Mobile object identification system
US5525991A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 1994 |
| Grant date | Jun 11, 1996 |
| Priority date | — |
| Expiry date | Feb 24, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07F7/1008
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The primary object of the invention is to realize a mobile object identification system of simple construction and low cost, in which the responding unit attached to a mobile object writes data only once when it receives write signals repeatedly in communication with antenna units. When a tag unit (responding unit) receives a write signal from a writing antenna unit, it writes data to the data memory when a completion flag is cleared. When the data is first written, a control circuit sets the completion flag. Then, if the tag unit receives additional write signals in the communication area of the same writing antenna unit, the control circuit invalidates the data write command on the ground that the completion flag is set, thereby preventing duplicate data writing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.