US6449239B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical information recording medium with thermal diffusion layer
Assignee: Panasonic Holdings Corp
•
Filing: 1999-11-18
•
Granted: 2002-09-10
•
Expires: 2019-11-18
Abstract
Abstract An optical information recording medium is provided in which recording can be performed at higher speed with higher density by enabling the cooling power of the recording medium to be improved, the overwritten-mark distortion to be decreased, and an medium with high transmittance to be obtained. The optical information recording medium is formed by laminating, sequentially on a substrate: a protective layer; an interface layer; a recording layer whose optical characteristics are varied reversibly by irradiation of a laser beam; an interface layer; a light transmittance type reflective layer that transmits the laser beam with a wavelength lambd; and a thermal diffusion layer. A thickness d of the thermal diffusion layer is set to be within a range of 0<d<=({fraction (5/16)})lambd/n or ({fraction (7/16)})lambd/n<=d<=(½)lambd/n, wherein n indicates a refractive index of the thermal diffusion layer.
Inventors
- 👤 Mayumi Uno
- 👤 Noboru Yamada
- 👤 Ken'ichi Nagata
- 👤 Hideo Kusada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:43
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/2403; G11B7/241; G11B7/252; G11B7/254; G11B7/2548; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24304; G11B2007/24308; G11B2007/2431; G11B2007/24312; G11B2007/24314; G11B2007/24316; G11B2007/25408; G11B2007/25411; G11B2007/25414; G11B2007/25417; G11B7/257; G11B2007/25705; G11B2007/25706; G11B2007/25708; G11B2007/2571; G11B2007/25711; G11B2007/25713; G11B2007/25715; G11B2007/25716; G11B2007/25718; G11B7/253; G11B7/2531; G11B7/2533; G11B7/2534; G11B7/256; G11B7/258; G11B7/259; G11B7/2595
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
79 words
An optical information recording medium, comprising: a recording layer whose optical characteristics are varied reversibly by irradiation of a laser beam; a reflective layer that transmits a laser beam with a wavelength λ; and a thermal diffusion layer that is provided while being in contact with the reflective layer, wherein a thickness d of the thermal diffusion layer is within a range of 0<d≦({fraction (5/16)})λ/n or ({fraction (7/16)})λ/n≦d≦(½)λ/n, wherein n indicates a refractive index of the thermal diffusion layer.
Claim 2
Dependent Claim
79 words
An optical information recording medium, comprising: a recording layer whose optical characteristics are varied reversibly by irradiation of a laser beam; a reflective layer that transmits a laser beam with a wavelength λ; and a thermal diffusion layer that is provided while being in contact with the reflective layer, wherein a thickness d of the thermal diffusion layer is within a range of 0<d≦({fraction (5/16)})λ/n or ({fraction (7/16)})λ/n≦d≦(½)λ/n, wherein n indicates a refractive index of the thermal diffusion layer.
Claim 3
Dependent Claim
29 words
The optical information recording medium according to claim 1 , wherein thermal conductivity of a material forming the thermal diffusion layer is at least 0.05 W/m·K at 500 K.
Claim 4
Dependent Claim
39 words
The optical information recording medium according to claim 1 , wherein a refractive index of the thermal diffusion layer is at least 1.6 with respect to a wavelength of a laser beam used for recording and reproduction of information.
Claim 5
Dependent Claim
39 words
The optical information recording medium according to claim 1 , wherein an absorption coefficient of the thermal diffusion layer is 1.5 or less with respect to a wavelength of a laser beam used for recording and reproduction of information.
Claim 6
Dependent Claim
56 words
The optical information recording medium according to claim 1 , wherein the thermal diffusion layer contains at least one selected from a group consisting of Al—N, Al—O—N, Al—C, Si, Si—N, SiO 2 , Si—O—N, Si—C, Ti—N, TiO 2 , Ti—C, Ta—N, Ta 2 O 5 , Ta—O—N, Ta—C, Zn—O, ZnS, ZnSe, Zr—N, Zr—O—N, Zr—C, and W—C.
Claim 7
Dependent Claim
28 words
The optical information recording medium according to claim 1 , wherein the reflective layer contains at least one selected from a group consisting of Au, Ag, and Cu.
Claim 8
Dependent Claim
23 words
The optical information recording medium according to claim 1 , wherein the reflective layer has a thickness between 1 nm and 20 nm.
Claim 9
Dependent Claim
23 words
The optical information recording medium according to claim 1 , wherein the recording layer has a thickness between 3 nm and 20 nm.
Claim 10
Dependent Claim
35 words
The optical information recording medium according to claim 1 , wherein the recording layer is formed of a phase change material containing at least one selected from a group consisting of Te, Se, and Sb.
Claim 11
Dependent Claim
31 words
The optical information recording medium according to claim 1 , wherein the optical information recording medium has an average light transmittance between 40% and 80% with respect to the laser beam.
Claim 12
Dependent Claim
33 words
The optical information recording medium according to claim 10 , wherein at least one other optical information recording medium is provided on an opposite side to an incident side of the laser beam.
Claim 13
Dependent Claim
46 words
The optical information recording medium according to claim 1 , wherein the optical information recording medium further comprises an interface layer that has an effect for facilitating crystallization of the recording layer and that is in contact with at least one side of the recording layer.
Claim 14
Dependent Claim
23 words
The optical information recording medium according to claim 12 , wherein the interface layer is formed of a material containing at least N.
References Cited (Backward Citations)
US5654058A
Cited
US5309427A
Cited
US5545454A
Cited
EP0566107A1
Cited
EP0569664A1
Cited
US5383172A
Cited
JPH0850739A
Cited
US5652036A
Cited
JPH08129777A
Cited
EP0766240A2
Cited
EP0887791A1
Cited
US5774430A
Cited
EP0810590A2
Cited
US5999512A
Cited
US6017620A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-09-09 | 2006-03-11 | 2006-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-09-09 | 2010-03-11 | 2010-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-09-09 | 2014-03-11 | 2014-09-10 | $7700.00 | Window Closed / Lapsed |