Abstract: Transmitting via color signals or vertical signals to control a computer's display monitor using software adjustments of the display parameters. A user can vary the display parameters including, for example, the contrast, brightness, horizontal and vertical size and position, inter alia, and transmit other commands and other data using codes transmitted with the color codes, or alternatively, with the vertical synchronization pulses.

Abstract: A data decoding device capable of decoding plural kinds of data superimposed in a vertical blanking period of a video signal.

Abstract: A system for processing multiple signals. The system includes a receiver for receiving a video signal representative of a camera image, the video signal being represented as multiple horizontal lines in a video frame, a receiver for receiving multiple analog signals, the analog signals being representative of different analog inputs, a buffer for digitally double buffering at least some of the analog signals, wherein the buffer effects repetition of analog signals within a single video image frame, repeats sampling of the analog signals more than once within a single video frame and the digitization enhances recovery of the signal resolution of the analog signal with greater frequency and representation than an analog signal on a video signal. The system also comprises a mixer for mixing the analog signals with the video signal whereby the analog signals are contained on at least some of the horizontal lines of the video frame, and an output for outputting the mixed analog and video signals.

Abstract: An NTSC television signal transmitter also transmits through the same transmission channel a suppressed data carrier having a frequency differing from that of video carrier, having a symbol rate that is a multiple of horizontal scanning rate of video signal, having data frames occurring at a data frame rate that is the same as the video frame rate, and transmitting the symbols transmitted in each of alternate data frames in opposite phase during the next data frame. The data carrier has no image on the other side of the video carrier and preferably its modulation spectrum overlaps the video carrier. A receiver recovers data from such a data carrier buried in an NTSC television signal, using frame-comb filtering to separate data from interfering video signal.

Abstract: A television broadcasting system intended to bestow a certain level of selectivity on compression systems and multiplexing systems for broadcast program pictures. A transmitting equipment transmits the broadcast program pictures, and transmits control information on transmission systems for the transmitted broadcast program pictures. A receiving equipment includes a reception module which receives a program channel having a plurality of sorts of video information multiplexed therein, selected by a viewer, and also the control information concerning the selected program channel. A reception controller commands a signal separator to produce the outputs of the video information interleaved in those positions of the program channel which are designated by the control information. Besides, the reception controller sends a decoder a decoding program contained in the control information.

Abstract: A time code or other digital code is inserted into a video signal by modulating the video signal itself or the signal's radio frequency (RF) carrier. This allows the code to be recorded concurrently with recording of the video signal, thereby obviating the need for a specially adapted recording apparatus. Furthermore, since the code is embedded in the recorded video signal, the encoded information may be retrieved from the video signal in a unit that is external to the playback apparatus. In combination with a conventional video cassette recorder (VCR), the video signal that is tuned to by the VCR is processed to extract raster synchronization signals. A modulator inserted ahead of the RF input to the VCR modulates the RF carrier in response to the digital code. Feedback of the tuned video signal insures proper synchronization of the broadband RF modulation so that the digital code is inserted into a non-viewable portion of the recorded video signal.

Abstract: An apparatus for providing close captioning in a digital program services delivery system comprises: a rate converter circuit for receiving video codes and outputting video data; a video decoder circuit for receiving the video data and outputting digital Y, U, V data; a digital to analog converter/analog encoder circuit for converting the Y, U, V data into an analog video signal in a prescribed format; a line 21 former circuit for receiving close captioning digital data and forming a line 21 analog signal; and a multiplexor for inserting the line 21 analog signal into the analog video signal.

Abstract: An additive video information inserting device includes a MUSE-NTSC converter, and an additive video information encoder for receiving an output video signal of the MUSE-NTSC converter and inserting into the video signal an additive video information indicating a frame mode for the video signal. The additive video information is so set as to correspond to a frame mode in a conversion operation of the MUSE-NTSC converter. The additive video information is inserted into a predetermined position in a vertical blanking period of the video signal.

Abstract: A standard video signal is processed by including an interval of an insertion signal whose potential varies continuously between the video sync tip level and a level substantially above blanking level during at least part of the active interval of at least one blank line in the vertical blanking interval.

Abstract: Control data indicating the vertical start positions of display characters is written into the locations of a video RAM determined by a common column address and a plurality of column addresses. In each horizontal synchronizing period, all control data is read in sequence from the video RAM and set in sequence in a vertical start position register. A match is found between the contents of the vertical position counter indicating the current vertical position and the contents of the vertical start position register. When they match, after the horizontal synchronizing period, the video RAM is accessed with the control data as the vertical position start address.

Abstract: A synchronizing/separator circuit separates a horizontal synchronizing signal and a vertical synchronizing signal contained within a television signal. A phase locked loop synthesizes a clock signal at 32 fH by phase locking the horizontal synchronizing signal with a divided version of the 32 fH clock signal. The phase locked loop includes a voltage controlled oscillator (VCO) responsive to the phase comparison to perform the phase lock. A circuit separates the run-in clock and caption data in horizontal scanning period 21 H in the vertical blanking interval. A phase comparator receives the run-in clock and phase compares it with the 32 fH clock to produce an alternating control signal which is applied directly to the voltage controlled oscillator for rapid phase locking of the voltage controlled oscillator in preparation for decoding the caption data. The voltage controlled oscillator is controlled by the charging and discharging rate of a capacitor charged by a constant current source.

Abstract: Specific clock periods in each machine cycle MC used by a CPU are used for accessing a video RAM synchronized with the operation of the operation of the CPU and the remaining clock periods of the machine cycle MC are used for accessing the video RAM synchronized with horizontal scanning and vertical scanning of television signal. Therefore, accessing synchronized with television signals is also performed in response to clock periods of a machine cycle MC and the video RAM can be made of a single port.

Abstract: A ghost cancelling system includes a ghost cancelling IIR filter and channel modelling circuitry for generating tap weighting coefficients for programming the ghost cancelling IIR filter. The channel modelling circuitry includes means for calculating the sum of all of the generated weighting coefficient values. If the sum exceeds a predetermined value indicative of the IIR filter becoming unstable, the weighting coefficients are conditionally scaled in a manner to reduce the sum, thus tending to reduce the possibility of filter instability.

Abstract: Signal processors for permitting the transparent, simultaneous transmission and reception of a secondary data signal with a video signal in the video band is disclosed. The signal processor in the transmitter rasterizes the data at the horizontal scanning rate and modulates the data with a data carrier at a non-integral multiple of the horizontal scanning rate to obtain frequency interleaving. The data is transmitted during the active video portion of each video line.

Abstract: Unique digital codes are encoded on a video signal, the codes are retrieved at receivers and precise information concerning the time of occurrence, length, nature and quality of a monitored broadcast at a frame by frame level, is generated. The codes are inserted on scan lines of the video, and vary either on a field-to-field or frame-to-frame basis. The code has a repeating first part having a unique program material identifier indicating the time, date and place of encoding, and has a second portion that varies in a predetermined non-repeating sequence which varies along the entire length of the tape, thereby uniquely identifying each frame of the video program material. Also encoded upon successive frames is a cyclic counter code with a count corresponding to the sequence of the identifier data on successive frames.

Abstract: A video recording system is provided with a copy guard arrangement which can readily discriminate a video signal having pseudo horizontal synchronizing pulses in a portion of a vertical blanking interval, from a normal video signal, without deteriorating the quality of recorded pictures. Preferably, an analog circuitry or a microcomputer is designed to count the horizontal synchronizing pulses received during a predetermined portion of the vertical blanking interval, and to discriminate a copy-guarded video signal from an unguarded video signal in accordance with the result of the counting. In the case of the copy-guarded video signal, an inhibit signal is produced to prevent a normal recording operation.

Abstract: An encoder disconnects video data between a video source and a video using device only during 21H in the vertical blanking interval. During 21H, it applies locally generated coded data signals, in a format detectable by conventional data decoding devices, to the video using device. The video source may be a camera or tape playback, and the using device may be a TV set or a video tape recorder.

Abstract: A system and method for transmitting digital data in the horizontal overscan portion of a composite video signal is presented. A source supplies digital data which is encoded by a 32-state QAM encoder using a symbol clock having a frequency 4f.sub.sc, 4 times the color subcarrier frequency (f.sub.sc), then the encoded data is quadrature amplitude modulated using a carrier signal with a frequency of f.sub.sc /2. The modulated digital data replaces the video signal in the horizontal and vertical overscan portions of the baseband video signal. The video signal is received, the modulated digital data is extracted from the video signal, demodulated using QAM techniques, and decoded with a reconstructed version of the symbol clock.

Abstract: A slice circuit for a data signal includes a clamp for clamping the data signal and a comparator having a first input coupled to the clamp, a second input coupled to a filter and an output coupled to a D/A converter. The output of the D/A converter is coupled to the filter such that a pulse width modulated signal is developed in the comparator output which is converted to a DC voltage by the D/A converter and filter for controlling the data slice level. The pulse width modulated signal is the sliced data.

Abstract: A television signal receiving apparatus with a channel tuner, such as a television, VCR, or cable box has circuitry for extracting nonprogram type information such as may be carried in the vertical blanking interval of a broadcast signal. In order to ensure a reliable signal source for the nonprogram type information the apparatus has a controller for setting the channel tuner to the proper channel and selecting the proper signal source to receive the nonprogram type information when the apparatus is not used for receiving regular programming signals selected by the viewer.

Abstract: A method of decoding data for a language having the Roman alphabet or a language having a syllabic alphabet from a composite video signal comprises the steps of receiving the data in the form of data packets and determining from bit values stored at particular bit positions whether the data is control data or represents printable character data comprising a head code or a tail code. Once it is determined that the data represents either a head code or a tail code of a printable character, the data bytes are valued for parity and, from that determination, a letter component is generated which points to a letter component or complete character for one or the other alphabet. Because characters of a syllabic language may be quite complex, the step of displaying the syllabic language character includes the steps of overlaying two or more letter components to form the syllabic character image.