Pick Your Community: | Hopkins | Muhlenberg | Daviess | Christian | Fayette | Henderson | Lakes | McCracken | Warren | Webster
Davis Motor Sales banner ad

How It’s Done: iPhone Touch-Screens

Among these advancements, perhaps one of the most ingenious is “touch-screen” technology. Though the touch-screen is utilized on everything from laptop computers, GPS units, MP3 players, digital cameras, and even printers, most anyone would agree that Apple’s iPhone was the device most instrumental in bringing touch-screen technology to the masses. However, it’s a safe bet that most of us have no idea how the technology in an iPhone’s touch-screen actually works.

In all reality, the basic idea is pretty simple: when you place your finger or a stylus on the touch screen, it changes the state that the device is monitoring. In screens that rely on sound or light waves, your finger physically blocks or reflects some of the waves. Capacitive touch-screens use a layer of capacitive material to hold an electrical charge; touching the screen changes the amount of charge at a specific point of contact. In resistive screens, the pressure from your finger causes conductive and resistive layers of circuitry to touch each other, changing the circuits' resistance.

Whereas most touch-screen systems are good at detecting the location of exactly one touch, which can result in some pretty erratic behavior if another finger happens to touch on the screen accidentally, the touch screen on an Apple iPhone is different. Many of the elements of the iPhone’s “multi-touch” user interface actually require you to touch multiple points on the screen simultaneously. For example, you can zoom in to web pages or pictures by placing your thumb and finger on the screen and spreading them apart. To zoom back out, you can pinch your thumb and finger together. The iPhone's touch screen is able to respond to both touch points and their movements simultaneously.

To allow people to use touch commands that require multiple fingers, the iPhone uses an innovative arrangement of preexisting technology. Its touch-sensitive screen includes a layer of capacitive material, just like many other touch-screens. However, the iPhone's capacitors are arranged according to a coordinate system. Its circuitry can sense changes at each point along the grid. In other words, every point on the grid generates its own signal when touched and relays that signal to the iPhone's processor. This allows the phone to determine the location and movement of simultaneous touches in multiple locations. Because of its reliance on this capacitive material, the iPhone works only if you touch it with your fingertip. Surprisingly enough, the iPhone’s multi-touch screen won't work if you use a stylus or wear non-conductive gloves.

At its base, the iPhone's screen detects touch through one of two methods: Mutual capacitance or self capacitance. In mutual capacitance, the capacitive circuitry requires two distinct layers of material. One houses driving lines, which carry current, and the other houses sensing lines, which detect the current at nodes. Self capacitance uses one layer of individual electrodes connected with capacitance-sensing circuitry.

Both of these possible setups send touch data as electrical impulses.

However, the iPhone's processor and software are essential to accurately interpreting input sent from the touch-screen. The capacitive material sends raw touch-location data to the iPhone's processor. The processor uses software located in the iPhone's memory to interpret the raw data as commands and gestures.

What follows is a step-by-step explanation of this process:

1.)  Signals travel from the touch screen to the processor as electrical impulses.
2.)  The processor uses software to analyze the data and determine the features of each touch. This includes size, shape and location of the affected area on the screen. If necessary, the processor arranges touches with similar features into groups. If you move your finger, the processor calculates the difference between the starting point and ending point of your touch.
3.)  The processor uses its gesture-interpretation software to determine which gesture you made. It combines your physical movement with information about which application you were using and what the application was doing when you touched the screen.
4.)  The processor relays your instructions to the program in use. If necessary, it also sends commands to the iPhone's screen and other hardware. If the raw data doesn't match any applicable gestures or commands, the iPhone disregards it as an extraneous touch.

All these steps happen in an instant, much like the interpretation of electrical impulses in the human brain. You see changes in the screen based on your input almost instantaneously. This process allows you to access and use all of the iPhone's applications with your fingers and all but eliminates the need for raised button operations of the past.

Luke Short
Information courtesy of Discovery’s HowStuffWorks.com

 

© Copyright 2014 SurfKY News Group, Inc. All rights reserved. This material may not be published, broadcast, or rewritten without permission. SurfKY News encourages you to share this story by using one of the social media links below.

Posted on 2/2/14
Genovese - http://www.mchky.org/staff/bio.php?doc_id=35646&sub= Lewis - http://www.mchky.org/getpage.php?name=bracken_lewis Holt - http://www.mchky.org/getpage.php?name=drholt Napier - http://www.mchky.org/getpage.php?name=dr.napier_page Newman - http://www.mchky.org/staff/bio.php?doc_id=50353
Genovese - http://www.mchky.org/staff/bio.php?doc_id=35646&sub= Lewis - http://www.mchky.org/getpage.php?name=bracken_lewis Holt - http://www.mchky.org/getpage.php?name=drholt Napier - http://www.mchky.org/getpage.php?name=dr.napier_page Newman - http://www.mchky.org/staff/bio.php?doc_id=50353
3/12 - 718 switched from reg 2 to hopkins only
2/6/2014 - posted
Started 11/8/2013
Started 11/8/2013
Genovese - http://www.mchky.org/staff/bio.php?doc_id=35646&sub= Lewis - http://www.mchky.org/getpage.php?name=bracken_lewis Holt - http://www.mchky.org/getpage.php?name=drholt Napier - http://www.mchky.org/getpage.php?name=dr.napier_page Newman - http://www.mchky.org/staff/bio.php?doc_id=50353
Genovese - http://www.mchky.org/staff/bio.php?doc_id=35646&sub= Lewis - http://www.mchky.org/getpage.php?name=bracken_lewis Holt - http://www.mchky.org/getpage.php?name=drholt Napier - http://www.mchky.org/getpage.php?name=dr.napier_page Newman - http://www.mchky.org/staff/bio.php?doc_id=50353
3/12 - 718 switched from reg 2 to hopkins only
2/6/2014 - posted
Started 11/8/2013
Started 11/8/2013
Genovese - http://www.mchky.org/staff/bio.php?doc_id=35646&sub= Lewis - http://www.mchky.org/getpage.php?name=bracken_lewis Holt - http://www.mchky.org/getpage.php?name=drholt Napier - http://www.mchky.org/getpage.php?name=dr.napier_page Newman - http://www.mchky.org/staff/bio.php?doc_id=50353
Genovese - http://www.mchky.org/staff/bio.php?doc_id=35646&sub= Lewis - http://www.mchky.org/getpage.php?name=bracken_lewis Holt - http://www.mchky.org/getpage.php?name=drholt Napier - http://www.mchky.org/getpage.php?name=dr.napier_page Newman - http://www.mchky.org/staff/bio.php?doc_id=50353
3/12 - 718 switched from reg 2 to hopkins only
2/6/2014 - posted
Started 11/8/2013
Started 11/8/2013
Genovese - http://www.mchky.org/staff/bio.php?doc_id=35646&sub= Lewis - http://www.mchky.org/getpage.php?name=bracken_lewis Holt - http://www.mchky.org/getpage.php?name=drholt Napier - http://www.mchky.org/getpage.php?name=dr.napier_page Newman - http://www.mchky.org/staff/bio.php?doc_id=50353
Genovese - http://www.mchky.org/staff/bio.php?doc_id=35646&sub= Lewis - http://www.mchky.org/getpage.php?name=bracken_lewis Holt - http://www.mchky.org/getpage.php?name=drholt Napier - http://www.mchky.org/getpage.php?name=dr.napier_page Newman - http://www.mchky.org/staff/bio.php?doc_id=50353
3/12 - 718 switched from reg 2 to hopkins only
2/6/2014 - posted
Started 11/8/2013
Started 11/8/2013

Most Read This Week (Site-Wide)

July 28, 2014 3183

Madisonville Woman Arrested for Being a…

in Top Stories by Madisonville Police Department
July 28, 2014 2806

Madisonville Man Arrested for Endangering…

in Top Stories by Madisonville Police Department
July 30, 2014 2640

UPDATE: Waide Responds to Allegations of…

in Top Stories by Rita Dukes Smith, SurfKY News Director
July 28, 2014 2355

Disagreement Over Killing Snake in House…

in Top Stories by Madisonville Police Department
July 30, 2014 1703

UPDATE: Muhlenberg Man, Woman Arrested in…

in Top Stories by Sheriff Curtis McGehee

Most Read Stories from Hopkins County

July 28, 2014 3183

Madisonville Woman Arrested for Being a…

in Top Stories by Madisonville Police Department
July 28, 2014 2806

Madisonville Man Arrested for Endangering…

in Top Stories by Madisonville Police Department
July 28, 2014 2355

Disagreement Over Killing Snake in House…

in Top Stories by Madisonville Police Department
July 28, 2014 1642

Two Injured in Vehicle Collision on…

in Top Stories by William Roundtree
July 28, 2014 1633

Madisonville Man Arrested for Assault,…

in Top Stories by Madisonville Police Department

Most Read Stories from Owensboro

July 28, 2014 978

Zuberer Takes Over at Quarterback for…

in News by Steve LeMaster
July 28, 2014 894

Dont Miss Out on a Howl of a Good Time

in News by Brittni Bunn
July 28, 2014 756

Instant Admissions Day is Aug. 1, 2014

in News by Bernie Hale
July 29, 2014 563

Happenings and Meetings - Daviess County

in News by Owensboro-Daviess County Convention & Visitors Bureau
July 28, 2014 404

Prosecutors Mull Over Whether to Charge…

in Top Stories by Dennis Beard, SurfKY News

Most Read Stories from Muhlenberg County

July 30, 2014 1703

UPDATE: Muhlenberg Man, Woman Arrested in…

in Top Stories by Sheriff Curtis McGehee
July 28, 2014 1263

Foot Pursuit Ends with Arrest

in Top Stories by Christopher Rogers
July 28, 2014 1172

Boys of Broad to Launch Video at Cinema 4

in Top Stories by Paul McRee, SurfKY News
July 29, 2014 1113

Muhlenberg District Court Fines Handed…

in Top Stories by Charles W. Riley II, SurfKY News
July 29, 2014 1001

McLean County Man Charged for Alleged…

in Top Stories by Sheriff Curtis McGehee

SurfKY News Group, Inc. Central Office & Printing Division
1125 Nebo Rd.  •  Madisonville, KY 42431  •  270.452.2249 (fax)
Main Number: 270.452.2727 (phone)  •  Printing Division Direct Line: 270.821.8600 (phone)

SurfKY Owensboro News Bureau
920 Frederica St. / Suite 210  •  Owensboro, KY 42301  •  270.683-8060 (phone)


Contact a member of our staff: www.surfky.com/contact
Copyright © 2014 SurfKY News Group, Inc.  •  Terms of Use  •  Site Map

social 06social 21social 22social 04social 03