Patent Number: 7,826,636

Title: Visual watermark in both data area and inner-ring of record carrier

Abstract: A record carrier including a data area for storing data in the form of marks, in which the data is encoded by means of a channel code, wherein a parameter of the channel code is controlled so as to introduce a predetermined run length distribution in the marks on the record carrier, thereby introducing first information relating to a watermark, and a non-data area comprising second information relating to a watermark, the first and the second information forming the watermark. This watermark, extending over the data-area and the inner-ring area and/or the outer-ring area, can be used for checking the authenticity of the record carrier and/or the recordings made on this record carrier.

Inventors: Yntema; Gertjan (Eindhoven, NL)

Assignee: Koninklijke Philips Electronics N.V.

International Classification: G06K 9/00 (20060101); G11B 7/24 (20060101)

Expiration Date: 2019-11-02 0:00:00