Optical disk reproducing apparatus

An optical disk reproducing apparatus for reproducing digital signals from an optical disk,

• the optical disk including at least a first recording surface and a second recording surface each being readable from a same side of the optical disk,
• the digital signals being in the form of a data frame,
• the data frame including a lead-in block and a plurality of data blocks,
• each of the data blocks including a block address assigned to the data block, and data,
• the data blocks being recorded on the first recording surface and the second recording surface,
• the lead-in block being recorded at a head of the data frame and including disk information relating to a number of data blocks recorded on the first recording surface and the second recording surface,
• the optical disk reproducing apparatus comprising:
• an optical pickup which picks up and reproduces digital signals from the optical disk;
• a focus control circuit which performs focus control of the optical pickup;
• a pickup movement control circuit which performs tracking control of the optical pickup;
• a disk information detection circuit which detects disk information included in a reproduced lead-in block based on the digital signals reproduced by the optical pickup;
• a block address detection circuit which detects block addresses included in reproduced data blocks based on the digital signals reproduced by the optical pickup;
• and
• an access/reproduction control circuit which controls the focus control circuit and the pickup movement control circuit to access the first recording surface and the second recording surface and reproduce data blocks recorded on the first recording surface and the second recording surface;
• wherein the access/reproduction control circuit controls the focus control circuit to perform focus changing of the optical pickup to access the first recording surface and the second recording surface in accordance with block addresses of data blocks to be reproduced and the disk information detected by the disk information detection circuit.