IP Library Granted Patent US 8,114,496
Granted Patent B2
US 8,114,496 · App. 12/160,856 · Granted Feb 14, 2012

Optical recording medium

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Quick Facts
Patent No.
US 8,114,496
App. No.
12/160,856
Granted
Feb 14, 2012
Kind
B2
Abstract

Provided is an extremely high-density optical recording medium with excellent jitter characteristics and good recording/reproducing characteristics. An optical recording medium 20 comprises a substrate 21 with a guide groove formed therein, a layer 23 with a light reflection function, a recording layer 22 comprising a dye as a main component with a light absorption function for a wavelength of recording/reproducing light in an unrecorded state, and a cover layer 24 capable of transmitting the recording/reproducing light incident to the recording layer 22 , in the order mentioned; an interlayer 30 containing at least one element selected from the group consisting of Ta, Nb, V, W, Mo, Cr and Ti, is provided between the layer 23 with the light reflection function and the recording layer 22.

Claims (22)

1. An optical recording medium comprising:

a substrate with a guide groove formed therein,

a layer with a light reflection function comprising Ag as a main component, a recording layer comprising a dye as a main component with a light absorption function for a wavelength of recording/reproducing light in an unrecorded state, and a cover layer capable of transmitting the recording/reproducing light incident to the recording layer, in the order mentioned, on the substrate,

wherein an interlayer is provided between the layer with the light reflection function and the recording layer, and

wherein the interlayer contains at least one element selected from the group consisting of Ta, Nb, V, W, Mo, Cr and Ti.

2. The optical recording medium according to claim 1 , wherein the interlayer has a thickness of at least 1 nm and at most 15 nm.

3. The optical recording medium according to claim 1 , wherein the layer with the light reflection function comprising Ag as a main component has a thickness of at least 30 nm and at most 90 nm.

4. The optical recording medium according to claim 1 , wherein when a recording groove part is a guide groove part on the far side from a surface where a recording/reproducing light beam resulting from focusing of the recording/reproducing light is incident to the cover layer, a reflected light intensity of a recorded pit portion formed in the recording groove part is higher than a reflected light intensity of the recording groove part in the unrecorded state.

5. The optical recording medium according to claim 4 , wherein the recording layer has a thickness of at least 5 nm and at most 70 nm in the recording groove part in the unrecorded state.

6. The optical recording medium according to claim 4 , wherein the recording layer has a thickness of at most 10 nm between the recording groove parts in the unrecorded state.

7. The optical recording medium according to claim 1 , wherein the recording/reproducing light has the wavelength λ of at least 350 nm and at most 450 nm.

8. The optical recording medium according to claim 1 , further comprising an interface layer provided between the recording layer and the cover layer to prevent interfusion of a material of the recording layer and a material of the cover layer.

9. The optical recording medium according to claim 8 , wherein the interface layer has a thickness of at least 1 nm and at most 50 nm.

10. The optical recording medium according to claim 1 , wherein the interlayer contains at least one element selected from the group consisting of Ta and Nb.

11. The optical recording medium according to claim 2 , wherein when a recording groove part is a guide groove part on the far side from a surface where a recording/reproducing light beam resulting from focusing of the recording/reproducing light is incident to the cover layer, a reflected light intensity of a recorded pit portion formed in the recording groove part is higher than a reflected light intensity of the recording groove part in the unrecorded state.

12. The optical recording medium according to claim 3 , wherein when a recording groove part is a guide groove part on the far side from a surface where a recording/reproducing light beam resulting from focusing of the recording/reproducing light is incident to the cover layer, a reflected light intensity of a recorded pit portion formed in the recording groove part is higher than a reflected light intensity of the recording groove part in the unrecorded state.

13. The optical recording medium according to claim 5 , wherein the recording layer has a thickness of at most 10 nm between the recording groove parts in the unrecorded state.

14. The optical recording medium according to claim 2 , wherein the recording/reproducing light has the wavelength λ of at least 350 nm and at most 450 nm.

15. The optical recording medium according to claim 3 , wherein the recording/reproducing light has the wavelength λ of at least 350 nm and at most 450 nm.

16. The optical recording medium according to claim 4 , wherein the recording/reproducing light has the wavelength λ of at least 350 nm and at most 450 nm.

17. The optical recording medium according to claim 5 , wherein the recording/reproducing light has the wavelength λ of at least 350 nm and at most 450 nm.

18. The optical recording medium according to claim 6 , wherein the recording/reproducing light has the wavelength λ of at least 350 nm and at most 450 nm.

Assignments (4)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 23, 2020
From: MITSUBISHI CHEMICAL MEDIA CO., LTD.
To: CMC MAGNETICS CORPORATION
Reel/Frame 051688/0598 →
CHANGE OF ADDRESS Recorded Nov 11, 2019
From: MITSUBISHI KAGAKU MEDIA CO., LTD.
To: MITSUBISHI KAGAKU MEDIA CO., LTD.
Reel/Frame 050977/0911 →
CHANGE OF NAME Recorded Nov 11, 2019
From: MITSUBISHI KAGAKU MEDIA CO., LTD.
To: MITSUBISHI CHEMICAL MEDIA CO., LTD.
Reel/Frame 050978/0091 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 23, 2008
From: HORIE, MICHIKAZU; KIYONO, KENJIROU; KUBO, MASAE
To: MITSUBISHI KAGAKU MEDIA CO., LTD.
Reel/Frame 021727/0722 →