System for reading magnetic information provided with a thermal asperity detector
US5956197A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1997 |
| Grant date | Sep 21, 1999 |
| Priority date | — |
| Expiry date | Apr 7, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/40
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to a system for reading magnetic information, comprising at least one read head H0 provided with two magnetoresistive rods (MR10, MR20) whose electrical resistivities (RMR10, RMR20) vary in mutually opposite senses when they are subjected to a same variation in magnetic field. According to the invention, the reading system comprises a detection module DET which comprises two resistors R of substantially the same resistance value, an amplifier A having one input and one output, and a comparator Cp having two inputs and one output. Each resistor R has a terminal connected to the output terminal (M10, M20) of one of the magnetoresistive rods, while the other terminals of the resistors are interconnected so as to form a common junction point NC. The voltage of the common junction point NC is amplified and compared with a reference voltage Vref by the comparator Cp. The output of the comparator Cp signals an accidental contact between the read head and a foreign body or asperity which may be present on the surface on which the information is stored.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.