Touchscreen: technology, types, history and common uses

Touchscreens are used as information monitors, for example at trade fairs, for orientation in large department stores, for operating smartphones or for timetable information at railway stations. From time to time, touchscreens can also be found in the shop windows of pharmacies or tour operators, which can be used to call up detailed information. In addition, touchscreens are used in slot machines and arcade games. They are also often used to control machines in industry (industrial PCs), in particular because they are less susceptible to dirt than other input devices such as keyboards. Some banks have ATMs with touchscreen displays. In banks, they are increasingly used for transfer terminals, with SAW (Surface Acoustic Wave) technology being used because it is relatively vandal-proof. Due to its glass surface, it does not scratch and damage as quickly as, for example, resistive systems with ITO foil as a surface.

Touch screen terminals that are used for public information dissemination are called point of interest (POI) or kiosk systems in the IT industry. Terminals that are used for sales are called point of sale or abbreviated POS. Contrary to the high expectations of the economy and the IT industry, the latter have only gained limited acceptance. The reasons for this, apart from the maintenance effort for the devices, are often the lack of adaptation of the software to the special operating conditions of the touch screen devices or often simply the unergonomic and unattractive software and lack of benefit for the operators.

In newer, modern cars, multifunction displays are increasingly being designed as touchscreens. New technologies even offer electronically generated, tactile perceptibility here.

In the meantime, touchscreens have become widespread in home systems, especially in the field of PDAs, tablet PCs, smartphones, digital cameras and in the game consoles Nintendo DS, PlayStation Vita and Wii U. The input pens (also: stylus) used in the past due to the small screens and the user interfaces not adapted to them are quite unergonomic and have long prevented the breakthrough of touchscreens in this area. Only with the projected capacitive systems (first in the LG Prada) has this changed permanently.

A touchscreen does not need to be mounted in front of a display, it can also be used as a replacement for a membrane keyboard. For this purpose, a printed (polyester) foil is applied behind the touchscreen (at the place where the computer screen normally sits). There are various approaches to detach touchscreens completely from physical monitors in order to also make projections of user interfaces usable interactively. An example of this is the "Virtual Touchscreen" from Siemens, which has since been discontinued, or various systems from the Fraunhofer-Gesellschaft.

These systems use several techniques to compensate for each other's disadvantages.

• Samsung Galaxy Note and successor
• Capacitive technology is used for hand input and inductive for the S-Pen, with inductive technology having increased priority.
• Microsoft Surface Pro
• iPad Pro
• Various graphics tablets in the medium to higher price range
• Pen is prioritized over hand to allow undisturbed writing

Application examples for optical touch screens

• Measuring devices
• Bank terminals
• HP-150
• Sony PRS-650 eReader
• Kindle Touch
• Tolino Shine
• Evoluce ONE (optical sensors track an unlimited number of touches on or above the surface)