Sony Corporation

Masahiro Kambara

Minoru Morio

Yukio Kubota

Hidehiko Okada

Keitaro Yamashita

Tadahiko Nakamura

In a video signal reproducing apparatus for converting a first video signal having a first field frequency to a second video signal having a second field frequency, there are provided a tape scanning device which is made movable in a direction perpendicular to the recording track on a tape, a system for controlling the speed of the scanning device, a system for shifting the scanning device in the aforesaid direction according to the difference between the first and second field frequencies, in order to skip or repeat selected fields so that the video signal is reproduced with the second field frequency. Also provided is a system for converting the number of lines contained in one field of the first video signal. In the above converting system there is included a memory, and the first video signal is written into the memory and read out therefrom so that a predetermined number of lines of the first video signal are discarded or repeated and the reproduced video signal has the required number of lines for each field of the second video signal.

Video signal reproducing apparatus for converting a video signal from a

In a recording and reproducing apparatus in which a video signal is recorded by at least one rotary head in successive parallel tracks on a recording medium while the latter is being driven at a predetermined or standard speed in a direction to which said tracks are skewed, and in which the recorded video signal is reproduced by the rotary head repeatedly scanning the recording medium while the latter is selectively driven at the standard speed, as in the normal reproducing mode, or at an arbitrary speed other than such standard speed, for example, at zero speed for the still-motion reproducing mode, or at speeds less than and greater than the standard speed for the slow-motion and quick-motion reproducing modes, respectively; a variable delay circuit is operative during reproducing with the recording medium being driven at an arbitrary speed other than standard speed for variably delaying the video signal reproduced by said rotary head, and a control circuit controls the amounts by which the variable delay circuit delays the reproduced video signal in accordance with the arbitrary speed to cause fields of the reproduced video signal which are contiguous or next adjacent in point of time to be continuous in the delayed video signal and to contain respective horizontal synchronizing signals which are in predetermined phase relationships to each other, that is, precisely in phase or out of phase by one-half horizontal period, as when even- and odd-numbered fields are to be interlaced.

Avoidance of disturbance of horizontal sync signals in video signal

A method of and apparatus for modifying a video signal such that a video picture can be reproduced by a video display device in response to the modified video signal, but if the modified video signal is transmitted and then recorded on a video signal recorder, a satisfactory video picture cannot be reproduced if that recorded modified video signal subsequently is played back. A pulse whose amplitude is substantially equal to the peak white level of the video signal is inserted into respective horizontal blanking intervals of the video signal. If this modified video signal is recorded on a conventional type of video signal recorder, the presence of the inserted pulse signal is detected by an automatic gain control (AGC) detector which, in turn, controls an AGC amplifier to substantially attenuate the modified video signal which then is recorded.

Method of and apparatus for modifying a video signal to prevent

Tracking control apparatus for a signal reproducing system of the type wherein at least one transducer scans successive parallel tracks on a record medium in which information signals, such as video signals, are recorded. The transducer preferably is of the rotary type so that, during its orbit, it is brought into and then out of reproducing relation with respect to the record medium. Any deviation between the scanning trace of the transducer across the medium and a given track which is being scanned is detected, and a control signal is produced as a function of this detected deviation. The transducer is supported by an adjustable support which is responsive to the control signal so as to displace the transducer transversely of the given track by an amount determined by the control signal. A predetermined sample of the control signal is produced while the transducer scans the given track, and this predetermined sample is stored. Prior to the time that the transducer moves into a reproducing relation with respect to the medium, the stored sample is supplied to the adjustable support so that the transducer is pre-displaced before signals are reproduced thereby.

Tracking control apparatus

A method and apparatus for correcting tracking errors of a transducer which scans successive, parallel, adjacent record tracks of a record medium so as to reproduce information signals therefrom. The information signals, which may comprise video signals, are recorded in the parallel record tracks, and predetermined signals also are recorded at predetermined locations in the information signals. When the information and predetermined signals are played back, at least one cross-talk predetermined signal which is recorded in at least one adjacent track also is played back. The cross-talk predetermined signal is detected and a control signal is produced in response to the level of the detected cross-talk predetermined signal. The position of the transducer with respect to the track being scanned thereby is adjusted in accordance with the control signal. In one embodiment, the control signal is recorded at a predetermined location in each horizontal blanking interval of the video signals; and the horizontal blanking intervals which are recorded in one track are displaced with respect to the horizontal blanking intervals which are recorded in the adjacent track. This displacement of the horizontal blanking intervals, and thus the predetermined signals, in adjacent tracks facilitates the detection of the cross-talk predetermined signals which, for example, may comprise pilot signals.

Method and apparatus for correcting tracking errors of a transducer

A video signal reproducing system having a magnetic head deflector for automatic head scan tracking, the deflector being displaced corresponding to an error signal obtained from crosstalk pilot signals in a reproduced video signal.

Video signal recording and/or reproducing apparatus

A system for reproducing video signals recorded on a magnetic recording medium as a suppressed-carrier modulated signal in which the video information is carried primarily on only one sideband and the frequency of the suppressed carrier is within the band occupied by the video signals prior to modulation. Jitter components in the reproduced signals are substantially cancelled out.

System for reproducing a video signal

A method of and apparatus for modifying a video signal such that a video picture can be reproduced on a television receiver in response to the modified video signal, but if the modified video signal is transmitted and then recorded on a video signal recorder, an accurate video picture cannot be reproduced if that recorded modified video signal subsequently is played back. The vertical blanking interval containing one set of equalizing pulses followed by a set of vertical synchronizing pulses followed by another set of equalizing pulses is modified by replacing a portion of the vertical synchronizing pulses and a portion of the set of equalizing pulses following the vertical synchronizing pulses with simulated equalizing pulses in at least some of the vertical blanking intervals. The amplitude and frequency of the simulated equalizing pulses are equal to that of the actual equalizing pulses. In one embodiment, the modified video signal is transmitted via, for example, cable or RF transmission. In another embodiment, the modified video signal is recorded on a master recording medium. If the master recording medium subsequently is reproduced, the resulting, reproduced modified video signal can be transmitted for video display. However, if a copy of the master recording medium is made, an accurate video picture cannot be reproduced from subsequent reproduction of the copy medium.

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Tokyo, Japan

Masahiro Kambara