Patent ID: 7916602

Claim:
An optical recording and reproducing apparatus that records information according to a front edge and a rear edge of a mark formed on one side of a recording medium in which the information is recorded by a laser, the optical recording and reproducing apparatus comprising: a recording-pulse-shift setting unit that shifts a front edge and a rear edge of a recording pulse, which is a recording waveform of the laser, according to an immediately-preceding space length between one mark and another mark located immediately in front of the one mark and an immediately-following space length between the one mark and another mark located immediately behind the one mark, and that sets a write strategy of the recording pulse; a mark-edge-position evaluating unit that detects a front edge and a rear edge of a mark formed on the basis of the write strategy and detects a front mark edge position error, which is a position error of the front edge of the mark, and a rear mark edge position error, which is a position error of the rear edge of the mark; an assuming unit that assumes that the front mark edge position error is represented by a first linear function having a shift amount of the front edge of the recording pulse and a shift amount of the rear edge of the recording pulse as variables and assumes that the rear mark edge position error is represented by a second linear function having the shift amount of the front edge of the recording pulse and the shift amount of the rear edge of the recording pulse as variables; a sensitivity calculating unit that executes test recording for each of combinations of immediately-preceding space lengths and immediately-following space lengths and then calculates sensitivities represented as respective proportional coefficients included in the first linear function and the second linear function according to the front mark edge position error and the rear mark edge position error detected by the mark-edge-position evaluating unit; and a write-strategy calculating unit that calculates a write strategy of the recording pulse on the basis of the sensitivities, wherein the sensitivity calculating unit calculates the sensitivities assuming that the sensitivity represented by the proportional coefficient included in the first linear function depends on only the immediately-preceding space length and the sensitivity represented by the proportional coefficient included in the second linear function depends on only the immediately-following space length.