Apparatus for and method of detecting a coded magnetic thread
US7516893B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 25, 2006 |
| Grant date | Apr 14, 2009 |
| Priority date | — |
| Expiry date | Jan 12, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07D7/04
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A method of detecting a coded magnetic thread is provided that includes sensing the response of a magnetic field detector as a thread passes the detector, the response varying from an initial magnitude in first and second senses to exhibit a first peak, and then in the first sense to exhibit a second peak; comparing the response with first and second thresholds disposed about the initial magnitude in the first and second senses respectively; and indicating the passage of a code element of the thread when the response passes the second threshold and then the first threshold in a predetermined manner characterized in that the first threshold is adjusted in accordance with a first predetermined algorithm based on the magnitude of the first peak. The first predetermined algorithm adjusts the first threshold so that the magnitude of the first threshold is the average of a predetermined number of preceding first peaks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.