US5552884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Calibration standard for flying height tester having a head mounted on a multilevel surface transparent disc
Assignee: Seagate Technology LLC
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Filing: 1994-12-16
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Granted: 1996-09-03
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Expires: 2014-12-16
Abstract
Abstract The present invention provides a calibration standard for the uniform calibration of flying height testers. The calibration standard comprises a head assembly held in contact with a transparent disc through the use of a load spring. The transparent disc has a plurality of grooves formed in a surface facing the head assembly. A cover case is attached to the glass disc at one end and provides a sealed environment for the interface between the head assembly and the transparent disc.
Inventors
- 👤 Yufeng Li
- 👤 Peter R. Goglia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:36
CPC Classifications
G; G11; G11B; G11B21/00; G11B21/16; G11B21/20; G11B21/21; G11B33/00; G11B33/10
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
135 words
A calibration standard for calibrating a flying height tester that uses optical interference techniques to determine flying heights of head assemblies, the calibration standard comprising: a head assembly including a read/write head, the head assembly having a first surface: a transparent disc having a first surface and a second surface, wherein both the first surface and the second surface of the transparent disc face the first surface of the head assembly and wherein the second surface of the transparent disc is positioned on said transparent disc inward of said first surface to form a multilevel disc surface; and holding means for holding the head assembly such that the first surface of the head assembly contacts the first surface of the transparent disc to result in being spaced from the second surface of the transparent disc.
Claim 2
Dependent Claim
135 words
A calibration standard for calibrating a flying height tester that uses optical interference techniques to determine flying heights of head assemblies, the calibration standard comprising: a head assembly including a read/write head, the head assembly having a first surface: a transparent disc having a first surface and a second surface, wherein both the first surface and the second surface of the transparent disc face the first surface of the head assembly and wherein the second surface of the transparent disc is positioned on said transparent disc inward of said first surface to form a multilevel disc surface; and holding means for holding the head assembly such that the first surface of the head assembly contacts the first surface of the transparent disc to result in being spaced from the second surface of the transparent disc.
Claim 3
Dependent Claim
17 words
The calibration standard of claim 1 wherein the second surface of the transparent disc is substantially flat.
Claim 4
Dependent Claim
34 words
The calibration standard of claim 1 wherein the transparent disc has a third surface which contacts the first surface of the head assembly and is coplanar with the first surface of the transparent disc.
Claim 5
Dependent Claim
40 words
The calibration standard of claim 3 wherein the transparent disc has a fourth surface which faces and is spaced from the first surface of the head assembly in being positioned on the transparent disc inward of the first surface thereof.
Claim 6
Dependent Claim
40 words
The calibration standard of claim 1 and further comprising a cover having a first end in contact with the transparent disc, the cover and the transparent disc combining to form a head chamber in which is located the head assembly.
Claim 7
Dependent Claim
36 words
The calibration standard of claim 5 wherein the holding means includes a spring having a first end in contact with the head assembly and a second end in contact with an inner portion of the cover.
Claim 8
Dependent Claim
48 words
The calibration standard of claim 5 wherein the cover includes a desiccant chamber, in which is located a desiccant, the desiccant chamber being separated from the head chamber such that the desiccant is prevented from entering the head chamber but air flow is permitted between the two chambers.
Claim 9
Dependent Claim
32 words
The calibration standard of claim 1 wherein the head assembly used in the calibration standard is similar to head assemblies whose flying height is to be measured by the flying height tester.
Claim 10
Independent Claim
162 words
A method of calibrating a flying height tester that uses optical interference techniques to determine flying heights of head assemblies, the method comprising the steps of: inserting a calibration standard in the flying height tester, the calibration standard having a head assembly having a first surface and a transparent disc having a first surface facing and contacting the first surface of the head assembly and a second surface facing the first surface of the head assembly with this second surface positioned in the transparent disc inward of the first surface thereof to form a multilevel disc surface and spaced apart from the first surface of the head assembly; determining an expected distance between the first surface of the transparent disc and the second surface of the transparent disc; measuring an optically measured distance between the first surface of the transparent disc and the second surface of the transparent disc through optical interference techniques; and comparing the expected distance with the measured distance.
Claim 11
Independent Claim
162 words
A method of calibrating a flying height tester that uses optical interference techniques to determine flying heights of head assemblies, the method comprising the steps of: inserting a calibration standard in the flying height tester, the calibration standard having a head assembly having a first surface and a transparent disc having a first surface facing and contacting the first surface of the head assembly and a second surface facing the first surface of the head assembly with this second surface positioned in the transparent disc inward of the first surface thereof to form a multilevel disc surface and spaced apart from the first surface of the head assembly; determining an expected distance between the first surface of the transparent disc and the second surface of the transparent disc; measuring an optically measured distance between the first surface of the transparent disc and the second surface of the transparent disc through optical interference techniques; and comparing the expected distance with the measured distance.
Claim 12
Dependent Claim
88 words
The method of claim 9 wherein the measured distance between the first and second surfaces of the transparent disc is measured by measuring a first measured distance between the first surface of the head assembly and the first surface of the transparent disc at a selected position on the first surface of the transparent disc and measuring a second measured distance between the second surface of the transparent disc and the first surface of the head assembly and subtracting the first measured distance from the second measured distance.
Claim 13
Dependent Claim
31 words
The method of claim 9 wherein the head assembly used in the calibration standard is similar to head assemblies whose flying height is to be measured by the flying height tester.
Claim 14
Dependent Claim
27 words
The method of claim 9 wherein the expected distance between the first and second surfaces of the transparent disc is determined through the use of a profilometer.
Claim 15
Dependent Claim
16 words
The method of claim 9 wherein the second surface of the transparent disc is substantially flat.
Claim 16
Dependent Claim
22 words
The method of claim 9 wherein the transparent disc has a third surface which contacts the first surface of the head assembly.
Claim 17
Dependent Claim
39 words
The method of claim 14 wherein the transparent disc has a fourth surface which faces and is spaced from the first surface of the head assembly in being positioned on the transparent disc inward of the first surface thereof.
Claim 18
Dependent Claim
41 words
The method of claim 9 wherein the calibration standard includes a cover having a first end in contact with the transparent disc, the cover and the transparent disc combining to form a head chamber in which is located the head assembly.
Claim 19
Dependent Claim
47 words
The method of claim 16 wherein the cover includes a desiccant chamber in which is located a desiccant, the desiccant chamber being separated from the head chamber such that the desiccant is prevented from entering the head chamber, but air flow is permitted between the two chambers.
Claim 20
Independent Claim
117 words
A method of calibrating a flying height tester that uses optical interference techniques to determine flying heights of head assemblies, the method comprising the steps of: inserting a calibration standard in the flying height tester, the calibration standard having a head assembly having a first surface and a transparent disc having a first surface facing and contacting the first surface of the head assembly and a second surface facing and spaced from the first surface of the head assembly; measuring an optically measured distance between the first surface of the transparent disc and the second surface of the transparent disc through optical interference techniques; and calibrating the flying height tester as a function of the measured distance.
Claim 21
Independent Claim
117 words
A method of calibrating a flying height tester that uses optical interference techniques to determine flying heights of head assemblies, the method comprising the steps of: inserting a calibration standard in the flying height tester, the calibration standard having a head assembly having a first surface and a transparent disc having a first surface facing and contacting the first surface of the head assembly and a second surface facing and spaced from the first surface of the head assembly; measuring an optically measured distance between the first surface of the transparent disc and the second surface of the transparent disc through optical interference techniques; and calibrating the flying height tester as a function of the measured distance.
Claim 22
Dependent Claim
63 words
A calibration standard for calibrating a flying height tester that uses optical interference techniques to determine flying heights of head assemblies, the calibration standard comprising: a head assembly including a read/write head; a transparent disc having a first surface in which a groove is formed; and holding means for holding the head assembly in contact with the first surface of the transparent disc.
Claim 23
Dependent Claim
63 words
A calibration standard for calibrating a flying height tester that uses optical interference techniques to determine flying heights of head assemblies, the calibration standard comprising: a head assembly including a read/write head; a transparent disc having a first surface in which a groove is formed; and holding means for holding the head assembly in contact with the first surface of the transparent disc.
Claim 24
Dependent Claim
18 words
The calibration standard of claim 19 wherein the transparent disc has a plurality of additional grooves formed therein.
Claim 25
Dependent Claim
16 words
The calibration standard of claim 20 wherein each of the additional grooves has a different depth.
Claim 26
Dependent Claim
38 words
The calibration standard of claim 19 wherein the holding means includes a cover attached to the transparent disc to provide a sealed environment for an interface between the head assembly and the first surface of the transparent disc.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-09-03 | 2000-03-04 | 2000-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-03 | 2004-03-04 | 2004-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-03 | 2008-03-04 | 2008-09-03 | $7700.00 | Window Closed / Lapsed |