Abstract: A current source (70) is coupled to supply an output current to a circuit node (60) proportional to a video input signal (R). A first resistor (65), coupled between the circuit node (60) and a source of supply voltage (68), develops an amplified video signal which is coupled from the circuit node to the cathode (K1) of a kinescope (20) via a second resistor (85). A capacitor (100 or 110) is provided having a first electrode coupled to the cathode (K1) of the kinescope (20) and having a second electrode coupled to the circuit node (60) via an amplifier(90). Advantageously, the combined resistance of the two resistors imparts gamma correction to the kinescope, the capacitor and amplifier compensate for stray capacitance associated with the cathode without subjecting low frequency components to any possibility of distortion in the amplifier. Additionally, the capacitance (110) may be varied as a function of the beam current for stabilizing the overall driver amplifier frequency response.

Abstract: A video input signal is amplified and applied to the cathode of a kinescope via linear kinescope driver amplifier provided with an output impedance sufficiently high to impart gamma correction to images displayed by the kinescope but tending to diminish the bandwidth of the amplified video signal applied to the cathode. A capacitor is included in the driver for restoring the bandwidth of the amplified video signal. For stabilizing the high frequency response (detail) of displayed images the value of the capacitor is varied as a function of the brightness of displayed images.

Abstract: A video input signal is applied to a bridged-T attenuator which includes a non-linear element in the shunt branch thereof that provides increasing attenuation as the input signal increases to thereby produce a gamma corrected video output signal at the attenuator output. A current sensor in the shunt branch generates an exponentially increasing detail signal for increases in the video input signal. The detail signal is high pass filtered and combined with the gamma corrected signal by a summing circuit for providing a video output signal having gamma correction and high frequency detail augmentation.

Abstract: A high voltage, inverting, kinescope driver amplifier is coupled at the input thereof to a source of low voltage video input signals to be amplified and is coupled at the output thereof for supplying amplified video output signals to the cathode of a kinescope. The high voltage amplifier includes linear and non-linear feedback paths which, in combination, determine a nominal closed loop gain for the amplifier. The non-linear path includes amplitude and frequency dependent elements for increasing the closed loop gain of the amplifier by a given amount in low brightness areas (black to gray) displayed by the kinescope (thus improving dark picture detail) and increases the closed loop gain of the amplifier by substantially the same given amount for high frequency video detail signal components in high brightness picture areas (thus improving subjective contrast without spot blooming and avoiding the impression of "washed-out" pictures.

Abstract: A television-type video signal containing main information, and auxiliary information modulating an auxiliary subcarrier having a controlled phase, is applied to a field storage network. First and second adaptive luminance-chrominance separators of the line comb filter type are coupled to the field storage network for receiving input signals from adjacent image fields, respectively. Chrominance outputs from the separators are combined to produce a separated main chrominance signal. Luminance outputs from the separators are combined to produce a separated main luminance signal. The modulated auxiliary subcarrier is derived from the field storage network.

Abstract: An apparatus is employed to compensate for time-variant field interference in magnetic fields of electromagnets with high field homogeneity, in particular in specimen areas of superconductive electromagnets for measurements of magnetic resonance. The magnetic field that permeates a specimen area of the electromagnet is identified by means of at least one induction coil, a voltage induced in the induction coil is supplied to a control stage, and a compensating current that flows through a compensating coil that surrounds the specimen area is set by means of an output signal from the control stage. In order to be able to compensate for remote interference emanating from far outside the magnet, at least one compensating coil and at least two induction coils, or vice versa, are disposed.