What Is Projected Capacitance Touchscreen?

In searching for new touchscreen solutions, you may come across the term “projected capacitance.” Based on the name alone, it’s difficult to comprehend what exactly this solution is or how it works. If you’re still scratching your head trying to grasp the concept of projected capacitance, keep reading to learn more about it.

Projected capacitance (abbreviated PCT or PCAP for short) is a variation of capacitive touchscreen technology. As you may already know, capacitive touchscreens consist of an insulator layer (usually glass) that’s coated with some type of transparent conductor material. It registers touches my identifying electrical signals created by the user’s touch. When you press your finger against a capacitive touchscreen, for instance, it causes distortion in the device’s electromagnetic field; thus allowing the device to measure it as capacitance.

Projected capacitance touchscreen devices work in a similar manner as capacitive. The displays consist of  several rows and columns of conductive material (usually indium tin oxide) that’s coated on one or more sheets of glass. While manufacturing methods vary, this is often done by etching the conductive material to create a grid pattern of electrodes. Another commonly used method for creative projected capacitance touchscreens is etching two perpendicular layers of conductive material, each of  which has parallel lines to form of a grid. The device then emits voltage to the grid, creating a standard electrostatic field that can be measured by the respective device. When a user touches the conductive material, it triggers distortion in its electromagnetic field, at which point the point of contact can be identified.

The human body is a natural conductor of electricity, which is essentially how projected capacitance and capacitive touchscreens operate. Touching your finger to the display bridges the gap (so to speak) between the tracks. This interrupts the displays original electromagnetic field, allowing the system to pinpoint exactly where the touch occurred. The key difference between projected capacitance and capacitive, however, is that PCT touchscreens support the use of a stylus or gloves finger. However, high humidity, dust or  sweaty fingers may adversely affect the performance of a projected capacitance touchscreen

Did this give