Methods of and information recording devices for recording and/or inhibiting recording of an information signal having copy bits with logic values which alternate in accordance with a pattern

• US 5,453,968 A
• Filed: 08/16/1994
• Issued: 09/26/1995
• Est. Priority Date: 09/21/1989
• Status: Expired due to Term

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Heemskerk, Jacobus P. J., Roth, Rudolf, Veldhuis, Hindrik
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): HUBER, PAUL W
• Application Number:
  US08/291,328
• Time in Patent Office: 406 Days
• Field of Search: 360/40, 360/60, 369/47, 369/48, 369/59, 369/83, 369/84, 380/3, 380/4, 380/15, 380/23
• US Class Current: 369/47.12
• CPC Class Codes: G06F 21/109 by using specially-adapted hardware at the client
• CPC Class Codes: G06F 2211/007 Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
• 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 2020/10592 specifically adapted for recording or reproducing multichannel signals
• CPC Class Codes: G11B 2220/218 Write-once discs
• CPC Class Codes: G11B 2220/2545 CDs
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 2220/913 Digital audio tape [DAT] format
• CPC Class Codes: G11B 27/031 Electronic editing of digitised analogue information signals, e.g. audio or video signals
• CPC Class Codes: G11B 27/032 on tapes G11B27/036, G11B27/038 take precedence
• CPC Class Codes: G11B 27/034 on discs G11B27/036, G11B27/038 take precedence
• CPC Class Codes: G11B 27/3063 Subcodes
• CPC Class Codes: G11B 7/28 Re-recording, i.e. transcribing information from one optical record carrier on to one or more similar or dissimilar record carriers

Abstract

Methods of and information recording devices for recording and/or inhibiting recording of a signal including copy bits on a record carrier, and a record carrier including that signal. The signal has successive information frames including main data and subcode data. The subcode data of the information frames make up successive subcode frames having copy bits with logic values which alternate among the subcode frames in accordance with a predetermined pattern. Each subcode frame has at least one copy bit. In one of the embodiments, the signal is received and a determination is made whether to inhibit its recording on the basis of the predetermined pattern exhibited by the logic values of the copy bits contained in the subcode frames. In another embodiment the subcode frames are replaced by substitute subcode frames having copy bits with logic values which alternate among the substitute subcode frames in accordance with a selected pattern prior to recording of the signal. The predetermined and selected patterns are indicative of a particular characteristic of the main data (e.g., whether the main data is copy protected).

Claims

1. A method of recording a digital information signal on a record carrier, the signal having successive information frames which each include main data and subcode data, the subcode data of the information frames forming consecutive subcode frames, each subcode frame including the subcode data of a predetermined number of the information frames, the method comprising:

generating the signal such that copy bits are provided in the subcode data of the subcode frames, each subcode frame having at least one copy bit and the copy bits having logic values which alternate among the subcode frames in accordance with a predetermined pattern which is indicative of a particular characteristic of the main data being recorded whereby the copy bits in at least two of the subcode frames have logic values which are different; and

recording the information frames.

2. The method as claimed in claim 1, wherein the main data being recorded has previously been recorded, and the pattern is indicative of a generation number signifying the number of times the main data will have been recorded.

3. The method as claimed in claim 2, wherein the pattern is periodic, and the ratio of the number of copy bits of a first logic value in a period of the pattern to the total number of copy bits in the period is indicative of the generation number.

4. The method as claimed in claim 1, wherein the signal is in a standardized format for recording on a Compact Disc.

5. The method as claimed in claim 1, wherein the pattern signifies that the main data is copy protected.

6. An information recording device for recording a digital information signal on a record carrier, the signal having successive information frames which each include main data and subcode data, the subcode data of the information frames forming consecutive subcode frames, each subcode frame including the subcode data of a predetermined number of the information frames, the device comprising:

generating means for generating the signal such that copy bits are provided in the subcode data of the subcode frames, each subcode frame having at least one copy bit; and

assignment means, coupled to said generating means, for assigning logic values for the copy bits such that the copy bits have logic values which alternate among the subcode frames in accordance with a selected pattern which is indicative of a particular characteristic of the main data being recorded whereby the copy bits in at least two of the subcode frames have logic values which are different.

7. The device as claimed in claim 6, wherein said assignment means comprises:

pattern generation means for generating logic values for the copy bits in accordance with a plurality of different patterns; and

selection means coupled to said pattern generation means for selecting one of the different patterns, depending on the particular characteristic, as the selected pattern.

8. The device as claimed in claim 7, wherein each of the different patterns is periodic, and said selection means is adapted to select one of the different patterns in which the ratio of the number of logic values of a first type in a period of that pattern to the total number of logic values in the period corresponds to a generation number indicative of the number of times the main data being recorded will have been recorded.

9. The device as claimed in claim 6, wherein the signal is in a standardized format for recording on a Compact Disc.

10. The device as claimed in claim 6, wherein the selected pattern signifies that the main data is copy protected.

11. The device as claimed in claim 7, wherein each of the different patterns corresponds to a generation number indicative of the number of times in which the main data being recorded will have been recorded.

12. An information recording device for recording a digital information signal supplied thereto on a record carrier, the signal having successive information frames which each include main data and subcode data, the subcode data of the information frames forming consecutive subcode frames, the device comprising:

decision means for producing a disabling control signal when the subcode frames include copy bits having logic values which alternate among the subcode frames in accordance with a predetermined pattern whereby the copy bits in at least two of the subcode frames have logic values which are different; and

inhibiting means, coupled to said decision means, for inhibiting the device from recording the signal when said decision means produces the disabling control signal.

13. The device as claimed in claim 12, wherein said decision means is adapted to produce said disabling control signal when the predetermined pattern indicates that the main data is copy protected.

14. The device as claimed in claim 12 wherein the logic values of the copy bits alternate among the subcode frames in a periodic pattern, and said decision means determine whether the predetermined pattern exists on the basis of the ratio of the number of copy bits of a first logic value in a period of the periodic pattern to the total number of copy bits in the period.

15. The device as claimed in claim 12, further comprising:

replacement means for replacing the subcode frames with substitute subcode frames, each substitute subcode frame having at least one substitute copy bit; and

assignment means, coupled to said replacement means, for assigning logic values for the substitute copy bits such that the substitute copy bits have logic values which alternate among the substitute subcode frames in accordance with a selected pattern which is indicative of a particular characteristic of the main data which will be recorded whereby the substitute copy bits in at least two of the substitute subcode frames have logic values which are different.

16. The device as claimed in claim 15, wherein the copy bits in the subcode frames have logic values which alternate among the subcode frames and form an original pattern, and the selected pattern is selected by said assignment means on the basis of the original pattern.

17. The device as claimed in claim 16, wherein the original pattern is periodic, and said assignment means assigns logic values for the substitute copy bits so that the selected pattern is periodic and the ratio of the number of substitute copy bits of a first logic value in a period of the selected pattern to the total number of substitute copy bits in the period of the selected pattern is dependent on the ratio of the number of copy bits of a first logic value in a period of the original pattern to the total number of copy bits in the period of the original pattern.

18. The device as claimed in claim 12, wherein the signal has a format in accordance with a standardized audio interface.

19. The device as claimed in claim 15, wherein the selected pattern is indicative of the number of times the main data which will be recorded will have been recorded.

20. The device as claimed in claim 12, further comprising detection means, coupled to said decision means, for detecting whether the subcode frames include copy bits having logic values which alternate.

21. The device as claimed in claim 16, wherein the original pattern is indicative of the number of time the main data of said signal has been recorded, and selected patterns is indicative of the number of times the main data which will be recorded will have been recorded.

22. The device as claimed in claim 13, wherein said decision means is adapted to produce said disabling control signal when the predetermined pattern indicates that the main data is copy protected.

23. A method for inhibiting recording of a digital information signal on a record carrier, the signal having successive information frames which each include main data and subcode data, the subcode data of the information frames forming consecutive subcode frames, the method comprising:

determining whether the subcode frames include copy bits having logic values which alternate among the subcode frames whereby the copy bits in at least two of the subcode frames have logic values which are different; and

inhibiting recording of the signal when the logic values of the copy bits alternate among the subcode frames in accordance with a predetermined pattern.

24. The method as claimed in clam 23, wherein the pattern signifies that the main data is copy protected.

25. A method of recording a digital information signal on a record carrier, the signal having successive information frames which each include main data and subcode data, the subcode data of the information frames forming consecutive subcode frames, the method comprising:

replacing the subcode frames with substitute subcode frames prior to recording the signal on the record carrier, each substitute subcode frame having at least one substitute copy bit; and

assigning logic values for the substitute copy bits such that the substitute copy bits have logic values which alternate among the substitute subcode frames in accordance with a selected pattern which is indicative of a particular characteristic of the main data which will be recorded whereby the substitute copy bits in at least two of the substitute subcode frames have logic values which are different.

26. The method as claimed in claim 25, wherein the selected pattern is indicative of the number of times the main data which will be recorded will have been recorded.

27. The method as claimed in claim 25, wherein the copy bits in the subcode frames have logic values which alternate among the subcode frames and form an original pattern, and the selected pattern is selected on the basis of the original pattern.

28. The method as claimed in claim 27, wherein the original pattern is indicative of the number of time the main data of the signal has been recorded, and the selected pattern is indicative of the number of times the main data which will be recorded will have been recorded.

29. The method as claimed in claim 27, wherein the original pattern is periodic, and the logic values for the substitute copy bits are assigned so that the selected pattern is periodic and the ratio of the number of substitute copy bits of a first logic value in a period of the selected pattern to the total number of substitute copy bits in the period of the selected pattern is dependent on the ratio of the number of copy bits of a first logic value in a period of the original pattern to the total number of copy bits in the period of the original pattern.

30. An information recording device for recording a digital information signal supplied thereto on a record carrier, the signal having successive information frames which each include main data and subcode data, the subcode data of the information frames forming consecutive subcode frames, the device comprising:

replacement means for replacing the subcode frames with substitute subcode frames prior to recording the signal on the record carrier, each substitute subcode frame having at least one substitute copy bit; and

assignment means, coupled to said replacement means, for assigning logic values for the substitute copy bits such that the substitute copy bits have logic values which alternate among the substitute subcode frames in accordance with a selected pattern which is indicative of a particular characteristic of the main data which will be recorded whereby the substitute copy bits in at least two of the substitute subcode frames have logic values which are different.

31. The device as claimed in claim 30, wherein the selected pattern is indicative of the number of times the main data which will be recorded will have been recorded.

32. The device as claimed in claim 30, wherein the copy bits in the subcode frames have logic values which alternate among the subcode frames and form an original pattern, and the selected pattern is selected by said assignment means on the basis of the original pattern.

33. The device as claimed in claim 32, wherein the original pattern is indicative of the number of time the main data of the signal has been recorded, and the selected pattern is indicative of the number of times the main data which will be recorded will have been recorded.

34. The device as claimed in claim 32, wherein the original pattern is periodic, and said assignment means assigns logic values for the substitute copy bits so that the selected pattern is periodic and the ratio of the number of substitute copy bits of a first logic value in a period of the selected pattern to the total number of substitute copy bits in the period of the selected pattern is dependent on the ratio of the number of copy bits of a first logic value in a period of the original pattern to the total number of copy bits in the period of the original pattern.