Record carrier having first variations of a first physical parameter corresponding to information recorded thereon and second variations of a second physical parameter relating to recovery of the information

• US 5,724,327 A
• Filed: 02/14/1995
• Issued: 03/03/1998
• Est. Priority Date: 12/02/1991
• Status: Expired due to Term

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Timmermans, Jozef M.K., Schylander, Erik C., Mons, Johannes J.
• Primary Examiner(s): YOUNG, WAYNE R
• Application Number:
  US08/388,536
• Time in Patent Office: 1,113 Days
• Field of Search: 369/47-48, 369/53-54, 369/58, 369/44.13, 369/44.26, 369/275.3-275.4, 369/44.39, 369/100, 369/109, 369/111, 360/133
• US Class Current: 369/47.24
• CPC Class Codes: G11B 13/00 Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for G11B9/14, G11B11/002 take precedence; driving or moving of heads G11B3/02, G11B5/48, G11B7/08, G11B21/02
• 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 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 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00405 the key being stored by varying characteristics of the recording track, e.g. by altering the track pitch or by modulating the wobble track
• CPC Class Codes: G11B 20/00586 said format change concerning the physical format of the recording medium
• CPC Class Codes: G11B 20/00594 wherein the shape of recording marks is altered, e.g. the depth, width, or length of pits
• CPC Class Codes: G11B 20/00601 wherein properties of tracks are altered, e.g., by changing the wobble pattern or the track pitch, or by adding interruptions or eccentricity
• CPC Class Codes: G11B 20/1809 by interleaving
• CPC Class Codes: G11B 23/281 by changing the physical properties of the record carrier
• CPC Class Codes: G11B 23/284 on the record carrier
• CPC Class Codes: G11B 5/02 Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
• CPC Class Codes: G11B 5/74 Record carriers characterised by the form, e.g. sheet shaped to wrap around a drum
• CPC Class Codes: G11B 7/0037 with discs
• CPC Class Codes: G11B 7/005 Reproducing G11B7/0065 takes precedence
• CPC Class Codes: G11B 7/00736 Auxiliary data, e.g. lead-in, lead-out, Power Calibration Area [PCA], Burst Cutting Area [BCA], control information sector headers or adresses in prepits G11B7/00745; address data in track wobble G11B7/24082
• CPC Class Codes: G11B 7/0901 for track following only G11B7/0925, G11B7/094, G11B7/0941, G11B7/0943, G11B7/0945, G11B7/0946, G11B7/0948 take precedence
• CPC Class Codes: G11B 7/0938 servo format, e.g. guide tracks, pilot signals
• CPC Class Codes: G11B 7/24085 Pits
• CPC Class Codes: G11B 9/00 : Recording or reproducing using a method not covered by one of the main groups G11B3/00 - G11B7/00; Record carriers therefor G11B11/00 takes precedence driving or moving of heads G11B21/02
• CPC Class Codes: H04N 2005/91342 : the copy protection signal being an authentication signal
• CPC Class Codes: H04N 2005/91364 : the video signal being scrambled
• CPC Class Codes: H04N 5/913 : for scrambling ; for copy protection

Abstract

A record carrier, a playback apparatus and a system including the record carrier and the playback apparatus. Information has been recorded on the record carrier in the form of variations of a first physical parameter. The playback apparatus scans the record carrier by means of a transducer which is responsive to the variations of the first physical parameter. An information recovering circuit recovers the information from a detection signal received from the transducer. The record carrier exhibits second variations of a second physical parameter, which differs from the first physical parameter, but which second variations are of a type that are detectable by the transducer. A detection circuit detects the presence of a predetermined property of the second variations (e.g., that the second variations exhibit a modulation pattern representing a code) on the basis of a detection signal received from the transducer. A circuit responsive to the detection circuit enables the information recovering circuit when the presence of the predetermined property of the second variations is detected, causing it to recover the information.

Claims

1. A record carrier, exhibiting:

first variations of a first physical parameter of the record carrier, said first variations corresponding to information recorded on the record carrier, which information is recoverable by means of a predetermined type of data processing; and

second variations of a second physical parameter of the record carrier, said second variations exhibiting a modulation pattern representing a code which indicates the type of data processing to be used to recover the information, and said second physical parameter is caused by variations associated with a track of said record carrier.

2. The record carrier as claimed in claim 1, wherein the record carrier is of an optical readable type in which the information has been recorded thereon as a pattern of optically detectable marks alternating with intermediate areas arranged along said track thereof.

3. The record carrier as claimed in claim 2, wherein said second variations are variations in the track position in a direction transverse to the track direction.

4. The record carrier as claimed in claim 3, wherein the record carrier is a Compact Disc, and said second variations result in variations in a detection signal with a frequency substantially corresponding to 22 kHz when the track is scanned with a scanning speed between 1.2 and 1.4 meter per second.

5. A record carrier, having information marks along a track thereof, exhibiting:

first variations caused by existence and non-existence of the information marks along the track, which first variations represent an information signal recorded on the record carrier; and

second variations caused by variations associated with the track, which second variations exhibit a modulation pattern representing a code which indicates at least one of whether the information signal is recoverable and how to recover the information signal.

6. The record carrier as claimed in claim 5, wherein the information signal recorded on the record carrier is of a type which is recoverable by means of a predetermined type of data processing, and the code indicates the type of data processing to be used to recover the information signal.

7. The record carrier as claimed in claim 5, wherein the record carrier is of an optical readable type in which the existence and non-existence of the information marks along the track correspond to a pattern of optically detectable information marks alternating with intermediate areas arranged along the track.

8. The record carrier as claimed in claim 7, wherein said second variations are caused by variations in the track position in a direction transverse to the track direction.

9. The record carrier as claimed in claim 8, wherein the record carrier is a Compact Disc, and said second variations result in variations in a detection signal with a frequency substantially corresponding to 22 kHz when the track is scanned with a scanning speed between 1.2 and 1.4 meter per second.

10. The record carrier as claimed in claim 5, wherein the code indicates that the information signal recorded on the record carrier is recoverable.