Tips to Understanding Your Touch Screen

original touch screenIf Justin Bieber songs are all over your playlist, chances are you don’t even remember a time before touch screens; they are just a part of your every-day life, ubiquitous and expected.  To the rest of us, touch screens are still a bit awe inspiring.  ATM machines, cell phones, car navigation systems, retail point-of-sale terminals, monitors and industrial control panels – they are almost everywhere.

Credit the Brits for bringing us touch screen technology.   Historians consider the first touch screen to be a capacitive touch screen invented by E.A. Johnson at the Royal Radar Establishment in Malvern, UK between 1965 – 1967 which he was developing for air traffic control.  However, it wasn’t until 1973 that Bent Stumpe and Frank Beck, engineers with CERN, developed a transparent touch screen that was put to actual use by CERN.

American inventor and University of Kentucky instructor G. Samuel Hurst, PhD developed the transparent resistive touch screen in 1977, still in use today.  Advancements in touch screen technology came in 1977 when Siemens developed the curved touch screen; in 1983 when Hewlett Packard developed the troublesome infrared HP-150 home computer with a touch screen; in 1993 when Apple introduced the Newton PDA and IBM the Simon PDA followed in 1996 by the Palm Pilot PDA (remember those?).

The 2000s brought an explosion of touch screen devices into all facets of manufacturing and daily living, especially Apple’s iconic iPhone in 2007.  Although touch screens are still in their relative infancy, already it is hard to imagine life without them.

We know it’s not magic, so how does touch screen technology actually work?  Keeping it very basic, these are the three major components to touch screen technology:

  • Touch Sensor – a panel with a touch responsive surface based on one of three different types of sensors including resistive (common), surface acoustic wave, and capacitive (used by most smart phones).  The sensors have an electrical current running through them and touching the screen causing a voltage change which signals the touch location.
  • Controller – the hardware that converts the voltage changes on the sensor into signals the device can receive.
  • Software – tells the device what is happening on the sensor and the information coming from the controller and allows the device to react accordingly.

So what’s the difference between resistive and capacitive and which one do you have?

  • Resistive – uses six basic components including a screen base, glass panel, a resistive coating, a separator dot, a conductive cover sheet and a tough top coating.  When a finger or stylus presses down on the top surface, the two metallic layers touch, the surface acts as a pair of voltage dividers with connected outputs. This causes a change in the electrical current. The pressure from your finger causes conductive and resistive layers of circuitry to touch each other, changing the circuits’ resistance, which registers as a touch screen event that is sent to the computer controller for processing.
  • Capacitive – uses a layer of capacitive material (capacitive means it senses anything conductive or that has a dielectric different from that of air and yes, humans are conductive) to hold an electrical charge; touching the screen changes the amount of charge at a specific point of contact.  Capacitive sensors can be constructed of copper, indium tin oxide (most touch phone screens use this type), and printed ink.

Touch screens, even the industrial sort, are easily damaged.  Common touchscreen problems include:

  • Calibration – Touch screens can lose their calibration and may not judge the user’s input correctly, causing incorrect operations requiring the screen to be recalibrated.
  • Dirt and Grease –  Frequent touches cause grease to soon be visible on the screens. If left uncleaned, the grease and dirt damage internal components. Use the cleaning cloth that came with the screen to avoid touch screen repairs.
  • Operation and System – The relatively delicate nature of touch screens and sheer age are often the cause of errors and calibration problems.
  • Hardware – If you’ve ever dropped your smart phone or a POS terminal, you know it doesn’t take much to cause catastrophic damage.  This type of damage can sometimes be repaired but is often “fatal” to the device.Get Fast & Accurate Quotes for Idustrial Touch Screen & Monitor Repair

If you have damaged commercial or industrial touch screens that are no longer under warranty, they can often be repaired.  Seek out an industrial electronic repairs firm that has good experience repairing touch screens, that offers free evaluations and that warranties their work.