Patent ID: 7386770

Claim:
An information reproduction apparatus for reproducing information from an information storage medium, including a read-in area; a data area consisting of blocks; and a read-out area, wherein the data area includes a user area and a spare area, a defective block of the blocks is replaced by a spare block of the spare area, the read-in area and the read-out area include defect management area sets to be used in due order, each defect management area set includes first, second, third, and fourth defect management areas to store defect management information, the read-in area includes the first and second defect management areas of each defect management area set, the read-out area includes the third and fourth defect management areas of each defect management area set, wherein upon detection of a defect in a current defect management area set included in the defect management area sets, the current defect management area set is replaced to the next defect management area set of the current defect management area set, the second defect management area is the next defect management area of the first defect management area, and the fourth defect management area is the next defect management area of the third defect management area, the apparatus comprising: a reading unit configured to read information from the information storage medium, wherein the reading unit reads the latest defect management information from the current defect management area set.