Recording/reproducing apparatus and recording medium

A recording/reproducing apparatus for recording or reproducing information with respect to a recording medium, comprising:

• a medium rotation unit including a spindle and motor to mount and rotate the recording medium around a predetermined rotational axis;
• a pickup to record or reproduce the information with respect to the recording medium;
• a displacement stage having a movable portion that moves along at least two driving axes in a predetermined plane, and the medium rotation unit is fixed onto the movable portion;
• a mark detection unit for detecting a predetermined mark disposed on the recording medium;
• and
• a transportation unit on which the displacement stage and the mark detection unit are fixed,
• wherein the movable portion moves the medium rotation unit relative to the transportation unit, and
• wherein the pickup is disposed separately from the transportation unit.

A recording medium for recording or reproducing information, comprising:

• a concentric angle-detection-dedicated mark for detecting a rotational angle of the recording medium;
• and
• a concentric eccentricity-detection-dedicated mark for detecting an eccentricity where a rotational center of the recording medium does not coincide with a geometric center of the recording medium,
• wherein the concentric eccentricity-detection-dedicated mark is provided at a radial distance from the geometric center of the recording medium different from the concentric angle-detection-dedicated mark.