US5508077A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Textured disc substrate and method
Assignee: WD Media LLC
•
Filing: 1993-07-30
•
Granted: 1996-04-16
•
Expires: 2013-07-30
Abstract
Abstract A disc substrate having a selected roughness gradient from an inner-diameter region to an outer-diameter region, and a method of producing the texturing on the substrate are disclosed. The method includes simulating the movement of texturing particles produced by rotating a texturing pad against a rotating disc substrate, at selected substrate and pad rotational speeds and directions, and for a selected run time. Simulation conditions which produce an averaged cross-hatch angle of intersecting texture lines that is at least about 2 times greater at the inner-diameter region of the substrate than at the outer-diameter region are selected.
Inventors
- 👤 Ga-Lane Chen
- 👤 Jack Xuan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:42
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/8404; G11B5/62; G11B5/73; G11B5/739; G11B5/73911; G11B5/73913; G11B5/73917; G11B5/73919; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/913; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/259
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
92 words
A disc substrate for use in forming a magnetic recording medium comprising an annular surface having inner, middle, and outer diameter regions, and formed on said surface, a gradient textured pattern of grooves in and between the inner and outer diameter regions that is characterized by an averaged cross-hatch angle which is at least about 2 times greater at the inner-diameter region than at the outer-diameter region, where the averaged cross-hatch angle is defined as the average of twice the angle a groove makes with a line extending in a circumferential direction.
Claim 2
Dependent Claim
92 words
A disc substrate for use in forming a magnetic recording medium comprising an annular surface having inner, middle, and outer diameter regions, and formed on said surface, a gradient textured pattern of grooves in and between the inner and outer diameter regions that is characterized by an averaged cross-hatch angle which is at least about 2 times greater at the inner-diameter region than at the outer-diameter region, where the averaged cross-hatch angle is defined as the average of twice the angle a groove makes with a line extending in a circumferential direction.
Claim 3
Dependent Claim
33 words
The substrate of claim 1, wherein the averaged cross-hatch angle at the inner-diameter region is between about 20-30 degrees, and the averaged cross-hatch angle at the outer-diameter region is between about 3-8 degrees.
Claim 4
Dependent Claim
25 words
The substrate of claim 1, wherein the averaged cross-hatch angle is at least 4 times greater at the inner-diameter region than at the outer-diameter region.
Claim 5
Dependent Claim
24 words
The substrate of claim 1, wherein said pattern of grooves is further characterized as having a minimum average summit density of 1000/mm 2 .
References Cited (Backward Citations)
US4330910A
Cited
US4430782A
Cited
US4535567A
Cited
US4656790A
Cited
US4656790B1
Cited
US5123933A
Cited
US5070425A
Cited
US4941293A
Cited
US5155372A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-16 | 1999-10-16 | 2000-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-16 | 2003-10-16 | 2004-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-16 | 2007-10-16 | 2008-04-16 | $7700.00 | Window Closed / Lapsed |