GB2222181A - Optical data storage disks - Google Patents

Optical data storage disks Download PDF

Info

Publication number
GB2222181A
GB2222181A GB8914698A GB8914698A GB2222181A GB 2222181 A GB2222181 A GB 2222181A GB 8914698 A GB8914698 A GB 8914698A GB 8914698 A GB8914698 A GB 8914698A GB 2222181 A GB2222181 A GB 2222181A
Authority
GB
United Kingdom
Prior art keywords
disk
data storage
optical data
storage disks
overcoating layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB8914698A
Other versions
GB2222181B (en
GB8914698D0 (en
Inventor
Robert James Longman
Peter Roy Helfet
Philip Adrian Storey
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PLASMON DATA SYTEMS Inc
Original Assignee
PLASMON DATA SYTEMS Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by PLASMON DATA SYTEMS Inc filed Critical PLASMON DATA SYTEMS Inc
Publication of GB8914698D0 publication Critical patent/GB8914698D0/en
Publication of GB2222181A publication Critical patent/GB2222181A/en
Application granted granted Critical
Publication of GB2222181B publication Critical patent/GB2222181B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/14—Metallic material, boron or silicon
    • C23C14/20—Metallic material, boron or silicon on organic substrates
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/2403—Layers; Shape, structure or physical properties thereof
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/254—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of protective topcoat layers
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/254—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of protective topcoat layers
    • G11B7/2542—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of protective topcoat layers consisting essentially of organic resins
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/254—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of protective topcoat layers
    • G11B7/2548—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of protective topcoat layers consisting essentially of inorganic materials

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Optical Record Carriers And Manufacture Thereof (AREA)
  • Manufacturing Optical Record Carriers (AREA)

Abstract

A method of adapting the characteristics of optical data storage disks involves applying an overcoating layer to the disk in order to reduce the reflectivity and/or recording sensitivity of the disk. The overcoating layer may be a thin metal film or a thin film of an organic material, eg an absorbing dye.

Description

IMPROVEMENTS RELATING TO OPTICAL DATA STORAGE DISKS This invention relates to optical data storage disks.
At the present time a variety of different technologies are used in the production of recordable optical disks.
It is well know that the characteristics of the different technologies are not compatible which makes the interchange of disks between drives difficult or impossible.
This invention discloses a method of changing the characteristics of a recording medium by a modification to the disk substrate. In particular, the reflectivity (which influences servo performance) can be modified and the sensitivity reduced (for example to match the sensitivity of a dye polymer or thin metal film medium to the characteristics of a phase change recording layer).
In one aspect, the invention provides a method of modifying the characteristics of an optical data storage disk, which is characterised by applying an overcoating layer to the disk in order to reduce the reflectivity and/or recording sensitivity of the disk.
In another aspect, the invention provides a method of producing optical data storage disks of pre-selected characteristics, which is characterised in that a predetermined quantity of an optically absorbent material is incorporated into the substrate of the disk.
The laser energy used to read and write to the active layer passes through the substrate. The reflected light makes two passes while the writing energy only makes one pass. By increasing the absorption of the substrate material the apparent reflectivity of the recording layer is reduced as a result of the two passes through the absorbing layer while the sensitivity during recording is reduced only by one pass.
For example, a thin layer of an absorbing dye or a thin metal film may be deposited on the top surface of a ready-to-use recordable disk. If the absorption of this layer is 20% the apparent reflectivity of the recording layer will be reduced by 36% on the two passes. Thus with a recording medium with a starting reflectivity of 15% and a recording threshold of 4mW, such a change in absorbance of the substrate will effectively change the read/write parameters of the disk such that the reflectivity becomes 10% and the recording threshold becomes 5 mW.
The absorption in the substrate can be produced by surface treatment such as the overcoats described above; or by incorporating an absorbing material in the bulk of the substrate. The latter route is preferred for high volume application of the invention; this modification of the substrate (e.g. polycarbonate or PMMA) will be effected before or during disk manufacture and can readily be controlled to give substrates of the desired absorbance (from approximately zero with no added absorbing material up to any desired value of absorbance) with only minor adjustments during the production process.
In addition to allowing the modification of read and write characteristics the use of absorbing layers reduces the risk of damage to the substrate or recording layer caused by continuous reading. Because the signal and unwritten reflectivity signals are equally affected the signal to noise ratio of the medium is not reduced.
Thus by means of the present invention, it is possible to use an absorbing substrate or overcoating layer to match the characteristics of one optical recording medium to those of another type of medium. A metal or organic overcoating layer may be used to achieve this, and/or the use of an absorbing dye in the substrate material.

Claims (4)

1. A method of modifying the characteristics of an optical data storage disk, which is characterised by applying an overcoating layer to the disk in order to reduce the reflectivity and/or recording sensitivity of the disk.
2. A method according to claim 1, characterised in that said overcoating layer is a thin metal film.
3. A method according to claim 1, characterised in that said overcoating layer is a thin film of an organic material.
4. A method of producing optical data storage disks of pre-selected characteristics, which is characterised in that a predetermined quantity of an optically absorbent material is incorporated into the substrate of the disk.
GB8914698A 1988-06-27 1989-06-27 Improvements relating to optical data storage disks Expired - Fee Related GB2222181B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8815235A GB8815235D0 (en) 1988-06-27 1988-06-27 Improvements relating to optical data storage disks

Publications (3)

Publication Number Publication Date
GB8914698D0 GB8914698D0 (en) 1989-08-16
GB2222181A true GB2222181A (en) 1990-02-28
GB2222181B GB2222181B (en) 1993-01-06

Family

ID=10639418

Family Applications (2)

Application Number Title Priority Date Filing Date
GB8815235A Pending GB8815235D0 (en) 1988-06-27 1988-06-27 Improvements relating to optical data storage disks
GB8914698A Expired - Fee Related GB2222181B (en) 1988-06-27 1989-06-27 Improvements relating to optical data storage disks

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB8815235A Pending GB8815235D0 (en) 1988-06-27 1988-06-27 Improvements relating to optical data storage disks

Country Status (1)

Country Link
GB (2) GB8815235D0 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0642124A1 (en) * 1993-09-08 1995-03-08 Sony Corporation Optical information recording medium

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1331491A (en) * 1969-06-06 1973-09-26 Chase Manhattan Capital Corp Laser recording
GB2005457A (en) * 1977-09-29 1979-04-19 Philips Nv Optically written information recording element
GB1547009A (en) * 1976-11-15 1979-06-06 Ibm Magnetic recording medium
EP0026496A1 (en) * 1979-10-01 1981-04-08 Xebec Magnetic recording disc and method for forming a protective overcoating thereon
EP0084729A1 (en) * 1981-12-22 1983-08-03 Fujitsu Limited Recording elements
US4451915A (en) * 1982-04-15 1984-05-29 Burroughs Corporation Optical storage system employing a multi-layer optical medium
EP0135370A1 (en) * 1983-08-19 1985-03-27 Hitachi, Ltd. Information recording member
US4525412A (en) * 1982-11-15 1985-06-25 Sony Corporation Information recording medium
EP0186467A2 (en) * 1984-12-28 1986-07-02 Pioneer Electronic Corporation Optical data recording medium and method
US4719170A (en) * 1985-03-02 1988-01-12 Basf Aktiengesellshaft Optical recording material
US4751309A (en) * 1985-09-21 1988-06-14 Basf Aktiengesellschaft Methine dyes and preparation thereof

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4527173A (en) * 1984-04-16 1985-07-02 Eastman Kodak Company Erasable, reusable optical recording element and method

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1331491A (en) * 1969-06-06 1973-09-26 Chase Manhattan Capital Corp Laser recording
GB1547009A (en) * 1976-11-15 1979-06-06 Ibm Magnetic recording medium
GB2005457A (en) * 1977-09-29 1979-04-19 Philips Nv Optically written information recording element
EP0026496A1 (en) * 1979-10-01 1981-04-08 Xebec Magnetic recording disc and method for forming a protective overcoating thereon
EP0084729A1 (en) * 1981-12-22 1983-08-03 Fujitsu Limited Recording elements
US4451915A (en) * 1982-04-15 1984-05-29 Burroughs Corporation Optical storage system employing a multi-layer optical medium
US4525412A (en) * 1982-11-15 1985-06-25 Sony Corporation Information recording medium
EP0135370A1 (en) * 1983-08-19 1985-03-27 Hitachi, Ltd. Information recording member
EP0186467A2 (en) * 1984-12-28 1986-07-02 Pioneer Electronic Corporation Optical data recording medium and method
US4719170A (en) * 1985-03-02 1988-01-12 Basf Aktiengesellshaft Optical recording material
US4751309A (en) * 1985-09-21 1988-06-14 Basf Aktiengesellschaft Methine dyes and preparation thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
H. Zollinger "Color Chemistry", pub. 1987, VCH Verlagsgesellschaft, pages 296-298 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0642124A1 (en) * 1993-09-08 1995-03-08 Sony Corporation Optical information recording medium
US5556681A (en) * 1993-09-08 1996-09-17 Sony Corporation Optical information recording medium

Also Published As

Publication number Publication date
GB2222181B (en) 1993-01-06
GB8815235D0 (en) 1988-08-03
GB8914698D0 (en) 1989-08-16

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19930627