Hal Philipp, CEO of Quantum Research Group, was granted US and European patents for a technology that eliminates ambiguity between adjacent keys in touch keypads and keyboards. The AKS (adjacent key suppression) technique uses an iterative technique that repeatedly measures a detected signal strength associated with each key, compares all of the measured signal strengths to find a maximum signal change, and then determines that the maximum signal change comes from the user-selected key.
AKS then suppresses or ignores signals from all other keys as long as the signal from the selected key signal change remains above a nominal threshold value.
The technique was developed for keyboards using Quantum's patented charge-transfer sensing technology. However, it is applicable to other kinds of non-bi-stable touch sensors, including those based on piezoelectric sensors.
It is particularly important for smaller keyboards and keypads, such as those found on mobile phones and remote controls, where the user's fingertip may be large enough to cover more than one key at a time.