Playback apparatus for a record carrier providing physical copy protection

• US 6,226,244 B1
• Filed: 04/21/1999
• Issued: 05/01/2001
• 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:
  US09/295,535
• Time in Patent Office: 741 Days
• Field of Search: 369/44.13, 369/44.26, 369/44.39, 369/47-48, 369/53-54, 369/58, 369/100, 369/109, 369/111, 369/124, 369/275.3-275.4, 369/124.04, 369/124.07 , 369/124.09, 360/133
• US Class Current: 369/47.19
• 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

Playback apparatus for a record carrier on which information is recorded 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 recovery circuit recovers the information from a detection signal produced by the transducer. The record carrier also exhibits a variation of a second physical parameter, which differs from the first physical parameter but is of a type which is detectable by the same transducer. A detection circuit detects the presence of the second variation on the basis of a further detection signal produced by the transducer. A circuit controlled by the detection circuit enables the information recovery circuit in the event that the presence of the second variations is detected. Since copying recorders of the usual type only copy variations of the first physical parameter, representing the recorded information, and do not copy variations of the second physical parameter, such copiers cannot copy the information recorded on the described record carrier.

Claims

1. A playback apparatus for recovering information recorded on a record carrier, the record carrier exhibiting (i) first variations of a first physical parameter of the record carrier, said first variations corresponding to the recorded information, and (ii) also exhibiting, when provided therewith, second variations of a second physical parameter of the record carrier, the second physical parameter differing from the first physical parameter;

said apparatus comprising;

a transducer for scanning the record carrier and outputting a detection signal, said detection signal having first variations in response to said first variations of said first parameter, said detection signal also having second variations in response to said second variations of said second parameter, said second variations of the detection signal having a frequency spectrum which is outside the frequency spectrum of said first variations of the detection signal;

recovery means coupled to said transducer and responsive to said first variations of the detection signal to recover the recorded information therefrom;

detection means also coupled to said transducer and responsive to said second variations of the detection signal to produce an output signal indicating whether the record carrier is provided with said second variations of said second parameter; and

enabling means coupled to said detection means for enabling said recovery means to recover the recorded information only when the output signal of said detection means indicates that the record carrier is provided with said second variations of said second parameter.

2. A playback apparatus as claimed in claim 1, wherein said second variations exhibit a modulation pattern representing a code, said detection means includes demodulation means for recovering said code on the basis of at least one signal indicative of said second variations and originating from said transducer means, and the apparatus further comprises means for setting said recovery means in an operating mode in which a predetermined type of data processing indicated by said code is performed during recovery of the recorded information.

3. A playback apparatus for recovering information recorded on a record carrier, the record carrier exhibiting (i) first variations of a first physical parameter of the record carrier, said first variations corresponding to the recorded information, and (ii) also exhibiting, when provided therewith, second variations of a second physical parameter of the record carrier, the second physical parameter differing from the first physical parameter;

said apparatus comprising;

a transducer for scanning the record carrier and outputting a detection signal having first variations in response to said first variations of said first parameter, said transducer also outputting a further detection signal having second variations in response to said second variations of said second parameter, the second variations of the further detection signal having a frequency spectrum which is substantially all outside the frequency spectrum of the detection signal having said first variations;

recovery means coupled to said transducer and responsive to the detection signal having said first variations to recover the recorded information therefrom;

detection means also coupled to said transducer and responsive to the detection signal having said second variations to produce an output signal indicating whether the record carrier is provided with said second variations of said second parameter; and

disabling means coupled to said detection means for disabling said recovery means from recovering the recorded information when the output signal of said detection means indicates that the record carrier is not provided with said second variations of said second parameter.

4. A playback apparatus for recovering copy protected information recorded on a record carrier, the record carrier exhibiting (i) first variations of a first physical parameter of the record carrier, said first variations corresponding to the recorded information, and (ii) also exhibiting, when provided therewith, second variations of a second physical parameter of the record carrier, the second physical parameter differing from the first physical parameter;

said apparatus comprising;

a transducer for scanning the record carrier and outputting a detection signal having first variations in response to said first variations of said first parameter, said transducer also outputting a further detection signal having second variations in response to said second variations of said second parameter, the second variations of the further detection signal having a frequency spectrum which is substantially all outside the frequency spectrum of the detection signal having said first variations;

recovery means coupled to said transducer and responsive to said first variations of the detection signal to recover the recorded information therefrom;

detection means also coupled to said transducer and responsive to said second variations of the detection signal to produce an output signal indicating whether the record carrier is provided with said second variations of said second parameter; and

disabling means coupled to said detection means for preventing said recovery means from recovering the recorded information when the output signal of said detection means indicates that the record carrier is provided with a type of said second variations signifying that said record carrier is recordable and therefore is not copy protected.

5. Playback apparatus as claimed in claim 4, wherein said type of second variations of a recordable record carrier is a wobble of a recording track thereof.

6. Playback apparatus as claimed in claim 5, wherein the frequency spectrum of said second variations is substantially in the vicinity of 22 kHz.