Back in 2000 we developed and produced the world-wide first capacitive touch screen for industrial mass production use. Widely used on ATM machines, retail point-of-sale terminals, car navigation systems, medical monitors and industrial control panels, it became extremely popular on touch screen handhelds after Apple introduced the iPhone in 2007.
“Capacitive Touch Sensing” is a capacitive detection technique with a simple construction and decoding. This variant uses a light electrical charge that is spread over the entire screen. When you touch the display with your finger, the electrical current is interrupted (otherwise conducted) as your body conducts electricity. The point where this happens is detected by the software. Capacitive screens can be touched in more than one place at once. Unlike most other types of touchscreen, they don’t work if you touch them with a plastic stylus (because the plastic is an insulator and stops your hand from affecting the electric field).
Unlike some other techniques (resistive, infrared, surface wave, etc.) where the sensor is at the front and therefore more vulnerable, projected capacitance (PCAP) technology mounts the sensor foil behind a protective overlay, so that it does not has shortcomings of, for example, resistive touchscreens, which means that they are used in many high-quality and large-scale applications. Due to the attractive features of touchscreens with projected capacitance, there is an increasing number of consumers who want devices that use this technology.
The PCAP touchscreens have a superior multi-touch performance, durability, excellent optical transmissivity (greater than 90%), scratch-resistance, free of aging symptoms, offer high performance in accuracy, power consumption and refresh rate.
The multi-finger touch input and gestures, enables significant improvements to the user interface. Popular gestures such as two-finger pinch and zoom let users zoom in or out on an image. With multi-touch we are able to develop custom gestures, which add value for end users and can be promoted as product differentiators.
The cover lens and touchscreen sensor are complex structures that constitute a touchscreen’s stack-up. The cover lens, the topmost layer, can be made of a variety of materials. Glass gives the high-end finishing and PC (poly carbonate) or PMMA (poly methyl methacrylate AKA Acrylic or plexi glass) instead of glass is most of the time cheaper, shatter-resistant but may lower signal sensitivity.
De ClickTouch standard PCAP solutions
Ever since ClickTouch developed the ﬁrst PCAP-solution for the industrial market in 2000, it has offered various capacitive touch solutions. The world is continuously evolving, thus the needs for standard solutions increase more and more.
The CTG ‘Touch on Glass’ is based on an innovative Glass on Glass construction. The (standard) cover glass is optically laminated with the capacitive ‘ITO on glass’ part. This ensures an extremely high transparency and simple construction.
Clicktouch offers all the needed support in integrating and the custom programming of the touchscreen controller. It impacts performance, functionality, and the user experience by how well it handles processing of noise-sensitive signals. At a minimum, a controller needs high-quality analog front ends, built-in noise handling capabilities, and sophisticated processing algorithms. By providing a high signal-to-noise ratio (SNR) and effective noise handling, a controller can compensate for the signal-strength degradation that comes from noise sources.
We use tailor-written algorithms compatible with the sensors being used. The programming of the controller also determines which advanced features, such as water tolerance, water operation or glove control, the system can support.