Abstract: An optical disc device and a recording method is provided in which information can be additionally recorded on an optical disc, which has a servo layer and recording layers separately formed, by accurately correcting a relative angle between a light beam and the optical disc used in the previous recording without providing an area where recording is not performed while maintaining the stability of tracking servo. The above subject can be solved by studying with high accuracy the relative angle between the optical disc and the optical axis used in the previous recording by applying a radial tilt servo according to a signal from the recording layers with the tracking servo applied by the servo layer. Further, the additional recording can be performed stably by fixing the radial tilt at the previously studied angle when the recording is performed.

Abstract: An optical disc device and information recording/reading method for an optical disc in which a recording layer is formed through volume recording by aligning recording tracks, which hold information, in a homogenous recording region that does not internally have a layer defining a recording position. The information recording method includes a step in which a first recording layer forming a complex recording layer is formed by forming a recording track while recording information by focusing a main beam at a predetermined depth position in the recording region, and a step in which a second recording layer forming the complex recording layer is formed by forming a recording track while recording information by focusing the main beam at a depth position that is separated from the first recording layer in a depth direction by a depth offset greater than ? of a wavelength of the main beam.

Abstract: An optical drive apparatus that reproduces an optical disk having a land and a groove, the optical drive apparatus including a first tracking-error-signal generating unit that generates a first tracking error signal by using a DPD method, a second tracking-error-signal generating unit that generates a second tracking error signal by using a DPP method, a tracking servo unit that controls the optical system, and a determining unit that determines that an irradiation point of an optical beam is in a non-recorded area. The tracking servo unit switches over to a control based on the second tracking error signal in response to a result of determination by the determining unit during performing a control based on the first tracking error signal.