Abstract: A method for reducing the blank spaces resulting from the storage of multiple data blocks on a storage medium. In one embodiment, data is stored on a magnetic tape. Data to be written to the tape is partitioned into user data blocks and management data blocks, the user data blocks being written on the tape sequentially in a longitudinal direction in tracks along the tape, and the management data blocks being written in tracks on the tape sequentially in a longitudinal direction that is opposite the write direction of the user data blocks. Writing the user data and management data in directions that are inversely related allows the amount of wasted storage space to be reduced.

Abstract: Data of a recording medium in a storage device is read out for every sector and is stored in a ring buffer under the control of a CPU which can vary the speed of readout from the buffer as the load on the system varies. Data stored in the ring buffer is read out for every frame and is outputted to an output device. When data read out from the recording medium is to be reproduced in real time, the data can be reproduced substantially at a speed corresponding to a reading speed of the data from the recording medium, with a minimum of data loss and enhanced temporal quality.

Abstract: An optical disc has a storage storing addresses of information parts for forwardly reproducing, and the information parts are divided at every information unit. A first table and a second table are provided. The first table stores an address of a last information part of each information unit, and the second table stores an address of an information part to be reversely reproduced next. Reverse reproduction of information parts is performed by retrieving the data stored in the first and second tables.

Abstract: A method for magnetically recording/reproducing comprising recording an information signal by forming a pattern of a soft magnetic material in a magnetic recording medium; providing a magnetoeletric converting element a place neighboring a face of forming the pattern of the magnetic recording medium on which the pattern formed; applying a magnetic field to the pattern; and reproducing the information by detecting a variation of the magnetic field caused by the pattern of the soft magnetic material of the magnetic recording medium while relatively moving the magnetoelectric converting element and the magnetic recording medium.

Abstract: A reading head has odd and even elemental areas for reading corresponding odd and even information segments that alternate to make up a frame of information on a record medium. The odd elemental areas provide a train of sequential odd information segments, each odd segment having cross-talk associated with the neighboring even segments which are on either side thereof when it is read from the record medium. Similarly, the even elemental areas provide a train of even information segments, each even segment having cross-talk associated with the odd segments which neighbored it on either side when it is read from the record medium. To correct for such cross-talk in both signal trains, both are fed to each of two cross-talk correcting circuits. These circuits derive needed adjacent segment information as to the cross-talk producing adjacent segments from one of the trains being fed thereto so as to process the segments of the other train being fed thereto for cross-talk correction.

Abstract: An 8-9 converting circuit converts 8-bit data into 9-bit parallel data. A sync pattern/ID pattern adding circuit adds sync patterns and ID patterns to the 9-bit parallel data and sets values for the ID patterns according to a predetermined correlation between a position of an mth ID pattern and a distance from an nth sync pattern to an mth sync pattern. A parallel/serial converting circuit converts the parallel data into serial data and the resultant serial data is recorded on a tape. Data reproduced from a tape is supplied to a serial/parallel converting circuit which converts the serial data into parallel data. A sync pattern/ID pattern extracting circuit extracts sync patterns and ID patterns from the parallel data, extracting as valid an mth sync pattern whose corresponding mth ID pattern has a value set in accordance with the predetermined correlation. An 8-9 inverse converting circuit converts the parallel data into 8-bit data corresponding to the extracted sync patterns and ID patterns.

Abstract: A video time-shifting system characterized in having a continuous recording track accessed by separate, asychronous read and write facilities enables playback of a video program to commence from any point in the program while continuing to be recorded in real time, thus providing VCR-like program control features such as PAUSE/RESUME, REWIND, and FAST FORWARD. A memory is used to store information relating to various points in the program so that even upon receipt of multiple PAUSE commands, the system automatically keeps track of correct program re-entry. In the preferred embodiment, the storage means takes the form of a continuous recording track in a magnetic disk drive.

Abstract: An apparatus and method for rapidly controlling the disk rotation by detecting a high speed rotation and a reverse rotation of a disk. The disk driving apparatus for controlling rotation of a disk in a normal mode includes a spindle motor for driving the rotation of the disk by a spindle control signal and for generating a spindle driving voltage as the disk rotates, a servo control for generating the spindle control signal of the spindle motor by a servo control signal, a device for converting the spindle driving voltage into digital data, a device for storing a rotation range data table of the spindle driving voltage corresponding to ah abnormal rotation of the disk, and a controller for comparing and analyzing the converted digital data with the rotation range data table, sensing normal and abnormal states, and generating the servo control signal from the sensed results.

Abstract: Methods and apparatus are provided for simultaneously reading data from multiple tracks of an optical disk at a high rate. Circuitry is provided for use with a detector matrix to read and buffer data in parallel from the multiple adjacent tracks, while asynchronously providing processed data to a host processor. Circuitry is also provided for electronic tracking of tracks on the optical disk and for reducing cross-talk between adjacent tracks. Circuitry is further provided for correcting phase errors resulting from variations in the linear velocity of the tracks being read, depending upon the radial position of the tracks.

Abstract: A spindle motor driver is provided. The spindle motor driver includes a spindle motor for rotating an optical disc, an optical head for reading signals from the optical disc to reproduce the information recorded on the optical disc, a processor for processing the detected signals, and a constant linear velocity (CLV) servo for controlling the spindle motor to rotate with a CLV according to the signal processed by the processor. A constant angular velocity (CAV) servo is connected in parallel to the CLV servo to control the spindle motor to rotate with a CAV when the optical head performs jumping. Additionally, a feedback loop is provided between the spindle motor and the CAV servo for feeding back the rotation speed signal of the optical disc. A switching means selectively connects the processor with the CAV servo and the CLV servo. Thus, access time of the optical head can be effectively shortened.

Abstract: A method and apparatus for transferring data in a disc apparatus are disclosed which perform on-the-fly correction. The disc apparatus includes a disc drive for transferring read data to a disc controller after a head has read the data from a storage disc. This disc controller transfers the data from the disc drive to a host device. The data transferring method reads data recorded on the storage disc in a CKD format in which one block is composed of a plurality of subblocks each having an error correction code. Errors in the data are detected by use of an error detection code on a subblock-unit; and after correcting the data of the error-detected subblock, the corrected data on the subblock-unit are transferred with the data of at least the previous subblock, at a speed higher than a reading speed.

Abstract: Methods and apparatus are provided for determining a servo offset value and a take-up reel velocity for imparting a desired linear velocity to tape in a helical scan recording system (20). The helical scan recorder system records information on a magnetic tape (22), the magnetic tape being transported between a supply reel (24) and a take-up reel (26) in the helical scan recorder through a tape path, which tape path includes at least a partial wrapping of the tape around a drum (30) of the helical scan recorder. The methods include moving the tape from the supply reel to the take-up reel whereby the tape travels a predetermined displacement; rewinding the tape by the tape extraction displacement and determining an angular rewind displacement of the take-up reel; and using the determined displacements to ascertain parameters including a desired velocity of the take-up reel.

Abstract: An optical pickup for reading information recorded on a recording surface of an optical information storage medium such as a compact disc or a laser video disc has a light beam source for emitting a linear light beam, and an optical system including an objective lens for converging the linear light beam as a linear image on the recording surface and collecting and emitting a light beam reflected from the recording surface.

Abstract: A video tape recorder for long-play mode recording/reproducing includes a capstan servo circuit including a N-multiplying means for inputting a capstan frequency signal and multiplying the input signal by N times, first switching means for switching each signal multiplied by the N-multiplying means according to a mode selecting signal for selecting a mode and down counting means for counting down the output signal of the first switching means, and a drum servo circuit including a synchronization dividing means for receiving a complex synchronous signal and dividing the input signal into a vertical and horizontal synchronous signal, drum reference frequency generating means for receiving the output signal of the synchronization dividing means and generating a drum reference frequency signal, delay means for delaying a drum phase signal by predetermined degrees, 180+.theta..degree. (here, .theta.

Abstract: A method for recovering a user table of contents data for use by an optical disc driving apparatus which records data in a data record area of an optical disc. The method regenerates the data recorded in the data record area and records information relative to the regenerated data in the user table of contents data record area of the optical disc.

Abstract: Servo data respectively recorded in the peripheral and innermost tracks of a magnetic disk at low and high densities in synchronism with a predetermined write period are read back and binarized by the magnetic head as flux reversal patterns. In this case, on the basis of a table stored in the EEPROM in advance, the filter characteristic of a characteristic variable type low-pass filter is variably set to be a characteristic defined by a low cutoff frequency fc and a small boost amount in the peripheral zone and to be a characteristic defined by a high cutoff frequency and a boost amount, which is large on a high-frequency side, on the central zone. The peak waveforms of a servo signal in the central side are raised to be sharpened, and a qualification level in a pulse decoder is variably set to be high in the outermost tracks and to be low in the innermost tracks.

Abstract: A optical recording/playback apparatus projects a laser beam on to a recording medium to read out precoded address data and record or read out data in the data recording area of the recording medium. The reflected light from the recording medium is detected by photosensors which produce currents from the received light intensity, and the currents are converted into voltage signals by current-to-voltage converting amplifiers and the signals are summed by a summing amplifier. The summing amplifier has a switching means, by which the gain is brought to unity or near-unity value during the period of reading the data recording area, so that the summed output has a smaller difference of voltage levels for the address area and data recording area even though the detected light intensity has a large difference between these portions.

Abstract: A digital servo circuit for an optical disk player having a tracking actuator utilizes a digital filter for alternately extracting from a tracking error signal a frequency component within a specified band and a high-frequency component. In response to the high-frequency component, a braking force is applied to the tracking actuator when a brake ON command is issued. Coefficient values in the digital filter are set up depending on whether the brake ON command is issued.

Abstract: In a disk drive and a method for retrying to check data in the disk drive, a magnetic disk subsystem comprises a magnetic disk control unit and a drive module. The magnetic disk control unit is provided with a unit for controlling data check retry sequence which has a dummy write control unit. The drive module is provided with heads and a positioning unit. When the data read from the medium contain error, the above unit controls the data check retry sequence in order to read again the data using the same head. The dummy write control unit seeks a dummy write cylinder during the data check retry sequence, effects the dummy writing, seeks the original cylinder again, and reads the data again.

Abstract: Disclosed is a magnetic recording circuit for magnetically recording data on a magnetic record medium with a high density. This magnetic recording circuit comprises a magnetic head and a drive circuit for the magnetic head. This drive circuit includes a variable damping circuit for variably setting a damping factor, of the magnetic head, for controlling a damping characteristic of a record current of the magnetic head. The magnetic recording circuit further comprises a frequency detection circuit for detecting a frequency of the data given to the drive circuit and selecting the damping factor of the variable damping circuit on the detected frequency. The damping factor corresponding to the frequency of the data to be written is set, and hence a resolution required is obtained in a high record frequency range, while a shooting quantity can be reduced in a low record frequency range.