Infra-red wireless keyboard system
US5189543A · kind A · utility
37Cited by
4References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 19, 1990 |
| Grant date | Feb 23, 1993 |
| Priority date | — |
| Expiry date | Nov 19, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/114
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A communication system comprising a wireless keyboard for emitting infra-red signals, a receiving unit for converting the infra-red signals to an electrical signal, a tuning and amplifying circuit coupled to the receiving unit for tuning and amplifying the electrical signals, a carrier filtering circuit for removing the carrier component of the input signal, a single-shot circuit coupled to the carrier filtering circuit for converting its input signal to a known code wave form, and a microprocessor for receiving the code wave. The invention allows multiple users to operate their wireless keyboards without interference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.