Abstract: Magnetic field sensor, in particular for measuring magnetic noise fields caused by environmental magnetic noise in combination with MRI apparatus, the magnetic field sensor being further provided with field compensation coils assembly and with a compensation circuit driving the field compensation coils assembly to generate a magnetic field compensating the static magnetic field dissipating outside from the static magnetic field generator or from the gantry of the MRI apparatus at the position of the magnetic sensor. A method for operating the magnetic field sensor and a method and a system for compensation magnetic noise caused by environmental noise are also provided. An MRI apparatus is also disclosed comprising such a system and carrying out such a method for compensating magnetic noise fields.

Abstract: A color cathode-ray tube apparatus having: a glass bulb including a face panel, a funnel, and a neck; a deflection yoke attached to the funnel to surround thereof; and a color-selection electrode disposed inside the face panel. A pair of degaussing coils are wound around the upper and lower portions of the glass bulb, respectively. A loop coil, which is disposed around the glass bulb between the color-selection electrode and the deflection yoke, includes: a first portion including two extending portions of the loop coil positioned over and below the glass bulb respectively, each center of the extending portions being substantially in a plane perpendicular to a tube axial of the glass bulb; and a second portion including two bent portions that are formed by bending right and left sides of an original form of the loop coil toward the neck.

Abstract: The invention provides a deflection yoke device comprising a main yoke portion 4 for deflecting an electron beam emitted by an electron gun, and a convergence yoke portion 5 for adjusting the convergence of the electron beam. The convergence yoke portion 5 comprises an annular convergence core 53, a convergence horizontal coil 51 wound around both of left and right two regions of the core 53 which intersect a horizontal axis, and a convergence vertical coil 52 wound around both of upper and lower two regions of the core 53 which intersect a vertical axis. Short-circuited coils 54, 54 are provided around the respective left and right two regions of the core 53.

Abstract: Sensitivity of a velocity modulation device is increased and noise such as a leakage magnetic field and a leakage electric field from the device are reduced to thereby lower power consumed by the device. A cathode ray tube device and a television set each include a velocity modulation device on a cathode side of a deflection yoke. All or part of the circumference of a velocity modulation coil to modulate scan beam velocity is covered with material having an initial permeability of at least 10 at 2 MHz.

Abstract: Disclosed is a deflection yoke mounted around a glass bulb of a CRT so as to cover a predetermined area of the glass bulb. The predetermined area is where an outer shape of the glass bulb smoothly goes from circular to substantially rectangular along a tube axis of the CRT. The deflection yoke includes a horizontal deflection coil disposed in a shape to fit with the outer shape of the glass bulb, and a funnel-shaped ferrite core disposed to surround the horizontal deflection coil. The inner shape of the ferrite core is circular throughout a length of the ferrite core.

Abstract: A transformer for cathode tube inverter in accordance with claim 1 is capable of driving a plurality of light tubes while also balancing light intensity of each light tube, thereby offering better efficiencies and reducing production cost of related circuits thereof.

Abstract: Sensitivity of a velocity modulation device is increased and noise such as a leakage magnetic field and a leakage electric field from the device are reduced to thereby lower power consumed by the device. A cathode ray tube device and a television set each include a velocity modulation device on a cathode side of a deflection yoke. All or part of the circumference of a velocity modulation coil to modulate scan beam velocity is covered with material having an initial permeability of at least 10 at 2 MHz.

Abstract: A control circuit of a power supply delivering a supply current to an inductor connected in series with the horizontal deflection yoke of a cathode ray tube display, the inductor being the primary coil of a transformer operatively connected for delivering a rectified low-pass filtered biasing voltage to the anode of the display, the low-pass filtering having a first time constant corresponding to the duration of a plurality of pictures, the control circuit having feedback circuitry for generating a monitoring voltage substantially proportional to the biasing voltage and for controlling the supply current to keep the monitoring voltage equal to a reference voltage; and feedforward circuitry for measuring the cathode current and for adding to the monitoring voltage a compensation voltage corresponding to the cathode current, low-pass filtered with a second time constant corresponding to the duration of a small number of lines and high-pass filtered with the first time constant.

Abstract: A deflection yoke has first and second horizontal deflection coils formed of a solid wire. A first bobbin and a second bobbin are formed in one-piece construction with each other. The first coil-end lead of the first horizontal deflection coil and the second coil-end lead of the second horizontal deflection coil are wound around the second bobbin to form a balance coil such that the balance coil is formed continuous with horizontal deflection coils. After the first and second horizontal deflection coils and the balance coil have been wound around the respective bobbins, the second bobbin may be separated from the first bobbin and then the second bobbin may be mounted to a desired part of the first bobbin.

Abstract: A cathode ray tube display having an in-line tube includes an electromagnetic unit for dynamically influencing the path or shape of the electron beams. The power for supplying current to the electromagnetic unit is drawn from the line deflection circuit, either through supply coil on a transformer arranged in parallel with the line deflection coil, or from a supply coil sound around the deflection unit core.

Abstract: The invention relates to a color display device comprising an in-line electron gun (5) for generating three electron beams (6, 7, 8), and a convergence unit (14′) to dynamically influence the convergence of the electron beams and deflecting means (51) for deflecting the electron beams (6, 7, 8). The convergence unit (14′) comprises a ring-shaped element (21′), said ring-shaped element comprising two parts, a first part (60) being positioned closer to the in-line gun (5) than a second part (68), and the first and/or the second part having four coils (22′) for generating a magnetic quadrupole field.

Abstract: In a deflection yoke for a braun tube deflecting an electron beam radiated from an electron gun to a screen and including a horizontal deflection coil, a vertical deflection coil and a ferrite core, the horizontal deflection coil is installed inside a funnel, the ferrite core is installed outside of the funnel, the vertical deflection coil is installed inside or outside of the funnel, accordingly the convergence and deflection sensitivity of an electron beam can be easily compensated, the deflection sensitivity of a braun tube can improve, and the degree of freedom in designing the deflection yoke and an electron gun related to enlarging a diameter of the electron gun can increase.

Abstract: In order to nullify the adverse effect of an external magnetic field on a static magnetic field generated in an MRI system, small-size coils are used to generate a compensation magnetic field. Thus, the component of the static magnetic field to be applied to a magnetic sensor is canceled. The magnetic sensor can therefore detect the external magnetic field highly precisely. A correction current proportional to the external magnetic field detected highly precisely is fed to BO correction coils. Eventually, the external magnetic field that adversely affects the static magnetic field is canceled.

Abstract: Horizontal line misconvergences produced at screen upper and lower portions, among rasters displayed by side electron beams are corrected without producing degradation in vertical deflection sensitivity so much and changing horizontal trapezoidal distortion. In a deflection yoke provided with a top-and-bottom pair of saddle-type horizontal deflection coils and a right-and-left pair of saddle-type deflection coils and mounted to and used in a color cathode ray tube having an in-line arranged electron gun, a pair of sub-cores is provided from side to side or above and below on the electron gun side of the deflection yoke. At least one pair of correction coils is wound around each of the pair of sub-cores.

Abstract: A deflection yoke is described for use in a cathode ray tube, which has an improved deflection sensitivity. The deflection yoke includes a ferrite core, a vertical coil to generate a vertically defecting magnetic field and a horizontal coil to generated a horizontally deflecting magnetic field. The core has a funnel-shaped body with an opening therethrough defining an inner surface. The horizontal coil includes a pair of saddle-type coils positioned in the core such that at least a portion of the horizontal coil is in contact with the inner surface of the core.

Abstract: A main lens comprises a second segment G5-2, a sixth grid G6 and an additional electrode GM disposed between the second segment G5-2 and sixth grid G6. A first-level constant voltage and a second-level constant voltage are applied to the second segment and sixth grid, respectively. A third-level voltage, which is at a level between the first level and the second level, is applied to the additional electrode. In accordance with the increase in deflection amount of an electric beam, the third-level voltage varies a value expressed by ((voltage to the additional electrode)—(voltage to the second segment))/((voltage to the sixth grid)—(voltage to the second segment)). An auxiliary lens comprising lenses including a third grid G3 and a first segment G5-1 has a focusing power decreasing in accordance with an increase in deflection amount of the electron beam.

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 current variable inductor having closed loop characteristics and a horizontal linearity compensation circuit. The current variable inductor having the closed loop characteristics is constructed with the legs of the first E-shaped core and the legs of the second E-shaped core extend toward each other, an I-shaped core is arranged between the first E-shaped core and the second E-shaped core such that the I-shaped core is in contact with the first E-shaped core, and the I-shaped core is spaced apart from the second E-shaped core. A primary coil is wound around a center leg of the first E-shaped core and a secondary coil is wound around a center leg of the second E-shaped core. A magnetic flux generated from the primary coil is cut due to the magnetic resistance characteristics of the I-shaped core to vary the inductance of the secondary coil, to thereby form enclosed loops of magnetic flux inside the first and second E-shaped cores, respectively.

Abstract: In a deflection yoke for use in a color cathode ray tube receiver, two sets of sextuple pole coils formed of bifilar windings are disposed around the orbits of three electron beams emitted from an electron gun of a cathode ray tube. Horizontal-period parabolic currents produced in a bridge circuit consisting of saturable reactors are caused to flow in such sextuple pole coils. Further the parabolic currents are modulated at the vertical period by the saturable reactor. Then sextuple-pole magnetic fields are generated by the modulated parabolic currents to thereby exert vertical force on the three electron beams, hence realizing proper correction of &Dgr;VCR to consequently optimize the balance between the corners and the center of a screen. Such optimization is conventionally difficult due to some restrictions existing in the winding distribution of a vertical deflection coil and a horizontal deflection coil in relation to convergence and focus of side beams.

Abstract: The invention relates to a method and a device for reducing an electric field produced by display devices equipped with cathode ray tubes, in their surroundings. According to the invention, a part of a spectrum (ff), caused by a picture content, the level of which is separately adjusted, is discriminated from an interference voltage frequency spectrum (fs), produced by the display terminal and caused by deflection signals (fv, fh). Spurious pulses, significant for the generation of the electric field, are connected to a compensation circuit, wherein they are summed and supplied to a common emitter. The directions of the pulses are determined so that the electric field produced by the emitter reverses the field produced by the display device.

Abstract: An image distortion correction circuit is provided in which a horizontal deflection current (IH) flows through horizontal correction coils (L1, L2) and a vertical deflection current (IV) flows through either of vertical correction coils (L3, L4). The vertical correction coils (L3, L4) and the horizontal correction coils (L1, L2) are wound on the same core (4). A pair of magnets (2, 3) on opposite ends of the core (4) apply a biased magnetic field from the north pole toward the south pole. The anode of a diode (D1), the cathode of a diode (D2) and a first end of a resistor (R1) are connected to an intermediate terminal (P11) through which the vertical deflection current (IV) flows. A first end of the vertical correction coil (L3) is connected to the cathode of the diode (D1). A second end of the resistor (R1) and a terminal (P4) are connected to a second end of the vertical correction coil (L3).

Abstract: A deflection yoke and a color cathode ray tube using the same therein and adapted for exact correction of misconvergence caused when horizontal positional deviations are induced between electron beams and a vertical deflection magnetic field. In the deflection yoke, two magnetic coil pairs are positioned opposite to each other horizontally in such a manner as to interpose the neck of a cathode ray tube therebetween. The first coil of the first coil pair is connected in series or parallel to the fourth coil of the second coil pair. The second coil of the first coil pair is connected in series or parallel to the third coil of the second coil pair. The coils thus connected are further connected in series to a vertical deflection coil. In this structure, the first and second electric coil pairs are so connected as to generate magnetic fields in mutually reverse directions. The two electric coil pairs in combination with a variable resistor constitute a bridge circuit.

Abstract: An electronic circuit for switching an inductive load (10) by means of a bipolar transistor (1) whereby a switching signal is supplied to the base (5) of a switching transistor (1) via an LRC circuit (6, 7, 9). During switching off the LRC circuit (6, 7, 9) causes a peak voltage at the base (5) of the switching transistor (1). The value of the peak voltage is a maximum when the power dissipation of the switching transistor (1) is a minimum. A regulator circuit (12-17) regulates a current source (18) in a primary winding of a switched transformer (22) in such a way that the peak voltage (Vp) is maximized.

Abstract: The present invention is intended to provide a deflection apparatus which is able to effect an excellent convergence correction by improving an interference between a coma aberration correction coil and a convergence correction coil. In the deflection apparatus according to the present invention, a circuit comprising a coma aberration correction coil, resistors and a reactance means is connected to a vertical deflection coil in series. In the above-mentioned circuit, coil pair comprising the coma aberration correction coil are connected in series. One end of the reactance means is connected to a junction, i.e. middle point of the coil pair. One ends of the respective resistors are connected across the respective ends of the coil pair connected in series. Remaining one ends of those resistors are connected to a remaining one end of the reactance means.

Abstract: A linearity correction coil device and a video display apparatus using the same are disclosed. In a video display apparatus having a cathode-ray tube, a deflecting yoke for deflecting the electron beam and a linearity correction coil device for compensating a linearity of the electron beam, the linearity correction coil device is horizontally installed on a printed circuit board for the cathode-ray tube, and wherein a vertical length of said linearity correction coil in an intersecting direction to a progressive direction of the electron beam has a shorter length than a horizontal length of said linearity correction coil device in a parallel direction to the progressive direction of the electron beam. Accordingly, it is able to prevent the electron beam from running off a normal orbit by a magnetic field generated from the linearity correction coil device. Therefore, since the electron beam exactly collides with fluorescent material, it is able to prevent a stained image from showing on the cathode-ray tube.