Abstract: A video display apparatus incorporates a picture tube, such as a square-planar picture tube, that includes a phosphor screen located on a faceplate having an aspherically curved geometry that produces a relatively flat surface contour. Deflection circuitry generates line and field scanning currents in respective line and field deflection windings to enable the electron beams of the picture tube to scan a raster on the phosphor screen. The electron beams are subject to a scanning error that results in raster distortion, such as side pincushion distortion. A parabola generator produces a parabolic modulation of the scanning of the electron beams to generally correct the raster distortion while retaining a residual error due to the aspherically curved geometry of the faceplate.

Abstract: Line and field deflection circuits generate line and field deflection currents in respective line and field deflection windings to scan a raster on the phosphor screen of a square-planar picture tube having an aspherical faceplate. The asphericity of the faceplate subjects the scanned raster to gullwing distortion. A gullwing distortion correction circuit is responsive to signals repeating at line and field rates, respectively, for modulating the field deflection current during a line deflection period within the field deflection trace interval in a manner that corrects gullwing distortion of a corresponding raster scan line.

Abstract: A field deflection amplifier generates a field deflection current in a field deflection winding. An LC resonant circuit is coupled to the deflection winding and to an output switching amplifier. A control circuit switches conductive states of the amplifier at a line rate, with a 50% duty cycle, to excite the LC resonant circuit into providing a line rate correction current for the field deflection winding. The control circuit varies the modulation envelope of the field deflection current at a field rate in a generally sawtooth manner to provide north-south pincushion correction. When used in conjunction with raster scanning in a square-planar picture tube, the modulation envelope is nonlinearly waveshaped to take into account the aspherical nature of the picture tube faceplate.

Abstract: In a deflection circuit, a flyback transformer and a retrace resonant circuit that includes a deflection winding are mutually coupled by a relatively small capacitor during the retrace interval so as to reduce transient distortions that may be caused by a sudden high beam current change. East-west modulation is provided to the deflection circuit output stage via an impedance having a relatively large value at the retrace frequency. A resonant circuit that includes the deflection winding and the flyback transformer is tuned to the retrace frequency. Synchronization information of the current through the deflection winding may be derived from a winding of the flyback transformer.

Abstract: A linearity correction circuit for correcting asymmetrical linearity errors of the line deflection current includes a resonant capacitor coupled to a first inductor for forming a resonant circuit having a resonant frequency greater than or equal to the deflection retrace frequency. A controllable switch coupled to the resonant circuit and to the deflection trace capacitor becomes conductive at the beginning of retrace to generate an oscillatory current pulse in the resonant circuit that removes a predetermined amount of charge from the trace capacitor during retrace. A second, relatively large valued inductor is coupled to the line deflection winding and is responsive to the deflection retrace pulse voltage for supplying during the trace interval a linearity correction current to the trace capacitor via the resonant capacitor.

Abstract: A deflection circuit is coupled to a horizontal deflection winding for generating scanning current in the winding. A retrace pulse voltage is developed across the deflection winding during the retrace interval. A flyback transformer is coupled to the deflection circuit and has retraced pulse voltages developed across windings thereof. A source of supply energy is coupled to a first winding of the flyback transformer and a load circuit, such as a high power audio circuit, is coupled to a second winding of the transformer and draws load current therefrom. A switched mode power supply is coupled to the source of supply energy and to the flyback transformer for controlling the transfer of energy between the source and the load circuit. A compensation circuit responsive to the operation of the switched mode power supply produces variations in current in an inductance coupled to the flyback transformer. These variations are indicative of variations in load current drawn by the load circuit.

Abstract: A horizontal deflection circuit with raster distortion correction includes a horizontal deflection winding coupled to a first retrace capacitor and an input inductance such as the primary winding of a flyback transformer coupled to a second retrace capacitor. Horizontal switching elements are operated at a horizontal deflection rate for generating current in the inductance and a horizontal scanning current in the deflection winding. During retrace, the horizontal deflection winding and the first retrace capacitor form a first resonant circuit and the input inductance and the second retrace capacitor form a second resonant circuit. One of the switching elements decouples the resonant circuits from each other to minimize the interaction therebetween. A source of raster distortion correction current is coupled to the deflection winding to provide the required scanning current modulation.

Abstract: An energizing voltage is series coupled with a diode, an inductor, a flyback transformer primary winding and an input terminal of a deflection circuit. During trace, the diode is forward biased causing a voltage to be developed across and an input current to flow in the inductor. During retrace, opposite polarity retrace voltage commutates off the diode and decouples the input terminal from the energizing voltage at a varied instant within retrace, in accordance with the amplitude of the input current. The amplitude of the input current is related to the ultor load current. A voltage that is indicative of the input current is developed across a capacitor. A DC voltage between one plate of the capacitor and a reference conductor controls the deflection current in the deflection winding such that variations in the ultor voltage produce the same sense variations in the DC voltage that is supplied by the capacitor for maintaining a substantially constant raster width.

Abstract: An inside-outside pincushion correction circuit includes an arrangement of first and second branches that provide a pair of current paths to a deflection current that flows in a deflection winding. The first branch includes a modulation inductance and the second branch includes a modulation capacitance that is coupled across the modulation inductance by a switch at a controllable time during the retrace interval. The controllable time varies in a vertical rate parabolic manner to provide deflection current modulation to correct inside and outside pincushion distortions. Variation of the retrace interval associated with the modulation inductance are compensated by offsetting variations produced by the retrace capacitance.

Abstract: The faceplate of a square-planar picture tube is relatively flat, with a curvature along the major axis and lines parallel thereto that is generally greater near the left and right edges than in the center. An LC tuned circuit, coupled to the deflection winding, has a resonant period of oscillation approximately half that of the line trace interval. The tuned circuit introduces an oscillatory correction component into the trace current that provides additional S-shaping in that portion of the line scan intermediate the center and the left or right edge.

Abstract: A horizontal deflection circuit periodically applies a horizontal trace voltage to a horizontal deflection winding for generating horizontal scanning current therein. A modulator circuit is responsive to control signals for varying the horizontal trace voltage to develop concurrent variations in the amplitude of the horizontal scanning current. A side pincushion control signal is applied to the modulator circuit to vary the horizontal trace voltage at a vertical rate for developing variations in the amplitude of the horizontal scanning current that produce side pincushion correction. A horizontal size control signal is applied to the modulator circuit to vary the horizontal trace voltage for changing the picture size in the horizontal direction. A vertical deflection circuit generates in a vertical deflection winding a vertical scanning current having an amplitude that varies with variations in a vertical size control signal for changing the picture size in the vertical direction.

Abstract: A switched vertical deflection circuit derives vertical deflection current from horizontal deflection energy. A single switching element operates during both horizontal trace and retrace intervals. Conduction of the switching element is controlled by a vertical control circuit to provide the desired vertical deflection current. Feedback to the control circuit is referenced to ground potential to eliminate nonlinearity caused by voltage supply variations. The vertical circuit voltage supply is adapted to sink as well as supply current, thereby stabilizing the supply.

Abstract: A deflection generator of a television receiver includes a trace switch that during normal mode of operation is switched at a deflection rate to generate scanning current in a deflection winding. The deflection generator includes a retrace capacitance for forming a retrace resonant circuit with the deflection winding to produce a retrace pulse voltage. A load circuit is coupled to the deflection generator and is energized by the retrace pulse voltage during normal operation. A remote control circuit develops a remote ON-OFF command signal. A standby circuit is series coupled with the deflection generator and is responsive to a remote ON-OFF command signal for producing a substantially short circuited trace switch upon receipt of the OFF-state of the command signal. The retrace pulse voltage collapses and places the load circuit in a standby mode of operation.

Abstract: A linearity correction circuit for use with the horizontal deflection circuit of a television receiver comprises an inductor having two inductor portions. A capacitor, coupled to the S-shaping capacitor of the horizontal deflection circuit, is charged through one portion of the inductor during the horizontal trace interval, and discharged through another portion of the inductor during the horizontal retrace interval in order to provide linearity correction. The inductor may be tapped to allow charge/discharge current switching during the trace interval without introducing beam velocity modulation errors so that the linearity correction circuit may be efficiently combined with horizontal driver circuitry.

Abstract: The picture tube of a television receiver includes, inter alia, a plurality of electrodes to develop and accelerate an electron beam, and a phosphor screen on which the electron beam impinges. A deflection generator is coupled to a deflection winding for generating scanning current to produce a sweep of the electron beam across the phosphor screen. A remote control circuit develops an on/off command signal for switching the television receiver between normal run and standby modes of operation. A first switch is responsive to the command signal and disables normal generation of the scanning current upon the occurrence of the off-state of the command signal to inhibit normal sweep of the electron beam.

Abstract: A deflection generator of a television receiver is coupled to a deflection winding for generating scanning current during a deflection cycle. The generator includes a retrace capacitor coupled to the deflection winding for forming a retrace resonant circuit therewith to produce a retrace pulse voltage during a retrace interval of the deflection cycle. An inductor and another capacitor form a second resonant circuit that is coupled to the retrace resonant circuit. A switching arrangement is coupled to a source of energy and the second resonant circuit in a push-pull configuration. The switching arrangement is responsive to a deflection rate switching signal to store during trace a controllable amount of energy from the source in the second resonant circuit. This stored energy is then transferred to the retrace resonant circuit during the retrace interval to replenish losses sustained during the deflection cycle.

Abstract: A horizontal deflection nonlinearity correction circuit utilizes horizontal retrace pulse energy to provide nonlinearity correction of the horizontal deflection current. An inductor stores retrace pulse energy during the horizontal retrace interval and releases the energy during the horizontal trace interval. Nonlinearity correction is accomplished by appropriate charging and discharging of the horizontal deflection circuit S-shaping capacitor. The nonlinearity correction circuit may be combined with horizontal driver circuitry to provide economy of circuit components.

Abstract: A controllable switch operated at the horizontal deflection rate is coupled to a horizontal deflection winding to generate scanning current during a trace interval of a deflection cycle. A deflection retrace capacitor forms a retrace resonant circuit with the deflection winding during the retrace interval. A supply inductance such as a winding of a horizontal output transformer is coupled either conductively or magnetically to a source of supply energy. A second capacitor is coupled to the supply inductance and to the controllable switch and forms a second resonant circuit with the supply inductance within the retrace interval to generate a pulse voltage. The pulse voltage energizes a load circuit such as the ultor high voltage circuit.

Abstract: A synchronous switched vertical deflection circuit for use with a television receiver comprises first and second bidirectional switches coupled to conduct current in opposite directions. Horizontal rate energy is coupled into one end of the switches. Vertical deflection means are connected to the other end of the switches. Pulse-width modulated signals are applied to the control terminals of the switches to allow conduction of the horizontal rate energy in the vertical deflection means during selected portions of each vertical deflection interval.

Abstract: First and second resonant circuits store energy from a supply. First and second switches are respectively coupled to the first and second resonant circuits for generating resonant oscillations in the resonant circuits. A deflection circuit coupled to one of the resonant circuits has energy transferred to the deflection circuit during the resonant oscillations. A control circuit coupled to the switches varies the conduction angle overlap of the resonant oscillations in the resonant circuits for providing energy regulation.