Mark forming apparatus, method of forming laser mark on optical disk, reproducing apparatus, optical disk and method of producing optical disk
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsMitsuaki Oshima, Yoshiho Gotoh
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Abstract
An object of the present invention is to provide a marking forming apparatus, a method of forming a laser marking on an optical disk, a reproduction apparatus, an optical disk, and a method of manufacturing an optical disk, capable of providing a greatly improved copy prevention capability as compared to prior known construction. To achieve this object, in the optical disk of the invention, for example, a marking is formed by a laser on a reflective film of a disk holding data written thereon and at least position information of the marking or information concerning the position information is written on the disk in an encrypted form or with a digital signature appended thereto.
Claims27
A marking forming apparatus comprising:
- marking forming means for applying at least one marking to at least one reflective film formed to a disk;
- marking position detecting means for detecting at least one position of said marking;
- and
- position information output means for outputting said detected position as position information of said marking.
A method of forming a laser marking to an optical disk, comprising the steps of:
- forming at least one disk;
- forming a reflective film to said formed disk;
- laminating two disks together, said disks including at least one disk with said reflective film formed thereon;
- and
- forming at least one marking by a laser on said reflective layer of the laminated disks.
A reproduction apparatus comprising:
- position information reading means for reading position information of at least one marking or information concerning said position information, said marking being formed to at least one reflective film formed to a disk and being detected for a position thereof, at least the position thus detected being output as said position information of said marking;
- marking reading means for reading information concerning at least one actual position of said marking;
- comparing/judging means for performing comparison and judgement by using a result of reading by said position information reading means and a result of reading by said marking reading means;
- and
- reproducing means for reproducing recorded data on said optical disk in accordance with a result of the comparison and judgement performed by said comparing/judging means.
A method of manufacturing an optical disk, comprising the steps of:
- forming at least one disk;
- forming a reflective film to said formed disk;
- applying at least one marking to said reflective film;
- detecting at least one position of said marking;
- and
- outputting said detected position as position information of said marking, and encrypting said information for writing to said disk.
A method of manufacturing an optical disk, comprising the steps of:
- forming at least one disk;
- forming a reflective film to said formed disk;
- applying at least one marking to said reflective film;
- detecting at least one position of said marking;
- and
- outputting said detected position as position information of said marking, and applying a digital signature in relation to said position information for writing to said disk.
An optical disk wherein at least one marking is formed by a laser to at least one reflective film of the disk holding data written thereon and at least position information of said marking or information concerning said position information is written to said disk in an encrypted form or with a digital signature applied thereto.
An optical disk having a structure such that at least one reflective film is one of sandwiched directly and sandwiched indirectly between two members formed from material resistant to laser light,
- wherein at least one marking is formed by a laser to said reflective film.
Dependencies are inferred from the claim text.