Patent ID: 7512046

Claim:
An optical disk apparatus comprising: a mounting unit configured to selectively mount first and second optical disks in which characteristics of recording films are different from one another, and selectively mount the first optical disk on which information is recorded by varying a first recording film having a first light reflectance factor to a second light reflectance factor lower than the first light reflectance factor, and the second optical disk on which information is recorded by varying a second recording film having the second light reflectance factor to the first light reflectance factor higher than the second light reflectance factor; a discriminating unit configured to discriminate which of the first and second optical disks is mounted on the mounting unit based on a level of a reproduction signal which is obtained by reproducing innermost peripheral portion of the first or second optical disk mounted on the mounting unit, discriminate which of the first and second optical disks is mounted based on a ratio at which a reproduction signal at a level corresponding to a region having the first light reflectance factor can be obtained and a ratio at which a reproduction signal at a level corresponding to a region having the second light reflectance factor can be obtained, by reproducing the first or second optical disk mounted on the mounting unit, discriminate to be the first optical disk when a ratio at which a reproduction signal at a level corresponding to a region having the first light reflectance factor can be obtained is higher than a ratio at which a reproduction signal at a level corresponding to a region having the second light reflectance factor can be obtained, and discriminate to be the second optical disk when a ratio at which a reproduction signal at a level corresponding to a region having the second light reflectance factor can be obtained is higher than a ratio at which a reproduction signal at a level corresponding to a region having the first light reflectance factor can be obtained; and a control unit configured to control a signal processing unit for recording or reproducing information based on a discrimination result of the discriminating unit.