Abstract: A method for use in the construction of a color display screen using deposition of a plurality of electroluminescent materials onto a substrate bearing said screen. The method comprises the forming operations a), b), and c) in any sequence: a) forming on the substrate a first pattern of deposition sites covered with a first material selectively strippable by a first agent; b) forming on the substrate a second pattern of deposition sites covered with a second material strippable by a second agent but not significantly attacked by said first agent; and c) forming on the substrate a matrix surrounding the first and second patterns of deposition sites. The method includes thereafter performing a first stripping of the first material with the first agent to reveal first deposition sites within the matrix and performing a first depositing of a first electroluminescent material within the first revealed deposition sites.

Abstract: A television signal audio transmission system comprises transmission means for developing first and second stereophonically related audio signals and means for developing a third audio signal. The transmission means further includes circuitry for developing a composite baseband signal having a first component comprising the sum of the first and second audio signals, a second component comprising a double sideband suppressed carrier signal formed by amplitude modulating a 2f.sub. H subcarrier with the difference between the first and second audio signals, a third component comprising a pilot signal having a frequency f.sub.H and a fourth component comprising a 4f.sub. H subcarrier signal frequency modulated according to the third audio signal, where f.sub.H represents the horizontal scanning line frequency. The composite baseband signal may include a fifth component comprising an approximately 5.5f.sub.

Abstract: A tuner includes a channel or target frequency selection means, a tunable oscillator, a tunable circuit means having at least one tunable circuit, and tuning means, responding to the target frequency select means, for automatically and individually tuning the tunable circuit. Typically the tuner includes several tunable circuits, which are tuned successively.The illustrated embodiments have three individually controlled varactor tuned circuits and a varactor tuned oscillator. To move to a new target frequency, the tuner locks the oscillator to the target frequency via a phase locked loop. This target frequency is inputted to the first varactor tuned circuit, and a microprocessor cooperating with a DC detector for sensing the output of the set of tuned circuits steps a voltage step generator which controls the first varactor tuned circuit while the tuning of the other varactor tuned circuits is held fixed.

Abstract: A system is disclosed for utilizing command buffers in a microprocessor controlled electronic code keyer for storing, rather than text to be transmitted, command strings for keyer operation. The command string is defined by a series of keypad closures for selecting a sequence of text buffers to be transmitted. In addition, the command buffers may be used during automatic text transmission to selectively change keyer parameters such as the speed of character transmission, inter-character and inter-word spacing, dot-to-dash-to-space ratio, or the number of times the contents of a text buffer will be automatically repeated. The use of text and command buffers permits the formation of essentially errorless Morse code transmissions, substantially enhances keyer operating and makes more efficient use of available memory.

Abstract: An equalizer and decoder system compensating for multipath distortion in digital format signals sent by teletext, for example. The system loads demodulated data signals and a received reference signal into a charge coupled device clocked in real time by a clock circuit. Later, the reference pulse is clocked to a microprocessor which determines tap coefficients for a transversal filter to correct the multipath distortion in the reference signal. The data signals are then applied to a transversal filter weighted with the calculated tap weights. After filtering, signals are decoded by the microprocessor.In another embodiment a charge coupled device with tapped stages is used at one time for receiving the data signals in real time, and at a later time for part of a transversal filter.In a simplest embodiment, distortions are removed by the microprocessor itself, without any separate transversal filter.