Information recording/reproducing apparatus that improves recording/reproducing characteristics

Abstract

An information recording/reproducing apparatus includes a use condition determination part that reproduces a specific area on a rewritable recording medium and determines whether an unused area exists. A recording linear velocity changing part changes a recording linear velocity in a radial direction of the medium. A recording clock cycle changing part changes a recording clock cycle in accordance with a change in the velocity. A test writing part performs test writing with a different recording power for each step. An optimum recording power determination part reproduces test-written information and determines an optimum recording power for a recording linear velocity in test writing based on a characteristic value of a reproduction signal. When the unused area exists, test writing is performed thereon at a recording linear velocity the same as that in recording, the optimum recording power for the area is determined, and information is recorded with the optimum recording power.