Methods and systems of scanning an input device having multiple key switches
US7849240B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2007 |
| Grant date | Dec 7, 2010 |
| Priority date | — |
| Expiry date | Sep 23, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M11/20
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method of having multiple devices share a circuit's input/output (I/O) terminals includes applying first and second input signals to first and second I/O terminals to generate first and second output signals at the second and first I/O terminals, respectively. The first and second I/O terminals are coupled to first, second, and third devices via a plurality of signal paths. The method determines which, if any, of the first, second, and third devices is activated based on the first and second output signals. In some embodiments, the three devices correspond to three key switches of a keyboard through which a user can enter operation instructions. In some other embodiments, the three devices correspond to three signal receivers, which are controlled by a local or remote signal source that transmits activation signals in a wired or wireless manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.