Sony Corporation

Masao Tomioka

Takashi Okada

Takao Mogi

Takamichi Mitsuhashi

Yasunori Orihara

A sound field expansion system applicable to a magnetic recording and reproducing apparatus (VTR) which can expand the sound field in a simple construction. In the sound field expansion system, a circuit for virtually forming two comb filter characteristics is provided by adding a first audio signal and a second audio signal delayed by a predetermined interval of time with respect to the first audio signal and adding the first audio signal which is passed through a phase shift circuit which shifts the phase of the first audio signal so that the reproduced sound field can remarkably be expanded. Furthermore, a correction circuit for providing a predetermined frequency characteristic for the first or second audio signal is installed so that an acoustic image having a desired frequency band can be positioned. The first and second audio signals may be monaural or stereophonic and are derived from demodulations of audio frequency-modulated (AFM) signal recorded on a common track of a magnetic tape together with a one-field video signal in a frequency division multiplex mode and time-axis-compressed pulse-code-modulated audio (PCM) signal recorded on the common track together with the one-field video signal in a time share mode.

Sound field expansion system for a video tape recorder

A scrambled television program is received and recorded in a scrambled fashion automatically in a video tape recorder by detecting program code signals placed in vertical blanking intervals of ten fields preceding the commencement of the scrambled program signal and upon sensing such program code signals the video tape recorder is activated to record the scrambled television program. A stop code signal is arranged following the coded television program and is detected for stopping operation of the video recorder, so that the scrambled program is recorded without requiring the manual setting of automatic timers or the like. In addition to the program code, a key code, and scene change signals are transmitted and these are used to produce a descramble pattern to descramble the television program when it is reproduced by the video tape recorder. By placing the key code after the television program, the entire program must be recorded in scrambled form before it can be reproduced and descrambled for viewing, thereby automatically recording the scrambled program without requiring a timer.

Method and apparatus for recording scrambled television signals

In a cassette tape device having tape guide means movable around a tape guide drum, the operating time of the tape guide means is measured to actuate a protecting circuit to stop the tape drive motor if the operative time of the tape guide means exceeds the estimated operating time, as such excessive time would be indicative of trouble in the guide means.

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Yamato, Japan

Masao Tomioka