Projective capacitive (PCT)

Inno/Zytronic/3M

Projected Capacitive Touch (PCT; also PCAP) technology is a variant of capacitive touch technology. All PCT touch screens are made up of a matrix of rows and columns of conductive material, layered on sheets of glass. This can be done either by etching a single conductive layer to form a grid pattern of electrodes, or by etching two separate, perpendicular layers of conductive material with parallel lines or tracks to form a grid. Voltage applied to this grid creates a uniform electrostatic field, which can be measured. When a conductive object, such as a finger, comes into contact with a PCT panel, it distorts the local electrostatic field at that point. This is measurable as a change in capacitance. If a finger bridges the gap between two of the "tracks", the charge field is further interrupted and detected by the controller. The capacitance can be changed and measured at every individual point on the grid (intersection). Therefore, this system is able to accurately track touches. Due to the top layer of a PCT being glass, it is a more robust solution than less costly resistive touch technology. Additionally, unlike traditional capacitive touch technology, it is possible for a PCT system to sense a passive stylus or gloved fingers. However, moisture on the surface of the panel, high humidity, or collected dust can interfere with the performance of a PCT system. There are two types of PCT: mutual capacitance and self-capacitance.

Untempered – Tempered glass

Both types of glass are safety and when broken up, they still stay together in one piece. The untempered glass breaks into single wide and sharp edges. The tempered glass breaks into small pieces with safe edges.

Glass bonding – dual glass

Make integration of the front (cover) glass and touch sensor into one compact part possible to reduce sunshine reflections and improve anti-vandal resistance.

Anti-glare (AG) – anti-reflective (AR) coating

The additional anti-glare layer features light scattering with a matt surface, which reduces glare at the cost of decreased contrast and colour intensity.
The anti-reflective coating is a type of optical coatingapplied to the glass surface to reduce reflection. This improves the efficiency of the system since less light is lost compared with AG. The reduction of reflections also improves the contrast of the image and AR is the first choice for outdoor applications exposed to sunshine.

For more information please contact us: info@prtronic.at