Hologram printed on optical recording medium for copy protection

• US 5,587,984 A
• Filed: 09/08/1995
• Issued: 12/24/1996
• Est. Priority Date: 09/13/1994
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Owa, Hideo, Kobayashi, Seiji
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): CHU, KIM KWOK
• Application Number:
  US08/525,191
• Time in Patent Office: 473 Days
• Field of Search: 369/103, 369/83, 369/84, 369/280, 369/275.5, 364/286.6, 380/3.4
• US Class Current: 369/103
• CPC Class Codes: G03H 1/0011 for security or authentication holograms on information-bearing cards B42D25/328; testing papers with holograms G07D7/0032
• CPC Class Codes: G03H 2270/22 Disc shaped
• 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 20/00123 the record carrier being identified by recognising some of its unique characteristics, e.g. a unique defect pattern serving as a physical signature of the record carrier
• 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 23/284 on the record carrier
• CPC Class Codes: G11B 23/40 Identifying or analogous means applied to or incorporated in the record carrier and not intended for visual display simultaneously with the playing-back of the record carrier, e.g. label, leader, photograph
• CPC Class Codes: G11B 7/263 Preparing and using a stamper, e.g. pressing or injection molding substrates production of optical record carriers, e.g. optical discs B29D17/005

Abstract

An optical recording medium is disclosed, in which holograms for recording medium discrimination are recorded in a recording medium discrimination information recording area provided on the side of an inner circle within an information recording area on a compact disc. Thus, it is difficult to copy an original optical recording medium to produce a fake product, and it is possible to distinguish the original optical recording medium from the fake product by external appearance.

Claims

1. An optical recording medium having signals optically recorded therein, the optical recording medium comprising a hologram for recording medium discrimination recorded in an area other than an information recording area in which information signals are recorded.

2. The optical recording medium as claimed in claim 1, wherein the hologram is recorded in the optical recording medium by processes of cutting the hologram on a base plate of the recording medium by laser and producing a stamper from the base plate of the recording medium on which the hologram is cut.

3. The optical recording medium as claimed in claim 2, wherein the hologram is recorded in a form of two-dimensional signal pattern in the optical recording medium.

4. The optical recording medium as claimed in claim 2, wherein the hologram is identified using a diffraction image produced by radiating a light emitted from optical means other than an optical pickup for reproducing the information signals.

5. The optical recording medium as claimed in claim 2, wherein plural holograms are provided in the area other than the information recording area, the holograms being discontinuously located at predetermined intervals.

6. The optical recording medium as claimed in claim 5, wherein the plural holograms are located at intervals of 2-5 mm.

7. The optical recording medium as claimed in claim 2, wherein the hologram is recorded in a recording/reproducing mode which differs from a recording/reproducing mode of the information signals.

8. The optical recording medium as claimed in claim 7, wherein the hologram is recorded in the optical recording medium in a CAV mode and wherein the information signals are recorded in the optical recording medium in a CLV mode.

9. The optical recording medium as claimed in claim 2, wherein the hologram is recorded as a binary pattern with random distribution in the optical recording medium.

10. A signal recording method for recording signals in an optical recording medium, the method comprising:

a first step of receiving information signals to be recorded in the optical recording medium;

a second step of receiving a hologram for discriminating the optical recording medium;

a third step of recording the information signal in an information recording area of the optical recording medium; and

a fourth step of recording the hologram in an area other than the information recording area.

11. The signal recording method as claimed in claim 10, wherein the fourth step comprises

a step of cutting the hologram on a base plate of the recording medium by laser, and

a step of producing a stamper from the base plate on which the hologram is cut.

12. The signal recording method as claimed in claim 11, wherein the hologram is in a form of two-dimensional signal pattern.

13. The signal recording method as claimed in claim 11, wherein the fourth step further comprises a step of, when plural holograms are received, locating the holograms discontinuously at predetermined intervals in the area other than the information recording area.

14. The signal recording method as claimed in claim 13, wherein in the step of locating the holograms, the plural holograms are located at intervals of 2-5 mm.

15. The signal recording method as claimed in claim 11, wherein in the step of cutting the hologram, the hologram is cut on the base plate of the recording medium in a recording/reproducing mode which differs from a recording/reproducing mode of the information signals.

16. The signal recording method as claimed in claim 15, wherein the hologram is recorded in the optical recording medium in a CAV mode and wherein the information signals are recorded in the optical recording medium in a CLV mode.

17. The signal recording method as claimed in claim 11, wherein the third step further comprises a step of converting the hologram to a binary pattern with random distribution.