Adaptor for inter-relating an external audio input device with a standard television receiver, and an audio recording for use therewith
First Claim
1. A recording medium having recorded thereon on the same portion of a single channel thereof both binary coded video information and analog audio information in a predetermined form which permits said video information and said audio information to be separated on playback of said recording medium, said predetermined form comprising a first carrier at a given audio frequency phase-shift-keyed with said binary-coded video information so that a first binary value is manifested by said first carrier having a given phase and a second binary value is manifested by said first carrier having a phase of substantially 180°
- with respect to said given phase, and said predetermined form further comprising a second carrier at said given audio frequency having a phase which is substantially in quadrature with said given phase, said second carrier being amplitude-modulated by said analog audio information.
2 Assignments
0 Petitions
Accused Products
Abstract
A standard audio cassette may be employed to provide various types of binary-coded video information, such as alphanumeric symbols and graphic elements, for display on a standard television receiver and also provide analog audio information as respective first and second components of a single composite signal applied to a suitable adaptor for inter-relating an external standard cassette player with a standard television receiver. The present invention is concerned with various improvements in the cassette recording and the adaptor. These improvements include (1) a cassette recording for simultaneous transmission of both binary-coded video information and analog audio information over a single channel, and improved coupling means in the adaptor which is responsive to such simultaneous binary and audio transmission; (2) improved coupling means in the adaptor for preventing the switching between sequentially transmitted analog audio information and binary-coded video information from being heard as audio clicks; (3) improved means for translating binary-coded alphanumeric video information which compensates for the limited video bandwidth of some standard television receivers, and (4) an improved graphic display capability, in addition to the conventional alphanumeric display capability, of a display provided on a standard television receiver.
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Citations
13 Claims
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1. A recording medium having recorded thereon on the same portion of a single channel thereof both binary coded video information and analog audio information in a predetermined form which permits said video information and said audio information to be separated on playback of said recording medium, said predetermined form comprising a first carrier at a given audio frequency phase-shift-keyed with said binary-coded video information so that a first binary value is manifested by said first carrier having a given phase and a second binary value is manifested by said first carrier having a phase of substantially 180°
- with respect to said given phase, and said predetermined form further comprising a second carrier at said given audio frequency having a phase which is substantially in quadrature with said given phase, said second carrier being amplitude-modulated by said analog audio information.
- View Dependent Claims (2)
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3. An adaptor for inter-relating an external audio input device with a standard television receiver, wherein said device plays back simultaneously over a single channel both a first carrier and a second carrier, wherein said first carrier consists of a given audio frequency phase-shift-keyed with binary-coded video information so that a first binary value is manifested by said first carrier having a given phase and a second binary value is manifested by said first carrier having a phase of substantially 180°
- with respect to said given phase, said first carrier persisting with said given phase in those recorded intervals in which all video information is absent, and said second carrier consists of said given audio frequency having a phase which is substantially in quadrature with said given phase, said second carrier being amplitude-modulated by analog audio information;
said adaptor comprising;a video-information channel; an audio-information channel, and phase-sensitive coupling means responsive to the phase of said given audio frequency applied thereto over said single channel from said device for simultaneously supplying solely said first carrier to said video-information channel and solely said second carrier to said audio information channel. - View Dependent Claims (4)
- with respect to said given phase, said first carrier persisting with said given phase in those recorded intervals in which all video information is absent, and said second carrier consists of said given audio frequency having a phase which is substantially in quadrature with said given phase, said second carrier being amplitude-modulated by analog audio information;
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5. In an adaptor for inter-relating an external audio input device with a standard television receiver;
- wherein said device plays back a time-division-multiplexed audio information and frequency-shift-keyed binary-coded video information for deriving a serial signal which is applied as the signal input to said adaptor;
wherein any sequence of video information is immediately preceded by a preamble code comprising a given length of a single one of the frequency-shift keying tones, and wherein said adaptor comprises a video-information channel, an audio-information channel, coupling means for initially coupling said audio-information channel to said signal input, a preamble code detector coupled to said coupling means for continuously monitoring said signal input, and control means coupled to said preamble code detector, said coupling means and said video-information channel for decoupling said audio-information channel from said signal input and coupling said video-information channel thereto in response to the detection of said preamble code by said preamble code detector;
the improvement for eliminating crosstalk between said channels, wherein said coupling means comprises;a normally open gate having its output coupled to said audio-information channel, a delay means providing a given delay substantially equal to the duration of said given length preamble code coupled between said signal input and said normally open gate for passing said input signal to said audio channel only after it has experienced said given delay, and means coupling said gate to said control means to close said gate in response to the detection of said preamble code.
- wherein said device plays back a time-division-multiplexed audio information and frequency-shift-keyed binary-coded video information for deriving a serial signal which is applied as the signal input to said adaptor;
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6. In an adaptor for inter-relating a binary-coded video-information signal input with a raster-scan display means consisting of a television receiver which may have limited video bandwidth;
- said adaptor comprising signal-translation means including a read-only-memory dot-matrix character generator responsive to a binary-coded video-information signal manifesting any given alpha-numeric character for deriving a video signal component for display of said given alpha-numeric character by said television receiver;
the improvement;wherein said signal-translation means includes video-signal distorting means for sufficiently increasing the relative duration of those components of said video signal contributing to the display of any first line-portion of a character which is oriented normal to the direction of a raster scan line with respect to the duration of those components of said video signal contributing to the display of any second line-portion of a character which is oriented along a raster scan line to make the displayed contrast exhibited by said first-line portion substantially the same as the contrast exhibited by said second-line portion despite the limited video bandwidth of said television receiver. - View Dependent Claims (7, 8, 9, 10)
- said adaptor comprising signal-translation means including a read-only-memory dot-matrix character generator responsive to a binary-coded video-information signal manifesting any given alpha-numeric character for deriving a video signal component for display of said given alpha-numeric character by said television receiver;
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11. In a raster-scan video display apparatus of the type including a page memory for storing at each of predetermined addresses character-information binary codes for display in a predetermined format of contiguous character spaces each of which uniquely corresponds to a different one of said predetermined addresses, each character space being composed of a predetermined two-dimensional arrangement of a given number of dot positions, and said apparatus including readout means including a dot-matrix read-only-memory character generator coupled to said page memory for deriving a video signal in accordance with said stored binary coded character information to be displayed in said predetermined format of contiguous character spaces;
- the improvement;
wherein any individual one of said dot positions is uniquely specified by a respective one of a group of said character-information binary codes, and wherein said dot-matrix read-only-memory character generator when addressed by anyone of said group of character information codes during readout of said page memory derives a video signal for displaying only a single dot in the dot position specified by the addressing one of said character-information binary codes of the displayed character space corresponding to the predetermined address of said page memory which stores said addressing one of said character-information binary codes. - View Dependent Claims (12, 13)
- the improvement;
Specification