Abstract: A method for optimizing the storage capacity of miniature disk drives without affecting reliability or yields of the disk drives uses an iterative seek process to define track zero. Initially, a physical reference point is defined and a transducer is moved in coarse steps from the physical reference point until interference with a stationery loading ramp or other mechanical component, hereinafter, "ramp," is detected. Upon detection of interference, the transducer is moved one coarse step away from the ramp and then the transducer is moved in fine steps towards the ramp until interference is again detected. Upon detection of interference, the transducer is moved away from the ramp a predetermined distance. After the transducer is moved the predetermined distance, a check is made for interference. If interference is detected, the transducer is moved in fine step towards the center of the disk until interference is no longer detected.

Abstract: In order to bring and keep a slave phase of rotation of a slave spindle into and in synchronism with a master phase, the master phase is represented in a predetermined time duration by zeroth through (N-1)-th master region data with an N-th master region datum added, where N represents a predetermined integer which is not less than two. The slave phase is represented, during one rotation of the slave spindle, by zeroth through (N-1)-th slave region data with an N-th slave region datum additionally used to provide a guard time. The zeroth through the (N-1)-th slave and master region data are compared to render a phase difference between the master and the slave phases either to zero or to a predetermined value. Alternatively, the master phase is represented in the predetermined time duration by a sequence of composite pulses which comprise N master clock pulses with at least one of the clock pulses omitted to indicate a start point of the sequence.

Abstract: An automatic video tape running mode setting circuit for programmed recordings is disclosed which comprises a programmed recording time memory means for memorizing and outputting the programmed start and end times successively for a plurality of broadcast programs set by the user; a programmed recording time detector for detecting the total programmed recording time by subtracting said start time from said end time individually, and by summing up all the individual times; a recording capacity detector and a recording capacity time base data generator for detecting and generating a recording capacity time base data off the loaded video tape; and a running mode signal generator for a predetermined video tape running mode signal to a microcomputer for controlling the operation of the whole system.

Abstract: In a magnetic reproduction system in which a magnetic tape must be controlled to run so as to keep a specified relative phase to a rotary phase of a rotary head, a tracking control apparatus obtains a characteristic curve showing a characteristic relationship between the relative phase and an envelope level of a reproduced information signal obtained by the rotary head by changing the relative phase, obtains a regression curve with respect to the characteristic curve, and controls the magnetic tape to run so that the relative phase becomes a value corresponding to a maximum value point of the regression curve.

Abstract: A magnetic tape drive system (20) records a directory block (CL) at a predetermined position on tape (22), and preferably at the beginning of tape. The directory includes, for each recorded track on tape (22), a data block number of the data block recorded at an end of the track. Preferably a plurality of copies of directory block (CL) are recorded, preferably in reverse direction. Upon receipt of a command to locate a target data block recorded on tape (22), a processor (102) directs a transport controller (82) to position a read element (30R) at the predetermined position on tape (22) for reading the directory. The read element reads the directory from tape (22).

Abstract: A method for synchronously operating two or more rotary head digital audio tape recorders without having to dedicate a separate timing track. The present invention synchronizes the machines in three steps. First, the slave unit reads the time code value from the data stream and compares this time code to the master's time code, examining the difference in time code values and adjusting the transport speed so that the values are approximately equal. Next, the slave's capstan motors are slowed down (or sped up) so that the slave and master units are within one drum revolution of each other. Finally, the slave's microprocessor adjusts the speed of the entire system to skip individual samples until the master and slave units are synchronized.

Abstract: A method for defining and writing parallel and concentric magnetic signal tracks to a spinning disk surface of a magnetic data storage disk drive system using the components of the Head Disk Assembly (HDA) implemented by an appropriately programmed digital signal central processing unit (CPU) or micro code in an integrated circuit (IC) and a digital signal random access memory RAM is described wherein an initial magnetic signal track is written under least (minimum) energy equilibrium conditions with undulating boundaries and a meandering center line relative to axes of the spinning disk surface for one revolution of the surface. Then servoing to an edge of the just written track, a digitized position signal table is created in memory for storing digital position signals representing the amplitude of the signals read from n sampling points per disk revolution over a number of disk revolutions, where n is determined with reference to `Nyquist criteria`.

Abstract: A diskette comprising a jacket, a liner material disposed within said jacket, a flat circular media having a magnetic coating on both sides disposed within said liner material, a hub attached at the center of said media, a plurality of servo grooves on at least one of said sides of said media that have stitched patterns that will alternate on-and-off at twenty kilohertz in the presence of a constant, unmodulated light source. The diskette is magnetically formatted with reference and data tracks recorded in such a way that extremely accurate position determinations can be made by looking at the analog amplitude of the detected tracks and comparing them at different head positions.

Abstract: A seek command including a cylinder address and a head address is generated from a disk control unit. In a magnetic disk unit, an off-track amount is read out by the head address obtained by the reception of the seek command with reference to a correction table, and an off-track correcting state in which the off-track amount is eliminated from a position control signal is produced during the seeking operation until the start of the position control. A function to instruct the dependent magnetic disk unit to execute the measuring process of the off-track amount in accordance with a time schedule stored in a time table is provided for a higher-order magnetic disk control unit. The generation of a measuring command during the execution of a command chain is suppressed. When receiving the measuring command from the disk control unit, the magnetic disk unit measures the off-track amount of each data disk for a reference position of a servo disk and stores into the correction table.

Abstract: An embedded servo system for a disk drive is disclosed. An asymmetrical position sub-field reduces the overhead of the disk position system. The sub-field includes at least two normal frame pairs and only one quadrature frame pair interleaved with one of the normal pairs to form the asymmetrical position sub-field. The prerecorded embedded servo information in each track of the disk includes a multiplicity of different length servo fields, i.e, each track includes at least two types of servo fields where the first type has a first length and the second type has a second length that is different from the first length. The length of a servo field refers to the number of prerecorded bytes in the servo field. The multiplicity of different length servo fields includes a first type having a full track address sub-field and a second type having a modulo track address sub-field in place of the full track address sub-field.

Abstract: A sector servo, zone bit recording disk drive includes a sector architecture in which the recording head locates and identifies data sectors without using data ID fields, but instead using information obtained from electronic storage and from servo sectors which need not be adjacent to the data sectors. The tracks contain servo information and data, but not data sector ID information. The tracks in each zone are circumferentially divided into segments. Included in each segment is a number of data regions separated from one another by servo sectors. The data regions may contain partial data sectors and complete data sectors. The format information provided to identify and locate data sectors, including ones whose region locations are not adjacent to servo sectors, includes an entry for each region in the section.

Abstract: A rotary head tape recording and reproducing apparatus drives a rotary drum and a capstan by a common driving motor. In the reproducing mode, rotary heads generate a scanning position detection signal by picking up an address signal indicating the current scanning position from the recording track, and the driving motor is controlled so as to match the scanning position detection signal with a reference scanning position signal.

Abstract: A diskette comprising a jacket, a liner material disposed within said jacket, a flat circular media having a magnetic coating on both sides disposed within said liner material, a hub attached at the center of said media, a plurality of servo grooves on at least one of said sides of said media that have stitched patterns that will alternate on-and-off at twenty kilohertz in the presence of a constant, unmodulated light source. The diskette is magnetically formatted with reference and data tracks recorded in such a way that extremely accurate position determinations can be made by looking at the analog amplitude of the detected tracks and comparing them at different head positions.

Abstract: A magnetic head loading/unloading apparatus has a head arm being maintained in either a loading state or an unloaded state by means of a permanent magnet. The head arm has a magnetic head on one end thereof, and is fixed on an end of a first yoke. A second yoke is arranged parallel to the first yoke, and is rotatable on the first yoke. A touching member is fixed on the second yoke, the touching member pressing a bottom surface of the head arm so as to elastically deform the head arm so that the magnetic head is positioned in an unload position. A permanent magnet is provided on the first yoke and a coil is provided on the second yoke. When the second yoke is moved to a first position, the head arm is elastically bent by a pressing force exerted by the contacting member so that the magnetic head is positioned in an unload position. When the second yoke is moved to a second position, the contacting member is apart from the head arm so that the magnetic head is in a load position.

Abstract: For disk drives having dual element heads, an invention for providing self-calibration of hard-disk writer elements to reader elements offsets. A method is provided for positioning a reader element for reading information on a disk, and from the information read, determining a reference line for the writer element. The method may be incorporated into a hard-disk in the form of a self-calibration routine in memory. The self-calibration routine may be used for computing offsets for separate writer/reader elements in a dual head assembly. Also, apparatus are provided for self-calibration of hard-disk writer to reader element offsets.

Abstract: A technique for writing a servo-pattern on a storage medium located in a recording device having an internal recording head. A timing pattern is generated on the storage medium with the internal recording head and a radial positioning value is determined in order to radially position the internal recording head. The servo-pattern is written using the internal recording head at locations determined by the timing pattern and the radial positioning value.

Abstract: A method and an apparatus for optimizing movement of a disk drive's head actuator arm away from a magnetic latch that holds the arm in a parked position at the Inner Diameter (ID) of a disk. Current energizing of the arm's actuator motor moves the arm away from the magnetic latch and is controlled to compensate for any change in magnetic holding force. When the disk drive is powered up, a current pulse of one polarity is applied to the actuator motor. This initial current pulse normally moves the arm away from the magnetic latch and is followed by a current pulse of the opposite polarity to decelerate movement of the arm. If this initial sequence fails to move the arm away from the magnetic latch, the magnitude of the two current pulses is increased, and the opposite polarity pulse is followed by a small magnitude current of the one polarity. The read signal from the head is monitored to indicate that the arm has moved into the disk's central databand area, and then into the disk's Outer Diameter (OD) area.

Abstract: A high speed dubbing apparatus for producing magnetic tapes such as video, audio or computer soft tapes, is provided. Typical form of the apparatus may comprise 2 master tape playback devices for synchronously playing back 2 divided master tapes respectively recorded with 2 divided master signals obtained by dividing time-divisionally an original master signal having an original data sequence by 2 and for outputting the 2 divided master signals, a double speed recording signal producing device for time-compressing each of the 2 divided master signals to 1/2 to obtain a double speed recording signal from the 2 divided master signals while restoring the original data sequence in the double speed recording signal and a recording device for recording the double speed recording signal on a slave tape running at a speed which is twice the nominal playback speed of the slave tape.

Abstract: An editing apparatus is for use with a tape-form recording medium in which a tracking pilot signal and several synchronizing blocks each of which contains a synchronizing signal, a synchronizing signal number and a recording mode data are multiplex-recorded into a first recording area of each track which has a plurality of recording areas. Using the synchronizing signal and the synchronizing signal number, a pilot sampling signal for determining the timing of sampling the pilot signal and an editing timing signal for determining the recording location in a desired recording area following the first recording area are produced. Using the recording mode data, the discrimination of the current recording mode is carried out. After the tracking control is executed through sampling the tracking pilot signals from adjacent tracks at timing of the pilot sampling signal, a data signal is recorded into the desired recording area after the first recording area according to the editing timing signal.

Abstract: A protective reflex system for a portable computer hard disk initiates protective action before the hard disk suffers the shock of an impact in the event they fall from, for example, a user's lap. A three axis accelerometer is mounted in the portable computer. The output of the accelerometer is continuously monitored by a dedicated processor. In the event of an acceleration event within a preset range of values, the dedicated processor passes a high priority interrupt to the central processing unit of the portable computer and then proceeds to park the disk heads. Alternately, the interrupt routine of the central processing unit may also cause the park operation. In addition to park operation, a brake operation may be performed by either the dedicated processor or the central processing unit.