Abstract: An optical disk has a recording region divided into ones, each zone including physical tracks which are divided into a number of sectors. The optical disk further includes a structure management table which stores an attribute for each zone indicating whether the corresponding zone is a recording area which permits rewriting or a recording area that does not permit rewriting.

Abstract: An optical disk has a recording region divided into zones, each zone including a number of adjacent physical tracks. An integer number of sectors are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sequentially numbered sectors. A logical track includes a series of 2.sup.n sectors, n being an integer.

Abstract: An optical disk physical has a recording region divided into zones, each zone including physical tracks adjacent to each other. An integer number of sectors are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sectors, independent of the physical tracks. The conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from a host device is easy. The addresses written in headers of the sectors in the logical track in which data are actually recorder, including substitute sectors used in place of defect sectors, are preferably consecutive to further facilitate the conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from the host device.

Abstract: An optical disk physical has a recording region divided into zones, each zone including physical tracks adjacent to each other. An integer number of sectors are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sectors, independent of the physical tracks. The conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from a host device is easy. The addresses written in headers of the sectors in the logical track in which data are actually recorded, including substitute sectors used in place of defect sectors, are preferably consecutive to further facilitate the conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from the host device.

Abstract: An optical disk physical has a recording region divided into zones, each zone including physical tracks adjacent to each other. An integer number of sectors are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sectors, independent of the physical tracks. The conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from a host device is easy. The addresses written in headers of the sectors in the logical track in which data are actually recorded, including substitute sectors used in place of defect sectors, are preferably consecutive to further facilitate the conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from the host device.

Abstract: An optical disk physical has a recording region divided into zones, each zone including physical tracks adjacent to each other. An integer number of sectors are provided in each physical track. The angular recording density is higher in the more outward zones such that the linear recording density is substantially constant throughout the recording region, and logical tracks are formed of a predetermined number of sectors, independent of the physical tracks. The conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from a host device is easy. The addresses written in headers of the sectors in the logical track in which data are actually recorded, including substitute sectors used in place of defect sectors, are preferably consecutive to further facilitate the conversion between the logical track and sector addresses read from the disk and the linear logical addresses supplied from the host device.

Abstract: The disk drive apparatus of the present invention has an optical pickup that jumps a track to perform track jumping when a jumping voltage is impressed, and that traces a track by performing brake operation when a braking voltage is applied, and actuator that drives the optical pickup, a signal processing part that performs focus and tracking control with respect to the optical pickup, a movement time measurement part that measures the movement time when a light beam emitted from the optical pickup is moved to cross a track to a required track, a voltage control part that uses the results of measurement to generate parameters and a voltage value that is applied to the actuator, a storage part that stores voltage value that is generated by the voltage value setting part, and that after a disk is loaded, first stores data of that disk in the storage part and uses those data values according to the track jump operation.

Abstract: An optical disc recording apparatus which records data with a second rotation frequency on an optical disc containing a preliminarily written recording condition in relation to a first rotation frequency. The optical disc recording apparatus preliminarily possesses recording condition in relation to the first and second rotation frequencies. The optical disc recording apparatus initially reads the recording condition in relation to the first rotation frequency, and then, in accordance with the read-out recording condition in relation to the first rotation frequency and the stored recording condition in relation to the first and second rotation frequencies, the recording apparatus computes the recording condition applicable to the optical disc in relation to the second rotation frequency. Finally, the optical disc recording apparatus records data on the optical disc by applying the computed recording condition.

Abstract: A miniaturized optical disk apparatus which performs a pull-in of a focus servo and a pull-in of a tracking servo without a position detector for detecting an optical head. If the optical head is located at a non-reflection film area and thus the focus servo cannot be performed, then the optical head is moved and the focus servo is performed again. This process is repeated until the focus servo can be achieved. In addition, if the optical head is located at a non-track area, then the optical disk is moved to a track area and then the tracking servo is performed. This process also repeated until the optical head is located over the track area. The tracking servo can be stably performed since it is performed only when the optical head is located over the track area. The present invention is applicable to the optical disk apparatus which uses a 3.5 in optical disk.

Abstract: A magneto-optic recording medium has a cartridge provided with a magnetization direction indicating portion for indicating the direction of magnetization of a second magnetic layer. Alternatively, the direction of magnetization of the second magnetic layer is recorded in advance in the first magnetic layer. The direction of magnetization of the second magnetic layer indicated or recorded is detected and recognized. A magnetic field oriented in an opposite direction to the direction of magnetization detected is imparted to the magneto-optic recording medium. Alternatively, predetermined information is recorded in the first magnetic layer, the direction of magnetization of the second magnetic layer is detected on the basis of a signal reproducing that information, and the direction of a magnetic field to be applied to the magneto-optic recording medium is set on the basis of the direction of magnetization thus detected.

Abstract: A sampled servo type optical disc and its driving apparatus is disclosed, in which by cyclically repeating wobbled pits or address pits of the optical disc composed by two significant digits at every N tracks, and preformatting by patterns spaced in different intervals at every track, when the optical disc driving apparatus seeks an object track, the seek direction of the optical head can be detected by the sequence of change of the pattern, and its seek speed can be detected at high speed by the detected result of the pattern, ensuring the speed control of the optical head in response to the detected seek direction and speed.

Abstract: A method for rewriting four defect management areas on an optical disk according to an ECMA standard is performed by means of deleting an old data which has been recorded on the respective defect management areas and then sequentially writing down a new data on respective defect management areas.

Abstract: An optical data medium driving apparatus which constitutes amplifiers for an output current signal of photosensor by a plurality of current mirror circuits different in an amplification factor in order to switch in a wide range the output current signal of the photosensor which detects quantity of the reflected light corresponding to variation of the quantity of reflected light from an optical data medium having various characteristics, thereby obtaining the output with high accuracy and in a wide band, and a servo circuit which uses for an AGC circuit nomalizing a difference signal from each light receiving surface at a photosensor having a plurality of the light receiving surfaces an A/D converter which is given the difference signal as an analog input signal and the sum signal as the reference input signal and outputs an offset binary type digital signal, thereby being inexpensive to be produced, easy to be integrated and have high function, and high in reliability.

Abstract: Methods and apparatuses are disclosed for improving accuracy of recording and reproducing information onto and from a magneto-optic recording information medium. In the first method, a width of a mark formed by a relatively low intensity light beam between two kinds of light beam intensities used for recording information is made larger than a sum of a track land width and the maximum track offset of the light beam, thereby the mark formed by the relatively low intensity light beam covers the track land portion in its full width. In the first apparatus, a reflected light beam from the magneto-optic recording information medium is split into a reflected beam for information reproducing and a reflected beam for tracking and focusing servos at the reproducing, thereby the apparatus can remove part being affected by the track groove portion from the reflected light beam for information reproducing.

Abstract: Methods and apparatuses are disclosed for improving accuracy of recording and reproducing information onto and from a magneto-optic recording information medium. In the first method, a width of a mark formed by a relatively low intensity light beam between two kinds of light beam intensities used for recording information is made larger than a sum of a track land width and the maximum track offset of the light beam, thereby the mark formed by the relatively low intensity light beam covers the track land portion in its full width. In the first apparatus, a reflected light beam from the magneto-optic recording information medium is split into a reflected beam for information reproducing and a reflected beam for tracking and focusing servos at the reproducing, thereby the apparatus can remove part being affected by the track groove portion from the reflected light beam for information reproducing.

Abstract: In an optical disk storage, the seek of an optical head is controlled so that the number of seek times cannot exceed a threshold number of times in a predetermined period or an accumulated seek period cannot exceed a threshold period in a predetermined period. Therefore, a wasteful power consumption and a rise in the internal temperature associated with the seek activity can be effectively prevented.

Abstract: An optical disk drive for recording and reproducing information on an optical disk medium includes a servo circuit for controlling tracking of a light beam on a predetermined track and a servo circuit for controlling focus of the light beam on the disk surface. The disk surface is divided into a plurality of regions, and calibration values for adjusting the servo circuits are determined in each region. The calibration values are stored in a memory and are used to adjust the servo circuits during tracking on a predetermined track. The calibration values include tracking offset values, focus offset values, servo deviation threshold values and sensor gain values. A number of techniques are disclosed for automatically determining the calibration values.

Abstract: An optical or magneto-optical disk storage which automatically adjusts a recording/reproducing level of a number of kinds of optical or magneto-optical disks having different recording/reproducing levels to an optimum recording/reproducing level. The optical or magneto-optical disk storage has an attenuator which applies a predetermined attenuation amount to a reproduced signal reproduced from an optical or magneto-optical disk so as to attenuate the reproduced signal, or intensity adjusting means for adjusting the intensity of a laser beam used for recording and/or reproducing. The optical or magneto-optical disk storage detects an amplitude of the reproduced signal and feed-back-controls the attenuation amount or intensity of the laser beam in accordance with the detected amplitude.

Abstract: A magneto-optic recording medium has a cartridge provided with a magnetization direction indicating portion for indicating the direction of magnetization of a second magnetic layer. Alternatively, the direction of magnetization of the second magnetic layer is recorded in advance in the first magnetic layer. The direction of magnetization of the second magnetic layer indicated or recorded is detected and recognized. A magnetic field oriented in an opposite direction to the direction of magnetization detected is imparted to the magneto-optic recording medium. Alternatively, predetermined information is recorded in the first magnetic layer, the direction of magnetization of the second magnetic layer is detected on the basis of a signal reproducing that information, and the direction of a magnetic field to be applied to the magneto-optic recording medium is set on the basis of the direction of magnetization thus detected.

Abstract: An optical data medium driving apparatus which constitutes amplifiers for an output current signal of a photosensor including a plurality of current mirror circuits having different amplification factors in order to switch, in a wide range, the output current signal of the photosensor. The photosensor detects a quantity of the reflected light corresponding to a variation of the quantity of reflected light from an optical data medium having various characteristics. The output is obtained with high accuracy and in a wide band. A servo-circuit is used for an AGC circuit and normalizes a difference signal from each light receiving surface at a photosensor having a plurality of light receiving surfaces. An A/D converter is given the difference signal as an analog input signal and the sum signal as the reference input signal. The A/D converter outputs an offset binary type digital signal, thereby being inexpensive to produce, easy to be integrated having high function, and high in reliability.