Abstract: A mixture of starting materials, corresponding to an oxide composition within an area of the ternary diagram for (Hf,Zr)O.sub.2, A.sub.2 O, P.sub.2 O.sub.5 formed by connecting end member points defined by the molar compositions: 45 (Hf,Zr)O.sub.2 - 10 A.sub.2 O - 45 P.sub.2 O.sub.5 ; 45 (Hf,Zr)O.sub.2 - 45 A.sub.2 O - 10 P.sub.2 O.sub.5 ; and 10 (Hf,Zr)O.sub.2 - 45 A.sub.2 O - 45 P.sub.2 O.sub.5, reacts to form large single crystalline essentially hexagonal particles of a new compound (Hf.sub.1-x Zr.sub.x).sub.3-y A.sub.4y (PO.sub.4).sub.4, and an aqueous-soluble second phase removable by washing. The large single crystalline hexagonal particles are useful as the luminescent material in x-ray intensifying screens, with band emission which overlaps at least partially the absorption edge of an x-ray film base to give good image resolution without crossover distortion.
November 8, 1976
Date of Patent:
September 5, 1978
GTE Sylvania Incorporated
Charles Frederic Chenot, James Evan Mathers, Francis Nathan Shaffer
Abstract: Sintered and unsintered articles of refractory metal carbide and cementing metal having thicknesses greater than those obtainable by tape casting a slurry of ingredients onto a substrate, and having a cross section of substantially uniform appearance, are described, as well as a laminating method for producing such articles, the method comprising; (1) pressing the top surface of one or more unsintered flexible tape cast sheets against a smooth rigid surface to achieve a top surface smoothness comparable to the bottom surface smoothness achieved by tape casting, and (2) forming a laminate of at least 3 unsintered flexible tape cast layers by bringing the respective smooth surfaces of the layers into mutual contact and pressing the layers together to achieve bonding.
Abstract: Luminescent materials having a host of controlled amounts of barium oxide, controlled amounts of lithium oxide, and the balance aluminum oxide when activated by divalent europium alone yield a blue emission when excited by ultraviolet light and activated by europium in combination with divalent manganese yield a bright green emission under ultraviolet light. The host can be a solid solution of the foregoing oxides or it can contain alpha alumina and spinel as additional phases. These materials are used to produce lamps having enhanced emission characteristics as compared to lamps employing luminescent materials having a host of aluminum oxide in combination with barium oxide and activated by europium or europium manganese or to lamps employing magnesium gallate, activated by manganese.
Abstract: A high power factor conversion circuit suitable as a ballast circuit for lamps includes a full-wave rectifier coupled to an AC potential source and providing a pulsating DC potential. A high frequency inverter is coupled to a load circuit and to a feedback rectifier circuit supplying a rectified high frequency potential to an energy storage feedback circuit which provides energy in a manner to inhibit a decline in the pulsating DC potential thereby providing a substantially uniform DC potential to the high frequency inverter.
Abstract: In a color cathode ray tube deflection apparatus having a deflection yoke with horizontal, vertical and quadrupole windings and affixed to a color cathode ray tube, a quadrupole convergence circuit includes a quadrupole winding coupled to a source of substantially parabolic-shaped horizontal and vertical frequency signals and coupled by a signal clamping circuit which is, in turn, shunted by an impedance varying in proportion and an opposite direction to variations in the impedance of the clamping circuit as determined by the value of the substantially parabolic-shaped vertical frequency signal whereby convergence at the corners of a cathode ray tube is enhanced.
Abstract: A horizontal electron beam crossover correction circuit for an in-line color cathode ray tube having an associated toroid-wound deflection yoke with first and second horizontal deflection windings each having first and second winding portions coupled to a horizontal deflection signal source includes an adjustable impedance shunting at least one of the winding portions of one of the first and second horizontal deflection windings for controlling current flow in one with respect to the other of the winding portions.
Abstract: A receiver incorporating a phase-locked loop to demodulate a signal comprising a plurality of distinct baseband components is disclosed. The loop filter circuit includes an adjustable resistive element for varying the loop damping factor, thereby providing optimum separation of the baseband components. In addition, the loop filter circuit provides a bandpass high-frequency noise output to a noise-activated muting circuit.
Abstract: A light-indicator circuit is disclosed which permits visual indication of clipping caused by the over-driving of a transistor amplifier. The circuit includes a light-emitting diode connected in parallel with the collector-emitter path of a switching transistor which is biased to conduct during low-signal-level operation of the amplifier. The switching transistor is caused to switch to its non-conducting state when the amplifier is overdriven, thereby activating the light-emitting diode. Means may be provided to delay switch-back once activation of the light-emitting diode has occurred. Means may be provided to inhibit activation of the circuit by over-driving signals of limited duration.
Abstract: Contrast and color levels in a color television receiver are automatically varied with ambient light variations by an RC circuit AC coupling an ambient light responsive device to a luminance signal channel and DC coupling the ambient light responsive device to a DC potential source and a chrominance signal channel.
Abstract: An electrical circuit arrangement for filtering electrical brush noise transmitted from an open switching wire connected at one end to an intermittently used brush of a multi-speed electric motor driven by a power source and having an electrically grounded housing and stator, said circuit arrangement utilizing a switching transistor located in close proximity to said brush and motor.
Abstract: A logic circuit providing a bi-level signal, one level of which agrees with eriods of time during which the video signal corresponds to a quadrant of a first broadcast television program, said quadrant being free from horizontal and vertical synchronizing pulses present in the video signal of a second broadcast program.
March 17, 1977
Date of Patent:
April 18, 1978
Saba Schwarzwaelder Apparate-Bau-Anstalt August Schwer Soehne GmbH
Abstract: A video processing system for a television receiver is shown. The video processing system includes a gain controlled stage through which a video signal is coupled. The gain of the stage is controlled to provide contrast control of the video signal. The gain of the gain controlled stage is also automatically controlled in response to a beam current feedback to provide automatic contrast or white level control. In addition, the automatic control circuit provides beam circuit limiting by reducing the gain of the gain controlled stage to minimum in response to beam currents in excess of a threshold. An aperture correction signal is also coupled through the gain controlled stage so that it is amplified or attenuated by the same amount as the video signal. The output of the gain controlled stage is coupled to an output stage where the black level of the video signal is controlled by a black level control circuit. The disclosed video processing system is further adapted for fabrication in integrated circuit form.
Abstract: A method is provided for disposing a tripartite electrical connective-resistive system of related coating areas upon interior portions of a cathode ray tube envelope to effect arc suppression in the region of the electron generating assembly. The tripartite means is comprised of a first low resistive electrical conductive coating disposed on the forward portion of the envelope. A durable high resistive electrical conductive coating is disposed contiguous to and rearward of the first coating extending therefrom to the neck of the envelope. This resistive coating is an amorphous deposition of a homogeneous composition of an insulative vitreous frit material admixed with at least one particulate material selected from the group consisting essentially of cadmium oxide, indium oxide and copper oxide.
Abstract: Improved bracket means for supporting a cathode ray tube in a display enclosure. The improvement resides in the formation of the seating portion of the bracket which enables the implosion-inhibiting tensioned banding surrounding the tube to make substantially constant uninterrupted contact with the periphery of the tube.