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Particulate Recording Medium of Ultrahigh Smoothness using Field Gradient

IP.com Disclosure Number: IPCOM000085746D
Original Publication Date: 1976-May-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Romankiw, LT: AUTHOR

Abstract

A particulate recording medium of high smoothness may be obtained, having a high density of magnetic particles, by utilizing the method illustrated.

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Particulate Recording Medium of Ultrahigh Smoothness using Field Gradient

A particulate recording medium of high smoothness may be obtained, having a high density of magnetic particles, by utilizing the method illustrated.

An ultrasmooth tape 10 is disposed between rollers 12 and 14. A magnetic material dispersion roller or applicator 16 applies a magnetic coating to tape 10 prior to its movement through a first pair of poles 18N and 18S, for applying an in-plane field to orient the magnetic particles. The tape 10 is then passed through a magnetic field applied orthogonal to its surface by poles 20N and 20S. The orthogonal field is strong and the tape 10 is made to run close to the surface of pole piece 20N, to provide a very strong field gradient. This field gradient pulls the magnetic particles to the surface of tape 10.

The tape 10 is then passed through an in-plane orienting field produced by poles 22N and 22S. The tape is then dried by an infrared lamp or microwave source 24 prior to passing station 26, which is a wedge equipped with a knife blade shaped jet of pressurized air to gently lift magnetic film 28 off the ultrasmooth master surface tape 10.

The film 28 is then passed through heated lamination rolls 30 and 32 to which a supply of carrier substrate 34 is also applied. The film 28 on substrate 34 is then taken up in pickup spool 36.

The same principle can be used to form films of small surface area by batch techniques on top of optical flats. Consequ...