Record carrier, method of and information recording device for obtaining such record carriers, and information recording device comprising anti-copy means to inhibit unauthorized copying

Claim 2

A record carrier as claimed in Claim 1, characterized in that the form of the pattern indicates the generation number of the information in a copying cycle.

Claim 3

A record carrier as claimed in Claim 2, characterized in that the detected pattern is a periodic pattern in which the ratio between the number of "copy" bits of a first logic value in a period and the total number of "copy" bits in said period indicates the generation number.

Claim 4

A record carrier as claimed in Claim 1, 2 or 3, characterized in that the recorded information is a standard CD signal.

Claim 5

A method of obtaining a record carrier as claimed in Claim 1, 2, 3 or 4, main information together with a series of subcode frames which each comprise a "copy" bit being recorded on the record carrier, characterized in that during recording logic values are assigned to the "copy" bits of consecutive subcode frames in accordance with an alternation pattern.

Claim 6

A method as claimed in Claim 5, characterized in that the information to be copied is previously recorded information, the form of the alternation pattern being dependent upon the generation number of the previously recorded information.

Claim 7

A method as claimed in Claim 6, characterized in that the detected pattern is a periodic pattern, the ratio between the number of "copy" bits of a first logic value in a period the and total number of "copy" bits in said period being selected depending upon the generation number.

Claim 8

A method as claimed in Claim 5, 6 or 7, characterized in that the information being recorded is a standard CD signal.

Claim 9

An information recording device for obtaining a record carrier as claimed in Claim 1, 2, 3 or 4, which device is constructed to record on the record carrier main information together with a series of subcode frames which each comprise a "copy" bit, characterized in that the device comprises assignment means for assigning the logic values in accordance with an alternation pattern to the "copy" bits of consecutive subcode frames of information to be recorded.

Claim 10

An information recording device as claimed in Claim 9, characterized in that the assignment means comprise selection means for selecting an alternation pattern of a specific form from a plurality of patterns of predetermined forms depending upon a control signal.

Claim 11

An information recording device as claimed in Claim 10, characterized in that the selection means are adapted to select a periodic pattern whose ratio between the number of "copy" bits of a first logic value in a period and the total number of "copy" bits in said period depends upon the control signal.

Claim 12

An information recording device as claimed in Claim 9, 10 or 11, characterized in that the device is adapted to record standard CD signals.

Claim 13

An information recording device comprising anti-copy means for inhibiting unauthorized copying of received information, for recording main information, which is received together with a series of subcode frames which each comprise a "copy" bit, which anti-copy means comprise decision means for deciding whether recording of received information is allowed depending upon the logic value of the received "copy" bits and means responsive to a decision that recording is not allowed to inhibit recording, characterized in that the device comprises detection means for detecting an alternation pattern in the logic values of the received "copy" bits of consecutive subcode frames, the decision means being adapted to decide whether recording is allowed depending upon the detection of the alternation pattern.

Claim 14

An information recording device as claimed in Claim 13, characterized in that the detection means are adapted to detect alternation patterns of different forms, the decision means being adapted to decide whether recording is allowed depending upon the form of the detected alternation pattern.

Claim 15

An information recording device as claimed in Claim 14, characterized in that the detection means are adapted to detect in a period of a periodically alternating pattern the ratio between the number of "copy" bits of a first logic value and the total number of "copy" bits in said period, the decision means being adapted to decide whether recording is permitted depending upon the detected ratio.

Claim 16

An information recording device as claimed in Claim 13, 14 or 15, for recording main information together with a series of second subcode frames, which each comprise a second copy bit, characterized in that the device comprises assignment means for assigning the logic values to the second "copy" bits of consecutive second subcode frames in accordance with an alternation pattern.

Claim 17

An information recording device as claimed in Claims 14 and 16, characterized in that the assignment means are adapted to assign the logic value to the second copy bit in accordance with a pattern whose form depends on the form of the detected alternation pattern in the logic values of the "copy" bits in the subcode frames of the received information.

Claim 18

An information recording device as claimed in Claims 15 and 17, characterized in that the assignment means are adapted to assign the logic values to the second copy bits in accordance with a periodic pattern, the ratio between second "copy" bits of a first logic value in a period and the total number of second copy bits in said period being dependent upon the detected ratio.

Claim 19

An information recording device as claimed in any one of the Claims 13 to 18, characterized in that the device is adapted to receive information formatted in accordance with a standard audio interface format.