Method and system for optical disc copy-protection

• US 20050084645A1
• Filed: 12/07/2004
• Published: 04/21/2005
• Est. Priority Date: 02/07/2002
• Status: Abandoned Application

• Current Assignee: Junzhong Li, Peter Miller, Rakesh Vig, Richard H. Selinfreund
• Original Assignee: Junzhong Li, Peter Miller, Rakesh Vig, Richard H. Selinfreund
• Inventors: Miller, Peter, Li, Junzhong, Vig, Rakesh, Selinfreund, Richard H.
• Application Number:
  US11/006,337
• Publication Number:
  US 20050084645A1
• Time in Patent Office: Days
• US Class Current: 428/64.400
• CPC Class Codes: G06K 19/06009 with optically detectable marking G06K19/063, G06K19/08 take precedence
• CPC Class Codes: G06K 19/06046 Constructional details
• CPC Class Codes: G11B 19/04 Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
• CPC Class Codes: G11B 19/12 by sensing distinguishing features of or on records, e.g. diameter end mark
• CPC Class Codes: G11B 19/122 involving the detection of an identification or authentication mark record carriers indicating unauthorised or prior use G11B23/28
• 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 20/00586 said format change concerning the physical format of the recording medium
• CPC Class Codes: G11B 20/00768 wherein copy control information is used, e.g. for indicating whether a content may be copied freely, no more, once, or never, by setting CGMS, SCMS, or CCI flags
• 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 20/00927 wherein said defects or errors are generated on purpose, e.g. intended scratches
• 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: G11B 7/243 comprising inorganic materials only, e.g. ablative layers
• CPC Class Codes: G11B 7/247 methine or polymethine dyes
• CPC Class Codes: G11B 7/26 Apparatus or processes specially adapted for the manufacture of record carriers

Abstract

A method and system for providing copy-protected optical medium using a substrate having information stored thereon in information pits and information lands, wherein the information lands comprise lands in two different planes.

Claims

1. A method for fabricating an optical medium readable by an optical reader, said method comprising the steps of:

molding a substrate so as to have a first major surface with information pits and information lands thereon and a second major surface that is relatively planar, said information lands on said first major surface being in either a first plane or a second plane, said second plane more proximal to said second major surface than said first plane;

applying a reflective material over the first major surface so as to cover said information pits and information lands;

removing the reflective material over said information lands in said first plane;

applying a layer over said first major surface comprising an optically-changeable security material;

wherein the locations of the first and second planes are pre-selected taking into account said optical reader, and optionally said optically-changeable security material, such that said information lands in said fabricated optical medium may be read by a signal directed by said optical reader through said second major surface whether the optically-changeable security material is in a first optical state or a second optical state and wherein the read by said optical reader is true to the physical structure of said information pits and said information lands when the optically-changeable security material is in at least one of said optical states.

2. The method of claim 1 wherein said first plane is further from the bottom of said pits than said second plane by a factor of about 2.

3. The method of claim 1 wherein said first plane is further from the bottom of said pits than said second plane by a factor such that the optical reader records any reflected signal from said optical medium, as adjudged by the transition between tandem information pits and information lands, as differing by ¼

wavelength from the signal directed by said optical reader to said optical medium.

4. An optical medium readable by an optical reader comprising:

a substrate having a first major surface with information pits and information lands thereon and a second major surface that is relatively planar, said information lands on said first major surface being in either a first plane or a second plane, said second plane more proximal to said second major surface than said first plane;

a reflective material layer in contact with said first major surface so as to cover said information pits, and said information lands in either said first plane or said second plane;

a layer over said reflective material layer comprising an optically-changeable security material;

wherein the locations of the first and second planes are such that said information lands may be read by a signal directed by said optical reader through said second major surface whether the optically-changeable security material is in its first optical state or its second optical state and wherein the read by said optical reader is true to the physical structure of said information pits and said information lands when the optically-changeable security material is in at least one of said optical states.

5. The optical medium of claim 4 wherein said first plane is further from the bottom of said pits than said second plane by a factor of about 2.

6. The optical medium of claim 4 wherein said first plane is further from the bottom of said pits than said second plane by a factor such that the optical reader records any reflected signal from said optical medium, as adjudged by the transition between tandem information pits and information lands, as differing by ¼

wavelength from the signal directed by said optical reader to said optical medium.

7. A method for authenticating an optical medium having an optical data structure representative of a series of bits, said optical data structure comprising information pits and information lands, said information lands being in either a first plane or second plane, said second plane more proximal to said second major surface than said first plane, and further comprising a layer containing an optically-changeable security material, the method comprising the steps of:

(a) reading the optical medium at a locus to obtain data true to the series of bits represented by the optical data structure at such locus;

(b) re-reading said optical medium at said locus to determine if the data obtained varies by one or more bits in the series of bits represented by the optical data structure at such locus; and

(c) authenticating the optical storage medium if the data obtained in step (b) differs from the data obtained in step (a).

8. The authentication method of claim 7 wherein said first plane is further from the bottom of said pits than said second plane by a factor of about 2.

9. The authentication method of claim 7 wherein said first plane is further from the bottom of said pits than said second plane by a factor such that the optical reader records any reflected signal from said optical medium, as adjudged by the transition between tandem information pits and information lands, as differing by ¼

wavelength from the signal directed by said optical reader to said optical medium.