摘要:
A disk-shaped recording medium includes a transparent substrate, and an optical recording layer and a magnetic recording layer formed at one side of the transparent substrate. An optical head applies light to the optical recording layer from a light source via the transparent substrate, and focuses the light on the optical recording layer and reproduces information from the optical recording layer. A magnetic head records information on the magnetic recording layer or reproduces information from the magnetic recording layer. An optical head moving device serves to move the optical head by a movement amount so as to focus the light on an optical track on the optical recording layer which has specified address information. A magnetic head moving device serves to move the magnetic head to a specified magnetic track on the magnetic recording layer by referring to the movement amount of the optical head.
摘要:
A disk-shaped recording medium includes a transparent substrate, and an optical recording layer formed on the transparent substrate. A light source emits light. An optical head is operative for applying the light to the optical recording layer from the light source via the transparent substrate, for focusing the light on the optical recording layer, and for reproducing information from the optical recording layer. A position detecting device is operative for detecting at least one of a pit depth and a physical position of information which has a first given relation with a specified address and which is recorded on the recording medium, and for generating first positional information representing at least one of the pit depth and the physical position. A previously-recorded secret code is reproduced from the recording medium. The secret code represents second positional information. The secret code is decoded into the second positional information. The second positional information represents at least one of a predetermined reference pit depth and a predetermined reference physical position. The first positional information and the second positional information are collated, and a check is made as to whether or not the first positional information and the second positional information are in a second given relation. When the first positional information and the second positional information are not in the second given relation, one of outputting of a reproduced signal of the recording medium, operation of a program stored in the recording medium, and decoding of the secret code is stopped.