Method of operation of touch screens
A touch screen is defined as a touch-sensitive, transparent surface which is as a rule mounted over a display screen. Using a touch screen it is possible by touching it to actively intervene in a programme sequence.
This brings together the mouse function and on-screen keyboard or softkeys in a single dedicated program environment. The fundamental principle is based on only those menu options and information being shown on the display screen which are relevant at any given moment. The user/ operator can touch these directly and does not have to look away from the screen in order to find a specific key combination. Particularly in extreme conditions it is simpler to navigate around an easy to clean touch screen than to work one's way through the operating menu using a mouse and keyboard. This means that there is no need for various different keyboards since differing applications can be adapted using software that is created only once.
Touch screen technologies
When selecting the suitable touch screen technology its advantages and disadvantages must be matched against the requirements of the application. For example, a PCAP touch screen tends to be unsuitable for safety-critical applications since although it is sufficiently robust to withstand environmental influences it can be triggered in the presence of stray electromagnetic radiation. On the other hand, a resistive touch system can easily be scratched. Specialist advice is therefore indispensable.