US5213859A
Expired / Lapsed
US
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Optical recording disk
Assignee: TDK Corp
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Filing: 1991-06-25
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Granted: 1993-05-25
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Expires: 2011-06-25
Abstract
Abstract In an optical recording disk 1 comprising a dye layer 2 formed on a substrate 3 as a light absorbing layer and a reflective layer 4 stacked thereon, tracking servo control is carried out by the push-pull method. To produce normal and accurate tracking error signals, the surface of the dye layer 2 includes depressed and raised sections corresponding to grooves 31 and lands 35 and ΔD which is given by the formula: ΔD=D.sub.L +d.sub.G -D.sub.G wherein D G is the thickness of the dye layer on the groove 31, D L is the thickness of the dye layer on the land 35, and d G is the depth of the groove has a higher magnitude than ΔD 0 which is associated with a tracking error signal of zero.
Inventors
- 👤 Toshiki Aoi
- 👤 Masahiro Shinkai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:42
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/244; G11B7/246; G11B7/08; G11B7/09; G11B7/0901; G11B7/252; G11B7/258; G11B7/247; G11B7/2472; G11B7/2595; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
107 words
An optical recording disk comprising at least a light absorbing layer and a reflective layer stacked on a substrate having grooves formed between lands wherein the grooves from recording tracks for detecting tracking errors by the push-pull method, characterized in that the disk meets ΔD>ΔD.sub.0 wherein ΔD is given by the formula: ΔD=D.sub.L +d.sub.G -D.sub.G wherein D G is the thickness of the light absorbing layer on the groove, D L is the thickness of the light absorbing layer on the land, and d G is the depth of the groove, and ΔD 0 is a value of ΔD associated with a tracking error signal of zero.
Claim 2
Dependent Claim
107 words
An optical recording disk comprising at least a light absorbing layer and a reflective layer stacked on a substrate having grooves formed between lands wherein the grooves from recording tracks for detecting tracking errors by the push-pull method, characterized in that the disk meets ΔD>ΔD.sub.0 wherein ΔD is given by the formula: ΔD=D.sub.L +d.sub.G -D.sub.G wherein D G is the thickness of the light absorbing layer on the groove, D L is the thickness of the light absorbing layer on the land, and d G is the depth of the groove, and ΔD 0 is a value of ΔD associated with a tracking error signal of zero.
Claim 3
Dependent Claim
38 words
The optical recording disk of claim 1 wherein the groove has a depth d G of 500 to 2,500 Å, a width W G of 0.35 to 0.6 μm and a pitch P of 1.5 to 1.7 μm.
Claim 4
Dependent Claim
17 words
The optical recording disk of claim 2, wherein D G >D L and D L ≦2,200 Å.
Claim 5
Dependent Claim
23 words
The optical recording disk of claim 3, wherein said light absorbing layer is a film obtained by coating a solution containing a dye.
Claim 6
Dependent Claim
16 words
The optical recording disk of claim 3, further comprising a topcoat stacked on the reflective layer.
Claim 7
Dependent Claim
28 words
The optical recording disk of claim 2, wherein said light absorbing layer has a refractive index of 2.0 to 2.9 and an extinction coefficient of 0.02 to 0.08.
Claim 8
Dependent Claim
23 words
The optical recording disk of claim 2, wherein said light absorbing layer is a film obtained by coating a solution containing a dye.
Claim 9
Dependent Claim
16 words
The optical recording disk of claim 2, further comprising a topcoat stacked on the reflective layer.
Claim 10
Dependent Claim
17 words
The optical recording disk of claim 1 wherein D G ≦D L and D L ≦2,200 Å.
Claim 11
Dependent Claim
28 words
The optical recording disk of claim 9, wherein said light absorbing layer has a refractive index of 2.0 to 2.9 and an extinction coefficient of 0.02 to 0.08.
Claim 12
Dependent Claim
23 words
The optical recording disk of claim 9, wherein said light absorbing layer is a film obtained by coating a solution containing a dye.
Claim 13
Dependent Claim
16 words
The optical recording disk of claim 9, further comprising a topcoat stacked on the reflective layer.
Claim 14
Dependent Claim
28 words
The optical recording disk of claim 1, wherein said light absorbing layer has a refractive index of 2.0 to 2.9 and an extinction coefficient of 0.02 to 0.08.
Claim 15
Dependent Claim
23 words
The optical recording disk of claim 13, wherein said light absorbing layer is a film obtained by coating a solution containing a dye.
Claim 16
Dependent Claim
16 words
The optical recording disk of claim 13, further comprising a topcoat stacked on the reflective layer.
Claim 17
Dependent Claim
23 words
The optical recording disk of claim 1, wherein said light absorbing layer is a film obtained by coating a solution containing a dye.
Claim 18
Dependent Claim
16 words
The optical recording disk of claim 16, further comprising a topcoat stacked on the reflective layer.
Claim 19
Dependent Claim
17 words
The optical recording disk of claim 1 which further comprises a topcoat stacked on the reflective layer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-24 | 1996-11-23 | 1997-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-24 | 2000-11-23 | 2001-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-24 | 2004-11-23 | 2005-05-25 | $7700.00 | Window Closed / Lapsed |