Patent · US Expired

Device with read head for magnetically recorded information

US4984117A · kind A · utility

8Cited by

4References

20Claims

0Family size

Assignee

Mannesmann AG · DE

Inventors

Gunter Nolke · Villingen-Schwenningen, DE
Gunter Ketterer · Unterkirnach, DE
Horst Dyma · Villingen-Schwenningen, DE

Key dates

Filing date	Jul 11, 1988
Grant date	Jan 8, 1991
Priority date	—
Expiry date	Jul 11, 2008

Classification

Technology area (CPC G)Physics
CPC primaryG06K7/087
WIPO fieldComputer technology
WIPO sectorElectrical engineering

Abstract

A device with a read head (16) for magnetically recorded information in electronic data processing plants, in particular in document processing systems, is subject to disturbances by the document operation systems, where modular device units cause magnetic interference fields in the area of the read head (16). In view of the unavoidability of such magnetic interference fields and in order to dispense substantially with a respective shielding for a magnetic read head and in order to generate nevertheless a sufficiently accurate read signal (20), it is disclosed that a read head (16) and a reference head (17) are combined to a read system (33), where the read head and the reference head are respectively associated with the same mechanical and electrical values. The difference signal of the read head (16) and the reference head (17) is composed of the interference signal (19) and a combination of an interference signal and the read signal (20) at the output (21) of the difference circuit (18) and can be fed to a read electronic (23).

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.