Abstract: Data is written on a plurality of data tracks on an optical disk by a plurality of laser beams. The spots illuminated by the beams are spaced apart to prevent thermal interference. The spots are aligned along a line at an angle to the tangent of the data tracks. The angle of the line of spots is determined by an equation using variables that include the track pitch, the minimum distance between spots and the difference in track numbers between tracks being written.

Abstract: A system for recording data to a disc shaped record medium. The data is recorded according to a universal disc format employing a hierarchical file system, and data within the hierarchical structure is referenced using pointer information. The pointer information includes a file identifier descriptor and a file entry and is recorded such that the pointer information and its corresponding substantive data are stored at successive addresses.

Abstract: A method and apparatus for audibly indicating when a predetermined location has been encountered in stored data is disclosed. A predetermined location is first identified. An audible indicator associated with the predetermined location is then generated when the predetermined location is encountered. The predetermined location can be an electronic bookmark, a section boundary or a program boundary. The invention includes a method and apparatus for audibly setting an electronic bookmark in stored data by selecting a location within the stored data, associating an electronic bookmark with the location, and generating an audible message for the electronic bookmark.

Abstract: A method and system for enhancing the efficiency of data accessing within a storage subsystem which is coupled to a host system via a storage subsystem controller and a data channel. The storage subsystem controller preferably includes a tracked cyclic storage device which has multiple disks which are rotatable about a single spindle. Recording tracks within each disk are then accessed utilizing multiple switchable transducer heads. A signal transmitted from the host system is utilized to define a sequence in which a group of recording tracks are to be accessed. That signal is then utilized to create a transducer head switching table within the storage subsystem controller which lists each recording track to be accessed and an associated control parameter for selecting a particular transducer head to be utilized to access a subsequent recording track.

Abstract: An optical card for storing data includes a base member and a plurality of parallel linear tracks on the base member for storing the data. Address data is recorded alternately on an opposite end of each successive track for storing an identifying code corresponding to the respective track.

Abstract: A high density spiral track forming apparatus according to the present invention includes a linear motion mechanism for moving an optical recording system in a radial direction of a disk-shaped substrate, and a length measurement machine for detecting the distance travelled by the optical recording system in the radial direction of the substrate disk. The apparatus further includes a velocity computing device for detecting the travel velocity of the optical recording system according to the detected result of the length measurement instrument, and a velocity control device which detects the difference between the travel velocity of the optical recording system which is detected by the velocity computing device and a predetermined velocity, and controls the linear motion mechanism so as to eliminate that difference.

Abstract: A device for tracking a movable body along a linear path parallel to a plane includes a linear motor for driving the body along the linear path. The body is mounted, as by rollers, for movement along a guide, such as a pair of parallel guide rails, supported on a base which also supports the motor. To enhance stability of the body during tracking movement, the rollers or other mounts for the body are urged against the guide by the magnetic action of a flux which is separate from the principal flux used to generate thrust for the linear motor and which provides an attractive force against preferably a pair of members, such as steel plates, of high magnetic permeability fixed to the movable body.

Abstract: A drive system for use in an optical disk file device has a multipolar motor such as a three-phase linear DC motor for positionally controlling a read/write head and driving the same to track an optical disk. Selection of the coils of the motor and phase switching of the coils are stopped while the drive system is in the tracking mode.

Abstract: A modulation and demodulation system for an optical data recording and reproducing apparatus is disclosed in which, in an optical disc having an optical guide track and capable of recording and reproducing optically, the guide track is divided into a plurality of data sectors and the recording or reproduction or reading is effected by data sector. The modulation system for the data field for recording the data is different from that for the identification field containing identification data such as a track address and a sector address in such a way that the identification field is reproduced at high reliability and high demodulation speed while at the same time recording data at high density in the data field.

Abstract: A device for rapidly moving an optical pick-up device in an optical reproducing apparatus to a desired position on a record disc having a plurality of record tracks with an information signal recorded therein, includes a tracking error signal generating circuit for producing a tracking error signal corresponding to deviation of the pick-up device from the center of each record track; a drive device for moving the pick-up device in a direction transverse to the record tracks; and a track jump signal forming circuit for producing a track jump signal comprised of a drive signal followed by a brake signal, in response to the tracking error signal, the drive signal having a duration corresponding to the number of tracks traversed by the pick-up device and the brake signal having a duration corresponding to the speed of movement of the optical pick-up device in traversing the tracks, and for supplying the track jump signal to the drive device to control the latter to rapidly move the optical pick-up device in a dir

Abstract: An optical head is mounted on a carrier of a linear motor, and is moved at a high speed to a desired track, i.e., a target position, of an optical disk by the linear motor. In the optical head, a laser oscillator for generating a laser beam, a tracking unit for tracking a laser beam and a focusing unit for focusing a laser beam onto an optical disk are integrally assembled.