Optical data storage medium and use of such medium

Patent metadata

Field	Value
Publication number	US-9324356-B2
Application number	US-51791703-A
Country	US
Kind code	B2
Filing date	Jun 13, 2003
Priority date	Jun 18, 2002
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A multi-stack optical data storage medium ( 30 ) for recording and reading using a focused radiation beam ( 40 ) entering through an entrance face ( 41 ) of the medium ( 30 ) is described. It has a first substrate ( 31 a ) with present on a side thereof a first recording stack ( 33 ) named L 0 , comprising a recordable type L 0 recording layer ( 35 ), formed in a first L 0 guide groove ( 38 a, 38 b ). A first reflective layer ( 39 ) is present between the first L 0 recording layer ( 35 ) and the first substrate ( 31 a ). A second substrate ( 31 b ) with present on a side thereof a second recording stack ( 32 ) named L 1 is present at a position closer to the entrance face ( 41 ) than the L 0 recording stack ( 33 ) and formed in a second L 1 guide groove ( 37 ). A transparent spacer layer ( 36 ) is sandwiched between the recording stacks ( 32, 33 ). The first L 0 guide groove ( 38 a, 38 b ) has a depth G L0 <100 nm. In this way a relatively high reflection value of the L 0 stack is achieved at a radiation beam wavelength of approximately 655 nm.

First claim

The invention claimed is:

1. A multi-stack optical data storage medium for recording and reading using a focused radiation beam having a wavelength of 655 nm entering through an entrance face of the medium during recording and reading, comprising:
a first substrate having, on a side thereof, a first recording stack L 0 comprising a recordable type L 0 recording layer comprising a dye, and formed in a first L 0 guide groove, and a first reflective layer present between the L 0 recording layer and the first substrate;
a second substrate having, on a side thereof, a second recording stack L 1 comprising a recordable type L 1 recording layer, said second recording stack L 1 being at a position closer to the entrance face than the first recording stack L 0 and formed in a second L 1 guide groove;
a transparent spacer layer sandwiched between the first and second recording stacks; and
a dielectric layer present at a side of the L 0 recording layer opposite from the side where the first reflective layer is present,
wherein the dielectric layer has a thickness in the range of 5 nm to 14 nm.

2. The multi-stack optical data storage medium as claimed in claim 1 , wherein said multi-stack optical data storage medium further comprises a second reflective layer comprising a metal present at a side of the L 0 recording layer opposite from the side where the first reflective layer is present.

3. The multi-stack optical data storage medium as claimed in claim 2 , wherein the second reflective layer has a thickness in the range of 5 nm-15 nm.

4. The multi-stack optical data storage medium as claimed in claim 2 , wherein the metal is selected from the group of Ag, Au, Cu, Al.

5. The multi-stack optical data storage medium as claimed in claim 1 , wherein the effective reflection level of the stacks is at least 0.18 at a radiation beam wavelength of approximately 655 nm.

6. The multi-stack optical data storage medium of claim 1 , wherein the multi-stack optical data storage medium has a modulation M of 75% and a reflection level of 70%, and wherein the modulation is M=(R no-mark −R mark )/R no-mark , R mark and R no-mark being reflection levels from a read out laser beam when respectively a written mark and no mark are present.

7. The multi-stack optical data storage medium of claim 1 , wherein a thickness of the spacer layer is between 40 μm to 70 μm.

8. The multi-stack optical data storage medium of claim 1 , further comprising a third recording stack formed over the second recording stack L 1 , wherein the third recording stack includes a third guide groove in the first substrate, the third guide groove having a thickness from 25 nm to 40 nm, a dye layer formed over the third guide groove and having a thickness from 90 nm to 160 nm, and a third reflective layer formed over the dye layer and having a thickness of 100 nm.

9. A multi-stack optical data storage medium for recording and reading using a focused radiation beam having a wavelength of 655 nm entering through an entrance face of the medium during recording and reading, comprising:
a first substrate having, on a side thereof, a first recording stack L 0 comprising a recordable type L 0 recording layer comprising a dye, and formed in a first L 0 guide groove, and a first reflective layer present between the L 0 recording layer and the first substrate, wherein the first L 0 guide groove has a width of 500<W L0 <600 nm;
a second substrate having, on a side thereof, a second recording stack L 1 comprising a recordable type L 1 recording layer and a second reflective layer present at a side of the L 0 recording layer opposite from the side where the first reflective layer is present, said second recording stack L 1 being at a position closer to the entrance face than the first recording stack L 0 and formed in a second L 1 guide groove;
a transparent spacer layer sandwiched between the first and second recording stacks; and
a dielectric layer present at a side of the L 0 recording layer opposite from the side where the first reflective layer is present,
wherein the dielectric layer has a thickness in the range of 5 nm to 14 nm, and
wherein the second reflective layer has a thickness in the range of 5 nm to 15 nm.

10. The multi-stack optical data storage medium of claim 9 , wherein a thickness of the spacer layer is between 40 μm to 70 μm.

11. The multi-stack optical data storage medium of claim 9 , further comprising a third recording stack formed over the second recording stack L 1 , wherein the third recording stack includes a third guide groove in the first substrate, the guide groove having a thickness from 25 nm to 40 nm, a dye layer formed over the third guide groove and having a thickness from 90 nm to 160 nm, and a third reflective layer formed over the dye layer and having a thickness of 100 nm.

Assignees

• Martens Hubert Cécile François
• Van Den Oetelaar Ronald Joseph Antonius
• Koninkl Philips Nv

Inventors

• Martens Hubert Cécile François
• Van Den Oetelaar Ronald Joseph Antonius

Classifications

• G11B7/24

  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 title

• G11B7/00455 Primary

  involving reflectivity, absorption or colour changes · CPC title

• G11B7/007

  Arrangement of the information on the record carrier, e.g. form of tracks {, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track} · CPC title

• G11B7/0052

  involving reflectivity, absorption or colour changes · CPC title

• G11B7/24079 Primary

  Width or depth (G11B7/24076 takes precedence) · CPC title