Shri Ram Murti Smarak College of Engineering And Technology, Bareilly

PRESENTATION TOPIC :-TOUCH SCREEN TECHNOLOGY

PRESENTED TO:- PRESENTED BY:-

MR. ABHISHEK SRIVASTAVA SHUDHANSHU AGARWAL

B.TECH (EC-2011)

ROLL NO.-1101421102

Points of Discussion

Introduction History Working Process Technologies Applications Advantages & Disadvantages Conclusion References

Introduction:

A touch screen is an electronic visual display that can detect the presence and location of a touch within the display area. Touch screens can sense Finger and other passive objects, such as a stylus. However, if the objects sensed is active, as with a light pen.

History:

In 1971 Dr. Sam Hurst, founder of Elographics developed the first touch opaque sensor “Elograph” at the University of Kentucky.

In 1974 He developed the first real touch screen. In 1977, Elographics developed the five-wire resistive technology

then with the backing of Siemens Corporation, developed a curved glass sensor called the Touch screen.

The new transparent technology, AccuTouch, was later developed by the founders of Elographics, Dr. Hurst and Bill Colwell.

Now days, Multipoint touchscreen facilitates the tracking of more than one finger on the screen.

How Does a Touchscreen Work? 

1. Touch Sensor

2. Controller

3. Software Driver

1. Touchsensor:

2. Controller:

The controller is a small PC card that connects between the touch sensor and the PC. It takes information from the touch sensor and translates it into information that PC can understand.

3. Software Driver:

The driver is a software that allows the touch screen and computer to work together. It tells the operating system how to interpret the touch event information that is sent from the controller.

Technologies:

1. Resistive

2. Infrared

3. Capacitive

4. Surface acoustic wave

1.Resistive:

Two layers of conductive material Touch creates contact between

resistive layers completing circuit Voltage in circuit changes based on

position Controller determines location

based on voltages Any material can trigger sensors

2.Infrared:

Uses infrared LEDs and matching photodetectors

Touching screen interrupts LEDs Cameras detect reflected LED

caused by touch Controller able to calculate

coordinates from camera data

3.Capacitive: Glass panel with conductive layer

(Indium Tin Oxide) Small amount of voltage applied to

four corners of touch screen Touch draws minute

amount of current creating voltage drop

Coordinates of point of contact calculated by controller

4. Surface acoustic wave: Surface consists of glass overlay with

transmitting and receiving transducers Electrical signals sent to the

transmitting transducers converts to ultrasonic waves

Waves are directed across screen by reflectors then directed to receiving transducers

Received values are compared to stored digital maps to calculate x and y coordinates

Applications:

Many games use the touchscreens as a primary controlling device.

The popularity of smart phones, ATMs, and many types of information appliances is driving the demand for touchscreens.

Touchscreens are popular in heavy industry and in other situations, such as museum displays or room automation.

Casino and other gaming systems Computer access for the physically disabled Point-of-sale terminals Restaurant systems Employee time clocks

Advantages:► Mostly used in manufacturing and medical applications since it

can be completely sealed. ► Operated using a stylus or a gloved finger.► Mechanically stronger ► Clearer► More wear resistant

Disadvantages:►It is very sensitive and can be activated by stray touches.►Low resolution ►Parallax problems

Conclusion: Designers are trying to use touch screen to simplify input

commands Today , touch screen has becomes adopted by computers 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 touch screen.

References:

► www.engineersgarage.com

► www.nptel.iitk.ac.in

► www.google.co.in

► www.wikipedia.com

► www.touchscreensolutions.com.au

► www.norteng.com

Thank You….

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