Patent ID: 7907487

Claim:
A recording/reproduction apparatus, comprising: a first recording section for recording at least one piece of test information onto a medium using at least one recording power; a reproduction section for reproducing at least one test signal indicating the at least one piece of test information from the medium; and a second recording section for recording information onto the medium using one of the at least one recording power, wherein the reproduction section comprises: a decoding section for performing maximum likelihood decoding of the at least one test signal and generating at least one binary signal indicating a result of the maximum likelihood decoding; a calculation section comprising: a differential metric detection section for calculating a reliability of the result of the maximum likelihood decoding based on a state transition sequence identified by a binary signal of the at least one binary signal corresponding to an edge of a recorded mark formed on the medium and a result of calculation of a Euclid distance between a test signal of the at least one test signal corresponding to the edge of the recorded mark and at least one target value used in the maximum likelihood decoding; a determination section for determining whether or not a recorded state is normal based on the reliability calculated by the differential metric detection section; and an adjustment section for adjusting a recording power for recording the information onto the medium to the one recording power based on the reliability calculated by the differential metric detection section.