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Active Double Gap Head for High Resolution Magnetic Recording

IP.com Disclosure Number: IPCOM000035219D
Original Publication Date: 1989-Jun-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 78K

Publishing Venue

IBM

Related People

Ashar, KG: AUTHOR [+2]

Abstract

This article describes a new head structure which has more than one active gap. A double-gap head structure is analyzed by computer analysis for 2-7 code recording. The analysis results show about 33% improvement in high frequency resolution over the normal single-gap ferrite head. It is also shown that a double-gap head gives a lower peak-shift than a single-gap head at relatively high density. (Image Omitted)

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Active Double Gap Head for High Resolution Magnetic Recording

This article describes a new head structure which has more than one active gap. A double-gap head structure is analyzed by computer analysis for 2-7 code recording. The analysis results show about 33% improvement in high frequency resolution over the normal single-gap ferrite head. It is also shown that a double- gap head gives a lower peak-shift than a single-gap head at relatively high density.

(Image Omitted)

The construction of a double-gap head is illustrated in Figs. A and B. In Fig. A, 1 is made of ferrite, such as MnZn, NiZn or a magnetically equivalent material. 3 is the main gap length of 0.2 to 1 um. The material for the gap may be glass or other non-magnetic type to assure rigidity on air-bearing surface 5. 4 is an auxiliary gap length of 0.01 to 0.1 um. 2 is a magnetically active, preferably high Bs material layer, such as permalloy, sendust or an amorphous type usually deposited by sputtering, evaporation or ion beam deposition techniques. The current in coil 6 will provide a writing field and also signal output during reading. Fig. B illustrates a conceptually similar head but the core is divided in two parts separated by the auxiliary gap material. This arrangement eases fabrication of the head and allows automated coil winding.

Figs. C and D are the performance comparisons of a conventional single-gap head and a proposed double-gap head. The second gap length of a double-gap head used...