Ampex Corporation

Western Digital (fremont), Inc.

Rex Niedermeyer

Beverley R Gooch

Roger William Wood

Soo-Choon Kang

Beverly R Gooch

Michael Nojaba

A novel method for defining a touch-down power for a head that has a head-based flying height actuator is disclosed and claimed. A linear relationship between power and spacing is derived by fitting to first and second transducer-disk spacings corresponding to first and second electrical powers applied to the head-based flying height actuator. A third spacing between the transducer and the disk is determined when a greater third electrical power is applied to the flying height actuator. An estimated third spacing between the transducer and the disk, corresponding to application of the third electrical power to the flying height actuator, is calculated using the derived linear relationship and the third electrical power. The touch-down power is defined to be substantially equal to the second electrical power if an error between the third spacing and the estimated third spacing is larger than a first threshold.

Method for defining a touch-down power for head having a flying height actuator

A magnetic transducer is batch fabricated from a pair of confronting elongate composite block substrates each formed of a thin cap of non-magnetic material bonded to a much larger block of magnetic material, such as ferrite. An intermediate winding groove is formed in proximate relation to the non-magnetic material along the length of one or both composite block substrates. One (or both) of the substrates is provided with a plurality of parallel spaced V-shaped grooves oriented in a direction perpendicular to the winding groove, wherein adjacent grooves form therebetween track width defining lands. A core layer of high permeability magnetic material, such as Alfesil material, is deposited over the edges whereby magnetic poles are formed of the edges. A gap layer of insulating material is deposited on the edges over the high permeability magnetic material. Two of the composite block substrates are placed with the edges in aligned abutting relation and are assembled by glass bonding. Individual transducers are sliced from the bonded assembly of substrates and are lapped and polished and a coil is added to provide the finished transducers. Alternative embodiments may employ winding and V-shaped grooves in only one composite block substrate with the matching substrate being flat, and/or may employ either rectangular solid or wedge-shaped non-magnetic caps bonded to the ferrite blocks.

Method for manufacturing a composite metal and ferrite head transducer

A magnetic transducer is batch fabricated from a pair of confronting elongate composite block substrates each formed of a thin cap of non-magnetic material bonded to a much larger block of magnetic material, such as ferrite. An intermediate winding groove is formed in proximate relation to the non-magnetic material along the length of one or both composite block substrates. One (or both) of the substrates is provided with a plurality of parallel spaced V-shaped grooves oriented in a direction perpendicular to the winding groove, wherein adjacent grooves form therebetween track width defining [prtopms. A core layer of high permeability magnetic material, such as Alfesil material, is deposited over the edges whereby magnetic poles are formed of the edges. A gap layer of insulating material is deposited on the edges over the high permeability magnetic material. Two of the composite block substrates are placed with the edges in aligned abutting relation and are assembled by glass bonding. Individual transducers are sliced from the bonded assembly of substrates and are lapped and polished and a coil is added to provide the finished transducers. Alternative embodiments may employ winding and V-shaped grooves in only one composite block substrate with the matching substrate being flat, and/or may employ either rectangular solid or wedge-shaped non-magnetic caps bonded to the ferrite blocks.

Composite metal and ferrite head transducer and manufacturing method

Magnetic record media are described that have an overlying or underlying magnetically saturable high permeability keeper layer in addition to a high coervicity magnetic layer in which magnetic signals are stored. These media are used in magnetic signal processing devices whose transducers are capable of generating a keeper layer-saturating bias flux. In signal reproduction the bias flux magnetically forms a saturation zone in the nature of virtual gap in the keeper layer that directs signal flux between the media and the transducer.

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Newark, CA, United States of America

Rex Niedermeyer