Sony Corporation

Ryusuke Moriya

Takeo Eguchi

Takeo Ohba

Yasuhiro Fujimori

Kazuo Hashizaki

Apparatus for simultaneously reproducing video signals having block synchronization signals and that have been recorded in successive, parallel channel tracks extending obliquely on a magnetic tape, with adjacent ones of the tracks having the video signals recorded therein with different azimuth angles, the apparatus including two magnetic heads movable in a direction along the channel tracks for reproducing the signals recorded therein; a phase detecting circuit for detecting a phase error between the block synchronization signals reproduced from adjacent ones of the tracks by the two magnetic heads; and a control circuit for controlling the relative positions between the tracks and the magnetic heads in response to the detected phase error so that the two magnetic heads accurately scan respective ones of the tracks.

Tracking control system for magnetic recording and reproducing system

A video signal reproducing apparatus comprising an integrating drive circuit for controlling the position of a rotary magnetic reproducing head in the traverse direction of a skew recorded track formed on a magnetic tape, a trace control circuit for supplying a jump signal to the drive circuit which causes the magnetic head to jump to the beginning of a track to be traced next on completion of each tracing, a memory for storing the output signal from the magnetic head corresponding to at least one track tracing, and a memory reading and writing control circuit for writing the head output signal into the memory only when the jump signal is absent during slow-motion or still-picture reproduction, and for reading the stored head output out of the memory repetitively.

Video signal reproducing apparatus

Apparatus for simultaneously reproducing information signals that have simultaneously been recorded in four successive, parallel channel tracks on a record medium, with a first pair of first and second ones of the four channel tracks being adjacent to each other and having the information signals recorded therein with different azimuth angles and with the information signals recorded in one of the first or second channel track being delayed relative to the information signals recorded in the other of the first and second channel tracks, and with a second pair of the remaining third and fourth ones of the four channel tracks being adjacent to each other and having the information signals recorded therein with different azimuth angles; said apparatus including four magnetic heads movable in a direction along the four channel tracks for reproducing the signals recorded therein; and a tracking control circuit for controlling the relative positions of the four magnetic heads and the record medium so that the four magnetic heads accurately scan respective ones of the four channel tracks in response to the phase difference between the signals recorded in the first pair of channel tracks or the phase difference between the signals recorded in the second pair of channel tracks.

Tracking control system for an information signal recording and

A video signal reproducing apparatus for high-speed playback comprises a fixed head mounted on a rotary head drum, and a movable head supported on the head drum so as to lag the fixed head by a predetermined phase, and mounted on a bimorph plate so that the position of the movable head can be controlled transversely of a skew track on a magnetic tape. A delay circuit matches the phases of the signals reproduced by the fixed and movable heads, and in dependence on the levels of the reproduced signals the scanning path of the movable head is adjusted relative to the scanning path of the fixed head such that a reduction in one reproduced signal level causes an increase in the other reproduced signal level when the reproduced signals are phase-matched. The output is then complemented by at all times selecting the higher level reproduced signal with a selection switch.

Head control and signal selector for playback at high-speed of helical

An automatic phase-controlled oscillator circuit for producing an output clocking signal whose phase and frequency vary with those of an input information signal applied thereto comprises an input circuit for receiving the input information signal; a variable-frequency tuning circuit for receiving a control signal and coupled to the input circuit for tuning on the basis of the frequency of the control signal to pass the information signal as a tuned signal; and a clocking signal generator, such as a phase-locked loop circuit, for providing the output clocking signal in dependence upon the phase of the tuned signal. The invention is favorably applied to a digital video tape recorder (DVTR) wherein the information signal is a digital signal reproduced from a tape as a result of relative motion between the tape and the DVTR, and the control signal is also reproduced from the tape to represent such relative motion. The oscillator circuit also preferably includes a phase comparator providing an error signal representing the phase difference as between the input information signal and the output clocking signal, and a phase adjuster, such as a variable delay line, responsive to the error signal.

Phase locked loop having automatic-input tuning and phase control

In an apparatus having at least one rotary head for reproducing video signals recorded in successive parallel tracks extending obliquely across a tape which is advanced longitudinally and also has control signals recorded therein in predetermined positional relationship to the respective record tracks to be reproduced by a fixed transducer or head with a repetition rate that is dependent on the speed of advancement of the tape: a speed and phase control system for the rotary head or heads has a rotational speed detector for producing pulse signals representative of the rotational position of each rotary head and having a repetition rate that is a function of the rotational speed of the rotary head; a phase comparator for producing a phase responsive signal having a voltage level that is varied in response to changes in the relative timing of the reproduced control signals and the pulse signals; a digital device for producing a speed responsive signal having a voltage level that generally corresponds to the repetition rate of the pulse signals, but which is varied in response to changes in the repetition rate of the pulse signals only when such changes occur without corresponding changes in the repetition rate of the reproduced control signals; and a brake or other means for controlling the rotation of the rotary head in response to the voltage levels of the phase responsive signal and the speed responsive signal. In a preferred embodiment, the digital device for producing the speed responsive signal includes a source of clock pulses, a counter for counting the clock pulses for time intervals determined by the repetition rate of the pulse signals from the rotational speed detector, a digital-analog converter for converting the count of the counter, at the end of the mentioned time intervals, to a corresponding voltage level of the speed responsive signal, and an arrangement for establishing the initial count of the counter at the commencement of each of the time intervals in dependence on the repetition rate of the reproduced control signals.

Growing community of inventors

Hadano, Japan

Ryusuke Moriya