Abstract: The relative height between two sets of magnetic head groups shared for recording and reproduction and mounted on actuators is adjusted at high accuracy, so that a track of a predetermined track width and track pitch can be formed. In a rotary head type magnetic recording/reproduction apparatus including two sets of magnetic head groups AT and BT of one or a plurality of magnetic heads displaceable in the track width direction by actuators 100A and 100B, a signal which becomes the reference for relative height adjustment of the heads is recorded by one of the magnetic head groups. Then, the magnetic tape is rewound, and the run of the magnetic tape is controlled by one of the magnetic head groups. Under this state, the relative height between the two sets of magnetic head groups is detected by the other magnetic head group, whereby the relative height of the two sets of magnetic head groups is adjusted according to that information.

Abstract: The presence of a disk cartridge in a disk drive is detected by obtaining a measure of the load on the spindle motor of the disk drive and comparing that measure to a threshold value. The measure of load on the spindle motor may comprise (i) the time the spindle motor takes to spin-up to its full operating speed, (ii) the time the spindle motor takes to coast down to its operating speed from a first speed in excess of the operating speed, (iii) the voltage applied across the coils of the spindle motor, or (iv) the current drawn by the spindle motor.

Abstract: Video information records are recorded in a small capacity memory included in a tape cassette under the control of a system controller supplied with date information from a calendar circuit, clock information from a clock circuit, place information from a GPS (global positioning system) circuit, and scene setting information from a scene setting switch of an operation unit (such as a video camera). When video information is recorded by using the date information, for example, the system controller uses that date information as well as date information previously stored in the memory to process the just-recorded video information record.

Abstract: A sliding mode controller is disclosed for controlling a read/write head actuator in a magnetic disk drive storage system wherein a voice coil motor connected to the actuator operates to adjust the position of the read/write head over a selected data track recorded on a magnetic medium. The sliding mode controller comprises an improved technique for reducing chatter associated with the inherent operation of such a controller--rapid switching between gains to force the observable phase states to follow a predetermined phase state trajectory. The sliding mode controller generates a motor control command by multiplying an actuator position error and an actuator position error velocity by respective switching gains. The gains are switched according to a predetermined relationship .sigma. between the phase states and a phase state trajectory. In order to reduce the switching frequency (i.e.

Abstract: A reproducing apparatus for a tape-shaped recording medium having two channels recorded in forward and backward directions, respectively. The reproducing apparatus is arranged to cause a reproducing head to scan concurrently regions which respectively include the two channels, reproduce data in the forward and backward directions at a time, and convert the backward-reproduced data into forward data through writing and reading to and from a memory.

Abstract: A high-speed dubbing system which is not a complicated system adjusts phase shifts to return a plurality of multiple divided master tape audio signals to a time series signal array which is the same as that of the original master tape signal. The dubbing system has a continuous digital audio signal obtained by playing back the master tape at a nominal playback speed; the audio signal is divided by a specified division unit and an array of data blocks is obtained and converted to generate N units of divided master tape playback signals, a specified length portion of each data blocks of the N systems of divided master tape playback signals is replaced by phase matching code data. The N systems of divided master tape playback signals are intermittently recorded onto tape at the nominal playback speed to produce N divided master tapes. These N divided master tapes are played back simultaneously and in synchronism to obtain N systems of playback signals.

Abstract: In a storage system using multiple disk drives, the disk drive spindles are rotated at the same frequency and at a predetermined phase relationship. A phase angle, measured as the difference between an index mark recorded on the disk and the disk's read head, is used to control the spindle rotation speed. Each of the disk drives are first independently frequency locked to a target frequency, and once frequency locked, each disk drive is phase locked in relation to one another. In the phase locking process, each disk generates a synchronizing signal for synchronizing the rotation of the disks to a predetermined phase relationship. If any one of the disk drives becomes inoperable (due to a failure or "hot-swapping"), the other disk drives remain synchronized since the synchronizing signal is not lost.

Abstract: A circuit discriminates the tape speed in a speed-change playback mode in a video processing system based upon the drop out signal derived from the video signal read off the tape. The circuit discerns differences between the pulse widths of the drop out signals of standard play (SP) and long play (LP) recorded video signals. The circuit has a low pass filter (51) connected in series with a comparator (53). The low pass filter (51) takes the drop out pulse signal from a pre-amplifier (10) or from a luminance/chroma processor and filters the drop out pulse signal to determine its DC level. The comparator compares the filtered DC level of the drop out pulse signal to a reference voltage, and based upon the comparison makes a determination whether the video signal on the tape is recorded at standard play speed or long play speed.

Abstract: Disclosed are a method of and an apparatus for controlling a magnetic disc drive including a magnetic head in which a write head and a read head are separated. The control method comprises: a step of calculating a moving quantity up to a designated target track position in accordance with a write instruction or a read instruction and calculating a moving quantity from the moving quantity up to the target track position and a yaw angle offset quantity in accordance with the read instruction or the write instruction; and a step of locating the magnetic head in the target track position by seek-controlling the rotary type actuator in accordance with the calculated moving quantity.

Abstract: A highly reliable magnetic record 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 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 servo control method of a disk recording system for detecting position of a head using a digital servo control method in which a disk contains an embedded burst recording region comprising four servo bursts. The servo control method contemplates on reading track identification information and servo burst information on the disk recording medium, determining whether a track on which the head is positioned is one of an odd and even track from the track identification information and the servo burst information, and generating an odd/even information bit and first and second position error signals in accordance with the determination; generating seek information from addition/subtraction to and from the odd/even information bit and the first and second position error signals; and correcting the track identification information in correspondence with the seek information and outputting a current position error signal.

Abstract: A sliding mode controller is disclosed for controlling the motion of a read/write 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: Gain information in a read amplifier, which is recorded when data to be measured is reproduced, is stored in an AGC control memory circuit in advance. By reproducing the data using the gain information, reproduced data varied according to the amount of flotation of a magnetic head and the position of the magnetic head alone can be obtained. A variation in voltage amplitude of the reproduced data is detected by an envelope signal generating circuit and a variation in phase difference between a reading cycle in which the reproduced data is read and a reference cycle is detected by a phase difference signal generating circuit. A calculator calculates a float interval of the magnetic head and a variation in the position thereof based on these detected variations. As a result, a decision can be made as to whether the float interval of the magnetic head and the variation in the position thereof exceed an allowable range.

Abstract: A record and play-back system in a still video device, in which a picture signal and an audio signal associated therewith are recorded on a first track and a second track of a recording medium, wherein a first code signal and a second code signal are recorded together with the associated picture signal and the associated audio signal to discriminate that the respective picture signal and audio signal are recorded together with the corresponding audio signal or the picture signal. The second track is played-back when the first code signal is recorded on the first track upon play-back of the first track. The audio signal can be be post-recorded on the second track when no signal is recorded on the second track.

Abstract: A motor control device of an information recording and reproducing apparatus has a disturbance observer for outputting a compensating voltage signal. The compensating voltage signal compensates for a drive voltage signal of a head-moving swing motor on the basis of the drive voltage signal and a detected signal from a velocity sensor detecting an angular velocity of the swing motor. In such a motor control device, amplitude of the drive voltage signal inputted into the disturbance observer is limited by a limiter not to exceed a maximum amplitude at which a driver of the motor generates a maximum drive signal for the motor within the drive ability of the driver. Therefore, even if an input signal to the motor is too great because the uncompensated drive voltage signal is excessive or external disturbance affects the swing motor, the amplitude of the signal inputted to the motor is limited. In other words, even if the input signal is too great, the compensating voltage signal is not affected.

Abstract: In a recording and/or reproducing apparatus, a memory is provided within a mechanism portion which is formed separately from a control portion, but contained in one housing. The memory stores a negative adjusting data corresponding to the mechanism portion which is necessary to operate the mechanism portion in the specified condition, so that even if one of the mechanism portion or control portion is replaced separately, the storing operation of new adjusting data can be omitted. Thereby, such a replacement operation can be simplified.

Abstract: A disk and a disk drive having a servo start mark for identifying a servo-information start position recorded on the disk is provided. The servo start mark has a plurality of bit patterns unused for other areas in servo information. A method for identifying the position of a signal transducer on a disk is also provided in which it is judged that the signal transducer is present at a predetermined position even if an error is present and the error is a one-bit error. This is accomplished by assuming that the position is correct when the following conditions are confirmed: (a) a parity error occurs in a read servo-information bit pattern and (b) read servo-information bit pattern does not coincide with servo information of an adjacent track.

Abstract: A microfabricated wobble motor with a positioning arm attached to the wobble motor rotor acts as a fine positioner with bidirectional movement. The primary application is a rotary actuator for the read/write head in a very small magnetic recording disk drive. An integrated head-arm assembly is attached at one end to the rotor of the wobble motor. The other end of the head-arm assembly has a head carrier that is maintained in contact with the disk. Head position error information is read from the disk and used to provide control signals to each of the stator elements. The stator elements are sequentially addressed by applying a voltage from a driver circuit. This causes the rotor to be electrostatically attracted to the activated stators, so that the rotor is movable bidirectionally. The read/write head can thus be moved bidirectionally to any of the data tracks on the disk and maintained on a desired data track for reading or writing data.

Abstract: Track information decoding circuitry of a data storage device servo control system decodes binary track information in a readback servo signal by detecting opposite polarity track information pulse pairs so as to produce a track information signal "one" bit if the presence of an opposite polarity pulse pair is detected and produce a track information signal "zero" bit in the absence of an opposite polarity pulse pair, wherein a one bit is produced only if there has been detected a second pulse of a readback signal pulse pair having a magnitude greater than a predetermined threshold value and having a correct polarity. The polarity of the last di-bit of the servo signal AGC field can be used to set the polarity in the pulse qualification process.