LONDON Hal Philipp, CEO of Quantum Research Group, the charge-transfer (QT) capacitive touch technology developer, has been granted both US and European patents for a technology that eliminates ambiguity between adjacent keys in touch keypads and keyboards.
The technique, known as adjacent key suppression (trademarked AKS), uses an iterative technique that repeatedly measures a detected signal strength associated with each key, compares all the measured signal strengths to find a maximum signal change, 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 (Southampton, U.K.) patented charge-transfer sensing technology but is applicable to other kinds of non-bi-stable touch sensors including ones 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. AKS ensures that the key which is covered most by the fingertip is determined to be the required one and that there is no false triggering of nearby keys.
Hal Phlipp, CEO of Quantum Research demonstrates his new patents on adjacent key suppression for touch panels.