Planer reader of non-erasable magnetic media and local permeability
US7233142B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 2, 2004 |
| Grant date | Jun 19, 2007 |
| Priority date | — |
| Expiry date | May 1, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/145
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A planer reader and method of probing the magnetic permeability of a material using a magnetic flux circuit comprises a substrate; a near-circular soft magnetic layer adjacent to the substrate; a gap configured in the soft magnetic layer, wherein the gap creates an opening between two ends of the soft magnetic layer, and wherein the gap is configured to align with a material located a distance from the soft magnetic layer; a magnetic flux generator adapted to provide magnetic flux to the material; and a magnetic sensor adapted to measure the magnetic flux traversing the material. The circuit further comprises an insulator covering the soft magnetic layer, the gap, the magnetic flux generator, and the magnetic sensor. The magnetic flux generator comprises a magnet or a magnetic coil proximate to the soft magnetic layer. Moreover, the soft magnetic layer comprises a soft ferromagnet. In one embodiment, the substrate is flexible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.