How Does a Projected Capacitive Touchscreen Work?
Projected capacitive touchscreens have become increasingly popular in recent years. Like other capacitive touchscreens, they are designed to measure a uniform electrostatic field to detect touch commands. When you tap or touch the display interface with a bare finger - or any conductive object for that matter - the voltage will drop. Capacitive touchscreens register this voltage reduction as a touch command. While all capacitive touchscreens use this basic mechanism to detect touch commands, there are several different types of capacitive technology, one of the most popular being projected capacitive.
Projected Capacitive Touchscreens Explained
Also known as PCT or PCAP, projected capacitive is a form of touchscreen technology that's used in smartphones, tablets, human machine interfaces (HMIs) and dozens of other touchscreen devices. It's essentially the same as surface capacitive technology but with a few added upgrades.
Projected capacitive touchscreens, for example, are designed with more electrodes than their surface capacitive counterparts. As a result, they support a greater number of touch commands. Some projected capacitive touchscreens, in fact, support touch commands in thousands of different areas on the display interface.
How Projected Capacitive Touchscreens Work
Although there are different ways to design and manufacture a projected capacitive touchscreen, most feature an X-Y grid of intersecting electrodes. The intersecting electrodes are made of a conductive material that, when exposed to a similar conductive material, allows for a reduction of voltage.
Tapping or touching the display interface of a projected capacitive touchscreen will cause the device's voltage to drop. When a projected capacitive touchscreen is turned on, electricity runs through the X-Y grid of intersecting electrodes. And if you tap or touch the display interface, your finger or stylus will absorb some of the electricity from that area, which the device registers as a touch command.
