Patent ID: 8134909

Claim:
An optical information storage medium where information is recorded in a form of prepits each made up of at least either a concavity or a convexity, and the information is reproduced by irradiating light to the prepits in an optical information storage medium playback apparatus, the optical information storage medium comprising: an information signal region where a content is recorded; and a test read region where reproduction setting value adjustment information is recorded for adjusting a setting value for the reproduction performed by the optical information storage medium playback apparatus, wherein: the information signal region has a first prepit row which is made up of a plurality of prepits, and a shortest mark length on the first prepit row is shorter than a length of an optical system resolution limit of the optical information storage medium playback apparatus; the test read region has a second prepit row which is made up of a plurality of prepits for the adjustment, and types of mark lengths on the second prepit row are the same as all types of mark lengths on the first prepit row; the second prepit row includes a prepit having a mark length shorter than the length of the optical system resolution limit of the optical information storage medium playback apparatus; and each of the first and second prepit rows has each have at least three types of mark lengths, wherein a ratio of prepits having the shortest mark length to total number of prepits on the second prepit row is lower than a ratio of prepits having the shortest mark length to total number of prepits on the first prepit row.