History of Projected Capacitance Touchscreen Technology

Origins and History of Projected Capacitance

Some people assume that projected capacitance is a new form of touch-sensing technology, but this isn't necessarily true. It's actually been around for several decades, with some of the earliest examples dating back to the mid-1980s. According to Wikipedia, brothers Ronald and Malcolm Binstead developed projected capacitance technology in 1984. The brotherly duo were able to create a projected capacitance touchpad featuring 16 individual keys. Pressing any of these keys caused the user to absorb some of the keypad's electrostatic charge - much like a traditional capacitive touchscreen device.

The Binstead brothers were able to create a highly accurate and responsive projected capacitance device by updating the idle, "no touch" position for each key and reducing problems associated with dirt and debris. Furthermore, they designed their projected capacitance keypad so that the value of each key was relative to the value of the other keys.

A defining feature that distinguishes projected capacitance touchscreen devices from traditional capacitive touchscreen devices is that the former can identify touches from a gloved finger or stylus. This is a huge benefit that allows for greater versatility. While traditional capacitive touchscreen devices only identify touches from a bare finger, projected capacitance devices support touch commands from a bare finger, gloved finger or even a stylus.