Abstract: The information signal for a green camera tube modulated to scan each line in an undulating path is sampled by a filter trap at the frequency of modulation in a narrow band (about .+-.1/2 MHz) and combined with the red and blue camera tube signals in the same proportion that each contributes to the total luminance relative to the green information signal thereby pseudomodulating the red and blue camera tube information signals. Although it is preferable to do this at the camera, thereby having to do it only once for the television transmission system, it may be done at the display tube. This modulation of the green tube scan, and pseudomodulation of the red and blue tube scan not only increases resolution for color television but also eliminated aliasing because the scan of all color camera tubes is effectively undulating so that there can be no scan parallel to horizontal edges of an image that causes aliasing in normal interlaced field of scan lines that are straight horizontal lines.

Abstract: Resolution of a dot-matrix character display system for a CRT is enhanced by storing two bits for each dot space, thus storing qMxn bits, where M is the number of dot spaces in a row, and N is the number of rows. The clock for reading M bits of a character in a row is increased by a factor q to generate q dots per dot space, while the CRT beam is sinusoidally modulated at the clock rate. The phase and amplitude of the modulation is selected to place the q dots displayed in a dot space at maxima of the modulation within a dot space of an MxN matrix, with a vertical displacement of .+-.1/4 raster scan width of the CRT.

Abstract: An improved color television transmission compatible with NTSC standards produces a controlled horizontal scan rate at about 15,734 Hz with 227.5 cycles of color subcarrier per line, and a controlled vertical scan rate at about 59.940 Hz to produce frames of two interlaced fields each at a rate of about 29.970 Hz with 59,718.5 cycles of the color subcarrier per field, instead of 59,718.75, thereby eliminating "chroma crawl." The vertical scan rate is controlled by dividing a clock frequency of four times the color subcarrier by four to produce the color subcarrier, and dividing the clock frequency by some set of multiples to produce the horizontal and vertical scan rates with 227.5 cycles of color subcarrier per line and 59,718.75 cycles per field, and once every field, at the end thereof, skipping one cycle of the clock frequency in the generation of the horizontal and field sync pulses for the next field, thereby causing each field to have 59.718.5 cycles of the color subcarrier instead of the 59,718.

Abstract: In a system for high resolution television achieved by vertical modulation of the horizontal scan at a frequency twice the color subcarrier, the modulation signal is derived from the color subcarrier at both the camera and receiver by squaring the color subcarrier sinusoidal signal, inverting the squared waveform, differentiating the inverted and uninverted square waveforms and from the combined differentiated pulses producing a train of pulses at a frequency twice the color subcarrier. This train is then applied to a transistor connected as a class B amplifier with the vertical deflection coil and a parallel capacitor as an LC resonant load. The current to the coil is provided by a regulated power supply that is adjustable to adjust the amplitude of the vertical deflection of the horizontal scan.

Abstract: The full potential of high resolution television by synchronized modulation of the scan lines at the camera and display unit is achieved in standard transmission through band limited channels by: separating out of the video signal from the television camera the modulation frequency as sidebands with pixel information, for example 7.16.+-.1/2 MHz in the case of a color subcarrier at 3.58 MHz under the NTSC standards and pixel information modulated on sidebands in a narrow band (about .+-.1/2 MHz); converting the sidebands with pixel information down to within the color subcarrier band (in the range of 3.75 MHz to 4.2 MHz) using a heterodyne converter; and adding back to the video signal out of the camera the down-converted sidebands with pixel information before processing it through the color encoder for transmission through the bandwidth limited channel.

Abstract: Color picture resolution is improved in a color television display system by threshold detecting the luminance signal, and, in response to the threshold detected luminance signal, switching the color signals off when the luminance signal is below a predetermined threshold level. Nonlinear amplifiers which couple the color signals to the display system are provided with gain that decreases as signal amplitude increases to restore color signal pulses to a form commensurate with the luminance signal fast rise and fall times.