Adjacent Key Suppression Receives US Patent

Hal Philipp, Quantum CEO, has been assigned US patent number 6,993,607 for Adjacent Key Suppression™, a technology that eliminates ambiguity between adjacent keys in touch keypads and keyboards. The technique, known as 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, then determines that the maximum signal strength 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 remains above a nominal threshold value.

The technique was developed for keyboards using Quantum's patented charge-transfer sensing technique but is applicable to other kinds of non-bi-stable keyboards 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.

A number of other algorithms are possible. For example, simultaneous activation of more than one key can be avoided by ensuring that the first key touched is accepted as the intended key.

Formal publication will be 31 January 2006.

Quantum also has two other AKS-related patents currently under review by the patent office.