Touch Screen - Ppt Final

1

Touch Screen Technology

A PRESENTATION BY :-

AHMED A. S.(1GC06EC092)

UNDER THE GUIDANCE OF :-

MR. C.K. VENKATESH

2

CONTENTS

Introduction (What are Touch Screens?) History Components Of Touch Screen Types Of Touch Screens Comparision Of Technologies Advantages And Disadvantages Applications Recent Trends & Recent Products Cost Conclusion

3

What are Touch Screens?

• It is the most user friendly input device used to interface with a PC.

• The user touches the screen to select options presented on it, where associated hardware and software locates that touch.

4

History

-1971 the first "touch sensor" was developed by Doctor Sam Hurst (founder of Elographics) called “Elograph”.

5

History

-1974 the first true touch screen incorporating a transparent curved glass sensor surface came on the scene developed by Sam Hurst and Elographics.

-1977Elographics developed & patented five-wire resistive technology, called “AccuTouch”.

6

History

-1987 new technology were purchased. The surface acoustic wave product, named “IntelliTouch”.

7

Components Of Touch Screen

There Are Three Major Components Of The Touch Screen

Touch Sensors

Controller

Software Driver

8

Touch sensor

Covering screen


TOUCH SENSORS

9


Contd..

Touch Sensors are located In Between Clear Glass Panels

Responsive Area -> Entire Area Of The Display Screen

Sensors -> Detects Electrical Current Or Signal

Touching -> Causes A Voltage Or Signal Change, Thereby The Location Can Be Determined

TOUCH SENSORS

10


CONTROLLER

11


Contd..

PC card -> Touch sensor and the PC.

Change in voltage -> Translated into the information that CPU understands.

Translated bits -> Position where the touch occurs.

Processor -> change the screen accordingly.

CONTROLLER

12


SOFTWARE DRIVER Acts as a bridge Between the Screen and the

processor.

Makes the operating system to interpret the touch event information.

Touch screen drivers today are like Mouse-emulation type driver ( like touching the screen the same as clicking mouse)

Recent research -> To make it as PNP

13

Types Of Touch Screen

Resistive Touch screen

Capacitive Touch screen Surface capacitive Projected capacitive

Surface wave Touch screen

Infrared Touch screen

14


RESISTIVE TOUCH SCREENS

15

Types Of Touch Screen->Resistive Touch Screens

16

Contd..1. Polyester Film.

2. Top Resistive Layer.

3. Conductive Transparent Metal Coating.

4. Bottom Resistive Layer .

5. Insulating Dots .

6. Glass Substrate


17


Working Of Resistive Sensors

When the screen is touched, it pushes the conductive layer on the PET film. That results the electrical contact, producingThe voltages. It presents the position touched

The microprocessor applies +5V to pin (X left) on the glass panel, and the voltage is uniformly decreasing to pin (X right) for 0V because of the resistive ITO coating on the glass substrate, and the PET film is grounded.

Contd..

18

-> Consists of a glass or acrylic panel that is coated with electrically conductive and resistive layers. The thin layers are separated by invisible separator dots. Advantages :-

->High touch resolution->Pressure sensitive, works with any stylus->Not affected by dirt, dust, water, or light- >Costs are relatively low when compared with active touch screen technologies.

Disadvantages :-->75 % clarity->Resistive layers can be damaged by a sharp object->Less durable then 5-Wire Resistive technology

4-Wire Resistive TouchScreens


19

- better version of 4-Wire Resistive technology.

Advantages :--> High touch resolution-> Pressure sensitive, works with any stylus-> Not affected by dirt, dust, water, or light-> More durable than 4-Wire Resistive technology

Disadvantages :-->75 % clarity->Resistive layers can be damaged by a sharp object->much expensive than 4-Wire Resistive technology

5-Wire Resistive TouchScreens


20

CAPACITIVE TOUCH SCREENS


21

Types Of Touch Screen->Capacitive Touch Screens

22


WORKING OF CAPACITIVE TOUCHSCREEN Uniform conductive coating on a glass panel.

Operation --> Electrodes around the panel's edge evenly distribute a low voltage across the conductive layer & creates an uniform electric field.

Finger touch --> Draws current from each corner.

Controller --> Measures ratio of the current flow from the corners & calculates the touch location.

23

Advantages->High touch resolution->Pressure sensitive, works with any stylus->Not affected by dirt, dust, water, or lightDisadvantages->Must be touched by finger, will not work with any non-conductive input

Capacitive Touch Screens


24

-> is a durable Capacitive type touch screen with an attached pen stylus. It can be set to respond to finger input only, pen input only, or both.

Advantages->High touch resolution->Pressure sensitive, works with any stylus->Not affected by dirt, dust, water, or lightAttached pen stylus for precise inputDisadvantages-> Must be touched by finger or attached pen stylus, will not work with any non-conductive input

Pen TouchCapacitive Touch Screens


25

SURFACE ACOUSTIC WAVE TOUCH

SCREENS


26

Types Of Touch Screen-> SAW Touch Screens

SAW TOUCH SCREEN

27


WORKING OF SAW SENSORS Contains Transmitting and receiving transducers

Touchscreen controller --> 5 MHz electrical signal to the transmitting transducer.

Converts electrical signal --> ultrasonic waves within the glass.

Waves --> Directed across the front surface of screen.

Reflectors - -> Reflects & directs towards receiving transducer.

Receiving transducer --> reconverts --> An electrical signal & digitally maps the touchscreen

28

AdvantagesHigh touch resolutionHighest image clarity All glass panel, no coatings or layers that can wear out or damage.Disadvantages Must be touched by finger, gloved hand, or soft-tip stylus. Something hard like a pen won't work Not completely sealable, can be affected by large amounts of dirt, dust, and / or water in the environment.


SAW TOUCH SCREEN

29


INFRARED TOUCH SCREENS

30

Types Of Touch Screen-> IR Touch Screens

Conventional optical-touch systems use an array of infrared (IR) light-emitting diodes (LEDs) on two adjacent bezel edges of a display, with photo sensors placed on the two opposite bezel edges to analyze the system and determine a touch event.

IR TOUCH SCREEN

31

Types Of Touch Screen-> IR Touch Screens

IR TOUCH SCREENAdvantages IR eliminates the use of glass or plastic overlay that most

other touch technologies require in front of the display.

Disadvantages High cost of the technology.

IR increases the noise floor at the optical sensor

32

Comparision Of Technologies

Technology Resistive SAW Infrared Capacitive

Durability 5 years 5 years 3 years 2 years

Stability High Higher High Ok

Transparency Ok Good Good Ok

Touch Anything Finger/ pen Sharp Conductive

Response time <10ms 10ms <20ms <15ms

33

Advantages Of Touch Screen

User FriendlyFast ResponsiveError Free InputEasy To InstallUse Finger, Fingernail, Glovehand Or Stylus To OperateEasy To Clean And MaintainCompatible With Windows, Macintosh And LinuxDoes Not Interfere Mouse And Keyboard FunctionMakes Computing Easy Powerful And Fun

34

Disadvantages Of Touch Screen

Creates Stress On Human Fingers When Used For More Than A Few Minutes Continuously (For Example ATMs)

Touch Screens Suffer From The Problem Of Finger Prints On The Display Which Makes It Dirty.

Big screen leads to low battery life.

35

Applications Of Touch screens

Credit Card Scanners Uses The

Touch Screen Interface.

Many Public Utility Displays are used

by many people that have little or no

Computing experience. The

user-friendly touch screen interface can be less intimidating and

easier to use than other input devices, especially for novice

users. A touch screen can help make your information more

easily accessible by allowing users to navigate your presentation

by simply touching the display screen.

Credit Card Scanners

36


Consumer Electronics• Phones• PDA’s• Digital Cameras• GPS• etc

37


ATM

Interactive Kiosks and learning stations

38

Recent Trends• Introduction of

– i-PAN7: Flat Touch Screen computer - Panel PC

– Introduced by Keith & Koep of Japan.

– Small frame computer.

– Runs with Windows Embedded CE & built with low power ARM processor.

– Uses Capacitive touch panels.

39

Recent Products Under Development

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.

3-dimensional Touchscreens

40

Cost (Approximate)

Overlay screen -> $169 - $299 (Approx Rs. 7.5K to 13.3K)

Integrated Touch Screen Monitor

15” LCD (ELO Touch Systems) -> $186 (Approximately Rs. 8.3 K)

21.5” LCD (DELL) -> $300 (Approximately Rs. 13.4 K)

42” LCD (SONY) -> $3600 (Approx. Rs. 161K)

USD to INR Conversion As Per http://www.xe.com/ucc

http://www.xe.com/

41

Conclusion

Though The Touch Screen Technology Contains Some Limitations It’s

• User Friendly.• Fast.• Accurate.• Easy To Operate.

It Has Been Widely Accepted And A Little Modification Can Replace The Mouse And Key Board Completely In Near Future.

42

References

http://en.wikipedia.org/wiki/Touch_screenhttp://www.edufive.com/seminartopics/computer/CS35.htmlhttp://www.ehow.com/about_5436883_history-touchscreens.html?ref=fuel&utm_source=yahoo&utm_medium=ssp&utm_campaign=yssp_arthttp://bugclub.org/beginners/history/TouchScreen.htmlhttp://electronics.howstuffworks.com/iphone1.htmhttp://inventors.about.com/gi/dynamic/offsite.htm?site=http://www.touchscreens.com/compare.shtmlhttp://inventors.about.com/gi/dynamic/offsite.htm?site=http://www.touchscreens.com/uses.shtmlwww.touchscreens.com

http://inventors.about.com/gi/dynamic/offsite.htm?site=http://www.touchscreens.com/uses.shtml

http://inventors.about.com/gi/dynamic/offsite.htm?site=http://www.touchscreens.com/uses.shtml

http://www.touchscreens.com/

43

THANK YOU . . . . .

Touch Screen - Ppt Final

Documents

high touch

capacitive

resistive

wire resistive

wire resistive

touch screengt

touch screens

resistive