US5768221A
Expired / Lapsed
US
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Method of and apparatus for initializing multi-layer optical recording medium
Assignee: Sony Corp
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Filing: 1996-09-19
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Granted: 1998-06-16
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Expires: 2016-09-19
Abstract
Abstract A multiple-recording-layer optical recording medium has a plurality of recording layers to be initialized by exposure to light, with a transparent layer interposed between the recording layers. Light is applied simultaneously to the to the recording layers to initialize the recording layers simultaneously.
Inventors
- 👤 Yutaka Kasami
- 👤 Koichi Yasuda
- 👤 Atsushi Fukumoto
- 👤 Shigeki Takagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:28
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/26; G11B7/08; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10523; G11B11/1055; G11B11/10552; G11B11/10554; G11B2007/0003; G11B2007/0009; G11B2007/0013; G11B7/004; G11B7/0055; G11B7/00557
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
87 words
A method of initializing a multiple-recording-layer optical recording medium, comprising the steps of: providing a multiple-recording-layer optical recording medium having a plurality of recording layers to be initialized by exposure to light, with a transparent layer interposed between the recording layers; and thereafter, applying light simultaneously to the recording layers to initialize the recording layers simultaneously, using an objective lens having a numerical aperture of at most (λ/d) 1/2 where d is the thickness of the transparent layer and λ is the wavelength of the light beam.
Claim 2
Independent Claim
87 words
A method of initializing a multiple-recording-layer optical recording medium, comprising the steps of: providing a multiple-recording-layer optical recording medium having a plurality of recording layers to be initialized by exposure to light, with a transparent layer interposed between the recording layers; and thereafter, applying light simultaneously to the recording layers to initialize the recording layers simultaneously, using an objective lens having a numerical aperture of at most (λ/d) 1/2 where d is the thickness of the transparent layer and λ is the wavelength of the light beam.
Claim 3
Dependent Claim
18 words
A method according to claim 1, wherein each of the recording layers is made of a phase-change material.
Claim 4
Independent Claim
126 words
An apparatus for initializing a multiple-recording-layer recording medium having a plurality of recording layers to be initialized by exposure to light, with a transparent layer interposed between the recording layers, comprising: light applying means for applying light simultaneously to the recording layers to initialize the recording layers simultaneously, said light applying means comprising a light source for emitting a light beam; and an objective lens for applying the light beam emitted by said light source to said first recording layer and said second recording layer to initialize said first recording layer and said second recording layer; said objective lens having a numerical aperture of at most (λ/d) 1/2 where d is the thickness of the transparent layer and λ is the wavelength of the light beam.
Claim 5
Independent Claim
126 words
An apparatus for initializing a multiple-recording-layer recording medium having a plurality of recording layers to be initialized by exposure to light, with a transparent layer interposed between the recording layers, comprising: light applying means for applying light simultaneously to the recording layers to initialize the recording layers simultaneously, said light applying means comprising a light source for emitting a light beam; and an objective lens for applying the light beam emitted by said light source to said first recording layer and said second recording layer to initialize said first recording layer and said second recording layer; said objective lens having a numerical aperture of at most (λ/d) 1/2 where d is the thickness of the transparent layer and λ is the wavelength of the light beam.
Claim 6
Dependent Claim
32 words
An apparatus according to claim 3, wherein said light applying means has a plurality of objective lenses associated with the recording layers, respectively, for focusing light beams respectively onto the recording layers.
Claim 7
Dependent Claim
18 words
An apparatus according to claim 3, wherein each of the recording layers is made of a phase-change material.
Claim 8
Independent Claim
137 words
An apparatus for initializing a multiple-recording-layer optical recording medium having a substrate, a first recording layer to be initialized by exposure to light, the first recording layer being disposed on the substrate, a transparent layer disposed on the first recording layer, and a second recording layer to be initialized by exposure to light, the second recording layer being disposed on the transparent layer, comprising: a light source for emitting a light beam; and an objective lens for applying the light beam emitted by said light source to said first recording layer and said second recording layer to initialize said first recording layer and said second recording layer; said objective lens having a numerical aperture of at most (λ/d) 1/2 where d is the thickness of the transparent layer and λ is the wavelength of the light beam.
Claim 9
Independent Claim
137 words
An apparatus for initializing a multiple-recording-layer optical recording medium having a substrate, a first recording layer to be initialized by exposure to light, the first recording layer being disposed on the substrate, a transparent layer disposed on the first recording layer, and a second recording layer to be initialized by exposure to light, the second recording layer being disposed on the transparent layer, comprising: a light source for emitting a light beam; and an objective lens for applying the light beam emitted by said light source to said first recording layer and said second recording layer to initialize said first recording layer and said second recording layer; said objective lens having a numerical aperture of at most (λ/d) 1/2 where d is the thickness of the transparent layer and λ is the wavelength of the light beam.
Claim 10
Dependent Claim
18 words
An apparatus according to claim 6, wherein each of the recording layers is made of a phase-change material.
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) | 2001-06-15 | 2001-12-15 | 2002-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-06-15 | 2005-12-15 | 2006-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-06-15 | 2009-12-15 | 2010-06-16 | $7700.00 | Window Closed / Lapsed |