Extended time-shared scanning keyboard interface
US5274371A · kind A · utility
25Cited by
4References
2Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1991 |
| Grant date | Dec 28, 1993 |
| Priority date | — |
| Expiry date | Jan 29, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M11/20
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A time-shared scanning technique is employed to detect the maximum keys with a keyboard interface. A detecting signal is transmitted, in turn, to the keyboard interface ports in consecutive clock phases. Since every keyboard interface port is independent of each other port, each can detect and record the status of the keyboard except when activated by the detecting signal to transmit a scanning signal utilized to scan all of the other ports. The number of keys that can be detected by the present keyboard interface is about twice that of the conventional keyboard interface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.