Victor Company of Japan, Limited

Yositeru Kosaka

Kunio Yamada

Yoshihiko Ota

A switching circuit built in a record/playback mode switching circuit of a video tape recorder. Compulsory local overwriting can be executed while the playback of a recorded magnetic tape is under way. This allows characters, graphic information, VITC signal or similar multiplex signal carrying desired information to be recorded in the same manner as postrecording in a recorded magnetic tape which is being played back.

Switching circuit

A first video signal processing apparatus for processing a video signal including first and second color difference signals transmitted line-sequentially for outputting simultaneously two fundamental color difference signal, used in SECAM system comprises: a time-adjusting circuit for time-adjusting the first and second color difference signals of successive first, second, and third lines each other; a mixing circuit for combining the first line with the third line of time-adjusted color difference signals at a ratio determined by detected vertical correlation error between first and third lines; a switching circuit for outputting simultaneously the second line of the second color difference signal and an output signal from the mixing circuit being interchanged each other with respect to output terminals therefor in response to a timing signal produced from the video signal. A second video signal processing apparatus used in the MAC system comprises a second vertical correlation detection circuit for detecting whether hue change exists on the side of first line or third line in addition to the circuit arrangemints of the first video processing apparatus. The second vertical correlation detecting circuit switches over second switch for selecting a mixing ratio.

Video signal processing apparatus

A voltage controlled comb filter comprises a 1 H delay circuit, an inverting circuit, and a mixing circuit. A playback carrier chrominance signal is delayed by the delay circuit for 1 H period and is inverted by the inverting circuit. The playback and delayed playback carrier chrominance signals are inputted to the mixing circuit which mixes these signals in proportion variable in accordance with the degree of a line correlation error signal. Therefore, there is no switching noise inherent in the conventional comb filter having a switch circuit used in a video tape recorder.

Voltage controlled comb filter

A recorded tape, speed-change reproducing system comprises a transport for transporting a tape at a speed which is different from that used for normal reproduction (and recording). The tape carries a video signal which was recorded, by a rotary video head, on parallel video tracks which are disposed obliquely relative to the longitudinal direction of tape travel. An audio signal is recorded by a stationary audio head with an audio track extending longitudinally along the length of the tape. The rotary video heads scan the video tracks on the tape to reproduce the recorded video signal when the tape speed changes. The stationary audio head also scans the audio track on the tape under speed-change situations. The pitch of the reproduced audio signal is corrected in such a manner that the pitch is returned to become substantially equal to the pitch of the reproduced audio signal, as if the tape was travelling at the recording speed.

Recorded tape, speed-change reproducing system

A system for reproducing a video signal in a slow-motion reproduction comprises at least one rotary head for reproducing and operating to trace a tape on which has been recorded a video signal along tracks extending obliquely to the longitudinal direction of the tape thereby to pick up or reproduce the recorded video signal from the track, a circuit for intermittently driving a capstan motor for rotating a capstan for driving the tape thereby to shift the tape and to stop the tape intermittently in a slow-motion reproducing mode, and a circuit for controlling rotation of said rotary head so that the relative tracing speed of the rotary head relative to said tape becomes the same both at the time of intermittent tape travel and at the time of intermittent tape stoppage in the slow-motion reproducing mode.

System for reproducing video signals in slow-motion mode

A signal processing circuit is used in a color video signal recording and/or reproducing apparatus. The frequency of an original carrier chrominance signal is separated from an input color video signal and is converted into a low frequency band and/or reconverted from the low frequency band, back into the original frequency band. Rotating heads record and/or reproduce a video signal, including the converted carrier chrominance signal, on and/or from parallel tracks on the recording medium. The signal processing circuit determines the timing of phase shifting for every successive horizontal scanning period in response to a horizontal synchronizing signal separated from the video signal. The direction of phase shifting is determined in response to a signal supplied responsive to every scanning period of the rotating heads. A signal of frequency 4fs and the timing of phase shifting cooperate for determining the direction of phase shifting, and for forming a signal having a frequency fs. The phase angle shifts by 90 degrees for every successive horizontal scanning period. The phase shifting direction is inverted alternately for every successive scanning period of the rotating heads. The formed signal, of frequency fs, is utilized for a frequency conversion signal to be supplied to the frequency conversion means.

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Zushi, Japan

Yositeru Kosaka