Write-once-read-many optical disk having low-to-high recording property accommodating short wavelength recording

• US 20070037095A1
• Filed: 07/28/2005
• Published: 02/15/2007
• Est. Priority Date: 07/28/2005
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Sasa, Noboru
• Granted Patent: US 8,859,184 B2
• Time in Patent Office: Days
• US Class Current: 430/270.180
• 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 write-only-read-many type optical recording medium comprising:

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;

wherein 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.

3. The write-only-read-many type optical recording medium as claimed in claim 1, further comprising:

a heat insulating layer situated between the organic material layer and the reflection layer.

4. The write-only-read-many type optical recording medium as claimed in claim 3, wherein the heat insulating layer includes any of SiO₂, ZnS.SiO₂, and ZrO₂ as a main component.

5. The write-only-read-many type optical recording medium as claimed in claim 3, wherein the heat insulating layer includes ZnS, ZrO₂, Y₂O₃, and SiO₂.

6. The write-only-read-many type optical recording medium as claimed in claim 3, 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.

7. The write-only-read-many type optical recording medium as claimed in claim 1, wherein the organic material layer includes an organic material having a main absorption band situated toward the long wavelength side with respect to the recording/reproduction wavelength range and a second absorption band situated in the vicinity of the recording/reproduction wavelength range.

8. The write-only-read-many type optical recording medium as claimed in claim 1, wherein the substrate include groove parts and land parts, wherein recording can be performed on both the groove parts and land parts.

2. A write-only-read-many type optical recording medium comprising:

a substrate;

a reflection layer being situated on the 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 reflection layer; and

a cover layer being situated on the organic material layer;

wherein 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.

9. A write-only-read-many type optical recording medium comprising:

a substrate;

an organic material layer being situated on the substrate; and

a light absorption layer being situated adjacent to the organic material layer;

wherein 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.

10. The write-only-read-many type optical recording medium as claimed in claim 9, further comprising:

a reflection layer,

wherein the light absorption layer, the organic material layer, and the reflection layer are layered in this order.

11. The write-only-read-many type optical recording medium as claimed in claim 9, further comprising:

a reflection layer; and

a cover layer;

wherein the reflection layer, the organic material layer, the light absorption layer, and the cover layer are layered in this order.

12. The write-only-read-many type optical recording medium as claimed in claim 9, wherein the light absorption layer has a light absorption function for providing the Low-to-High recording property by generating change of complex refractive index, change of volume, or space parts in the organic material layer.

13. The write-only-read-many type optical recording medium as claimed in claim 9, wherein the light absorption layer has a light absorption function for providing the Low-to-High recording property by transforming the light absorption layer.

14. The write-only-read-many type optical recording medium as claimed in claim 9, wherein the organic material layer includes an organic material having a main absorption band situated toward the long wavelength side with respect to the recording/reproduction wavelength range and a second absorption band situated in the vicinity of the recording/reproduction wavelength range.

15. The write-only-read-many type optical recording medium as claimed in claim 14, wherein the organic material satisfies a relation of (light absorption function of organic material layer in recording/reproduction wavelength area)<

(light absorption function of light absorption layer in recording/reproduction wavelength area).

16. The write-only-read-many type optical recording medium as claimed in claim 9, wherein the substrate include groove parts and land parts, wherein recording can be performed on both the groove parts and land parts.