Abstract: A demodulator for demodulating an input signal including a predetermined modulated signal includes a multiplication fundamental wave generator for outputting a multiplication fundamental wave for the predetermined modulated signal, a calculator for multiplying the multiplication fundamental wave by the input signal and for integrating the multiplication result, a demodulated signal generator for generating a demodulated signal of the modulated signal using the output from the calculator, a phase determiner for determining a cross-phase state of the input signal and the multiplication fundamental wave on the basis of a balance of levels of a plurality of integrated values, obtained as the integration result, for an interval containing the modulated signal in the input signal, and a phase adjuster for adjusting a phase of the multiplication fundamental wave to be supplied to the calculator on the basis of the determination result of the phase determiner.

Abstract: In a demodulation process of a first modulated signal and a second modulated signal, phase adjustment is automatically performed by generating, in response to demodulation results, an optimum phase value of a second internal reference wave for demodulating the second modulated signal. A phase of a second internal reference wave for demodulating the first modulated signal is also adjusted using the optimum phase value for the automatic adjustment.

Abstract: A demodulator for demodulating an input signal including a predetermined modulated signal includes a multiplication fundamental wave generator for outputting a multiplication fundamental wave for the predetermined modulated signal, a calculator for multiplying the multiplication fundamental wave by the input signal and for integrating the multiplication result, a demodulated signal generator for generating a demodulated signal of the modulated signal using the output from the calculator, a phase determiner for determining a cross-phase state of the input signal and the multiplication fundamental wave on the basis of a balance of levels of a plurality of integrated values, obtained as the integration result, for an interval containing the modulated signal in the input signal, and a phase adjuster for adjusting a phase of the multiplication fundamental wave to be supplied to the calculator on the basis of the determination result of the phase determiner.

Abstract: A recording/reproducing apparatus comprising an OP head 11, a wobble circuit 12, a system controller 13, and an address-decoding timing generator 14. The wobble circuit 12 extracts a wobble signal from the signal the OP head 11 has read. A PLL circuit for generating a sync signal from the wobble signal is held while no normal wobble signal is generated. The address-decoding timing generator (Address DEC TG) 14 receives a signal the OP head 11 has reproduced, decodes the address represented by the signal, and supplies the address data to the system controller 13. The generator 14 also generates a timing signal from the sync signal supplied from the wobble circuit 12 and supplies the timing signal to the other components of the recording/reproducing apparatus.

Abstract: A recording/reproducing apparatus and method are provided to record and reproduce data on and from a disk-shaped recording medium that has an address data area with embossed pits and a recording/reproducing area with a wobbling spiral groove. A wobble-signal processing circuit is used to extract a wobble signal from the signal the head obtains from the wobbling spiral groove and to provide the wobble signal to a PLL circuit to produce a sync signal therefrom. A pulse is produced at least during a wobble signal disturbance period occurring when switching between at least one of a recording and reproducing operation and provided to the PLL circuit in order to provide an unchanging sync signal during the wobble signal disturbance period to avoid the wobble disturbances from being carried over to the sync signal.

Abstract: In a demodulation process of a first modulated signal and a second modulated signal, phase adjustment is automatically performed by generating, in response to demodulation results, an optimum phase value of a second internal reference wave for demodulating the second modulated signal. A phase of a second internal reference wave for demodulating the first modulated signal is also adjusted using the optimum phase value for the automatic adjustment.

Abstract: The present invention relates to an information recording/reproducing apparatus that radiates a laser beam to an information recording medium for recording and/or reproducing information, comprising: a laser beam generating means for generating a laser beam that records information to or reproduces information from the information recording medium; a timing control means for controlling information recording timing so that a recording area on a track of the information recording medium is followed by another recording area in a partially overlapping manner; and a laser beam intensity control means for controlling an intensity of the laser beam generated by the laser beam generating means so that a first area with information recorded, a second area with information erased, and a third area with information neither recorded nor erased are formed in the recording area in which information is at least recorded in an overlapping manner.

Abstract: An optical recording method according to the invention is provided such, that when an optical pickup (2) is moved over an optical disk (1), the optical pickup (2) being positioned onto the target track location, record marks are recorded on the optical disk (1) by a light beam irradiated onto the optical disk (1) through the optical pickup (2). An irradiation position of the light beam is offset during recording by a predetermined amount to a track at the recording direction side relative to the target track location, and a record mark is formed on a target track by the offset light beam.

Abstract: A disk to which sectors and clusters of data can be written, wherein each of the sectors includes an arbitrary first number of data frames and each of the clusters includes an arbitrary number of sectors, wherein the disk includes a region for recording the data, wherein the region is segmented into zones, a first set of at least one of the zones is located adjacent to a second set of at least one of the zones, the second set is located closer to an outer circumferential side of the disk than is the first set, each track of the first set is segmented into a second number of data frames, and each track of the second set is segmented into a third number of data frames, where the third number is the sum of the second number and a fourth number smaller than the first number. Other aspects of the invention are a method and apparatus for recording data to or reproducing data from such a disk.

Abstract: In a disk with a wobbling pregroove, data can be recorded in high density. A recording/reproducing apparatus for recording/reproducing data on/from a disk in which a sector is constituted by one arbitrary integer (F) of data frames, a cluster is constituted by another arbitrary integer (S) of the sectors, and data is recorded or reproduced in unit of the sector, or in unit of the cluster, is comprised of: reading means for reading a track number of an access point of the disk; storing means for storing a table about the track number and a zone, in which the following relationship is established, i.e.

Abstract: In a magneto-optical recording apparatus, since a magnetic field is not generated in a data recording impossible area in order to lower power consumption, sufficient intensity of the magnetic field can be obtained at the head of a data recording area. In the case of recording information data in a data recording area of a magneto-optical recording medium, a magnetic field is generated in a data recording impossible area which exists between a pit formed at the latest end side of the data recording impossible area and the head of a data recording area located just after the data recording impossible area, without generating the magnetic field during the time of scanning a laser beam from the head of a data impossible area located just before a data recording area and a pit formed at the latest end side of the data recording impossible area. Thereby practically sufficient intensity of the magnetic field can be steadily and surely obtained at the time of recording information data in the data recording area.