Abstract: A method for a computer system includes opening a model of an object, wherein the model comprises a plurality of geometric elements, determining a subset of geometric elements from the plurality of geometric elements of the model, modifying properties of one or more of the geometric elements in the subset of geometric elements to form a modified subset of geometric elements, and using the modified subset of geometric elements to represent the model of the object in the computer system.

Abstract: A deflection device for a projection tube includes a main deflection device for generating a raster and an auxiliary deflection device for correcting a convergence. The auxiliary deflection device includes a toroidal auxiliary horizontal coil, a saddle-type auxiliary vertical coil, and a ferrite core. According to this configuration, the deflection efficiency is enhanced, and pincushion distortion in upper and lower portions can be corrected efficiently while a change in the shape of a beam spot is reduced.

Abstract: Device for correcting the line and/or frame fields of a deflector for cathode ray tube comprising: a current sensor for evaluating the value of a line current Il a series of comparators intended to compare the value of the line current Il with reference values a current sensor for evaluating the value of the frame current It an analogue/digital converter for converting the analogue value of the frame current a programmed correction memory which is addressed by the output signals from the comparators and from the analogue/digital converter so as to deliver to at least one digital/analogue converter, data which are dependent on the addressing signals a low-pass filter for filtering the output of the digital/analogue converter at least one correction coil for correcting the deflection fields of the deflector, and generating a correction field as a function of the output value from the low-pass filter.

Abstract: Apparatus and method are provided for using a multi-element field emission cathode in a color cathode ray tube. The field emission cathode may have from four to ten field emission arrays linearly arranged. The arrays are preferably formed from carbon-based material. An electron gun assembly focuses electron beams from each array on to a phosphor stripe or dot on the screen of the cathode ray tube. Deflection apparatus moves the beam from each field emission array according to clock signals. Clock signals also turn on or turn off voltage to contacts controlling electron current from the array. Values of voltage applied, determined by a video signal, determine the intensity of electron current from each array, which controls the intensity of the light emitted by each color stripe or dot of phosphor on the phosphor screen.

Abstract: Apparatus and method are provided for using a multi-element field emission cathode in a color cathode ray tube. The field emission cathode may have from four to ten field emission arrays linearly arranged. The arrays are preferably formed from carbon-based material. An electron gun assembly focuses electron beams from each array on to a phosphor stripe or dot on the screen of the cathode ray tube. Deflection apparatus moves the beam from each field emission array according to clock signals. Clock signals also turn on or turn off voltage to contacts controlling electron current from the array. Values of voltage applied, determined by a video signal, determine the intensity of electron current from each array, which controls the intensity of the light emitted by each color stripe or dot of phosphor on the phosphor screen.

Abstract: Disclosed is a method for correcting inner pin distortion generated in the CRT product and deflection yoke thereof. According to the disclosed method and deflection yoke thereof, the additional circuit for suppressing inner pin distortion phenomenon on the screen is not required as the related art, reduction in manufacturing costs is possibly achieved. Also, as the circuit for suppressing pincushion is not used, power dissipation could be reduced, and instability in dispersion and characteristics of a pin in the middle portion due to increase of dispersion generation by a wiring of a coil could be resolved.

Abstract: An electron gun for a color CRT includes a triode including cathodes for emitting electron beams, a control electrode, and a screen electrode, at least two focusing electrodes on the same axis of the triode portion for forming a quadrupole lens, and a final focusing electrode forming a large diameter lens with the focusing electrodes and through which three electron beams commonly pass. The electron gun includes a correction unit producing a correction force acting on the three electron beams and that is larger for two side electron beams than for a central electron beam of the three electron beams when a dynamic voltage, synchronized with a deflection signal, is applied to at least one of the focusing electrodes for forming the quadrupole lens.

Abstract: An electron gun for a cathode ray tube has a cathode structure, a control electrode, a screen electrode, focusing electrodes, and a final accelerating electrode. R, G, and B electron apertures of one pair of the focusing electrodes face each other to form a quadrupole lens unit, to which an AC voltage having a relatively low peak or a static voltage is applied to converge R, G, and B electron beams into one point, even when the electron beams deviate to the corner of a screen. Asymmetrical enlargement portions are included in the rims of each of the R and B electron beam apertures.

Abstract: A color cathode ray tube has quadrupole elements which increase and decrease the distance between the electron beams as a function of the deflection. Two co-operating elements have their windings connected in series with each other to minimize dissipation in the driving circuits. One driving circuit provides a common current which flows through both quadrupole elements, while another driving circuit provides a difference current to a node between the quadrupole elements.

Abstract: A secondary winding of a horizontal flyback transformer of a horizontal deflection circuit develops a horizontal retrace pulse voltage. A secondary winding of a second transformer is coupled in series with a vertical deflection coil of a vertical deflection circuit. An R-C filter is coupled between the secondary winding of the flyback transformer and a primary winding of the second transformer. Horizontal parallelogram errors are corrected by a horizontal rate current injected in a current path of the vertical deflection coils. The R-C filter prevents the vertical deflection current from being parasiticaly coupled to the horizontal deflection circuit.

Abstract: A dual-gun, single neck CRT focuses two beams, with significantly differing energies, onto a secondary emission target while maintaining compatibility with a standard fourteen-rotation stem and achieving FTU in excess of 95%. A pair of Einzel guns (write and erase) are mounted in parallel and aligned in the vertical direction rather than the horizontal inside the CRT. The write and erase guns are configured to share a common second accelerator electrode, a common final accelerator electrode, mounting beads and a magnetic deflection yoke. The guns' focus voltages are independently adjusted so that both the write and erase beams have the same focal length.

Abstract: Methods and apparatus are provided for equally aging a cathode ray tube (CRT). A video input terminal is coupled to the CRT and receives an external video signal. Control circuitry is provided, which detects the aspect ratio of the signal and determines whether there is a mismatch between the signal aspect ratio and an aspect ratio of a display screen in association with the CRT. If a mismatch between the signal aspect ratio and the screen aspect ratio exists, an equalization video signal is derived from the external video signal. A primary region of the CRT is illuminated in response to the external video signal, and a secondary region of the CRT, which would otherwise be unilluminated in response to the external video signal due to the mismatch between the signal aspect ratio and the screen aspect ratio, is illuminated in response to the equalization video signal. In this manner, the CRT is uniformly aged.

Abstract: As described above, according to the present invention, there is provided a color CRT display having a one-beam electron gun for reproducing colors by sequentially switching respective chrominance signals, R, G, and B, supplied to the one-beam electron gun. The color CRT display is characterized in that a color image displayed on a CRT screen is picked up by a CCD image pickup device and the image pickup signal is stored in an image pickup signal memory, the image pickup signal is compared with an original video signal stored in a video signal memory in terms of components of chromaticity using an arithmetic operator, and the frequency and phase of the image pickup signal of a VCO, which are required for determining the switching timing of chrominance signals in a multiplexer, are adjusted so that the difference between the image pickup signal and the original video signal in terms of components of chromaticity is minimized.

Abstract: A monitor deflection circuit includes a bipolar power transistor for applying power from a high voltage supply to a horizontal deflection coil. The monitor deflection circuit further includes a base drive circuit for selectively turning the bipolar power transistor on and off. The base drive circuit includes a flyback transformer having a primary winding and a secondary winding coupled to the base of the bipolar power transistor, a voltage source coupled to one end of the primary winding, and a drive switch coupling the other end of the primary winding to ground. The base driver circuit further includes a constant current circuit coupled between the voltage source and the primary winding of the flyback transformer for controlling a base current of the bipolar power transistor before the bipolar power transistor conducts.

Abstract: A horizontal position adjusting circuit for a raster includes a reference voltage outputting unit for outputting a reference voltage to enable a raster to be centered on a fluorescent screen; a reference voltage adjusting unit for varying an output voltage of the reference voltage outputting unit in accordance with an operating mode for displaying an image signal; and a deflection voltage outputting unit for generating a deflection voltage in accordance with the output signal of the reference voltage outputting unit, and for applying it to a horizontal deflection coil. In accordance with the present invention, the position of the raster formed on the fluorescent screen of the cathode-ray tube is automatically adjusted according to the operating mode so that positioning of the image screen on the fluorescent screen is simply adjusted to be at the center of the fluorescent screen, resulting in improved reliability of the display device.

Abstract: A resistor-capacitor-diode clamp is coupled to an S-capacitance of a horizontal deflection circuit output stage for reducing ringing by causing critical damping. The supply voltage of the output stage varies at a vertical rate parabolic manner for modulating the horizontal deflection current to provide East-West correction. A clamp capacitor of the clamp has a terminal that is direct current coupled to the supply voltage. Therefore, each terminal of the clamp capacitor has the same vertical rate parabola component. Consequently, the DC voltage difference developed between the terminals of the clamp capacitor does not include any vertical rate parabola component, the result is that the sensitivity of the damping to the supply voltage vertical rate variations is, advantageously, eliminated or reduced.

Abstract: In a fluorescent display device having control electrodes and anodes, each anode having an anode electrode and a fluorescent layer formed thereon, a filament is installed between the control electrodes and the anode electrodes. When an anode is selected to be turned on to emit light, a first voltage (V1) is applied to the filament, a second voltage (V2) is applied to the selected anode and a third voltage (V3) is applied to a control electrode facing the selected anode, wherein V2 is greater than V1 and V3 is equal to or greater than V1. When a voltage applied to a target control electrode is lower than a voltage applied to the filament by more than a predetermined voltage difference, an anode facing the target control electrode is not turned on to emit light even when V2 is applied thereto.

Abstract: A system and method for controlling an electron beam in accordance with the present invention includes an electron gun, a cathode ray tube with a faceplate, a deflection drive, a pair of positioning electrodes, an electron beam controller, and a pair of capacitors. The electron gun generates an electron beam in the cathode ray tube which is deflected in a desired direction towards and between at least one pair of positioning electrodes formed on the inner surface of the faceplate. Each of the positioning electrodes generates a position signal which is capacitively coupled by the capacitors to the electron beam controller. The electron beam controller adjusts the deflection of the electron beam in response to the position signals. The capacitors comprise a pair of first and second capacitor plates which are separated by the cathode ray tube. The first capacitor plates are disposed on opposing sides of an inner surface of the cathode ray tube adjacent to the faceplate.

Abstract: A horizontal deflection circuit is provided in which a large retrace pulse voltage applied to a horizontal deflection yoke can be taken to reduce the deflection current and which is capable of easily performing horizontal image size adjustment and distortion adjustment. A parallel connection of a switching element, a damper diode, and a resonance capacitor is connected in series to a parallel connection of another switching element, another damper diode, and another resonance capacitor, and power is supplied from the connection point via a fly-back transformer. The comparison value of the retrace pulse voltages applied across both ends of the switching elements is fed back through a switching element control circuit to the switching element so that the deflection current of the horizontal deflection yoke is controlled.

Abstract: A method for correcting distortion of an image displayed on a screen of a display device. The method includes steps of taking a picture of a test pattern displayed on the screen of the display device in an adjusting state, extracting distortion information representing distortion of the test pattern from an image obtained from a result of the above step, extracting additional information as a distortion characteristic, the distortion information being approximately represented by a plurality of basic information items which are known and the additional information coupled to the basic information items, storing the additional information in a storage unit, reproducing the distortion information using the additional information stored in the storage unit and the plurality of basic information items when an image is displayed on the screen of the display device, and controlling the display device based on the reproduced distortion information so that the distortion is canceled.

Abstract: A compensating circuit is for compensating distortion of a picture which is displayed on a display unit having a yoke. The compensating circuit controls a yoke current to compensate a picture distortion. The compensating circuit comprises a first generating section for generating a digital deflecting compensation signal in accordance with deflecting compensation data representative of compensation value of the picture. A second generating section generating a variable voltage (+B voltage) in accordance with a PWM pulse signal to control the yoke current on the basis of the variable voltage. A peak holding circuit holds a peak voltage of a flyback pulse based on the variable voltage to produce a peak voltage signal representative of the peak voltage. An A/D converter circuit converts the peak voltage signal into a digital peak signal. A PWM section produces the above-mentioned PWN pulse signal in accordance with the digital deflecting compensation signal and the digital peak signal.

Abstract: A horizontal deflection drive circuit using a plurality of FETs is provided, which includes a base drive current supply for receiving an oscillation pulse in a low level generated by an oscillation element, to perform switching operation, a P-channel FET for receiving the oscillation pulse in a low level generated by the oscillation element, and receiving current from the base drive current supply, to perform switching operation, an N-channel FET for receiving an oscillation pulse in a high level generated by the oscillation element, to perform switching operation, and a drive transformer for inducing current supplied from a deflection current supply according to the switching operations of the P-channel FET and N-channel FET, the P-channel FET being switched by the current supplied from the base drive current supply.

Abstract: A method and projection television system for projecting images having a plurality of color components, includes a device for filtering a first color component signal from a composite signal to provide a filtered first color component signal. A defocusing mechanism defocuses the first color component signal based on the filtered first color component signal. A gain adjustment device adjusts a gain of at least one other of a plurality of color component signals of the composite signal. An amount of defocusing performed by the defocusing mechanism and a gain adjustment by the gain adjustment device are dependent on a content of the composite signal. In another aspect of the invention, a spot wobble scheme may be employed alone in a static defocussing system, without dependence upon the video signal content.

Abstract: A time-varying control signal is developed by a current sensor connecting the imaging screen and a closely proximate screen grid of a cathode ray tube as an imaging electron beam is operatively swept across the screen to produce images thereon. The control signal is processed and then applied to at least one of the tube operating elements--such as the horizontal and vertical deflection coils, the focusing lens, the electron beam generator and, in a plural beam tube, the convergence assembly--which controls a characteristic affecting the quality of an image. Specific arrangements for using the time-varying control signal to compensate for geometric image distortions affecting horizontal linearity and to increase the imaging resolution of the tube are disclosed.

Abstract: A time-varying control signal is developed by a current sensor connecting the imaging screen and a closely proximate screen grid of a cathode ray tube as an imaging electron beam is operatively swept across the screen to produce images thereon. The control signal is processed and then applied to at least one of the tube operating elements--such as the horizontal and vertical deflection coils, the focusing lens, the electron beam generator and, in a plural beam tube, the convergence assembly--which controls a characteristic affecting the quality of an image. Specific arrangements for using the time-varying control signal to compensate for geometric image distortions affecting horizontal linearity and to increase the imaging resolution of the tube are disclosed.

Abstract: An improved system for continuously detecting and correcting the display in a cathode ray tube for errors in size and linearity. The system employs a crystal oscillator as a reference frequency to determine absolute error which is represented as "size" on the display screen, and relative error which is represented as linearity. The error is determined from the index pulse feedback, which is an output of a phase lock loop voltage controlled oscillator which is compared to the reference frequency to provide an error voltage level. This output level is then digitized and processed in terms of general control, interpolation, extrapolation, filtering, etc., testing, and stored in digital memory. The digital error data is converted back to analog levels for insertion into a horizontal auxiliary amplifier circuit for linearity correction. A main horizontal amplifier circuit receives size correction.

Abstract: An image display apparatus which controls electron beams emitted from an electron source by electrodes having an arrangement of electron beam passage apertures and displays an image by irradiating the electron beams onto phosphors on a screen. The image display apparatus includes a means which changes at least a position of the electron beam passage aperture of a second electrode of the electrodes corresponding to the electron beam passage aperture of a first electrode of the electrodes in accordance with the position on the screen and controls the potential difference between the two electrodes, thereby making it possible to control the landing position of the electron beams on the screen.

Abstract: A flat type cathode ray tube. Electrode beams are vertically emitted from electron beam emitting sources along vertical scanning electrodes which have a strip-shaped configuration in horizontal direction and are insulated from each other and lined up in the vertical direction. The beams turn at a predetermined position toward a phosphor screen for vertically scanning and are horizontally focussed and deflected onto the phosphor screen by horizontal focussing and deflection electrodes.

Abstract: Deflection control apparatus for a beam index color television receiver includes a phase-locked loop for synchronizing an oscillating signal with an index signal generated by an electron beam scanning index stripes on the screen of the cathode ray tube of the receiver. The oscillating signal is supplied to a color switcher so that the scanning electron beam is modulated with color information corresponding to the respective color phosphor stripe being scanned. An error signal representative of the horizontal scanning speed of the beam is supplied to a deflection device to cause the generation of a compensating magnetic field to correct for non-linearities in the scanning speed. A compensation circuit delays the error signal so that the elapsed time from the detection of the scanning of one of the index stripes to the time of generation of the compensating magnetic field in accordance therewith equals one horizontal line period.

Abstract: A television receiver in which a plurality of picture-displaying fluorescent lines (3), which are disposed on a screen (2) as the display surface of a cathode ray-tube so as to extend in the horizontal direction (in the direction of the arrow X) as the beam main-scanning direction, and in the vertical direction (in the direction of the arrow Y) as the beam sub-scanning direction, and a single electron beam is arranged to scan across the screen (2) to display a picture. The television receiver has two kinds of beam detection stripes (5A), (5B) disposed in each respective guard band portion between adjacent fluorescent lines (3) so as to be parallel to the fluorescent lines (3). On the basis of beam detection signals independently taken from the beam detection stripes (5A), (5B) in correspondence to beam spots (S) of the electron beam on the screen (2), the vertical positions (in the direction of the arrow Y) of the electron beam spots (S) with respect to the fluorescent lines (3) are controlled.

Abstract: In shadow mask color cathode-ray tube apparatus, the shadow mask is provided with slits or rows of slots extending from side to side of the mask and a line raster is constrained so that the lines of the raster are colinear with the slits, there being just one slit to each line of the raster. Open loop control may be used to achieve colinearity, but closed loop control is preferred. Beam position signals may be drived from the shadow mask by sensing secondary emission from different phosphors on the gun side of the mask or be sensing currents generated in the mask. In the preferred embodiment, the beams are dithered as they traverse the raster and the difference in the currents generated by a beam at the mask and at the conductive layer at the tube screen is detected. The first fundamental of the difference current indicates by its amplitude and phase the amount and direction of the misregistration of a beam and a slit. Different beams are distinguished by frequency multiplexing.

Abstract: An coherent light optical system is described wherein a high frequency electrical signal modulates an optical signal. An electronic lens, whose optical properties may be easily controlled, results from control of the modulating signal. The principles of feedback are utilized for optical aberration detection and correction of the lens.

Abstract: An electron source section including a first detecting sub-section and a first control sub-section and an image formation section including a second detecting sub-section and a second control sub-section are arranged in series. The first detecting sub-section detects at least one of the shape, diameter, brightness and spatial position of a crossover image formed by the electron source section to become an electron source of the image formation section and the direction of emission of the electron beam emitted from such crossover image, thereby to control the first control sub-section. The second detecting sub-section detects at least one of the shape and size of an electron beam image formed on a subject to be irradiated by the beam, and the current of the electron beam forming the electron beam image, thereby to control the second control sub-section.

Abstract: Programmable power supplies are made responsive to beam-index and timing signals in order to automatically control the size and position of the display on a cathode ray tube. The high voltage power supply is also made programmable, responsive to video signal content, to reduce the energy stored in the high voltage circuits. Savings in energy consumption are also obtained by efficiently modulating the target screen of a beam-index type color cathode ray tube. Energy lost at the target screen is less than 10% compared to approximately 70% for a conventional color tube, an improvement factor of 7:1 or more.

Abstract: In the course of each horizontal blanking interval, the spot of the flying spot tube is deflected in the vertical direction causing an image of the spot to meet a perforation of the film in fixed space relationship with the film frame being scanned. A pulse signal, generated when the image of the spot reaches the concerned perforation, is used as an input signal for the circuit delivering an error signal for controlling the vertical deflection of the tube.