WRITE-ONCE-READ-MANY OPTICAL DISK HAVING LOW-TO-HIGH RECORDING PROPERTY ACCOMMODATING SHORT WAVELENGTH RECORDING

• US 20110116353A1
• Filed: 11/08/2010
• Published: 05/19/2011
• Est. Priority Date: 07/28/2005
• Status: Active Grant

• Current Assignee: Noboru Sasa
• Original Assignee: Noboru Sasa
• Inventors: Sasa, Noboru
• Granted Patent: US 8,846,298 B2
• Time in Patent Office: Days
• US Class Current: 369/100
• CPC Class Codes: G11B 2007/24705 Cyanine
• CPC Class Codes: G11B 2007/25706 containing transition metal elements (Zn, Fe, Co, Ni, Pt)
• CPC Class Codes: G11B 2007/2571 containing group 14 elements except carbon (Si, Ge, Sn, Pb)
• CPC Class Codes: G11B 2007/25715 containing oxygen
• CPC Class Codes: G11B 2007/25716 containing sulfur
• CPC Class Codes: G11B 7/00455 involving reflectivity, absorption or colour changes
• CPC Class Codes: G11B 7/00456 Recording strategies, e.g. pulse sequences G11B7/0062 takes precedence
• CPC Class Codes: G11B 7/24 Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the arrangement of information on the carrier G11B7/007
• CPC Class Codes: G11B 7/24035 Recording layers substrates also used as recording layers G11B7/24047
• CPC Class Codes: G11B 7/258 of reflective layers

Abstract

A write-only-read-many type optical recording medium includes a substrate, an organic material layer having a light absorption function that is sufficient for recording in the recording/reproduction wavelength range, the organic material layer being situated on the substrate, and a reflection layer being situated on the organic material layer. The recording medium is configured to have a Low-to-High recording property and record with a laser having a wavelength that is no greater than 500 nm.

Claims

1. A recording/reproduction method exhibiting a Low-to-High recording property, the method comprising a step of:

performing a recording/reproduction process on an optical recording medium by using a laser having a wavelength that is no greater than 500 nm;

wherein the optical recording medium includes a substrate,

an organic material layer provided on the substrate, the organic material layer having a light absorption function that is sufficient for recording in a recording/reproduction wavelength range,

a reflection layer provided on the organic material layer, and

a heat insulating layer provided adjacent to the organic material layer;

wherein the organic material layer contains an organic material having a first absorption band situated toward a long wavelength side with respect to the recording/reproduction wavelength range,

a second absorption band that does not belong to the first absorption band, the second absorption band situated in the vicinity of the recording/reproduction wavelength range, and

a third absorption band situated toward a short wavelength side with respect to the recording/reproduction wavelength range, the third absorption band exhibiting an absorption greater than an absorption of another absorption band situated toward the long wavelength side with respect to the recording/reproduction wavelength range, wherein the third absorption band has a largest absorption wavelength that is no greater than 300 nm.

2. The recording/reproduction method as claimed in claim 1, wherein the heat insulating layer includes any of SiO₂, ZnS.SiO₂, and ZrO₂ as a main component.

3. The recording/reproduction method as claimed in claim 1, wherein the heat insulating layer includes ZnS, ZrO₂, Y₂O₃, and SiO₂.

4. The recording/reproduction method as claimed in claim 1, wherein the heat insulating layer includes ZrO₂, TiO₂, SiO₂, and X, wherein X includes at least one of Al₂O₃, MgO, CaO, NbO, Y₂O₃, and CeO.

5. The recording/reproduction method as claimed in claim 1, wherein the substrate includes groove parts and land parts, wherein recording areas are formed in both the groove parts and the land parts.

6. A recording/reproduction method exhibiting a Low-to-High recording property, the method comprising a step of:

performing a recording/reproduction process on an optical recording medium by using a laser having a wavelength that is no greater than 500 nm;

wherein the optical recording medium includes a substrate,

a reflection layer provided on the substrate,

an organic material layer provided on the reflection layer, the organic material layer having a light absorption function that is sufficient for recording in a recording/reproduction wavelength range,

a cover layer, and

a heat insulating layer provided adjacent to the organic material layer,

wherein the organic material layer contains an organic material having a first absorption band situated toward a long wavelength side with respect to the recording/reproduction wavelength range,

a second absorption band that does not belong to the first absorption band, the second absorption band situated in the vicinity of the recording/reproduction wavelength range, and

a third absorption band situated toward a short wavelength side with respect to the recording/reproduction wavelength range, the third absorption band exhibiting an absorption greater than an absorption of another absorption band situated toward the long wavelength side with respect to the recording/reproduction wavelength range, wherein the third absorption band has a largest absorption wavelength that is no greater than 300 nm.

7. The recording/reproduction method as claimed in claim 6, wherein the heat insulating layer includes any of SiO₂, ZnS.SiO₂, and ZrO₂ as a main component.

8. The recording/reproduction method as claimed in claim 6, wherein the heat insulating layer includes ZnS, ZrO₂, Y₂O₃ and SiO₂.

9. The recording/reproduction method as claimed in claim 6, wherein the heat insulating layer includes ZrO₂, TiO₂, SiO₂ and X, wherein X includes at least one of Al₂O₃, MgO, CaO, NbO, Y₂O₃, and CeO.