CAPACITIVE AND RESISTIVE TOUCH SCREEN TECHNOLOGY

By:Aarti

HOW TOUCH TECHNOLOGY DIFFERS FROM OTHER DEVICES

• No special commands to learn.• The user doesn’t need to look away from the

screen to a keyboard and back again.• Entering wrong information is impossible, only

valid options are offered on the screen.• There are no loose pieces of hardware to be

damaged or lost.

The Basic Touchscreen Components

1.Touch sensor

2.Controller

3.Software Driver

TOUCH SENSOR>>The touch sensor is a clear glass panel with a touch responsive area and it is placed over the display screen.>>It allows the electric current and signal to pass through it and change in these signal is used to detect the location of touch on the screen.

Controller

>>The controller connects between the touch sensor and the PC.

>>Take information from the touch sensor and translate it into the information that PC can understand.

Software DriverThe driver allows the touch screen and the computer to work together

It tells the computer's operating system how to interpret the touch event information that is sent from the controller.

This makes touching the screen the same as clicking your mouse at the same location on the screen.

TOUCH TECHNOLOGIES

Touch techno

logy

CAPACITIVE

RESISTIVESURFACE ACOUSTIC WAVEINFRARE

D

RESISTIVE TOUCH SCREEN

•It is compose of a flexible top layer and a rigid bottom layer separated by insulating dots, attached to a touchscreen controller.

•The inside surface of each of the two layers is coated with a transparent metal oxide coating of IndiumTin Oxide(ITO).

•With a light touch, the conductive coating makes electrical contact with the coating on the glass.

•The voltages at the point ofcontact are the analog representation of the position touched. The controller digitizes these voltages and transmits them to the computer for processing.

TYPES OF RESISTIVE TOUCHSCREEN

4 Wire Resistive 5 Wire Resistive

CHARACTERISTICS

Cost effective solutions.75% clarityActivated by a stylus, a finger or a gloved

hand.Not affected by dirt , dust , water and light.Resistive layers can be damaged by a very

sharp objects.Multi touch capabilities are not there.

CAPACITIVE TOUCH SCREEN

• It consists of a glass panel with a capacitive (charge storing) material coating its surface.

• Touching the surface of the screen results in a distortion of the screen’s electostatic field,measurable as a change in the capacitance.

TYPES OF CAPACITIVE TOUCHSCREEN

Surface Capacitive Projected Capacitive

CHARACTERISTICS

High touch resolutionHigh clarityDurable and resistant to scratches for demanding

applications.Faster and more responsive.Immune to surface contaminants.Must be touched by fingers, will not work with

any non conductive input.Multi touch capabilities are there.

Comparison of Resistive and CapacitiveResistive Touchscreen Capacitive Touchscreen

Visibility in indoor: Very Good Very Good

Visibility in sunlight: Not very Good Good

Touch sensitivity: Light Pressure is needed. Touch screen can respond with fingers (even with gloves on), fingernails, stylus, etc.

Responds very well even with the slightest contact of your finger .Doesn't work with gloved fingers/stylus.

Accuracy: Accurate to at least display pixel resolution, as can be seen when drawing (or writing characters) with a stylus. Useful for handwriting recognition .

Accurate to within a few pixels, in theory, but seriously limited by the physical size of your fingertips, which make it hard to accurately press any control element.

Cost: Affordable More expensive than resistive

Multi-touch: No Yes

Screen Durability: Vulnerable to scratches is more resistant to casual scratches.

PROS&

CONS

Pros ConsFast responseError free inputUse finger , fingernail , gloved hands , stylus or any soft tip pointerEasy to cleanDoes not interfere mouse and keyboardMake computing easy , powerful and funIt benefits children

FingerprintsFinger stressScreen has to be really big not to miss things when pressing them with your finger big screen leads to low battery life touch screen means screen can’t be read too well in direct sunlight Fatigue

Applications

CONCLUSION

• Designers are trying to use touchscreen to simplify input commands for largely unsophisticated computer users.

• Today, a larger share of population is PC literate, yet the touchscreen has become adopted by computer users of all abilities because it is simple, fast, and innovative.

• In future there is no usage of mouse and keyboards as they will be replaced by touchscreens.

FUTURE SCOPE

RPO’ s Digital Waveguide Touch:• Minimal power requirements. • High inherent accuracy & precession.• Zero-pressure touch & allows finger scrolling.• Allows100% display light output, picture definition

and colour clarity.• Low-cost & Excellent durability.

3-dimensional Touchscreens

Thank youAny QUERIES……????