| 摘要 |
An optical disk (12) has: a substrate (13) of disk shape; a recording medium formed on the substrate, and having a recording surface on which a plurality of tracks are formed; and information pits (11) formed on the tracks. Each of the information pits has a first pit portion having a first level from the recording surface and a second pit portion having a second level lower than the first level. A pit direction angle indicating an angle between a direction connecting the first pit portion and the second pit portion to each other and a circular direction of the optical disk, is equal to one of predetermined equiangular angles around the center of the information pit. The pit direction angle corresponding to recorded information pieces read by projecting a laser beam onto the recording medium. <IMAGE> |
