Touch screen

TOUCH SCREEN

CONTENTS

• Introduction• History• Components• Various technologies and Working• Applications• Advantages• Disadvantages• Conclusion

INTRODUCTION

In recent time one of the most important inventions is

"touch screen" technology. Today most of the people like

to use touch screen devices because it helps them to make

a quick and accurate interaction with the content.

The touch screen is an electronic visual display that

can detect the presence and location of a touch with in

the display area.

Now day touch-screen is utilized on various devices such

as game consoles, tablet computers and smart phones.

HISTORY

Touch screens emerged from academic and corporate research labs.

In 1971, the first "touch sensor" was developed by Doctor Sam Hurst (founder of Elographics) while he was an instructor at the University of Kentucky.

In1974, the first true touch screen incorporating a transparent surface was developed by Sam Hurst and Elographics.

COMPONENTS

A basic touch screen has three main

components• Touch sensor

• Controller

• Software driver

TOUCH SENSOR

A touch screen sensor is a

clear glass panel with a

touch responsive area.

The touch sensor is

placed over a display

screen so that the

responsive area of the

panel covers the viewable

area of the screen.

CONTROLLER

A printed circuit board (PCB) that is the interface between the sensor and the display. The controller takes information from the touch sensor and translates it into information a computer can understand.

SOFTWARE DRIVERA computer program that allows the computer operating

system and the controller to communicate and helps the

controller recognize input.

1 Polyester Film2 Upper Resistive Circuit Layer3 Conductive ITO (Transparent Metal Coating)4 Lower Resistive Circuit Layer5 Insulating Dots6 Glass/Acrylic Substrate7 Touching the overlay surface causes the Upper resistive Circuit Layer to contact the Lower Resistive Circuit Layer, producing a circuit switch from the activated area.8 The touch controller gets the alternating voltages between the two circuit layers and converting them into the digital X and Y coordinates of the activated area.

TECHNOLOGIES

• Resistive

• Capacitive

• Infrared

• Surface acoustic wave (SAW)

• Optical imaging

RESISTIVEIt is the most commonly used

touch screen. Resistive screens

are composed of various

layers. There are two layers,

which have a small gap in

between and when you apply

pressure to the screen a

contact is created by the top

layer and touching the bottom

layer.

CAPACITIVE

As the name describe the type

of this touch screen. A thin

capacitor or electronically

charge sheet is placed on the

glass. In response to the

finger touch some of the

charge from the capacitive

layer shifts to the finger and

sending the information to the

touch controller.

INFRAREDIt works with small infra red LED’s mounted around the outer edges of the glass front and basically divides the surface of the screen into small squares, pressing with your finger or any object on the screen interrupt an infrared beam vertical and horizontal. The system detects what rays have been interrupted, thus knows where we hold and act on consequences.

SURFACE ACOUSTIC WAVE

These are the most sensitive of the touch screens as it works by sending an ultrasonic wave across the screen, when the screen is touched the ultrasonic beam is altered and the information is sent to the touch controller.

OPTICAL IMAGING

Optical imaging uses two or more

sensors around the corner edges of

the screen coupled with infrared back

lights.

The lighting, placed in the field of a

camera’s view of the other side of the

screen, sense a touch when a

shadow appears.

The camera’s triangulate the touch to

locate its location.

APPLICATIONS

• Library resource guides• Aerospace• ATM’s• Restaurants• Road transport• Industrial process control• Gaming machines in public areas• Museums

ADVANTAGES

• Touch screen gadgets usually have simple user interfaces.

• Big screen is ideal for web browsing, picture and movies.• Touch screen monitors are made out of glass or

something similar, so it is easier to clean than a regular monitor.

• For people new or uncomfortable with normal desktops, touch screen are easy to use helping more people get used to using computers.

DISADVANTAGES

• The screen has to be big enough to be able to touch the buttons with out missing.

• The big screen leads to low battery life.• Screen get very dirty because of constant touching with

oily or sweaty fingers.• They usually cost more than ordinary devices.

CONCLUSION

In my view touch screen which reduces human efforts.

Touch screen are fastest pointing devices and have easier

hand eye coordination than mouse or key boards. In future

there is no usage of mouse and keyboards as they will be

replaced by touch screen.

THANK YOU