Abstract: An electromagnetic induction device comprises a closed magnetic circuit, without air gap, of which at least one first part is substantially rectilinear and surrounded by a sleeve, the sleeve being surrounded by an electrical conductor which comprises at least one metal sheet electrically insulated on at least one of its faces, wherein at least the first part of the magnetic circuit has a section of circular form.

Abstract: An electron gun used in a particle beam device, for example in an electron microscope, has a relatively good brightness and may be operated under vacuum conditions which can be easily achieved (i.e., for example, at a residual pressure of about 10?6 or 10?7 mbar). The electron gun comprises an electron source having an electron emission surface. Furthermore, the electron gun comprises a first electrode configured to control a path of electrons emitted from the electron emission surface, a second electrode which is configured to suppress emissions of electrons from a side surface of the electron source and a third electrode configured to accelerate electrons emitted from the electron source to a final energy. A first voltage, a second voltage and a third voltage are adjusted to avoid any crossover of electrons emitted from the electron emission surface.

Abstract: A system and method for controlling the temperature of both an electron emitter and a filament to their lowest possible operating temperature is disclosed. The apparatus includes a filament, an electron emitter heated by the filament to generate an electron beam, and a power supply configured to supply power to each of the filament and the electron emitter. The apparatus also includes a control system to control a supply of power to each of the filament and the electron emitter, with the control system being configured to receive an input indicative of a desired electron emitter operating temperature, cause a desired voltage to be applied between the electron emitter and the filament, and cause a desired voltage to be applied to the filament based on the desired emitter element operating temperature, so as to minimize an operating temperature of the electron emitter and the filament.

Abstract: An electron gun used in a particle beam device, for example in an electron microscope, has a relatively good brightness and may be operated under vacuum conditions which can be easily achieved (i.e., for example, at a residual pressure of about 10?6 or 10?7 mbar). The electron gun comprises an electron source having an electron emission surface. Furthermore, the electron gun comprises a first electrode configured to control a path of electrons emitted from the electron emission surface, a second electrode which is configured to suppress emissions of electrons from a side surface of the electron source and a third electrode configured to accelerate electrons emitted from the electron source to a final energy. A first voltage, a second voltage and a third voltage are adjusted to avoid any crossover of electrons emitted from the electron emission surface.

Abstract: A power supply for supplying an electric power to an electron gun, which is used in an electron microscope, and an electron microscope having the same are disclosed. The power supply includes a base board, and at least one sub-board vertically mounted on the base board to supply an electric power to an anode electrode, a filament for emitting electrons, and a grid. The at least one sub-board can include a first sub-board to supply an accelerating voltage to the anode electrode, a second sub-board to supply a heating current to the filament, and a third sub-board to supply a grid voltage to the grid.

Abstract: A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.

Abstract: A level-shifting inverting circuit provides a blanking signal to Grid 1 of a CRT. The circuit provides the blanking signal from a blanking logic signal according to a voltage transfer characteristic that is substantially similar to the voltage transfer characteristic of a standard CMOS inverter. Also, the level-shifting inverting circuit includes a switch circuit that includes a differential pair. The differential pair has the blanking logic signal at one input, and a bias signal at the other input. The switch circuit is coupled to a voltage divider that provides an output voltage that is pre-determined by a resistor ratio when the switch circuit is open. If the blanking logic signal is low, the switch circuit is open. Conversely, if the blanking logic signal is high, the switch circuit is closed, and sinks current from the voltage divider, causing the output voltage to correspond to a second pre-determined voltage level.

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: A main lens is composed of a dynamic focus electrode, a first auxiliary electrode, a second auxiliary electrode and an anode, which are successively arranged in a direction of travel of electron beams. A sub-lens provided on a cathode side of the main lens is composed of a third grid, a fourth grid and a fifth grid. The first auxiliary electrode is connected to the fourth grid, and both are connected to a voltage supply terminal on a resistor near the fourth grid. A fixed focus voltage is applied to the third grid and fifth grid sandwiching the fourth grid.

Abstract: A method for operating a cathode-ray tube electron gun, suitable for multimode operation, for example, in order to display television images and multimedia images of the SVGA, XGA type, in which the zone for forming the electron beam generated by the cathode has at least two control electrodes. The two control electrodes are connected to voltage sources in such a way that the potential difference between the two control electrodes increases when the beam current decreases.

Abstract: There is proposed laser cathode-ray tube for simplification of its electrical circuit and lower manufacturing cost of its apparatuses, provided with an electron gun having a cathode for generating an electron beam; a laser screen having a laser target, of semiconductor plate, a focusing system for focusing the electron beam on the laser target, a deflection system for deflecting the beam and a cooling system for cooling the laser target, characterized in that the cathode is connected substantially to ground potential and the laser target is connected to high positive potential.

Abstract: A cathode ray tube is described having at least one electron gun including a cathode, a control grid, and a focusing unit, and a strip made of electrically conductive material applied to the cathode ray tube in parallel to the outer coating of the tube and connected to ground potential. Means and measures are provided to eliminate harmful effects of high-voltage sparkovers. The cathode ray tube may be is used, for example, in monitors.

Abstract: An electron gun assembly which integrates electronics required to power the electron gun and the electron gun itself in one module in a high voltage operating environment. The assembly has four major sections: interface cables; electronic circuits (active and high voltage); the electron emitter; and a mechanical enclosure for the assembly. The electronics portion of the assembly has two distinct sections: an active electronics section (which contains digital to analog converters, interface to a control computer, and analog outputs terminals to control the high voltage electronics) and a high voltage electronics section (which contains high-voltage multiplying circuits and feedback and filtering elements). These two sections are electrically connected and are present within an internal box at one end of the assembly, or alternately, the high voltage electronics section is disposed below the active electronics section and outside the internal box.

Abstract: A multiplexed video amplifier circuit includes a video preamplifier and a bias/brightness circuit the output of both being coupled to a switch. The video preamplifier provides a video signal, the bias/brightness circuit provides a DC bias signal, and the switch selectively couples to the output of either the video preamplifier or the bias/brightness circuit. In this way, the switch alternately receives the video signal and the DC bias signal and combines them to provide a single multiplexed video signal with both video and DC bias signal data. This multiplexed video signal is sent to a clamp amplifier and a video amplifier, both of which compare the magnitude of the multiplexed video signal with a reference signal. When the magnitude of the multiplexed video signal transcends the reference signal in a first direction, for example is lower than the reference signal, the clamp amplifier provides the DC bias signal to an external circuit.

Abstract: An electron gun is provided, in which a capacitance between a cathode and other electrodes, especially a control electrode is reduced largely without substantially changing a structure for supporting the cathode with an insulator. The cathode of this electron gun is disposed inside of the cylindrical metal shell. The cathode and the cylindrical metal shell are connected by three metal tabs. The cylindrical metal shell fits into a hole formed in the center portion of the insulator, and a metal outer frame is attached to the periphery of the insulator. The metal outer frame is welded to the inner surface of a cathode metal support. There is a control electrode facing the electron emitting surface of the cathode at a predetermined distance. Plural electrodes including an accelerating electrode are disposed in turn beyond the control electrode.

Abstract: A color cathode ray tube (CRT) includes a multi-beam electron gun capable of operating in two or more modes for use as either a television receiver display or as a high resolution video monitor. The electron gun directs a plurality of electron beams onto the CRT's display screen, with the electron beams arranged in two or more groups. In one group of electron beams, the beam forming portion of the electron gun provides small diameter electron beams having reduced spot size on the CRT's display screen for high video image resolution when used as a monitor for graphics and/or character display. In another group of electron beams, the beam forming portion of the electron gun provides electron beams having a larger diameter and current for increased video image brightness when used as a television receiver. Each group of electron beams includes a plurality of horizontally aligned electron beams, with each beam providing one of the primary colors of red, green, or blue.

Abstract: An electron beam current modulator is provided between a cathode and a laser screen of a cathode-ray tube and has at least three deflecting plates positioned around, and symmetrically with respect to an optical axis of the cathode-ray tube and a diaphragm having an aperture of a regular shape. An electromagnetic control system is provided between the cathode and deflecting plates. A pickup senses position of the electron beam and produces a signal in case of an offset of the electron beam with respect to the optical axis. A video signal source is connected to a carrier generator having an output connected to an input of a phase shifter. The phase shifter has its outputs connected to the deflecting plates to rotate the cross-section of the electron beam in a plane drawn perpendicularly with respect to the optical axis. The apparatus has a control unit having an input connected to the pickup and an output connected to the electromagnetic control system.

Abstract: The disclosure relates to cathode-ray tubes that have to be used at a low level of luminance. The cut-off voltage of the tube is modified by using two servo-control loops, the first one as a function of the value of the cathode current and the second one as a function of the luminance value of a zone that is located outside the operational image of the screen and consists of a particular luminophore. Selector means are used to change over from one loop to the other and vice versa as a function of the values of the cathode current and of the luminance of the zone with respect to certain predetermined thresholds.

Abstract: In a grid drive-type CRT display apparatus, the impedance of a second grid voltage supply circuit is made a high impedance and a low-frequency band rejecting streaking interference caused by the high impedance is compensated by low-frequency range emphasizing circuit means. The low-frequency range emphasizing circuit means compensates for the low-frequency range rejection characteristic which is an adverse effect of the high impedance to the second grid and this results in an improvement in the high-frequency transmission characteristic. Also, there is the effect of improving the frequency bandwidth and reducing the consumption of power.

Abstract: A cathode-ray display for displaying a trace has a memory to store portions of digitized input signal. An analogue signal is created from the memory and is added to a ramp signal corresponding to the ramp signal utilized to control the field scanning of the cathode-ray display. A further high frequency signal is added to the superimprosed analogue signal and ramp signal. The resultant combined signal is supplied to voltage discrimination means which control a switch which, in turn, controls the electron gun of the cathode-ray display.

Abstract: An electron beam is aligned with the center of an aperture in a plate in the path of the beam by cyclically scanning the beam across the aperture through equal distances on opposite sides of an initial beam location, measuring the beam current that flows through the aperture when the beam is on opposite sides of the initial location, which opposite sides correspond to adjacent half cycles of the scan, determining the difference in beam currents flowing in adjacent half cycles, and deflecting the beam in a direction toward the center of the aperture until there is reached a condition wherein the difference in currents is zero, which condition indicates that the beam is aligned with the center of the aperture. The currents may be measured by converting them to signals having a frequency proportional to the current, counting the signal cycles during each half cycle, and then subtracting the count for one half cycle from that of an adjacent half cycle.

Abstract: A television receiver high voltage generator includes a high voltage transformer for developing an ultor accelerating potential at an ultor output terminal. A high voltage protection circuit comprises a comparator and a disabling circuit coupled to an output terminal of the comparator. An ultor accelerating potential representative signal is applied to an input terminal of the comparator to disable normal television receiver operation when the ultor accelerating potential exceeds predetermined values. To avoid nuisance tripping or energization of the disabling circuit at lower beam current levels, beam current information is applied to an input terminal of the comparator such that at low beam current operating levels, a greater ultor accelerating potential must be exceeded before the disabling circuit is energized, than at high beam current operating levels.

Abstract: A horizontal width control circuit for use with an image display apparatus includes first and second variable inductors connected in series and shunt relationship respectively with a horizontal deflection coil. The inductance of the inductors are variable in opposite directions for controlling the extent of horizontal deflection through a relatively large range of values without detuning the horizontal deflection circuits.

Abstract: A general-purpose oscilloscope system is disclosed wherein waveforms acquired by the vertical and horizontal preamplifier channels can be displayed immediately, or they can be digitized and stored in a memory from where they can be recalled, reconstituted in their analog form and displayed at a later time. The processing system permits simultaneous display of instantaneous and processed waveforms, and includes facilities for processing associated z-axis signals and readout data as well. Access to peripheral equipment, such as a computer or the like, permits the digitized waveforms to be mathematically manipulated and returned to the memory in the processing system for ultimate display. The oscilloscope system can be assembled in a modular manner, whereby the processing unit becomes an integral part of the instrument, or the system can be assembled as a general-purpose oscilloscope without the processing unit, allowing a user to add the processing capability to his system at a later time.

Abstract: The invention relates to a camera tube arrangement utilizing a so-called H.O.P. (highlight overload protection) or A.C.T. (anti-comet tail) type of camera tube. In order to mitigate the problem of highlights appearing at the top of the picture, in addition to the beam being arranged to discharge overloads in the target area during line flyback, the beam is also arranged to operate in a highlight discharge mode for a predetermined number (for example one) of scanning lines after field flyback but before the end of field system blanking.

Abstract: A recurrent digital sweep signal starts an integrator fed by a constant current. The integrator includes push-pull Darlington stages, which act as alternately conducting controlled current sources for split deflection coils outside the integrator feedback loop. A phase shifter provides arcsine correction. A time-out circuit avoids excessive dissipation if the sweep signal should be lost.

Abstract: A protection circuit for a television receiver which disables the television receiver by disabling the horizontal deflection circuit in response to fault conditions is shown. The protection circuit detects excessive current drain by a low voltage supply, excessive current drain by a high voltage supply, and excessive high voltage. In response to any one of these fault conditions, the horizontal deflection circuit is disabled.

Abstract: An improved X-Y or vector type cathode ray tube circuit includes means to sense the imminence of and to inhibit excessive concentrations of electron beam current during the plotting of X-Y loops, which concentrations produce spots or points on the cathode ray tube screen that are essentially repetitive and convey no useful information to the observer, and if allowed to persist, tend to burn the phosphor coating of said screen.

Abstract: A system for enlarging the image on the screen of a cathode ray picture tube by increasing the deflection of the electron beam. Accompanying deterioration in contrast and brightness is reduced by blanking the overscan portions of the raster. In addition, contrast and color level controls are automatically adjusted to match the expanded image to the normal image. The blanking for both the horizontal and vertical deflection is handled by a common circuit.

Abstract: A constant voltage converter for use with a cathode ray tube in which a voltage regulator is controlled by both the output of the regulator and beam current from the cathode ray tube by way of beam detecting means. The output of the regulator is applied separately to a stabilizing circuit including another feedback circuit for CRT, and also to deflection circuits so as to better prevent fluctuation of picture on the CRT.

Abstract: A system for compensating for mislanding of electron beams in a color cathode ray tube, which comprises a coil device provided on the color cathode ray tube in addition to a main deflection coil, a circuit for producing a plurality of currents having different wave forms, respectively, and a connecting device for connecting the coil device to selected one of connection points of the circuit so as to supply one or more of the currents produced in the circuit, which has a desired wave form, to said coil device selectively in response to the direction to which the color cathode ray tube faces, thereby to achieve sufficient compensation for mislanding of electron beams caused by the earth's magnetic field regardless of the directional situation of the cathode ray tube.

Abstract: The present invention relates to deflection apparatus which can appropriately scan the target and other parts of a storage tube when recording and reproducing on the storage tube a plurality of signals which are different from one another. The apparatus can be constructed from simple circuits and is directed toward the driving of a deflection coil of high inductance.

Abstract: A video amplifier for driving an electron beam intensity controlling electrode of a cathode ray tube comprises at least one solid state high speed binary switch which is connected via a coupling capacitor to the controlling electrode while a D.C. restoration means eliminates the chance of any droop in D.C. level of the signal fed to the controlling electrode.