capacitive touchscreen, PCAP multitouch

Multi-touch screens, which are used in the mobile and industrial environment, usually use the "projected capacitive touchscreen" technology, which is also known under the designations PCT (ProjectedCapacitive Touch) or in short: ProCap or PCAP is known.
In contrast to resistive touchscreens, which react to pressure by means of a plastic membrane, PCAP versions have a protective glass pane (cover lens) on the front and back, which also ensures high resistance and good visual representation.

The excellent optical impression is enhanced by the high light transmission of the cover lens. In contrast to the plastic protective film on the analogue resistive front cover, this is significantly higher. A particular advantage arises when the touch screen cover lens and the LCD behind it are "cast" together. The so-called "bounding". There are several performances of this. Full surface or just around the edge. Especially with regard to the ingress of dirt particles between the touch and LCD, this type of bonding offers an extreme advantage. But even with extremely fluctuating temperatures, the bounding can prevent the formation of condensate.

FORSIS has integrated the PCAP touchscreens into its offering. The series PROFI MT and EXPERT SBC MT are equipped with it.

High-quality and high-contrast LED backlight displays in widescreen format 16:9 are used for this. These are offered by FORSIS in the sizes 18.5" - 21.5" -24" and 27". WIN10 and WIN11 are clearly preferred as operating systems. The support of the common touch controllers works smoothly.

In connection with a suitable viewer, the employees can then very quickly and conveniently switch back and forth between several applications or rotate, slide and zoom complex CAD objects using simple two-finger gestures.

Because the touch sensor is securely located on the back of the cover glass, operation can be carried out on the glass surface without wear.
In order to achieve a particularly high degree of robustness, the sensor is often firmly glued to the protective glass and the LED display. This "optical bonding" prevents the ingress of dust and moisture. If necessary, particularly strong protective glasses can also be used.

Another advantage of the capacitive touch screen PCAP compared to other multi-touch technologies is the high degree of creative freedom. The protective glass can extend over the entire front and form a consistently smooth, elegant and easy-to-clean surface, similar to smartphones and tablets.
In this case, all parts surrounding the display are covered by a layer of paint printed on the back of the cover glass.

Complex calibration: who does it?

In order to function properly, the PCAP touchscreen must be precisely calibrated. This is by no means trivial, because its capacitive field constantly acts outwards. All environmental influences such as front glass, metal housing and display must be filtered out using special processes.
In addition, the touchscreen should usually be adjusted so that it can be operated even with thick leather gloves. This complex task is usually taken on by the manufacturers and solution providers.

FORSIS also uses its specific know-how to relieve the user of any setup work before delivery. In addition to the calibration, this also includes the installation of the necessary touch drivers. However, this is only required for Microsoft Windows XP and Windows 7, because the drivers are included as standard from Windows 8 onwards.
In this way, all FORSIS devices with a multi-touch function are delivered to the customer fully set up and only need to be in the best plug & Play-style to be connected.