Browse Prior Art Database

Magnetic Media Copying

IP.com Disclosure Number: IPCOM000089894D
Original Publication Date: 1968-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Hobgood, GW: AUTHOR [+2]

Abstract

The apparatus establishes predetermined digital flux patterns in a magnetic media from an etched ferrous master plate. Flux patterns are established in the oxide layer of copy media 1 which consists of an oxide layer coated on a suitable base material. These flux patterns are established by positioning adjacent to media 1 assembly 2 containing master ferrous plate 3, a layer of high-permeability material, such as Hy Mu 80, etched in the desired digital patterns. Assembly 2 further includes insulating sheet 4 and copper sheet 5. In operation, current is passed through sheet 5 to establish flux lines 6 which can alternatively be obtained by selectively arranged permanent magnetic elements.

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Magnetic Media Copying

The apparatus establishes predetermined digital flux patterns in a magnetic media from an etched ferrous master plate. Flux patterns are established in the oxide layer of copy media 1 which consists of an oxide layer coated on a suitable base material. These flux patterns are established by positioning adjacent to media 1 assembly 2 containing master ferrous plate 3, a layer of high- permeability material, such as Hy Mu 80, etched in the desired digital patterns. Assembly 2 further includes insulating sheet 4 and copper sheet 5. In operation, current is passed through sheet 5 to establish flux lines 6 which can alternatively be obtained by selectively arranged permanent magnetic elements. At positions where the high-permeability material is retained, the flux is shunted and very little flux passes through the oxide layer of media 1. In some cases it is desirable to previously saturate the oxide layer on media 1 so that a full flux reversal from one magnetic state to the other is obtained. This is done with a permanent magnet, as an example. The technique offers considerable accuracy in bit placement on the copy media if photographic reduction of a larger scale master is used to generate the etched pattern. Thus, the apparatus can be used for generating master alignment media on any prerecorded information which is to be generated many times.

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