Rapid signal validity checking apparatus
US4864158A · kind A · utility
67Cited by
9References
2Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1988 |
| Grant date | Sep 5, 1989 |
| Priority date | — |
| Expiry date | Jan 28, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/0008
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention relates to an improved signal reader for reading signals from transponders placed on moveable objects such as ship containers, automobiles or railroad cars. The reader sends out a continuous signal, which is modified by the information contained in the transponder attached to the moveable object. Multiple antennas, each of which receive separate signals, may be multiplexed at the reader. The improved circuit of the invention provides quick recognition of the receipt of a valid signal from a transponder or, in the alternative, the absence of such a valid signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.