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US5221459A
Expired / Lapsed
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Method of manufacturing a magnetic disk substrate of titanium
Assignee: JFE Engineering Corp
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Filing: 1992-04-24
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Granted: 1993-06-22
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Expires: 2012-04-24
Abstract
Abstract A method of manufacturing a magnetic disk substrate made of titanium, in which chemical etching is performed on a titanium disk for magnetic disk substrate, thereby removing a surface portion thereof having a thickness of at least 2 nm, and the new surface of the titanium disk, formed by the chemical etching, is anodized, thereby forming anodized film on the titanium disk.
Inventors
- 👤 Yoko Okano
- 👤 Hiroyoshi Suenaga
- 👤 Toshio Sakiyama
- 👤 Kenji Morita
- 👤 Masanori Ohmura
- 👤 Iwao Ida
- 👤 Hitoshi Nagashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:14
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/8404; C; C25; C25D; C25D11/00; C25D11/02; C25D11/26
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
69 words
A method of manufacturing a magnetic disk substrate made of titanium, comprising the steps of: performing chemical etching on a titanium disk to be used for a magnetic disk substrate, thereby removing a surface portion thereof having a thickness of at least 2 nm; and anodizing the new surface of the titanium disk, which has been formed by the chemical etching, thereby forming anodized film on the titanium disk.
Claim 2
Independent Claim
69 words
A method of manufacturing a magnetic disk substrate made of titanium, comprising the steps of: performing chemical etching on a titanium disk to be used for a magnetic disk substrate, thereby removing a surface portion thereof having a thickness of at least 2 nm; and anodizing the new surface of the titanium disk, which has been formed by the chemical etching, thereby forming anodized film on the titanium disk.
Claim 3
Dependent Claim
28 words
The method according to claim 1, wherein that surface portion of said titanium disk, which is removed by chemical etching, has a thickness of 200 nm at most.
Claim 4
Dependent Claim
26 words
The method according to claim 1, wherein a negative DC voltage ranging from -2V to -25V is applied to said titanium disk during the chemical etching.
Claim 5
Dependent Claim
25 words
The method according to claim 1, wherein the anodized film formed on said titanium disk has a thickness ranging from 2 nm to 350 nm.
References Cited (Backward Citations)
JPS52105804A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-21 | 1996-12-21 | 1997-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-21 | 2000-12-21 | 2001-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-21 | 2004-12-21 | 2005-06-22 | $7700.00 | Window Closed / Lapsed |