared Grid
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Optical Imaging

3. Capacitive
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Newer kind of touch screen
You have to use a finger with
it
Relies on a change of current
in the skin

4. Capacitive
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Made popular by Apple's
iPhone and iPad
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More responsive
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More expensive

5. Resistive
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A mesh between the screen
and the touch panel.
Where the mesh meets the
touch panel, a touch is
registered.

6. Resistive
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A stylus is usually used, as it
is more accurate.
Not usually multi-touch
Was proven possible in the
1970's
First consumer use was in the
Apple Newton

7. Infrared
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Not common.
A very old type of touch
screen.
Uses an array of infrared
LED and detector pairs
around the screen.

8. Infrared
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Accepts any kind of input.
Generally used outdoors and
sometimes in point-of-sales
systems.

9. Optical Imaging
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Relatively new
Image sensors placed in the
corners
Infrared backlights are
placed in the camera's point
of view
A touch shows up as a
shadow, cameras can
pinpoint the touch

10. Optical Imaging
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●
●
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Relatively new
Image sensors placed in the
corners
Infrared backlights are
placed in the camera's point
of view
A touch shows up as a
shadow, cameras can
pinpoint the touch