Patent US4449138A successfully refreshed from Google Patents.
US4449138A
Expired / Lapsed
US
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Information recording medium
Assignee: Toshiba Corp
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Filing: 1982-04-13
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Granted: 1984-05-15
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Expires: 2002-04-13
Abstract
Abstract Disclosed is an information recording medium, comprising a pair of disk-shaped substrates disposed apart from each other; protective layers each formed on the inner surface of the substrate; and optical information recording layers each consisting of an energy-absorbing layer or light reflective layer and formed on the protective layer. The clearance between the mutually facing recording layers may be filled with an adhesive layer. Also, the protective layer, which serves to prevent water or oxygen from entering the recording layer, may be formed on the outer surface of the substrate.
Inventors
- 👤 Hideo Ando
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:43
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/24015; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
51 words
An information recording medium, comprising a pair of disk-shaped transparent substrates disposed apart from each other; intermediate transparent protective layers each formed on the inner surface of the substrate; and optical information recording layers each consisting of an energy-absorbing layer or light reflective layer and formed on the intermediate transparent layer.
Claim 2
Dependent Claim
51 words
An information recording medium, comprising a pair of disk-shaped transparent substrates disposed apart from each other; intermediate transparent protective layers each formed on the inner surface of the substrate; and optical information recording layers each consisting of an energy-absorbing layer or light reflective layer and formed on the intermediate transparent layer.
Claim 3
Dependent Claim
20 words
The recording medium according to claim 1, wherein a surface protective layer is formed on the optical information recording layer.
Claim 4
Dependent Claim
29 words
The recording medium according to claim 2, wherein the surface protective layer consists of an inorganic material layer and an organic material layer formed on the inorganic material layer.
Claim 5
Dependent Claim
27 words
The recording medium according to claim 3, wherein the inorganic material layer included in the surface protective layer is equal in material to the intermediate protective layer.
Claim 6
Dependent Claim
42 words
The recording medium according to claim 3, wherein the organic material layer is formed of a material selected from the group consisting of polystyrene, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polyester, methyl methacrylate resin, polyurethane, epoxy resin, melamine resin, and silicone resin.
Claim 7
Dependent Claim
34 words
The recording medium according to claim 1, wherein the disk-shaped substrates are held apart from each other by an annular outer spacer and an annular inner spacer smaller in diameter than the outer spacer.
Claim 8
Dependent Claim
18 words
The recording medium according to claim 1, wherein the substrates have a thickness of 1.0 to 1.5 mm.
Claim 9
Dependent Claim
67 words
An information recording medium, comprising a pair of disk-shaped transparent substrates disposed apart from each other; intermediate protective layers each formed on the inner surface of the substrate; optical information recording layers each consisting of an energy-absorbing layer or light reflective layer and formed on the intermediate protective layer, and an adhesive layer filling the clearance between the mutually facing information recording layers for the bonding purpose.
Claim 10
Dependent Claim
67 words
An information recording medium, comprising a pair of disk-shaped transparent substrates disposed apart from each other; intermediate protective layers each formed on the inner surface of the substrate; optical information recording layers each consisting of an energy-absorbing layer or light reflective layer and formed on the intermediate protective layer, and an adhesive layer filling the clearance between the mutually facing information recording layers for the bonding purpose.
Claim 11
Dependent Claim
45 words
The recording medium according to claim 1 or 8, wherein the intermediate protective layer is formed of an inorganic material selected from the group consisting of oxides of Zn, Al, Mg, Si, Zr, Ce, In, Ti, Sn, Nb and fluorides of Mg, Ca and Ce.
Claim 12
Dependent Claim
28 words
The recording medium according to claim 3, wherein an indented layer provided with signal information or tracking guides is formed between the substrate and the intermediate protective layer.
Claim 13
Dependent Claim
31 words
The recording medium according to claim 8, wherein an indented layer provided with signal information or tracking guides is formed between the optical information recording layer and the intermediate protective layer.
Claim 14
Dependent Claim
28 words
The recording medium according to claim 11, wherein an intermediate layer consisting of an organic material is formed between the optical information recording layer and the adhesive layer.
Claim 15
Dependent Claim
25 words
The recording medium according to claim 8, wherein a second intermediate protective layer is formed between the optical information recording layer and the adhesive layer.
Claim 16
Dependent Claim
28 words
The recording medium according to claim 13, wherein an indented layer provided with signal information or tracking guides is formed between the substrate and the intermediate protective layer.
Claim 17
Dependent Claim
18 words
The recording medium according to claim 8, wherein the substrates have a thickness of 1.0 to 1.5 mm.
Claim 18
Dependent Claim
19 words
The recording medium according to claim 8, wherein the adhesive layer has a thickness of 50 to 300 μm.
Claim 19
Dependent Claim
71 words
An information recording medium, comprising a pair of disk-shaped transparent substrates disposed apart from each other; optical information recording layers each consisting of an energy-absorbing layer or light reflective layer and formed on the inner surface of the substrate; an adhesive layer filling the clearance between the mutually facing optical information recording layers for the bonding purpose; and outer transparent protective layers each formed on the outer surface of the substrate.
Claim 20
Dependent Claim
71 words
An information recording medium, comprising a pair of disk-shaped transparent substrates disposed apart from each other; optical information recording layers each consisting of an energy-absorbing layer or light reflective layer and formed on the inner surface of the substrate; an adhesive layer filling the clearance between the mutually facing optical information recording layers for the bonding purpose; and outer transparent protective layers each formed on the outer surface of the substrate.
Claim 21
Dependent Claim
42 words
The recording medium according to claim 17, wherein the outer protective layer is formed of an inorganic material selected from the group consisting of oxides of Zn, Al, Mg, Si, Zr, Ce, In, Ti, Sn, Nb fluorides of Mg, Ca and Ce.
Claim 22
Dependent Claim
18 words
The recording medium according to claim 17, wherein the substrates have a thickness of 1.0 to 1.5 mm.
Claim 23
Dependent Claim
19 words
The recording medium according to claim 17, wherein the adhesive layer has a thickness of 50 to 300 μm.
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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) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |