Optical recording medium and reproducing apparatus
AssigneeSharp Kabushiki Kaisha
InventorToshihisa Matsuo
Life of this patent
Estimating the term…
Abstract
In an optical recording medium of the present invention, plural pits which carry main information recorded in a user area and tangential push/pull (T-PP) information required for reproducing the main information recorded in T-PP area are formed. The pit length in a track direction is formed according to the main information, and the pit depth is formed according to the T-PP information, and copyright protection information by digital watermarking is embedded in the main information. Also, if the optical disk by unauthorized copying is loaded, a reproducing apparatus restricts the reproduction thereof.
Claims18
An optical recording medium, wherein
- main information is recorded on the optical recording medium, the main information having digital watermarking embedded therein, such that copying of the main information also copies the digital watermarking, the digital watermarking indicating copyright information, and
- additional information is formed on the optical recording medium, such that the additional information cannot be copied.
A reproducing apparatus comprising:
- reproducing means for reproducing an optical recording medium having main information stored thereon;
- and
- reproduction restricting means for determining whether additional information is formed on the optical recording medium such that the additional information cannot be copied and determining whether digital watermarking is embedded in the main information such that copying of the main information also copies the digital watermarking, the reproduction restricting means restricting reproduction of the main information if it is determined that:
- (i) digital watermarking is embedded in the main information such that copying of the main information also copies the digital watermarking, and
- (ii) additional information that cannot be copied indicating that the recording medium is original is not formed on the optical recording medium.
A method of reproducing main information stored on an optical recording medium comprising:
- (a) determining whether additional information that cannot be copied is formed on the optical recording medium;
- (b) if it is determined in (a) that additional information that cannot be copied is not formed on the optical recording medium, determining whether digital watermarking is embedded in the main information such that copying of the main information also copies the digital watermarking;
- (c) if it is determined in (a) that additional information that cannot be copied is formed on the optical recording medium, reproducing the main information;
- (d) if it is determined in (b) that digital watermarking is not embedded in the main information such that copying of the main information also copies the digital watermarking, reproducing the main information;
- and
- (e) if it is determined in (a) that additional information that cannot be copied is not formed on the optical recording medium and it is determined in (b) that digital watermarking is embedded in the main information such that copying of the main information also copies the digital watermarking, restricting reproduction of the main information.
Dependencies are inferred from the claim text.