Patent ID: 8395976

Claim:
An optical disc apparatus comprising: an objective lens that converges an information light beam for recording information on or reproducing information from, a single uniform recording layer, of an optical disc, in which two or more mark layers are to be formed one on the other with a plurality of recording marks representing information and arranged in a planar arrangement and also a servo light beam for determining the position of irradiation of the information light beam; an optical path forming section that forms the optical path of the information light beam and that of the servo light beam entering the objective lens so as to separate the focus of the servo light beam produced by the objective lens from the focus of the information light beam also produced by the objective lens by a predetermined distance in the layering direction with regard to the direction of the optical axis of the information light beam; a light receiving section that receives the servo reflected light beam produced as the servo light beam is reflected by the optical disc; and a position control section that controls the position of the objective lens, so as to focus the servo light beam on a formed mark layer, according to the outcome of receiving the servo reflected light beam, wherein the position control section controls the position of the objective lens according to the outcome of receiving the servo reflected light beam so as to make the focus of the servo light beam agree with a desired track formed by recorded recording marks on the mark layer.