How do Touch Screens Work?

To the untrained eye touch screens are a marvel. You touch a part of the screen and it recognizes that you touched it and then performs an action. In our case, it rings up an item.

What you might not know is that there are different types of touch screen technologies and each has a purpose. 

The Basics

In their simplest form a touch screen is just like a regular monitor except that it has an overlay over the screen or a special bezel surrounding the screen. Touch screens start off as a regular computer monitor and are modified to send a signal to the computer when they are touched.

The signal comes from different sensors in the overlay or bezel and transmits this via a cable to the computer. The connection is serial or USB and uses the standard connections on the computer.

From here the signal is interpreted by a touch driver that then translates the signal into a mouse signal. That’s right. When you touch the screen the computer thinks that you are using a desktop style mouse.

With a touch screen you can run any Windows program where a left mouse or double click would be used with a desktop mouse. Games and other software will not know the difference between your touch and a left mouse click.

About the only thing you cannot do is a right mouse click. So functions that are accessed by clicking the right mouse button are excluded with a touch driver.

The Technology

There are different technologies used for touch screens. Each has its purpose, reason for use and specialty.

Capacitive Touch

Capacitive touch works off the static electricity in your body. Therefore, you must be alive to use it.

Capacitive touch works best when your hands are dry, not wet. The screen also needs to be relatively clean and free from debris or dirt.

Capacitive touch requires a thin overlay and new bezel on the monitor. However, the overlay is very thin and easy to see through.

With capacitive touch you may not use gloves, pencils, pens or other devices to use the touch terminal. Also, people with long fingernails may have problems with a capacitive touch screen.

Resistive Touch

Resistive touch works when 2 overlays are placed onto the monitor and contact is made by depressing the overlays together. You truly are making contact between the 2 overlays and a signal is then sent with the location of the touch.

The overlays are very thin but can be seen if you look closely.

This technology works well in environments where people have wet hands and does work with gloves, pencils and pens. However, sharp objects can and will cut the overlays and cause the touch screen not to work.

Infrared Touch

This technology is a little more expensive than Capacitive or Resistive but is far more reliable than either of those technologies.

Infrared touch requires that a special bezel be placed onto the monitor. A series of thin infrared beams are then crisscrossed over the screen. Touching the screen then breaks these beams letting the touch driver know the exact location of the touch.

Infrared touch works in almost any environment and with gloved hands, pencils, pens and even keys. Since you are touching the glass of the monitor you stand less chance of scratching the monitor.

Acoustic Pulse Recognition

Acoustic Pulse Recognition (APR) is the latest in technology and was released in 2007 by Elo Touch. Designed specifically for the point of sale industry it works off the sound vibration made when the screen is touched.

APR will work with wet hands, gloves, pencils, pens and keys. Almost anything that can touch the screen can activate the touch.

Administrator

www.MyPosTerminal.com
www.MyPosPrinter.com