Abstract: To increase the recording capacity of a magnetic disc, tracks of this magnetic disc are divided into a number of sectors, with each sector being formed from a number of segments. Each segment is basically made up of a data region and a servo region with data being recorded on the data region and a clock pattern which becomes the basis for generation of a clock, a fine pattern which becomes the basis for the tracking operation, and an access pattern which becomes the basis for a seek operation being recorded on the servo region. An ID region and servo region are formed before the data region and servo region which make up the leading segment with the sector ID for this region being recorded in this ID region. After this ID has been read from this ID region, while it is being determined whether or not this ID is the same as the designated ID, the servo operation corresponding to the servo control signal occurring in the servo region is carried out.

Abstract: Provided is a disk drive with a disk and an actuator assembly on which a communication device is mounted for communication with the disk. Position information read from the disk is processed through a channel that generates an analog position error signal that is then converted to a digital position error signal by a first signal converter. Based on the digital position error signal, a controller determines whether realignment of the communication device with the disk is required. The operation of the first signal converter is only periodically required. When realignment is required, then a digital position control signal is generated by the controller and is then converted to an analog position control signal by a second signal converter, which shares circuitry with the first signal converter. Normally, the second signal converter is operating to realign the communication device. Therefore, the shared circuitry is normally operating as part of the second signal converter.

Abstract: In an apparatus for recording and/or reproducing digital audio and video signals in slanted tracks on a magnetic tape, an integral number of samples of the digital audio signals, which forms a unit thereof, are allocated to a plurality of fields of the digital video signals. Sequence signals are recorded in both slanted and longitudinal tracks on the tape. The sequence signals indicate the conclusion of the digital audio data, that is, the units of the digital audio signals on the basis of the fields of the digital video signals. During reproduction of the sequence signals, the error rate of the sequence signals reproduced from the slanted and longitudinal tracks, respectively, are detected. Based on the detected error rate, the sequence signals reproduced from either the slanted tracks or the longitudinal tracks are selected. Therefore, if the sequence signals are lost or distorted on either the slanted or longitudinal tracks, the sequence signals may be still reproduced from the other track.

Abstract: A synchronization technique is described which finds use in a disk array subsystem comprising a plurality of disk storage devices connected to a controller. In response to signals from each of the devices specifying their angular position at a particular time, the controller calculates the relative angular positions of the devices and issues a signal to each of the devices specifying the amount and direction of chance in rotational velocity required to achieve synchronization. In a two device subsystem, the signal to one device will specify a speed decrease and the signal to the second device will specify a speed increase.

Abstract: In a data transmitting/reproducing equipment, e.g., a digital audio tape-recorder, etc., adapted for transmitting data on an information transmission line such as a magnetic tape, etc. where a plurality of formats exist, and reproducing that data through the information transmission line, a scheme is adopted in this invention to guarantee an upgradable format having compatibility in which there are not only so called an upper compatibility but also a lower compatibility with respect to apparatuses already existing. To realize this scheme, on the transmitting or recording side, format ID information indicating a format of transmit data, and a plurality of compatibility ID information indicating compatibility of that format relative to other formats are generated and added to the transmit data, thus to transmit the transmit data on the information transmission line along with the format ID information and the compatibility ID information added thereto.

Abstract: A recording and reproducing system is arranged to record converted two-channel audio signals obtained by using all four-channel stereophonic audio signals and audio signals of two specific channels included in the four-channel stereophonic audio signals on a recording medium as four-channel recording audio signals and, at the time of reproduction, to be capable of restoring the four-channel recording audio signals to the four-channel stereophonic audio signals and also to permit either the four-channel stereophonic audio signals or the converted two-channel audio signals to be selectively outputted.

Abstract: A recording medium cartridge includes a memory circuit for storing information concerning signals recorded on the recording medium within the cartridge. The information is stored in the memory circuit in the form of a hierarchic data structure which includes a plurality of data packets having a predetermined form and length. Each data packet includes a code indicative of a level in the data structure to which the data packet belongs. At least some of the data packets include data indicative of starting and ending positions on the recording medium of recorded signals which the data packet represents. The hierarchic (or "tree") data structure facilitates rapid retrieval and reproduction of the signals recorded on the recording medium, particularly when the recording medium is a magnetic tape. The tree structure also facilitates storage of information in connection with recording of additional signals on the recording medium.

Abstract: A highly reliable magnetic recording and playback apparatus utilizes an independent magnetic clock pattern region and a pattern set region to provide a common timing reference between a data recording region and its adjacent tracks. In the apparatus, the pattern set region provides a reference point so that the circumferential location of the magnetic pattern region can be determined. In one embodiment, the apparatus includes elements for playback of reproduced information recorded on a magnetic disk and an arrangement which provides for the generation of a data existing point clock.

Abstract: A sliding mode controller is disclosed for controlling the motion of a magnetoresistive (MR) read head actuated by a voice coil motor over a rotating magnetic disk storage medium. The magnetic disk comprises a plurality of concentric data tracks recorded thereon wherein each data track comprises user data and servo data. The sliding mode controller operates by multiplying a head position error phase state and a head position error velocity phase state by respective switching gains to force the phase states to follow a predetermined phase state trajectory. The phase state trajectory can be defined by a single linear segment, a variable linear segment, multiple linear segments over the entire region of excursion, or optimum parabolic acceleration and deceleration segments. Switching logic, responsive to the phase states and a trajectory segment value .sigma., switches between positive and negative feedback gains to drive the phase states toward a current trajectory segment. A .sigma.

Abstract: This invention provides a small-sized and easy assembling head positioning apparatus having a coarse moving mechanism and fine moving mechanism, by which the desired fine moving accuracy is easy to attain. A head positioning apparatus has a first stepping motor, a lead screw, and a cylindrical rack for coarse moving. The cylindrical rack is formed by rotating a rack around the axis of the lead screw and is provided with the lead screw. The head positioning apparatus has a second stepping notor and gears for reducing the speed of the rotation of the second stepping motor for fine moving means, and fine moving is carried out by moving the cylindrical rack by the gear. The lead screw is provided so that the first stepping motor could be moved in a X1, X2 direction in the fixed moving range.

Abstract: A cassette tape player has two reel bases which couple with the reels of a cassette tape located in the hold position of the tape player, a drive motor which drives the reel bases to rotate, a tape slack eliminating mechanism which rotates each reel base in its own tape winding direction, two pulse generators, each of which outputs pulse signals that depend on the rotational states of one of the reel bases, and a pulse width comparator which detects whether the pulse widths of the pulse signals from the pulse generators have exceeded a prescribed value. During the tape slack eliminating operation, if a width of the pulse signal from at least one of the pulse generators exceeds the prescribed value, the player terminates the tape slack eliminating operation and proceeds to another operational mode. The player thereby eliminates tape slack in the cassette irrespective of the tape position.

Abstract: An apparatus for preventing a picture fluctuation and correcting a reverse pulse in a servo system for a video cassette recorder having a still or slow motion playback function. The apparatus comprises speed and phase error detectors for detecting speed and phase errors, speed and phase controllers for controlling a speed and a phase in response to output signals from the speed and phase error detectors, mixers for mixing output signals from the speed and phase controllers, a system control circuit for controlling an operation of the servo system, the system control circuit including a correction circuit for varying widths or edges of correction signals in response to speed and phase information, and drivers for driving motors of the servo system in response to the correction signals.

Abstract: Method and apparatus for dynamically compensating for servo burst measurement offsets in a disc drive. A first type of servo position error signal is used during a compensation routine to position a head adjacent a selected track on a disc, the first type of servo position error signal determined from servo burst signals read by the head from servo position fields on the disc. A second type of servo position error signal is also generated from the servo burst signals and the difference between selected values of the second type of servo position error signal is compared to an acceptance limit. Compensation terms are incrementally added to the servo burst signals used to generate the second type of servo position error signal until the difference is below the acceptance limits. Thereafter, the compensation terms are stored and retrieved during normal track following operations to generate a compensated servo position error signal.

Abstract: A recording and/or reproducing apparatus for a magnetic record carrier such as a tape or disk. The apparatus includes a magnetic recording/reproducing head, a guide for positioning the face of the head relative to a recording surface of the record carrier, and an actuator for moving the head relative to the guide in a direction normal to the recording surface. The actuator is driven by a control unit which receives a control signal from a detector upon detection thereby of frictional contact between the face of the magnetic head and the recording surface. That causes the control unit to cause the actuator to move the head so as to increase the distance between the face thereof and the recording surface.

Abstract: An apparatus and method are disclosed for detecting the velocity of a tape in a tape transport system having a write head and a read head separated by a known distance and formatting the tape using marks. The tape transport system generates a write signal indicating when one of the marks is written to the tape by the write head and a read signal indicating when one of the marks is read from the tape by the read head. An accumulator determines the amount of time between the write signal and the read signal. A velocity detector determines the velocity of the tape based on said time determined by the accumulator and the known distance between the write head and the read head.

Abstract: A switch is provided which successively switches contacts at a timing sufficiently quick with respect to reproduced signals in reproducing a magnetic tape on which digital recording is effected, and which switches contacts at similar timing in reproducing a magnetic tape on which analog recording is effected. On signals provided through this switch and through an analog-digital converting circuit, processing such as waveform equalization corresponding to the type of magnetic tape is effected by a digital equalizer. By this digital equalizer, correction of frequency characteristic in accordance with the type of the magnetic tape and correction of frequency characteristic inherent to the head per se are effected.

Abstract: Various data storage formats help to efficiently locate, read, and write user data stored on magnetic tape media. A tape is formatted by writing multiple segment-headers, free from any interleaved access of user data. Adjacent segment-headers are spaced by a predetermined interval to define multiple data storage segments. Segment-headers all contain a unique key, which is copied into a key index to identify valid segments. After formatting, normal tape accesses can be performed. Without erasing any old headers or data, a new formatting scheme can be established by writing new segment-headers on the tape. The new segment-headers include a new unique key, replacing the previous key in the key index. Previous segment-headers stored on the tape are ignored, since they lack the updated key. Segments may be selectively grouped to provide independently addressable partitions. Mapping between segments and partitions can use a fixed relationship (e.g.

Abstract: A disk apparatus in which the position of a head is detected using servo information recorded on a recording plane of a disk. A first phase difference detecting section uses a zero-cross signal, a master clock, servo patterns corresponding to N cylinders (N is an integer equal to or greater than 2) so as to discriminate the different polarity information items contained in servo patterns from one another and to output phase difference information. A second phase difference detecting section uses the zero-cross signal, the master clock, half the servo patterns corresponding to the N cylinders so as to output phase difference information without discriminating the different polarity information items contained in the servo patterns from one another. When seek operation is performed, a selecting section outputs the phase difference information delivered from the first phase difference detecting section.

Abstract: In a reproducing apparatus having the capability of reproducing data in both directions from a recording medium in the form of a tape, when a program recorded on the recording medium in the form of a tape is accessed in a high speed mode, a fast forward tape travel operation or a fast reverse tape travel operation is performed while monitoring the program number recorded in the area opposite to the current reproducing position, and the searching speed is controlled when the searching position reaches a location near a reverse position so that the searching position does not go beyond the reverse position. A recording apparatus operates to record a program number on a recording medium in the form of a tape on the basis of the program number which was recorded at the end of the previous recording operation so that a correct value is given as the program number to the current recording operation.

Abstract: The present invention relates to a capstan phase control method for a video cassette tape recorder (VCR), and an improved capstan phase control method for a VCR capable of reducing a phase locking time by detecting a new capstan phase in cooperation with a reproducing control signal and a speed detection signal whenever the speed detection signal is inputted. By adopting the detected capstan phase as a phase control information, the time required for the mode of the system to be changed from the stop mode to the reproducing mode or from the searching mode to the reproducing mode, namely while the mode of the system is changed from the speed variation mode to a normal speed mode is reduced, so that it is possible to obtain a more stable reproducing operation at a high speed.