Process and apparatus for identification of objects
US4134538A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1977 |
| Grant date | Jan 16, 1979 |
| Priority date | — |
| Expiry date | Mar 16, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B13/2402
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
An apparatus and process for identifying objects marked by a magnetic band or thin filament comprising detecting the passage of the magnetic band in a detection zone comprising a framework having an excitation coil fed with alternating current to produce an alternating magnetic field and a detecting coil balanced with the excitation coil such that no signal normally will appear in the absence of a magnetic body in proximity to the framework. The passage of an object carrying a magnetic band in proximity to the framework producing for each alternation of the excitation field an unbalance in a detecting circuit and the appearance of a signal which is fed to apparatus for the detection and measurement of the phase of the signal with respect to the excitation field. The magnetic band is selectively divided at variable predetermined locations by cuts of variable predetermined extent such that at the time of passage of the bands proximate the detection zone, signals of variable amplitudes are also produced, the decoding of the signals being effected in the detection apparatus by measurement of their amplitude.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.