Write head apparatus for recognizing magnetic characters and method therefor
US4922086A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 19, 1987 |
| Grant date | May 1, 1990 |
| Priority date | — |
| Expiry date | Oct 19, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/084
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for recognizing characters printed in magnetic ink on a document has a write head including a permanent magnet and soft iron pole pieces curving arcuately from opposite poles of the magnet to juxtaposed ends forming a gap underlying a curved, nonmagnetic cap along which a document is moved. The pole pieces are unequally magnetized to provide a component of magnetic induction normal to the upper surface of the cap that has opposite signs on opposite sides of the gap and differing peak values, the peak value to one side of the gap being in the range from 450 gauss to 650 gauss and the peak value on the other side of the gap being in the range from 200 gauss to 340 gauss.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.