Abstract: A method and system for translating between three complementary color component slow scan video signals and a composite color slow scan video signal containing a luminance information signal within a visible line interval of each slow scan video signal line and a chrominance information signal within the non-visible portion of each slow scan video signal line. The chrominance information signal includes during the non-visible portions of alternate slow scan video signal lines, a first color difference signal derived by subtracting the luminance information signal from one of three complementary color slow scan video signals and a second color difference signal derived by subtracting the luminance information signal from another of three complementary color slow scan video signals. The three complementary color component slow scan video signals are translated into the composite color slow scan video signal for transmission.

Abstract: A modulation system wherein a carrier signal is modulated by an input signal having a variable amplitude, either analog or digital. The amplitude of the input signal is sampled every predetermined fractional cycle of the modulated signal; and the carrier signal is modulated in response to the sampled amplitude of the input signal to provide a modulated signal of which each predetermined fractional cycle has an amplitude and a duration that are inversely proportional to each other and related to the sampled amplitude of the input signal. The modulated signal is demodulated by either or both of the techniques of zero-crossing detection and peak-amplitude detection. The system is self-clocking, without discontinuous phase or amplitude changes and without DC components being introduced. The system transmits its own signal-recovering clock information and thereby permits modulation at a rate in excess of the carrier signal frequency.

Abstract: A method and system for translating between three complementary color component slow scan video signals and a composite color slow scan video signal containing a frequency modulated (FM) luminance information signal within a first frequency range of the slow scan video signal frequency band and an FM chrominance information signal within a separate second frequency range of the slow scan video signal frequency band, wherein the chrominance information signal includes a first color difference signal derived by subtracting the luminance information signal from one of three complementary color slow scan video signals and a second color difference signal derived by subtracting the luminance information signal from another of three complementary color slow scan video signals. The three complementary color component slow scan video signals are translated into the composite color slow scan video signal for transmission.

Abstract: A system for transmitting and receiving both a slow scan television signal and a voice signal over a common communication channel is disclosed. The slow scan television signal includes horizontal sync pulses provided at a predetermined rate for defining a predetermined period. The horizontal sync pulse and video information for a video scan line are contained within a first portion of the predetermined duration.A multiplexing device alternately connects either a video transceiver or an audio transceiver to the communication channel. The multiplexing device connects the video transceiver to the communication channel during the duration of a first multiplexing control signal and during the duration of a second multiplexing control signal.The first multiplexing control signal is provided in response to the slow scan television signal provided by the video transceiver and has a duration corresponding to the first portion of the predetermined period.

Abstract: A system for storing video information at both a slow scan rate and a fast scan rate, and for retrieving video information signals from the stored information at both the slow scan rate and the fast scan rate. A random access memory stores information provided by digital video information signals. An address selector addresses a selected location in the memory. A slow scan counter provides a count at the slow scan rate. The slow scan count is provided to the address selector for indicating the selected location to be addressed in the memory when either storing or retrieving information at the slow scan rate. A fast scan counter provides a count at the fast scan rate. The fast scan count is provided to the address selector for indicating the selected location to be addressed in the memory when either storing or retrieving information at the fast scan rate.

Abstract: Apparatus for producing a video signal from digitally stored information representing the video signal intensity in each of a plurality of picture element locations within a plurality of scan lines. An analog video signal produced for display from the stored information is blanked during the first half of each picture element location during alternately displayed lines and blanked during the last half of each picture element location during the remaining alternately display lines. This apparatus is used in slow-scan television.