Abstract: A heat generating portion of a heater which is incorporated in an indirectly heated cathode structure of an electron gun for a cathode ray tube is formed by joining a first winding portion and a second winding portion which differ in the number of coil winding layers and by twisting and winding a joined body in a double helical structure. The present invention allows a cathode temperature to have a high temperature and hence, it is possible to enhance the electron irradiation characteristics even when a degree of in-tube vacuum is lowered.

Abstract: Provided are an image correcting method and device capable of reducing power consumption necessary for correcting an image for a long-time use and a cathode ray tube display unit. A microcomputer 2 calculates a value of a correction current in such a manner that the correction current is more decreased monotonously as a time passes after a cathode ray tube is turned on. Drivers 3 to 7 and 22 generate and output the correction current according to the value of the correction current calculated by the microcomputer 2. A correcting device C is provided in the cathode ray tube and serves to correct an image displayed on the cathode ray tube on receipt of the correction currents from the drivers 3 to 7 and 22.

Abstract: One embodiment of the present invention includes a temperature sensor with current mode output utilized within a cathode ray tube (CRT)-based display system for providing thermal protection to a CRT driver. Specifically, the current mode output temperature sensor of the present embodiment is implemented with the CRT driver of the CRT display system. Furthermore, the temperature sensor has a current sink output that is connected to an Automatic Brightness Limiter (ABL) circuit of the CRT display. The current sink of the temperature sensor operates in a manner similar to an “OR gate” with the CRT anode current. As such, when the CRT driver temperature rises above a threshold temperature, the current mode output temperature sensor sinks a current and activates the ABL circuit. As a result, the video amplitude of the CRT driver is reduced and its temperature is stabilized.

Abstract: A device for correcting a landing position of an electron beam in a color cathode ray tube has a funnel temperature sensor, an ambient temperature sensor, a landing correction coil disposed on or around a corner of the outer surface of the color cathode ray tube, and a processor and controller for calculating a first temperature difference between the temperature of the funnel and the ambient temperature and a second temperature difference between a predetermined design temperature and the ambient temperature, and calculating a current value for the landing correction coil according to the first and second temperature differences to supply a current of the obtained current value to the landing correction coil.

Abstract: In a television receiver, a higher beam current is enabled and a brighter image is provided, without adversely effecting the life of the cathode ray tube or endangering the high-tension transformer. The high-tension transformer includes a temperature sensor which acts with a control circuit for reducing the beam current when the temperature of the transformer rises above a specific temperature.

Abstract: A difference is calculated between convergence data in accordance with a temperature detected from the deflecting coil of a cathode ray tube and optimum convergence data. The convergence of the cathode ray tube is then corrected in accordance with the calculated difference.

Abstract: A cathode ray tube (CRT) display arrangement including protection means for protecting the screen of the CRT (1) against excessive heating, by the electron beam, e.g. due to failure of the beam deflection drive circuits (5), the protection means comprising an electronic storage means (27 to 41) having storage locations in which are stored values indicative of the temperature at different locations on the CRT screen, and means (7) for controlling the electron beam current in dependence on the contents of the storage means.

Abstract: A scanning CRT display system is disclosed in which transitions of a horizontal sync signal are directly utilized to provide control signals for driving a FET (field effect transistor) power drive device which controls horizontal deflection yoke current. Protection circuitry is provided such that the FET power drive device is turned off if excessive FET through current is sensed, and protection circuitry also prevents turning on the FET drive device if an excessively high flyback voltage is present at the drain terminal of the FET device. Linearization of the horizontal deflection yoke current is provided by effectively sensing the temperature variable on resistance of the FET output drive device and providing a compensation control signal in accordance therewith, wherein this compensation control signal controls the magnetization provided by a control winding on a saturable magnetic core on which a linearity compensation coil is also wound.

Abstract: A temperature compensated G2 grid drive circuit for use with a video display having a high voltage section supplying a high voltage signal to a cathode, filament and G2 grid of a CRT, wherein the high voltage section has a negative temperature coefficient, includes an input terminal for receiving the high voltage signal and a temperature compensating circuit coupled between the input terminal and the G2 grid of the CRT. The temperature compensating circuit is characterized as having a slightly positive temperature coefficient for maintaining the brightness of the video display substantially constant by driving the G2 grid for compensating for variations with temperature in the high voltage signal supplied to the cathode, filament and G2 grid.

Abstract: A horizontal deflection circuit for a CRT display includes a horizontal output transistor having an emitter-base junction presenting a resistance which varies as a function of temperature, a transformer having a 5 to 1 turns ratio coupling the emitter-base junction to a horizontal driver transistor which is driven by a horizontal oscillator transistor. A synchronizing signal controls initiation of the horizontal oscillator transistor. A feedback resistor is connected in the transformer primary circuit and supplies signal to a peak detector which develops a DC potential for varying the delay of the synchronizing signal to compensate for temperature change in the emitter-base junction which would otherwise horizontally displace the display on the CRT screen.

Abstract: A transformerless switching circuit is described for rapidly turning a horizontal output transistor off and on in response to horizontal rate input pulses. The switching circuit includes a first transistor which is rendered alternately conductive and non-conductive by the input pulses, a second transistor which supplies base drive to the horizontal output transistor in response to the first transistor being conductive, and a third transistor which turns off the horizontal output transistor rapidly in response to the first transistor being non-conductive. The conduction level of the second transistor is controlled by temperature compensating means such that base drive to the horizontal output transistor is varied to compensate for temperature induced current gain changes in the output transistor, thereby holding the latter transistor to a substantially constant saturation current.

Abstract: In a transistor firing circuit including a transistor, a firing coil having a primary winding across which a flyback voltage appears, and a Zener diode connected at the input side of the transistor for limiting the amplitude of the flyback voltage, there is further provided a resistive voltage divider connected to the transistor and the diode and composed of at least one resistor having a temperature coefficient selected for at least partly compensating for the temperature coefficient of the Zener diode in a manner to maintain the flyback voltage amplitude within narrow, defined limits over the operating temperature range of the circuit.

Abstract: A voltage buffering coupling circuit for coupling a ground-referenced control signal to a high voltage biased CRT includes all solid state elements, thereby avoiding the tendency of the arc breakdown characteristic of gaseous voltage regulator tubes. The circuits include temperature compensating elements of opposite thermal coefficient characteristics.

Abstract: A horizontal deflection circuit in a television device comprises a circuit for generating a saw-tooth waveform current for horizontal deflection, a horizontal coil supplied with the saw-tooth waveform current thus generated, a saturable reactor type linearity coil having a winding connected in series with the horizontal deflection coil, and a circuit for substantially supplying a correction current to the winding of the linearity coil. The correction current thus supplied varies in response to a temperature variation so that the inductance value of the linearity coil will become constant irrespective of the temperature variation.

Abstract: In a vertical deflection circuit, a deflection winding is coupled to an output terminal of a deflection amplifier. The amplifier generates a trace current in the winding in response to drive signals coupled to an input terminal of the amplifier. A first voltage source provides an operating voltage for the amplifier. A bidirectional retrace switch couples the output terminal to a second voltage source for providing a greater magnitude voltage for generating a retrace current in the winding. The bidirectional switch has a controlled semiconductor which is responsive to the drive signals for controlling a main conductive path of the switch during a portion of the retrace interval.

Abstract: A vertical deflection circuit having a vertical amplifier stage bias voltage stabilizing circuit including a differential amplifier circuit which operates only during the retrace period. One input of the differential amplifier circuit receives a D.C. bias voltage and the other input receives the mean voltage of an output signal. The output of the differential amplifier circuit is fed back to a drive stage to stabilize the bias voltage.

Abstract: A system for compensating for mislanding of electron beams on the screen of a color cathode ray tube resulting from thermal expansion of a beam selecting structure in the tube which comprises electromagnetic devices provided on the tube for producing respective magnetic fields by means of a current supplied thereto so as to change the paths of the electron beams passing through the beam selecting structure, and a circuit for supplying to the electro-magnetic devices a first correcting current varying substantially in response to changes in the temperature of the beam selecting structure and a second correcting current varying in accordance with a predetermined change in value during the initial period of the operating condition of the tube.

Abstract: A system for compensating for mislanding of electron beams on the screen of a color cathode ray tube as a result of thermal expansion of a beam selecting structure in the tube comprises electromagnetic devices provided on the tube for producing respective magnetic fields by means of a current supplied thereto so as to change the paths of the electron beams passing through the beam selecting structure, and a circuit for supplying to the electromagnetic devices a current varying in response to a difference between the temperature of the beam selecting structure and the ambient temperature about the tube.