Touch technologies for your business and their varieties

Sergiy Babych
Tecnología
24 feb 2010
25

Touch screen (from English touch screen) is a coordinate device that allows you to select the desired data element, menu, or enter data into a computer by touching (with a finger, stylus, etc.) an area of the monitor screen.

We are increasingly using touch technologies to pay for various types of services. Their use is gradually being introduced not only for any financial transactions, but also in the field of information, management, games, advertising, etc. They are distinguished by the most convenient interface, understandable and simple for any user. Touch screens have become as familiar as a button and a wheel.

It is necessary to immediately distinguish between a touch screen and a display. The latter performs the function of displaying information, but the touch screen is responsible for data input. It is the touch screen that perceives actions and converts them into commands for the machine processor.

Some history

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First generation AccuTouch touch screen

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Second-generation AccuTouch touchscreen with patented "T" pattern for linearization, eliminating hand-soldered diodes around the edge.

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The first personal computer equipped with a touch screen was the HP-150

The first personal computer equipped with a touch screen was the HP-150, released by Hewlett-Packard in 1983. To track keystrokes, a network of infrared beams was used, organized in front of a regular CRT screen. The system was a 21x14 matrix, composed of infrared LEDs and photodiodes.

Modern touch technologies

Various sources distinguish six (sometimes seven) technologies by which touch screens are produced. But upon closer examination, you can see that these devices use only four basic principles.

That is why there are problems with choosing a touch screen - the variety of modern technologies allows you to choose the option that will satisfy you in all respects. And before buying a touch screen, you need to familiarize yourself with all the varieties of touch monitors.

As already mentioned, touch screens are based on four principles: resistive, capacitive, acoustic and infrared.

Resistive touch technology. The screen consists of a glass panel hidden behind a layer of plastic. Between the plastic and the screen are micro-insulators that reliably isolate the conductive surfaces, and with a light touch these surfaces are connected. The controller registers these changes and converts them into coordinates on the computer's system bus.

Characteristics:

no vandalism protection device (the top plastic layer is easily damaged by a metal object, and the screen simply breaks);
temperature - from -10 to +50;
not afraid of bright sunlight;
not afraid of water and condensation;
can be used with gloves.

Capacitive technology. The screen consists of a uniform conductive layer applied to a glass panel. Electrodes located around the edges of the panel distribute low voltage across the conductive layer and create a uniform electric field. Touching the screen seems to "attract" current from the corners of the screen, and the controller measures the changes in current and calculates the location of the touch.

Characteristics:

has a vandal-proof device;
temperature from -15 to +70;
not afraid of bright sunlight;
does not perceive the touch of fingers in gloves;
not afraid of water and condensation.

Acoustic technology. Piezoelectric transducers are located on the glass panel of the screen. They receive an electrical signal from the controller and convert the signal into an acoustic wave. It is distributed along the perimeter of the screen, and receiving sensors collect the reflected wave and direct it back to the piezoelectric elements. The wave becomes an electrical signal registered by the controller, and when you touch the screen, part of the surface wave is absorbed. The received signal allows you to determine the coordinates of the touch.

Characteristics:

no vandal-proof device;
temperature from -20 to +60;
not afraid of bright sunlight;
not afraid of water and condensation;
does not perceive the touch of fingers in gloves.

Infrared technology. The screen is a thin frame with LEDs installed on the inside, covered with a transparent plate. The LEDs create a grid of infrared rays, and when a touch overlaps one or more From these, the controller calculates the coordinates.

Characteristics:

no vandal-proof device (plastic is easy to damage);
temperature from -20 to +70;
reacts poorly to bright sunlight;
not afraid of water and condensation;
can be used with gloves.

Resistive technology is the most popular due to its availability, high sensitivity and immunity to dust and moisture. Its disadvantages are low screen brightness,