Abstract: In a beam index color television receiver of the type having a cathode ray tube provided with beam-excitable color elements disposed on an image area of a display screen of the cathode ray tube and index elements disposed on the image area and a contiguous run-in area of the display screen, both of the color elements and index elements being scanned by the electron beam as the beam scans the display screen, apparatus for controlling the electron beam includes an index signal generator for generating a periodic index signal as the index elements are scanned by the beam, a phase-locked loop for producing an output signal having a frequency related to the index signal, color gates which sequentially gate respective color control signals individually to modulate the electron beam as the beam scans the color elements, a gating signal circuit which generates sequential gating signals at a frequency synchronized with the frequency of the output signal from the phase-locked loop and which supplies the gating signals

Abstract: In a beam index color television receiver having the screen of its color cathode ray tube provided with color phosphor elements and index elements adapted to be excited by an electron beam as the latter scans the screen, and in which index signals, resulting from the excitation of the index elements by the beam, are employed to control the gating or switching of color signals for modulating the beam so that, at any instant during the scanning of an image area of the screen in each scanning interval, the electron beam is modulated, or has its beam current determined, by the color signal corresponding to the color phosphor element then being scanned by the beam; a potential applied to the cathode ray tube determining its beam current is controlled so as to maintain constant the level of the index signals during scanning by said beam of a run-in area at the initiation in each scanning interval; and such controlled potential has its level shifted downwardly a predetermined amount to provide a reference potential

Abstract: In a beam index color television receiver having the screen of its color cathode ray tube provided with a repetitive pattern of a plurality of groups of different primary color phosphor elements arranged side-by-side across the image area of the screen to be scanned by a single electron beam as the latter is selectively modulated by respective color signals, index and mode set signals are provided in response to scanning by the beam of respective locations on the screen which are interspersed across the latter with distances therebetween which are non-integrally different from the pitch of the groups of color phosphor elements, and with adjacent locations corresponding to the mode set signal being spaced apart by an integral multiple of such pitch.

Abstract: A clamping circuit for color television signals includes a demodulator for demodulating the chrominance component of the color television signals to produce first and second color difference signals, and first and second adders for adding adjustable first and second control signals to the first and second color difference signals so as to produce modified first and second color difference signals. A matrix circuit is responsive to the outputs from the first and second adders to produce a third color difference signal.

Abstract: This invention is a phase inversion circuit of improved stability of operation for a master-slave flip-flop circuit. An additional gating circuit is controlled by two signals, one from an output of the slave flip-flop circuit and the other from an externally applied phase inversion signal. The output of the additional gating circuit is connected to the master flip-flop circuit through a circuit means that also receives a signal from the slave flip-flop output circuit. In the absence of inversion signals the circuit means controls the master flip-flop circuit from the slave flip-flop circuit and the master flip-flop circuit controls the slave flip-flop circuit with the assistance of the timing pulses in the usual manner.

Abstract: A detector circuit for a color television receiver includes a pair of transistors whose collector-emitter circuits are connected in parallel with each other, an input circuit, such as a differential amplifier, for supplying a differential input signal to the base electrodes of the pair of transistors, an impedance element coupled between the collector electrodes of the pair of transistors and a voltage source, and an integration circuit for integrating a detected signal taken from the collector electrodes of the pair of transistors and thereby providing an output signal. A reference-voltage circuit is included to supply a reference voltage, which can be used as a threshold voltage, to the emitter electrodes of the pair of transistors.

Abstract: An automatic chrominance control and color killer circuit for use in a color television receiver having a gain controllable chrominance amplifier for selectively amplifying chrominance signals and a color burst signal transmitted with a composite television signal during a color television transmission.