Abstract: An address information modulation method includes using a first characteristic of a first modulation method and a second characteristic of a second modulation method to modulate address information and/or additional information. Accordingly, a data amount of information, to access a disc, in a predetermined space of the disc is increased, and the modulated information is formed in a form of a wobble signal in a track. Here, the first characteristic of the first modulation method can be physical location information of an MSK-modulated signal, and the second characteristic of the second modulation method can be sign information of a second harmonic wave obtained by an HMW modulation, which synthesizes a cosine function of a basic frequency of a wobble signal with a sine function having a frequency that is a multiple of the basic frequency of the wobble signal.

Abstract: A data recorder for recording data that prevents buffer overrun errors emits a laser beam against a recording medium to record data. The data has a level that determines the power of the laser beam. When there is a possibility of a buffer overrun, data recording is interrupted. The interruption is carried out when the power of the laser beam is a low level. Data recording is restarted with the laser beam generated at the low level.

Abstract: A magneto-optical recording medium includes a substrate and a reproducing layer and a recording layer provided on the substrate. A recording magnetic domain is provided in the recording layer by heating the recording layer by irradiation with light and applying a recording magnetic field to the recording layer in such a manner that information is recorded in the recording layer. The recording layer is a magnetic film having magnetic anisotropy in a direction perpendicular to the film surface, and the magnetic film holds the recording magnetic domain formed therein. The magneto-optical recording medium further comprises a intermediate layer and a reproducing aid layer between the reproducing layer and the recording layer. Saturated magnetization of the reproducing aid layer increases with an increase in the temperature of the reproducing aid layer.

Abstract: A magneto-optical recording medium, including a recording layer, a transfer control layer magnetically coupled to the recording layer, and a reproduction layer. The recording layer includes a recording magnetic domain in which information is recorded by a magnetization direction vertical to the surface of the film. The reproduction layer includes a reproduction magnetic domain in which information in the recording layer is transferred and formed as a magnetization direction by magnetic coupling. The direction of magnetization of the recording magnetic domain of the recording layer and the direction of magnetization of the transfer control layer corresponding to the recording magnetic domain are in opposite directions in at least part of the range of temperatures less than a transfer temperature where the reproduction magnetic domain is transferred to the reproduction layer. The Curie point temperature of the transfer control layer is higher than this transfer temperature.

Abstract: A highlight of a representative track of each album stored in a recording medium and a highlight of each track of a designated album are pre-set. Highlights of representative tracks of albums are successively reproduced from album 1. As a result, albums are searched for a desired track. When the desired album has been found, highlights of tracks of the album are successively reproduced from track 1. As a result, the album is searched for the desired track.

Abstract: A dielectric recording medium in a disc form is provided with: a center hole; an inner area; a recording area; and an outer area, arranged concentrically from the inside in this order. The inner area, the recording area, and the outer area contain a uniform and flat dielectric material and are polarized with the polarization direction of the recording area opposite to that of the inner area and the outer area in their initial condition. The recording area in which data is recorded has tracks and spaces, each of which is between two of the tracks, and is provided with areas in which control information about the recording/reproducing is recorded, in the track and the space.

Abstract: It is an object of the present invention to provide a method for recording information in an optical recording medium with a good direct overwriting characteristic. The method for recording information in an optical recording medium according to the present invention forms record marks in a recording layer containing a phase change material by modulating the power of a laser beam between a plurality of power levels including a recording power Pw, an erasing power Pe and ground power Pb. The erasing power Pe is set to a level within a region where a reflection coefficient of a region between neighboring record marks approaches a reflection coefficient of the record mark as the erasing power Pe increases. As a result, a good overwriting characteristic can be obtained when data are recorded at a high linear velocity.

Abstract: Management information is read from an information storage medium having the management information recorded thereon, the management information including track number information imparted to at least one track and group management information for managing as selective recording information one or a plurality of tracks as one group. Judgment is then made upon whether the group management information is included in that management information. A display mode is changed depending on a case where the group management information is recorded and a case where it is not recorded, and it is then displayed in a displaying device.

Abstract: An audio device is compatible with a recordable medium such as a CD-R. The audio device manages track files in each session of the recordable medium and displays the session containing the file of an arbitrary track on a display. For example, each session is regarded as a virtual disk and the name of the virtual disk corresponding to the session containing the track is displayed. Accordingly, the device can be used like a CD-changer with a better operationality, and the user can easily find a desired track from the many tracks recorded on the CD-R and play it back. Also, the device automatically plays back a track of the latest session first.

Abstract: The present invention provides a magneto-optical recording method capable of securing a sufficient phase margin, even if a recording power or medium temperature fluctuates, and obtaining a reproduction signal having a preferable quality, wherein the time phases of a laser pulse and a modulation magnetic field are set to a time phase of maximizing in which a recording power margin.

Abstract: Provided are a method and apparatus for canceling noise from a track cross signal, a method for controlling an optical disc drive, an optical disc drive, and an optical disc reproducing apparatus. The method for removing noise from a track cross signal includes (a) removing noise from the track cross signal by binarizing the track cross signal with reference to hysteresis set values that are determined according to a command speed for a tracking actuator; and (b) removing glitch noise from the binarized track cross signal based on a predetermined time value. Accordingly, it is possible to effective remove noise to obtain information regarding the precise speed and position of a desired track.

Abstract: Provided are an apparatus and method of operating a multi-changer of an optical disc player which restricts an initial operation of the multi-changer of the optical disc by referring to a disc chucking and tray open/close states. According to the method, it is determined whether a type of a disc, which is currently mounted in the disc mounting unit, has been determined before, if a tray open or close key is inputted. If it is determined that the type of the disc has not been determined before, the tray is opened or closed. Then, if the tray is closed, the type of the disc is determined after chucking the disc which is currently mounted in the disc mounting unit. According to the method, it is possible to stabilize a player by restricting an initiating operation of the multi-changer of the optical disc, which occurs needlessly due to a tray open/close key, when a disc is not yet chucked.

Abstract: A magnetooptic recording medium has at least a recording layer for recording data and a reproducing layer for reproducing the data recorded in the recording layer onto a substrate and reproduces the data by setting a proper reproducing laser power upon reproduction. According to the magnetooptic recording medium, magnetizing directions of a buffer area, a sector address area, and a gap area which are sandwiched between data areas in which the data is recorded are uniformly magnetized in the recording direction.

Abstract: In a magneto-optical recording medium, a first magnetic layer is made of a material using a Gd—Fe film or a Gd—Fe—Co film as a base so that a magnetic field normalized based on saturation magnetization of a magnetic domain wall driving field can be smaller than 1. A second magnetic layer is made of a material using a Tb—Fe film or a Dy—Fe film as a base, to which a nonmagnetic element such as Al or Cr, and Co are added. A third magnetic layer is made of a material using a Tb—Fe—Co film or a Dy—Fe—Co film as a base, and an element concentration ratio (at. % ratio) of Tb or Dy to Fe—Co is set in a range of 24.5?Tb?26.5 or 26.5?Dy?29.5. Addition amounts of Co and a nonmagnetic element to each magnetic layer are adjusted to set Curie temperatures Tc11, Tc12, and Tc13 of the first, second and third magnetic layers to Tc13>Tc11>Tc12.

Abstract: A device that records information on an optical disc and a method for recording the information on the optical disc, so as to maintain a constant recording quality when the information is recorded on the optical disc using a constant number of the rotations to control the speed. The recording device includes a linear velocity detector detects a linear velocity which is a velocity of a spot of a light, which is irradiated to record the information on a surface of the optical disc, in a tangential direction of a circumference of the optical disc, and an optical power controller controlling the optical power of the light to record the information on the surface of the optical disc based on the linear velocity detected by the linear velocity detector.

Abstract: An apparatus to remove periodic disturbances in a recording medium having large eccentricity and deflection mass includes an actuator to change a position of a pickup in response to a combination of first and second compensation signals, an error detector to detect an error between positions actuator and the recording medium, a first compensator to receive the detected error and to output the first compensation signal that the actuator uses to actuate the pickup along the recording medium in upper and lower directions, and right and left directions; and a second compensator to output the second compensation signal from which the disturbance has been removed, to combine the compensated error and previous first and second compensation signals, and to filter the combined result at a predetermined bandwidth.

Abstract: An optical head for recording or reproducing a signal with respect to an optical recording medium, which includes an optical element disposed between a light source and an optical recording medium. The optical element has an optically active polymer film in which an optical rotation property changes with respect to an applied voltage, a pair of conductive transparent thin films for applying a voltage to the optically active polymer film, and a transmittance polarization anisotropic part having a different transmittance with respect to a polarization direction, which is disposed on one of the conductive transparent thin films. By changing the applied voltage to the optically active polymer film, a light quantity of a linearly polarized light transmitted through the optical element can be changed substantially instantaneously. Therefore, the power of light reaching the optical recording medium can be switched substantially instantaneously at the time when switched between recording and reproduction.

Abstract: An optical information storage medium includes information on recording layers having the same reproduction channel characteristics or different reproduction channel characteristics. Nominal recording speed information is recorded in a read-only zone, and maximum and minimum recordable speed information is recorded in a recordable zone of an area other than a user data area. The nominal recording speed information is reproduced using a differential signal channel or a sum channel, and the maximum and the minimum recordable speed information is reproduced using the sum channel. The optical information storage medium addresses a situation where the nominal recording speed is not satisfied due to errors occurring during the manufacture of the storage medium. Thus, the defective disc proportion can be reduced, and loss of user data due to application of inaccurate recording layer information can be prevented.

Abstract: A sub-code providing method that provides correct sub-code data when sub-code data is requested from a host when a reproduction mode is performed in an optical disc drive. In a method providing sub-code data to a host computer in an optical disc drive formed so that data from a pick-up is reproduced through a buffer, the method includes the operations of setting sub-code data whenever data of a predetermined unit is output from the buffer, and transmitting the set sub-code data to the host computer when the sub-code data is requested from the host computer during the reproduction mode. Therefore, it is possible to provide more accurate sub-code data to the host computer and to thus prevent the reproduction of unnatural screen during operations such as automatic reproduction or game CD reproduction.

Abstract: When data recording is interrupted, a location at which data have been last recorded is accurately detected and a seamless restart of the recording is achieved even if reproducing errors occur due to scratches or the like on an optical disk. A pattern data that indicates a pit pattern of data to be recorded or having been recorded is compared to a pattern data that is reproduced within a predetermined range (window) of clock cycles, and when a match is obtained, a recording restart signal is output to restart the recording operation.