Back to results
US 5,844,749 AGranted
Thin film magnetic head with an induction type magnetic transducer for suppressing sub-pulses
AssigneeTDK Corporation
InventorsMasanori Sakai, Makoto Yoshida, Kazumasa Fukuda, Mikio Matsuzaki
Life of this patent
Estimating the term…
Abstract
In the thin film magnetic transducer element, the front end portions of the upper pole piece and the lower pole piece are partially removed in such a manner that they align non parallel to the gap film on he opposite sides of the gap film. The condition .DELTA.P1>.DELTA.P2 is satisfied when the difference between the maximum pole length P1max and the minimum pole length P1min of the lower pole piece is .DELTA.P1 and the difference between the maximum pole length P2max and the minimum pole length P2min of the upper pole piece is .DELTA.P2. The sub pulse is reduced and so the partial response method can be employed.
Claims10
A thin film magnetic head provided with a slider and a thin film magnetic transducer element wherein:
- said slider is constituted of non-magnetic material and is provided with an air bearing surface on a side opposite a recording medium;
- said thin film magnetic transducer element is provided with a thin film magnetic circuit that includes a lower magnetic film, an upper magnetic film and a coil film, and is positioned on said slider, and is covered with a protective film formed of insulating material;
- said lower magnetic film and said upper magnetic film have a lower pole piece and an upper pole piece opposite each other across a gap film with front end surfaces of said lower pole piece and said upper pole piece emerging on said air bearing surface;
- said lower pole piece is provided with a first depressed area and said upper pole piece is provided with a second depressed area and said first and second depressed areas are formed by partially removing said front end surfaces along with the surfaces of said slider and said protective film on the opposite sides of said gap film in such a manner that the end edges that are formed at the boundary with said front end surfaces are non parallel to said gap film;
- and
- when a maximum pole length of the front end surface from the gap film to the first depressed area at a first edge of the lower pole piece and a minimum pole length of the front end surface from the zap film to the first depressed area of a second edge opposite the first edge of the lower pole piece are P1max and P1min respectively, and the difference between the maximum pole length P1max and the minimum pole length P1min is .DELTA.P1, and when a maximum pole length of the front end surface from the gap film to the second depressed area at a first edge of the upper pole piece and a minimum pole length of the front end surface from the gap film to the second depressed area at a second edge opposite the first edge of the upper pole piece are P2max and P2min respectively, and the difference between the maximum pole length P2max and the minimum pole length P2min is .DELTA.P2, the condition .DELTA.P1>.DELTA.P2 is satisfied.
3 more elements
A thin film magnetic head provided with a slider and a thin film magnetic transducer element wherein:
- said slider is constituted of non-magnetic material and is provided with an air bearing surface on the side that faces opposite the medium,
- said thin film magnetic transducer element is provided with a thin film magnetic circuit that includes a lower magnetic film, an upper magnetic film and a coil film, and is positioned on said slider, and is covered with a protective film formed of insulating material;
- said lower magnetic film and said upper magnetic film have a lower pole piece and an upper pole piece respectively that face opposite each other across a gap film with front end surfaces of said lower pole piece and said upper pole piece emerging on said air bearing surface,
- said lower pole piece has a first removal and said upper pole piece has a second removal respectively at the two sides in the direction of the track width, said first and second removals being extended to the surface of said slider or said protective film;
- when a maximum pole length of the front end surface from the gap film to the first removal at a first edge of the lower pole piece and a minimum pole length of the front end surface from the gap film to the first removal at a second edge opposite the first edge of the lower pole piece are P1max and P1min respectively, and the difference between the maximum pole length P1max and the minimum pole length P1min is .DELTA.P1, and when a maximum pole length of the front end surface from the gap film to the second removal at a first edge of the upper pole piece and a minimum pole length of the front end surface from the gap film to the second removal at a second edge opposite the first edge of the upper pole piece are P2max and P2min respectively, and the difference between the maximum pole length P2max and the minimum pole length P2 min is .DELTA.P2, the condition .DELTA.P1>.DELTA.P2 is satisfied.
2 more elements
Dependencies are inferred from the claim text.