Abstract: Amplitude or phase modulated un-compensated wobble patterns representing address patterns for track addresses of optical media are generated. A filter is applied to the un-compensated wobble patterns to pre-compensate the un-compensated wobble patterns. When an inverse of the filter is applied to a signal representing the pre-compensated wobble patterns in the presence of noise, the noise is suppressed and the un-compensated wobble patterns are substantially recovered.

Abstract: Provided is an optical recording medium, including a recording target track that is a track on which small record carriers are arranged and on which information recording is performed by modulating the small record carriers through light irradiation; and a wobbling track on which the small record carriers are arranged in a wobbling manner, wherein a single wobbling track is formed to run parallel to a set of a plurality of recording target tracks.

Abstract: An optical disk device is provided in which stable operation is realized even when an offset amount of a signal to be used for servo control changes due to environmental variations. The optical disk device generates a signal for servo control based on signals corresponding to a reflected light of a laser light irradiated to an optical disk, and detects an offset superimposed on a signal for the servo control. The optical disk device compensates the amount of the adjusted offset which has been set up so as to reduce the offset amount in initial setting for light detection corresponding to an optical disk loaded, according to the amount of change of the offset amount detected, adjusts the signal to be used for the servo control based on the amount of the offset control after the compensation, and performs the servo control based on the adjusted signal.

Abstract: Methods and systems are described for correcting repeatable runout. In one aspect, an open loop tracking signal is received and squared. A discrete Fourier transform (DFT) of the squared open loop tracking signal is obtained. A velocity magnitude and an absolute value of the phase of the open loop tracking signal is determined. A RRO correction signal is iteratively constructed by performing a partial correction based on an initial phase selected and an initial velocity amplitude, measuring a relative velocity amplitude, performing a partial control correction using the initial phase and relative velocity amplitude if the amplitude is smaller than an initial amplitude; performing a partial control correction using the initial phase and the relative velocity amplitude if the amplitude is smaller than an initial amplitude, and repeating the above steps until a tracking controller can perform closed loop control of the track to optical pickup unit velocity.

Abstract: An optical disc device includes a tracking error signal amplitude adjuster for measuring the amplitude of a tracking error signal when an optical pickup is located at an inside peripheral location of an optical disc, and at one or more outside peripheral location, and calculating a ratio of the measured amplitude to a target amplitude as an adjustment value. The tracking controller controls tracking while adjusting the amplitude of the tracking error signal according to the adjustment value, on the basis of the current radial location of the optical pickup, and the calculated adjustment value.

Abstract: Provided is an optical disc drive device which stably controls an actuator of an optical pickup, by individually controlling an optical spot when following the guide track and an optical spot when recording/reproducing information on/from each recording layer. An optical spot when following the guide track and an optical spot when recording/reproducing information on/from each recording layer are individually controlled. At this time, the optical spot exclusive for the track and the optical spot exclusive for the recording/reproducing are formed on an optical disc.

Abstract: The pit arrays on an optical disc medium are made to wobble at a frequency which is higher than the band of frequencies that a tracking servo can follow and which is lower than the band of frequencies of the reproducing signal. A wobble detection signal according to the amount of wobble is obtained from the tracking error signal and used as a reference signal for frequency acquisition. Alternatively, the pit arrays on the medium are wobbled at a frequency which is within the band of frequencies that the tracking servo can follow and which is lower than the band of frequencies of the reproducing signal. In addition, a wobble detection signal corresponding to the amount of wobble is obtained either from the output signal from a compensator included in a tracking servo system or from a tracking drive signal and is used as a reference signal for frequency acquisition.

Abstract: The present invention achieves higher precision and lower power consumption by reducing semiconductor chip occupation area. A semiconductor integrated circuit which can be mounted on an optical disk device has: a wobble signal generating circuit capable of receiving first, second, third, and fourth light reception output signals A, B, C, and D of a light receiving element in an optical pickup and detecting a wobble in a recordable disk; a differential phase detection signal (DPD) generating circuit for tracking an unrecordable disk; and two A/D converters and an arithmetic circuit.

Abstract: An optical disc drive for reading or writing information on a multilayer optical disc having three or more recording layers by irradiating the disc with a light beam includes an optical pickup for irradiating the disc with the light beam, a recording state detector for detecting data recording states at a start point of a focus jump, a transit point or transit points on a recording layer or recording layers to be passed through, and an expected landing point of a focal point of the light beam in a focus jump, and a controller for moving the optical pickup to a position where the recording states are the same at all of the start point, the transit point(s) on the recording layer(s) to be passed through, and the expected landing point if the recording states are different among those points, before starting the focus jump.

Abstract: A tracking error (TE) signal polarity determining method, comprising: (a) obtaining a wobble related signal and a TE signal from an optical pick-up unit accessing an optical disc; (b) determining an accessing direction; and (c) determining if an original polarity of the TE signal from the optical disc should be changed or not according to the relation between the wobble related signal and the accessing direction.

Abstract: An information recording medium 1 at least comprises a substrate 13 having a microscopic pattern 20, which is constituted by a shape of continuous substance of approximately parallel grooves formed with a groove section G and a land section L alternately, a recording layer 12 formed on the microscopic pattern 20 and a light transmission layer 11 formed on the recording layer. The microscopic pattern 20 is formed so as to satisfy a relation of P<?<NA and a thickness of the light transmission layer 11 is within a range of 0.07 to 0.12 mm, wherein P is a pitch of the groove section G or the land section L, ? is a wavelength of reproducing light beam and NA is a numerical aperture of an objective lens.