Optical recording medium having a non-volatile identification code and method for encoding data using same

• US 5,812,501 A
• Filed: 03/13/1997
• Issued: 09/22/1998
• Est. Priority Date: 06/27/1995
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Fujitsu Limited
• Inventors: Moribe, Mineo, Izumi, Haruhiko, Taguchi, Masakazu, Tsugawa, Iwao
• Primary Examiner(s): DINH, TAN X
• Application Number:
  US08/815,947
• Time in Patent Office: 558 Days
• Field of Search: 369/14, 369/275.1, 369/47, 369/48, 369/54, 369/58, 235/454, 235/487, 235/468
• US Class Current: 369/53.22
• CPC Class Codes: G11B 11/10582 Record carriers characterised by the selection of the material or by the structure or form
• CPC Class Codes: G11B 19/02 Control of operating function, e.g. switching from recording to reproducing
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00876 wherein physical copy protection means are attached to the medium, e.g. holograms, sensors, or additional semiconductor circuitry
• CPC Class Codes: G11B 23/281 by changing the physical properties of the record carrier
• CPC Class Codes: G11B 23/284 on the record carrier
• CPC Class Codes: G11B 23/36 Signals on record carriers or on containers and recorded by the same method as the main recording
• 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 7/24085 Pits
• CPC Class Codes: G11B 7/26 Apparatus or processes specially adapted for the manufacture of record carriers

Abstract

An optical recording medium in which a medium identification code is recorded as a nonvolatile mark which is formed through irreversible change of a recording film, such as magnetization characteristic change, deformation and formation of a hole, so as to prevent illegal copying of the optical recording medium, and a recording/reproducing method for the same.

Claims

1. An optical recording medium, comprising:

a substrate;

a recording film formed on the substrate having plural tracks for storing user data and further having a track gap interposed between each of said plural tracks, and

a medium identification code recorded on the recording film as a nonvolatile mark formed by irreversibly changing a portion of the recording film.

2. The optical recording medium according to claim 1, wherein said medium identification code is recorded in each of plural portions of said recording film.

3. The optical recording medium according to claim 1, wherein one medium identification code is formed in each of an odd number of adjacent said track areas.

4. The optical recording medium according to claim 1, wherein one medium identification code is recorded in one said track area and each of two said groove areas sandwiching said track area.

7. The optical recording medium according to claim 1 wherein said medium identification code is unique for each recording medium.

5. An optical recording medium, comprising:

a substrate;

a recording film formed on the substrate, for recording data;

wherein on the recording film-are recorded;

a medium identification code recorded as a nonvolatile mark formed by irreversibly changing a portion of the recording film; and

a recording program for encoding data based on the reproduced medium identification code.

6. An optical recording medium, comprising:

a substrate; and

a recording film formed on the substrate, for recording data;

wherein on the recording film are recorded;

a medium identification code as a nonvolatile mark formed by irreversibly changing a portion of the recording film; and

a reproducing program for decoding reproduced data based on said medium identification code.

8. The optical recording medium according to claim 6 wherein said medium identification code is unique for each recording medium.