Abstract: An information playback apparatus includes first and second heads which trace a tape on which tracking pilot signals having at least two different frequencies are selectively and periodically recorded with a period of at least 4 tracks, a pilot detector and identifier for generating an identification signal identifying the kind of tracking pilot signal dominantly contained in a playback signal of the first head, and a tracking error detector for detecting and outputting a tracking error signal from tracking pilot signals contained in a playback signal of the second head, wherein tracking control is performed based on the tracking error signal and the identification signal.

Abstract: A tracking error detecting circuit is used in a magnetic reproducing apparatus for reproducing an information signal from tracks which are formed on a magnetic tape obliquely in a longitudinal direction of the magnetic tape. The tracks have selectively recorded thereon a pilot signal multiplexed with the information signal. The tracking error detecting circuit comprises: a rotating magnetic head scanning the tracks for reproducing the information signal on which the pilot signal is selectively multiplexed to obtain a reproduced signal; a comparator for comparing a level of the reproduced signal with a specified level and for issuing a binary signal representing a comparison result; and a level detecting circuit for detecting a level of the pilot signal contained in the reproduced signal from an output of the comparator.

Abstract: A reproducing apparatus reproduces information signals recorded multi-segmentally on oblique tracks on a tape. Track ID information recorded in the tracks is detected and compared with a reference frame to obtain a phase difference. The tape transportation is controlled in response to this phase difference to correct a reproduced phase so that it is made to coincide with a reference frame phase, as well as to perform tracking control using a tracking pilot signal recorded on the oblique track together with the information signal.

Abstract: An information reproducing apparatus for reproducing information recorded on slant information tracks includes magnetic heads mounted on a rotary cylinder. The magnetic heads scan a magnetic tape which has slant information tracks on which tracking pilot signals are formed. A tracking error detector detects the tracking error signal of the magnetic head scanning using the tracking pilot signal recorded on the slant information tracks. The tracking error detector then generates a tracking error signal indicating the amount of the track bending. A control signal generator generates a control signal in response to the tracking error signal for controlling the scanning position of the magnetic head. A tracking controller controls the slant track scanning position of the magnetic head.

Abstract: A signal reproducing apparatus, which reproduces data from a tape in which data and a pilot signal for tracking have been recorded In oblique tracks, includes a tape driver for running the tape in the longitudinal direction, a rotary head for rotating and scanning the tape to produce reproduction signals, a reference generator for generating a reference signal which Is the rotation standard of the rotary head, a tracking error detector for producing a tracking error signal from the pilot signal contained in the reproduction signals, and a timing controller for controlling the start timing of tape running of the tape driver with respect to the reference signal, on the basis of the tracking error signal and reference signal in the stopped state of tape running.

Abstract: A control apparatus for controlling a motor includes: a command unit for generating a command signal including a running command signal and a stopping command signal; a rotation sensor for generating an AC signal having a period corresponding to a rotational speed of the motor; a speed detector for detecting a rotational speed of the motor from the AC signal generated by the rotation sensor; a compensator for generating a control signal for controlling the motor, and a driver for driving the motor in response to the control signal generated by the compensator.

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 tape medium recording and/or reproducing apparatus suited for use in recording or reproducing information on or from a plurality of tracks on a tape medium. Each track has first and second regions defined therein in a direction conforming to the direction of scan. Each first region has a positioning signal recorded therein while a tracking pilot signal is recorded in selected ones of the first regions. The apparatus includes a positioning signal detector for detecting the positioning signal to provide a reproducing position signal, and a reproduction timing generator for generating a reproduction timing signal at a first timing determined by the reproducing position signal. A timing memory is provided to store the length of time from the timing, at which the rotational reference position of a cylinder has been detected, to the first timing.

Abstract: A magnetic recording and reproducing apparatus records video signals divided into plural segments in every specific group, and also records index signals accompanying the video signals in different areas on a magnetic tape having oblique tracks. The apparatus also records the time code of at least the video signal as the index signal, and records the same time code in the index areas of at least three continuous plural tracks. The index area for recording the time code is divided into a plurality of small areas in one track, and the same time code is recorded in each small region. The leader code is recorded in the index area for recording at least the time code.

Abstract: A multiple channel magnetic recording and reproducing apparatus records data on oblique tracks on a tape by a leading head and trailing head mounted on a rotating drum. First and second pilot areas for tracking are turned at opposite ends of each track. A tracking error detector is provided for receiving, when the leading head is scanning the first pilot area, a first reproduced signal from the first head, and for detecting two pilot signals from the tracks on both Sides of a scanning track, and for generating a first tracking error signal indicative of a difference between the detected two pilot signals. Similarly, the tracking error detector receives, when the trailing head is scanning the second pilot area, a second reproduced signal from the second head, and for detecting two pilot signals from tracks on both sides of a scanning track, and for generating a second tracking error signal indicative of a difference between the detected two pilot signals.

Abstract: Disclosed is a speed controller of a motor which comprises a rotation sensor for generating an A.C. signal having a period in accordance with a rotating speed of a motor; speed detection device for effecting detection operations a plurality of times per round of the motor by the A.C.

Abstract: In an apparatus for multi-segment recording/reproducing of a compressed digital video signal, a reproduced position within a group unit of the video signal is detected by a reproduced position detector in its reproducing state. A relative position detector detects and stores a phase difference of the reproduced position and a position indicated by a reference signal synchronized with the input video signal. A delay time adjuster adjusts a delay time of the compressed video signal according to this phase difference. A head is changed over from its reproducing state to its recording state by a switch so as to record the compressed video signal delayed by the delay time adjuster on a recording medium.

Abstract: An editing apparatus for use with a tape-form recording medium is provided in which, according to a positioning signal and a tracking pilot signal multiplex-recorded into the first recording area of each track of the recording medium which consists of a plurality of recording areas separated from each other by gaps, a pilot sampling signal for determining the timing of sampling and an editing timing signal for determining the recording location in a desired recording area following the first recording area are produced. After the tracking control is executed through sampling the tracking pilot signals from adjacent tracks at the 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 tracking error detecting circuit in which tracking error detecting pilot signals having different frequencies are added to a main signal every track and recorded onto a magnetic recording medium, and upon reproduction, reproduction output levels of the pilot signals reproduced as crosstalks from both of adjacent tracks are compared, and a tracking error is detected. n signals having the same frequencies as those of the pilot signals and whose phases are different are generated and multiplied to the reproduction signal. Unnecessary components are eliminated by n LPFs (Lowpass filters). The amplitude values of the reproduced pilot signals are vector separated and detected. Further, the vector separated amplitude values are vector synthesized and detected. Therefore, by multiplying the signals having the same frequencies as those of the pilot signals, the synchronous detection is performed.

Abstract: In a sensorless brushless motor which does not have a position sensor for detecting a rotational position of a rotor, the rotational position thereof is detected by detecting the zero-crossing points of the counter electromotive forces induced in the stator windings of the rotor. A shaping signal obtained by detecting the zero-crossing point of each of the counter electromotive forces and a slant waveform signal generated in response to the shaping signal thus obtained are combined to form a trapezoidal waveform position signal, and an electric current of a trapezoidal waveform is supplied in response to the position signal thus obtained to the corresponding one of the stator windings, so that the electric current commutation of the stator windings can be performed smoothly. As a result, the motor can be practically driven with reduced vibration and noise generation.

Abstract: A brushless DC motor which does not have a position sensor for detecting a rotational position of the rotor, is arranged so that conducting phases of the stator windings to be detected are subsequently selected by multi-phase selection signals in response to a conducting state of the stator windings; then, a pulse signal train is generated by detecting the counter electromotive forces induced in the conducting phases subsequently selected and a trapezoidal waveform signal is formed by a slant waveform signal generated in response to the pulse signal train thus obtained. Furthermore, with the trapezoidal waveforms signal thus formed as position signal of the rotor, an electric current signal having a trapezoidal waveform is supplied; to the stator windings, resulting in smooth commutation of the conducting phase of the stator windings.

Abstract: A brushless DC motor which does not have a position sensor for detecting a rotational point of a rotor, instead of using a position sensor, detects the zero-crossing points of counter electromotive forces induced in the stator windings of the motor to obtain a pulse signal train. From the pulse signal train thus obtained and a slant waveform signal generated in response to the pulse signal train, a position signal with a trapezoidal waveform is formed. An electric current signal with a trapezoidal waveform is supplied to the stator windings of the motor in response to the position signal thus formed for effecting an electric current switching of the stator windings smoothly, resulting in realizing a motor drive which is less in vibration and noise even when rotating at a high speed.

Abstract: A full wave drive brushless DC motor system detects zero-crossing points of counter electromotive forces respectively induced by the stator windings, and then pulse-shapes the thus detected zero-crossing points to obtain a pulse signal train, and then measures the thus obtained period of the pulse signal train to determine a conducting phase of the stator windings in response to the thus counted period. The system is thereby capable of supplying an electric current bidirectionally to each of the stator windings without using a position sensor for detecting a position of a rotor.

Abstract: A control system has a detecting block for obtaining a detected signal corresponding to a controlled variable of a controlled system, and a controlling block for supplying the controlled system with a control signal according to the detected signal. The controlling block includes an error signal producing block for producing an error signal from the detected signal at intervals of a detecting period of time, a memorizing block for storing a plurality of memorized values corresponding to the error signal, and a control signal producing block for producing the control signal by mixing the error signal with one or more of the memorized values. The memorizing block renews the memorized values sequentially and periodically at intervals of a renewing cycle period of time proportional to the detecting period, each with a mixed value computed from the error signal and one or more of the memorized values having been renewed at intervals of L renewing cycle periods, where L is an integer at least equal to 2.

Abstract: A control system has a detecting block for obtaining a detected signal corresponding to a controlled variable of a controlled system and a controlling block for supplying the controlled system with a control signal corresponding to the detected signal. The controlling block comprises an error block for producing an error signal corresponding to the detected signal at a detecting block, a memorizing block having a plurality of memorized values corresponding to the error signal, an output block for producing the control signal by mixing the error signal and one or more memorized values of the memorizing block and a adapting block for changing the number of a plurality of memorized values of the memorizing block according to a frequency of fluctuation of a disturbance source.