Sony Corporation

Yukihiko Machida

Kenji Nakano

Mitsugu Ishihara

Kentaro Odaka

Takao Takahashi

Tadafusa Tomitaka

Kazuo Yamagiwa

Keiichiro Shimada

Shinji Takada

Shoji Nemoto

Tooru Akutagawa

In a video signal recording and/or reproducing apparatus including four magnetic heads mounted on a rotary drum for forming four parallel recording tracks in a repeating sequence on a recording medium with each track having an azimuth gap angle different from the azimuth gap angles of the next adjacent tracks; pilot signals having different frequencies are recorded in a superimposed manner upon the information signals recorded by the four magnetic heads, respectively, and, upon reproducing, tracking control is effected so as to ensure that the magnetic heads which recorded the pilot signals with different respective frequencies are used to reproduce the signals recorded in the respective recording tracks so that a period of a timing signal, for example, a horizontal synchronizing signal, contained in the reproduced signal will not be disturbed upon switching from one to another of the magnetic heads in the reproducing mode.

Video signal recording and/or reproducing apparatus

A communication system for video information apparatus for carrying out a communication between a video information apparatus and a peripheral apparatus arranged so that a communication is repeatedly carried out at a period synchronized with a signal of a vertical period having a constant phase relation relative to a vertical synchronizing signal.

Communication system for video information apparatus

A motor rotation control apparatus employs a comb filter circuit operable to filter out a signal component and its higher harmonics. An error signal indicative of an error between actual and target conditions of rotation of the motor is applied to the comb filter circuit after its DC component is removed. The filtered signal and the error signal are added in a circuit which produces a control signal used to control the motor rotation. In another aspect of the invention, the error signal is divided into a first digital signal having upper bits of data having a predetermined bit number and a second digital signal having the remaining lower bits of data. The lower bits of data are delayed a predetermined time and added to the error signal to compensate for lower bits of data which may be ignored in a digital-to-analog converter operable, with a limited bit number, to provide a control analog signal used to control the motor rotation.

Motor rotation servo control apparatus

Data communication apparatus

A signal translating circuit comprises first and second transistors connected to each other in such a manner that a collector of the first transistor is coupled with a base of the second transistor and an emitter of the second transistor is coupled with a base of the first transistor so as to form a negative feedback circuit arrangement, an input resistor connected between the base of the first transistor and a source of an input voltage signal for converting the input voltage signal into an input current signal to be supplied to the base of the first transistor, a biasing current source connected to the base of the first transistor, first and second current sources supplying the same currents and connected to the emitter of the first transistor and a collector of the second transistor, respectively, and means for deriving an output current signal from the collector of the second transistor.

Signal translating circuit

Information is digitized, and the digital information signals are used to produce frequency modulated signals the instantaneous frequency of which is a function of the content of the digital information signals. The frequency-modulated signals are recorded in alternate tracks with alternate recording heads having air gaps of different azimuth angles. In one embodiment, the recording heads are the rotary heads of a VTR, and the digital information signals are digital audio signals which are recorded in the same tracks as the usual video signals.

Method and apparatus for recording digital information in alternate

Apparatus for recording and reproducing an information signal comprised of a video signal and an audio signal in a plurality of tracks extending obliquely on a magnetic tape includes a sample and hold circuit, an analog-to-digital converter and an encoder for converting the audio signal to a pulse code modulation (PCM) audio signal; a time base compression circuit for compressing the PCM audio signal; and two rotary magnetic heads for recording the compressed PCM audio signal in the plurality of tracks, each of the tracks being divided into a first leading audio track section, a contral video track section and a trailing audio track section, with the two heads recording one field interval of the video signal in the central track section of each track and recording the audio signal corresponding to one field interval of the video signal recorded in an adjacent track, in the first and second audio track sections of each track such that odd samples of the audio signal are recorded in each first leading audio track section and even samples of the audio signal are recorded in each second trailing audio track section.

Apparatus for recording a digital audio signal in a track with a video

In apparatus for reproducing a video signal which is recorded on a recording medium with a luminance component thereof non-linearly pre-emphasized and the signal portions thereof greater than a predetermined level being clipped; there are provided a non-linear de-emphasizing circuit which non-linearly attenuates the reproduced luminance component in a manner substantially complementary to the amount of the non-linear pre-emphasis, a gain control element, for example, in the form of a transistor, having a variable gain, and a compensating circuit for substantially recovering the clipped signal portions upon reproduction of the video signal, and in which the compensating circuit increases the gain of the gain control element for the portions of the reproduced luminance component at the predetermined level. The compensating circuit desirably includes a switching diode connected at one terminal to the collector of the gain control transistor and to a reference voltage at the other terminal such that the diode is made conductive for the portions of the reproduced luminance component of the video signal at the predetermined level to increase the gain of the transistor at the collector thereof.

Video signal recording and/or reproducing apparatus with gain control

A phase compressor for a phase modulated signal comprises n phase suppressors (n is an integer greater than 2), each of which includes an adder and a limiter. The n phase suppressors are connected in series with one another. In this case, outputs from the limiters of nth, (n - 1)th, (n - 2)th, . . . . 2nd phase suppressors are individually supplied to the adders along with outputs from the (n - 1)th, (n - 2)th, . . . . 1st phase suppressors, respectively. A reference signal is supplied to the adder of the nth phase suppressor, by which a modulated phase angle of the phase modulated signal with a wide modulation index is phase-compressed by 1/.sub.n.sub.+1. The phase compressed signal is phase-demodulated by a phase demodulator without decreasing a signal-noise ratio.

Phase compressor for phase modulated signal

A brushless DC motor having a plurality of stator windings and a rotor made of a magnet is driven by energizing the stator windings successively, and in which signals induced in the plurality of stator windings resulting from the rotation of the rotor are detected as position signals of the rotor and at least one of the stator windings which corresponds to the position signal is supplied with a driving signal.

Brushless DC motor driving circuit

Video signals are recorded in successive record tracks on a record medium without guard bands or spaces between adjacent tracks, thereby enhancing the utilization of the record medium. Interference between the signals recorded in adjacent tracks is avoided during reproduction thereof by recording such video signals in adjacent tracks with their respective synchronizing signals aligned in the direction substantially at right angles to the length of the tracks and with carrier components of the signals recorded in the adjacent tracks being of the same frequency and having the same phase relation to the effective scanning direction during recording. During reproduction of the signals thus recorded, non-interfering signals recorded in two or more adjacent tracks are simultaneously reproduced by a reproducing magnetic head without the necessity of a servo tracking arrangement to align the scanning paths of the magnetic reproducing head relative to the record tracks.

Video signal recording/reproducing apparatus wherein the phase of the

A reference carrier signal is combined with a phase modulated signal of the same basic frequency to generate an output signal the amplitude of which varies in accordance with the phase difference between the phase modulated signal and the reference carrier. The permissible modulation angle is increased by vectorally adding the phase modulated signal with a reference signal having a phase different from the comparison reference carrier. The vector sum signal is amplitude-limited so that the signal produced by the comparison will only be responsive to phase angle and not amplitude.

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Tokyo, Japan

Yukihiko Machida