Method for modifying optical path on optical recording medium having distortion regions

• US 7,944,806 B2
• Filed: 04/17/2008
• Issued: 05/17/2011
• Est. Priority Date: 12/14/2000
• Status: Expired due to Fees

• Current Assignee: SCA IPLA Holdings Incorporated (Sony Group Corp.)
• Original Assignee: SCA IPLA Holdings Incorporated (Sony Group Corp.)
• Inventors: Hart, John J. III, Howard, Daniel G., Lee, Andrew R., LeVine, Richard B.
• Primary Examiner(s): Dinh; Tan X
• Application Number:
  US12/105,054
• Publication Number:
  US 20080212450A1
• Time in Patent Office: 1,125 Days
• Field of Search: 369/275.5, 369/275.1, 369/275.2, 369/275.4, 369/53.2, 369/53.41, 428/64.1, 430/321, 430/320, 430/270.11, 380/201, 380/202, 380/203, 726/26, 726/32, 726/33
• US Class Current: 369/275.5
• 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 20/00173 wherein the origin of the content is checked, e.g. determining whether the content has originally been retrieved from a legal disc copy or another trusted source
• CPC Class Codes: G11B 20/00586 said format change concerning the physical format of the recording medium
• CPC Class Codes: G11B 20/00608 wherein the material that the record carrier is made of is altered, e.g. adding reactive dyes that alter the optical properties of a disc after prolonged exposure to light or air
• CPC Class Codes: G11B 20/00659 involving a control step which is implemented as an executable file stored on the record carrier
• CPC Class Codes: G11B 20/00927 wherein said defects or errors are generated on purpose, e.g. intended scratches
• CPC Class Codes: G11B 2220/2562 DVDs [digital versatile discs]; Digital video discs; MMCDs; HDCDs
• CPC Class Codes: G11B 23/281 by changing the physical properties of the record carrier
• 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: Y10T 428/21 Circular sheet or circular blank

Abstract

Theft, distribution, and piracy of digital content on optical media (software, video, audio, e-books, any content of any kind that is digitally stored and distributed) is often accomplished by copying it directly to another disc using commonly available copy tools and recordable optical media, or the copying of media to another mass manufactured disc. Methods which cause—the copy process to become lengthy and inconvenient, or which produce copies that are significantly measurably different from the original and therefore be recognizable as copies, deter or prevent an unauthorized individual from making copies. This is accomplished by modifying the optical path of an optical medium to include regions of selective distortion. This, in turn, modifies the read operation of the data in the regions, which can be used to identify and authenticate the medium.

Claims

1. A method for modifying an optical path of an optical medium, the optical medium including a first layer adjacent to a data layer and a back layer on the data layer opposite the first layer, the method comprising:

selecting a region of the optical medium to be distorted; and

prior to a reading operation of the medium, distorting the region of the data layer of the optical medium by forming an indentation in the back layer such that a reading operation of data stored in the data layer corresponding to the distorted region is modified, the distorted region maintaining its optical characteristics following irradiation of the distorted region during the reading operation.

2. The method of claim 1 wherein the distorted region extends in a direction along a track of the data layer.

5. The method of claim 1 wherein distorting the region of the data layer comprises changing a geometry of physical data of the data layer.

6. The method of claim 1 wherein distorting the region of the data layer comprises changing a geometry of tracks of the data layer.

7. The method of claim 1 wherein distorting the region of the data layer comprises causing data spirals of tracks of the data layer to be physically bent out of alignment.

8. The method of claim 1 further comprising encapsulating the indentation.

9. The method of claim 8 wherein encapsulating comprises providing a second layer on the indentation.

10. The method of claim 1 wherein distorting the region of the data layer is conducted during manufacture of the optical medium.

11. The method of claim 1 wherein distorting the region of the data layer is conducted following manufacture of the optical medium.

12. The method of claim 1 wherein distorting the region of the data layer is conducted by a distorting technique selected from a group of techniques consisting of:

pressure, heat, chemical, electrical, friction, and drilling.

13. The method of claim 1 wherein the optical medium is a dual-sided medium having dual opposed data layers and first layers.

3. An optical medium having a modified optical path comprising:

a first layer adjacent a data layer;

a back layer on the data layer opposite the first layer; and

a distorted region, including an indentation in the back layer, formed at the data layer prior to a reading operation of the medium such that a reading operation of data stored in the data layer corresponding to the distorted region is modified, the distorted region maintaining its optical characteristics following irradiation of the distorted region during the reading operation.

4. The optical medium of claim 3 wherein the distorted region extends in a direction along a track of the data layer.

14. The optical medium of claim 3 wherein a geometry of physical data of the data layer is changed in the distorted region.

15. The optical medium of claim 3 wherein a geometry of tracks of the data layer is changed in the distorted region.

16. The optical medium of claim 3 wherein data spirals of tracks of the data layer are physically bent out of alignment in the distorted region.

17. The optical medium of claim 3 further comprising an encapsulation layer on the indentation.

18. The optical medium of claim 3 wherein the distorted region is formed during manufacture of the optical medium.

19. The optical medium of claim 3 wherein the distorted region is formed following manufacture of the optical medium.

20. The optical medium of claim 3 wherein the distorted region is formed by a distorting technique selected from a group of techniques consisting of:

pressure, heat, chemical, electrical, friction, and drilling.

21. The optical medium of claim 3 wherein the optical medium is a dual-sided medium having dual opposed data layers and first layers.