System and apparatus for recovering information from a record carrier which exhibits variations of two different physical parameters thereof
First Claim
1. An information system, comprising:
- a record carrier having information marks along a track thereof and exhibiting;
first variations caused by existence and nonexistence of the information marks along the track, said first variations representing an information signal recorded on said record carrier, and second variations caused by variations associated with the information marks; and
a playback apparatus including;
transducer means for scanning said record carrier, said transducer means being adapted to detect said first variations and said second variations,recovery means coupled to said transducer means for recovering the information signal from said first variations,detection means for detecting whether said second variations exhibit a predetermined variation pattern on the basis of at least one signal, which is at least indicative of said second variations, originating from said transducer means, andenabling means for enabling said recovery means to recover the information signal when said detection means detects said predetermined variation pattern.
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Accused Products
Abstract
An information system including a record carrier and a 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 the second variations 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 second variations is detected causing it to recover the information.
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Citations
20 Claims
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1. An information system, comprising:
- a record carrier having information marks along a track thereof and exhibiting;
first variations caused by existence and nonexistence of the information marks along the track, said first variations representing an information signal recorded on said record carrier, and second variations caused by variations associated with the information marks; and a playback apparatus including; transducer means for scanning said record carrier, said transducer means being adapted to detect said first variations and said second variations, recovery means coupled to said transducer means for recovering the information signal from said first variations, detection means for detecting whether said second variations exhibit a predetermined variation pattern on the basis of at least one signal, which is at least indicative of said second variations, originating from said transducer means, and enabling means for enabling said recovery means to recover the information signal when said detection means detects said predetermined variation pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- a record carrier having information marks along a track thereof and exhibiting;
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11. A playback apparatus for recovering an information signal from a record carrier exhibiting first variations caused by existence and non-existence of information marks along a track thereof, which first variations represent the information signal, and second variations caused by variations associated with the information marks, the apparatus comprising:
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transducer means for scanning said record carrier, said transducer means being adapted to detect said first variations and said second variations, recovery means coupled to said transducer for recovering the information signal from said first variations, detection means for detecting whether said second variations exhibit a predetermined variation pattern on the basis of at least one signal, which is at least indicative of said second variations, originating from said transducer means, and enabling means for enabling said recovery means to recover the information signal when said detection means detects said predetermined variation pattern. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification