Abstract: A circuit for use in providing high voltage power to a neon bulb positioned on the vehicle utilizing the vehicle DC battery as the power source. The circuit includes an invertor, a transformer, and a rectifier. The invertor receives low voltage DC from the vehicle battery, converts the low voltage DC to a low voltage AC drive voltage, and delivers the AC drive voltage to the transformer primary for conversion to a high voltage AC at the transformer secondary. The rectifier receives the high voltage AC from the transformer secondary, converts the high voltage AC to high voltage DC, and delivers the high voltage DC to the neon bulb. Since the power delivered to the neon tube is DC there is less need to shield the tube with respect to electro magnetic emissions and parasitic losses in the wire runs between the battery and the neon tube are significantly reduced.

Abstract: An electrodeless fluorescent lamp comprises a sealed lamp vessel containing a fill capable of sustaining a discharge when suitably excited. The fill is excited by an RF electromagnetic field produced by a winding energized by an RF oscillator powered via a rectifier from the mains. To confine the RF field within the vessel a conductive coating FTO is provided inside the vessel. To at least reduce conducted interference a conductive coating A1 is provided on the outside of the vessel G. The coating A1 is electrically coupled (e.g., via 7) to RF ground which may be one side of the mains. An electrically insulative housing covers the coating A1. The housing which extends to a zone of maximum diameter of the vessel may grip the vessel.

Abstract: The present invention is concerned with a method and an arrangement relating to visual display units, preferably a picture tube (1), for reducing to a minimum the electrical alternating fields generated by the display unit in the unit surroundings. The visual display unit is provided with a voltage connected part (5) on which undesirable voltage variations occur. These voltage variations are indicated. A signal which is phase inverted in relation to the indicated voltage variations is generated. The generated phase-inverted signal is fed back to the voltage connected part (5), to compensate for the voltage variations.

Abstract: A luminaire includes a lamp connected at one electrode to an ordinary current loop and at the other electrode to the other current loop which is branched into more than two which are extending along two opposite sides of the lamp. Magnetic fields produced thus in the branched loops act to cancel each other, and any noise occurring due to generation of the magnetic field can be remarkably reduced.

Abstract: A compact color monitor device that utilizes active and passive magnetic shielding to eliminate the visible distortion of color displays due to externally-imposed magnetic fields. The color monitor device can be installed in standard 19-inch EIA rack enclosures used on-board surface vessels and remain operable with no color distortion when the vessel is subjected to .+-.5 Oersted degaussing fields. The color monitor device includes a quick-degaussing circuit for degaussing internal components in approximately 1/60 of a second.

Abstract: A fluorescent lamp for use in special applications includes an electrodeless envelope of glass or other light transmissive material carrying fluorescent material within the envelope. An RF energy source and coupler are embedded in epoxy as an integral power unit, thereby isolating the power unit from the hazardous environment. The power unit and the envelope are shaped in complementary form such that the coupler and envelope are in energy-transfer relation to excite the lamp, but the envelope may be removed from the power unit to re-lamp the fixture.

Abstract: A high intensity discharge light source that uses a pseudo-random sequence generator to modulate an RF drive signal, and reduce electromagnetic interference (EMI) produced by the light source. The light source includes a high intensity RF discharge lamp, control and RF drive electronics that are coupled between a power source and the lamp. The control and drive electronics include an electromagnetic interference filter, and a regulator that outputs a bias voltage. The drive electronics provide RF power to the lamp, and includes an oscillator, a mixer/modulator, an amplifier, and an impedance matching network. The control circuit includes a pseudo-random sequence generator that generates a pseudo-random sequence of pulses to modulate the mixer/modulator and thus the output of the oscillator to thereby reduce the EMI spectral density generated in driving the RF discharge lamp.

Abstract: A display comprising a cathode ray display tube (1) having an electromagnetic deflection yoke (2) is described. A pair of first deflection coils (7,6) are located symmetrically about the longitudinal axis of the tube (1) on opposite sides of the yoke (2) for producing within the tube (1) a first magnetic deflection field. A pair of second deflection coils (8,20) are similarly located symmetrically about the longitudinal axis on opposite sides of the yoke (2) for producing within the tube (1) a second magnetic deflection field at right angles to the first deflection field. The display is further provided with a pair of first cancellation coils (4,3) connected to the first deflection coils (7,6) for producing a first cancellation field which tends to cancel a first stray field produced by the first deflection coils (7,6). Support means (10,11) secure the first cancellation coils symmetrically about the longitudinal axis.

Abstract: Color display tube with a shadow mask, a shield of a ferromagnetic material and a demagnetizing device having a set of demagnetizing coils. The demagnetizing device is provided with means for energizing the demagnetizing coils in two steps which are shifted in time with respect to each other, while the location of the turns of the demagnetizing coils is such that upon the passage of current through only the one coil, the magnetic field generated by the coil is capable of demagnetizing those parts of color selection electrode and screen which are not demagnetized upon the passage of current through only the other coil, and conversely.

Abstract: In a magnetic field immersion type electron gun for controlling an electron beam emitted by an electron gun (51) with the use of an electric lens (56) and a magnetic field lens formed by permanent magnets (57, 58) of a coaxial ion pump (53), the ion pump magnets are a pair of cylindrical permanent magnets (57, 58) disposed coaxially with an optical axis (52) of the electron gun (51) in such a way as to sandwich a cylindrical ion pump anode (61) of the coaxial ion pump; the two permanent magnets are magnetized in a mutually opposing direction; a hollow cylindrical yoke (60) is disposed also coaxially with the optical axis (52) in such a way as to enclose the two permanent magnets (57, 58) within a hollow portion thereof; and the yoke (60) is formed with an annular yoke gap (63) in a radially inner circumferential surface of the yoke (60) to leak out a magnetic flux flowing through the yoke toward the optical axis.

Abstract: A simple and effective technique for reducing an external magnet flux emitted from a driven inductor surrounded by an ionizable gaseous medium. This technique includes surrounding the inductor with at least one shielding conductive loop, terminating the shielding loop in a capacitive termination to resonate, and maintaining a resonant frequency of the capacitive termination in series with an inductance of the shielding loop below the predetermined driving frequency of the inductor.

Abstract: A plasma processor includes a cylindrical processing chamber storing a semiconductor wafer to be processed, a slot antenna, wound around the outside of a peripheral wall of the processing chamber, for feeding an electromagnetic wave of several tens MHz to the chamber, and an electromagnetic coil, provided on the outside of the processing chamber, for generating plasma in a plasma generating section due to electron cyclotron resonance by applying a magnetic field of 30 gausses or less to said processing chamber. The slot antenna has an elongated conductive plate having a length of about 1/2 of the wavelength of the electromagnetic wave, and an elongate slot formed in the conductive plate.

Abstract: A method and apparatus for correcting the tracking of an electron beam which includes the steps of generating a supplemental magnetic field, generating a reverse magnetic field and removing the correcting magnetic field. The direction of the supplemental magnetic field is substantially the same as the direction of a terrestrial magnetism. The reverse magnetic field substantially offsets the terrestrial magnetism.

Abstract: A television receiver has a switched mode power supply controller, which may be deflection synchronized, which produces pulses in a power transformer. To power the controller during startup, before the internal power supply has started, a storage capacitor on the power supply input of the controller is coupled through a current limiting resistance to a rectified voltage from the AC mains so as to charge the storage capacitor during first polarity phases of the AC mains. The current limiting resistance includes a positive temperature coefficient (PTC) element which increases its impedance as it heats, to reduce power dissipation after initial connection of the television receiver to AC mains. In addition, a diode is coupled in a current path to the storage capacitor to charge the capacitor to the same polarity as during opposite polarity phases of the AC mains.

Abstract: In a monitoring device which forms a display image by using a cathode ray tube, leakage of electric field from the front side of the cathode ray tube is diminished with a simple construction. A leakage electric field compensation electrode is disposed to surround the display area of the front face of a cathode ray tube, a leakage electric field compensation signal, the level of which corresponds to fly-back pulse, is applied to this electrode, and the electric field compensation electrode corresponding forms a compensating electric field that cancels the leakage electric field.

Abstract: A cathode-ray tube apparatus capable of reducing a high frequency electric field radiated from the deflection yoke and the deflection and high voltage circuit to the outside of the cathode-ray tube apparatus. Mounted on the deflection yoke or on the cathode-ray tube are an induction coil for generating a pulse voltage opposite in polarity to a high pulse voltage applied to the h and an electric field cancellation electrode made of a conductive wire to which the opposite polarity pulse voltage is applied. When the opposite polarity pulse voltage is applied to the electric field cancellation electrode, the electric field cancellation electrode radiates an electric field opposite in polarity to the high frequency electric field radiated from the deflection yoke to the outside of the cathode-ray tube apparatus to reduce the intensity of the high frequency electric field.

Abstract: A deflection yoke has an induction coil wrapped about its ferrite core at an angle of from 0 to 70 degrees from the horizontal axis of the deflection yoke to supply current to a leakage magnetic-field canceling coil also mounted to the deflection yoke for attenuating a leakage magnetic field produced from the front, rear and side of a cathode ray tube within the deflection yoke without using a separate circular core. This improves the operation and simplifies the production of the deflection yoke as compared to deflection yokes having the leakage magnetic-field canceling coil serially connected to the horizontal deflection coil or using a separate circular core.

Abstract: The high voltage electrostatic accelerator of this invention has spark arrester rings which form magnetic shield elements around an acceleration tube and which together with mu-metal rings between accelerator segments shield the electrons being accelerated from stray static and dynamic magnetic fields. The spark arresters surround the accelerating electrodes. The rings between accelerator segments are formed of mu-metal, an alloy of nickel designed for its magnetic shielding properties and consisting of 77 percent nickel, 4.8 percent copper, 1.5 percent chrome and 14.9 percent iron. The mu-metal spark arresters together with the rings between accelerators segments provide an effective magnetic shield in a cost-effective manner. Because mu-metal has a high permeability, magnetic field lines tend to travel about the Mu-metal rings rather than pass through the acceleration tube, where they would influence electrons being accelerated.

Abstract: The present invention is a device to reduce the electromagnetic waves generated by electric appliances with surface displays including but not limited to computer monitors and televisions. Further, the electromagnetic waves can be reduced in electronic products generating high heat including, but not limited to, microwave ovens if the device is installed where the heat does not affect the strength of the magnet. The device, made up of several magnet joined together by joining opposite poles, reduces electromagnetic wave emission, and further, its strength affects the blood stream of the human being in vicinity of the device increasing the ions in the body and helps disposing of the food waste in the human body to enhance the metabolism.

Abstract: Human bodies are shielded from an alternating electric field radiated from a deflection yoke of a cathode-ray tube device to prevent the alternating electric field from adversely affecting the human bodies. For an alternating electric field traveling forward in the direction of a tube axis 28 of a cathode-ray tube, a cone section 1b is formed with a conductive film 17 for shielding an electric field and/or a face panel 2 is formed with a transparent conductive film 21 for shielding an electric field and the transparent conductive film 21 is grounded or an optimum potential is given only to the transparent conductive film 21 for shielding an electric field.

Abstract: The invention relates to a method and arrangement for reducing to a minimum the electrical alternating fields generated in the surroundings of a visual display unit (1). The visual display unit includes a voltage connected part (5), on which undesirable voltage variations occur. A smoothing high voltage capacitor (C3) of high capacitance is connected to the voltage connected part (5). Connected between the high voltage capacitor (C3) and earth is a compensating circuit (20) which functions as a negative capacitor whose capacitance is greater than the capacitance of the high voltage capacitor (C3) by a given factor.

Abstract: An electrostatic shield is provided between the induction coil and the arc tube of an electrodeless HID lamp. In one embodiment, the shield is a transparent glass cylinder coated with a thin, transparent, conductive layer of tin oxide. In another embodiment, the electrostatic shield is a conductive, transparent tin oxide coating applied to either the inner or outer surface of an outer light-transmissive jacket surrounding the arc tube. The tin oxide layer is discontinuous so as to minimize currents induced in the conductive tin oxide layer by the induction coil. The thickness of the tin oxide layer is sufficient to make it conductive and form an approximately equipotential surface, thereby shielding the arc tube and plasma discharge from intense electric fields, reducing arc tube wall damage and increasing lamp life. In addition, tin oxide functions as an infrared reflector which returns infrared radiation to the arc tube, resulting in higher efficacy.

Abstract: The present electrical apparatus comprises an antenna for directing towards an electric field source to detect the electric field (E) to be reduced. The antenna is connected to amplifier for generating an output signal in response to an input signal from the antenna. The output signal is in anti-phase to the input signal. A radiator is connected to the amplifier for radiating a cancelling electric field (E') in anti-phase to the electric field (E) from the source in response to the output signal from the amplifier to at least partially cancel reduce the electric field from the source. The antenna, when directed towards the source, is positioned relative to the radiator and the source to detect both the cancelling electric field (E') from the radiator and the electric field (E) from the source. The input signal produced by the antenna is thus derived from the sum of the electric field (E) to be reduced from the source and the cancelling electric field (E') from the radiator.

Abstract: A deflection yoke apparatus has a pair of horizontal and a pair of vertical deflection coils, a coil separator therebetween, and a funnel-shaped deflection core which provides a magnetic path for magnetic flux generated by the deflection coils. A pair of auxiliary coils are arranged at diametrically opposed positions outside the deflection core, and may be energized by the horizontal deflection current supplied to the horizontal deflection coils. The magnetic field generated by the auxiliary coils at least partially compensates the external magnetic leakage field which is radiated outside the deflection core by the horizontal deflection coils. The auxiliary coils have rod-shaped magnetic cores which are in magnetic flux coupling relationship with the smaller end of the deflection core. Leakage flux compensation is thereby achieved with minimal affect on the deflection fields and with low power dissipation in the auxiliary coils.

Abstract: Disclosed is an electrodeless, low pressure gas discharge lamp. The lamp includes a vitreous envelope containing a metal vapor and an inert gas. The envelope is shaped with an external chamber for receiving an electrical excitation circuit. The excitation circuit is effective for exciting the metal vapor to emit light with electromagnetic fields that are passed through the vitreous envelope from outside, to inside, the envelope. A circuit supplies electrical power from power mains to the excitation circuit. A transparent, electrically conductive coating is disposed on the inner surface of the vitreous envelope for suppressing electromagnetic interference on the power mains. An electrically conductive coating is disposed on the outer surface of the vitreous envelope; it is capacitively coupled to the inner conductive coating, via a wall of the vitreous envelope, and is maintained at a suitable potential for suppressing electromagnetic interference on the power mains.

Abstract: This invention relates to an unnecessary electromagnetic wave shielding structure of a magnetron for a microwave oven, comprising an electric wave absorbent filament ceramic disposed adjacent the lower end of a power input section to prevent unnecessary electromagnetic waves produced in an active space from being leaked from the input section through a center lead extending downwardly from an upper end shield of the active space and a side lead disposed adjacent the center lead; first and second ferrite cores having different frequency characteristics and inserted concentrically over the filament ceramics at the respective upper and lower sides of the outer periphery thereof to cooperate with the ceramics to shield the unnecessary electromagnetic waves; and an annular insulator placed between the second ferrite core and filament terminals to insulate the ferrite core from the terminals.

Abstract: An electric field cancellation apparatus that can reduce electric field radiation from a cathode ray tube inexpensively includes a canceling pulse generating circuit generating a pulse voltage that cancels a leaked electric field radiated from a high voltage generating circuit employed with a deflection circuit or the like. The canceling pulse voltage is superimposed upon an output voltage of the high voltage generating circuit and is applied through an anode to an aperture grill of the cathode ray tube, whereby an electric field having a phase opposite to that of the leaked electric field is radiated from the whole surface of the aperture grill, so that the leaked electric field radiated from the cathode ray tube can be canceled.

Abstract: A deflection yoke is mounted with a leaked magnetic-field canceling coil installed on a screen portion for attenuating externally emitted leakage magnetic field, using a horizontal deflection coil. The leaked magnetic-field canceling coil includes a bottom side in parallel with the surface of the screen portion of a coil separator contacting the horizontal deflection coil, left and right sides extending from both ends of the bottom side to an apex peak point to be set in the range of 1/4 of the length of the bottom side from the alternative one end of the bottom side; and and a first and second diagonal sides straightly connecting one end of the left and right sides to the right and left ends of the bottom side, respectively.

Abstract: Hook- and-loop-type tapes are selectively attached to a video display unit and to flexible elongated strips of magnetic material so that the strips of magnetic material may be removably mounted around the video display unit in orthogonally intersecting planes to absorb magnetic radiation from the source. Each strip of magnetic material has a grain orientation parallel to its longitudinal axis and may be formed from grain-oriented ferromagnetic material in the range from M3 to M7. A multiple-layer magnetic shielding material is provided by securing first and second layers of such grain-oriented ferromagnetic material together with the grain orientation of the first layer orthogonal to the grain orientation of the second layer. Each strip of magnetic material may also be formed from this multiple-layer magnetic shielding material.

Abstract: A shield for a computer monitor comprises a hollow cylindrical magnetic sleeve disposed around at least a portion of the yoke windings of the monitor. The sleeve has a diameter greater than the diameter of the yoke windings. A cathode ray tube (CRT) standoff for the shield provides for ease of shield installation and continued operation of the monitor within specification without impairing image integrity (i.e. distortion, color impurity or brightness). The standoff creates a specific distance (critical threshold) between the glass bell of the CRT and the shield that prevents image distortion that cannot be overcome through adjusments of the monitor controls (critical interference).

Abstract: A circuit for reducing extremely low frequency (ELF) electric fields on cathode ray robe (CRT) devices comprises a power supply means, a CRT, a voltage sensing means, an amplification means, and a capacitive coupling within a feedback path to the CRT. A CRT anode voltage variation sensed by the voltage sensing means is amplified and inverted by the amplification means, producing a signal which is applied to the capacitive coupling within the feedback path. This signal modifies the impedance at the CRT anode, decreasing the voltage variation and thereby reducing ELF electric field magnitudes.

Abstract: A cathode-ray tube has a tube body with an implosion-resistant band disposed on the side walls of the tube body. Two degaussing coils are mounted on the implosion-resistant band on opposite walls of the tube body. Each of the degaussing coils is of an annular shape including a flat portion and an extension coupled to opposite ends of the flat portion. The flat portion is attached to the implosion-resistant band by an attachment which has a joint arm fixed to the implosion-resistant band and a holder fitted over the joint arm. The flat portion is resiliently gripped between the joint arm and the holder.

Abstract: An automatic axial field compensation and quick-degauss control system is disclosed. Further, a CRT type monitor incorporating such an automatic compensation and quick-degauss control circuit, and a new degauss circuit are disclosed in accordance with the present invention. The compensation and quick-degauss control circuit relies upon three sensors to respectively detect and quantify the axial, lateral, and vertical components of a disturbing ambient magnetic field. The axial and lateral field component sensors have non-parallel axes of sensitivity such that the sum of values represented by the output signals from these sensors indicates the magnitude of the axial component of the disturbing field. Based upon this summation signal, the system applies a correction current to at least one correction coil. If more than one correction coil is employed, the coils are connected in series so that only one current need be generated to effect compensation.

Abstract: A horizontal deflection circuit for a CRT supplies an exciting current in such a way that flyback voltages including both a positive voltage and a negative voltage as components are generated in horizontal deflection coils of a horizontal deflection yoke, respectively, during energizing the horizontal deflection yoke to provide a magnetic field for horizontal scans. A positive electric field of VLF and a negative electric field of VLF which are generated in the horizontal deflection yoke by the respective flyback voltages cancel each other to decrease a composite electric field of VLF emitted from the horizontal deflection yoke. This prevents unwanted radiation leaking to the outside of the a CRT display.

Abstract: In a cathode-ray tube apparatus, a deflection yoke is provided on a funnel of a tube and a pair of closed loop coils are provided on a panel and the funnel of the tube at upper and lower sides, respectively. The deflection yoke generates effective magnetic fluxes in the tube and also generates ineffective magnetic fluxes as leakage magnetic fluxes outside of the tube. Some of the leakage magnetic fluxes pass through the coils so that currents are induced in the coils and the resulting induced magnetic fluxes compensate for the leakage magnetic fluxes. Thus, the leakage magnetic fluxes passing through a space in front of the tube are reduced by the compensating magnetic fluxes from the coils.

Abstract: A starting circuit for an electrodeless HID lamp includes a visible light radiator for illuminating a gas probe starter during lamp starting. In one embodiment, a light emitting diode (LED) illuminates the gas probe starter via a quartz tube. Excitation is provided to the LED by the same source used to excite the gas probe starter.

Abstract: A cathode-ray tube has a faceplate panel joined to a funnel. An internal magnetic shield is disposed within the tube and is connected to a bottom surface of a flange of a shadow mask frame. The flange of the shadow mask frame has a plurality of integral shield-retaining clips formed therein. Each of the clips overlaps at least a portion of the shield, to retain it in contact with the flange of the frame.

Abstract: An electrodeless fluorescent lamp of the type having a solenoidal drive coil wound about a ferrite core includes an inner shield between the coil and the core and further includes an outer shield about the coil. The shields are preferably constructed of sheets of flexible polyimide material with vertical bands of metal etched thereon. The metal bands are connected to ground in order to shield the core and the plasma from the electric field generated about the drive coil. By thus shielding the core, the capacitance between the coil and the core is effectively short-circuited, substantially reducing or eliminating dielectric losses of the core. The outer shield substantially reduces the EMI generated by the drive coil.

Abstract: An computer assembly having an integral video display and processor subsystem in a single enclosure is described. The assembly contains an electrically conductive safety wall inside the enclosure which separates the interior of the enclosure into a high-voltage region where the video display components are mounted, and a low-voltage region where the processor subsystem is mounted. The enclosure has a removable rear cover which allows access to the processor subsystem for upgrading memory. An electrically conductive liner is attached to the rear cover for EMI shielding of the low-voltage region.

Abstract: A headlamp for motor vehicles has a reflector having a light output opening, a gas discharge lamp arranged in the reflector, a screen covering the light output opening and means for shielding off interference radiation emitted by the gas discharge lamp and including a transparent interference-radiation-absorbing metallic coating.

Abstract: A display device is described, comprising a display tube and a deflection unit. The high DC voltage (EHT) is generated by a line output transformer, this transformer receiving the flyback pulse during the line flyback period. This flyback pulse is transferred through the line output transformer and supplied as the high DC voltage (EHT) to the inner coating of the display tube. Variation of the high DC voltage causes radiation in front of the display tube. To overcome this radiation, a conductor is coupled between the ground terminal (or a metal shield coupled to the ground terminal) of the line output transformer and the outer coating of the display tube. This conductor has at least one turn around one of the coils of the deflection unit for generating a complementary variation to overcome the radiation in front of the display tube.

Abstract: In order to eliminate any harmful influence due to electric field radiation on the human body, electric field radiation from a front surface of a cathode ray tube is reduced. A degaussing coil arranged in proximity to a peripheral edge of a front surface of a cathode ray tube is employed advantageously. The degaussing coil is supplied with a voltage which is opposite in polarity to an electric field radiated from the front surface of the cathode ray tube. The reverse polarity voltage is derived from an output signal obtained from an output signal of a horizontal deflection circuit by a flyback transformer and/or derived from a voltage obtained by phase-inverting an anode voltage fluctuating in vertical synchronization.

Abstract: A method and apparatus for compensating the alternating electrical fields present at the front surface of a cathode ray picture tube wherein the high-voltage signal supplied to the high-voltage terminal of the tube is tapped to extract an alternating voltage signal therefrom, and the alternating voltage signal is inverted and amplified and then applied to a suitable external electrode placed in the proximity of the picture tube. The external electrode can be a framing band, an aquadag region or a ring electrode, among other things. Furthermore, combination of these electrodes can be employed.

Abstract: An electrodeless low-pressure mercury vapor discharge lamp whose discharge vessel is provided with a core of magnetic material and a coil surrounding the core which coil connected to a high-frequency supply unit. An interference-suppressing, light transmissive electrically conductive layer is present on the outside of the discharge vessel, which layer can be connected to the supply mains through an electric conductor. The electric conductor comprises one or several capacitors connected in series to keep the conducting layer safe to touch during operation.

Abstract: A cathode ray tube has an external magnetic shield adapted for tight fitting positioning upon and about the funnel portion of the CRT. The external magnetic shield includes a shell preferably of conventional plastic and a soft magnetic material having high permeability and low coercivity. The soft magnetic material may be either disposed as a layer on the surface of the shell or distributed throughout the shell in the form of small particles. The external magnetic shield is installed over the CRT funnel following CRT evacuation and frit-sealing for improved magnetic shielding in a low cost, easily assembled magnetic shielding arrangement.

Abstract: An AC electric field emission suppressor for use in a CRT imaging system cancels the ripple voltage on the ultor voltage that generates the undesired emission. Ripple-cancelling pulses are derived from the horizontal deflection circuit and are capacitively coupled through the CRT wall to cancel the ripple voltage and suppress the undesired emission.

Abstract: An electrostatic shield and method for shielding an electric field are presented, having particular application to the reduction of electric field emissions from a CRT display. The electrostatic shield is formed from a flexible non-conductive substrate and includes a plurality of radially disposed conductive elements. The shield is secured to the outer surface of the CRT, between the deflection yoke and screen, and the conductive elements are coupled to ground potential. In addition to a method for using the abovedescribed shield, a method is presented for shielding the electric field by applying conductive traces directly to the surface of the CRT, again between the deflection yoke and screen. These traces are coupled to the aquadag coating on the outer surface of the CRT, effectively grounding the traces and providing the desired shielding effect.

Abstract: The object of the disclosure is a method and a coupling for decreasing the alternating current field produced by a cathode-ray tube in the environment. The said field or radiation is at least partly due to the capacitances (C1, C2) of the anode (A) with respect, on one hand, to the deflection coil (DY) and, on the other hand, to the ground. These capacitances produce, mainly because of the return pulse of the deflection coupling, a line rate noise voltage to the anode. According to the invention, a back-off voltage (U.sub.2) opposite to the noise voltage is fed to the anode (A) of the tube either directly or via a graphitizing (G). In cases where the same high-voltage transformer (TR) functions for both the high voltage of the anode and the horizontal deflection, the winding (L) of this transformer can also be used in generating the back-off voltage (U.sub.2). The back-off voltage can thus be coupled to the anode (A) via the high-voltage capacitor (C3) of the transformer.

Abstract: A stray magnetic field cancelling device for a cathode ray tube comprises an elongated member of adjustable length composed of at least two magnetizable metal plates in slidable relationship enveloped by an electromagnetic coil. The device is physically isolated from the yoke a distance effective to exert minimum effect on the yoke deflection fields. Also, the device is oriented transversely to the centerline of the cathode ray tube so as to generate a cancelling magnetic field in opposed relationship with, and transverse to, the stray magnetic field. A simple mechanical adjustment provides for adapting the device to CRTs of varying sizes.

Abstract: Unwanted electric fields in the area in front of a CRT can be produced by flyback voltage pulses which occur across the horizontal deflection coils and are coupled to the inner DAG coating of the CRT. The unwanted fields can be eliminated by providing voltage pulses equal and opposite to the causative voltage pulses and applying the provided voltage pulses to the inner coating and the anode button, leaving no fields to be cancelled in the relevant area.