Abstract: The invention concerns a scanning circuit, comprising a power supply providing a negative voltage on a first terminal (Tdown), an intermediate voltage on a second terminal (Gnd) and a positive voltage on a terminal of a switch (S), the other terminal of the switch being connected to a third terminal (Tup), a control circuit (6) supplied by connections to the second and third terminals, a differential amplifier receiving a positive and a negative input signal provided by the control circuit, a power amplifier controlled by the differential amplifier, both amplifiers being supplied by connections to the first and third terminals, a deflection coil (Ly) connected between the output of the power amplifier and the second terminal, biasing means setting, when the switch is open, the output of the differential amplifier so that the possible current paths through the power amplifier between the deflection coil and the first terminal are cut.

Abstract: It is capable of independently modulating the scanning velocities of multiple electron beams having a beam interval. Allowing a current to pass through the velocity modulation coils results in modulation of the scanning velocities of the multiple electron beams (19A, 19B) emitted from electron guns contained in a neck portion of a cathode ray tube to sharpen the outline of picture. The velocity modulation coils have a coil configuration including three upper coils (27A, 27B, and 27C) and lower three coils (28A, 28B, and 28C) for respectively generating asymmetrical quadri-pole magnetic fields. The magnetic fields independently generated by these two types of the velocity modulation coils allows the scanning velocities of the multiple electron beams (19A, 19B) to be almost independently modulated.

Abstract: A horizontal deflection circuit output stage includes a trace capacitor for developing a trace voltage. A retrace capacitance is coupled to a deflection winding to form a retrace resonant circuit with the deflection winding, during a retrace interval of a deflection cycle. A rectifier for rectifying a retrace pulse voltage developed in the retrace capacitance. A switching transistor is coupled to the inductance and to the trace capacitor for applying the rectified retrace pulse voltage to the inductance to generate a current in the inductance. The inductance current is coupled to the trace capacitor, during the trace interval, to provide for linearity correction. The rectifier is coupled to the switching transistor for producing a rectified control signal at a control terminal of the switching transistor to cause a change of state in the switching transistor, during the retrace interval.

Abstract: The present invention relates to a power-saving apparatus and method for computer peripheral devices.

Abstract: A horizontal deflection circuit comprising a centering circuit designed to change a direction of supplying a current to a deflection yoke, thereby to move a raster in a horizontal direction and, hence, adjust the position of the raster. The centering circuit comprises: a diode, of which cathode which is connected to the node of an S-shaped capacitor and the deflection yoke; a capacitor connected to the anode of the diode; a switching element connected in parallel to the diode; and a switching element control section for opening and closing the switching element, thereby to control a current to be supplied from the S-shaped capacitor to the capacitor and to control, ultimately, a current to be supplied to the deflection yoke. The raster position can be therefore continuously adjusted.

Abstract: A horizontal drive circuit for a video display device includes a switching device for switching according to a horizontal oscillation frequency generated by a horizontal oscillator and a surge protector, and a method therefor. A driving transformer has a primary winding connected to the switching means and a secondary winding. The secondary winding provides an amplified current according to the status of the switching device. A diode serves as the surge protection connected between the switching device and the primary winding of the driving transformer.

Abstract: A color cathode ray tube is disclosed in which a coating containing an aluminum phosphorus compound and fine particles of at least one of tungsten oxide and bismuth oxide and is formed on the surface of a shadow mask on the side of an electron gun.

Abstract: A circuit for driving a saw-tooth current in a coil includes a deflection circuit formed by the coil connected in parallel with a retrace capacitor and in series with a trace capacitor. The deflection circuit is connected in parallel with a first diode which conducts during the first half of the trace interval and in parallel with a second diode connected in series with a controllable switch which conducts during the second half of the trace interval. While the transistor is conductive, current flows through an inductor connected in series with it. The energy stored in this inductor is transferred at a subsequent stage partly to the deflection circuit and partly to a further capacitor. The further capacitor subsequently itself transfers the charge stored in it through a second inductor and a fourth diode to the deflection circuit so that at no time is energy dissipated in a load.

Abstract: A horizontal deflection output circuit free of a damper diode includes a horizontal output transistor, between collector and emitter of which a series circuit of a horizontal deflection coil and S-distortion compensation capacitor and a resonance capacitor are connected, and a pulsating switching signal is supplied between the base and emitter of the transistor through an inductive coupling so that the transistor is switched on and off by the pulsating switching signal. An excitation circuit of the horizontal output circuit comprises an excitation transformer having a secondary winding thereof connected to the base-emitter circuit of the output transistor and an excitation transistor connected to a primary winding of the excitation transformer.

Abstract: A circuit in a color television receiver for generating a correction current of field frequency for a quadripolar winding which is positioned on the core of the deflection coil. The circuit is in series with the deflection coil and constitutes a bridge circuit with diodes and resistors. A resistor is included in one diagonal branch and the winding in the other.

Abstract: A vertical sweep circuit includes a first transistor supplied with a sawtooth voltage. A voltage drop is developed across a resistor by a vertical sweep current for producing a first voltage across a first load. A second transistor is supplied with the first voltage for producing a second voltage across a second load, and a pair of push-pull connected transistors are supplied with the second voltage for producing the sweep current. An additional transistor of the same conductivity type as the second transistor is included in the circuit. Responsive to the first voltage, the additional transistor produces voltage pulses at a point of connection thereto of an additional load, which is greater than the second load to make the second and additional transistors operate as a linear amplifier transistor and a switching transistor, respectively. Vertical blanking pulses are produced from the voltage pulses.

Abstract: Circuit arrangement for combined line deflection and supply voltage stabilisation. The switched-mode transformer is connected via the secondary diode to a tapping on a winding coupled with the high-voltage winding. As a result, the maximum collector voltage is reduced and a greater range of supply voltage variations can be accommodated. All the windings may be wound on the same core.

Abstract: A class D amplifier, suitable for use as a vertical deflection amplifier in a television receiver, includes two transistors coupled to function in a push-pull manner. Two diodes are serially coupled with each other in parallel with the output transistors and are poled to conduct forward current in a direction opposite to the forward current of the two transistors. A junction of the two transistors is coupled to a junction of the two diodes and forms an output terminal to which a deflection winding is coupled. A series of pulses at a first frequency, such as the horizontal deflection frequency or a multiple thereof, are pulse width modulated in accordance with the amplitude of a sawtooth waveform at a second frequency, such as the vertical deflection frequency, in a pulse width modulation stage and are coupled to the input terminals of the two transistors. The two transistors are alternately enabled for conduction by the pulse width modulated signals.