Secure storage disc and disc surveillance system

• US 6,946,963 B2
• Filed: 10/16/2002
• Issued: 09/20/2005
• Est. Priority Date: 10/16/2001
• Status: Expired due to Fees

• Current Assignee: Spectra Research, Inc.
• Original Assignee: Spectra Research, Inc.
• Inventors: Mayle, Eugene E. Jr., Sellers, John W. Jr.
• Primary Examiner(s): TRIEU, VAN THANH
• Application Number:
  US10/272,518
• Publication Number:
  US 20030086361A1
• Time in Patent Office: 1,070 Days
• Field of Search: 340/572.1, 340/572.3, 340/572.4, 340/572.5, 340/572.8, 340/10.1, 340/10.42, 235/488, 235/492, 343/700.MS, 343/795
• US Class Current: 340/572.5
• CPC Class Codes: G08B 13/2414 using inductive tags
• CPC Class Codes: G08B 13/2445 Tag integrated into item to be protected, e.g. source tagging
• CPC Class Codes: G11B 23/0042 with provision for auxiliary features sensing such features G11B17/00, G11B19/02
• CPC Class Codes: G11B 23/286 Antitheft arrangements, e.g. Electronic Article Surveillance [EAS] tags
• 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

Abstract

An information storage disc, a method of disc manufacture, and a scheme for improved disc surveillance are provided. Generally, the present invention utilizes the geometry and conductivity of a disc'"'"'s information storage medium to establish an electrically resonant circuit in the disc body. The electrically resonant circuit may be used to detect, locate, and/or monitor the disc. In accordance with 37 CFR 1.72(b), the purpose of this abstract is to enable the United States Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract will not be used for interpreting the scope of the claims.

Claims

1. An information storage disc comprising:

an information storage layer comprising an electrically conductive information storage medium;

a capacitive plate layer comprising an electrically conductive capacitive plate;

a dielectric layer comprising a dielectric portion positioned to isolate electrically said information storage medium and said capacitive plate; and

an electrical inductor configured to complete an electrically resonant circuit comprising said electrical inductor and a dielectric capacitor, wherein said dielectric capacitor comprises at least a portion of said information storage medium, at least a portion of said electrically conductive capacitive plate, and at least a portion of said dielectric portion of said dielectric layer.

2. An information storage disc as claimed in claim 1 wherein said electrically resonant circuit is configured to resonate between about 7 MHz and about 9 MHz.

3. An information storage disc as claimed in claim 1 wherein said electrically resonant circuit is configured to resonate at about 8 MHz.

4. An information storage disc as claimed in claim 1 wherein said electrically resonant circuit is configured to resonate at RF frequencies.

5. An information storage disc as claimed in claim 1 wherein said electrically resonant circuit is configured to resonate at about 5 GHz.

6. An information storage disc as claimed in claim 1 wherein said electrically resonant circuit is configured to resonate at microwave frequencies.

7. An information storage disc as claimed in claim 1 wherein said electrically resonant circuit comprises said electrical inductor and a pair of dielectric capacitors.

8. An information storage disc as claimed in claim 7 wherein said electrical inductor is characterized by an inductance of about 4 μ

H.

9. An information storage disc as claimed in claim 7 wherein each of said capacitors is characterized by a capacitance of about 180 ρ

F.

10. An information storage disc as claimed in claim 7 wherein said pair of dielectric capacitors are connected in series.

11. An information storage disc as claimed in claim 7 wherein each dielectric capacitor comprises at least a portion of said information storage medium, at least a portion of said electrically conductive capacitive plate, and at least a portion of said dielectric portion of said dielectric layer.

12. An information storage disc as claimed in claim 1 wherein said information storage disc comprises a plurality of electrically resonant circuits.

13. An information storage disc as claimed in claim 12 wherein each of said electrically resonant circuits are configured to resonate at respective substantially different resonant frequencies.

14. An information storage disc as claimed in claim 1 wherein said capacitive plate layer comprises a plurality of independent electrically conductive capacitive plates.

15. An information storage disc as claimed in claim 14 wherein said independent electrically conductive capacitive plates are coplanar.

16. An information storage disc as claimed in claim 14 wherein said capacitive plate layer comprises a pair of capacitive plate sub-layers, each including independent electrically conductive capacitive plates lying in different planes.

17. An information storage disc as claimed in claim 14 wherein:

a first electrically conductive capacitive plate and said information storage medium form a first pair of capacitively coupled plates, and

a second electrically conductive capacitive plate and said information storage medium form a second pair of capacitively coupled plates.

18. An information storage disc as claimed in claim 14 wherein said independent electrically conductive capacitive plates are arranged so as to exclude intersection of said plates by a single linear projection extending through said disc body, substantially perpendicular to a surface of said disc body.

19. An information storage disc as claimed in claim 14 wherein said independent electrically conductive capacitive plates and said electrical inductor are arranged so as to exclude intersection of said plates and said electrical inductor by a single linear projection extending through said disc body, substantially perpendicular to a surface of said disc body.

20. An information storage disc as claimed in claim 1 wherein:

said capacitive plate layer comprises first and second electrically conductive capacitive plates;

said first capacitive plate and said information storage medium form a first pair of capacitively coupled plates; and

said second capacitive plate and said information storage medium form a second pair of capacitively coupled plates.

21. An information storage disc as claimed in claim 20 wherein said first and second electrically conductive capacitive plates and said electrical inductor are coplanar.

22. An information storage disc as claimed in claim 1 wherein said capacitive plate layer comprises a conductive coating that is substantially transparent to laser radiation.

23. An information storage disc as claimed in claim 1 wherein said capacitive plate layer comprises a conductive coating that is transparent to laser radiation.

24. An information storage disc as claimed in claim 1 wherein said electrical inductor is defined in a dielectric layer of said disc.

25. An information storage disc as claimed in claim 1 wherein said dielectric layer further comprises said electrical inductor.

26. An information storage disc as claimed in claim 1 wherein said capacitive plate and said electrical inductor are coplanar.

27. An information storage disc as claimed in claim 1 wherein said electrical inductor is defined as a generally planar spiral conductor.

28. An information storage disc as claimed in claim 27 wherein said spiral conductor is defined in a dielectric layer of said disc.

29. An information storage disc as claimed in claim 27 wherein said spiral conductor is defined in said dielectric layer comprising a dielectric portion positioned to isolate electrically said information storage medium and said capacitive plate.

30. An information storage disc as claimed in claim 1 wherein a space defined between a peripheral dimension of a central opening of said disc and an inner radius of said storage medium defines a storage medium free zone.

31. An information storage disc as claimed in claim 30 wherein said electrical inductor resides in said storage medium free zone.

32. An information storage disc as claimed in claim 31 wherein said electrically conductive capacitive plate does not extend into said storage medium free zone.

33. An information storage disc as claimed in claim 1 wherein said information storage medium and said electrical inductor are arranged so as to exclude intersection of said information storage medium and said electrical inductor by a single linear projection extending through said disc body, substantially perpendicular to a surface of said disc body.

34. An information storage disc as claimed in claim 1 wherein said electrically conductive capacitive plate and said electrical inductor are arranged so as to exclude intersection of said capacitive plate and said electrical inductor by a single linear projection extending through said disc body, substantially perpendicular to a surface of said disc body.

35. An information storage disc as claimed in claim 1 wherein said electrically resonant circuit comprises a fuse configured to open said circuit upon inducement of electrical resonance at an amplitude above a deactivation threshold.

36. An information storage disc as claimed in claim 35 wherein said fuse is defined as an electrical connection between said electrically conductive capacitive plate and said electrical inductor.

37. An information storage disc as claimed in claim 36 wherein portions of said fuse are insulated from said electrically conductive capacitive plate and said electrical inductor by a dielectric portion of said disc.

38. An information storage disc as claimed in claim 35 wherein:

said electrical inductor comprises a spiral conductor formed at an inner radial portion of said disc;

said electrically conductive capacitive plate layer comprises a capacitive plate formed at an outer radial portion of said disc; and

said fuse is defined as an electrical connection between an inner end of said spiral conductor and said capacitive plate.

39. An information storage disc as claimed in claim 38 wherein said fuse extends across said spiral conductor, insulated from a majority of said spiral conductor by a dielectric portion of said disc.

40. An information storage disc as claimed in claim 1 wherein said information storage layer comprises conductive and dielectric portions.

41. An information storage disc as claimed in claim 1 wherein said information storage disc comprises a plurality of information storage layers.

42. An information storage disc as claimed in claim 1 wherein said information storage medium comprises a single, substantially planar layer of electrically conductive material.

43. An information storage disc as claimed in claim 1 wherein said information storage medium comprises a pair of substantially planar layers of electrically conductive material.

44. An information storage disc as claimed in claim 1 wherein said information storage medium carries data selected from audio, video, software, and combinations thereof.

45. An information storage disc as claimed in claim 1 wherein said information storage medium is configured for reading of data from one of said upper and lower disc surfaces.

46. An information storage disc as claimed in claim 1 wherein said information storage medium is configured for reading of data from both said upper and said lower disc surfaces.

47. An information storage disc as claimed in claim 1 wherein said information storage medium comprises a metallic layer.

48. An information storage disc as claimed in claim 1 wherein said information storage medium comprises a conductive layer.

49. An information storage disc as claimed in claim 1 wherein said information storage medium comprises a substantially planar continuous layer.

50. An information storage disc as claimed in claim 1 wherein said capacitive plate layer comprises at least one dielectric portion.

51. An information storage disc as claimed in claim 1 wherein said information storage disc comprises a plurality of dielectric layers.

52. An information storage disc as claimed in claim 51 wherein one or more of said dielectric layers comprise electrically conductive portions.

53. An information storage disc as claimed in claim 1 wherein said dielectric layer includes a plurality of dielectric portions.

54. An information storage disc as claimed in claim 53 wherein said plurality of dielectric portions are coplanar.

55. An information storage disc as claimed in claim 53 wherein said plurality of dielectric portions lie in multiple planes.

56. An information storage disc as claimed in claim 1 wherein said disc comprises a disc body defining an outer periphery, an inner periphery, and a central opening.

57. An information storage disc as claimed in claim 1 wherein said information storage disc is formatted as one of a CD and a DVD.

58. An information storage disc comprising:

a disc body defining an outer periphery, an inner periphery, and upper and lower disc surfaces;

an information storage medium disposed between said upper and lower disc surfaces, wherein

said information storage medium extends from a storage medium inner radius to a storage medium outer radius,

said storage medium defines an electrical conductivity sufficient to function as a capacitance plate of a dielectric capacitor;

at least one electrically conductive region disposed between said upper and lower disc surfaces, wherein

said electrically conductive region and said information storage medium are electrically isolated by a dielectric portion of said disc body, and

at least a portion of said electrically conductive region and at least a portion of said information storage medium extend along a common radial portion of said disc body to define a capacitively coupled pair of capacitor plates;

an electrical inductor disposed between said upper and lower disc surfaces, wherein said electrical inductor and said capacitively coupled pair of capacitor plates define an electrically resonant circuit.

59. An information storage disc surveillance system comprising:

an electromagnetic transmitter configured to generate an electromagnetic signal comprising at least one predetermined frequency;

an electromagnetic receiver positioned to receive said electromagnetic signal and configured to detect resonance of said signal; and

at least one information storage disc comprising an electrically resonant circuit configured to resonate at said predetermined frequency, wherein said information storage disc comprises;

an information storage layer comprising an electrically conductive information storage medium;

a capacitive plate layer comprising an electrically conductive capacitive plate;

a dielectric layer comprising a dielectric portion positioned to isolate electrically said information storage medium and said capacitive plate; and

an electrical inductor configured to complete said electrically resonant circuit comprising said electrical inductor and a dielectric capacitor, wherein said dielectric capacitor comprises at least a portion of said information storage medium, at least a portion of said electrically conductive capacitive plate, and at least a portion of said dielectric portion of said dielectric layer.