Patent US5325353A successfully refreshed from Google Patents.
US5325353A
Expired / Lapsed
US
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Optical recording medium
Assignee: Sony Corp
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Filing: 1993-06-28
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Granted: 1994-06-28
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Expires: 2013-06-28
Abstract
Abstract An optical recording medium formed of a pre-grooved substrate provided with a recording layer formed on the groove, in which the groove has a shape to satisfy the condition I Gr /I 0 ≧0.85, where I 0 represents the reflected light quantity from the mirror surface and I Gr represents the reflected light quantity from the groove surface when the laser beam is concentrated to a spot size of approximately 1 μm on the surface of the medium, and to enable three-spot tracking to be performed. According to this invention, the CN ratio as the measure of noise in an optical recording medium can be improved.
Inventors
- 👤 Koji Sasaki
- 👤 Takashi Kishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:27
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0938; G11B11/00; G11B11/10; G11B11/105; G11B11/1055; G11B11/10576; G11B11/10578
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
107 words
An optical recording medium having a substrate with grooves thereon, said grooves having a recording layer formed thereon wherein each of said grooves has substantially flat bottom to satisfy the condition IGr/Io>/ 0.85, where Io represents the reflected light quantity from the mirror surface and IGr represents the reflected light quantity from groove surface when a laser beam is concentrated to a spot size of approximately 1 micrometer on the surface of the medium, and to enable three-spot tracking to be performed, wherein each of said grooves has a shape satisfying the condition IGr>/ILa where ILa represents the reflected light quantity from a land adjacent the groove.
Claim 2
Dependent Claim
107 words
An optical recording medium having a substrate with grooves thereon, said grooves having a recording layer formed thereon wherein each of said grooves has substantially flat bottom to satisfy the condition IGr/Io>/ 0.85, where Io represents the reflected light quantity from the mirror surface and IGr represents the reflected light quantity from groove surface when a laser beam is concentrated to a spot size of approximately 1 micrometer on the surface of the medium, and to enable three-spot tracking to be performed, wherein each of said grooves has a shape satisfying the condition IGr>/ILa where ILa represents the reflected light quantity from a land adjacent the groove.
Claim 3
Dependent Claim
37 words
An optical recording medium according to claim 1, wherein said recording layer is formed of an SiN film, a vertical magnetization film Mo film, an SiN film, and an Al film deposited on the groove in succession.
Claim 4
Dependent Claim
26 words
An optical recording medium according to claim 1, wherein said mirror surface is formed at the portion other than data areas, flag areas, and address areas.
Claim 5
Dependent Claim
22 words
An optical recording medium according to claim 1, wherein the width of the groove surface is most preferably set to 1.1-1.3 μm.
Claim 6
Dependent Claim
49 words
The optical recording medium according to claim 1, wherein said grooves constitute a spiral groove, said medium having a track pitch, and wherein the bottom of each of said grooves has a width in relation to a width of said track pitch in the ratio from 1.1/1.6 to 1.3/1.6.
References Cited (Backward Citations)
US4569881A
Cited
US5107486A
Cited
JPS62164237A
Cited
JPH01184736A
Cited
US4931336A
Cited
JPH02161632A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-27 | 2001-12-27 | 2002-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-27 | 2005-12-27 | 2006-06-28 | $7700.00 | Window Closed / Lapsed |