Audio-visual apparatus with control signal operated gating means

Claim 2

A recording medium having recorded thereon one or more time-division-multiplexed sequences of analog audio-information and sequences of binary-coded video information composed of first and second frequency-shift-keyed audio tones, any sequence of video information recorded on said medium being immediately preceded by a preamble code comprising a given length of a single one of the frequency-shift-keying audio tones, said given length being significantly longer than the interval of any signal component of said audio information whereby upon playback of said medium a sequence of video-information may be reliably distinguished from a preceding sequence of audio information.

Claim 3

The recording medium defined in claim 1, wherein each of said video-information binary codes consists of a first given number of consecutive binary bits that have binary values selectively determined by that particular code and said preamble code consists of a second given number of consecutive binary bits that all have the same predetermined binary value, said second given number being significantly larger than said first given number, whereby said given length of said preamble code is significantly longer than the length of any of said video-information binary codes.

Claim 4

An adaptor for inter-relating an external audio input device with a standard television receiver, wherein said device plays back one or more time-division-multiplexed sequences of analog audio-information and sequences of binary coded video information composed of first and second frequency-shift-keyed audio tones for deriving a serial signal which is applied as the signal input to said adaptor, and wherein any sequence of video information recorded on said tape is immediately preceded by a preamble code comprising a given length of a single one of the frequency-shift-keying audio tones, said given length being significantly longer than the interval of any signal component of said audio information; said adaptor comprising: a video-information channel initially decoupled from said signal input to said adaptor, first means including a preamble code detector for continuously monitoring said signal input applied to said adaptor, and second means coupled to said first means and said video-information channel for coupling said video-information channel to said signal input in response to the detection of said preamble code by said preamble detector.

Claim 5

An adaptor for inter-relating an external audio input device with a standard television receiver, wherein said device plays back one or more time-division-multiplexed sequences of analog audio-information and sequences of binary coded video information composed of first and second frequency-shift-keyed audio tones for deriving a serial signal which is applied as the signal input to said adaptor, and wherein any sequence of video information recorded on said tape is immediately preceded by a preamble code comprising a given length of a single one of the frequency-shift-keying audio tones, said given length being significantly longer than the interval of any signal component of said audio information; said adaptor comprising: a video-information channel initially decoupled from said signal input to said adaptor, first means including a preamble code detector for continuously monitoring said signal input applied to said adaptor, and second means coupled to said first means and said video-information channel for coupling said video-information channel to said signal input in response to the detection of said preamble code by said preamble detector.

Claim 6

The adaptor defined in claim 3, wherein each of said video-information binary codes consists of a first given number of consecutive binary bits that have binary values selectively determined by that particular code and said preamble code consists of a second given number of consecutive binary bits that all have the same predetermined binary value, said second given number being significantly larger than said first given number, and wherein said preamble detector includes means for producing a preamble detection output only in response to the receipt thereby of said second given number of consecutive binary bits all having said predetermined binary value.

Claim 7

The adaptor defined in claim 4, wherein said adaptor includes an end-of-message detector responsive to a preselected one of said video information binary codes which always occurs as the last code in any sequence of video information, and third means for applying the output from said end-of-message detector to said second means for decoupling said video-information channel from said input signal in response to the detection of said preselected one of said video-information binary codes by said end-of-message detector.

Claim 8

The adaptor defined in claim 5, wherein said adaptor includes an audio information channel coupled to said second means to couple said audio-information channel to said signal input only when said video-information channel is decoupled therefrom and to decouple said audio-information channel from said signal input only when said video-information channel is coupled thereto.