US5469312A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film magnetic head device having a core recess set to a predetermined spacing loss
Assignee: Sony Corp
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Filing: 1992-03-19
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Granted: 1995-11-21
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Expires: 2012-03-19
Abstract
Abstract There is disclosed a thin film magnetic head device of a structure such that a thin film magnetic head having a metal magnetic film as a magnetic core is directly formed on a slider by the thin film forming technology, thus to carry out recording onto a hard disk and reproducing therefrom. When polishing processing is implemented on an air bearing surface of the slider, the magnetic core (metal magnetic film) of the thin film magnetic head is withdrawn from the air bearing surface by a difference in polishing rate. A quantity of removal (core recess) at this time is set in a range such that the spacing loss is 0.5 to 1.5 dB. Accordingly, while the core recess varies depending upon a track recording density, it is set in this invention within a region indicated by slanting lines of FIG. 8 on the basis of a maximum value of a tracking recording density to be attained.
Inventors
- 👤 Takashi Watanabe
- 👤 Wataru Ishikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:05
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3103; G11B5/3106; G11B5/48; G11B5/488; G11B5/4886; G11B5/187; G11B5/1871; G11B5/58; G11B5/60; G11B5/6005; G11B5/6011; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49041
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
162 words
A thin film magnetic head device, comprising: a non-magnetic slider member having a first surface, including an air bearing portion, adapted to be positioned opposite to a hard disk and a substantially planar end surface extending generally perpendicular to said first surface, and having formed thereon a thin film magnetic head; said thin film magnetic head comprising an insulating layer positioned on said end surface and, disposed on said insulating layer, a lower magnetic film, an upper magnetic film, and an insulating film between said upper and said lower magnetic films and wherein said lower magnetic film, said insulating film, and said upper magnetic film are recessed from said air bearing portion of said first surface of said slider member by a core recess quantity d, said core recess quantity being in the range determined by the area between a 0.5 dB curve and a 1.5 dB curve in a plot of core recess quantity as a function of track recording density.
Claim 2
Dependent Claim
162 words
A thin film magnetic head device, comprising: a non-magnetic slider member having a first surface, including an air bearing portion, adapted to be positioned opposite to a hard disk and a substantially planar end surface extending generally perpendicular to said first surface, and having formed thereon a thin film magnetic head; said thin film magnetic head comprising an insulating layer positioned on said end surface and, disposed on said insulating layer, a lower magnetic film, an upper magnetic film, and an insulating film between said upper and said lower magnetic films and wherein said lower magnetic film, said insulating film, and said upper magnetic film are recessed from said air bearing portion of said first surface of said slider member by a core recess quantity d, said core recess quantity being in the range determined by the area between a 0.5 dB curve and a 1.5 dB curve in a plot of core recess quantity as a function of track recording density.
Claim 3
Dependent Claim
24 words
A thin film magnetic head device as set forth in claim 1, wherein said slider member is comprised of Al 2 O 3 --TiC.
Claim 4
Dependent Claim
21 words
A magnetic head device as set forth in claim 1 wherein said slider member is formed from a hard ceramic material.
Claim 5
Dependent Claim
42 words
A magnetic head device as set forth in claim 1 wherein said slider member further includes an air inflow groove formed as a recessed surface in said first surface the remaining surfaces of said first surface acting as said air bearing portion.
Claim 6
Dependent Claim
51 words
A magnetic head device as set forth in claim 4 where said air bearing portion comprises planar surface portions adjacent to and extending from said end surface and along said first surface and obliquely angled portions adjacent to an air inflow end side of said first surface opposite said end surface.
Claim 7
Dependent Claim
42 words
A magnetic head device as set forth in claim 1 wherein said core recess is formed as a result of polishing processing of said end surface and said upper and lower magnetic surfaces and said spacer, whereupon said core recess is formed.
References Cited (Backward Citations)
US5083365A
Cited
US4893203A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-11-20 | 1999-05-22 | 1999-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-20 | 2003-05-22 | 2003-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-20 | 2007-05-22 | 2007-11-21 | $7700.00 | Window Closed / Lapsed |